JP2011220275A - Fuel injection device and internal combustion engine with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve controllability of fuel injection into a combustion chamber of an internal combustion engine with a comparatively simple structure.SOLUTION: A sleeve 17 is provided in a hollow chamber 16a of a casing 16 of an injector 15 rotatably in a direction about an axis and movably in the axial direction. A needle 19 is movably provided in a hollow chamber 17a of the sleeve 17 in the axial direction. The second injection hole 17c is formed in the sleeve 17 so that it agrees with the first injection hole 16c of the casing 16 in response to the position of the rotation in the direction about the axis or the movement in the axial direction. The fuel injection position and the fuel injection amount are controlled by controlling the rotation angle of the sleeve 17.

Description

  The present invention relates to a fuel injection device and an internal combustion engine including the same, and more specifically, a fuel injection device capable of improving controllability of fuel injection into a combustion chamber of an internal combustion engine with a relatively simple structure, and the same The present invention relates to an internal combustion engine.

Diesel engines are advantageous from the viewpoint of global warming and oil depletion because they have better thermal efficiency and less carbon dioxide (CO ₂ ) emissions than gasoline engines. In addition, by adopting a common rail fuel injection device in recent years, fuel can be atomized and the fuel can be burned completely during the combustion period, thus reducing emissions of black smoke and unburned hydrocarbons. Has been.

  Also, fuel spray shape (distribution) and injection from the viewpoint of combustion optimization to achieve reduction of exhaust gases such as black smoke, unburned hydrocarbons and nitrogen oxides (NOx) and fuel consumption rate It is important to change the amount and the like according to the load, and various techniques have been proposed. For example, the fuel injection amount is controlled by controlling the up / down amount of the needle and the valve opening time due to the needle rising (see, for example, Patent Documents 1 and 2).

  Further, for example, by arranging two needles with the same shaft in the fuel injection device and opening a plurality of injection holes in order according to the axial movement of the two needles, the fuel injection rate can be changed. (For example, refer to Patent Documents 3 to 6).

  Also, for example, a rotary valve having a groove or hole formed on the outer periphery is provided at the tip of the needle, and the rotary valve is rotated to continuously change the area of the injection hole to control the fuel injection amount. (For example, refer to Patent Document 7).

  However, the above-described Patent Documents 1 to 7 have a problem that it is not sufficient in terms of controllability of fuel injection such as fuel injection position, injection shape (distribution), injection amount or responsiveness. .

  For example, in Patent Documents 1 to 6, there is a limit to increasing the number of nozzle holes and needles, and the fuel injection shape and fuel injection amount cannot be controlled more precisely. There is also a problem that the flow rate becomes constant when a part of the fuel injection flow path is closed.

  Further, in Patent Document 7 described above, grooves and holes for controlling the fuel injection shape and the fuel injection amount are formed in the rotary valve arranged at the tip of the fine needle. Since it is difficult to arrange from the viewpoint of ensuring processing accuracy and strength, it is difficult to control the fuel injection shape and the fuel injection amount more precisely.

  Further, in Patent Documents 3 to 6, two needles are arranged, and in Patent Document 7, a groove and a hole are arranged in the rotary valve at the tip of the needle. In addition, this causes a problem that the drive control of the needle is complicated and a problem that the strength is lowered.

JP 2004-176657 A JP 2007-032276 A JP 2006-105067 A JP 2007-224896 A JP 2008-38761 A JP 2007-218175 A Japanese Patent Laid-Open No. 10-184495

  An object of the present invention is to provide a fuel injection device capable of improving controllability of fuel injection into a combustion chamber of an internal combustion engine with a relatively simple structure, and an internal combustion engine including the same.

  In order to achieve the above object, a fuel injection device according to the present invention includes a housing having a first hollow chamber and a first fuel injection hole that communicates the first hollow chamber with the outside. A fuel injection device for injecting fuel supplied to the device main body into the combustion chamber of the internal combustion engine from the first fuel injection hole of the housing, and turning about the axis into the first hollow chamber A first fuel control member that is accommodated in an axially movable state and has a second hollow chamber; a first control unit that controls the rotation and movement of the first fuel control member; A second fuel control member that is accommodated in an axially movable state in the hollow chamber and that controls the supply of fuel to the first fuel injection hole by the axial movement; and A second control unit that controls movement in the axial direction, and the first fuel control member includes A second fuel injection hole communicating with the outside of the first fuel control member and the second hollow chamber is formed, and an outlet of the second fuel injection hole is located at one or a plurality of positions of the first fuel control member; The first fuel injection hole and the second fuel injection hole are provided so as to face the inlet of the first fuel injection hole, and the first fuel control member rotates and moves in the axial direction. The fuel injection flow path is formed and the cross-sectional area of the fuel injection flow path is changed by facing the outlet of the fuel.

  In the fuel injection device, the fuel seal portion between the wall surface of the first fuel control member and the wall surface of the first hollow chamber may be disposed in the first fuel control member. A first seal surface disposed at a position away from the surface, and a second seal surface facing the first seal surface on the wall surface of the first hollow chamber, wherein the first seal surface is the second seal. It is formed by contacting with the surface in contact.

  In the fuel injection device, an outer shape of the first fuel control member is formed in a truncated cone shape so that a wall surface of the first fuel control member and a wall surface of the first hollow chamber are along each other. Is formed.

  In order to achieve the above object, an internal combustion engine of the present invention comprises the fuel injection device.

  According to the fuel injection device and the internal combustion engine including the fuel injection device of the present invention, the first fuel control member accommodated in the casing of the fuel injection device rotates and moves in the axial direction, and the second fuel control member By controlling the fuel injection by the axial movement, the controllability of the fuel injection into the combustion chamber of the internal combustion engine can be improved with a relatively simple structure. Therefore, exhaust gas can be reduced and the fuel consumption rate can be reduced.

It is principal part sectional drawing of the internal combustion engine of embodiment of this invention. It is a whole sectional view of an example of a fuel injection device of a 1st embodiment of an internal-combustion engine of Drawing 1. It is an expanded sectional view of the fuel injection part of the fuel injection device of FIG. FIG. 4 is a main part cross-sectional view taken along line X1-X1 of FIG. 3. FIG. 4 is an enlarged cross-sectional view of a sleeve misalignment prevention mechanism portion of FIGS. FIG. 4 is an enlarged cross-sectional view of another example of the sleeve misalignment prevention mechanism portion of FIGS. 2 and 3. FIG. 4 is an enlarged cross-sectional view of another example of the sleeve control unit in FIGS. 2 and 3. It is the principal part perspective view which extracted and showed a part of sleeve control part of FIG. FIG. 3 is a perspective view of a main part of the fuel injection device schematically showing a state in which a first injection hole and a second injection hole of the fuel injection device of FIG. 2 are opposed to each other. It is a top view of an example of the opposing state of the 1st injection hole of the fuel injection device of Drawing 9, and the 2nd injection hole. FIG. 3 is a perspective view of a main part of the fuel injection device schematically showing a state in which a first injection hole and a second injection hole of the fuel injection device of FIG. 2 are opposed to each other. It is a top view of an example of the opposing state of the 1st injection hole of the fuel injection device of Drawing 11, and the 2nd injection hole. It is the graph which showed typically the change of the fuel injection quantity of the fuel-injection apparatus of FIG. It is the graph which showed typically the change of the fuel injection amount of the conventional injector. FIG. 3 is a configuration diagram of an internal combustion engine schematically showing the state of fuel during fuel injection when a homogeneous combustion state is formed using the fuel injection device of FIG. 2. It is a block diagram of the internal combustion engine which showed typically the state of the fuel after fuel injection in the case of forming a homogeneous combustion state using the fuel-injection apparatus of FIG. FIG. 3 is a configuration diagram of an internal combustion engine schematically showing a state of fuel during fuel injection when a stratified combustion state is formed using the fuel injection device of FIG. 2. FIG. 3 is a configuration diagram of an internal combustion engine schematically showing a state of fuel after fuel injection when a stratified combustion state is formed using the fuel injection device of FIG. 2. It is the perspective view which showed typically the principal part of the fuel-injection apparatus in the 2nd Embodiment of this invention. It is the principal part perspective view which extracted and showed the one part structure of FIG. It is the perspective view which showed typically the principal part at the time of the fuel injection of the fuel-injection apparatus of FIG. It is the perspective view which showed typically the principal part at the time of the fuel injection stop of the fuel-injection apparatus of FIG. It is an expanded sectional view of the arrangement | positioning part of the injection hole drilled in the housing | casing of the conventional injector. It is a partial expanded sectional view of the outer needle of the injector of FIG. It is a whole sectional view of the conventional general injector.

  Hereinafter, an internal combustion engine according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 shows a cross-sectional view of a main part of an internal combustion engine according to an embodiment of the present invention. The internal combustion engine of the present embodiment is configured as an in-line four-cylinder common rail type diesel engine 1 mounted on an automobile such as a truck, for example. In addition, this invention is not limited to a diesel engine, It can also apply to a gasoline engine etc.

  The diesel engine (hereinafter referred to as engine) 1 supplies fuel to air that has been compressed in a cavity (combustion chamber) 4 that is recessed in the top surface of a piston 3 in a cylinder (cylinder) 2 and that has become hot. The piston 3 is driven by the expanded gas generated by the combustion by the self-ignition at this time.

  The cylinder 2 is a cylindrical part that guides the reciprocating motion of the piston 3 and stores fuel gas. A liner (not shown) is formed on the inner peripheral surface of the cylinder 2. In the cylinder 2, a cooling passage 2 a through which a cooling medium for cooling the cylinder flows is formed in a thick portion outside the liner.

  Inside the cylinder 2, the piston 3 is installed in a state in which the piston 3 can reciprocate along the liner on the inner peripheral surface of the cylinder 2. The lower part of the piston 3 is connected to a crankshaft (not shown) via a connecting rod (not shown). The crankshaft converts the reciprocating motion of the piston 3 into a rotational motion. FIG. 1 shows the time when the piston 3 is at the top dead center.

  An intake port (intake port) 7 and an exhaust port (exhaust port) 8 are installed in the cylinder head 5 above the cylinder 2. The intake port 7 is connected to the intake pipe 9, and the exhaust port 8 is connected to the exhaust pipe 10.

  An intake valve 11a (11) is installed on the intake port 7 side, and an exhaust valve 11b (11) is installed on the exhaust port 8 side. The intake valve 11 a opens and closes the intake port 7, and the exhaust valve 11 b opens and closes the exhaust port 8.

  When the intake / exhaust valve 11 (11a, 11b) is moved downward in FIG. 1, the valve is opened, and when it is moved upward in FIG. 1, the valve is closed. These intake / exhaust valves 11 (11a, 11b) are mechanically connected to variable valve mechanisms (drive devices) 12 (12a, 12b) for driving the valves.

  An injector (fuel injection device) for directly injecting fuel into the cavity 4 is located between the intake port 7 and the exhaust port 8 of the cylinder head 5 and opposed to the center of the top surface of the piston 3. 15 is installed.

  The injector 15 is constantly supplied with high-pressure fuel stored in a common rail (not shown). A plurality of fine nozzle holes are formed in the nozzle portion of the injector 15 protruding into the cylinder 2, and fuel is simultaneously injected radially from the plurality of fine nozzle holes. The injection axis J of the fuel injected from each nozzle hole at the tip of the nozzle is inclined with respect to the axis C described above by a predetermined injection angle θ. The injection angle θ is set to an angle at which the fuel is accommodated in the cavity 4 in the cylinder 2 over the entire fuel injection period.

  Such an engine 1 includes an injector 15 according to any of the following first and second embodiments.

  First, the injector 15 which is the fuel injection device of the first embodiment will be described with reference to FIGS. 2 is an overall cross-sectional view of an example of the injector 15, FIG. 3 is an enlarged cross-sectional view of the fuel injection portion of FIG. 2, and FIG. 4 is a cross-sectional view taken along line X1-X1 of FIG.

  As shown in FIG. 2, the injector 15 includes a fuel injection section 15a, a needle control section (second control section) 15b, and a fuel inflow pipe T1, fuel flow pipes T2, T3, and a fuel outflow pipe T4. I have.

  In the casing 16 that forms the outer shape of the injector 15, a hollow chamber (first hollow chamber) 16a is formed in the fuel injection portion 15a. As shown in FIG. 3, the hollow chamber 16a has a large-diameter chamber 16a1, a hemispherical chamber 16a2, and an intermediate chamber 16a3 therebetween. The diameter of the large-diameter chamber 16a1 is larger than the uppermost diameter of the hemispherical chamber 16a2. The wall surface of the intermediate chamber 16a3 is formed in a tapered shape so as to continuously decrease in diameter from the large diameter chamber 16a1 toward the hemispherical chamber 16a2.

  As shown in FIGS. 2 to 4, the hollow chamber 16 a is formed outside (cavity 4) through a plurality of fine first injection holes (first fuel injection holes) 16 c drilled in the nozzle portion 16 b at the lower end of the housing 16. Connected with. In addition, the external shape of the nozzle part 16b is formed in hemispherical shape, for example.

  The shape (hole shape) of the opening surface of each first nozzle hole 16c is formed in a circular shape, for example. Here, the first nozzle holes 16c are arranged in two stages along the axial direction of the casing 16, and are arranged at predetermined intervals along the axis of the casing 16 in each stage. The case is illustrated. However, the number of arrangement stages of the first injection holes 16c may be one, or three or more. Further, one or a plurality of first injection holes 16c may be arranged at the tip (hemispherical bottom) of the nozzle portion 16b.

  Further, as shown in FIGS. 2 and 3, a sleeve (first fuel control member) 17 is accommodated in the hollow chamber 16a. The sleeve 17 is a control member that switches the fuel injection flow path and adjusts the fuel injection amount. The sleeve 17 has a shaft aligned with the shaft of the housing 16 and rotates around the shaft of the sleeve 17. It is accommodated in the hollow chamber 16a so as to be movable in the axial direction (vertical direction).

  A hollow chamber (second hollow chamber) 17a is formed in the sleeve 17 so as to extend along its axis. As shown in FIG. 3, the hollow chamber 17a has a large-diameter chamber 17a1, a small-diameter chamber 17a2, and an intermediate chamber 17a3 therebetween. The diameter of the large diameter chamber 17a1 is larger than the diameter of the small diameter chamber 17a2. The wall surface of the intermediate chamber 17a3 is formed in a tapered shape so that the diameter gradually decreases from the large diameter chamber 17a1 toward the small diameter chamber 17a2.

  The sleeve 17 has a large-diameter portion 17b1, a hemispherical portion (small-diameter portion) 17b2, and a tapered portion 17b3 between them. The large diameter portion 17b1 is accommodated in the large diameter chamber 16a1 of the hollow chamber 16a, and the side wall surface of the large diameter portion 17b1 is formed along the wall surface of the large diameter chamber 16a1. The diameter of the large diameter part 17b1 is larger than the diameter of the uppermost part of the hemispherical part 17b2.

  The hemispherical portion 17b2 of the sleeve 17 is accommodated in the hemispherical chamber 16a2, and the outer shape of the hemispherical portion 17b2 is formed along the wall surface of the hemispherical chamber 16a2. As shown in FIGS. 2 to 4, the semispherical portion 17 b 2 has a plurality of fine second injection holes (secondary holes) communicating the hollow chamber 17 a (small-diameter chamber 17 a 2) and the hollow chamber 16 a (hemispherical chamber 16 a 2). A fuel injection hole 17c is bored. The shape (hole shape) of the opening surface of each second nozzle hole 17c is formed in a circular shape, for example. The shape of the opening surface of the second injection hole 17c is not limited to a circular shape, and can be variously changed.

  The second nozzle hole 17c is provided such that the outlet thereof faces (matches) the inlet of the first nozzle hole 16c of the housing 16 at one or a plurality of positions in the rotational direction and the axial direction of the sleeve 17. Yes. Then, the rotation and the axial movement of the sleeve 17 cause the inlet of the first injection hole 16c and the outlet of the second injection hole 17c to face (match), thereby forming a fuel injection flow path. Thereby, the fuel supplied to the fuel injection part 15a through the fuel flow pipe T2 flows from the large diameter chamber 17a1 of the sleeve 17 to the small diameter chamber 17a2, and is injected into the cavity 4 through the second injection hole 17c and the first injection hole 16c. The

  For example, the second nozzle holes 17c are arranged in two stages along the axial direction of the sleeve 17 so as to match the first nozzle holes 16c, and along the axis of the sleeve 17 at each stage. They are arranged at intervals set in advance. The number of arrangement stages of the second nozzle holes 17c may be one or three or more. Further, one or a plurality of second injection holes 17c may be disposed at the tip end (hemispherical bottom) of the hemispherical portion 17b2.

  Here, one or a plurality of desired first injection holes 16c among the plurality of first injection holes 16c can be selected according to the position of the sleeve 17 (the position in the rotational direction or the axial direction). The configuration is illustrated. In other words, at the desired position of the sleeve 17, the desired first nozzle hole 16c of the plurality of first nozzle holes 16c and the second nozzle hole 17c face (match), but are not desired first nozzle holes 16c. The second nozzle hole 17c is not opposed (matched). Thereby, by controlling the position of the sleeve 17, the fuel injection position in the plane of the cavity 4 and in the depth direction can be controlled. Therefore, fuel spray (fuel distribution) can be formed in the cavity 4 at a position optimal for combustion.

  In the case of the injectors of Patent Documents 1 and 2, the fuel injection position is fixed. Moreover, in the case of the injectors of Patent Documents 3 to 6, the fuel injection position in the axial direction of the injector can be selected. On the other hand, in the case of the injector 15 of the first embodiment, for example, not only the axial direction of the injector 15 but also the fuel injection position in the direction around the axis can be selected. The fuel injection position can be set more finely than the case.

  In addition, in the case of the injector of Patent Document 7, grooves and holes for controlling the fuel injection position are formed in the rotary valve at the tip of a fine needle. Difficult from the viewpoint of securing strength. On the other hand, in the case of the injector 15 of the first embodiment, the second injection hole 17c for controlling the fuel injection position is formed in the sleeve 17, so that the shaft of the injector 15 is more than in the case of Patent Document 7. More second injection holes 17c can be arranged in both the direction and the direction around the axis (particularly in the axial direction). For this reason, the fuel injection position can be set more finely than in the case of Patent Document 7.

  The diameter of the second nozzle hole 17c is the same as the diameter of the first nozzle hole 16c. However, the diameter of one of the first and second nozzle holes 16c and 17c may be larger than the other diameter. Further, the diameter of the inlet portion of the first nozzle hole 16c may be partially larger than the diameter of the outlet portion of the second nozzle hole 17c, or vice versa. Thus, by changing the diameter (opposing opening area), the alignment accuracy between the first nozzle hole 16c and the second nozzle hole 17c can be relaxed.

  Further, the taper portion 17b3 of the sleeve 17 described above is continuously reduced in diameter from the large diameter portion 17b1 toward the hemispherical surface portion 17b2, and also along the wall surface (taper surface) of the intermediate chamber 16a3 of the hollow chamber 16a. It is formed in a taper shape.

  The taper surface (first seal surface) of the taper portion 17b3 of the sleeve 17 and the taper surface (second seal surface) of the intermediate chamber 16a3 of the hollow chamber 16a are between the wall surface of the sleeve 17 and the wall surface of the hollow chamber 16a. This is a portion that constitutes a seal portion for suppressing or preventing the fuel from leaking from the first injection hole 16c, and the seal portion has a taper surface of the taper portion 17b3 of the sleeve 17 and an intermediate chamber 16a3 of the hollow chamber 16a. It forms by contacting in the state contact | abutted on the taper surface of this wall surface.

  Here, FIG. 23 illustrates a configuration of a seal portion for preventing fuel leakage of the injector 50A of Patent Document 6. FIG. 23 shows an enlarged cross-sectional view of an arrangement portion of the injection hole 52 drilled in the casing 51 of the injector 50A.

  In patent document 6, it is the structure which forms the seal parts 53a-53c in the nozzle hole 52 with the needle 54 (the inner needle 54a and the outer needle 54b) itself. In this case, for example, one outer needle 54b needs to form two seal portions 53a and 53b in the upper and lower portions of one nozzle hole 52. The tip end surface of the fine outer needle 54b is formed on both seal portions 53a and 53b. It is extremely difficult to process so as to have a sufficient sealing property.

  FIG. 24 shows a partially enlarged sectional view of the outer needle 54b of FIG. Since the tip of the outer needle 54b is thin and has an acute angle, it tends to be chipped due to an operating load. However, if the tip of the outer needle 54b is chipped as shown by the broken line, the seal portions 53a and 53b shown in FIG. As a result of the reduced area, the fuel is liable to leak from the nozzle hole 52 to the cavity 4.

  As a result, in Patent Document 6, a new configuration is required to prevent fuel leakage, and the structure of the injector may be complicated. 23 and 24 are not shown in Patent Documents 3 to 5, but the injectors of Patent Documents 3 to 5 have a structure with two needles as in Patent Document 6, and the same problem may occur. is assumed.

  On the other hand, in the injector 15 of the first embodiment, as shown in FIG. 3 and the like, the first seal surface of the sleeve 17 (taper surface of the tapered portion 17b3) and the second seal surface of the hollow chamber 16a (hollow chamber). 16a3 taper surface) is arranged away from the arrangement surface of the plurality of first injection holes 16c, and the processing conditions of the seal portion are not affected by the first injection holes 16c, so that the processing accuracy of the seal portion Can be relaxed, and the area of the seal portion can be secured larger than in Patent Documents 3 to 6. For this reason, processing of a seal part can be made easy. Further, even if a part of the first seal surface and the second seal surface are missing, the sealing performance is not deteriorated. As a result, fuel leakage from the first nozzle hole 16c to the cavity 4 can be suppressed or prevented. In addition, this seal portion has a simple configuration, and even if the seal portion is provided, the configuration of the injector 15 is not complicated.

  Between the upper surface of the sleeve 17 and the ceiling surface of the hollow chamber 16a, a sleeve control unit (first control unit) 18 for controlling the driving of the sleeve 17 is installed. As shown in FIG. 3, the sleeve controller 18 includes, for example, a solenoid 18a, an ultrasonic motor 18b installed on the outer peripheral side, and a spring 18c.

  The solenoid 18a is a control unit that controls the movement of the sleeve 17 in the axial direction (the direction of the arrow P1), and includes a coil portion 18a1 and an iron core portion 18a2. The coil portion 18a1 is arranged in a ring shape along the outer periphery of the upper surface of the sleeve 17 on the ceiling surface of the hollow chamber 16a. The iron core portion 18a2 is installed in a ring shape at a position facing the coil portion 18a1 on the upper surface of the sleeve 17. A magnet may be used instead of the iron core portion 18a2.

  The ultrasonic motor 18b is a control unit that controls the rotation of the sleeve 17 about the axis (the direction of the arrow P2), and includes a stator unit 18b1 and a rotor unit 18b2. The stator portion 18b1 is installed in a ring shape along the outer periphery of the coil portion 18a1 on the ceiling surface of the hollow chamber 16a. The rotor portion 18b2 is installed in a ring shape at a position facing the stator portion 18b1 on the upper surface of the sleeve 17. The arrangement of the solenoid 18a and the ultrasonic motor 18b may be reversed.

  The spring 18c is arranged so as to surround the needle 19 between the upper surface of the sleeve 17 and the ceiling surface of the hollow chamber 16a. The spring 18c is set so as to urge the sleeve 17 downward (on the side of the first nozzle hole 16c of the hollow chamber 16a), and the spring 18c causes the sleeve 17 and the hollow chamber 16a to be inactive. The ceiling surface and the distance are kept at an appropriate distance.

  Further, a misregistration prevention mechanism for preventing relative misregistration between the sleeve 17 and the sleeve control unit 18 may be provided. 5 and 6 are enlarged cross-sectional views showing an example of the position shift prevention mechanism portion of the sleeve 17.

  As shown in FIG. 5, a groove 25a recessed upward (in the axial direction of the sleeve 17) is formed in the surrounding portion of the coil portion 18a1 of the solenoid 18a. On the other hand, a protrusion 26a protruding upward (in the axial direction of the sleeve 17) is formed at a position facing the groove 25a in the iron core portion 18a2. The protrusion 26a is fitted in the groove 25a. Thereby, the sleeve 17 can be prevented from shifting in a direction perpendicular to the axis. Therefore, the relative positional relationship between the sleeve 17 and the sleeve control unit 18 in the direction orthogonal to the axis of the sleeve 17 can always be kept in a good state.

  Further, in FIG. 6, the groove 25b in the outer portion of the coil portion 18a1 of the solenoid 18a and the protrusion portion 26b on the sleeve 17 fitted thereto are formed in a key shape, and the protrusion portion is formed in the groove 25b. 26b fits into mesh. As a result, the relative positional relationship between the sleeve 17 and the sleeve controller 18 in the direction orthogonal to the axis of the sleeve 17 can always be kept good, and the movement of the sleeve 17 in the axial direction can also be restricted. The opposing distance relationship between the sleeve 17 and the sleeve control unit 18 in the 17 axial direction can always be kept good.

  7 and 8 show another example of the sleeve control unit 18. FIG. 7 is a cross-sectional view of the sleeve control unit 18, and FIG. 8 is a perspective view of the sleeve 17 that rotates around the axis of the sleeve 17.

  Here, the case where the rotation control unit around the axis of the sleeve 17 is replaced with an ultrasonic motor is an electric motor 18m is illustrated. That is, on the upper surface of the sleeve 17, a base 18 d with a gear is arranged in a ring shape along the outer periphery of the sleeve 17. The pedestal 18d with gears is rotationally driven by an electric motor 18m through gears 18e1 and 18e2. The number of electric motors 18m is not limited to one, and a plurality of electric motors 18m may be provided. Also in this case, a mechanism for preventing displacement of the sleeve 17 shown in FIGS. 5 and 6 may be provided.

  On the other hand, as shown in FIGS. 2 and 3, a needle (second fuel control member, needle valve) 19 is provided in the hollow chamber 17a (large diameter chamber 17a1) of the sleeve 17, and the shaft of the needle (second fuel control member, needle valve) is used as the shaft. The needle 19 is accommodated so as to be movable in the axial direction (vertical direction, direction of arrow P1) of the needle 19 in a state where it is aligned with the 17 axis.

  The needle 19 is a member that controls the supply of fuel into the small-diameter chamber 17a2 of the hollow chamber 17a shown in FIG. The needle 19 is formed in a columnar shape, and its diameter is smaller than that of the large-diameter chamber 17a1, but larger than that of the small-diameter chamber 17a2.

  A taper is formed at the tip of the needle 19 that faces the wall surface of the intermediate chamber 17a3 so as to match the inclination of the wall surface of the intermediate chamber 17a3. The state where the tip of the needle 19 is in contact with the wall surface of the intermediate chamber 17a3 is a valve-closed state, and the state where the needle 19 is separated from the wall surface of the intermediate chamber 17a3 is a valve-open state.

  The movement of the needle 19 in the axial direction is controlled by a needle control unit 15b shown in FIGS. FIG. 2 illustrates, for example, a control unit using a solenoid S similar to the conventional one as the needle control unit 15b.

  The solenoid S is installed in the first control chamber FCR1 at the upper part of the housing 16, and has a coil part S1, a valve part S2, and a spring S3.

  The first control chamber FCR1 is connected to the fuel outflow pipe T4 and is connected to the second control chamber FCR2 through the fuel circulation pipe T3. In the second control chamber FCR2, a piston part PS and a spring SR are installed. The piston part PS is integrally connected to the needle 19.

  The first control chamber FCR1 is connected to the command chamber CMR through the flow path of the orifice OR. The command chamber CMR is connected to the fuel inflow pipe T1. The upper surface of the piston portion PS faces the command chamber CMR in a state corresponding to the orifice OR.

  Such a needle controller 15b is electrically connected to an electronic control unit (hereinafter referred to as ECU), and its operation (lift amount) is controlled by the ECU. The needle control unit 15b is not limited to a configuration using a solenoid, and for example, a piezo actuator (piezoelectric element) may be used.

  Here, FIG. 25 shows a conventional general injector 50B for comparison. As shown in FIGS. 2 and 25, in the injector 15 of the first embodiment, by providing the sleeve 17, the conventional general injector 50B shown in FIG. 25 is used as the needle 19 and the needle controller 15b. Needle 55 and needle controller 56 can be used.

  In the case of Patent Documents 3 to 7, the needle and the needle control unit are different from general ones, and the structure and control method thereof are complicated. In addition, high processing accuracy and alignment accuracy are required for the needle from the viewpoint of the above-described fuel leakage and the like.

  On the other hand, in the injector 15 according to the first embodiment, the needle 19 and the needle control unit 15b themselves can be general ones, and the sleeve 17 and the sleeve control can be controlled separately from the needle 19 and the needle control unit 15b. Only the portion 18 is installed, and the sleeve 17 is not required to have high machining accuracy and alignment accuracy as described above. Therefore, the fuel injection controllability of the injector 15 can be improved with a relatively simple structure. .

  Moreover, in patent document 7, the needle is formed in the hollow cylinder shape, for example, and the intensity | strength of the needle is falling. That is, the strength of the needle is weakened by giving the function of the on-off valve and the function of fuel injection control to one needle.

  On the other hand, in the injector 15 of the first embodiment, since the needle 19 itself can be a general one, the strength of the needle 19 can be ensured and its deformation and damage can be reduced. Therefore, the controllability of the fuel injection of the injector 15 can be improved without degrading the life and reliability of the injector 15.

  The fuel flow pipe T2 shown in FIGS. 2 and 3 is a passage for supplying the fuel supplied from the fuel inflow pipe T1 to the fuel injection portion 15a. The fuel flow pipe T2 is connected to the hollow chamber 16a and further formed in the sleeve 17. It is connected to the hollow chamber 17a (large diameter chamber 17a1) through the fuel supply passage 17d.

  Next, an example of control of the fuel injection amount, the fuel injection position, and the fuel injection shape (distribution) will be described with reference to FIGS.

  9 and 11 are perspective views of the main part of the injector 15 schematically showing the opposed state of the first injection hole 16c of the casing 16 and the second injection hole 17c of the sleeve 17 of the injector 15 of the first embodiment. FIGS. 10 and 12 are plan views of the first nozzle hole 16c and the second nozzle hole 17c in FIGS. 9 and 11 facing each other.

  In the case of the injector 15 according to the first embodiment, the fuel injection flow path is formed by rotating or axially moving the sleeve 17. The rotation angle of the sleeve 17 can be set at a fine angle with high definition. For this reason, the facing state of the opening surfaces of the first injection hole 16c and the second injection hole 17c can be continuously changed by a minute change in the rotation angle of the sleeve 17, and the cross-sectional area of the fuel injection flow path is continuously changed. Can be changed to Alternatively, the injection amount for each injection can be changed by rotating the sleeve 17 for each fuel injection.

  For example, FIG. 10 shows the case where the first injection hole 16c and the second injection hole 17c are almost completely aligned, and the cross-sectional area of the fuel injection flow path is the largest. FIG. 12 shows a case where the overlap between the first injection hole 16c and the second injection hole 17c is smaller than in the case of FIG. 10, and the cross-sectional area of the fuel injection flow path is also smaller than in the case of FIG.

  As described above, in the injector 15 of the first embodiment, the fuel injection amount can be increased or decreased with high precision by finely adjusting the rotation angle of the sleeve 17. Moreover, the fuel injection shape (fuel injection distribution) can be set with high precision by combining with the control of the fuel injection position described above.

  Further, in the case of a conventional injector in which the fuel injection amount is controlled by the up / down amount of the needle or the valve opening time, there is a problem that the fuel injection amount becomes constant when a part of the fuel injection flow path is blocked. That is, when the fuel injection is at a high pressure, the liquid reaches the sonic speed in the fuel injection flow path, causing a phenomenon of so-called clogging that is not accelerated further, and there is a problem that the injection flow rate does not become higher. On the other hand, in the injector 15 of the first embodiment, when a part of the fuel injection flow path is blocked, the cross-sectional area (hole diameter) of the fuel injection flow path is changed (made larger). Since the fuel injection amount can be changed, the above problem can be avoided.

  Further, when the sleeve 17 is rotated, by rotating the taper portion 17b3 of the sleeve 17 against the wall surface of the intermediate chamber 16a3, fuel leakage during rotation of the sleeve 17 can be suppressed or prevented.

  FIG. 13 schematically shows a change in the fuel injection amount of the injector 15 of the first embodiment. For comparison, FIG. 14 schematically shows a change in the fuel injection amount of a conventional injector that determines the fuel injection amount by the lift amount of one needle with a constant cross-sectional area (hole diameter) of the fuel injection flow path. Is.

  In the case of a conventional injector in which the fuel injection amount is determined by the lift amount of the needle, the fuel injection amount changes as shown in FIG. On the other hand, in the case of the injector 15 of the first embodiment, the fuel injection amount is obtained by changing the cross-sectional area (hole diameter) of the fuel flow path as described above and further changing the lift amount of the needle 19. To decide. Thereby, the fuel injection amount and the fuel injection shape (distribution) can be set more finely. Further, as shown in FIG. 13, the fuel injection amount can be changed nonlinearly. For this reason, by making the rise of the fuel flow rate steep, the fuel flow rate can be set to an amount necessary for combustion in a shorter period of time. That is, the responsiveness of fuel injection can be improved.

  In the case of the injector 15 of the first embodiment, the fuel injection amount is determined by changing the sectional area (hole diameter) of the fuel flow path and further changing the lift amount of the needle 19. The controllability of the fuel injection flow rate and the fuel injection shape (distribution) can be improved compared to the case of Document 7. Further, the rising of the fuel flow rate can be made steep, and the responsiveness of fuel injection can be improved as compared with the case of Patent Document 7.

  In Patent Document 7, since a groove or a hole is formed in the needle, precise processing of the needle is necessary. On the other hand, in the case of the injector 15 according to the first embodiment, the sleeve 17 itself can be manufactured independently, and the precision processing of the needle 19 is not required as described above, so that the mass productivity of the injector 15 is improved. be able to.

  Furthermore, in the injectors of Patent Documents 1 to 7, the use of a spring or the like is often mechanically complicated and the control is complicated. In contrast, the injector 15 of the first embodiment has a relatively simple structure. And control can be made relatively easy. In particular, since the sleeve 17 and the needle 19 are separated, each can be controlled separately, so that the control can be facilitated and the controllability of fuel injection can be improved.

  Next, an example of the fuel injection shape (distribution) by the injector 15 will be described with reference to FIGS.

  FIG. 15 and FIG. 16 schematically show the state of the fuel F when the homogeneous combustion state is formed using the injector 15. FIG. 15 shows the state of the fuel F, and FIG. 16 shows the state of the fuel F after the fuel injection.

  During homogeneous combustion, the spray of the fuel F is distributed in the cavity 4 over a relatively wide range. Homogeneous combustion is effective during high-load combustion or premixed compression ignition (hereinafter referred to as HCCI) combustion.

  HCCI combustion is a combustion method in which a uniform and lean air-fuel mixture in which fuel and air are mixed in advance is compressed and self-ignited. In the case of HCCI combustion, the generation of black smoke can be reduced by burning a uniform air-fuel mixture. Moreover, since it is a lean air-fuel mixture, the combustion temperature can be lowered and the generation of nitrogen oxides (NOx) can be reduced. Furthermore, since the compression ratio can be increased, high efficiency can be obtained.

  However, in the case of HCCI combustion, there is a risk that misfiring or pre-ignition may occur due to the lean fuel, and there is a problem that the operating range is narrow. In contrast, when the injector 15 of the first embodiment is used, the fuel can be ignited reliably by forming the fuel overconcentration region and the fuel lean region in the cavity 4, and It is possible to generate a fuel concentration distribution so that the entire inside of the cavity 4 becomes a lean air-fuel mixture. Thereby, the problem of misfire can be avoided and the operation area can be expanded. Therefore, combustion with low NOx by HCCI combustion and low PM (Particulate Matter) can be realized.

  FIGS. 17 and 18 schematically show the state of the fuel F when the stratified combustion state is formed using the injector 15. FIG. 17 shows the state of the fuel F, and FIG. 18 shows the state of the fuel F after the fuel injection.

  During stratified combustion, the spray of fuel F is distributed in the upper layer of the cavity 4. Stratified combustion is effective at light loads. When the injector 15 of the first embodiment is used, the sleeve 17 and the needle 19 are controlled so that the fuel injection shape (distribution) for homogeneous combustion is alternately switched to the fuel injection shape (distribution) for stratified combustion. be able to.

Injector of Second Embodiment FIG. 19 schematically shows a fuel injection portion of the injector 15 in the second embodiment, and FIG. 20 shows a housing 16 and a sleeve 17 of the fuel injection portion of the injector 15 of FIG. Shown extracted. In FIG. 19 and FIG. 20, the inside of the injector 15 is shown in a watermark for easy understanding.

  In the injector 15 of the second embodiment, the lower portion of the sleeve 17 and the shape of the surrounding hollow chamber 16a are formed in a truncated cone shape. That is, a frustoconical part (small diameter part) 17b4 is formed in the lower part of the sleeve 17 instead of the hemispherical part 17b2. In addition, a truncated cone chamber 16a4 is formed in the lower portion of the hollow chamber 16a instead of the hemispherical chamber 16a2. The wall surface of the frustoconical portion 17b4 of the sleeve 17 and the wall surface of the frustoconical chamber 16a4 of the hollow chamber 16a opposed thereto are formed in a straight line (flat) so as to be along each other. Thereby, when the sleeve 17 is pressed against the wall surface of the hollow chamber 16a, the adhesion between the wall surface of the sleeve 17 and the wall surface of the hollow chamber 16a can be improved, so that the above-described fuel sealing performance can be improved. . The other configuration is the same as that described in the first embodiment.

  Next, a rotation control method for the sleeve 17 according to the second embodiment will be described with reference to FIGS. 21 and 22.

  FIG. 21 schematically shows a state of a main part of the injector 15 at the time of fuel injection. FIG. 21 shows a stage where the desired first injection hole 16c of the nozzle portion 16b of the housing 16 and the desired second injection hole 17c of the frustoconical portion 17b4 of the sleeve 17 coincide with each other. Fuel is injected in this state.

  Next, FIG. 22 schematically shows the state of the main part of the injector 15 when the fuel injection is stopped. Here, the sleeve 17 and the needle 19 are slightly lowered in the axial direction indicated by the arrow P3. As a result, the tapered portion 17b3 of the sleeve 17 is pressed against the wall surface of the intermediate chamber 16a3 to suppress or prevent fuel leakage. Further, the tip of the needle 19 is pressed against the inclined surface of the intermediate chamber 17b3 to stop fuel injection.

  At this time, in the injector 15 according to the second embodiment, as described above, the wall surface of the frustoconical portion 17b4 of the sleeve 17 and the wall surface of the frustoconical chamber 16a4 of the hollow chamber 16a opposite to the wall surface are linear. Due to the shape (flat), when the sleeve 17 is lowered and the wall surface of the sleeve 17 is pressed against the wall surface of the hollow chamber 16a, the adhesion between the wall surface of the frustoconical portion 17b4 and the wall surface of the frustoconical chamber 16a4 Therefore, the sealing performance of the fuel can be improved. The other effects are the same as those described in the first embodiment.

  Thereafter, the sleeve 17 is indicated by an arrow P4 while maintaining the above-described state (the state in which the tapered portion 17b3 of the sleeve 17 is pressed against the wall surface of the intermediate chamber 16a3 and the tip of the needle 19 is pressed against the inclined surface of the intermediate chamber 17a3). The fuel injection stop operation is terminated by stopping the rotation when the desired first injection hole 16c and the desired second injection hole 17c are separated from each other.

  The fuel injection device of the present invention and the internal combustion engine including the fuel injection device are compared by controlling the fuel injection by rotating around the axis and moving in the axial direction of the first fuel control member housed in the casing of the fuel injection device. Since the controllability of fuel injection into the combustion chamber of the internal combustion engine can be improved with a simple structure, it can be used for a fuel injection device such as an automobile and an internal combustion engine equipped with the same.

1 Diesel engine (internal combustion engine)
2 cylinders
4 Cavity (combustion chamber)
15 Injector (fuel injection device)
15a Fuel injection unit 15b Needle control unit (second control unit)
16 Housing 16a Hollow chamber 16a1 Large diameter chamber 16a2 Hemispherical chamber (small diameter chamber)
16a3 Intermediate chamber 16a4 frustoconical chamber (small-diameter chamber)
16b Nozzle part 16c 1st injection hole (1st fuel injection hole)
17 Sleeve (first fuel control member)
17a Hollow chamber 17b1 Large diameter part 17b2 Hemispherical surface part (small diameter part)
17b3 Tapered portion 17b4 Frustum-shaped portion 17c Second injection hole (second fuel injection hole)
17d Fuel supply passage 18 Sleeve control unit (first control unit)
18a Solenoid 18a1 Coil portion 18a2 Iron core portion 18b Ultrasonic motor 18b1 Stator portion 18b2 Rotor portion 18c Spring 18d Base 18e1, 18e2 Gear 18m Electric motor 19 Needle (second fuel control member)
25a, 25b Groove 26a, 26b Protrusion S Solenoid S1 Coil part S2 Valve part S3 Spring OR Orifice SR Spring T1 Fuel inflow pipe T2, T3 Fuel flow pipe T4 Fuel outflow pipe FCR1 First control chamber FCR2 Second control chamber CMR Command chamber

Claims (4)

The apparatus main body includes a casing having a first hollow chamber and having a first fuel injection hole that communicates the first hollow chamber with the outside, and the fuel supplied to the apparatus main body A fuel injection device for injecting into the combustion chamber of an internal combustion engine from the first fuel injection hole,
A first fuel control member accommodated in the first hollow chamber in a state capable of rotating around an axis and moving in the axial direction, and having a second hollow chamber;
A first control unit for controlling rotation and movement of the first fuel control member;
A second fuel control member that is accommodated in the second hollow chamber so as to be movable in the axial direction, and that controls the supply of fuel to the first fuel injection hole by the movement in the axial direction;
A second control unit for controlling the axial movement of the second fuel control member,
The first fuel control member has a second fuel injection hole that communicates the outside of the first fuel control member with the second hollow chamber,
The outlet of the second fuel injection hole is provided to face the inlet of the first fuel injection hole at one or more positions of the first fuel control member,
The first fuel control member is rotated and moved in the axial direction so that the inlet of the first fuel injection hole faces the outlet of the second fuel injection hole, thereby forming a fuel injection flow path, and the fuel injection A fuel injection device that changes the cross-sectional area of the flow path.   The fuel seal portion between the wall surface of the first fuel control member and the wall surface of the first hollow chamber is disposed at a position away from the disposition surface of the first fuel injection hole in the first fuel control member. A first seal surface and a second seal surface facing the first seal surface on the wall surface of the first hollow chamber are provided, and the first seal surface is in contact with the second seal surface. The fuel injection device according to claim 1, wherein the fuel injection device is formed.   The outer shape of the first fuel control member is formed in a truncated cone shape, and the outer wall surface of the first fuel control member and the wall surface of the first hollow chamber are formed along each other. Or the fuel-injection apparatus of 2.   An internal combustion engine comprising the fuel injection device according to any one of claims 1 to 3.