JP6323265B2 - Injector for internal combustion engine - Google Patents

Description

  The present invention relates to an injector for an internal combustion engine that injects fuel into a combustion chamber of the internal combustion engine.

  Conventionally, as this type of injector for an internal combustion engine, for example, there is one described in Patent Document 1. The injector for an internal combustion engine described in Patent Document 1 is provided with two types of injection holes at the bottom of a bottomed cylindrical nozzle body, and independently drives two needles disposed in a reciprocating manner in the nozzle body. Thus, one of the two types of nozzle holes is opened.

  Further, as a means for driving the two needles, a piezoelectric actuator having a stack of piezoelectric elements and a hydraulic drive mechanism are used, and the expansion / contraction state of the piezoelectric actuator is controlled in three stages, so that three operating states, that is, A state in which only the nozzle hole is opened, a state in which only the other nozzle hole is opened, and a state in which all the nozzle holes are closed are realized.

JP 2010-112203 A

  However, since the conventional injector for an internal combustion engine uses two needles, the two types of nozzle holes must be shifted in the axial direction of the injector (that is, the moving direction of the needle). The degree of freedom in designing the position is low. Therefore, there is a problem that it is not easy to realize spraying that meets the requirements of the internal combustion engine to be mounted.

  In addition, a piezoelectric actuator in which piezoelectric elements are stacked has a problem that durability is inferior and cost is high as compared with, for example, a solenoid.

  In view of the above, the present invention increases the degree of freedom in designing the position of the nozzle hole in an injector for an internal combustion engine having different specifications, and also enables driving means other than the piezo actuator to be used as means for driving the needle. For the purpose.

In order to achieve the above object, in the first aspect of the present invention, a high-pressure fuel is supplied, and a communicating hole (12) through which the high-pressure fuel flows and a seat surface (13) are formed in a bottomed cylindrical shape. The inner body (1), the needle (2) that is disposed in the inner body and that opens and closes the communication hole in contact with and away from the seat surface, and is disposed outside the inner body so as to be rotatable with respect to the inner body, and combustion of the internal combustion engine A plurality of types of injection holes (31, 32, 35) having different specifications for injecting fuel into the chamber are formed, and a plurality of types of injection holes are selectively communicated with the communication holes according to the rotational position (3) ) And a driving means (5, 6, 7, 5A, 5B, 5C) for rotating the outer body , and the same communication hole is one of the plurality of types of nozzle holes of the outer body at a certain rotational position. One ( 1) and the other one communicates (32) and not communicating, that in another rotational position without communication with one of the other without the certain communication with one of said plurality of types of injection holes of the outer body Features .
The invention described in claim 3 is a bottomed cylindrical inner body (1) in which a high-pressure fuel is supplied and a communication hole (12) through which the high-pressure fuel flows and a seat surface (13) are formed at the bottom. ), A needle (2) that is disposed in the inner body, opens and closes the communication hole in contact with and away from the seat surface, and is disposed outside the inner body so as to be rotatable with respect to the inner body. A plurality of types of injection holes (31, 32, 35) having different specifications for injecting fuel into the combustion chamber are formed, and the plurality of types of injection holes selectively communicate with the communication holes according to the rotational position. Outer body (3), drive means (5, 6, 7, 5A, 5B, 5C) for rotating the outer body, and disposed outside the outer body, coupled to the inner body and the inner body A retaining nut (4) screwed into a cylinder head of the engine, and the outer body includes a slit portion (34) extending along a rotation direction of the outer body, and the retaining nut is disposed on the slit portion. An injector for an internal combustion engine comprising a protrusion (42) that is inserted and has a tip abutting against the inner body.

  According to this, since the injection hole for injecting fuel is switched according to the rotation position of the outer body, a plurality of types of injection holes can be arranged without shifting in the axial direction of the injector, and the design of the injection hole position is free. The degree can be increased.

  Further, since there is only one needle, it is not necessary to control the expansion / contraction state of the piezo actuator in three stages as in the conventional injector described above. Therefore, for example, a solenoid and a hydraulic drive mechanism that are advantageous in terms of durability and cost. It is also possible to adopt a needle driving means using

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

It is a front sectional view of the injector for internal-combustion engines concerning a 1st embodiment of the present invention. It is front sectional drawing which expands and shows the principal part of the injector of FIG. It is a bottom view of the injector of FIG. It is IV-IV sectional drawing of FIG. FIG. 2 is a cross-sectional view perpendicular to the axis showing a state of a first rotation position in the injector of FIG. 1. FIG. 2 is a cross-sectional view perpendicular to the axis showing a state of a second rotational position in the injector of FIG. 1. It is a figure which shows the example of the nozzle hole in the injector of FIG. It is an axis perpendicular sectional view showing the state of the 1st rotation position in the injector concerning a 2nd embodiment of the present invention. FIG. 9 is a cross-sectional view perpendicular to the axis showing a state of a second rotational position in the injector of FIG. 8. FIG. 9 is a cross-sectional view perpendicular to the axis showing a state of a third rotational position in the injector of FIG. 8.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings.

(First embodiment)
A first embodiment of the present invention will be described.

  As shown in FIGS. 1 to 3, the injector includes a bottomed cylindrical inner body 1 having a high-pressure fuel supply space 11 to which high-pressure fuel is supplied from a common rail (not shown). The inner body 1 is made of a nonmagnetic metal.

  A communication hole 12 through which high-pressure fuel flows is formed at the bottom of the inner body 1. The communication holes 12 penetrate the bottom of the inner body 1 and are arranged in a plurality (in this example, 10) along the circumferential direction of the inner body 1.

  A tapered seat surface 13 is formed on the inner peripheral surface of the bottom of the inner body 1 on the upstream side of the fuel flow from the communication hole 12.

  In the inner body 1, a needle 2 is disposed that reciprocates in the axial direction of the inner body 1 and opens and closes the communication hole 12 in contact with and away from the seat surface 13. As means for driving the needle 2, needle driving means using a piezo actuator and a hydraulic driving mechanism, needle driving means using a solenoid and a hydraulic driving mechanism, and the like can be employed.

  A cylindrical outer body 3 is disposed outside the inner body 1 so as to be rotatable with respect to the inner body 1. The outer body 3 is made of a nonmagnetic metal.

  A first injection hole 31 and a second injection hole 32 having different specifications for injecting high-pressure fuel into a combustion chamber of an internal combustion engine (not shown) (more specifically, a compression ignition internal combustion engine) are formed at the bottom of the outer body 3. Yes.

  The first nozzle holes 31 and the second nozzle holes 32 penetrate the bottom of the outer body 3 and are arranged in a plurality (10 in this example) along the rotation direction (that is, the circumferential direction) of the outer body 3. Yes. Further, the first nozzle holes 31 and the second nozzle holes 32 are arranged so as to be shifted along the rotation direction of the outer body 3 and are arranged alternately along the rotation direction of the outer body 3.

  The first injection hole 31 and the second injection hole 32 are selectively communicated with the communication hole 12 according to the rotational position of the outer body 3. That is, the first injection hole 31 communicates with the communication hole 12 at the first rotation position of the outer body 3 (see FIG. 5), and the second injection hole 32 communicates with the communication hole 12 at the second rotation position of the outer body 3. (See FIG. 6).

  A cylindrical retaining nut 4 is disposed outside the outer body 3. The retaining nut 4 is coupled to the inner body 1 and screwed to a cylinder head (not shown) of the internal combustion engine.

  As shown in FIGS. 1 and 4, the outer body 3 includes an outer body flat plate portion 33 extending in the radial direction at an axially intermediate portion thereof. The outer body flat plate portion 33 is formed with two slit portions 34 extending along the rotation direction of the outer body 3.

  The retaining nut 4 is provided with a retaining nut flat plate portion 41 extending along the radial direction at the end of the injection hole. In the retaining nut flat plate portion 41, two projecting portions 42 are formed on the end surface opposite to the injection hole and projecting toward the opposite side of the injection hole and extending along the rotation direction of the outer body 3. .

  The protruding dimension of the protruding portion 42 is set to be larger than the plate thickness of the retaining nut flat plate portion 41. Therefore, when the protruding portion 42 is inserted into the slit portion 34 and the retaining nut 4 and the inner body 1 are coupled, the tip of the protruding portion 42 comes into contact with the inner body 1. As a result, the assembly axial force acts between the retaining nut 4 and the inner body 1 and does not act on the outer body 3, so that the outer body 3 can be rotated with a small driving force.

  As shown in FIGS. 1, 5, and 6, a solenoid 5 that forms a magnetic field when energized is disposed in the inner body 1. An armature 6 made of a ferromagnetic metal is disposed on the inner periphery of the outer body 3. A spring 7 is disposed in a space defined by the inner body 1 and the outer body 3.

  The solenoid 5 and the armature 6 are arranged close to each other. As shown in FIG. 6, when the solenoid 5 is energized, the armature 6 is attracted to the solenoid 5 side by the magnetic attraction force, and the outer body 3 is moved accordingly. 6 is rotated counterclockwise on the paper surface of FIG.

  As shown in FIG. 5, when the energization of the solenoid 5 is stopped, the outer body 3 is moved away from the solenoid 5 by the biasing force of the spring 7 (that is, clockwise in the plane of FIG. 5). Is driven to rotate.

  The solenoid 5, the armature 6, and the spring 7 constitute the driving means of the present invention.

  The first injection hole 31 and the second injection hole 32 can arbitrarily set the injection direction, the cross-sectional shape, the cross-sectional area, the effective injection hole length, the number of injection holes, etc. according to the request of the internal combustion engine. A combination of various types of nozzle holes as shown in FIG. 7 can be used.

  The injection holes 31 and 32 shown in FIG. 7A have the same diameter as the communication hole 12 and are arranged coaxially with the communication hole 12.

  The injection holes 31 and 32 shown in FIG. 7B are smaller in diameter than the communication hole 12 and are arranged coaxially with the communication hole 12.

  The injection holes 31 and 32 shown in FIG. 7C have the same diameter as the communication hole 12 and are inclined with respect to the communication hole 12.

  The nozzle holes 31 and 32 shown in FIG. 7D are larger in diameter than the communication hole 12 and are arranged coaxially with the communication hole 12.

  The nozzle holes 31 and 32 shown in FIG. 7E expand in a tapered shape toward the downstream side and are arranged coaxially with the communication hole 12.

  Two injection holes 31 and 32 shown in FIG. 7 (f) have a diameter smaller than that of the communication hole 12 and are inclined with respect to the communication hole 12.

  Incidentally, in this embodiment, the nozzle hole shown in FIG. 7E is adopted as the first nozzle hole 31, and the nozzle hole shown in FIG. 7A is adopted as the second nozzle hole 32.

  In the above configuration, as shown in FIG. 5, when the solenoid 5 is not energized, the outer body 3 is in the first rotation position where the armature 6 is away from the solenoid 5, and the first injection hole 31 is the communication hole. 12 communicates.

  In this communication state, when the needle 2 is driven in the valve opening direction and is separated from the seat surface 13, the fuel in the high pressure fuel supply space 11 reaches the first injection hole 31 through the communication hole 12 and from the first injection hole 31. Fuel is injected into the combustion chamber of the internal combustion engine. When the needle 2 is driven in the valve closing direction and comes into contact with the seat surface 13, the injection is finished.

  On the other hand, as shown in FIG. 6, when the solenoid 5 is energized, the outer body 3 is in the second rotation position where the armature 6 approaches the solenoid 5, and the second injection hole 32 is connected to the communication hole 12. Communicate.

  In this communication state, when the needle 2 is driven in the valve opening direction to leave the seat surface 13, the fuel in the high-pressure fuel supply space 11 reaches the second injection hole 32 through the communication hole 12 and from the second injection hole 32. Fuel is injected into the combustion chamber of the internal combustion engine. When the needle 2 is driven in the valve closing direction and comes into contact with the seat surface 13, the injection is finished.

  According to this embodiment, since it is the structure which switches the nozzle hole which injects a fuel according to the rotation position of the outer body 3, it can arrange | position several types of nozzle holes 31 and 32, without shifting in the axial direction of an injector, The degree of freedom in designing the nozzle hole position can be increased.

  Further, since there is only one needle 2, for example, a needle driving means using a solenoid and a hydraulic pressure driving mechanism can be employed.

  In the present embodiment, the number of each of the first injection holes 31 and the second injection holes 32 is set to be the same as that of the communication holes 12, but one of the first injection holes 31 and the second injection holes 32 is a communication hole. The same number as 12 may be set, and the other may be smaller than the communication hole 12.

(Second Embodiment)
A second embodiment of the present invention will be described. Only the parts different from the first embodiment will be described below.

  As shown in FIGS. 8 to 10, three solenoids 5 </ b> A, 5 </ b> B, and 5 </ b> C that form a magnetic field when energized are arranged along the circumferential direction of the inner body 1 on the outer peripheral portion of the inner body 1. In addition, an armature 6 made of a ferromagnetic metal is disposed on the inner periphery of the outer body 3. The three solenoids 5A, 5B, and 5C and the armature 6 constitute the driving means of the present invention.

  A first nozzle hole 31, a second nozzle hole 32, and a third nozzle hole 35 having different specifications are formed at the bottom of the outer body 3. A plurality of these nozzle holes 31, 32, and 35 are arranged along the rotation direction of the outer body 3.

  In the above configuration, as shown in FIG. 8, when the first solenoid 5A is energized, the armature 6 is attracted to the first solenoid 5A, and the outer body 3 is at a position where the armature 6 approaches the first solenoid 5A. The first injection hole 31 is in communication with the communication hole 12 in the first rotation position. While in this communicating state and while the needle 2 is driven in the valve opening direction and away from the seat surface 13, fuel is injected from the first injection hole 31 into the combustion chamber of the internal combustion engine.

  Further, as shown in FIG. 9, when the second solenoid 5B is energized, the armature 6 is attracted to the second solenoid 5B, and the outer body 3 is the second position where the armature 6 is close to the second solenoid 5B. The second injection hole 32 communicates with the communication hole 12 in the rotational position. While in this communication state and while the needle 2 is driven in the valve opening direction and away from the seat surface 13, fuel is injected from the second injection hole 32 into the combustion chamber of the internal combustion engine.

  Furthermore, as shown in FIG. 10, when the third solenoid 5C is energized, the armature 6 is attracted to the third solenoid 5C, and the outer body 3 is the third position where the armature 6 is close to the third solenoid 5C. The third injection hole 35 communicates with the communication hole 12 in the rotational position. While in this communication state and while the needle 2 is driven in the valve opening direction and away from the seat surface 13, fuel is injected from the third injection hole 35 into the combustion chamber of the internal combustion engine.

  According to this embodiment, the same effect as that of the first embodiment can be obtained.

(Other embodiments)
In the above embodiment, the present invention is applied to a fuel injection valve of a compression ignition type internal combustion engine. However, the present invention can also be applied to a fuel injection valve of a direct injection gasoline internal combustion engine.

  In addition, this invention is not limited to above-described embodiment, In the range described in the claim, it can change suitably.

  Further, the above embodiments are not irrelevant to each other, and can be combined as appropriate unless the combination is clearly impossible.

  In each of the above-described embodiments, it is needless to say that elements constituting the embodiment are not necessarily indispensable except for the case where it is clearly indicated that the element is essential and the case where the element is clearly considered essential in principle. Yes.

  Further, in each of the above embodiments, when numerical values such as the number, numerical value, quantity, range, etc. of the constituent elements of the embodiment are mentioned, it is clearly limited to a specific number when clearly indicated as essential and in principle. The number is not limited to the specific number except for the case.

  Further, in each of the above embodiments, when referring to the shape, positional relationship, etc. of the component, etc., the shape, unless otherwise specified and in principle limited to a specific shape, positional relationship, etc. It is not limited to the positional relationship or the like.

1 Inner body 2 Needle 3 Outer body 5 Solenoid (drive means)
6 Armature (drive means)
7 Spring (drive means)
12 communication hole 13 sheet surface 31 1st injection hole 32 2nd injection hole 35 3rd injection hole 5A 1st solenoid (drive means)
5B Second solenoid (drive means)
5C 3rd solenoid (drive means)

Claims (5)

A bottomed cylindrical inner body (1) formed with a communication hole (12) and a seat surface (13) through which the high-pressure fuel is circulated, and a high-pressure fuel.
A needle (2) disposed in the inner body and opening and closing the communication hole in contact with and away from the seat surface;
A plurality of types of injection holes (31, 32, 35), which are arranged outside the inner body in a rotatable state with respect to the inner body and have different specifications for injecting fuel into the combustion chamber of the internal combustion engine, are formed at the rotational position. In response, the cylindrical outer body (3) in which the plurality of types of nozzle holes selectively communicate with the communication hole;
Drive means (5, 6, 7, 5A, 5B, 5C) for rotating the outer body ;
The same communication hole communicates with one (31) of the plurality of types of nozzle holes of the outer body at a certain rotational position, and does not communicate with the other one (32). An injector for an internal combustion engine, wherein the injector does not communicate with the certain one of the plurality of types of nozzle holes of the outer body and does not communicate with the other one . A retaining nut (4) disposed outside the outer body, coupled to the inner body and screwed into a cylinder head of the internal combustion engine;
The outer body includes a slit portion (34) extending along the rotation direction of the outer body,
2. The injector for an internal combustion engine according to claim 1 , wherein the retaining nut includes a protruding portion (42) inserted into the slit portion and having a tip abutting against the inner body. A bottomed cylindrical inner body (1) formed with a communication hole (12) and a seat surface (13) through which the high-pressure fuel is circulated, and a high-pressure fuel.
A needle (2) disposed in the inner body and opening and closing the communication hole in contact with and away from the seat surface;
A plurality of types of injection holes (31, 32, 35), which are arranged outside the inner body in a rotatable state with respect to the inner body and have different specifications for injecting fuel into the combustion chamber of the internal combustion engine, are formed at the rotational position. In response, the cylindrical outer body (3) in which the plurality of types of nozzle holes selectively communicate with the communication hole;
Drive means (5, 6, 7, 5A, 5B, 5C) for rotating the outer body ;
A retaining nut (4) disposed outside the outer body, coupled to the inner body and screwed into a cylinder head of the internal combustion engine ;
The outer body includes a slit portion (34) extending along the rotation direction of the outer body,
The internal combustion engine injector , wherein the retaining nut includes a protrusion (42) inserted into the slit portion and having a tip abutting against the inner body. The injector for an internal combustion engine according to any one of claims 1 to 3, wherein the plurality of types of nozzle holes are arranged so as to be shifted along a rotation direction of the outer body. The injector for an internal combustion engine according to any one of claims 1 to 4, wherein the driving means drives the outer body by a magnetic attraction force.

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