JP2015203403A - Injector for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To independently control fuel injections from injection holes of different specifications.SOLUTION: A plurality of kinds of injection holes 12, 13 of different specifications, are formed on a bottom portion of a nozzle body 1, and a rotary valve 3 is provided with a valve first communication hole 31 selectively communicated with the first injection hole 12, and a valve second communication hole 32 selectively communicated with the second injection hole 13. By rotating and driving the rotary valve 3 at a prescribed angle by an actuator 4, a communication state of the first injection hole 12 and the valve first communication hole 31, and a communication state of the second injection hole 13 and the valve second communication hole 32 are switched.

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 a plurality of injection holes at the bottom of a bottomed cylindrical nozzle body, and a needle valve disposed in a reciprocating manner in the nozzle body is brought into contact with and separated from the seat portion of the nozzle body. By doing so, the nozzle hole is opened and closed.

JP 2013-160194 A

  However, in the conventional injector for an internal combustion engine, all the injection holes communicate with the downstream side of the seat part of the nozzle body, and all the injection holes are simultaneously opened and closed by contact with and separation from the seat part of the nozzle body of the needle valve. It is impossible to independently control the injection period (time axis) of the nozzle holes, and it is also impossible to inject fuel independently from each of the nozzle holes having different injection angles (arrangement of nozzle holes). is there.

  In view of the above points, an object of the present invention is to enable independent control of fuel injection from nozzle holes having different specifications.

  In order to achieve the above object, according to the first aspect of the present invention, there is provided a bottomed cylindrical nozzle body (1) having a high pressure fuel supply space (11) to which high pressure fuel is supplied, and a bottom portion of the nozzle body. There are multiple types of injection holes (12, 13) with different specifications for injecting high-pressure fuel into the combustion chamber of the engine, and communication passages (31, 32, 41) for connecting the high-pressure fuel supply space with the multiple types of injection holes. And a communication switching means (3, 4) for switching the communication state between the high-pressure fuel supply space and the plurality of types of nozzle holes by rotating.

  According to this, the fuel injection from the nozzle holes with different specifications can be controlled independently by the rotating communication switching means.

  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 at the time of no injection in the injector for internal-combustion engines concerning one embodiment of the present invention. It is a bottom view of the injector for internal-combustion engines concerning one embodiment. It is a top view of the sheet board simple substance in the injector for internal-combustion engines concerning one embodiment. It is IV-IV sectional drawing of the rotary valve single-piece | unit in the injector for internal combustion engines which concerns on one Embodiment. It is a figure which shows the relative position of the seat board at the time of the non-injection in the injector for internal combustion engines which concerns on one Embodiment, and a rotary valve. It is front sectional drawing at the time of the 1st injection hole injection in the injector for internal combustion engines which concerns on one Embodiment. It is a figure which shows the relative position of the seat board at the time of the 1st injection hole injection in the injector for internal combustion engines which concerns on one Embodiment. It is front sectional drawing at the time of the 2nd injection hole injection in the injector for internal combustion engines which concerns on one Embodiment. It is a figure which shows the relative position of the seat board at the time of the 2nd injection hole injection in the injector for internal combustion engines which concerns on one Embodiment. It is front sectional drawing at the time of all the injection holes injection in the injector for internal combustion engines which concerns on one Embodiment. It is a figure which shows the relative position of the seat disk at the time of all the injection holes injection in the injector for internal combustion engines which concerns on one Embodiment.

  An embodiment of the present invention will be described.

  As shown in FIGS. 1 and 2, the injector includes a bottomed cylindrical nozzle body 1 having a high-pressure fuel supply space 11 to which high-pressure fuel is supplied from a common rail (not shown).

  A plurality of types of injection holes 12 and 13 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 nozzle body 1.

  Specifically, the diameter of the first nozzle hole 12 is set smaller than the diameter of the second nozzle hole 13. The angle θ1 of the first nozzle hole 12 with respect to the axis A of the nozzle body 1 is set smaller than the angle θ2 of the second nozzle hole 132 with respect to the nozzle body axis A.

  Six first nozzle holes 12 are provided at equal intervals along the circumferential direction of the nozzle body 1. Six second nozzle holes 13 are also provided at equal intervals along the circumferential direction of the nozzle body 1.

  The position of the downstream opening 121 (that is, the end on the combustion chamber side) 121 in the first injection hole 12 and the position of the downstream opening 131 in the second injection hole 13 are shifted in the radial direction of the nozzle body 1. Yes.

  More specifically, the position of the downstream opening 121 of the first nozzle hole 12 having a relatively small nozzle hole diameter and angle θ1 is the downstream opening of the second nozzle hole 13 having a relatively large nozzle hole diameter and angle θ2. It is on the radially inner side of the nozzle body 1 from the position 131.

  As shown in FIGS. 1 and 3, in the high-pressure fuel supply space 11, the seat board 2 is disposed at the downstream end. The sheet board 2 is provided with a sheet first communication hole 21 that always communicates with the first injection hole 12 and a sheet second communication hole 22 that always communicates with the second injection hole 13.

  Six sheet first communication holes 21 are arranged at equal intervals along the circumferential direction of the nozzle body 1. In addition, the sheet second communication holes 22 are located on the radially outer side of the nozzle body 1 with respect to the sheet first communication holes 21, and six are arranged at equal intervals along the circumferential direction of the nozzle body 1.

  As shown in FIGS. 1 and 4, a rotary valve 3 that is rotatable with respect to the nozzle body 1 and an actuator 4 that drives the rotary valve 3 are disposed upstream of the seat board 2 in the high-pressure fuel supply space 11. Has been placed. The rotary valve 3 and the actuator 4 constitute the communication switching means of the present invention.

  The rotary valve 3 includes a valve first communication hole 31 as a communication path that can selectively communicate with the seat first communication hole 21 and a valve as a communication path that can selectively communicate with the seat second communication hole 22. A second communication hole 32 is provided.

  Twelve valve first communication holes 31 are arranged along the circumferential direction of the nozzle body 1. Further, twelve sheet second communication holes 22 are located on the radially outer side of the nozzle body 1 with respect to the sheet first communication hole 21, and twelve are arranged along the circumferential direction of the nozzle body 1.

  The actuator 4 is constituted by an electric motor, for example, and drives the rotary valve 3 to rotate. The actuator 4 is disposed upstream of the rotary valve 3 and communicates with the actuator as a communication path through which the high-pressure fuel supplied from the common rail flows to the valve first communication hole 31 and the valve second communication hole 32 side. A hole 41 is provided.

  Next, the operation will be described. 5, 7, 9, and 11, the seat first communication hole 21 and the seat second communication hole 22 are clearly distinguished from the valve first communication hole 31 and the valve second communication hole 32. Therefore, the seat first communication hole 21 and the seat second communication hole 22 are indicated by broken lines, and the valve first communication hole 31 and the valve second communication hole 32 are indicated by solid lines.

  In the state shown in FIGS. 1 and 5, the seat first communication hole 21 and the valve first communication hole 31 are not in communication, and the seat second communication hole 22 and the valve second communication hole 32 are not in communication. . That is, FIGS. 1 and 5 show the non-injection state.

  When the rotary valve 3 is rotationally driven by a predetermined angle by the actuator 4 from this non-injection state to shift to the state shown in FIGS. 6 and 7, the second seat communication hole 22 and the second valve communication hole 32 are not in communication. As it is, the seat first communication hole 21 and the valve first communication hole 31 are changed to the communication state.

  Therefore, in this state, the high-pressure fuel supplied from the common rail is supplied to the first injection hole 12 via the actuator communication hole 41, the valve first communication hole 31, and the seat first communication hole 21, and the first injection fuel is supplied. High pressure fuel is injected from the holes 12 into the combustion chamber.

  Since the first injection hole 12 has a small angle θ1, the fuel is injected near the center of the combustion chamber, and combustion is started near the center of the combustion chamber.

  When the rotary valve 3 is further rotationally driven by a predetermined angle from the state in which fuel is injected from the first injection hole 12 to shift to the state shown in FIGS. 8 and 9, the seat first communication hole 21 and the valve first The communication hole 31 changes to a non-communication state, and the seat second communication hole 22 and the valve second communication hole 32 change to a communication state.

  Therefore, in this state, the high-pressure fuel supplied from the common rail is supplied to the second injection hole 13 through the actuator communication hole 41, the valve second communication hole 32, and the seat second communication hole 22, and the second injection High pressure fuel is injected from the holes 13 into the combustion chamber.

  Since the second injection hole 13 has a large angle θ2, the fuel is injected to the outer peripheral side portion in the combustion chamber, and the combustion spreads toward the outer peripheral side in the combustion chamber.

  When the rotary valve 3 is further rotationally driven by a predetermined angle from the state in which the fuel is injected from the second injection hole 13 to shift to the state shown in FIGS. 10 and 11, the seat second communication hole 22 and the valve second The first communication hole 21 and the first valve communication hole 31 change to the communication state while the communication hole 32 remains in the communication state. Therefore, in this state, high-pressure fuel is injected from the first nozzle hole 12 and the second nozzle hole 13 into the combustion chamber, and burns in almost the entire area of the combustion chamber.

  When the rotary valve 3 is further rotationally driven by a predetermined angle from the state in which fuel is injected from the first injection hole 12 and the second injection hole 13, the state is changed to the non-injection state shown in FIGS. .

  According to this embodiment, fuel injection from the first nozzle hole 12 and the second nozzle hole 13 having different specifications can be controlled independently.

  Further, by sequentially shifting to a state in which fuel is injected from the first injection hole 12, a state in which fuel is injected from the second injection hole 13, and a state in which fuel is injected from the first injection hole 12 and the second injection hole 13. Combustion spreads from the vicinity of the central portion of the combustion chamber toward the outer peripheral side, the utilization rate of the air in the combustion chamber is increased, and the combustion efficiency is increased.

  In the above embodiment, the fuel is injected from the first injection hole 12, the fuel is injected from the second injection hole 13, and the fuel is injected from the first injection hole 12 and the second injection hole 13. However, the injection state may be selected according to the load, for example.

  For example, only a state in which fuel is injected from the first injection hole 12 is selected at a low load, only a state in which fuel is injected from the second injection hole 13 is selected at an intermediate load, and the first injection hole 12 and the first injection state are selected at a high load. Only the state in which fuel is injected from the two nozzle holes 13 may be selected.

(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, in the above-described embodiment, 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 to be essential in principle. .

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

  In the above embodiment, when referring to the shape, positional relationship, etc. of components, the shape, position, etc., unless otherwise specified and in principle limited to a specific shape, positional relationship, etc. It is not limited to relationships.

1 Nozzle body 3 Rotary valve (communication switching means)
4 Actuator (communication switching means)
11 High-pressure fuel supply space 12 First injection hole 13 Second injection hole 31 Valve first communication hole (communication path)
32 Valve 2nd communication hole (communication path)
41 Actuator communication hole (communication path)

Claims (6)

A bottomed cylindrical nozzle body (1) having a high-pressure fuel supply space (11) to which high-pressure fuel is supplied;
A plurality of types of nozzle holes (12, 13) formed at the bottom of the nozzle body and having different specifications for injecting the high-pressure fuel into a combustion chamber of an internal combustion engine;
A communication passage (31, 32, 41) for communicating the high-pressure fuel supply space and the plurality of types of nozzle holes is provided. An injector for an internal combustion engine comprising communication switching means (3, 4) for switching.   2. The injector for an internal combustion engine according to claim 1, wherein the positions of the downstream openings (121, 131) in the plurality of types of nozzle holes are shifted in the radial direction of the nozzle body for each type. 3.   The injector for an internal combustion engine according to claim 1 or 2, wherein the plurality of types of injection holes have different injection hole diameters.   The positions of the downstream openings in the plurality of types of nozzle holes are such that the nozzle holes having a relatively small nozzle hole diameter are arranged on the radially inner side of the nozzle body than the nozzle holes having a relatively large nozzle hole diameter. The injector for an internal combustion engine according to claim 3.   5. The injector for an internal combustion engine according to claim 1, wherein the plurality of types of nozzle holes have different angles with respect to an axis of the nozzle body.   The positions of the downstream openings in the plurality of types of nozzle holes are such that the nozzle holes having a relatively small angle with respect to the axis of the nozzle body are larger in diameter than the nozzle holes having a relatively large angle with respect to the axis of the nozzle body. 6. The injector for an internal combustion engine according to claim 5, wherein the injector is disposed on an inner side in the direction.

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