JP2005220749A - Fuel supply mechanism and engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel supply mechanism 20 with a mixture forming part 21 for forming a mixture with variable density distribution in an intake passage 6 by jetting fuel G from a plurality of supply holes 22 dispersed in the intake passage 6 along a flowing direction during stopping the flow of oxygen containing gas and an engine 100 equipped therewith, using fuel supply technology for reducing a NOx production amount while maintaining a stable combustion condition at all times even when an engine operating condition is changed. <P>SOLUTION: The fuel supply mechanism 20 comprises the plurality of mixture forming parts 21 arranged side by side along the flowing direction and a mixture forming region regulating means 33 for adjusting the supply of fuel into the mixture forming parts 21 to regulate the condition of a mixture forming region. Besides, the engine 100 equipped with the fuel supply mechanism 20 comprises a control device 15 for controlling the mixture forming region regulating means 33 in accordance with the opening degree of a throttle valve. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention provides the oxygen-containing gas in the intake passage from a plurality of supply holes that are dispersedly arranged along the flow direction in the intake passage in the intake passage through which the oxygen-containing gas supplied to the combustion chamber of the engine flows. A fuel supply provided with an air-fuel mixture forming section for ejecting fuel in a direction crossing the flow direction in the intake passage to form an air-fuel mixture having a concentration distribution in the intake passage when the flow of the fuel is stopped The present invention relates to a mechanism and an engine including the mechanism.

  Conventionally, as a fuel supply mechanism that can reduce the amount of NOx generated in the combustion chamber while maintaining a stable combustion state of the air-fuel mixture in the combustion chamber of the engine even at high output, it is supplied to the combustion chamber of the engine. A fuel supply mechanism has been proposed that includes an air-fuel mixture forming section that forms an air-fuel mixture having a concentration distribution in an intake passage through which air (oxygen-containing gas) flows (see Patent Document 1).

  This fuel supply mechanism has a plurality of supply holes that are distributed along the flow direction in the intake passage, and when the air flow in the intake passage stops, for example, at a time other than the intake stroke, By ejecting fuel in a direction crossing the flow direction, for example, in a direction perpendicular to the flow direction, the mixture formed in the intake passage has a striped shape with a high fuel concentration and a low air ratio in the air flow direction. It is configured to generate a fuel density distribution that includes a dark portion and a striped light portion having a small fuel concentration between the adjacent dark portions and a high air ratio. Then, by combusting the air-fuel mixture in which the concentration distribution is generated in the combustion chamber of the engine, compared with the case of combusting the air-fuel mixture in which the overall air ratio is uniform and the concentration distribution is not generated, Combustion slows down due to a decrease in the combustion speed in the region, and a local temperature rise can be suppressed, so that NOx generation can be suppressed. Further, since the dark portion and the light portion are adjacent to each other, the dark portion is generated. It is said that an unstable flame in the light part can be stabilized by a stable flame, so that a stable combustion state can be maintained.

JP 2001-342860 A (10th and 11th pages, FIG. 8)

  As described above, in a fuel supply mechanism having an air-fuel mixture forming section that supplies fuel in a form that forms an air-fuel mixture having a concentration distribution in the intake passage of the engine, even if the operating state of the engine fluctuates, the intake passage If an air-fuel mixture is not formed in an appropriate region of NO, NOx generation may not be sufficiently suppressed or a stable combustion state may not be maintained.

  For example, in the conventional fuel supply mechanism, when the engine output is reduced, a part of the air-fuel mixture formed in the intake passage remains in the intake passage without being taken into the combustion chamber in the intake stroke, In the intake stroke, the air-fuel mixture in which the fuel is homogeneously mixed and the concentration distribution disappears is sucked into the combustion chamber, and NOx generation may not be sufficiently suppressed. For example, when the engine output is increased, in addition to the air-fuel mixture formed in the intake passage, a large amount of air on the rear end side of the air-fuel mixture is sucked into the combustion chamber, and the air propagates in the combustion chamber. By inhibiting this, a stable combustion state may not be maintained.

  The present invention has been made in view of the above problems, and an object of the present invention is to disperse and arrange along the flow direction in the intake passage in the intake passage through which the oxygen-containing gas supplied to the combustion chamber of the engine flows. The fuel is ejected from the plurality of supply holes in a direction intersecting the flow direction in the intake passage at a time when the air flow in the intake passage is stopped, and the intake passage has a light and shade distribution. In a fuel supply mechanism having an air-fuel mixture forming section that forms an air-fuel mixture and an engine equipped with the same, for example, even when the engine operating state fluctuates, the amount of NOx generated is constantly reduced while maintaining a stable combustion state It is in the point of providing a fuel supply technology that can.

  In order to achieve the above object, a fuel supply mechanism according to the present invention includes a plurality of air supply passages in which an oxygen-containing gas supplied to a combustion chamber of an engine circulates and distributed in the flow direction of the intake passage. When the flow of the oxygen-containing gas in the intake passage is stopped from the supply hole, the fuel is ejected in a direction crossing the flow direction in the intake passage, and mixing having a light and shade distribution in the intake passage A fuel supply mechanism including an air-fuel mixture forming section that forms air, wherein the first characteristic configuration is that a plurality of the air-fuel mixture forming sections are juxtaposed along the flow direction in the intake passage. There is provided an air-fuel mixture forming region adjusting means capable of adjusting the fuel supply in the air-fuel mixture forming portion and adjusting the state of the air-fuel mixture forming region in the intake passage.

According to the first characteristic configuration of the fuel supply mechanism, a plurality of the air-fuel mixture forming portions are juxtaposed along the flow direction in the intake passage, and the air-fuel mixture forming region adjusting means is provided, so that each mixture is provided. By adjusting the fuel supply from the air formation unit, the state of the air-fuel mixture formation area such as the length and position of the air-fuel mixture formed in the intake passage in the flow direction in the intake passage is adjusted to It can be adjusted appropriately to the one that is sucked into the combustion chamber according to the state, and the homogenization of the air-fuel mixture sucked into the combustion chamber due to the residual air-fuel mixture in the intake passage is suppressed, and the NOx generation is sufficiently suppressed In addition, it is possible to suppress the flame propagation from being hindered by the air sucked into the combustion chamber following the air-fuel mixture formed in the intake passage, and maintain a stable combustion state.
Therefore, according to the present invention, it is possible to realize a fuel supply mechanism capable of reducing the NOx generation amount while always maintaining a stable combustion state even when the engine operating state fluctuates.

  A second characteristic configuration of the fuel supply mechanism according to the present invention includes: a cylindrical casing member that defines the intake passage and surrounds an intake pipe in which the supply hole is bored; the intake pipe and the casing member; A partition wall that divides a space formed between the plurality of fuel supply chambers arranged in parallel along the flow direction in the intake passage, and a fuel supply passage that supplies fuel separately to the plurality of fuel supply chambers And the plurality of air-fuel mixture forming portions arranged in parallel along the flow direction in the intake passage are configured to correspond to the plurality of fuel supply chambers.

  According to the second characteristic configuration of the fuel supply mechanism, a cylindrical space is formed between the intake pipe and the casing member by surrounding the intake pipe in which the supply hole is formed with the cylindrical casing member. Furthermore, a plurality of cylindrical fuel supply chambers can be formed along the flow direction in the intake passage by partition walls that cross the cylindrical cross section of the cylindrical space. The fuel supplied to the respective fuel supply chambers is ejected in a direction intersecting the flow direction in the intake passage through the supply holes, so that an air-fuel mixture having a concentration distribution is formed in the intake passage. With the plurality of fuel supply chambers arranged in parallel, it is possible to realize a plurality of air-fuel mixture forming units arranged in parallel along the flow direction in the intake passage.

  A third characteristic configuration of the fuel supply mechanism according to the present invention is such that the air-fuel mixture formation region adjusting means adjusts the open / close states of a plurality of on-off valves capable of intermittently supplying fuel to the respective air-fuel mixture forming portions. It is in the point which is comprised.

  According to the third characteristic configuration of the fuel supply mechanism, the mixing adjusting means can be configured by the plurality of on-off valves disposed with respect to the respective mixing forming portions, and the fuel is opened and the fuel is opened. Utilizing the fact that a mixture having a concentration distribution is formed in the mixture formation portion that has been supplied, and a mixture having a concentration distribution is not formed in the mixture formation portion that has shut off the fuel supply by closing the on-off valve. It is possible to adjust the state of the air-fuel mixture forming region such as the length and position of the air-fuel mixture formed in the air intake passage in the flow direction in the air intake passage so as to have a light and shade distribution.

  A fourth characteristic configuration of the fuel supply mechanism according to the present invention is that the fuel is a gaseous fuel.

  According to the fourth characteristic configuration of the fuel supply mechanism, even if a gaseous fuel that is easily mixed with an oxygen-containing gas is used, a concentration distribution is generated in the air-fuel mixture formed in the intake passage of the engine, and the combustion chamber NOx generation can be suppressed by suppressing a local temperature rise at.

  In order to achieve the above object, an engine according to the present invention is an engine including a fuel supply mechanism having any one of the first to third characteristic configurations, wherein the first characteristic configuration is provided in the intake passage. There is a control means for controlling the air-fuel mixture formation region adjusting means based on the opening of the throttle valve provided.

According to the first characteristic configuration of the engine, the air-fuel mixture formation region adjusting means is controlled by the control means on the basis of the opening degree of the throttle valve, exclusively using the characteristics of the fuel supply mechanism described so far. Therefore, even when the engine output fluctuates at a constant rotation speed or when the rotation speed fluctuates at a constant output, the length of the air-fuel mixture formed in the intake passage in the direction of flow in the intake passage is Adjust the state of the air-fuel mixture formation region, such as the position, to an appropriate one that matches the intake air amount to the combustion chamber determined by the opening of the throttle valve, so that the air-fuel mixture having a concentration distribution in the appropriate region in the intake passage The air-fuel mixture can be sucked into the combustion chamber while maintaining its light and shade distribution well.
Therefore, according to the present invention, even when the opening degree of the throttle valve fluctuates, the air-fuel mixture having a concentration distribution can always be burned in the combustion chamber, and the NOx generation amount is reduced while maintaining a stable combustion state. The fuel supply mechanism that can be realized can be realized.

  In a second characteristic configuration of the engine according to the present invention, the control means shortens the length along the flow direction of the air-fuel mixture formed in the intake passage as the opening of the throttle valve is smaller. The air-fuel mixture formation region adjusting means is configured to be controlled.

  According to the second characteristic configuration of the engine, even when the opening of the throttle valve is reduced and the amount of intake air into the combustion chamber is reduced, the control unit controls the mixture formation region adjusting unit to control the mixture mixture. By shortening the length along the flow direction, the mixture shortened in the intake stroke can be reliably sucked into the combustion chamber, and is sucked into the combustion chamber due to the mixture remaining in the intake passage. It is possible to sufficiently suppress the generation of NOx by suppressing the homogenization of the air-fuel mixture.

  According to a third characteristic configuration of the engine according to the present invention, the control means brings the position of the rear end portion of the air-fuel mixture formed in the intake passage closer to the combustion chamber as the opening of the throttle valve is smaller. The air-fuel mixture formation region adjusting means is configured to be controlled.

According to the third characteristic configuration of the engine, when the opening of the throttle valve is reduced and the amount of intake air to the combustion chamber decreases, the mixture formation region adjusting means is controlled by the control means to By reducing the position of the rear end of the air-fuel mixture formed in the combustion chamber closer to the combustion chamber, it is possible to suppress a part of the rear end of the air-fuel mixture from remaining in the intake passage without being sucked into the combustion chamber. Further, it is possible to sufficiently suppress the generation of NOx by suppressing the homogenization of the air-fuel mixture sucked into the combustion chamber due to the residual air-fuel mixture in the intake passage.
On the other hand, when the throttle valve opening is increased and the amount of intake air into the combustion chamber increases, the control means controls the air-fuel mixture formation region adjusting means to control the rear end of the air-fuel mixture formed in the intake passage. By keeping the position of the part away from the combustion chamber, the amount of air that is taken into the combustion chamber following the air-fuel mixture formed in the intake passage is reduced as much as possible, and the flame propagation is inhibited by the air in the combustion chamber Can be suppressed, and a stable combustion state can be maintained.

Embodiments of the present invention will be described with reference to the drawings.
An engine 100 shown in FIG. 1 includes a cylinder 10 and a piston 3 housed in the cylinder 10 and forming a combustion chamber 1 together with the cylinder 10, and the piston 3 is linked to a crankshaft 9 via a connecting rod 4. It is connected.
The cylinder 10 is connected to an intake passage 6 having an intake valve 5 and an exhaust passage 8 having an exhaust valve 7, and opens and closes the intake valve 5 and the exhaust valve 7. The formed air-fuel mixture is sucked into the combustion chamber 1, undergoes a compression stroke, the spark plug 2 provided in the combustion chamber 1 is operated to ignite the air-fuel mixture, and various combustion / expansion and exhaust strokes are executed. The reciprocating motion of the piston 3 is changed to the rotational motion of the crankshaft 9 and is output as a so-called spark ignition engine (SI engine).

  Further, in the engine 100, the fuel G is ejected to the air A flowing through the intake passage 6 from a plurality of supply holes 22 distributed along the flow direction of the air A (an example of an oxygen-containing gas) in the intake passage 6. A fuel supply mechanism 20 for forming an air-fuel mixture in the intake passage 6 is provided, and the characteristic configuration will be described below.

The fuel supply mechanism 20 includes a plurality of air-fuel mixture forming portions 21 that supply fuel G in a form in which an air-fuel mixture having a concentration distribution is formed in the intake passage 6 along the flow direction in the intake passage 6. Has been.
As the fuel G, natural gas which is a gaseous fuel is used.

  The air-fuel mixture forming section 21 is connected to the intake passage 6 at a time when the flow of the air A in the intake passage 6 is stopped from the plurality of supply holes 22 dispersedly arranged along the flow direction in the intake passage 6. The fuel G is ejected in a direction crossing the flow direction to form an air-fuel mixture having a density distribution in the intake passage 6.

  Specifically, in the air-fuel mixture forming portion 21, a cylindrical casing member 24 into which fuel G is supplied from a fuel supply passage 31 is formed, and an intake pipe in which an intake passage 6 is formed and a supply hole 22 is formed. 16 is provided in a state of surrounding.

  Further, a rectifying member 25 to which fuel G is supplied is provided inside the casing member 24, and the fuel G supplied into the rectifying member 25 is supplied from a plurality of openings provided outside the rectifying member 25. Then, it flows out into the fuel supply chamber 27 outside the flow regulating member 25 and reaches the supply hole 22. The fuel supply chamber 27 is provided with a cylindrical punching plate 28 between the intake pipe 16 provided with the supply hole 22 and the rectifying member 34, and is supplied to the supply hole 22 by the punching plate 28. The flow direction and pressure of the fuel G can be adjusted.

  The supply holes 22 are distributed at regular intervals along the flow direction of the air A in the intake passage 6, and are further distributed at regular intervals in the circumferential direction around the axis of the intake passage 6.

The fuel supply passage 31 that supplies fuel to the fuel supply chamber 27 is provided with an on-off valve 32 that can intermittently supply fuel to the fuel supply chamber 27.
Then, when the flow of the air A in the intake passage 6 is stopped, that is, at a time other than the intake stroke, the on-off valve 32 is opened for a certain time, so that the intake passage 6 can be opened from the respective supply holes 22. In a direction crossing the intake passage 6 in a state where the fuel G is jetted in a direction orthogonal to the flow direction in the cylinder and the fuel G jetted into the intake passage 6 is suppressed from intermingling with each other. Will go on. Therefore, in the intake passage 6 where the flow of the air A is stopped, the stripe-like formed between the stripe-like dark portion where the fuel G is supplied in the flow direction of the air A in the intake passage 6 and the adjacent dark portion. The air-fuel mixture is formed in the state where the light and shade distribution consisting of the light portion of the light is generated.

  Then, the air-fuel mixture having the concentration distribution formed in the intake passage 6 in this way is sucked into the combustion chamber 1 in the next intake stroke while maintaining the mixture suppression state maintaining the concentration distribution.

  Therefore, the air-fuel mixture sucked into the combustion chamber 1 has a density distribution in which the mixing is hardly progressing. Even if the air-fuel mixture is compressed and ignited by the spark plug 2, the air-fuel mixture is initially in the rich portion. Since it ignites stably, the overall air ratio can be increased, and furthermore, when the flame propagates to the adjacent light part, the combustion rate is lowered, and the overall combustion rate is lowered. Thus, generation of NOx can be suppressed.

  Further, the space formed between the intake pipe 16 and the casing member 24 is divided into four fuel supply chambers 27 arranged in parallel along the air A flow direction in the intake passage 6 by the three partition walls 29. Accordingly, the four air-fuel mixture forming portions 21A, 21B, 21C, and 21D arranged in parallel along the flow direction of the air A in the intake passage 6 are configured to correspond to the four fuel supply chambers 27. ing.

  Further, the fuel supply mechanism 20 adjusts the open / close state of a plurality of on-off valves 32 capable of intermittently supplying fuel to the respective air-fuel mixture forming portions 21A, 21B, 21C, and 21D, thereby allowing the respective air-fuel mixture forming portions to be adjusted. The state of the air-fuel mixture formation region such as the length and position of the air-fuel mixture formed so as to have a density distribution in the intake passage 6 in the flow direction in the intake passage 6 by adjusting the fuel supply in 21A, 21B, 21C, and 21D The air-fuel mixture formation region adjusting means 33 is provided.

  That is, the air-fuel mixture formation region adjusting means 33 selects the open / close valve 32 to be opened from among the plurality of on-off valves 32, thereby forming the air-fuel mixture forming section in the plurality of air-fuel mixture forming sections 21. 21 is selected, and the state of the air-fuel mixture formation region such as the length and position of the air-fuel mixture formed in the intake passage 6 is adjusted. For example, with respect to the state in which the air-fuel mixture is formed in all the air-fuel mixture forming parts 21, the on-off valve 32 is sequentially closed so that the air-fuel mixture is not formed in the air-fuel mixture forming part 21 in order from the end. 6 can be shortened. Moreover, the position of the air-fuel mixture formed in the intake passage 6 can be changed by switching the air-fuel mixture forming unit 21 that forms the air-fuel mixture.

  Even when the operating state such as the output of the engine 100 fluctuates by the air-fuel mixture formation region adjusting means 33, the state of the air-fuel mixture forming region in the intake passage 6 is appropriately adjusted according to the engine operating state. It can be adjusted to what is inhaled.

A throttle valve 12 capable of adjusting the cross-sectional area of the intake passage 6 is provided upstream of the fuel supply mechanism 20 in the intake passage 6, and a control device 15 including a computer provided in the engine 100 is required. The throttle valve 21 is operated according to the engine output to adjust the intake amount of the air-fuel mixture into the combustion chamber 1.
When the torque applied to the crankshaft 9 is constant, the engine output includes the engine speed recognized from the detection result of the crank angle sensor 23 that detects the rotation speed of the crankshaft 9 and the opening degree of the throttle valve 21. Can be recognized from.

  The control device 15 is configured to function as control means for controlling the air-fuel mixture formation region adjusting means 33 based on the opening degree of the throttle valve 21, and the state of the air-fuel mixture formation region in the intake passage 6. Is automatically adjusted to a value suitable for the amount of intake air to the combustion chamber 1 determined by the opening of the throttle valve 21, the details of which will be described below.

Assuming that the engine 100 changes the engine output in a state where the rotational speed is constant, when the opening of the throttle valve 21 is reduced to reduce the engine output, the cross-sectional area of the intake passage 6 is reduced. Is reduced, and the amount of intake air into the combustion chamber 1 in one intake stroke is reduced.
That is, as shown in FIG. 1, the intake air amount at rated output is V1, the intake air amount at 75% output is V2, the intake air amount at 50% output is V3, and the intake air amount at 25% output is Assuming V4, V1>V2>V3> V4.

Further, when the opening degree of the throttle valve 21 is reduced, the intake air amount is reduced, so that the rear end portion of the air-fuel mixture formed in the intake passage 6 is sucked into the combustion chamber 1 in one intake stroke. The position approaches the combustion chamber 1.
That is, as shown in FIG. 1, the position of the rear end portion that is sucked into the combustion chamber 1 in one intake stroke when the intake amount is V1 at the rated output (100% output) is P1, 75% output. P2 is the position of the rear end portion that is sucked into the combustion chamber 1 in one intake stroke when the intake amount is V2, and one intake stroke when the intake amount is V3 at 50% output. If the position of the rear end portion that is sucked into the combustion chamber 1 is P3, and the position of the rear end portion that is sucked into the combustion chamber 1 in one intake stroke when the intake amount is V4 at 25% output is P4. The position P1, the position P2, the position P3, and the position P4 are arranged in this order from the side far from the combustion chamber 1 in the intake passage 6.

  The four air-fuel mixture forming portions 21A, 21B, 21C, and 21D are arranged in accordance with the above-described P1, P2, P3, and P4, and specifically, the air-fuel mixture forming portion 21A that is closest to the combustion chamber 1 Is disposed in a region closer to the combustion chamber 1 than the position P4, and the air-fuel mixture forming portion 21B next to the combustion chamber 1 is disposed in a region between the positions P3 and P4, and then is mixed closer to the combustion chamber 1. The gas forming part 21C is arranged in a region between the positions P2 and P3, and the air-fuel mixture forming part 21D farthest from the combustion chamber 1 is arranged in a region between the positions P1 and P2.

  Then, the control device 15 follows the flow direction of the air-fuel mixture formed in the intake passage 6 as the engine output decreases, for example, 75% output, 50% output, and 25% output with respect to the rated output. The mixture formation region adjusting means 33 is controlled in such a manner that the position of the rear end portion of the mixture formed in the intake passage 6 is made closer to the combustion chamber 1 while the length is shortened.

  That is, the control device 15 is arranged in the region from the combustion chamber 1 to the position P1 at the rated output at which the air-fuel mixture from the combustion chamber 1 to the position P1 is sucked into the combustion chamber 1 in one intake stroke. The air-fuel mixture forming portions 21A, 21B, 21C, and 21D form an air-fuel mixture having a light / dark distribution, thereby generating a light / dark distribution in the entire intake air amount V1 that is sucked into the combustion chamber 1. An appropriate amount of air-fuel mixture can be formed.

  Further, the control device 15 is arranged in a region from the combustion chamber 1 to the position P2 at the 75% output when the air-fuel mixture from the combustion chamber 1 to the position P2 is sucked into the combustion chamber 1 in one intake stroke. Only in the air-fuel mixture forming portions 21A, 21B, and 21C, an air-fuel mixture having a light and shade distribution is formed, so that a light and shade distribution is generated in the entire intake air amount V2 sucked into the combustion chamber 1 and matches the intake air amount V2. An appropriate amount of air-fuel mixture can be formed.

  Further, the control device 15 is disposed in the region from the combustion chamber 1 to the position P3 at the time of 50% output in which the air-fuel mixture from the combustion chamber 1 to the position P3 is sucked into the combustion chamber 1 in one intake stroke. Only in the air-fuel mixture forming portions 21A and 21B, an air-fuel mixture having a light / dark distribution is formed, so that a light / light distribution is generated in the entire intake air amount V3 sucked into the combustion chamber 1, and an appropriate air flow amount V3 is obtained. A proper amount of air-fuel mixture can be formed.

  Further, the control device 15 is disposed in the region from the combustion chamber 1 to the position P4 at the time of 25% output in which the air-fuel mixture from the combustion chamber 1 to the position P4 is sucked into the combustion chamber 1 in one intake stroke. Only in the air-fuel mixture forming portion 21A, an air-fuel mixture having a light / dark distribution is formed, so that a light / dark distribution is generated in the entire intake air amount V4 sucked into the combustion chamber 1 and an appropriate amount that matches the air intake amount V4. Can be formed.

  Therefore, even when the amount of intake air to the combustion chamber 1 determined by the opening degree of the throttle valve 21 fluctuates by controlling the mixture formation region adjusting means 33 based on the opening degree of the throttle valve 21 by the control device 15. In addition, the homogenization of the air-fuel mixture sucked into the combustion chamber 1 due to the remaining air-fuel mixture in the intake passage 6 is suppressed to sufficiently suppress the generation of NOx, and the air-fuel mixture formed in the intake passage 6 is followed. It is possible to suppress the flame propagation from being inhibited by the air A sucked into the combustion chamber 1 and maintain a stable combustion state.

[Another embodiment]
(1) In the above embodiment, the air-fuel mixture formation region adjusting means 33 in the fuel supply mechanism 20 adjusts the state of the air-fuel mixture formed in the intake passage 6 by adjusting the open / close state of the plurality of on-off valves 32. However, the air-fuel mixture formation region adjusting means 33 may have another configuration as described below.
For example, the description of the configuration similar to that of the above embodiment is omitted, but as shown in FIG. 2, one fuel supply chamber is formed without partitioning the space formed between the intake pipe 16 and the casing member 24. The fuel G is supplied to the fuel supply chamber 27 from one fuel supply passage 31 provided with an opening / closing valve 32.
Further, inside the intake pipe 16, a cylindrical slide pipe 41 slidable in the pipe axis direction of the intake pipe 16 is inserted in a state where the side end portion close to the combustion chamber 1 is disposed on the combustion supply mechanism 20 side. Has been. Therefore, the supply hole 22 disposed on the side farther from the combustion chamber 1 than the side end near the combustion chamber 1 of the slide tube 41 is closed by the slide tube 41, so that the intake air is sucked from the supply hole 22. The ejection of the fuel G to the path 6 is prevented.
In addition, an actuator 48 is provided which is connected to the operation unit 42 protruding outward from the slide tube 41 and slides the slide tube 41 in the direction of the pipe axis of the intake pipe 16 according to a command from the control device 15. By sliding the slide tube 41 in the tube axis direction, the region of the supply hole 22 where the fuel supply mechanism 20 prevents the fuel G from being ejected into the intake passage 6 by the slide tube 41 can be changed.
That is, by the slide tube 41 and the actuator 48 as described above, in the fuel supply mechanism 20, the length in the flow direction of the air-fuel mixture formed in the intake passage 6 so as to have a density distribution in the intake passage 6 and the rear end portion thereof. It is possible to configure the air-fuel mixture formation region adjusting means 33 that can adjust the state of the air-fuel mixture formation region such as the position.

(2) In the above-described embodiment, an example in which the fuel supply mechanism 20 according to the present invention is applied to a spark ignition engine has been described. Separately, for example, the fuel supply mechanism 20 according to the present invention is mixed with intake air from an intake passage, for example. The present invention may be applied to another type of engine such as a premixed compression ignition engine that compresses gas in a combustion chamber and self-ignites.

(3) In the above embodiment, natural gas is used as the fuel G, but gaseous fuel other than natural gas can be used as the fuel.

Schematic configuration diagram of an engine equipped with a fuel supply mechanism Schematic configuration diagram of combustion supply mechanism of another embodiment

Explanation of symbols

1: Combustion chamber 6: Intake passage 15: Control device (control means)
16: Intake pipes 21, 21A, 21B, 21C, 21D: Mixture formation unit 22: Supply hole 27: Fuel supply chamber 31: Fuel supply path 32: On-off valve 33: Mixture formation region adjusting means 40: Mixture formation region Adjustment means 41: slide tube 48: actuator A: air (oxygen-containing gas)
G: Fuel

Claims (7)

In the intake passage through which the oxygen-containing gas supplied to the combustion chamber of the engine flows, the flow of the oxygen-containing gas in the intake passage is stopped from a plurality of supply holes distributed along the flow direction in the intake passage. A fuel supply mechanism comprising an air-fuel mixture forming section that ejects fuel in a direction intersecting a flow direction in the intake passage at a time to form an air-fuel mixture having a concentration distribution in the intake passage. ,
A plurality of the air-fuel mixture forming portions are juxtaposed along a flow direction in the intake passage
A fuel supply mechanism comprising an air-fuel mixture forming region adjusting means capable of adjusting a fuel supply in each of the air-fuel mixture forming portions and adjusting a state of the air-fuel mixture forming region in the intake passage.   A cylindrical casing member that defines the intake passage and that surrounds the intake pipe in which the supply hole is formed, and a space formed between the intake pipe and the casing member flows in the intake passage A partition wall that is divided into a plurality of fuel supply chambers arranged in parallel along a direction; and a fuel supply passage that supplies fuel separately to the plurality of fuel supply chambers, and is along a flow direction in the intake passage. 2. The fuel supply mechanism according to claim 1, wherein the plurality of air-fuel mixture forming units arranged side by side are configured to correspond to the plurality of fuel supply chambers.   3. The fuel supply according to claim 1, wherein the air-fuel mixture formation region adjusting means is configured to adjust open / close states of a plurality of on-off valves capable of intermittently supplying fuel to each of the air-fuel mixture forming units. mechanism.   The fuel supply mechanism according to any one of claims 1 to 3, wherein the fuel is a gaseous fuel. An engine comprising the fuel supply mechanism according to any one of claims 1 to 4,
An engine comprising control means for controlling the air-fuel mixture formation region adjusting means based on an opening of a throttle valve provided in the intake passage.   The control means is configured to control the air-fuel mixture formation region adjusting means in such a form that the length along the flow direction of the air-fuel mixture formed in the intake passage is shortened as the opening of the throttle valve is smaller. The engine according to claim 5.   The control means controls the air-fuel mixture formation region adjusting means in such a manner that the position of the rear end portion of the air-fuel mixture formed in the intake passage is brought closer to the combustion chamber as the opening of the throttle valve is smaller. The engine of Claim 5 or 6 comprised by these.

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