JP2006046163A - Hydrogen added internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress knocking by increasing combustion speed in a cylinder with a simple construction. <P>SOLUTION: A hydrogen added internal combustion engine uses hydrogen gas together with hydrocarbon fuel as fuel for combustion, and is provided with a gasoline injection valve 26 injecting hydrocarbon fuel in an intake port, a hydrogen fuel cylinder injection valve 30 injecting hydrogen gas into a cylinder, and an ignition plug provided in the cylinder. At least a part of hydrogen gas injected from the hydrogen fuel cylinder injection valve 30 is injected toward the ignition plug 54. Flame ignited by the ignition plug 54 spreads through hydrogen jet 52 in which flame spread speed is high, and then spreads to hydrocarbon duel in the cylinder. Consequently, combustion speed in the cylinder is increased and occurrence of knocking is surely prevented. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hydrogenated internal combustion engine.

  There is known an internal combustion engine that improves ignitability and the lean limit of the fuel mixture by adding hydrogen to the fuel mixture formed of gasoline and air. In such an internal combustion engine, Japanese Patent Laid-Open No. 2004-68615 discloses that knocking by self-ignition of end gas is performed by performing hydrogen injection along a cylinder wall surface serving as a terminal of a flame propagation path and increasing a late combustion speed. A technique for preventing this is disclosed.

JP 2004-68615 A JP-A-7-63128 Japanese Patent Laid-Open No. 2004-76679

  However, in the technique described in the above publication, since hydrogen is injected from a plurality of locations toward the periphery of the cylinder, the configuration of the apparatus becomes large, which causes a problem of increasing the size of the apparatus and increasing the manufacturing cost. Arise.

  The present invention has been made to solve the above-described problems, and an object thereof is to suppress the occurrence of knocking by increasing the combustion speed in the cylinder with a simple configuration.

  In order to achieve the above object, a first invention is a hydrogenated internal combustion engine that uses hydrogen gas together with a hydrocarbon fuel as a combustion fuel, and a first injection valve that injects the hydrocarbon fuel into an intake port; A second injection valve for injecting hydrogen gas into the cylinder; and an ignition plug provided in the cylinder, wherein at least part of the hydrogen gas injected from the second injection valve is directed toward the ignition plug And jetting.

  A second invention is characterized in that, in the first invention, the second injection valve is provided in the center of a combustion chamber in a cylinder.

  According to a third aspect, in the second aspect, the second injection valve injects hydrogen gas radially from the center of the combustion chamber.

  According to a fourth aspect, in the third aspect, the spark plug is provided in the vicinity of the second injection valve.

  According to a fifth invention, in the first invention, the second injection valve is provided at a peripheral portion in the cylinder, and injects hydrogen gas so as to reach at least the opposite cylinder inner wall surface. .

  According to a sixth aspect, in the fifth aspect, the spark plug is provided in the center of the combustion chamber in the cylinder.

  According to the first invention, since at least a part of the hydrogen gas is injected toward the spark plug, when ignition is performed by the spark plug, the flame propagates through a hydrogen jet having a high flame propagation speed, and further, It will propagate to the hydrocarbon fuel in the cylinder. Therefore, a flame can be generated in the entire region of the combustion chamber 16 in a very short time, so that the thermal efficiency can be improved and the occurrence of knocking can be reliably suppressed.

  According to the second invention, since the second injection valve is provided at the center of the combustion chamber, a hydrogen jet can be formed from the center of the combustion chamber toward the periphery. Therefore, by igniting the hydrogen jet with the spark plug, the flame can be instantaneously propagated from the center of the combustion chamber to the periphery.

  According to the third aspect of the invention, since hydrogen gas is injected radially from the center of the combustion chamber, the flame can be propagated in the radial direction of the combustion chamber along the radially formed hydrogen jet. Since the flame propagates in the circumferential direction of the combustion chamber, the flame can be propagated to the mixture of hydrocarbon fuels adjacent in the circumferential direction. Therefore, the flame can be rapidly propagated throughout the cylinder.

  According to the fourth invention, since the spark plug is provided in the vicinity of the second injection valve, the hydrogen gas injected from the second injection valve is hydrogenated before being mixed with the hydrocarbon fuel mixture in the cylinder. Can ignite gas. Therefore, the flame can be reliably propagated to the hydrogen jet having a high flame propagation speed.

  According to the fifth aspect of the invention, the second injection valve is provided in the peripheral portion of the cylinder, and the hydrogen gas is injected at least toward the cylinder inner wall surface on the opposite side. Therefore, the hydrogen jet is caused to cross the cylinder. Can be formed. Therefore, by performing ignition with the spark plug, it is possible to propagate the flame so as to cross the inside of the cylinder, and it is possible to propagate the flame to the mixture of adjacent hydrocarbon fuels. Thereby, a flame can be rapidly propagated to the whole region in a cylinder.

  According to the sixth invention, since the ignition plug is provided in the center of the combustion chamber, the flame can be propagated along the hydrogen jet from the center of the combustion chamber to the periphery by igniting the hydrogen jet.

  Several embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the element which is common in each figure, and the overlapping description is abbreviate | omitted. The present invention is not limited to the following embodiments.

Embodiment 1 FIG.
FIG. 1 is a diagram for explaining the configuration of a system including a hydrogenated internal combustion engine 10 according to Embodiment 1 of the present invention. A piston 12 that reciprocates inside the cylinder of the internal combustion engine 10 is provided. Further, the internal combustion engine 10 includes a cylinder head 14. A combustion chamber 16 is formed between the piston 12 and the cylinder head 14. An intake port 18 and an exhaust port 20 communicate with the combustion chamber 16. An intake valve 22 and an exhaust valve 24 are disposed in the intake port 18 and the exhaust port 20, respectively.

  The intake port 18 is provided with a gasoline injection valve 26 that injects gasoline (hydrocarbon fuel) into the port. Further, a hydrogen fuel in-cylinder injection valve 30 for injecting hydrogen into the cylinder is disposed in the cylinder head 14.

  A gasoline tank 34 communicates with the gasoline injection valve 26 via a gasoline supply pipe 32. The gasoline supply pipe 32 includes a pump 36 between the gasoline injection valve 26 and the gasoline tank 34. The pump 36 can supply gasoline to the gasoline injection valve 26 at a predetermined pressure. For this reason, the gasoline injection valve 26 is able to inject an amount of gasoline into the intake port 18 according to the opening time by opening the valve in response to a drive signal supplied from the outside.

  The system of this embodiment includes a hydrogen tank 38 for storing hydrogen in a gaseous state at a high pressure. A hydrogen supply pipe 40 communicates with the hydrogen tank 38. The hydrogen supply pipe 40 communicates with the hydrogen fuel in-cylinder injection valve 30. In the system of this embodiment, hydrogen gas charged into the hydrogen tank 38 from the outside is used as the hydrogen fuel supplied to the hydrogen fuel in-cylinder injection valve 30, but the hydrogen fuel is limited to this. Instead, a hydrogen-rich gas containing a high concentration of hydrogen generated on the vehicle or supplied from the outside may be used.

  A regulator 44 is disposed in the hydrogen supply pipe 40 between the hydrogen tank 38 and the hydrogen fuel cylinder injection valve 30. According to such a configuration, hydrogen in the hydrogen tank 38 is supplied to the hydrogen fuel in-cylinder injection valve 30 at a predetermined pressure reduced by the regulator 44. Therefore, the hydrogen fuel in-cylinder injection valve 30 is able to inject into the cylinder an amount of hydrogen corresponding to the opening time by opening the valve in response to a driving signal supplied from the outside.

  In the hydrogen supply pipe 40, a fuel pressure sensor 48 is disposed between the regulator 44 and the hydrogen fuel in-cylinder injection valve 30. The fuel pressure sensor 48 is a sensor that emits an output corresponding to the pressure of hydrogen supplied to the hydrogen fuel in-cylinder injection valve 30. In the system of this embodiment, the regulator 44 is controlled based on the output generated by the fuel pressure sensor 48. For this reason, even when the pressure of the hydrogen supplied from the hydrogen tank 38 fluctuates, the hydrogen can be supplied to the hydrogen fuel in-cylinder injection valve 30 at a stable pressure.

  The system of this embodiment includes an ECU 50. In addition to the fuel pressure sensor 48 described above, the ECU 50 includes a KCS sensor that detects the occurrence of knocking in order to grasp the operating state of the internal combustion engine 10, a throttle opening, an engine speed, an exhaust temperature, a coolant temperature, a lubricating oil Various sensors (not shown) for detecting temperature, catalyst bed temperature and the like are connected. The ECU 50 is connected to actuators such as the gasoline injection valve 26, the hydrogen fuel in-cylinder injection valve 30, the pump 36, and the regulator 44 described above. According to such a configuration, the ECU 50 can arbitrarily select an injection valve that performs fuel injection according to the operating state of the internal combustion engine 10, and drives each actuator based on the outputs of various sensors. Can do.

  FIG. 2 is a schematic view showing the combustion chamber 16 as viewed from below, and shows a state immediately after hydrogen is injected from the hydrogen fuel in-cylinder injection valve 30 in the compression process. Hydrogen is injected radially from the hydrogen fuel in-cylinder injection valve 30 disposed in the center of the combustion chamber 16 in a radial direction so as to reach the periphery of the combustion chamber 16. As a result, as shown in FIG. 2, hydrogen jets 52 are formed in the four directions in which hydrogen is injected.

  In order to form the hydrogen jet 52 without depending on the air flow in the cylinder, it is preferable to inject high-pressure hydrogen from the hydrogen fuel in-cylinder injection valve 30. The injection direction when hydrogen is injected radially is not limited to four directions, and the injection direction can be appropriately determined according to the volume of the combustion chamber 16, the injection amount of hydrogen, and the like.

  In the state shown in FIG. 2, a mixture of gasoline and air sucked in the intake stroke stays in the combustion chamber 16. Accordingly, the peripheral edge of the hydrogen jet 52 is in contact with the mixture of gasoline and air.

  As shown in FIG. 2, a spark plug 54 is disposed at a position in contact with one of the radially formed hydrogen jets 52. That is, in this embodiment, the injection direction of the hydrogen gas from the hydrogen fuel in-cylinder injection valve 30 and the position of the spark plug 54 are defined so that the hydrogen gas is injected toward the spark plug 54.

  When ignition is performed by the spark plug 54 from the state of FIG. 2, a flame is generated in the hydrogen jet 52 in contact with the spark plug 54 and another hydrogen jet 52 adjacent in the vicinity of the hydrogen fuel in-cylinder injection valve 30. To do. At this time, since the flame propagation speed of hydrogen is as fast as about nine times that of gasoline, the flame first spreads radially in the radial direction of the combustion chamber 16 along the hydrogen jet 52 and reaches the entire area of the hydrogen jet 52. At the same time, the flame of the hydrogen jet 52 spreads in the circumferential direction of the combustion chamber 16 and propagates to the gasoline mixture adjacent in the circumferential direction. Thereby, combustion is performed in the whole region in the cylinder.

  Thus, by forming the hydrogen jet 52 in the combustion chamber 16 and igniting the hydrogen jet 52, the flame can be instantaneously propagated to the region where the hydrogen jet 52 is formed. In the example of FIG. 2, since the hydrogen jets 52 are formed radially from the center of the combustion chamber 16 to the periphery, the flame can instantaneously reach the periphery from the center of the fuel chamber 16.

  In addition, since the hydrogen jet flow 52 having a high flame propagation speed is interposed between the spark plug 54 and the gasoline mixture, the flame propagation distance can be remarkably shortened, and the hydrogen jet flow 52 exists relatively far from the spark plug 54. The flame can be instantly propagated to the gasoline mixture. As a result, an effect of increasing the combustion speed can be obtained, and a flame can be generated in the entire combustion chamber 16 in a very short time after ignition by the spark plug 54. Therefore, thermal efficiency can be improved and the occurrence of knocking can be reliably suppressed.

  In FIG. 2, in order to maximize the rapid flame propagation in the hydrogen jet 52, it is preferable to ignite the hydrogen jet 52 before the injected hydrogen diffuses into the gasoline mixture in the cylinder. . For this reason, it is desirable to arrange the hydrogen fuel in-cylinder injection valve 30 in the vicinity of the spark plug 54. However, even when the spark plug 54 is provided on the front end side of the hydrogen jet 52, the hydrogen jet 52 can be ignited by appropriately adjusting the hydrogen injection timing, the injection amount, the ignition timing, and the like. . Therefore, the position of the spark plug 54 can be set as appropriate based on these parameters.

  Note that if the hydrogen fuel in-cylinder injection valve 30 and the spark plug 54 are too close to each other, ignition may be performed before the hydrogen and the air in the cylinder are mixed, and the ignitability to the hydrogen jet 52 may be reduced. Therefore, it is desirable that the hydrogen fuel in-cylinder injection valve 30 and the spark plug 54 be separated by a certain distance. Alternatively, when the hydrogen fuel in-cylinder injection valve 30 and the spark plug 54 are brought close to each other, it is preferable to ignite after a period of time in which hydrogen and air are mixed after hydrogen is injected.

  As described above, according to the first embodiment, since the hydrogen jets 52 are formed radially in the combustion chamber 16 and the hydrogen jets 52 are ignited, the entire region of the hydrogen jets 52 having a high flame propagation speed. A flame can be generated instantly. In addition, since the flame generated in the hydrogen jet 52 propagates to the gasoline mixture adjacent to the hydrogen jet 52, the gasoline mixture is converted into the gasoline mixture via the flame of the hydrogen jet 52 even at a position away from the spark plug 54. A flame can be propagated instantly. Therefore, a flame can be generated in the entire region of the combustion chamber 16 in a very short time, so that the thermal efficiency can be improved and the occurrence of knocking can be reliably suppressed.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described. FIG. 3 is a diagram for explaining a configuration of a system including the hydrogenated internal combustion engine 10 according to the second embodiment. As shown in FIG. 3, in the second embodiment, the hydrogen fuel in-cylinder injection valve 30 is provided in the periphery of the cylinder. The other basic configuration is the same as the configuration of FIG. 1 described in the first embodiment.

  FIG. 4 is a schematic diagram showing a state in which the combustion chamber 16 is viewed from below in the hydrogenated internal combustion engine 10 of the second embodiment. FIG. 4 shows a state immediately after hydrogen is injected from the hydrogen fuel in-cylinder injection valve 30 in the compression step, as in FIG. 2.

  As shown in FIG. 4, hydrogen is injected from the hydrogen fuel cylinder injection valve 30 disposed in the peripheral portion in the cylinder toward at least the opposite cylinder inner wall surface. In the example of FIG. 4, hydrogen is injected from the hydrogen fuel in-cylinder injection valve 30 in three directions. Thereby, as shown in FIG. 4, a hydrogen jet 52 is formed from the hydrogen fuel in-cylinder injection valve 30 in three directions.

  As shown in FIG. 4, a spark plug 54 is disposed at a position in contact with the hydrogen jet 52 located at the center among the three hydrogen jets 52. That is, also in the second embodiment, the injection direction of the hydrogen gas from the hydrogen fuel in-cylinder injection valve 30 and the position of the spark plug 54 are defined so that the hydrogen gas is injected toward the spark plug 54.

  When ignition is performed by the spark plug 54 from the state of FIG. 4, the hydrogen jet 52 in contact with the spark plug 54 and the other hydrogen jet 52 adjacent in the vicinity of the hydrogen fuel in-cylinder injection valve 30 are flamed. Is generated, and the flame propagates across the combustion chamber 16 through the hydrogen jet 52 having a high flame propagation speed. As a result, as in the first embodiment, the flame reaches the entire area of the three hydrogen jets 52, further propagates to the adjacent gasoline mixture, and burns rapidly throughout the entire cylinder.

  As described above, the hydrogen fuel in-cylinder injection valve 30 may be provided in the periphery of the cylinder, and the hydrogen jet 52 may be formed so as to cross the combustion chamber 16 toward the cylinder inner wall surface. Also in this case, the flame generated in the hydrogen jet 52 can be propagated to the gasoline mixture to instantly generate a flame in the entire area of the combustion chamber 16. Therefore, the flame can be rapidly propagated throughout the combustion chamber 16 to improve the thermal efficiency and to reliably suppress the occurrence of knocking.

  In the second embodiment, as shown in FIG. 4, the spark plug 54 is provided in the center of the combustion chamber 16. Thereby, a flame can be made to reach the periphery of the combustion chamber 16 almost at the same time, and uniform combustion can be performed in the combustion chamber 16. However, as in the first embodiment, the position of the spark plug 54 can be appropriately set based on the hydrogen injection timing, the injection amount, the ignition timing, and the like.

  As described above, according to the second embodiment, the hydrogen jet flow 52 is formed from the peripheral portion in the combustion chamber 16 toward the central portion and the peripheral portion, and the hydrogen jet flow 52 is ignited. A flame can be instantly generated in the entire area of the hydrogen jet 52 having a high propagation speed. And since the flame generated in the hydrogen jet 52 propagates to the gasoline mixture adjacent to the hydrogen jet 52, the gasoline mixture is converted into the gasoline mixture via the flame of the hydrogen jet 52 even at a position away from the spark plug 54. A flame can be propagated instantly. Therefore, a flame can be generated in the entire region of the combustion chamber 16 in a very short time, so that the thermal efficiency can be improved and the occurrence of knocking can be reliably suppressed.

  In the first and second embodiments, the hydrogen fuel in-cylinder injection valve 30 is provided at one place in the combustion chamber 16. However, the hydrogen fuel in-cylinder injection valves 30 are provided at a plurality of places, Hydrogen may be injected from the injection valve 30 in a plurality of directions. Alternatively, hydrogen may be injected from the hydrogen fuel in-cylinder injection valve 30 in a wide-angle shape (fan shape) so that hydrogen injected in one direction is supplied in a wider range.

It is a schematic diagram which shows the structure of the system provided with the hydrogenation internal combustion engine which concerns on Embodiment 1 of this invention. In the hydrogenation internal combustion engine of Embodiment 1, it is a schematic diagram which shows the state which looked at the combustion chamber from the lower side. It is a schematic diagram which shows the structure of the system provided with the hydrogenation internal combustion engine which concerns on Embodiment 2 of this invention. In the hydrogenation internal combustion engine of Embodiment 2, it is a schematic diagram which shows the state which looked at the combustion chamber from the lower side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Hydrogen addition internal combustion engine 16 Combustion chamber 26 Gasoline injection valve 30 Hydrogen fuel cylinder injection valve 52 Hydrogen jet 54 Spark plug

Claims (6)

A hydrogenated internal combustion engine that uses hydrogen gas as a combustion fuel together with a hydrocarbon fuel,
A first injection valve for injecting hydrocarbon fuel into the intake port;
A second injection valve for injecting hydrogen gas into the cylinder;
A spark plug provided in the cylinder,
A hydrogenated internal combustion engine, wherein at least a part of hydrogen gas injected from the second injection valve is injected toward the spark plug.   2. The hydrogenated internal combustion engine according to claim 1, wherein the second injection valve is provided in the center of the combustion chamber in the cylinder.   The hydrogenated internal combustion engine according to claim 2, wherein the second injection valve injects hydrogen gas radially from the center of the combustion chamber.   4. The hydrogenated internal combustion engine according to claim 2, wherein the spark plug is provided in the vicinity of the second injection valve.   2. The hydrogenated internal combustion engine according to claim 1, wherein the second injection valve is provided at a peripheral portion in the cylinder and injects hydrogen gas so as to reach at least an opposite cylinder inner wall surface.   6. The hydrogenated internal combustion engine according to claim 5, wherein the spark plug is provided in the center of the combustion chamber in the cylinder.

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