JP2006132492A - Laser igniting engine with laser beam transmission prism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser igniting engine capable of setting an optimum relation between a laser beam and a target for providing excellent laser ignitability by enabling the selection of the installed position of the target in a wide range and the use of wide range of members for the target when a solid target is used as the target. <P>SOLUTION: In this laser igniting engine, the laser beam from a laser oscillator is radiated to the target installed in a combustion chamber through a laser beam transmission means such as optical fibers, and a gas in the combustion chamber is ignited by plasma generated by that radiation. A prism refracting the laser beam in the direction of the target to radiate it to the target is fitted to the cylinder head of the engine. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is mainly applied to a premixed combustion laser ignition type engine such as a gas engine, and irradiates laser light from a laser oscillation device to a target provided in a combustion chamber through laser light transmission means such as an optical fiber. The present invention relates to a laser ignition engine configured to ignite a gas in the combustion chamber by plasma generated by the above, and includes a laser light transmitting prism that refracts laser light and irradiates the combustion chamber.

  In a premixed lean combustion gas engine, a rich mixture ratio gas in the auxiliary chamber is ignited and ignited by an ignition plug attached to the auxiliary chamber, and the ignition flame is injected into the lean mixture in the main combustion chamber to perform main combustion. A pilot fuel is injected into the mixed gas in the auxiliary chamber by a spark plug ignition method or a pilot fuel injection valve mounted in the auxiliary chamber to ignite, and the ignition flame is injected into a lean mixture in the main combustion chamber. Instead of the pilot fuel injection ignition system that performs main combustion, a laser ignition system that irradiates a target in a combustion chamber with laser light to generate plasma ignition and ignite and burn gas in the combustion chamber. A technique for promoting ignition combustion and suppressing the amount of NOx generated has been proposed.

As a premixed lean combustion gas engine equipped with such a laser ignition system, techniques of Patent Document 1 (Japanese Patent Laid-Open No. 7-217521) and Patent Document 2 (Japanese Patent Laid-Open No. 9-42138) have been proposed.
In the technique of Patent Document 1, a plurality of wedge substrates are installed in the optical path of laser light, and laser light passing through the wedge substrates is irradiated to a target provided on the piston surface via a condenser lens. .
Further, in the technique of Patent Document 2, a focus variable device is provided in the optical path of the laser beam between the laser oscillation device and the target provided on the piston surface so that the laser beam can always be irradiated onto the target by engine rotation. Equipped.

JP-A-7-217521 Japanese Patent Laid-Open No. 9-42138

  In such a laser ignition type engine, a laser oscillation device is usually used as in the technique disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 7-217521) or Patent Document 2 (Japanese Patent Laid-Open No. 9-42138). The laser beam transmitted from a laser beam transmission means such as an optical fiber is incident vertically from above the cylinder head, and is provided on the piston surface through a condenser lens installed in the cylinder head. Irradiating a solid target.

For this reason, in such a conventional technique, when a solid target is used as the target, the laser beam is incident in the combustion chamber in the vertical direction (cylinder axis direction), so that the target is necessarily on the upper surface of the piston or the like. It must be installed.
Therefore, in such a conventional technique, the installation position of the target is limited to the upper surface of the piston that can receive the laser beam in the vertical direction, and the target itself is also limited to a member that can be installed on the upper surface of the piston. There is no room for selection in the installation position and the target itself, and it is difficult to obtain an optimum relationship between the laser beam and the target, which can provide good laser ignition performance.
There are problems such as.

  In view of the problems of the prior art, the present invention makes it possible to select a target installation position in a wide range when using a solid target as a target, and also to use a wide range of members for the target itself, so that good laser ignition performance is achieved. An object of the present invention is to provide a laser ignition type engine capable of setting a relationship between an optimum laser beam and a target to obtain.

  The present invention achieves such an object, and irradiates laser light from a laser oscillation device to a target provided in a combustion chamber through laser light transmission means such as an optical fiber, and plasma generated by the irradiation causes the laser to emit light in the combustion chamber. In a laser ignition type engine configured to ignite gas, a prism that refracts the laser light in the direction of the target and irradiates the target is mounted on a cylinder head of the engine.

In this invention, it is preferable to take the following two aspects.
(1) The target is provided in a portion facing either the exhaust valve or the intake valve of the engine facing the combustion chamber, and the laser light is refracted by the prism, passes through the combustion chamber, and is irradiated onto the target. Configure as follows.
(2) When the engine is a sub-chamber type gas engine, the target is provided in a portion facing the sub-chamber of the sub-chamber gas supply valve of the engine, and the laser beam is refracted by the prism provided in the cylinder head. And configured to pass through the sub-chamber and irradiate the target.

  According to this invention, the laser light from the laser oscillation device is refracted in a substantially right angle direction by the prism mounted on the cylinder head and irradiated to the target, so that the laser light incident through the prism and entering the combustion chamber is It can pass through the room almost horizontally and easily irradiate the target provided on the exhaust valve or intake valve. In the case of a sub-chamber type gas engine, it is refracted in a substantially right angle by a prism provided on the cylinder head. The target provided in the sub chamber of the sub chamber gas supply valve can be easily irradiated, and the prism mounting direction and refraction angle are adjusted so that the laser beam emitted from the prism is directed to the upper surface of the piston. Thus, the target provided on the upper surface of the piston can be easily irradiated.

Therefore, according to this invention, by adjusting the prism mounting direction and the refraction angle, it is possible to use the simplest laser beam injection means for laser beam injection in the vertical direction from above the cylinder head. The target can be installed in any place in the combustion chamber. The target itself is the side of the exhaust valve, the side of the intake valve, the top surface of the piston, and in the case of a sub-chamber gas engine, the sub-chamber gas supply valve Any part of the side of the can be used as a target.
Thereby, when using a solid target as a target, the target installation position can be selected in a wide range, and the target itself can also use a wide range of members in the combustion chamber. The optimum one can be selected to obtain a good laser ignition performance of the engine.

According to the present invention, in the laser ignition engine, the prism is installed outside the combustion chamber, and laser light refracted by the prism is transmitted between the light exit surface of the prism and the combustion chamber. In addition, a laser beam introduction glass for performing a gas seal between the combustion chamber and the prism is provided.
Preferably, in this invention, the light exit surface of the prism is formed in a circular shape, and the light exit surface and the combustion chamber are held in fluid nectar and attached to the engine by an attachment member.

According to this invention, the prism is installed outside the combustion chamber, and the laser beam that performs gas sealing between the light emission surface of the prism and the combustion chamber between the combustion chamber and the prism is made of a material that can be transmitted. Since the laser beam introduction glass is installed, the prism can be prevented from being exposed to the combustion gas in the combustion chamber, and the durability of the prism is improved.
Further, if the light exit surface of the prism is formed in a circular shape, the light exit surface and the combustion chamber are held in fluid nectar, and the structure is attached to the engine by an attachment member, the light exit surface of the prism is a circular surface. Therefore, the gas seal with the combustion chamber side can be ensured with a simple structure.

In the laser ignition engine, a prism for refracting the laser light in the direction of the target and irradiating the target is mounted on the cylinder head of the engine, and spark discharge is generated in the gas in the combustion chamber. An ignition plug for igniting and burning the gas is provided, and a controller for controlling the emission timing of the laser light from the laser oscillation device and the spark ignition timing by the ignition plug is provided.
In this invention, preferably, the controller uses both spark ignition by the spark plug and plasma ignition by laser light from the laser oscillation device at the time of starting the engine. It is configured to perform plasma ignition combustion by laser light from a laser oscillation device.

According to this invention, the laser beam firing timing of the ignition means by the laser beam, the ignition means by the laser beam that irradiates the target through the prism that refracts the laser beam, and the ignition means by the spark ignition of the spark plug, Since the ignition timing of the ignition means by the spark plug is controlled by the controller, when a malfunction such as a failure occurs in the ignition means by the laser light, it can be easily switched to the use of the ignition means by the spark plug, Even if a malfunction such as a failure occurs in the ignition means by the laser beam, the engine can be operated without any trouble.
Further, at the time of starting an engine that requires a large ignition energy, the ignition / combustibility at the start can be improved by using both the ignition means by the laser beam and the ignition means by the spark plug.

  According to the present invention, the target can be installed at any location in the combustion chamber by adjusting the mounting direction and the refraction angle of the prism mounted on the components around the combustion chamber such as the cylinder head and the cylinder liner. As for the target itself, any part such as an exhaust valve, an intake valve, an upper surface of a piston, a sub-chamber gas supply valve in the case of a sub-chamber type gas engine can be used as a target. In addition to being able to select a wide range, the target itself can also use a wide range of members in the combustion chamber, and it is possible to select an optimum target installation position and the target itself to obtain good laser ignition performance of the engine .

Further, according to the present invention, the laser light ignition means using the prism and the ignition means by spark ignition of the spark plug are provided together so that the controller controls the laser light emission timing and the ignition timing. When a malfunction such as a failure occurs in the ignition means by the laser beam, the engine can be easily switched to the use of the ignition means by the spark plug, so that even if a malfunction such as a failure occurs in the ignition means by the laser beam, the engine Can be operated without hindrance.
Further, when the engine is started, the ignition combustion performance at the time of starting can be improved by using both the ignition means by the laser beam and the ignition means by the spark plug.

  Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this example are not intended to limit the scope of the present invention only to specific examples unless otherwise specified. Only.

FIG. 6 is an overall configuration diagram of a laser light transmission system in a single chamber type laser ignition type gas engine to which the present invention is applied.
In FIG. 6, 12 is a cylinder head of a gas engine (hereinafter referred to as engine), 10 is a piston, 11 is a cylinder liner, 13 is a main combustion chamber defined by the cylinder head 12, piston 10 and cylinder liner 11, 22 is The connecting rod 23 is a crankshaft.
15 is an intake port, 14 is an intake valve for opening and closing the intake port 15, 17 is an exhaust port, and 16 is an exhaust valve for opening and closing the exhaust port 17.

1 is a laser oscillation device that oscillates a laser beam (laser pulse) 02, 2 is a laser control that controls a pulse interval of laser beam 02 oscillated from the laser oscillation device 1, laser beam energy (laser beam intensity), and the like. Device. Reference numeral 6 denotes a laser beam condensing lens installed in the cylinder head 12, and 9 denotes a support member that supports the condensing lens 6. Reference numeral 35 denotes a laser beam introducing glass that shields the condenser lens 6 side and the main combustion chamber 13 side, and is made of transparent glass having heat resistance.
Reference numeral 50 denotes an optical fiber for transmitting the laser beam 02 from the laser oscillation device 1 to the condenser lens 6 side.

51 is a rotational speed detector for detecting the rotational speed of the engine, 52 is a load detector for detecting the load of the engine, 53 is a timing disk constituting a crank angle sensor, and a crank of the crankshaft 23 via the rotational shaft 23a. A corner is detected.
Reference numeral 3 denotes a controller that detects the detected value of the engine speed from the engine speed detector 51, detects the detected engine load value from the load detector 52, and detects the crank angle of the engine from the crank angle sensor (timing disk) 53. Each value is input, and based on the detected value of the engine speed or the detected value of the engine load, the pulse interval of the laser beam 02 corresponding to the engine speed or the engine load, the laser beam energy (the intensity of the laser beam) ) And the like, and the oscillation timing of the laser beam in accordance with the ignition order of each cylinder is calculated based on the detected crank angle value and input to the laser control device 2.

During operation of the laser ignition type gas engine having such a configuration, the detected value of the engine speed from the speed detector 51, the detected value of the engine load from the load detector 52, the crank from the crank angle sensor 53 The detected corner value is input to the controller 3.
The controller 3 controls the laser control device 2 to control the oscillation timing of the laser light 02 from the laser oscillation device 1 based on the detected value of the engine speed, the detected value of the engine load, and the detected value of the crank angle. Output a signal.

  The laser control device 2 oscillates the laser beam 02 from the laser oscillation device 1 based on the control signal of the oscillation timing of the laser beam 02 output from the controller 3 to the laser control device 2. The laser beam 02 is transmitted through the optical fiber 50, enters the condenser lens 6 from the tip passing through the cylinder head 12, is condensed by the condenser lens 6, passes through the laser beam introduction glass 35, and the main combustion The target 5 in the chamber 13 is irradiated. By irradiation with the laser beam 02, high-temperature plasma is generated in the mixed gas in the main combustion chamber 13, and the gas is ignited and burned.

The present invention relates to a laser ignition type engine including a laser beam transmitting prism in a laser beam input portion to a combustion chamber in a laser ignition type engine including such a laser ignition type gas engine.
FIG. 1 is a block diagram of a laser light transmission system according to a single chamber laser ignition gas engine according to a first embodiment of the present invention.
In FIG. 1, reference numeral 10 denotes an engine piston, and 13 denotes a main combustion chamber defined by a cylinder head 12, a piston 10 and a cylinder liner 11.
1 is a laser oscillation device that oscillates a laser beam (laser pulse) 02, 2 is a laser control that controls a pulse interval of laser beam 02 oscillated from the laser oscillation device 1, laser beam energy (laser beam intensity), and the like. Device.

Reference numeral 20 denotes a prism which is fixed to the cylinder head 12 and has a refracting surface 20 a of about 90 °, and has a tip projecting into the main combustion chamber 13. Reference numeral 5 denotes a target made of a heat-resistant metal projecting from the cylinder head 12 into the main combustion chamber 13. The target 5 is at a position where the laser beam 02 refracted by the refractive surface 20a of the prism 20 is transmitted in a substantially horizontal direction to irradiate the target 5, and the target 5 is irradiated with the laser beam 02. It is installed in a place where the ignition flame due to is propagated uniformly throughout the main combustion chamber 13.
Reference numeral 6 denotes a laser light condensing lens installed on the laser light entrance side of the prism 20, and reference numeral 50 denotes an optical fiber for transmitting the laser light 02 from the laser oscillation device 1 to the condensing lens 6.

51 is a rotational speed detector for detecting the rotational speed of the engine, 52 is a load detector for detecting the load of the engine, 53 is a timing disk constituting a crank angle sensor, and a crank of the crankshaft 23 via the rotational shaft 23a. A corner is detected.
Reference numeral 3 denotes a controller that detects the detected value of the engine speed from the engine speed detector 51, detects the detected engine load value from the load detector 52, and detects the crank angle of the engine from the crank angle sensor (timing disk) 53. Each value is input, and based on the detected value of the engine speed or the detected value of the engine load, the pulse interval of the laser beam 02 corresponding to the engine speed or the engine load, the laser beam energy (the intensity of the laser beam) ) And the like, and the oscillation timing of the laser beam in accordance with the ignition order of each cylinder is calculated based on the detected crank angle value and input to the laser control device 2.
The configuration and operation of the rotation speed detector 51, load detector 52, crank angle sensor 53, and controller shown above are the same as those of the single-chamber laser ignition gas engine shown in FIG.

In the first embodiment, during the operation of the engine, the laser light 02 oscillated from the laser oscillation device 1 with the pulse interval corresponding to the engine speed or the engine load, the laser light energy, and the irradiation timing is The light enters the condenser lens 6 through the optical fiber 50, is condensed by the condenser lens 6, enters the prism 20, and is deflected to about 90 ° by the refracting surface 20 a of the prism 20. Projected on.
The laser beam 02 passes through the main combustion chamber 13 in a substantially horizontal direction and is irradiated onto the target 5. By irradiating the target 5 with the laser beam 02, high temperature plasma is generated in the mixed gas in the main combustion chamber 13, and the gas is ignited and burned.

FIG. 2A is a diagram corresponding to FIG. 1 showing a second embodiment of the present invention.
In this second embodiment, a target 5 that protrudes from the lower surface of the exhaust valve 16 into the main combustion chamber 13 is provided, and is deflected to about 90 ° by the refractive surface 20 a of the prism 20 and projected into the main combustion chamber 13. The laser beam 02 that has been transmitted passes through the main combustion chamber 13 in a substantially horizontal direction and is irradiated onto the target 5 provided on the exhaust valve 16.
Further, the target 5 protruding from the lower surface of the intake valve 14 into the main combustion chamber 13 can be provided on the intake valve 14 (see FIG. 6), similarly to the exhaust valve 16 in FIG.
In this case, if the target 5 is irradiated with the laser beam 02 while the exhaust valve 16 or the intake valve 14 is rotated at a minute speed by a known exhaust valve rotation device or intake valve rotation device (not shown), the strong laser beam 02 is generated. Since different portions of the target 5 are irradiated from time to time, the life of the target 5 can be extended.
Other configurations are the same as those of the first embodiment, and the same members are denoted by the same reference numerals.

FIG. 2B is a configuration diagram around the combustion chamber showing a third embodiment of the present invention.
In this third embodiment, the present invention is applied to a sub-chamber type gas engine, and 26 opens and closes a fuel gas inlet to the sub-chamber 25 communicated with the main combustion chamber 13 via a sub-chamber nozzle 25a. The sub chamber gas supply valve is provided with a target 5 projecting from the lower surface of the sub chamber gas supply valve 26 into the sub chamber 25.
In the third embodiment, the laser beam 02 which is deflected by about 90 ° by the refractive surface 20a of the prism 20 provided facing the sub chamber 25 and projected into the main combustion chamber 13 passes through the sub chamber 25. The target 5 provided in the sub chamber gas supply valve 26 is irradiated through the substantially horizontal direction.
In the third embodiment, if the target 5 is irradiated with the laser beam 02 while the sub chamber gas supply valve 26 is rotated at a minute speed by a known sub chamber gas supply valve rotating device (not shown), the strong laser beam 02 is emitted. Irradiates different parts of the target 5, so that the life of the target 5 can be extended.
The other configuration is the same as that of the first embodiment (including the portion omitted from the illustration of the first embodiment), and the same members are denoted by the same reference numerals.

As described above, according to the first embodiment shown in FIG. 1, the second embodiment shown in FIG. 2A, and the third embodiment shown in FIG. The laser beam 02 is refracted in a substantially right angle direction by the prism 20 mounted on the cylinder head 12 and irradiated to the target 5 installed in the main combustion chamber 13 in the case of the first to second embodiments. The laser beam 02 that has entered the main combustion chamber 13 through the prism 20 passes through the main combustion chamber 13 in a substantially horizontal direction,
The target 5 protruding in the main combustion chamber 13 as in the first embodiment, or the target 5 protruding on the lower surface of the exhaust valve 16 or the intake valve 14 as in the second embodiment can be easily irradiated.
Further, by adjusting the mounting direction of the prism 20 and the refraction angle of the refracting surface 20a so that the laser light 02 emitted from the prism 20 is directed toward the upper surface of the piston 10, the target 5 provided on the upper surface of the piston 10 is adjusted. Can be easily irradiated,
Further, in the case of the third embodiment, the laser beam 02 is refracted in a substantially right angle direction by the prism 20 provided in the cylinder head 12 of the sub chamber type gas engine, and the portion facing the sub chamber of the sub chamber gas supply valve 26. Thus, the target 5 provided on the substrate can be easily irradiated.

Therefore, according to the first to third embodiments of the present invention, the laser beam 02 is the simplest in that the laser beam 02 is injected vertically from above the cylinder head 12 by adjusting the mounting direction and the refraction angle of the prism 20. The target 5 can be installed in any place in the main combustion chamber 13 or the sub chamber 25 with the use of a proper charging means. The target 5 itself is also connected to the side of the exhaust valve 16 and the intake air. In the case of the side portion of the valve 14, the upper surface of the piston 10, and the sub chamber type gas engine, all portions of the side portion of the sub chamber gas supply valve 26 can be used as the target 5.
Accordingly, when a solid target is used as the target 5, the installation position of the target 5 can be selected in a wide range, and the target 5 itself can also use a wide range of members in the main combustion chamber 13 or the sub chamber 25. Thus, it is possible to select the optimum installation position of the target 5 and the target 5 itself to obtain a good laser ignition performance of the engine.

FIG. 3 is a view corresponding to FIG. 1 showing a fourth embodiment of the present invention.
In the fourth embodiment, in a single chamber laser ignition engine, in addition to the prism 20 similar to the first to third embodiments, a spark discharge is generated in the gas in the main combustion chamber 13 and the gas is discharged. The controller 3 is configured to control the emission timing of the laser beam 02 from the laser oscillation device 1 and the spark ignition timing by the ignition plug 18. ing.

  In the fourth embodiment, the controller 3 performs spark ignition by the spark plug 18 and plasma ignition by the laser beam 02 from the laser oscillation device 1 at the start of an engine with poor ignition conditions or at a low load. In combination, the spark ignition by the spark plug 18 is stopped in the high load operation range while exceeding a certain load of the engine, and plasma ignition combustion is performed by the laser light 02 from the laser oscillation device 1. .

According to the fourth embodiment, the laser beam 02 irradiates the target 5 through the prism 20 that refracts the laser beam 02 and the ignition unit by the spark ignition of the spark plug 18 and the laser beam 02 are provided side by side. Since the controller 3 controls the laser beam emission timing of the ignition means by the ignition plug 18 and the ignition timing of the ignition means by the ignition plug 18, when a malfunction such as a failure occurs in the ignition means by the laser beam 02, the ignition plug 18 The ignition means can be easily and quickly switched to use, and the engine can be operated without any trouble even if a malfunction such as a failure occurs in the ignition means by the laser beam 02.
Further, at the time of starting an engine that requires a large ignition energy, by using both the ignition means by the laser light 02 and the ignition means by the spark plug 18, the ignition and combustibility at the start can be improved.
Other configurations and operational effects are the same as those of the first to third embodiments, and the same members and elements are denoted by the same reference numerals.

FIG. 4 is a view corresponding to FIG. 1 showing a fifth embodiment of the present invention.
In the fifth embodiment, in the single chamber laser ignition engine, the prism 20 is installed outside the main combustion chamber 13 of the cylinder liner 11, and the light exit surface 20 c of the prism 20 and the main combustion are arranged. A laser beam introducing glass 20b made of a material through which the laser beam 02 refracted by the prism 20 is transmitted is provided between the chamber and the chamber, and the laser beam introducing glass 20b is provided between the main combustion chamber 13 and the prism 20. The gas seal is configured to be performed.

In the fifth embodiment, the laser beam 02 deflected in the horizontal direction by the prism 20 installed outside the main combustion chamber 13 passes through the main combustion chamber 13 and is irradiated onto the target 5. Therefore, according to the fifth embodiment, the prism 20 is installed outside the main combustion chamber 13, and the inside of the main combustion chamber 13 and the prism are disposed between the light exit surface 20c of the prism 20 and the main combustion chamber 13. Since the laser beam introduction glass 20b that performs gas sealing with the gas chamber 20 is installed, the prism 20 can be prevented from being exposed to the combustion gas in the main combustion chamber 13, and the durability of the prism 20 is improved.
Other configurations are the same as those of the first embodiment, and the same members and elements are denoted by the same reference numerals.

FIG. 5 is a view corresponding to FIG. 1 showing a sixth embodiment of the present invention.
In FIG. 5, the prism 20 is fixed to the cylinder liner 11 by a mounting member 21 and a presser screw 21a. In the prism 20, the laser beam 02 is incident on the prism 20 from above, and the laser beam 02 from the light exit surface 20 c of the prism 20 is transmitted through the main combustion chamber 13 in the substantially horizontal direction to the target 5. The presser screw 21a is screwed into the cylinder liner 11 in such a manner that it is irradiated, and is fixed to the cylinder liner 11 through the same laser light introducing glass 20b as in the fifth embodiment.
The light exit surface 20c of the prism 20 is formed in a circular shape, and the light exit surface 20c is brought into pressure contact with the laser light introducing glass 20b, and gas sealing with the inside of the main combustion chamber 13 is performed by the circular light exit surface 20c. Therefore, a gas seal with the main combustion chamber 13 side can be ensured with a simple structure.
Other configurations are the same as those of the fifth embodiment, and the same members and elements are denoted by the same reference numerals.

  According to the present invention, when a solid target is used as a target, the installation position of the target can be selected in a wide range, and the target itself can use a wide range of members, which is optimal for obtaining good laser ignition performance. It is possible to provide a laser ignition engine capable of setting a relationship between a laser beam and a target.

It is a block diagram of the laser beam transmission system which concerns on the single chamber laser ignition type gas engine which concerns on 1st Example of this invention. (A) is a view corresponding to FIG. 1 showing a second embodiment of the present invention, and (B) is a configuration diagram around a combustion chamber showing a third embodiment of the present invention. FIG. 6 is a view corresponding to FIG. 1 showing a fourth embodiment of the present invention. FIG. 9 is a view corresponding to FIG. 1 showing a fifth embodiment of the present invention. FIG. 9 is a view corresponding to FIG. 4 showing a sixth embodiment of the present invention. 1 is an overall configuration diagram of a laser light transmission system in a single chamber type laser ignition type gas engine to which the present invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser oscillation apparatus 2 Laser control apparatus 02 Laser beam 3 Controller 5 Target 6 Condensing lens 10 Piston 11 Cylinder liner 12 Cylinder head 13 Main combustion chamber 14 Intake valve 16 Exhaust valve 20 Prism 20a Refractive surface 20b Laser beam introduction glass 20c Outgoing surface 25 Sub chamber 26 Sub chamber gas valve 50 Optical fiber 51 Rotational speed detector 52 Load detector 53 Crank angle sensor

Claims (7)

  Laser ignition configured to irradiate laser light from a laser oscillation device to a target provided in a combustion chamber through laser light transmission means such as an optical fiber and ignite gas in the combustion chamber by plasma generated by the irradiation. A laser ignition type engine equipped with a laser beam transmitting prism, wherein a prism that refracts the laser beam in the direction of the target and irradiates the target is mounted on a cylinder head of the engine.   The target is provided at a portion facing either the exhaust valve or the intake valve of the engine facing the combustion chamber, and the laser beam is refracted by the prism and transmitted through the combustion chamber and irradiated to the target. A laser ignition engine comprising the laser beam transmitting prism according to claim 1.   The engine is a sub-chamber gas engine, the target is provided in a portion facing the sub-chamber of the sub-chamber gas supply valve of the engine, and the laser light is refracted by the prism provided in a cylinder head and 2. A laser ignition type engine equipped with a laser beam transmitting prism according to claim 1, wherein the laser beam is transmitted through a room and irradiated on the target.   Laser ignition configured to irradiate laser light from a laser oscillation device to a target provided in a combustion chamber through laser light transmission means such as an optical fiber and ignite gas in the combustion chamber by plasma generated by the irradiation. In the engine, the prism is installed outside the combustion chamber, and is made of a material that can transmit laser light refracted by the prism between the light exit surface of the prism and the combustion chamber. A laser ignition type engine provided with a laser beam transmitting prism, characterized in that a laser beam introduction glass for performing a gas seal with the prism is provided.   5. The laser beam transmission according to claim 4, wherein the light exit surface of the prism is formed in a circular shape, and the light exit surface and the combustion chamber are held in fluid nectar and attached to the engine by an attachment member. Laser ignition engine with prism.   Laser ignition configured to irradiate laser light from a laser oscillation device to a target provided in a combustion chamber through laser light transmission means such as an optical fiber and ignite gas in the combustion chamber by plasma generated by the irradiation. In the engine, a prism that refracts the laser light in the direction of the target and irradiates the target is mounted on the cylinder head of the engine, and spark discharge is generated in the gas in the combustion chamber to ignite and burn the gas. A laser ignition type engine provided with a laser light transmitting prism, characterized in that a spark plug is provided, and a controller for controlling the emission timing of laser light from the laser oscillation device and the spark ignition timing by the ignition plug is provided.   The controller uses both spark ignition by the spark plug and plasma ignition by the laser light from the laser oscillation device at the time of starting the engine, and the laser from the laser oscillation device in a high load operation range while exceeding a certain load. 7. A laser ignition type engine equipped with a laser beam transmitting prism according to claim 6, wherein the laser ignition type engine is configured to perform plasma ignition combustion by light.

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