JP2007107424A - Laser ignition device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate the need for a mechanical moving mechanism for moving an optical system, change the condensing number of laser beams to be emitted into a combustion chamber without suddenly increasing beam energy in the combustion chamber, and actualize multi-point ignition at sufficiently separate ignition positions in the combustion chamber. <P>SOLUTION: When a laser beam oscillating means 12 oscillates a plurality of oscillating patterns of laser beams, a laser beam emitting means 14 emits the laser beams into the combustion chamber 44 with the injection of the laser beams oscillated by the laser beam oscillating means 12 while changing at least one of the condensing number and the condensing position of the laser beams in the combustion chamber 44 corresponding to the oscillating patterns of the laser beams oscillated by the laser beam oscillating means 12. Then, a control means 16 differentiates the oscillating patterns of the laser beams oscillated by the laser beam oscillating means 12 to change at least one of the condensing number and the condensing position of the laser beams emitted into the combustion chamber 44 by the laser beam emitting means 14. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a laser ignition device for an internal combustion engine, and more particularly to a laser ignition device for an internal combustion engine that ignites combustion gas in the combustion chamber by condensing laser light in the combustion chamber of the internal combustion engine.

  The following are known as laser ignition devices for internal combustion engines that ignite the combustion gas in the combustion chamber with this type of laser light (see, for example, Patent Documents 1 to 4).

  For example, in the example described in Patent Document 1, a laser source, an expander lens, a condenser lens, a collimator lens, a microlens array, and a laser incident window are provided, and the condenser lens is moved. By changing the number of microlenses to be used by changing the diameter of the laser beam, the number of ignitions in the combustion chamber is changed, and the ignition position in the combustion chamber is changed by moving the microlens array.

  In the examples described in Patent Documents 2 and 3, a plurality of targets are fixed on the upper surface of the piston, and the target is irradiated with laser light through the same number of optical fibers as the targets. Further, the laser light reflected by the rotating mirror is incident on each optical fiber, and the optical fiber on which the laser light is incident can be changed by changing the angle of the rotating mirror.

  Furthermore, in the example described in Patent Document 4, a variable focus unit having a concave lens movable in the optical axis direction is provided, and the concave lens is arranged so that the flame propagation surface shape approximates a predetermined shape by the output signal of the control unit. The focal position, that is, the ignition position is variably controlled by being moved by an actuator.

In the example described in Patent Document 5, a plurality of wedge bases are installed in the optical path of the laser light, and each wedge base is rotated by a different motor so that the laser light is swung in a wide range. Yes.
Japanese Patent Laying-Open No. 2005-147109 JP 2005-42579 A JP 2005-42580 A JP-A-7-217521 JP-A-5-33755

  However, in the example described in Patent Document 1, a mechanical moving mechanism for moving an optical system such as a condenser lens is required. Further, in the example described in Patent Document 1, when the condensing lens is moved to expand the laser beam, the number of microlenses in the microlens array on which the laser light is incident increases rapidly, so that the number of ignitions in the combustion chamber. Increases rapidly, and at the same time, the light energy in the combustion chamber increases rapidly. Further, although the number of ignitions increases, the distance is the distance between the center positions of the microlenses of the microlens array, and therefore, multipoint ignition is performed at close positions.

  In the examples described in Patent Document 2 and Patent Document 3, the same number of optical fibers as the number of ignitions or ignition positions in the combustion chamber are required. However, it is difficult to arrange a large number of optical fibers on a cylinder head occupied by a fuel injection valve, an intake valve, an exhaust valve, or the like.

  Furthermore, in the examples described in Patent Document 2 and Patent Document 3, since the laser beam is emitted to the target fixed to the piston top surface, the ignition position is limited to the piston top surface. Similarly, in the example described in Patent Document 4, since the concave lens is movable only in the optical axis direction (cylinder radial direction), the ignition position is limited to the cylinder radial direction. However, in general, the optimum ignition position exists at an arbitrary position in the cylinder radial direction and the axial direction in the combustion chamber.

  Moreover, in the example described in Patent Document 4, a plurality of wedge bases installed in the optical path of the laser light are rotated by different motors. Therefore, the structure becomes larger as the number of motors increases along with the wedge base.

  The present invention has been made in view of the above circumstances, and its purpose is to eliminate the need for a mechanical movement mechanism for moving the optical system, without causing a rapid increase in light energy in the combustion chamber, Provided is a laser ignition device for an internal combustion engine that can change the number of condensing laser beams emitted into a combustion chamber and can sufficiently separate the ignition positions in the combustion chamber when performing multi-point ignition. There is.

  Another object of the present invention is to provide a laser ignition device for an internal combustion engine that can reduce the arrangement space.

  Another object of the present invention is to provide a laser ignition device for an internal combustion engine that can arbitrarily set the ignition position in the combustion chamber without being limited to a predetermined position.

  Another object of the present invention is to provide a laser ignition device for an internal combustion engine that can be reduced in size in a laser ignition device for an internal combustion engine using a wedge base.

  In order to solve the above-mentioned problem, an invention according to claim 1 is directed to a laser ignition device for an internal combustion engine that ignites combustion gas in the combustion chamber by condensing laser light in the combustion chamber of the internal combustion engine. Laser light oscillating means capable of oscillating laser beams having different oscillation patterns, and laser light emitted from the laser light oscillating means is emitted into the combustion chamber as the laser light is incident, and the laser light Laser light emitting means for changing at least one of the number of collected light and the light collecting position in the combustion chamber according to the oscillation pattern of the laser light oscillated from the laser light oscillating means, and emitted from the laser light emitting means into the combustion chamber If the oscillation pattern of the laser beam oscillated from the laser beam oscillation means is different so that at least one of the number of collected laser beams and the focusing position is changed And control means that, characterized by comprising a.

  According to the first aspect of the present invention, when the laser light oscillation means oscillates laser light having a plurality of different oscillation patterns, the laser light emission means is accompanied by the incidence of the laser light oscillated from the laser light oscillation means. Laser light is emitted into the combustion chamber, and at least one of the number of collected light beams and the light collection position of the laser light is changed according to the oscillation pattern of the laser light oscillated from the laser light oscillation means. Also, at this time, the control means controls the laser light oscillated from the laser light oscillation means so that at least one of the number of condensing numbers and the position of the laser light emitted from the laser light emitting means into the combustion chamber is changed. Different oscillation patterns.

  Thus, according to the above-described configuration of the invention described in claim 1, in order to change at least one of the number of condensing and the condensing position of the laser light emitted into the combustion chamber, the control means oscillates the laser light. It is only necessary to change the oscillation pattern of the laser light oscillated from the means, and there is no need to move the optical system. This eliminates the need for a mechanical movement mechanism for moving the optical system.

  At this time, as in the second aspect of the invention, more specifically, the internal combustion engine laser ignition device is configured as follows. In other words, the laser light oscillation means includes a laser light source group including a plurality of laser light sources capable of oscillating laser light, and a lens on which each laser light oscillated from the laser light source group is incident and collects each laser light. A plurality of lens arrays and each laser beam emitted from the lens array are condensed and laser beams (laser beams having a plurality of different oscillation patterns) are oscillated from positions corresponding to the condensing positions of the respective laser beams. A Q-switched solid-state laser, and the laser beam emitting means receives each laser beam oscillated from the Q-switched solid-state laser, and has a central region and a radially outer side from the central region. And a multi-focal lens in which the focal length of the laser light emitted into the combustion chamber is different between the peripheral region of the laser and the control means is a laser beam emitted from the multi-focal lens into the combustion chamber. A laser light source that oscillates laser light is selected from a plurality of laser light sources provided in the laser light source group so that at least one of the number of condensing the light beams and the light condensing position is changed, and the laser light is oscillated from the laser light source. Thus, the laser light is oscillated from the position corresponding to the condensing position of the laser light in the Q switch type solid-state laser (the oscillation pattern of the laser light is made different).

  According to this configuration, the laser light source that oscillates the laser light is selected from the plurality of laser light sources provided in the laser light source group by the control unit. When the laser light from the laser light source is incident on the Q-switched solid-state laser through the lenses of the lens array, and the laser light oscillated from the Q-switched solid-state laser is incident on the central region of the multifocal lens The laser beam emitted into the combustion chamber has one condensing position.

  In addition, when the laser light oscillated from the Q-switched solid-state laser is incident not only on the central region of the multifocal lens but also on the peripheral region thereof, there are a plurality of condensing positions of the laser light emitted into the combustion chamber. Become.

  Further, the laser light source that oscillates laser light from the plurality of laser light sources provided in the laser light source group is switched by the control means, and the laser light emitted from the Q-switched solid-state laser is By switching to, the condensing position of the laser light emitted into the combustion chamber is changed.

  Thus, according to the configuration of the invention described in claim 2, in order to change at least one of the number of condensing numbers and the condensing position of the laser light emitted from the multifocal lens into the combustion chamber, the laser light source It is only necessary to select a laser light source that oscillates laser light from a plurality of laser light sources provided in the group and oscillate the laser light from the laser light source.

  Therefore, when changing the number of condensing laser beams emitted from the multifocal lens into the combustion chamber, it is possible to precisely set the number of condensing laser beams emitted from the multifocal lens into the combustion chamber. Thereby, it is possible to change the number of condensing laser beams emitted into the combustion chamber without abruptly increasing the light energy in the combustion chamber.

  Further, when changing the condensing position of the laser light emitted from the multifocal lens into the combustion chamber, a laser light source that oscillates the laser light is selected from the plurality of laser light sources provided in the laser light source group. Since it is only necessary to oscillate the laser beam from the position, it is easy to change the condensing position of the laser beam emitted into the combustion chamber.

  Further, since the focal length of the central region of the multifocal lens and the focal length of the peripheral region can be freely set, the ignition positions in the combustion chamber can be sufficiently separated from each other when performing multipoint ignition. .

  According to the third aspect of the present invention, in the laser ignition device for an internal combustion engine, the laser light oscillation means includes a laser light source group including a plurality of laser light sources capable of oscillating laser light, and an oscillation from the laser light source group. A lens array having a plurality of lenses on which each laser beam is incident and condensing each laser beam, and each laser beam emitted from the lens array is condensed and a condensing position of each laser beam Q-switched solid-state lasers capable of oscillating laser beams (laser beams having a plurality of different oscillation patterns) from positions corresponding to the laser beam emitting means, the laser beam emitting means being oscillated from the Q-switched solid-state lasers Each laser beam is incident and a lens group having a plurality of lenses for condensing each laser beam, and each laser beam emitted from the lens group is incident and each laser beam And a multi-prism having a plurality of refracting surfaces that refract the laser beam in different directions in the combustion chamber, and the control means condenses the number and position of the laser beams emitted from the multi-prism into the combustion chamber. Laser light in a Q-switched solid-state laser is selected by selecting a laser light source that oscillates laser light from a plurality of laser light sources provided in the laser light source group so that at least one of the laser light sources is changed, and oscillating laser light from the laser light source The laser light may be oscillated from the position corresponding to the light condensing position (the laser light oscillation pattern is different).

  According to this configuration, the laser light source that oscillates the laser light is selected from the plurality of laser light sources provided in the laser light source group by the control unit. The laser light from the laser light source is incident on the Q-switched solid-state laser through the lenses of the lens array, and the laser light oscillated from the Q-switched solid-state laser is sent to the multi-prism via any lens in the lens group. When the laser beam is incident on one refracting surface, the condensing position of the laser beam emitted into the combustion chamber is one.

  In addition, when the laser light oscillated from the Q switch type solid-state laser is incident on the plurality of refractive surfaces of the multi-prism via the plurality of lenses of the lens group, the condensing position of the laser light emitted into the combustion chamber Are plural.

  Further, the laser light source that oscillates the laser light from the plurality of laser light sources provided in the laser light source group is switched by the control means, and the laser light incident on the plurality of refracting surfaces of the multi-prism is switched. The condensing position of the emitted laser light is changed.

  Thus, according to the above-described configuration of the invention described in claim 3, in order to change at least one of the number of condensing positions and the condensing position of the laser light emitted from the multi-prism into the combustion chamber, the laser light source group It is only necessary to select a laser light source that oscillates a laser beam from a plurality of laser light sources provided in, and oscillate the laser beam from the laser light source.

  Therefore, when the number of condensing laser beams emitted from the multifocal lens into the combustion chamber is changed, the number of condensing laser beams emitted from the multi-prism into the combustion chamber can be precisely set. Thereby, it is possible to change the number of condensing laser beams emitted into the combustion chamber without abruptly increasing the light energy in the combustion chamber.

  Furthermore, when changing the condensing position of the laser light emitted from the multi-prism into the combustion chamber, a laser light source that oscillates the laser light is selected from a plurality of laser light sources provided in the laser light source group. Since it is only necessary to oscillate the laser beam, it is easy to change the condensing position of the laser beam emitted into the combustion chamber.

  Further, since the refraction direction of the laser beam by the plurality of refracting surfaces provided in the multi-prism can be freely set, the ignition positions in the combustion chamber can be sufficiently separated from each other when multi-point ignition is performed. .

  According to a fourth aspect of the present invention, in the laser ignition device for an internal combustion engine, the laser light oscillation means receives a laser light source capable of oscillating the laser light and a laser light oscillated from the laser light source. And a lens for condensing the laser light, and laser light (laser light having a plurality of different oscillation patterns) having a spread angle corresponding to the intensity distribution of the laser light while condensing the laser light emitted from the lens. A Q-switched solid-state laser capable of oscillating, and the laser beam emitting means receives a laser beam oscillated from the Q-switched solid-state laser and is radially outside the central region and the central region. The control means is configured to have a multifocal lens in which the focal length of the laser light emitted into the combustion chamber differs between the peripheral region of the laser and the control means is a laser beam emitted from the multifocal lens into the combustion chamber. The spread angle of the laser light emitted from the Q-switched solid-state laser is changed by controlling the intensity distribution of the laser light emitted from the laser light source so that at least one of the number of light collection and the light collection position is changed. It is also possible to employ a configuration in which the oscillation pattern of the laser beam is made different.

  According to this configuration, the intensity distribution of the laser light oscillated from the laser light source is controlled by the control means, and the laser light from the laser light source is incident on the Q-switch type solid-state laser through the lens. At this time, if the intensity distribution of the laser beam is controlled so that the oscillation of the Q-switched solid-state laser becomes a low-order mode, a laser beam having a small divergence angle is oscillated, and the laser emitted from this Q-switched solid-state laser The light is incident on the central region of the multifocal lens, and the condensing position of the laser light emitted into the combustion chamber is one.

  Further, if the intensity distribution of the laser beam is controlled so that the oscillation of the Q-switched solid-state laser is in a higher order mode, a laser beam having a large spread angle is oscillated, and the laser beam oscillated from this Q-switched solid-state laser Is incident not only on the central region of the multifocal lens but also on the peripheral region thereof, and there are a plurality of condensing positions of the laser light emitted into the combustion chamber.

  Thus, according to the above-described configuration of the invention described in claim 4, in order to change at least one of the number of condensing numbers and the condensing position of the laser light emitted from the multifocal lens into the combustion chamber, the laser light source It is only necessary to control the intensity distribution of the laser beam from.

  Therefore, when changing the number of condensing laser beams emitted from the multifocal lens into the combustion chamber, it is possible to precisely set the number of condensing laser beams emitted from the multifocal lens into the combustion chamber. Thereby, it is possible to change the number of condensing laser beams emitted into the combustion chamber without abruptly increasing the light energy in the combustion chamber.

  Further, since the focal length of the central region of the multifocal lens and the focal length of the peripheral region can be freely set, the ignition positions in the combustion chamber can be sufficiently separated from each other when performing multipoint ignition. .

  According to a fifth aspect of the present invention, in the laser ignition device for an internal combustion engine, the laser light oscillation means includes a laser light source group including a plurality of laser light sources capable of oscillating laser light, and an oscillation from the laser light source group. And a fiber laser group including a plurality of Q-switched fiber lasers that are capable of oscillating laser beams (laser beams having a plurality of different oscillation patterns) that are incident on and excited by the laser beams. The laser beam emitting means is configured to receive a plurality of laser beams oscillated from the fiber lasers of the fiber laser group and to collect the laser beams in a combustion chamber while condensing or deflecting the laser beams. The control means is configured to change at least one of the number and position of condensing laser beams emitted from a plurality of emission optical systems into the combustion chamber. As described above, a laser light source that oscillates laser light is selected from a plurality of laser light sources provided in the laser light source group, and the laser light is oscillated from the laser light source to oscillate the laser light from the fiber lasers of the fiber laser group (laser The light oscillation pattern may be different.

  According to this configuration, the laser light source that oscillates the laser light is selected from the plurality of laser light sources provided in the laser light source group by the control unit. The laser light from this laser light source is incident on the Q-switched fiber laser of the fiber laser group. Each fiber laser has an emission optical system including a lens and a prism, and can focus the laser light from the fiber laser while deflecting the laser light to an arbitrary place in the combustion chamber.

  At this time, the laser light source that oscillates the laser light from the plurality of laser light sources provided in the laser light source group is switched by the control means, and the condensing position of the laser light emitted from the fiber laser emitted into the combustion chamber is changed. The

  Thus, according to the above-described configuration of the invention described in claim 5, in order to change at least one of the number of condensing numbers and the condensing position of the laser light emitted from each emission optical system into the combustion chamber, It is only necessary to select a laser light source that oscillates laser light from a plurality of laser light sources provided in the light source group and oscillate the laser light from the laser light source.

  Therefore, when changing the number of condensing laser beams emitted from each emitting optical system into the combustion chamber, it is possible to precisely set the number of condensing laser beams emitted from each emitting optical system into the combustion chamber. Thereby, it is possible to change the number of condensing laser beams emitted into the combustion chamber without abruptly increasing the light energy in the combustion chamber.

  Furthermore, when changing the condensing position of the laser light emitted from each emission optical system into the combustion chamber, a laser light source that oscillates laser light is selected from a plurality of laser light sources provided in the laser light source group. Since it is only necessary to oscillate the laser beam from the light source, it is easy to change the condensing position of the laser beam emitted into the combustion chamber.

  In addition, since the condensing position or deflection angle of each emission optical system can be set freely, the ignition positions in the combustion chamber can be sufficiently separated from each other in the case of multipoint ignition.

  Further, as in the sixth aspect of the invention, the laser ignition device for an internal combustion engine is further provided with an operating condition detecting means for detecting an operating condition of the vehicle, and the control means detects the operating condition detected by the operating condition detecting means. The oscillation pattern of the laser light oscillated from the laser light oscillating means is changed so that at least one of the number of condensing and the condensing position of the laser light emitted from the laser light emitting means into the combustion chamber is changed according to If so, at least one of the number of ignitions and the ignition position in the combustion chamber can be changed in accordance with the driving situation of the vehicle. As a result, the combustion of the internal combustion engine can be maintained in an optimum state in accordance with the driving situation of the vehicle.

  In order to solve the above-described problem, the invention according to claim 7 is directed to a laser ignition device for an internal combustion engine that ignites combustion gas in the combustion chamber by condensing laser light in the combustion chamber of the internal combustion engine. A Q-switched solid-state laser capable of oscillating laser light and a solid-state laser that are arranged so as to be movable in the optical axis direction with respect to the solid-state laser and constitute an optical resonator. An exit mirror capable of emitting a laser beam having a spread angle corresponding to a distance apart from each other, a moving mechanism for moving the exit mirror in the optical axis direction, and a laser beam emitted from the exit mirror is incident on the mirror. A convex lens that emits laser light into the combustion chamber, and the emission mechanism that controls the moving mechanism to change the condensing position of the laser light emitted from the convex lens into the combustion chamber. Characterized by comprising a control means for changing the spread angle of the laser light emitted from the radiating mirror by moving in the optical axis direction error.

  According to the seventh aspect of the present invention, when the Q-switch type solid-state laser oscillates the laser beam, the emission mirror emits a laser beam having a spread angle corresponding to the distance apart from the solid-state laser in the optical axis direction, and the emission mirror The laser beam emitted from the laser beam is emitted into the combustion chamber through a convex lens. Further, at this time, the control means controls the moving mechanism so that the condensing position of the laser light emitted from the convex lens into the combustion chamber is changed, and moves the exit mirror in the optical axis direction to emit from the exit mirror. The spread angle of the laser beam is changed.

  Thus, according to the configuration of the invention described in claim 7, the spread angle of the laser beam emitted from the emission mirror is controlled by the control means, so that the laser beam emitted from the convex lens into the combustion chamber is controlled. The condensing position can be freely changed. Thereby, the ignition position in the combustion chamber can be arbitrarily set without being limited to a predetermined position.

  According to the seventh aspect of the present invention, it is possible to change the condensing position of the laser beam emitted into the combustion chamber only by providing one emission optical system on the cylinder head or the like. As a result, it is not necessary to arrange the same number of emission optical systems as the ignition position in the combustion chamber (previously, the same number of optical fibers as the ignition position were installed on the cylinder head or the like), so that the arrangement space can be omitted. It becomes possible.

  At this time, as in the invention described in claim 8, the laser ignition device for an internal combustion engine is provided with an operating condition detecting means for detecting an operating condition of the vehicle, and the control means detects the operating condition detected by the operating condition detecting means. The laser beam emitted from the output mirror is spread by controlling the moving mechanism so that the condensing position of the laser light emitted from the convex lens into the combustion chamber is changed in accordance with the movement of the output mirror in the optical axis direction. With the configuration in which the angle is changed, the ignition position in the combustion chamber can be changed according to the driving situation of the vehicle. As a result, the combustion of the internal combustion engine can be maintained in an optimum state in accordance with the driving situation of the vehicle.

  In order to solve the above problem, the invention according to claim 9 is directed to a laser ignition device for an internal combustion engine that ignites combustion gas in the combustion chamber by condensing laser light in the combustion chamber of the internal combustion engine. A laser light source capable of oscillating laser light; a movable concave lens on which laser light oscillated from the laser light source is incident and movable in the optical axis direction of the laser light; and A moving mechanism for moving the laser beam in the direction, and the focal length of the laser beam that is incident on the laser beam emitted from the movable concave lens and that is emitted into the combustion chamber in a central region and a peripheral region radially outward from the central region And the mobile unit so that at least one of the number of condensing and the condensing position of laser light emitted from the multi-focal lens into the combustion chamber is changed. Controlled to a characterized by comprising a control means for changing the diameter of the laser beam incident on the plurality of focus lens by moving the movable concave lens in the optical axis direction.

  According to the ninth aspect of the present invention, when the laser light source oscillates the laser light, the laser light oscillated from the laser light source is incident on the multifocal lens through the movable concave lens. At this time, the movable concave lens changes the diameter of the laser beam incident on the multifocal lens by being moved in the optical axis direction by the moving mechanism. Since the multifocal lens is configured such that the focal length of the laser light emitted into the combustion chamber differs between the central region and the peripheral region radially outward from the central region, each laser emitted from the movable concave lens When light is incident, at least one of the number of condensing numbers and the condensing position of the laser light emitted to the combustion chamber is changed according to the diameter of the laser light emitted from the movable concave lens. Further, the control means moves the movable concave lens in the optical axis direction by controlling the moving mechanism so that at least one of the number of condensing and the condensing position of the laser light emitted from the multifocal lens into the combustion chamber is changed. As a result, the diameter of the laser light incident on the multifocal lens is changed.

  That is, when the diameter of the laser light emitted from the movable concave lens is small and the laser light emitted from the movable concave lens is incident on the central region of the multifocal lens, the collection of the laser light emitted into the combustion chamber There is one light position.

  Also, when the laser beam emitted from the movable concave lens is large and the laser beam emitted from the movable concave lens is incident on the peripheral region in addition to the central region of the multifocal lens, There are a plurality of condensing positions of the emitted laser light.

  Thus, according to the above-described configuration of the invention described in claim 9, the movable concave lens is moved in the optical axis direction to adjust the diameter of the laser light emitted from the movable concave lens and incident on the multifocal lens. The number of condensing laser beams emitted from the multifocal lens into the combustion chamber can be freely changed.

  Further, the virtual concave position of the laser light emitted from the movable concave lens is determined by moving the movable concave lens in the optical axis direction within a range where the laser light emitted from the movable concave lens is incident on the central region of the multifocal lens. By adjusting, the condensing position can be changed in a state where the number of condensing laser beams emitted into the combustion chamber is maintained at one.

  Similarly, the laser beam emitted from the movable concave lens by moving the movable concave lens in the optical axis direction within a range in which the laser beam emitted from the movable concave lens is incident on the central region and the peripheral region of the multifocal lens. By adjusting the virtual focal position, the condensing position can be changed while maintaining a plurality of condensing numbers of the laser beams emitted into the combustion chamber.

  As described above, according to the above-described configuration of the invention described in claim 9, the movable concave lens is moved in the optical axis direction to adjust the virtual focal position emitted from the movable concave lens, thereby burning from the multifocal lens. The condensing position of the laser beam emitted into the room can be freely changed. Thereby, the ignition position in the combustion chamber can be arbitrarily set without being limited to a predetermined position.

  According to the above-described configuration of the invention described in claim 9, at least one of the number of condensing numbers and the condensing position of the laser light emitted into the combustion chamber can be changed only by providing one emitting optical system on the cylinder head or the like. can do. As a result, it is not necessary to arrange the same number of emission optical systems as the number of ignitions or ignition positions in the combustion chamber (previously, the same number of optical fibers as the number of ignitions or ignition positions were installed on the cylinder head or the like). Space can be omitted.

  Furthermore, since the focal length of the central region of the multifocal lens and the focal length of the peripheral region can be freely set, the ignition positions in the combustion chamber can be sufficiently separated from each other when performing multipoint ignition. .

  At this time, as in the invention of claim 10, the laser ignition device for an internal combustion engine is provided with an operating condition detecting means for detecting an operating condition of the vehicle, and the control means detects the operating condition detected by the operating condition detecting means. By moving the movable concave lens in the optical axis direction by controlling the moving mechanism so that at least one of the number of condensing numbers and the condensing position of the laser light emitted from the multifocal lens into the combustion chamber is changed accordingly With the configuration in which the diameter of the laser light incident on the multifocal lens is changed, at least one of the number of ignitions and the ignition position in the combustion chamber can be changed according to the driving state of the vehicle. As a result, the combustion of the internal combustion engine can be maintained in an optimum state in accordance with the driving situation of the vehicle.

  In order to solve the above problem, an invention according to claim 11 is directed to a laser ignition device for an internal combustion engine that ignites combustion gas in the combustion chamber by condensing laser light in the combustion chamber of the internal combustion engine. A laser light source that can oscillate laser light, a condensing lens that condenses the laser light oscillated from the laser light source, and a direction that intersects the optical axis direction of the laser light emitted from the condensing lens rotates about a rotation axis A multi-wedge base that is arranged freely and has a plurality of refracting surfaces in the rotation direction that refract the laser beams emitted from the condenser lens in different directions and emit them into the combustion chamber; A rotating mechanism for rotating a wedge base around a direction intersecting the optical axis direction of the laser light emitted from the condenser lens; and the combustion from the multi-wedge base The direction of the laser light emitted from the multi-wedge base into the combustion chamber is controlled by rotating the multi-wedge base by controlling the rotation mechanism so that the condensing position of the laser light emitted into the inside is changed. And a control means for changing.

  Thus, in the invention described in claim 11, the multi-wedge substrate refracts the laser light oscillated from the laser light source through the condenser lens in different directions and emits the refracting surface in the rotation direction. It has the structure which has two or more. According to this configuration, the laser beam can be condensed at different positions in the combustion chamber by one multi-wedge base, and the multi-wedge base can be rotated by one rotating mechanism. As a result, the structure of the laser ignition device for an internal combustion engine using a wedge base can be reduced in size.

  At this time, as in the invention described in claim 12, the laser ignition device for an internal combustion engine is provided with an operating condition detecting means for detecting an operating condition of the vehicle, and the control means detects the operating condition detected by the operating condition detecting means. In response to this, the rotation mechanism is controlled so that the condensing position of the laser light emitted from the multi-wedge base into the combustion chamber is changed, and the multi-wedge base is rotated to be emitted from the multi-wedge base into the combustion chamber. If the configuration is such that the direction of the laser beam is changed, the ignition position in the combustion chamber can be changed according to the driving condition of the vehicle. As a result, the combustion of the internal combustion engine can be maintained in an optimum state in accordance with the driving situation of the vehicle.

  In order to solve the above problem, the invention according to claim 13 is the laser ignition device for an internal combustion engine that ignites the combustion gas in the combustion chamber by condensing the laser beam in the combustion chamber of the internal combustion engine. A laser light source capable of oscillating laser light, and a reflection that reflects the laser light oscillated from the laser light source and is rotatably arranged with a direction intersecting the optical axis direction of the laser light oscillated from the laser light source as a rotation axis A mirror, a rotating mechanism that rotates the reflecting mirror around a direction that intersects the optical axis direction of the laser light emitted from the laser light source, and the laser light reflected by the reflecting mirror is incident and the laser light And the laser beam emitted from the fθ lens is incident, and the laser beam is directed in different directions in the combustion chamber. A multi-prism having a plurality of refracting surfaces that refract to the light, and rotating the reflection mirror by controlling the rotation mechanism so that a condensing position of laser light emitted from the multi-prism into the combustion chamber is changed. And control means for changing the direction of laser light emitted from the multi-prism into the combustion chamber.

  According to the thirteenth aspect of the present invention, when laser light is oscillated from the laser light source, the laser light is incident on the fθ lens at a position corresponding to the rotation angle of the reflection mirror, and the laser light emitted from the fθ lens is The light is emitted into the combustion chamber through the prism. Further, by adjusting the rotation angle of the reflection mirror, the condensing position of the laser light emitted into the combustion chamber via the fθ lens and the multi-prism is changed.

  Thus, according to the above-described configuration of the invention described in claim 13, it is possible to change the condensing position of the laser beam emitted into the combustion chamber only by providing one emission optical system on the cylinder head or the like. As a result, it is not necessary to arrange the same number of emission optical systems as the ignition position in the combustion chamber (previously, the same number of optical fibers as the ignition position were installed on the cylinder head or the like), so that the arrangement space can be omitted. It becomes possible.

At this time, as in the invention described in claim 14, the laser ignition device for an internal combustion engine is provided with an operating condition detecting means for detecting an operating condition of the vehicle, and the control means detects the operating condition detected by the operating condition detecting means. The direction of the laser beam emitted from the multi-prism is changed by rotating the reflection mirror by controlling the rotation mechanism so that the condensing position of the laser beam emitted from the multi-prism into the combustion chamber is changed accordingly. With the configuration, the ignition position in the combustion chamber can be changed according to the driving situation of the vehicle. As a result, the combustion of the internal combustion engine can be maintained in an optimum state in accordance with the driving situation of the vehicle.

  As described in detail above, according to the first to fifth aspects of the invention, a mechanical moving mechanism for moving the optical system can be eliminated, and the light energy in the combustion chamber does not increase rapidly. The number of condensing laser beams emitted into the combustion chamber can be changed, and in the case of multipoint ignition, the ignition positions in the combustion chamber can be sufficiently separated from each other.

  According to the seventh aspect of the present invention, the condensing position of the laser beam emitted from the convex lens into the combustion chamber can be freely changed, thereby limiting the ignition position within the combustion chamber to a predetermined position. It is possible to arbitrarily set without being performed. Furthermore, there is no need to arrange as many emission optical systems as there are ignition positions in the combustion chamber (previously, the same number of optical fibers as the ignition positions have been installed on the cylinder head, etc.), so the arrangement space can be omitted. Is possible.

  According to the ninth aspect of the invention, the number of condensing laser beams emitted from the multifocal lens into the combustion chamber can be freely changed. In addition, the condensing position of the laser light emitted from the multifocal lens into the combustion chamber can be freely changed, so that the ignition position in the combustion chamber can be arbitrarily set without being limited to a predetermined position. Is possible. Furthermore, since there is no need to arrange the same number of emission optical systems as the number of ignitions or ignition positions in the combustion chamber (previously, the same number of optical fibers as the number of ignitions or ignition positions have been installed on the cylinder head or the like), the arrangement space Can be omitted. Further, since the focal length of the central region of the multifocal lens and the focal length of the peripheral region can be freely set, the ignition positions in the combustion chamber can be sufficiently separated from each other when performing multipoint ignition. .

  According to the invention of claim 11, the laser beam can be condensed at different positions in the combustion chamber by one multi-wedge base, and the multi-wedge base can be rotated by one rotating mechanism. Therefore, it becomes possible to reduce the size of the structure of the laser ignition device for an internal combustion engine using the wedge base.

  According to the invention described in claim 13, the condensing position of the laser beam emitted into the combustion chamber can be changed only by providing one emission optical system on the cylinder head or the like. As a result, it is not necessary to arrange the same number of emission optical systems as the ignition position in the combustion chamber (previously, the same number of optical fibers as the ignition position were installed on the cylinder head or the like), so that the arrangement space can be omitted. It becomes possible.

  According to the inventions described in claims 6, 8, 10, 12, and 14, at least one of the number of ignitions and the ignition position in the combustion chamber can be changed according to the driving situation of the vehicle. It becomes possible to keep the combustion of the internal combustion engine in an optimum state according to the driving situation of the vehicle

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. It should be noted that members, arrangements, and the like described below do not limit the present invention, and it goes without saying that various modifications can be made in accordance with the spirit of the present invention.

[First embodiment]
First, a laser ignition device 10 for an internal combustion engine according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 5.

  The internal combustion engine laser ignition device 10 according to the first embodiment of the present invention is suitably used to ignite the combustion gas 46 in the combustion chamber 44 in an internal combustion engine provided in a vehicle such as a passenger car, for example. It is.

  As shown in FIG. 1, a laser ignition device 10 for an internal combustion engine according to a first embodiment of the present invention includes a laser beam oscillation unit 12 as laser beam oscillation means capable of oscillating laser beam, and a combustion chamber 44. A laser beam emitting unit 14 serving as a laser beam emitting unit that emits a laser beam; a control unit 16 serving as a control unit that controls laser oscillation of the laser beam oscillation unit 12; and an operating condition detecting unit 18 serving as an operating condition detecting unit; Are provided as main components.

  The laser beam oscillator 12 oscillates laser beams having a plurality of different oscillation patterns to the laser beam emitter 14 as will be described in detail later. The laser beam source group 20, the optical fiber group 22, the lens array 24, And a Q-switch type solid-state laser 26.

  The laser light source group 20 includes a plurality of laser light sources 20a and 20b (for example, one laser light source 20a at the center and five laser light sources 20b around it). Each of the laser light sources 20a and 20b is configured to be able to oscillate laser light by being independently controlled by the laser control device 36 of the control unit 16.

  The entrance of the optical fiber group 22 is located on the laser light oscillation side of each of the laser light sources 20a and 20b. The optical fiber group 22 includes a plurality of optical fibers, and each optical fiber guides the laser light oscillated from the corresponding laser light sources 20a and 20b to the lens array 24 and emits it.

  The lens array 24 includes a plurality of lenses 24 a and 24 b on which the laser beams emitted from the laser light source group 20 through the optical fiber group 22 are incident. Each of the lenses 24 a and 24 b collects each laser beam emitted from the laser light source group 20 via the optical fiber group 22 and emits it to the Q switch type solid laser 26.

  The Q-switched solid-state laser 26 has a configuration including a total reflection mirror 26b and an emission mirror 26c on both sides of the optical amplification medium 26a, and each laser beam emitted from each lens 24a, 24b of the lens array 24 is condensed. Then, the laser beam is oscillated to the bifocal lens 28 in an excited state. At this time, the Q-switched solid-state laser 26 has different oscillation characteristics depending on the condensing position (that is, the excitation location) of each laser beam.

  That is, as shown in FIG. 2 (a), the laser light oscillated from the laser light source 20a is incident on the lens 24a near the center of the lens array 24 via the optical fiber group 22, and from this lens 24a. When the emitted laser light is incident near the center of the Q-switched solid-state laser 26, the portion where the laser light is incident is excited, and the central region of the bifocal lens 28 from the vicinity of the center of the Q-switched solid-state laser 26. Laser light is oscillated toward 28a (oscillation pattern 1).

  Further, as shown in FIG. 2B, the principle of operation is shown. Laser light oscillated from the laser light source 20b is incident on the lens 24b in the peripheral portion of the lens array 24 through the optical fiber group 22, and from this lens 24b. When the emitted laser light is incident on the peripheral portion of the Q-switched solid-state laser 26, the portion where the laser light is incident is excited, and the peripheral region of the bifocal lens 28 extends from the peripheral portion of the Q-switched solid-state laser 26. Laser light is oscillated toward 28b (oscillation pattern 2).

  Further, as shown in FIG. 2C, the principle of operation is shown. Laser light oscillated from the laser light sources 20a and 20b passes through the optical fiber group 22 to the lenses 24a and 24b in the vicinity of the center of the lens array 24 and in the peripheral portions. When the laser light that is incident and emitted from the lenses 24a and 24b is incident on the vicinity of the center of the Q-switched solid-state laser 26 and the peripheral portion thereof, the portion where the laser light is incident is excited, and the Q-switched solid-state laser is excited. Laser light is oscillated from the vicinity of the center of 26 and the peripheral portion toward the central region 28a and the peripheral region 28b of the bifocal lens 28 (oscillation pattern 3).

  As described above, the Q-switched solid-state laser 26 of the present embodiment oscillates laser beams having a plurality of different oscillation patterns to the bifocal lens 28 in accordance with the incident position of the laser light emitted from the lens array 24. ing.

  As shown in FIG. 1, the laser beam emitting unit 14 is configured to include a bifocal lens 28 as a multifocal lens and an emission window 30. The bifocal lens 28 has a central region 28a and a peripheral region 28b radially outside the central region 28a, and the central region 28a and the peripheral region 28b are connected to the combustion chamber via the exit window 30. The focal length of the laser light emitted into 44 is different. That is, the focal length is set short in the central region 28a, and the focal length is set long in the peripheral region 28b.

  In this embodiment, the lens array 24, the Q-switched solid-state laser 26, and the bifocal lens 28 are accommodated in the housing case 32. The optical fiber group 22 is introduced into one side of the housing case 32, and the other side of the housing case 32 is integrally fixed to the wall portion of the cylinder head 40. Further, the other side of the housing case 32 is isolated from the inside of the combustion chamber 44 by the emission window 30.

  The control unit 16 includes an engine controller 34 and a laser control device 36. The engine controller 34 is supplied with the driving condition detection signal output from the driving condition detector 18. When the engine controller 34 inputs the driving condition detection signal output from the driving condition detection unit 18, the engine controller 34 generates a control command corresponding to the driving condition detection signal and outputs it to the laser control device 36 as will be described in detail later. It is like that.

  A control command output from the engine controller 34 is input to the laser control device 36. The laser control device 36 includes an arithmetic device and a storage device, and an ignition number map 36a and an ignition position map 36b (see FIG. 3), which will be described in detail later, are stored in the storage device.

  In addition, when the laser controller 36 receives the control command output from the engine controller 34, the number and position of condensing laser light emitted from the bifocal lens 28 into the combustion chamber 44 through the emission window 30. The laser light source that oscillates laser light is selected from the plurality of laser light sources 20a and 20b provided in the laser light source group 20 so that the laser light source is changed, and the laser light is oscillated from the laser light source.

  The driving condition detection unit 18 detects the driving condition detection signal corresponding to the driving condition by detecting, for example, the EGR rate and engine speed during stratified operation, the torque and engine speed during stratified operation, as the driving condition of the vehicle. It is generated and output to the engine controller 34.

  Next, operation | movement of the laser ignition device 10 for internal combustion engines which concerns on 1st embodiment of this invention is demonstrated.

  First, the driving state detection unit 18 detects, for example, an EGR rate and engine speed during stratified operation, torque and number of rotation during stratified operation, and the like as the driving state of the vehicle. Then, the driving situation detection unit 18 generates a driving situation detection signal corresponding to the driving situation of these vehicles, and outputs this to the engine controller 34.

  When the engine controller 34 receives the driving condition detection signal output from the driving condition detection unit 18, the engine controller 34 generates a control command corresponding to the driving condition detection signal, and outputs this to the laser controller 36 together with the driving condition detection signal.

  When the laser control device 36 receives the control command output from the engine controller 34, the laser control device 36 starts the processing of the program shown in FIG. At this time, when the driving condition detection unit 18 detects the driving condition of the vehicle, for example, the EGR rate and engine speed during stratified operation, the torque and engine speed during stratified operation, the laser control device 36 Based on the driving condition detection signal, the EGR rate and the engine speed during the stratified operation, the torque and the engine speed during the stratified operation are detected. (Step S1).

  Subsequently, based on the EGR rate and engine speed during stratified operation detected based on the operating condition detection signal, and the ignition number map 36a shown in FIG. 3A, the EGR rate and engine speed during stratified operation. The number of ignitions is determined from the relationship with the number (step S2).

  In this case, when the engine speed is low and the EGR rate is low, the ignitability of the air-fuel mixture in the combustion chamber 44 is relatively good, so that one-point ignition is performed to suppress power consumption. On the other hand, in a state where the engine speed is high and the EGR rate is high, the ignitability is inferior, so multipoint ignition (two-point ignition as an example in the present embodiment) is performed.

  Further, based on the torque and engine speed during stratification operation detected based on the driving condition detection signal and the ignition position map 36b shown in FIG. 3B, the torque and engine speed during stratification operation are calculated. The ignition position is determined from the relationship (step S3).

  In this case, when the engine speed increases and the torque increases, the fuel injection timing advances, and the optimal mixture position also moves to the piston 42 side. Accordingly, in this state, the ignition position is set to the piston 42 side. Set. On the other hand, when the engine speed decreases and the torque decreases, the optimum gas mixture position moves to the cylinder head 40 side. In this state, the ignition position is set on the cylinder head 40 side.

  Based on the number of ignitions and the ignition position determined as described above, a laser light source that oscillates laser light is selected from the plurality of laser light sources 20a and 20b provided in the laser light source group 20, and the laser light source is selected from the laser light sources. Light is oscillated (step S4).

  That is, in the case of one-point ignition at the cylinder head 40 side position, laser light is oscillated from the laser light source 20a. When laser light is oscillated from the laser light source 20a, the laser light is incident on the lens 24a near the center of the lens array 24 via the optical fiber group 22, and the laser light emitted from the lens 24a is converted into a Q switch. Incident near the center of the solid-state laser 26. As a result, the portion where the laser beam is incident is excited, and the laser beam is oscillated from the vicinity of the center of the Q-switch type solid-state laser 26 toward the central region 28a of the bifocal lens 28 (oscillation pattern 1). Then, laser light is emitted from the center region 28 a of the bifocal lens 28 to the cylinder head 40 side position of the combustion chamber 44 through the emission window 30, and one-point ignition is performed at the cylinder head 40 side position of the combustion chamber 44.

  Further, in the case of single point ignition at the piston 42 side position, laser light is oscillated from the laser light source 20b. When laser light is oscillated from the laser light source 20b, the laser light is incident on the lens 24b in the peripheral portion of the lens array 24 via the optical fiber group 22, and the laser light emitted from the lens 24b is converted into a Q switch. The incident light is incident on the periphery of the solid-state laser 26. As a result, the portion where the laser beam is incident is excited, and the laser beam is oscillated from the peripheral portion of the Q-switch type solid-state laser 26 toward the peripheral region 28b of the bifocal lens 28 (oscillation pattern 2). Then, laser light is emitted from the peripheral region 28 b of the bifocal lens 28 to the piston 42 side position of the combustion chamber 44 through the emission window 30, and one-point ignition is performed at the piston 42 side position of the combustion chamber 44.

  In the case of multipoint ignition (two-point ignition), laser light is oscillated from the laser light sources 20a and 20b. When laser light is oscillated from the laser light sources 20a and 20b, the laser light is incident on the lenses 24a and 24b near and around the center of the lens array 24 through the optical fiber group 22, and is emitted from the lenses. The laser light is incident on the vicinity of the center and the periphery of the Q-switched solid-state laser 26. As a result, the place where the laser beam is incident is excited, and the laser beam is oscillated from the vicinity of the center of the Q-switched solid-state laser 26 and the peripheral portion toward the central region 28a and the peripheral region 28b of the bifocal lens 28 ( Oscillation pattern 3). Laser light is emitted from the central region 28a and the peripheral region 28b of the bifocal lens 28 to the cylinder head 40 side position and the piston 42 side position of the combustion chamber 44 through the emission window 30, and the combustion chamber 44 side of the combustion chamber 44 is located on the cylinder head 40 side. Two-point ignition is performed at the position and the position on the piston 42 side.

  As described above, in this embodiment, the laser light oscillated from the Q-switched solid-state laser 26 by selecting the laser light source that oscillates the laser light among the plurality of laser light sources 20 a and 20 b provided in the laser light source group 20. By changing the oscillation pattern, the number of condensings and the condensing position of the laser light emitted from the bifocal lens 28 into the combustion chamber 44 are changed, and the number of ignitions and the ignition position are changed.

  Next, the operation and effect of the laser ignition device 10 for an internal combustion engine according to the first embodiment of the present invention will be described.

  As described above in detail, in the laser ignition device 10 for an internal combustion engine according to the first embodiment of the present invention, at least one of the condensing number and the condensing position of the laser light emitted into the combustion chamber 44, that is, the ignition number. In order to change at least one of the ignition positions, a laser light source that oscillates laser light is selected from the plurality of laser light sources 20a and 20b provided in the laser light source group 20, and the laser light is oscillated from the laser light source. good.

  According to this configuration, in order to change at least one of the condensing number and the condensing position of the laser light emitted into the combustion chamber 44, that is, at least one of the ignition number and the ignition position, It is not necessary to move an optical system that emits light (for example, the bifocal lens 28 in this embodiment). Therefore, a mechanical moving mechanism for moving the optical system is not necessary. As a result, it is possible to change at least one of the number of ignitions and the ignition position without being affected by vibrations or the like accompanying traveling of the vehicle.

  In the laser ignition device 10 for an internal combustion engine according to the first embodiment of the present invention, laser light is oscillated from the plurality of laser light sources 20a and 20b provided in the laser light source group 20 in order to change the number of ignitions. Since it is only necessary to select a laser light source and oscillate laser light from the laser light source, it is possible to precisely set the number of condensing laser beams emitted from the bifocal lens 28 into the combustion chamber 44. Thereby, it is possible to change the number of condensing laser beams emitted into the combustion chamber 44 without the light energy in the combustion chamber 44 increasing rapidly.

  Furthermore, when changing the condensing position of the laser light emitted from the bifocal lens 28 into the combustion chamber 44, a laser that oscillates laser light from the plurality of laser light sources 20 a and 20 b provided in the laser light source group 20. Since it is only necessary to select a light source and oscillate laser light from the laser light source, it is easy to change the condensing position of the laser light emitted into the combustion chamber 44.

  In the internal combustion engine laser ignition device 10 according to the first embodiment of the present invention, the focal length of the central region 28a and the focal length of the peripheral region 28b of the bifocal lens 28 can be freely set. Thereby, when performing multipoint ignition, the ignition positions in the combustion chamber 44 can be sufficiently separated from each other.

  Further, in the laser ignition device 10 for an internal combustion engine according to the first embodiment of the present invention, as described above, at least one of the number of ignitions and the ignition position in the combustion chamber 44 can be changed according to the operating state of the vehicle. it can. According to this configuration, even in the stratified combustion system, ignition at the optimum mixing position is always possible even if the optimum mixture position changes as the operating state changes. Therefore, it is possible to keep the combustion of the internal combustion engine in an optimum state in accordance with the driving situation of the vehicle. As a result, the combustion efficiency is improved by reducing unburned fuel, suppressing the generation of soot, and the like, and it is possible to obtain a highly efficient and low emission engine.

  Further, according to the above-described configuration of the present embodiment, even in the homogeneous combustion system, multipoint ignition at the optimum position of the combustion chamber 44 is possible under knocking conditions, and knocking can be effectively suppressed. As a result, the compression ratio can be increased, and the thermal efficiency of the engine can be increased. Further, in the homogeneous combustion system, knocking is difficult when the torque is low or the engine speed is high, but in this embodiment, it is possible to perform one-point ignition in such a case. Thus, since the number of ignitions can be reduced according to the driving situation, it is possible to suppress excessive energy consumption required for ignition.

  Next, a modification of the laser ignition device 10 for an internal combustion engine according to the first embodiment of the present invention will be described.

  In the above embodiment, an EGR rate and engine speed during stratified operation, torque and engine speed during stratified operation, etc. are detected to generate an operating condition detection signal corresponding to the operating condition. Based on the ignition number map 36a and the ignition position map 36b shown in b), the ignition number is determined from the relationship between the EGR rate during stratified operation and the engine speed, and the relationship between the torque during stratified operation and the engine speed. However, the ignition position may be determined as follows.

  That is, the driving condition detection unit 18 detects, for example, the torque and engine speed during homogeneous operation as the driving condition of the vehicle. Based on the ignition number map 36a shown in FIG. The number of ignitions may be determined from the relationship with the number.

  In other words, at a low torque or high rotation speed that is difficult to knock, a single point ignition is performed to suppress power consumption. On the other hand, if the engine speed is decreased or the torque is increased, knocking is likely to occur in association with them, so at this time, multipoint ignition is performed. At this time, when two or more ignitions are performed in the combustion chamber 44, the number of laser light sources of the laser light source group 20, the number of lenses of the lens array 24, and the number of regions having different focal lengths of the bifocal lens 28 are set as the number of ignitions. It should be equivalent.

  Based on the determined number of ignitions, a laser light source that oscillates laser light is selected from the plurality of laser light sources 20a and 20b provided in the laser light source group 20, and the laser light source is excited to oscillate the laser light. May be.

  In the present embodiment, the laser beam among the plurality of laser light sources 20a and 20b provided in the laser light source group 20 is changed so that the number of condensing and the converging position of the laser light emitted into the combustion chamber 44 are changed. By selecting a laser light source that oscillates, the oscillation pattern of the laser light oscillated from the Q-switched solid-state laser 26 is varied, but the number of condensing numbers and condensing positions of the laser light emitted into the combustion chamber 44 are different. By selecting a laser light source that oscillates laser light among the plurality of laser light sources 20a and 20b provided in the laser light source group 20 so that at least one of them is changed, laser light oscillated from the Q-switched solid-state laser 26 is selected. The oscillation pattern may be different.

  In addition, the item detected as the driving state of the vehicle may be changed to other items according to the engine characteristics and the like, and the number of ignitions and the ignition position may be variously set according to the engine characteristics and the like.

  In the above embodiment, the bifocal lens 28 according to the present invention is configured by the bifocal lens 28. However, the number of lens regions having different focal lengths is not limited to two, and is two or more. Also good. Further, although the focal length of the central region 28a is shorter than the focal length of the peripheral region 28b, it may be longer.

[Second Embodiment]
Next, a laser ignition device 50 for an internal combustion engine according to a second embodiment of the present invention will be described with reference to FIG.

  A laser ignition device 50 for an internal combustion engine according to the second embodiment of the present invention includes a lens group 52 and a multi-prism 54 instead of the bifocal lens 28 of the laser ignition device 10 for the internal combustion engine according to the first embodiment. It has become. Therefore, in the laser ignition device 50 for an internal combustion engine according to the second embodiment of the present invention, the same reference numerals are used for the same configurations as the laser ignition device 10 for the internal combustion engine according to the first embodiment. Omitted.

  In the laser ignition device 50 for an internal combustion engine according to the second embodiment of the present invention, the lens group 52 includes a plurality of laser beams that are incident on each laser beam oscillated from the Q-switched solid-state laser 26 and collect each laser beam. Lenses 52a, 52b, and 52c are provided. The multi-prism 54 includes a plurality of refracting surfaces 54 a, 54 b, and 54 c that receive each laser beam emitted from the lens group 52 and refract each laser beam in different directions in the combustion chamber 44.

  In the present embodiment, the lens array 24, the Q switch type solid-state laser 26, and the bifocal lens are accommodated in the housing case 32. The optical fiber group 22 is introduced into one side of the housing case 32, and the other side of the housing case 32 is integrally fixed to the wall portion of the cylinder bore 48. Further, the other side of the housing case 32 is isolated from the inside of the combustion chamber 44 by the emission window 30.

  When the laser controller 36 receives the control command output from the engine controller 34, the laser controller 36 determines the number and position of condensing laser light emitted from the multi-prism 54 through the emission window 30 into the combustion chamber 44. A laser light source that oscillates laser light is selected from the plurality of laser light sources 20a, 20b, and 20c provided in the laser light source group 20 so as to be changed, and laser light is oscillated from this laser light source.

  Next, the operation of the laser ignition device 50 for an internal combustion engine according to the second embodiment of the present invention will be described.

  In the laser ignition device 50 for an internal combustion engine according to the second embodiment of the present invention, similarly to the laser ignition device 10 for the internal combustion engine according to the first embodiment, the EGR during the stratified operation detected based on the operation state detection signal. The ignition speed is determined from the relationship between the EGR rate and the engine speed during the stratified operation based on the rate, the engine speed, the torque and the engine speed during the stratified operation, and the ignition number map 36a and the ignition position map 36b. At the same time, the ignition position is determined from the relationship between the torque during the stratified operation and the engine speed.

  Based on the number of ignitions and the ignition position determined as described above, a laser light source that oscillates laser light is selected from the plurality of laser light sources 20a, 20b, and 20c provided in the laser light source group 20, and this laser light source The laser beam is oscillated from.

  That is, in the case of one-point ignition at the cylinder head 40 side position, laser light is oscillated from the laser light source 20a. When laser light is oscillated from the laser light source 20a, the laser light is incident on the lens 24a in the peripheral portion of the lens array 24 via the optical fiber group 22, and the laser light emitted from the lens 24a is converted into a Q switch. The incident light is incident on the periphery of the solid state laser 26. As a result, the portion where the laser beam is incident is excited, and the laser beam is oscillated from the peripheral portion of the Q-switch type solid-state laser 26 toward the refractive surface 54a of the multi-prism 54 through the lens 52a (oscillation pattern 1). ). Then, laser light is emitted from the refracting surface 54 a of the multi-prism 54 through the emission window 30 to the cylinder head 40 side position of the combustion chamber 44, and one-point ignition is performed at the cylinder head 40 side position of the combustion chamber 44.

  Further, in the case of single point ignition at an intermediate position of the combustion chamber 44, laser light is oscillated from the laser light source 20b. When laser light is oscillated from the laser light source 20b, the laser light is incident on the lens 24b near the center of the lens array 24 via the optical fiber group 22, and the laser light emitted from the lens 24b is Q-switched. Incident near the center of the solid-state laser 26. As a result, the portion where the laser beam is incident is excited, and the laser beam is oscillated from the vicinity of the center of the Q-switched solid-state laser 26 toward the refractive surface 54b of the multi-prism 54 via the lens 52b (oscillation pattern 2). ). Then, laser light is emitted from the refracting surface 54 b of the multi-prism 54 through the emission window 30 to the intermediate position of the combustion chamber 44, and one-point ignition is performed at the intermediate position of the combustion chamber 44.

  Further, when one-point ignition is performed at the position on the piston 42 side of the combustion chamber 44, laser light is oscillated from the laser light source 20c. When laser light is oscillated from the laser light source 20c, the laser light is incident on the lens 24c in the peripheral portion of the lens array 24 via the optical fiber group 22, and the laser light emitted from the lens 24c is converted into a Q switch. The incident light is incident on the periphery of the solid state laser 26. As a result, the portion where the laser beam is incident is excited, and the laser beam is oscillated from the peripheral portion of the Q-switch type solid-state laser 26 toward the refractive surface 54c of the multi-prism 54 via the lens 52c (oscillation pattern 3). ). Then, laser light is emitted from the refracting surface 54 c of the multi-prism 54 through the emission window 30 to the piston 42 side position of the combustion chamber 44, and one-point ignition is performed at the piston 42 side position of the combustion chamber 44.

  In the case of multipoint ignition (two-point ignition), laser light is oscillated from two of the laser light sources 20a, 20b, and 20c (oscillation patterns 4 to 6), and multipoint ignition (three-point ignition) is performed. In this case, laser light is oscillated from all of the laser light sources 20a, 20b, and 20c (oscillation pattern 7).

  As described above, in this embodiment, the laser light source 20a, 20b, 20c provided in the laser light source group 20 is oscillated from the Q-switched solid-state laser 26 by selecting a laser light source that oscillates the laser light. The condensing number and condensing position of the laser light emitted from the multi-prism 54 into the combustion chamber 44 are changed by changing the oscillation pattern of the laser light, and the ignition number and the ignition position are changed.

  Next, the operation and effect of the laser ignition device 50 for an internal combustion engine according to the second embodiment of the present invention will be described.

  As described above in detail, in the laser ignition device 50 for an internal combustion engine according to the second embodiment of the present invention, at least one of the condensing number and the condensing position of the laser light emitted into the combustion chamber 44, that is, the ignition number. In order to change at least one of the ignition positions, a laser light source that oscillates laser light is selected from the plurality of laser light sources 20a, 20b, and 20c provided in the laser light source group 20, and the laser light is oscillated from the laser light source. Just good.

  According to this configuration, in order to change at least one of the condensing number and the condensing position of the laser light emitted into the combustion chamber 44, that is, at least one of the ignition number and the ignition position, It is not necessary to move the optical system (for example, the lens group 52 and the multi-prism 54 in this embodiment). Therefore, a mechanical moving mechanism for moving the optical system is not necessary. As a result, it is possible to change at least one of the number of ignitions and the ignition position without being affected by vibrations or the like accompanying traveling of the vehicle.

  In the laser ignition device 50 for an internal combustion engine according to the second embodiment of the present invention, in order to change the number of ignitions, laser light is emitted from a plurality of laser light sources 20a, 20b, and 20c provided in the laser light source group 20. Since it is only necessary to select a laser light source to oscillate and oscillate laser light from the laser light source, the number of condensing numbers of laser light emitted from the multi-prism 54 into the combustion chamber 44 can be precisely set. Thereby, it is possible to change the number of condensing laser beams emitted into the combustion chamber 44 without the light energy in the combustion chamber 44 increasing rapidly.

  Further, when changing the condensing position of the laser light emitted from the multi-prism 54 into the combustion chamber 44, the laser light is oscillated from the plurality of laser light sources 20 a, 20 b, 20 c provided in the laser light source group 20. Since it is only necessary to select a laser light source and oscillate laser light from the laser light source, it is easy to change the condensing position of the laser light emitted into the combustion chamber 44.

  Further, in the laser ignition device 50 for an internal combustion engine according to the second embodiment of the present invention, the direction of refraction of laser light by the plurality of refracting surfaces 54a, 54b, 54c provided in the multi-prism 54 can be freely set. . Thereby, when performing multipoint ignition, the ignition positions in the combustion chamber 44 can be sufficiently separated from each other.

  Further, according to the laser ignition device 50 for an internal combustion engine according to the second embodiment of the present invention, as in the laser ignition device 10 for the internal combustion engine according to the first embodiment, the combustion of the internal combustion engine in the stratified combustion system is performed on the vehicle. It becomes possible to keep the optimum state according to the driving situation. As a result, the combustion efficiency is improved by reducing unburned fuel, suppressing the generation of soot, and the like, and it is possible to obtain a highly efficient and low emission engine.

  Moreover, according to the laser ignition device 50 for an internal combustion engine according to the second embodiment of the present invention, knocking can be effectively suppressed even in the homogeneous combustion system, thereby increasing the compression ratio. Therefore, the thermal efficiency of the engine can be increased. In addition, since the number of ignitions can be reduced according to the operating conditions, it is possible to suppress excessive energy consumption required for ignition.

  Next, a modification of the laser ignition device 50 for an internal combustion engine according to the second embodiment of the present invention will be described.

  In the above embodiment, an EGR rate and engine speed during stratified operation, torque and engine speed during stratified operation, etc. are detected to generate an operating condition detection signal corresponding to the operating condition. Based on the ignition number map 36a and the ignition position map 36b shown in b), the ignition number is determined from the relationship between the EGR rate during stratified operation and the engine speed, and the relationship between the torque during stratified operation and the engine speed. However, the ignition position may be determined as follows.

  That is, the driving condition detection unit 18 detects, for example, the torque and engine speed during homogeneous operation as the driving condition of the vehicle. Based on the ignition number map 36a shown in FIG. The number of ignitions may be determined from the relationship with the number.

  Further, in the present embodiment, among the plurality of laser light sources 20a, 20b, and 20c provided in the laser light source group 20 so that the number of condensing of the laser light emitted into the combustion chamber 44 and the condensing position are changed. By selecting a laser light source that oscillates the laser light, the oscillation pattern of the laser light oscillated from the Q-switched solid-state laser 26 is varied. The Q-switched solid-state laser 26 oscillates by selecting a laser light source that oscillates laser light among the plurality of laser light sources 20, 20b, 20c provided in the laser light source group 20 so that at least one of the positions is changed. The oscillation pattern of the laser beam may be different.

  In addition, the item detected as the driving state of the vehicle may be changed to other items according to the engine characteristics and the like, and the number of ignitions and the ignition position may be variously set according to the engine characteristics and the like.

[Third embodiment]
Next, a laser ignition device 60 for an internal combustion engine according to a third embodiment of the present invention will be described with reference to FIG.

  A laser ignition device 60 for an internal combustion engine according to the third embodiment of the present invention includes a Q switch type solid laser 62 instead of the Q switch type solid laser 26 of the laser ignition device 10 for the internal combustion engine according to the first embodiment. It has a configuration. Therefore, in the laser ignition device 60 for an internal combustion engine according to the third embodiment of the present invention, the same reference numerals are used for the same configurations as the laser ignition device 10 for the internal combustion engine according to the first embodiment. Omitted.

  In the laser ignition device 60 for an internal combustion engine according to the third embodiment of the present invention, the Q switch type solid-state laser 62 has a total reflection mirror 62b and an emission mirror 62c on both sides of the optical amplification medium 62a, and a lens. When the laser beams emitted from the lenses 24 a and 24 b of the array 24 are condensed, the laser beam is oscillated to the bifocal lens 28 in an excited state. At this time, the Q-switched solid-state laser 62 has different oscillation characteristics depending on the intensity (that is, light energy) distribution of each laser beam emitted from each lens 24a, 24b of the lens array 24, and more specifically. Specifically, the laser oscillation mode is changed in accordance with the intensity distribution of each laser beam emitted from each lens 24a, 24b of the lens array 24, and the spread angle of the laser beam can be changed.

  In other words, if the intensity distribution of each laser beam oscillated from the laser light source group 20 is controlled so that the Q-switched solid-state laser 62 oscillates in a low-order mode, the Q-switched solid-state laser 62 and the bifocal lens 28 Laser light with a narrow spread angle is oscillated toward the center region 28a (oscillation pattern 1).

  Further, if the intensity distribution of each laser beam oscillated from the laser light source group 20 is controlled so that the Q-switched solid-state laser 62 oscillates in a higher order mode, the central region 28a and the peripheral region 28b of the bifocal lens 28 are obtained. A laser beam with a wide spread angle is oscillated toward (oscillation pattern 2). Note that the oscillation pattern is not limited to two types of cases where the spread angle is wide and narrow, but continuously changes according to the intensity distribution of each laser beam oscillated from the laser light source group 20.

  As described above, the Q-switch type solid-state laser 62 of the present embodiment oscillates laser beams having a plurality of different oscillation patterns to the bifocal lens 28 in accordance with the intensity distribution of each laser beam emitted from the lens array 24. It has become.

  When the laser controller 36 receives the control command output from the engine controller 34, the number and position of condensing laser light emitted from the multi-prism through the exit window 30 into the combustion chamber 44 are changed. As described above, the intensity distribution of the laser light oscillated from the laser light source group 20 is controlled.

  Next, the operation of the laser ignition device 60 for an internal combustion engine according to the third embodiment of the present invention will be described.

  In the internal combustion engine laser ignition device 60 according to the third embodiment of the present invention, as in the internal combustion engine laser ignition device 10 according to the first embodiment, the EGR during the stratified operation detected based on the operation state detection signal. The ignition speed is determined from the relationship between the EGR rate during stratified operation and the engine speed based on the engine speed, engine speed, torque during stratified operation and engine speed, and the ignition number map 36a and ignition position map 36b. At the same time, the ignition position is determined from the relationship between the torque during the stratified operation and the engine speed.

  Then, the intensity distribution of the laser light oscillated from the laser light source group 20 is controlled based on the number of ignitions and the ignition position determined as described above.

  That is, when one-point ignition is performed at the cylinder head 40 side position, the intensity distribution of each laser beam oscillated from the laser light source group 20 is controlled so that the Q-switched solid-state laser 62 oscillates in a low-order mode. . As a result, the laser light emitted from the laser light source group 20 through the optical fiber group 22 and the lens array 24 is incident on the Q-switched solid-state laser 62, and the central region of the bifocal lens 28 from the Q-switched solid-state laser 62. Laser light having a narrow spread angle is oscillated toward 28a (oscillation pattern 1). Then, laser light is emitted from the center region 28 a of the bifocal lens 28 to the cylinder head 40 side position of the combustion chamber 44 through the emission window 30, and one-point ignition is performed at the cylinder head 40 side position of the combustion chamber 44.

  In the case of multipoint ignition (two-point ignition), the intensity distribution of each laser beam oscillated from the laser light source group 20 is controlled so that the Q-switched solid-state laser 62 oscillates in a higher order mode. As a result, the laser light emitted from the laser light source group 20 through the optical fiber group 22 and the lens array 24 is incident on the Q-switched solid-state laser 62, and the central region of the bifocal lens 28 from the Q-switched solid-state laser 62. Laser light having a wide spread angle is oscillated toward 28a and the peripheral region 28b (oscillation pattern 2). Laser light is emitted from the central region 28a and the peripheral region 28b of the bifocal lens 28 to the cylinder head 40 side position and the piston 42 side position of the combustion chamber 44 through the emission window 30, and the combustion chamber 44 side of the combustion chamber 44 is located on the cylinder head 40 side. Two-point ignition is performed at the position and the position on the piston 42 side.

  As described above, in this embodiment, by controlling the intensity distribution of the laser light from the laser light source group 20, the oscillation pattern of the laser light oscillated from the Q-switched solid-state laser 62 is varied to burn from the bifocal lens 28. The number of condensings and the condensing position of the laser light emitted into the chamber 44 are changed, and the number of ignitions and the ignition position are changed.

  Next, operations and effects of the laser ignition device 60 for an internal combustion engine according to the third embodiment of the present invention will be described.

  As described above in detail, in the laser ignition device 60 for an internal combustion engine according to the third embodiment of the present invention, at least one of the condensing number and the condensing position of the laser light emitted into the combustion chamber 44, that is, the ignition number. In order to change at least one of the ignition position, it is only necessary to control the intensity distribution of each laser beam from the laser light source group 20.

  According to this configuration, in order to change at least one of the condensing number and the condensing position of the laser light emitted into the combustion chamber 44, that is, at least one of the ignition number and the ignition position, It is not necessary to move an optical system that emits light (for example, the bifocal lens 28 in this embodiment). Therefore, a mechanical moving mechanism for moving the optical system is not necessary. As a result, it is possible to change at least one of the number of ignitions and the ignition position without being affected by vibrations or the like accompanying traveling of the vehicle.

  Further, in the laser ignition device 60 for an internal combustion engine according to the third embodiment of the present invention, in order to change the number of ignitions, it is only necessary to control the intensity distribution of each laser beam from the laser light source group 20. The number of condensing laser beams emitted from the focus lens 28 into the combustion chamber 44 can be precisely set. Thereby, it is possible to change the number of condensing laser beams emitted into the combustion chamber 44 without the light energy in the combustion chamber 44 increasing rapidly.

  Thus, even when the condensing position of the laser light emitted from the bifocal lens 28 into the combustion chamber 44 is changed, it is only necessary to control the intensity distribution of each laser light from the laser light source group 20. The condensing position of the laser beam emitted into the combustion chamber 44 can be easily changed.

  In the internal combustion engine laser ignition device 60 according to the third embodiment of the present invention, the focal length of the central region 28a and the focal length of the peripheral region 28b of the bifocal lens 28 can be freely set. When performing point ignition, the ignition positions in the combustion chamber 44 can be sufficiently separated from each other.

  Further, according to the laser ignition device 60 for an internal combustion engine according to the third embodiment of the present invention, as with the laser ignition device 10 for the internal combustion engine according to the first embodiment, the combustion of the internal combustion engine in the stratified combustion system is performed on the vehicle. It becomes possible to keep the optimum state according to the driving situation. As a result, the combustion efficiency is improved by reducing unburned fuel, suppressing the generation of soot, and the like, and it is possible to obtain a highly efficient and low emission engine.

  In addition, according to the laser ignition device 60 for an internal combustion engine according to the third embodiment of the present invention, knocking can be effectively suppressed even in the homogeneous combustion system, thereby increasing the compression ratio. Therefore, the thermal efficiency of the engine can be increased. In addition, since the number of ignitions can be reduced according to the operating conditions, it is possible to suppress excessive energy consumption required for ignition.

  Next, a modification of the laser ignition device 60 for an internal combustion engine according to the third embodiment of the present invention will be described.

  In the above embodiment, an EGR rate and engine speed during stratified operation, torque and engine speed during stratified operation, etc. are detected to generate an operating condition detection signal corresponding to the operating condition. Based on the ignition number map 36a and the ignition position map 36b shown in b), the ignition number is determined from the relationship between the EGR rate during stratified operation and the engine speed, and the relationship between the torque during stratified operation and the engine speed. However, the ignition position may be determined as follows.

  That is, the driving condition detection unit 18 detects, for example, the torque and engine speed during homogeneous operation as the driving condition of the vehicle. Based on the ignition number map 36a shown in FIG. The number of ignitions may be determined from the relationship with the number.

  Further, in the present embodiment, the intensity distribution of each laser beam oscillated from the laser light source group 20 is controlled so that the number and position of condensing of the laser beam emitted into the combustion chamber 44 are changed, and Q Although the oscillation pattern of the laser light oscillated from the switch type solid-state laser 62 is varied, the laser light source group so that at least one of the number of condensing numbers and the condensing position of the laser light emitted into the combustion chamber 44 is changed. The intensity distribution of each laser beam oscillated from 20 may be controlled to vary the oscillation pattern of the laser beam oscillated from the Q switch type solid state laser 62.

  In addition, the item detected as the driving state of the vehicle may be changed to other items according to the engine characteristics and the like, and the number of ignitions and the ignition position may be variously set according to the engine characteristics and the like.

[Fourth embodiment]
Next, a laser ignition device 70 for an internal combustion engine according to a fourth embodiment of the present invention will be described with reference to FIGS.

  The internal combustion engine laser ignition device 70 according to the fourth embodiment of the present invention includes a laser light oscillation unit 72 instead of the laser light oscillation unit 12 of the internal combustion engine laser ignition device 10 according to the first embodiment. It has become. Accordingly, in the internal combustion engine laser ignition device 70 according to the fourth embodiment of the present invention, the same components as those in the internal combustion engine laser ignition device 10 according to the first embodiment will be described using the same reference numerals. Omitted.

  In the laser ignition device 70 for an internal combustion engine according to the fourth embodiment of the present invention, the laser beam oscillation unit 72 oscillates laser beams having a plurality of different oscillation patterns on the laser beam emission unit 14 as will be described in detail later. And a laser light source group 73, a lens array 74, an optical fiber group 75, a Q-switched solid-state laser 76, and an external mirror 77.

  The laser light source group 73 includes a plurality of laser light sources 73a and 73b (for example, one laser light source 73a at the center and five laser light sources 73b around the laser light source 73b). Each of the laser light sources 73a and 73b is configured to be able to oscillate laser light by being independently controlled by the laser controller 36.

  The lens array 74 includes a plurality of lenses 74a and 74b (for example, one lens 74a at the center and five lenses 74b around it) to which each laser beam emitted from the laser light source group 73 is incident. The lenses 74 a and 74 b collect the laser light emitted from the laser light source group 73 and emit the condensed laser light to the optical fibers 75 a and 75 b of the optical fiber group 75.

  The optical fiber group 75 includes a plurality of optical fibers 75 a and 75 b that guide each laser beam emitted from the lens array 74. Each optical fiber 75a, 75b guides and emits the laser light oscillated from the corresponding lens 74a, 74b to the surface 76d of the Q-switch type solid laser 76 as shown in FIG. Note that an optical system for light projection is required at the ends of the optical fibers 75a and 75b, but these are not shown in FIGS.

  The Q switch type solid state laser 76 has a configuration including an optical amplifying medium 76 a, a total reflection mirror 76 b, and a cooling mechanism 76 c. Each of the Q switch type solid state lasers 76 emitted from the lenses 74 a and 74 b of the lens array 74 via the optical fiber group 75 is provided. When the laser beam is condensed, the laser beam is oscillated to the bifocal lens 28 in an excited state. At this time, the Q-switch type solid-state laser 76 has different oscillation characteristics according to the intensity (that is, light energy) distribution of each laser beam oscillated from the laser light source group 73. More specifically, The laser oscillation mode is changed in accordance with the intensity distribution of each laser beam oscillated from the light source group 73, and the spread angle of the laser beam can be changed.

  That is, if the intensity distribution of each laser beam oscillated from the laser light source group 73 is controlled so that the Q-switched solid-state laser 76 oscillates in a low-order mode, the Q-switched solid-state laser 76 can change the intensity of the bifocal lens 28. Laser light with a narrow spread angle is oscillated toward the center region 28a (oscillation pattern 1).

  Further, if the intensity distribution of each laser beam oscillated from the laser light source group 73 is controlled so that the Q-switched solid-state laser 76 oscillates in a high-order mode, the Q-switched solid-state laser 76 and the bifocal lens 28 Laser light with a wide spread angle is oscillated toward the central region 28a and the peripheral region 28b (oscillation pattern 2). The oscillation pattern is not limited to two types of cases where the spread angle is wide and narrow, but continuously changes depending on the intensity distribution of each laser beam oscillated from the laser light source group 73.

  As described above, the Q-switched solid-state laser 76 of the present embodiment oscillates laser beams having a plurality of different oscillation patterns to the bifocal lens 28 in accordance with the intensity distribution of each laser beam oscillated from the laser light source group 73. It has become.

  When the laser controller 36 receives the control command output from the engine controller 34, the number and position of condensing laser light emitted from the bifocal lens 28 into the combustion chamber 44 through the emission window 30. The intensity distribution of the laser light oscillated from the laser light source group 73 is controlled so that is changed.

  In the Q-switched solid-state laser 76, the optical amplifying medium 76a is cooled via a total reflection mirror 76b composed of a dielectric multilayer film (or metal film) or the like.

  Next, the operation of the laser ignition device 70 for an internal combustion engine according to the fourth embodiment of the present invention will be described.

  In the internal combustion engine laser ignition device 70 according to the fourth embodiment of the present invention, as in the internal combustion engine laser ignition device 10 according to the first embodiment, the EGR during the stratified operation detected based on the operation state detection signal. The ignition speed is determined from the relationship between the EGR rate during stratified operation and the engine speed based on the engine speed, engine speed, torque during stratified operation and engine speed, and the ignition number map 36a and ignition position map 36b. At the same time, the ignition position is determined from the relationship between the torque during the stratified operation and the engine speed.

  The intensity distribution of the laser light oscillated from the laser light source group 73 is controlled based on the number of ignitions and the ignition position determined as described above.

  That is, when one-point ignition is performed at the cylinder head 40 side position, the intensity distribution of each laser beam oscillated from the laser light source group 73 is controlled so that the Q-switched solid-state laser 76 oscillates in a low-order mode. . As a result, the laser light emitted from the laser light source group 73 through the optical fiber group 75 and the lens array 74 is incident on the Q-switched solid-state laser 76, and the central region of the bifocal lens 28 from the Q-switched solid-state laser 76. Laser light having a narrow spread angle is oscillated toward 28a (oscillation pattern 1). Then, laser light is emitted from the center region 28 a of the bifocal lens 28 to the cylinder head 40 side position of the combustion chamber 44 through the emission window 30, and one-point ignition is performed at the cylinder head 40 side position of the combustion chamber 44.

  In the case of multi-point ignition (two-point ignition), the intensity distribution of each laser beam oscillated from the laser light source group 73 is controlled so that the Q-switched solid-state laser 76 oscillates in a higher order mode. As a result, the laser light emitted from the laser light source group 73 through the optical fiber group 75 and the lens array 74 is incident on the Q-switched solid-state laser 76, and the central region of the bifocal lens 28 from the Q-switched solid-state laser 76. Laser light having a wide spread angle is oscillated toward 28a and the peripheral region 28b (oscillation pattern 2). Laser light is emitted from the central region 28a and the peripheral region 28b of the bifocal lens 28 to the cylinder head 40 side position and the piston 42 side position of the combustion chamber 44 through the emission window 30, and the combustion chamber 44 side of the combustion chamber 44 is located on the cylinder head 40 side. Two-point ignition is performed at the position and the position on the piston 42 side.

  As described above, in the present embodiment, by controlling the intensity distribution of each laser beam from the laser light source group 73, the oscillation pattern of the laser beam oscillated from the Q switch type solid-state laser 76 is made different from the bifocal lens 28. The condensing number and condensing position of the laser light emitted into the combustion chamber 44 are changed, and the ignition number and the ignition position are changed.

  Next, operations and effects of the laser ignition device 70 for an internal combustion engine according to the fourth embodiment of the present invention will be described.

  As described above in detail, in the laser ignition device 70 for an internal combustion engine according to the fourth embodiment of the present invention, at least one of the condensing number and the condensing position of the laser light emitted into the combustion chamber 44, that is, the ignition number. In order to change at least one of the ignition position, it is only necessary to control the intensity distribution of each laser beam from the laser light source group 73.

  According to this configuration, in order to change at least one of the condensing number and the condensing position of the laser light emitted into the combustion chamber 44, that is, at least one of the ignition number and the ignition position, It is not necessary to move an optical system that emits light (for example, the bifocal lens 28 in this embodiment). Therefore, a mechanical moving mechanism for moving the optical system is not necessary. As a result, it is possible to change at least one of the number of ignitions and the ignition position without being affected by vibrations or the like accompanying traveling of the vehicle.

  Further, in the laser ignition device 70 for an internal combustion engine according to the fourth embodiment of the present invention, in order to change the number of ignition, it is only necessary to control the intensity distribution of each laser beam from the laser light source group 73. The number of condensing laser beams emitted from the focus lens 28 into the combustion chamber 44 can be precisely set. Thereby, it is possible to change the number of condensing laser beams emitted into the combustion chamber 44 without the light energy in the combustion chamber 44 increasing rapidly.

  Thus, even when the condensing position of the laser light emitted from the bifocal lens 28 into the combustion chamber 44 is changed, it is only necessary to control the intensity distribution of the laser light from the laser light source group 73. The condensing position of the laser beam emitted into the chamber 44 can be easily changed.

  Further, in the laser ignition device 70 for an internal combustion engine according to the fourth embodiment of the present invention, the focal length of the central region 28a and the focal length of the peripheral region 28b of the bifocal lens 28 can be freely set. When performing point ignition, the ignition positions in the combustion chamber 44 can be sufficiently separated from each other.

  Further, according to the internal combustion engine laser ignition device 70 according to the fourth embodiment of the present invention, as in the internal combustion engine laser ignition device 10 according to the first embodiment, the combustion of the internal combustion engine in the stratified combustion system is performed on the vehicle. It becomes possible to keep the optimum state according to the driving situation. As a result, the combustion efficiency is improved by reducing unburned fuel, suppressing the generation of soot, and the like, and it is possible to obtain a highly efficient and low emission engine.

  Further, according to the laser ignition device 70 for an internal combustion engine according to the fourth embodiment of the present invention, knocking can be effectively suppressed even in the homogeneous combustion system, and thereby the compression ratio can be increased. Therefore, the thermal efficiency of the engine can be increased. In addition, since the number of ignitions can be reduced according to the operating conditions, it is possible to suppress excessive energy consumption required for ignition.

  Next, a modification of the internal combustion engine laser ignition device 70 according to the fourth embodiment of the present invention will be described.

  In the above embodiment, an EGR rate and engine speed during stratified operation, torque and engine speed during stratified operation, etc. are detected to generate an operating condition detection signal corresponding to the operating condition. Based on the ignition number map 36a and the ignition position map 36b shown in b), the ignition number is determined from the relationship between the EGR rate during stratified operation and the engine speed, and the relationship between the torque during stratified operation and the engine speed. However, the ignition position may be determined as follows.

  That is, the driving condition detection unit 18 detects, for example, the torque and engine speed during homogeneous operation as the driving condition of the vehicle. Based on the ignition number map 36a shown in FIG. The number of ignitions may be determined from the relationship with the number.

  Further, in the present embodiment, the intensity distribution of each laser beam oscillated from the laser light source group 73 is controlled so that the number and position of condensing of the laser light emitted into the combustion chamber 44 are changed, and Q Although the oscillation pattern of the laser light oscillated from the switch type solid-state laser 76 is made different, the laser light source group so that at least one of the number of condensing numbers and the condensing position of the laser light emitted into the combustion chamber 44 is changed. The intensity distribution of each laser beam oscillated from 73 may be controlled to vary the oscillation pattern of the laser beam oscillated from the Q switch type solid state laser 76.

  In addition, the item detected as the driving state of the vehicle may be changed to other items according to the engine characteristics and the like, and the number of ignitions and the ignition position may be variously set according to the engine characteristics and the like.

[Fifth embodiment]
Next, a laser ignition device 80 for an internal combustion engine according to a fifth embodiment of the present invention will be described with reference to FIGS.

  The internal combustion engine laser ignition device 80 according to the fifth embodiment of the present invention includes a laser light oscillation unit 82 instead of the laser light oscillation unit 72 of the internal combustion engine laser ignition device 70 according to the fourth embodiment. It has become. Accordingly, in the internal combustion engine laser ignition device 80 according to the fifth embodiment of the present invention, the same components as those in the internal combustion engine laser ignition device 70 according to the fourth embodiment will be described using the same reference numerals. Omitted.

  In the laser ignition device 80 for an internal combustion engine according to the fifth embodiment of the present invention, the laser beam oscillator 82 oscillates laser beams having a plurality of different oscillation patterns on the bifocal lens 28 as will be described in detail later. The laser light source group 83, the lens array 84, the optical fiber group 85, and the Q switch type solid state laser 86 are configured.

  The laser light source group 83 includes a plurality of laser light sources 83a (for example, 12 in the circumferential direction). Each laser light source 83a is configured to be able to oscillate laser light by being independently controlled by the laser control device 36.

  The lens array 84 includes a plurality of lenses 84a (for example, twelve in the circumferential direction) on which each laser beam emitted from the laser light source group 83 is incident. Each lens 84 a condenses each laser beam emitted from the laser light source group 83 and emits it to each optical fiber 85 a of the optical fiber group 85.

  The optical fiber group 85 includes a plurality of optical fibers 85 a (12 fibers) that guide each laser beam emitted from the lens array 84. Each optical fiber 85a guides and emits the laser light oscillated from the corresponding lens 84a to the side surface 86e of the Q-switch type solid state laser 86 as shown in FIG. Note that a light projecting optical system is required at the tip of the optical fiber 85a, which is not shown in FIGS.

  The Q-switched solid-state laser 86 has a configuration including an optical amplification medium 86a, a total reflection mirror 86b, a cooling mechanism 86c, and an output mirror 86d, and is emitted from each lens 84a of the lens array 84 via the optical fiber group 85. When each laser beam is condensed, the laser beam is oscillated to the bifocal lens 28 in an excited state. At this time, the Q-switched solid-state laser 86 has different oscillation characteristics according to the intensity (that is, light energy) distribution of each laser beam oscillated from the laser light source group 83. More specifically, The laser oscillation mode is changed in accordance with the intensity distribution of each laser beam oscillated from the light source group 83, and the spread angle of the laser beam can be changed.

  That is, if the intensity distribution of each laser beam oscillated from the laser light source group 83 is controlled so that the Q-switched solid-state laser 86 oscillates in a low-order mode, the Q-switched solid-state laser 86 to the bifocal lens 28 Laser light with a narrow spread angle is oscillated toward the center region 28a (oscillation pattern 1).

  Further, if the intensity distribution of each laser beam oscillated from the laser light source group 83 is controlled so that the Q-switched solid-state laser 86 oscillates in a higher order mode, the Q-switched solid-state laser 86 to the bifocal lens 28 Laser light with a wide spread angle is oscillated toward the central region 28a and the peripheral region 28b (oscillation pattern 2). The oscillation pattern is not limited to the two types of cases where the spread angle is wide and narrow, but continuously changes according to the intensity distribution of each laser beam oscillated from the laser light source group 83.

  As described above, the Q-switched solid-state laser 86 according to the present embodiment oscillates laser beams having a plurality of different oscillation patterns to the bifocal lens 28 according to the intensity distribution of each laser beam oscillated from the laser light source group 83. It has become.

  When the laser controller 36 receives the control command output from the engine controller 34, the number and position of condensing laser light emitted from the bifocal lens 28 into the combustion chamber 44 through the emission window 30. The intensity distribution of the laser light oscillated from the laser light source group 83 is controlled so that is changed.

  In the Q-switched solid-state laser 86, the optical amplifying medium 86a is cooled through a total reflection mirror 86b composed of a dielectric multilayer film (or metal film).

  Next, the operation of the laser ignition device 80 for an internal combustion engine according to the fifth embodiment of the present invention will be described.

  In the internal combustion engine laser ignition device 80 according to the fifth embodiment of the present invention, the EGR rate and engine speed during stratified operation, the torque and engine speed during stratified operation detected based on the operating condition detection signal, and the ignition Based on the number map 36a and the ignition position map 36b, the ignition number is determined from the relationship between the EGR rate during stratified operation and the engine speed, and the ignition position is determined from the relationship between the torque during stratified operation and the engine speed. To do. Based on the determined number of ignitions and ignition position, the intensity distribution of the laser light oscillated from the laser light source group 83 is controlled.

  That is, when one-point ignition is performed at the cylinder head 40 side position, the intensity distribution of each laser beam oscillated from the laser light source group 83 is controlled so that the Q-switched solid-state laser 86 oscillates in a low-order mode. . As a result, the laser light emitted from the laser light source group 83 through the optical fiber group 85 and the lens array 84 is incident on the Q-switched solid-state laser 86, and the central region of the bifocal lens 28 from the Q-switched solid-state laser 86. Laser light having a narrow spread angle is oscillated toward 28a (oscillation pattern 1). Then, laser light is emitted from the center region 28 a of the bifocal lens 28 to the cylinder head 40 side position of the combustion chamber 44 through the emission window 30, and one-point ignition is performed at the cylinder head 40 side position of the combustion chamber 44.

  In the case of multi-point ignition (two-point ignition), the intensity distribution of each laser beam oscillated from the laser light source group 83 is controlled so that the Q-switched solid-state laser 86 oscillates in a higher order mode. As a result, the laser light emitted from the laser light source group 83 through the optical fiber group 85 and the lens array 84 is incident on the Q-switched solid-state laser 86, and the central region of the bifocal lens 28 from the Q-switched solid-state laser 86. Laser light having a wide spread angle is oscillated toward 28a and the peripheral region 28b (oscillation pattern 2). Laser light is emitted from the central region 28a and the peripheral region 28b of the bifocal lens 28 to the cylinder head 40 side position and the piston 42 side position of the combustion chamber 44 through the emission window 30, and the combustion chamber 44 side of the combustion chamber 44 is located on the cylinder head 40 side. Two-point ignition is performed at the position and the position on the piston 42 side.

  As described above, in the present embodiment, by controlling the intensity distribution of each laser beam from the laser light source group 83, the oscillation pattern of the laser beam oscillated from the Q-switched solid-state laser 86 is made different from the bifocal lens 28. The condensing number and condensing position of the laser light emitted into the combustion chamber 44 are changed, and the ignition number and the ignition position are changed.

  The operation, effect, and modification of the internal combustion engine laser ignition device 80 according to the fifth embodiment of the present invention are the same as the operation, effect, and modification of the internal combustion engine laser ignition device 70 according to the above-described fourth embodiment. It is. Therefore, for the operation, effect, and modification of the internal combustion engine laser ignition device 80 according to the fifth embodiment of the present invention, refer to the description of the internal combustion engine laser ignition device 70 according to the fourth embodiment. The description is omitted.

[Sixth embodiment]
Next, a laser ignition device 90 for an internal combustion engine according to a sixth embodiment of the present invention will be described with reference to FIG.

  A laser ignition device 90 for an internal combustion engine according to a sixth embodiment of the present invention is a laser light oscillation instead of the laser light oscillation unit 12 and the laser light emission unit 14 of the laser ignition device 10 for an internal combustion engine according to the first embodiment. The unit 92 and the laser beam emitting unit 94 are provided. Therefore, in the laser ignition device 90 for an internal combustion engine according to the sixth embodiment of the present invention, the same components as those in the laser ignition device 10 for the internal combustion engine according to the first embodiment are denoted by the same reference numerals, and the description thereof will be made. Omitted.

  In the laser ignition device 90 for an internal combustion engine according to the sixth embodiment of the present invention, the laser light oscillation unit 92 includes a laser light source group 95 and a fiber laser group 96. The laser light source group 95 includes a plurality of laser light sources 95a, 95b, and 95c that can oscillate laser light. The fiber laser group 96 receives each laser light oscillated from the laser light source group 95. A plurality of Q-switch type fiber lasers 96a, 96b, and 96c are provided. The plurality of Q-switch type fiber lasers 96a, 96b, and 96c are excited by each laser beam to oscillate the laser beam.

  The laser beam emitting section 94 is configured to include a plurality of emission optical systems 97a, 97b, 97c and an emission window 30. Each of the emission optical systems 97a, 97b, and 97c includes a lens and a prism, and each laser beam oscillated from each Q-switch type fiber laser 96a, 96b, and 96c is incident and each laser beam is received. The light is condensed or deflected in the combustion chamber 44.

  In the present embodiment, the respective emission optical systems 97 a, 97 b, 97 c of the laser beam emission portion 94 are accommodated in the housing case 32. The Q-switch type fiber lasers 96 a, 96 b, 96 c are introduced into the housing case 32, and the emission side of the housing case 32 is integrally fixed to the wall portion of the cylinder head 40. Further, the other side of the housing case 32 is isolated from the inside of the combustion chamber 44 by the emission window 30.

  When the laser controller 36 receives the control command output from the engine controller 34, the laser controller 36 condenses the laser light emitted from the emission optical systems 97a, 97b, and 97c into the combustion chamber 44 through the emission window 30. The laser light source that oscillates the laser light is selected from the plurality of laser light sources 95a, 95b, and 95c provided in the laser light source group 95 so that the number and the condensing position are changed, and the laser light is oscillated from the laser light source. It is like that.

  Next, the operation of the laser ignition device 90 for an internal combustion engine according to the sixth embodiment of the present invention will be described.

  In the internal combustion engine laser ignition device 90 according to the sixth embodiment of the present invention, as in the internal combustion engine laser ignition device 10 according to the first embodiment, the EGR during the stratified operation detected based on the operation state detection signal. The ignition speed is determined from the relationship between the EGR rate during stratified operation and the engine speed based on the engine speed, engine speed, torque during stratified operation and engine speed, and the ignition number map 36a and ignition position map 36b. At the same time, the ignition position is determined from the relationship between the torque during the stratified operation and the engine speed.

  Based on the number of ignitions and the ignition position determined as described above, a laser light source that oscillates laser light is selected from the plurality of laser light sources 95a, 95b, and 95c provided in the laser light source group 95. The laser beam is oscillated from.

  That is, in the case of single point ignition at the cylinder head 40 side position, laser light is oscillated from the laser light source 95a. When laser light is oscillated from the laser light source 95a, this laser light is incident on the Q-switch type fiber laser 96a. As a result, the Q-switched fiber laser 96a to which the laser light is incident is excited, and the laser light is oscillated from the Q-switched fiber laser 96a toward the emission optical system 97a (oscillation pattern 1). Then, laser light is emitted from the emission optical system 97 a to the cylinder head 40 side position of the combustion chamber 44 through the emission window 30, and one-point ignition is performed at the cylinder head 40 side position of the combustion chamber 44.

  Further, in the case of single point ignition at an intermediate position of the combustion chamber 44, laser light is oscillated from the laser light source 95b. When laser light is oscillated from the laser light source 95b, this laser light is incident on the Q-switch type fiber laser 96b. As a result, the Q-switched fiber laser 96b to which the laser light is incident is excited, and the laser light is oscillated from the Q-switched fiber laser 96b toward the emission optical system 97b (oscillation pattern 2). Then, laser light is emitted from the emission optical system 97 b to the intermediate position of the combustion chamber 44 through the emission window 30, and one-point ignition is performed at the intermediate position of the combustion chamber 44.

  Further, when one-point ignition is performed at the position on the piston 42 side of the combustion chamber 44, laser light is oscillated from the laser light source 95c. When laser light is oscillated from the laser light source 95c, this laser light is incident on the Q-switch type fiber laser 96c. As a result, the Q-switched fiber laser 96c to which the laser light is incident is excited, and the laser light is oscillated from the Q-switched fiber laser 96c toward the emission optical system 97c (oscillation pattern 3). Then, laser light is emitted from the emission optical system 97 c to the piston 42 side position of the combustion chamber 44 through the emission window 30, and one-point ignition is performed at the piston 42 side position of the combustion chamber 44.

  In the case of multipoint ignition (two-point ignition), laser light is oscillated from two of the laser light sources 95a, 95b, and 95c (oscillation patterns 4 to 6), and multipoint ignition (three-point ignition) is performed. In this case, laser light is oscillated from all of the laser light sources 95a, 95b, and 95c (oscillation pattern 7).

  As described above, in the present embodiment, the laser light oscillated from the fiber laser group 96 by selecting the laser light source that oscillates the laser light among the plurality of laser light sources 95a, 95b, and 95c provided in the laser light source group 95. By changing the oscillation patterns, the number of condensing numbers and the condensing position of the laser light emitted from the respective emitting optical systems 97a, 97b, 97c into the combustion chamber 44 are changed, and the number of ignitions and the ignition position are changed. Each of the Q-switch type fiber lasers 96a, 96b, and 96c has emission optical systems 97a, 97b, and 97c including lenses and prisms, and collects light while deflecting the laser light to an arbitrary place in the combustion chamber. Can be made.

  Next, operations and effects of the laser ignition device 90 for an internal combustion engine according to the sixth embodiment of the present invention will be described.

  As described above in detail, in the laser ignition device 90 for an internal combustion engine according to the sixth embodiment of the present invention, at least one of the condensing number and the condensing position of the laser light emitted into the combustion chamber 44, that is, the ignition number. In order to change at least one of the ignition position, a laser light source that oscillates laser light is selected from the plurality of laser light sources 95a, 95b, and 95c provided in the laser light source group 95, and the laser light is oscillated from the laser light source. Just good.

  According to this configuration, in order to change at least one of the condensing number and the condensing position of the laser light emitted into the combustion chamber 44, that is, at least one of the ignition number and the ignition position, It is not necessary to move the optical system that emits light (for example, in this embodiment, the outgoing optical systems 97a, 97b, and 97c). Therefore, a mechanical moving mechanism for moving the optical system is not necessary. As a result, it is possible to change at least one of the number of ignitions and the ignition position without being affected by vibrations or the like accompanying traveling of the vehicle.

  Further, in the laser ignition device 90 for an internal combustion engine according to the sixth embodiment of the present invention, in order to change the number of ignitions, laser light is emitted from a plurality of laser light sources 95a, 95b, and 95c provided in the laser light source group 95. Since it is only necessary to select a laser light source to oscillate and oscillate the laser light from the laser light source, it is possible to precisely set the number of condensing laser beams emitted from the respective emission optical systems 97a, 97b, 97c into the combustion chamber 44. it can. Thereby, it is possible to change the number of condensing laser beams emitted into the combustion chamber 44 without the light energy in the combustion chamber 44 increasing rapidly.

  Further, when changing the condensing position of the laser light emitted from the respective emission optical systems 97a, 97b, 97c into the combustion chamber 44, a plurality of laser light sources 95a, 95b, 95c provided in the laser light source group 95 are also provided. Therefore, it is only necessary to select a laser light source that oscillates laser light and oscillate the laser light from the laser light source.

  Further, in the laser ignition device 90 for an internal combustion engine according to the sixth embodiment of the present invention, the condensing position or deflection angle of each of the emission optical systems 97a, 97b, 97c can be freely set, so that multipoint ignition is performed. In this case, the ignition positions in the combustion chamber 44 can be sufficiently separated from each other.

  Further, according to the laser ignition device 90 for an internal combustion engine according to the sixth embodiment of the present invention, as in the laser ignition device 10 for the internal combustion engine according to the first embodiment, the combustion of the internal combustion engine is performed in the stratified combustion system. It becomes possible to keep the optimum state according to the driving situation. As a result, the combustion efficiency is improved by reducing unburned fuel, suppressing the generation of soot, and the like, and it is possible to obtain a highly efficient and low emission engine.

  Further, according to the laser ignition device 90 for an internal combustion engine according to the sixth embodiment of the present invention, knocking can be effectively suppressed even in the homogeneous combustion system, and thereby the compression ratio can be increased. Therefore, the thermal efficiency of the engine can be increased. In addition, since the number of ignitions can be reduced according to the operating conditions, it is possible to suppress excessive energy consumption required for ignition.

  Next, a modification of the laser ignition device 90 for an internal combustion engine according to the sixth embodiment of the present invention will be described.

  In the above embodiment, an EGR rate and engine speed during stratified operation, torque and engine speed during stratified operation, etc. are detected to generate an operating condition detection signal corresponding to the operating condition. Based on the ignition number map 36a and the ignition position map 36b shown in b), the ignition number is determined from the relationship between the EGR rate during stratified operation and the engine speed, and the relationship between the torque during stratified operation and the engine speed. However, the ignition position may be determined as follows.

  That is, the driving condition detection unit 18 detects, for example, the torque and engine speed during homogeneous operation as the driving condition of the vehicle. Based on the ignition number map 36a shown in FIG. The number of ignitions may be determined from the relationship with the number.

  Further, in the present embodiment, among the plurality of laser light sources 95a, 95b, and 95c provided in the laser light source group 95 so that the number and position of condensing of the laser light emitted into the combustion chamber 44 are changed. By selecting a laser light source that oscillates the laser light, the oscillation pattern of the laser light oscillated from the Q-switch type fiber laser group 96 is varied. The fiber laser group 96 oscillates by selecting a laser light source that oscillates laser light among the plurality of laser light sources 95a, 95b, and 95c provided in the laser light source group 95 so that at least one of the light positions is changed. The oscillation pattern of the laser beam may be different.

  In addition, the item detected as the driving state of the vehicle may be changed to other items according to the engine characteristics and the like, and the number of ignitions and the ignition position may be variously set according to the engine characteristics and the like.

[Seventh embodiment]
Next, a laser ignition device 100 for an internal combustion engine according to a seventh embodiment of the present invention will be described with reference to FIGS.

  The internal combustion engine laser ignition device 100 according to the seventh embodiment of the present invention is suitably used to ignite the combustion gas 46 in the combustion chamber 44 in an internal combustion engine provided in a vehicle such as a passenger car, for example. It is.

  As shown in FIG. 13, a laser ignition device 100 for an internal combustion engine according to a seventh embodiment of the present invention includes a laser light source 101, an optical fiber 102, a Q-switched solid-state laser 103, an output mirror 104, and a moving A mechanism 105, a convex lens 106, a control unit 107 as a control unit, and an operation state detection unit 18 as an operation state detection unit are provided as main components.

  The Q-switched solid-state laser 103 is composed of a Q-switched solid-state laser that can oscillate laser light, and the emission mirror 104 constitutes an optical resonator with the Q-switched solid-state laser 103. Further, the exit mirror 104 is disposed so as to be movable in the optical axis direction (X direction) with respect to the Q-switched solid-state laser 103. The moving mechanism 105 is configured to move the exit mirror 104 in the optical axis direction by a motor (not shown) or the like, and the laser light emitted from the exit mirror 104 is incident on the convex lens 106. Yes.

  At this time, in this embodiment, the oscillation characteristics of the laser light emitted from the emission mirror 104 are different depending on the distance between the emission mirror 104 and the Q-switched solid-state laser 103 in the optical axis direction. More specifically, the spread angle of the laser beam emitted from the emission mirror 104 can be changed according to the distance between the emission mirror 104 and the Q-switch type solid-state laser 103 in the optical axis direction. ing.

  In other words, as shown in FIG. 14A, the operating angle of the laser light emitted from the output mirror 104 is as follows when the output mirror 104 is moved to the position on the Q-switched solid-state laser 103 side. When the output mirror 104 is moved to a position away from the Q-switched solid-state laser 103 as shown in the operation principle diagram in FIG. The spread angle of the laser beam is narrow (oscillation pattern 2). The oscillation pattern is not limited to two types of cases where the spread angle is wide and narrow, and continuously changes according to the distance between the output mirror 104 and the Q-switched solid-state laser 103 in the optical axis direction. To do.

  In this embodiment, the Q-switched solid-state laser 103, the output mirror 104, the convex lens 106, and the housing case 32 are accommodated. The optical fiber 102 is introduced into one side of the housing case 32, and the other side of the housing case 32 is integrally fixed to the wall portion of the cylinder head 40. Further, the other side of the housing case 32 is isolated from the inside of the combustion chamber 44 by the emission window 30.

  The control unit 107 includes an engine controller 34 and a laser control device 109. The engine controller 34 is supplied with the driving condition detection signal output from the driving condition detector 18. When the engine controller 34 receives the driving condition detection signal output from the driving condition detection unit 18, the engine controller 34 generates a control command corresponding to the driving condition detection signal and outputs the control command to the laser control device 109 as described in detail later. It is like that.

  A control command output from the engine controller 34 is input to the laser control device 109. The laser control device 109 includes an arithmetic device and a storage device, and an ignition position map 36b (see FIG. 3B) is stored in the storage device.

  Further, when the laser controller 109 receives the control command output from the engine controller 34, the condensing position of the laser beam emitted from the convex lens 106 through the emission window 30 into the combustion chamber 44 is changed. The spread angle of the laser beam emitted from the emission mirror 104 is changed by controlling the moving mechanism 105 to move the emission mirror 104 in the optical axis direction.

  The driving condition detection unit 18 detects the driving condition detection signal corresponding to the driving condition by detecting, for example, the EGR rate and engine speed during stratified operation, the torque and engine speed during stratified operation, as the driving condition of the vehicle. It is generated and output to the engine controller 34.

  Next, the operation of the laser ignition device 100 for an internal combustion engine according to the seventh embodiment of the present invention will be described.

  First, the driving state detection unit 18 detects, for example, an EGR rate and engine speed during stratified operation, torque and number of rotation during stratified operation, and the like as the driving state of the vehicle. Then, the driving situation detection unit 18 generates a driving situation detection signal corresponding to the driving situation of these vehicles, and outputs this to the engine controller 34.

  When the engine controller 34 receives the driving condition detection signal output from the driving condition detection unit 18, the engine controller 34 generates a control command corresponding to the driving condition detection signal, and outputs this to the laser controller 109 together with the driving condition detection signal.

  When the control command output from the engine controller 34 is input, the laser control device 109 starts processing of the program shown in FIG. At this time, when the driving condition detection unit 18 detects, for example, the torque and engine speed during stratified operation as the driving condition of the vehicle, the laser control device 109 performs the stratified operation based on the driving condition detection signal. And the engine speed are detected (step S11).

  Subsequently, based on the torque and engine speed during stratified operation detected based on the driving condition detection signal, and the ignition position map 36b (see FIG. 3B), the torque and engine speed during stratified operation From this relationship, the ignition position is determined (step S12).

  In this case, when the engine speed increases and the torque increases, the fuel injection timing advances, and the optimal mixture position also moves to the piston 42 side. Accordingly, in this state, the ignition position is set to the piston 42 side. Set. On the other hand, when the engine speed decreases and the torque decreases, the optimum gas mixture position moves to the cylinder head 40 side. In this state, the ignition position is set on the cylinder head 40 side.

  Then, based on the ignition position determined as described above, the moving mechanism 105 is controlled to move the emission mirror 104 in the optical axis direction, thereby changing the spread angle of the laser light emitted from the emission mirror 104 (step). S13).

  That is, in the case of one point ignition at the cylinder head 40 side position, the moving mechanism 105 is controlled to move the exit mirror 104 to the Q switch type solid laser 103 side position. As a result, the spread angle of the laser light emitted from the emission mirror 104 is widened (oscillation pattern 1). Then, laser light is emitted from the convex lens 106 to the cylinder head 40 side position of the combustion chamber 44 through the emission window 30, and one-point ignition is performed at the cylinder head 40 side position of the combustion chamber 44.

  Further, in the case of single point ignition at the position on the piston 42 side, the moving mechanism 105 is controlled to move the exit mirror 104 to a position away from the Q switch type solid state laser 103. As a result, the spread angle of the laser light emitted from the emission mirror 104 is narrowed (oscillation pattern 2). Then, laser light is emitted from the convex lens 106 to the piston 42 side position of the combustion chamber 44 through the emission window 30, and one-point ignition is performed at the piston 42 side position of the combustion chamber 44.

  As described above, in this embodiment, the condensing position of the laser light emitted from the convex lens 106 into the combustion chamber 44 is changed by changing the oscillation pattern of the laser light oscillated from the laser light oscillation unit, and the ignition position is set. change.

  Next, operations and effects of the laser ignition device 100 for an internal combustion engine according to the seventh embodiment of the present invention will be described.

  As described above in detail, according to the laser ignition device 100 for an internal combustion engine according to the seventh embodiment of the present invention, the laser control device 109 controls the spread angle of the laser light emitted from the emission mirror 104. The condensing position of the laser light emitted from the convex lens 106 into the combustion chamber 44 can be freely changed. Thereby, the ignition position in the combustion chamber 44 can be arbitrarily set without being limited to a predetermined position.

  Further, according to the laser ignition device 100 for an internal combustion engine according to the seventh embodiment of the present invention, the condensing position of the laser light emitted into the combustion chamber 44 only by providing one emitting optical system on the cylinder head 40 or the like. Can be changed. As a result, it is not necessary to arrange the same number of emission optical systems as the ignition position in the combustion chamber 44 (conventionally, the same number of optical fibers as the ignition position are installed on the cylinder head or the like). The arrangement space can be omitted.

  Further, in the laser ignition device 100 for an internal combustion engine according to the seventh embodiment of the present invention, as described above, the ignition position in the combustion chamber 44 can be changed in accordance with the operating state of the vehicle. According to this configuration, even in the stratified combustion system, ignition at the optimum mixing position is always possible even if the optimum mixture position changes as the operating state changes. Therefore, it is possible to keep the combustion of the internal combustion engine in an optimum state in accordance with the driving situation of the vehicle. As a result, the combustion efficiency is improved by reducing unburned fuel, suppressing the generation of soot, and the like, and it is possible to obtain a highly efficient and low emission engine.

  In the above-described embodiment, the torque and engine revolution speed during stratified operation are detected to generate an operating condition detection signal corresponding to the operating condition, and based on the ignition position map 36b (see FIG. 3B), Although the ignition position is determined from the relationship between the torque during the stratified operation and the engine speed, it may be as follows.

  That is, the item detected as the driving state of the vehicle may be changed to other items according to the engine characteristics and the ignition position may be set variously according to the engine characteristics and the like.

  In the above-described embodiment, an example using a single-focus convex lens is shown. However, the number of ignitions can be changed by using the multi-focus lens.

[Eighth embodiment]
Next, a laser ignition device 110 for an internal combustion engine according to an eighth embodiment of the present invention will be described with reference to FIGS.

  The internal combustion engine laser ignition device 110 according to the eighth embodiment of the present invention is suitably used to ignite the combustion gas 46 in the combustion chamber 44 in an internal combustion engine provided in a vehicle such as a passenger car, for example. It is.

  As shown in FIG. 16, a laser ignition device 110 for an internal combustion engine according to an eighth embodiment of the present invention includes a laser light source 111, an optical fiber 112, a movable concave lens 113, a moving mechanism 114, and a bifocal lens. 28, a control unit 16 as a control unit, and an operation state detection unit 18 as an operation state detection unit are provided as main components.

  The laser light source 111 is configured to be able to oscillate laser light, and the laser light oscillated from the laser light source 111 enters the movable concave lens 113 via the optical fiber 112. The movable concave lens 113 is disposed so as to be movable in the optical axis direction of the laser light oscillated from the laser light source 111 via the optical fiber 112.

  The moving mechanism 114 is configured to move the movable concave lens 113 in the optical axis direction (X direction), so that the laser light emitted from the movable concave lens 113 is incident on the bifocal lens 28. It has become. The bifocal lens 28 has a central region 28a and a peripheral region 28b radially outside the central region 28a, and the central region 28a and the peripheral region 28b are connected to the combustion chamber via the exit window 30. The focal length of the laser light emitted into 44 is different. That is, the focal length is set short in the central region 28a, and the focal length is set long in the peripheral region 28b.

  At this time, in the present embodiment, the diameter of the laser beam emitted from the movable concave lens 113 and incident on the bifocal lens 28 is changed according to the distance between the movable concave lens 113 and the bifocal lens 28 in the optical axis direction. It is configured to be able to.

  That is, as shown in FIG. 17 (a), the movable concave lens 113 is emitted from the movable concave lens 113 and is incident on the bifocal lens 28 when the movable concave lens 113 is moved away from the bifocal lens 28. In the state where the movable concave lens 113 is moved to the position on the bifocal lens 28 side as shown in FIG. 17B, the diameter of the laser beam to be emitted is emitted from the movable concave lens 113. The diameter of the laser beam incident on the bifocal lens 28 is increased. The diameter of the laser light emitted from the movable concave lens 113 and incident on the bifocal lens 28 continuously changes in accordance with the distance between the movable concave lens 113 and the bifocal lens 28 in the optical axis direction. .

  In the present embodiment, the movable concave lens 113 and the bifocal lens 28 are accommodated in the housing case 32. An optical fiber 112 is introduced into one side of the housing case 32, and the other side of the housing case 32 is integrally fixed to the wall portion of the cylinder head 40. Further, the other side of the housing case 32 is isolated from the inside of the combustion chamber 44 by the emission window 30.

  The control unit 16 includes an engine controller 34 and a laser control device 36. The engine controller 34 is supplied with the driving condition detection signal output from the driving condition detector 18. When the engine controller 34 inputs the driving condition detection signal output from the driving condition detection unit 18, the engine controller 34 generates a control command corresponding to the driving condition detection signal and outputs it to the laser control device 36 as will be described in detail later. It is like that.

  A control command output from the engine controller 34 is input to the laser control device 36. The laser control device 36 includes an arithmetic device and a storage device, and an ignition number map 36a and an ignition position map 36b (see FIG. 3), which will be described in detail later, are stored in the storage device.

  In addition, when the laser controller 36 receives the control command output from the engine controller 34, the number and position of condensing laser light emitted from the bifocal lens 28 into the combustion chamber 44 through the emission window 30. By moving the movable concave lens 113 in the direction of the optical axis by controlling the moving mechanism 114 so as to be changed, the diameter of the laser light emitted from the movable concave lens 113 and incident on the bifocal lens 28 is changed. ing.

  The driving condition detection unit 18 detects the driving condition detection signal corresponding to the driving condition by detecting, for example, the EGR rate and engine speed during stratified operation, the torque and engine speed during stratified operation, as the driving condition of the vehicle. It is generated and output to the engine controller 34.

  Next, the operation of the laser ignition device 110 for an internal combustion engine according to the eighth embodiment of the present invention will be described.

  First, the driving state detection unit 18 detects, for example, an EGR rate and engine speed during stratified operation, torque and number of rotation during stratified operation, and the like as the driving state of the vehicle. Then, the driving situation detection unit 18 generates a driving situation detection signal corresponding to the driving situation of these vehicles, and outputs this to the engine controller 34.

  When the engine controller 34 receives the driving condition detection signal output from the driving condition detection unit 18, the engine controller 34 generates a control command corresponding to the driving condition detection signal, and outputs this to the laser controller 36 together with the driving condition detection signal.

  When the laser control device 36 receives the control command output from the engine controller 34, the laser control device 36 starts the processing of the program shown in FIG. At this time, when the driving condition detection unit 18 detects the driving condition of the vehicle, for example, the EGR rate and engine speed during stratified operation, the torque and engine speed during stratified operation, the laser control device 36 Based on the driving condition detection signal, the EGR rate and the engine speed during the stratified operation, the torque and the engine speed during the stratified operation are detected (step S21).

  Subsequently, based on the EGR rate and engine speed during stratified operation detected based on the driving condition detection signal, and the ignition number map 36a (see FIG. 3A), the EGR rate and engine speed during stratified operation. The number of ignitions is determined from the relationship with the number (step S22).

  In this case, when the engine speed is low and the EGR rate is low, the ignitability of the air-fuel mixture in the combustion chamber 44 is relatively good, so that one-point ignition is performed to suppress power consumption. On the other hand, in a state where the engine speed is high and the EGR rate is high, the ignitability is inferior, so multipoint ignition (two-point ignition as an example in the present embodiment) is performed.

  Further, based on the torque and engine speed during stratification operation detected based on the driving condition detection signal, and the ignition position map 36b (see FIG. 3B), the torque and engine speed during stratification operation are calculated. The ignition position is determined from the relationship (step S23).

  In this case, when the engine speed increases and the torque increases, the fuel injection timing advances, and the optimal mixture position also moves to the piston 42 side. Accordingly, in this state, the ignition position is set to the piston 42 side. Set. On the other hand, when the engine speed decreases and the torque decreases, the optimum gas mixture position moves to the cylinder head 40 side. In this state, the ignition position is set on the cylinder head 40 side.

  Then, the movable concave lens 113 is moved in the optical axis direction by controlling the moving mechanism 114 based on the number of ignitions and the ignition position determined as described above (step S24).

  That is, in the case of single point ignition at the cylinder head 40 side position, the movable concave lens 113 is moved to the bifocal lens 28 position by controlling the moving mechanism 114. Thereby, a laser beam having a small diameter is emitted only from the movable concave lens 113 to the central region 28 a of the bifocal lens 28. Then, laser light is emitted from the center region 28 a of the bifocal lens 28 to the cylinder head 40 side position of the combustion chamber 44 through the emission window 30, and one-point ignition is performed at the cylinder head 40 side position of the combustion chamber 44.

  At this time, if the position of the movable concave lens 113 is adjusted within a range in which the laser light emitted from the movable concave lens 113 is incident on the central region 28 a of the bifocal lens 28, the laser light emitted into the combustion chamber 44. The condensing position is changed in a state where the number of condensing light is maintained at one.

  In the case of multipoint ignition (two-point ignition), the movable concave lens 113 is moved to a position away from the bifocal lens 28 by controlling the moving mechanism 114. Thereby, a laser beam having a large diameter is emitted from the movable concave lens 113 to the central region 28a and the peripheral region 28b of the bifocal lens 28. Laser light is emitted from the central region 28 a of the bifocal lens 28 and its peripheral region 28 b to the cylinder head 40 side position and the piston 42 side position of the combustion chamber 44 through the emission window 30, and the cylinder head 40 of the combustion chamber 44. Two-point ignition is performed at the side position and the piston 42 side position.

  At this time, if the position of the movable concave lens 113 is adjusted within a range in which the laser light emitted from the movable concave lens 113 is incident on the central region 28 a and the peripheral region 28 b of the bifocal lens 28, The condensing position is changed in a state where the number of condensing laser beams to be emitted is maintained in plural.

  As described above, in the present embodiment, the diameter of the laser light emitted from the movable concave lens 113 and incident on the bifocal lens 28 is changed by moving the movable concave lens 113 in the optical axis direction by controlling the moving mechanism 114. Thus, the number and position of condensing laser light emitted from the bifocal lens 28 into the combustion chamber 44 are changed, and the number of ignition and the ignition position are changed.

  Next, operations and effects of the laser ignition device 110 for an internal combustion engine according to the eighth embodiment of the present invention will be described.

  As described in detail above, according to the laser ignition device 110 for an internal combustion engine according to the eighth embodiment of the present invention, the movable concave lens 113 is moved in the optical axis direction and emitted from the movable concave lens 113, and the bifocal lens 28. By adjusting the diameter of the laser beam incident on the laser beam, the number of condensing laser beams emitted from the bifocal lens 28 into the combustion chamber 44 can be freely changed.

  Further, the laser beam emitted from the movable concave lens 113 by moving the movable concave lens 113 in the optical axis direction within a range in which the laser beam emitted from the movable concave lens 113 is incident on the central region 28 a of the bifocal lens 28. By adjusting the virtual focal position, the condensing position can be changed in a state where the number of condensing laser beams emitted into the combustion chamber 44 is maintained at one.

  Similarly, the movable concave lens 113 is moved in the optical axis direction within a range in which the laser light emitted from the movable concave lens 113 is incident on the central region 28a and the peripheral region 28b of the bifocal lens 28, thereby moving the movable concave lens 113. By adjusting the virtual focal position of the laser light emitted from the laser beam, the condensing position can be changed in a state where the number of condensing laser beams emitted into the combustion chamber 44 is maintained in plural.

  Thus, according to the laser ignition device 110 for an internal combustion engine according to the eighth embodiment of the present invention, the virtual focal position of the laser light emitted from the movable concave lens 113 by moving the movable concave lens 113 in the optical axis direction. By adjusting this, the condensing position of the laser light emitted from the bifocal lens 28 into the combustion chamber 44 can be freely changed. Thereby, the ignition position in the combustion chamber 44 can be arbitrarily set without being limited to a predetermined position.

  Further, according to the laser ignition device 110 for an internal combustion engine according to the eighth embodiment of the present invention, the number of condensing laser beams emitted into the combustion chamber 44 only by providing one emitting optical system on the cylinder head 40 or the like. And at least one of the light collecting positions can be changed. Accordingly, it is necessary to arrange the same number of emission optical systems as the number of ignitions or ignition positions in the combustion chamber 44 (in the past, the same number of optical fibers 112 as the number of ignitions or ignition positions were installed on the cylinder head 40 or the like). Therefore, it is possible to omit the arrangement space on the cylinder head 40 and the like.

  In the internal combustion engine laser ignition device 110 according to the eighth embodiment of the present invention, the focal length of the central region 28a and the focal length of the peripheral region 28b of the bifocal lens 28 can be freely set. Thereby, when performing multipoint ignition, the ignition positions in the combustion chamber 44 can be sufficiently separated from each other.

  Further, in the laser ignition device 110 for an internal combustion engine according to the eighth embodiment of the present invention, as described above, at least one of the number of ignitions and the ignition position in the combustion chamber 44 can be changed in accordance with the driving state of the vehicle. it can. According to this configuration, even in the stratified combustion system, ignition at the optimum mixing position is always possible even if the optimum mixture position changes as the operating state changes. Therefore, it is possible to keep the combustion of the internal combustion engine in an optimum state in accordance with the driving situation of the vehicle. As a result, the combustion efficiency is improved by reducing unburned fuel, suppressing the generation of soot, and the like, and it is possible to obtain a highly efficient and low emission engine.

  Further, according to the above-described configuration of the present embodiment, even in the homogeneous combustion system, multipoint ignition at the optimum position of the combustion chamber 44 is possible under knocking conditions, and knocking can be effectively suppressed. As a result, the compression ratio can be increased, and the thermal efficiency of the engine can be increased. Further, in the homogeneous combustion system, knocking is difficult when the torque is low or the engine speed is high, but in this embodiment, it is possible to perform one-point ignition in such a case. Thus, since the number of ignitions can be reduced according to the driving situation, it is possible to suppress excessive energy consumption required for ignition.

  Next, a modification of the laser ignition device 110 for an internal combustion engine according to the eighth embodiment of the present invention will be described.

  In the above embodiment, an EGR rate and engine speed during stratified operation, torque and engine speed during stratified operation, etc. are detected to generate an operating condition detection signal corresponding to the operating condition. Based on the ignition number map 36a and the ignition position map 36b shown in b), the ignition number is determined from the relationship between the EGR rate during stratified operation and the engine speed, and the relationship between the torque during stratified operation and the engine speed. However, the ignition position may be determined as follows.

  That is, the driving condition detection unit 18 detects, for example, the torque and engine speed during homogeneous operation as the driving condition of the vehicle. Based on the ignition number map 36a shown in FIG. The number of ignitions may be determined from the relationship with the number.

  In other words, at a low torque or high rotation speed that is difficult to knock, a single point ignition is performed to suppress power consumption. On the other hand, if the engine speed is decreased or the torque is increased, knocking is likely to occur in association with them, so at this time, multipoint ignition is performed. At this time, when two or more ignitions are performed in the combustion chamber 44, the number of regions having different focal lengths of the bifocal lens 28 may be made equal to the number of ignitions.

  Then, the diameter of the laser light emitted from the movable concave lens 113 and incident on the bifocal lens 28 may be adjusted by moving the movable concave lens 113 in the optical axis direction based on the determined number of ignitions.

  Further, in the present embodiment, the movable concave lens 113 is moved in the optical axis direction so as to change the condensing number and condensing position of the laser light emitted into the combustion chamber 44 and is emitted from the movable concave lens 113. Although the diameter of the laser light incident on the bifocal lens 28 is adjusted, the movable concave lens 113 is changed so that at least one of the number of condensing numbers and the condensing position of the laser light emitted into the combustion chamber 44 is changed. The diameter of the laser beam emitted from the movable concave lens 113 and incident on the bifocal lens 28 may be adjusted by moving in the optical axis direction.

  In addition, the item detected as the driving state of the vehicle may be changed to other items according to the engine characteristics and the like, and the number of ignitions and the ignition position may be variously set according to the engine characteristics and the like.

In the above embodiment, the bifocal lens 28 according to the present invention is configured by the bifocal lens 28. However, the number of lens regions having different focal lengths is not limited to two, and is two or more. Also good. Further, although the focal length of the central region 28a is shorter than the focal length of the peripheral region 28b, it may be longer. Further, the method of making the laser light incident on the movable concave lens 113 is not limited to the optical fiber 112.
[Ninth embodiment]
Next, a laser ignition device 130 for an internal combustion engine according to a ninth embodiment of the present invention will be described with reference to FIGS.

  In the laser ignition device 130 for an internal combustion engine according to the ninth embodiment of the present invention, the laser light oscillated from the laser light source 121 is incident on the condenser lens 133 via the optical fiber 122. Further, the laser light emitted from the condenser lens 133 is made incident on each of the refractive surfaces 136a, 134b, 134c, and 134d (see FIG. 20) of the multi-wedge base 132.

  The multi-wedge base 132 is rotatably arranged with the direction orthogonal to the optical axis direction of the laser light emitted from the condensing lens 133 as a rotation axis, and the laser light emitted from the condensing lens 133 in different directions. A plurality of refracting surfaces 136a, 134b, 134c, and 134d (see FIG. 20) that refract and exit into the combustion chamber 44 are provided in the rotational direction. The rotation mechanism 134 is configured to rotate the multi-wedge base 132 with a direction orthogonal to the optical axis direction of the laser light emitted from the condenser lens 133 as a rotation axis. In the present embodiment, the condenser lens 133 and the multi-wedge base 132 are accommodated in the housing case 32.

  When the laser controller 129 receives the control command output from the engine controller 34, the condensing position of the laser light emitted from the multi-wedge base 132 through the emission window 30 into the combustion chamber 44 is changed. In this way, by rotating the multi-wedge base 132 by controlling the rotation mechanism 134, the direction of the laser light emitted from the multi-wedge base 132 into the combustion chamber 44 is changed.

  Next, the operation of the laser ignition device 130 for an internal combustion engine according to the ninth embodiment of the present invention will be described.

  In the laser ignition device 130 for an internal combustion engine according to the ninth embodiment of the present invention, based on the torque and engine speed and the ignition position map 36b at the time of stratification operation detected based on the operation state detection signal, at the time of stratification operation. The ignition position is determined from the relationship between the torque and the engine speed.

  Then, by rotating the multi-wedge base 132 by controlling the rotation mechanism 134 based on the ignition position determined as described above, the direction of the laser light emitted from the multi-wedge base 132 into the combustion chamber 44 is changed. change.

  That is, in the case of one-point ignition at the cylinder head 40 side position, the rotation mechanism 134 is controlled to rotate the multi-wedge base 132, and the plurality of refractive surfaces 136a, 134b, 134c, 134d (see FIG. 20). Of these, the laser beam emitted from the condenser lens 133 is made incident on the refracting surface having a predetermined refraction direction. As a result, laser light is emitted from the multi-wedge base 132 to the cylinder head 40 side position of the combustion chamber 44 through the emission window 30, and one-point ignition is performed at the cylinder head 40 side position of the combustion chamber 44.

  Further, in the case of single point ignition at the position on the piston 42 side, the rotation mechanism 134 is controlled to rotate the multi-wedge base 132, and among the plurality of refractive surfaces 136a, 134b, 134c, 134d (see FIG. 20). The laser beam emitted from the condenser lens 133 is made incident on the refracting surface having a predetermined refraction direction. As a result, laser light is emitted from the multi-wedge base 132 to the cylinder head 40 side position of the combustion chamber 44 through the emission window 30, and one-point ignition is performed at the cylinder head 40 side position of the combustion chamber 44.

  As described above, in the present embodiment, the multi-wedge base 132 is rotated and emitted from the condensing lens 133 to a refracting surface having a predetermined refraction direction among the plurality of refracting surfaces 136a, 134b, 134c, and 134d (see FIG. 20). The laser light emitted from the multi-wedge base 132 into the combustion chamber 44 is changed by allowing the laser light to enter, thereby changing the ignition position.

  Next, operations and effects of the laser ignition device 130 for an internal combustion engine according to the ninth embodiment of the present invention will be described.

  As described above in detail, according to the laser ignition device 130 for an internal combustion engine according to the ninth embodiment of the present invention, laser light can be condensed at different positions in the combustion chamber 44 by one multi-wedge base 132. In addition, the multi-wedge base 132 can be rotated by one rotation mechanism 134. As a result, the structure of the laser ignition device 130 for an internal combustion engine using a wedge base can be reduced in size.

  Further, according to the laser ignition device 130 for an internal combustion engine according to the ninth embodiment of the present invention, the inside of the combustion chamber 44 can be provided only by providing one emission optical system in the cylinder bore 48 (may be provided in the cylinder head 40). The condensing position of the emitted laser light can be changed. As a result, there is no need to arrange the same number of emission optical systems as the ignition position in the combustion chamber 44 (conventionally, the same number of optical fibers as the ignition position have been installed on the cylinder head or the like). It is possible to omit the arrangement space such as 40.

  In the internal combustion engine laser ignition device 130 according to the ninth embodiment of the present invention, as described above, the ignition position in the combustion chamber 44 can be changed in accordance with the operating state of the vehicle. According to this configuration, even in the stratified combustion system, ignition at the optimum mixing position is always possible even if the optimum mixture position changes as the operating state changes. Therefore, it is possible to keep the combustion of the internal combustion engine in an optimum state in accordance with the driving situation of the vehicle. As a result, the combustion efficiency is improved by reducing unburned fuel, suppressing the generation of soot, and the like, and it is possible to obtain a highly efficient and low emission engine.

  In the above-described embodiment, the torque and engine revolution speed during stratified operation are detected to generate an operating condition detection signal corresponding to the operating condition, and based on the ignition position map 36b (see FIG. 3B), Although the ignition position is determined from the relationship between the torque during the stratified operation and the engine speed, it may be as follows.

  That is, the item detected as the driving state of the vehicle may be changed to other items according to the engine characteristics and the ignition position may be set variously according to the engine characteristics and the like.

[Tenth embodiment]
Next, a laser ignition device 140 for an internal combustion engine according to a tenth embodiment of the present invention will be described with reference to FIG.

  In the laser ignition device 140 for an internal combustion engine according to the tenth embodiment of the present invention, the laser light oscillated from the laser light source 121 is incident on the fθ lens 135 via the galvanometer mirror 138. The laser light emitted from the fθ lens 135 is incident on the refractive surfaces 136a, 136b, and 136c of the multi-prism 136.

  The galvanometer mirror 138 is rotatably disposed around a direction orthogonal to the optical axis direction of the laser light oscillated from the laser light source 121 and has a plurality of reflecting surfaces that reflect the laser light oscillated from the laser light source 121. Configured. The rotation mechanism 134 is configured to rotate the galvanometer mirror 138 about a direction orthogonal to the optical axis direction of the laser light oscillated from the laser light source 121 as a rotation axis.

  The fθ lens 135 is configured to collect the laser light reflected by the galvanometer mirror 138, and the multi-prism 136 refracts the laser light emitted from the fθ lens 135 in different directions in the combustion chamber 44. The plurality of refracting surfaces 136a, 136b, and 136c are provided. In the present embodiment, the fθ lens 135 and the multiprism 136 are accommodated in the housing case 32.

  When the control command output from the engine controller 34 is input, the laser control device 129 controls the rotation mechanism 134 so that the condensing position of the laser light emitted from the multi-prism 136 into the combustion chamber 44 is changed. By rotating the galvanometer mirror 138, the direction of the laser beam emitted from the multi-prism 136 into the combustion chamber 44 is changed.

  Next, the operation of the laser ignition device 140 for an internal combustion engine according to the tenth embodiment of the present invention will be described.

  In the internal combustion engine laser ignition device 140 according to the tenth embodiment of the present invention, based on the stratified operation torque and engine speed detected based on the operating condition detection signal and the ignition position map 36b, during the stratified operation. The ignition position is determined from the relationship between the torque and the engine speed.

  Then, the direction of the laser beam emitted from the multi-prism 136 into the combustion chamber 44 is changed by controlling the rotation mechanism 134 based on the ignition position determined as described above and rotating the galvano mirror 138.

  That is, in the case of one-point ignition at the cylinder head 40 side position, the rotation mechanism 134 is controlled to rotate the galvanometer mirror 138 to thereby rotate the fθ lens 135 on the refractive surface 136a among the plurality of refractive surfaces of the multi-prism 136. The laser beam emitted from the laser beam is made incident. Thus, laser light is emitted from the multi-prism 136 to the cylinder head 40 side position of the combustion chamber 44 through the emission window 30, and one-point ignition is performed at the cylinder head 40 side position of the combustion chamber 44.

  Further, in the case of one-point ignition at an intermediate position in the combustion chamber 44, the rotation mechanism 134 is controlled to rotate the galvano mirror 138, so that the fθ lens is applied to the refractive surface 136 b among the plurality of refractive surfaces of the multiprism 136. The laser beam emitted from 135 is made incident. As a result, the laser beam is emitted from the multi-prism 136 to the intermediate position of the combustion chamber 44 through the emission window 30, and one-point ignition is performed at the intermediate position of the combustion chamber 44.

  Further, in the case of one-point ignition at the position on the piston 42 side, the rotation mechanism 134 is controlled to rotate the galvanometer mirror 138, so that the refraction surface 136 c among the plurality of refraction surfaces of the multi-prism 136 is moved from the fθ lens 135. The emitted laser light is made incident. Thus, laser light is emitted from the multi-prism 136 to the cylinder head 40 side position of the combustion chamber 44 through the emission window 30, and one-point ignition is performed at the cylinder head 40 side position of the combustion chamber 44.

  As described above, in the present embodiment, the laser light emitted from the fθ lens 135 to the refracting surface having a predetermined refraction direction among the plurality of refracting surfaces 136a, 136b, and 136c of the multi-prism 136 by rotating the galvanometer mirror 138. The incident position of the laser beam emitted from the multi-prism 136 into the combustion chamber 44 is changed to change the ignition position.

  Next, operations and effects of the laser ignition device 140 for an internal combustion engine according to the tenth embodiment of the present invention will be described.

  As described above in detail, according to the laser ignition device 140 for an internal combustion engine according to the tenth embodiment of the present invention, combustion can be performed only by providing one emission optical system in a cylinder bore (may be provided in the cylinder head 40) or the like. The condensing position of the laser beam emitted into the chamber 44 can be changed. As a result, there is no need to arrange the same number of emission optical systems as the ignition position in the combustion chamber 44 (conventionally, the same number of optical fibers as the ignition position have been installed on the cylinder head or the like). It is possible to omit the arrangement space such as 40.

  In the internal combustion engine laser ignition device 140 according to the tenth embodiment of the present invention, as described above, the ignition position in the combustion chamber 44 can be changed in accordance with the operating state of the vehicle. According to this configuration, even in the stratified combustion system, ignition at the optimum mixing position is always possible even if the optimum mixture position changes as the operating state changes. Therefore, it is possible to keep the combustion of the internal combustion engine in an optimum state in accordance with the driving situation of the vehicle. As a result, the combustion efficiency is improved by reducing unburned fuel, suppressing the generation of soot, and the like, and it is possible to obtain a highly efficient and low emission engine.

  In the above-described embodiment, the torque and engine revolution speed during stratified operation are detected to generate an operating condition detection signal corresponding to the operating condition, and based on the ignition position map 36b (see FIG. 3B), Although the ignition position is determined from the relationship between the torque during the stratified operation and the engine speed, it may be as follows.

  That is, the item detected as the driving state of the vehicle may be changed to other items according to the engine characteristics and the ignition position may be set variously according to the engine characteristics and the like.

  Further, as shown in FIG. 22, a polygon mirror 139 is used instead of the galvanometer mirror 138, and by rotating the polygon mirror 139, the condensing position of the laser light emitted from the multi-prism 136 into the combustion chamber 44 is changed. It is also possible to change the ignition position.

FIG. 1 is a diagram showing a configuration of a laser ignition device for an internal combustion engine according to the first embodiment of the present invention. FIG. 2 is a diagram showing the operating principle of the laser ignition device for an internal combustion engine according to the first embodiment of the present invention. FIG. 3A is a diagram showing an ignition number map according to the first embodiment of the present invention, and FIG. 3B is a diagram showing an ignition position map according to the first embodiment of the present invention. FIG. 4 is a diagram showing the operation of the laser control apparatus according to the first embodiment of the present invention. FIG. 5 is a view showing a modification of the ignition number map according to the first embodiment of the present invention. FIG. 6 is a diagram showing a configuration of a laser ignition device for an internal combustion engine according to the second embodiment of the present invention. FIG. 7 is a view showing a configuration of a laser ignition device for an internal combustion engine according to the third embodiment of the present invention. FIG. 8 is a view showing a configuration of a laser ignition device for an internal combustion engine according to the fourth embodiment of the present invention. FIG. 9 is an explanatory view showing a Q-switched solid-state laser according to the fourth embodiment of the present invention. FIG. 10 is a diagram showing a configuration of a laser ignition device for an internal combustion engine according to the fifth embodiment of the present invention. FIG. 11 is a diagram showing a Q-switched solid-state laser and an optical fiber group according to the fifth embodiment of the present invention. FIG. 12 is a view showing a configuration of a laser ignition device for an internal combustion engine according to the sixth embodiment of the present invention. FIG. 13 is a diagram showing a configuration of a laser ignition device for an internal combustion engine according to the seventh embodiment of the present invention. FIG. 14 is a diagram showing the operating principle of the laser ignition device for an internal combustion engine according to the seventh embodiment of the present invention. FIG. 15 is a view showing the operation of the laser control apparatus according to the seventh embodiment of the present invention. FIG. 16 is a view showing a configuration of a laser ignition device for an internal combustion engine according to the eighth embodiment of the present invention. FIG. 17 is a view showing the operating principle of the laser ignition device for an internal combustion engine according to the eighth embodiment of the present invention. FIG. 18 is a diagram showing the operation of the laser control apparatus according to the eighth embodiment of the present invention. FIG. 19 is a diagram showing a configuration of a laser ignition device for an internal combustion engine according to the ninth embodiment of the present invention. FIG. 20 is a diagram showing the configuration of the multi-wedge base according to the ninth embodiment of the present invention. FIG. 21 is a diagram showing a configuration of a laser ignition device for an internal combustion engine according to the tenth embodiment of the present invention. FIG. 22 is a view showing a modification of the laser ignition device for an internal combustion engine according to the tenth embodiment of the present invention.

Explanation of symbols

10, 50, 60, 70, 80, 90, 100, 110, 130, 140 Laser ignition device for internal combustion engine 12, 72, 82, 92 Laser light oscillation unit (laser light oscillation means)
14, 94 Laser light emitting part (laser light emitting means)
16, 107, 126 Control unit (control means)
18 Driving status detection unit (Driving status detection means)
20, 73, 83, 95 Laser light source groups 24, 74, 84 Lens array 26, 62, 76, 86, 103 Q-switched solid-state laser 28 Bifocal lens (multifocal lens)
34 Engine controller (control means)
36 Laser control device (control means)
44 Combustion chamber 46 Combustion gas 52 Lens group 54 Multi prism 96 Q-switch type fiber laser groups 97a, 97b, 97c Emitting optical system 104 Emitting mirrors 105, 114, 124 Moving mechanism 106 Convex lenses 111, 121 Laser light source 113 Movable concave lens 123 Movable Type convex lens 132 multi-wedge base 133 condensing lens 134 rotating mechanism 135 fθ lens 136 multi-prism 138 galvanometer mirror (reflection mirror)
139 Polygon mirror (reflection mirror)

Claims (14)

In a laser ignition device for an internal combustion engine that ignites combustion gas in the combustion chamber by condensing laser light in the combustion chamber of the internal combustion engine,
A laser beam oscillation means capable of oscillating a plurality of laser beams having different oscillation patterns;
The laser beam emitted from the laser beam oscillation means is incident on the laser beam, and the laser beam is emitted into the combustion chamber. Laser light emitting means for changing the laser light emitted from the light oscillating means according to the oscillation pattern;
Control to vary the oscillation pattern of the laser light oscillated from the laser light oscillation means so that at least one of the number of condensing numbers and the position of the laser light emitted from the laser light emitting means into the combustion chamber is changed. Means,
A laser ignition device for an internal combustion engine, comprising: The laser light oscillation means includes a laser light source group including a plurality of laser light sources capable of oscillating laser light,
A lens array including a plurality of lenses on which each laser beam oscillated from the laser light source group is incident and focuses each laser beam;
Each laser beam emitted from the lens array is condensed and configured to have a Q-switched solid-state laser capable of oscillating the laser beam from a position corresponding to the condensing position of each laser beam,
The laser beam emitting means receives each laser beam oscillated from the Q-switched solid-state laser and emits laser beam emitted into the combustion chamber in a central region and a peripheral region radially outside the central region. Consists of multifocal lenses with different focal lengths,
The control unit is configured to emit laser light from a plurality of laser light sources provided in the laser light source group so that at least one of the number of condensing numbers and the condensing position of laser light emitted from the multifocal lens into the combustion chamber is changed. A laser light source that oscillates light is selected, and laser light is oscillated from the laser light source, whereby the laser light is oscillated from a position corresponding to the converging position of the laser light in the Q-switched solid-state laser. Item 2. A laser ignition device for an internal combustion engine according to Item 1. The laser light oscillation means includes a laser light source group including a plurality of laser light sources capable of oscillating laser light,
A lens array including a plurality of lenses on which each laser beam oscillated from the laser light source group is incident and focuses each laser beam;
Each laser beam emitted from the lens array is condensed and configured to have a Q-switched solid-state laser capable of oscillating the laser beam from a position corresponding to the condensing position of each laser beam,
The laser beam emitting means includes a lens group including a plurality of lenses on which each laser beam oscillated from the Q-switched solid-state laser is incident and collects each laser beam;
A multi-prism having a plurality of refractive surfaces on which each laser beam emitted from the lens group is incident and which refracts each laser beam in different directions in the combustion chamber,
The control means is configured to emit laser light from a plurality of laser light sources provided in the laser light source group so that at least one of the number of condensing numbers and condensing positions of laser light emitted from the multi-prism into the combustion chamber is changed. The laser light is oscillated from a position corresponding to a condensing position of the laser light in the Q-switch type solid-state laser by selecting a laser light source that oscillates and oscillating laser light from the laser light source. 2. A laser ignition device for an internal combustion engine according to 1. The laser light oscillation means includes a laser light source capable of oscillating laser light,
A lens on which the laser light oscillated from the laser light source is incident and collects the laser light;
A Q-switch type solid-state laser that is capable of oscillating a laser beam having a spread angle corresponding to the intensity distribution of the laser beam while condensing the laser beam emitted from the lens,
The laser beam emitting means receives the laser beam oscillated from the Q-switched solid-state laser and focuses the laser beam emitted into the combustion chamber in a central region and a peripheral region radially outside the central region. Consists of multifocal lenses with different distances,
The control means controls the intensity distribution of the laser light oscillated from the laser light source so that at least one of the number of condensing and the condensing position of the laser light emitted from the multifocal lens into the combustion chamber is changed. 2. The laser ignition device for an internal combustion engine according to claim 1, wherein the spread angle of the laser light oscillated from the Q-switched solid-state laser is changed. The laser light oscillation means includes a laser light source group including a plurality of laser light sources capable of oscillating laser light,
A fiber laser group including a plurality of Q-switched fiber lasers that receive each laser beam oscillated from the laser light source group and are excited by each laser beam to oscillate the laser beam. ,
The laser beam emitting means receives a plurality of laser beams emitted from the fiber lasers of the fiber laser group and collects the laser beams in the combustion chamber while condensing or deflecting the laser beams. Configured with a system,
The control means includes a plurality of laser light sources provided in the laser light source group so that at least one of the number of condensing numbers and condensing positions of laser light emitted from the plurality of emitting optical systems into the combustion chamber is changed. 2. The internal combustion engine according to claim 1, wherein a laser beam is emitted from a fiber laser of the fiber laser group by selecting a laser light source that oscillates laser light from the laser light source and oscillating the laser light from the laser light source. Laser ignition device. Comprising driving state detecting means for detecting the driving state of the vehicle;
The control means changes at least one of the number of condensing numbers and the condensing position of the laser light emitted from the laser light emitting means into the combustion chamber in accordance with the operating condition detected by the operating condition detecting means. The laser ignition device for an internal combustion engine according to any one of claims 1 to 5, wherein the oscillation pattern of the laser beam oscillated from the laser beam oscillation means is varied. In a laser ignition device for an internal combustion engine that ignites combustion gas in the combustion chamber by condensing laser light in the combustion chamber of the internal combustion engine,
A Q-switched solid-state laser capable of oscillating laser light;
A laser beam that is arranged to be movable in the optical axis direction with respect to the solid-state laser, and that forms an optical resonator with the solid-state laser and has a spread angle corresponding to a distance apart from the solid-state laser in the optical axis direction. An output mirror capable of emitting
A moving mechanism for moving the exit mirror in the optical axis direction;
A convex lens that receives the laser beam emitted from the exit mirror and emits the laser beam into the combustion chamber;
Laser light emitted from the exit mirror by moving the exit mirror in the optical axis direction by controlling the moving mechanism so that the condensing position of the laser light emitted from the convex lens into the combustion chamber is changed. Control means for changing the spread angle of
A laser ignition device for an internal combustion engine, comprising: Comprising driving state detecting means for detecting the driving state of the vehicle;
The control means controls the moving mechanism so that the condensing position of the laser light emitted from the convex lens into the combustion chamber is changed in accordance with the operating condition detected by the operating condition detecting means, and the emission is performed. The laser ignition device for an internal combustion engine according to claim 7, wherein a spread angle of the laser light emitted from the emission mirror is changed by moving the mirror in the optical axis direction. In a laser ignition device for an internal combustion engine that ignites combustion gas in the combustion chamber by condensing laser light in the combustion chamber of the internal combustion engine,
A laser light source capable of oscillating laser light;
A movable concave lens on which laser light oscillated from the laser light source is incident and which is arranged to be movable in the optical axis direction of the laser light;
A moving mechanism for moving the movable concave lens in the optical axis direction;
A multifocal lens in which the laser light emitted from the movable concave lens is incident and the focal length of the laser light emitted into the combustion chamber is different between a central region and a peripheral region radially outward from the central region;
The movable concave lens is moved in the optical axis direction by controlling the moving mechanism so that at least one of the number of condensings and the condensing position of laser light emitted from the multifocal lens into the combustion chamber is changed. Control means for changing the diameter of the laser light incident on the multifocal lens by:
A laser ignition device for an internal combustion engine, comprising: Comprising driving state detecting means for detecting the driving state of the vehicle;
The control means is configured to change at least one of the number of condensing numbers and the condensing position of the laser light emitted from the multifocal lens into the combustion chamber according to the operating condition detected by the operating condition detecting means. 10. The laser ignition for an internal combustion engine according to claim 9, wherein the diameter of the laser light incident on the multifocal lens is changed by controlling the moving mechanism to move the movable concave lens in the optical axis direction. apparatus. In a laser ignition device for an internal combustion engine that ignites combustion gas in the combustion chamber by condensing laser light in the combustion chamber of the internal combustion engine,
A laser light source capable of oscillating laser light;
A condenser lens that condenses the laser light emitted from the laser light source;
The laser beam emitted from the condenser lens is rotatably arranged with the direction intersecting with the optical axis direction of the laser light as a rotation axis, and the laser beams emitted from the condenser lens are refracted in different directions to enter the combustion chamber. A multi-wedge base configured with a plurality of refracting surfaces in the rotational direction;
A rotation mechanism that rotates the multi-wedge base around a direction that intersects the optical axis direction of the laser light emitted from the condenser lens;
The rotation mechanism is controlled to rotate the multi-wedge base so that the condensing position of the laser light emitted from the multi-wedge base into the combustion chamber is changed, and the multi-wedge base is emitted into the combustion chamber. Control means for changing the direction of the laser beam to be emitted;
A laser ignition device for an internal combustion engine, comprising: Comprising driving state detecting means for detecting the driving state of the vehicle;
The control means controls the rotation mechanism so that the condensing position of the laser light emitted from the multi-wedge base into the combustion chamber is changed according to the operating condition detected by the operating condition detecting means. The laser ignition device for an internal combustion engine according to claim 11, wherein the direction of laser light emitted from the multi-wedge base into the combustion chamber is changed by rotating the multi-wedge base. In a laser ignition device for an internal combustion engine that ignites combustion gas in the combustion chamber by condensing laser light in the combustion chamber of the internal combustion engine,
A laser light source capable of oscillating laser light;
A reflection mirror that is rotatably arranged with a direction intersecting the optical axis direction of the laser light oscillated from the laser light source as a rotation axis and reflects the laser light oscillated from the laser light source;
A rotation mechanism that rotates the reflection mirror around a direction that intersects the optical axis direction of the laser light emitted from the laser light source;
An fθ lens on which the laser beam reflected by the reflecting mirror is incident and collects the laser beam;
A multi-prism having a plurality of refracting surfaces on which laser light emitted from the fθ lens is incident and refracted in different directions in the combustion chamber;
A laser emitted from the multi-prism into the combustion chamber by controlling the rotating mechanism and rotating the reflecting mirror so that a condensing position of laser light emitted from the multi-prism into the combustion chamber is changed. Control means for changing the direction of the light;
A laser ignition device for an internal combustion engine, comprising: Comprising driving state detecting means for detecting the driving state of the vehicle;
The control means controls the rotating mechanism so that the condensing position of the laser light emitted from the multi-prism into the combustion chamber is changed according to the operating condition detected by the operating condition detecting means. The laser ignition device for an internal combustion engine according to claim 13, wherein the direction of laser light emitted from the multi-prism into the combustion chamber is changed by rotating a reflection mirror.

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