JP2006009585A - Laser ignition device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser ignition device capable of optionally changing an ignition position in a combustion chamber of an engine for a vehicle. <P>SOLUTION: The laser ignition device has a cylindrical case 10; a laser unit 20 enclosed in the case 10 and emitting laser beams; an electronic shutter 30 disposed on an optical axis of the laser beams and transmitting or intercepting the laser beams; a condensing lens 60 for condensing laser beams irradiated from the laser unit 20; a pedestal 50 formed in hollow cylinder shape and fixing the condensing lens 60 inclined at a desired angle to a plane perpendicular to the optical axis of the laser beams; and a superconductive motor 40 for rotating the pedestal 50 around the optical axis of the laser beams. The condensing lens 60 is fixed to the pedestal 50 being inclined so that a diameter of a circle described by the focal points of laser beams by the rotation of the condensing lens 60 is at least 3.5 mm. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a laser ignition device that uses a laser to ignite an engine combustion chamber in a vehicle engine.

  Conventionally, an ignition device using a laser has been proposed as an ignition device for a vehicle engine. In such an ignition device using a laser, attention has been paid as being able to irradiate and condense a laser at an arbitrary position in an engine combustion chamber at an arbitrary timing to ignite.

  As the above-described laser ignition device, one that swings the focal position of laser light, that is, the ignition position, has been proposed (see, for example, Patent Document 1). In this laser ignition device, the laser beam of the laser is condensed by a lens, and a prism is arranged between this lens and the ignition position which is the focal position of the lens, and this prism is rotated. Thus, the ignition position on the upper surface of the piston is swung.

On the other hand, a laser ignition device that can move the focal position of laser light in the direction of the optical axis of the laser has been proposed (see, for example, Patent Document 2). The laser ignition device is installed for each cylinder on the cylinder side surface of the engine. The laser ignition device has a variable focus unit including a condensing lens, and the focal point of the condensing lens provided in the variable focus unit is moved in the optical axis direction so that the ignition position is illuminated. It is moved in the axial direction.
Japanese Patent Laid-Open No. 7-217521 JP-A-5-33755

  However, in a laser ignition device that swings the ignition position, the prism is rotated to swing the ignition position, but in order to avoid melting the upper surface of the piston that is the focal point of the lens, It is just shifting the focus position. Therefore, the focal position of the laser, that is, the ignition position is not arbitrarily changed.

  In the laser ignition device installed on the side surface of the cylinder, although the focal position of the laser beam can be changed, the focal position is limited to the optical axis of the laser beam.

  An object of the present invention is to provide a laser ignition device capable of arbitrarily changing an ignition position in a combustion chamber of a vehicle engine.

  In order to achieve the above object, according to the first aspect of the present invention, a cylindrical case (10, 12), a laser unit (20) that is housed in the case and emits laser light, and an optical axis of the laser light are provided. An electronic shutter (30) that is disposed above and transmits or blocks laser light, a condensing lens (60) that condenses laser light emitted from the laser unit, and a hollow cylindrical shape that emits laser light A pedestal (50) for tilting and fixing the condenser lens at a desired angle with respect to a plane perpendicular to the axis; and a pedestal driving means (40) for rotating the pedestal about the optical axis of the laser beam. It is a feature.

  In this way, the laser light is rotated around the optical axis of the laser light while the condenser lens is tilted. Thereby, the focal position of the laser beam can be arbitrarily moved. Also, it is possible to ignite at the focal point of the laser beam only when the laser beam is passed through the electronic shutter.

  Further, the focal point of the laser light moves so as to draw a circle according to the inclination of the condenser lens. Therefore, the focal point of the laser beam moving on the circumference of a circle having a predetermined diameter can be used as the ignition source. Thereby, the number of ignition points in the combustion chamber of the engine can be increased, and combustion after ignition can be promoted.

  In the invention according to claim 2, the condensing lens is tilted and fixed to the pedestal so that the diameter of the circle drawn by the focus of the laser beam by the rotation of the condensing lens is at least 3.5 mm or more. It is characterized by.

  Thus, the condenser lens is tilted and fixed so that the diameter of the circle drawn by the focus of the laser light is at least 3.5 mm or more. Thereby, the circle drawn by the focus of the laser beam at the time of ignition, that is, the size of the flame kernel can be set to 3.5 mm or more in advance, and combustion can be started immediately after ignition. Therefore, the combustion after ignition can be stabilized and the thermal efficiency can be improved.

  In the third aspect of the invention, the cylindrical case (10, 12), the laser unit (20) that emits laser light while being housed in the case, and disposed on the optical axis of the laser light, the laser light An electronic shutter (30) that transmits or blocks light, a condensing lens (60) that condenses the laser light emitted from the laser unit, and a plurality of concentrating lenses that are installed on the outer edge of the condensing lens and fix the condensing lens And a piezoelectric element (70) that expands and contracts according to the applied voltage.

  In this way, the condenser lens is fixed by a plurality of piezoelectric elements, and a voltage is applied to each piezoelectric element. Thereby, the focus position of a condensing lens can be moved arbitrarily. Furthermore, the focal position of the condensing lens can be moved in the optical axis direction of the laser light by expanding and contracting all the piezoelectric elements. Therefore, the focal point of the laser beam can be moved three-dimensionally in the combustion chamber of the engine.

  Further, when the laser light is transmitted through the electronic shutter, it is ignited at the focal point of the laser light. Therefore, multi-point ignition can be performed by the combination of the transmission of the laser light by the electronic shutter and the inclination of the condenser lens by the piezoelectric element. If multi-point ignition can be performed in this way, the flame propagation speed by ignition can be improved, and the combustion speed can be increased.

  In the fourth aspect of the invention, the focal length adjustment unit (80) is disposed between the electronic shutter and the condenser lens on the optical axis of the laser beam. A focal length adjustment lens (81) for adjusting the focal length of the optical lens, and a focal length adjustment lens driving means (82) for driving the focal length adjustment lens in the optical axis direction of the laser light, are configured. When the focal length adjustment lens is driven by the lens driving means, the focal length of the condenser lens is moved in the optical axis direction.

  In this way, the focal length adjustment unit is installed between the electronic shutter and the condenser lens. And the focal position of the optical axis direction of a condensing lens can be moved by this focal length adjustment unit. In this case, the focal position can be moved more in the optical axis direction by the focal length adjustment lens.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view of a laser ignition device according to a first embodiment of the present invention. FIG. 2 is a view showing a state in which the laser ignition device shown in FIG. 1 is installed in the cylinder head of the engine.

  As shown in FIG. 1, the laser ignition device includes a case 10, a laser unit 20, an electronic shutter 30, an ultrasonic motor 40, a pedestal 50, and a condenser lens 60. . In addition, in FIG. 1, the ultrasonic motor 40, the base 50, and the condensing lens 60 are schematic sectional drawings.

  The case 10 is a cylindrical housing and includes a cooling medium 11 and a glass window 12. The cooling medium 11 sucks heat generated from a laser unit 20 described later, and is composed of, for example, a Peltier element. The glass window 12 is a window that is irradiated with laser light from the case 10. The glass window 12 is disposed on one end side of the case 10 and is integrated with the case 10.

  In such a case 10, as shown in FIG. 2, one end side (glass window 12 side) of the case 10 is inserted into a hole 111 formed in the upper surface of the cylinder head 110 of the engine 100 to be integrated. .

  The laser unit 20 emits laser light. The laser unit 20 includes a semiconductor laser 21, a YAG crystal 22, a wiring 23, and an electrode 24.

  The semiconductor laser 21 is a known laser light source. The YAG crystal 22 is a well-known yttrium (Y) / aluminum (Al) / garnet (G) crystal. The wiring 23 and the electrode 24 are for supplying power to the semiconductor laser 21, and the power supplied from the electrode 24 is supplied to the semiconductor laser 21 through the wiring 23. The electrode 24 is disposed outside the other end side of the case 10.

  Such a laser unit 20 is configured as a solid-state laser using neodymium (Nd) mixed in the YAG crystal 22 as a light emitter. In the present embodiment, the laser power of the laser unit 20 is several tens of mJ, and the fundamental wavelength of the laser is 1064 nm.

  The electronic shutter 30 is for transmitting or blocking the laser light emitted from the laser unit 20, and is composed of, for example, two polarizing plates. That is, the transmittance of the electronic shutter 30 is changed by shifting one of the two polarizing plates around the optical axis of the laser light. Thereby, a laser beam is irradiated from case 10 at arbitrary timings. A signal is input to the electronic shutter 30 from an engine ECU (not shown), and the opening / closing timing of the electronic shutter 30 is controlled by the engine ECU.

  The ultrasonic motor 40 rotates the pedestal 50 about the optical axis of the laser beam, and includes a hollow cylindrical stator (elastic body) and a rotor (moving body) not shown. An AC voltage that generates a standing wave in the stator and an AC voltage that generates another standing wave whose period is shifted by ¼ are applied to the ultrasonic motor 40. Then, ultrasonic vibration is generated in the stator, and the rotor is rotated by a traveling wave in which two ultrasonic vibration waves are superimposed. Such rotation control of the ultrasonic motor 40 is performed by an engine ECU (not shown). The ultrasonic motor 40 corresponds to the pedestal driving means of the present invention.

  The pedestal 50 fixes the condenser lens 60, and is fixed to the rotor of the ultrasonic motor 40 by adhesion. Therefore, when the ultrasonic motor 40 is rotated, the pedestal 50 rotates around the optical axis of the laser beam together with the condenser lens 60.

  The condensing lens 60 condenses the laser light emitted from the laser unit 20 and irradiates it into the combustion chamber 120 of the engine 100 shown in FIG. Here, the combustion chamber 120 refers to a space closed by the wall surface 131 of the cylinder 130 of the engine 100, the intake valve 141, the exhaust valve 142, the piston 150, and the glass window 12 of the case 10 of the present apparatus. In the present embodiment, the diameter of the focal point of the condenser lens 60 is several tens of μm.

  The condensing lens 60 is tilted and fixed at a desired angle with respect to a plane perpendicular to the optical axis of the laser light. Further, when the apparatus is installed on the cylinder head 110 of the engine 100, the focusing lens 60 is focused on the substantially central position of the space of the combustion chamber 120 when the piston 150 is positioned at the highest point in the cylinder 130. To be adjusted in advance.

  Note that the focal length of the condenser lens 60 differs depending on the engine 100 on which the present apparatus is mounted, and is set for each engine 100. The above is the configuration of the laser ignition device according to the present embodiment.

  Subsequently, the operation of the laser ignition device according to the present embodiment will be described. First, as shown in FIG. 2, power is supplied to the electrode 24 of the laser unit 20 in a state where the case 10 is installed on the cylinder head 110 of the engine 100.

  Then, the semiconductor laser 21 of the laser unit 20 is operated, and laser light is emitted from the semiconductor laser 21. Laser light is applied to the condenser lens 60 via the electronic shutter 30, the ultrasonic motor 40, and the pedestal 50.

  Then, the combustion timing of the electronic shutter 30 and the rotation angle of the ultrasonic motor 40 are controlled by the engine ECU, so that the combustion chamber 120 of the engine 100 is ignited. As described above, the condenser lens 60 is fixed to the pedestal 50 at a predetermined angle. Therefore, when the electronic shutter 30 is opened and the ultrasonic motor 40 is operated and the pedestal 50 is rotated, the focal point of the laser light enters the combustion chamber 120 so as to draw a circle having a predetermined diameter as shown in FIG. Will be scanned. In this way, by rotating the tilted condenser lens 60, the number of ignition points is increased by moving the focal position to the circumference.

  Here, ignition and combustion occurred in the combustion chamber 120, and when the piston 150 reciprocated in the cylinder 130, the piston 150 reached the highest point with the intake valve 141 and the exhaust valve 142 closed. Time is the ignition timing. There are the following two methods for setting multiple ignition points at such ignition timing.

  One is a method in which all points on a circle of a circle drawn by the laser beam in the combustion chamber 120 are set as ignition points by keeping the electronic shutter 30 open at the ignition timing. The other is a method in which the electronic shutter 30 is opened and closed a plurality of times at the ignition timing, so that arbitrary several points on a circle of a circle drawn in the combustion chamber 120 by the focal point of the laser light are used as the ignition points. By such a method, the number of ignition points at the ignition timing is made many.

  As described above, the ignition point is set to multiple points, so that the flame after ignition is reliably grown. In this embodiment, the diameter of the circle drawn by the focal position of the laser beam is 3.5 mm or more. This will be described with reference to FIG. In the following, the circle drawn by the focal position of the laser beam is called a flame kernel.

  The inventors performed an ignition simulation by regarding the spark gap between the center electrode and the ground electrode of the spark plug as the size (diameter) of the flame kernel. In the ignition simulation, assuming that a small-diameter ground plug is used, the A / F (air to fuel ratio) is 22, the pressure is 0.5 MPa, the oxygen concentration is 18%, the plug electrode temperature is 200 ° C., and the initial mixture is The condition was that the temperature was 300 ° C.

  FIG. 3 is a graph showing the size of the flame kernel with respect to the time after ignition. In FIG. 3, the horizontal axis represents time [ms] after ignition, and the vertical axis represents the size [mm] of the flame kernel. As shown in FIG. 3, when the spark gap is 0.8, 1.1, and 2.0 mm, the size of the flame kernel is substantially constant in about 2 ms after ignition. That is, it shows that the growth of the flame kernel is slow. On the other hand, when the spark gap is 3.2 mm, the size of the flame kernel increases immediately after ignition. In other words, if the spark gap is 3.2 mm or more, the flame kernel reliably grows after ignition.

  Thus, the larger the spark gap, that is, the larger the diameter of the circle drawn by the focal position of the laser beam, the more reliably ignition can be performed in the combustion chamber 120. Accordingly, it can be said that, by setting the diameter of the circle drawn by the focal position of the laser beam to at least 3.5 mm or more in this apparatus, flame nuclei can be grown immediately after ignition, as in the above results.

  Note that the upper limit of the size of the flame kernel is set to be equal to or less than the inner wall surface 131 of the cylinder 130. That is, the upper limit of the size of the flame kernel differs depending on the engine 100 in which the present apparatus is installed, and is set by each engine 100.

  As described above, in the present embodiment, the condenser lens 60 is fixed to the pedestal 50 at a predetermined angle. Thus, the condensing lens 60 is tilted and rotated about the optical axis of the laser light. Thereby, the focal position of the laser beam can be arbitrarily moved.

  Further, the focal point of the laser beam is moved so as to draw a circle by the inclination of the condenser lens 60. Thereby, the number of ignition points in the combustion chamber 120 of the engine 100 can be increased, and the combustion speed and thermal efficiency after ignition can be improved.

  Further, the condenser lens 60 is tilted and fixed to the pedestal 50 so that the diameter of the circle drawn by the focus of the laser beam is at least 3.5 mm or more. Thereby, the circle drawn by the focus of the laser beam at the time of ignition, that is, the size of the flame kernel can be increased, and combustion can be started immediately after ignition.

(Second Embodiment)
In the present embodiment, only different parts from the first embodiment will be described. In this embodiment, it differs from 1st Embodiment that the condensing lens 60 is being fixed to the piezo stack. In the present embodiment, this piezo stack enables the focal position of the condenser lens 60 to be moved.

  FIG. 4 is a schematic view of the laser ignition device according to the present embodiment. As shown in FIG. 4, the laser ignition device according to the present embodiment includes a piezo stack 70.

  The piezo stack 70 is a known piezo element (piezoelectric element) that deforms when a voltage is applied. In this embodiment, the piezo stack 70 is constituted by a hollow cylindrical piezo element, and the piezo element is further divided into three in the circumferential direction around the optical axis of the laser beam. The condensing lens 60 is held in a state where both surfaces are sandwiched between the three divided piezo stacks 70.

  Each piezo element is in an insulated state, and wiring is connected to each piezo element. That is, each piezo element can be expanded and contracted independently according to the applied voltage. In such a piezo stack 70, in addition to the piezo element that holds the condenser lens 60, a plurality of piezo elements that can be expanded and contracted in the optical axis direction of the laser light are also provided.

  In the laser ignition device including the piezo stack 70, a voltage is applied to each piezo element divided into three parts by the engine ECU. That is, the inclination of the condenser lens 60 is arbitrarily changed by the voltage applied to each piezo element of the piezo stack 70.

  Specifically, a desired voltage is applied to each piezo element. That is, the inclination of the condenser lens 60 is changed by changing the value of the voltage applied to each piezo element and changing the amount of expansion / contraction of each piezo element. Thereby, similarly to the first embodiment, the focal position of the condenser lens 60 can be rotated in the circumferential direction. Further, the focal position of the condenser lens 60 can be moved to an arbitrary position in the combustion chamber 120. Further, when a voltage is applied to each piezo element and the piezo elements are expanded and contracted in the optical axis direction, the focal position of the condenser lens 60 can be moved in the optical axis direction as shown in FIG.

  That is, the focusing lens 60 according to the present embodiment can move the focal position three-dimensionally by the piezo stack 70. Therefore, in the combustion chamber 120 of the engine 100, the focal point of the condenser lens 60 can be moved to a position where ignition is desired, and ignition can be performed at the focal position.

  Note that, similarly to the first embodiment, the laser light is emitted from the apparatus when the electronic shutter 30 is opened and closed by the engine ECU.

  As described above, in the present embodiment, the condenser lens 60 is fixed by the piezo stack 70. In this way, the condenser lens 60 is fixed by a plurality of piezo elements, and a voltage is applied to each piezo element. Thereby, the focal position of the condensing lens 60 can be moved arbitrarily.

  Furthermore, the focal position of the condensing lens 60 can be moved in the optical axis direction of the laser light by expanding and contracting the piezo element in the optical axis direction of the laser light. Therefore, the focal point of the laser beam can be moved three-dimensionally in the combustion chamber 120 of the engine 100.

  Further, when the laser light is transmitted through the electronic shutter 30, it is ignited at the focal point of the laser light. Therefore, multipoint ignition can be performed by combining the transmission of the laser light by the electronic shutter 30 and the inclination of the condenser lens by the piezo element. If multi-point ignition can be performed in this way, the flame propagation speed by ignition can be improved, and the combustion speed can be increased.

(Third embodiment)
In the present embodiment, only different parts from the second embodiment will be described. This embodiment is different from the second embodiment in that a focal length adjustment unit is provided between the electronic shutter 30 and the piezo stack 70. In the present embodiment, this focal length adjustment unit enables the focal position of the laser light to be moved.

  FIG. 5 is a schematic view of the laser ignition device according to the present embodiment. As shown in FIG. 5, the laser ignition device according to the present embodiment includes a focal length adjustment unit 80 between the electronic shutter 30 and the piezo stack 70 in the case 10.

  The focal length adjustment unit 80 includes a focal length adjustment lens 81 and a real solenoid coil 82. The focal length adjusting lens 81 has a concave mirror on the surface and a surface facing the surface, and a conductive member (not shown) is provided on the outer edge of the lens. And the focal position of the optical axis direction of the condensing lens 60 is changed by changing the position in the case 10.

  The real solenoid coil 82 is a well-known coil arranged in parallel to the optical axis of the laser beam, and the focal length adjustment lens 81 is made parallel to the optical axis by the magnetic force generated by the direction of the applied voltage. Move. The real solenoid coil 82 corresponds to the focal length adjusting lens driving means of the present invention.

  Such a focal length adjustment unit 80 is provided with a guide (not shown) so that the focal length adjustment lens 81 can move in the optical axis direction of the laser light. When a current flows through the real solenoid coil 81 to generate a magnetic field, the current flows through the conductive member of the focal length adjustment lens 81, and the focal length adjustment lens 81 moves along the real solenoid coil 82 in the optical axis direction along the guide. Moving.

  Therefore, when the focal length adjustment lens 81 is moved to the piezo stack 70 side, the focal position of the condenser lens 60 is moved to the piston 150 side. Conversely, when the focal length adjustment lens 81 is moved to the electronic shutter 30 side, the focal position of the condenser lens 60 is moved to the glass window 12 side.

  In the present embodiment, the focal length adjustment unit 80 is used to move the focal position of the condenser lens 60 in the optical axis direction. The piezo stack 70 is used to move the focal position of the condenser lens 60 in a plane direction perpendicular to the optical axis. In this way, the focal position of the condenser lens 60 can also be moved three-dimensionally within the combustion chamber 120 by combining the focal length adjustment unit 80 and the piezo stack 70.

  The timing of irradiating laser light is the same as in the first and second embodiments.

  As described above, in the present embodiment, the focal length adjustment unit 80 moves the focal position of the condenser lens 60 in the optical axis direction. Thereby, the focal position of the condensing lens 60 can be moved more greatly by the focal length adjustment lens 81.

(Other embodiments)
In the first to third embodiments, the laser ignition device is installed in the cylinder head 110, but the place where the laser ignition device is installed is not limited to the cylinder head 110. That is, it may be arranged in the cylinder 130 of the engine 100.

  When rotating the condenser lens 60 around the optical axis of the laser light, the ultrasonic motor 40 is employed in the first embodiment, but the condenser lens 60 may be rotated by other methods. . For example, a belt or gear may be provided on the condensing lens 60 and indirectly driven by a motor.

  In the third embodiment, the focal length adjustment lens 81 is moved using the real solenoid coil 82. However, the focal length adjustment lens 81 is not limited to the real solenoid coil 82 and is moved using, for example, the piezo stack 70. It doesn't matter.

  In the third embodiment, the piezo stack 70 may be replaced with the ultrasonic motor 40 and the pedestal 50 of the first embodiment.

  In the first to third embodiments, the condenser lens 60 may be a compound eye lens. For example, when a compound eye lens including three lenses is used as the condensing lens 60, the laser light incident on the condensing lens 60 is irradiated to three places. Thereby, the number of ignition points can be three. When the condensing lens 60, which is such a compound eye lens, is rotated, more ignition points can be generated, so that it is possible to improve the flame transmission speed after ignition, improve the thermal efficiency, and avoid knocking.

1 is a schematic view of a laser ignition device according to a first embodiment of the present invention. It is the figure which showed a mode that the laser ignition apparatus shown in FIG. 1 was installed in the cylinder head of the engine. It is the figure which represented the size of the flame kernel after ignition by the ignition test in the graph. It is the schematic of the laser ignition apparatus which concerns on 2nd Embodiment of this invention. It is the schematic of the laser ignition apparatus which concerns on 3rd Embodiment of this invention.

Explanation of symbols

10 ... Case, 11 ... Cooling medium, 12 ... Glass window, 20 ... Laser unit,
21 ... YAG crystal, 22 ... semiconductor laser, 23 ... wiring, 24 ... electrode,
30 ... Electronic shutter, 40 ... Ultrasonic motor, 50 ... Base, 60 ... Condensing lens,
70 ... Piezo stack, 80 ... Focal length adjustment unit, 81 ... Focal length adjustment lens,
82 ... Real solenoid coil.

Claims (4)

A cylindrical case (10, 12);
A laser unit (20) that is housed in the case and emits laser light;
An electronic shutter (30) disposed on the optical axis of the laser beam and transmitting or blocking the laser beam;
A condenser lens (60) for condensing the laser light emitted from the laser unit;
A pedestal (50) having a hollow cylindrical shape and tilting and fixing the condenser lens at a desired angle with respect to a plane perpendicular to the optical axis of the laser beam;
And a pedestal driving means (40) for rotating the pedestal about the optical axis of the laser beam. The condensing lens is tilted and fixed to the pedestal so that a diameter of a circle drawn by the focus of the laser beam is at least 3.5 mm or more by rotation of the condensing lens. Item 2. The laser ignition device according to Item 1. A cylindrical case (10, 12);
A laser unit (20) that is housed in the case and emits laser light;
An electronic shutter (30) disposed on the optical axis of the laser beam and transmitting or blocking the laser beam;
A condenser lens (60) for condensing the laser light emitted from the laser unit;
A laser ignition device comprising: a plurality of piezoelectric elements (70) which are installed at an outer edge portion of the condenser lens, fix the condenser lens, and expand and contract in accordance with an applied voltage. On the optical axis of the laser beam, a focal length adjustment unit (80) is disposed between the electronic shutter and the condenser lens.
The focal length adjustment unit includes a focal length adjustment lens (81) for adjusting the focal length of the condenser lens, and a focal length adjustment lens driving unit (82) for driving the focal length adjustment lens in the optical axis direction of the laser beam. ) And comprising
4. The focal length of the condensing lens is moved in the optical axis direction when the focal length adjustment lens is driven by the focal length adjustment lens driving means. Laser igniter.

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