WO2021131600A1 - Prechamber-type ignition device - Google Patents

Prechamber-type ignition device Download PDF

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Publication number
WO2021131600A1
WO2021131600A1 PCT/JP2020/045179 JP2020045179W WO2021131600A1 WO 2021131600 A1 WO2021131600 A1 WO 2021131600A1 JP 2020045179 W JP2020045179 W JP 2020045179W WO 2021131600 A1 WO2021131600 A1 WO 2021131600A1
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WO
WIPO (PCT)
Prior art keywords
sub
chamber
ignition device
heat shield
shield material
Prior art date
Application number
PCT/JP2020/045179
Other languages
French (fr)
Japanese (ja)
Inventor
知幸 保坂
健太 光藤
英一郎 大畠
石井　英二
Original Assignee
日立Astemo株式会社
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Publication of WO2021131600A1 publication Critical patent/WO2021131600A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B19/00—Engines characterised by precombustion chambers
    • F02B19/12—Engines characterised by precombustion chambers with positive ignition
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B19/00—Engines characterised by precombustion chambers
    • F02B19/16—Chamber shapes or constructions not specific to sub-groups F02B19/02 - F02B19/10
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F1/00—Cylinders; Cylinder heads 
    • F02F1/24—Cylinder heads
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
    • F02P13/00—Sparking plugs structurally combined with other parts of internal-combustion engines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
    • F02P5/00—Advancing or retarding ignition; Control therefor
    • F02P5/04—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions
    • F02P5/145—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions using electrical means
    • F02P5/15—Digital data processing
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies

Definitions

  • a sub-chamber type ignition device is known in which pre-combustion is performed indoors and the combustion chamber is ignited by a jet of flame injected from a high-pressure sub-chamber.
  • auxiliary chamber type ignition device for example, a technique disclosed in Japanese Patent Application Laid-Open No. 8-284665 (Patent Document 1) is known.
  • Patent Document 1 discloses a technique for improving combustibility at the time of starting by keeping the sub-chamber warm, consideration for raising the temperature immediately after starting the engine is not sufficient, and the ignition performance is improved. There is a problem in.
  • An object of the present invention is to improve the spotting performance at the time of starting the engine in the sub-chamber type ignition device.
  • the sub-chamber type ignition device of the present invention includes a sub-chamber forming member for forming a sub-chamber for accommodating a plug electrode of a spark plug, and a passage leading to a main combustion chamber of an internal combustion engine.
  • the sub-chamber type ignition device when the sub-chamber forming member is divided into a first region embedded in the cylinder head and a second region protruding into the main combustion chamber of the internal combustion engine, the first region A first heat shield having a lower thermal conductivity than the material for forming the sub chamber forming member is provided on the inner surface of the sub chamber forming member.
  • Example 1 The internal combustion engine and the sub-chamber type ignition device according to the first embodiment of the present invention will be described below with reference to FIGS. 1 to 8.
  • FIG. 1 is a diagram showing an outline of the configuration of an engine (internal combustion engine) having an auxiliary chamber type ignition device.
  • a combustion chamber 104 is formed by a cylinder head 101, a cylinder block 102, and a piston 103 inserted into the cylinder block 102, and an intake pipe 105 and an exhaust pipe 106 are branched into two toward the combustion chamber 104, respectively. Is connected.
  • An intake valve 107 is provided at the opening of the intake pipe 105
  • an exhaust valve 108 is provided at the opening of the exhaust pipe 106, and the intake valve 107 and the exhaust valve 108 operate so as to open and close by a cam operation method.
  • the piston 103 is connected to the crankshaft 115 via a connecting rod 114, and the engine speed can be detected by the crank angle sensor 116.
  • the value of the number of revolutions is sent to the ECU (engine control unit, control device) 118.
  • a starter motor (not shown) is connected to the crankshaft 115, and the crankshaft 115 can be rotated and started by the starter motor when the engine is started.
  • the cylinder block 102 is provided with a water temperature sensor 117, and can detect the temperature of engine cooling water (not shown). The temperature of the engine cooling water is sent to the ECU 118.
  • FIG. 1 shows only one cylinder
  • a collector (not shown) is provided upstream of the intake pipe 105 to distribute air to a plurality of cylinders connected to the collector.
  • An air flow sensor and a throttle valve (not shown) are provided upstream of the collector, and the amount of air sucked into the fuel chamber 104 can be adjusted by the opening degree of the throttle valve.
  • a sub chamber 109 is provided in the upper part of the combustion chamber 104, and a spark plug 110 is inserted inside the sub chamber 109.
  • An ignition signal is sent from the ECU 118 to the spark plug 110, and sparks are generated between the plug electrodes (not shown) to ignite the gas in the sub chamber 109.
  • the combustion chamber 104 constitutes a main combustion chamber with respect to the sub chamber (sub-combustion chamber) 109.
  • the combustion chamber 104 will be referred to as a main combustion chamber and will be described.
  • FIG. 2 is a cross-sectional view showing the configuration of an auxiliary chamber type ignition device 100 which is a base on which the present invention is carried out.
  • the vertical direction may be specified, but the vertical direction is based on the vertical direction in FIGS. 1 and 2, and the vertical direction is the vertical direction in the mounted state of the sub-chamber type ignition device 100. It does not always match. That is, the central axis 100a of the spark plug 110 shown in FIG. 2 is along the vertical direction. In the following description, the direction along the central axis 100a may be referred to as an axial direction.
  • the sub-chamber ignition device 100 is in the vicinity of the plug electrode 203 including the plug electrode 203 of the spark plug 110 in the sub-chamber 109 (see FIG. 2) formed in the sub-chamber forming member 201 (see FIG. 2). It is configured to accommodate 203 parts of the plug electrode).
  • the spark plug 110 includes a terminal 111, an insulator 112, a housing 202, a plug electrode 203, and the like.
  • the insulator 112 is usually composed of insulators.
  • the housing 202 is usually made of a metal member, and a screw portion 101A is formed on the outer periphery thereof.
  • a plug electrode 203 is provided at the tip end portion (lower end portion) of the housing 202.
  • the plug electrode 203 is composed of a center electrode 203A serving as a positive electrode and a ground electrode 203B serving as a negative electrode.
  • the ground electrode 203B extends from the outer peripheral portion of the housing 202 toward the center side in the radial direction and faces the center electrode 203A.
  • the center electrode 203A serving as the positive electrode and the ground electrode 203B serving as the negative electrode are formed of a conductive material.
  • a sub-chamber forming member 201 defining a sub-chamber 109 is inserted in the cylinder head 101.
  • a spark plug 110 is provided above the sub-chamber forming member 201 so that the plug electrode 203 is arranged inside the sub-chamber 109, and is fixed to the sub-chamber forming member 201 by a screw portion 202A formed in the housing 202. Has been done.
  • the flame jet 205 is a burnt gas that has become hot, and when the unburned gas in the main combustion chamber 104 ignites, the flame spreads in the main combustion chamber 104. Since the flame jet 205 has a large momentum and quickly spreads to the main combustion chamber 104, high-speed combustion can be realized.
  • the cylinder head 101 is provided with a cooling water channel 206, and the passage of the cooling water prevents overheating of the spark plug 110 and the auxiliary chamber forming member 201 due to combustion.
  • the temperature of the inner wall 201A of the auxiliary chamber forming member 201 near the plug electrode 203 is low, and the temperature of the cooling water (not shown) is also low, so that the heat of the flame is transferred to the inner wall 201A and the flame temperature is lowered. As a result, there is a problem that the ignition performance is significantly deteriorated.
  • FIG. 3 is an enlarged cross-sectional view of the sub-chamber ignition device 100A according to the first embodiment of the present invention.
  • the second region 302 projects into the combustion chamber 104, the combustion heat is applied through the path 305, and the heat generated in the sub chamber 109 is further transmitted through the path 306.
  • the second region 302 since the second region 302 is not in contact with the cylinder head 101, it is difficult for cooling to be performed. Therefore, the temperature of the second region 302 tends to rise at the time of starting, but there is a problem that cooling is insufficient at the time of high load operation and abnormal combustion is likely to occur.
  • the temperature of the inner wall of the sub chamber 109 can be raised at the time of starting, and the ignition performance can be improved, which is sufficient even at a high temperature. Cooling can be performed.
  • the thermal conductivity of the material constituting the member 307 is lower than the thermal conductivity of the material constituting the auxiliary chamber forming member 201.
  • the member 307 has a film-like or layer-like shape, and can be called a heat-shielding film or a heat-shielding layer.
  • the "film” and “layer” are not limited to the “film” and “layer” produced by depositing materials, and may be members processed by cutting or other processing methods.
  • the heat shield film will be referred to as a heat shield material and will be described.
  • the heat shield material 307 is provided on the entire circumference in the circumferential direction surrounding the central axis 100a (see FIG. 2).
  • the heat shield material 307 may be provided by forming a film on the inner surface of the sub chamber forming member 201, or a preformed annular member (or cylindrical member) may be provided on the inner surface of the sub chamber forming member 201. It may be fitted.
  • the sub-chamber forming member 201 forming the sub-chamber 109 accommodating the plug electrode 203 part of the spark plug 110 and the main combustion chamber (engine main chamber) 104 of the internal combustion engine
  • a sub-chamber type ignition device 100A including a passage (injection hole) 204 through which the sub-chamber forming member 201 is embedded in a cylinder head 102, and a first region 303 protruding into a main combustion chamber 104.
  • a heat shield material first heat shield material having a lower thermal conductivity than the material for forming the sub chamber forming member 201 on the inner surface (inner peripheral surface) 303A of only the first region 303.
  • the heat shield material 307 does not have to be provided on the entire inner peripheral surface of the first region 303, and may be only a part of the heat shield material 307. In this case, in the first region 303, the heat shield material 307 is provided at a portion close to the plug electrode 203 with respect to a portion away from the plug electrode 203.
  • the volume specific heat of the heat shield material 307 smaller than that of the first region 303, the temperature rise rate at the time of starting can be increased and the ignition performance can be improved.
  • the heat shield material (first heat shield material) 307 is formed of a material having a volume specific heat smaller than the volume specific heat of the material forming the sub chamber forming member 201. As a result, the temperature rise rate of the heat shield material 307 can be increased, and the ignition performance at the time of starting can be improved.
  • the material of the heat shield material 307 for example, silica-reinforced alumite (aluminum oxide film) or porous ceramics may be used. That is, the heat shield material (first heat shield material) 307 is preferably made of an aluminum oxide film or porous ceramics.
  • the control device 118 that controls the ignition timing of the sub-chamber type ignition device of the present embodiment includes a sub-chamber forming member that forms the sub-chamber 109 that houses the plug electrode 203 of the spark plug 110, and the main combustion of the internal combustion engine.
  • a first region 303 having a passage (injection hole) 204 leading to the chamber (engine main chamber) 104 and having an auxiliary chamber forming member 201 embedded in the cylinder head 102 and a second region projecting into the main combustion chamber 104.
  • the heat shield material (first heat shield material) 307 having a lower thermal conductivity than the material for forming the sub chamber forming member 201 on the inner surface (inner peripheral surface) 303A of only the first region 303.
  • the sub-chamber type ignition device 100A formed in the above is used to control the pre-ignition so as to pre-ignite earlier than the normal ignition timing (regular ignition timing) defined by the control device 118.
  • the temperature of the gas around the spark plug can be suitably raised, and the ignition performance at the time of starting can be improved.
  • FIG. 5 is an enlarged cross-sectional view of the vicinity of the spark plug 203 of the sub-chamber ignition device 100A according to the first embodiment of the present invention.
  • a spark is generated between the center electrode 502 as the positive electrode and the negative electrode (ground electrode) 203B.
  • the heat shield material 307 is a conductive material
  • sparks may occur between the center electrode 203A and the heat shield material 307, and the heat shield material 307 is consumed by the sparks. Therefore, by using a non-conductive material, for example, a porous ceramic material, for the heat shield material 307, it is possible to prevent the heat shield material 307 from becoming a ground potential, and to prevent sparks between the center electrode 203A and the heat shield material 307. Prevent or suppress the occurrence. As a result, the heat shield material 307 is prevented or suppressed from being worn by sparks.
  • the heat shield material (first heat shield material) 307 is preferably made of a non-conductive material. Thereby, the generation of sparks due to the grounding of the heat shield material 307 can be prevented or suppressed, and the wear of the heat shield material 307 can be prevented or suppressed.
  • FIG. 6 is an enlarged cross-sectional view of the vicinity of the plug electrode 203 of the sub-chamber ignition device 100A-1 according to the modified example (first modified example) of the first embodiment of the present invention.
  • the heat shield material 307-1 is provided so as to be embedded in the auxiliary chamber forming member 201 instead of the heat shield material 307 of the above-described embodiment.
  • Other configurations are the same as those in the first embodiment.
  • the spark plug 203 and the heat shield material 307-1 can be arranged in a small space while preventing interference between the members.
  • the heat shield material 307-1 may be embedded in the sub chamber forming member 201 by forming a heat shield film in the groove formed on the inner surface of the sub chamber forming member 201, or may be embedded in the sub chamber forming member 201.
  • a heat shield member molded in advance may be embedded in a groove formed on the inner surface of 201. That is, in the first modification, the heat shield material (first heat shield material) 307-1 is embedded in the inner surface of the first region 303.
  • FIG. 7 is a diagram showing a sub-chamber ignition device 100A-2 according to a modification (second modification) of the first embodiment of the present invention, and is a plug electrode from the lower end side of the sub-chamber ignition device 100A-2. It is sectional drawing which looked at the direction of 203. That is, FIG. 7 shows a viewpoint oriented in the direction of the plug electrode 203 from the tip end side of the sub chamber 109 on the injection hole 204 side in the cross section of the sub chamber 109 (the cross section perpendicular to the central axis 100a).
  • the plug electrode 203 is provided so as to extend radially outward from the center of the cross section (the position of the cross section through which the central axis 100a passes).
  • the heat shield material 307-2 may not be provided with a uniform thickness in the circumferential direction, and a notch portion 307-2A may be provided in a part thereof. That is, the heat shield material (first heat shield material) 307-2 may have a notch portion 307-2A in a part in the circumferential direction.
  • the heat shield material 307-2 of this modified example is the heat shield material 307 of the first embodiment provided with a notch 307-2A, and other configurations are the same as those of the first embodiment. Further, the heat shield material 307-2 of the present modification example may be provided so as to be embedded in the sub chamber forming member 201 as in the modification example 1.
  • the heat shield material 307-2 prevents interference between the heat shield material 307-2 and the plug electrode 203 by matching the position of the cutout portion 307-2A with the position of the plug electrode 203. Further, the heat shield material 307-2 is not limited to having a uniform thickness in the circumferential direction, and a bias may be provided in the circumferential direction. With this configuration, the sub-chamber ignition device 100A of this modified example can be configured as a heat shield material 307 that can be suitably cooled in consideration of the temperature distribution at the time of high load.
  • FIG. 8 shows an enlarged cross-sectional view of the sub-chamber ignition device 100A-3 according to the present invention.
  • FIG. 8 is an enlarged cross-sectional view of the sub-chamber ignition device 100A-3 according to a modified example (third modified example) of the first embodiment of the present invention.
  • the heat shield material 307 of the first embodiment does not have to have a uniform thickness in the axial direction of the sub chamber 109, and is a heat shield material 307-3 having a bias in the axial direction as in this modified example. Is also good.
  • the thickness of the heat shield material 307-3A is configured to be larger than the thickness of the heat shield material 307-3B.
  • the heat shield material 307-3A is a heat shield material provided in the vicinity of the plug electrode 203 in the first region 303 (see FIG. 3), and is another portion separated from the plug electrode 203 in the direction along the central axis 100a.
  • a heat shield material 307-3B is provided in (range).
  • the heat shield material 307-3A By configuring the heat shield material 307-3A in this way, it is possible to suitably retain the high temperature gas produced by preheating ignition, improve the ignition performance, and at the same time sufficiently perform cooling under a high load.
  • FIG. 9 is an enlarged cross-sectional view of the sub-chamber ignition device 100B according to the second embodiment of the present invention.
  • the member region (first region) 303 of the auxiliary chamber forming member 201 inserted into the cylinder head 101 is formed in an L shape accommodating the plug electrode 203 as shown by the alternate long and short dash line L1. ..
  • the sub-chamber 109 extends in the direction perpendicular to the axial direction from one end of the first sub-chamber 109A and the first sub-chamber 109A extending in the axial direction. It is provided with a second sub-chamber 109B to be used.
  • the plug electrode 203 is arranged in the second sub chamber 109B.
  • the heat shield material (first heat shield material) 307B is provided on the inner surfaces 901A and 901B of the second sub chamber 109B.
  • the first sub chamber 109A has a cylindrical shape
  • the second sub chamber 109B extends in a direction perpendicular to the axial direction from the upper end portion (one end portion on the plug electrode 203 side) of the first sub chamber 109A.
  • the inner surface of the second sub chamber 109B provided with the heat shield material 307B includes an inner surface 901A facing the center electrode 203A.
  • the structure of the sub-chamber shown in this example is an example, and its shape is not limited to a cylindrical shape and an L-shape.
  • FIG. 10 is an enlarged cross-sectional view of the sub-chamber ignition device 100C according to the third embodiment of the present invention.
  • FIG. 11 is a diagram showing a time history of gas temperatures inside and outside the sub-chamber ignition device 100C according to the third embodiment of the present invention.
  • the heat shield material 1001 is cooled by exchanging heat with air during the intake stroke.
  • FIG. 11 shows the transition of the gas temperature in each stroke of the engine for each of the inside of the sub chamber 109 and the outside of the sub chamber 109, and the gas temperature inside the sub chamber 109 flows in from the main combustion chamber 104 in the compression stroke.
  • the fresh air reduces the temperature for only a short time, and the flow inside the sub chamber 109 is weak, while the gas outside the sub chamber 109 is cooled by the fresh air from the intake stroke.
  • heat transfer is preferably performed by the flow generated by the flow of the main combustion chamber 104, and the heat shield material 1001 can be cooled.
  • the sub-chamber ignition device 100C of the present embodiment is formed of a material having a thermal conductivity smaller than that of the material forming the sub-chamber forming member on the outer surface of the second region 302 facing the main combustion chamber 104.
  • the heat shield material 1001 is provided.
  • the sub-chamber ignition device 100C of this embodiment can suppress heat input from the main combustion chamber 104 to the second region 302 at the time of high load.
  • the present invention is not limited to each of the above-described embodiments, and includes various modifications.
  • the above-described embodiment has been described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to the one including all the configurations.
  • it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment and it is also possible to add the configuration of another embodiment to the configuration of one embodiment.
  • Sub-chamber type spark plug 102 ... Cylinder head, 104 ... Main combustion chamber (engine main chamber) of internal combustion engine, 109 ... Sub-chamber, 109A ... First sub-chamber, 109B ... Second sub-chamber, 110 ... spark plug, 118 ... control device (ECU), 201 ... sub chamber forming member, 203 ... plug electrode, 204 ... passage (injection hole), 302 ... second region of sub chamber forming member 201, 303 ... sub chamber forming First region of member 201, 303A ...
  • Heat shield material (No. 1) 1 heat shield material, first low thermal conductivity member), 307-2A ... notch portion of heat shield material 307-2, 901A, 901B ... inner surface of second sub chamber 109B, 1001 ... heat shield material (second heat shield) Material, second low thermal conductivity member).

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Combustion Methods Of Internal-Combustion Engines (AREA)
  • Cylinder Crankcases Of Internal Combustion Engines (AREA)
  • Ignition Installations For Internal Combustion Engines (AREA)
  • Electrical Control Of Ignition Timing (AREA)

Abstract

The purpose of the present invention is to improve the ignition performance of a prechamber-type ignition device upon starting of an engine. A prechamber-type ignition device 100A is provided with a prechamber-forming member 201 forming a prechamber 109 accommodating a plug electrode 203 portion of an ignition plug 110, and a passageway (injection hole) 204 communicating with a main combustion chamber (engine main chamber) 104 of an internal combustion engine. The prechamber-forming member 201 includes a first region 303 embedded in a cylinder head 102, and a second region 302 protruding into the main combustion chamber 104. The prechamber-type ignition device 100A is further provided with a heat-shield material (first heat-shield material) 307 on an inner surface (inner-peripheral surface) 303A of only the first region 303, the heat-shield material 307 having a heat conductivity smaller than that of the material of the prechamber-forming member 201.

Description

副室式点火装置Sub-chamber ignition device
　本発明は、内燃機関に用いられる点火装置であって、副室を有する副室式点火装置に関する。 The present invention relates to an ignition device used for an internal combustion engine and is a sub-chamber type ignition device having a sub-chamber.
　化石燃料の使用量を削減するため、自動車内燃機関の燃料消費量を低減する技術開発が必要となっている。燃費低減のためには、燃焼室内で高速に燃焼を行うことが効果的であり、高速燃焼を実現するエンジンとして、燃焼室（主燃焼室）と副室（副燃焼室）を有し、副室内で予備燃焼を行い、高圧となった副室から噴射される火炎のジェットにより燃焼室内の着火を行う、副室式点火装置が知られている。副室式点火装置として、例えば特開平８－２８４６６５号公報（特許文献１）に開示された技術が知られている。 In order to reduce the amount of fossil fuel used, it is necessary to develop technology to reduce the fuel consumption of automobile internal combustion engines. In order to reduce fuel consumption, it is effective to perform high-speed combustion in the combustion chamber, and as an engine that realizes high-speed combustion, it has a combustion chamber (main combustion chamber) and a sub-combustion chamber (sub-combustion chamber). A sub-chamber type ignition device is known in which pre-combustion is performed indoors and the combustion chamber is ignited by a jet of flame injected from a high-pressure sub-chamber. As an auxiliary chamber type ignition device, for example, a technique disclosed in Japanese Patent Application Laid-Open No. 8-284665 (Patent Document 1) is known.
特開平８－２８４６６５号公報Japanese Unexamined Patent Publication No. 8-284665
　特許文献１には、副室内を保温することで始動時の燃焼性を高める技術が公開されているものの、エンジンの始動直後の温度を上昇させることについての配慮が十分でなく、点火性能の向上に課題がある。 Although Patent Document 1 discloses a technique for improving combustibility at the time of starting by keeping the sub-chamber warm, consideration for raising the temperature immediately after starting the engine is not sufficient, and the ignition performance is improved. There is a problem in.
　本発明の目的は、副室式点火装置における、エンジン始動時の点化性能を向上することにある。 An object of the present invention is to improve the spotting performance at the time of starting the engine in the sub-chamber type ignition device.
　上記目的を達成するために、本発明の副室式点火装置は、　点火プラグのプラグ電極を収容する副室を形成する副室形成部材と、内燃機関の主燃焼室に通じる通路と、を備える副室式点火装置であって、　前記副室形成部材をシリンダヘッドに埋入される第１領域と、内燃機関の主燃焼室に突出する第２領域とに分けた場合に、前記第１領域のみの前記副室形成部材の内面に前記副室形成部材を形成する材料よりも熱伝導率の小さい第１遮熱材を備える。 In order to achieve the above object, the sub-chamber type ignition device of the present invention includes a sub-chamber forming member for forming a sub-chamber for accommodating a plug electrode of a spark plug, and a passage leading to a main combustion chamber of an internal combustion engine. In the sub-chamber type ignition device, when the sub-chamber forming member is divided into a first region embedded in the cylinder head and a second region protruding into the main combustion chamber of the internal combustion engine, the first region A first heat shield having a lower thermal conductivity than the material for forming the sub chamber forming member is provided on the inner surface of the sub chamber forming member.
　本発明によれば、副室式点火装置における、エンジン始動時の点火性能を向上することができる。上記した以外の課題、構成及び効果は、以下の実施形態の説明により明らかにされる。 According to the present invention, it is possible to improve the ignition performance at the time of starting the engine in the auxiliary chamber type ignition device. Issues, configurations and effects other than those described above will be clarified by the description of the following embodiments.
本発明に係る、副室式点火装置を有するエンジン（内燃機関）の構成の概要を示した図である。It is a figure which showed the outline of the structure of the engine (internal combustion engine) which has the sub-chamber type ignition device which concerns on this invention. 本発明が実施される基盤となる副室式点火装置の構成を示す断面図である。It is sectional drawing which shows the structure of the sub-chamber type ignition device which becomes the base on which this invention is carried out. 本発明の第１実施例に係る副室式点火装置の拡大断面図である。It is an enlarged sectional view of the sub chamber type igniter which concerns on 1st Example of this invention. 本発明の第１実施例に係る副室式点火装置のプラグ電極周辺の拡大断面図である。It is an enlarged cross-sectional view around the plug electrode of the sub-chamber type igniter which concerns on 1st Example of this invention. 本発明の第１実施例に係る副室式点火装置のプラグ電極周辺の拡大断面図である。It is an enlarged cross-sectional view around the plug electrode of the sub-chamber type igniter which concerns on 1st Example of this invention. 本発明の第１実施例の変更例（第１変更例）に係る副室式点火装置のプラグ電極周辺の拡大断面図である。It is an enlarged cross-sectional view around the plug electrode of the sub-chamber type igniter which concerns on the modification (1st modification) of 1st Embodiment of this invention. 本発明の第１実施例の変更例（第２変更例）に係る副室式点火装置を示す図であり、副室式点火装置の下端側からプラグ電極の方向を見た断面図である。It is a figure which shows the subchamber type igniter which concerns on the modification (2nd modification) of 1st Embodiment of this invention, is is the sectional view which looked at the direction of the plug electrode from the lower end side of the subchamber type igniter. 本発明の第１実施例の変更例（第３変更例）に係る副室式点火装置の拡大断面図である。It is an enlarged sectional view of the sub chamber type igniter which concerns on the modification (third modification) of 1st Embodiment of this invention. 本発明の第２実施例に係る副室式点火装置の拡大断面図である。It is an enlarged sectional view of the sub chamber type igniter which concerns on 2nd Embodiment of this invention. 本発明の第３実施例に係る副室式点火装置の拡大断面図である。It is an enlarged sectional view of the sub chamber type igniter which concerns on 3rd Example of this invention. 本発明の第３実施例に係る副室点火装置の内部と外部のガス温度の時間履歴を示した図である。It is a figure which showed the time history of the gas temperature inside and outside the auxiliary chamber ignition device which concerns on 3rd Example of this invention.
　以下、本発明に係る実施例を説明する。なお、各図及び各実施例において同様な構成には同じ符号を付し、重複する説明は省略する。 Hereinafter, examples according to the present invention will be described. In addition, the same reference numerals are given to the same configurations in each figure and each Example, and duplicate description is omitted.
　［実施例１］　本発明の第１実施例に係る内燃機関および副室式点火装置について、図１から図８を用いて以下説明する。 [Example 1] The internal combustion engine and the sub-chamber type ignition device according to the first embodiment of the present invention will be described below with reference to FIGS. 1 to 8.
　図１を用いてエンジンの基本的な動作を説明する。図１は、副室式点火装置を有するエンジン（内燃機関）の構成の概要を示した図である。 The basic operation of the engine will be described with reference to FIG. FIG. 1 is a diagram showing an outline of the configuration of an engine (internal combustion engine) having an auxiliary chamber type ignition device.
　図１において、シリンダヘッド１０１、シリンダブロック１０２及びシリンダブロック１０２に挿入されたピストン１０３により燃焼室１０４が形成され、燃焼室１０４に向けて吸気管１０５と排気管１０６とがそれぞれ２つに分岐して接続されている。吸気管１０５の開口部には吸気弁１０７が、排気管１０６の開口部には排気弁１０８がそれぞれ設けられ、吸気弁１０７及び排気弁１０８はカム動作方式により開閉するように動作する。 In FIG. 1, a combustion chamber 104 is formed by a cylinder head 101, a cylinder block 102, and a piston 103 inserted into the cylinder block 102, and an intake pipe 105 and an exhaust pipe 106 are branched into two toward the combustion chamber 104, respectively. Is connected. An intake valve 107 is provided at the opening of the intake pipe 105, and an exhaust valve 108 is provided at the opening of the exhaust pipe 106, and the intake valve 107 and the exhaust valve 108 operate so as to open and close by a cam operation method.
　ピストン１０３はコンロッド１１４を介してクランク軸１１５と連結されており、クランク角センサ１１６によりエンジン回転数を検知できる。回転数の値はＥＣＵ（エンジンコントロールユニット、制御装置）１１８に送られる。クランク軸１１５には図示しないセルモータが連結され、エンジン始動時にはセルモータによりクランク軸１１５を回転させ始動することができる。シリンダブロック１０２には水温センサ１１７が備えられ、図示しないエンジン冷却水の温度を検知できる。エンジン冷却水の温度はＥＣＵ１１８に送られる。 The piston 103 is connected to the crankshaft 115 via a connecting rod 114, and the engine speed can be detected by the crank angle sensor 116. The value of the number of revolutions is sent to the ECU (engine control unit, control device) 118. A starter motor (not shown) is connected to the crankshaft 115, and the crankshaft 115 can be rotated and started by the starter motor when the engine is started. The cylinder block 102 is provided with a water temperature sensor 117, and can detect the temperature of engine cooling water (not shown). The temperature of the engine cooling water is sent to the ECU 118.
　図１は１気筒のみを図示しているが、吸気管１０５の上流には図示しないコレクタが備えられ、コレクタに接続される複数の気筒に空気を分配する。コレクタの上流には図示しないエアフローセンサとスロットル弁が備えられ、燃料室１０４に吸入される空気量をスロットル弁の開度によって調節できる。 Although FIG. 1 shows only one cylinder, a collector (not shown) is provided upstream of the intake pipe 105 to distribute air to a plurality of cylinders connected to the collector. An air flow sensor and a throttle valve (not shown) are provided upstream of the collector, and the amount of air sucked into the fuel chamber 104 can be adjusted by the opening degree of the throttle valve.
　燃焼室１０４の上部には副室１０９が備えられ、副室１０９の内部には点火プラグ１１０が挿入されている。点火プラグ１１０へはＥＣＵ１１８から点火信号が送られ、図示しないプラグ電極間で火花が発生することで副室１０９内のガスに点火する。燃焼室１０４は副室（副燃焼室）１０９に対して主燃焼室を構成する。以下、燃焼室１０４は主燃焼室と呼んで説明する。 A sub chamber 109 is provided in the upper part of the combustion chamber 104, and a spark plug 110 is inserted inside the sub chamber 109. An ignition signal is sent from the ECU 118 to the spark plug 110, and sparks are generated between the plug electrodes (not shown) to ignite the gas in the sub chamber 109. The combustion chamber 104 constitutes a main combustion chamber with respect to the sub chamber (sub-combustion chamber) 109. Hereinafter, the combustion chamber 104 will be referred to as a main combustion chamber and will be described.
　図２を用いて、本発明が実施される基盤となる副室式点火装置１００の構成及び基本的な動作を説明する。図２は、本発明が実施される基盤となる副室式点火装置１００の構成を示す断面図である。 The configuration and basic operation of the sub-chamber ignition device 100, which is the basis on which the present invention is carried out, will be described with reference to FIG. FIG. 2 is a cross-sectional view showing the configuration of an auxiliary chamber type ignition device 100 which is a base on which the present invention is carried out.
　以下の説明では上下方向を指定して説明する場合があるが、上下方向は図１及び図２における上下方向に基づいており、この上下方向は副室式点火装置１００の実装状態における上下方向と必ずしも一致するものではない。すなわち、図２に示す点火プラグ１１０の中心軸線１００ａは、上下方向に沿う。なお、以下の説明では、中心軸線１００ａに沿う方向を軸方向と呼んで説明する場合がある。 In the following description, the vertical direction may be specified, but the vertical direction is based on the vertical direction in FIGS. 1 and 2, and the vertical direction is the vertical direction in the mounted state of the sub-chamber type ignition device 100. It does not always match. That is, the central axis 100a of the spark plug 110 shown in FIG. 2 is along the vertical direction. In the following description, the direction along the central axis 100a may be referred to as an axial direction.
　本発明に係る副室式点火装置１００は、副室形成部材２０１（図２参照）に形成された副室１０９（図２参照）に点火プラグ１１０のプラグ電極２０３を含むプラグ電極２０３の近傍（プラグ電極２０３部）を収容して構成される。 The sub-chamber ignition device 100 according to the present invention is in the vicinity of the plug electrode 203 including the plug electrode 203 of the spark plug 110 in the sub-chamber 109 (see FIG. 2) formed in the sub-chamber forming member 201 (see FIG. 2). It is configured to accommodate 203 parts of the plug electrode).
　点火プラグ１１０は、ターミナル１１１と、絶縁体１１２と、ハウジング２０２と、プラグ電極２０３等を含んで構成される。絶縁体１１２は通常、碍子で構成される。ハウジング２０２は通常、金属部材で構成され、外周にねじ部１０１Ａが形成される。さらにハウジング２０２の先端部（下端部）には、プラグ電極２０３が設けられる。プラグ電極２０３は、正極となる中心電極２０３Ａと、負極となる接地電極２０３Ｂと、で構成される。接地電極２０３Ｂは、ハウジング２０２の外周部から径方向中心側に延設され、中心電極２０３Ａと対向する。当然ではあるが、正極となる中心電極２０３Ａ及び負極となる接地電極２０３Ｂは導電性材料で形成される。 The spark plug 110 includes a terminal 111, an insulator 112, a housing 202, a plug electrode 203, and the like. The insulator 112 is usually composed of insulators. The housing 202 is usually made of a metal member, and a screw portion 101A is formed on the outer periphery thereof. Further, a plug electrode 203 is provided at the tip end portion (lower end portion) of the housing 202. The plug electrode 203 is composed of a center electrode 203A serving as a positive electrode and a ground electrode 203B serving as a negative electrode. The ground electrode 203B extends from the outer peripheral portion of the housing 202 toward the center side in the radial direction and faces the center electrode 203A. As a matter of course, the center electrode 203A serving as the positive electrode and the ground electrode 203B serving as the negative electrode are formed of a conductive material.
　図２において、シリンダヘッド１０１には副室１０９を画成する副室形成部材２０１が挿入されている。副室形成部材２０１の上部には、プラグ電極２０３が副室１０９の内側に配置されるようにして点火プラグ１１０が備えられ、ハウジング２０２に形成されたねじ部２０２Ａで副室形成部材２０１に固定されている。 In FIG. 2, a sub-chamber forming member 201 defining a sub-chamber 109 is inserted in the cylinder head 101. A spark plug 110 is provided above the sub-chamber forming member 201 so that the plug electrode 203 is arranged inside the sub-chamber 109, and is fixed to the sub-chamber forming member 201 by a screw portion 202A formed in the housing 202. Has been done.
　副室１０９側に配置された中心電極２０３Ａに、図示しない点火コイルで発生した高電圧が印加されると、中心電極２０３Ａと接地電極２０３Ｂとの間に火花が発生し、副室１０９内の燃焼を引き起こす。副室１０９内で発生した燃焼により、副室１０９内の圧力が急上昇し、副室形成部材２０１に設けられた噴孔２０４から火炎ジェット２０５となり、主燃焼室１０４へと噴出される。 When a high voltage generated by an ignition coil (not shown) is applied to the center electrode 203A arranged on the side of the sub chamber 109, sparks are generated between the center electrode 203A and the ground electrode 203B, and combustion in the sub chamber 109 occurs. cause. Due to the combustion generated in the sub chamber 109, the pressure in the sub chamber 109 suddenly rises, becomes a flame jet 205 from the injection hole 204 provided in the sub chamber forming member 201, and is ejected to the main combustion chamber 104.
　火炎ジェット２０５は高温となった既燃ガスであり、主燃焼室１０４の未燃ガスが着火することで主燃焼室１０４内に火炎が広がる。火炎ジェット２０５は運動量が大きく、主燃焼室１０４に素早く広がるため、高速燃焼を実現することができる。シリンダヘッド１０１には冷却水路２０６が備えられ、冷却水が通過することで、燃焼による点火プラグ１１０及び副室形成部材２０１の過熱が防止される。 The flame jet 205 is a burnt gas that has become hot, and when the unburned gas in the main combustion chamber 104 ignites, the flame spreads in the main combustion chamber 104. Since the flame jet 205 has a large momentum and quickly spreads to the main combustion chamber 104, high-speed combustion can be realized. The cylinder head 101 is provided with a cooling water channel 206, and the passage of the cooling water prevents overheating of the spark plug 110 and the auxiliary chamber forming member 201 due to combustion.
　一方、エンジン始動時はプラグ電極２０３付近の副室形成部材２０１の内壁２０１Ａの温度が低く、また図示しない冷却水の温度も低いため、火炎の熱が内壁２０１Ａに伝達し、火炎温度が低下することで点火性能が著しく悪化する課題がある。 On the other hand, when the engine is started, the temperature of the inner wall 201A of the auxiliary chamber forming member 201 near the plug electrode 203 is low, and the temperature of the cooling water (not shown) is also low, so that the heat of the flame is transferred to the inner wall 201A and the flame temperature is lowered. As a result, there is a problem that the ignition performance is significantly deteriorated.
　図３は、本発明の第１実施例に係る副室式点火装置１００Ａの拡大断面図である。 FIG. 3 is an enlarged cross-sectional view of the sub-chamber ignition device 100A according to the first embodiment of the present invention.
　副室形成部材２０１のうち、シリンダヘッド１０１に埋入される第１領域（埋入領域）３０３と、主燃焼室１０４に突出する第２領域（突出領域）３０２があるとき、第１領域３０３の熱は経路３０４を通ってシリンダブロック１０１に伝達され、冷却水路２０６によって冷やされる。第１領域３０３は、高温時の冷却が十分に行われる一方、始動時の冷却が大きく、点火性能が悪化する課題がある。 Among the sub-chamber forming members 201, when there is a first region (embedding region) 303 embedded in the cylinder head 101 and a second region (protruding region) 302 projecting into the main combustion chamber 104, the first region 303 The heat is transferred to the cylinder block 101 through the path 304 and cooled by the cooling water channel 206. While the first region 303 is sufficiently cooled at a high temperature, there is a problem that the cooling at the time of starting is large and the ignition performance is deteriorated.
　第２領域３０２は、燃焼室１０４に突出しているため、燃焼熱が経路３０５を通って加わり、さらに副室１０９で発生する熱が経路３０６を通って伝達される。一方、第２領域３０２は、シリンダヘッド１０１に接していないため、冷却が行われにくい。このため、第２領域３０２は、始動時には温度が上がりやすい一方、高負荷運転時には冷却が不十分となり異常燃焼を引き起こしやすい課題がある。 Since the second region 302 projects into the combustion chamber 104, the combustion heat is applied through the path 305, and the heat generated in the sub chamber 109 is further transmitted through the path 306. On the other hand, since the second region 302 is not in contact with the cylinder head 101, it is difficult for cooling to be performed. Therefore, the temperature of the second region 302 tends to rise at the time of starting, but there is a problem that cooling is insufficient at the time of high load operation and abnormal combustion is likely to occur.
　そこで、第１領域３０３のみに、熱伝導率の低い部材（遮熱膜）３０７を備えることで、始動時に副室１０９内壁の温度を上昇させ、点火性能を高めることができ、高温時にも十分な冷却を行うことができる。この場合、部材３０７を構成する材料の熱伝導性は副室形成部材２０１を構成する材料の熱伝導性よりも低いものとする。 Therefore, by providing a member (heat shield film) 307 having a low thermal conductivity only in the first region 303, the temperature of the inner wall of the sub chamber 109 can be raised at the time of starting, and the ignition performance can be improved, which is sufficient even at a high temperature. Cooling can be performed. In this case, the thermal conductivity of the material constituting the member 307 is lower than the thermal conductivity of the material constituting the auxiliary chamber forming member 201.
　部材３０７は、膜状又は層状をなし、遮熱膜又は遮熱層と呼ぶことができる。この場合、「膜」及び「層」は材料を堆積して製作する「膜」及び「層」に限定されず、切削やその他の加工方法で加工される部材であってもよい。以下、遮熱膜を遮熱材と呼んで説明する。 The member 307 has a film-like or layer-like shape, and can be called a heat-shielding film or a heat-shielding layer. In this case, the "film" and "layer" are not limited to the "film" and "layer" produced by depositing materials, and may be members processed by cutting or other processing methods. Hereinafter, the heat shield film will be referred to as a heat shield material and will be described.
　本実施例では、遮熱材３０７は中心軸線１００ａ（図２参照）を囲む周方向の全周に設けられるものとする。遮熱材３０７は副室形成部材２０１の内面に膜を形成することにより設けられたものであってもよいし、あらかじめ成形した環状部材（又は円筒状部材）を副室形成部材２０１の内面に嵌め合わせたものであってもよい。 In this embodiment, the heat shield material 307 is provided on the entire circumference in the circumferential direction surrounding the central axis 100a (see FIG. 2). The heat shield material 307 may be provided by forming a film on the inner surface of the sub chamber forming member 201, or a preformed annular member (or cylindrical member) may be provided on the inner surface of the sub chamber forming member 201. It may be fitted.
　遮熱材３０７が材料を堆積して製作する膜の場合、副室形成部材２０１に遮熱材３０７を密着させることができ、放熱効率を高めることができる。また狭小なスペースに配置する場合には、材料を堆積して製作する膜の方が厚みを小さくできるため有利である。一方、例えば切削加工したような部品は、円筒内の任意の位置に容易に取り付けることができる。 When the heat shield material 307 is a film produced by depositing materials, the heat shield material 307 can be brought into close contact with the auxiliary chamber forming member 201, and the heat dissipation efficiency can be improved. Further, when arranging in a narrow space, a film produced by depositing materials is advantageous because the thickness can be reduced. On the other hand, for example, a machined part can be easily attached to an arbitrary position in the cylinder.
　すなわち本実施例の副室式点火装置１００Ａは、点火プラグ１１０のプラグ電極２０３部を収容する副室１０９を形成する副室形成部材２０１と、内燃機関の主燃焼室（エンジン主室）１０４に通じる通路（噴孔）２０４と、を備える副室式点火装置１００Ａであって、副室形成部材２０１をシリンダブヘッド１０２に埋入される第１領域３０３と、主燃焼室１０４に突出する第２領域３０２とに分けた場合に、第１領域３０３のみの内面（内周面）３０３Ａに副室形成部材２０１を形成する材料よりも熱伝導率の小さい遮熱材（第１遮熱材）３０７を備える。これにより、始動時の点火性能を高めることができ、高温時にも十分な冷却を行うことができる。この場合、遮熱材３０７は第１領域３０３の内周面全面に設けられている必要はなく、一部のみとしてもよい。この場合、第１領域３０３において、プラグ電極２０３から離れた部位に対してプラグ電極２０３に近接する部位に遮熱材３０７を設けるようにする。 That is, in the sub-chamber type ignition device 100A of this embodiment, the sub-chamber forming member 201 forming the sub-chamber 109 accommodating the plug electrode 203 part of the spark plug 110 and the main combustion chamber (engine main chamber) 104 of the internal combustion engine A sub-chamber type ignition device 100A including a passage (injection hole) 204 through which the sub-chamber forming member 201 is embedded in a cylinder head 102, and a first region 303 protruding into a main combustion chamber 104. When divided into two regions 302, a heat shield material (first heat shield material) having a lower thermal conductivity than the material for forming the sub chamber forming member 201 on the inner surface (inner peripheral surface) 303A of only the first region 303. 307 is provided. As a result, the ignition performance at the time of starting can be improved, and sufficient cooling can be performed even at a high temperature. In this case, the heat shield material 307 does not have to be provided on the entire inner peripheral surface of the first region 303, and may be only a part of the heat shield material 307. In this case, in the first region 303, the heat shield material 307 is provided at a portion close to the plug electrode 203 with respect to a portion away from the plug electrode 203.
　また、遮熱材３０７の熱伝導率は10 W/mK以下の材料とすることで、始動時の温度を好適に高め、点火性能を高めることができる。すなわち本実施例の副室式点火装置１００Ａの遮熱材（第１遮熱材）３０７は、熱伝導率が10 W/mK以下の材料で形成される。これにより、始動時の温度を好適に高め、点火性能を高めることができる。 Further, by using a material having a thermal conductivity of 10 W / mK or less for the heat shield material 307, the temperature at the time of starting can be appropriately raised and the ignition performance can be improved. That is, the heat shield material (first heat shield material) 307 of the sub-chamber type ignition device 100A of this embodiment is formed of a material having a thermal conductivity of 10 W / mK or less. As a result, the temperature at the time of starting can be suitably increased and the ignition performance can be improved.
　また、遮熱材３０７の体積比熱を第１領域３０３よりも小さい材質とすることで、始動時の温度上昇速度を高め、点火性能を高めることができる。 Further, by making the volume specific heat of the heat shield material 307 smaller than that of the first region 303, the temperature rise rate at the time of starting can be increased and the ignition performance can be improved.
　すなわち遮熱材（第１遮熱材）３０７は、副室形成部材２０１を形成する材料の体積比熱よりも小さい体積比熱を有する材料で形成される。これにより、遮熱材３０７の温度上昇速度を高め、始動時の点火性能を高めることができる。 That is, the heat shield material (first heat shield material) 307 is formed of a material having a volume specific heat smaller than the volume specific heat of the material forming the sub chamber forming member 201. As a result, the temperature rise rate of the heat shield material 307 can be increased, and the ignition performance at the time of starting can be improved.
　遮熱材３０７の材料として、例えばシリカ強化したアルマイト（アルミ酸化被膜）又は多孔質セラミックスなどを用いると良い。すなわち遮熱材（第１遮熱材）３０７は、アルミ酸化被膜又は多孔質セラミックスで構成されるとよい。 As the material of the heat shield material 307, for example, silica-reinforced alumite (aluminum oxide film) or porous ceramics may be used. That is, the heat shield material (first heat shield material) 307 is preferably made of an aluminum oxide film or porous ceramics.
　図４は、本発明の第１実施例に係る副室式点火装置の点火プラグ２０３周辺の拡大断面図である。なお、シリンダヘッド１０１は図示を省略している。 FIG. 4 is an enlarged cross-sectional view of the vicinity of the spark plug 203 of the sub-chamber ignition device according to the first embodiment of the present invention. The cylinder head 101 is not shown.
　始動時の点火性能を高めることを目的に、エンジンの点火タイミングより早期に、予め火花４０１を発生させる予備点火を行う。これにより、点火プラグ２０３の周囲のガス４０２の温度が昇温され、点火性能を高めることができる。このとき、副室形成部材２０１の内周に設けられた遮熱材３０７に高温ガス４０２が接触することで、遮熱材３０７の温度が上昇して熱損失を低減することにより、予備点火による熱を効率的に点火性能の向上に用いることができる。 For the purpose of improving the ignition performance at the time of starting, pre-ignition to generate spark 401 is performed earlier than the ignition timing of the engine. As a result, the temperature of the gas 402 around the spark plug 203 is raised, and the ignition performance can be improved. At this time, the high-temperature gas 402 comes into contact with the heat-shielding material 307 provided on the inner circumference of the sub-chamber forming member 201, so that the temperature of the heat-shielding material 307 rises and the heat loss is reduced. Heat can be efficiently used to improve ignition performance.
　すなわち、本実施例の副室式点火装置の点火時期を制御する制御装置１１８は、点火プラグ１１０のプラグ電極２０３部を収容する副室１０９を形成する副室形成部材と、内燃機関の主燃焼室（エンジン主室）１０４に通じる通路（噴孔）２０４と、を備え、副室形成部材２０１をシリンダブヘッド１０２に埋入される第１領域３０３と、主燃焼室１０４に突出する第２領域３０２とに分けた場合に、第１領域３０３のみの内面（内周面）３０３Ａに副室形成部材２０１を形成する材料よりも熱伝導率の小さい遮熱材（第１遮熱材）３０７を形成した副室式点火装置１００Ａを用い、制御装置１１８で定められた通常の点火時期（正規の点火時期）よりも早期に予備点火するように制御する。これにより、点火プラグ周囲ガスの温度を好適に高め、始動時の点火性能を高めることができる。 That is, the control device 118 that controls the ignition timing of the sub-chamber type ignition device of the present embodiment includes a sub-chamber forming member that forms the sub-chamber 109 that houses the plug electrode 203 of the spark plug 110, and the main combustion of the internal combustion engine. A first region 303 having a passage (injection hole) 204 leading to the chamber (engine main chamber) 104 and having an auxiliary chamber forming member 201 embedded in the cylinder head 102 and a second region projecting into the main combustion chamber 104. When divided into the region 302, the heat shield material (first heat shield material) 307 having a lower thermal conductivity than the material for forming the sub chamber forming member 201 on the inner surface (inner peripheral surface) 303A of only the first region 303. The sub-chamber type ignition device 100A formed in the above is used to control the pre-ignition so as to pre-ignite earlier than the normal ignition timing (regular ignition timing) defined by the control device 118. As a result, the temperature of the gas around the spark plug can be suitably raised, and the ignition performance at the time of starting can be improved.
　図５を用いて、遮熱材３０７に導電性材料を用いた場合の火花５０１の挙動の一例を説明する。図５は、本発明の第１実施例に係る副室式点火装置１００Ａの点火プラグ２０３周辺の拡大断面図である。 An example of the behavior of the spark 501 when a conductive material is used for the heat shield material 307 will be described with reference to FIG. FIG. 5 is an enlarged cross-sectional view of the vicinity of the spark plug 203 of the sub-chamber ignition device 100A according to the first embodiment of the present invention.
　プラグ電極２０３では、中心電極５０２を正極として、負極（接地電極）２０３Ｂとの間に火花が生じる。ここで遮熱材３０７が導電性材料である場合、中心電極２０３Ａと遮熱材３０７との間で火花が生じることがあり、火花により遮熱材３０７が消耗する。そこで、遮熱材３０７を非導電性材料、例えば多孔質セラミックス材料とすることで、遮熱材３０７が接地電位となることを防止し、中心電極２０３Ａと遮熱材３０７との間の火花の発生を防止又は抑制する。これにより、遮熱材３０７は火花による摩耗の発生が防止又は抑制される。 In the plug electrode 203, a spark is generated between the center electrode 502 as the positive electrode and the negative electrode (ground electrode) 203B. Here, when the heat shield material 307 is a conductive material, sparks may occur between the center electrode 203A and the heat shield material 307, and the heat shield material 307 is consumed by the sparks. Therefore, by using a non-conductive material, for example, a porous ceramic material, for the heat shield material 307, it is possible to prevent the heat shield material 307 from becoming a ground potential, and to prevent sparks between the center electrode 203A and the heat shield material 307. Prevent or suppress the occurrence. As a result, the heat shield material 307 is prevented or suppressed from being worn by sparks.
　すなわち遮熱材（第１遮熱材）３０７は、非導電性の材料で構成されることが好ましい。これにより、遮熱材３０７の接地による火花の発生を防止又は抑制し、遮熱材３０７の摩耗を防止又は抑制することができる。 That is, the heat shield material (first heat shield material) 307 is preferably made of a non-conductive material. Thereby, the generation of sparks due to the grounding of the heat shield material 307 can be prevented or suppressed, and the wear of the heat shield material 307 can be prevented or suppressed.
　［変更例１］　図６を用いて、第１実施例の変更例（第１変更例）を説明する。図６は、本発明の第１実施例の変更例（第１変更例）に係る副室式点火装置１００Ａ－１のプラグ電極２０３周辺の拡大断面図である。 [Modification 1] A modification of the first embodiment (first modification) will be described with reference to FIG. FIG. 6 is an enlarged cross-sectional view of the vicinity of the plug electrode 203 of the sub-chamber ignition device 100A-1 according to the modified example (first modified example) of the first embodiment of the present invention.
　本変更例では、上述した実施例の遮熱材３０７の代りに、副室形成部材２０１に埋入するように遮熱材３０７－１を設けている。これ以外の構成は、第１実施例と同様に構成される。 In this modified example, the heat shield material 307-1 is provided so as to be embedded in the auxiliary chamber forming member 201 instead of the heat shield material 307 of the above-described embodiment. Other configurations are the same as those in the first embodiment.
　このような構成にすることで、遮熱材３０７－１の剥落を防止し、強度を高めることができる。また、点火プラグ２０３との距離が離れることで、小さなスペース内に点火プラグ２０３及び遮熱材３０７－１を部材間の干渉を防いで配置することができる。 With such a configuration, it is possible to prevent the heat shield material 307-1 from peeling off and increase the strength. Further, by increasing the distance from the spark plug 203, the spark plug 203 and the heat shield material 307-1 can be arranged in a small space while preventing interference between the members.
　遮熱材３０７－１は、副室形成部材２０１の内面に形成した溝に遮熱膜を形成することにより副室形成部材２０１に埋入されたものであってもよいし、副室形成部材２０１の内面に形成した溝にあらかじめ成形した遮熱部材を埋入したものであってもよい。すなわち第１変更例では、遮熱材（第１遮熱材）３０７－１は第１領域３０３の内面に埋入される。 The heat shield material 307-1 may be embedded in the sub chamber forming member 201 by forming a heat shield film in the groove formed on the inner surface of the sub chamber forming member 201, or may be embedded in the sub chamber forming member 201. A heat shield member molded in advance may be embedded in a groove formed on the inner surface of 201. That is, in the first modification, the heat shield material (first heat shield material) 307-1 is embedded in the inner surface of the first region 303.
　［変更例２］　図７を用いて、第１実施例の変更例（第２変更例）を説明する。図７は、本発明の第１実施例の変更例（第２変更例）に係る副室式点火装置１００Ａ－２を示す図であり、副室式点火装置１００Ａ－２の下端側からプラグ電極２０３の方向を見た断面図である。すなわち図７は、副室１０９の断面（中心軸線１００ａに垂直な断面）において、副室１０９の噴孔２０４側の先端部側から、プラグ電極２０３方向へと指向した視点を示す。 [Modification 2] A modification of the first embodiment (second modification) will be described with reference to FIG. 7. FIG. 7 is a diagram showing a sub-chamber ignition device 100A-2 according to a modification (second modification) of the first embodiment of the present invention, and is a plug electrode from the lower end side of the sub-chamber ignition device 100A-2. It is sectional drawing which looked at the direction of 203. That is, FIG. 7 shows a viewpoint oriented in the direction of the plug electrode 203 from the tip end side of the sub chamber 109 on the injection hole 204 side in the cross section of the sub chamber 109 (the cross section perpendicular to the central axis 100a).
　図７において、プラグ電極２０３は断面中心（中心軸線１００ａが通る断面位置）から径方向外側に延設されるように設けられている。このとき遮熱材３０７－２は、周方向に一様の厚さに設けず、一部分に切り欠き部３０７－２Ａを設けても良い。すなわち、遮熱材（第１遮熱材）３０７－２は、周方向の一部に切欠き部３０７－２Ａを有していてもよい。 In FIG. 7, the plug electrode 203 is provided so as to extend radially outward from the center of the cross section (the position of the cross section through which the central axis 100a passes). At this time, the heat shield material 307-2 may not be provided with a uniform thickness in the circumferential direction, and a notch portion 307-2A may be provided in a part thereof. That is, the heat shield material (first heat shield material) 307-2 may have a notch portion 307-2A in a part in the circumferential direction.
　本変更例の遮熱材３０７－２は、第１実施例の遮熱材３０７に切り欠き部３０７－２Ａを設けたものであり、その他の構成は第１実施例と同様に構成される。また本変更例の遮熱材３０７－２は、変更例１と同様に、副室形成部材２０１に埋入するように設けてもよい。 The heat shield material 307-2 of this modified example is the heat shield material 307 of the first embodiment provided with a notch 307-2A, and other configurations are the same as those of the first embodiment. Further, the heat shield material 307-2 of the present modification example may be provided so as to be embedded in the sub chamber forming member 201 as in the modification example 1.
　遮熱材３０７－２は、切り欠き部３０７－２Ａの位置をプラグ電極２０３の位置と一致させることで、遮熱材３０７－２とプラグ電極２０３との干渉が防止される。また、遮熱材３０７－２は周方向に一様の厚さであることに限らず、周方向に偏りを設けても良い。このように構成することで、本変更例の副室式点火装置１００Ａは、高負荷時の温度分布を鑑みながら、好適に冷却を行うことができる遮熱材３０７の構成にすることができる。 The heat shield material 307-2 prevents interference between the heat shield material 307-2 and the plug electrode 203 by matching the position of the cutout portion 307-2A with the position of the plug electrode 203. Further, the heat shield material 307-2 is not limited to having a uniform thickness in the circumferential direction, and a bias may be provided in the circumferential direction. With this configuration, the sub-chamber ignition device 100A of this modified example can be configured as a heat shield material 307 that can be suitably cooled in consideration of the temperature distribution at the time of high load.
　［変更例３］　図８を用いて、第１実施例の変更例（第３変更例）を説明する。図８に、本発明に係る副室式点火装置１００Ａ－３の拡大断面図を示す。図８は、本発明の第１実施例の変更例（第３変更例）に係る副室式点火装置１００Ａ－３の拡大断面図である。 [Modification 3] A modification of the first embodiment (third modification) will be described with reference to FIG. FIG. 8 shows an enlarged cross-sectional view of the sub-chamber ignition device 100A-3 according to the present invention. FIG. 8 is an enlarged cross-sectional view of the sub-chamber ignition device 100A-3 according to a modified example (third modified example) of the first embodiment of the present invention.
　第１実施例の遮熱材３０７は副室１０９の軸方向に一様の厚さである必要はなく、本変更例のように軸方向に偏りを設けた遮熱材３０７－３であっても良い。図８の遮熱材３０７－３では、遮熱材３０７－３Ａの厚みが遮熱材３０７－３Ｂの厚みよりも大きくなるように構成されている。遮熱材３０７－３Ａは、第１領域３０３（図３参照）において、プラグ電極２０３の近傍に設けられる遮熱材であり、中心軸線１００ａに沿う方向において、プラグ電極２０３から離れたその他の部位（範囲）には遮熱材３０７－３Ｂを設ける。 The heat shield material 307 of the first embodiment does not have to have a uniform thickness in the axial direction of the sub chamber 109, and is a heat shield material 307-3 having a bias in the axial direction as in this modified example. Is also good. In the heat shield material 307-3 of FIG. 8, the thickness of the heat shield material 307-3A is configured to be larger than the thickness of the heat shield material 307-3B. The heat shield material 307-3A is a heat shield material provided in the vicinity of the plug electrode 203 in the first region 303 (see FIG. 3), and is another portion separated from the plug electrode 203 in the direction along the central axis 100a. A heat shield material 307-3B is provided in (range).
　言い換えれば、遮熱材３０７－３Ａは、中心軸線１００ａに沿う方向において、プラグ電極２０３が設けられた範囲とオーバーラップする副室形成部材２０１の内面部（内周面部）を含む範囲に設けられ、遮熱材３０７－３Ｂは遮熱材３０７－３Ａは遮熱材３０７－３Ａの噴孔２０４側の端部から噴孔２０４側の内面部に設けられている。 In other words, the heat shield material 307-3A is provided in the direction along the central axis 100a, in a range including the inner surface portion (inner peripheral surface portion) of the sub chamber forming member 201 that overlaps the range in which the plug electrode 203 is provided. The heat shield material 307-3B is provided on the heat shield material 307-3A from the end portion of the heat shield material 307-3A on the injection hole 204 side to the inner surface portion on the injection hole 204 side.
　遮熱材３０７－３Ａは、このように構成することで、予熱点火による高温ガスを好適に保温し、点火性能を向上すると同時に、高負荷時の冷却を十分に行うことができる。 By configuring the heat shield material 307-3A in this way, it is possible to suitably retain the high temperature gas produced by preheating ignition, improve the ignition performance, and at the same time sufficiently perform cooling under a high load.
　すなわち遮熱材（第１遮熱材）３０７－３は軸方向において厚みが異なっており、プラグ電極２０３の近傍に設けられる第１遮熱材３０７－３Ａは、プラグ電極２０３から離れた位置に設けられる第１遮熱材３０７－３Ｂに比べて、厚みが大きい。これにより、点火プラグ周囲ガスの温度を好適に高め、始動時の点火性能を高めると同時に、高負荷時の冷却を十分に行うことができる。特に、遮熱材３０７－３Ａの厚みが遮熱材３０７－３Ｂの厚みよりも大きいことで、プラグ電極２０３の近傍のガスの温度を高める効果が高まる。そのため、上述した予備点火を行う場合に、プラグ電極２０３の近傍のガスの温度を高める効果がより高まる。 That is, the heat shield material (first heat shield material) 307-3 has a different thickness in the axial direction, and the first heat shield material 307-3A provided in the vicinity of the plug electrode 203 is located at a position away from the plug electrode 203. The thickness is larger than that of the first heat shield material 307-3B provided. As a result, the temperature of the gas around the spark plug can be suitably raised to improve the ignition performance at the time of starting, and at the same time, sufficient cooling at the time of high load can be performed. In particular, when the thickness of the heat shield material 307-3A is larger than the thickness of the heat shield material 307-3B, the effect of increasing the temperature of the gas in the vicinity of the plug electrode 203 is enhanced. Therefore, when the above-mentioned pre-ignition is performed, the effect of raising the temperature of the gas in the vicinity of the plug electrode 203 is further enhanced.
　その他の構成は第１実施例と同様に構成される。また本変更例の遮熱材３０７－３は、変更例１と同様に副室形成部材２０１に埋入するように設けてもよいし、変更例２と同様な切り欠き部３０７－２Ａを設けてもよい。 Other configurations are the same as those in the first embodiment. Further, the heat shield material 307-3 of the present modification example may be provided so as to be embedded in the sub-chamber forming member 201 as in the modification example 1, or a notch portion 307-2A similar to the modification example 2 may be provided. You may.
　［実施例２］　本発明の第２実施例に係る副室式点火装置１００Ｂについて、図９を用いて以下説明する。図９は、本発明の第２実施例に係る副室式点火装置１００Ｂの拡大断面図である。 [Example 2] The sub-chamber ignition device 100B according to the second embodiment of the present invention will be described below with reference to FIG. FIG. 9 is an enlarged cross-sectional view of the sub-chamber ignition device 100B according to the second embodiment of the present invention.
　図９において、副室形成部材２０１のうちシリンダヘッド１０１に挿入される部材領域（第１領域）３０３は、一点鎖線Ｌ１で示すように、プラグ電極２０３を収容するＬ字状に形成されている。言い換えれば、本実施例の副室式点火装置１００Ｂでは、副室１０９は軸方向に延設される第１副室１０９Ａと第１副室１０９Ａの一端部から軸方向に垂直な方向に延設される第２副室１０９Ｂとを備える。この場合、プラグ電極２０３は第２副室１０９Ｂに配置される。また、遮熱材（第１遮熱材）３０７Ｂは第２副室１０９Ｂの内面９０１Ａ，９０１Ｂに設けられる。第１副室１０９Ａは円筒状であり、第２副室１０９Ｂは第１副室１０９Ａの上端部（プラグ電極２０３側の一端部）から軸方向に垂直な方向に延設される。遮熱材３０７Ｂが設けられる第２副室１０９Ｂの内面は、中心電極２０３Ａと対向する内面９０１Ａを含む。 In FIG. 9, the member region (first region) 303 of the auxiliary chamber forming member 201 inserted into the cylinder head 101 is formed in an L shape accommodating the plug electrode 203 as shown by the alternate long and short dash line L1. .. In other words, in the sub-chamber type ignition device 100B of the present embodiment, the sub-chamber 109 extends in the direction perpendicular to the axial direction from one end of the first sub-chamber 109A and the first sub-chamber 109A extending in the axial direction. It is provided with a second sub-chamber 109B to be used. In this case, the plug electrode 203 is arranged in the second sub chamber 109B. Further, the heat shield material (first heat shield material) 307B is provided on the inner surfaces 901A and 901B of the second sub chamber 109B. The first sub chamber 109A has a cylindrical shape, and the second sub chamber 109B extends in a direction perpendicular to the axial direction from the upper end portion (one end portion on the plug electrode 203 side) of the first sub chamber 109A. The inner surface of the second sub chamber 109B provided with the heat shield material 307B includes an inner surface 901A facing the center electrode 203A.
　本実施例では、プラグ電極２０３が第１副室３０３Ｃの容積よりも小さい容積の第２副室３０３Ｄに配置されるため、第１実施例の効果に加えて、予熱点火時の高温ガスの保温を好適に行い、始動時の点火性能を高めることができるという効果を奏することができる。
さらに、遮熱材９０２がプラグ電極２０３を囲む第２副室３０３Ｄの内面９０１Ａ，９０１Ｂに設けられることにより、遮熱材９０２が設けられない第１副室３０３Ｃの内面（内周面）３０３Ａからシリンダヘッド１０１への放熱効果が高まるため、高負荷時の冷却を十分に行うことができる。 In this embodiment, since the plug electrode 203 is arranged in the second sub chamber 303D having a volume smaller than the volume of the first sub chamber 303C, in addition to the effect of the first embodiment, the heat retention of the high temperature gas at the time of preheating ignition is maintained. It is possible to achieve the effect that the ignition performance at the time of starting can be improved.
Further, since the heat shield material 902 is provided on the inner surfaces 901A and 901B of the second sub chamber 303D surrounding the plug electrode 203, the inner surface (inner peripheral surface) 303A of the first sub chamber 303C in which the heat shield material 902 is not provided is provided. Since the heat dissipation effect to the cylinder head 101 is enhanced, it is possible to sufficiently cool the cylinder head 101 when the load is high.
　本実施例に示した副室の構造は一例であり、その形状は円筒状およびＬ字状に限られるものではない。 The structure of the sub-chamber shown in this example is an example, and its shape is not limited to a cylindrical shape and an L-shape.
　その他の構成は実施例１と同様であり、さらに第１実施例及びその変更例で説明した遮熱材３０７，３０７－１，３０７－２，３０７－３に係る構成を本実施例に適宜組み合わせることができる。 Other configurations are the same as those in the first embodiment, and the configurations according to the heat shield materials 307, 307-1, 307-2, 307-3 described in the first embodiment and its modified examples are appropriately combined with this embodiment. be able to.
　［実施例３］　本発明の第３実施例に係る副室式点火装置１００Ｃについて、図１０及び図１１を用いて以下説明する。図１０は、本発明の第３実施例に係る副室式点火装置１００Ｃの拡大断面図である。図１１は、本発明の第３実施例に係る副室点火装置１００Ｃの内部と外部のガス温度の時間履歴を示した図である。 [Example 3] The sub-chamber ignition device 100C according to the third embodiment of the present invention will be described below with reference to FIGS. 10 and 11. FIG. 10 is an enlarged cross-sectional view of the sub-chamber ignition device 100C according to the third embodiment of the present invention. FIG. 11 is a diagram showing a time history of gas temperatures inside and outside the sub-chamber ignition device 100C according to the third embodiment of the present invention.
　第３実施例では、主燃焼室１０４に突出する第２領域３０２において、主燃焼室１０４に接する面（露出面又は外側面）に遮熱材１００１を設ける。すなわち第２領域３０２は、内燃機関の主燃焼室１０４に面する外面に、副室形成部材２０１を形成する材料よりも熱伝導性の低い遮熱材（第２遮熱材）１００１を備える。それ以外の構成は第１実施例と同様である。このように構成することで、高負荷において領域３０２への主燃焼室１０４からの入熱を抑制することができる。それ以外の構成は第１実施例と同様であり、遮熱材３０７は第１実施例と同様に設けられている。遮熱材３０７は変更例として説明した遮熱材３０７－１，３０７－２，３０７－３のように変更するができ、第２実施例の構成に本実施例の遮熱材１００１を適用することも可能である。 In the third embodiment, in the second region 302 protruding from the main combustion chamber 104, the heat shield material 1001 is provided on the surface (exposed surface or outer surface) in contact with the main combustion chamber 104. That is, the second region 302 includes a heat shield material (second heat shield material) 1001 having a lower thermal conductivity than the material forming the sub chamber forming member 201 on the outer surface facing the main combustion chamber 104 of the internal combustion engine. Other configurations are the same as those in the first embodiment. With this configuration, it is possible to suppress heat input from the main combustion chamber 104 into the region 302 under a high load. The other configurations are the same as those in the first embodiment, and the heat shield material 307 is provided in the same manner as in the first embodiment. The heat shield material 307 can be changed as in the heat shield materials 307-1, 307-2, and 307-3 described as modification examples, and the heat shield material 1001 of the present embodiment is applied to the configuration of the second embodiment. It is also possible.
　本実施例では、遮熱材１００１の冷却は、吸気行程中の空気との熱交換によって行う。図１１は、エンジンの各行程におけるガス温度の推移を、副室１０９内部と副室１０９外部のそれぞれについて示しており、副室１０９内部のガス温度は、圧縮行程において主燃焼室１０４から流入する新気によってわずかな時間低下するのみであり、副室１０９内の流動も弱い一方で、副室１０９外部のガスは、吸気行程から新気によって冷却される。また、主燃焼室１０４の流動によって生じた流れにより熱伝達が好適に行われ、遮熱材１００１の冷却が可能になる。 In this embodiment, the heat shield material 1001 is cooled by exchanging heat with air during the intake stroke. FIG. 11 shows the transition of the gas temperature in each stroke of the engine for each of the inside of the sub chamber 109 and the outside of the sub chamber 109, and the gas temperature inside the sub chamber 109 flows in from the main combustion chamber 104 in the compression stroke. The fresh air reduces the temperature for only a short time, and the flow inside the sub chamber 109 is weak, while the gas outside the sub chamber 109 is cooled by the fresh air from the intake stroke. Further, heat transfer is preferably performed by the flow generated by the flow of the main combustion chamber 104, and the heat shield material 1001 can be cooled.
　すなわち本実施例の副室式点火装置１００Ｃは、第２領域３０２の主燃焼室１０４に面する外面に、副室形成部材を形成する材料の熱伝導率よりも小さい熱伝導率の材料で形成される遮熱材１００１を設ける。これにより本実施例の副室式点火装置１００Ｃは、高負荷時における主燃焼室１０４から第２領域３０２への入熱を抑制することができる。 That is, the sub-chamber ignition device 100C of the present embodiment is formed of a material having a thermal conductivity smaller than that of the material forming the sub-chamber forming member on the outer surface of the second region 302 facing the main combustion chamber 104. The heat shield material 1001 is provided. As a result, the sub-chamber ignition device 100C of this embodiment can suppress heat input from the main combustion chamber 104 to the second region 302 at the time of high load.
　なお、本発明は上記した各実施例に限定されるものではなく、様々な変形例が含まれる。例えば、上記した実施例は本発明を分かりやすく説明するために詳細に説明したものであり、必ずしも全ての構成を備えるものに限定されるものではない。また、ある実施例の構成の一部を他の実施例の構成に置き換えることが可能であり、また、ある実施例の構成に他の実施例の構成を加えることも可能である。また、各実施例の構成の一部について、他の構成の追加・削除・置換をすることが可能である。 The present invention is not limited to each of the above-described embodiments, and includes various modifications. For example, the above-described embodiment has been described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to the one including all the configurations. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Further, it is possible to add / delete / replace a part of the configuration of each embodiment with another configuration.
　１００Ａ，１００Ｂ，１００Ｃ…副室式点火装置、１０２…シリンダヘッド、１０４…内燃機関の主燃焼室（エンジン主室）、１０９…副室、１０９Ａ…第１副室、１０９Ｂ…第２副室、１１０…点火プラグ、１１８…制御装置（ＥＣＵ）、２０１…副室形成部材、２０３…プラグ電極、２０４…通路（噴孔）、３０２…副室形成部材２０１の第２領域、３０３…副室形成部材２０１の第１領域、３０３Ａ…第１領域３０３の内面（内周面）、３０７，３０７－１，３０７－２，３０７－３，３０７－３Ａ，３０７－３Ｂ，３０７Ｂ…遮熱材（第１遮熱材、第１低熱伝導率部材）、３０７－２Ａ…遮熱材３０７－２の切欠き部、９０１Ａ，９０１Ｂ…第２副室１０９Ｂの内面、１００１…遮熱材（第２遮熱材、第２低熱伝導率部材）。 100A, 100B, 100C ... Sub-chamber type spark plug, 102 ... Cylinder head, 104 ... Main combustion chamber (engine main chamber) of internal combustion engine, 109 ... Sub-chamber, 109A ... First sub-chamber, 109B ... Second sub-chamber, 110 ... spark plug, 118 ... control device (ECU), 201 ... sub chamber forming member, 203 ... plug electrode, 204 ... passage (injection hole), 302 ... second region of sub chamber forming member 201, 303 ... sub chamber forming First region of member 201, 303A ... Inner surface (inner peripheral surface) of first region 303, 307, 307-1, 307-2, 307-3, 307-3A, 307-3B, 307B ... Heat shield material (No. 1) 1 heat shield material, first low thermal conductivity member), 307-2A ... notch portion of heat shield material 307-2, 901A, 901B ... inner surface of second sub chamber 109B, 1001 ... heat shield material (second heat shield) Material, second low thermal conductivity member).

Claims (11)

  1. 　点火プラグのプラグ電極を収容する副室を形成する副室形成部材と、内燃機関の主燃焼室に通じる通路と、を備える副室式点火装置であって、
    　前記副室形成部材をシリンダヘッドに埋入される第１領域と、内燃機関の主燃焼室に突出する第２領域とに分けた場合に、前記第１領域のみの前記副室形成部材の内面に前記副室形成部材を形成する材料よりも熱伝導率の小さい第１遮熱材を備えることを特徴とする副室式点火装置。     A sub-chamber type ignition device including a sub-chamber forming member forming a sub-chamber for accommodating a plug electrode of a spark plug and a passage leading to a main combustion chamber of an internal combustion engine.
    When the sub-chamber forming member is divided into a first region embedded in the cylinder head and a second region protruding into the main combustion chamber of the internal combustion engine, the inner surface of the sub-chamber forming member only in the first region. The sub-chamber type ignition device is provided with a first heat-shielding material having a thermal conductivity smaller than that of the material forming the sub-chamber forming member.
  2. 　請求項1に記載の副室式点火装置であって、
    　前記第１遮熱材は、熱伝導率が10 W/mK以下の材料で形成されることを特徴とする副室式点火装置。     The sub-chamber ignition device according to claim 1.
    The first heat shield material is a sub-chamber type ignition device characterized in that it is made of a material having a thermal conductivity of 10 W / mK or less.
  3. 　請求項１に記載の副室式点火装置であって、
    　前記第１遮熱材は、前記副室形成部材を形成する材料の体積比熱よりも小さい体積比熱を有する材料で形成されることを特徴とする副室式点火装置。     The sub-chamber type ignition device according to claim 1.
    The first heat shield material is a sub-chamber type ignition device characterized in that it is formed of a material having a volume specific heat smaller than the volume specific heat of the material forming the sub-chamber forming member.
  4. 　請求項１に記載の副室式点火装置であって、
    　前記第１遮熱材は、シリカ強化したアルミ酸化被膜又は多孔質セラミックスで構成されることを特徴とする副室式点火装置。     The sub-chamber type ignition device according to claim 1.
    The first heat shield is a sub-chamber ignition device characterized by being composed of a silica-reinforced aluminum oxide film or porous ceramics.
  5. 　請求項１に記載の副室式点火装置であって、
    　前記第１遮熱材は、非導電性の材料で構成されることを特徴とする副室式点火装置。     The sub-chamber type ignition device according to claim 1.
    The first heat shield material is a sub-chamber type ignition device characterized in that it is made of a non-conductive material.
  6. 　請求項１に記載の副室式点火装置であって、
    　前記第１遮熱材は、前記第１領域の内面に埋入されることを特徴とする副室式点火装置。     The sub-chamber type ignition device according to claim 1.
    The sub-chamber type ignition device, wherein the first heat shield material is embedded in the inner surface of the first region.
  7. 　請求項１に記載の副室式点火装置であって、
    　前記第１遮熱材は、周方向の一部に切欠き部を有していることを特徴とする副室式点火装置。     The sub-chamber type ignition device according to claim 1.
    The first heat shield material is a sub-chamber type ignition device characterized in that it has a notch in a part in the circumferential direction.
  8. 　請求項１に記載の副室式点火装置であって、
    　前記第１遮熱材は、軸方向において、厚みが異なっており、
    　前記プラグ電極の近傍に設けられる第１遮熱材は、前記プラグ電極から離れた位置に設けられる第１遮熱材に比べて、厚みが大きいことを特徴とする副室式点火装置。     The sub-chamber type ignition device according to claim 1.
    The first heat shield material has a different thickness in the axial direction.
    The first heat shield material provided in the vicinity of the plug electrode is a sub-chamber type ignition device characterized in that the thickness is larger than that of the first heat shield material provided at a position away from the plug electrode.
  9. 　請求項１に記載の副室式点火装置であって、
    　前記副室は、軸方向に延設される第１副室と、前記第１副室の一端部から前記軸方向に垂直な方向に延設される第２副室と、を備え、
    　前記プラグ電極は、前記第２副室に配置され、
    　前記第１遮熱材は、第２副室の内面に設けられることを特徴とする副室式点火装置。     The sub-chamber type ignition device according to claim 1.
    The sub-chamber includes a first sub-chamber extending in the axial direction and a second sub-chamber extending in a direction perpendicular to the axial direction from one end of the first sub-chamber.
    The plug electrode is arranged in the second sub-chamber.
    The first heat shield material is a sub-chamber type ignition device characterized in that it is provided on the inner surface of the second sub-chamber.
  10. 　請求項１に記載の副室式点火装置であって、
    　前記第２領域は、内燃機関の主燃焼室に面する外面に、前記副室形成部材を形成する材料よりも熱伝導性の低い第２遮熱材を備えることを特徴とする副室点火装置。     The sub-chamber type ignition device according to claim 1.
    The second region is provided with a second heat shield having a lower thermal conductivity than the material forming the sub chamber forming member on the outer surface of the internal combustion engine facing the main combustion chamber. ..
  11. 　副室式点火装置の点火時期を制御する制御装置であって、
    　請求項１に記載の副室式点火装置を用い、当該制御装置で定められた通常の点火時期よりも早期に予備点火するように制御することを特徴とする副室点火装置の制御装置。     It is a control device that controls the ignition timing of the sub-chamber type ignition device.
    A control device for a sub-chamber ignition device according to claim 1, wherein the sub-chamber ignition device is used to control pre-ignition earlier than the normal ignition timing defined by the control device.
PCT/JP2020/045179 2019-12-27 2020-12-04 Prechamber-type ignition device WO2021131600A1 (en)

Applications Claiming Priority (2)

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JP2019-237751 2019-12-27
JP2019237751A JP7339157B2 (en) 2019-12-27 2019-12-27 Pre-chamber ignition system

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JP2023068723A (en) * 2021-11-04 2023-05-18 日立Astemo株式会社 Engine control device and engine control method

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JPS5675970A (en) * 1979-11-26 1981-06-23 Nissan Motor Co Ltd Plasma ignition plug
JPH08284665A (en) * 1995-04-14 1996-10-29 Mazda Motor Corp Combustion control method for engine and its device
JP2006177249A (en) * 2004-12-22 2006-07-06 Nissan Motor Co Ltd Divided chamber type internal combustion engine
WO2016057556A1 (en) * 2014-10-06 2016-04-14 Advanced Green Innovations, LLC Structures to insulate ignition system high-voltage within a direct injection gaseous diffusion burn fuel prechamber

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FR2846044B1 (en) 2002-10-18 2006-07-14 Peugeot Citroen Automobiles Sa PRECHAMBRE IGNITION DEVICE COATED WITH A REFRACTORY COATING, FOR AN INTERNAL COMBUSTION ENGINE, AND PRE-CHAMBER IGNITER

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Publication number Priority date Publication date Assignee Title
JPS5675970A (en) * 1979-11-26 1981-06-23 Nissan Motor Co Ltd Plasma ignition plug
JPH08284665A (en) * 1995-04-14 1996-10-29 Mazda Motor Corp Combustion control method for engine and its device
JP2006177249A (en) * 2004-12-22 2006-07-06 Nissan Motor Co Ltd Divided chamber type internal combustion engine
WO2016057556A1 (en) * 2014-10-06 2016-04-14 Advanced Green Innovations, LLC Structures to insulate ignition system high-voltage within a direct injection gaseous diffusion burn fuel prechamber

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