JP2006098404A - Viewing structure for optical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a viewing structure for optical device to be installed on a combustion chamber wall, which is applicable to incidence of laser beam in a combustion detecting optical device and in the relation with a laser emitting device so as to be flexibly usable in various purposes in an internal combustion engine. <P>SOLUTION: This viewing structure for optical device 1 comprises a casing 4 installed in a hole 2 of the combustion chamber wall 3. An incoming/outgoing optical element 6 is provided on the combustion chamber side of the casing 4, an automatic centering and positioning seat 7 is provided on the opposite side of the optical element 6, and the seat 7 is connected to a terminal end part 11 of an optical device 10. The seat 7 has a conical bearing surface 8, and a cylindrical guide member having an assembling screw part 9 for fixing the optical device 10 is connected to the conical bearing surface 8. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is a peeping structure for an optical device comprising a casing mounted in a hole in a combustion chamber wall, wherein an incident / exit optical element is provided on the combustion chamber side of the casing and the incident / exit optical element is The present invention relates to an apparatus in which an automatic alignment positioning seat is provided on the opposite side, and the automatic alignment positioning seat is connected to a terminal portion of an optical device formed to correspond to the automatic alignment positioning seat.

  For a peeping structure for establishing optical access to the combustion chamber of an internal combustion engine, for example, a peeping structure for an optoelectronic measuring device as described above is used to study the temporal and local progress of the combustion process. Known in the field of engine development in use. For example, an optical peeping structure in the form of a spherical lens is known (for example, see Patent Document 1). In this peeping structure, the lens and the optical fiber are arranged in a hole of a metal holder with a space between each other. The size of the hole opening, the diameter of the optical fiber, and the distance between the optical fiber and the spherical lens determine the imaging characteristics of the device. Since the entrance window (spherical lens) is permanently connected to the optical device (optical fiber), various other systems that are suitable for being arranged in a certain cylinder head gasket cannot be applied.

  Another optical device is also known in which the incident optical system is realized by a plano-convex rod-shaped lens made of quartz or sapphire, the convex side of which is directed to the combustion chamber, and the plane side is simultaneously the focal plane of the lens. (For example, refer to Patent Document 2). Again, since the plane side is used as a contact surface for the optical fiber or bundle of optical fibers, the optical fiber can be pulled up to the rod-shaped lens during assembly. The rod lens and the optical fiber are housed in a common sensor cover and bonded together by an adhesive, preferably an epoxy adhesive or glass ceramic. When this is applied to a peep structure for another optical device such as a laser ignition device, for example, a fitting / adjusting step that increases the cost is essential.

  A peeping structure used when performing a test operation for making a laser beam incident on a combustion chamber of an internal combustion engine is known (for example, see Non-Patent Document 1). This peeping structure has a substantially cylindrical casing, and an incident optical element is disposed at the end of the casing on the combustion chamber side. This peeping structure is configured to be attached to an adapter screwed into a spark plug hole of a stationary gas-internal combustion engine. The peeping structure is sealed with a sealing shoulder with respect to the adapter, and has an incident opening for laser light on the side opposite to the combustion chamber. Since the incident optical element is 24 mm away from the inner wall of the combustion chamber, when the focal length of the optical element is 30 mm, the ignition point is disposed approximately 6 mm inside the combustion chamber. The disadvantage is that the amount of damage in the laser igniter part is large.

  A peeping structure having a light guiding rod (optical fiber rod) made of quartz glass extending over the entire length and capable of being attached to the combustion chamber wall is also known (for example, see Patent Document 3). . In this peeping structure, it is possible to mount the optical device on the opposite side of the combustion chamber. At this time, the flange of the optical device is positioned between the projecting portion of the peeping structure and the seal ring provided in the peeping structure. Is producing. An optical device that can be used for the peeping structure includes a lens that focuses light guided through the light guiding rod of the peeping structure on the photodetector.

  As a similar embodiment, a peeping structure mounted on the combustion chamber wall has a penetrating rod-like light means (see, for example, Patent Document 4). In the end region of the peeping structure on the side opposite to the combustion chamber, it is possible to place the optical device on a protrusion provided with a seal ring. Fixing the optical axis only by the penetrating light guide rod and the O-ring is inappropriate for operating the image display measuring device or the laser light emitting device by the peeping structure.

European Patent No. 0593413 Specification for Austrian utility model 002910 US Pat. No. 4,484,469 US Pat. No. 4,665,740 Michael McMillian et al., “Laser-Spark Ignition for Natural Gas Fuel Reciprocating Engines”; Gas Machinery Conference 2003 DOE Research Review October 5-8, 2003

  In view of the above situation, an object of the present invention is to improve a peeping structure for an optical device mounted on a combustion chamber wall so that it can be used as flexibly as possible in various applications in an internal combustion engine. In this case, the present invention is applicable to a laser beam used for an optical device for combustion detection and used in relation to a laser light emitting device.

According to the present invention, there is provided a viewing structure for an optical device including a casing mounted in a hole of a combustion chamber wall, wherein an incident / exit optical element is provided on the combustion chamber side of the casing and the incident An automatic alignment positioning seat is provided on the side opposite to the output optical element, and the automatic alignment positioning seat is connected to a terminal portion of an optical device formed to correspond to the automatic alignment positioning seat. ,
The self-aligning positioning seat has a conical seat surface, and a cylindrical guide member provided with an assembly screw portion for fixing the optical device with a screw is connected to the conical seat surface. It is solved by doing. The optical device referred to here is a laser light emitting device, an optical fiber flange (optical fiber bundling terminal portion), or the like.

  The peeping structure according to the present invention shows separate parts that can be flexibly connected to the optical device used each time. The detachable connection structure with the optical device (for example, laser light emitting device or image display measuring device) in the present invention enables easy attachment or detachment, and the optical axis of the peeping structure is adjusted by the conical seating surface of the positioning seat. It becomes possible to match the optical device connected reproducibly. By using the self-aligning positioning seat, the peeping structure is fixed to the end portion of the optical device formed so as to correspond to the positioning seat, and then inserted into the hole in the combustion chamber wall. For example, the peeping structure is fixed through an optical device such as a laser light emitting device fixed to the cylinder head.

  In one preferred embodiment of the present invention, the casing is extended so as to be an optical element sleeve portion having a reduced diameter in the end region on the combustion chamber side, and the transition to the optical element sleeve portion is performed. A conical sealing shoulder is formed in the region, and the sealing shoulder contacts the corresponding stepped portion of the hole in the combustion chamber wall. The stepped portion and the sealing shoulder of the hole function as a stopper for attaching the peeping structure to align the member and seal against the gas in the combustion chamber.

As another preferred embodiment of the present invention, a plano-convex lens that is substantially planarly in close contact with the optical element sleeve portion is disposed at the end of the optical element sleeve portion located on the combustion chamber side. The lens is hermetically connected to the optical element sleeve by soldering, bonding, shrink fitting, or screw fixing, or the incident / exiting optical element (lens or optical fiber) is quartz or It consists of sapphire.
Other features and advantages of the present invention will become apparent from the following description of embodiments using the drawings.

  1 and 2 show a peeping structure 1 according to the invention for an optical device 10, for example a laser emitting device. It is also possible to connect the peeping structure 1 and the light guide flange (optical fiber bundle connector) instead of the laser light emitting device, and only the structure of the terminal portion of the optical device 10 is required at that time. There are no restrictions on the structure and shape of

  As can be seen in particular from FIG. 2, the peeping structure 1 comprises a casing 4 fitted in a hole 2 in the combustion chamber wall (cylinder head in the illustrated example) 3, this casing 4 being formed as a metal socket, An incident / exit optical element 6 is fixed on the opposite side of the combustion chamber 5. On the side opposite to the entrance / exit optical element 6, the casing 4 is provided with an automatic alignment positioning seat 7 that enables connection to a terminal portion 11 of an optical device 10 (for example, a laser emitting device). The positioning seat 7 is constituted by a conical seating surface 8 formed on the ring-shaped shoulder of the casing, and for fixing the optical device 10 in a region extending on the opposite side of the seating surface 8 from the combustion chamber 5. A mounting screw 9 is formed. It is also possible to provide a guide member constituting a receiving and holding structure with respect to the end portion 11 of the optical device 10 instead of the mounting screw 9. In the illustrated embodiment, the end portion 11 of the optical device is constituted by a cover pipe 12 which forms a self-aligning positioning seat with the conical seat surface 8 by means of a conical end surface. In FIG. 2, the laser tube 13 of the laser light emitting device and the coupling mirror 14 of the laser light emitting device disposed at the end are clearly shown.

  The casing 4 of the peeping structure 1 is arranged in the cylinder head to move to the optical element sleeve portion 15 having a reduced outer diameter (diameter: 6 mm to 8 mm, length: 10 mm to 18 mm) in the terminal region on the combustion chamber side. In this case, the peeping structure 1 can be mounted in the immediate vicinity of the injection device 16 shown in FIGS. In the transition region to the optical element sleeve portion 15, the peeping structure 1 is formed with a conical sealing shoulder 17 that presses against the stepped portion of the hole 2 when the peeping structure 1 is attached to the hole 2. . This pressing pressure of the sealing shoulder 17 is created by a fixing device for the optical device 10 not shown here.

  The end of the optical element sleeve portion 15 on the combustion chamber side is provided with a lens as the incident / exit optical element 6 that is substantially flat and in close contact with the optical element sleeve portion 16, and this lens is soldered, bonded, and baked. The optical element sleeve portion 15 is hermetically joined by fitting. The incident / exit optical element 6 is a plano-convex incident lens in the illustrated example, and focuses the laser beam to an ignition point 22 in the combustion chamber 5. It is possible to select a focal length between 3 mm and 25 mm by selecting the entrance and exit optical elements.

  The optical element sleeve portion 15 has a narrow annular gap 18 of about 0.05 mm with respect to the hole 2 in the combustion chamber wall 3 and terminates so as to be flush with the inner surface 19 of the combustion chamber wall 3. Further, since the ring groove 20 between the positioning seat 7 and the sealing shoulder 17 is equipped with the seal ring 21, the amount of the gap is reduced, and the hydrocarbon (HC) discharge amount is positively affected.

  The embodiment of the peeping structure 1 according to the invention shown in FIG. 3 comprises a self-aligning positioning seat 7, whose conical seating surface 8 accurately supports an optical device not shown in detail here. A cylindrical guide member is connected in the direction of the incident / exit optical element 6 by a female screw 9 ′ as a mounting screw. The incident / outgoing optical element 6 has a socket 23, and this socket 23 is screwed into the optical element sleeve portion 15 by a fine screw 26, and the terminal portion of the optical element sleeve portion 15 formed so as to correspond to each other. The incident / outgoing optical element 6 is pressed against 27. In the illustrated embodiment, a ring-shaped gasket 25 made of a heat-resistant material is disposed between the socket 23 and the shoulder 24 of the optical element sleeve portion 15.

  The fixing method shown in FIG. 3 is advantageous when the lens 6 as an optical element is provided with a surface coating that is not fixed by soldering.

  The peeping structure 1, particularly the optical element sleeve portion 15, is long and thin, so that a small space is required in the vicinity of the combustion chamber or in the injection device.

  In addition, although the code | symbol is written in order to make contrast with drawing convenient for the term of a claim, this invention is not limited to the structure of an accompanying drawing by this entry.

Sectional view of a peeping structure according to the invention applied to a cylinder head of an internal combustion engine in relation to a laser emitting device Detailed view of the peeping structure of FIG. Sectional drawing which shows the area | region of the optical element sleeve part in the peeping structure based on this invention

Explanation of symbols

1: Peeping structure 2: Hole 3: Combustion chamber wall
4: Casing 6: Incident / exit optical element (lens, optical fiber)
7: Self-aligning positioning seat 8: Conical seating surface 9, 9 ': Assembly screw part 10: Optical device 11: Terminal part

Claims (7)

An optical device peep structure (1) comprising a casing (4) mounted in a hole (2) in a combustion chamber wall (3), wherein an incident / exit optical element ( 6) and an automatic alignment positioning seat (7) is provided on the opposite side of the incident / exit optical element (6), and is formed so as to correspond to the automatic alignment positioning seat (7). In the automatic alignment positioning seat (7) connected to the terminal portion (11) of the optical device (10),
The self-aligning positioning seat (7) has a conical seating surface (8), and a cylindrical guide member provided with an assembly screw portion (9, 9 ') for fixing the optical device (10) with screws. Is connected to the conical seating surface (8).   The casing (4) is extended so as to be an optical element sleeve (15) having a reduced diameter in the end region on the combustion chamber side, and a cone is formed in the transition region to the optical element sleeve (15). A shaped sealing shoulder (17) is formed, the sealing shoulder contacting the corresponding stepped portion of the hole (2) of the combustion chamber wall (3). Peeping structure described.   At the end of the optical element sleeve portion (15) located on the combustion chamber side, a plano-convex lens (6) that adheres substantially in plane with the optical element sleeve portion is provided as the incident / exit optical element, 3. The peeping structure according to claim 2, wherein the lens (6) is hermetically connected to the optical element sleeve (15) by soldering, bonding, shrink fitting, or fixing with screws.   The optical element sleeve portion (15) is provided with an annular gap (18) with respect to the combustion chamber wall (3), and an end is formed so as to be flush with the inner surface (19) of the combustion chamber wall (3). The peeping structure according to claim 2 or 3, wherein the peeping structure is provided.   5. A ring groove (20) for receiving a seal ring (21) is provided between the positioning seat (7) and the sealing shoulder (17). The peeping structure according to any one of the above.   The entrance / exit optical element (6) includes a socket (23), and the socket (23) is screwed to the optical element sleeve portion (15) using a fine screw (26) and the entrance / exit The optical element (6) is pressed against an end portion (27) of the optical element sleeve portion (15) formed so as to correspond to the optical element (6), according to any one of claims 1 to 3. Peeping structure described.   The peeping structure according to any one of claims 1 to 6, wherein the incident / exiting optical element (6) is made of quartz or sapphire.

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