JPH0622548U - Sealing device for sub-chamber engine - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] The present invention provides a sealing device for a sub-chamber engine that improves the heat insulation of the sub-chamber and achieves a high temperature and prevents the generation of HC and smoke. According to the present invention, a sub chamber member is composed of an upper member 5 and a lower member 4, and a heat shield gasket 25 is arranged between a lower surface of the lower member 4 and an upper surface of the cylinder block 11. The heat flow from the lower member 4 to the cylinder block 11 is blocked by 25. The heat shield gasket 25 is
It is composed of a ceramic plate 23 made of potassium titanate whiskers, potassium titanate fibers, partially stabilized zirconia or aluminum titanate, which is a low thermal conductive material ceramics, and an outer plate 26 made of metal such as SUS covering the ceramic plate 23.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a sealing device for a subchamber engine in which a subchamber having a heat shield structure formed of subchamber members is arranged in a mounting hole of a cylinder head.

[0002]

[Prior art]

 Conventionally, as a sub-chamber engine, a sub-chamber member that forms a sub-chamber is fitted into a mounting hole formed in a cylinder head having an intake / exhaust port, and fuel from the fuel injection nozzle is introduced into the sub-chamber to the sub-chamber member. It is disclosed that a fuel injection hole for spraying and a communication hole communicating with the main chamber are formed and a cooling water chamber is provided on the outer periphery of a sub chamber member formed in the cylinder head. Further, the sub-chamber member is a lower member as a hot plug having a communication hole for communicating the sub-chamber with the main chamber, and an upper member having a fuel injection hole for injecting fuel from a fuel injection nozzle into the sub-chamber. What is produced with a member is disclosed.

JP-A-62-29752 discloses a cylinder head packing for an internal combustion engine having a pre-combustion chamber. The cylinder head packing is used in an internal combustion engine having a pre-combustion chamber with a part of the bottom surface placed on the cylinder head packing, and the cylinder head packing corresponding to the bottom surface of the pre-combustion chamber. All or part of the area is made of heat-resistant material. This refractory material is plastically deformable and is made from spongy graphite, optionally reinforced with metal, annealed steel or coated graphite.

Further, Japanese Utility Model Laid-Open No. 59-11140 discloses a metal laminated cylinder head gasket for an internal combustion engine with an auxiliary combustion chamber. The cylinder head gasket comprises an upper plate, a lower plate, and an intermediate plate interposed between these plates to form a gasket base material, and a portion of the portion of the cylinder base gasket, which comes into contact with a die forming a sub-combustion chamber of the gasket base material. A heat-resistant compression material such as graphite, which replaces the intermediate plate, is arranged in a range beyond the outer peripheral portion, and the compression material is interposed between the upper and lower plates.

[0005]

[Problems to be solved by the device]

 With respect to the combustion in the swirl chamber type auxiliary combustion chamber, air is introduced into the auxiliary combustion chamber, that is, the auxiliary chamber through the communication hole of the swirl chamber as the piston moves upward. The communication hole is eccentric with respect to the center of the sub chamber, forming a strong swirl in the sub chamber. Therefore, the sub chamber is eccentrically provided on the outer peripheral side of the cylinder, and the sub chamber member made of ceramics that constitutes the sub chamber has a lower surface facing the upper surface of the cylinder block and a seal between the two. Therefore, the gasket is interposed.

Further, in the sub-chamber engine, it is conventionally disclosed that the sub-chamber member constituting the sub-chamber is made of ceramics and the sub-chamber has a heat shield structure. By constructing the sub-chamber with a heat shield structure, the cooling water loss can be reduced, and the rise in temperature of the sub-chamber can reduce the generation of HC and smoke. At this time, when the sub-chamber member is fitted into the mounting hole formed in the cylinder head, a heat shield air layer is formed between the sub-chamber member and the mounting hole of the cylinder head to prevent heat flow from the sub-chamber to the cylinder head. It shuts off and raises the temperature of the sub-chamber.

However, a gasket such as a metal gasket is arranged in a portion where the sub chamber member and the cylinder block face each other, and the heat flow from the sub chamber to the cylinder block is not blocked via the gasket. is the current situation. Therefore, even if the sub-chamber is constructed with a heat shield structure, heat flow through the gasket to the cylinder block, the heat shield structure of the sub-chamber is not fully utilized, and the generation of HC and smoke due to high temperature in the sub-chamber is reduced. However, there is a problem that the cooling water loss due to the cooling water chamber formed in the cylinder block cannot be reduced.

[0008] Therefore, an object of the present invention is to solve the above-mentioned problems. A sub-chamber is constituted by a sub-chamber member made of ceramics so as to have a heat-shielding structure, and is arranged between the sub-chamber member and the cylinder block. The heat-shielding gasket is used as a gasket to block heat flow from the sub-chamber through the gasket to the cylinder block, reducing the generation of HC and smoke due to high temperature in the sub-chamber, and forming the cylinder block. It is an object of the present invention to provide a sealing device for a sub-chamber engine that reduces cooling water loss in the cooling water chamber and suppresses generation of HC and smoke in combustion in the sub-chamber.

[0009]

[Means for Solving the Problems]

 The present invention is configured as follows to achieve the above object. That is, according to this invention, a cylinder block that constitutes a cylinder, a cylinder head attached to the cylinder block via a gasket, and a sub-chamber of a heat shield structure are formed by fitting the cylinder head into a mounting hole formed in the cylinder head. And a sub-chamber engine having a communication hole communicating with the main chamber and a sub-chamber member having a fuel injection hole for spraying fuel from a fuel injection nozzle into the sub-chamber. The present invention relates to a sealing device for a sub-chamber engine, characterized in that the portion of the gasket located between the upper surface of the cylinder block and the upper surface of the cylinder block is a heat-shielding gasket having a heat-shielding structure made of a ceramic low-thermal-conductivity material.

Further, in the sealing device for the sub-chamber engine, the heat shield gasket includes a ceramic plate made of potassium titanate fiber, potassium titanate whiskers, partially stabilized zirconia or aluminum titanate, and the ceramic plate. It is composed of an outer plate made of coated SUS.

Alternatively, in this sub-chamber engine sealing device, the heat shield gasket includes a metal plate made of SUS in which a portion corresponding to a lower surface of the sub-chamber member is formed thin, and a thin portion of the metal plate. And a ceramic plate made of potassium titanate fiber, potassium titanate whiskers, partially stabilized zirconia, or aluminum titanate, which is disposed between the lower surface of the sub chamber member and the lower chamber member.

[0012]

Operation The present invention is configured as described above and operates as follows. That is, the sealing device in this sub-chamber engine is a heat-shielding gasket of a heat-shielding structure in which the gasket portion located in the region between the lower surface of the sub-chamber member and the upper surface of the cylinder block is made of a ceramic low-thermal-conductivity material. Since the heat shield gasket blocks the heat flow from the sub chamber where the temperature has risen, the heat radiation from the sub chamber to the cylinder block is reliably prevented, and the effect of the heat shield structure of the sub chamber is achieved. Is exhibited, the generation of HC and smoke can be reduced, and the cooling water loss can be reduced.

[0013]

【Example】

 An embodiment of a sealing device in a subchamber engine according to the present invention will be described below with reference to the drawings. First, with reference to FIGS. 1 and 2, an embodiment of a sealing device in a sub-chamber engine according to the present invention will be described. FIG. 1 is a sectional view showing an embodiment of a sub-chamber engine according to the present invention, and FIG. 2 is an explanatory view showing a part of a gasket incorporated in the sub-chamber engine of FIG.

As shown in FIG. 1 and FIG. 2, this sub-chamber engine is a swirl chamber type diesel engine, and a cylinder liner 12 constituting a cylinder 13 fitted in a hole 22 of a cylinder block 11, A cylinder head 3 attached to the cylinder block 11 with a gasket 15 interposed therebetween, a sub-chamber member in which a heat-shielding air layer 8 is formed and fitted in an attachment hole 9 formed in the cylinder head 3, and the sub-chamber member. It has a fuel injection nozzle 17 for injecting fuel into a sub chamber 2 which is a swirl chamber of the diesel engine thus formed, and a glow plug 18 arranged in the sub chamber 2. Since the sub chamber member does not apply thermal stress to the sub chamber 2 from the cylinder head 3, the sub chamber member is composed of an upper member 5 and a lower member 4 serving as a hot plug which are divided into two, and are made of ceramics such as silicon nitride. ing. The upper member 5 has a fuel injection hole 20 for injecting fuel from the fuel injection nozzle 17 into the sub chamber 2 and an insertion hole 21 for the glow plug 18. Further, the lower member 4 is formed with a communication hole 7 communicating with the main chamber 1 formed on the cylinder 13 side.

Further, the heat shield structure in this sub-chamber engine is that a damping ring 10 having a sealing function and a cushioning action therebetween is interposed between the upper member 5 and the lower member 4. The damping ring 10 is made of a metal material such as SUS, has a hollow shape in which the inside is cut out, and has a U-shaped cross section having an annular groove that opens toward the sub chamber 2.

The lower member 4 is positioned with respect to the cylinder head 3 by the circumferential positioning member 24, and is fixed to the cylinder head 3 by a fixing ring 6. The upper member 5 and the lower member 4 are made of high-strength ceramics such as silicon nitride. A water jacket or cooling water chamber 14 in which cooling water circulates is formed in the cylinder head 3, and a cooling cut is formed between valve seats so that the cooling water passes between intake and exhaust ports where intake and exhaust valves are seated. The hole 16 is formed. A heat-shielding air layer 8 for reducing the thermal stress of the sub-chamber member is formed in a region covering the outer surfaces of the cylinder head 3, the upper member 5, and the lower member 4.

By forming a heat-shielding air layer 8 between the upper member 5 and the lower member 4 and the inner wall surface of the mounting hole 9 of the cylinder head 3 to form the sub-chamber 2 in a heat-shielding structure, the sub-chamber 2 Although the inside becomes hot, the heat shield structure minimizes the heat flow from the sub-chamber 2 to the cylinder head 3 to reduce the temperature difference in the region of the cylinder head portion 19, thereby causing cracks and cracks in the ceramic lower member 4. Can be prevented.

As described above, the sealing device in this sub-chamber type engine is formed in the cylinder block 11 constituting the cylinder 13, the cylinder head 3 attached to the cylinder block 11 via the gasket 15, and the cylinder head 3. A fuel injection for spraying the fuel from the communication hole 7 and the fuel injection nozzle 17 which are fitted into the mounting hole 9 to form the sub chamber 2 of the heat shield structure and communicate with the main chamber 1 into the sub chamber 2. The sub-chamber member has a hole 20 formed therein, and the sub-chamber member is composed of an upper member 5, a lower member 4, and a damping ring 10 arranged between the two members. In this sealing device, a gasket 15 of a type in which metal gaskets made of a metal such as SUS are laminated is arranged between the upper surface of the cylinder block 11 and the lower surface of the cylinder head 3, and particularly, the lower surface of the lower member 4 and the cylinder. The part of the gasket 15 located in the area between the upper surface of the block 11 and the upper surface of the block 11 is configured as a heat shield gasket 25 having a heat shield structure made of a ceramic low heat conductive material.

The heat shield gasket 25 includes a ceramic plate 23 made of a low heat conductive material made of potassium titanate fiber, potassium titanate whiskers, potassium titanate whiskers, partially stabilized zirconia or aluminum titanate, and the ceramic plate 23. It is composed of an outer plate 26 made of a metal such as SUS that covers the entire surface of the lamic plate 23. Further, in the gasket 15, the ceramic plate 23 is located only on the lower surface of the lower member 4, and the wire ring 27 is incorporated on the outer peripheral surface of the ceramic plate 23. The wire ring 27 is installed along the cylinder bore hole 28 formed in the gasket 15, and significantly increases the surface pressure for preventing gas leakage from the combustion chamber, that is, the main chamber 1, and improves the sealing performance. ing.

Further, by forming the sub chamber member by the upper member 5 and the lower member 4 and disposing the damping ring 10 at the boundary surface between the upper member 5 and the lower member 4, the damping ring 10 fulfills the function of the damping ring and the dimensional variation. Therefore, the lower surface of the cylinder head 3 on the main chamber 1 side and the lower surface of the lower member 4 of the sub chamber member can be set on the same plane. Further, the damping ring 10 can perform the sealing of the boundary interface between the upper member 5 and the lower member 4, and the heat shield formed between the upper member 5 and the lower member 4 and the mounting hole 9 of the cylinder head 3. The air layer 8 can be sealed, gas can be prevented from flowing out to the heat shield air layer 8, and thus the damping ring 10 can reduce the dead volume.

Since the sealing device in this sub-chamber engine is configured as described above, the outer peripheries of the sub-chamber members constituting the sub-chamber 2, that is, the upper member 5 and the lower member 4 are completely outside. It is thermally blocked, and it is possible to greatly improve the heat insulation degree of the sub chamber member 2, that is, the heat shield degree. In particular, it is arranged between the lower surface of the lower member 4 and the upper surface of the cylinder block 11 constituting the sub chamber member. Due to the heat shield gasket 25 thus formed, the heat flow from the lower member 4 to the cylinder block 11 through the heat shield gasket 25 is surely cut off, and the temperature rise of the sub chamber 2 can be promoted. Therefore, since the sub chamber 2 can be maintained at a high temperature, the generation of HC, smoke, etc. can be reduced, and the cooling water loss can be reduced to improve the engine output.

Next, another embodiment of the sealing device in the sub-chamber engine according to the present invention will be described with reference to FIG. Compared with the above-mentioned embodiment, this embodiment has the same structure except that the structure of the heat shield gasket is different. Therefore, the same parts are designated by the same reference numerals and duplicate description will be given. Is omitted.

In this embodiment, in particular, the heat shield gasket 29 includes a metal plate 31 made of a metal such as SUS in which a portion corresponding to the lower surface of the lower member 4 is formed thin, and a thin portion of the metal plate 31. It is composed of a ceramic plate 30 made of potassium titanate fiber, potassium titanate whiskers, partially stabilized zirconia or aluminum titanate and disposed between the lower member 4 and the lower member 4. In particular, the ceramic plate 30 is preferably made of partially stabilized zirconia ceramics, which is a material having low thermal conductivity and high strength. The sealing device of this embodiment has the same effects as those of the above embodiment.

[0024]

[Effect of device]

 The sealing device in the sub-chamber engine according to the present invention is configured as described above and has the following effects. The sealing device in this sub-chamber engine is designed to shield the portion of the gasket located between the lower surface of the sub-chamber member, that is, the lower member, and the upper surface of the cylinder block with a low-heat-conducting ceramic material. Since it is constructed as a hot gasket, the heat shield gasket blocks the heat flow from the sub chamber where the temperature is high, and the heat radiation from the sub chamber to the cylinder block is surely blocked, thereby shielding the sub chamber. The effect of the thermal structure is exerted, the generation of HC and smoke can be reduced, and the cooling water loss can be reduced.

Further, the heat shield gasket includes a ceramic plate made of potassium titanate fiber, potassium titanate whiskers, partially stabilized zirconia or aluminum titanate, and an outer plate made of SUS covering the entire surface of the ceramic plate. Or a metal plate made of SUS having a portion corresponding to the lower surface of the sub-chamber member formed thin, and a potassium titanate fiber arranged between the thin portion of the metal plate and the lower surface of the sub-chamber member. , A potassium titanate whisker, a ceramic plate made of partially stabilized zirconia or aluminum titanate, the heat insulating gasket has a very good heat insulating property.

Therefore, the sealing device in this sub-chamber engine forms a heat-shielding air layer between the outer peripheral surface of the sub-chamber member and the mounting hole of the cylinder head, and also protects the lower member of the sub-chamber member. Since the heat shield gasket is placed between the lower surface and the upper surface of the cylinder block, the sub chamber is structured to be completely thermally shielded from the outside, improving the heat shield of the sub chamber and increasing the temperature of the sub chamber. It is possible to provide a diesel engine that can be achieved and that can suppress the generation of HC, smoke, and the like.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a sealing device in a sub-chamber engine according to the present invention.

FIG. 2 is an explanatory view showing a part of a gasket incorporated in the sub-chamber engine of FIG.

FIG. 3 is a sectional view showing another embodiment of the sealing device in the sub-chamber engine according to the present invention.

[Explanation of symbols]

 1 Main Chamber 2 Sub Chamber 3 Cylinder Head 4 Lower Member 5 Upper Member 7 Communication Hole 8 Heat Shielding Air Layer 9 Mounting Hole 10 Damping Ring 11 Cylinder Block 12 Cylinder Liner 13 Cylinder 15 Gasket 20 Fuel Injection Hole 23, 30 Ceramic Plate 24 Positioning Member 25, 29 Heat shield gasket 26 Outer plate 27 Wiring 28 Cylinder bore hole 31 Metal plate

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical display location F16J 15/10 F 8207-3J (72) Creator Takahiro Tsubonuma 8th floor of the shelf, Fujisawa City, Kanagawa Stock Company Isuzu Ceramics Research Center

Claims (3)

[Scope of utility model registration request] 1. A cylinder block constituting a cylinder,
A cylinder head attached to the cylinder block through a gasket, and a fuel from a fuel injection nozzle and a communication hole that is fitted into an attachment hole formed in the cylinder head to form a sub chamber of the heat shield structure and communicates with the main chamber. In a sub-chamber engine having a sub-chamber member having fuel injection holes for spraying into the sub-chamber, a portion of the gasket located in a region between the sub-chamber member lower surface and the cylinder block upper surface, A sealing device for a sub-chamber engine, comprising a heat-shielding gasket having a heat-shielding structure made of a ceramic low-thermal-conductivity material. 2. The heat shield gasket comprises a ceramic plate made of potassium titanate fiber, potassium titanate whiskers, partially stabilized zirconia or aluminum titanate, and an outer plate made of SUS covering the entire surface of the ceramic plate. The sealing device in a sub-chamber engine according to claim 1, wherein 3. The heat shield gasket is disposed between a metal plate made of SUS in which a portion corresponding to the lower surface of the sub-chamber member is formed thin, and between the thin portion of the metal plate and the lower surface of the sub-chamber member. Potassium titanate fiber,
2. The sealing device for a sub-chamber engine according to claim 1, wherein the sealing device comprises a potassium titanate whisker, a ceramic plate made of partially stabilized zirconia, or aluminum titanate.