JP6042263B2 - Gas seal device for engine combustion chamber - Google Patents

Description

  The present invention relates to a gas seal device for a combustion chamber of an engine, and more particularly, to a gas seal device for a combustion chamber of an engine that can improve gas sealing performance without reducing the width of a joint gap of a pressure ring.

  Conventionally, as a gas seal device for an engine combustion chamber, there is one in which a piston is fitted in a cylinder and a pressure ring is fitted in a pressure ring groove of the piston (see, for example, Patent Document 1).

  According to this type of gas seal device, combustion gas generated in the combustion chamber is sealed by the pressure ring, and there is an advantage that leakage of blow-by gas from the combustion chamber to the crank chamber can be suppressed.

  However, in this prior art, the abutment gap is formed in consideration of the elongation due to the thermal expansion of the pressure ring. However, in order to improve the gas sealing performance, there is only means for reducing the width of the abutment gap of the pressure ring.

Japanese Utility Model Publication No. 62-88856 (see FIGS. 1 and 2)

<Problem> Improvement of gas sealing performance has reached its limit.
The only way to improve the gas sealing performance is to narrow the width of the gap between the pressure rings, so that improvement of the gas sealing performance has reached its limit.

  As a result of research, the inventors of the present invention improve the gas sealing performance without reducing the width of the pressure ring joint gap by forming a recess or a receding part at the end of the pressure ring facing the joint gap of the pressure ring. It was discovered that it was possible to achieve this invention.

  The subject of this invention is providing the gas seal apparatus of the combustion chamber of an engine which can improve gas-seal property, without narrowing the width | variety of the gap gap of a pressure ring.

Invention specific matters of the invention according to claim 1 are as follows.
As illustrated in FIG. 1A, an engine in which a piston (2) is fitted in a cylinder (1) and a pressure ring (4) is fitted in a pressure ring groove (3) of the piston (2). In the gas seal device of the combustion chamber of
As illustrated in FIG. 1 (C) (D) or FIG. 4 (A) (B), the gas guide recess (7) is formed in the pressure ring end (6) facing the joint gap (5) of the pressure ring (4). The gas guide recess (7) is recessed on the piston top dead center side of the pressure ring end (6), and approaches the piston top dead center side as it approaches the gap (5) on the inner bottom thereof. A gas guide surface (8) is provided, and a corner (10) is formed at the gas guide terminal edge (9) on the side of the joint gap (5) of the gas guide surface (8) .
The gas guide recess (7) is formed only at the pressure ring end (6) on the piston top dead center side of the pressure ring (4), and the gas radial direction is the width direction of the pressure ring end (6). The concave portion (7) and the corner portion (10) are formed over the entire width direction of the pressure ring end portion (6), and the inner bottom of the gas guide concave portion (7) is formed between the gas guide surface (8) and the gas guide. The engine is characterized in that it is formed in a V-shape that is tapered toward the boundary (38) with the gas running surface (35) that is further away from the joint gap (5) than the surface (8). Gas chamber device for combustion chamber.

(Invention of Claim 1)
The invention according to claim 1 has the following effects.
<Effect> Gas sealing performance can be enhanced without narrowing the width of the gap of the pressure ring.
As illustrated in FIG. 1 (C) (D) or FIG. 4 (A) (B), the gas guide recess (7) is formed in the pressure ring end (6) facing the joint gap (5) of the pressure ring (4). The gas guide recess (7) is recessed on the piston top dead center side of the pressure ring end (6), and approaches the piston top dead center side as it approaches the gap (5) on the inner bottom thereof. Since the gas guide surface (8) is provided and the corner (10) is formed at the gas guide terminal edge (9) on the side of the joint gap (5) of the gas guide surface (8), the pressure ring (4) Gas sealing performance can be improved without narrowing the width (L) of the gap (5).
The reason is presumed as follows.
The combustion gas (26) in the combustion chamber (25) is guided by the gas guide surface (8) of the gas guide recess (7), and from the gas guide surface (8) at the corner (10) of the gas guide terminal edge (9). When peeling, a turbulent flow (27) is generated downstream of the corner (10), and this turbulent flow (27) flows into the abutment gap (5) from the combustion chamber (25) and flows into the blow-by gas (28). It becomes resistance, and the gas sealing performance can be improved without reducing the width (L) of the joint gap (5) of the pressure ring (4).

<Effect> The amount of blow-by gas generated can be reduced.
As illustrated in FIGS. 1C and 4D and FIGS. 4A and 4B, the gas sealability can be improved, so that the generation amount of blow-by gas (28) can be reduced.
For this reason, deterioration of the engine oil due to the blow-by gas (28) is suppressed, the oil change interval is lengthened, the occurrence of rust due to the blow-by gas (28) is suppressed, and the freezing of the blow-by gas passage during cold weather is prevented. Specific effects such as suppression are obtained.

<Effect> It is not necessary to strictly control the size of the gap.
As illustrated in FIG. 1 (C) (D) or FIG. 4 (A) (B), it is not necessary to narrow the width (L) of the abutment gap (5). There is no need to

<Effect> There is no possibility that the production of the pressure ring is complicated due to the formation of the gas guide recess.
As illustrated in FIGS. 1 (C) (D) or 4 (A) (B), the gas guide recess (7) is recessed on the piston top dead center side of the pressure ring end (6). Therefore, it can be easily formed by press working or the like, and there is no possibility that the production of the pressure ring (4) is complicated due to the formation of the gas guide recess (7).

(Invention of Claim 2)
The invention according to claim 2 has the following effect in addition to the effect of the invention according to claim 1.
<Effect> It has a high function of improving gas sealing performance.
As illustrated in FIGS. 1 (C) (D) or 4 (A) (B), the gas guide recess (7) is formed in the top ring (11), so the function of improving the gas sealing performance is high. .
The reason is presumed as follows.
In the gas guide recess (7) of the top ring (11), the flow velocity of the combustion gas (26) guided by the gas guide surface (8) is fast, and a strong turbulent flow (27) is generated downstream of the corner (10). And since this strong turbulent flow (27) becomes a strong inflow resistance of the blow-by gas (28) flowing into the joint gap (5) from the combustion chamber (25), the function of improving the gas sealing performance is high.

(Invention of Claim 3)
The invention according to claim 3 has the following effect in addition to the effect of the invention according to claim 1 or claim 2.
<Effect> It has a high function of improving gas sealing performance.
As illustrated in FIGS. 1 (C) (D) or 4 (A) (B), the gas guide recess (7) has a pair of pressure ring ends (6) facing each other across the gap (5). Since it is formed in (6), it has a high function of improving gas sealing performance.
The reason is presumed as follows.
Turbulence (27) is generated on both sides of blow-by gas (28) flowing into the gap (5) from the combustion chamber (25), and blow-by gas (28) is sandwiched from both sides by this turbulence (27). Since this turbulent flow (27) becomes a strong inflow resistance of the blow-by gas (28) flowing into the gap (5) from the combustion chamber (25), the function of improving the gas sealing property is high.

(Invention of Claim 4)
The invention according to claim 4 has the following effects in addition to the effects of the invention according to any one of claims 1 to 3.
<< Effect >> Manufacture of a pressure ring becomes easy.
As illustrated in FIG. 1 (C) or FIG. 4 (A) (B), the abutment gap (5) is formed in a direction along the cylinder center axis (12). The pressure ring (4) can be easily manufactured.

(Invention according to claim 5)
The invention according to claim 5 has the following effects in addition to the effects of the invention according to any one of claims 1 to 4.
<Effect> The production of the pressure ring is not complicated by the formation of the corner.
As illustrated in FIG. 1 (C) (D) or FIG. 4 (A) (B), the cross line between the piston top dead center side surface (13) of the pressure ring end portion (6) and the gas guide surface (8). Since the corner (10) is formed on the gas guide terminal edge (9), the gas guide recess (7) is simply formed on the piston top dead center side of the pressure ring end (6) by pressing or the like. Thus, the corner portion (10) is naturally formed, and the formation of the corner portion (10) does not cause the production of the pressure ring (4) to be complicated.

(Invention of Claim 6)
The invention according to claim 6 has the following effects in addition to the effects of any one of claims 1 to 5.
<Effect> Gas sealing performance can be enhanced without narrowing the width of the gap of the pressure ring.
As illustrated in FIGS. 4A and 4B, a receding portion (14) is formed at the pressure ring end portion (6) facing the joint gap (5) of the pressure ring (4), and the receding portion (14). Is provided with a receding surface (17) in which the piston bottom dead center side portion of the pressure ring end surface (15) recedes in the circumferential direction of the pressure ring (4) from the joint gap (5), and the pressure ring end surface (15) on the piston Since the corner portion (19) is formed at the boundary between the dead point side portion (18) and the receding surface (17), the gas does not decrease the width (L) of the joint gap (5) of the pressure ring (4). Sealability can be improved.
The reason is presumed as follows.
When the blow-by gas (28) is guided by the piston top dead center side portion (18) of the pressure ring end face (15) and peeled from the piston top dead center side portion (18) by the corner portion (19), the corner portion (19 ), A turbulent flow (27) is generated, and this turbulent flow (27) becomes an outflow resistance of the blow-by gas (28) that is about to flow out from the joint gap (5) into the crank chamber. ) Can be improved without narrowing the width (L) of the joint gap (5).

<Effect> The production of the pressure ring is not complicated by the formation of the receding portion.
As illustrated in FIGS. 4 (A) and 4 (B), the retreating portion (14) is formed by retreating the piston bottom dead center side portion of the pressure ring end portion (6). The production of the pressure ring (4) is not likely to be complicated by the formation of the retreating part (14).
(Invention of Claim 7)
The invention according to claim 7 has the following effect in addition to the effect of the invention according to claim 6.
<Effect> The production of the pressure ring is not complicated due to the formation of the receding surface.
As illustrated in FIG. 4 (A), the receding surface (17) is formed by the inclined surface (20) that recedes as it approaches the piston bottom dead center side, so that it can be easily formed by pressing or the like, There is no possibility that the production of the pressure ring (4) becomes complicated due to the formation of the receding surface (17).
(Invention of Claim 8)
The invention according to claim 8 has the following effect in addition to the effect of the invention according to claim 6.
<Effect> The production of the pressure ring is not complicated due to the formation of the receding surface.
As illustrated in FIG. 4B, the receding surface (17) is formed of a concave bent surface (21) that recedes as it approaches the piston bottom dead center side. There is no possibility that the production of the pressure ring (4) becomes complicated by the formation of the receding surface (17).

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram for explaining a gas seal device for a combustion chamber of an engine according to a first embodiment of the present invention. FIG. 1 (A) is a schematic view of a piston and its peripheral portion, and FIG. FIG. 1C is an enlarged view of a portion indicated by an arrow C in FIG. 1A, and FIG. 1D is a sectional view taken along a line DD in FIG. 1C. 2A and 2B are views for explaining a gas seal device for a combustion chamber of an engine according to the first reference embodiment of the present invention. FIG. 2A is a view corresponding to FIG. 1C, and FIG. FIG. FIG. 3A is a view for explaining a gas seal device for a combustion chamber of an engine according to a second embodiment of the present invention, FIG. 3A is a view corresponding to FIG. 1C, and FIG. FIG. FIG. 4A is a view corresponding to FIG. 1C of the gas seal device for the combustion chamber of the engine according to the second embodiment of the present invention, and FIG. 4B is the combustion of the engine according to the third embodiment of the present invention . It is a figure corresponding to Drawing 1 (C) of a gas seal device of a room.

1-4 is a figure explaining the gas seal apparatus of the combustion chamber of the engine which concerns on the 1st-3rd embodiment and 1st-2nd reference form of this invention, In each embodiment and each reference form , A gas seal device for a combustion chamber of a vertical diesel engine will be described.

The configuration of the first embodiment shown in FIG. 1 is as follows.
As shown in FIG. 1A, the piston (2) is fitted in the cylinder (1), and the pressure ring (4) is fitted in the pressure ring groove (3) of the piston (2).
A cylinder head (37) is assembled to the upper part of the cylinder (1), and a combustion chamber (25) sandwiched between the cylinder head (37) and the piston (2) is formed in the cylinder (1). A fuel injector (38), an intake valve (39), and an exhaust valve (40) face the combustion chamber (25).
A crankshaft (31) is linked to the piston (2) via a connecting rod (30).
The piston (2) is provided with two pressure ring grooves (3) (3) and one oil ring groove (32).
The pressure ring (4) is composed of a top ring (11) and a second ring (33). The top ring (11) is fitted in the pressure ring groove (3) on the most dead center side, and the second ring (33) is fitted in the pressure ring groove (3) below the top ring (11). An oil ring (34) is fitted in the oil ring groove (32).

As shown in FIGS. 1C and 1D, a gas guide recess (7) is formed at the pressure ring end (6) facing the joint gap (5) of the pressure ring (4), and this gas guide recess (7 ) Is recessed on the piston top dead center side of the pressure ring end (6), and has a gas guide surface (8) that approaches the piston top dead center side as it approaches the joint gap (5) on its inner bottom. A corner (10) is formed on the gas guide terminal edge (9) on the side of the joint gap (5) of the gas guide surface (8).
The inner bottom of the gas guide recess (7) is formed in a V shape by the gas guide surface (8) and the gas running surface (35) that is further away from the joint gap (5) than the gas guide surface (8). The gas run-up surface (35) is inclined so as to approach the piston bottom dead center as it approaches the gas guide surface (8), and the gas guide start end of the gas run-up surface (35) and the gas guide start end of the gas guide surface (8). The boundary (36) with the edge is the valley bottom of the inner bottom of the gas guiding recess (7). The combustion gas (26) in the combustion chamber (25) runs along the gas running surface (35) and then is guided to the corner (10) by the gas guiding surface (8).
Specifically, as shown in FIGS. 1C and 1D, the gas guide recess (7) is formed only at the pressure ring end (6) on the piston top dead center side of the pressure ring (4), and the piston diameter With the direction being the width direction of the pressure ring end (6), the gas guide recess (7) and the corner (10) are formed over the entire width direction of the pressure ring end (6), and the gas guide recess (7 The inner bottom of the gas guide surface is a gas guide surface (8) and a gas running surface (35) that is further away from the joint gap (5) than the gas guide surface (8), and is tapered toward the boundary (38). It is formed in a rounded V shape.

As shown in FIG. 1A, a gas guide recess (7) is formed in the top ring (11).
As shown in FIGS. 1C and 1D, gas guide recesses (7) are respectively formed in a pair of pressure ring ends (6) and (6) facing each other with the abutment gap (5) interposed therebetween.
As shown in FIG. 1C, the joint gap (5) is formed in a direction along the cylinder center axis (12).
As shown in FIGS. 1 (C) and 1 (D), the gas guide terminal edge (9) is formed by a cross line between the piston top dead center side surface (13) and the gas guide surface (8) of the pressure ring end (6). Corners (10) are formed.
The gas guide recess (7) may be formed not only in the top ring (11) but also in the second ring (33) and the oil ring (34).

Next, the first reference embodiment shown in FIGS. 2A and 2B will be described.
The first reference embodiment uses a retreating portion (14) on the piston bottom dead center side instead of the gas guiding recess (7) at the piston top dead center of the first embodiment.
As shown in FIGS. 2 (A) and 2 (B), a receding portion (14) is formed at the pressure ring end (6) facing the joint gap (5) of the pressure ring (4). The piston bottom dead center side portion of the pressure ring end surface (15) has a retreating surface (17) that retreats in the circumferential direction of the pressure ring (4) from the joint gap (5), and the piston top dead center of the pressure ring end surface (15) A corner (19) is formed at the boundary between the point side portion (18) and the receding surface (17).

As shown in FIGS. 2A and 2B, a receding portion (14) is formed on the top ring (11).
As shown in FIGS. 2 (A) and 2 (B), the retreating portion (14) is formed in a pair of pressure ring end portions (6) and (6) facing each other with the joint gap (5) interposed therebetween.
As shown in FIG. 2A, the joint gap (5) is formed in a direction along the cylinder center axis (12).
As shown in FIGS. 2A and 2B, the receding surface (17) is formed by an inclined surface (20) that recedes as it approaches the piston bottom dead center side.
The receding part (14) may be formed not only on the top ring (11) but also on the second ring (33) or the oil ring (34).
Other configurations are the same as those of the first embodiment, and in FIGS. 2A and 2B, the same elements as those of the first embodiment are denoted by the same reference numerals as those of FIGS. 1C and 1D. deep.

Next, a second reference embodiment shown in FIGS. 3A and 3B will be described.
In the second reference embodiment , the receding surface (17) of the first reference embodiment is formed by a bent surface (21) instead of the inclined surface (20).
Other configurations are the same as those of the first reference embodiment . In FIGS. 3A and 3B, the same elements as those of the first reference embodiment are denoted by the same reference numerals as those of FIGS. deep.

In the second embodiment and the third embodiment , the retracted portion (14) of the first reference embodiment or the second reference embodiment is added to the first embodiment .
The second embodiment shown in FIG. 4A is obtained by adding the inclined surface 20 of the first reference embodiment to the first embodiment , and the third embodiment shown in FIG. 4B is the first embodiment. The concave bending surface (21) of the second reference form is added to the form .
The receding part (14) may be formed not only on the top ring (11) but also on the second ring (33) or the oil ring (34).
Other configurations are the same as those of the first embodiment, the first reference embodiment, and the second reference embodiment . In FIGS. 4A and 4B, the same configurations as those of the first embodiment, the first reference embodiment, and the second reference embodiment are used. These elements are given the same reference numerals as in FIGS. 1C, 2D, 2A, 2B, and 3A, 3B.

(Functions common to the inventions of the first and second reference embodiments)
<< Function >> Gas sealing performance can be enhanced without narrowing the width of the gap of the pressure ring.
As shown in FIG. 2 (A) (B) or FIG. 3 (A) (B), a receding portion (14) is formed at the pressure ring end (6) facing the joint gap (5) of the pressure ring (4). The retreating portion (14) includes a retreating surface (17) in which the piston bottom dead center side portion of the pressure ring end surface (15) retreats in the circumferential direction of the pressure ring (4) from the joint gap (5). Since the corner portion (19) is formed at the boundary between the piston top dead center side portion (18) and the receding surface (17) of the ring end surface (15), the width of the joint gap (5) of the pressure ring (4) Gas sealing performance can be improved without narrowing (L).
The reason is presumed as follows.
The blow-by gas (28) passing through the joint gap (5) is guided by the piston top dead center side portion (18) of the pressure ring end face (15), and from the piston top dead center side portion (18) by the corner portion (19). When separating, a turbulent flow (27) is generated in the receding portion (14) on the downstream side of the corner portion (19), and this turbulent flow (27) flows into the crank chamber from the joint gap (5) (28 ), The gas sealability can be improved without reducing the width (L) of the joint gap (5) of the pressure ring (4).

<< Function >> The amount of blow-by gas generated can be reduced.
As shown in FIG. 2 (A) (B) or FIG. 3 (A) (B), the gas sealability can be improved, so that the amount of blow-by gas (28) generated can be reduced.
For this reason, deterioration of the engine oil due to the blow-by gas (28) is suppressed, the oil change interval is lengthened, the occurrence of rust due to the blow-by gas (28) is suppressed, and the freezing of the blow-by gas passage during cold weather is prevented. A specific function such as suppression is obtained .

<Function> It is not necessary to strictly control the size of the gap.
As shown in Fig. 2 (A) (B) or Fig. 3 (A) (B), it is not necessary to narrow the width (L) of the abutment gap (5). There is no need to do.

<Function> The production of the pressure ring is not likely to be complicated due to the formation of the receding portion.
As shown in FIGS. 2 (A) (B) or 3 (A) (B), the retreating portion (14) is a retraction of the piston bottom dead center side portion of the pressure ring end portion (6). The pressure ring (4) can be easily formed by pressing or the like, and the production of the pressure ring (4) is not likely to be complicated by the formation of the receding portion (14).

<< Function >> High function to enhance gas sealing performance.
As shown in FIG. 2 (A) (B) or FIG. 3 (A) (B), since the receding portion (14) is formed on the top ring (11), the function of improving the gas sealing performance is high.
The reason is presumed as follows.
In the top ring (11), the flow speed of the blow-by gas (28) guided by the piston top dead center side portion (18) of the pressure ring end face (15) is high, and the retreating portion (14) downstream of the corner portion (19). Strong turbulent flow (27) is generated, and this strong turbulent flow (27) becomes a strong outflow resistance of blow-by gas (28) flowing out from the joint gap (5) into the crank chamber, so that the function of improving the gas sealing performance is achieved. high.

<< Function >> High function to enhance gas sealing performance.
As shown in FIG. 2 (A) (B) or FIG. 3 (A) (B), the retracted portion (14) has a pair of pressure ring ends (6), (6) facing each other across the gap (5). ), The function of improving the gas sealability is high.
  The reason is presumed as follows.
  Turbulence (27) is generated on both sides of the blow-by gas (28) that is about to flow into the crank chamber from the joint gap (5), and the blow-by gas (28) is sandwiched from both sides by the turbulent flow (27). Since the turbulent flow (27) becomes a strong outflow resistance of the blow-by gas (28) flowing out from the joint gap (5) into the crank chamber, the function of improving the gas sealing performance is high.

<< Function >> Manufacture of pressure ring is facilitated.
As shown in FIG. 2 (A) or FIG. 3 (A) (B), the abutment gap (5) is formed in a direction along the cylinder center axis (12). It is easy to manufacture the pressure ring (4).

(Functions unique to the invention of the first reference form)
Among the inventions of the first and second reference embodiments, functions unique to the invention of the first reference embodiment are as follows.
<< Function >> The production of the pressure ring is not complicated by the formation of the receding surface.
As shown in FIGS. 2 (A) and 2 (B), since the receding surface (17) is formed with the inclined surface (20) that recedes as it approaches the piston bottom dead center side, it can be easily formed by pressing or the like. In addition, the production of the pressure ring (4) is not complicated by the formation of the receding surface (17).

(Functions unique to the invention of the second reference form)
Among the inventions of the first and second reference embodiments, functions unique to the invention of the second reference embodiment are as follows.
<< Function >> The production of the pressure ring is not complicated by the formation of the receding surface.
As shown in FIGS. 3 (A) and 3 (B), the receding surface (17) is formed of a concave bent surface (21), so it can be easily formed by pressing or the like, and the receding surface (17). Formation of the pressure ring (4) does not become complicated.

(1) Cylinder
(2) Piston
(3) Pressure ring groove
(4) Pressure ring
(5) Joint gap
(6) Pressure ring end
(7) Gas guide recess
(8) Gas guide surface
(9) Gas guide end edge
(10) Corner
(11) Top ring
(12) Cylinder center axis
(13) Piston top dead center side
(14) Retreating part
(15) Pressure ring end face
(17) Receding surface
(18) Piston top dead center side
(19) Corner
(20) Slope
(21) Concave bending surface

Claims (8)

In a gas seal device for a combustion chamber of an engine, in which a piston (2) is fitted in a cylinder (1) and a pressure ring (4) is fitted in a pressure ring groove (3) of the piston (2),
A gas guide recess (7) is formed in the pressure ring end (6) facing the joint gap (5) of the pressure ring (4), and this gas guide recess (7) is located on the piston of the pressure ring end (6). A gas guide surface (8) that is recessed on the dead center side and that approaches the piston top dead center side as it approaches the joint gap (5) on the inner bottom thereof, is provided on the joint gap (5) side of the gas guide surface (8). A corner (10) is formed at the gas guide terminal edge (9) of
The gas guide recess (7) is formed only at the pressure ring end (6) on the piston top dead center side of the pressure ring (4), and the gas radial direction is the width direction of the pressure ring end (6). The concave portion (7) and the corner portion (10) are formed over the entire width direction of the pressure ring end portion (6), and the inner bottom of the gas guide concave portion (7) is formed between the gas guide surface (8) and the gas guide. The engine is characterized in that it is formed in a V-shape that is tapered toward the boundary (38) with the gas running surface (35) that is further away from the joint gap (5) than the surface (8). Gas chamber device for combustion chamber. The gas seal device for the combustion chamber of the engine according to claim 1,
A gas seal device for a combustion chamber of an engine, characterized in that a gas guide recess (7) is formed in the top ring (11). The gas seal device for the combustion chamber of the engine according to claim 1 or 2,
Gas seal device for a combustion chamber of an engine, characterized in that gas guide recesses (7) are formed in a pair of pressure ring ends (6) and (6) facing each other with a gap gap (5) interposed therebetween . The gas seal device for the combustion chamber of the engine according to any one of claims 1 to 3,
A gas seal device for a combustion chamber of an engine, wherein the abutment gap (5) is formed in a direction along the cylinder center axis (12). The gas seal device for the combustion chamber of the engine according to any one of claims 1 to 4,
A corner (10) is formed on the gas guide terminal edge (9) at the cross-section between the piston top dead center side surface (13) and the gas guide surface (8) of the pressure ring end (6). A gas seal device for a combustion chamber of an engine. The gas seal device for the combustion chamber of the engine according to any one of claims 1 to 5,
A retreating portion (14) is formed at the pressure ring end (6) facing the joint gap (5) of the pressure ring (4), and this retreating portion (14) is located on the piston bottom dead center side of the pressure ring end surface (15). The portion includes a receding surface (17) that recedes from the joint gap (5) in the circumferential direction of the pressure ring (4), and the piston top dead center side portion (18) and the receding surface (17) of the pressure ring end surface (15) A gas seal device for a combustion chamber of an engine, characterized in that a corner (19) is formed at the boundary of the engine. The gas seal device for the combustion chamber of the engine according to claim 6 ,
A gas seal device for a combustion chamber of an engine, characterized in that the receding surface (17) is formed by an inclined surface (20) that recedes as it approaches the piston bottom dead center side. The gas seal device for the combustion chamber of the engine according to claim 6 ,
A gas seal device for a combustion chamber of an engine, wherein the receding surface (17) is formed of a concave bent surface (21).

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