JP2002349345A - Combining sealing method and multicylindered engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a cylinder from being distorted by a bump on an upper surface of a flange and improve sealing performance for combustion gas, for a multicylindered engine in which a flanged cylinder liner is inserted into a cylinder bore of a cylinder block and a cylinder head gasket is interposed between the cylinder block and a cylinder head. SOLUTION: The upper surface of the flange of the cylinder liner is processed into a flat surface. A specified metal gasket is interposed between the cylinder block and the cylinder head. In this manner, the combustion gas can be sealed off by joining between the upper surface of the flange of the cylinder liner and a mating surface of the cylinder head.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-cylinder engine in which a cylinder liner with a flange is inserted into a cylinder hole of a cylinder block and a cylinder head gasket is interposed between the cylinder block and the cylinder head.

[0002]

2. Description of the Related Art In a large or medium-sized diesel engine, a cylinder liner with a flange is inserted into a cylinder hole of a cylinder block to perform maintenance.
The cylinder liner can be replaced without removing the engine body including the cylinder block from the vehicle body. Therefore, as shown in FIG. 12, a counterbore machining Z is provided on the upper cylinder portion 11a of the cylinder block 11, and the cylinder liner 22 is provided on the step surface 11Z.
The lower surface of the flange 22b is closely inserted, and the integral cylinder head 33 is superimposed on the flange lower surface 22b. Here, a fire ring 22R is provided on the cylinder hole side flange surface of the cylinder liner so that the tightening load of the gasket 44 is applied to the liner flange lower surface 22b.

[0003]

However, as shown in FIG. 13, the upper surfaces 22a and 22a 'of the flanges of the cylinder liners 22 and 22' have thicknesses T of each liner flange.
Due to the total error of the counterbore machining depths Z11 and Z11 'and the counterbore depths Z11 and Z11', a maximum of 0.06
A step D of about 0.08 mm occurs. Each flange upper surface 22a, 22 of the cylinder liner 22, 22a '
a ′ is a cylinder head 33 which is left unprocessed after insertion through a cylinder head gasket 44.
And the bolts are fastened. As a result, the axial force for tightening the bolts is increased by the side 22a ′ where the flange upper surface is higher.
And contribute to cylinder distortion. On the other hand, a load that bends to the cylinder head mating surface 33a is only applied to the side 22a where the flange upper surface is low,
The load applied to the flange upper surface 22a is low, and the force for vertically fixing the cylinder liner 22 is reduced. In this regard, it is necessary to increase the load applied to the side 22a where the upper surface of the flange is lower, and to maintain the close contact with the cylinder head mating surface 33a of the side 22a 'where the upper surface of the flange is high.
As long as the spring satisfies the above two conditions and has resilience within the allowable stress, it is possible to solve such a problem by reducing its constant. However, in practice, it is difficult to realize because the thickness of the gasket material is thin. For this reason, the combustion gas sealing ability of the cylinder head gasket is hindered, the oil consumption is increased due to the cylinder distortion, and the cylinder liner cannot withstand the side pressure of the piston applied to the cylinder liner at the time of the explosion. There is a possibility that the counterbore of the liner holding portion in the cylinder block where the flange portion is overlapped is hit and the bolt torque is reduced.

[0004] In addition, a gasket made of the same metal as the engine has been widely used recently. However, when this metal gasket is used, unlike the conventional soft gasket, the surface roughness of the gasket surface of the engine itself is reduced. Fine and constant flatness is required. In the case of diesel engines as well, there is a tendency to increase the explosion pressure in order to reduce exhaust gas pollution. For this reason, in recent years, it has been necessary to further improve the sealing performance of explosive gas. It is important.

The present invention has been devised to solve such a problem.

[0006]

In order to achieve the above object, a combination sealing method according to the present invention comprises inserting a cylinder liner with a flange into a cylinder hole of a cylinder block and disposing the cylinder block and the cylinder head together. In the sealing method for a multi-cylinder engine having a cylinder head gasket interposed therebetween, a mating surface of a cylinder block body provided with a cylinder hole with a cylinder head is a plane processing surface, and the mating surface is inserted into the cylinder liner. The cylinder head gasket is a metal gasket having an inner diameter larger than the flange outer diameter of the cylinder liner, and the metal gasket includes cooling water on the cylinder side and the head side. For passage holes and oil passage holes Bead disposed of for that seal,
When the cylinder block and cylinder head are tightened with bolts, the combustion gas is sealed by joining the upper surface of the cylinder liner flange and the mating surface of the cylinder head, and the cooling water and oil are sealed by the metal gasket. This is performed by a combination sealing method characterized by performing the above.

Further, the metal gasket is of a laminated type, wherein the inner diameter of the substrate on the cylinder head side is made larger than the inner diameter of the cylinder liner, the substrate is superposed on the upper surface of the flange of the cylinder liner, and the beads are formed within a range corresponding to the lower surface of the flange. Wherein the inner diameter of the laminated metal plate other than the cylinder head-side substrate is larger than the outer diameter of the flange of the cylinder liner.

[0008] Further, a gasket for combustion gas sealing is provided, in which an inner diameter is provided around the inner diameter of the cylinder liner, a bead is provided for each cylinder, and a surface sealing material is applied to both sides or one side, for each cylinder or integrally for the multiple cylinders. Then, the combustion gas sealing gasket is fixed on the upper surface of the flange of the cylinder liner by polymerization, and the polymerization fixing method may be any of the following.

1. 1. A method of mounting and fixing to a step or a groove provided on the outer surface of the flange of the cylinder liner by providing several small overhangs on the outer periphery of the gasket for combustion gas sealing and forming a bent claw. The outer circumference of the gasket for combustion gas sealing is made larger than the inner diameter of the intermediate sub-plate of the metal gasket, and is superimposed. A method in which several notches having a small width are provided, bent, and fixed to the intermediate sub-plate of the gasket, or the outer diameter of the gasket for combustion gas sealing is made circular to be fixed to the intermediate sub-plate of the gasket.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In the first embodiment of the present invention, as shown in FIG. 1, a cylinder hole D2 in a cylinder block 1 (D3 indicates an outer diameter of a cylinder liner).
A multi-cylinder engine in which a cylinder liner 2 with a flange is inserted into the cylinder block and a cylinder head gasket 4 is interposed between the cylinder block 1 and the cylinder head 3, wherein a mating surface 1 a of the cylinder block with the cylinder head is flat. The mating surface 1a of the cylinder liner and the lower surface 2b of the flange of the cylinder liner are in close contact with each other. The gasket 4 having an inner diameter D5 larger than the outer diameter D4 of the flange of the cylinder liner is arranged. The gasket is
Beads 4c and 4d for sealing the cooling water passage holes 1c and 3c and the oil passage holes 1d and 3d on the cylinder side and the head side, respectively, are provided. The cooling water and oil are sealed by the gasket, and the combustion gas is This is performed by joining the upper surface 2a of the flange of the cylinder liner to the mating surface 3a of the cylinder head. In addition, such joining is performed by tightening the bolt 5. As shown in FIG. 2, the method of joining the upper surface 2a of the flange of the cylinder liner 2 and the mating surface 3a of the cylinder head 3 according to the present invention is more reliable, and the cylinder block 1 and the cylinder head 3 are tightened with bolts 5. As a method of avoiding distortion of the cylinder inner diameter due to the tightening force at the time, the thickness T4 of the cylinder liner 2 inside the inner diameter D7 of the range L2 corresponding to the flange lower surface 2b is made smaller than the flange thickness T1. For example, the above effect can be obtained by setting T4 to 1.4 mm when T1 is set to 1.5 mm. A method for preventing the liner from being deformed by tightening is that the pressing force P generated by joining the upper surface 2a of the flange of the cylinder liner 2 and the mating surface 3a of the cylinder head 3 is applied to the range L1 of the lower surface 2b of the flange of the cylinder liner 2. Is also applicable.

Further, as shown in FIG. 3, a groove 2m is provided on the upper surface 2a of the flange of the cylinder liner 2 of the present invention, and a sheet material S such as molybdenum disulfide or a silicone resin is applied to the upper surface of the flange. Even when the upper surface 2a of the flange of the cylinder liner 2 and the mating surface 3a of the cylinder head 3 are joined in a cylinder engine, the effects of thermal expansion difference, explosion pressure, and vibration of both are reduced, and the sliding performance of the surface is reduced. Is improved. This makes it possible to prevent wear of the surface, and as a result, it is possible to improve the sealing performance of the combustion gas.

Further, when the upper surface 2a of the flange of the cylinder liner 2 and the mating surface 3a of the cylinder head 3 are joined to each other in the multi-cylinder engine of the present invention, bending is caused by the tightening axial force, and a minute gap is formed between the bolts. In this case, as shown in FIG. 4, in order to fill the gap, a concave portion 2u is provided on the upper surface 2a of the flange of the cylinder liner 2 and a hard synthetic resin or the like J may be applied to the concave portion. It is possible and can be used in combination with the above embodiment.

Next, a second embodiment of the present invention will be described. As shown in FIG. 5, in order to prevent the leakage of the combustion gas generated between the upper surface 2d of the flange and the mating surface 3a of the cylinder head 3 and the abrasion of the surface, the flange upper surface 2a of the cylinder liner 2 and the cylinder head 3 The lamination type metal gasket 4 is polymerized between the mating surface 3a and
A bead 4f was provided. In a more preferred embodiment,
It is also possible to apply molybdenum disulfide to the sealing material on both surfaces of the substrate 4a on the cylinder head side to improve the sliding performance. Furthermore, by preparing the thickness t1 of the substrate 4a of the metal gasket 4 on the cylinder head 3 side in several stages, it can be used for adjusting the compression ratio by stacking the tolerances required for the diesel engine. .

The cylinder liner is generally mechanically machined from a casting, but a part of the cylinder liner is also made of a metal pipe. The present invention is more preferably implemented in combination with such a metal pipe cylinder liner. That is, the cylinder liner made of a metal pipe has a smaller thickness than that of a cast product, so that the cylinder gasket made of the metal plate of the present invention can be made thinner.

Finally, a third embodiment of the present invention will be described. As shown in FIGS.
The combination sealing method and the multi-cylinder engine of the present invention are realized by using a combustion gas sealing gasket 6 separate from the cylinder block 1. Here, the following two methods are considered as a method of superposing and fixing the gasket 6 on the flange upper surface 2a of the cylinder liner 2. That is, as shown in FIGS. 6 and 7, one of the cylinder liners 2 is formed by providing several small overhangs 6h on the outer periphery D8 of the combustion gas seal gasket 6 and forming the bent claws 6j. Flange outer diameter D4
The other is to attach and fix to the step 2d or the groove 2e provided on the surface of the gasket 6 as shown in FIGS. The inner diameter of the sub-plate 4d is set to be larger than the inner diameter d5, and the substrates 4a and 4b are formed so that the inner diameters of the substrates 4a and 4b are different from the overlapped combustion gas sealing gasket 6, and several small cutouts 6f are formed in the hard plate of the gasket. The gasket 4 is fixed to the intermediate sub-plate 4d of the gasket 4 by welding or the like, or is fixed to the intermediate sub-plate 4d of the gasket 4 by welding or the like.

According to this configuration, since the gasket for sealing the combustion gas is provided separately, it is possible to employ a material most suitable for sealing the combustion gas, for example, molybdenum disulfide, silicon resin or the like. In addition, compared with a case where a rubber system used for sealing of cooling water or oil is used for a combustion gas seal, a decrease in sealing performance and a decrease in cylinder liner holding force can be prevented. As described above, the thickness t2 of the combustion gas sealing gasket 6
By preparing the thickness T2 of the metal gasket 4 in several stages, the metal gasket 4 can be used for adjusting the compression ratio by stacking the parts tolerance required for the diesel engine.

[0017]

As described above, according to the multi-cylinder engine and the combination sealing method of the present invention, the tightening surface pressure on the upper surface of the flange of the cylinder liner is integrated, so that the conventional multi-cylinder engine with liner insertion can be used. In comparison, it is possible to prevent a problem such as distortion of the inner diameter of the cylinder and hitting of the liner holding portion caused by the distortion and bolt torque reduction. Also, an excellent effect that the combustion gas sealing property is improved is exhibited. As a result, fuel efficiency and oil consumption can be improved, and the exhaust gas emission performance of a diesel engine can be expected to be improved, and it is possible to suitably cope with recent environmental problems.

[Brief description of the drawings]

FIG. 1 is a drawing for explaining a first embodiment of the present invention.

FIG. 2 is a drawing for explaining a first embodiment of the present invention.

FIG. 3 is a drawing for explaining a first embodiment of the present invention, particularly, a groove 2m is provided on a flange upper surface 2a.

FIG. 4 is a view for explaining a first embodiment of the present invention, in particular, a concave portion 2u is provided on a flange upper surface 2a.

FIG. 5 is a drawing for explaining a second embodiment of the present invention.

FIG. 6 is a view for explaining a method of fixing by polymerization according to a third embodiment of the present invention.

FIG. 7 is a view for explaining a method of fixing by polymerization according to a third embodiment of the present invention.

FIG. 8 is a view for explaining a polymerization fixing method according to a third embodiment of the present invention.

FIG. 9 is a view for explaining a polymerization fixing method according to a third embodiment of the present invention.

FIG. 10 is a drawing for explaining a combustion gas sealing gasket 6 independent for each cylinder of a multi-cylinder engine used in a third embodiment of the present invention.

FIG. 11 is a view for explaining a combustion gas sealing gasket 6 integrated in a multi-cylinder engine used in a third embodiment of the present invention.

FIG. 12 is a diagram for explaining a conventional technique.

FIG. 13 is a drawing for explaining a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Cylinder block 1a Mating surface of cylinder block with cylinder head 2 Cylinder liner 2a Upper surface of flange 2b Lower surface of flange 3 Cylinder head 3a Mating surface of cylinder head 4 Cylinder gasket 5 Bolt 6 Gasket for combustion gas seal

Claims (6)

[Claims] 1. A cylinder liner with a flange is inserted and arranged in a cylinder hole of a cylinder block,
In the sealing method for a multi-cylinder engine in which a cylinder head gasket is interposed between a cylinder block and a cylinder head, a mating surface of the cylinder block body having a cylinder hole with the cylinder head is a plane processing surface, and the mating surface is The cylinder head gasket is a metal gasket having an inner diameter larger than the outer diameter of the flange of the cylinder liner, and the metal gasket includes a cylinder side gasket. ,
A bead for sealing the cooling water passage hole and the oil passage hole on the head side is provided, and when the cylinder block and the cylinder head are tightened with bolts, the combustion gas seal is formed on the upper surface of the flange of the cylinder liner,
Performed by joining with the mating surface of the cylinder head,
A combination sealing method wherein sealing of cooling water and oil is performed with the metal gasket. 2. A cylinder liner with a flange is inserted and arranged in a cylinder hole of a cylinder block.
In a multi-cylinder engine in which a cylinder head gasket is interposed between a cylinder block and a cylinder head, the mating surface of the cylinder block body provided with the cylinder holes with the cylinder head is a plane processing surface, and The cylinder head gasket is formed so as to be in close contact with the lower surface of the flange of the inserted cylinder liner, and the cylinder head gasket is a metal gasket having an inner diameter larger than the outer diameter of the flange of the cylinder liner. The cooling water passage hole and the oil passage hole are provided with beads for sealing, and the combustion gas is sealed by joining the upper surface of the flange of the cylinder liner with the mating surface of the cylinder head. The oil seal is Multi-cylinder engine, characterized in that performed by gasket. 3. The metal gasket is of a laminated type, wherein the inner diameter of the substrate on the cylinder head side is larger than the inner diameter of the cylinder liner, the substrate is overlapped on the upper surface of the flange of the cylinder liner, and the beads are formed within a range corresponding to the lower surface of the flange. The combination sealing method according to claim 1, wherein an inner diameter of the laminated metal plate other than the cylinder head side substrate is larger than an outer diameter of a flange of the cylinder liner. 4. The metal gasket is of a laminated type, wherein the inner diameter of the substrate on the cylinder head side is made larger than the inner diameter of the cylinder liner, and the substrate is superposed on the upper surface of the flange of the cylinder liner, and beads are formed within a range corresponding to the lower surface of the flange. 3. The multi-cylinder engine according to claim 2, wherein an inner diameter of the laminated metal plate other than the cylinder head side substrate is larger than an outer diameter of a flange of the cylinder liner. 5. A combustion gas sealing gasket or a gasket having a bead for each cylinder, a bead for each cylinder, and a surface sealing material applied to both sides or one side of the cylinder liner or the multi-cylinder unit. Wherein the gasket for combustion gas sealing is fixed on the upper surface of the flange of the cylinder liner by polymerization, and the polymerization fixing method is one of the following: 1. A method of mounting and fixing to a step or a groove provided on the outer surface of the flange of the cylinder liner by providing several small overhangs on the outer periphery of the gasket for combustion gas sealing and forming bent claws. The outer circumference of the gasket for combustion gas sealing is made larger than the inner diameter of the intermediate sub-plate of the metal gasket, and is superimposed. A method in which several notches having a small width are provided, bent, and fixed to the intermediate sub-plate of the gasket, or the outer diameter of the gasket for combustion gas sealing is made circular and fixed to the intermediate sub-plate of the gasket. 4. The combination sealing method according to claim 1, wherein: 6. A gasket for combustion gas sealing, wherein a cylinder sealer is provided with an inner diameter around the cylinder liner inner diameter, a bead for each cylinder, and a surface sealing material applied to both sides or one side, for each cylinder or integrally for the multiple cylinders. The gasket for combustion gas sealing is fixed by polymerization on the upper surface of the flange of the cylinder liner, and the polymerization fixing method is one of the following methods: 1. A method of mounting and fixing to a step or a groove provided on the outer surface of the flange of the cylinder liner by providing several small overhangs on the outer periphery of the gasket for combustion gas sealing and forming bent claws. The outer circumference of the gasket for combustion gas sealing is made larger than the inner diameter of the intermediate sub-plate of the metal gasket, and is superimposed. By providing several small notches, forming a bend, and fixing it to the intermediate sub-plate of the gasket, or by fixing the combustion gas seal gasket to a circular outer diameter and fixing it at the intermediate sub-plate of the gasket. 5. The multi-cylinder engine according to claim 2, wherein the engine is fixed.