JPH0614624U - Metal cylinder head gasket for engines with liner - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent damage and deformation of the liner 1 while ensuring sealing performance and improving engine performance. [Structure] The first and second metal thin plates 18 and 22 are stacked. The coil ring 11 is held by the folded-back portion 23 of the second thin metal plate 22, and the collar portion 5 is suppressed by the elasticity of the coil ring 11. A first ridge 20 is formed on the peripheral edge of the bore hole 19 formed in the first thin metal plate 18. The first protrusion 20 is pressed between the upper end surface of the liner 1 and the lower surface of the cylinder head. The first ridges 20 prevent gas in the combustion chamber from entering between the upper end surface of the liner 1 and the lower surface of the cylinder head.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The metal cylinder head gasket for a liner engine according to the present invention is sandwiched between the upper surface of the cylinder block and the lower surface of the cylinder head of the vehicle engine to maintain airtightness and liquid tightness between both surfaces.

[0002]

[Prior art]

 A cylinder head gasket is sandwiched between the upper surface of the cylinder block of the engine and the lower surface of the cylinder head, and high-pressure combustion gas generated in the cylinder chamber and cooling water flowing between the cylinder block and the cylinder head. It prevents the oil and lubricating oil from leaking to the outside. On the other hand, a cylindrical liner is fitted inside the cylinder hole formed in the cylinder block, and a piston is fitted inside this liner, for the purpose of improving the degree of freedom in selecting the material forming the cylinder block. Things are also commonplace. Further, when the liner is used in this way, a jacket through which cooling water flows is provided between the outer peripheral surface of the liner and the inner peripheral surface of the cylinder hole to cool the liner. .

FIG. 5 is a partial cross-sectional view of a so-called wet liner type cylinder block in which a jacket is provided between the outer peripheral surface of the liner and the inner peripheral surface of the cylinder hole as described above. The liner 1 has an outer diameter dimension D (R> D) smaller than the inner diameter dimension R of the cylinder hole 3 formed in the cylinder block 2. A step portion 4 is provided at the upper end opening of the cylinder hole 3 over the entire circumference of the cylinder hole 3, and a flange portion 5 formed on the outer peripheral edge of the upper end portion of the liner 1 is fitted into the step portion 4. I am combining.

As described above, a cylinder head gasket is sandwiched between the upper surface of the cylinder block 2 having the liner 1 mounted inside the cylinder hole 3 and the lower surface of the cylinder head so that the inside of the cylinder chamber inside the liner 1 is covered. It prevents the high pressure combustion gas generated and the cooling water and lubricating oil flowing between the cylinder block 2 and the cylinder head from leaking to the outside, but ensures sufficient sealability and damages the liner 1 above. In order to prevent this, it is necessary to consider the following points.

First, as a first point of caution, the upper surface of the collar portion 5 must be pressed at the portion where the step portion 4 and the collar portion 5 overlap each other. When the upper surface of the collar portion 5 is strongly pressed at a portion closer to the inner diameter side (right side in FIG. 5) than the inner peripheral edge of the step portion 4, the lower surface of the collar portion 5 and the outer peripheral surface of the liner 1 are A large stress acts on the continuous portion 6, and cracks are easily generated from the continuous portion 6. If the upper surface of the collar 5 is not pressed sufficiently strongly, not only will the airtightness between the upper surface of the collar 5 and the lower surface of the cylinder head be insufficient, but the lower surface of the collar 5 and the step 4 will not be maintained. Due to insufficient contact pressure with the upper surface of the, the water existing in the jacket 7 between the outer peripheral surface of the liner 1 and the inner peripheral surface of the cylinder hole 3 leaks to the outside.

As a second point of caution, even when the height dimension h of the step portion 4 and the height dimension h ′ of the collar portion 5 are slightly different from each other, the force pressing the upper surface of the collar portion 5 largely changes. It is necessary not to do it. That is, the parts 4 and 5 are manufactured such that the heights h and h ′ are the same, but the heights h and h ′ may be different due to unavoidable manufacturing errors. . When the cylinder head gasket has a structure that cannot absorb this difference, when the height dimension h'of the collar portion 5 becomes larger than the height dimension h of the step portion 4, the force pressing the upper surface of the collar portion 5 is increased. If the height dimension h'of the collar portion 5 becomes smaller than the height dimension h of the step portion 4 on the contrary, the force pressing the upper surface of the collar portion 5 becomes too small.

If the above-mentioned force becomes excessive, the cross-sectional shape of the liner 1 changes subtly via the collar portion 5, and the contact state between the inner peripheral surface of the liner 1 and the outer peripheral surface of the piston becomes unsuitable, and the engine oil Of the inner surface of the liner 1, scratches on the inner surface of the liner 1 may occur, and in a further significant case, the inner surface of the liner 1 and the outer surface of the piston may be seized. On the other hand, if the above force is too small, the airtightness between the upper surface of the collar 5 and the lower surface of the cylinder head is insufficient, and the contact pressure between the lower surface of the collar 5 and the upper surface of the step 4 is insufficient. Then, the water existing in the jacket 7 between the outer peripheral surface of the liner 1 and the inner peripheral surface of the cylinder hole 3 leaks to the outside.

In consideration of these points, as a cylinder head gasket that secures sufficient sealability and prevents the liner 1 from being damaged, Japanese Patent Publication No. 60-22184 discloses a cylinder head gasket shown in FIG. A cylinder head gasket having a structure as shown in is described.

In this conventionally known cylinder head gasket, a bore hole 10 is formed in a gasket body 9 in which a plurality of metal thin plates 8, 8 are laminated, and a coil ring 11 is wrapped inside the bore hole 10. It is equipped with a grommet 12. The collar portion 5 is formed at a portion slightly lower than the upper end portion of the liner 1, and the coil ring 11 and the grommet 12 are formed on the upper surface of the collar portion 5 and the lower surface of the cylinder head 14 when the cylinder head gasket is used. Elastically compresses between.

When the coil ring 11 and the grommet 12 are elastically compressed and elastically deformed, if the amount of deformation is regulated within a certain range, the pushing force applied from the coil ring 11 and the grommet 12 to the collar portion 5 is increased. The pressure (elastic repulsion) becomes almost constant. Therefore, regardless of the difference between the thickness dimension of the collar portion 5 and the height dimension of the step portion 4 due to a manufacturing error, the above-mentioned thickness dimension and height are set so that the above deformation amount falls within the above range. If the elasticity of the coil ring 11 and the grommet 12 is regulated as well as the size is regulated, the force for pressing the collar portion 5 against the step portion 4 can always be set to an appropriate value.

[0011]

[Problems to be solved by the device]

 The metal cylinder head gasket for a liner engine of the present invention improves the handleability without complicating the manufacturing process while maintaining the effect of the invention described in Japanese Patent Publication No. 60-22184. Furthermore, it aims to improve the performance of an engine that incorporates a cylinder head gasket.

In the case of the cylinder head gasket described in the above publication, since the gasket body 9 and the grommet 12 are independent, this cylinder head gasket is mounted between the upper surface of the cylinder block 2 and the lower surface of the cylinder head 14. Until then, it is necessary to consider so that both members 9 and 12 are not separated from each other, and the handling is poor and the assembly work to the engine becomes troublesome. For this reason, the above-mentioned publication describes that the grommet 12 is glued to the gasket main body 9, but after the grommets 12 and the gasket main body 9 which are separately manufactured are aligned with each other, both members 12, 9 are The work of gluing the two together is troublesome and complicates the manufacturing process of the cylinder head gasket, which is not desirable.

Further, the leakage prevention of the high-pressure combustion gas generated in the combustion chamber 15 existing inside the liner 1 during the operation of the engine is prevented by the mounting portion of the coil ring 11 and the grommet 12. In other words, the gas existing in the combustion chamber 15 enters into the annular space 16 existing between the combustion chamber 15 and the mounting portion. Therefore, when the volume of the space 16 is large, the compression ratio of the engine is reduced correspondingly, and the performance cannot be improved. In addition, the unburned gas that has entered the space 16 is incompletely burned, and the exhaust gas There is a problem such that the amount of harmful components contained in is increased.

Therefore, in the structure described in the above publication, the upper end portion 17 of the liner 1 is made to project beyond the upper surface of the cylinder block 2 so that the volume of the space 16 is reduced. However, when the upper end portion 17 is projected from the upper surface of the cylinder block 2, the upper end portion 17 collides with other portions during transportation of the cylinder block 2 and the liner 1 is not only easily damaged, but also manufactured. Considering the error, it is difficult to make the volume of the space 16 sufficiently small.

What is necessary is to reliably prevent the upper end surface of the upper end portion 17 and the lower surface of the cylinder head 14 from directly contacting each other. This is because when the two surfaces directly contact each other, an excessive downward force is applied to the liner 1 as the cylinder block 2 and the cylinder head 14 are coupled, and the collar portion 5 is damaged. Therefore, irrespective of manufacturing errors, the size of each part is set so that the protruding amount of the upper end part 17 from the upper surface of the cylinder block 2 is smaller than the thickness size of the gasket body 9 in the compressed state. Must be regulated. As a result, the amount of protrusion of the upper end portion 17 cannot be increased so much in consideration of safety, and the volume of the space 16 also increases to some extent.

The metal cylinder head gasket for an engine with a liner according to the present invention has been devised in view of the above circumstances.

[0017]

[Means for Solving the Problems]

 The metal cylinder head gasket for an engine with a liner of the present invention is formed by stacking at least a first thin metal plate and a second thin metal plate, and a cylinder block upper surface and a cylinder head in which a liner is fitted inside a cylinder hole. The first thin metal plate is used to face the lower face of the cylinder head, and the second thin metal plate is placed to face the upper face of the cylinder block so as to maintain the seal between the lower face and the lower face of the cylinder block.

The metal cylinder head gasket for an engine with a liner according to the present invention which is used in this way is formed at a position aligned with the upper end opening of the liner, which is a part of the first thin metal plate. A bore hole having a diameter substantially equal to the inner diameter of the liner, and a ridge formed around the entire circumference of the bore hole at a portion facing the inner peripheral portion of the upper end surface of the liner. A part of the second thin metal plate is folded around the bore hole by 180 degrees or more, so that the bore is formed concentrically with the bore hole while protruding toward the opposite side of the first thin metal plate. A folded-back portion having a diameter larger than that of the hole, and a hollow seal ring held by the folded-back portion are provided. Then, at the time of use, this seal ring is made to enter into the concave portion of the outer peripheral edge of the collar portion provided at the upper end portion of the liner.

[0019]

[Action]

 When the metal cylinder head gasket for an engine with a liner according to the present invention constructed as described above is used, the hollow seal ring is elastically compressed, but a space still remains inside. For this reason, the force that elastically presses the flange portion of the liner can be regulated to be substantially constant, and the liner can be prevented from being damaged and the sealing property around the cylinder hole can be reliably ensured.

In use, the ridge formed on the first thin metal plate is elastically compressed between the upper end surface of the liner and the lower surface of the cylinder head. For this reason, the communication between the combustion chamber existing inside the liner and the outside is blocked by the protruding portion. Therefore, the volume of the space that exists between the upper end surface of the liner and the lower surface of the cylinder head and into which the gas in the combustion chamber can enter becomes small.

[0021]

【Example】

 1 and 2 show a first embodiment of the present invention. A liner 1 is mounted inside a cylinder hole 3 formed in a cylinder block 2 of an engine in which the metal cylinder head gasket for an engine with a liner of the present invention is mounted. The upper end surface of the liner 1 is located on the same plane as the upper surface of the cylinder block 2 (within the manufacturing error). That is, the collar portion 5 formed on the outer peripheral surface of the upper end portion of the liner 1 is fitted to the step portion 4 formed on the inner peripheral surface of the upper end portion of the cylinder hole 3 so that the liner 1 is provided inside the cylinder hole 3. I support you. A jacket 7 for circulating cooling water is formed between the inner peripheral surface of the cylinder hole 3 and the outer peripheral surface of the liner 1. Further, a concave portion 13 is formed on the outer peripheral portion of the upper surface of the collar portion 5.

For example, a circular bore hole 19 is formed in the first metal thin plate 18 made of a stainless steel spring material having a thickness of about 0.3 mm so as to match the upper end opening of the liner 1. There is. The first and second ridges 20 and 21 are formed concentrically around the bore hole 19. Each of the ridges 20 and 21 is of a so-called diaphragm type in which a pair of inner and outer flat surfaces are continuously formed by inclined surfaces. The first ridge 20 of these is opposed to the inner peripheral portion of the upper end surface of the liner 1, and the second ridge 21 is opposed to the peripheral portion of the cylinder hole 3 on the upper surface of the cylinder block 2. ing.

On the other hand, a second metal thin plate 22 made of, for example, stainless steel having a thickness of about 0.2 mm is attached to the lower surface of the first metal thin plate 18. At a part of the second thin metal plate 22, the peripheral part of the bore hole 19 formed in the first thin metal plate 18 is folded back to the side opposite to the first thin metal plate 18 by about 180 degrees. As a result, the folded portion 23 having a U-shaped cross section is formed. The folded-back portion 23 has a larger diameter than the bore hole 19 and is formed concentrically with the bore hole 19, and when used, enters the recess 13 on the upper surface of the collar portion 5.

Further, a coil ring 11 that is a hollow seal ring is held inside the folded-back portion 23. The coil ring 11 is formed by closely winding an elastic thin metal wire into a coil spring shape, and connecting both ends thereof to form a ring shape as a whole. As described in the above-mentioned publication, such a coil ring 11 has a substantially constant elastic repulsion force if the deformation amount is restricted to a certain range when elastically compressed and elastically deformed. You can

When the metal cylinder head gasket for a liner engine of the present invention constructed as described above is used, the first protrusion 20 is provided between the upper end surface of the liner 1 and the lower surface of the cylinder head 14. Then, the second protrusion 21 is elastically compressed between the upper surface of the cylinder block 2 and the lower surface of the cylinder head 14, and at the same time, it is held by the folded portion 23 and the folded portion 23. The coil ring 11 is elastically compressed between the bottom surface of the recess 13 and the bottom surface of the cylinder head 14.

However, the coil ring 11 is not completely crushed, and a space remains inside the coil ring 11 even during use. Therefore, the force for elastically pressing the collar portion 5 of the liner 1 can be regulated to be substantially constant. Further, the recess 13 is formed near the outer periphery of the collar portion 5, so that the force pressing the collar portion 5 based on the elasticity of the coil ring 11 causes the step portion 4 formed at the upper end of the cylinder hole 3. Is reliably supported by. In other words, the point of action of the force does not deviate radially inward from the stepped portion 4.

Therefore, an unreasonable force is not applied to the collar portion 5 of the liner 1, so that the liner 1 can be prevented from being damaged and the liner 1 can be prevented from being deformed. Further, the contact pressure between the lower surface of the cylinder head gasket and the upper surface of the collar portion 5 and the contact pressure between the lower surface of the collar portion 5 and the upper surface of the step portion 4 are both sufficient. Therefore, it is possible to surely prevent the combustion gas in the combustion chamber 15 from leaking to the outside and the cooling water in the jacket 7 from leaking to the outside.

In use, the first ridges 20 formed on the first thin metal plate 18 are provided between the upper end surface of the liner 1 and the lower surface of the cylinder head 14 as shown in FIG. It is elastically compressed by. Therefore, the communication between the combustion chamber 15 existing inside the liner 1 and the outside is blocked by the first ridge 20 portion. Therefore, the volume of the space 16 existing between the upper end surface of the liner 1 and the lower surface of the cylinder head 14 and into which the gas in the combustion chamber 15 can enter has a triangular cross section shown by a slanted lattice in FIG. Only the part is provided, and the volume of this space 16 can be made extremely small. In addition, since the first ridge 20 is not completely crushed even during use, an excessive pressing force does not act on the upper end surface of the collar portion 5. The second ridge 21 has a function of more reliably maintaining airtightness around the bore hole 19.

Next, FIG. 3 shows a second embodiment of the present invention. In the case of this embodiment, as the hollow seal ring, a seal ring 27 formed by superposing three metal thin plates 24, 25, 26 is used instead of the coil ring 11 in the above-mentioned first embodiment. is doing. Further, the folded-back portion 23 formed on the second thin metal plate 22 is folded back by approximately 360 degrees to completely enclose the above-mentioned seal ring 27. Even when the seal ring 27 is compressed, similarly to the coil ring 11, the elastic repulsion force can be made substantially constant by limiting the compression amount within a certain range. Other configurations and operations are similar to those of the first embodiment described above.

Further, FIG. 4 shows a third embodiment of the present invention. In the case of this embodiment, a part of the second metal thin plate 22 is once bent in a crank shape toward the opposite side of the first metal thin plate 18 and then folded back 180 degrees to form a folded portion 23. The coil ring 11 is attached to the inside of the folded portion 23. In the case of the present embodiment, even if the cooling water in the jacket 7 (FIG. 1) leaks, it is possible to prevent the cooling water from touching the coil ring 11. Other configurations and operations are similar to those of the above-described first embodiment.

[0031]

[Effect of device]

 Since the metal cylinder head gasket for engine with liner of the present invention is constructed and operates as described above, it is possible to reliably prevent the liner from being damaged or deformed, ensure the sealing performance around the cylinder hole, and further, to prevent the liner from being damaged. By reducing the volume of the space into which gas enters, it is possible to improve engine performance and reduce harmful components in exhaust gas.

[Brief description of drawings]

FIG. 1 is a partial longitudinal sectional view showing a first embodiment of the present invention.

2 is a cross-sectional view corresponding to a portion A in FIG. 1, showing a usage state.

FIG. 3 is a partial vertical cross-sectional view showing a second embodiment of the present invention by extracting only the changes from the first embodiment.

FIG. 4 is a view similar to FIG. 3, showing a third embodiment of the present invention.

FIG. 5 is a partial vertical cross-sectional view of a cylinder block incorporating a liner.

FIG. 6 is a partial vertical sectional view showing an example of a conventional cylinder head gasket.

[Explanation of symbols]

 1 Liner 2 Cylinder block 3 Cylinder hole 4 Step part 5 Collar part 6 Continuous part 7 Jacket 8 Metal thin plate 9 Gasket body 10 Bore hole 11 Coil ring 12 Grommet 13 Recess 14 Cylinder head 15 Combustion chamber 16 Space 17 Upper end 18 18 First Metal thin plate 19 Bore hole 20 First ridge 21 Second ridge 22 Second metal thin plate 23 Folding part 24, 25, 26 Metal thin plate 27 Seal ring

Claims (1)

[Scope of utility model registration request] 1. A seal holding between a top surface of a cylinder block and a bottom surface of a cylinder head, which is formed by stacking at least a first metal thin plate and a second metal thin plate and has a liner fitted inside a cylinder hole. In order to achieve the above, a metal cylinder head gasket for a liner engine, which is used in a state where a first metal thin plate is opposed to a lower surface of a cylinder head and a second metal thin plate is opposed to an upper surface of a cylinder block. A bore hole having a diameter substantially corresponding to the inner diameter of the liner, which is formed at a position aligned with the upper end opening of the liner in a part of the thin metal plate, and the upper end surface of the liner around the bore hole. A ridge formed over the entire circumference in a portion facing the inner peripheral portion, and the peripheral portion of the bore hole being folded back 180 degrees or more by a part of the second thin metal plate, the above-mentioned first In a state of protruding to the side opposite to the one metal thin plate, provided with a folded portion formed concentrically with the bore hole, having a diameter larger than the bore hole, and a hollow seal ring held in the folded portion, A metal cylinder head gasket for a engine with a liner, which allows the seal ring to enter a recess on the outer peripheral edge of the collar portion provided at the upper end of the liner when in use.