JPH0520925Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention is a cylinder called a laminate type, which is arranged between a cylinder head and a cylinder block, and has thin metal plates stacked around the bore having a bore grommet. This relates to head gaskets.

(Prior art) A cylinder head gasket placed between the cylinder head and cylinder block to prevent leakage of fuel gas, cooling oil, and water is called a steel vest, which is made by incorporating steel into asbestos. There are various types depending on the purpose, such as the solid core type, which has a metal plate coated with asbestos on both surfaces, and the wiring insert type, which has a metal wire built into the bore grommet. As shown in Figures 5 and 6, there is a known type used in large diesels, etc., which has a shape in which thin metal plates with bore grommets are stacked around the bore, and is called a laminate type. . In FIG. 6, several thin plates 1a, 1 made of metal such as stainless steel or iron are drawn in an exaggerated thickness direction.
A laminate type cylinder head gasket 1 in which cylinders b, 1c, 1d, 1e, and 1f are stacked has holes 2 for passing combustion gas, and a plurality of holes 3 for passing water and oil for cooling. Through-holes such as a plurality of holes 4 for passing the push rod and cooling oil and a plurality of holes 5 for inserting fastening bolts between the cylinder block and the cylinder head are provided,
A bore grommet 6, which is mainly made of metal and is used to improve the durability of the gasket, is placed around the circumferential end of the hole 2 of the cylinder head gasket 1 so as to have a U-shaped cross section. As shown in FIG. 8, shims 7 made of stainless steel or iron are installed around the holes 3 and 4 to sandwich the thin plates 1a, 1b, . . . 1f that constitute the cylinder head gasket 1, as shown in FIG. , 8 are glued.

In this way, the thickness H of the cylinder head gasket 1 including the bore grommet around the bore and the thickness H
The thickness L of the cylinder head gasket 1 including the shims 7 and 8 around the cooling water and oil passage holes 3 and 4 is approximately equal to the thickness of the other parts, that is, the cylinder head and cylinder block. By making it thicker than the thickness M of the peripheral part of the hole 5 for fastening the bolt,
The surface pressure around the bore and around the cooling hole was made particularly higher than in other parts, to prevent combustion gas, water, and oil from leaking there as much as possible.

(Problems to be solved by the invention) As mentioned above, the laminated type cylinder head gasket has a thickness H around the bore including the bore grommet, and a thickness around the hole 5 for inserting the fastening bolt between the cylinder block and the cylinder head. As shown in FIG. 7, for example, when a bolt inserted into one hole 5a of the fastening bolt insertion holes 5 is first tightened, the tightening force is different. Accordingly, the thin plates 1a, 1b, . . . 1 around the hole 5a
f and cylinder head 9 are cylinder block 10
When the cylinder block 10 and the cylinder head 9 try to come into close contact with each other, the cylinder block 10 and the cylinder head 9 are deformed due to the difference in thickness as shown in the figure, and the cylinder block 10 and the cylinder head 9 are pressed into contact. On the other hand, in the vicinity of the other fastening bolt insertion hole 5, especially the hole 5b located diagonally to 5a, as shown in the figure, the cylinder head 9 bends, so there is a large gap between the lower surface of the cylinder head 9 and the upper surface of the thin plate 1a. d will occur, and even if the bolt inserted into the hole 5b is tightened to the fullest, the rigidity of the cylinder head 9 is high, so the tightening bolt cannot be tightened sufficiently and the cylinder block around the hole 5b will be damaged. 10 and the cylinder head 9 may not be pressed together. When such a situation occurs, the surface pressure on the bore grommet is not uniform over the entire surface, resulting in the problem that combustion gas and the like leak out from areas where the surface pressure is low.

(Means for Solving the Problems) In order to solve the above problems, the present invention aims to improve the thickness of the cylinder head gasket including the bore grommet, the thickness of the cylinder head gasket around the tightening bolt insertion hole, and the communication passage. Shims for thickness adjustment that make the thickness of the cylinder head gasket at the peripheral part approximately equal are provided around the fastening bolt insertion hole and around the communication passage, and the bore grommet part, the bolt part, and the peripheral part of the communication passage are provided. By making the thicknesses approximately equal, the surface pressure between the bore grommet part, the area around the insertion hole for the fastening bolt, and the area around the communication path of the fluid passage when the cylinder head and cylinder block are connected is reduced. This ensures uniformity of combustion gases and prevents leakage of combustion gas, etc.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

1 and 2 show a first embodiment of the present invention. The difference between this embodiment and the prior art is that cooling water and oil passage holes 3 and 4 are provided around the holes 3 and 4 in order to increase the surface pressure around them to the same level as the bore grommet. , Thickness adjustment shims 7 and 8 that sandwich the cylinder head gasket 1 in a sandwich-like manner so as to make the thickness H of the cylinder head gasket around the bore substantially equal to the thickness around the holes 3 and 4, Both bolts extend to the periphery of the bolt insertion hole 5 between the cylinder head and the cylinder block. It should be noted that the configurations of other parts are completely the same as those of the prior art, so their explanations are omitted here, and in order to avoid complexity, the same reference numerals will be used in FIG.

The thus expanded thickness adjustment shim 17,
The thickness X of the cylinder head gasket 1 around the fastening bolt insertion hole 5 including the bolt hole 18 is the same as the thickness H of the cylinder head gasket around the bore including the bore grommet and around the water and oil passage holes 3 and 4. The thickness L of the gasket is approximately equal to that of the cylinder head, in other words, there is no difference in thickness due to the difference in thickness, so even when tightening the fastening bolt, the cylinder head does not bend like in the conventional case, and the entire fastening bolt can be tightened with an approximately uniform force. Since it is possible to tighten the bore grommet 6, the surface pressure on the bore grommet 6 is always uniform in all parts, and leakage of combustion gas etc. can be prevented.

In addition, the thickness adjustment shim is used to adjust the thickness X of the peripheral part of the fastening bolt insertion hole 5 to the thickness H of the cylinder head gasket 1 around the bore including the bore grommet 6.
If the thickness is approximately equal to the thickness L of the gasket around the water and oil passage holes 3 and 4, the shim 117 shown on the right side of the center line in FIG.
It may be inserted between the thin plates of a conventional laminate type cylinder head gasket 1 like 118, or it may be inserted between any thin plates. Furthermore, a shim 100 shown on the left side of the center line may have a thickness different from that of other thin plates. Here, the shims 100, 117, and 118 shown in FIG. , 118 are used, the shims around the cooling holes 3 and 4 are as follows:
It has the same shape and arrangement as the shims 100, 117, and 118. On the other hand, as shown in Fig. 4, the thickness adjustment shims around the fastening bolt insertion holes 5 are made independent from the shims 7 around the cooling water and oil passage holes 3 and 4, rather than extending from them. (Shim 20 in the figure).
Although the shims 7 and 20 are arranged on the thin plate 1a in FIG. 4, they may be inserted between the thin plates as described above, or may have a different thickness from other thin plates. In this case, the shims around the hole 5 and the shims around the hole 3 are not connected, so for example, the shim around the hole 5 is on the thin plate 1a, and the shim around the hole 3 is on the thin plate 1a. It is also possible to change the arrangement and shape of the shim depending on the location, such as inserting the shim between the thin plates 1a and 1b.

(Effects of the invention) As described above, according to the invention, by making the thicknesses of the bore grommet part, the fastening bolt part, and the peripheral part of the communication passage of the laminate type cylinder head gasket approximately equal, it is possible to insert the bore grommet part and the fastening bolt. Ensures that combustion gas leaks from the holes in the cylinder head gasket through which combustion gas passes, and fluid leaks from the communication passages, making it possible to equalize the surface pressure around the holes and the communication passages of the fluid passages. can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a schematic front view of a cylinder head gasket showing an embodiment of the present invention, and Fig. 2 is a diagram showing C in Fig. 1.
3 is a schematic sectional view of a cylinder head gasket showing another embodiment of the present invention, FIG. 4 is a schematic front view of the same as the above showing another embodiment of the present invention, and FIG. 5 is a conventional one. 6 is a sectional view taken along the line A-A in FIG. 5, FIG. 7 is a schematic sectional view when the gasket according to the prior art is incorporated, and FIG. 8 is a sectional view taken along line AA in FIG. 5. It is a BB sectional view. 1...Cylinder head gasket, 1a, 1
b, 1c, 1d, 1e, 1f... thin metal plate, 3,
4... Cooling water and oil passage holes, 5, 5a, 5
b...Hole for fastening bolt insertion, 6...Bore grommet, 7, 8, 17, 18, 20, 100, 11
7,118...Thickness adjustment shim, 9...Cylinder head, 10...Cylinder block, X, M...
Thickness of the cylinder head gasket around the tightening bolt insertion hole, H: Thickness of the cylinder head gasket including the bore grommet.

Claims (1)

[Scope of utility model registration request] In a laminated type cylinder head gasket, which is arranged between a cylinder head and a cylinder block and is made of stacked thin metal sheets having a bore grommet around the bore, the thickness of the cylinder head gasket including the bore grommet and the thickness of the cylinder head The thickness of the cylinder head gasket around the fastening bolt insertion hole for fastening the gasket to the cylinder block, and the fluid passage formed between the cylinder head and the cylinder block are determined by Thickness adjustment shims are provided around the tightening bolt insertion hole and around the communication path to make the thickness of the cylinder head gasket approximately equal to the thickness of the cylinder head gasket around the communication path that communicates between the cylinder head gasket and the cylinder head gasket. cylinder head gasket.