JPH0516460Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The metal cylinder head gasket according to this invention is sandwiched between the upper surface of the cylinder block and the lower surface of the cylinder head of an automobile engine, and is used to maintain airtightness and liquidtightness between both surfaces. Used to hold.

(Prior Art) A cylinder head gasket is sandwiched between the upper surface of the cylinder block and the lower surface of the cylinder head of an engine to prevent high-pressure combustion gas generated within the cylinder formed in the cylinder block, and to prevent the high-pressure combustion gas from flowing between the cylinder block and the cylinder head. This prevents the cooling water or lubricating oil flowing between the two from leaking to the outside.

Conventionally, such cylinder head gaskets have been widely used, with layers of gasket material such as asbestos or carbon formed on both the front and back sides of a core material such as a steel plate with a hook. Due to increased output, cylinder head gaskets are now required to have a high degree of heat resistance.
Metal cylinder head gaskets made of metal plates are increasingly being used.

This metal cylinder head gasket is constructed as shown in FIG. 7, for example.

That is, this metal cylinder head gasket 1
consists of one or a plurality of laminated metal plates 2, and a plurality of bore holes 3, which are aligned with the cylinder holes opened on the top surface of the cylinder block, are formed in the metal plate 2.
As in 3, the water opening on the top of the cylinder block,
Through holes 4, 4 are formed to match the oil holes.

Around each bore hole 3, 3, as shown by the chain line in Fig. 7 and the cross section shown in Figs. , or the inner circumferential flat part and the outer circumferential flat part are continuous at the inclined part to form a diaphragm shape (example shown in FIGS. 9 and 10), and the beads 5, 5 surround the entire circumference of each bore hole 3, 3. By increasing the pressing force around the bore holes 3, 3, the high pressure fuel gas generated within the cylinder hole during engine operation is prevented from leaking to the outside.

(Problems to be Solved by the Invention) However, in the case of the conventional metal cylinder head gasket 1 constructed and operated as described above, the following disadvantages occur.

That is, the force that presses the metal cylinder head gasket 1 between the upper surface of the cylinder block and the lower surface of the cylinder head is obtained by the tightening force of the bolts used to connect the cylinder block and cylinder head to each other. This tightening force is applied to adjacent bore holes 3, 3, which are located at a greater distance from the bolt.
It is unavoidable that it becomes smaller in the area between.

For this reason, the airtightness around the bore holes 3, 3 by the beads 5, 5 tends to be incomplete in the above-mentioned space,
If it is incomplete, engine performance will deteriorate due to leakage of high-pressure combustion gas (so-called blow-through) between adjacent cylinder holes.

In order to ensure airtightness around the bore holes 3, 3, it is effective to form a double bead around each bore hole 3, 3. The spacing is often narrow, and each bore hole 3, 3
It is often difficult to double the beads formed around the bore holes 3 and form a total of four beads between the adjacent bore holes 3, 3.

The metal cylinder head gasket of this invention is
This solves the above-mentioned inconveniences.

(Means for Solving the Problems) The metal cylinder head gasket of the present invention, like the conventional metal cylinder head gasket described above, is made of one or a plurality of laminated metal plates, and the upper surface of the cylinder block is It has multiple bore holes that match the cylinder hole opened in the
Furthermore, in the metal cylinder head gasket of the present invention, the inner peripheral flat part and the outer peripheral flat part are connected to each other by a conical inclined part around the plurality of bore holes. A first bead is provided surrounding the entire circumference of each borehole.

In the case of the metal cylinder head gasket according to claim 1, a second bead having a substantially V-shaped or substantially U-shaped cross section is provided around each first bead, and a second bead having a substantially V-shaped or substantially U-shaped cross section is arranged around each first bead. It is provided so as to surround the entire circumference. Portions of the second bead formed around adjacent boreholes and located between the adjacent boreholes overlap each other to form a single bead.

As mentioned above, of both the first and second beads formed to double surround each bore hole, the height of the first bead is set higher than the height of the second bead. It's getting bigger.

Further, in the second aspect of the present invention, the second beads formed on each of the plurality of metal plates are made to protrude in the same direction, and one of the second beads formed around the adjacent bore holes is made to protrude in the same direction. At this point, the portions located between adjacent bore holes are overlapped to form a single bead, and the single bead portions formed on the plurality of metal plates are fitted into each other.

(Function) The metal cylinder head gasket of the present invention, constructed as described above, is sandwiched between the top surface of the cylinder block and the bottom surface of the cylinder head, similar to the conventional metal cylinder head gasket described above, to prevent the occurrence of gas within the cylinder. This prevents high-pressure combustion gas from leaking to the outside, as well as cooling water or lubricating oil flowing between the cylinder block and cylinder head.

However, in the case of the metal cylinder head gasket of the present invention, the first and second beads are provided around each bore hole so as to double surround each bore hole. Airtightness is ensured,
Deterioration in engine performance due to leakage of high-pressure combustion gas can be reliably prevented.

In particular, in the case of the metal cylinder head gasket described in claim 2, since the elasticity of the mutually overlapping portions of the second beads is sufficiently large, airtightness between adjacent bore holes can be maintained more reliably. It will be done.

In the case of the metal cylinder head gasket of the present invention, three beads are formed between adjacent bore holes, and each bore hole is surrounded twice by these three beads. Even if the distance between matching bore holes is narrow, it is possible to reliably maintain airtightness around each bore hole.

(Example) Next, the present invention will be explained in more detail while explaining the illustrated embodiment.

1 to 3 show an embodiment of the present invention according to claim 1, FIG. 1 is a schematic plan view showing the arrangement of beads, and FIG.
A sectional view and FIG. 3 are sectional views similar to FIG. 2, showing an example of the height of a bead formed on one metal plate.

The metal cylinder head gasket 1, which is made by laminating two metal plates 2, 2, has a plurality of bore holes 3, 3 that align with the cylinder holes opened on the top surface of the cylinder block, and a transparent hole for passing cooling water. hole 4,4
Although not shown, oil holes for circulating lubricating oil and small circular holes for inserting bolts for connecting the cylinder block and cylinder head are formed, respectively.

Around the plurality of bore holes 3, 3, a first part is formed by connecting inner peripheral side flat parts 6, 6 and outer peripheral side flat parts 7, 7 with inclined parts 8, 8 which are inclined in a mortar shape. The beads 9, 9 are as shown by chain lines in Fig. 1,
It is provided so as to surround the entire circumference of each bore hole 3,3.

Around each first bead 9, 9, a second bead 10, 10 having a substantially V-shaped or substantially U-shaped cross section,
It is provided so as to surround the entire circumference of each first bead 9,9. The portions of the second beads 10, 10 formed around the adjacent bore holes 3, 3 and located between the adjacent bore holes 3, 3 are overlapped with each other and are aligned with the chain lines and the dashed lines in FIG. As shown in Figure 2, it is a single bead.

As described above, both the first and second beads 9, 10 are formed to double surround each bore hole 3, 3.
Among them, the height dimension H of the first beads 9, 9 is the height dimension H of the second beads 1 surrounding the first beads 9, 9.
It is made larger than the height dimension h of 0 and 10.

For example, as shown in FIG.
The width dimension of 6 is 0.5 mm each, the width dimension of the inclined parts 8, 8 is 1.2 mm each, the dimension of the flat parts 7, 7 on the outer peripheral side is 0.6 mm each, and the second bead in the overlapping part in the middle of the bore hole. When the width dimension of 10 is 1.4 mm, the height dimension H of the first beads 9, 9 is
400μm, the height dimension of the second bead 10, 10
The thickness is preferably 200 to 250 μm. However, in this case, the thickness of the metal plate 2 is approximately 0.3 mm.

Furthermore, in the case of the illustrated embodiment, a third bead 11 is provided over the entire circumference of the metal cylinder head gasket 1 at a portion closer to the outer peripheral edge of the metal cylinder head gasket 1 than the portion where the through holes 4, 4 are formed. This third bead 11 and the second beads 10, 10 prevent the cooling water flowing inside the through holes 4, 4 from leaking to the outside.

That is, the third bead 11 prevents the cooling water flowing inside the through holes 4, 4 from leaking from the outer peripheral edge side of the metal cylinder head gasket 1, and the cooling water from leaking from the bore holes 3, 3 side is prevented by the third bead 11. second bead 1
Prevented by 0,10. Therefore, the second beads 10, 10 serve both of the roles of preventing combustion gas leakage and cooling water leakage prevention.

When the metal cylinder head gasket 1 of the present invention constructed as described above is held between the upper surface of the cylinder block and the lower surface of the cylinder head, a double gasket formed around the plurality of bore holes 3, 3 is formed. one,
The second beads 9 and 10 reliably prevent high-pressure combustion gas generated within the cylinder from leaking to the outside.

Also, leakage of the cooling water flowing inside the through holes 4, 4 to the outside is caused by the second and third beads 10, 11.
This is prevented by

Next, an embodiment of the invention described in claim 2 will be described with reference to FIGS. 4 to 6.

4 to 6, FIG. 4 is a cross-sectional view similar to FIG. 2, FIG. 5 is a diagram for explaining the elasticity obtained by the beads combined as shown in FIG. FIG. 6 is a diagram for explaining the elasticity obtained by the beads combined as shown in FIG. 4.

In this embodiment, as in the embodiment shown in FIG. 3, around each first bead 9, 9,
A second bead 1 having a substantially V-shaped or U-shaped cross section
0 and 10 are provided so as to surround the entire circumference of each first bead 9, 9. However, in the case of this embodiment, the portions of the second beads 10, 10 formed around the adjacent bore holes 3, 3, located between the adjacent bore holes 3, 3 are overlapped with each other. A part of the second bead 10, 10 formed on the two metal plates 2, 2 and located between the adjacent bore holes 3, 3 is combined into a single bead. are fitted together.

In the case of this embodiment, the same mechanism as in the embodiment shown in FIGS. Since the elasticity of the beads 10, 10 portions becomes sufficiently large, the airtightness between the adjacent bore holes 3, 3 can be maintained more reliably.

That is, when a pair of second beads 10, 10 are combined in a hollow shape as shown in FIG. 2, the elasticity obtained by both beads 10, 10 is as shown in FIG. , which is relatively weak when a pair of springs 12, 12 are connected in series, whereas when a pair of beads 10, 10 are combined in a state where they fit together as shown in FIG. In this case, the elasticity obtained by both beads 10, 10 will be sufficiently large as if a pair of springs 12, 12 were connected in parallel, as shown in FIG.

Therefore, the pressing force between the adjacent bore holes 3, 3 becomes sufficiently large, and the airtightness between the two bore holes 3, 3 is further improved.

(Effects of the invention) The metal cylinder head gasket of the invention is
Since it is configured and operates as described above, it is possible to reliably maintain airtightness between the upper surface of the cylinder block and the lower surface of the cylinder head of the engine, and it plays a major role in improving the performance of the engine.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the invention described in claim 1, in which FIG. 1 is a schematic plan view showing the arrangement of beads, FIG. 2 is a sectional view taken along line A-A in FIG. Figure 3 shows the height of the bead formed on one metal plate.
A cross-sectional view similar to FIG. 2 and FIGS. 4 to 6 show examples of the invention according to claim 2,
Figure 4 is a sectional view similar to Figure 2, Figure 5 is a diagram for explaining the elasticity obtained by the beads combined as shown in Figure 2, and Figure 6 is a diagram similar to that shown in Figure 4. Figure 7 is a schematic plan view showing an example of a conventional metal cylinder head gasket;
Figures 1 to 10 are views corresponding to the BB cross section in Figure 7, showing three examples of the shapes of beads formed around the bore hole. 1...Metal cylinder head gasket, 2...
... Metal plate, 3 ... Bore hole, 4 ... Through hole, 5 ... Bead, 6 ... Flat part on the inner peripheral side, 7 ... Flat part on the outer peripheral side, 8 ... Inclined part, 9 ... First Bead, 10...
...Second bead, 11...Third bead, 12...
...Spring.

Claims (1)

[Claims for Utility Model Registration] (1) A metal cylinder head gasket consisting of one or a plurality of laminated metal plates and having a plurality of bore holes aligned with the cylinder holes opened on the top surface of the cylinder block. , surrounding the entire circumference of each bore hole, a first bead formed by connecting an inner peripheral flat part and an outer peripheral flat part with an inclined part inclined in a mortar shape, around the plurality of bore holes. A second bead having a substantially V-shaped or substantially U-shaped cross section is provided around each first bead, surrounding the entire circumference of each first bead, The part of the second bead formed around the hole located between adjacent boreholes is overlapped to form a single bead, and the height dimension of the first bead is set to the height of the second bead. A metal cylinder head gasket characterized by being larger than the height dimension. (2) In a metal cylinder head gasket consisting of a plurality of laminated metal plates and having a plurality of bore holes that align with the cylinder holes opened on the top surface of the cylinder block, each of the cylinder head gaskets has a plurality of bore holes around each of the plurality of bore holes. A first bead consisting of an inner circumferential flat part and an outer circumferential flat part connected to each other by a mortar-shaped inclined part is provided to surround the entire circumference of each bore hole, and the circumference of each first bead is A second bead having a substantially V-shaped or substantially U-shaped cross section is arranged around the entire periphery of each first bead, and the second beads each formed on a plurality of metal plates are arranged in the same direction. A part of the second bead that is provided in a protruding state and formed around adjacent boreholes, and the part located between the adjacent boreholes is overlapped with each other to form a single bead, and a plurality of beads are A metal cylinder head gasket characterized by a single bead formed on a metal plate that fits together.