JPH0562672B2 - - Google Patents

Description

[Detailed Description of the Invention] a. Purpose of the Invention (Field of Industrial Application) A method for manufacturing a cylinder head gasket with double wiring according to the present invention is to provide a method for manufacturing a cylinder head gasket with double wiring in a cylinder head gasket between an upper surface of a cylinder block and a lower surface of a cylinder head of an automobile engine. This invention relates to improvements in the technology of manufacturing a cylinder head gasket which is sandwiched between both surfaces in order to maintain airtightness and liquidtightness.

(Prior Art) For example, a cylinder head gasket 1 as shown in FIG. 3 is sandwiched between the upper surface of the cylinder block and the lower surface of the cylinder head of an engine to maintain airtightness and liquidtightness between the two surfaces. I have to.

This cylinder head gasket 1 consists of a gasket sheet 2 made by imprinting a compound on both sides of a core material such as an iron plate with a hook, or pasting a sheet on both sides, and a gasket sheet 2 having bore holes 3, 3 aligned with the openings of the cylinder holes.
4, water and oil holes 4, 4, and small through holes 5, 5 for inserting bolts for connecting the cylinder head to the cylinder block. As shown in the figure, it is constructed by attaching grommets 6, 6 made of thin metal plates.

The grommets 6, 6 are attached to the periphery of each bore hole 3, 3 in order to increase the pressing force around the cylinder hole, which particularly requires a high degree of airtightness.

By the way, in order to further increase the pressing force of such a grommet mounting part and improve the airtightness around the cylinder hole, as shown in FIG. Generally, a wiring ring 7 made of a metal wire rolled into an annular shape is supported between the grommet 6 attached to the grommet 6 and the grommet 6 attached to the grommet 6.

Furthermore, the airtightness is further improved by attaching the wiring, and the grommet 6 is installed at the part where the wiring is attached.
In order to prevent the occurrence of cracks, the wire rings 7a and 7b that are supported between the inner peripheral edge of the bore hole 3 and the grommet 6 are doubled, as shown in FIG. .

(Problem to be solved by the invention) However, as shown in Fig. 6, the wiring 7
If a and 7b are provided twice, the following inconvenience will occur during manufacture of the cylinder head gasket.

That is, when providing double wiring, the outer wire ring 7b of the inner wire ring 7a is arranged so that there is no gap between the outer circumferential edge of the inner wire ring 7a and the inner circumferential edge of the outer diameter wire ring 7b.
The inner diameter of the inner wire ring 7a is equal to or the outer diameter of the inner wire ring 7a is slightly smaller than the inner diameter of the outer wire ring 7b.
is pushed inside the outer wire ring 7b, insert both wire rings 7a and 7b inside the bore hole 3, and attach the grommet 6 to the inner peripheral edge of the bore hole 3 by caulking the grommet 6 to improve sealing performance. Retention,
This is preferable from the standpoint of preventing cracking of the grommet 6, but when both the wire rings 7a and 7b are combined in this way, the positional relationship between the two wire rings 7a and 7b is adjusted as shown in FIG. 7 before the grommet 6 is caulked. Easy to shift and move.

If the caulking work of the grommet 6 is performed with both the wiring rings 7a and 7b shifted as shown in FIG. Even if the attachment work can be carried out, there will be problems such as not being able to sufficiently maintain airtightness around the peripheral edge of the bore hole 3.

The manufacturing method of the cylinder head gasket with double wiring of the present invention reliably prevents the wiring rings 7a and 7b, which are attached inside and outside in combination, from shifting as shown in FIG. This is to reliably prevent such inconveniences.

b. Structure of the Invention (Means for Solving Problems) The method for manufacturing a cylinder head gasket with double wiring according to the present invention includes two wirings each formed by abutting both ends of a metal wire rod rolled into an annular shape.
The holes 3 formed in the gasket sheet 2 are assembled concentrically with each other as shown in FIG.
This is a method of manufacturing a cylinder head gasket with double wiring supported between the inner peripheral edge of the cylinder head and a grommet 6 attached to the peripheral edge of the bore hole 3.

When manufacturing a cylinder head gasket by the manufacturing method of the present invention, first, the inner wire ring 7a, whose outer diameter is slightly larger than the inner diameter of the outer wire ring 7b, is inserted into the outer wire ring 7a, as shown in FIG. Push the outer and inner wire rings 7a, 7b inwardly into the wire ring 7b with the joints 8, 8 shifted in the circumferential direction, and press the wire rings 7a, 7b from above and below between mutually parallel surfaces. By attaching them, the positional relationship between both wiring rings 7a and 7b becomes a regular positional relationship as shown in FIG.

In this case, the inner and outer wiring 7a,
The reason why the seams 8, 8 of 7b are arranged to be shifted in the circumferential direction is to prevent the airtightness from deteriorating due to the presence of the seams 8, 8. In other words, unlike the other parts, it is unavoidable that the seams 8 and 8 have slight unevenness, and are inevitably inferior to other parts in terms of airtightness. By arranging the eyes 8, 8 so as to be shifted in the circumferential direction, this seam 8,
This minimizes the deterioration in airtightness due to the presence of No. 8.

Once both wiring rings 7a and 7b have been held in their proper positional relationship as described above, then, as shown in FIG. Both wire rings 7 are welded together by spot welding or soldered at multiple points to the periphery.
A and 7b are inseparably connected.

Then, the double wiring rings 7a, which are thus concentrically combined and unfavorably connected to each other,
7b is inserted inside the bore hole 3, a grommet 6 is attached to the peripheral edge of the bore hole 3, and both wire rings 7a, 7b are supported between the inner peripheral edge of the bore hole 3 and the grommet 6.

c. Effects of the Invention Since the method for manufacturing a cylinder head gasket with double wiring of the present invention is configured as described above, it is possible to always keep the positional relationship of the double-combined wiring in the correct state. It is possible to reliably prevent the occurrence of cracks in the grommet, and also to reliably maintain airtightness around the bore hole.

[Brief explanation of drawings]

Figure 1 is a plan view of a double wire ring, Figure 2 is an enlarged sectional view taken along line A-A in Figure 1 showing the welded parts between the wire rings, and Figure 3 is an example of a cylinder head gasket. A plan view, FIG. 4 is a view corresponding to the BB cross section of FIG. 3, showing the cylinder head gasket without wiring;
Fig. 5 shows a cylinder head gasket with a wiring ring, which corresponds to the CC cross section of Fig. 3. Fig. 6 shows a cylinder head gasket with a double wiring ring, and is similar to Fig. 5. , and FIG. 7 are cross-sectional views showing a state in which the positional relationship between the inner and outer wirings is shifted. 1: Cylinder head gasket, 2: Gasket sheet, 3: Bore hole, 4: Water, oil hole, 5: Small through hole, 6: Grommet, 7, 7a, 7b: Wiring, 8: Seam.

Claims (1)

[Claims] 1. Two wire rings made by abutting both ends of metal wire rods rolled into an annular shape are combined concentrically with each other and attached to the inner periphery of a bore hole formed in the gasket sheet and the periphery of this bore hole. A method for manufacturing a cylinder head gasket with a double wiring ring supported between the gasket and a grommet, the method comprising: placing an inner wire ring with an outer diameter slightly larger than the inner diameter of the outer wire ring inside the outer wire ring; Push in the outer and inner wire rings with their seams offset in the circumferential direction, and while pressing both wire rings from above and below between parallel surfaces, press the outer circumferential edge of the inner wire ring and the outer wire ring. Both wire rings are inseparably joined by welding or soldering to each other at multiple points with the inner peripheral edge of the bore hole, and this combined double wire ring is attached to the inner peripheral edge of the bore hole and the peripheral edge of this bore hole. A method for manufacturing a cylinder head gasket with double wiring, which is supported between a grommet and a grommet.