JP5057357B2 - How to modify the gasket - Google Patents

Description

  The present invention relates to a method for correcting a gasket in which a grommet is provided on the periphery of a hole, such as an engine cylinder head gasket.

  For example, in a cylinder head gasket interposed between a cylinder block and a cylinder head of an engine, a grommet is provided at a peripheral portion of a hole serving as a cylinder bore portion or a water / oil passage, and a gasket body in which plate-like materials are overlapped. Gas, water, and the like are prevented from entering the inside of the space from the hole, and the contact surface pressure at the peripheral edge is increased to prevent gas leakage from the hole side to the contact surface and water leakage.

In FIG. 1, an example of the grommet part of the cylinder head gasket 1 is shown. In the figure, symbol B indicates a cylinder bore portion, and W indicates a water hole. A grommet 5 is provided on the periphery of the bore portion B, and a section aa thereof is shown in FIG.
In FIG. 2, the gasket body 2 is composed of an upper surface plate 2a, a lower surface plate 2b, and an intermediate plate 2c sandwiched therebetween, and a state in which the cylinder head H is attached and tightened with a predetermined tightening torque. It is comprised so that it may become predetermined thickness. As shown in the figure, beads b and b projecting outward are formed around the bores B of the gasket upper surface plate 2a and the lower surface plate 2b, respectively. It is formed in a letter-shaped cross section and is attached to the gasket body 1 along the inner periphery of the bore portion B with the bead portions b and b interposed therebetween.

  FIG. 2 shows a state in which the gasket 1 is mounted between the cylinder block C and the cylinder head H. A grommet 5 of the gasket 1 is interposed between the cylinder liner flange F and the cylinder head lower surface H1, and mainly the above-mentioned. The cylinder head H and the liner flange portion F are pressed by the reaction force caused by the elastic deformation of the bead portions b and b, and a high surface pressure is formed along the periphery of the bore portion to achieve a gas seal against the combustion pressure in the cylinder.

Next, a procedure for mounting the grommet 5 on the periphery of the bore portion of the gasket body 2 will be described with reference to FIGS. First, as shown in FIG. 7, a grommet formed of a plate-like material (either above or below the gasket) and composed of a flat portion 6 a serving as the peripheral edge of one bore portion and a cylindrical portion 6 b fitted to the inner periphery of the bore portion. The rough shape member 6 is inserted into the bore portion B of the gasket body 1.
And the tip end pressing surface 16a presses the other cylindrical end using a conical tool 16, and the diameter is increased in a tapered shape (see FIG. 8). Next, the tip pressing surface is pressed with a flat tool 17 so that the cross-sectional shape of the grommet is U-shaped, the gasket body (bead portions b, b) is wrapped inside, and the grommet 5 is bored in the gasket body 2. Crimp along the inner circumference of part B.
Grommets are formed by the above procedure, and each grommet is mounted in each hole (B, W,...).
Japanese Utility Model Publication No. 6-6829

  When the grommet 5 is attached to the gasket body 2 in the above procedure, it is difficult to ensure the flatness of the contact surface 5a of the grommet, and as shown in FIG. D) is easily generated. Such a convex portion d causes a hindrance to the cylinder head H or the cylinder block C (cylinder liner flange portion F) to which the gasket 1 is attached, and furthermore, the surface pressure is reduced when the cylinder head H is tightened with a bolt. Evenly (as shown in FIG. 11, the upper and lower portions c of the bead b have a high surface pressure for gas sealing, but the surface pressure becomes discontinuous when the convex portion d is generated at a position deviated from the bead position. .) It was a cause of problems such as gas leaks.

  The present invention copes with the above-mentioned problems, keeps the surface of the grommet attached to the periphery of the hole formed in the gasket flat, and causes wrinkles on the surface of the mating part or uneven surface pressure. It is an object of the present invention to provide a method for correcting a gasket which has been improved.

  According to the present invention, the upper and lower surfaces of the plate members (2a, 2b) are wrapped along the peripheral edge of the hole (B) of the gasket body (2) formed by superposing a plurality of plate members (2a, 2b). In the gasket correction method for flattening the convex portion (d) generated on the contact surface (5a) with the molding of the grommet (5) in the gasket (1) provided with the grommet (5), a guide pin The upper jig (12, 13) in which the lower jig (11) on which (11a) is erected and the pressing surface (12a, 13a) are formed in a spherical shape or a conical shape and are guided by the guide pin (11a). The gasket is set on the jig lower die (11) with the contact surface (5a) having the convex portion (d) facing upward, and the jig upper die (12, 13) is pushed down to press the pressing surface ( 12a, 13a) said convex part (d It is flat so as to average the.

  Further, according to the present invention, the upper and lower surfaces of the plate members (2a, 2b) are formed along the peripheral edge of the hole (B) of the gasket body (2) formed by overlapping a plurality of plate members (2a, 2b). In the gasket correction method for flattening the convex part (d) generated on the contact surface (5a) with the molding of the grommet (5) in the gasket (1) provided with the enveloping grommet (5), a guide is provided. A protrusion (14b) for preventing opening is provided radially outward of the lower jig (11) with the pin (11a) standing upright and the pressing surface (14a) formed in a spherical shape, and the guide A jig upper die (14) guided by the pin (11a) is prepared, and the gasket is set on the jig lower die (11) with the contact surface (5a) having the convex portion (d) facing upward. The upper die (14) is pushed down to So that the flat to equalizing the protrusion (d) by 4a).

The operational effects of the present invention having the above-described configuration are as follows.
(1) The deformation protrusion generated at the time of forming the grommet can be corrected by a simple device.
(2) According to the gasket modified by this modification method, there is no fear of scuffing the mating part surface, and the surface is flattened, and a predetermined surface pressure can be secured to prevent leakage. For example, when a bead is provided inside the grommet and the surface pressure is secured by elastic deformation of the portion, it is prevented that the surface pressure becomes discontinuous due to the deforming protrusion and causes leakage.
(3) The opening of the grommet caused by pressing during molding can be prevented.

  Hereinafter, embodiments of the gasket structure of the present invention will be described with reference to the drawings, including a correction method and an apparatus thereof. In addition, the same code | symbol is attached | subjected about the component similar to the component of the gasket by the prior art demonstrated in the above-mentioned "background art", and the overlapping description is abbreviate | omitted.

  The gasket 10 according to the present invention is a state in which the grommet 5 is manufactured by the procedure described with reference to FIGS. 7 to 9, that is, a state in which the convex portion d is generated in the pressing direction on the grommet surface 5a shown in FIG. Therefore, the following means is further applied to ensure the flatness of the surface 5a.

  FIG. 3 shows an embodiment of the correction device of the present invention. In the figure, a guide pin 11 a is erected on the lower jig 11, and the upper jig 12 having a spherical pressing surface 12 a guided by the guide pin 11 a is pushed down. The projection d is pressed and leveled flat. The grommet 5 is pressed from the cylindrical portion 6a side of the rough shape member 6 (FIGS. 8 and 9) and protrudes in the opposite direction (plane portion 6a side). Inverted and set with respect to the jig (from FIG. 9). The pressing surface 12a of the upper mold 12 has a spherical shape with a radius of curvature selected so as to contact the convex portion d of the grommet 5.

  FIG. 4 shows an embodiment in which the pressing surface 13a of the upper mold 13 is tapered. Here, if the taper angle θ is appropriately selected and formed so as to be in contact with and pressed against the convex portion d, a correcting device can be obtained using a jig having such a tapered surface.

  According to the present invention, the upper and lower surfaces of the grommet 5 are flattened by the above-described steps, and there is no risk of scuffing the mating contact surface. Further, the surface sandwiching the bead portions b and b shown in FIG. The flatness of the position c where the pressure is high is ensured, and there is no possibility of causing gas leakage.

However, when the convex portion d is pressed by the above procedure, as the convex portion d is leveled, a so-called open state may occur in the grommet 5 on the opposite side as shown in FIG. .
This problem is dealt with by applying the means and correction method shown in FIG. In the figure, the upper mold 14 is provided with a protrusion 14b for preventing opening of the mouth from the radial direction of the pressing surface 14a formed in a spherical shape.
By comprising in this way, the opening prevention protrusion part 14b can press the whole width | variety of a grommet, and can eliminate opening of a mouth. Although this embodiment is preferably implemented in place of the jig (12 or 13) shown in FIGS. 3 and 4, it may be carried out in addition to the one having a mouth opening.

  In addition, although the above description was performed about the grommet attached to the bore part, it is similarly applied to a water hole or an oil hole, and the present invention is also applied to other than the cylinder gasket. Is.

The top view which shows the hole part vicinity in which the grommet of the gasket by this invention is provided. The figure which showed the aa cross section of FIG. 1 in the state which interposed between the cylinder block and the cylinder head. Sectional drawing explaining one Embodiment of the correction apparatus by this invention. Sectional drawing explaining another embodiment of a correction apparatus. Sectional drawing explaining the opening state of a grommet. Sectional drawing explaining another embodiment of correction apparatus. The figure which shows the 1st process of grommet mounting | wearing. The figure which shows the next process of FIG. The figure which shows the next process of FIG. Sectional drawing of the grommet which shows a convex part. The figure explaining the contact of the grommet outer surface by a bead part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Gasket 2 ... Gasket main body 5 ... Grommet 11 ... Lower mold | type 12, 13, 14 ... Upper mold | type B ... Bore part W ... Water hole

Claims (2)

A grommet (5) that wraps the upper and lower surfaces of the plate members (2a, 2b) along the peripheral edge of the hole (B) of the gasket body (2) formed by overlapping a plurality of plate members (2a, 2b). A guide pin (11a) is erected in a gasket correction method for flattening the convex portion (d) generated on the contact surface (5a) with the molding of the grommet (5) in the gasket (1) provided. The jig lower mold (11) and the pressing surface (12a, 13a) are formed in a spherical shape or a conical shape, and a jig upper mold (12, 13) guided by the guide pin (11a) is prepared, The gasket is set on the jig lower die (11) with the contact surface (5a) having the convex portion (d) facing upward, and the jig upper die (12, 13) is pushed down to push the pressing surface (12a, 13a). Leveling the protrusion (d) flatly Gasket method of modification according to claim. A grommet (5) that wraps the upper and lower surfaces of the plate members (2a, 2b) along the peripheral edge of the hole (B) of the gasket body (2) formed by overlapping a plurality of plate members (2a, 2b). A guide pin (11a) is erected in a gasket correction method for flattening the convex portion (d) generated on the contact surface (5a) with the molding of the grommet (5) in the gasket (1) provided. A protrusion (14b) for preventing opening is provided radially outward of the lower jig (11) and the pressing surface (14a) formed in a spherical shape, and is guided by the guide pin (11a). The jig upper die (14) is prepared, the gasket is set on the jig lower die (11) with the contact surface (5a) having the convex portion (d) facing upward, and the jig upper die (14) is pushed down. The pressing surface (14a) Gasket method modification, wherein the leveling part (d) is flat.

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