JPH0614625U - Metal gasket - Google Patents

Abstract

(57) [Summary] [Purpose] A metal gasket that has excellent conformability to the flange contact surface and has dramatically improved sealing performance. [Structure] A bead is provided on a base material obtained by laminating a foamed rubber layer having closed cells on the surface of a metal substrate such as a mild steel plate, a stainless steel plate, or an aluminum plate. [Effect] The initial familiarity with the flange contact surface can be dramatically improved, and as a result, the sealing performance can be exhibited under a wider range of use conditions.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a metal gasket which is excellent in familiarity with a flange contact surface and has dramatically improved sealing performance.

[0002]

[Prior art]

 In general, when a metal gasket is used around the engine, in order to obtain familiarity with the surface of the flange 14 as in the full bead specification shown in FIGS. 9 and 10 or the half bead specification shown in FIGS. 9 and 10. First, rubber coating is applied to the surface of the metal substrate 11, and a fluorine-based or silicone-based coating film 12 is formed. In addition, the sealing performance can be dramatically improved by forming the bead 13 in the subsequent step. However, depending on the following flange properties-for example, parts with extremely poor surface roughness, parts with surface waviness, parts with large steps on the mating flange, parts with multiple cavities, etc. It was not possible to fully demonstrate the sealing performance of the product.

When sealing an aqueous fluid, a mild steel plate may be used for the metal substrate 11 mainly in consideration of cost, but rust may occur on the end face of the substrate 11 depending on the use conditions. Of course, since the bead 13 was provided, the fluid entered the clearance 15 which is the remaining height of the bead 13 and passed through the coating film 12 to promote the progress of rust. .

[0004]

[Problems to be solved by the device]

 The present invention has been made in view of the above circumstances, and an object thereof is to obtain a metal gasket capable of overcoming the conventional drawbacks by providing a bead after laminating a foamed rubber layer having closed cells on the surface of a metal substrate. .

[0005]

[Means for Solving the Problems]

 The present invention has been made in view of the above point of view, and a bead is applied to a base material obtained by laminating a foamed rubber layer having closed cells on the surface of a metal substrate such as a mild steel plate, a stainless steel plate, and an aluminum plate. The purpose is to provide the provided metal gasket.

[0006]

[Action and Example]

 Hereinafter, the structure of the present invention will be described together with its operation with reference to the drawings. 1 and 2 show the case of a full bead specification showing an embodiment of the present invention, and FIGS. 3 and 4 show the case of a half bead specification showing another embodiment of the present invention. In either case, mild steel is used. A bead 3 is processed after laminating a foamed rubber layer 2 composed of closed cells on the surface of a metal substrate 1 such as a plate, a stainless steel plate, or an aluminum plate.

2 and 4 showing a state in which the metal gasket according to the present invention is fastened to the flange, and FIG. 10 and FIG. 12 showing a state in which a corresponding conventional metal gasket is fastened to the flange 3, respectively. Correspondence will be compared and examined below.

In the metal gasket according to the present invention, as shown in FIGS. 2 and 4, the foamed rubber layer is laminated on the outside of the bead portion. Therefore, if the foamed rubber layer is not present, the bead portion is tightened when tightened. The foamed rubber layer can fill any gaps that may arise due to the height of the foam. Also, when this state is viewed with pressure-sensitive paper, it can be confirmed that the surface pressure is sufficiently acting on the foamed rubber layer filling the above-mentioned gap, so that the infiltration of fluid from the contact part with the flange is suppressed. It will be possible. On the other hand, in the case of the conventional bead, as shown in FIGS. 10 and 12, due to its height, a gap is inevitably generated during tightening, and it is unavoidable that the fluid enters there. Become.

The case of FIGS. 5 and 6 will be described below as a specific example. [Case 1] Sealing characteristics of 3-sided flange <Usage conditions>

[0010]

[Table 1]

<Usage Conditions> A sample is mounted on a flange and fastened with a predetermined torque. The parts A and B are each charged with N ₂ gas to gradually increase the internal pressure. Confirm the fluid leakage by the underwater replacement method, and read the internal pressure at that time from the gauge to obtain the leakage pressure. <result>

[0012]

[Table 2]

When the conventional metal gasket was used, it was not possible to prevent the air leakage generated from the flange mating portion, but it was confirmed that this specification provides a very good sealing property.

[Case 2] Effect of Corrosion in Salt Spray Test The corrosion resistance in the salt spray test ( J IS _Z 2371) was evaluated in comparison with the conventional metal gasket. The results are as follows. <Test condition>

[0015]

[Table 3] <Test specimen conditions> See FIGS. 7 and 8.

[0016]

[Table 4]

<Test method> According to the salt spray test method ( J IS _Z 23 71). Corrosion evaluation method: Photograph the gasket before and after the test with soft X-rays. The difference in the X-ray transmission amount at the part where corrosion is occurring is read with a digitizer and the corrosion area is calculated. <result>

[0018]

[Table 5]

Note) Corrosion area ( _% ): A value determined by the ratio of the total area of corrosion points to the total area. The total corroded area under the conventional specifications is 1.34 cm ² , which shows that rust has progressed inside the substrate to a small extent. On the other hand, for this specification, although some rust was observed on the board end face by visual observation, it was not possible to find the progress of rust inside the board because the corrosion area was zero. From the above, this specification makes it possible to dramatically improve the corrosion resistance, despite the fact that the board is the same as the conventional specification.

[0020]

[Effect of device]

 As described above, according to the present invention, it is possible to dramatically improve the initial familiarity with respect to the flange property <usage condition> for which the conventional metal gasket could not sufficiently exhibit the sealing performance. As a result, it becomes possible to exhibit sealing performance under a wider range of use conditions.

When a mild steel plate is used for the metal substrate, a conventional metal gasket has a gap corresponding to the remaining height of the bead when it is fastened to the flange. When the water-based fluid is sealed in such a state, water may be attacked not only from the end face of the substrate but also from the above-mentioned gap, and rust may progress inside the substrate. However, in the gasket according to the present invention, as shown in the above-mentioned “Case 2”, the gap at the time of fastening can be filled with the foam rubber layer, so that the attack of water from the gap can be suppressed. Stainless steel and aluminum substrates have been used for parts that hate the progress of rust as much as possible, but even mild steel plates have only the substrate end faces, so they can be fully used, which is extremely advantageous for cost reduction. It is a thing.

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[Table 5]

[Submission date] January 20, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[0002]

[Prior art]

Generally, when a metal gasket is used around the engine, in order to obtain familiarity with the surface of the flange 14, as in the full bead specification shown in FIGS. 9 and 10 or the half bead specification shown in FIGS. 11 and 12 , On the surface of the metal substrate 11, a coating film 12 of fluorine type, silicone type or the like is formed in addition to rubber coating. In addition, the sealing performance can be dramatically improved by forming the bead 13 in the subsequent step. However, depending on the following flange properties-for example, parts with extremely poor surface roughness, parts with surface waviness, parts with large steps on the mating flange, parts with multiple cavities, etc. It was not possible to fully demonstrate the sealing performance of the product.

[Brief description of drawings]

FIG. 1 is a front view of an embodiment of the present invention formed into a full bead specification.

FIG. 2 is a front explanatory view showing a flange fastening state of a gasket formed in a full bead specification according to an embodiment of the present invention.

FIG. 3 is a front view of an embodiment of the present invention formed into a half bead specification.

FIG. 4 is a front explanatory view showing a flange fastening state of a gasket formed in a half bead specification according to an embodiment of the present invention.

FIG. 5 is a plan view showing a gasket shape in a three-sided mating flange.

FIG. 6 is a front view showing a state in which a gasket is fastened to the three-sided mating flange.

FIG. 7 is a plan view showing a gasket shape according to the present invention.

FIG. 8 is a front view showing a state in which the gasket according to the present invention is fastened to the flange.

FIG. 9 is a front view of a conventional example formed into a full bead specification.

FIG. 10 is a front explanatory view showing a flange fastening state of a gasket having a full bead specification formed by a conventional example.

FIG. 11 is a front view of a conventional example formed in a half bead specification.

FIG. 12 is a front explanatory view showing a flange fastening state of a gasket formed in a half bead specification as a conventional example.

[Explanation of symbols]

 1 metal substrate 2 foam rubber layer 3 bead

[Procedure amendment]

[Submission date] January 20, 1992

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

[Figure 3]

[Figure 4]

[Figure 5]

[Figure 6]

[Figure 7]

[Figure 8]

[Figure 9]

[Figure 10]

FIG. 11

[Fig. 12]

Claims (1)

[Scope of utility model registration request] 1. A metal gasket, wherein a bead is provided on a base material obtained by laminating a foamed rubber layer having closed cells on the surface of a metal substrate such as a mild steel plate, a stainless steel plate, and an aluminum plate.