JPH09236179A - Large gasket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a sealing performance by joining gasket members obtained by division in a thickness direction together such that the joined parts of the gasket members of the peripheral direction alternately cross one another in the peripheral direction in both surfaces of the thickness direction in a device constructed by joining a plurality of gasket members obtained by division. SOLUTION: A plurality of gasket members 1 divided into two parts in a thickness direction are prepared, the members being formed in a peripheral direction by punching gasket materials, and by joining these gasket members l to one another in the peripheral and thickness directions, a large gasket is provided. In this case, each gasket member 1 is formed in such a manner that an engaging projecting part 2 formed in one joining end part 1 is engaged with an engaging recessed part 3 formed in the other joining end part lb. On the other hand, the gasket members 1 divided into two parts in the thickness direction are formed in such a manner that the joined parts of the adjacent gasket members 1 are positioned alternately in the peripheral direction in both surfaces of the gasket thickness direction and based on this relationship, opposing surface and back surfaces 1c and 1d are joined together by an adhesive.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a large gasket,
More specifically, the present invention relates to a large-sized gasket used for sealing various fluid devices and joints of pipes and the like.

[0002]

2. Description of the Related Art Conventionally, as a large gasket of this kind,
A configuration as shown in FIGS. 11 and 12 is known. FIG. 11 shows two joining end portions 101a and 101b of the divided gasket members 101 and 101 which are stamped and formed from a sheet-like gasket material.
Are cut obliquely in the thickness direction, and the inclined joining end surfaces 102a and 102b are superimposed and bonded to each other, and FIG. 12 shows the divided gasket members 101 and 101 joined to each other. Steps 103a, 103b each having a half (0.5t) of the thickness (t) of the divided gasket member 101, 101 are formed by cutting a part of each of the joining end portions 101a, 101b in the thickness direction.
Are formed, and these step portions 103a and 103b are superposed face to face and bonded together.

Separately, as shown in FIG. 13, an engagement projection 101c is formed at one joint end of the divided gasket members 101, 101, and an engagement recess is formed at the other joint end. It is also known that the two split gasket members 101, 101 are joined by forming an engaging projection 101c and an engaging recess 101d in the same plane.

[0004]

Among the large gaskets having the above structure, those shown in FIGS. 11 and 12 have an adhesive joint formed on a part of the peripheral surface of the gasket. The strength of the adhesive joint is weak, and when a large pressure or tensile force is applied in a usage state in a strong tightening state, excessive stress is concentrated on the adhesive joint and local slipping or cracking in the circumferential direction Is easy to occur. For this reason, there is a problem that the sealing property at the time of use is deteriorated and leakage is likely to occur, and also in the one shown in FIG. It is joined only by engaging with it, and there is no overlapping part, so the joining strength is insufficient,
There is a disadvantage that the occurrence of leakage due to deterioration of the sealing property is inevitable.

Accordingly, the present invention has been made in view of the above circumstances, and it is possible to increase the strength of the joint between the divided gasket members so as to exhibit the same sealing performance as a gasket having no joint. It is an object of the present invention to provide a large-sized gasket which can be easily formed and has a large diameter.

[0006]

In order to achieve the above object, a large gasket according to the first aspect of the present invention is stamped and formed from a sheet-like gasket material and divided into a plurality of pieces in a circumferential direction and a thickness direction. In a large gasket configured by joining gasket members, the divided gasket members that are circumferentially adjacent to each other are joined in a state where their joint ends are in contact with each other, and are divided in the thickness direction. The member is characterized in that the joining portions of the adjacent divided gasket members in the circumferential direction are arranged so as to be alternately positioned in the circumferential direction on both surfaces in the thickness direction, and the opposite front and back surfaces are completely bonded to each other and joined. It is. In the large gasket having the above configuration, the bonding area of each joint portion in the divided gasket member adjacent in the circumferential direction can be increased to increase the joint strength, and the joint portion is formed in the circumferential direction on both surfaces in the thickness direction of the gasket. Since they are alternately located, even if a large pressure or tensile force is applied in the use mode, the force can be dispersed to a large number of joints, and local slippage and cracks can be prevented. As a result, it is possible to ensure the same sealing performance as that of a gasket having no joint and to reliably prevent leakage.

In the large-sized gasket having the above-described structure, an engagement projection and an engagement recess are formed at both joint ends of the divided gasket members adjacent in the circumferential direction. In addition, as described in claim 3, the bonding strength between both bonding ends and the leakage preventing performance can be further improved by filling the bonding part between the two bonding ends with the adhesive.

Further, as a gasket material of the large gasket having the above-mentioned structure, a gasket material obtained by dispersing aramid short fibers in a rubber base material and vulcanizing them into a sheet is used, as described in claim 4. In this case, since the base material is reinforced with short fibers, it is possible to maintain excellent sealing properties over a long period without creep and stress relaxation of the gasket, and also excellent in resilience. In addition, it is possible to improve the durability of the gasket.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view in which a part of a large gasket according to the present invention is cut away.
... are stamped and formed from a sheet-like gasket material (not shown) obtained by uniformly dispersing aramid short fibers in a rubber base material and subjecting both to a sheet shape, and are formed in a plurality in the circumferential direction and in the thickness direction. The large gasket G is formed by joining the plurality of divided gasket members 1 to each other in the circumferential direction and the thickness direction.

As shown in FIG. 2, each of the plurality of divided gasket members 1 has a substantially dovetail-shaped engaging projection 2 integrally formed at one of its joining ends 1a in the circumferential direction. An engagement recess 3 having the same shape as that of the other joint end 1b is formed, and the divided gasket members 1, 1... It is made to engage within.

The plurality of circumferentially divided gasket members 1 engage the engaging projections 2 and the engaging recesses 3 in the adjacent divided gaskets 1, 1... In the same plane. The gasket members 1, 1 which are joined in a state where the joining ends 1a, 1b are in contact with each other and are divided into two in the thickness direction are divided gasket members which are adjacent in the circumferential direction as shown in FIG. 1, 1 ... joints a ...
Are superposed and arranged so that they are alternately arranged in the circumferential direction on both surfaces in the thickness direction of the gasket G, and the opposing front and back surfaces 1c and 1d are entirely adhered to each other via an adhesive and joined.

In the large gasket G having the above structure,
Since the circumferentially adjacent divided gasket members 1, 1... Are joined by the engagement of the engaging projections 2 and the engaging recesses 3 and the bonding over a large area in the entire circumferential direction,
It is possible to obtain very high bonding strength,
Since the circumferential joints a... Are located alternately in the circumferential direction on both surfaces in the thickness direction of the gasket G, when a large pressure or tensile force is applied in the usage mode, the force is applied to a large number of the joints a. , It is possible to prevent the occurrence of local slip and cracks, and it is possible to secure the same sealing performance as a gasket having no joint.

FIG. 4 shows a modification of the joining structure of the divided gasket members 1, 1... Adjacent to each other in the circumferential direction in the large gasket. These end faces are formed as flat faces along a plane perpendicular to the circumferential direction, and the gasket members 1, 1 divided into two in the thickness direction are formed simply by bringing these flat end faces into contact with each other. Opposite front and back sides 1
The divided gasket members 1, 1... adjoining each other in the circumferential direction are joined to each other through the adhesion between c and 1d. In addition,
In the case of the large gasket shown in FIG. 4 as well, the joints a of the divided gasket members 1, 1... Of course.

[0014]

Experimental Example Next, the following sample gaskets were prepared in order to compare the characteristics of a large gasket according to the present invention and a standard product having the same constituent material as the gasket and having no joint. The product of the present invention: A two-piece gasket member having a thickness of 1.5 mm stamped and formed from aramid short fiber reinforced rubber sheet-like gasket material in the thickness direction is formed from a base rubber of the same quality as the rubber base material in the gasket material. A large sample gasket having an outer diameter of 338 mm and an inner diameter of 275 mm having six joints in the circumferential direction and having the same shape as that shown in FIG. In addition,
In the product of the present invention, an unvulcanized rubber base material was dissolved in toluene, and a solution having a concentration of 25% was used. The solvent used is not limited to toluene, but may be trichloroethane, ME
It is also possible to use K (methyl ethyl ketone) or the like. The concentration of the solution is preferably in the range of 20 to 30%. Standard product: A large sample gasket having a thickness of 3 mm, an outer diameter of 338 mm, and an inner diameter of 275 mm was integrally formed from the aramid short fiber reinforced rubber sheet-like gasket material so as not to have a joint.

The following is a description of a seal test performed for comparing the characteristics of the large sample gaskets described above. FIG. 5 shows a seal test apparatus, in which a sample gasket G is shown.
Polyethylene flat face A between the flanges F, F facing each other
And a predetermined tightening surface pressure (4.9, 9.8, 14.7, 19.6 MPa) with a bolt B.
Was applied, a water pressure was applied via a pump P, and the internal pressure at which a leak occurred was measured by a pressure gauge P. Here, the tightening surface pressure Pg by the bolt B is as follows: Pg = (M · N / 0.2D · Ag) where M (Kgf · cm): tightening torque, N: number of bolts, D: effective bolt diameter, Ag (cm ² ): calculated by gasket contact area.

The results of the seal test are shown in FIG. 6. As is apparent from FIG. 6, the product of the present invention has the same sealing performance as the standard product, and both gaskets cause abnormal deformation and breakage. Nothing.

The following is a description of a bonding strength test performed to ascertain the characteristics of the large gasket corresponding to the above-described product of the present invention. This bonding strength test is shown in FIG.
The tensile test for the joint sample taken as shown by the solid line and the peeling test for the adhesive sample taken as shown by the dotted line in FIG. 7, both tests being the gasket after the seal test as described above. And the gasket after being immersed in warm water of 100 ° C. and boiled for 1000 hours (Hr). In addition, of the above two tests, the latter peel test was performed by the method shown in FIG. 8, and the tensile speed was 300 mm / min in both tests.

Of the above-mentioned bonding strength tests, the results of the former tensile test are as shown in FIG. 9, and the results of the latter peel test are as shown in FIG. 10, as apparent from these tables. , The tensile strength after the seal test is high, and the tensile strength after boiling is not significantly reduced, and has the property of stably maintaining the high tensile strength regardless of the use conditions. You can see that. Also, there is almost no decrease in peel strength after boiling, and it can be said that there is no practical problem when considering that this kind of gasket is used in a tightened state.

In each of the above embodiments, the gasket is divided into two parts in the thickness direction.
However, the present invention is not limited to this. For example, the gasket may be divided into three or more in the thickness direction.

[0020]

As described above, according to the first aspect of the present invention, it is possible to increase the bonding area of each joint portion in the circumferentially adjacent divided gasket member to significantly increase the joining strength, and to improve the joining strength. In order to locate the parts alternately in the circumferential direction on both sides in the thickness direction of the gasket, the large pressure and tensile force acting on the gasket in the usage mode are distributed to many joints to prevent the occurrence of local slip and cracks can do. Therefore, it is possible to ensure the same sealing performance as that of a gasket having no joint portion, to reliably prevent leakage, and to easily increase the diameter.

In particular, an engaging projection and an engaging recess which engage with each other in the same plane are formed at both joint ends of the divided gasket members which are circumferentially adjacent to each other. As described above, the bonding strength between the two bonding ends and the leakage prevention performance can be further improved by filling the bonding part with the adhesive.

According to a fourth aspect of the present invention, the gasket material used in the large gasket having the above-mentioned structure is formed by dispersing aramid short fibers in a rubber base material and vulcanizing the two into a sheet. Since the base material is reinforced with short fibers, the gasket does not creep or relieve stress, not only can maintain excellent sealing properties over a long period of time, but also has excellent resilience, The durability can be improved.

[Brief description of drawings]

FIG. 1 is a partially broken perspective view showing an embodiment of a large gasket according to the present invention.

FIG. 2 is an enlarged perspective view showing one divided gasket member in the same large gasket.

FIG. 3 is an enlarged perspective view of a main part showing a joining state of a plurality of divided gasket members in the large gasket.

FIG. 4 is an enlarged perspective view of a main part showing another embodiment of the large gasket according to the present invention.

FIG. 5 is a longitudinal sectional view of a seal test apparatus used for comparing characteristics between a large gasket according to the present invention and a standard product.

FIG. 6 is a graph showing a comparison of characteristics based on the same test result.

FIG. 7 is a partially cutaway perspective view illustrating a sampling location of a sample for a joint strength test of a large gasket according to the present invention.

FIG. 8 is an explanatory view showing a method of a peeling test in the same bonding strength test.

FIG. 9 is a table showing the results of a tensile test in the same bonding strength test.

FIG. 10 is a table showing the results of a peeling test in the same bonding strength test.

FIG. 11 is a perspective view of a main part showing an example of a conventional joint structure of a divided gasket member of a large gasket.

FIG. 12 is a perspective view of a main part showing another example of a joint structure of a divided gasket member of a conventional large gasket.

FIG. 13 is a perspective view of a main part showing another example of a conventional joint structure of a divided gasket member of a large gasket.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Split gasket member 1a, 1b Joining end 1c, 1d Front and back of split gasket member 2 Engagement convex part 3 Engagement concave part

Claims (4)

[Claims] 1. A large gasket formed by joining gasket members which are formed by punching and forming a plurality of gasket members in a circumferential direction and a thickness direction from a sheet-like gasket material. The joining end portions thereof are joined in abutting state with each other, and the split gasket member divided in the thickness direction is such that the joining portions of the adjacent divided gasket members in the circumferential direction alternate in the circumferential direction on both surfaces in the thickness direction. A large-sized gasket characterized in that the opposite front and back surfaces are entirely bonded and joined in an arrangement relationship as described above. 2. An engaging projection is formed at one of both joining ends of the divided gasket member adjacent in the circumferential direction, and the other is engaged with the engaging projection in the same plane. The large gasket according to claim 1, wherein an engagement recess is formed. 3. The large-sized gasket according to claim 1, wherein an adhesive is also filled in a joint between both joint ends of the divided gasket members adjacent in the circumferential direction. 4. The large gasket according to claim 1, wherein the gasket material is obtained by dispersing aramid short fibers in a rubber base material and vulcanizing the two into a sheet shape. .