JPH0778212B2 - Heat-resistant gaskets and manufacturing method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to heat-resistant gaskets used for shaft sealing parts of fluid machinery, sealing parts of gas appliances, etc., and a method for manufacturing the same.

[0002]

2. Description of the Related Art Generally, gaskets of this type mainly use rubber or asbestos.
However, recently, constituent materials having higher heat resistance, wear resistance and lubricity than these materials, such as JP-A-60-
The expanded graphite shown in Japanese Patent No. 60174 or the like, or the expanded vermiculite shown in Japanese Patent Publication No. 58-9304 or the like has received special attention. That is, as shown in FIG. 18,
For example, to a sheet-shaped gasket 102 graphite 101 inflated processed by press molding, as shown in FIG. 19, the sheet substrate 102A of the graphite 101 is inflated treatment to pressure molding, metal between 102B For example, a gasket 104 with a foil 103 interposed.

[0003]

By the way, in the gasket using the expanded graphite 101 or the like, conventionally, as shown in FIG. 20, the expanded graphite 101 is supplied from the hopper 105 through the feeder 106. The graphite 101, which is supplied onto the transport path 107 and is transported in one direction through the transport path 107, is passed between a plurality of pressure rollers 108 and 109 arranged vertically above and below the transport direction.
It is adjusted to the desired thickness. That is, the graphite 101
18 is pressure-molded from a direction orthogonal to the longitudinal direction (X direction), the particle orientation of the graphite 101 in the conventional gaskets 102 and 104 of this type is naturally the enlarged portion B in FIG. As shown in, the layered structure extends along the longitudinal direction. Therefore, the interlayer strength against sliding is weak and peeling is easy, and the heat dissipation in the direction orthogonal to the longitudinal direction is poor. In particular, even when pressure is applied, it slips and plastically deforms, so the restoring property is extremely small, and it is difficult to exhibit the proper function for a long period of time. In addition, even when a reinforcing material or the like is additionally provided, the effect may be halved due to lateral displacement.

The present invention has been made in order to solve the above-mentioned problems, and can enhance the shear strength against sliding, excel in heat dissipation, and particularly increase the pressure recovery rate. It is an object of the present invention to provide a gasket and a method for manufacturing the same, which are capable of achieving the above-mentioned effects and effectively exhibiting a reinforcing effect.

[0005]

In order to achieve the above object, the heat-resistant gaskets according to the present invention are obtained by pressing expanded graphite or vermiculite in one direction to form a longitudinal shape, and at the same time, the graphite or vermiculite is expanded. The particle orientation is set in the direction orthogonal to the longitudinal direction.

A reinforcing material may be provided along the longitudinal direction in a plane perpendicular to the grain orientation of the graphite or vermiculite.

Further, in the method for manufacturing heat-resistant gaskets according to the present invention, while the expanded graphite or vermiculite is supplied from the hopper to the pressure cylinder, the pressure rod fitted to the pressure cylinder is intermittently supplied. The graphite or vermiculite is pressure-formed in one direction by linearly reciprocating and is continuously discharged from the pressure cylinder.

[0008]

According to the above construction, since the particles of the expanded graphite or vermiculite are oriented in the direction orthogonal to the longitudinal direction, the shear strength due to sliding is increased and the heat dissipation in the direction orthogonal to the longitudinal direction is also improved. In particular, the compressive strength is increased and the restoring force under pressure is increased. In addition, the increased shear strength and the like can sufficiently exert the effect when used in combination with the reinforcing material.

Further, in the case where the reinforcing material is provided along the longitudinal direction in the plane perpendicular to the grain orientation, the durability is further improved.

Further, by the manufacturing method using the pressure cylinder and the pressure rod, gaskets having desired characteristics can be continuously produced.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a heat resistant gasket according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 is an expanded graphite 2.
The gasket 3 is composed of a sheet-shaped substrate obtained by pressure-forming. This sheet-shaped substrate 1 has graphite 2 in one direction,
That is, the graphite 3 is pressure-molded in the longitudinal direction (arrow X direction) to direct the particle orientation of the graphite 3 in the direction orthogonal to the longitudinal direction as shown in the enlarged portion A.

The heat resistant gasket 1 is manufactured by the manufacturing apparatus M shown in FIG. First, as shown in FIG. 3, a box-shaped pressure cylinder 4 is prepared. The pressurizing cylinder 4 has a material supply port 6 into which a hopper 5 is fitted, a fitting hole 8 into which a pressurizing rod 7 is intermittently fitted for linear reciprocal movement, and a discharge port 9. There is. In front of the pressure cylinder 4, a plurality of upper and lower pressure rollers 10 and 11 for thickness control are arranged.

In FIG. 2, expanded graphite 2 is contained in a hopper 5, and the graphite 2 is continuously supplied into the pressure cylinder 4. In this state, when the pressure rod 7 is intermittently reciprocated linearly in the front-rear direction (arrow X direction), the graphite 2 in the pressure cylinder 4 is compression-molded in the X direction, that is, the longitudinal direction to form the graphite. The particles 2 are discharged from the discharge port 9 of the pressurizing cylinder 4 in a state in which the particle orientation is in the direction orthogonal to the longitudinal direction. After the pressured graphite 2 is discharged from the discharge port 9, the thickness is controlled by the pressure rollers 10 and 11, whereby the sheet-shaped substrate 1 can be continuously obtained.

In the gasket 3 as described above, the expanded graphite 2 is pressure-molded so that the particle orientation of the graphite 2 is in the direction orthogonal to the longitudinal direction, so that the shearing force against sliding is increased and at the same time, it is orthogonal to the longitudinal direction. Excellent heat dissipation in the direction. Especially, the compression strength is increased,
The particles of the graphite 2 are less likely to shift in the longitudinal direction, the compression recovery rate is increased, and the service life of the gasket 3 in use can be extended.

The gasket 3 is not limited to the one formed of the sheet-like substrate 1, but a prismatic gasket 12 as shown in FIG. 4 can be similarly formed.

FIG. 5 shows a pair of upper and lower sheet-like substrates 1A and 1B.
Gasket 14 with metal foil 13 as a reinforcing material interposed therebetween
Is shown. The metal foil 13 is on a surface perpendicular to the grain orientation of the graphite 2 and is provided along the longitudinal direction of the sheet-shaped substrates 1A and 1B. In this case, the method of forming the sheet-shaped substrates 1A and 1B is as described above, and the metal foil 13 is sent to the pressure rollers 10 and 11 side by the metal foil supply spool 15 separately provided as shown in FIG. You can do it like this.

By the way, the expanded graphite 2 can be increased in density to about 0.9 to 1.9 g / cm ^{3 by} pressure molding. At this density, the expanded graphite 2 formed intermittently.
Since the respective layers are not adhered to each other and may peel off between the layers orthogonal to the longitudinal direction, a low density layer lower than this density, for example, a low density layer of about 0.5 g / cm ³ and the above high density layer are alternately formed. If the amount of supply from the hopper and the stroke of the pressure rod are adjusted so that the sheet is formed, the sheet-like substrate 1 does not peel without requiring any binder or the like.
A and 1B can be formed. In particular, in the sheet-shaped substrates 1A and 1B, since the particle orientation of the graphite 2 is orthogonal to the longitudinal direction and the sideslip in the longitudinal direction of the particles is unlikely to occur, the reinforcing effect with the intervening metal foil 13 is effective. To be demonstrated.

FIG. 7 shows a sheet-like gasket 17 in which a geometrical shape, for example, a dogleg-shaped pressing surface 16 is formed on the sheet-like substrates 1A and 1B. In this case, the formation of the pressing surface 16 causes mechanical strength, especially graphite 2
Slip between the particles is prevented, and the bending strength is increased.
The pressing surface 16 can be easily formed by forming the tip end surface of the pressing rod 7 with a sawtooth surface 18 as shown in FIG. 8 or a dogleg surface 19 as shown in FIG. Can be formed.

FIG. 10 shows a pair of upper and lower sheet-like substrates 21A and 21B using the vermiculite 20 subjected to the expansion treatment.
Are pressure-molded by the same method as described above,
A steel plate 22 is interposed between 1B as a reinforcing material, and claw pieces 23 are formed on the steel plate 22 by cutting and raising. Heat-resistant gasket 24 configured in this way
Has a high bending strength by being bitten by the claw pieces 23, and the vermiculite 20 can be positively used.

FIG. 11 shows expanded graphite 2 and a composite 25 obtained by impregnating expanded graphite 2 with PTFE resin.
Composite columnar gasket 2 formed by alternately press-molding in the longitudinal direction
6 is shown. In this case, although a uniform density distribution is obtained by pressurization, the portion containing the PTFE resin acts as a reinforcing effect, and if the pressurizing surface 27 is formed in a dogleg shape as shown in the drawing, bending strength and the like are enhanced. . In order to manufacture such a gasket 26, as shown in FIG. 12, a hopper 5 for containing the expanded graphite 2 and a PTF for the graphite 2 are prepared.
A hopper 28 for accommodating the one containing E resin 25 is juxtaposed, and these two 2, 25 are alternately supplied into the pressurizing cylinder 4 as the shutter member 31 having the openings 29, 30 is slid. By doing so, it can be easily molded. It is also possible to use a phenol resin or vermiculite instead of the PTFE resin.

Further, using the above composite type, FIG.
You may comprise the ring-shaped packing 32 as shown in FIG.

As yet another example of the present invention, FIG. 14 shows a filament 34 in which expanded graphite 2 is pressure-molded and linear fibers 33 are embedded as a reinforcing core material. Such a filament 34 is shown in FIG. 15 and FIG.
As shown in FIG. 3, a circular pressure rod 36 having a reinforcing core material insertion hole 35, a fitting hole 37 into which the rod is inserted, and a discharge port 3
By using the pressurizing cylinder 39 having No. 8, it is possible to easily supply the reinforcing core material 33 fed from the spool 40 into the pressurizing cylinder 39 through the insertion hole 35 when pressurizing the graphite 2. Will be produced. Also in this case,
It is possible to increase the strength by forming the tip end surface of the pressure rod 36 with a chrysanthemum-shaped uneven surface 41 as shown in FIG. 17 to make the pressure surface of the graphite 2 bite into it. Also,
This thread-like body 34 can be woven or braided, and can be formed into a cloth or a braided cord-like body to be used as a gasket or a gland packing.

[0024]

As described above, according to the present invention, the expanded graphite or vermiculite is pressure-molded so that the grain orientation thereof is oriented in the direction orthogonal to the longitudinal direction.
The compression resistance strength is enhanced, the compression recovery rate can be increased, the shear strength against sliding can be increased, and the heat dissipation in the longitudinal direction and the orthogonal direction can be improved. The effect when used can also be exerted effectively.

According to the second aspect of the present invention, since the reinforcing material is provided along the longitudinal direction on the surface perpendicular to the particle orientation of the expanded graphite or vermiculite, a gasket having further excellent mechanical strength can be obtained. Obtainable.

Further, according to the third aspect of the present invention, it is possible to continuously manufacture the gasket excellent in pressure restoring property with good productivity.

[Brief description of drawings]

FIG. 1 is a perspective view showing a sheet-shaped gasket according to an embodiment of the present invention.

2 is a block diagram showing an apparatus for manufacturing the gasket of FIG. 1. FIG.

3 is a perspective view showing a pressure cylinder and a pressure rod used in the manufacturing apparatus of FIG.

FIG. 4 is a perspective view showing a prismatic gasket as another example of the present invention.

FIG. 5 is a perspective view showing a sheet-shaped gasket as another example of the present invention.

6 is a block diagram showing an apparatus for manufacturing the one shown in FIG.

FIG. 7 is a perspective view showing a gasket as still another example of the present invention.

FIG. 8 is a view showing still another example of the pressure rod.

FIG. 9 is a view showing still another example of the pressure rod.

FIG. 10 is a perspective view showing a gasket as another example of the present invention.

FIG. 11 is a perspective view showing a gasket as still another example of the present invention.

12 is a block diagram showing an apparatus for manufacturing the one shown in FIG. 11. FIG.

13 is a perspective view showing a ring packing obtained from that of FIG. 11. FIG.

FIG. 14 is a perspective view showing still another embodiment of the present invention.

15 is a configuration diagram showing an apparatus for manufacturing the one shown in FIG.

16 is a perspective view showing a pressure rod and a pressure cylinder used in the device in FIG.

FIG. 17 is a view showing another example of the pressure rod.

FIG. 18 is a perspective view showing a conventional heat resistant gasket.

FIG. 19 is a perspective view showing another conventional heat-resistant gasket.

FIG. 20 is a configuration diagram showing an apparatus for manufacturing a conventional heat resistant gasket.

[Explanation of symbols]

 2 Expanded graphite 4,39 Pressurizing cylinder 5,28 Hopper 7,36 Pressurizing rod 13,22,25,33, Reinforcing material 20 Expanded vermiculite X Longitudinal direction

Claims (3)

[Claims] 1. Expanded graphite or vermiculite is pressed in one direction to be formed into a longitudinal shape, and
A heat-resistant gasket, wherein the graphite or vermiculite particle orientation is set in a direction orthogonal to the longitudinal direction. 2. The heat-resistant gaskets according to claim 1, wherein a reinforcing material is provided along the longitudinal direction in a plane perpendicular to the grain orientation of the graphite or vermiculite. 3. A graphite rod or vermiculite, which has been expanded, is supplied to the pressure cylinder from a hopper while the pressure rod fitted in the pressure cylinder is intermittently reciprocated in a linear motion. A method for manufacturing heat-resistant gaskets, which comprises press-molding in one direction and continuously discharging it from a pressurizing cylinder.