JPH0245064B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a seal member, and particularly to a seal member suitable for a pipe joint for a vibrating high-temperature pipe. Front-wheel drive vehicles with front transverse engine (hereinafter referred to as FF)
In a car (abbreviated as a car), the axis of the engine and the center line of the vehicle body are at right angles, so the axis of the exhaust manifold and the exhaust pipe are also at right angles, and rotational vibrations centering on the axis of the exhaust manifold caused by engine rotation. However, it acts on the exhaust pipe as a bending moment in a direction perpendicular to the axis. For this reason, a pipe joint that can absorb this bending moment is required at the connection between the exhaust manifold and the exhaust pipe, but conventional FF
Seal members used in pipe joints in cars do not have such a function. Figure 1 shows a pipe joint in a conventional front-wheel drive vehicle. Here, 1 is an exhaust manifold connected to an exhaust manifold (not shown), and 2 is an exhaust pipe extending in the longitudinal direction of the vehicle body. 3 is exhaust collecting pipe 1
A pair of elongated holes 4 are provided in the flange 3 at the end thereof, extending in a direction perpendicular to the plane of the paper.
5 is a spherical flange at the end of the exhaust pipe 2, and a ring-shaped seal member 6 is pressed against the surface of the flange 3.
is pressed down from its outer circumference. The outer peripheral surface of the spherical flange 5 is parallel to the surface of the flange 3, and has a bolt insertion hole 7 formed therethrough corresponding to the elongated hole 4 of the flange 3. The spherical flange 5 and the flange 3 are pressed against each other by bolts 8, nuts 9, and pressing springs 10, and the sealing member 6 is fitted onto the end of the exhaust manifold 1 and pressed against the flange 3. There is. As the sealing member 6 of the pipe joint as described above, there is a known sealing member disclosed in, for example, Japanese Unexamined Patent Publication No. 76759/1983. As shown in FIG. 2, this known sealing member consists of a band-shaped fireproof plate 11 made of graphite or silicone-bonded mica paper, etc., and a metal mesh 12 of the same width as the band-shaped fireproof plate 11, as shown in FIG. After being rolled up, it is compression-molded in the axial direction to form a seal member 6 having a cross-sectional shape as shown in FIG. However, the above-mentioned known seal members had the following drawbacks and were unsuitable as seal members for pipe joints in front-wheel drive vehicles. That is, (a) if the fireproof board material is graphite, it will oxidize and disappear at temperatures above 400°C, making it unsuitable as a high-temperature sealing member; (b) if the fireproof board material is silicone-bonded mica paper, the silicone (c) As shown in Figure 2, the width of the fireproof board 11 and the metal mesh 12 are the same, and the surface is as shown in Figure 4. Since the metal mesh layer 12 is exposed, there are drawbacks such as loss of sealing performance. In addition, in the pipe joint shown in FIG. 1 incorporating a known seal member, since the seal member has a substantially spherical outer circumferential surface, bending moments in a direction perpendicular to the pipe axis and rotational vibrations about the pipe axis can be avoided. However, if a tensile force in the tube axis direction is applied, flanges 3 and 5
It also has the disadvantage that the sealing member 6 separates from the sealing member 6, and the sealing action is lost. The object of the present invention is to provide an improved sealing member, which does not have the disadvantages of the known sealing members mentioned above, and is particularly suitable for pipe fittings for vibrating, high-temperature pipes. Another object of the invention is to provide an improved sealing member capable of compensating for the shortcomings of the connecting pipe joint. The present invention provides a sealing member installed between high-temperature exhaust pipe flanges in which the flanges of two connected pipes are biased in the pressure direction by a spring, and at least one of the pipe flanges has a spherical surface. The common structure of the second invention includes a refractory layer formed by winding several layers of band-shaped refractory plate material mainly composed of vermiculite into a cylindrical or annular shape, and a plurality of layers that bite into the refractory plate material. It consists of a cylindrical or annular thin metal plate core material formed by rolling together a thin metal plate having claws or small protrusions on at least one surface with the fireproof plate material. Furthermore, the structure of the sealing member of the first invention is comprised of a pair of annular portions arranged in the axial direction so that their respective end faces face each other, and between the pair of annular portions, the respective annular portions are arranged in opposite directions. A biasing spring member is provided. . Furthermore, the structure of the sealing member according to the second invention is characterized in that an elastic member is provided on one end surface of the fireproof material layer. The sealing member in a preferred embodiment of this invention is:
The core material made of thin metal plate is embedded so as not to be exposed on the surface of the refractory material layer. The fireproof plate material used in this invention is based on the applicant's existing patent application, and is suitable as a high-temperature sealing material because it is stable and expands at high temperatures. The core material to be embedded does not create any voids within the sealing member, so there is no risk of gas leaking inside the sealing member, and the claws provided on the surface of the core material dig into the refractory material layer, so the refractory material layer and the core It has the advantage of being strongly bonded to the material. Since the sealing members of the first and second inventions installed between the exhaust pipe flanges have a structure incorporating a spring member or an elastic member, they follow the vibrations of the exhaust pipe and eliminate the risk of gas leakage. do not have. Reference examples and examples will be described below with reference to the drawings. FIG. 5 is a half longitudinal sectional view of the sealing member 13 of the first reference example. In the figure, the entire sealing member 13 is composed of a refractory material layer 14 mainly composed of vermiculite.
At least one thin metal plate core material 1 is embedded in the refractory material layer 14 so as not to be exposed from the surface. The refractory material layer 14 can be formed by laminating plate materials as shown later, and then putting it in a mold and compression molding it to give the final shape of the sealing member 13, or by putting a powder in a mold and compression molding it in the same way. It is molded by methods such as As shown in FIGS. 6 and 7, the core material 15 made of thin metal plate has a large number of claws or small protrusions 15 on both sides thereof.
a, and is completely embedded in the refractory material layer 14 in an annular or cylindrical shape. When embedded, the small protrusions 15a dig into the refractory material layer 14, strengthen the bond between the refractory material layer 14 and the core material 15, and increase the overall strength of the seal member 13. In order to laminate the refractory material layer 14 using plate materials, the eighth
As shown in the figure and FIG.
A thin metal plate core material 15 having a smaller width and length than the refractory plate material 16 are laminated together and rolled into a cylindrical shape to create a rolled body as shown in Fig. 3, and then compressed in an annular mold. It can be obtained by molding. In the sealing member of the first reference example as shown in FIG. 5, the core material 15 is not exposed on the surface of the refractory material layer 14, and
Unlike known sealing members, it is not a metal mesh with built-in voids, so gas does not enter or pass through, and it has high sealing performance. In addition, the fireproof material layer 14 mainly contains vermiculite,
Since it has heat resistance and high temperature expandability, it also has good sealing performance at high temperatures. A method for manufacturing a fireproof plate material whose main component is vermiculite as shown in FIG. 8, and a sealing member using the same, will be described below. No. 2 vermiculite rapidly expanded at 1300℃
After immersing 80 kg in 5 tons of water for 16 hours to thoroughly moisten it, the water/vermiculite mixture was put into a fiberbrator and sheared at high speed, and the scaly vermiculite was dispersed into flocs. Obtain a dispersion. This dispersion was added to
While stirring for a while, 10 kg of hemp pulp and 30 kg of talc were added and uniformly dispersed, and then 8 kg of a mixture of NBR latex and vulcanizing agent was diluted with twice as much water and gradually added. When the latex is uniformly dispersed, add a 5% aluminum sulfate solution little by little and mix the latex with vermiculite, hemp pulp, etc.
After fixing it uniformly on the talc, it was made into a sheet with a thickness of 0.5mm and a density of 1000Kg/ ^m2 , dried at 120℃ for 30 minutes, and slit into a tape with a width of 26mm. A fireproof plate material 16 as shown in the figure was obtained. On the other hand, as a core material, a cold-rolled steel plate with a thickness of 0.2 mm was cut into a strip shape with a width of 21 mm, and holes with a hole diameter of 1.2 mmφ were bored at a pitch of 3 mm, and nail stands were made on both sides, as shown in Figure 8. A core material 15 made of thin metal plate was obtained. The above-mentioned fireproof plate material 16 and thin metal plate core material 15 are stacked together as shown in FIG. 8, and are wound around a round rod of a predetermined diameter and then pulled out to obtain a cylindrical rolled body. This rolled body was placed in a mold and compression molded to obtain a sealing member 13 as shown in FIG. 5 having a spherical curved profile with an outer diameter of 59 mm, an inner diameter of 42.8 mm, and an axial length of 17 mm. When the seal member 13 of this first reference example was attached to the pipe joint shown in Fig. 1 and tested by mounting it on the pipe joint testing device shown in Fig. 14, the good measured values shown in Table 1 were obtained. was gotten. The test device shown in Fig. 14 simulates the movement of a pipe joint in a front-wheel drive vehicle. In the figure, a pipe joint 141 equipped with a seal member to be tested is fixed to a supporter 142, and vibrations indicated by double arrows V, which correspond to vibrations emitted from the front transverse engine, are applied to a vibration tester 143 and an inertial weight 144. It is added artificially. In addition, the frequency of the vibration tester 143,
Amplitude, rocking force, etc. are controlled and measured by a control measuring device 145. Further, the pipe joint 141 is heated by a gas burner 146, and the temperature of the pipe portion at this time is measured by a thermocouple 147. The test items and measured values in Table 1 were tested using the following method. First, the axial load (180 kg) of the compression characteristics is calculated from the shrinkage of the pressing spring 10 when the seal member 13 is tightened with the bolt 8 to the pipe joint shown in FIG. The compression amount (0.4 mm) of the seal member 13 as a compression property was calculated from the distance between the spherical flange 5 and the flange 3 at this time. The next swinging characteristic is determined by placing the pipe fitting 141 after measuring the compression characteristic in the test device shown in FIG.
It was fixed at
f-cm). Next, the gas seal characteristics are first determined by the inertia weight 144.
The side pipe was blindly sealed, air piping was connected to the gas burner 146 side pipe via a flow meter, and the amount of air leaking from the sealing member 13 when an internal pressure of 0.2 Kgf/cm ² G was applied was measured using the flow meter. Measure and confirm that the air leakage amount before rocking is 80c.c./min. After that, the air piping is removed and the gas burner 146 is connected to the gas burner 146 as shown in the apparatus in FIG.
The inside of the pipe joint 141 is heated and maintained at 500°C. While maintaining this temperature, the swing tester 14
3 and conduct a vibration durability test five times with one vibration period of 10Hz x 5 minutes - 50Hz x 55 minutes for a total of 5 hours. After the vibration durability test, the air piping was reconnected, an internal pressure of 0.2 kgf/cm ² G was applied, and the amount of leakage (120 c.c./min) from the seal member 13 after shaking was measured using a flow meter. Seal characteristics. Next, heat resistance was determined by disassembling the pipe fitting after measuring the gas seal characteristics, and measuring the outside diameter of the seal member before the test (59.0
It was evaluated based on the amount of change (0.07 mm) in mm).

[Table] FIG. 10 shows a seal member 17 of a second reference example. The first method for manufacturing this seal member 17 will be described below.
This will be explained with reference to FIG. A sealed fireproof plate material 16 mainly made of vermiculite obtained in the same manner as in the first reference example is prepared. Next, a mixture of 35% scaly graphite, 28% molybdenum disulfide, 5% asbestos fiber, and 27% talc was made, and this mixture and rubber glue (rubber content 5%) made by swelling NBR rubber in toluene were mixed in a kneader. The mixture was forcibly kneaded for about 1 hour to form a clay-like material. This clay-like material was made into a seal with two rolling rolls, dried in an oven at 70°C for 15 minutes, and then slit into a tape with a width of 26 mm to form a second sealed fireproof board 18'. to make. The above two types of fireproof board materials 1
6 and 18' and the same thin metal plate core material 15 used in the first reference example are stacked as shown in FIG. Obtain a molded body. This molded body is put into a mold and compression molded to have an outer diameter of 59mmφ and an inner diameter of 42.8mm.
No. 10 with a spherical curved contour shape with φ and axial length of 17 mm.
A sealing member 17 was obtained. The seal member 17 of this second reference example was attached to the pipe joint shown in FIG. 1 in the same manner as the first reference example, and the same tests as described above were conducted, and the good measured values shown in Table 2 were obtained.

[Table] As is clear from Table 2, the sealing member 17 of the second reference example maintains the overall characteristics of the sealing member 13 of the first reference example, but especially the flange surface of the exhaust pipe 2. Seal member 1 of the first reference example has the advantage that it can maintain smooth contact with less friction.
It turned out to be better than 3. Further, in the seal member 13 of the first reference example,
During the 10Hz low-frequency vibration of the above-mentioned vibration durability test, the spherical flange surface of the exhaust pipe 2 and the surface of the sealing member 13 rub against each other, producing a small frictional noise commonly called "squeal" (which can be heard from a distance of approximately 1 meter). However, in the seal member 17 of the second reference example, this fricative noise called "squeak" was eliminated. Eliminating this "squeal" has a great effect on improving the quality of the vehicle, as it eliminates the perception of abnormal noise from the exhaust pipe swing joint located under the floor of the vehicle. Furthermore, in the sealing member 17 of the second reference example, since the swing rotation moment of the pipe joint is reduced, the load on the support part that fixes the exhaust pipe to the automobile floor is reduced, and the weight of the structure can be reduced. There is. Next, the embodiment of the second invention (second embodiment) will be described in the first embodiment.
An embodiment of the first invention (first embodiment) is shown in FIG. 1, and FIG. 13 shows an embodiment of the first invention (first embodiment). In the second and first embodiments, the sealing member 13 of the first reference example and the sealing member 17 of the second reference example are arranged such that the sealing member remains inside the spherical flange even when an axial tensile force is applied to the exhaust pipe 2. It is constructed so that an elastic force is generated in the axial direction so as not to separate from the circumferential surface. The seal member 19 of the second embodiment shown in FIG.
A shallow annular groove 19b of ×50.8 mmφ×2 mm depth is formed by lathe processing, and a plate spring (54.8 mm
φ×51.0mmφ×height 4mm) 20 is fitted. The height of the unevenness of the leaf spring 20 is designed to be slightly larger than the depth of the annular groove 19b, and when the seal member 19 is pressed against the flange 3, the restoring force of the leaf spring 20 causes it to come into close contact with the spherical flange 5, and is pulled into the exhaust pipe 2. Even if force is applied, the adhesion will not be lost. This adhesion was confirmed by a test using the testing apparatus shown in FIG. As shown in the figure, the sealing member 19 and the spherical flange 5 are placed on the compression jig 16 of an Instron type universal testing machine, and the load and water pressure are calculated when the axial load of the exhaust pipe is applied in the direction of the arrow. The relationship was determined and curve B in FIG. 17 was obtained. In addition, in the same figure, curve A shows the result in the first reference example (the second reference example is also almost the same) in FIG. As can be seen from FIG. 17, the seal members of the first reference example (curve A) and the second reference example do not seal with the spherical flange 5 when a sudden tensile force of 0.4 mm or more is applied due to vibration, etc. On the other hand, in the sealing member 19 of the second embodiment shown in FIG. 11, a load of about 100 kgf still remains, and the spherical flange 5 and the sealing member surface are separated. Contact and seal maintained. In the first embodiment of FIG. 13, the sealing member 21 has annular portions 22, 23 aligned in the axial direction;
A plurality of recesses 22 are provided on each opposing end surface.
a, 23a (see FIG. 18) are provided facing each other, and both annular portions 22, 2 are provided in the recesses 22a, 23a.
A coil spring 24 is housed therein, which biases the two parts in the direction of separating them from each other. To manufacture the seal member 21 as shown in Fig. 13, the seal member 13 obtained in the first reference example (see Fig. 5, inner diameter: 42.8 mm, outer diameter: 59.0 mm, thickness: 17 mm) is cut into the seal member 13 using a high-speed cutter. Divide into two as shown. Holes 22a and 23a each having a diameter of 3 mm and a depth of 2 mm are drilled with a drill press at positions facing each other so that the centers are on the circumference of each of these 48.0 mm. Place) Wire diameter 0.5 in this hole
A coil spring 24 made of high-tensile spring steel with mmφ, winding diameter 2.5 mmφ, number of turns 5, and height 6 mm is accommodated. If the seal member 21 of the first embodiment is attached to the pipe joint shown in FIG. , and the other annular portion 2
3 is pressed against the flange 3 by the force of the coil spring 24, so that the sealing member 21 and both flanges 3 and 5 do not lose their close contact. Regarding the sealing member 21 of the first embodiment, the 17th
The result of determining the relationship between the load and strain in the figure is curve C in the figure, which shows that the seal member 21 of the first embodiment has a 0.4
Even if a tensile force of mm or more is applied, it is still 100Kg
It can be seen that a load of a little more than f remains and the spherical flange 5 and the seal member surface come into contact and a good seal is maintained. Furthermore, the refractory material 14 of the first embodiment is a refractory material whose main component is vermiculite, and has the characteristics of a heat insulating material with extremely low thermal conductivity (λ=
0.102 kcal/mh°C), the coil spring 24 installed therein is not affected by the high temperature from the exhaust pipe, so it has the advantage that deterioration of the spring constant is prevented and the elastic force of the sealing member can be maintained. The effects of this invention are listed below. (i) Since the refractory material used in the sealing member is mainly composed of vermiculite, it does not become brittle at high temperatures and does not lose its sealing function. (ii) Since a thin metal core material is used that does not create any voids inside the seal member (and even more so if the core material is not exposed to the surface of the seal member), there is a risk of gas leakage through the seal member. There is no. (iii) Providing a smooth layer of refractory material on the surface of the sealing member further reduces the risk of gas leakage since the sealing member maintains a tight and smooth contact with the components of the joint. (iv) Since elastic force was applied in the axial direction, there was no risk of gas leakage even if a tensile force was applied in the axial direction. As described above, according to the present invention, a sealing member suitable as a component of a pipe joint for a high-temperature pipe subjected to vibration is provided.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a known example of a pipe joint to which the seal member of the present invention is installed, FIGS. 2 to 4 are diagrams showing the manufacturing method and structure of the known seal member, and FIG. FIG. 6 is a plan view of a portion of the core material used in the seal member of the present invention, and FIG.
8 is an explanatory diagram of an example of the manufacturing method of the present invention; FIG. 9 is a sectional view taken along the line - - of FIG. 8; and FIG. FIG. 11 is a longitudinal sectional view of a sealing member according to a second embodiment of the present invention, FIG. 12 is a perspective view of a leaf spring attached to the sealing member of FIG. 11, and FIG.
14 is a front view schematically showing a pipe joint testing device, FIG. 15 is an explanatory diagram of the manufacturing method of the seal member 17 of FIG. Fig. 16 is an explanatory diagram of the axial load test device for pipe joints, Fig. 17 is a graph showing the results of the axial load test using the Fig. 16 device, and Fig. 18 is the coil spring fitting recess of the seal member shown in Fig. 13. It is a top view showing the position of. 1... Exhaust collecting pipe, 2... Exhaust pipe, 3... Flange, 4... Long hole, 5... Spherical flange, 6...
Known seal members, 13, 17...Seal members of reference examples of this invention, 19...Seal members of second embodiment of this invention, 21...Seal members of first embodiment of this invention, 14... Refractory material layer, 15... Core material made of thin metal plate, 16... Fireproof plate material, 20... Elastic member, 24... Spring member.

Claims (1)

[Scope of Claims] 1. A sealing member installed between high-temperature exhaust pipe flanges in which the flanges of two connected pipes are biased in a pressure contact direction by a spring, and at least one of the pipe flanges has a spherical surface, It consists of a pair of annular parts arranged in the axial direction so that their end faces face each other, and each of the annular parts is made of a band-like fireproof plate material mainly composed of vermiculite in a cylindrical or annular shape. It is composed of a layer of refractory material wound in several layers to form a shape, and a core material made of a thin metal plate with a large number of claws or small protrusions on at least one surface is embedded in the layer of refractory material. . A sealing member characterized in that a spring member is provided between the pair of annular portions and biasing the annular portions in opposite directions. 2 A sealing member installed between high-temperature exhaust pipe flanges in which the flanges of two connected pipes are biased in the pressure direction by a spring, and at least one of the pipe flanges has a spherical surface, the sealing member being mainly made of vermiculite. A refractory material layer made by winding several layers of band-shaped refractory plate material into a cylindrical or annular shape, and embedded in the refractory material layer, and a large number of claws or small protrusions on at least one surface. A sealing member comprising a thin metal plate core material and an elastic member attached to one end surface of the refractory material layer.