JPS62151694A - Member for sealing exhaust pipe joint section and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] a0Object of the invention (industrial application field) A sealing member for an exhaust pipe joint portion, which is the subject of this invention,
It is installed in a joint part provided in the middle of an exhaust pipe for dispersing exhaust gas emitted from an automobile engine into the atmosphere, and is intended to prevent exhaust gas from leaking from this joint part.

(Prior Art) Exhaust gas discharged from an automobile engine is released into the atmosphere through a long exhaust pipe provided along the underfloor. An exhaust purifier and a muffler are installed in the middle of the exhaust pipe to detoxify harmful components contained in the exhaust gas and attenuate noise components.

Engine vibrations are transmitted to the exhaust pipe, which has one end connected to the engine's exhaust port, which vibrates when the engine rotates, but if these vibrations are transmitted to the entire exhaust pipe, the exhaust purifiers and mufflers, which are relatively heavy, will be required. This is undesirable because the large vibrations may damage the connections between the exhaust pipe and these devices, or cause abnormal noise under the floor.

For this reason, a vibration-proof joint 1 as shown in FIG. 6 has been conventionally provided in a part of the exhaust pipe near the engine to prevent engine vibrations from being directly transmitted to the entire exhaust pipe. This anti-vibration joint has a flange-like shape as a whole and a spherical receiving surface on the opposite side from the exhaust pipe element 2 at the end of one of the two exhaust pipe elements 2 and 3 to be connected. 4 is fixed, and an annular sealing member 7 and a flange piece 8 are attached to the end of the other exhaust pipe element 3, and the annular sealing member 7 has a sliding surface 6 that comes into close contact with the receiving surface 4 of the receiver 5. is fixed. Bolts 10.10 inserted from the side opposite to the flange piece 8 into the through holes 9.9 bored in a portion closer to the outer periphery than the receiving surface 4 of the receiver 5 are attached to the flange pieces 8.
Each bolt 10 is screwed into a screw hole 11.11 provided near the outer periphery and fixed with a lock nut 12.12.
．． A compression spring 14 is provided between the head 13.13 of 10 and the receiver.
．． 14 is provided to press the sliding surface 6 of the sealing member 7 against the receiving surface 4 of the receiver 5.

The exhaust pipe elements 2 and 3 connected to each other by such an anti-vibration joint 1 can be freely displaced in the direction in which the connecting portion is bent by sliding the receiving surface 4 and the sliding surface 6 against each other. Even if the vibration is transmitted to one exhaust pipe element 2, this vibration will not be directly transmitted to the other exhaust pipe element 3.

By the way, in order to effectively prevent vibrations from being transmitted from one exhaust pipe element 2 to the other exhaust pipe element 3 with the vibration isolating joint l constructed and operated in this way, it is necessary to adjust the sliding surface of the sealing member 7. 6 must slide against the receiving surface 1 of the receiver 5 with a light force. For this reason, sealing members 7 made of various materials have been used or proposed in the past.

Among these, the sealing member disclosed in Japanese Patent Publication No. 5B-21144 is one in which a band-shaped refractory material 15 made of graphite or the like and a wire mesh 16 are aligned as shown in FIG. The sealing member 7 as shown in FIG. 9 is obtained by winding it into a cylindrical shape as shown and press-forming it in a mold.
That is. During this press forming, the refractory material is evenly filled into the inside of each mesh of the wire mesh that is the core material.

(Problem to be solved by the invention) However, as mentioned above, when the sheet-shaped refractory material is wound around
In conventional sealing members manufactured by press-forming, the refractory material is not completely integrated even after press-forming, and the sheet-like refractory material is likely to peel off.

In addition, since the core material made of wire mesh has low rigidity, the rigidity of the completed sealing member will not be that high, and if it is assembled into an exhaust pipe joint and used for a long period of time, the sealing member will deform and cause the above-mentioned problems. The sealing properties of the joint are likely to be poor.

An object of the present invention is to provide a sealing member for an exhaust pipe joint and a method for manufacturing the same, which is free from such inconveniences.

b1 Structure of the Invention The sealing member of the exhaust pipe joint of the present invention has an annular shape as a whole and has a sliding surface that makes close sliding contact with the spherical receiving surface of the vibration-proof exhaust pipe joint, and has both front and back surfaces. Glue with hooks formed by punching out hooks; It is made by press-molding expanded graphite particles using a core material made of an F-shaped metal plate wound several times in a spiral shape. Expanded graphite powder is made by expanding graphite particles in the absence of an adhesive, and is disclosed, for example, in Japanese Patent Publication No. 23966/1983.

This expanded graphite powder has a small bulk density (for example, 0.008
~0.40 g/cm"), when press-formed, the volume decreases significantly and the individual particles interlock with each other and solidify into one piece. For this reason, a strip-shaped metal plate with hooks is used as a core material for expansion. In the case of the sealing member of the present invention made by press-molding graphite powder, the particles of expanded graphite are integrally bonded to each other through the inside of the hook, and sufficient strength can be obtained.

Furthermore, Teflon powder can be added to the above-mentioned expanded graphite powder as a friction reducing agent. The greater the amount of Teflon powder added, the greater the friction reduction effect, but as long as it does not interfere with solidification of the expanded graphite powder by pressing,
It can be added up to 50% by weight.

Next, a method of manufacturing such a sealing member for an exhaust pipe joint will be described.

When manufacturing a sealing member for an exhaust pipe joint by the method of the present invention, as shown in FIG. The expanded graphite powder 19 and the core material 20 are inserted into the molding space 18 using a male mold 21 that tightly fits into the molding space 18. The expanded graphite particles are brought into close contact with each other and the individual particles are crushed to integrally form an annular sealing member 7. At this time, in order to ensure that the surface of the sealing member 7 after molding is covered with graphite and the core material 20 is not exposed to the surface of the sealing member 7 as much as possible, the inside of the molding space 18 of the female mold is initially Small amount of expanded graphite powder 19
Thereafter, the spirally wound core material 20 is inserted into the space 18. In this way, the core material 20 is
After inserting the expanded graphite powder into the molding space 18, the expanded graphite powder 19 is filled into the molding space 18 until the core material 20 is completely hidden.

Once a sufficient amount of expanded graphite powder 19 has been filled into the molding space 18, the male mold 21 is then inserted into the molding space 18, and the core material 20 and the expanded graphite powder 19 described above are inserted into the molding space 18. Press toward the bottom of the molding space 18. In addition, male type 21
In order to efficiently fill the expanded graphite powder 19 prior to pressing, it is effective to apply fine vibrations to the female die 17 during the filling operation.

For the expanded graphite powder 19 that is filled into the molding space 18 of the female mold 17 and molded into one piece by pressing, commercially available expanded graphite powder may be used as it is, or Nika Film (Nippon Carbon) A sheet of expanded graphite, which is commercially available under the trade name (trade name) manufactured by Co., Ltd., can be used by pulverizing it into granules.

Although it is preferable for appearance that the core material 20 is not exposed at all on the surface of the sealing member 7, some exposure is not a problem in terms of the sealing effect. In particular, exposing the core material to surfaces other than the sliding contact surface 6 has no effect on the sealing performance at all.

Incidentally, as the material of the hooked metal plate used in the sealing member of the present invention, stainless steel copper plate, galvanized steel plate, etc. can be used. Further, the thickness T (Fig. 2) of the metal plate is 0.05 to 0.25 mm, preferably 0.1 to 0.1 mm.
Hooks 2 with a diameter of 5 mm are formed on both the front and back sides of this metal plate.
The diameter R of each hook 22.22 is preferably 0.8 to 2.0+ nm, and the pitch P and height H of each hook 22.22 are preferably 2.0 to 3.0 mm+, respectively. Furthermore, the particle size of the expanded graphite powder constituting the sealing member together with the core material made of a metal plate on which the hooks 22 are formed on both the front and back surfaces is such that the expanded graphite powder is free between the spirally wound metal plates. It is preferable that the thickness be 1 mm or less so that it can penetrate into the body.

Furthermore, regarding the cross-sectional shape of the hook 22, it is better to have a rounded base as shown in FIG. 3 than to have an angular shape as shown in FIG. This is preferable because it makes it easier to fill the particles.

C1 Effects of the Invention The sealing member for the hand portion of the exhaust pipe 111 of the present invention is configured and manufactured as described above, but since the expanded graphite powder sticks to each other and becomes integral after press molding, it is different from the conventional method. 71 of graphite, as in the case of press-forming a graphite sheet of
There will be no separation.

In addition, since the surface of the sealing member covered with graphite becomes homogeneous, the sliding contact surface of this sealing member and the receiving surface 4 of the receiver 5 (
(Fig. 6) is improved. Sample 1 in which the present inventor hardened mica using a wire mesh as a core material, and Sample 2 in which sheet-like graphite was hardened in a wire mesh as a core material as shown in Figures 7 to 9.
As shown in Fig. 1, a sealing property test was conducted with Sample 3 (product of the present invention), in which expanded graphite powder was hardened using a metal plate with a hook as a core material, and the results were shown in Fig. 4. is obtained,
It has been found that the exhaust pipe joint according to the present invention not only has good strength but also good sealing performance.

Furthermore, by making the sliding surface uniform, there is an effect that no large noise is generated when the sliding surface and the receiving surface slide against each other due to engine vibration. That is, when the present inventor measured the level of noise generated when the sliding surface and the receiving surface were rubbed together using the above samples 1 to 3, the results shown in FIG. 5 were obtained. . On the vertical axis of the same figure, A is a noise level that feels continuously noisy, B is a noise level that sometimes feels a little noisy, C is a noise level that can be exceeded if you are careful, and D indicates a state where there is almost no delay. The reason for the low noise level is that the sliding surface 6 of the sealing member 7 is smooth and has a small coefficient of friction with the receiving surface 4. The noise level can be further reduced by mixing Teflon powder as a friction reducing agent.

[Brief explanation of drawings]

Fig. 1 is a half longitudinal sectional view showing the manufacturing state of the sealing member of the present invention, Fig. 2 is a first example of a metal plate with hooks used as a core material, and Fig. 3 is a second example of the same. A cross-sectional view showing,
Figure 4 is a diagram comparing the sealing performance of the sealing member of the present invention with conventional products, Figure 5 is a diagram comparing the noise level, and Figure 6 is an exhaust pipe joint incorporating the sealing member. 7 to 9 show an example of a conventional sealing member, FIG. 7 is a perspective view showing a core material and a refractory material before molding, and FIG. 8 shows a cylindrical member before molding. FIG. 9 is a plan view showing the state in which the material is wound, and FIG. 9 is a partially cutaway perspective view showing the state after molding. 1: Anti-vibration joint, 2.3: Exhaust pipe element, 4: Reception surface, 5: Receptacle, 6: Sliding surface, 7: Seal member, 8: Flange piece, 9
: Through hole, 10: Bolt, 11: Screw hole, 12: Lock nut, 13: Head, 14: Compression spring, 15: Fireproof material, 1
6: wire mesh, 17: female mold, 18: molding space, 19: expanded graphite powder, 20: core material, 21: male mold, 22: hook. Patent applicant: Japan Reinz Co., Ltd. Agent: Kinzo Koyama (one idiot) Figure 1
Figure 6 Figure 2 Figure 3 Figure 4 Toss pressure (One consideration, go to Figure 5 t?' (NO Figure 8 Figure 9 A)

Claims (1)

[Scope of Claims] 1) A sealing member for an exhaust pipe joint that is entirely circular and has a sliding surface that comes into close contact with a spherical receiving surface of a receiver that constitutes a vibration-proof exhaust pipe joint. The core material is a band-shaped metal plate with hooks formed by punching out hooks on both the front and back sides, wound several times in a spiral shape, and expanded graphite particles are press-molded to form the expanded graphite particles as the core material. A sealing member for an exhaust pipe joint portion, which is made by entering the inside of a hook of a metal plate and integrally solidifying the expanded graphite particles present on both the front and back surfaces of a metal plate forming a core material. 2) A sealing member for an exhaust pipe joint that has an annular shape as a whole and has a sliding surface that comes into close contact with the spherical receiving surface of the receiver that constitutes a vibration-proof exhaust pipe joint, and has a sealing member on both the front and back sides. The core material is a band-shaped metal plate with a hook formed by punching it out and wound several times in a spiral shape, and expanded graphite particles of 50% by weight or more and Teflon powder particles of 50% by weight or less are mixed. The product is press-molded and a mixture of expanded graphite particles and Teflon powder particles is introduced into the inside of the hook of the core material,
A sealing member for an exhaust pipe joint that is made by integrally solidifying a mixture of expanded graphite particles and Teflon that are present on both the front and back sides of a metal plate that forms a core material. 3) After introducing a small amount of expanded graphite particles into a molding space with an annular cross section and an upper opening formed in a female mold, a metal plate with hooks with hooks formed by punching out hooks on both the front and back surfaces is inserted into this molding space. A spirally wound core material is inserted, and then expanded graphite powder is filled into the molding space until the core material is completely hidden, and then a male mold with an annular cross section is inserted into the molding space. A method for manufacturing a sealing member for an exhaust pipe joint, in which expanded graphite particles and a core material are press-molded between the lower surface of the male mold and the inner surface of the molding space of the female mold.