JPH0120292B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an exhaust pipe structure for a vehicle engine.

(Prior Art) In the exhaust pipe structure of a vehicle engine, an annular seal member is held at the end of one exhaust pipe, the end of the other exhaust pipe is brought into spherical contact with the seal member, and both exhaust pipes are By providing a radially projecting flange on each side, positioning the annular seal member between the flanges, and urging the flanges toward each other with a spring,
A so-called flexible joint structure in which both exhaust pipes are slidably connected is known (for example,
(Refer to Publication No. 57-148014). This joint structure can buffer vibrations transmitted from the engine and vibrations transmitted from the road surface through the vehicle body, thereby preventing damage to the exhaust pipe. In addition, from the viewpoint of heat resistance, the seal member is made of, for example, a graphite molded body whose surface is coated with fluorine resin. It also improves the lubricity between the pipe and the pipe to prevent exhaust gas leakage.

(Problem to be Solved by the Invention) However, in the joint structure described above, the seal member is affected by the heat of exhaust gas when the vehicle is running, and furthermore, the seal member is affected by the heat of friction at the spherical contact portion between the seal member and the exhaust pipe. As a result, the temperature can rise up to about 420℃. This is because, in the flexible joint structure described above, one of the flanges that connect the exhaust pipes is located in front of the spherical contact part of the annular seal member and blocks the running wind, and it is not expected that the seal member will be cooled by the running wind. One reason is that they cannot.

As a result, the fluororesin of the sealing member (heat resistant temperature is approximately 350°C) decomposes and peels off at the spherical contact area, impairing lubricity and sealing performance, and causing the graphite of the sealing member body to bond with the exhaust pipe. This metal-to-metal contact causes an abnormal noise, and furthermore, there is a problem that the sealing member main body may be damaged prematurely. Such problems occur not only at the joint between the exhaust pipes, but also when the joint structure is adopted at the joint between the exhaust pipe and the contact converter.

(Means for Solving the Problems) In order to solve the above-mentioned problem of deterioration or damage of the annular seal member due to heat, the present invention solves the problem of abnormal temperature rise due to frictional heat of the spherical contact portion and damage caused by the flange. Focusing on the unique feature of the flexible joint structure, which blocks the traveling wind, we made good use of the above flanges.In other words, the outer peripheral edge of the flange has a slight negative pressure compared to the front of the flange, where the wind pressure from the traveling wind acts. By taking advantage of this fact, it is possible to actively introduce the traveling wind into the annular seal member, and for this purpose, this annular seal member is seated on a member having an L-shaped cross section, and the passage of the traveling wind is By using a portion of the seating member, the annular seal member is forced to be cooled while improving its installation stability.

That is, in the exhaust pipe structure for a vehicle engine according to the present invention, an annular seal member having a spherical outer circumferential surface is interposed between each of the pipe members on the front side and the rear side of the vehicle that are connected to each other, and the annular seal member has a spherical outer peripheral surface. The member is held on the front tubular member and is brought into contact with the rear tubular member in spherical contact, and the annular seal member extends in the radial direction of the tubular member and faces each of the two tubular members in between. The flanges are fixed, and a spring force that urges the flanges toward each other brings the rear tubular member and the annular seal member into pressure contact so that the two tubular members can move relative to each other. In the exhaust pipe structure of a vehicle engine, the front pipe member is provided on either one of the front pipe member and a flange fixed to the front pipe member, and a space is formed between the front pipe member and the front pipe member. The cylinder part and the collar part extending outward in the radial direction from the cylinder part are formed into an L-shaped cross section, and the annular seal member is seated on the outer peripheral surface of the cylinder part and the rear surface of the collar part that continues to the outer peripheral surface. an annular portion held by the front tube member and a flange fixed to the front tube member, and a traveling wind introduction passageway opening in front of the flange and communicating with the space portion; , a traveling wind outlet path that forms a passage wall in the brim portion, opens outward in the radial direction from between the two flanges, and communicates with the space. .

(Function) In the above exhaust pipe structure, since the traveling wind introduction passage is opened in front of the flange inside the outer peripheral edge of the flange fixed to the front pipe member, the wind pressure from the traveling wind acts on the flange. Since the traveling wind outlet path opens outward in the radial direction from between the two flanges, there is a slight negative pressure with respect to the traveling wind introducing path, and the traveling wind from the traveling wind introducing path to the traveling wind outlet path is A flow occurs. Therefore, the annular seal member is cooled by the traveling wind introduced into the space, and
Since the passage wall of the traveling wind outlet path is formed by the collar of the annular portion on which the sealing member is seated,
The cooling described above is promoted by the running wind passing through this brim portion. The annular portion on which the sealing member is seated has an L-shaped cross section and holds the sealing member on two sides, so that the sealing member is moved in its axial and radial directions by the relative movement of the tubular members. Even if it receives the load of both, it will hold it reliably.

Embodiments of the present invention will be described below based on the drawings.

Example 1 This example is shown in FIG. Reference numeral 1 designates a front exhaust pipe located on the front side of the vehicle as one pipe member of the vehicle engine, and reference numeral 2 represents a rear exhaust pipe located on the rear side of the vehicle as the other pipe member. The front end of an inner pipe 3 through which exhaust gas passes is joined to the inner peripheral surface of the rear end of the front exhaust pipe 1, and a tubular member 4 is joined to the outer peripheral surface of the rear end of this inner pipe 3. An annular seal member 5 is interposed between the annular member 4 and the front end of the rear exhaust pipe 2. Then, the seal member 5 is held by the rear end portion of the front exhaust pipe 1, the inner pipe 3, and the annular member 4 to the holding member 4.
A running air passage 6 is configured to cool the vehicle from the side.

That is, the annular member 4 has a cylindrical portion 4 that forms a space 18 between it and the inner tube 3 for introducing the traveling wind.
a, and the exhaust pipe 1 on the front side from the front end of this cylindrical portion 4a.
The seat portion has a flange portion 4b that extends outward in the radial direction, and the seat portion has an L-shaped longitudinal section. The inner circumferential surface of the joint portion folded forward and inward from the rear end of the cylindrical portion 4a is joined to the outer circumferential surface of the rear end portion of the inner tube 3. On the other hand, the rear exhaust pipe 2 is
The contact portion 7 has a spherical inner peripheral surface formed by expanding the front end opening into a spherical shape outward over its entire circumference.
It is equipped with

The seal member 5 is held with the inner circumferential surface and front surface of the seal member 5 seated on the seating portion of the annular member 4, that is, the outer circumferential surface of the cylindrical portion 4a and the rear surface of the collar portion 4b following this outer circumferential surface. A spherical contact portion 9 is formed on the outer periphery, with which the contact portion 7 of the rear exhaust pipe 2 comes into sliding contact. This sealing member 5 is made by coating a stainless steel wire mesh frame with graphite and molding the main body, and coating the surface of the main body with fluororesin.

Further, on the outer periphery of the rear end of the front exhaust pipe 1, there is a front flange 10 that projects outward in the radial direction, and on the back surface of the contact portion 7 of the rear exhaust pipe 2, the front flange 10 also projects outward. The rear flanges 11 are fixed at predetermined intervals. The seal member 5 is located between the front and rear flanges 10 and 11 with its outer peripheral surface partially exposed.

A through hole 12 is formed in the front flange 10, and a bolt 13 passed through the through hole 12 is fixed to the rear flange 11 with a nut 14, and the head of the bolt 13 and the front A conical coil spring 15 is installed between the side flange 10 and the side flange 10.
is interposed. As a result, the front and rear flanges 10 and 11 are urged toward each other so that the outer peripheral surface of the annular seal member 5 and the contact portion 7
The exhaust pipes 1 and 2 are brought into pressure contact with each other so that both the exhaust pipes 1 and 2 can move relative to each other.

Next, to explain the cooling air passage 6,
Between the inner pipe 3 and the front flange 10, specifically between the inner circumferential surface of the rear end of the inner pipe 3 and the front exhaust pipe 1, the front exhaust pipe is located in front of the front flange 10. A traveling wind introduction passage 16 is formed by cutting and raising a part of the pipe wall of the vehicle 1 outward and opening toward the front, and this traveling wind introduction passage 16 communicates with the space 18 . In addition, a passage wall is formed in the space 18 by the rear end of the front exhaust pipe 1 and the collar part 4b of the annular member 4, and from between the flanges 10 and 11, the passage wall is formed from between the flanges 10 and 11. A running wind outlet path 17 that opens toward the outside communicates with the vehicle.

In the case of this example, the vehicle travels in the direction of arrow A, and wind pressure due to the traveling wind acts on the front side of the front flange 10, that is, the pressure becomes high.On the other hand, both the front and rear flanges 10, On the other hand, between 11 and 11, the pressure is lower than the front side and becomes negative. That is, the traveling wind introduction passage 1 corresponding to the upstream side of the said traveling wind passage 6
6 and the traveling wind outlet path 17 corresponding to the downstream side,
This means that each opening is located at a position where a pressure difference is created by the wind generated by the vehicle. Note that exhaust gas from the vehicle engine flows from the front exhaust pipe 1 to the rear exhaust pipe 2.

Therefore, in the above structure, the front exhaust pipe 1
Since the sealing member 5 held in the rear exhaust pipe 2 is in slidable spherical contact with the rear exhaust pipe 2,
The joint portion is bendable, in other words, it is flexible. Therefore, the joints are prevented from being damaged due to engine vibrations or vibrations of the vehicle body during running.

Therefore, in the abutting portion 9 of the seal member 5,
The heat of the exhaust gas is transmitted through both exhaust pipes 1 and 2,
Furthermore, frictional heat is generated due to sliding with the rear exhaust pipe 2. However, as the vehicle travels, the wind flowing in from the wind inlet path 16 as shown by the white arrow is introduced into the space 18, and further into the wind outlet path 1.
7, that is, both flanges 10 and 11 pass through the collar portion 4b of the annular member 4 on which the sealing member 5 is seated.
Since the air flows out from between, the seating part of the annular member 4 is cooled by the traveling wind, and the sealing member 5 is cooled through the seating part, and the temperature does not rise excessively. Moreover, since the seating part of the annular member 4 on which the seal member 5 is seated has an L-shaped cross section and holds the seal member 5 on two sides, the seal member 5 is Even if it receives loads in both the axial and radial directions due to the movement, it will be held securely.

<Example 2> This example is shown in FIG. 2, in which the annular portion that holds the seal member is constituted by a front flange, and the traveling air directly touches the seal member.

That is, in the same figure, 23 is a front side flange fixed to the outer circumferential surface of the rear end of the front side exhaust pipe 21, the inner circumferential side of which is formed in an L-shape in longitudinal section, and there is a gap between the front side exhaust pipe 21 and the front side flange. A cylindrical portion 23a in which a space 33 for introducing running wind is formed, and this cylindrical portion 23
A collar portion 23b extends outward in the radial direction of the front exhaust pipe 21 from the front end of the exhaust pipe 21. The rear end portion of the cylinder portion 23a is bent inward and joined to the front exhaust pipe 21. Furthermore, the inner and outer peripheral edges of the annular support member 24 are respectively joined to the front side exhaust pipe 21 and the front surface of the flange portion 23b.

On the other hand, at the front end of the rear exhaust pipe 22, the
Similarly, a spherical contact portion 25 is formed.
The annular seal member 26 is connected to the cylindrical portion 23.
The inner circumferential surface and front surface of the seal member 26 are seated and held on the outer circumferential surface of a and the rear surface of the collar portion 23b. The contact portion 25 is then manually abutted against the spherical abutment portion 28 on the outer periphery of the seal member 26. A bolt 29 passes through the front flange 23 and is screwed onto the rear flange 31 fixed to the rear exhaust pipe 22. 32 is a contact portion 2 between the contact portion 28 of the seal member and the rear exhaust pipe 22;
5 is a coil spring that presses into contact with 5.

Next, to explain the running wind passage, in the case of this example, a running wind introduction passage 34 that opens toward the front of the front side flange 23 is formed in the support member 24, and this running wind introduction passage 34 is connected to the above-mentioned space. It communicates with section 33. On the other hand, the sealing member 26 is formed with an L-shaped groove 35 extending from its inner peripheral surface to the front surface. A traveling wind outlet passage 36 is formed between both flanges 23, 31 and opens outward in the radial direction, and this traveling wind outlet passage 36 connects to the space through a communication port 37 formed in the cylindrical portion 23a. It is connected to 33.

Therefore, in this example, as the vehicle travels in the direction of arrow A, the wind introduction path 3
The running wind flowing in from 4 is introduced into the space 33,
Further, the air flows out from between the flanges 23 and 31 through the air outlet path 36, that is, the groove 35 of the seal member 5. Stand over. Since the seal member 26 is directly cooled by the traveling wind passing through the groove 35, a higher cooling effect can be expected compared to the first embodiment. The mounting stability of the seal member 26 is the same as in Example 1, and a detailed explanation thereof will be omitted.

Although each of the above embodiments relates to a structure at the joint between exhaust pipes, it goes without saying that the present invention can also be applied to a joint between an exhaust pipe and a catalytic converter.

(Effects of the Invention) Therefore, according to the present invention, the running wind is actively applied to the annular seal member by utilizing the fact that the outer peripheral edge side of the flange has a slight negative pressure with respect to the front surface of the flange on which the wind pressure from the running wind acts. For this purpose, this annular seal member is seated on a member having an L-shaped cross section, and the traveling air passage is constructed using a part of the seating member. While improving the installation stability of the seal, it is now possible to perform forced cooling by the flow of running air, improving the durability of the seal member and maintaining sealing performance and lubricity for a long period of time. In addition, it is also possible to use a material with relatively low heat resistance for this sealing member, which has the effect of widening the range of material selection for this sealing member.

[Brief explanation of drawings]

The drawings show embodiments of the present invention; FIG. 1 is a longitudinal cross-sectional view showing the exhaust pipe structure of the first embodiment, and FIG. 2 is a longitudinal cross-sectional view showing the exhaust pipe structure of the second embodiment. 1, 2, 3, 21, 22... Exhaust pipe, 4... Annular member, 4a, 23a... Cylinder part, 4b, 23b
...Brim portion, 5...Seal member, 7,25...
Contact portion, 9, 28... Contact portion (outer peripheral portion), 10,
11, 23, 31... flange, 15, 32...
Spring, 16, 34... Traveling wind introduction path, 1
7, 36... Traveling wind outlet path, 18, 33... Space part.

Claims (1)

[Claims] 1. An annular seal member having a spherical outer circumferential surface is interposed between the front and rear tubular members of the vehicle that are connected to each other, and the annular seal member is attached to the front tubular member. The flanges extending in the radial direction of the tubular member and facing each other with the annular seal member in between are fixed to each of the two tubular members, and the flanges are held in place and brought into contact with the rear tubular member in spherical contact. In the exhaust pipe structure for a vehicle engine, the rear side pipe member and the annular seal member are brought into pressure contact with each other by a spring force that urges the two pipe members to approach each other, so that the two pipe members can move relative to each other. , a cylindrical portion provided on either one of the front tubular member and a flange fixed to the front tubular member, and forming a space between the front tubular member and the cylindrical portion; an annular portion formed into an L-shaped cross section by the radially outwardly extending collar portion, and holding the annular seal member seated on the outer peripheral surface of the cylindrical portion and the rear surface of the collar portion following the outer peripheral surface; a traveling wind introduction passage formed between the front side pipe member and a flange fixed to the front side pipe member, opening to the front of the flange and communicating with the space; a passage wall at the brim portion; An exhaust pipe structure for a vehicle engine, characterized in that the exhaust pipe structure for a vehicle engine is characterized in that the exhaust pipe structure includes: a traveling wind outlet path that opens outward in the radial direction from between the flanges and communicates with the space.