JPH06129249A - Exhaust pipe coupling mechanism of internal combustion engine - Google Patents

Abstract

PURPOSE:To improve acceleration performance by smoothly circulating exhaust gas in an exhaust pipe in the case of acceleration for decreasing the internal resistance of an internal combustion engine. CONSTITUTION:An exhaust front pipe 3 is communicated with an engine. An exhaust rear pipe 5 is communicated with the exhaust front pipe 3 through a movable coupling 4. In the case where the exhaust front pipe 3 and the exhaust rear pipe 5 make relative bending movement according to the displacement of the engine, on the basis of the vibration of the engine or the vibration of a car body while the vehicle travels, the bending movement is permitted by the movable coupling 4. And a shaft center Sf of the end on the movable coupling 4 side of the exhaust front pipe 3 is made eccentric in the moving direction r2 of the end on the movable coupling 4 side of the exhaust front pipe 3 caused by the rolling of the engine during its deceleration in relation to a shaft center Sr on the end on the movable coupling 4 side of the exhaust rear pipe 5 in the normal state where the engine is not displaced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust pipe joint structure constituting an exhaust system of an internal combustion engine mounted on a vehicle.

[0002]

2. Description of the Related Art Generally, an exhaust pipe constituting an exhaust system of an internal combustion engine is divided into two parts, an exhaust pipe connected to the internal combustion engine side and an exhaust pipe supported on the vehicle body side, both of which are movable joints. Are connected to each other via. If relative refraction movement occurs between the exhaust pipes due to displacement such as vibration of the internal combustion engine or vibration during traveling of the vehicle, the refraction movement is allowed by the movable joint. ing.

Conventionally, as such an exhaust pipe joint structure, for example, one disclosed in Japanese Utility Model Laid-Open No. 58-134617 is known. This conventional joint structure
As shown in FIG. 8, a spring receiver 32 and a seal ring 33 are fixed to the outer periphery of one end of an exhaust pipe 31 which is connected to the internal combustion engine side (not shown), and a convex spherical surface 33a is formed on the outer peripheral surface of the seal ring 33. ing. On the other hand, the flange portion 3 is provided at one end of the exhaust pipe 34 supported on the vehicle body side (not shown).
5 is formed, and on the inner peripheral side of the flange portion 35, there is formed a concave spherical seat 35a capable of sliding contact with the spherical surface 33a of the seal ring 33.

A spring seat 36 is fixed to the outer peripheral side of the flange portion 35 so as to enclose the seal ring 33 and one end of the exhaust pipe 31 to which the seal ring 33 is fixed. A coil spring 37 is provided between the spring seat 36 and the spring receiver 32.
The spherical seat 35a of the flange portion 35
The spherical surface 33a of the seal ring 33 is brought into pressure contact with the two exhaust pipes 31 and 34 in an airtight manner.

If, for example, the exhaust pipe 31 moves as shown by the chain line in FIG. 8 due to the vibration of the internal combustion engine, etc., and the axial centers of the exhaust pipes 31 and 34 deviate,
The seal ring 33 slides along the spherical seat 35a. Therefore, the sliding allows the relative movement of the exhaust pipes 31 and 34 while the airtightness between the exhaust pipes 31 and 34 is reliably maintained.

[0006]

However, in the above-mentioned prior art, in the normal state of the internal combustion engine, that is, in the state where the internal combustion engine is not displaced by vibration or the like, the exhaust pipe 31 on the internal combustion engine side and the exhaust pipe 34 on the vehicle body side. And are arranged on the same axis. That is, in the normal state of the internal combustion engine, the one end opening of the exhaust pipe 31 on the internal combustion engine side and the one end opening of the exhaust pipe 34 on the vehicle body side match, and the exhaust pipe 31 on the internal combustion engine side exhausts the vehicle body side. The exhaust gas is smoothly distributed to the pipe 34.

However, when the vehicle accelerates, the internal combustion engine rolls, and as shown by the chain line in FIG.
If there is a misalignment of the axial centers of 1, 34, both exhaust pipes 3
Exhaust gas is not smoothly circulated because the facing relationship of the openings of 1, 34 shifts. That is, the exhaust pipe 31 on the internal combustion engine side
Since a part of the opening of the exhaust pipe 3 is arranged so as to face the spherical seat 35a of the flange portion 35, a part of the exhaust gas flow from the exhaust pipe 31 hits the spherical seat 35a, so that the exhaust gas is discharged from the exhaust pipe 3 on the vehicle body side.
No smooth flow to 4. Therefore, this conventional technique has a problem that the internal resistance of the internal combustion engine increases and the acceleration performance deteriorates during acceleration of the vehicle.

The present invention has been made in order to solve the above problems, and an object thereof is to reduce the internal resistance of an internal combustion engine by allowing exhaust gas in an exhaust pipe to smoothly flow during acceleration. Another object of the present invention is to provide an exhaust pipe joint structure for an internal combustion engine, which is capable of improving the acceleration performance and has a simple structure.

[0009]

In order to achieve the above object, in the present invention, a first exhaust pipe connected to the internal combustion engine side of a vehicle and a second exhaust pipe supported on the vehicle body side. In the exhaust pipe joint structure of the internal combustion engine, wherein the movable joint allows relative bending movement of both exhaust pipes due to displacement of the internal combustion engine. In the normal state, the axis of the movable joint side end of the first exhaust pipe is caused by the rolling of the internal combustion engine during deceleration with respect to the axis of the movable joint side end of the second exhaust pipe. It is characterized in that the first exhaust pipe is eccentric in the moving direction of the movable joint side end portion.

[0010]

Therefore, according to the present invention, the internal combustion engine is displaced due to the vibration of the internal combustion engine or the vibration of the vehicle during traveling,
In the case where both the exhaust pipes are relatively bent and moved, the movable joint allows the bending and movement.

Further, in a normal state where the internal combustion engine is not displaced, the axial center of the end portion of the first exhaust pipe on the movable joint side is set to the axial center of the end portion of the second exhaust pipe on the movable joint side. The movable joint side end of the first exhaust pipe is eccentric in the moving direction due to rolling of the internal combustion engine during deceleration. Therefore, when the internal combustion engine rolls during acceleration of the vehicle, the end portion of the first exhaust pipe on the movable joint side is moved in the direction opposite to the eccentric direction, and the axial center and the second exhaust pipe are separated from each other. The axis of the end of the movable joint intersects. Therefore, at the time of acceleration, the openings of both exhaust pipes face each other and the passage cross-sectional area becomes large, so that the exhaust gas flows smoothly from the first exhaust pipe to the second exhaust pipe,
The internal resistance of the internal combustion engine is reduced and the acceleration performance is improved.

On the other hand, when the internal combustion engine rolls during deceleration of the vehicle, the end portion of the first exhaust pipe on the side of the movable joint is further moved in the eccentric direction, and its axial center and the second exhaust pipe are separated. The amount of deviation between the end of the movable joint and the axis is further increased. Therefore, at the time of deceleration, the cross-sectional area of the passage becomes small, and the exhaust gas does not flow smoothly from the first exhaust pipe to the second exhaust pipe, so that the exhaust noise is reduced and the internal resistance of the internal combustion engine is increased. . Therefore, the engine brake is effectively applied, and the vehicle is effectively decelerated.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment embodying the present invention will now be described with reference to FIGS.
This will be described in detail with reference to FIG. As shown in FIG. 4, an engine 1 as an internal combustion engine mounted in an engine room of a vehicle (not shown)
One end of an exhaust front pipe 3 as a first exhaust pipe is connected. Also, at the other end of the exhaust front pipe 3,
One end of an exhaust rear pipe 5 as a second exhaust pipe is connected via the movable joint 4. This exhaust rear pipe 5
Is hung and supported below the vehicle body 7 via a hang member 6. Then, the exhaust gas discharged from the engine 1 passes through the exhaust manifold 2, the exhaust front pipe 3, the movable joint 4, and the exhaust rear pipe 5, and is discharged to the outside via a muffler (not shown).

Here, the movable joint 4 will be described in detail. As shown in FIG. 1, the exhaust front pipe 3
An intermediate pipe 8 is externally fitted and fixed to the outer periphery of the other end (on the side of the movable joint 4) so as to surround the front pipe 3, and a ring-shaped metal plate is fixed to the outer periphery of the intermediate pipe 8 to form a flange. The part 9 is formed. Further, a seal ring 10 is fitted and fixed on the outer periphery of the intermediate pipe 8 so as to abut the flange portion 9.
A convex spherical surface 10a is formed on the outer peripheral surface of the.

On the other hand, one end of the exhaust rear pipe 5 (on the side of the movable joint 4) has a substantially funnel-shaped seal receiving member 11.
Is inserted and fixed by the tubular portion 12. The seal receiving body 11 includes a spherical surface 10 of the seal ring 10.
A concave spherical seat 13 that can be slidably contacted with a is formed.
A flange portion 14 is integrally formed on the outer peripheral side of the seal receiving body 11 so as to face the flange portion 9 on the exhaust front pipe 3 side.

As shown in FIG. 4, the exhaust front pipe 3
The flange portion 9 on the side is formed with a through hole 9a.
With the stepped bolt 15 loosely fitted in a,
The exhaust front pipe 3 and the exhaust rear pipe 5 are connected to each other by screwing the bolt 15 onto the flange portion 14 of the seal receiving body 11. A coil spring 16 is interposed between the head portion of the stepped bolt 15 and the flange portion 9, and the urging force of the spring 16 causes the spherical seat 13 of the seal receiver 11 to attach to the spherical surface 10a of the seal ring 10.
Are pressure-welded, and both pipes 3 and 5 are airtightly connected. Although only one stepped bolt 15 is shown in FIG. 4, a plurality of stepped bolts 15 are actually provided at equal intervals along the outer circumferences of the flange portions 9 and 14.

Further, in this embodiment, the front-back direction of the engine 1 is the left-right direction of FIG. Then, as indicated by the chain line in FIG. 4, the engine 1 is rotated at the time of acceleration and deceleration of the vehicle.
When rolling in the 1 direction and the R 2 direction, the exhaust front pipe 3 is moved along with the rolling of the engine 1. That is, when the vehicle accelerates, the engine 1 rolls in the R1 direction, and as shown in FIG. 2, the end portion of the exhaust front pipe 3 on the side of the movable joint 4 bends and moves in the r1 direction.
The seal ring 10 is slid in the r1 direction along the spherical seat 13 of the seal receiver 11. On the other hand, when the vehicle decelerates, the engine 1 rolls in the R2 direction, and as shown in FIG. 3, the end of the exhaust front pipe 3 on the side of the movable joint 4 bends in the r2 direction, causing the seal ring 10 to move along the spherical seat 13. Slide in the r2 direction.

As shown in FIG. 1, in this embodiment, when the engine 1 is not displaced due to vibration or rolling, the shaft center Sf of the end portion of the exhaust front pipe 3 on the side of the movable joint 4 is exhausted. The rear pipe 5 is offset by a predetermined amount in the r2 direction with respect to the axial center Sr of the end of the rear pipe 5 on the movable joint 4 side. That is, in this embodiment, in the normal state of the engine 1, the exhaust front pipe 3 and the exhaust rear pipe 5 are not arranged on the same axis, but the axes Sf and Sr of both are eccentric.

This offset amount is from the exhaust front pipe 3 to the exhaust rear pipe 5 in the normal state of the engine 1.
The exhaust gas is allowed to flow to the vehicle to such an extent that it does not hinder normal running of the vehicle.

Next, the operation of the exhaust pipe joint structure of the internal combustion engine configured as described above will be described. Now, along with the vibration of the engine 1 and the vibration of the vehicle body 7 during traveling of the vehicle,
When the exhaust front pipe 3 and the exhaust rear pipe 5 move relative to each other, the spherical surface 10a of the seal ring 10 and the spherical seat 13 of the seal receiving body 11 slide with each other. At this time, since the stepped bolt 15 is loosely fitted in the through hole 9a of the flange portion 9, both pipes 3, 5
Relative refraction movement is easily allowed, and the coil spring 16 expands and contracts in accordance with the relative movement, so that the close contact state between the seal ring 10 and the spherical seat 13 is reliably maintained. Therefore, even if the two pipes 3 and 5 are moved relative to each other, the airtightness between the two pipes 3 and 5 is reliably maintained, and there is no risk of exhaust gas leaking from the movable joint 4.

Further, as shown by the chain line in FIG. 4, when the engine 1 rolls in the R1 direction during acceleration of the vehicle, the seal ring 10 moves along the spherical seat 13 along the spherical seat 13 as shown in FIG.
Sliding in one direction, movable joint 4 of exhaust front pipe 3
Refractive movement of the side edge in the r1 direction is allowed. That is, the end of the exhaust front pipe 3 on the side of the movable joint 4 is moved in the direction opposite to the offset direction r2, and the axis Sf thereof intersects with the axis Sr of the end of the exhaust rear pipe 5 on the side of the movable joint 4.

Therefore, at the time of acceleration, the end opening of the exhaust front pipe 3 faces the end opening of the exhaust rear pipe 5, and the passage cross-sectional area increases. Therefore, the flow resistance of the exhaust gas is reduced, and the exhaust gas is smoothly flowed from the exhaust front pipe 3 to the exhaust rear pipe 5. Therefore, the internal resistance of the engine 1 can be reduced during acceleration, and the acceleration performance can be improved.

On the other hand, as shown by the chain line in FIG. 4, when the engine 1 rolls in the R2 direction during deceleration of the vehicle, as shown in FIG.
As shown in FIG. 5, the seal ring 10 is slid along the spherical seat 13 in the r2 direction, and the end portion of the exhaust front pipe 3 on the side of the movable joint 4 is allowed to bend and move in the r2 direction. That is,
The end of the exhaust front pipe 3 on the side of the movable joint 4 is further moved in the offset direction r2, and the amount of deviation between the axis Sf and the axis Sr of the end of the exhaust rear pipe 5 on the side of the movable joint 4 is further increased. .

Therefore, at the time of deceleration, the passage cross-sectional area is reduced, and the exhaust gas from the exhaust front pipe 3 does not flow smoothly to the exhaust rear pipe 5. That is, since a part of the opening of the exhaust front pipe 3 is arranged to face the spherical seat 13, a part of the exhaust gas flow from the exhaust front pipe 3 hits the spherical seat 13 and the exhaust gas smoothly flows to the exhaust rear pipe 5 side. Disappear. Therefore, at the time of deceleration, the pressure loss increases, the direction of the exhaust noise is bent to reduce the noise, and the internal resistance of the engine 1 increases, so that the engine braking is effectively applied. Therefore, the vehicle can be efficiently decelerated.

Further, in this embodiment, the exhaust front pipe 3
With a simple configuration in which the axes Sf and Sr of the exhaust rear pipe 5 are eccentric, it is possible to improve acceleration performance, reduce exhaust noise during deceleration, and improve engine braking performance. That is, there is a conventional one in which an opening / closing valve is provided in the exhaust pipe, and the opening / closing valve controls the opening / closing valve to change and adjust the cross-sectional area of the exhaust gas flowing in the exhaust pipe.
However, in this case, an on-off valve and an electrical mechanism for controlling the on-off of the on-off valve are required, which complicates the configuration and increases the manufacturing cost. However,
In this embodiment, the flow resistance of exhaust gas can be controlled with a very simple structure.

The present invention is not limited to the above-mentioned embodiment, and a part of the constitution can be appropriately modified and carried out as follows without departing from the gist of the invention. (1) As shown in FIG. 5, bending the end of the exhaust front pipe 3 on the side of the movable joint 4 to offset only the end of the pipe 3 on the side of the movable joint 4 in the r2 direction from the other portions of the pipe 3. Thus, the shaft center Sf of the end portion of the exhaust front pipe 3 on the side of the movable joint 4 and the movable joint 4 of the exhaust rear pipe 5 are
Eccentricity with the axis Sr of the side end. (2) As shown in FIG. 6, by bending or bending the end portion of the exhaust front pipe 3 on the side of the movable joint 4 in the direction r2, the axis Sf of the end portion of the exhaust front pipe 3 on the side of the movable joint 4 and the exhaust rear pipe 5 are formed. Axis S of the movable joint 4 side end of
eccentric r and. (3) Although the spherical joint is used as the movable joint 4 in the above-described embodiment, as shown in FIG. 7, the bellows pipe 17 having the bellows-shaped flexible portion 17a in the middle is used as the movable joint, and the bellows thereof is used. Connecting both pipes 3 and 5 via a pipe 17 so as to be relatively movable. In the case of FIG. 7, the intermediate pipe 8 is unnecessary. (4) The spherical seat 13 is provided on the exhaust front pipe 3 side, and the seal ring 10 is provided on the exhaust rear pipe 5 side. (5) In the embodiment of FIGS. 1 to 6 and the embodiment of the above (4), the intermediate pipe 8 is omitted and the flange portion 9 and the seal ring 10 are directly provided on the exhaust front pipe 3.

[0027]

As described above in detail, according to the present invention, in the normal state of the internal combustion engine, the shaft center of the end portion of the first exhaust pipe on the side of the movable joint is set to the end of the second exhaust pipe on the side of the movable joint. The axial center of the portion is eccentric in the moving direction of the movable joint side end of the first exhaust pipe due to rolling of the internal combustion engine during deceleration. Therefore, when the internal combustion engine rolls when the vehicle accelerates, the openings of both exhaust pipes are aligned and the exhaust gas smoothly flows from the first exhaust pipe to the second exhaust pipe. Therefore, the internal resistance of the internal combustion engine at the time of acceleration can be reduced, and the excellent effect that the acceleration performance can be improved is exhibited.

When the internal combustion engine rolls during deceleration of the vehicle, the displacement of the first exhaust pipe from the second exhaust pipe becomes large, and the exhaust gas flows from the first exhaust pipe to the second exhaust pipe. It will not flow smoothly to the exhaust pipe. Therefore, at the time of deceleration, the exhaust noise can be reduced, and the internal resistance of the internal combustion engine increases, so that the engine braking can be effectively applied and the vehicle can be decelerated efficiently. Exert.

Furthermore, the flow resistance of the exhaust gas can be suitably controlled by a simple structure in which the axes of the first exhaust pipe and the second exhaust pipe are eccentric, and the flow of the exhaust gas can be controlled. The excellent effect that a mechanism for controlling the resistance can be provided at low cost is exhibited.

[Brief description of drawings]

FIG. 1 is a partial sectional view showing an embodiment of an exhaust pipe joint structure of an internal combustion engine embodying the present invention.

FIG. 2 is a partial cross-sectional view showing the operation of the exhaust pipe joint structure when the engine rolls during acceleration.

FIG. 3 is a partial cross-sectional view showing the operation of the exhaust pipe joint structure when the engine rolls during deceleration.

FIG. 4 is a schematic side view showing an engine and an exhaust system connected to the engine.

FIG. 5 is a partial cross-sectional view showing another example of the present invention.

FIG. 6 is a partial cross-sectional view showing another example of the present invention.

FIG. 7 is a partial cross-sectional view showing another example of the present invention.

FIG. 8 is a partial cross-sectional view showing a conventional exhaust pipe joint structure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine as an internal combustion engine, 3 ... Exhaust front pipe as 1st exhaust pipe, 4 ... Movable joint, 5 ... Exhaust rear pipe as 2nd exhaust pipe, 7 ... Car body, 17 ... Bellows pipe as movable joint, R1 ... engine rolling direction during acceleration, R2 ... engine rolling direction during deceleration, r1, r2 ... moving direction of movable joint side end of exhaust front pipe, Sf ... axial center of movable joint side end of exhaust front pipe, Sr: The axial center of the end of the movable joint of the exhaust rear pipe.

Claims (1)

[Claims] 1. A first exhaust pipe connected to the internal combustion engine side of a vehicle and a second exhaust pipe supported to the vehicle body side are connected via a movable joint, and both exhausts based on displacement of the internal combustion engine. In an exhaust pipe joint structure for an internal combustion engine in which relative bending movement of a pipe is allowed by the movable joint, in a normal state in which the internal combustion engine is not displaced, a movable joint side end portion of the first exhaust pipe is The shaft center is eccentric with respect to the shaft center of the movable joint side end of the second exhaust pipe in the moving direction of the first exhaust pipe on the movable joint side end due to rolling of the internal combustion engine during deceleration. An exhaust pipe joint structure for an internal combustion engine, comprising: