JPH0629549B2 - Exhaust pipe connecting device for engine - Google Patents

Description

The present invention relates to an exhaust pipe connecting device for an engine used in, for example, a motorcycle.

[Prior art]

Conventionally, when connecting an exhaust pipe to an exhaust port of an engine, a flange portion is provided at an opening end of the exhaust pipe as seen in, for example, Japanese Utility Model Laid-Open No. 56-3517.
A retaining ring is inserted around the outer periphery of the end of the exhaust pipe, and the retaining ring is tightened to the engine side with a bolt, so that the flange portion is pressed against the exhaust port side for tightening.

[Problems to be solved by the invention]

By the way, it is of course that there should be no leakage of exhaust gas at the connecting portion of the exhaust pipe, and various vibrations such as engine vibrations and road surface vibrations during traveling are transmitted. Careful consideration is required.

However, according to the above-described conventional configuration, since the exhaust pipe is firmly bolted through the holding ring, many vibrations act directly on the connecting portion of the exhaust pipe, and there are problems such as easy damage. there were.

[Means for solving problems]

Therefore, in the present invention, a flange portion is provided at the opening end portion of the exhaust pipe, and a retaining ring having a pressing flange portion for pressing the flange portion toward the exhaust port side is inserted through the outer periphery of the end portion of the exhaust pipe. Assuming a connecting device for tightening the exhaust pipe by tightening this retaining ring on the engine side with a bolt, between the flange and the opening of the exhaust port, and between this flange and the pressing flange. A plurality of disc springs are superposed on each other, and a gasket material which is elastically deformable in the axial direction is interposed therebetween in a compressed state.

[Action]

According to this configuration, when the retaining ring is tightened, the flange portion of the exhaust pipe is pressed and urged in opposite axial directions by the gasket material from both sides, and thus is held in a floating state with respect to the engine side. However, the gasket material is in a state in which it can move freely as much as elastically deformed.

In addition, since the gasket material sandwiches the flange portion from both sides, and both of them share and absorb the vibration, the spring constant of the gasket material can be set lower by that amount, and the vibration absorbing function is enhanced.

Therefore, when vibration is applied to the connecting portion of the exhaust pipe, the gasket material is softly and elastically deformed to absorb and relax the vibration. Therefore, the vibration applied to the connecting portion is efficiently damped, resonance of the exhaust pipe due to vibration transmission, and vehicle body The vibration of the can be suppressed to a small level, and the loosening of bolts and the damage of connecting parts can be reliably prevented.

Further, since the gasket material is only elastically deformed in the axial direction, it is possible to prevent misalignment between the exhaust pipe and the exhaust port, and it is possible to sufficiently maintain the sealing property.

Example of Invention

The present invention will be described below based on an embodiment shown in the drawings.

Reference numeral 1 in FIG. 3 is a two-cycle engine, and in the case of the present embodiment, it is rubber-mounted on the vehicle body frame 2 of the motorcycle through a vibration-proof rubber. An exhaust port 4 is opened in a cylinder block 3 of the engine 1, and an exhaust pipe 5 is connected to the exhaust port 4. The connecting structure of the exhaust pipe 5 will be described with reference to FIG. 1. A tubular body 6 is coaxially welded to the outer periphery of the open end of the exhaust pipe 5. At the end of the tubular body 6 on the exhaust port 4 side, a flange portion 7 that extends radially outward is formed over the entire circumference.
Are opposed to the recesses 8 formed at the peripheral edge of the opening of the exhaust port 4.

A retaining ring 9 is fitted on the outer periphery of the tubular body 6 so as to be movable in the axial direction. A pressing flange portion 10 for pressing the flange portion 7 toward the exhaust port 4 side is formed on the inner peripheral portion on one end side of the holding ring 9, and the pressing flange portion 10 is formed.
Are opposed to the flange portion 7 in the axial direction of the tubular body 6 at a distance. The holding ring 9 is fastened and fixed to the front surface of the cylinder block 3 connected to the exhaust port 4 with a bolt 11 between the holding ring 9 and the cylinder block 3. Gasket material
Twelve are pinched.

By the way, ring-shaped gasket materials 13 and 14 are respectively provided between one end surface of the flange portion 7 and the recessed portion 8 connected to the exhaust port 4, and between the other end surface of the flange portion 7 and the pressing flange portion 10. It is installed. As shown in FIG. 2, for example, the gasket materials 13 and 14 are formed by stacking four disc springs 15 made of metal, two by two in opposite directions, and elastically deformable only in the axial direction. Has been formed. The gasket materials 13 and 14 are elastically compressed in the axial direction by tightening the retaining ring 9 with the bolts 11. Therefore, both surfaces of the flange portion 7 are axially reversed between the gasket materials 13 and 14. It is pressed and biased in the direction and is supported by the holding ring 9 and the cylinder block 3 in a floating state. In addition, the gasket material 13 on the exhaust port 4 side is the concave portion 8 of the cylinder block 3.
The inner peripheral surface of the gasket member 13 is in contact with the outer peripheral surface of the concave portion 8 and the other gasket material 14 located outside the gasket material 13 is sandwiched between the tubular body 6 and the retaining ring 9. Therefore, both gasket materials 13 and 14 are positioned in the radial direction.

The downstream end of the exhaust pipe 5 has a silencer as shown in FIG.
It is connected to an exhaust expansion pipe 17 having 16 and an intermediate part of the exhaust expansion pipe 17 is fixed to the frame 2 via a bracket 18.

According to such a configuration, the flange portion 7 of the exhaust pipe 5 is
When the retaining ring 9 is tightened, the gasket material 1
It is sandwiched by 3 and 14, and is pressed and biased in the opposite direction along the axial direction. As a result, the cylinder block 3 and the retaining ring 9 are supported in a floating state, and the gasket members 14 and 15 are in a state where they can move freely by the amount of elastic deformation.

Moreover, since the gasket materials 13 and 14 are located on both sides of the flange portion 7 and both of them share and absorb the vibration, the spring constant of the gasket materials 13 and 14 can be set lower by that amount. Therefore, when the vibration of the engine 1 or the road surface vibration during traveling is transmitted to the connecting portion of the exhaust pipe 5, the gasket materials 13, 1
Since 4 softly and elastically deforms to absorb and relax the vibration, the vibration applied to the connecting portion of the exhaust pipe 5 is efficiently damped.

Therefore, the exhaust pipe 5 and the exhaust expansion pipe 17 accompanying the transmission of vibrations
And the vibration of the frame 2 can be suppressed to a small extent, and damage to the retaining ring 9 and the flange portion 7 including the loosening of the bolt 11 can be reliably prevented.

Further, since the gasket materials 13 and 14 are elastically deformable only in the axial direction and the position is regulated in the circumferential direction, it is possible to prevent misalignment between the exhaust pipe 5 and the exhaust port 4 at the same time. There is an advantage that the sealing property of exhaust gas can be sufficiently secured.

The exhaust pipe connecting device according to the present invention can be applied to vehicles other than motorcycles as well as various fields other than vehicles.

〔The invention's effect〕

According to the present invention described in detail above, the vibration applied to the connecting portion of the exhaust pipe is effectively and efficiently damped, so that the loosening of the bolt and the damage of the connecting portion are surely caused, including the resonance of the exhaust pipe and the vibration of the vehicle body. Therefore, there is an advantage that it can be prevented and the exhaust gas sealing property can be sufficiently secured.

[Brief description of drawings]

The drawings show one embodiment of the present invention. FIG. 1 is a sectional view of an exhaust pipe connecting portion, FIG. 2 is a sectional view of a gasket material, and FIG. 3 is a side view of an exhaust system. 1 ... Engine, 4 ... Exhaust port, 5 ... Exhaust pipe, 7 ...
Flange, 9 ... Retaining ring, 10 ... Pressing flange, 11 ... Bolt, 13,14 ... Gasket material, 15 ... Disc spring.

Claims (1)

[Claims] 1. A flange portion is provided at an opening end portion of an exhaust pipe that abuts an exhaust port of an engine, a holding ring is inserted into an outer periphery of an end portion of the exhaust pipe, and the flange portion is provided at the holding ring. In the exhaust pipe connecting device of the engine, which is provided with a pressing flange portion to be pressed to the side, and the retaining ring is fastened to the engine side by a bolt, so that the exhaust pipe is fastened to the exhaust port. A plurality of disc springs are overlapped with each other between the opening portion and between the flange portion and the pressing flange portion, and a gasket material that is elastically deformable in the axial direction is interposed in a compressed state. Exhaust pipe connecting device for engine.