JP2581386Y2 - Engine exhaust pipe mounting device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust pipe mounting device for an engine in which a mounting portion between an exhaust port of a cylinder and an exhaust pipe is improved.

[0002]

2. Description of the Related Art In a mounting portion between an exhaust port of a cylinder and an exhaust pipe, leakage of the exhaust gas from the mounting portion affects the combustion efficiency of an engine, so that the exhaust gas must be prevented from leaking. In addition, since the mounting portion is a so-called dissimilar metal mounting in which the engine vibrates and an iron exhaust pipe is attached to an exhaust port of an aluminum alloy cylinder, the mounting portion is easily worn. Below. Therefore, this mounting portion must be structured so as not to be worn by the above conditions. Since cylinders are mass-produced, a structure that is easy to attach to this attachment portion is desired from the viewpoint of productivity.

A conventional mounting structure between an exhaust port of a cylinder and an exhaust pipe has a stepped portion 3 provided from an exhaust port 2 of a cylinder 1 to form an enlarged diameter portion 4 as shown in FIG. Insert the flange 6 fixed to the tip of the
A washer 7 is interposed between the tip of the nozzle 3 and the step 3 to reduce wear between the exhaust port 2 and the flange 6. The seal is provided with an O-ring 8 on the outer periphery of the flange 6 to seal between the flange 6 and the inner peripheral surface of the enlarged diameter portion 4.

In Japanese Utility Model Application Laid-Open No. 60-125315, a cylindrical seal member is fitted around the outer periphery of an exhaust cylinder of an engine, and the end of the exhaust cylinder is covered with a flange having a bent bottom portion. On the other hand, a socket is provided at the end of the exhaust pipe, a predetermined gap is provided between the end of the exhaust pipe and the outer periphery of the seal member, and the fitting is performed.A washer is interposed between the step portion of the socket and the flange portion of the seal member. There is disclosed a technique for simultaneously performing wear resistance and sealing.

[0005]

SUMMARY OF THE INVENTION In the above conventional example,
First, in FIG. 6, the enlarged diameter portion 4 is made of an aluminum alloy.
Since the flange 6 is made of iron, there is a problem in that the enlarged diameter portion 4 is worn by the vibration of the engine and the exhaust gas leaks.
When the O-ring 8 is replaced to prevent the leakage of the exhaust gas, the inner peripheral surface of the enlarged-diameter portion 4 is not smooth because the enlarged-diameter portion 4 is worn. There is a problem that the leakage of the exhaust gas cannot be reliably stopped due to the scratching or breaking of the exhaust gas 8. Further, when the enlarged diameter portion 4 is worn, the vibration of the exhaust pipe is further increased, and there is a problem in durability.

[0006] Next, the structure disclosed in Japanese Utility Model Application Laid-Open No. 60-125315 has no problem in terms of the above-mentioned abrasion resistance due to the use of a sealing member, but the prior art shown in FIG. There is a problem in terms of assembly. In other words, when assembling with a washer interposed, it is necessary to attach wax etc. to the washer to prevent the washer from falling off and insert it into the step part, which is troublesome, especially in the case of mass production. There is a problem in productivity.

The present invention is to provide an exhaust pipe mounting device for an engine which simultaneously satisfies wear resistance, sealing properties and assembling properties.

[0008]

Means for Solving the Problems of the Cylindrical Body At the mounting portion between the exhaust port of the cylinder and the exhaust pipe, the inner surface shape of the exhaust port of the cylinder is provided with a step from the inside of the cylinder and the outside is enlarged in diameter. And forming a flange at the bottom with a hole having a diameter substantially equal to the diameter of the exhaust port of the cylinder.
At the same time , there is provided a tubular body whose central portion is pressed against the enlarged diameter portion, and a flange portion of the tubular body is pressure-bonded to a step portion of the exhaust port.
Then, the central part of the cylindrical body is pressed against the enlarged diameter part of the exhaust port.
As described above, the tubular body is press-fitted into the exhaust port, and the tubular body is inserted into the exhaust port.
Fixed, and the inside diameter of the cylindrical body is the inside diameter of the exhaust port.
Approximately equal, the outer diameter is almost equal to the inner diameter of the central part of the cylindrical body
Equalize, attach a seal ring to the outer peripheral surface, and attach
A connecting member integrally provided in the portion is inserted.

[0009]

SUMMARY OF Invention The present invention, the inner surface shape of the exhaust port of the cylinder and expanded by providing a stepped portion from the exhaust port of the cylinder, since the press-fitted cylindrical member to the inner surface of the enlarged diameter portion, the cylindrical body to an exhaust port Fix
In addition, there is no play between the exhaust port and the cylindrical body, and there is no wear of the exhaust port due to vibration of the engine. The central well as pressure wearing the collar portion of the cylindrical body to the stepped portion
Part was crimped to the enlarged diameter part of the exhaust port, so the exhaust port and the cylindrical body
There is no leakage of gas from between, and the connecting member provided on the exhaust pipe inserted into the enlarged diameter portion is in contact with the inner peripheral surface of the cylindrical body and the flange of the cylindrical body, and is made of an aluminum alloy cylinder. The exhaust port is not in direct contact with the exhaust port, so that it is possible to eliminate wear of the exhaust port due to vibration of the engine. And providing a flange on the tubular body
The inner diameter of the exhaust port and the inner diameter of the connecting member
Exhaust gas in the connecting member, reducing the flow resistance of the gas
Crimping between the flange and the end of the connection member, eliminating pressure rise
Can provide a sealing effect, and since the inner surface of the cylindrical body is smooth, there is no catch of the seal ring when the connecting member of the exhaust pipe is inserted into the cylindrical body, and
Since the connecting member is inserted between the inner peripheral surface of the cylindrical body and the sealing member via a seal ring for sealing, the connecting member is in contact with the flange.
A double seal is made with the end of the connecting member.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 and FIG. 3 show a tubular body 9 according to the present invention. The cylindrical body 9 is made by drawing an iron plate, and a hole 11 having a diameter substantially equal to the diameter of the exhaust port 2 of the cylinder 1 is formed in a bottom portion to form a flange portion 10.
2 is dimensioned so as to be pressed against the enlarged diameter portion 4 of the exhaust port 2. 13 is opening, connected as shown in FIG. 1 member 6
An O-ring 15 as a seal ring is fitted in the concave groove 14 and the diameter thereof is enlarged so as not to damage the O-ring 15 when the O-ring 15 is inserted into the cylindrical body 9.

The cylindrical body 9 having such a structure is pressed into the exhaust port 2 of the cylinder 1 as shown in FIGS.
That is, the inner surface shape of the exhaust port 2 of the cylinder 1 is provided with a stepped portion 3 from the inside and the outside is formed in the enlarged diameter portion 4, and the cylindrical body 9 is press-fitted into the enlarged diameter portion 4 from the outside. .
This press-fitting, flange portion 10 of the cylindrical body 9 is crimped to the step portion 3 of the cylinder 1, the central portion 12 is pressed against the enlarged diameter portion 4.

The operation of the embodiment constructed as described above will be described. First, the cylindrical body 9 is located inside the exhaust port 2 of the cylinder 1.
The cylindrical body 9 takes special fixing means
Without being fixed to the exhaust port 2. Exhaust port of this cylindrical body 9
The press-fitting into the cylinder 2 is performed in the processing line of the cylinder 1. Next
The on-site assembly will now be described. The O-ring 15 is fitted into the concave section 14 (see FIGS. 1 and 5) provided on the connecting member 6 from the opening 13 of the tubular body 9 fitted to the exhaust port 2. Wore
The insertion of the exhaust pipe to the exhaust port 2 is completed only by inserting the connecting member 6 into the tubular body 9.

Next, the abrasion resistance will be described. The inner surface of the exhaust port 2 of the cylinder 1 is formed with a stepped portion 3 from the exhaust port 2 of the engine to form an enlarged diameter portion 4. Since the cylindrical body 9 is press-fitted, there is no backlash between the enlarged diameter part 4 of the exhaust port 2 and the cylindrical body 9, and the wear between the enlarged diameter part 4 and the cylindrical body 9 due to engine vibration is reduced. Absent. Also, the bottom of the cylindrical body 9
Hole 11 having substantially the same diameter in section the diameter of the exhaust port 2 of the engine
The flange 10 is formed by pressing the flange 10 and the flange 10 is press- fitted to the stepped portion 3. Therefore, the connecting member 6 provided on the exhaust pipe 5 inserted into the enlarged diameter portion 4 is formed of the cylindrical body 9. The exhaust port 2 of the aluminum alloy engine, the step 3 and the enlarged diameter section 4 are not in direct contact with the inner peripheral surface and the flange 10 formed on the cylindrical body 9, and the exhaust port 2, the step The wear of the portion 3 and the enlarged diameter portion 4 can be eliminated.

Then, the flange 10 of the cylindrical body 9 is connected to the step 3.
The cylindrical body is pressed so that the central portion 12 is pressed against the enlarged diameter portion 4.
9 is press-fitted into the exhaust port 2 so that the outer peripheral surface of the cylindrical body 9 and the diameter increase.
Exhaust gas leaks from between the step 4 and the flange 10 and the step 3.
No leaks. Also, as is apparent from FIG.
10, the inner diameter of the connection member 6
The exhaust port 2 and the connecting member 6 can be matched to the inner diameter.
The flow resistance of the exhaust gas flowing through is equalized. Therefore
No increase in the gas pressure of the exhaust gas in the connecting member 6
One end of the connection member 6 is crimped to the flange 10
Is perpendicular to the gas flow,
The gas sealing effect can be enhanced even on the wearing surface
You. Then, the diameter of the opening 13 of the tubular body 9 is increased, and the tubular body 9 is pressed to form a smooth inner surface, so that the connecting member 6 of the exhaust pipe 5 is connected to the tubular body 9. Since the O-ring 15 is not damaged at the time of insertion, the connecting member 6 is inserted into the tubular body 9 via the O-ring 15 between the inner peripheral surface of the tubular body 9 and sealed. ,
Leakage of exhaust gas can be reliably prevented by the O-ring 15.

[0015]

As described above in detail, according to the present invention, the inner surface of the exhaust port of the engine is enlarged by providing a step from the exhaust port of the engine, and a cylindrical body is press-fitted into the inner surface of the enlarged portion. Therefore, the tubular body can be fixed to the exhaust port without taking special fixing means , and there is no backlash between the exhaust port and the tubular body, and there is no vibration due to engine vibration. An engine which can eliminate wear of the exhaust port and is made of an aluminum alloy in which a connecting member provided on an exhaust pipe inserted into the cylindrical body is in contact with an inner peripheral surface of the cylindrical body and a flange formed on the cylindrical body. Since the exhaust port does not directly contact the exhaust port, wear of the exhaust port due to vibration of the engine can be prevented. Then, the cylindrical body is compressed by the expanded diameter part.
Between the outer peripheral surface of the cylindrical body and the inner peripheral surface of the enlarged diameter part.
Never gas leaking from, and the flange portion to the tubular body
By providing the inner diameter of the exhaust port and the inner diameter of the connection member,
Flow resistance of the exhaust gas to reduce
Of the exhaust gas pressure of the
Sealing effect can be obtained by crimping between the tip
Can, and because the inner surface of the tubular body is smooth, never as damaging the sealing ring when inserting the connecting member of the exhaust pipe to the tubular body, and, between the inner peripheral surface of the cylindrical body Since the exhaust pipe is inserted into the cylindrical body through the seal ring and sealed, the leakage of the exhaust gas can be reliably prevented by the seal ring. In this way, the wear of the exhaust port has been improved without using a washer, and the leakage of exhaust gas has been reliably prevented by the seal ring, so a simple assembly that simply inserts the connecting member into the tubular body is possible. It is possible to improve the assemblability of the engine exhaust pipe mounting device.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a main part of an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the cylindrical body in FIG.

FIG. 3 is a perspective view of FIG. 2;

FIG. 4 is a longitudinal sectional view showing the whole embodiment of the present invention;

FIG. 5 is a perspective view of an exhaust pipe.

FIG. 6 is a longitudinal sectional view showing the entire conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Cylinder 2 Exhaust port 3 Step part 4 Large diameter part 6 Connection member 9 Cylindrical body 10 Flange part 11 Hole 15 O ring

Claims (1)

(57) [Scope of request for utility model registration] In an attachment portion between an exhaust port of a cylinder and an exhaust pipe, an inner surface of the exhaust port of the cylinder is provided with a stepped portion from the inside of the cylinder to have a shape in which the outside is enlarged, and a bottom portion is provided. to form a flange portion at an approximately equal diameter of the hole to the diameter of the exhaust port of the cylinder, provided with a cylindrical member of which center portion in pressure-contact with the enlarged diameter portion, the flange of the cylindrical body
Part is pressed against the step of the exhaust port, and the center of the cylindrical body is
The exhaust port has a cylindrical shape so as to be crimped to the enlarged diameter portion of the exhaust port.
The body is press-fitted and the tubular body is fixed to the exhaust port, and the inside of the tubular body is
In addition, the inside diameter is made substantially equal to the inside diameter of the exhaust port, and the outside diameter is
Approximately equal the inner diameter of the central part of the cylindrical body, and seal the outer peripheral surface.
Connecting part attached to the end of the exhaust pipe with a ring attached
An exhaust pipe mounting device for an engine, wherein a material is inserted.