JPH0128268Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) This invention relates to an improvement in the exhaust port structure of a rotary piston engine.

(Prior art) Conventionally, for example, a polygonal rotor was moved inside a casing formed of a rotor housing having a polygonal inner circumferential surface and side housings that were in close contact with each other on both sides of the rotor housing. In a rotary piston engine that performs planetary rotational motion while in contact with the air to perform the suction, compression, explosion, expansion, and exhaust processes, a cylindrical insert is fitted into an exhaust port formed in the rotor housing, and the outer periphery of this insert is inserted into the exhaust port formed in the rotor housing. A gap is formed between the insert and the rotor housing to form a heat insulating layer, which prevents the exhaust gas discharged inside the insert from losing heat from the rotor housing, and prevents re-burning of the exhaust gas. Structures designed to do this are known.

Furthermore, Japanese Utility Model Application No. 52-39910 proposes a structure in which the insert is extended to the upstream end of the exhaust port, and a flange is formed at the upstream end of the insert to reduce the gap at that part. ing. The purpose of this is to prevent secondary air from leaking through the flange from the gap on the outer periphery of the insert, and to facilitate control of the amount of secondary air supplied. Additionally, a partition plate is provided on the cylindrical portion of the insert, which reduces the noise generated by the sudden expansion of exhaust gas when it is discharged from the rotor housing into the insert. . However, when this partition plate is fixed to the cylindrical part, the partition plate is heated to a higher temperature than the cylindrical part by the exhaust gas, so stress is generated at the joint between the two due to the difference in thermal expansion. It is desirable to adopt a structure that does not generate this stress.

(Purpose of the invention) This invention was made against this technical background, and is designed to prevent stress due to differences in thermal expansion from occurring at the joint between the cylindrical part of the insert inserted into the exhaust port and the partition plate. Thus, a structure is provided that increases the life of the insert.

(Structure of the device) This device is a rotary piston engine in which a cylindrical insert is fitted into an exhaust port of a rotor housing. is supported by a cylindrical insert so as to be movable by a predetermined amount in the width direction of the rotor housing. That is, the partition plate is supported in such a manner that thermal expansion is absorbed by the cylindrical insert.

(Example) In FIG. 1, a multi-arc shaped inner circumferential surface 2 is formed inside a rotor housing 1.
The top side of the rotor 3 is in contact with the top side of the rotor 3 to perform planetary rotational motion. An exhaust port 4 is formed in the rotor housing 1, and a cylindrical insert 5 is inserted into the exhaust port 4 from the outside.

As shown in FIGS. 2 and 3, the insert 5 has a flange portion 7 formed at one end of a cylindrical portion 6, and a partition plate 8 in the width direction of the rotor housing is provided inside the cylindrical portion 6. It is being This partition plate 8
is provided to reduce the noise generated by sudden expansion of exhaust gas when it is discharged from inside the rotor housing into the insert 5. Grooves 61 are formed on the inside of the cylindrical portion 6 to face each other, and both ends of the partition plate 8 are fitted into the grooves 61. A slight gap is formed between the bottom of the groove 61 and the end of the partition plate 8, and the partition plate 8 is supported so that it can expand in both directions.

The cylindrical portion 6 is formed into an oval shape, and the flange portion 7
A recess 9 is formed in a circular shape and faces upstream. When the insert 5 is attached to the exhaust port 4, a gap 11 is formed between the outer periphery of the cylindrical part 6 and the rotor housing 1, and the recess 9 communicates with the opening of the exhaust port 4 through this gap 11. The recess 9 is configured to introduce exhaust gas. The reason why the flange portion 7 is formed into a circular shape is to facilitate machining of this portion and the stepped portion 13 of the rotor housing 1 into which it is fitted. The insert 5 is positioned by fitting the flange portion 7 into the stepped portion 13, and the insert 5 is fixed by fixing the flange portion 7 with a pin (not shown).

FIG. 4 shows another embodiment of this invention, in which the partition plate 80 is divided into two parts in the plane direction, and each divided piece 82,
The end portion of 83 is fixed to the cylindrical portion 6 by means such as welding,
As shown in FIG. 5, stepped portions formed at the ends of each of the divided pieces 82 and 83 in the center are overlapped with each other to form a joint portion 85. In this joint portion, a gap is provided in the plane direction so that the two divided pieces 82 and 83 are in contact with each other in the thickness direction and can expand in the plane direction.

In the above configuration, exhaust gas is discharged from the exhaust port 4 through the insert 5, thereby heating the cylindrical portion 6 and the partition plates 8, 80.
The partition plates 8 and 80 are heated from both sides, whereas the cylindrical part 6 is heated only from the inside, so the partition plates 8 and 80 are heated to a higher temperature than the cylindrical part 6.
For this reason, a difference in thermal expansion occurs between the partition plates 8 and 80 and the cylindrical portion 6, but this difference in thermal expansion is caused by the end of the partition plate 8 being inserted deeper into the groove 61, or by the split piece 82 of the partition plate. , 83 is absorbed by increasing the overlapping amount of the stepped portions. This prevents thermal stress from occurring between the partition plate and the cylindrical portion 6 due to the difference in thermal expansion.

(Effects of the invention) As explained above, this invention is a rotary piston engine in which a cylindrical insert is fitted into the exhaust port of the rotor housing, in which the partition plate is supported with a structure in which thermal expansion is absorbed by the cylindrical part. Since no stress is generated due to the difference in thermal expansion, there is no risk of distortion or cracking at the joint between the two, and the durability of the insert can be improved.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the exhaust port portion of the rotor housing showing an embodiment of this invention, Fig. 2 is a perspective view of the insert, Fig. 3 is a front view thereof, and Fig. 4 shows another example of the insert. The perspective view, FIG. 5, is an enlarged perspective view of the joint portion. 1...Rotor housing, 4...Exhaust port,
5...Insert, 6...Cylinder part, 8, 80...Partition plate, 61...Groove, 85...Joint part.

Claims (1)

[Scope of utility model registration request] In a rotary piston engine in which a cylindrical insert is fitted into an exhaust port of a rotor housing, a partition plate is provided inside the cylindrical insert in the width direction of the rotor housing, and this partition plate is arranged in a predetermined amount in the width direction of the rotor housing. An exhaust port structure for a rotary piston engine, characterized in that it is movably supported on a cylindrical insert.