JPS6210439Y2 - - Google Patents

Description

[Detailed description of the invention] This invention consists of a rotor housing having a multi-arc inner peripheral surface and a side housing with a sealing member interposed inside the rotor housing. The present invention relates to a rotor housing for a rotary piston engine in which a supported polygonal rotor moves in planetary rotation.

Conventionally, in this type of rotary piston engine, an exhaust port and a secondary air passage communicating with the exhaust port are provided in the rotor housing.
It has been proposed to purify the exhaust gas by supplying secondary air through the secondary air passage and re-burning HC and CO in the exhaust gas (Utility Model Application No. 139833/1983). .

However, in a rotary piston engine with such a structure, when exhaust gas flows back into the secondary air passage when the supply of secondary air is cut off, the heat of the exhaust gas damages the seal member near the secondary air passage. Since the seal member is heated, there is a problem that the durability of the seal member deteriorates.

Therefore, the purpose of this invention is to solve the above problem by reducing the transfer of heat to the sealing member even if exhaust gas flows back into the secondary air passage, thereby increasing the durability of the sealing member. It is about improving sexuality.

In order to achieve the above object, the structure and operation of this invention is such that an insert member is inserted into an exhaust port opened in a rotor housing in which a side housing is provided with a seal member interposed on both sides, with a gap between the exhaust port and the port wall. a secondary air passage provided in the rotor housing near the sealing member is connected to the gap, and a secondary air control valve is connected to the secondary air passage communicating with the upstream side of the secondary air passage. established,
By providing a heat insulating section in the rotor housing between the secondary air passage and the sealing member, conduction of heat from exhaust gas that has entered the secondary air passage to the sealing member when the secondary air supply is stopped is blocked. It is characterized by the fact that

This invention will be explained in detail below with reference to illustrated embodiments.

In FIG. 1, 1 is composed of a rotor housing 2 having a multi-arc inner circumferential surface 2a and side housings 3, 3 disposed on both sides thereof with seal members 4, 5 interposed therebetween along the inner circumferential surface 2a. 6 is an intake port opened in the side housing 3 and into which the air-fuel mixture is introduced through an intake passage 8 having a throttle valve 7; 11 is an exhaust port opened in the rotor housing 2; A polygonal rotor (not shown) rotates planetarily within the engine 1, and the suction, compression, explosion, and exhaust strokes are successively repeated.

As shown in FIG. 2, a cylindrical insert member 13 having a predetermined gap 12 between the port wall 11a and the exhaust port 11 is fitted into the exhaust port 11, so that the exhaust gas inside the insert member 13 is flushed with cooling water. Passage 21
It is made so that it is difficult to be cooled by the circulating cooling water. The insert member 13 has a through hole 1
4 are provided symmetrically (only one side is shown).
Secondary air passage sections 15, 15 provided in the rotor housing 2 are communicated with the gap 12, and the upstream ends of the secondary air passage sections 15, 15 are connected to the secondary air passage 1.
It is connected to 6. This secondary air passage 16 is
It passes through the rotor housing 2 and the side housing 3, further along a part of the intake passage 8, and is further connected to an air pump (not shown).

A secondary air control valve 1 is provided in the secondary air passage 16.
7 is provided so that a required amount of secondary air can be supplied depending on the operating state of the engine. That is, when the engine temperature is higher than the set value and there are a lot of HC and CO in the exhaust gas, for example at a light load, the secondary air control valve 17 is opened and the necessary amount of secondary air is sent to the secondary air passages 16, 2. Next air passage section 15,1
5. Through the gap 12 and the through hole 14, it is supplied to the part inside the insert member 13 of the exhaust port 11 to re-burn HC and CO in the exhaust gas and purify the exhaust gas. When the engine temperature is lower than the set value, such as immediately after starting the engine, the secondary air control valve 17 is closed to cut off the supply of secondary air, and the exhaust gas purification device installed in the exhaust passage (Fig. (not shown) is designed to prevent abnormal combustion.

As shown in FIG. 2, blind holes 18, 18, which are open to the atmosphere, are provided in the rotor housing 2 between the secondary air passages 15, 15 and the seal members 5, 5, as an example of a heat insulating part. ing. Blind hole 1 above
As shown in FIG. 1, 8 and 18 are open at the left end surface of the rotor housing 2 in the figure.

In FIG. 1, 21 is a cooling water passage provided in the rotor housing 2 and side housing 3, and 22 is a hole for a tension bolt.

In the rotary piston engine configured as described above, if the engine is currently in a light load, low rotational state immediately after starting, and the engine temperature is low, 2
It is assumed that the secondary air control valve 17 is closed and the supply of secondary air to the exhaust port 11 is stopped.

At this time, even if exhaust gas flows back into the secondary air passages 15, 15 through the through hole 14 and the gap 12, the gas remains between the secondary air passages 15, 15 and the seal members 5, 5. Blind hole 1 open to atmosphere
Due to the heat insulating effect of the seal members 8 and 18, it is possible to reduce the transfer of the heat of the exhaust gas to the seal members 5, 5, and improve the durability of the seal member 5.

In the above embodiment, the blind holes 18, 18 are used as the heat insulating part.
However, a heat insulating material may be provided as a heat insulating part.

As is clear from the above explanation, the rotor housing of the rotary piston engine of this invention has a gap between the port wall and the exhaust port opened in the rotor housing, which has side housings with seal members interposed on both sides. Then, the insert member is fitted, a secondary air passage provided in the rotor housing near the sealing member is communicated with the gap, and a secondary air passage is connected to the secondary air passage communicating with the upstream side of the secondary air passage. Since a secondary air control valve is provided and a heat insulating section is provided in the rotor housing between the secondary air passage and the seal member, the heat of the exhaust gas that has entered the secondary air passage when the supply of secondary air is stopped. The durability of the seal member can be improved by reducing the transmission of to the seal member.

[Brief explanation of drawings]

FIG. 1 is a front view of an embodiment of this invention, and FIG. 2 is a sectional view taken along the line A--A in FIG. 1. 1...Casing, 2...Rotor housing,
3... Side housing, 4, 5... Seal member, 11... Exhaust port, 12... Gap, 13...
...Insert member, 15...Secondary air passage section, 1
6... Secondary air passage, 17... Secondary air control valve,
18...Blind hole (insulation part).

Claims (1)

[Claims for Utility Model Registration] The interior of the casing is composed of a rotor housing having a multi-arc inner circumferential surface, and side housings with sealing members interposed along the inner circumferential surface on both sides of the rotor housing. In a rotary piston engine in which a rotor rotates planetarily, an insert member is fitted into an exhaust port opened in the rotor housing with a gap between the insert member and the port wall, and secondary air is introduced into the exhaust port through the gap. A secondary air passage is provided in the rotor housing near the sealing member, and a secondary air control valve is provided in the secondary air passage communicating with the upstream side of the secondary air passage. The rotor housing between the passage part and the sealing member is provided with a heat insulating part that blocks heat from the exhaust gas that has entered the secondary air passageway from being conducted to the sealing member when the secondary air supply is stopped. Rotor housing of rotary piston engine.