JPS627368B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotary piston engine that improves combustion conditions when the engine is at low temperatures.

Generally, in a rotary piston engine, a working chamber formed by a casing and a rotor has a large surface area of a peripheral wall surrounding the working chamber in relation to its volume. Therefore, when the engine is at low temperature, the fuel sucked into the working chamber is not easily evaporated and atomized due to the low temperature of the working chamber, but also because the casing wall and rotor wall are low temperature. A large amount of fuel adheres to the wall surface, which deteriorates the combustion state and becomes a factor that impedes driving performance.

In view of this point, the present invention forms a communication passage in the casing that communicates the working chamber in the expansion or exhaust stroke with the working chamber in the suction or compression stroke,
Part of the combustion gas is returned to the working chamber during the intake or compression stroke to raise the temperature of the intake air-fuel mixture, which promotes fuel vaporization and atomization, improving combustion conditions and increasing engine temperature. The aim is to complete the project as soon as possible. However, when the engine is at a high temperature, the vaporization and atomization of combustion are good, so there is no need to circulate the combustion gas through the communication passage to the working chamber in the intake or compression stroke; It has been found that this causes problems such as a decrease in charging efficiency and an increase in engine output loss, and the present invention is designed to recirculate combustion gas only when the engine is at a low temperature.

That is, the present invention provides a rotary piston engine in which a polygonal rotor rotates planetarily within a casing having a trochoidal inner peripheral surface. forming a recess that communicates with the working chamber, and providing the recess with a valve body that substantially eliminates the volume of the recess when the engine temperature is high;
This rotary piston engine is characterized in that when the engine is at low temperature, combustion gas in the working chamber in the expansion and exhaust stroke is recirculated to the working chamber in the suction and compression stroke through the recess.

Embodiments of the present invention will be described below with reference to the drawings.

In the rotary piston engine shown in FIG. 1, 1 is a casing composed of a rotor housing 2 having a trochoidal inner circumferential surface 2a and side housings 3 disposed on both sides of the rotor housing 2; A polygonal rotor 6a, 6b and 6c rotates planetarily by slidingly contacting the apex seal 5 attached to the casing 1.
a variable volume working chamber defined by the inner surface of the rotor 4 and each flank surface 4a of the rotor 4;
The suction, compression, expansion (explosion), and exhaust strokes are repeated in sequence according to the rotation of the cylinder. 7 is an intake port opened in the side housing 3, 8 is the rotor housing 2
An exhaust port is opened at 9, and 9 is a spark plug.

In addition, in the illustrated rotational position of the rotor 4, the upper working chamber 6a is in the suction stroke, and the lower right working chamber 6a is in the suction stroke.
A is in the expansion stroke, and the lower left working chamber 6c is in the exhaust stroke.

Next, a through hole 10 is provided in the casing 1, and a valve body 11 is provided in the through hole 10. The valve body 11 is composed of a sliding body 13 fitted into the through hole 10, a wax type thermopellet 14, and a spring 15. That is, a sliding body 13 is inserted into the through hole 10 from the outside of the rotor housing 2 with a spring 15 interposed therebetween, and a wax type thermopellet 14 is attached to the back of the sliding body 13 from the outside of the rotor housing 2 as well. The slider 13 is biased by a spring 15 so that the slider 13 always comes into contact with the tip of the operator 14a of the thermopellet 14. The thermo pellet 14 detects the temperature of the rotor housing 2, that is, the engine temperature, and when the engine temperature is low, the operator 14a moves back and the sliding body 13 moves to the spring 15.
The recess 12 is formed by retreating under the biasing force of the recess 12, and when the temperature is high, the operator 14a expands and moves the slider 13 forward against the spring 15, thereby substantially eliminating the volume of the recess 12. ing.

The sliding body 13 is made of the same material (aluminum alloy) as the rotor housing 2 so that it expands and deforms in the same way, and the tip of the sliding body 13 touches the rotor housing 2 when the sliding body 13 is at the most advanced position.
When machining the inner circumferential surface 2a of the rotor housing 2, the inner circumferential surface 2a of the rotor housing 2 is co-processed so that the inner circumferential surface 2a of the rotor housing 2 completely coincides with the inner circumferential surface 2a of the rotor housing 2. Preferably, means are provided.

Therefore, according to the valve body 11, when the engine is at a low temperature, the sliding body 13 retreats and its tip is displaced so as to sink from the inner circumferential surface 2a of the rotor housing 2, and the tip of the sliding body 13 and the through hole are displaced. A recess 12 is formed at 10, and when the engine is at high temperature, the sliding member 13 moves forward and its tip coincides with the inner circumferential surface 2a of the rotor housing 2, thereby substantially eliminating the volume of the recess 12. be.

The through hole 10 and the valve body 11 are connected to the casing 1
It is provided at a predetermined position on the upper part of the explosion side of the engine to form a recess 12 when the engine is at low temperature and serves as the working chamber 6b for the expansion stroke.
and the working chamber 6a of the suction stroke with an apex seal 5.
The working chamber 6 is in communication with the passage of the working chamber 6 and is in the expansion stroke.
The high-temperature combustion gas in the rear part (trailing part) of the working chamber 6a is recirculated to the front part (leading part) of the working chamber 6a in the suction stroke. In this case, the recirculation of combustion gas promotes vaporization and atomization of the intake air-fuel mixture, and the fuel adhering to the inner surface of the casing 1 is removed by the apex seal 5 or the like in the trailing portion of the working chamber 6b during the expansion stroke. A large amount of unburned components remain after being scraped off, and these unburned components are also refluxed at the same time to improve combustion efficiency.

In addition, as shown by the chain line in Fig. 1, the casing 1
A through hole 16 and a valve body 1 are provided at the upper position on the intake and exhaust side of the
7 is provided, and the exhaust stroke working chamber 6 is opened when the engine is at low temperature.
c and the working chamber 6a for the suction stroke may be communicated through an apex seal 5.
In this case, the combustion gas in the leading part of the working chamber 6c in the exhaust stroke is transferred to the working chamber 6c in the intake stroke.
Since the flow is returned to the trailing portion of a and the pressure difference between the two is small, the opening area of the through hole 16 needs to be large.

On the other hand, in the above embodiment, the working chamber 6a of the suction stroke
The through holes 10 or 1 are arranged so as to recirculate the combustion gas from the working chambers 6b, 6c during the expansion or exhaust stroke.
6 is provided at a predetermined position, but after the rotor 4 in the rotational position shown in FIG. The combustion gas may be recirculated from the working chamber in the chamber to promote vaporization and atomization.

That is, although not shown, a communication passage that communicates the working chamber of the expansion stroke and the working chamber of the compression stroke is provided at a predetermined position below the through hole 10 on the explosion side of the casing 1, and this communication passage when the engine is at low temperature. A valve body that opens may be provided to allow combustion gas in the working chamber in the expansion stroke to flow back to the working chamber in the compression stroke.

Further, at a predetermined position above the through hole 16 on the intake and exhaust side of the casing 1, there is provided a communication passage that communicates the working chamber of the exhaust stroke and the working chamber of the compression stroke, and a valve body that opens this communication passage when the engine is at low temperature. established,
Combustion gas in the working chamber in the exhaust stroke may be returned to the working chamber in the compression stroke.

In this case, the pressure in the exhaust stroke working chamber is at a relatively low pressure state, approximately atmospheric pressure, so under high load conditions, blowback occurs from the compression stroke working chamber to the exhaust stroke operation. When the combustion gas is recirculated to the chamber, it is preferable to recirculate it from the working chamber in the expansion stroke rather than from the working chamber in the exhaust stroke.

In the above embodiment, the communication path is formed by a recess formed in the casing 1, but this communication path maintains a predetermined gap in the rotational direction of the rotor, and both ends thereof are formed on the inner surface of the casing. An open air passage may be formed in the casing 1, and a valve body that opens and closes depending on the engine temperature may be provided in the middle of this air passage.

As detailed above, according to the present invention, a recess is formed in the casing that communicates the working chamber in the expansion and exhaust stroke with the working chamber in the suction and compression stroke, and when the engine temperature is high, the volume of the recess increases. By providing a valve body that substantially eliminates this, when the engine is cold, high-temperature combustion gas in the working chamber in the expansion and exhaust stroke is recirculated through the recess into the working chamber in the intake compression stroke, thereby increasing the intake air-fuel mixture. In order to increase the temperature, vaporization and atomization of the fuel are promoted to improve the combustion state, and the temperature increase of the engine can be completed at an early stage. Furthermore, when the engine is at a high temperature, the volume of the recess is substantially eliminated by the valve body to prevent combustion gas from flowing back, thereby improving charging efficiency and reducing output loss.

[Brief explanation of the drawing]

The drawings illustrate embodiments of the present invention; FIG. 1 is a schematic sectional view of a rotary piston engine, and FIG. 2 is an enlarged sectional view of the same essential parts. 1...Casing, 2...Rotor housing,
2a...inner peripheral surface, 3...side housing, 4...
...Rotor, 5... Apex seal, 6a, 6
b, 6c... Working chamber, 10, 16... Through hole, 1
1, 17...valve body, 12...recess, 13...sliding body, 14...thermo pellet, 14a...operator, 15...spring.

Claims (1)

[Claims] 1. In a rotary piston engine in which a polygonal rotor rotates planetarily within a casing having a trochoidal inner peripheral surface, a working chamber for an expansion/exhaust stroke and a working chamber for an intake/compression stroke are communicated with the casing. At the same time, a valve body is provided in the recess to substantially eliminate the volume of the recess when the engine temperature is high, and combustion gas from the working chamber in the expansion and exhaust stroke is sucked through the recess when the engine is low. A rotary piston engine characterized by circulating air to the working chamber during the compression stroke.