JPH02528B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a housing structure for a rotary piston engine, and more particularly to a housing structure for a rotary piston engine in which a trochoidal inner peripheral surface is formed of a ceramic layer.

(Prior Art) Forming a ceramic layer on the trochoidal inner circumferential surface of the rotor housing of a rotary piston engine has conventionally been known, for example, as disclosed in Japanese Patent Application Laid-Open No. 59-153925.
It is publicly known as seen in the publication No. If this trochoidal inner circumferential surface is made of ceramic material, it is possible to reduce cooling loss due to the heat insulation effect and improve combustibility, and the ceramic material has excellent wear resistance, so vertical scratches may occur on the inner circumferential surface. It has the effect of eliminating the problem of

However, in the above-mentioned conventional device, coating the inner peripheral surface of the trochoidal shape with ceramic by thermal spraying to form a thick ceramic layer is time consuming and has the problem of poor productivity.

To solve this problem, a pre-formed ceramic member having a relatively thick trochoidal inner peripheral surface is fitted and fixed to a light metal member forming the outer peripheral part of the rotor housing.
The application was previously filed by the same applicant (Japanese Patent Application Laid-Open No. 1989-1999-
No. 147732).

However, in this case, since the ceramic member has a smaller coefficient of thermal expansion than the light metal member, there is a risk that a gap may be formed between the light metal member and the ceramic member during thermal expansion. In this case, the ceramic member can follow the thermal elongation of the light metal member in the radial direction to some extent due to the fitting force during housing molding, and the generation of gaps can be suppressed, but in the output axis direction, that is, It is not possible to suppress the occurrence of a gap between the ceramic member and the side housing. Therefore, the gap created between the ceramic member and the side housing becomes an unburned zone, which results in an increase in HC and CO emissions, deterioration in fuel efficiency, and loss of the compressed air-fuel mixture in the working chamber during the compression stroke. There is a problem in that the air blows through to other working chambers, resulting in a decrease in output.

(Object of the Invention) The present invention has been made in view of the above-mentioned conventional problems, and while maintaining the original function of the ceramic member, emissions due to the generation of gaps during thermal expansion of the rotor housing and deterioration of fuel consumption. Another object of the present invention is to provide a housing structure for a rotary piston engine that is highly practical and reliable and does not cause a decrease in output.

(Structure of the Invention) In order to achieve the above object, the present invention provides a rotary piston engine in which side housings and rotor housings are arranged alternately, the rotor housing being formed of a light metal member, and
A ceramic member having a trochoidal inner peripheral surface and approximately the same width as the rotor housing is fitted and fixed into the rotor housing, and when the engine is assembled, the end face of the side housing and the end face of the ceramic member An annular groove is formed along the inner circumferential surface of the trochoid in at least one of the areas where the two abut, and a sealing member is interposed in this annular groove. A rotor housing made of an alloy member and a ceramic member are elastically pressed together in the direction of the output shaft of the engine so as to close a gap caused by thermal expansion.

(Effects of the Invention) Since the present invention is constructed as described above, while maintaining the original function of the ceramic member, the ceramic member and the side housing which are generated during thermal expansion of the light metal member forming a part of the rotor housing By providing a sealing member that completely partitions the working chamber from the gap between the two, the air-fuel mixture is prevented from flowing into the gap, and it is possible to prevent emissions, deterioration of fuel efficiency, and reduction in output.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

1, 2, 3, and 4 show a first embodiment of the present invention, in which 1 is a rotor housing of a rotary piston engine, and the rotor housing 1 is a trochoidal engine. It is formed by shrink-fitting an aluminum alloy 1b as a light metal member located on the outer periphery of a ceramic member 1a having a shaped inner peripheral surface. In the aluminum alloy 1a forming the rotor housing 1, cooling water passages 2 and tension bolt holes 3 are formed during casting, as in the conventional case. Further, 4 is a side housing made of cast iron, and the side housing 4
An intake port 8 and a cooling water passage 5 are formed therein. Cooling water passage 2 of the rotor housing 1
The cooling water passage 5 of the side housing 4 and the cooling water passage 5 of the side housing 4 are sealed at their mating surfaces by an O-ring 6 made of fluorocarbon rubber or the like, as in the prior art.

Furthermore, 7 is the end face 1C of the ceramic member 1a.
The seal member 7 is interposed between the coil spring 7a and the side housing 4, and has excellent heat resistance to follow the thermal expansion of the aluminum alloy 1b. It is formed by wrapping a soft thin metal body 7b made of stainless steel, copper, etc., for heat protection, around the outer periphery of the body. The seal member 7 is attached to the rotor housing 4
In the fixed state, the ceramic member 1a is fitted into a trochoidal groove 4a formed in the side housing 4, and is clamped by the ceramic member 1a and the side housing 4. The groove 4a is formed at a position corresponding to the trochoidal inner peripheral surface of the ceramic member 1a, that is, at a position closest to the working chamber of the gap A generated when the aluminum alloy 1b thermally expands. prevents the mixture from entering.

In addition, in the first embodiment, the seal member 7
A coil spring 7a was used as a part of the
Anything that simply has an elastic function is fine;
Also, of the O-rings 6, the O-ring 6 on the side closer to the ceramic member 1a is eliminated, and the sealing member 7 is removed.
However, the cooling water may also be sealed.

Further, FIG. 5 shows a second embodiment of the present invention, in which the sealing member is made of a material having a larger coefficient of thermal expansion than the ceramic member 1a. Specifically, this sealing member 9 is Rotor housing 1
It is made of the same material as the aluminum alloy 1b.
Due to this, when the aluminum alloy 1b thermally expands,
Although a gap A is created between the ceramic member 1a and the side housing 4, the thermal expansion of the seal member 9 follows the thermal expansion of the aluminum alloy 1b, and the sealing function of the seal member 9 is fully demonstrated. can do.

As described above, the present invention prevents air-fuel mixture from flowing into the gap A created between the ceramic member 1a and the side housing 4 when the aluminum alloy 1b forming the outer periphery of the rotor housing 1 thermally expands. The gap A does not become an unburned zone, improving emission and fuel efficiency, and preventing a decrease in output due to the blow-through of the compressed air-fuel mixture in the compression working chamber to other working chambers.

In addition, in the first and second embodiments, the seal member 7,
9 is provided on a part of the side surface of the ceramic member 1a, but it may be provided on the entire side surface. Also, the first and second
In the embodiment, the seal members 7 and 9 are housed in the grooves 4a provided in the side housing 4, but they may also be housed in the grooves provided on the ceramic member 1a side or in both the side housing 4 and the ceramic member 1a. You may also do this.

[Brief explanation of drawings]

1, 2, 3, and 4 show a first embodiment of the present invention, in which FIG. 1 is an overall view of the rotor housing, FIG. 2 is a sectional view of main parts, FIG. 3 is a schematic diagram of the sealing member 7, and FIG. 4 is an enlarged sectional view of the main part showing the state of thermal expansion of the aluminum alloy 1a. Further, FIG. 5 is an enlarged cross-sectional view of a main part showing a second embodiment of the present invention. 1... Rotor housing, 1a... Ceramic member, 1b... Aluminum alloy (light metal member), 4...
...Side housing, 7, 9...Sealing member.

Claims (1)

[Claims] 1. A rotary piston engine in which side housings and rotor housings are arranged alternately, the rotor housing being formed of a light metal member and having a trochoidal inner peripheral surface,
A ceramic member having approximately the same width as the rotor housing is fitted and fixed into the rotor housing, and at least one of the end faces of the side housing and the end face of the ceramic member come into contact with each other when the engine is assembled. An annular groove is formed along the inner peripheral surface of the trochoid on one side, and a sealing member is interposed in the annular groove, and this sealing member is connected to the rotor housing formed of the light alloy member and the ceramic member. A housing structure for a rotary piston engine, characterized in that the housing structure is elastically pressed in the direction of the output shaft of the engine so as to close a gap caused by thermal expansion.