JPH0612203Y2 - Casing seal structure of rotary piston engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a casing seal structure for a rotary piston engine, and more particularly to an improvement of a sealing rubber.

(Prior Art) Conventionally, there is known a casing sealing structure of a rotary piston engine in which a sealing rubber groove is provided in a housing mating surface, and a sealing rubber is fitted in the groove to seal the housing mating surface. See, for example, Japanese Utility Model Laid-Open No. 60-81201).

On the other hand, there is a possibility that the durability and reliability of the sealing rubber may decrease due to the increase in the combustion pressure and the temperature of the combustion gas accompanying the increase in output in recent years. Similarly, there is a rubber body 60a provided with a synthetic resin layer 60b having excellent durability such as Teflon on the inside and outside. The method of molding the sealing rubber 60 is such that three layers of the rubber main body 60a and the two synthetic resin layers 60b are fastened with one end aligned and inevitably formed as shown in FIG.

However, in the above-mentioned one, since the four synthetic resin layers 60b are present in the joining portion 60d joined by the silicon-based joining rubber 60c, the ratio indicated by the rubber main body 60a or the joining rubber 60c is less than that. There is a problem that it becomes small and sufficient sealing performance cannot be ensured. By arranging the joint portion 60d on the intake side where the influence of combustion gas pressure is small, blow-by of combustion gas into the cooling water passage is prevented as much as possible. I was trying to do it. However, in order to increase the engine output, in the case of using a supercharger, the intake pressure rises, and it is meaningless to dispose the joint portion 60d on the intake side where the damage caused by the combustion gas is low. It is had.

In order to solve this problem, in order to increase the proportion of the rubber body 60a or the bonding rubber 60c in the joint 60d, the two layers of the synthetic resin layer 60b located on the joint surface side of the joint 60d are eliminated. However, there is a possibility that the strength of the joint portion 60d may be reduced, which may be disadvantageous (causing cutting) to the tensile load. Further, when the synthetic resin layer 60b is removed from the joint surface, the removed portion of the synthetic resin layer 60b varies due to the relationship of the molding method described above, and when the distance from the joint surface to the removed portion becomes long, the pressure There is a problem that the synthetic resin layer 60b peels off due to fluctuations or the like, or cracks occur with the removed portion as a base point.

(Object of the Invention) The present invention has been made in view of the above-mentioned problems of the related art. An object of the present invention is to provide a casing seal structure for a rotary piston engine, which is excellent in durability and durability.

(Structure of the Invention) In order to achieve the above object, the present invention connects one of the engagement protrusions forming the joint of the sealing rubber to one engagement protrusion from the stepped joint surface to the joint surface. Over the side surface to be provided with a removing portion without the synthetic resin layer,
A joining rubber is interposed between the removing portion and the other engaging projection portion, and an end portion of the joining rubber covers the outside of the removing portion located on the side surface connected to the one engaging projection portion and is combined. An extension portion extending to the resin layer is provided.

(Effect of the Invention) Since the present invention is configured as described above, among the synthetic resin layers located on the joint surface side of the joint portion of the sealing rubber,
By eliminating one, it is possible to prevent the strength of the joint from decreasing as much as possible, improve the sealing performance of the joint, and locate the end of the joining rubber on the side surface connected to the one engaging protrusion. By providing an extension that covers the outside of the removed portion and extends to the synthetic resin layer, peeling of the synthetic resin layer due to pressure fluctuations or the like, and cracks originating from the removed portion due to the peeling occur Can be prevented.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. The rotary piston engine 1 includes a rotor housing (not shown) having a trochoidal inner peripheral surface, side housings 2 arranged on both sides of the rotor housing, and a casing formed by both the housings, which performs a planetary rotational motion. 3 and 3. Further, the side housing 3 is provided with a plurality of cooling water passages 4 and tension bolt holes 5 corresponding to the rotor housing side. The cooling water passage 4 and the tension bolt hole 5 are located at a position sandwiched between them.
The outer sealing rubber groove 7 and the inner sealing rubber groove 8 in which the sealing rubber 6 shown in FIG. 2 is inserted and has a function of preventing the combustion gas from entering the inside and a function of preventing the leakage of the cooling water. Has been formed.

Among the sealing rubbers 6, the sealing rubber 6 fitted into the inner sealing rubber groove 8 has a synthetic resin layer 6b such as Teflon which is superior in heat resistance and durability on the inside and outside of the rubber body 6a. It is formed by coating. Further, as a method of molding the sealing rubber 6, a synthetic resin layer 6b is arranged at a position sandwiching the rubber body 6a, and one end thereof is wound together to perform a tightening process. It is molded by joining with.

Further, the outer engagement protrusion 6e and the inner engagement protrusion 6f forming the joint 6d are formed in a stepped shape, and the joining rubber 6c is interposed between the stepped portions and joined. There is. Then, in the range from the step-shaped joining surface of the outer engaging protrusion 6e to the side surface 6h connected to the joining surface, the removing portion 6g without the synthetic resin layer 6b is provided, and the joining rubber 6c is formed. The end portion is provided with an extension portion 6i which covers the removal portion 6g located on the side surface 6h of the outer engagement protrusion portion 6e and extends to the synthetic resin layer 6b.

With the above-described configuration, the synthetic resin layer 6b only on the side of the outer engagement protrusion 6e located on the joint surface side of the joint portion 6d of the sealing rubber 6 is eliminated, so that the rubber main body 6 is formed.
The ratio indicated by b becomes large, the decrease in strength of the joint 6d can be prevented as much as possible, the sealability of the joint 6d can be improved, and the outer engagement protrusion is provided at the end of the joint rubber 6C. By providing the extension 6i that extends to the synthetic resin layer 6b so as to cover the outside of the removed portion 6g located on the side surface 6h of 6e, the synthetic resin layer 6b is peeled off due to pressure fluctuation or the like, and It is possible to prevent the occurrence of cracks with the removed portion 6g as a base point.

In this embodiment, the synthetic resin layer 6b is located on the side of the working chamber, and the synthetic resin layer is relatively thick (because the combustion gas directly hits) on the joint surface side of the outer engagement protrusion 6e. Although 6b is eliminated, the inner engagement protrusion 6f side may be eliminated.

[Brief description of drawings]

FIG. 1 and FIG. 2 show this embodiment. FIG. 1 is an overall view of a rotary piston engine, and FIG. 2 is an enlarged view of a main part of a sealing rubber. Further, FIG. 3 is an enlarged view of a main part of a conventional sealing rubber. 6 ... Sealing rubber, 6b ... Synthetic resin layer, 6c ...
... Joining rubber, 6d ... Joining portion, 6e ... Outer engaging protrusion, 6f ... Inner engaging protrusion, 6g ... Removing portion, 6h ...
… Side, 6i …… extension, 7 …… outer sealing rubber groove, 8 …… inner sealing rubber groove.

Claims (1)

[Scope of utility model registration request] 1. A sealing rubber groove is provided on a housing mating surface, the inner side and the outer side corresponding to the side wall of the groove are covered with a synthetic resin layer, and the inner side and the outer side are alternately formed in a step shape and extended. A rotary piston engine in which a sealing rubber formed by joining a stepped portion between the outer engaging protrusion and the inner engaging protrusion that are joined together with a joining rubber is inserted to seal the housing mating surface. In the casing seal structure of the above, of the two engaging protrusions forming the joint of the sealing rubber, one of the engaging protrusions extends from the stepped joint surface to the side surface connected to the joint surface. In addition to providing a removal part that eliminates the resin layer,
A joining rubber is interposed between the removing portion and the other engaging projection portion, and an end portion of the joining rubber covers the outside of the removing portion located on the side surface connected to the one engaging projection portion and is combined. A casing seal structure for a rotary piston engine, which is provided with an extension portion extending to a resin layer.