JPH0658164A - Rotary piston engine - Google Patents

Abstract

PURPOSE:To greatly improve the scavenging efficiency and improve emission by preventing air-fuel mixture from blowing through an operation chamber on the leading side to an operation chamber on the trailing side. CONSTITUTION:A rotary piston engine comprises a casing 1 comprising a rotary housing 2 having a trochoidal inner peripheral surface and a side housing 3, a rotor 4 effecting planetary rotational movement in the casing 1, one set each of exhaust gas ports 9 and 10 and scavenging ports 11 and 12 arranged on both sides between which a trochoidal short shaft X is nipped and opened and closed by means of the rotor, ignition plugs 7L, 7T, 8L, and 8T arranged on the respective two end sides of the trochoidal short shaft X, two combustion chambers formed corresponding to the respective ignition plugs, and a supercharging means to supercharge intake air. Each scavenging port is set to a peripheral port and meanwhile each exhaust gas port is set to a side port. The forming position of the scavenging port is set to a position where the scavenging port is closed and the opening timing of the exhaust gas port is set such that the opening timing comes after an apex seal 6 passes through the scavenging port.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides, for example, a leading side spark plug and a trailing side spark plug at both ends of a trochoidal short shaft to form two combustion chambers per cylinder to form one revolution of an eccentric shaft. It relates to a two-cycle rotary piston engine that explodes twice.

[0002]

2. Description of the Related Art Conventionally, a rotary piston engine having two cycles of operation is disclosed, for example, in Japanese Patent Laid-Open No. 1-1.
There is an engine described in Japanese Patent No. 51720. That is,
As shown in FIG. 8, a casing 83 composed of a rotor housing 81 having an inner peripheral surface formed in a trochoid shape and side housings 82, 82 (only one of which is shown in FIG. 8) located on both sides of the rotor housing 81. A rotor 84 that makes a planetary rotational movement in the casing 83; a leading side ignition plug 85L and a trailing side ignition plug 85T, which are provided at both ends of the trochoid short axis X.
Exhaust gas opened and closed by the rotor 84 provided on the other side with the leading side ignition plug 86L, the trailing side ignition plug 86T, two combustion chambers per cylinder, and one set on each side sandwiching the trochoid short axis X described above. Ports 87, 8
8 and scavenging ports 89, 90, and configured so that the two-cycle operation is performed twice for each rotation of the rotor 84 in each working chamber, which is different from the conventional four-cycle rotary piston engine. This is a rotary piston engine with improved output per cylinder.

In FIG. 8, 91 is an air cleaner,
Reference numeral 92 is an air flow meter, 93 is a throttle valve, 94 is a supercharger, 95 is an intercooler, 96 is an intake passage, 97 is an exhaust passage, 98 is a catalytic converter, 99 is an injector, and 100 is an eccentric shaft.

In such a two-cycle rotary piston engine, as shown in FIG.
If both 88 and the scavenging ports 89, 90 are set as side ports (side holes), the ports 87, 88, 89, 90 will be affected by the number of explosions, the outer shell of the rotor 84, the rotation trajectory of the oil seal, etc. Since the opening shape is restricted and the degree of freedom of the shape is small, the sweep exhaust port has a large overlap amount as shown in FIG.

The above-mentioned scavenging ports 89 and 90 are ports for scavenging burnt gas by inhaling supercharged intake air (scavenging air). If the overlap amount is large as described above,
Since the scavenging ports 89, 90 are closed immediately after the scavenging ports 87, 88 are closed by the rotation of the rotor 84, both ends on the leading side and the trailing side in the working chamber are closed. The burned gas is liable to remain, the scavenging effect becomes insufficient, and there is a problem that a sufficiently high output cannot be obtained.

[0006]

DISCLOSURE OF THE INVENTION The present invention prevents emission of air-fuel mixture from the working chamber on the leading side to the working chamber on the trailing side, while significantly improving scavenging efficiency to improve emission. An object of the present invention is to provide a rotary piston engine that can be driven.

[0007]

According to the present invention, a casing composed of a rotor housing having an inner peripheral surface formed in a trochoid shape and side housings located on both sides of the rotor housing, and a planetary rotation motion in the casing. Corresponding to the rotor, an exhaust port and a scavenging port that are provided on both sides of the trochoid short shaft and are opened and closed by the rotor, spark plugs respectively provided on both ends of the trochoid short shaft, and the spark plug Is a rotary piston engine having two combustion chambers formed as described above and a supercharging means for supercharging intake air, wherein each scavenging port is set as a peripheral port and each exhaust port is set as a side port. Setting, the scavenging port formation position is set to a position where the port is closed before ignition, and the exhaust port opening timing is set. The grayed, wherein the apex seal is rotary piston engine was set to be after passing through the scavenging port.

[0008]

According to the present invention, the formation position of the scavenging port of the peripheral port structure is set to a position where the port is closed (the working chamber on the compression side is blocked from the port) before ignition. The working chamber on the leading side (compression side) and the working chamber on the trailing side (expansion side) are closed by an apex seal, so that the air-fuel mixture blows from the working chamber on the leading side to the working chamber on the trailing side. Can be reliably prevented.

Further, since the opening timing of the exhaust port of the side port structure is set to be after the apex seal has passed through the scavenging port, pressure rise due to ignition in the working chamber on the leading side (compression side) and trailing When blowdown (pressure reduction) is performed in the side working chamber by exhaust gas, both working chambers are closed by the apex seal, so that the pressure balance between the two working chambers is not greatly disturbed.

Moreover, at the start of scavenging, the scavenging port is located on the leading side of the rotor in the above-mentioned working chamber on the expansion side, and the burned gas on the leading side in this working chamber can be scavenged efficiently and the same operation can be performed. Since the burnt gas on the trailing side in the room is agitated by the scavenging air and flows out from the exhaust port, there is an effect that the scavenging efficiency can be greatly improved and the emission can be improved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. The drawing shows a two-cycle rotary piston engine. In FIG. 1, a casing 1 of the rotary piston engine includes a rotor housing 2 having a peritrochoidal inner peripheral surface of two sections, and both side portions of the rotor housing 2. Positioned side housings 3, 3 (however,
In the drawings, only one is shown).

A substantially triangular rotor 4 is provided in the casing 1 described above, the rotor 4 is supported by an eccentric shaft 5, and an apex seal 6 (see FIG. 2) at each apex of the triangular shape is provided in the rotor housing. Two
The three working chambers a, b, and c are formed between the rotor 4 and the inner surface of the casing 1 so as to expand and contract with the rotation of the rotor 4 while keeping a sliding contact with the inner peripheral surface of the rotor 1. .

A pair of spark plugs are attached to the rotor housing 2 at positions corresponding to both ends of the trochoid short axis X, respectively. That is, in the drawing of the trochoid short axis X, the leading side ignition plug 7L is attached to the leading side on the right side, and the trailing side ignition plug 7T is attached to the driven side, and the leading side ignition plug is attached to the left side of the leading side on the drawing of the trochoid short axis X. The trailing side ignition plug 8T is attached to the driven side of the plug 8L to form two combustion chambers C1 and C2 (see FIGS. 2 and 5) per cylinder.

Further, a pair of exhaust ports 9 and 10 and scavenging ports 11 and 12 are formed on both sides (the upper side and the lower side in the drawing) of the trochoid minor axis X of the casing 1 described above. Here, the scavenging ports 11 and 12 described above
Are set to peripheral ports (peripheral holes) formed in the rotor housing 2, and the exhaust ports 9 and 10 described above are set to side ports (side holes) formed in the side housing 3 to set exhaust ports of each set. 9, 10, scavenging port 11,
12 are arranged symmetrically with respect to the center of the eccentric shaft 5, and these ports 9 to 12 are opened and closed by the rotor 4 and the apex seal 6.

Moreover, the above-mentioned scavenging port 11 has a pressure in the working chamber b on the leading side (compression side) and a pressure on the trailing side (expansion side) working chamber a as shown in FIG. It is formed around the timing of pressure balance. That is, the change of the in-cylinder pressure P with respect to the eccentric shaft rotation angle θ of the three working chambers a, b and c is shown in FIG.
Eccentric shaft rotation angle θ
Is equal to the pressure on the expansion side (see the solid line in FIG. 7) and the pressure on the compression side (see the dotted line in FIG. 7) at a position of about minus 45 degrees shown in FIG. The state of the predetermined eccentric shaft rotation angle at which both the pressures are equal corresponds to FIG.

In addition, the formation position of the above-mentioned scavenging port 11 is set to a position where the port 11 is closed (the compression side working chamber b and the port 11 are blocked) before ignition, as shown in FIG. Along with the opening timing of the exhaust port 9,
As shown in the figure, the apex seal 6 is the scavenging port 11.
It is set to be after passing through.

In the above description, only the upper ports 9 and 11 separated by the trochoid minor axis X are described, but below the trochoid minor axis X symmetrically arranged with respect to the center of the eccentric shaft 5. Each port 1
The same applies to 0 and 12.

That is, at the position where the eccentric shaft rotation angle θ is about plus 135 degrees shown in FIG. 7, the pressure on the expansion side (see the dotted line in FIG. 7) and the pressure on the compression side (see the phantom line in FIG. 7) are equal. The scavenging port 12 is formed so that the apex seal 6 is located at the center of the scavenging port 12 under the condition of the predetermined eccentric shaft rotation angle where both the pressures are equal, and in addition, the formation position of the scavenging port 12 described above. Is set to a position where the port 12 is closed (the working chamber c on the compression side is blocked from the port 12) before ignition, and the opening timing of the exhaust port 10 is set to the scavenging port 12 by the apex seal 6. It is set to be after passing.

By the way, as shown in FIG. 1, the exhaust passages 13 and 14 connected to the exhaust ports 9 and 10 are connected to
An exhaust system is formed by assembling at the collecting portion 15 and providing a catalytic converter 17 in the collecting exhaust passage 16 connected to the collecting portion 15.

On the other hand, in the intake system, an air flow meter 20 is provided downstream of the element 19 of the air cleaner 18, and the downstream side of the air flow meter 20 is connected to the throttle body 21 and the inlet port 23 of the supercharger 22, and the throttle body is connected. A throttle valve 24 is provided inside 21, and an intercooler 26 is connected to the supercharging pressure outlet 25 of the supercharger 22. Further, the throttle valve 24 downstream side of the throttle body 21 and the outlet portion of the intercooler 26 are connected. Are joined at a confluence point 27 and connected to an intake passage 28, and this intake passage 28 is branched into two intake passages 30 and 31 at a branch point 29, and these intake passages 30 and 31 are connected to the above-mentioned scavenging port 11, 12, and injectors 32 and 33 as fuel injection means are provided near these scavenging ports 11 and 12, respectively. Wearing.

In addition, check valves 34 and 35, which allow the scavenging air to be supplied only from the intake passages 30 and 31 side to the working chamber side, are attached to the above-mentioned scavenging ports 11 and 12, respectively, so that the cylinder pressure becomes excessive. When the pressure becomes higher than the supply pressure (scavenging pressure), the mixture and the exhaust gas are configured to be prevented from returning to the intake system. In the figure, Y is the trochoid major axis, and the rotation direction of the rotor 4 is clockwise in the drawing.

The illustrated embodiment is configured as described above, and the operation will be described below. The spark plugs 8L and 8T are ignited at the position of the eccentric shaft rotation angle θ = −180 ° (see FIG. 2) shown in FIG. 7, and an explosion occurs in the combustion chamber C2. After the ignition and explosion, when the eccentric shaft 5 rotates about 135 degrees, the rotor 4 changes from the state shown in FIG. 2 to the state shown in FIG.

That is, the apex seal 6 is located at the center of the scavenging port 11 and the working chamber a on the expansion side and the working chamber b on the compression side are in communication with each other via the scavenging port 11. The state shown in FIG. 3 corresponds to the position of the eccentric shaft rotation angle θ = −45 ° in FIG.
Since the pressure difference of b is small or equal, spits back and spits forward do not occur, and blowback of burnt gas to the intake system can be reliably prevented by the check valve 34.

When the rotor 4 rotates from the state shown in FIG. 3 by a predetermined rotation angle of the exhaust shaft, it becomes as shown in FIG. That is, before the ignition of the air-fuel mixture in the working chamber b shown in the figure, in other words, before the ignition of the ignition plungers 7L and 7T, the scavenging port 11 is surely closed (the working chamber b on the compression side and the port 11 are closed). Shut off). Therefore, it is possible to reliably prevent the air-fuel mixture in the working chamber b on the compression side from blowing through to the working chamber a on the expansion side.

The state shown in FIG. 4 is a state in which the scavenging port 11 is completely opened when viewed from the working chamber a on the expansion side, and when the rotor 4 further rotates from the state shown in FIG. 4, the exhaust port 9 opens. start. That is, the above-mentioned opening timing of the exhaust port 9 is after the apex seal 6 has passed through the scavenging port 11, and therefore the pressure balance between the working chambers a and b is not greatly disturbed.

In this way, when the above-mentioned exhaust port 9 is opened, blowdown occurs, and scavenging is started when the pressure in the working chamber a falls below the scavenging pressure. At the start of this scavenging, since the apex seal 6 described above has just passed through the scavenging port 11, the scavenging port 11 is located on the leading side of the rotor 4 in the working chamber a. Therefore, the burned gas on the leading side in the working chamber a can be efficiently scavenged, and the burned gas on the trailing side in the working chamber a is agitated by the scavenging air supplied from the scavenging port 11, It flows out from the exhaust port 9.
As a result, burned gas does not remain at both ends of the leading side and the trailing side in the working chamber a, and the scavenging efficiency can be greatly improved.

When the rotor 4 rotates from the state shown in FIG. 4 to the compression top (corresponding to TDC in FIG. 7) as shown in FIG. 5, the spark plugs 7L, 7T are ignited and the combustion chamber While the explosion occurs at C1, after the exhaust port 9 is completely closed as shown in FIG. 6, the cylinder pressure in the working chamber b in FIG. Even when the boost pressure is higher than
The check valve 34 described above can reliably prevent the air-fuel mixture from being blown back into the intake system.

In summary, each scavenging port 11, 12 is set as a peripheral port, each exhaust port 9, 10 is set as a side port, and each of these ports 9-1 is set.
Since the formation position and the opening / closing timing of 2 are specified, there is an effect that the emission efficiency can be improved by significantly improving the scavenging efficiency while preventing the air-fuel mixture and the burnt gas from being blown through in the entire operation region.

In the correspondence between the structure of the present invention and the above-described embodiment, the spark plug of the present invention is the spark plugs 7L and 8L on the leading side and the spark plug 7 on the trailing side.
Corresponding to T, 8T, and so on, the supercharging means is similar to the supercharger 2
However, the present invention is not limited to the configuration of the above-described embodiment.

For example, the structure of the spark plugs provided at both ends of the trochoid short axis X may be a four spark plug structure, and a total of three spark plugs on the leading side, the trailing side, and the far trailing side. Simultaneously ignite 3
It may have a spark plug structure.

[Brief description of drawings]

FIG. 1 is a system diagram showing a two-cycle rotary piston engine of the present invention.

FIG. 2 is an explanatory view showing an explosion stroke in a combustion chamber on one side.

FIG. 3 is an explanatory view showing a pressure balanced state between the expansion side working chamber and the compression side working chamber.

FIG. 4 is an explanatory diagram showing a state before ignition.

FIG. 5 is an explanatory diagram showing an explosion stroke in the combustion chamber on the other side.

FIG. 6 is an explanatory view showing a closed state of an exhaust port.

FIG. 7 is a characteristic diagram showing a change in in-cylinder pressure with respect to an eccentric shaft rotation angle.

FIG. 8 is a system diagram showing a conventional two-cycle rotary piston engine.

[Explanation of symbols]

 1 ... Casing 2 ... Rotor housing 3 ... Side housing 4 ... Rotor 6 ... Apex seal 7L, 7T, 8L, 8T ... Spark plug 9, 10 ... Exhaust port 11, 12 ... Scavenging port 22 ... Supercharger C1, C2 ... Combustion Chamber X ... Trochoid short axis

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Eiji Takano 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Motor Corporation

Claims (1)

[Claims] 1. A casing comprising a rotor housing having an inner peripheral surface formed in a trochoid shape and side housings located on both sides of the rotor housing, a rotor for planetary rotation in the casing, and a trochoid minor axis sandwiched between the rotor housing. 1 on both sides
An exhaust port and a scavenging port, which are provided for each set and opened and closed by the rotor, spark plugs respectively provided on both ends of the trochoid short shaft, two combustion chambers formed corresponding to the spark plug, and intake air A rotary piston engine having a supercharging means for supercharging, wherein each of the scavenging ports is set to a peripheral port, each of the exhaust ports is set to a side port, and the formation position of the scavenging port is set before ignition. A rotary piston engine in which the port is set to a position to be closed and the opening timing of the exhaust port is set after the apex seal passes through the scavenging port.