JPS606604Y2 - Rotary piston engine ignition system - Google Patents

Description

[Detailed description of the invention] The present invention relates to the advance angle control of an ignition system for a rotary piston engine, particularly a two-plug type ignition system in which spark plugs are arranged on the leading side and the trailing side, respectively, across the short axis of the trochoid. It is something.

Conventionally, in rotary piston engines, a leading side spark plug (hereinafter simply referred to as an L plug) is used.

), there is also a spark plug (hereinafter simply referred to as a T plug) on the trailing side to assist in ignition.

), and while the ignition timing is substantially controlled by the L plug,
T improves the ignitability and combustibility of the mixture, which is insufficient with L plugs alone.
I am trying to compensate with a plug (for example, in the Utility Model Showa 50-
(See Publication No. 42132-W).

By the way, the T plug is exposed to combustion gas for a longer time than the L plug, and the thermal load is large, causing pre-ignition under high load conditions, so the ignition timing of the T plug is
These L plugs need to be delayed compared to plugs,
In the case where the ignition timing of the T plug is controlled by a vacuum advance control device operated by negative pressure immediately upstream of the throttle valve,
S゛A vacuum advance angle control device having the same advance angle characteristic is provided for each of the L plug and T plug distributors, and the T side distributor is retarded by a preset angle with respect to the L side distributor. I am trying to set it initially.

Therefore, even when the engine is idling, the ignition of the T plug is controlled to be delayed by a set angle with respect to the L plug.

However, when the engine is idling, the heat load on the T plug is low and the T plug is easily contaminated with carbon etc., which impairs ignitability. It is rather preferable to stabilize the ignitability during idling by increasing the temperature and preventing its fouling.

This invention was made based on such a request, and
An object of the present invention is to provide an ignition device for a rotary piston engine that can set the ignition timing of a T plug to be the same as that of an L plug when the engine is idling.

Therefore, in the present invention, the vacuum advance angle control device that controls the ignition advance angle of the L plug is located upstream of the throttle valve when it is fully closed, and downstream of the throttle valve when it is opened beyond the set opening. On the other hand, the vacuum advance angle control device that controls the ignition advance angle of the T plug is always located in the intake passage downstream of the throttle valve. At the same time, when the engine is idling, atmospheric air is introduced through the relief passage to dilute the intake negative pressure downstream of the throttle valve. The basic feature is that the ignition timing of the T plug and the ignition timing of the L plug are made to be the same timing as S by acting on the side vacuum advance angle control device.

Hereinafter, the present invention will be described in more detail with reference to the illustrated embodiments.

In Fig. 1, 1 is a casing consisting of a rotor housing having a trochoidal inner circumferential surface and side housings arranged on both sides of the rotor housing, and 2 is a casing that rotates around an eccentric shaft 3 with its top edge slidingly in contact with the trochoidal inner circumferential surface. a triangular rotor that rotates planetarily; 4 an intake passage communicating with an intake port 5;
6 is the L plug placed on the leading side of the trochoid short axis, and 7 is the T plug placed on the trailing side of the trochoid short axis.
The plug 8 is an exhaust port, and these constitute a rotary piston engine that continuously repeats intake, compression, explosion, expansion, and exhaust strokes in accordance with the planetary rotational motion of the rotor 2.

On the other hand, in 10, the primary side is the ignition switch IgSw
Similarly, 11 is the ignition coil of the T-plug 7 connected to the battery 23 via the ignition switch IgSwA, and 12 is the ignition coil of the L-side ignition coil. 10 is a distributor having a well-known structure, 13 is an L-side vacuum advance device consisting of a diaphragm device that controls the opening/closing timing of the L-side distributor 12, and 14 is a T-side vacuum advance device.
A distributor 15 having a well-known structure provided for the side ignition coil 11 is a diaphragm type T-side vacuum advance angle control device that controls the opening/closing timing of the T-side distributor 14.

Note that the initial setting of the ignition timing of the L side distributor 12 is an advance angle of 0 degrees, and the ignition timing of the T side distributor 1 is set to zero degrees.
The initial setting of the ignition timing in No. 4 is set to 15 degrees behind the L side distributor.

The negative pressure chamber 13a of the above-mentioned side vacuum advance angle control device 13 is located upstream of the throttle valve 9 provided in the intake passage 4 when the throttle valve 9 is fully closed, and is located upstream of the throttle valve 9 provided in the intake passage 4 when the throttle valve 9 is opened beyond the set opening degree. It communicates with the first negative pressure outlet 16 opened downstream through a communication passage 17, and the advance angle is zero when the throttle valve is fully closed and when the throttle valve is fully open, when atmospheric pressure acts on the first negative pressure outlet 16. Therefore, the throttle valve 9
When the valve is at an intermediate opening between fully closed and fully open, the ignition timing of the L plug 6 is advanced in accordance with the value of the intake negative pressure.

On the other hand, the negative pressure chamber 15a of the T-side vacuum advance angle control device 15 communicates with a second negative pressure outlet 18 provided in the intake passage 4 downstream of the throttle valve 9 through a communication passage 19. The ignition timing of the T plug 7 is advanced by a set value delayed compared to the ignition timing of the L plug 6 by the downstream intake negative pressure.

As shown in FIG. 1, a communication passage 19 introduces the intake negative pressure downstream of the throttle valve 9 into the negative pressure chamber 15a of the T-side vacuum advance angle control device 15.
A relief passage 20 having one end 20a open to the atmosphere and having an orifice 20b in the middle is communicated with the relief passage 20, and one end opening 20a of this relief passage 20 is provided with a solenoid valve 21 for opening and closing the solenoid valve 21. The opening and closing of the valve 21 is controlled by an idle switch 22 connected to a battery 23.

The relief passage 20 dilutes the intake negative pressure acting on the second negative pressure outlet 18 when the engine is idling, so that the pressure in the negative pressure chamber 15a of the T-side vacuum advance control device 15 is lower than the pressure in the intake passage. By setting the value to be high and lower than the atmospheric pressure, the ignition advance angle of the T plug 7 is advanced by a set value from the initial setting and made equal to the ignition advance angle of the L plug 6.

In other words, when the engine is idling, the thermal load on the T plug 7 is low, so the ignition timing of the T plug 7 is set to L.
This is because, rather than delaying the timing compared to the plug 6, it is preferable to set the timing S to be the same as that of the L plug 6, thereby increasing the temperature of the T plug 7 and preventing its fouling, thereby improving the ignitability during idling.

Next, ignition advance angle control of the ignition device of the rotary piston engine will be explained.

(I) When the engine is idling, the throttle valve 9 is fully closed, and the first negative pressure outlet 16 is located upstream of the throttle valve 9, so that the negative pressure of the L side vacuum advance device 13 is Atmospheric pressure acts on the chamber 13a, and the L-side vacuum advance device 13 holds the L-side distributor 12 at an advance angle of zero (initial setting), and as shown by point A1 in FIG. Set the timing to the regular ignition timing.

On the other hand, when the engine is idling, the throttle valve 9 is fully open and the idle switch 22 is turned on, so the solenoid valve 21 is connected to the battery 23 and the T
Relief passage 2 provided for side vacuum advance angle control device 15
0 to the atmosphere.

Therefore, the intake negative pressure acting on the second negative pressure outlet 1B provided downstream of the throttle valve 9 is diluted in the communication passage 19 by the atmospheric pressure introduced via the relief passage 20, and the T-side vacuum advance angle control is performed. The negative pressure chamber 15a of the device 15 has a relatively low negative pressure.

Therefore, as shown by point B in FIG. The ignition timing is set to be equal to S.

That is, when the engine is idling, the L plug 6
The T-plug 7 and the T-plug 7 are ignited at the same timing, and the T-plug 7 is exposed to the combustion gas for a longer period of time, increasing its temperature, so that the T-plug 7 is reliably prevented from becoming contaminated.
The ignitability during idling can be stabilized.

(II) At partial load When the engine is at partial load, the throttle valve 9 is opened according to the load at that time, and as a result, the intake negative pressure downstream of the throttle valve 9 acts on the first negative pressure outlet 16, and the L side vacuum The intake negative pressure is introduced into the negative pressure chamber 13a of the advance angle control device 13 via the communication passage 17, and the L side vacuum advance angle control device 13 operates as shown in FIG. As shown by the arrow or A3, when the intake negative pressure is, for example, 250 mmHg or more, the ignition advance angle of the L plug 6 is controlled via the L side distributor 12 so as to advance the ignition angle by about 30 degrees.

On the other hand, when the engine is operating at a partial load, the idle switch 22 is turned off and the relief passage 20 is closed to the atmosphere by the Tsuremade valve 21.
The intake negative pressure downstream of the throttle valve 9 directly passes through the communication passage 19 to T.
When the intake negative pressure is introduced into the negative pressure chamber 15a of the side vacuum advance angle control device 15 and is larger than the negative pressure acting on the negative pressure chamber 15a during idling, the T plug 7 is advanced with respect to the normal ignition timing of the L plug 6, and when it is small, is relatively retarded as shown by arrow B3, and as a whole, the T plug 7 is set at the required angle with respect to the L plug 6. The advance angle is controlled to have a delay of .

(III) When the throttle valve is fully open During high load operation of the engine, when the throttle valve 9 is fully open, the first negative pressure outlet 16 and the second negative pressure outlet 18 are fully opened.
Atmospheric pressure acts on both.

Therefore, the negative pressure chamber 13a of the L-side vacuum advance angle control device 13 becomes atmospheric pressure, and therefore the L plug 6 is ignited at the regular ignition timing A1, as in the case of idling.

On the other hand, when atmospheric pressure acts on the negative pressure chamber 15a of the T-side vacuum advance control device 15, the lower vacuum advance control device 15 sets the T-side distributor 14 to the retard side, and as shown in FIG.
As shown, the T plug 7 is maintained at an ignition advance angle that is retarded by a set angle with respect to the normal ignition timing of the L plug 6.

As is clear from the above explanation, the ignition system for a rotary piston engine according to the present invention always synchronizes the ignition timing of the T plug with a set delay with respect to the L plug, and also synchronizes the ignition timing of the T plug with a set delay when the engine is idling. This feature is characterized in that it is made to be around the same time as the L plug.

According to the ignition device for a rotary piston engine according to the present invention, both T plugs can be ignited at the same time when the engine is idling, thereby preventing contamination of the T plug during idling. Can improve the ignitability and stability of the plug,
As a result, it is possible to improve drivability and exhaust performance.

[Brief explanation of the drawing]

Fig. 1 is an overall schematic explanatory diagram showing an embodiment of the ignition system for a rotary piston engine according to the present invention, and Fig. 2 is a graph showing the ignition advance angle control characteristics of the L plug and T plug by the ignition system shown in Fig. 1. It is. 1...Casing, 2...Rotor, 6
...L plug, 7...T plug, 12
...L side distributor, 13...
・L side vacuum advance angle control device, 14...T side distributor, 15...T side vacuum advance angle control device, 16...First negative pressure outlet, 17・・・・・・
Communication path, 18...Second negative pressure outlet, 19...
...Communication passage, 20...Relief passage, 21.
... Solenoid valve, 22 ... Idle switch.

Claims (1)

[Scope of utility model registration request] In an ignition system for a low-repetition piston engine that has spark plugs on both the leading and trailing sides across the short shaft, the ignition timing of the trailing side plug when the throttle valve is fully opened is delayed by a set value compared to the leading side plug. , a pressure conduit is provided that applies the pressure immediately upstream of the throttle valve in the fully open state to the vacuum advance device that controls the advance angle of the leading side spark plug, while the vacuum advance device that controls the advance angle of the trailing side spark plug is provided. In addition to providing a negative pressure conduit that applies negative intake pressure downstream of the throttle valve to the device, a relief passage is also provided to remove the negative intake pressure that acts on the trailing side vacuum advance device when the engine is idling. An ignition system for a rotary piston engine, characterized in that the ignition timing of the trailing side spark plug is equal to the ignition timing of the leading side spark plug.