JPH06280730A - Ignition device for engine - Google Patents

Abstract

PURPOSE:To prevent generation of delay angle resonance by retarding only ignition timing of one side spark plug of a plurality of the spark plugs at the time of retarding ignition under a prescribed operating condition. CONSTITUTION:In an ignition device for an engine comprising at least two spark plugs P3, P4 provided in a combustion chamber P2 and a combustion chamber constitutional wall P6 formed with a throttle part P5 for throttling communication between at least the two spark plugs P3, P4 in the combustion chamber P2 at top dead center time of a piston P1, an operation condition detecting means P7 for detecting a prescribed operation condition of the engine, such as requesting a retard of ignition timing, is provided. A delay angle means P8 for retarding only ignition timing of the one side spark plug P3 of at least the two spark plugs P3, P4, when the ignition timing is retarded in the prescribed operation condition detected by the operation condition detecting means P7, is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is provided with a combustion chamber forming wall having a throttle portion for restricting communication between at least two spark plugs in a combustion chamber at the top dead center of a piston (including a rotor of a rotary piston engine). Ignition device for such an engine.

[0002]

2. Description of the Related Art Heretofore, as an engine ignition device of the above-mentioned example, there are, for example, a device described in Japanese Patent Laid-Open No. 63-235625 and a device described in Japanese Patent Laid-Open No. 3-117684. As shown in FIG. 7, the former one disclosed in Japanese Patent Laid-Open No. 63-235625 has spark plugs 72L and 7L on the leading side and the trailing side of the combustion chamber 71, respectively.
In a rotary piston engine having 2T, the leading side ignition plug 72L and the trailing side ignition plug 72T in the combustion chamber 71 are arranged at the piston top dead center (the top dead center of the rotor 73 in the state of FIG. 7). It is provided with a combustion chamber constituting wall (rotor housing 75) in which a narrowed portion 74 for narrowing communication between them is formed. In FIG. 7, X is the trochoid short axis and Y is the trochoid long axis.

In the latter one disclosed in Japanese Patent Laid-Open No. 3-117768, a plurality of spark plugs are arranged at intervals around the circumference of a cylinder in a reciprocating engine to ensure uniformity of flame propagation. It is a peripheral multi-point ignition device in a reciprocating engine.

However, as described above, in the engine in which the throttle portion that narrows the communication between the two spark plugs in the combustion chamber at the top dead center of the piston is formed, the retarded resonance (resonance on the retarded side) occurs at the ignition retard. There was a problem that occurred.

The above problems will be described in more detail with reference to FIGS. 8 to 16, taking a rotary piston engine as an example. Generally, the ignition timing of the rotary piston engine is set so that the engine efficiency is the best. That is, as shown in FIGS. 8 and 9, the flame propagation speed is increased and the increase rate dp / dθ of the pressure in the combustion chamber 71 is set large in order to maximize the engine efficiency. When the pressure increase rate dp / dθ is set to a large value, a rapid pressure increase occurs and the end gas burns at once, which is extremely disadvantageous for knocking. In the figure, t1 indicates time.

Therefore, conventionally, the ignition timing between the leading spark plug (main spark plug) 72L and the trailing spark plug (sub spark plug) 72T in the rotary piston engine has a phase difference timing as shown in FIGS. By setting it, the rate of increase dp / dθ of the pressure in the combustion chamber 71 is set to be slightly small, and a countermeasure against knocking is generally taken. In the figure, t2 indicates time, and t2> t1.

Therefore, the leading-side spark plug 72L is first ignited at an ignition timing having a phase difference timing, and the trailing-side spark plug 72T is ignited after the phase difference timing has passed. When rotated to the position shown in FIG. 12, the leading side ignition plug 72L is formed in the minimum volume portion (see the throttle portion 74) formed by both the position of the rotor 73 and the shape of the combustion chamber 71.
When the flame propagation from the vehicle and the flame propagation from the trailing side ignition plug 72T arrive at the same timing, a local pressure increase occurs in this minimum volume part, and this pressure wave is transmitted to the combustion chamber 71 slowly. Angular resonance occurs, and the P-θ diagram of this retarded resonance becomes as shown in FIG. 13, which is substantially the same as the P-θ diagram of knocking shown in FIG. 14. Here, P is the pressure in the combustion chamber, and θ is the rotation angle.

Further, since the resonance levels with respect to the frequencies of the above-mentioned retarded resonance and knocking are substantially equal as shown in FIG. 15, the knock sensor for detecting vibration erroneously determines the retarded resonance as knocking.

Generally, in a conventional engine, when knocking occurs, a means for lowering the resonance level of knocking is taken by retarding the ignition timings of both spark plugs together as shown in FIG. When the above-mentioned retarded resonance occurs in the state where the ignition has not occurred, if the retarded resonance is erroneously determined as knocking and the ignition timing is retarded, the initial ignition start approaches the top period, so Since the narrowed portion 74 (see FIG. 12) is further narrowed and the squish area is narrowed, the resonance level of the retarded angle resonance is further increased. For this reason, in the conventional engine ignition device, the ignition timing retard, the resonance level increase of the retardation resonance, and the vicious cycle of the ignition timing retard are repeated due to the misjudgment of the retardation resonance as knocking. Has a problem that the power down control is undesirably executed.

[0010]

SUMMARY OF THE INVENTION The invention according to claim 1 (first invention) of the present invention is to set only the ignition timing of one ignition plug of a plurality of ignition plugs at the time of ignition retard under a predetermined operating condition. An object of the present invention is to provide an engine ignition device that can prevent retarded angle resonance from occurring by retarding.

According to the second aspect of the present invention, in addition to the object of the first aspect of the invention, only the ignition timing of the ignition plug on one side of the plurality of ignition plugs at the time of ignition retard under knocking condition. It is an object of the present invention to provide an engine ignition device capable of preventing the occurrence of retarded angle resonance by retarding.

According to a third aspect of the present invention (the second invention), the ignition timing of one spark plug is retarded so that the total ignition timing is retarded when knocking is detected, and the spark plug of the other spark plug is retarded. An object of the present invention is to provide an engine ignition device that can prevent the occurrence of retarded resonance while controlling knocking by advancing the ignition timing.

The invention according to claim 4 of the present invention has the object of the invention according to claim 1, 2 or 3 above, and at the time of ignition retard under a predetermined operating condition, ignition timing is retarded on one side. An object of the present invention is to provide an engine ignition device that can prevent knocking more reliably by setting the plug as a main ignition plug having a large combustion contribution.

According to the invention of claim 5 of the present invention, in addition to the object of the invention of claim 4, knocking is controlled in a rotary piston engine having a combustion chamber shape in which the retarded angle resonance is likely to occur. At the same time, it is an object of the present invention to provide an engine ignition device capable of preventing the occurrence of retarded resonance.

[0015]

According to a first aspect of the present invention, at least two ignition plugs provided in a combustion chamber and at least two ignitions in the combustion chamber at the time of piston top dead center are provided. An ignition device for an engine, comprising: a combustion chamber-constituting wall in which a throttle portion that restricts communication between plugs is formed; operating state detecting means for detecting a predetermined operating state of the engine in which retard of ignition timing is required. And retarding means for retarding only the ignition timing of one of the at least two ignition plugs when retarding the ignition timing under a predetermined operating state detected by the operating state detecting means. It is an engine ignition device.

The invention according to claim 2 of the present invention is, in addition to the configuration of the invention according to claim 1, an engine ignition device in which the predetermined operating state is set to a knocking state.

According to claim 3 (the second invention) of the present invention, there is provided at least two spark plugs provided in the combustion chamber, and a throttle portion for restricting communication between the at least two spark plugs in the combustion chamber at the top dead center of the piston. An ignition device for an engine, comprising: a formed combustion chamber forming wall; knocking detection means for detecting a knocking state of the engine; and at least two of the knocking detection means when the knocking state of the engine is detected by the knocking detection means. Total ignition timing determining means for determining the total ignition timing so that the total ignition timing of the spark plug is retarded, and ignition of an ignition plug arranged on one side of the throttle portion based on the total ignition timing determining means. Retarding means for retarding the timing, and advancing means for advancing the ignition timing of the ignition plug arranged on the other side of the throttle portion based on the total ignition timing determining means. Characterized in that it is a ignition device for an engine equipped with and.

According to a fourth aspect of the present invention, in addition to the configuration of the first, second or third aspect of the invention, the one side spark plug is set as a main spark plug having a large combustion contribution, The ignition device for an engine is characterized in that the spark plug on the other side is set as a sub spark plug having a small combustion contribution.

According to a fifth aspect of the present invention, in addition to the structure of the fourth aspect of the present invention, the invention is an engine ignition device in which the engine is a rotary piston engine.

[0020]

According to the invention (first invention) described in claim 1 of the present invention, as shown in the claim correspondence diagram in FIG. 6, in the combustion chamber P2 at the top dead center of the piston P1 (state shown). In an engine provided with a combustion chamber constituting wall P6 in which a throttle portion P5 that restricts communication between at least two spark plugs P3 and P4 is formed, an operating state detecting means P7 is used for a predetermined operating state of the engine (retarding ignition timing is required. When the traction control and the occurrence of knocking, etc. are detected, the retarding means P8 controls the ignition timing of only one ignition plug P3 of the at least two ignition plugs P3 and P4. To retard.

For this reason, the above-mentioned both spark plugs P3 and P4 are provided.
It is possible to avoid the phenomenon in which the flame propagation reaches the throttle portion P5 at the same timing, and as a result, it is possible to prevent the occurrence of retarded resonance.

According to the invention of claim 2 of the present invention,
In addition to the effect of the invention as set forth in claim 1, since the predetermined operation state is set to the knocking state, only the ignition timing of the ignition plug on one side of the plurality of spark plugs is retarded at the time of ignition retard under the knocking state. Therefore, there is an effect that the occurrence of retarded angle resonance can be prevented.

According to the third aspect of the present invention (the second invention), when the knocking detecting means detects the knocking state of the engine, the total ignition timing determining means determines the total ignition timing of at least two spark plugs. The total ignition timing is determined to be retarded, and the retarding means retards the ignition timing of the spark plug arranged on one side of the throttle portion in correspondence with the total ignition timing determined by the total ignition timing determining means. Then, the advance means advances the ignition timing of the ignition plug arranged on the other side of the throttle portion in correspondence with the total ignition timing determined by the total ignition timing determining means. Knocking can be controlled by the above retard of the total ignition timing, and the ignition timing of the one side spark plug is retarded and the ignition timing of the other side spark plug is advanced, so that the flame propagation from the multiple ignition plugs is reduced. There is an effect that it is possible to surely avoid the phenomenon of arriving at the same timing and prevent the occurrence of retarded resonance. In short, there is an effect that the retarded angle resonance can be prevented while controlling the knocking.

The invention according to claim 4 of the present invention, together with the effect of the invention according to claim 1, 2 or 3, is provided for ignition at the time of ignition retard under a predetermined operating condition (traction control, knocking occurrence, etc.). Since the spark plug on the one side at which the timing is retarded is set to the main spark plug having a large combustion contribution, there is an effect that the ignition retard of the main spark plug can more reliably prevent knocking.

According to the invention of claim 5 of the present invention, in addition to the effect of the invention of claim 4, since the engine is set as a rotary piston engine, it has a combustion chamber shape in which retarded angle resonance is likely to occur. In the rotary piston engine, it is possible to prevent knocking resonance while controlling knocking.

[0026]

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 an engine ignition device. In FIG. 1, a rotary piston engine 1 comprises a rotor housing 2 composed of a base material and a liner made of a hard chrome plating layer formed on the inner peripheral surface of the base material. Two
The working chamber 3 is formed inside the peritrochoid surface. The intake port 4 and the exhaust port 5 are formed on one side of the rotor housing 2, and the leading side spark plug 6 as a main spark plug having a large combustion contribution and the auxiliary spark plug having a small combustion contribution on the other side. The trailing side ignition plug 7 is provided. The rotor housing 2 described above
The inside of the eccentric shaft 8 has a shaft center 9
A rotor 10 is provided which is eccentrically moved about. The rotor 10 has a trilobal inner envelope surface, and an apex seal is attached to the rotor apex.

On the other hand, the air cleaner 11, the air flow sensor 12, the air intake hose 13, and the turbocharger 1
4, the intake manifold 18 is connected through the intercooler 15, the throttle body 16, and the surge tank 17, the intake manifold 18 is connected to the intake port 4 described above, and the exhaust manifold 19 is connected to the exhaust port 5 described above.
Are connected for communication.

Here, in the rotary piston engine 1 described above, the throttle portion 21 that restricts the communication between the two spark plugs 6 and 7 in the combustion chamber 20 is formed at the top dead center of the rotor 10 (see the state of FIG. 1). It has a combustion chamber forming wall, that is, the rotor housing 2, and has a combustion chamber shape in which retarded angle resonance is likely to occur.

FIG. 2 shows the control circuit of the engine ignition device. The CPU 30 has an intake air amount Q from the air flow sensor 12 and an engine speed N from the distributor 22.
e, throttle opening TV from throttle sensor 23
O, the crank angle CA from the crank angle sensor 24 (in the case of a rotary piston engine, the eccentric shaft rotation angle CA from the sensor 24 that detects the rotation angle of the eccentric shaft 8), the knocking signal K from the knock sensor 25, etc. Based on various signal inputs,
According to the program stored in the ROM 26, the leading spark plug 6 and the trailing spark plug 7
The RAM 27 stores necessary maps and data.

Here, the above-mentioned CPU 30 is an operating state detecting means for detecting a predetermined operating state of the engine in which retard of ignition timing is required, specifically, an operating state detection for detecting the knocking state of the rotary piston engine 1. When the knocking state of the rotary piston engine 1 is detected by means (see the sixth step S6 of the flowchart shown in FIG. 3) and the operating state detecting means (in this embodiment, the means serves as knocking detecting means), Total ignition timing determining means for determining the total ignition timing so that the total ignition timings of the leading spark plug 6 and the trailing spark plug 7 become retarded (see 7th step S7 of the flowchart shown in FIG. 3). And the leading-side ignition based on the total ignition timing determined by the above-described total ignition timing determination means. The retarding means (retarding) for retarding the ignition timing of the lug 6 (refer to the eighth step S8 of the flowchart shown in FIG. 3) and the trailing side based on the total ignition timing determined by the total ignition timing determining means described above. Advancement means for advancing the ignition timing of the ignition plug 7 (see ninth step S9 in the flowchart shown in FIG. 3)
Also serves as.

The operation of the engine ignition device thus constructed will be described in detail below with reference to the flow chart shown in FIG.

In the first step S1, the CPU 30 reads various signals necessary for determining the ignition timing, such as the intake air amount Q from the air flow sensor 12 and the engine speed Ne from the distributor 22, and CE = Q / N
The load CE is calculated by the arithmetic expression of e.

Next, in a second step S2, the CPU 30 calculates the ignition timing of the leading side ignition plug 6, and in the next third step S3, the CPU 30 calculates the ignition timing of the trailing side ignition plug 7.

Next, in a fourth step S4, the CPU 30 energizes the leading-side spark plug 6 through the igniter coil (not shown) in accordance with the ignition timing, and in a fifth step S5, the CPU 30 Performs energization to the trailing spark plug 7 in accordance with the above ignition timing via an igniter coil (not shown).

Next, in a sixth step S6, the CPU 30 determines whether or not knocking has occurred based on the input from the knock sensor 25, and when knocking has occurred, the process proceeds to the next seventh step S7.

In the above-described seventh step S7, the CPU 30 determines the knocking control amount for eliminating knocking. For example, as shown in FIG. 4, a predetermined knocking control amount KC in the guard direction from the initial value (current ignition timing)
Is determined and the total ignition timing is determined to a predetermined value Ig2 retarded from the current ignition timing.

The total ignition timing Ig2 is the ignition timing of the leading side ignition plug 6 and the trailing side ignition plug 7
It is the ignition timing that combines the ignition timing of

Next, in an eighth step S8, the CPU 30 determines the retard amount of the leading spark plug 6 as the main spark plug in accordance with the above-mentioned total ignition timing Ig2. Ignition timing I including the retard amount of the leading spark plug 6
g1 is as shown in FIG.

Next, in a ninth step S9, the CPU 30 determines the advance amount of the trailing spark plug 7 as a sub spark plug in accordance with the above-mentioned total ignition timing Ig2. Ignition timing I including the amount of advance of the spark plug 7 on the trailing side
g3 is as shown in FIG.

After the above-described processing in the eighth and ninth steps S8 and S9, the process returns to the second step S2, and each step S
The calculation of the ignition timing and the ignition are executed by S2, S3, S4 and S5.

Thus, at the time of top dead center of the rotor 10 (see FIG.
In the rotary piston engine 1 including the rotor housing 2 in which the throttle portion 21 that restricts the communication between the two ignition plugs 6 and 7 in the combustion chamber 20 is formed (see the state of FIG. ) Detects a predetermined operating state of the engine (an operating state in which retard of ignition timing is required), the retarding means (see the eighth step S8) causes one of the two spark plugs 6, 7 described above. Only the ignition timing of the spark plug 6 on the side is retarded.

Therefore, it is possible to avoid the phenomenon that the flame propagation of both spark plugs 6 and 7 reaches the throttle portion 21 at the same timing, and as a result, it is possible to prevent the occurrence of retarded resonance. There is.

In addition, since the above-mentioned predetermined operation state is set to the knocking state, only the ignition timing of the ignition plug 6 on one side of the plurality of ignition plugs 6 and 7 is retarded when the ignition is retarded under the knocking state. Therefore, there is an effect that the occurrence of retarded angle resonance can be prevented.

Further, when the knocking detecting means (knock sensor 25 and see sixth step S6) detect the knocking state of the rotary piston engine 1, the total ignition timing determining means (see seventh step S7) shows the two spark plugs 6 , 7 are retarded so that the total ignition timing is retarded, and the retarding means (see the eighth step S8) corresponds to the total ignition timing determined by the total ignition timing determining means described above.
The ignition timing of the spark plug 6 disposed on one side of the first ignition timing is retarded (retarded), and the advance means (see ninth step S9) reduces the total ignition timing by the total ignition timing determination means described above. The ignition timing of the spark plug 7 arranged on the other side of the portion 21 is advanced. Therefore, knocking can be controlled by the retard of the total ignition timing described above, and the ignition timing of the one side ignition plug 6 can be retarded and the ignition timing of the other side ignition plug 7 can be advanced to advance the multiple ignition plugs 6, 6. Flame spread from 7 is throttle part 2
Be sure to avoid the phenomenon that 1 is reached at the same timing,
There is an effect that it is possible to favorably prevent the occurrence of retarded angle resonance.

Further, at the time of ignition retard under a predetermined operating condition, the ignition plug on the one side where the ignition timing is retarded is set to the main ignition plug (see the leading ignition plug 6) having a large combustion contribution. With the ignition retard of the spark plug, knocking can be prevented more reliably.

Furthermore, as shown in the embodiment, when the above-mentioned engine is set as a rotary piston engine,
In a rotary piston engine having a combustion chamber shape in which retarded resonance is likely to occur, knocking can be controlled and retarded resonance can be prevented from occurring.

The characteristics in which the ignition timing control is set for the knocking control amount shown in FIG. 4 are stored in advance in the RAM 27 as a map, and the total ignition timing, the ignition timing of the main spark plug, and the auxiliary ignition plug are set according to the knocking control amount. The ignition timing of the spark plug may be read from the RAM 27.

FIG. 5 shows a reciprocating engine 31 in which two ignition plugs are arranged in one cylinder, and a cylinder head 34 is fixed on a cylinder block 33 in which a piston 32 is slidably fitted. An intake valve 36 that opens and closes the intake port 35 is provided in 34, and a substantially concave combustion chamber 37 that opens to the cylinder bore is formed at the lower end of the cylinder head 34 on the exhaust port side.
7, a fuel injection nozzle 38 is arranged, and a first ignition plug 39 as a main ignition plug having a large combustion contribution is arranged in the vicinity of the injection port of the fuel injection nozzle 38.

Further, while the injector 40 is arranged on the upstream side of the intake port 35, the second ignition as a sub-ignition plug which is operated at the time of premixed combustion and has a small combustion contribution is provided in the cylinder head 34 substantially in the center of the cylinder bore. Plug 41
Are installed.

Further, the CPU 30 receives the signal from the knock sensor, the crank angle signal from the crank angle sensor 24, the airflow sensor signal, the throttle opening signal, and the engine speed signal in accordance with the program stored in the ROM 26. 1 through the 1 igniter coil 42
The ignition plug 39 drives and controls the second ignition plug 41 via the second igniter coil 43, and the RAM 27 stores necessary data and maps.

Even if the above ignition control is applied to the reciprocating engine having the above-described structure, the same operation and effect as in the previous embodiment can be obtained. Therefore, in FIG. And detailed description thereof is omitted.

In the correspondence between the structure of the present invention and the above-described embodiment, the combustion chamber forming wall of the present invention corresponds to the rotor housing 2 of the rotary piston engine 1 and the cylinder head 34 of the reciprocating engine 31,
Similarly, the operating state detecting means of claim 1 is the CPU 3
Corresponding to the sixth step S6 by 0 control, the retarding means of claim 1 corresponds to the eighth step S8, the knocking detecting means of claim 3 corresponds to the knock sensor 25 and the sixth step S6, The total ignition timing determining means of claim 3 corresponds to the seventh step S7, and the retarding means of claim 3 is the eighth step.
Corresponding to step S8, the advance means of claim 3 corresponds to ninth step S9, and the main spark plug of claim 4 is the leading spark plug 6 in the rotary piston engine 1 and the first ignition in the reciprocating engine 31. Corresponding to the plug 39, the auxiliary spark plug of claim 4 is the trailing spark plug 7 in the rotary piston engine 1.
The second spark plug 41 in the reciprocating engine 31 corresponds to the present invention, but the present invention is not limited to the configuration of the above-described embodiment.

For example, when the ignition retard is increased, the fuel increase rate is decreased and the air-fuel ratio A / F is made lean.
Means for reducing combustion noise and lowering the resonance level may be added to the above configuration.

[Brief description of drawings]

FIG. 1 is a system diagram of a rotary piston engine including an ignition device of the present invention.

FIG. 2 is a control circuit block diagram of the engine ignition device of the present invention.

FIG. 3 is a flowchart showing engine ignition control.

FIG. 4 is an explanatory diagram showing ignition timing control with respect to a knocking control amount.

FIG. 5 is a system diagram showing an ignition device for a reciprocating engine according to the present invention.

FIG. 6 is a diagram for responding to a complaint.

FIG. 7 is an explanatory view of the shape of a combustion chamber having a throttle portion.

FIG. 8 is an explanatory view showing an ignition timing at which the engine efficiency is best in the conventional rotary piston engine.

9 is a P-θ diagram corresponding to FIG. 8. FIG.

FIG. 10 is an explanatory diagram showing an ignition timing after a knocking countermeasure in a conventional rotary piston engine.

11 is a P-θ diagram corresponding to FIG.

FIG. 12 is an explanatory diagram of occurrence of retarded angle resonance.

FIG. 13 is a P-θ diagram of retarded angle resonance.

FIG. 14 is a P-θ diagram of knocking.

FIG. 15 is a characteristic diagram showing a resonance level with respect to frequency.

FIG. 16 is a characteristic diagram showing a resonance level with respect to ignition timing.

[Explanation of symbols]

 2 ... Rotor housing 6, 7 ... Spark plug 10 ... Rotor 20 ... Combustion chamber 21 ... Throttling part 25 ... Knock sensor 32 ... Piston 37 ... Combustion chamber 39, 41 ... Spark plug S6 ... Operating state detection means (knocking detection means) S7 ... total ignition timing determining means S8 ... retarding means S9 ... advancing means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Onose 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Motor Corporation

Claims (5)

[Claims] 1. A combustion chamber constituting wall having at least two spark plugs provided in the combustion chamber, and a throttle portion for restricting communication between the at least two spark plugs in the combustion chamber at the time of top dead center of a piston. An ignition device for an engine, comprising an operating state detecting means for detecting a predetermined operating state of the engine in which a retard of ignition timing is required, and an ignition timing retard under a predetermined operating state detected by the operating state detecting means. And an ignition timing retarding means for retarding only the ignition timing of one ignition plug of the at least two ignition plugs. 2. The engine ignition device according to claim 1, wherein the predetermined operating state is set to a knocking state. 3. A combustion chamber constituting wall having at least two spark plugs provided in the combustion chamber, and a throttle portion for restricting communication between the at least two spark plugs in the combustion chamber at the time of top dead center of the piston. An ignition device for an engine, comprising: knocking detection means for detecting a knocking state of the engine; and when the knocking state of the engine is detected by the knocking detection means, a total ignition timing of the at least two spark plugs is retarded. Total ignition timing determining means for determining the total ignition timing, retarding means for delaying the ignition timing of the ignition plug arranged on one side of the throttle portion based on the total ignition timing determining means, and An ignition device for an engine, comprising: advance means for advancing the ignition timing of an ignition plug arranged on the other side of the throttle portion based on the total ignition timing determination means. 4. The spark plug on the one side is set as a main spark plug having a large combustion contribution, and the spark plug on the other side is set as a sub spark plug having a small combustion contribution. The engine ignition device described. 5. The engine ignition device according to claim 4, wherein the engine is a rotary piston engine.