CN113775458A - Ignition frequency acquisition method of engine ignition device - Google Patents

Ignition frequency acquisition method of engine ignition device Download PDF

Info

Publication number
CN113775458A
CN113775458A CN202111082825.9A CN202111082825A CN113775458A CN 113775458 A CN113775458 A CN 113775458A CN 202111082825 A CN202111082825 A CN 202111082825A CN 113775458 A CN113775458 A CN 113775458A
Authority
CN
China
Prior art keywords
ignition
voltage
module
circuit module
frequency acquisition
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202111082825.9A
Other languages
Chinese (zh)
Other versions
CN113775458B (en
Inventor
郭庆
刘红震
梅屿钒
黄国峻
邸士杰
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Aerospace Era Feipeng Co ltd
Original Assignee
Aerospace Era Feipeng Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Aerospace Era Feipeng Co ltd filed Critical Aerospace Era Feipeng Co ltd
Priority to CN202111082825.9A priority Critical patent/CN113775458B/en
Publication of CN113775458A publication Critical patent/CN113775458A/en
Application granted granted Critical
Publication of CN113775458B publication Critical patent/CN113775458B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02PIGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
    • F02P11/00Safety means for electric spark ignition, not otherwise provided for
    • F02P11/02Preventing damage to engines or engine-driven gearing
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02PIGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
    • F02P17/00Testing of ignition installations, e.g. in combination with adjusting; Testing of ignition timing in compression-ignition engines
    • F02P17/12Testing characteristics of the spark, ignition voltage or current
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02PIGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
    • F02P17/00Testing of ignition installations, e.g. in combination with adjusting; Testing of ignition timing in compression-ignition engines
    • F02P17/12Testing characteristics of the spark, ignition voltage or current
    • F02P2017/121Testing characteristics of the spark, ignition voltage or current by measuring spark voltage
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02TCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00Road transport of goods or passengers
    • Y02T10/10Internal combustion engine [ICE] based vehicles
    • Y02T10/40Engine management systems

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Ignition Installations For Internal Combustion Engines (AREA)

Abstract

The invention relates to an ignition frequency acquisition device of an engine ignition device, which comprises: the device comprises a voltage division circuit module, a filtering module, an overvoltage protection circuit module, a comparison module and a processor module; the voltage division circuit module is used for carrying out voltage reduction processing on the ignition voltage of the engine ignition device; the filtering module is used for filtering abnormal clutter in the ignition voltage; the overvoltage protection circuit module is used for performing overvoltage protection processing on the ignition voltage after voltage division; the comparison module generates PWM waves according to the input voltage subjected to the overvoltage protection treatment; the processor module collects and calculates the ignition frequency signal according to the PWM wave. The invention is used for carrying out treatments such as voltage division, filtering and the like on the ignition voltage of the engine ignition device, so that the ignition frequency obtained by the processor module according to the PWM wave acquisition and calculation is stable.

Description

Ignition frequency acquisition method of engine ignition device
Technical Field
The invention belongs to the technical field of ignition control of engines, and particularly relates to an ignition frequency acquisition method of an engine ignition device.
Background
The piston engine is an efficient thermal machine, plays an important role in production and life, and in recent years, the piston engine is used as a power source of an unmanned aerial vehicle, plays an important role in tasks of aerial photography, agriculture, plant protection, self-timer, express transportation, disaster rescue, wild animal and plant observation, infectious disease monitoring, surveying and mapping, news reporting, electric power inspection, disaster relief, movie and television shooting and the like of the unmanned aerial vehicle, and becomes one of the most important power source components of the unmanned aerial vehicle.
The piston engine requires an ignition signal to ignite the spark plug prior to normal start-up. In the prior art, when a piston engine is ignited, if the voltage generating a spark signal contains interference or the voltage is unstable, when a spark plug is ignited, weak or no spark jumping may be caused, and the weak spark or no spark jumping at an electric nozzle causes the explosion pressure of each cylinder of the piston engine to be uneven or not to explode, so that the piston engine vibrates; the gas is not completely or uncombusted in the cylinder in which the gas is mixed, and the gas is re-combusted in the exhaust pipe to generate a blasting phenomenon, so that the power of the piston engine is obviously reduced, the operation of the piston engine is unstable, and the function of the piston engine is reduced.
Disclosure of Invention
The invention aims to solve the defects of high ignition signal voltage, more ignition signal noise waves, namely interference signals, wide frequency band coverage range and the like of an engine ignition device in the prior art, and provides an ignition frequency acquisition method of the engine ignition device, which is used for solving the problems in the prior art.
The above technical object of the present invention will be achieved by the following technical solutions.
An ignition frequency acquisition device of an engine ignition device, the ignition frequency acquisition device comprising: the device comprises a voltage division circuit module, a filtering module, an overvoltage protection circuit module, a comparison module and a processor module;
the voltage division circuit module, the filtering module, the overvoltage protection circuit module, the comparison module and the processor module are electrically connected in sequence;
the voltage division circuit module is used for carrying out voltage reduction processing on the ignition voltage of the engine ignition device;
the filtering module is used for filtering abnormal noise waves in the ignition voltage;
the overvoltage protection circuit module is used for performing overvoltage protection processing on the ignition voltage after voltage division;
the comparison module generates PWM waves according to the input voltage subjected to the overvoltage protection treatment;
the processor module collects the ignition frequency signal according to the PWM wave.
The above aspects and any possible implementations further provide an implementation, where the voltage divider circuit module includes a voltage regulator circuit module; the input end of the voltage regulating circuit module is connected with the ignition voltage of the engine ignition device, and the output end of the voltage regulating circuit module is connected with the filtering module and/or the overpressure protection circuit module.
The aspect described above and any possible implementation manner further provide an implementation manner that the voltage regulating circuit module includes a resistor with a fixed resistance value and a resistor with a variable resistance value.
The above-described aspects and any possible implementation manners further provide an implementation manner, and the filtering module adopts a capacitive or inductive filtering manner.
The above aspects and any possible implementations further provide an implementation where the overvoltage protection circuit module includes a zener diode and an optocoupler, and the zener diode is configured to be reverse broken down by the ignition voltage after an excessively high voltage division.
The above aspect and any possible implementation further provide an implementation, where the comparison module employs a voltage-type PWM comparator.
The above-described aspect and any possible implementation further provide an implementation in which the processor module includes a timer that collects the firing frequency signal according to a duration set by the timer.
The invention also provides an ignition frequency acquisition method of the engine ignition device, which comprises the following steps:
s1, initializing the ignition frequency acquisition device;
s2, starting a timer of the processor module, starting timing, and entering a capture mode;
s3, capturing the PWM wave signal in the capturing mode;
and S4, calculating the captured PWM wave signal to obtain the ignition frequency.
The above-mentioned aspect and any possible implementation manner further provide an implementation manner that performs a smoothing filtering process on the ignition frequency obtained in step S4.
The above aspect and any possible implementation manner further provide an implementation manner, in which a timing duration is set, and when the capturing operation exceeds the timing duration, the capturing mode is ended.
The invention has the beneficial technical effects
The embodiment provided by the invention is an ignition frequency acquisition device of an engine ignition device, comprising: the device comprises a voltage division circuit module, a filtering module, an overvoltage protection circuit module, a comparison module and a processor module; the voltage division circuit module, the filtering module, the overvoltage protection circuit module, the comparison module and the processor module are electrically connected in sequence; the voltage division circuit module is used for carrying out voltage reduction processing on the ignition voltage of the engine ignition device; the filtering module is used for filtering abnormal noise waves in the ignition voltage; the overvoltage protection circuit module is used for performing overvoltage protection processing on the ignition voltage after voltage division; the comparison module generates PWM waves according to the input voltage subjected to the overvoltage protection treatment; the processor module collects and calculates the ignition frequency signal according to the PWM wave. The technical scheme of the invention is used for carrying out voltage division, filtering and comparison processing on the ignition voltage of the engine ignition device, and ensuring that the ignition signal is stable and does not jump into the voltage burning comparison module of the comparison module; the processor module is fixed according to the frequency band range of the ignition frequency acquired and calculated by the PWM wave, and the ignition frequency is stable. The voltage signal obtained by the ignition frequency acquisition device of the invention does not jump, thereby stabilizing the electric spark generated after the ignition frequency acquisition device is used for a spark plug and improving the service performance of an engine.
Drawings
Embodiments of the invention are described in detail below with reference to the attached drawing figures, wherein:
fig. 1 is a schematic structural diagram of an ignition frequency acquisition device in an embodiment of the invention;
FIG. 2 is a schematic structural diagram of a voltage divider circuit module according to an embodiment of the invention;
FIG. 3 is a schematic structural diagram of a filter circuit module according to an embodiment of the invention;
FIG. 4 is a schematic diagram of an embodiment of an overvoltage protection module;
fig. 5 is a schematic structural diagram of a comparison module in an embodiment of the invention.
Detailed Description
In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the following detailed description is made with reference to the accompanying drawings and specific examples, but the embodiments of the present invention are not limited thereto.
As shown in fig. 1, the ignition frequency acquisition device of the engine ignition device of the present invention includes: the device comprises a voltage division circuit module, a filtering module, an overvoltage protection circuit module, a comparison module and a processor module; the voltage division circuit module, the filtering module, the overvoltage protection circuit module, the comparison module and the processor module are electrically connected in sequence;
the voltage division circuit module is used for carrying out voltage reduction processing on the ignition voltage of the engine ignition device; the filtering module is used for filtering abnormal noise waves in the ignition voltage; the overvoltage protection circuit module is used for performing overvoltage protection processing on the ignition voltage after voltage division; the comparison module generates PWM waves according to the input voltage subjected to the overvoltage protection treatment; the processor module collects the ignition frequency signal according to the PWM wave. The ignition frequency acquisition device is suitable for the piston engine.
Preferably, the voltage dividing circuit module in the embodiment of the present invention is implemented by using a voltage regulating circuit, as shown in fig. 3, the voltage regulating circuit may be implemented by using a first resistor R1 with a fixed resistance value and a second resistor R2 with a variable resistance value, the ignition voltage of the ignition frequency acquisition device is used as an input end of the voltage regulating circuit, the first resistor R1 and the second resistor R2 are connected in series, and an output end is connected to two ends of the second variable resistor R2.
Preferably, the filtering module in the embodiment of the present invention may adopt a capacitive or inductive filtering manner, so that signal components within a certain frequency range in the ignition voltage signal after passing through the voltage dividing circuit module normally pass through, and clutter signals of abnormal frequency included in the ignition voltage signal are removed, thereby preventing the clutter signals from forming interference on subsequent circuit signals. Preferably, the invention can also adopt a software filtering mode, a filtering algorithm is arranged in the processor module, no additional hardware is needed to be arranged, the filtering algorithm can adopt median filtering, arithmetic mean filtering, program judgment, weighted filtering and the like, and because clutter in the ignition voltage signal after voltage division can simultaneously comprise random noise and impulse noise, the median filtering and the arithmetic mean filtering are fused in the processor module in the invention to eliminate the random noise and the impulse noise. The hardware circuit module adopted by the capacitive or inductive filtering mode in the embodiment of the invention is a common setting mode, and detailed description is omitted in the invention.
Preferably, an overvoltage protection circuit module is further provided in the embodiment of the present invention, and is configured to process the filtered ignition voltage signal, so as to ensure that the filtered ignition voltage signal does not burn the comparison module when entering the comparison module. As shown in fig. 4, the overvoltage protection circuit module includes a zener diode connected to the filtered ignition voltage signal and connected in series with a third resistor R3 and a fourth resistor R4, and an optocoupler connected in parallel to both ends of the third resistor R3, wherein when the filtered ignition voltage signal is too high, i.e., exceeds the regulated voltage of the zener diode, the zener diode is broken down in reverse direction, and a voltage drop is generated across the third resistor R3, which causes the output voltage of the optocoupler to drop, i.e., pulls the voltage at the input end of the comparison module down, thereby protecting the comparison module from being burned by the too high input voltage, and the fourth resistor R4 is provided to ensure that the overvoltage protection circuit is grounded.
Preferably, the comparison module in the embodiment of the present invention employs a voltage-type PWM comparator, as shown in fig. 5, a positive input terminal of the PWM comparator inputs the voltage output by the overvoltage protection circuit module, a negative input terminal of the PWM comparator is connected to the waveform generator, the voltage at the positive input terminal is compared with the waveform generated in the waveform generator, a PWM signal is generated at an output terminal of the PWM comparator, and a duty ratio of the PWM signal varies with the magnitude of the voltage input at the positive input terminal. The waveform generator of the invention can generate triangular wave, rectangular wave or square wave and other waveforms.
Preferably, the processor module in an embodiment of the present invention is configured to receive the PWM signal generated by the comparison module, and to calculate the firing frequency based on the PWM signal. The processor module is also provided with a timer, the timer is used for setting a certain time length, and the processor module receives the PWM signal within a preset time length range.
Preferably, the ignition frequency acquisition method of the engine ignition device in the embodiment of the present invention, as shown in fig. 2, includes the steps of:
s1, initializing the ignition frequency acquisition device;
s2, starting a timer of the processor module, starting timing, and entering a capture mode;
s3, capturing the PWM signal in the capturing mode;
and S4, calculating the captured PWM signal to obtain the ignition frequency.
Preferably, in the embodiment of the present invention, in order to avoid the influence of noise in the ignition frequency on the acquisition effect, the method further includes performing filtering processing on the ignition frequency obtained in step S4 to obtain a smooth ignition frequency.
Preferably, in order to avoid the problem that the adoption of excessively long sampling time causes damping identification errors when noise interference is caused in the embodiment of the present invention, the processor module sets a timer for setting the timing duration and presets a duration threshold, the method of the present invention further includes step s5. judging whether the timing duration exceeds a preset threshold, when the capturing operation exceeds the preset threshold, ending the capturing mode, and stopping the capturing action; if the preset threshold is not exceeded, the method continues to steps S3-S4.
Preferably, the processor module is further provided with a counter and preset a PWM signal threshold, and in step S3, when capturing the PWM signal, the PWM signal exceeding the threshold is retained for subsequent filtering processing; and performing rejection processing on the PWM signal lower than the threshold value, enabling the counter to count, and judging that the ignition frequency device is abnormal and stopping working when the count value of the counter exceeds a preset count threshold value.
The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
The above description is only for the specific embodiments of the present disclosure, but the scope of the present disclosure is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present disclosure should be covered within the scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be subject to the protection scope of the claims.

Claims (10)

1. An ignition frequency acquisition device of an engine ignition device, characterized in that the ignition frequency acquisition device comprises: the device comprises a voltage division circuit module, a filtering module, an overvoltage protection circuit module, a comparison module and a processor module;
the voltage division circuit module, the filtering module, the overvoltage protection circuit module, the comparison module and the processor module are electrically connected in sequence;
the voltage division circuit module is used for carrying out voltage reduction processing on the ignition voltage of the engine ignition device;
the filtering module is used for filtering abnormal noise waves in the ignition voltage;
the overvoltage protection circuit module is used for performing overvoltage protection processing on the ignition voltage after voltage division;
the comparison module generates PWM waves according to the input voltage subjected to the overvoltage protection treatment;
the processor module collects the ignition frequency signal according to the PWM wave.
2. The ignition frequency acquisition device according to claim 1, wherein the voltage division circuit module comprises a voltage regulation circuit module; the input end of the voltage regulating circuit module is connected with the ignition voltage of the engine ignition device, and the output end of the voltage regulating circuit module is connected with the filtering module and/or the overpressure protection circuit module.
3. The ignition frequency acquisition device according to claim 2, wherein the voltage regulation circuit module comprises a resistor with a fixed resistance value and a resistor with a variable resistance value.
4. The ignition frequency acquisition device of claim 3, wherein the filtering module adopts a capacitive or inductive filtering mode.
5. The ignition frequency acquisition device according to claim 1, wherein the overvoltage protection circuit module comprises a zener diode and an optocoupler, and the zener diode is used for reverse breakdown of the ignition voltage after excessive voltage division.
6. The ignition frequency acquisition device according to claim 1, wherein the comparison module employs a voltage-type PWM comparator.
7. The ignition frequency acquisition device of claim 6 wherein the processor module includes a timer that acquires the ignition frequency signal according to a duration set by the timer.
8. An ignition frequency acquisition method of an engine ignition device, characterized in that the method is realized by the ignition frequency acquisition device of any one of claims 1-7, and the method comprises the following steps:
s1, initializing the ignition frequency acquisition device;
s2, starting a timer of the processor module, starting timing, and entering a capture mode;
s3, capturing the PWM wave signal in the capturing mode;
and S4, calculating the captured PWM wave signal to obtain the ignition frequency.
9. The ignition frequency acquisition method according to claim 8, wherein the ignition frequency obtained in step S4 is subjected to smoothing filtering processing.
10. The ignition frequency acquisition method according to claim 9, wherein a timer period is set, and when the capturing operation exceeds the timer period, the capturing mode is ended.
CN202111082825.9A 2021-09-15 2021-09-15 Ignition frequency acquisition method of engine ignition device Active CN113775458B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202111082825.9A CN113775458B (en) 2021-09-15 2021-09-15 Ignition frequency acquisition method of engine ignition device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202111082825.9A CN113775458B (en) 2021-09-15 2021-09-15 Ignition frequency acquisition method of engine ignition device

Publications (2)

Publication Number Publication Date
CN113775458A true CN113775458A (en) 2021-12-10
CN113775458B CN113775458B (en) 2022-10-14

Family

ID=78844248

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202111082825.9A Active CN113775458B (en) 2021-09-15 2021-09-15 Ignition frequency acquisition method of engine ignition device

Country Status (1)

Country Link
CN (1) CN113775458B (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN201292907Y (en) * 2008-10-31 2009-08-19 比亚迪股份有限公司 Ignition coil test device
CN105317613A (en) * 2015-11-01 2016-02-10 四川泛华航空仪表电器有限公司 Spark frequency online detection device for engine ignition system
CN107477610A (en) * 2017-09-22 2017-12-15 中山华帝电子科技有限公司 A kind of igniter fire frequency target test device
CN208224376U (en) * 2018-09-13 2018-12-11 天津市机电工艺学院(天津市机电工业学校) A kind of contactless ignition coil diagnostic device
CN113161870A (en) * 2021-04-15 2021-07-23 常州易控汽车电子股份有限公司 Spark plug discharge time detection system

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN201292907Y (en) * 2008-10-31 2009-08-19 比亚迪股份有限公司 Ignition coil test device
CN105317613A (en) * 2015-11-01 2016-02-10 四川泛华航空仪表电器有限公司 Spark frequency online detection device for engine ignition system
CN107477610A (en) * 2017-09-22 2017-12-15 中山华帝电子科技有限公司 A kind of igniter fire frequency target test device
CN208224376U (en) * 2018-09-13 2018-12-11 天津市机电工艺学院(天津市机电工业学校) A kind of contactless ignition coil diagnostic device
CN113161870A (en) * 2021-04-15 2021-07-23 常州易控汽车电子股份有限公司 Spark plug discharge time detection system

Also Published As

Publication number Publication date
CN113775458B (en) 2022-10-14

Similar Documents

Publication Publication Date Title
JP5773059B2 (en) Control device for internal combustion engine
US4106447A (en) Engine spark timing system with retard means and minimum burn timer
DE3933008C2 (en)
JP3827083B2 (en) Knock detection device for internal combustion engine
JPH109108A (en) Knock controller for internal combustion engine
US6298823B1 (en) Knock control apparatus for internal combustion engine
JP2012241554A (en) Control unit of internal combustion engine
CN108730057B (en) Abnormal combustion detection device for internal combustion engine
CN113775458B (en) Ignition frequency acquisition method of engine ignition device
JP2011085069A (en) Combustion state detector for internal combustion engine
US6474302B2 (en) Knock control apparatus for internal-combustion engine
KR100424214B1 (en) Ignition device of internal combustion engine
JP2017207015A (en) Knocking detection device and knocking detection method for internal combustion engine
JP4573048B2 (en) Misfire detection device for internal combustion engine
EP1146226A2 (en) Capacitor discharge engine ignition system with automatic ignition advance/retard timing control
JP4642808B2 (en) Knock control device for internal combustion engine
JP5447446B2 (en) Abnormal combustion detection device and internal combustion engine control device
JP2011140881A (en) Knocking detection device for internal combustion engine
CN116025479A (en) Method, system, equipment and storage medium for controlling preignition of extended-range engine
TH2001004371A (en) Ignition timing control device for the internal combustion engine.
US10626807B2 (en) Controller and control method for internal combustion engine
JP2003013832A (en) Device for detecting misfire of internal combustion engine
JP6049171B2 (en) Combustion control device for internal combustion engine
JP2013163989A (en) Combustion control device for internal combustion engine
JPH08210175A (en) Knock detecting device for engine

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant