JPH10213056A - Flashover detecting method for ignition plug and detection alarm device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect generation of flashover not by judgment of a user of an engine and but at the time of an engine operation. SOLUTION: This device detects light generated by flashover of an ignition plug by a photosensor arranged in the vicinity of the ignition plug at first (SP 1). Next, whether the light detected exceeds a preliminarily set light detection level or not is discriminated (SP 2). When it is discriminated that light detected exceeds the preliminarily set light detection level, generation of flashover is notified to a user by an alarm lamp (SP 3). By this detecting method, generation of flashover which is affected by an operation condition and has no reproducibility can be exactly detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for detecting flashover occurring in a spark plug of a spark ignition engine.

[0002]

2. Description of the Related Art Conventionally, when a spark plug 1 as shown in FIG. 5 is used for a life longer than the service life, a spark gap increases, a required ignition voltage increases, and the rubber of a plug cap 8 deteriorates to improve insulation. The decrease causes the phenomenon of flashover to occur easily. The flashover refers to a phenomenon in which the spark 41 flies directly from the terminal 43 of the spark plug 1 to the spark plug body 40 as shown in FIG. When flashover occurs, spark plug 1
In this case, the spark state of the ignition section 42 is not stable, the rotation of the engine fluctuates, and finally the engine stops.

[0003]

Therefore, when the flashover occurs, it is necessary to detect the flashover state as soon as possible to prevent the flashover such as replacing the plug cap 8 and the ignition plug 1. However, the detection of flashover has the following problems. (1) Flashover is the engine speed, load,
It occurs when various conditions such as the atmosphere and temperature around the engine overlap, and does not necessarily occur when the spark plug and the plug cap deteriorate. Therefore, it is difficult to reproduce and confirm the flashover even if a serviceman repairing the engine abnormality goes to the site where the engine is used. Further, when performing maintenance of the engine, since the engine housing is opened, the temperature of the atmosphere in the housing changes, and sunlight enters the housing, making it difficult to visually check the flashover phenomenon. Therefore, at present, it is necessary to judge whether flashover has occurred or not based on the intuition of a service person or a user.

(2) When a flashover has occurred, both the high tension cord including the plug cap and the spark plug must be replaced, but the user simply determines that the spark plug is defective. It is often the case that only the spark plug is replaced upon judgment. In such a case, as long as the spark plug is new, flashover does not occur because the required ignition voltage is low. Has been a problem.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a piston cooling device for an engine which can solve the above problems. The specific purpose is to make it possible to detect a flashover as soon as it occurs. The occurrence of flashover is accurately detected regardless of the judgment of the engine user or service person, and the state is notified. Sometimes. In addition, the subject of the invention other than those described above and means for solving the problem will be described in detail in embodiments of the invention described later.

[0006]

Means for Solving the Problems The first invention is, for example,
Referring to FIG. 1, light detection means 2 for detecting light generated by flashover of a spark plug 1 of a spark ignition engine, and the fact that flashover has occurred based on the output of the light detection means 2 will be described. It is characterized by including a notifying means 6 for notifying the user.

The second invention will be described with reference to, for example, FIG. 3. Light detecting means 2 for detecting light generated by flashover of a spark plug 1 of a spark ignition engine.
And an engine speed detecting means 21 (a speed sensor in FIG. 3) for detecting the engine speed, and calculating a speed change based on the detected engine speed. Rotation fluctuation state determination means 22 (rotation fluctuation state determination section in FIG. 3) for determining whether or not flashover is large, and flashover is performed based on the output of light detection means 2 and the rotation number fluctuation state determination means 22 determination result. A determination unit 4 (a system controller in FIG. 3) for determining whether or not a flashover has occurred, and an alarm unit 5 for notifying a user that a flashover has occurred.
(In FIG. 3, an alarm device), and the alarm unit 5 is activated in response to the determination unit 4 determining that the flashover has occurred.

[0010] The third invention will be described with reference to, for example, FIG. 2. The process of detecting light generated by flashover of an ignition plug, and the detected light determines a preset light detection level. And informing the user that a flashover has occurred if the time has been exceeded.

[0009]

According to the first aspect of the invention, the light detecting means detects the light generated by the flashover, and the notifying means notifies the user of the occurrence of the flashover based on the output of the light detecting means. . Therefore, the occurrence of the flashover is automatically performed by the apparatus without depending on the judgment of the user's intuition, so that the occurrence of the flashover can be accurately detected. Further, it is possible to detect an unstable flashover that occurs only during a predetermined operation of the engine.

According to the second aspect, the light detecting means detects light generated by flashover of the spark plug,
The engine speed detecting means detects the engine speed,
The rotational fluctuation state determining means calculates the rotational speed fluctuation based on the detected engine rotational speed and determines whether the rotational speed fluctuation is greater than a predetermined reference value. Then, the determining means determines whether or not a flashover has occurred based on the output of the light detecting means and the determination result of the rotational speed fluctuation state determining means, and the determining means determines that the flashover has occurred. The alarm is activated in response to the determination. Therefore, the user of the engine can be informed that the flashover has occurred automatically.
Further, it is possible to detect an unstable flashover that occurs only during a predetermined operation of the engine. Furthermore, since the determination means makes a final determination as to whether or not a flashover has occurred in consideration of fluctuations in the engine speed, the accuracy of flashover detection can be improved. According to the third aspect of the present invention, the occurrence of flashover can be easily and accurately notified to the user through two steps.

[0011]

According to the first and third aspects of the present invention, the following specific effects (a) and (b) are obtained. (A) Unstable flashover that occurs only during predetermined operation of the engine can be detected. (B) The occurrence of flashover can be accurately detected irrespective of the judgment of the engine user. According to the second aspect, in addition to the effects of (a) and (b) above, the determination as to whether or not a flashover has occurred is performed not only by the light detection means but also by considering the engine speed. Therefore, there is a specific effect that the accuracy of detection can be improved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic block diagram showing a configuration of an ignition plug flashover detection alarm device as one embodiment of the present invention. This flashover detection alarm device includes an optical sensor 3 as the light detecting means 2,
The system includes a system controller 4 and an alarm 5.
The optical sensor 3 is provided at a position for detecting light generated by flashover of the ignition plug 1. Also,
The system controller 4 and the alarm 5 make the notifying means 6
Is formed. The optical sensor 3 is attached by the optical sensor attachment member 7 to a position where light generated by flashover of the ignition plug 1 is easily detected. The location where flashover light is likely to occur is determined in consideration of the configuration of each spark plug. In the ordinary spark plug 1, sparks often fly toward the lower end 8a of the plug cap 8 and the upper part of the hexagonal opposite side 9 of the spark plug 1, so that it is preferable to provide the spark corresponding to the position.

The sensor mounting member 7 has a substantially cylindrical base 12 made of a flexible insulator such as silicon rubber.
An insertion hole 13 penetrating the base 12 up and down is provided, the ignition plug 1 is passed through the insertion hole 13, and the lower end of the base 12 is fixed with a stop ring 14. The light sensor 3 is embedded in the base 12, and the light receiving surface 3 a of the light sensor 3 faces the insertion hole 13. The insertion hole 13 has a large-diameter portion 15 that can accommodate the hexagonal opposite side 9 of the ignition plug 1 and an opening 16 into which the lower end portion 8a of the plug cap 8 is inserted. The lower end 8a of the plug cap 8 is inserted into the opening 16 in a press-fit state, so that external light does not enter the inside.

The system controller 4 compares the output of the light sensor 3 with a light detection level as a preset reference value. If the output of the light sensor 3 exceeds the light detection level, a flashover occurs. A light detection level discriminating unit for discriminating that the detection has been performed. System controller 4
Is often configured to include a central processing unit (CPU), but may be configured by a simple comparator. The alarm device 5 includes, for example, an alarm lamp 17 (see FIG. 1B), an alarm buzzer, an engine emergency stop device, and the like. When the alarm lamp 17 is employed as the alarm device 5, the alarm lamp 17 is provided at a position that is easily noticeable by a user of the engine, at an operation panel, or in front of the engine. FIG. 1B is a circuit diagram showing an example in which an optical switch 11 is employed as the light detection means 2 and the notification means 6 is constituted by a notification circuit 18 in which an alarm lamp 17 and the optical switch 11 are connected in series to a power supply 10. is there. With this configuration, the flashover detection alarm device can be configured with a simple configuration.

FIG. 2 is a flowchart showing an example of a method for detecting flashover of a spark plug.
In P1, the detection of light generated by flashover of the spark plug is detected, and in step SP2,
It is determined whether or not the detected light has exceeded a preset light detection level. If it is determined that the detected light has exceeded the preset light detection level, the user is notified in step SP3 that flashover has occurred. To end the series of processing. On the other hand, if it does not exceed the preset light detection level in step SP3,
The process from P1 is repeated. It is simplest to use the light amount as the light detection level, but the light intensity level may be used.

[0016]

Second Embodiment FIG. 3A is a schematic block diagram showing a flashover detection alarm device according to a second embodiment of the present invention, and FIG. 3B is a flowchart showing the operation thereof. The first feature of the second embodiment is that an engine package 20 such as a gas heat pump (GHP) or a cogeneration apparatus that does not receive light from the outside is used.
This is characterized in that the optical sensor 3 is provided near the ignition plug 1 without providing any special light shielding means. That is, this is a configuration example in which it is not necessary to provide the sensor mounting member 7 that blocks external light as in the first embodiment.

The second feature of the second embodiment is that FIG.
In addition to the optical sensor 3 and the alarm 5 shown in FIG. 2A, a rotation speed sensor 21 for detecting the rotation speed of the engine is provided, and the rotation speed fluctuation is calculated in the system controller 4 from the output of the rotation speed sensor 21. The difference is that a rotation fluctuation state determination unit 22 that determines whether the calculated rotation fluctuation is large is provided. The system controller 4 is configured to drive the alarm 5 based on the output of the optical sensor 3 and the determination result of the rotation fluctuation state determination unit 22. This embodiment also has a light detection level discriminating unit for discriminating whether or not the output of the optical sensor 3 exceeds a light detection level as a preset reference value, as in the first embodiment. It is. In addition, since the rotation speed sensor is already provided if the engine is applied to the GHP or the cogeneration device, it is not necessary to attach it specially, which is advantageous in cost.

The operation of the flashover detection / alarm device having the above configuration will be described with reference to FIG. First, in step SP1, the system controller 4
Determines whether the rotation fluctuation is large by the rotation fluctuation state determination unit 22. If it is determined that the rotation speed is large, the output of the optical sensor 3 is determined by the light detection level determination unit in step SP2. It is determined whether or not the output level exceeds the output level. If it is determined that the output of the optical sensor 3 has exceeded the output level, in step SP3,
For example, the warning lamp 17 as the warning device 5 is continuously turned on to notify the user of flashover. On the other hand, if it is determined in step SP2 that the output of the optical sensor 3 does not exceed the output level, it is determined in step SP4 that the spark plug or the like is defective. Notify that it is defective. In the above-described determination process, the fluctuation of the rotational speed is measured because, when a flashover occurs, the ignition of the fuel by the spark plug is not performed accurately, so that the number of explosions for the engine rotation becomes irregular, and as a result, This is because the fluctuation of the rotation speed increases.

In this embodiment, it is possible to determine that flashover has occurred when the engine speed fluctuates and flashover light is detected. , It is possible to accurately determine whether or not flashover has occurred. If the rotation fluctuation is larger than the predetermined reference value but does not exceed the light output level (refer to NO in step SP2), it may indicate that a problem such as an increase in the gap of the spark plug has occurred. The user can be notified (step SP4)
), There is an advantage that the user can be notified of the engine failure more finely.

The present invention is not limited to the above embodiment, and various design changes can be made without departing from the scope of the present invention. Hereinafter, such an embodiment will be described. (1) FIG. 4A is a schematic block diagram of an embodiment showing a modification of the sensor mounting member, and FIG. 4B is an explanatory diagram of the sensor mounting member. In this embodiment, the sensor mounting member 7 is configured by a bundle of a large number of optical fibers 30 so that the flashover light can be guided to the optical sensor 3 provided at a position separated from the ignition plug 1. As shown in FIG. 4B, the sensor mounting member 7 forms an inner cylindrical surface 33 on which light is incident around the ignition plug 1 by stacking the input surfaces 31 of the optical fibers 30. A light-shielding layer 32 is formed around the detection device 34 including the sensor mounting member 7 and the optical sensor 3 so that light from outside does not enter. According to this embodiment, it is possible to dispose the optical sensor 3 avoiding the vicinity of the high-temperature engine. Further, the light in the entire circumferential direction of the ignition plug 1 can be incident on the optical sensor 3 by the inner cylindrical surface 33 of the light incidence.

(2) In the second embodiment, the fluctuation of the engine speed is used for determining whether or not flashover has occurred. However, a torque fluctuation sensor for detecting a torque fluctuation,
By installing various sensors that detect abnormal changes in the engine state caused by flashover, such as acceleration sensors that detect vibration fluctuations, and by combining this with light detection,
The accuracy of flashover detection can be improved.

[Brief description of the drawings]

FIG. 1A is a schematic block diagram showing a first embodiment of the present invention, and FIG. 1B is another circuit configuration diagram of a notification means.

FIG. 2 is a flowchart for explaining the method of the present invention.

FIG. 3A is a schematic block diagram showing a second embodiment of the present invention, and FIG. 3B is a flowchart showing an example of the operation.

FIG. 4 (A) is a schematic block diagram showing a third embodiment of the present invention, and FIG. 4 (B) is an explanatory view of a main part thereof.

FIG. 5 is a longitudinal sectional view of a spark plug for explaining a flashover phenomenon.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Spark plug, 2 ... Light detection means, 4 ... System controller, 5 ... Alarm device, 6 ... Notification means, 21 ... Rotation speed sensor, 22 ... Rotation fluctuation state discrimination part.

Claims (3)

[Claims] 1. A light detecting means (2) for detecting light generated by flashover of a spark plug (1) of a spark ignition engine, and a flashover occurring based on an output of the light detecting means (2). For notifying the user of the
(6) An alarm device for detecting flashover of a spark plug, comprising: 2. A light detecting means (2) for detecting light generated by flashover of a spark plug (1) of a spark ignition engine; an engine speed detecting means (21) for detecting an engine speed; Rotation fluctuation state determination means (22) for calculating a rotation fluctuation based on the determined engine rotation speed and determining whether the rotation fluctuation is greater than a predetermined reference value.
And the output of the light detecting means 2 and the rotational speed fluctuation state determining means (2
A determination means (4) for determining whether or not a flashover has occurred based on the determination result of (2), and an alarm means (5) for notifying the user that the flashover has occurred. A flashover detection / warning device for a spark plug, characterized in that the warning means (5) is activated in response to the determination means (4) determining that a flashover has occurred. 3. A process for detecting light generated by flashover of a spark plug of a spark ignition engine, and determining that flashover has occurred when the detected light exceeds a predetermined light detection level. And detecting the flashover of the spark plug.