KR920000995B1 - Pre-heated flug trouble display circuit in diesel engine - Google Patents

Abstract

The circuit for automatically displaying disorder generated from a plurality of preheating plugs, facilitates checking of the engine starting in a short time. The circuit of the engine having a power- supply battery (1), preheating switch (2), preheating relay (3) for supplying power from battery (1) to preheating plugs (4a-4d), a plurality of the plugs (4a-4d) for preheating suction air in cylinder, comprises a comparing device (13) for converting variable voltage level from disorder of the plugs to the voltage signal and amplifying the signal and generating the output voltage signal; OP amplifier (14) for amplifying the signal from the device (13); transistor (19) for switching ON/OFF by the signals; light emitting diode (21) for displaying disorder of plugs.

Description

Preheating plug fault indication circuit of diesel engine

1 is a circuit diagram of a glow plug fault display circuit according to an embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

1: Battery power 2: Preheat switch

3: preheating relay 4a ~ 4d: preheating plug

8 ~ 12: Resistance 13: Comparator

14: OP amplifier 15-18, 20: resistance

19 transistor 21 fault light emitting diode

22: Zener diode 23 ~ 26: fault detection and display circuit

[Industrial use]

The present invention relates to a preheating plug fault display circuit of a diesel engine of the present invention, and more particularly, to a preheating plug fault display circuit configured to display an individual fault occurring in a plurality of preheating plugs.

[Traditional Technology and Problems]

In general, unlike a gasoline engine, in which a spark plug is used to ignite and burn a fuel, a diesel engine uses a heat generated when compressing air drawn into a cylinder to ignite and burn a fuel. This eliminates the need for an electric ignition device, such as in a gasoline engine, but requires a preheater to preheat the aspirated air to a suitable temperature. As a preheating device of such a diesel engine, a preheating plug is mainly used. The preheating plug is installed in each cylinder of the diesel engine and uses air, for example, a heating coil, that is sucked in during the intake stroke. Preheated by use.

By the way, when a failure such as overheating of the diesel engine or excessive heating of the heating coil installed inside the preheating plug occurs, the fault indicator of the driver's seat is conventionally only when all the preheating plugs installed in each cylinder are disconnected. The preheating plug failure is indicated on the display, so if only some of the preheating plugs are broken, it is not possible to identify which preheating plug has failed, and the startability of the diesel engine is poor due to the failure of the preheating plug. Will be lost. In addition, when the startability of the diesel engine is poor, the driver continues to start the starting motor forcibly, thereby overdischarging the battery and shortening the life of the battery as well as causing the battery discharge state to be poor. Problems such as this occur. In addition, if a failure occurs in only a part of the plurality of preheating plugs, it is difficult to know the location of the preheating plug. Therefore, all the preheating plugs installed in the plurality of cylinders need to be inspected one by one. There was a problem.

[Purpose of invention]

The present invention has been invented to solve the above-mentioned problems in the prior art, and it is possible to easily identify and repair the cause of a poor startability of a diesel engine by automatically detecting and displaying a failure occurring individually in a plurality of preheating plugs. The purpose is to provide a preheating plug fault indication circuit of a diesel engine.

[Configuration of Invention]

The preheating plug fault display circuit of the diesel engine according to the present invention for achieving the above object is supplied to the battery power source (1) and the preheating switch (2), and the battery power source (1) to a plurality of preheating plugs (4a ~ 4d) Preheating relay (3), a plurality of preheating plugs (4a to 4d) for preheating the air sucked into the cylinder, the potential difference detection position (a, b) on the power line connected to the plurality of preheating plugs (4a to 4d) in parallel Receives the voltage level change according to whether the glow plugs 4a to 4d are broken as a voltage signal, and differentially amplifies the input voltage signal to determine whether the glow plug has a predetermined level. A comparator 13 for outputting a voltage signal of a level, an OP amplifier 14 for receiving and amplifying the output voltage signal of the comparator 13, and when a high level signal is inputted from the OP amplifier 14, Low level signal from the OP amplifier 14 The transistor 19 which is turned off when input, and when the transistor 19 is turned on, the battery power source 1 is supplied and emits light, while the battery power source 1 is supplied when the transistor 19 is turned off. The failure detection and display circuit unit 23, which is configured as a failure display light emitting diode 21 for indicating whether or not the preheating plug is broken, is connected to the plurality of preheating plugs 4a to 4d, respectively. , 24, 25, 26).

[Action]

In the present invention configured as described above, by detecting the potential difference generated between the potential difference detection position (a, b) on the power supply line of the preheating plug, the individual failures generated in the plurality of preheating plugs to automatically display the diesel to maintain the preheating plug By eliminating the need to inspect every preheating plug installed on each cylinder of the engine, this saves the time and money required to service the preheating plug.

EXAMPLE

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a circuit diagram showing a specific configuration of a preheating plug fault display circuit according to an embodiment of the present invention. In the drawing, reference numeral 2 denotes a preheating switch, 3 denotes a preheating relay, 4a to 4d a preheating plug, and 23 to 26. Fault detection and display circuits are shown respectively. The failure detection and display circuits 23 to 26 connected to the respective preheating plugs 4a to 4d have the same circuit configuration, and correspond to the plurality of the preheating plugs 4a to 4d, respectively. 4d) is connected in parallel to the power supply line. In FIG. 1, only the fault detection and display circuit unit 23 is representatively shown, and the operation diagrams of the other fault detection and display circuit units 24, 25, and 26 are shown. Since the failure detection and display circuit unit 23 is the same, a description thereof will be omitted.

In addition, since each of the preheating plugs 4a to 4d is formed of a resistor, a heating coil for preheating the air sucked into the cylinder is simply indicated as a resistor in FIG.

In the circuit configuration shown in FIG. 1, first, when the driver turns on the preheating switch 2 to operate the diesel engine, the battery power source 1 passes through the preheating relay 3 to the respective preheating plugs 4a to 4d. Since the preheating plug generates heat and preheats the air sucked into the cylinder, in this case, when all the preheating plugs 4a to 4d perform the preheating operation normally, the battery power is supplied through the heating coil in the preheating plug. Since (1) flows normally, the potential difference detection position (for example, points (a) and (b) in the drawing) for detecting a voltage drop according to whether or not the preheating plug is broken on the power line of the corresponding preheating plugs 4a to 4d. The voltage drop at a predetermined level (for example, 100 to 200 mA) is generated. On the other hand, for example, when one of the preheating plugs is disconnected and a failure occurs, the battery power source 1 does not flow with the corresponding preheating plug that has the failure, and thus the voltage difference between the potential difference detecting positions a and b of the preheating plug. No signal (i.e. voltage drop of 100 to 200 kHz) is generated.

Here, for example, an operation of detecting and displaying a failure of the preheating plug 4a will be described.

That is, the voltage drop (100-200 kV) generated on the power line of the preheating plug 4a is applied to both input terminals of the comparator 13 through the resistors 8 and 9, and the comparator ( 13), when the voltage drop signal is applied, the voltage drop signal is differentially amplified and outputted to the OP amplifier 14 at the rear stage, and a breakdown or the like occurs in the preheating plug, so that the voltage signal is at the same level (for example, O). When the voltage is applied to the input terminal of the comparator 13, for example, the voltage signal of OV is outputted to the OP amplifier 14 at the rear stage. At this time, the resistors 8 and 10 are for setting the amplification factor of the voltage input to the comparator 13, and the resistors 9, 11 and 12 are provided for stabilization of the circuit.

Next, the output voltage signal of the comparator 13 is amplified by the OP amplifier 14 and then applied to the transistor 19 having a collector terminal connected to the output side of the preheating relay 3. When 4a) is normally operated, a voltage signal of high level is applied to the transistor 19 as a voltage signal of 100 to 200 kV is generated between the potential difference detecting positions a and b on the power line of the preheating plug 4a. Since the transistor 19 is turned on and the battery power source 1 is supplied, the LED 21 for the fault display is driven by being applied. However, a breakdown or the like occurs in the preheating plug and the output of the comparator 13 becomes OV ( That is, in the case where the voltage drop is not generated), the transistor 19 is turned off so that the battery power source 1 is not supplied so that the failure display light emitting diode 21 is not driven. Therefore, it is possible to accurately identify whether the corresponding glow plug 4a is broken by whether the failure display light emitting diode 21 emits light. At this time, the zener diode 22 is installed to prevent the overvoltage from being applied to the fault display light emitting diode 21, and the resistors 15 and 16 are used to set the voltage amplification factor of the OP amplifier 14. The resistor 18 is a bias resistor for the transistor 19, the resistors 17 and 20 are provided for stabilization of the circuit.

Further, other preheating plugs 4b to 4d connected in parallel to the output side of the preheating relay 3 while the fault detection and display circuits 24, 25 and 26, which are configured in the same manner as the fault detection and display circuit unit 23, are connected thereto. In the case of), the above-described fault detection and display operations for detecting a voltage level at the potential difference detecting positions a and b with respect to the preheating plug 4a and identifying whether there is a failure are similarly performed. The failures generated individually for the plurality of preheating plugs 4a to 4d provided can be accurately identified by whether the light emitting diodes emit light.

In addition, although this embodiment demonstrates the case where four preheating plugs are installed, it can be applied to the diesel engine in which more preheating plugs were installed.

[Effects of the Invention]

As described above, according to the preheating plug fault display circuit of the diesel engine according to the present invention, since a failure occurring in the preheating plug of some of the plurality of preheating plugs can be accurately identified, The poor startability can be easily repaired, greatly reducing the time and cost required to service the glow plugs.

Claims (1)

Preheating relay 3 for supplying the battery power source 1, the preheating switch 2, the battery power source 1 to the plurality of preheating plugs 4a to 4d, and a plurality of preheating units for preheating the air sucked into the cylinder. In a diesel engine with plugs 4a to 4d, each of the preheating plugs 4a to 4d between the potential difference detecting positions a and b on a power supply line in which the plurality of preheating plugs 4a to 4d are connected in parallel. Comparator 13 for receiving a voltage level change according to whether or not a fault is inputted as a voltage signal and differentially amplifying the input voltage signal to output a voltage signal of a predetermined level or a low level voltage signal according to whether the corresponding preheating plug is broken. And an op amp 14 that receives and amplifies the output voltage signal of the comparator 13, and when a high level signal is input from the op amp 14, the op amp 14 is turned on and a low level signal from the op amp 14; Transistor 19 that is turned off when is input, and this transistor When the battery 19 is turned on, the battery power source 1 is supplied and emits light. When the transistor 19 is turned off, the battery power source 1 is not supplied and does not emit light. A plurality of fault detection and display circuits 23 to 26 composed of a fault display light emitting diode 21 for displaying a plurality of the preheating plugs 4a to 4d are provided to correspond to the respective preheating plugs 4a to 4d. Preheating plug fault indication circuit of a diesel engine, characterized in that it automatically displays individual faults.

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