KR100992757B1 - Engine protecting device causing EGR cooler fail condition in vehicle - Google Patents

Abstract

The engine protection device of the present invention is caused by the gas leaking into each of the EGR coolers 1 so as to detect in advance the cracks of the EGR coolers 1 that lower the temperature of the exhaust gas reused by combustion through the engine. In addition to the installation of a pressure sensor 5 for detecting pressure and a flow rate sensor 6 for detecting leaking coolant, an ECU 4 which implements control through measurement signals of the sensors 5 and 6 is started. According to the starter 20, which is a device, and a protection circuit, the ECU 4, which has determined the abnormal state of the EGR cooler 1 initially through the sensors 5 and 6, starts the starter 20 of the starter 20. In addition, the engine operating condition is controlled to prevent engine damage, while preventing excessive engine start-up and engine relief and excessive white smoke caused by the crack of the EGR cooler 1, Post-processing PMC (Paticulate Matters Catalyst) There is a feature that can prevent clogging phenomenon.

Easy, breakdown, engine protection

Description

Engine protecting device causing EGR cooler fail condition in vehicle

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an EEG cooler, and more particularly to an engine protection device according to an abnormal operation of an IG cooler.

In general, the exhaust gas emitted from the engine contains a large amount of harmful components such as CO, HC, and NOx (nitrogen compounds). Of these, NOx has a characteristic that the amount of NOx increases as the combustion temperature increases. In order to reduce, various methods for reducing the combustion temperature of the engine have been implemented.

As such, in order to reduce the amount of NOx, which is a pollutant, a method using an exhaust gas recirculation (EGR) device is generally used. Such an exhaust gas recirculation device includes a part of exhaust gas discharged after combustion in a suction mixer. By flowing into the combustion chamber, the mixer has a characteristic of lowering the combustion temperature by lowering the density of the mixer without changing the air-fuel ratio of the mixer.

That is, when the EGR needs to reduce the amount of NOx according to the operating state of the engine, when a part of the exhaust gas is supplied to the intake intake through the EGR valve and introduced into the combustion chamber together with the mixer, the EGR flows into the combustion chamber. Since the exhaust gas is an inert gas and the volume of the intake gas does not change, the density of the mixer is relatively lowered and the combustion speed is lowered by lowering the propagation speed of the flame, thereby preventing the rise of the combustion temperature to suppress the generation of NOx. do.

As such, the gas supplied to the engine combustion chamber through the EGR lowers the high temperature of about 600 ° C. to about 140 ° C. For this purpose, the EGR cooler circulates through the path through which the EGR gas passes to circulate the coolant. Will be installed.

However, the EGR cooler that circulates the coolant to cool the EGR gas is always subject to the risk of failure (eg, cracks), for example if the EGR cooler fails during engine operation. Gas can enter the coolant circulation path, which can overheat the coolant and cause an overflow phenomenon, or some coolant flows into the engine combustion chamber beyond the EGR cooler, causing engine failure and failure. There may be a phenomenon.

In other words, when the coolant leaks due to minute cracks in the EGR cooler while driving, the coolant pressure and the coolant temperature gradually increase, and when a relatively large crack occurs, the coolant temperature warning lights and the fuel cutting are output as a sudden increase. Deterioration occurs.

In addition, when the engine is turned off while the coolant is leaked due to the crack of the EGR cooler, as the start-up is turned off, the coolant pressure is greater than the internal pressure of the EGR cooler and the coolant flows toward the EGR cooler. In this state, when the engine is started again, the accumulated coolant enters the engine and generates engine relief and white smoke, and if severe, scuffing occurs, and the coolant is detected by the reed valve housing sensor to start the engine. Will be blocked.

Accordingly, the present invention has been made in view of the above, and as the coolant detects leaked water by using the conductor property of the coolant circulating the EGR cooler to cool the EGR gas supplied to the combustion chamber of the engine, the coolant is In addition to detecting leaks in the EGR cooler, which can cause leakage, it also detects an increase in the coolant pressure so that EGR gas can be detected quickly, preventing engine failure or failure due to an EGR cooler failure. The purpose is to make it possible.

In order to achieve the above object, the present invention is equipped with an EGR cooler that coolant circulates through the coolant inlet and the coolant outlet to reduce the exhaust gas temperature, and uses the sensor to detect the coolant leaked from the EGR cooler. In the exhaust gas recirculation apparatus for forming a circuit that turns on, and supplies a portion of the exhaust gas generated from the engine to the combustion chamber,

The sensor is installed on the reed valve portion of the EGR cooler is installed as a flow sensor for detecting the leaked and elevated flow rate of the EGR cooler into the space of the reed valve housing, and the discharge portion of the cooling water introduced into the EGR cooler Composed of a pressure sensor that detects the pressure rise due to the exhaust gas leaking from the EGR cooler,

The protection circuit formed with the ECU further includes a starter control circuit leading to a starting line with a relay between the battery and the starter for starting the engine, and a signal circuit for reading signals of the pressure sensor and the flow sensor.

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The flow pressure sensor may include a sensor housing coupled to a space of a reed valve housing to which a reed valve of an EGR cooler is coupled;

A pair of sensing electrodes protruding to sense a flow rate collected in the space of the reed valve housing;

In addition to the voltage line for supplying voltage to the sensing electrode, characterized in that consisting of a sensing line consisting of a signal line connected to the ECU while connecting a voltage line to one of the resistance.

According to the present invention, the leakage of the EGR cooler that causes the coolant leakage by determining whether or not the leakage by using the conductor property of the coolant circulating the EGR cooler for cooling the hot gas while surrounding the EGR gas supply path supplied to the engine combustion chamber There is an effect that can prevent the engine abnormality caused by the starting abnormality and engine relief and white soot caused by the crack.

In addition, the present invention detects the crack of the EGR cooler that cools the EGR gas supplied to the engine combustion chamber and prevents engine abnormalities and failures, thereby incurring additional costs such as engine boring damaged by the EGR cooler. In addition, it also prevents excessive smoke generation, which is blocked by the post-treatment PMC (Paticulate Matters Catalyst), thereby preventing unnecessary costs caused by abnormal EGR coolers.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Since the exemplary embodiments of the present invention may be embodied in various different forms, one of ordinary skill in the art to which the present invention pertains may be described herein. It is not limited to the Example to make.

Figure 1 (a) is a block diagram of the engine protection device according to the abnormal operation of the cooler cooler according to the present invention, the engine protection device according to the present invention to supply a part of the exhaust gas generated from the engine to the combustion chamber exhaust EGR cooler (1) having a coolant inlet (2) and a coolant outlet (3) to surround the EGR, a gas recirculation device, and a coolant outlet (3), and the EGR cooler (1), respectively, to provide pressure and coolant due to gas leakage. A sensor for detecting a flow rate due to leakage, a circuit configured to input a measurement signal sensed by the sensor, and an ECU 4 for implementing engine control, and the ECU according to an abnormality of the EGR cooler 1. And a protection circuit formed together with the ECU 4 to perform engine control in 4).

To this end, the EGR cooler 1 surrounds the exhaust gas flow path supplied to the engine combustion chamber through the EGR, as shown in FIG. 1 (b), while the coolant inlet 2 into which the coolant flows is directed toward the gas inlet. And a cooling water outlet 3 through which the cooling water exits is formed toward the gas outlet.

In addition, the sensor is a pressure sensor (5) for detecting the pressure rise due to the leakage of the exhaust gas due to the crack (cracks) of the EGR cooler 1, and the coolant leaked due to the crack (cracks) of the EGR cooler (1) It consists of a flow rate sensor (6) for detecting the raised flow rate of the sensor, these sensors (5, 6) all form a circuit to transmit a measurement signal to the ECU (4).

In this case, the pressure sensor 5 is typically installed as a portion for discharging the cooling water introduced into the EGR cooler 1, and the flow sensor 6 is disposed at the EGR cooler 1 surrounding the outlet portion through which the exhaust gas is discharged. It is installed on the provided Reed Valve.

In addition, the flow sensor 6 is a sensor housing 7 coupled to the space of the reed valve housing 10 to which the reed valve of the EGR cooler 1 is coupled, as shown in FIG. ) And a sensing electrode 8 which protrudes to sense the flow rate of the coolant accumulated in the space of the reed valve housing 10 and a sensing line 9 which transmits a signal detected by the sensing electrode 8 to the ECU 4. )

Here, two sensing electrodes 8 are formed in pairs, and the sensing line 9 has one voltage line together with voltage lines 9a and 9b respectively supplying voltages to the two sensing electrodes 8. It consists of a signal line 9c leading to the ECU 4 while being connected via a resistor R to 9b.

Also, as shown in FIG. 2, the protection circuit is formed together with the ECU 4 between the battery 30 for supplying power to the respective devices and the starter 20 for starting the engine. The ECU 4 forms a starter control circuit for controlling the starter 20 through the start line 40 having a relay, and receives a measurement value generated by the flow sensor 6 connected to the battery 30. It forms a signal circuit with the flow sensor 6, and forms a warning circuit with a warning light (50) which is turned on to inform the abnormal state through the signal generated by the flow sensor (6).

Here, the starter control circuit means a starter circuit of a general vehicle.

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

The engine protection device of the present invention is a pressure due to the gas leaking from the EGR cooler (1) in order to detect in advance the crack of the EGR cooler (1) that lowers the temperature of the exhaust gas reused by combustion through the engine The pressure sensor 5 for detecting the rise and the flow rate sensor 6 for detecting the elevated flow rate of the leaked coolant are installed, and the ECU 4 for implementing control through the measurement signals of the sensors 5 and 6 is provided. It consists of the starting circuit of the starter 20 which is an engine starting device, and a protection circuit. Accordingly, the ECU 4, which initially determined the abnormal state of the EGR cooler 1 through the sensors 5 and 6, cuts off the start circuit of the starter 20, and operates the engine to prevent engine damage. Control the state. In this way, the aftertreatment PMC (Paticulate Matters Catalyst) is blocked due to excessive soot caused by an engine failure while preventing starting abnormalities due to a crack of the EGR cooler 1 and engine relief and excessive white smoke. There is a feature to prevent the.

To this end, the present invention forms an engine protection circuit together with an EGR cooler 1, a gas pressure sensor 5, a flow pressure sensor 6, and the like together with an engine starting circuit formed by the ECU 4 with the starter 20. As shown in FIG. 2, the protection circuit of the engine includes a starter 20 control circuit, which is an engine start circuit having a plurality of relays controlled by the ECU 4, between the battery 30 and the ECU 4, and a pressure. A warning circuit provided with a sensor 5 and a signal circuit between the flow sensor 6 and the ECU 4 for detecting a leak of the EGR cooler 1, and a warning lamp 50 to recognize an abnormal state of the EGR cooler 1. It is formed into a circuit.

The protection circuit of such an engine may shut down the ECU 4 when the exhaust gas leaks due to the crack of the EGR cooler 1 or when the coolant circulating the EGR cooler 1 leaks to cool the exhaust gas. Works through. As shown in Fig. 1 (a) and (b), when a circulating process is carried out after entering the EGR cooler 1 wrapped to lower the gas temperature supplied to the combustion chamber after passing through the EGR, the exhaust gas recirculating device, In addition, it is implemented through gas leakage and cooling water leakage due to cracks formed in the EGR cooler 1.

That is, when the engine and the EGR cooler 1 are continuously operated in a state where cracks are formed in the EGR cooler 1, the cracks of the EGR cooler 1 leak the exhaust gas toward the coolant. This coolant side leakage of the gas leads to an increase in pressure of the coolant flowing through the EGR cooler (1).

As such, the pressure rise of the coolant flowing through the EGR cooler 1 is detected by the pressure sensor 5 installed at the coolant outlet 3 of the EGR cooler 1 and transmitted to the ECU 4 through the ECU. If (4) determines that the pressure of the cooling water circulating in the EGR cooler 1 exceeds the set allowable pressure, the output of the engine is lowered to prevent engine abnormality while preventing an overflow phenomenon of the cooling water in the EGR cooler 1 and Then, the lymph home mode (Limp Home Mode) is performed.

At this time, the rise of the coolant pressure in the EGR cooler 1 is determined to be a range rising from the normal region of 0.5bar ~ 0.7bar to 1,2bar ~ 1.5bar region.

Here, the lymph-home mode (Limp-Home Mode) is a way to run even without the coolant when there is a problem in the cooling water circulation system, in the case of an eight-cylinder engine, the ECU alternately enters the fuel only four cylinders, the remaining four It is a control mode in which only the air is injected into the cylinder and cooled.

On the other hand, when the coolant leaks due to the crack of the EGR cooler 1 and accumulates in the reed valve housing 10 in which the reed valve is installed, the flow sensor 6 mounted on the reed valve housing 10 is cooled by the coolant. An electrical signal is generated according to the high ration of the engine and is sent to the ECU (4). The ECU (4), which has received this, is an abnormal phenomenon of the engine as the coolant flows into the combustion chamber together with the gas due to leakage of the coolant from the EGR cooler (1). You will implement controls to prevent this.

This is because if the coolant is leaked due to the crack of the EGR cooler 1 and the engine is started again, the coolant accumulated on the EGR cooler 1 side enters the engine at the pressure of the coolant larger than the internal pressure of the EGR cooler. Silver engine relief and white fumes are generated, as well as severe scuffing. Therefore, the ECU 4 uses the signal of the flow sensor 6 provided on the reed valve housing 10 side of the EGR cooler 1 to block the phenomenon in advance.

As shown in FIG. 2, when the flow rate of the coolant accumulated on the reed valve housing 10 of the EGR cooler 1 is detected through the sensing electrode 8 forming the flow sensor 6, the sensing electrode ( The current generated through 8 generates a voltage difference between the voltage line 9b and the signal line 9c through the resistor R.

In this way, the signal for the voltage difference generated by the flow sensor 6 through the resistor R is detected on the ECU 4 connected to the voltage line 9b, and the ECU 4 uses the detected voltage difference. The control for engine protection is realized while recognizing the coolant leveled toward the reed valve housing 10 of the EGR cooler 1. That is, the ECU 4 protects the engine by turning off the starter 20 by sending a control signal to the relay of the starter control circuit constituting the starting circuit.

At the same time, the warning lamp 50 connected to the flow sensor 6 is turned on by the voltage difference generated by the flow sensor 6, which warns the driver that a coolant leak has occurred due to the crack of the EGR cooler 1. Is given.

1 (a), (b) is a configuration diagram of the engine protection device according to the abnormal operation of the cooler cooler according to the present invention

Figure 2 is a circuit diagram for protecting the engine when the EG cooler abnormality according to the present invention

    <Description of the symbols for the main parts of the drawings>

1: EGR cooler 2: Cooling water inlet

3: coolant outlet 4: ECU

5: gas pressure sensor 6: flow pressure sensor

7: sensor housing 8: sensing electrode

9: sensing line 9a, 9b: voltage line

9c: signal line 10: reed valve housing

20: starter 30: battery

40: starting line 50: warning light

Claims (3)

EGR cooler that coolant circulates coolant inlet and coolant outlet to reduce exhaust gas temperature, and forms a circuit to turn on ECU side and warning lamp by using sensor to detect coolant leaked from the EGR cooler, and exhaust generated from engine In the exhaust gas recirculation apparatus for supplying a portion of the gas to the combustion chamber, The sensor is installed on the reed valve portion of the EGR cooler is installed as a flow sensor for detecting the leaked and elevated flow rate of the EGR cooler into the space of the reed valve housing, and the discharge portion of the cooling water introduced into the EGR cooler Composed of a pressure sensor that detects the pressure rise due to the exhaust gas leaking from the EGR cooler, The protective circuit formed with the ECU further includes a starter control circuit connected to a starting line with a relay between a battery and an engine starter, and a signal circuit for reading signals of the pressure sensor and the flow sensor. Engine protection device due to cooler abnormal operation. delete The method of claim 1, wherein the flow pressure sensor is a sensor housing coupled to the space of the reed valve housing to which the reed valve (Reed Valve) of the EGR cooler is coupled; A pair of sensing electrodes protruding to sense a flow rate accumulated in the space of the reed valve housing; Engine protection device according to the abnormal operation of the cooler cooler, characterized in that consisting of a sensing line consisting of a signal line connected to the ECU connected to the voltage line of one side and a voltage line for supplying voltage to the sensing electrode, respectively. .

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