System and method for preventing bearing seizure by means of a knock sensor

Abstract

System for preventing bearing seizure by means of a knock sensor, comprising: a knock sensor (15) provided on one side of an internal combustion engine (10) and configured to measure vibration transmitted by the internal combustion engine (10) and to detect knocking of the internal combustion engine (10); and a control device (20) provided for controlling the operation of the internal combustion engine (10) and for assessing that a bearing (13) of the internal combustion engine (10) is damaged when the magnitude of the vibration of the internal combustion engine (10) input by the knock sensor (15) is greater than a bearing damage assessment threshold, while the internal combustion engine (10) is operated in a bearing damage detection range, which is a range in which knocking does not occur.

Description

[0001] This application claims priority to Korean Patent Application No. 10-2018-0100513 filed on August 27, 2018, the entire contents of which are incorporated herein by reference.

[0002] The invention relates to a system and a method for preventing seizure of a bearing by means of a knock sensor, wherein the knock sensor detects damage to a bearing provided on a movable part in a region other than a region in which knocking (abnormal combustion, combustion knocking) of an internal combustion engine is detected and reduces friction, thereby preventing seizure of the internal combustion engine or damage to the internal combustion engine caused by seizure of the bearing and enabling a driver to prevent damage to the bearing from progressing to seizure of the bearing.

[0003] An internal combustion engine of a vehicle is operated in a state where various components are coupled together, and a bearing is mounted on a portion where components are coupled and operated to reduce friction.

[0004] In Fig. 1A shows a section where a connecting rod 11 and a crankshaft are coupled together. A large connecting rod eye of the connecting rod 11 is coupled to a crankshaft in such a way that it has a crank pin 12 encloses, and a warehouse 13 is between the large connecting rod eye of the connecting rod 11 and the crank pin 12 In addition, a gap is provided between the large connecting rod eye of the connecting rod 11 and the crank pin 12 filled with combustion engine oil to reduce friction between the large connecting rod eye of the connecting rod 11 and the crank pin 12to reduce when the combustion engine is running. In a normal condition ( Fig. 1A) is a gap between the bearing 13 and the crank pin 12 small, and an oil film is between the bearing 13 and the crank pin 12 formed by the combustion engine oil, so that the noise and vibration are low.

[0005] However, if the internal combustion engine is operated for a long period of time under abnormal conditions (e.g. foreign matter ingress, oil shortage, poor crankpin machining condition, etc.) ( Fig. 1B) and in a condition in which the bearing 13 is worn and damaged, a gap G between the bearing 13 and the crank pin 12 enlarged, and a noise and vibration are caused by a knocking of the connecting rod 11 and the crank pin 12 generated during operation of the combustion engine.

[0006] If the above-mentioned condition continues, as in Fig. 1C shown, the bearing 13 on the crank pin 12 fixed, and therefore an oil supply between the large connecting rod eye of the connecting rod 11 and the crank pin 12 interrupted. If the internal combustion engine is operated in a condition in which the bearing 13 on the connecting rod 11 is damaged, as described above, the seizure of the bearing progresses 13 continues, and a metal contact occurs at the bearing 13 , the large connecting rod eye of the connecting rod 11 and the like, generating noise and vibration beyond the normal range. Likewise, the bearing 13 or the like.

[0007] If the warehouse 13is damaged due to an increase in frictional resistance, a blocking phenomenon of the vehicle's internal combustion engine is created. That is, if the bearing 13 is damaged, the engine's power is reduced due to an increase in frictional resistance, and the engine speed (rpm) is increased when an accelerator pedal is depressed to compensate for the reduction in power. However, an increase in the engine speed repeats a faulty cycle in which the frictional resistance of the portion where the bearing 13 installed, is increased again. At this time, the temperature of the friction section is increased due to an increase in frictional resistance, seizure is accelerated, as the temperature of the bearing 13 increased, and the camp 13 adjacent components, ie the connecting rod 11and the crank pin 12 are also damaged, causing damage to the combustion engine.

[0008] If the bearing seizes 13 occurs as described above, this leads to a general problem with the internal combustion engine and causes a problem such as engine stalling. This cannot be solved by simply repairing or replacing any of the components, and the entire internal combustion engine must be repaired or replaced.

[0009] An object of the invention is to provide a system and a method for preventing seizure of a bearing by means of a knock sensor, in which the knock sensor, which detects knocking of an internal combustion engine, detects vibration of the internal combustion engine in a range in which knocking (abnormal combustion, combustion knocking or pre-ignition) does not occur, thereby detecting damage to a bearing when the bearing in the internal combustion engine is damaged and preventing the damaged bearing from further seizing.

[0010] Another object of the invention is to provide a system and a method for preventing seizure of a bearing by means of a knock sensor, which can detect damage to a bearing in advance and send a warning signal to a driver so that the driver can detect damage to the bearing in advance to prevent seizure of the bearing and enable the driver to repair a vehicle.

[0011] Another object of the invention is to provide a system and method for preventing seizure of a bearing by means of a knock sensor, which enables the internal combustion engine to enter a limp-home mode when damage to the bearing is detected.

[0012] To achieve the above-mentioned objects, a bearing seizure prevention system using a knock sensor according to the invention may include a knock sensor provided on a side of an internal combustion engine and configured to measure vibration transmitted from the internal combustion engine and detect knocking of the internal combustion engine, and a controller configured to control operation of the internal combustion engine and judge (or evaluate or decide) that a bearing of the internal combustion engine is damaged when a magnitude of vibration of the internal combustion engine input from the knock sensor is larger than a bearing damage (damaged bearing) judgment threshold while the internal combustion engine is operated in a bearing damage (damaged bearing) detection range, which is a range in which knocking does not occur.

[0013] The control device may set the bearing failure detection range from a relationship between a rotational speed of the engine and any one of a load of the engine, an amount of air flowing into the engine, and a throttle opening degree.

[0014] The controller may set a plurality of bearing damage (damaged bearing) detection windows in each of which the rotational speed and the load of the internal combustion engine are within a specified range, and set a threshold value for detecting damage to the bearing for each bearing damage detection window.

[0015] When a cumulative number of times that the magnitude of the vibration of the internal combustion engine measured by the knock sensor is greater than the bearing damage judgment threshold (or bearing damage determination threshold) is equal to or greater than a predetermined cumulative number of times within a predetermined cycle, the controller may determine that the bearing is damaged.

[0016] The control device judges (or evaluates or decides) whether the knock sensor is in a normal state, and if the knock sensor is in a normal state, the control device judges whether the bearing is damaged.

[0017] The bearing seizure prevention system by means of the knock sensor according to the invention may further comprise warning means configured to inform an occupant of the damage to the bearing when the control device judges that the bearing is damaged.

[0018] The warning device may be a warning light provided on a side of an interior of a vehicle or a dashboard of the vehicle.

[0019] If it is judged that the bearing is damaged, the control device may control the internal combustion engine to operate at a predetermined safe maximum speed or below so that the damage to the bearing does not progress further.

[0020] If it is judged that the bearing is damaged, the control device may control the internal combustion engine to operate at a predetermined minimum speed that maintains ignition to prevent the internal combustion engine from locking.

[0021] The control device can process knocking noises caused by knocking during combustion and by bearing seizure among the signals transmitted to the knock sensor by means of a different frequency range.

[0022] Meanwhile, a method for preventing seizure of a bearing by means of a knock sensor according to the invention is characterized in that it is judged (or evaluated or decided) that a bearing provided between a crankshaft and a connecting rod is damaged when a magnitude of vibration input to a knock sensor mounted on an internal combustion engine is larger than the magnitude of a predetermined bearing damage (damaged bearing) judgment vibration while the internal combustion engine is operated in a region where knocking does not occur.

[0023] The method according to the invention may comprise judging whether the bearing starts to be damaged by detecting whether the magnitude of the vibration measured by the knock sensor exceeds a predetermined magnitude while the internal combustion engine is operated in the range in which knocking does not occur, and determining that the bearing is damaged when the magnitude of the vibration measured by the knock sensor repeatedly exceeds the predetermined magnitude.

[0024] Judging whether the bearing starts to be damaged may include judging whether the internal combustion engine is operating in a bearing damage (damaged bearing) detection range in which damage to the bearing is detected, and determining, by the controller, that the bearing is damaged when the magnitude of the vibration measured by the knock sensor is greater than a predetermined bearing damage (damaged bearing) judgment threshold at which the bearing is considered to be damaged.

[0025] In judging whether the internal combustion engine is operated in the bearing failure detection range, the bearing failure detection range may be set by a relationship between the rotational speed of the internal combustion engine and any one of a load of the internal combustion engine, an amount of air entering the internal combustion engine, and a throttle opening degree.

[0026] When determining that the bearing is damaged, a plurality of bearing damage detection windows in each of which the rotational speed and the load of the internal combustion engine are within a specified range may be set, and a threshold value for detecting damage to the bearing for each bearing damage detection window may be set to determine damage to the bearing.

[0027] The method according to the invention may further include checking the knock sensor to judge whether the value output by the knock sensor is within the range in which knocking of the internal combustion engine is detected or includes an abnormal signal other than the knock signal. Here, if each of checking the knock sensor and judging whether the bearing is starting to be damaged is satisfied, determining that the bearing is damaged may be performed.

[0028] In judging whether the bearing starts to be damaged, the number of times that the magnitude of the vibration measured by the knock sensor exceeds the bearing damage judgment threshold may be accumulated, and when the accumulated number of times exceeds a predetermined number of times within a predetermined cycle, it may be determined that the bearing is damaged.

[0029] The testing of the knock sensor may include judging whether an output value of the knock sensor enters a range in which the knock sensor is monitored, and judging, by the control device, whether there is an abnormality in the output value of the knock sensor when the output value of the knock sensor enters the range in which the knock sensor is monitored.

[0030] The method according to the invention may further comprise operating a warning means provided in an interior of a vehicle for informing an occupant of damage to the bearing when the bearing is damaged, after judging whether the bearing starts to be damaged.

[0031] The method according to the invention may further comprise performing an emergency mode for limiting the speed of the internal combustion engine to the predetermined safe maximum speed or below, after judging whether the bearing starts to be damaged.

[0032] When performing limp home mode, the engine maintains a speed equal to or greater than a predetermined minimum speed that maintains ignition.

[0033] When testing the knock sensor, damage to the bearing is detected using a different frequency range when knocking noises caused by knocking during combustion and bearing seizure are signal processed.

[0034] The invention is explained in more detail with reference to the drawing. The drawing shows: Fig. 1A to Fig. 1C are sectional views illustrating a process in which a bearing seizes in a region where a connecting rod and a crankpin are connected in an internal combustion engine; Fig. 2 is a block diagram illustrating a system for preventing seizure of a bearing by means of a knock sensor according to the invention; Fig. 3 is a flowchart illustrating a method for preventing seizure of a bearing by means of a knock sensor according to the invention; and Fig. 4 and Fig. 5 diagrams illustrating a region where knocking occurs and a region where knocking does not occur in an operating range of an internal combustion engine.

[0035] A system and method for preventing seizure of a bearing by means of a knock sensor according to a preferred embodiment of the invention will be described in detail below with reference to the drawings.

[0036] A system for preventing seizure of a bearing by means of a knock sensor according to a preferred embodiment of the invention comprises a knock sensor 15 , which is mounted on one side of an internal combustion engine 10 is installed to measure a combustion engine 10 transmitted vibration to detect knocking of the combustion engine, and a control device 20 which is intended to control the operation of the internal combustion engine 10 and to assess that a warehouse 13 of the combustion engine 10 is damaged if a magnitude of the vibration of the combustion engine 10 , which is generated by the knock sensor 15entered is greater than a bearing damage assessment threshold while the combustion engine 10 is operated in a bearing damage detection range, which is a range in which knocking does not occur.

[0037] The knock sensor 15 to detect knocking caused by vibration in the combustion engine 10 is generated when the combustion engine 10 is operated on one side of the combustion engine 10 provided.

[0038] The knock sensor 15 normally detects knocking of the combustion engine 10 by the vibration that occurs in the combustion engine 10 is generated when the combustion engine 10 is operated in an area where knocking occurs. Since the combustion engine 10the knocking is generated at a certain load or above according to the speed, the knock sensor detects the knocking by the magnitude of the vibration in a range where knocking may occur (a knocking occurrence range in Fig. 4), and detects no knocking in the other area (a knock non-occurrence area in Fig. 4). The knock non-occurrence region is a region in which the load is light and the vibration caused by the operating vibration of another mechanism is greater than the vibration caused by combustion. For this reason, knocking may be mistakenly detected in the knock non-occurrence region, so that knocking is not judged in the knock non-occurrence region. If the ignition timing at which the maximum braking torque (MBT) is generated is earlier than the knock occurrence ignition timing (detonation boundary line DBL) when the ignition timing is normally advanced, this can be considered the knock non-occurrence region. The knock occurrence region and the knock non-occurrence region in the relationship between the engine speed 10 and the load can be shown in a diagram as shown in Fig. 4. In addition, the control device analyzes 20, which will be described later, the vibration that is transmitted to the knock sensor 15 in the knock non-occurrence area to prevent damage to the bearing 13 In other words, according to the invention, the knock non-occurrence range is the bearing damage detection range.

[0039] On the other hand, although it is possible to divide an operating range of the internal combustion engine into the knocking occurrence range and the knocking non-occurrence range (the bearing failure detection range) according to a relationship between the rotational speed and the load, the operating range of the internal combustion engine into the knocking occurrence range and the knocking non-occurrence range according to a relationship between the rotational speed of the internal combustion engine 10 and the amount of air that enters the combustion engine 10 flows, or a relationship between the speed of the combustion engine 10and a throttle opening degree. That is, in the diagram of Fig. 4 Instead of the load, the air quantity or the throttle opening degree can be the y-axis.

[0040] Furthermore, just as a knock detection window is set to detect knocking, if knocking of the internal combustion engine 10 by the knock sensor 15 recorded, even if damage to the bearing 13 by the knock sensor 15 is recorded as in Fig. 5, a plurality of bearing damage detection windows are set to detect damage to the bearing 13 Here, each window can be defined as an area in which the speed and load of the combustion engine are within a certain range.

[0041] On the other hand, the bearing damage detection window may be set different from or equal to the knock detection window for detecting knocking caused by combustion. If a crank angle at which the maximum vibration occurs is different, the bearing damage detection window and the knock detection window may be set differently. However, a threshold value for detecting bearing damage and a threshold value for detecting knocking, which are different from each other, are used in the bearing damage detection window and the knock detection window, respectively. Likewise, the threshold values ​​that are different from each other are used for detecting bearing damage. 13 used for each bearing damage detection window.

[0042] In general, one knock sensor 15 for the four-cylinder combustion engine 10I-type engine, and two knock sensors are provided for a V-type internal combustion engine. At this time, based on the crank angle of each cylinder, a vibration signal related to the connecting rod bearing can be 13 of each cylinder. At this time, it is also possible to confirm in which cylinder the bearing is damaged by processing a signal input to the bearing damage detection window according to a load and speed. 13 is damaged.

[0043] In general, noise is maximized when a contact area between the connecting rod 11 and the crank pin 12before top dead center (TDC), however, it can be varied depending on the characteristics of the internal combustion engine. Therefore, if the crank angle at which the magnitude of the vibration corresponding to a rotation angle of the crankshaft is maximum is assigned for each cylinder, it is possible to detect in which cylinder the bearing 13 is damaged. Since the positions in which the crankshaft and the connecting rod 11 generate a knocking noise, corresponding to a vibration transmission path caused by the damage to the bearing 13 generated vibration are different, the bearing damage detection window can be divided and used for each cylinder.

[0044] However, although the cylinder in which the bearing 13is damaged, can be determined as described above, it is not necessary to detect the cylinder in which the bearing is damaged. This is because if the bearing 13 in any of the cylinders of the combustion engine 10 is damaged, since repairs such as dismantling and replacing the combustion engine are required, it is only necessary to determine whether the bearing 13 is damaged.

[0045] The control device 20 controls the combustion in the internal combustion engine 10 according to a driver operation and processes a signal from the knock sensor 15 is entered to assess whether the connecting rod bearing 13 is damaged. For example, the control device 20 an internal combustion engine control section 21 , which is configured to control the combustion of the internal combustion engine 10controls according to the driver's operation, a signal input section 22 in which the signal from the knock sensor 15 is entered, and a bearing damage assessment section 23 which is configured to prevent damage to the bearing 13 by a signal input section 22 input signal is evaluated. A method for preventing bearing seizure by means of a knock sensor, which will be described later, is incorporated in the control device 20 stored as a logic, so that the method for preventing bearing seizure by means of the knock sensor from the control device 20 is carried out.

[0046] The internal combustion engine control section 21 the combustion in the combustion engine 10 control to enable the combustion engine 10generates a required torque according to the driver's operation, the driving condition of a vehicle, etc. Since the control of the combustion engine 10 , which is controlled by the internal combustion engine control section 21 is carried out, a conventional control of the combustion engine 10 corresponds, a detailed description of it is omitted.

[0047] The signal input section 22 receives the signal from the knock sensor 15 is output. The control device 20 processes the signal sent to the signal input section 22 is entered to report damage to the bearing 13 to capture.

[0048] The bearing damage assessment section 23 assesses whether the combustion engine 10 in the knock non-occurrence range, according to the load and speed of the combustion engine 10, which is controlled by the internal combustion engine control section 21 be obtained, and if the combustion engine 10 is operated in the knock non-occurrence range, the bearing damage assessment section assesses 23 by the vibration transmitted via the knock sensor 15 is entered whether the warehouse 13 is damaged. The bearing damage assessment section 23 provisionally determines that the camp 13 is damaged if the magnitude of the vibration transmitted to the knock sensor 15 is greater than the bearing damage judgment threshold. In addition, the number of times the magnitude of the vibration detected by the knock sensor 15 measured exceed the bearing damage judgment threshold, and when the cumulative number of times exceeds a predetermined number of times within a predetermined cycle, the bearing damage judgment section determines 23that the camp 13 is damaged. The method for preventing bearing seizure by means of the knock sensor, which will be described later, is essentially described in the bearing damage judgment section 23 carried out to assess whether the camp 13 is damaged.

[0049] However, if the bearing damage assessment section 23 assessed that the camp 13 is damaged, the combustion engine control section 21 that the combustion engine 10 can be operated in an emergency mode. Since the damage progresses quickly when the bearing 13 begins to be damaged, in order to prevent further damage, the combustion engine control section 21 the combustion engine 10such that it operates at a speed equal to or less than the predetermined safe maximum speed. In addition, to prevent ignition of the internal combustion engine 10 is switched off, the combustion engine control section 21 the operation of the combustion engine 10 at the predetermined minimum speed that the ignition can maintain. At this time, if the bearing damage assessment section 23 judged that the magnitude of the vibration detected by the knock sensor 15 entered, exceeds the bearing damage assessment threshold even once, the internal combustion engine control section 21 that the combustion engine enters emergency mode.

[0050] A warning device can alert an inmate to report damage to the storage 13 to recognize when the control device 20 assessed that the camp 13is damaged.

[0051] For example, a warning light 31 installed in an interior or on a dashboard of the vehicle may be used as the warning device.

[0052] If damage to the bearing 13 is detected, the control device 20 the warning light 31 to enable the inmate to assess the damage to the bearing 13 recognizes.

[0053] On the other hand, a loudspeaker installed on one side of the vehicle's interior can be used as another example of a warning device. If damage to the bearing 13 is detected, the loudspeaker can generate a warning sound to allow the occupant to detect the damage to the bearing 13 recognizes.

[0054] If it is judged that the magnitude of the vibration exceeds the bearing damage judgment condition even once, the warning device is also activated.

[0055] The following is based on Fig. 3 describes the method for preventing bearing seizure by means of the knock sensor according to the invention.

[0056] The method for preventing bearing seizure by means of the knock sensor according to the invention is carried out by the system for preventing bearing seizure by means of the knock sensor described above, and when it is judged that the magnitude of the vibration transmitted to the knock sensor 15 which is connected to the combustion engine 10 mounted, is greater than the magnitude of a predetermined bearing damage assessment vibration, while the internal combustion engine 10 operated in the area where knocking does not occur, it is judged that the bearing 13, which is between the crankshaft and the connecting rod 11 intended is damaged.

[0057] According to the invention, in a state in which the knock sensor 15 is operated normally when a vibration greater than the bearing damage judgment threshold is detected by the knock sensor 15 is entered when the combustion engine 10 operated in the knock non-occurrence range, judges that the bearing is damaged.

[0058] In a knock sensor test step S110 It is assessed whether a knock sensor 15 output value is within a range in which knocking of the combustion engine 10is detected, and whether an abnormal signal, such as damage to the bearing, is input. If the bearing is damaged, the knock sensor receives knock signals caused by the damaged bearing from both an area where engine knocking occurs and an area where engine knocking does not occur, and the knock sensor check step S110 is performed based only on the signal in the bearing damage detection area to prevent the bearing from being mistakenly judged as damaged. Since in the knock sensor test step S110 assesses whether the knock sensor 15 is operated normally, it is possible to reduce an error that occurs when the damaged bearing 13 only through a bearing damage assessment step S120which will be described later. That is, in a case where, when the knock sensor signal having the maximum value or a value equal to or greater than a certain value is continuously generated due to the damaged bearing, the vibration is judged to be abnormal vibration such as an unusual vibration caused by the bearing other than combustion knocking, in a case where it is judged that an abnormal signal other than combustion knocking is input to the knock sensor when the knock signal is continuously generated at the same level even if ignition retardation is performed according to a judgment that knocking is occurring in the combustion knocking range, or in a case where an abnormal signal is detected at a certain frequency different from the combustion knock detection frequency.is continuously generated and caused by the damaged bearing, it is possible to perform logic configured to detect the damaged bearing.

[0059] For this purpose, the knock sensor test step includes S110 a knock sensor monitoring area entry judgment step S111 to judge whether the output value of the knock sensor 15 has entered an area in which the knock sensor 15 is monitored, and a knock sensor signal test step S112 to judge whether there is an abnormal signal, such as damage to the bearing, in the output value of the knock sensor 15 when the output value of the knock sensor 15 has entered the area in which the knock sensor 15 is monitored.

[0060] The knock sensor monitoring area entry judgment step S111judges whether the output value of the knock sensor 15 in the area in which the knock sensor 15 is monitored to proceed to a subsequent step when the knock sensor output value 15 which is greater than a general knock sensor signal is input a certain number of times repeatedly, if the signal is not returned to the normal level under the same conditions, even if the ignition delay occurs as a result of knock detection, or if an abnormal signal occurs in the frequency range which is different from that of the combustion knock. If damage to the bearing 13 occurs, a vibration is transmitted from both the area where combustion knocking occurs and the area where no combustion knocking occurs to the knock sensor 15To distinguish between knocking caused by combustion in the knock occurrence range and signal amplification caused by the damaged bearing, a frequency of knocking caused by combustion is used as a specific frequency that matches the inherent characteristics of the internal combustion engine. A frequency that best embodies vibration characteristics caused by the damaged bearing is selected from frequencies other than the frequency range caused by combustion knocking, and it is possible to detect the damaged bearing at this frequency. This makes it possible to detect the damaged bearing even in the range where combustion knocking occurs without confusing it with combustion knocking.This is one of both the method of detecting the damaged bearing in the range where the combustion knocking does not occur and the method of discriminating whether the gain of the knock sensor . 15 output signal is caused by combustion knocking or the damaged bearing.

[0061] The knock sensor signal test step S112 judges whether an abnormal signal other than combustion knocking is detected by the knock sensor 15 to the control device 20 This means that the knock sensor signal test step S112 judges that an abnormal signal caused by external noise such as the damaged bearing is input when the maximum value or the calibration value of the output value of the knock sensor 15 is equal to or greater than a predetermined value.

[0062] In the knock sensor signal test step S112It is judged whether the abnormal signal, such as the damaged bearing, is considered to be the knock sensor signal 15 is entered, and damage to the bearing 13 is detected by the knock sensor 15 only detected if the signal from the knock sensor 15 is not normal.

[0063] On the other hand, if the conditions of the knock sensor monitoring area entry judgment step S111 and the knock sensor signal test step S112 are not met, the process returns to an initial step. That is, if the output value of the knock sensor 15 is in an area in which the knock sensor 15 is not monitored, or if in the knock sensor signal test step S112 It is judged that there is no abnormal signal, such as damage to the bearing, in the output value of the knock sensor 15 the process is returned to the initial step.

[0064] On the other hand, as a method for preventing erroneous detection for the damaged bearing, if it is possible to clearly judge whether the damaged bearing is clearly detected by the signal in the bearing damage detection area (the area where knocking caused by combustion does not occur), the knock sensor signal checking step S112 be omitted.

[0065] The bearing damage assessment step S120 uses the output value of the knock sensor 15 to assess whether the bearing is damaged.

[0066] For this purpose, the bearing damage assessment step includes S120 a bearing damage detection area entry assessment step S121 to judge whether the output value of the knock sensor 15 in the area where damage to the bearing 13 is recorded, and a bearing damage determination step S122 to determine that the warehouse13 is damaged if the output value of the knock sensor 15 is greater than a signal value which is predetermined to mean that the bearing 13 is damaged.

[0067] The bearing damage detection area entry assessment step S121 judges on the basis of a ratio of the load in relation to the speed whether the combustion engine 10 in the bearing damage detection area.

[0068] Since the combustion engine 10 a knocking is generated at a certain load or above according to the speed, a knocking with the size of a vibration is detected in the area where knocking can occur (the knocking occurrence area in Fig. 4), and will not be in the area (the knock non-occurrence area in Fig. 4) below the above mentioned range. This can be seen as a curve in Fig.4, where the knock non-occurrence area in which knocking is not detected is defined as the bearing damage detection area, and damage to the bearing 13 is determined by analyzing the signals sent to the knock sensor 15 entered vibration is recorded.

[0069] In the bearing damage detection area entry assessment step S121 It is assessed accordingly whether the combustion engine 10 in the knock non-occurrence range, ie the bearing damage detection range.

[0070] On the other hand, although the operating range of the internal combustion engine is divided into the knocking occurrence range and the knocking non-occurrence range (the bearing failure detection range) according to a relationship between the rotational speed of the internal combustion engine and the load, the operating range of the internal combustion engine can be divided into the knocking occurrence range and the knocking non-occurrence range (the bearing failure detection range) according to a relationship between the rotational speed of the internal combustion engine and the load. 10and the amount of air that enters the combustion engine 10 occurs, or a relationship between the speed and the throttle opening of the combustion engine 10 be divided into the knocking occurrence area and the knocking non-occurrence area.

[0071] The bearing damage investigation step S122 determines that the bearing is damaged when the knock sensor 15 output signal, ie the magnitude of the vibration meets a predetermined bearing damage assessment condition, while the internal combustion engine 10 in the knock non-occurrence range. Here, the bearing damage judgment condition is a circumstance in which the magnitude of the vibration detected by the knock sensor 15 measured, repeatedly exceeds the threshold a certain number of times.

[0072] That is, the number of times the output value of the knock sensor 15is greater than the bearing damage judgment threshold, it is counted cumulatively, and if the cumulative number of times exceeds the certain number of times of bearing damage determination within a predetermined cycle, it is determined that the bearing 13 is damaged.

[0073] Just as the knock detection window is set to detect knocking when knocking of the combustion engine 10 recorded, even if damage to the bearing 13 is recorded, the bearing damage detection window must be set to detect damage to the bearing 13 to capture.

[0074] Meanwhile, the bearing failure detection window may be set different from or equal to the knock detection window for detecting combustion-induced knocking. If a crank angle at which the maximum vibration occurs is different, the bearing failure detection window and the knock detection window may be set differently. However, a threshold value for detecting bearing failure and a threshold value for detecting knocking, which are different from each other, are used in the bearing failure detection window and the knock detection window, respectively.

[0075] The one knock sensor 15 is in the four-cylinder combustion engine 10 At this time, based on the crank angle of each cylinder, the vibration signal related to the connecting rod bearing 13of each cylinder. At this time, it is also possible to confirm in which cylinder the bearing is damaged by processing a signal input to the bearing damage detection window according to a load and speed. 13 is damaged.

[0076] In general, noise is maximized when the contact area between the connecting rod 11 and the crank pin 12 before top dead center (TDC). Therefore, if the crank angle at which the magnitude of the vibration corresponding to a rotation angle of the crankshaft is maximum is assigned for each cylinder, it is possible to detect in which cylinder the bearing 13 is damaged. Since the positions in which the crankshaft and the connecting rod 11 generate a knocking noise, corresponding to a vibration transmission path caused by the damage to the bearing 13generated vibration are different, the bearing damage detection window can be divided and used for each cylinder.

[0077] Since the knocking noises of the connecting rod caused by the damaged bearing 11 and the crank pin 12 have different frequencies, one of them can be set to differ from the frequency of the knocking generated by combustion.

[0078] If any of the bearing damage detection area entry judgment step S121 and the bearing damage determination step S122 is not met, the process is returned to the initial step. That is, if the operating range of the combustion engine 10 is not the bearing damage detection range, or if the magnitude of the vibration detected by the knock sensor 15entered is not greater than the bearing damage judgment threshold, the process is moved to a point before the bearing damage detection area entry judgment step S121 However, if possible, an assessment can be made solely through the bearing damage assessment step S122 clearly carry out the bearing damage detection area entry assessment step S121 not be carried out.

[0079] Meanwhile, the knock sensor test step S110 and the bearing damage assessment step S120 It is preferable to perform a bearing damage determination step S130 described below only if each of the knock sensor test steps S110 and the bearing damage assessment step S120 However, the knock sensor test step S110not be carried out if the damaged bearing has only been assessed by the bearing damage assessment step S120 is clearly assessed.

[0080] However, any of the knock sensor test steps S110 and the bearing damage assessment step S120 be carried out first, and the other can be carried out later. In this case, too, the bearing damage determination step S130 performed when each of the knock sensor test steps S110 and the bearing damage assessment step S120 are fulfilled.

[0081] In addition, as described above, it is possible that damage to the bearing 13 by only performing the bearing damage assessment step S120 is carried out without the knock sensor test step S110 However, since it is not assessed whether the knock sensor 15normal or not, a possibility that an error occurs if there is damage to the bearing 13 Accordingly, it is preferable to perform each of the knock sensor testing steps S110 and the bearing damage assessment step S120 to carry out.

[0082] In addition, if the signal value of the knock sensor 15 in the knock sensor test step S110 is continuously generated even if the ignition delay occurs at a level at which knocking does not occur, the bearing damage determination step S130 be carried out immediately.

[0083] If in the bearing damage assessment step S120 it is assessed that the camp 13 is damaged while the condition in the knock sensor test step S110 is fulfilled, in the bearing damage determination step S130 determines that the camp 13 is damaged.

[0084] If in the bearing damage determination step S130 it is determined that the warehouse 13 is damaged, the warning device installed in the vehicle is activated in a warning device activation step S141 activated so that the occupant can identify the damaged bearing. For example, a warning light 31 installed on one side of the interior or the dashboard of the vehicle, and the warning light 31 is switched on so that the occupant can see the damage to the bearing 13 Meanwhile, in the warning device activation step S141 possible to compensate the inmate for the damage to the camp 13 not just by switching on the warning light 31 , but also by a warning sound or vibration, thereby preventing the damage to the bearing from progressing to the point of seizure.

[0085] In particular, even if the magnitude of the vibration detected by the knock sensor 15 measured, the bearing damage assessment threshold in the bearing damage determination step S122 only once, it is possible to activate the warning device in the warning device activation step S141 If the magnitude of the vibration exceeds the bearing damage judgment threshold in the bearing damage detection step S122 only once, the warning device is activated immediately without any additional action, such as switching the ignition on or off. This is to prevent further damage to the bearing, as the damage progresses quickly if the bearing 13 is damaged.

[0086] The combustion engine 10 is operated at the predetermined safe maximum speed or below in an emergency mode step S142 operated so that the warehouse 13does not progress further into a seizure condition if in the bearing damage determination step S130 it is determined that the warehouse 13 is damaged.

[0087] In the emergency mode step S142 Furthermore, the combustion engine 10 operated at the predetermined minimum speed, which maintains the ignition, so that the ignition of the internal combustion engine 10 can be maintained.

[0088] If the bearing is damaged, it allows the vehicle to be driven in a state where the power is limited and the ignition of the combustion engine is prevented by the emergency mode step S142 is maintained so that the vehicle can be driven to a location where the vehicle can be repaired.

[0089] However, even if the magnitude of the vibration detected by the knock sensor 15measured, exceeds the bearing damage judgment condition (for example, the size exceeds a predetermined size, and the cumulative number of times exceeds a certain number of times) only once, allows the emergency mode step S142 can be carried out.

[0090] The system and method for preventing seizure of the bearing by means of the knock sensor according to the invention having the above-described configuration uses the knock sensor to detect damage to the bearing in the area where knocking does not occur, so that it is possible to prevent knocking of the bearing in advance.

[0091] In the system and method according to the invention, when damage to the bearing is detected, the warning means notifies a driver of the damage to the bearing and enables the driver to repair the internal combustion engine.

[0092] Furthermore, when damage to the bearing is detected, the system and method according to the invention allow the internal combustion engine to enter limp home mode to limit the speed of the internal combustion engine, thereby making it possible to prevent the damaged bearing from progressing further to seizure and preventing the internal combustion engine from locking up to allow the vehicle to be driven to a safety zone or a garage. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] KR 1020180100513

[0001]

Claims

[1] A system for preventing seizure of a bearing by means of a knock sensor, comprising: a knock sensor (15) provided on one side of an internal combustion engine (10) and configured to measure a vibration transmitted from the internal combustion engine (10) and detect knocking of the internal combustion engine (10); and a control device (20) provided for controlling the operation of the internal combustion engine (10) and for judging that a bearing (13) of the internal combustion engine (10) is damaged when a magnitude of vibration of the internal combustion engine (10) input from the knock sensor (15) is greater than a bearing damage judgment threshold while the internal combustion engine (10) is operated in a bearing damage detection range, which is a range in which knocking does not occur. [2] System according to claim 1, wherein the control device (20) sets the bearing damage detection range from a relationship between a rotational speed (rpm) of the internal combustion engine (10) and any one of a load of the internal combustion engine (10), an amount of air flowing into the internal combustion engine (10), and a throttle opening degree, and wherein the control device (20) sets a plurality of bearing damage detection windows in each of which the rotational speed and the load of the internal combustion engine (10) are within a specified range, and sets a threshold value for detecting damage to the bearing (13) for each bearing damage detection window. [3] The system according to claim 1 or 2, wherein, when a cumulative number of times that the magnitude of vibration of the internal combustion engine (10) measured by the knock sensor (15) is greater than the bearing damage judgment threshold is equal to or greater than a predetermined cumulative number of times within a predetermined cycle, the control means (20) determines that the bearing (13) is damaged. [4] A system according to any one of claims 1 to 3, wherein the control means (20) judges that an abnormal signal is transmitted to the knock sensor (15), and when it is confirmed that the knock sensor (15) detects a signal other than knocking caused by combustion, the control means (20) judges that the bearing (13) is damaged. [5] The system according to any one of claims 1 to 4, further comprising warning means configured to inform an occupant of the damage to the bearing (13) when the control device (20) judges that the bearing (13) is damaged. [6] System according to one of claims 1 to 5, wherein, if it is judged that the bearing (13) is damaged, the control device (20) controls the internal combustion engine (10) such that it is operated at a predetermined safe maximum speed or below so that the damage to the bearing (13) does not progress further, and wherein, when it is judged that the bearing (13) is damaged, the control device (20) controls the internal combustion engine (10) to operate at a predetermined minimum speed that maintains ignition to prevent the internal combustion engine (10) from locking up. [7] The system according to any one of claims 1 to 6, wherein the control device (20) processes knocking noises caused by knocking during combustion and by bearing seizure among the signals transmitted to the knock sensor (15) by means of a different frequency range. [8] Method for preventing seizure of a bearing by means of a knock sensor, characterized by that a bearing (13) provided between a crankshaft and a connecting rod (11) is judged to be damaged when a magnitude of vibration input to a knock sensor (15) mounted on an internal combustion engine (10) is larger than the magnitude of a predetermined bearing damage judgment vibration while the internal combustion engine (10) is operated in a region in which knocking does not occur. [9] Method according to claim 8, comprising: Judging, by means of a control device (20), whether the bearing (13) begins to be damaged by detecting whether the magnitude of the vibration measured by the knock sensor (15) exceeds a predetermined magnitude while the internal combustion engine (10) is operated in the range in which knocking does not occur; and Determining by means of the control device (20) that the bearing (13) is damaged when the magnitude of the vibration measured by the knock sensor (15) repeatedly exceeds the predetermined magnitude. [10] The method of claim 9, wherein assessing whether the bearing (13) begins to be damaged comprises: Judging by means of the control device (20) whether the internal combustion engine (10) is operated in a bearing damage detection range in which damage to the bearing (13) is detected (S121); and Determining by means of the control device (20) that the bearing (13) is damaged if the magnitude of the vibration measured by the knock sensor (15) is greater than a predetermined bearing damage judgment threshold at which the bearing (13) is considered to be damaged (S122), wherein, in judging whether the internal combustion engine (10) is operating in the bearing damage detection range, the bearing damage detection range is set by a relationship between the rotational speed of the internal combustion engine (10) and any one of a load of the internal combustion engine (10), an amount of air entering the internal combustion engine (10), and a throttle opening degree, and wherein, upon determining that the bearing (13) is damaged, a plurality of bearing damage detection windows, in each of which the rotational speed and the load of the internal combustion engine (10) are within a specified range, are set, and a threshold value for detecting damage to the bearing (13) is set for each bearing damage detection window to determine damage to the bearing (13). [11] The method according to claim 9, further comprising checking the knock sensor (15) to judge by the control device (20) whether the value output from the knock sensor (15) is in the range in which knocking of the internal combustion engine (10) is detected or has an abnormal signal other than the knock signal (S110), wherein, when each of the checking of the knock sensor (15) and the judging whether the bearing (13) starts to be damaged is satisfied, the determination that the bearing (13) is damaged is performed (S120). [12] The method according to claim 10, wherein in judging whether the bearing (13) starts to be damaged, the number of times that the magnitude of the vibration measured by the knock sensor (15) exceeds the bearing damage judgment threshold is accumulated, and when the accumulated number of times exceeds a predetermined number of times within a predetermined cycle, it is determined that the bearing (13) is damaged. [13] The method according to claim 11, wherein checking the knock sensor (15) comprises judging by the control device (20) whether an output value of the knock sensor (15) enters a range in which the knock sensor (15) is monitored (S111), and judging by the control device (20) whether there is an abnormality in the output value of the knock sensor (15) when the output value of the knock sensor (15) enters the range in which the knock sensor (15) is monitored (S112). [14] The method according to any one of claims 8 to 13, further comprising actuating a warning means provided in an interior of a vehicle for alerting an occupant of damage to the bearing (13) when the bearing (13) is damaged, after judging whether the bearing (13) starts to be damaged by the control device (20) (S141). [15] The method according to any one of claims 8 to 14, further comprising performing an emergency mode for limiting the rotational speed of the internal combustion engine (10) to the predetermined safe maximum rotational speed or below, after judging whether the bearing (13) starts to be damaged, by means of the control device (20) (S142). [16] Method according to claim 11, wherein, when testing the knock sensor (15), damage to the bearing (13) is detected by means of a different frequency range when knocking noises caused by knocking during combustion and by bearing seizure are signal processed.

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