Apparatus and method for diagnosing a positive crankcase ventilation breather line

Abstract

An apparatus and method for diagnosing a PCV breather line. The apparatus includes a crankcase pressure sensor installed on a PCV breather line including a front end connected to an intake line and a rear end connected to a crankcase, and detecting the pressure in the crankcase; and a processor, which diagnoses abnormality of the PCV breather line based on the crankcase pressure.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2019-0165927, filed on Dec. 12, 2019, which is hereby incorporated by reference herein in its entirety. Technical Field

[0003] The present disclosure relates to an apparatus and method for diagnosing a positive crankcase ventilation (PCV) breather line. Background Art

[0004] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

[0005] The positive crankcase ventilation (PCV) system connects a breather hose as a ventilation pipe to the air filter or intake manifold to forcibly discharge and reburn the air pollutant gas generated in the crankcase, etc. In this conventional PCV system, we found that the structure of the breather line is complicated, so it may not be possible to diagnose abnormalities in the breather line using the MAP sensor (intake pressure sensor) installed on the engine. Summary of the invention

[0006] An aspect of the present disclosure provides a system and method for diagnosing a PCV (Positive Crankcase Ventilation) breather line, which diagnoses abnormality of a connection portion of the PCV breather line using a crankcase pressure sensor.

[0007] The technical problems to be solved by the present inventive concept are not limited to the above-mentioned problems, and any other technical problems not mentioned herein will be clearly understood by those skilled in the art to which the present disclosure belongs from the following description.

[0008] According to one aspect of the present disclosure, a device for diagnosing a positive crankcase ventilation (PCV) ventilation line includes: a crankcase pressure sensor installed on the PCV ventilation line including a front end connected to an intake line and a rear end connected to a crankcase, and configured to detect the pressure inside the crankcase; and a processor configured to diagnose an abnormality of the PCV ventilation line based on the detected crankcase pressure.

[0009] In one form, the processor is operable to determine whether to activate the diagnostic mode based on boost pressure, cooling water temperature, barometric pressure and engine status.

[0010] In one form, the processor may determine a diagnostic mode that activates a rear end of the PCV vent line when the engine state is in a cranking state.

[0011] In one form, the processor may calculate a negative pressure accumulation value and a positive pressure accumulation value of the crankcase based on the detected crankcase pressure, and compare the negative pressure accumulation value with the positive pressure accumulation value; and when no negative pressure is formed as a result of the comparison, determine that the rear end of the PCV ventilation line is abnormal.

[0012] In one form, the processor may determine a diagnostic mode that activates a front end of the PCV vent line when the engine status is an operating state.

[0013] In one form, when the accelerator pedal position change rate is equal to or greater than a reference change rate, the processor may calculate the current negative pressure accumulation value of the crankcase based on the detected crankcase pressure; and when the ratio of the current negative pressure accumulation value to a predetermined reference value is equal to or less than the reference ratio, it is determined that the front end of the PCV ventilation line is abnormal.

[0014] According to aspects of the present disclosure, a method for diagnosing a PCV ventilation line by a device for diagnosing a crankcase positive ventilation ventilation line is provided. Specifically, the device includes: a pressure sensor mounted on a PCV ventilation line having a front end connected to an intake line and a rear end connected to a crankcase; and a processor to diagnose the PCV ventilation line. In one form, the method for diagnosing the PCV ventilation line includes: detecting a pressure inside a crankcase by the pressure sensor; and diagnosing an abnormality of the PCV ventilation line based on the detected crankcase pressure by the processor.

[0015] In one form, the method further includes determining, by the processor, whether to activate the diagnostic mode based on boost pressure, cooling water temperature, barometric pressure, and engine status.

[0016] In one form, determining whether to activate the diagnostic mode may include determining to activate the diagnostic mode of the rear end of the PCV vent line when the engine state is a cranking state.

[0017] In one form, diagnosing an abnormality in the PCV ventilation line may include: after activating a diagnostic mode of the rear end, calculating a negative pressure accumulation value and a positive pressure accumulation value of the crankcase based on a detected crankcase pressure; comparing the negative pressure accumulation value and the positive pressure accumulation value to each other to determine whether a negative pressure is formed on the PCV ventilation line; and determining whether the rear end of the PCV ventilation line is abnormal based on the negative pressure formed on the PCV ventilation line.

[0018] In one form, determining whether the rear end of the PCV vent line is abnormal may include determining that the rear end of the PCV vent line is abnormal when negative pressure is not formed.

[0019] In one form, determining whether to activate the diagnostic mode may include determining to activate the diagnostic mode of the front end of the PCV ventilation line when the engine status is an operating state.

[0020] In one form, diagnosing an abnormality in the PCV ventilation line may include: when an accelerator pedal position change rate is equal to or greater than a reference change rate, calculating a current negative pressure accumulation value of the crankcase based on a detected crankcase pressure; determining the current negative pressure accumulation value as a current pressure accumulation value; and determining whether a ratio of the current pressure accumulation value to a predetermined reference value is equal to or less than a reference ratio to determine whether a front end of the PCV ventilation line is abnormal.

[0021] In one form, the method further includes determining that a front end of the ventilation line is abnormal when a ratio of a current pressure accumulation value to a predetermined reference value is equal to or less than a reference ratio.

[0022] Further areas of applicability will become apparent from the description provided herein.It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to make the present disclosure easier to understand, various forms of the present disclosure will now be described by way of example with reference to the accompanying drawings, in which:

[0024] Figure 1 is a block diagram showing a crankcase ventilation system;

[0025] Figure 2 is a block diagram showing a PCV vent line diagnostic device.

[0026] Figure 3 is a diagram showing abnormal and normal states of the rear end of the ventilation line;

[0027] Figure 4 is a diagram showing abnormal and normal states of the front end of the ventilation line; and

[0028] Figures 5 to 7 1 and 2 are flowcharts respectively showing a PCV ventilation line diagnostic method.

[0029] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. DETAILED DESCRIPTION

[0030] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate the same or corresponding parts and features.

[0031] Hereinafter, some forms of the present disclosure will be described in detail with reference to the exemplary drawings. When adding reference numerals to the components of each drawing, it should be noted that even if the same or equivalent components are shown on other drawings, they are represented by the same reference numerals. In addition, when describing the forms of the present disclosure, when it is determined that the relevant known configurations or functions hinder the understanding of the forms of the present disclosure, the detailed description of the relevant known configurations or functions will be omitted.

[0032] When describing components according to the form of the present disclosure, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are intended only to distinguish components from other components, and these terms do not limit the nature, order, or sequence of the components. Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as those commonly understood by those skilled in the art to which the present disclosure belongs. It will also be understood that the terms defined in general dictionaries should be interpreted as having a meaning consistent with the contextual meaning of the relevant field, and should not be interpreted in an idealized or overly formal sense, otherwise they are clearly defined herein.

[0033] The present disclosure relates to a technology for diagnosing abnormality of a connection portion of a breather line connected to an intake line (intake hose) and a top cover using a crankcase pressure sensor (CKCPS).

[0034] Figure 1 is a block diagram illustrating a crankcase ventilation system associated with the present disclosure.

[0035] Reference Figure 1 The crankcase ventilation system includes: a crankcase 10 , a top cover 20 , a pressure regulating box 30 , an air filter 40 , a compressor 50 , an intercooler 60 and an electronic throttle control (ETC) 70 .

[0036] The crankcase 10, which is a space in which a crankshaft is installed in a cylinder frame below a cylinder, is connected to a head cover 20. A positive crankcase ventilation (PCV) line L1 equipped with a PCV valve 25 is embedded in the head cover 20 so as not to be exposed to the outside.

[0037] The breather line L2 allows air to enter and leave the crankcase 10. The breather line L2 is a structure exposed to the outside. The front end of the breather line L2 is connected to the intake line L3, and the rear end thereof is connected to the crankcase 10. In this connection, the front end and the rear end of the breather line L2 can be fixed with a clamp.

[0038] A crankcase pressure (CKCP) sensor 15 is installed at the rear end of the breather line L2 . The crankcase pressure sensor 15 measures the internal pressure of the crankcase 10 .

[0039] The surge tank 30 is a space located between the electronic throttle control 70 and the intake manifold, and temporarily stores therein the air flowing in through the intake lines L3 to L5. The surge tank 30 supplies intake air to each cylinder of the engine through the intake manifold. A manifold absolute pressure (MAP) sensor 35 is installed at the front end of the surge tank 30. The MAP sensor 35 is a sensor that detects the pressure of the air flowing into the engine (i.e., the intake pressure). The processor 170 can determine the load state of the engine by sensing the pressure change of the intake manifold through the MAP sensor 35, and can indirectly measure the intake air amount.

[0040] An air cleaner 40 , a compressor 50 , an intercooler 60 , and an electronic throttle control 70 are installed on the intake lines L3 to L5 .

[0041] The air filter 40 removes (filters) foreign matter such as dust contained in air flowing in from the outside. The air filter 40 supplies the filtered air to the compressor 50. An air flow sensor (AFS) for measuring the amount of air sucked into the air filter 40 is installed near the air filter 40.

[0042] The compressor 50 as a part of the turbocharger compresses the filtered intake air supplied through the air filter 40. In this regard, the turbocharger includes a turbine rotated by exhaust gas exhausted from the engine, and a compressor for compressing the intake air rotated by the turbine and supplied to the engine.

[0043] The intercooler 60 is a device for cooling high-temperature compressed air compressed by the compressor 50. That is, the intercooler 60 cools the intake air compressed by the compressor 50 to increase the air density. The electronic throttle controller 70 adjusts the amount of intake air supplied to the engine.

[0044] The opening degree of the electronic throttle controller 70 is controlled by a processor 170 described later. A boost sensor 65 is installed on an intake line L5 connecting the intercooler 60 and the electronic throttle controller 70 to each other. The boost sensor 65 measures the boost pressure supplied by the compressor 50 to the intake manifold.

[0045] Figure 2 is a block diagram illustrating a PCV vent line diagnostic device according to one form of the present disclosure.

[0046] Reference Figure 2 The PCV ventilation line diagnostic device 100 includes: a CKCP sensor 15, a boost sensor 65, an atmospheric pressure sensor 110, a temperature sensor 120, a revolutions per minute (RPM) sensor 130, an accelerometer position sensor (APS) 140, a memory 150, an output device 160 and a processor 170.

[0047] The CKCP sensor 15 detects crankcase pressure (ie, pressure inside the crankcase). The boost pressure sensor 65 detects intake manifold pressure, ie, boost pressure.

[0048] The atmospheric pressure sensor 110 is attached to the air flow sensor to measure (detect) the atmospheric pressure (barometric pressure).

[0049] The temperature sensor 120 may measure the intake air temperature, the cooling water temperature, etc. That is, the temperature sensor 120 may include an air temperature sensor (air temperature sensor), a water temperature sensor (WTS), etc. The air temperature sensor may be implemented as a thermistor, which is attached to an air flow sensor (AFS) installed near the air filter 40 to detect the temperature of the intake air. The water temperature sensor is installed in the cooling water passage of the intake manifold to measure the temperature of the engine cooling water. As the water temperature sensor, a bimetal, a thermistor, etc. are used.

[0050] The RPM sensor 130 measures the revolutions per minute (RPM) of the engine. The accelerator position sensor 140 measures the position of the accelerator pedal, that is, the degree to which the accelerator pedal is depressed.

[0051] The memory 150 stores a program for the operation of the processor 170. The memory 150 may temporarily store input data and / or output data of the processor 170. The memory 150 may be implemented as at least one storage medium (recording medium) of a flash memory, a hard disk, a secure digital card (SD card), a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), a programmable read-only memory (PROM), an electrically erasable programmable ROM (EEPROM), an erasable programmable ROM (EPROM), a resistor, or the like.

[0052] The output device 160 outputs progress and / or results based on the operation of the processor 170 as visual information, auditory information, and / or tactile information, etc. The output device 160 may output the PCV ventilation line diagnosis result based on the instruction of the processor 170. The output device 160 may be implemented as a display, a speaker, and / or a vibrator, etc.

[0053] Processor 170 controls the overall operation of PCV vent line diagnostic device 100. Processor 170 may be implemented as at least one of an application specific integrated circuit (ASIC), a digital signal processor (DSP), a programmable logic device (PLD), a field programmable gate array (FPGA), a central processing unit (CPU), a microcontroller, and a microprocessor.

[0054] When power is supplied to the vehicle, the processor 170 detects the initial CKC pressure (CKC pressure before starting) through the CKCP sensor 15. Thereafter, when the engine is started, the processor 170 determines to activate the ventilation line diagnostic mode based on the boost pressure, atmospheric pressure, cooling water temperature, engine state and / or accelerator pedal position change rate. Specifically, the processor 170 detects the boost pressure, atmospheric pressure, cooling water temperature and engine state through the boost sensor 65, the atmospheric pressure sensor 110, the temperature sensor 120 and the RPM sensor 130, respectively. The processor 170 can determine to activate the ventilation line rear end diagnostic mode or activate the ventilation line front end diagnostic mode based on the boost pressure, atmospheric pressure, cooling water temperature and engine state. For example, when the boost pressure is equal to or less than 1 atmospheric pressure, the atmospheric pressure is equal to or less than 1 atmospheric pressure, and the cooling water temperature is equal to or greater than -7 degrees and the engine is shaking, the processor 170 determines to activate the ventilation line L2 rear end diagnostic mode (hereinafter, referred to as the activation of the rear end diagnostic mode). On the other hand, when the boost pressure is equal to or less than 1 atmosphere, the atmospheric pressure is equal to or less than 1 atmosphere, and the cooling water temperature is equal to or greater than -7 degrees, and the engine is running, the processor 170 determines to activate the ventilation line L2 front end diagnostic mode (hereinafter referred to as the activated front end diagnostic mode).

[0055] When it is determined that the rear end diagnostic mode is activated, the processor 170 starts the diagnosis of the rear end of the ventilation line L2. The processor 170 calculates the negative pressure cumulative value and / or the positive pressure cumulative value of the crankcase 10 based on the crankcase (hereinafter referred to as CKC) pressure measured (detected) by the CKCP sensor 15. If the CKC pressure is a negative number, the processor 170 detects the current CKC pressure (hereinafter referred to as CKC pressure) through the CKCP sensor 15, and adds the detected current CKC pressure to the previous negative pressure cumulative value CKC_neg (old) to calculate the current negative pressure cumulative value CKC_neg (new). On the other hand, when the initial CKC pressure is a positive number, the processor 170 detects the CKC pressure through the CKCP sensor 15, and adds the CKC pressure to the previous positive pressure cumulative value CKC_pos (old) to calculate the current positive pressure cumulative value CKC_pos (new).

[0056] The processor 170 compares the calculated current positive pressure cumulative value with the calculated current negative pressure cumulative value to determine whether negative pressure is formed. When negative pressure is formed, the processor 170 determines that the rear end of the ventilation line L2 is normal; when negative pressure is not formed, the processor 170 determines that the rear end of the ventilation line L2 is abnormal. Specifically, the processor 170 adds the current positive pressure cumulative value and the current negative pressure cumulative value to calculate the current pressure cumulative value CKC_P of CKC. When the current pressure cumulative value CKC_P is less than a reference cumulative value (e.g., -0.15), the processor 170 determines that the rear end of the ventilation line L2 is normal. On the other hand, when the current pressure cumulative value CKC_P is equal to or greater than the reference cumulative value, the processor 170 determines that the rear end of the ventilation line L2 is abnormal.

[0057] When it is determined that the front-end diagnostic mode is to be activated after the abnormality diagnosis of the rear end of the ventilation line L2 is completed, the processor 170 starts the diagnosis of the front end of the ventilation line L2. After activating the front-end diagnostic mode, the processor 170 uses the accelerometer position sensor 140 to detect the accelerator pedal position change rate to determine whether the accelerator pedal position change rate is equal to or greater than the reference change rate (e.g., 5% / second). When the vehicle is in a transition interval where the accelerator pedal position change rate is equal to or greater than the reference change rate, the processor 170 determines whether the initial CKC pressure is a negative number. When the initial CKC pressure is a negative number, the processor 170 calculates the current negative pressure accumulated value CKC2_neg (new) based on the CKC pressure measured by the CKCP sensor 15. That is, the processor 170 adds the CKC pressure measured by the CKCP sensor 15 to the previous negative pressure accumulated value CKC2_neg (old) to obtain the current negative pressure accumulated value.

[0058] The processor 170 determines the current negative pressure cumulative value as the current pressure cumulative value CKC_P2, and determines whether the ratio of the current pressure cumulative value to the reference value is equal to or lower than the reference ratio. In this regard, the reference value is predetermined based on test result data using a vehicle with a normal PCV ventilation line. When the ratio of the current pressure cumulative value to the reference value is lower than the reference ratio, the processor 170 determines that the front end of the ventilation line L2 is abnormal. When the ratio of the current pressure cumulative value to the reference value is higher than the reference ratio, the processor 170 determines that the front end of the ventilation line L2 is normal. In other words, the processor 170 diagnoses the abnormality of the front end of the ventilation line L2 based on the cumulative value of the pressure change of the ventilation line L2 in the acceleration / deceleration interval (i.e., the transition interval).

[0059] Figure 3 is a diagram showing abnormal and normal states of the rear end of the ventilation line associated with the present disclosure, Figure 4 is a diagram showing abnormal and normal states of the front end of the ventilation line associated with the present disclosure.

[0060] Reference Figure 3 , when the rear end of the breather line is normally connected to the crankcase 10 in the cranking state of the engine, negative pressure is formed on the breather line, but when the rear end of the breather line is separated, negative pressure is not formed on the breather line.

[0061] Reference Figure 4 , when the engine is running, negative pressure is formed in a transition interval where the accelerator pedal position change rate is equal to or greater than 5% / sec, and no negative pressure is formed in an interval where the accelerator pedal position change rate is less than 5% / sec.

[0062] Considering Figure 3 and Figure 4 The features shown, when starting the vehicle to diagnose an abnormality due to the rear end of the breather line being separated, Figure 2 The PCV vent line diagnostic device 100 shown in FIG. 1 determines whether negative pressure is formed on the vent line. In addition, the PCV vent line diagnostic device 100 uses the cumulative value of the pressure change of the vent line in the section where the pressure is applied in the acceleration / deceleration section during driving to diagnose the separation abnormality of the front end of the vent line.

[0063] Figures 5 to 7 is a flow chart illustrating a PCV vent line diagnostic method according to another form of the present disclosure.

[0064] First, when power is supplied to the vehicle, the processor 170 detects an initial CKC pressure through the CKCP sensor 15 (S110). The processor 170 measures the CKC pressure before starting.

[0065] The processor 170 determines whether the engine is started (S120).

[0066] When the engine is started, the processor 170 determines to activate the breather line rear end diagnostic mode in consideration of the vehicle state (S130). The processor 170 determines whether to activate the breather line rear end diagnostic mode based on the boost pressure, atmospheric pressure, cooling water temperature, and engine state obtained by the boost pressure sensor 35, the atmospheric pressure sensor 110, the temperature sensor 120, and the RPM sensor 130, respectively. When the boost pressure is equal to or less than 1 atmosphere, the atmospheric pressure is equal to or less than 1 atmosphere, and the cooling water temperature is equal to or greater than -7 degrees, and when the engine is cranking, the processor 170 determines to activate the breather line rear end diagnostic mode.

[0067] The processor 170 determines whether the initial CKC pressure is a negative number after activating the ventilation line rear end diagnostic mode (S140). When the initial CKC pressure is a negative number, the processor 170 uses the CKCP sensor 15 to detect the CKC pressure CKC_neg (current) (S150). The processor 170 adds the detected CKC pressure CKC_neg (current) to the previous negative pressure accumulated value CKC_neg (old) to calculate the current negative pressure accumulated value CKC_neg (new) (S160). On the other hand, when the initial CKC pressure is not a negative number, the processor 170 uses the CKCP sensor 15 to detect the CKC pressure CKC_pos (current) (S170), and adds the detected CKC pressure CKC_pos (current) to the previous positive pressure accumulated value CKC_pos (old) to calculate the current positive pressure accumulated value CKC_pos (new) (S180).

[0068] The processor 170 calculates the current CKC pressure accumulation value CKC_P using the current negative pressure accumulation value CKC_neg(new) and the current positive pressure accumulation value CKC_pos(new) (S190). That is, the processor 170 obtains the current CKC pressure accumulation value CKC_P by adding the current negative pressure accumulation value CKC_neg(new) and the current positive pressure accumulation value CKC_pos(new).

[0069] The processor 170 determines whether the current CKC pressure accumulation value CKC_P is less than a reference accumulation value (e.g., -0.15) (S200). When the current CKC pressure accumulation value CKC_P is less than the reference accumulation value, the processor 170 determines that a negative pressure is formed on the ventilation line L2. When the current CKC pressure accumulation value CKC_P is equal to or greater than the reference accumulation value, the processor 170 determines that no negative pressure is formed on the ventilation line L2. When the current CKC pressure accumulation value CKC_P is less than the reference accumulation value, the processor 170 determines that the rear end of the ventilation line L2 is normal (S210). On the other hand, when the current CKC pressure accumulation value CKC_P is equal to or greater than the reference accumulation value, the processor 170 determines that the rear end of the ventilation line L2 is abnormal (S220).

[0070] When the diagnosis of the rear end of the vent line L2 is completed, the processor 170 determines to activate the vent line front end diagnosis mode in consideration of the vehicle condition (S230). The processor 170 detects the boost pressure, atmospheric pressure, cooling water temperature, and engine state obtained by the boost pressure sensor 35, the atmospheric pressure sensor 110, the temperature sensor 120, and the RPM sensor 130, respectively. When the boost pressure is equal to or less than 1 atmosphere, the atmospheric pressure is equal to or less than 1 atmosphere, the cooling water temperature is equal to or greater than -7 degrees, and the engine is running, the processor 170 determines to activate the vent line front end diagnosis mode.

[0071] When the ventilation line front end diagnosis mode is activated, the processor 170 determines whether the accelerator pedal position change rate (APS change rate) is equal to or greater than the reference change rate (S240) through the APS 140. When the accelerator pedal position change rate is equal to or greater than the reference change rate, the processor 170 activates the transition mode (S250).

[0072] The processor 170 determines whether the initial CKC pressure is a negative number (S260). When the initial CKC pressure is a negative number, the processor 170 detects the CKC pressure CKC2_neg (current) through the CKCP sensor 15 (S270). The processor 170 adds the detected CKC pressure CKC2_neg (current) to the previous negative pressure accumulated value CKC2_neg (old) to calculate the current negative pressure accumulated value CKC2_neg (new) (S280). The processor 170 determines the calculated current negative pressure accumulated value CKC2_neg (new) as the current CKC pressure accumulated value CKC_P2 (S290).

[0073] The processor 170 determines whether the ratio of the current CKC pressure accumulation value CKC_P2 to the reference value exceeds the reference ratio (S300). When the ratio of the current CKC pressure accumulation value CKC_P2 to the reference value exceeds the reference ratio, the processor 170 determines that the front end of the ventilation line L2 is normal (S310). On the other hand, when the ratio of the current CKC pressure accumulation value CKC_P2 to the reference value does not exceed the reference ratio, the processor 170 determines that the front end of the ventilation line L2 is abnormal (S320).

[0074] The above description only illustrates the technical ideas of the present disclosure, and those skilled in the art may make various modifications and changes without departing from the basic features of the present disclosure. Therefore, the exemplary forms of the present disclosure are provided to explain the spirit and scope of the present disclosure, rather than to limit them, so that the spirit and scope of the present disclosure are not limited by the exemplary forms. The scope of the present disclosure should be interpreted based on the attached claims, and all technical ideas within the scope equivalent to the claims should be included in the scope of the present disclosure.

[0075] According to the present disclosure, a crankcase pressure sensor is added to a positive crankcase ventilation (PCV) breather line, thereby diagnosing abnormality of a connection portion of the breather line connected to an intake line and a header.

[0076] Although the present disclosure has been described above with reference to exemplary forms and drawings, the present disclosure is not limited thereto, and those skilled in the art to which the present disclosure pertains may make various modifications and changes to the present disclosure without departing from the spirit and scope of the present disclosure.

Claims

1. A device for diagnosing a crankcase positive ventilation breather line, the device include: a crankcase pressure sensor mounted on a crankcase positive ventilation breather line including a front end connected to an intake line and a rear end connected to a crankcase, and configured to detect a pressure inside the crankcase; and a processor configured to determine whether to activate a diagnostic mode based on boost pressure, cooling water temperature, atmospheric pressure, and engine status and to diagnose abnormality of the PCV breather line based on the detected crankcase pressure in the diagnostic mode, In the diagnostic mode of the back end of the positive crankcase ventilation breather line, the processor is configured to: Based on the detected crankcase pressure, calculating a negative pressure cumulative value and a positive pressure cumulative value of the crankcase, and comparing the negative pressure cumulative value with the positive pressure cumulative value; and When the negative pressure is not formed as a result of the comparison, it is determined that the rear end of the crankcase positive ventilation breather line is abnormal, In the diagnostic mode of the front end of the positive crankcase ventilation breather line, the processor is configured to: When the accelerator pedal position change rate is equal to or greater than a reference change rate, calculating a current negative pressure accumulation value of the crankcase based on the detected crankcase pressure; and When the ratio of the current negative pressure cumulative value to a predetermined reference value is equal to or smaller than a reference ratio, it is determined that the front end of the PCV breather line is abnormal.

2. The device according to claim 1, in, The processor is configured to determine a diagnostic mode that activates a rear end of the positive crankcase ventilation breather line when the engine state is a cranking state.

3. The device according to claim 1, in, The processor is configured to determine a diagnostic mode that activates a front end of the positive crankcase ventilation breather line when the engine status is an operating state.

4. A method for diagnosing a positive crankcase ventilation breather line by means of a device for diagnosing a positive crankcase ventilation breather line, in, The apparatus comprises: a pressure sensor mounted on the crankcase positive ventilation breather line having a front end connected to an intake line and a rear end connected to a crankcase; and a processor to diagnose the crankcase positive ventilation breather line, the method comprising: The pressure sensor detects the pressure inside the crankcase; determining, by the processor, whether to activate a diagnostic mode based on boost pressure, cooling water temperature, atmospheric pressure, and engine status; and In the diagnosis mode, the processor diagnoses abnormality of the crankcase positive ventilation breather line based on the detected crankcase pressure, In the diagnosis mode of the rear end of the crankcase positive ventilation breather line, diagnosing abnormality of the crankcase positive ventilation breather line includes: Calculating a negative pressure accumulation value and a positive pressure accumulation value of the crankcase based on the detected crankcase pressure; comparing the negative pressure accumulated value and the positive pressure accumulated value to each other to determine whether a negative pressure is formed on the positive crankcase ventilation breather line; and When the negative pressure is not formed as a result of the comparison, it is determined that the rear end of the crankcase positive ventilation breather line is abnormal, In the diagnosis mode of the front end of the crankcase positive ventilation breather line, diagnosing abnormality of the crankcase positive ventilation breather line includes: When the accelerator pedal position change rate is equal to or greater than a reference change rate, calculating a current negative pressure accumulation value of the crankcase based on the detected crankcase pressure; When the ratio of the current negative pressure cumulative value to a predetermined reference value is equal to or smaller than a reference ratio, it is determined that the front end of the PCV breather line is abnormal.

5. The method according to claim 4, in, Determining whether to activate the diagnostic mode includes: When the engine state is a cranking state, a diagnostic mode is determined to activate a rear end of the PCV breather line.

6. The method according to claim 4, in, Determining whether to activate the diagnostic mode includes: When the engine status is an operating state, a diagnostic mode is determined to activate a front end of the positive crankcase ventilation breather line.

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