Engine oil emulsification and deposition suppression device

Abstract

The present invention provides an engine oil emulsification and deposition suppression device that can prevent engine oil from mixing with condensation water and emulsifying and accumulating inside the chain cover. [Solution] In an environment where the ambient temperature is below a predetermined temperature, the HEV-CU80 counts the number of driving cycles in which, after starting the engine 10 and before stopping the engine 10, the engine oil temperature does not rise above a predetermined temperature, or the engine oil temperature rises above a predetermined temperature but this state does not continue for a predetermined time or longer. When the count value of the driving cycles reaches a predetermined number of times, the electric motor 21 is reversed to motor the engine 10 in reverse.

Description

Technical Field

[0001] The present invention relates to an apparatus for suppressing emulsification and deposition of engine oil.

Background Art

[0002] For example, Patent Document 1 discloses an oil injection port structure for preventing white turbidity (emulsion) generated by mixing moisture and lubricating oil contained in blow-by gas in a cylinder head cover from depositing on a cap of an oil injection port provided in the cylinder head cover, by providing ribs for guiding lubricating oil (oil) scraped upward by the rotation of a timing chain to the oil injection port.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, for example, when short-time and short-distance driving is repeated in a low outside air temperature environment, condensation may occur in the chain cover. Then, the condensed water may mix with the engine oil to cause emulsification (emulsion). Further, the emulsified engine oil may adhere and deposit.

[0005] However, in the above-described Patent Document 1, adhesion and deposition of white turbidity (emulsion) to other parts than the cap of the oil injection port provided in the cylinder head cover are not considered. That is, emulsification and deposition of engine oil occurring in the chain cover are not considered at all.

[0006] The present invention was made to solve the above-mentioned problems, and aims to provide an engine oil emulsification and deposition suppression device that can suppress the emulsification and deposition of engine oil by mixing with condensation water inside the chain cover. [Means for solving the problem]

[0007] An engine oil emulsification deposition suppression device according to one aspect of the present invention comprises an engine that lubricates the timing chain by scattering engine oil into a chain cover covering the timing chain due to the rotation of the timing chain wrapped around the crankshaft and camshaft, an electric motor connected to the engine's crankshaft in a torque-transmitting manner, and a control unit that controls the driving of the engine and the electric motor. The control unit counts the number of driving cycles in which, when the ambient temperature is below a predetermined temperature, the engine oil temperature does not rise above a predetermined temperature, or the engine oil temperature rises above a predetermined temperature but this condition does not continue for a predetermined time or longer, and when the count value of the driving cycles reaches a predetermined number of times, it reverses the rotation of the electric motor to motor the engine in reverse.

[0008] According to one embodiment of the present invention, in an environment where the ambient temperature is below a predetermined temperature, the number of driving cycles in which the engine oil temperature does not rise above a predetermined temperature, or in which the engine oil temperature rises above a predetermined temperature but this state does not continue for a predetermined time, is counted. When the count of driving cycles reaches a predetermined number, the electric motor is rotated in reverse, and the engine is motored in reverse. In other words, the timing chain is rotated in reverse. As a result, engine oil can be applied to areas that are difficult to reach with forward rotation (i.e., areas where engine oil emulsification and accumulation are likely to occur). As a result, engine oil emulsification and accumulation of emulsified engine oil can be eliminated and suppressed. [Effects of the Invention]

[0009] According to the present invention, it is possible to suppress the emulsification and accumulation of engine oil by mixing with condensation water inside the chain cover. [Brief explanation of the drawing]

[0010] [Figure 1] This figure shows an engine oil emulsification and deposition suppression device according to an embodiment, and the configuration of a hybrid vehicle to which the engine oil emulsification and deposition suppression device is applied. [Figure 2] This figure shows the configuration of an engine to which an engine oil emulsification deposition suppression device according to the embodiment is applied. [Figure 3] This is a flowchart showing the processing procedure for suppressing the emulsification and deposition of engine oil using an engine oil emulsification and deposition suppression device according to the embodiment. [Modes for carrying out the invention]

[0011] Preferred embodiments of the present invention will be described in detail below with reference to the drawings. In the drawings, the same or corresponding parts will be denoted by the same reference numerals. In addition, in each drawing, the same elements will be denoted by the same reference numerals, and redundant explanations will be omitted.

[0012] First, the configuration of the engine oil emulsification and deposition suppression device 1 according to the embodiment will be described using Figures 1 and 2 together. Figure 1 is a diagram showing the configuration (system configuration) of the engine oil emulsification and deposition suppression device 1 and a hybrid vehicle to which the engine oil emulsification and deposition suppression device 1 is applied. Figure 2 is a diagram showing the configuration of the engine 10 to which the engine oil emulsification and deposition suppression device 1 is applied.

[0013] A hybrid vehicle is equipped with an engine 10 and an electric motor (motor generator) 21, and is a hybrid vehicle that can use both the engine 10 and the electric motor 21 as power sources.

[0014] The engine 10 can be of any type, but for example, it is a horizontally opposed four-cylinder gasoline engine (details will be described later). An electric motor 21 is connected to the crankshaft (output shaft) 10a of the engine 10, for example, via a flywheel damper that absorbs rotational fluctuations of the engine 10. In other words, the electric motor 21 is connected to the engine 10 in a torque-transmitting manner.

[0015] The electric motor 21 is configured as a synchronous generator motor (three-phase AC type synchronous motor) that combines the function of a motor that converts supplied power into mechanical power and the function of a generator that converts input mechanical power into electricity. In other words, the electric motor 21 operates as a motor that generates driving torque when the vehicle is driven, and operates as a generator when regenerating. The electric motor 21 also operates as a starter generator. That is, the electric motor 21 has the function of a starter motor that starts the engine 10. The electric motor 21 is controlled by a hybrid vehicle control unit (hereinafter referred to as "HEV-CU") 80, which will be described later.

[0016] The electric motor (motor generator) 21 is connected to the high-voltage battery 90 via an inverter 82a. When the electric motor 21 is used as a motor and starter motor, the inverter 82a converts the DC power supplied from the high-voltage battery 90 into AC power to drive the electric motor 21. When the electric motor 21 is used as a generator, the inverter 82a converts the AC power generated by the electric motor 21 into DC power to charge the high-voltage battery 90.

[0017] An engine 10 and an electric motor 21 are connected to a transmission 30 (e.g., an automatic transmission (step AT) or a continuously variable transmission (CVT), etc.) via a clutch 23. That is, the clutch 23 is interposed between the electric motor 21 and the transmission 30 (to the drive wheels). When the clutch 23 is in the engaged state, the driving forces of the engine 10 and the electric motor 21 are transmitted to the transmission 30 (to the drive wheels). On the other hand, when the clutch 23 is in the released state, the transmission of the driving forces of the engine 10 and the electric motor 21 to the transmission 30 (to the drive wheels) is blocked. Note that the engagement and release of the clutch 23 are controlled by an HEV-CU 80 described later.

[0018] The output shaft of the transmission 30 is connected to the left and right wheels (not shown) via a differential 50 and the left and right drive shafts. Therefore, the driving force converted by the transmission 30 is transmitted to the left and right wheels (drive wheels) via the differential 50 and the left and right drive shafts. Note that the differential 50 is, for example, a bevel gear type differential device.

[0019] With the above-described configuration, the hybrid vehicle has, for example, an engine driving function that runs with the engine 10 as a driving force source, an HEV driving function that runs with both the engine 10 and the electric motor 21 as driving force sources, a function of generating electricity in the electric motor (generator) 21 by using the output of the engine 10, and the like.

[0020] Next, while referring to FIG. 2, the configuration of the engine 10 mounted on the hybrid vehicle will be described in more detail.

[0021] As described above, the engine 10 may be of any type, for example, a horizontally opposed four-cylinder gasoline engine. Further, the engine 10 is an in-cylinder injection type engine that directly injects fuel into the cylinder (inside the cylinder). In the engine 10, the air inhaled from the air cleaner 116 is throttled by an electronically controlled throttle valve (hereinafter, also simply referred to as "throttle valve") 113 provided in the intake pipe 115, passes through the intake manifold 111, and is inhaled into each cylinder formed in the engine 10.

[0022] Here, the amount of air inhaled from the air cleaner 116 is detected by an air flow meter 114 disposed between the air cleaner 116 and the throttle valve 113. Further, inside the collector portion (surge tank) constituting the intake manifold 111, a vacuum sensor (intake pressure sensor) 130 for detecting the pressure in the intake manifold 111 (intake manifold pressure) is disposed. Furthermore, a throttle sensor 131 for detecting the opening degree of the throttle valve 113 is disposed on the throttle valve 113.

[0023] In the cylinder head, an intake port 122 and an exhaust port 123 are formed for each cylinder (only one bank is shown in FIG. 2). An intake valve 124 and an exhaust valve 125 for opening and closing the intake port 122 and the exhaust port 123 are provided in each of the intake port 122 and the exhaust port 123. A variable valve timing mechanism 126 is disposed between the intake camshaft that drives the intake valve 124 and the intake cam pulley to continuously change the rotational phase (displacement angle) of the intake camshaft with respect to the crankshaft 10a by relatively rotating the intake cam pulley and the intake camshaft, thereby advancing or retarding the valve timing (opening and closing timing) of the intake valve 124. The opening and closing timing of the intake valve 124 is variably set according to the engine operating state by this variable valve timing mechanism 126.

[0024] Similarly, a variable valve timing mechanism 127 is provided between the exhaust camshaft and the exhaust cam pulley. This mechanism rotates the exhaust cam pulley and the exhaust camshaft relative to each other, continuously changing the rotational phase (displacement angle) of the exhaust camshaft with respect to the crankshaft 10a, thereby advancing or retarding the valve timing (opening / closing timing) of the exhaust valve 125. This variable valve timing mechanism 127 allows the opening and closing timing of the exhaust valve 125 to be variably set according to the engine operating conditions.

[0025] In the engine 10, the rotation of the timing chain, which is wrapped around the crankshaft 10a, intake camshaft, and exhaust camshaft, causes engine oil (hereinafter simply referred to as "oil") to be sprayed into the chain cover that surrounds the timing chain, thereby providing lubrication. The engine 10 is also equipped with a mechanical oil pump or an electric oil pump (not shown) that pressurizes and discharges the oil.

[0026] Each cylinder of the engine 10 is fitted with an injector 112 that injects fuel into the cylinder. The injector 112 directly injects fuel pressurized by a high-pressure fuel pump (not shown) into the combustion chamber of each cylinder.

[0027] Furthermore, each cylinder head is fitted with a spark plug 117 for igniting the fuel-air mixture, and an igniter-integrated coil 121 for applying a high voltage to the spark plug 117. In each cylinder of the engine 10, the fuel-air mixture, consisting of the intake air and the fuel injected by the injector 112, is ignited by the spark plug 117 and combusted. The exhaust gas after combustion is discharged through the exhaust pipe 118.

[0028] An air-fuel ratio sensor 119 is installed downstream of the manifold in the exhaust pipe 118 and upstream of the exhaust gas purification catalyst 120. The air-fuel ratio sensor 119 is a linear air-fuel ratio sensor (LAF sensor) that can output signals corresponding to the oxygen concentration and unburned gas concentration in the exhaust gas (i.e., signals corresponding to the air-fuel ratio of the mixture) and can linearly detect the air-fuel ratio.

[0029] A catalytic converter 120 is installed downstream of the LAF sensor 119. The catalytic converter 120 is a three-way catalytic converter that simultaneously oxidizes hydrocarbons (HC) and carbon monoxide (CO) in the exhaust gas and reduces nitrogen oxides (NOx), thereby purifying harmful gas components in the exhaust gas into harmless carbon dioxide (CO2), water vapor (H2O), and nitrogen (N2). A muffler 143 is installed downstream of the catalytic converter 120 to reduce exhaust noise.

[0030] In addition to the airflow meter 114, LAF sensor 119, vacuum sensor 130, and throttle sensor 131 mentioned above, a cam angle sensor 132 for determining the cylinder of the engine 10 is mounted near the camshaft of the engine 10. Furthermore, a crank angle sensor 133 for detecting the rotational position of the crankshaft 10a is mounted near the crankshaft 10a of the engine 10.

[0031] These sensors are connected to the engine control unit (hereinafter referred to as "ECU") 81. In addition, the ECU 81 is also connected to various other sensors, such as a water temperature sensor 134 that detects the temperature of the engine 10's coolant (water temperature) and an oil temperature sensor 135 that detects the oil temperature (oil temperature).

[0032] The engine 10 and electric motor 21, which are the driving forces of the vehicle, are comprehensively controlled by the HEV-CU80.

[0033] The HEV-CU80 and ECU81, for example, are configured with a microprocessor that performs calculations, an EEPROM that stores programs for the microprocessor to execute various processes, a RAM that stores various data such as calculation results, a backup RAM that holds the contents of the RAM, and input / output interfaces.

[0034] The HEV-CU80 is connected to various sensors, including, for example, an accelerator sensor 91 that detects the amount the accelerator pedal is pressed, i.e., the amount of accelerator operation; an outside temperature sensor 92 that detects the outside air temperature (air temperature outside the vehicle); and a resolver 93 that detects the rotational speed of the electric motor 21.

[0035] Furthermore, the HEV-CU80 is connected to the ECU81, which controls the engine 10, and the transmission control unit (hereinafter referred to as "TCU")83, which controls the transmission 30, via the CAN (Controller Area Network) 100, enabling mutual communication. The HEV-CU80 receives various information from the ECU81 and TCU83, etc., via the CAN 100, such as engine speed and oil temperature. On the other hand, the HEV-CU80 transmits various information to the ECU81 and TCU83, etc., via the CAN 100, such as the rotational speed of the electric motor 21, accelerator pedal input, and ambient temperature.

[0036] Based on the various information acquired, the HEV-CU80 comprehensively controls the operation of the engine 10 and the electric motor 21. For example, based on the accelerator input (driver's requested driving force), the vehicle's operating state, and the charge level (SOC: State of Charge) of the high-voltage battery 90, the HEV-CU80 determines and outputs the requested output of the engine 10 and the torque command value (target motor torque) of the electric motor 21. The HEV-CU80 also controls the engagement and disengagement of the clutch 23.

[0037] The power control unit (hereinafter referred to as "PCU") 82 drives the electric motor 21 via the inverter 82a based on the torque command value. The PCU 82 has an inverter 82a that converts the DC power of the high-voltage battery 90 into three-phase AC power and supplies it to the electric motor 21. As described above, the PCU 82 drives the electric motor 21 via the inverter 82a based on the torque command value received from the HEV-CU 80. On the other hand, during regeneration, the inverter 82a converts the AC voltage generated by the electric motor 21 into a DC voltage to charge the high-voltage battery 90.

[0038] The ECU81 includes an injector driver that drives the injector 112, an output circuit that outputs an ignition signal, and a motor driver that drives the electric motor 113a that opens and closes the electronically controlled throttle valve 113. The ECU81 also receives information from the HEV-CU80 via CAN100, such as the engine 10's requested output, the rotational speed of the electric motor (motor generator) 21, and the accelerator pedal input.

[0039] In the ECU81, the cylinder is identified from the output of the camshaft angle sensor 132, and the rotational angular velocity and engine speed are determined from the output of the crankshaft angle sensor 133. In addition, the ECU81 acquires various information such as intake air volume, intake manifold negative pressure, air-fuel ratio of the air-fuel mixture, and engine water temperature and oil temperature of the engine 10 based on the detection signals input from the various sensors mentioned above. The ECU81 then controls the engine 10 by controlling the fuel injection amount, ignition timing, and various devices such as the throttle valve 113 based on the engine 10's requested output from the HEV-CU80 and the various information acquired.

[0040] Furthermore, the TCU83 is connected to an output shaft rotation sensor that detects the rotation speed of the output shaft, and a range switch that detects the selected position of the shift lever. The TCU83 also receives information such as accelerator operation amount, engine speed, and engine shaft torque (output torque) via CAN100. Based on control commands from the HEV-CU80 and various information obtained from the aforementioned sensors, the TCU83 performs gear shift control of the transmission 30.

[0041] Incidentally, for example, if short-duration riding is repeated in low ambient temperature environments, condensation may occur inside the chain cover. This condensed water can then mix with the oil, causing emulsification (emulsion). Furthermore, the emulsified oil may adhere to and accumulate.

[0042] In particular, the area where the timing chain is not wrapped around the variable valve timing mechanism 126 of the left bank's intake system is less likely to receive oil during forward rotation, making it prone to oil emulsification (see the dashed circle in Figure 2).

[0043] More specifically, the oil is stored at the bottom of the engine 10. Also, in the case of a horizontally opposed engine 10, the intake is at the top and the exhaust is at the bottom. And, in the left bank, the timing chain rotates from the intake side to the exhaust side, so the distance the oil-soaked timing chain at the bottom of the engine 10 travels to reach the variable valve timing mechanism 126 on the intake side is long, and the oil tends to drip down during that time, resulting in a reduced oil supply. The variable valve timing mechanism 127 on the exhaust side of the left bank is located at the bottom of the engine 10, so it receives sufficient oil.

[0044] On the other hand, in the right bank, the timing chain rotates from the exhaust side to the intake side. The variable valve timing mechanism 127 on the exhaust side of the right bank is located at the bottom of the engine 10, so it is sufficiently coated with oil. Also, because the distance between the intake side and the exhaust side is short, the variable valve timing mechanism 126 on the intake side is also sufficiently supplied with oil. As a result, the oil circulation tends to be poor only in the variable valve timing mechanism 126 on the intake side of the left bank, and oil emulsification is likely to occur around the variable valve timing mechanism 126 on the intake side of the left bank (see the dashed circle in Figure 2).

[0045] Therefore, the HEV-CU80 has a function to suppress the emulsification and accumulation of oil by mixing with condensation water inside the chain cover that surrounds the timing chain (particularly around the variable valve timing mechanism 126 on the intake side of the left bank). In other words, the HEV-CU80 functions as the control unit described in the claims. In the HEV-CU80, this function is realized by the execution of a program stored in EEPROM or the like by a microprocessor.

[0046] Therefore, the HEV-CU80 counts the number of driving cycles in which, under conditions where the ambient temperature is below a predetermined temperature (e.g., 0°C), the oil temperature does not rise above a predetermined temperature (e.g., 80°C) or, although the oil temperature rises above a predetermined temperature, this condition does not last for a predetermined time (e.g., 10 minutes) or longer, from the time the engine 10 is started until it is stopped (i.e., during one driving cycle). Here, a driving cycle refers to the period from when the engine 10 is started until the ignition switch is turned off and the engine 10 is stopped. The above oil temperature conditions and predetermined time (duration) are set considering conditions for water evaporation, etc.

[0047] Then, when the count value of the above driving cycle reaches a predetermined number of times (for example, 3 times), the HEV-CU80 reverses the rotation of the electric motor 21 (in the opposite direction to the rotation direction during forward driving) to motor the engine 10 in reverse (that is, the engine 10 is rotated in reverse with fuel injection and ignition stopped). It is preferable to keep the throttle valve 113 open when motoring the engine 10 in reverse.

[0048] Here, from the viewpoint of scattering oil, it is preferable that the rotational speed when the engine 10 is motored in reverse is high. Also, it is preferable that the duration of the reverse motoring be varied according to the rotational speed of the reverse motoring. That is, it is preferable to lengthen the execution time (for example, about 3 minutes) when the rotational speed of the reverse motoring is relatively low, and shorten the execution time (for example, about 1 minute) when the rotational speed of the reverse motoring is high. As the engine 10 is motored in reverse, the timing chain rotates in reverse, so oil is applied (supplied) to areas that are difficult to apply oil to during forward rotation (for example, around the variable valve timing mechanism 126 on the intake side of the left bank). Therefore, oil emulsification and accumulation of emulsified oil are eliminated or suppressed.

[0049] At that time, that is, when the electric motor 21 is rotated in reverse to motor the engine 10 in reverse, the HEV-CU80 releases the clutch 23. This interrupts the transmission of the driving torque of the electric motor 21 to the wheels, thus preventing the wheels from rotating in reverse (spinning freely).

[0050] Furthermore, when the vehicle is stopped or parked (for example, in P or N range, when the vehicle speed is zero), the HEV-CU80 reverses the rotation of the electric motor 21 to motor the engine 10 in reverse. This allows for reverse motoring without affecting the vehicle's movement.

[0051] On the other hand, if the HEV-CU80 maintains a condition where the oil temperature rises above a predetermined temperature (e.g., 80°C) for a predetermined time (e.g., 10 minutes) or longer during a single driving cycle, it resets the driving cycle count value (returns it to zero). This allows for accurate determination (understanding) of the degree of oil emulsification and deposition, etc., and manages the driving cycle count value, preventing unnecessary reverse motoring.

[0052] Next, the operation of the engine oil emulsification and deposition suppression device 1 will be explained with reference to Figure 3. Figure 3 is a flowchart showing the processing procedure for engine oil emulsification and deposition suppression by the engine oil emulsification and deposition suppression device 1. This process is mainly performed repeatedly at predetermined timings in the HEV-CU80.

[0053] In step S100, the ignition switch is turned on. Next, in step S102, a determination is made as to whether the count value of a counter that counts driving cycles in which the oil temperature did not rise above a predetermined temperature, or in which the oil temperature rose above a predetermined temperature but this condition did not continue for a predetermined time, is "3" when the outside temperature is below a predetermined temperature (e.g., 0°C) between the start of the engine 10 and the stop of the engine 10 (i.e., during one driving cycle). If the count value of the driving cycle is "3", the process proceeds to step S104. On the other hand, if the count value of the driving cycle is not "3", the process proceeds to step S110.

[0054] In step S104, a determination is made as to whether the vehicle is stopped or not (for example, whether the vehicle speed is zero in P or N range). If the vehicle is not stopped, the process is exited. On the other hand, if the vehicle is stopped, the process proceeds to step S106.

[0055] In step S106, the clutch 23 is released, and for a predetermined time, the motor generator rotates in reverse (in the opposite direction to the rotation direction during forward driving) at a predetermined speed, causing the engine 10 to motor in reverse (that is, the engine 10 rotates in reverse with fuel injection and ignition stopped).

[0056] Subsequently (after the reverse motoring of engine 10 has finished), in step S108, the driving cycle count value is reset (returned to zero). Then, the process is exited.

[0057] In step S110, a determination is made as to whether the outside temperature is below a predetermined temperature (for example, 0°C). If the outside temperature is above the predetermined temperature, the process is temporarily exited. On the other hand, if the outside temperature is below the predetermined temperature, the process proceeds to step S112.

[0058] In step S112, a determination is made as to whether or not the engine 10 has been started. If the engine 10 has not been started, the process is temporarily exited. On the other hand, if the engine 10 has been started, the process proceeds to step S114.

[0059] In step S114, the driving cycle count value is incremented.

[0060] Next, in step S116, a determination is made as to whether the oil temperature is above a predetermined temperature (for example, 80°C). If the oil temperature is below the predetermined temperature, the process proceeds to step S122. On the other hand, if the oil temperature is above the predetermined temperature, the process proceeds to step S118.

[0061] In step S118, a determination is made as to whether a predetermined time (e.g., 10 minutes) has elapsed since the oil temperature reached a predetermined temperature or higher, that is, whether the state of the oil temperature being above the predetermined temperature has continued for a predetermined time or longer. If the predetermined time has elapsed, in step S120, the driving cycle count value is reset (returned to zero), and the process is exited. On the other hand, if the predetermined time has not elapsed, the process proceeds to step S122.

[0062] In step S122, a determination is made as to whether or not the engine 10 has been stopped. If the engine 10 has not been stopped, the process proceeds to step S116, and the processes from step S116 onward described above are repeated. On the other hand, if the engine 10 has been stopped, the process is exited.

[0063] As described in detail above, according to this embodiment, in an environment where the ambient temperature is below a predetermined temperature, the number of driving cycles in which the oil temperature does not rise above a predetermined temperature, or in which the oil temperature rises above a predetermined temperature but this state does not continue for a predetermined time, between the start of the engine 10 and the stop of the engine 10 (during one driving cycle), is counted. When the count value of the driving cycles reaches a predetermined number, the electric motor 21 is rotated in reverse, and the engine 10 is motored in reverse. In other words, the timing chain is rotated in reverse. Therefore, oil can be applied to areas that are difficult to apply oil to during forward rotation (for example, around the variable valve timing mechanism 126 on the intake side of the left bank). As a result, oil emulsification and accumulation of emulsified oil can be eliminated and suppressed. In other words, it is possible to suppress the emulsification and accumulation of oil by mixing with condensation water inside the chain cover.

[0064] According to this embodiment, when the electric motor 21 is rotated in reverse and the engine 10 is motored in reverse, the clutch 23 is released. As a result, the transmission of the driving torque of the electric motor 21 to the wheels is interrupted. Therefore, it is possible to prevent the wheels from rotating in reverse (spinning freely) when reverse motoring is performed.

[0065] According to this embodiment, when the vehicle is stopped (for example, in P or N range, when the vehicle speed is zero), the electric motor 21 is rotated in reverse, and the engine 10 is motored in reverse. Therefore, reverse motoring can be performed without affecting the vehicle's movement.

[0066] According to this embodiment, if the oil temperature remains above a predetermined temperature (e.g., 80°C) for a predetermined time (e.g., 10 minutes) or longer during one driving cycle, the driving cycle count value is reset (returned to zero). In other words, if it is determined that the water has evaporated and the oil emulsification (emulsion) has been resolved, the driving cycle count value is reset. Therefore, the degree of oil emulsification and deposition can be accurately determined (understood), and the driving cycle count value can be managed, preventing unnecessary reverse motoring.

[0067] Incidentally, as mentioned above, in particular, the area where the timing chain is not wrapped around the variable valve timing mechanism 126 on the intake side of the left bank is difficult to apply oil to during forward rotation, making it prone to emulsification. However, according to this embodiment, by rotating the engine 10 in reverse (i.e., rotating the timing chain in reverse), oil can be applied to this area, thereby eliminating and suppressing oil emulsification and accumulation.

[0068] Although embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and various modifications are possible. For example, in the above embodiment, reverse rotation motoring of the engine 10 was performed when the driving cycle count value reached 3, but the count value at which reverse rotation motoring is performed is not limited to 3, but may be 2 or 4 or more.

[0069] Furthermore, in the above embodiment, reverse rotation motoring of the engine 10 was performed after ignition was turned on but before the engine started. However, reverse rotation motoring may also be performed after the vehicle has stopped and the engine 10 has been stopped.

[0070] Furthermore, the configuration of the hybrid vehicle shown in the above embodiment is illustrative and can be applied to different types of hybrid vehicles. For example, although the above embodiment was described using the case of application to a one-motor hybrid vehicle as an example, it can also be applied to two-motor hybrid vehicles, etc. Also, although the above embodiment was described using the case of application to a 2WD vehicle (FF vehicle or FR vehicle) as an example, the present invention can also be applied to, for example, an AWD vehicle (all-wheel drive vehicle).

[0071] Furthermore, the clutch 23 can be positioned anywhere downstream of the electric motor 21 (between the electric motor 21 and the wheel) (as long as the wheel does not rotate when the electric motor 21 is rotated in reverse). Also, in the above embodiment, a hydraulic clutch was used as the clutch 23, but instead of a hydraulic clutch, an electric clutch, for example, may be used.

[0072] Furthermore, although the above embodiment described the case in which the present invention is applied to a horizontally opposed engine 10 as an example, the present invention can also be applied to, for example, an in-line engine or a V-type engine.

[0073] Furthermore, the system configuration of controllers (control systems) such as HEV-CU80 and ECU81, and the division of functions among the controllers, are not limited to the above embodiment. For example, in the above embodiment, HEV-CU80, ECU81, TCU83, etc., are connected to communicate with each other via CAN100, but the system configuration is not limited to this form and can be arbitrarily changed (integrated, etc.) considering, for example, functional requirements and costs.

[0074] Furthermore, the dimensions, materials, and other specific numerical values ​​shown in the above embodiments are illustrative examples to facilitate understanding of the present invention and do not limit the present invention unless otherwise specified. [Explanation of symbols]

[0075] 1. Engine oil emulsification and deposition suppression device 10 Engines 21 Electric motor (motor generator) 23 Clutch 30-speed transmission 50 Differential 80 HEV-CU 81 ECU 82 PCU 83 TCU 90 High-voltage batteries 91 Accelerator sensor 92 Outdoor temperature sensor 93 Resolver 100 CAN 111 Intake Manifold 112 Injectors 113 Electronically controlled throttle valve 114 Airflow Meter 115 Intake pipe 117 Spark plug 118 Exhaust pipe 119 Air-fuel ratio sensor 120 Exhaust purifying catalyst 124 Intake valve 125 Exhaust Valve 126, 127 Variable valve timing mechanism 130 Vacuum Sensor (Intake Pressure Sensor) 131 Throttle Sensor 133 Crank Angle Sensor 134 Water temperature sensor 135 Oil temperature sensor

Claims

1. An engine that lubricates the timing chain, which is wrapped around the crankshaft and camshaft, by causing engine oil to splash into the chain cover that surrounds the timing chain as the chain rotates. The crankshaft of the aforementioned engine and an electric motor connected in a manner that allows for torque transmission, The system includes a control unit that controls the operation of the engine and the electric motor, The control unit counts the number of driving cycles in which, when the ambient temperature is below a predetermined temperature, the engine oil temperature does not rise above a predetermined temperature, or the engine oil temperature rises above a predetermined temperature but this condition does not continue for a predetermined time, and when the count value of the driving cycles reaches a predetermined number of times, it reverses the rotation of the electric motor to motorize the engine in reverse. This is an engine oil emulsification deposition suppression device.

2. The electric motor is equipped with a clutch interposed between it and the drive wheel, The engine oil emulsification deposition suppression device according to claim 1, characterized in that the control unit reverses the rotation of the electric motor to motorize the engine in reverse, and releases the clutch.

3. The engine oil emulsification deposition suppression device according to claim 2, characterized in that the control unit reverses the rotation of the electric motor when the vehicle is stopped, thereby motoring the engine in reverse.

4. The engine oil emulsification deposition suppression device according to claim 3, characterized in that the control unit resets the count value of the driving cycle if the engine oil temperature remains above a predetermined temperature for a predetermined period of time or longer during one driving cycle.

5. The engine oil emulsification and deposition suppression device according to claim 4, characterized in that the engine is a horizontally opposed engine having a variable valve timing mechanism that rotates the cam pulley and the camshaft relative to each other and continuously changes the rotational phase of the camshaft with respect to the crankshaft to advance or retard the valve timing.

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