Hybrid vehicle control device

Abstract

To provide a hybrid vehicle control device that can fill oil into a hydraulic holding part when an internal combustion engine starts up.SOLUTION: A hybrid vehicle control device comprises: a mechanical oil pump connected to a crank shaft; a cam rotating in linkage with the crank shaft; a rocker cam which is pressed by the cam to oscillate, thereby driving a valve provided in an internal combustion engine; a rush adjuster to which a hydraulic pressure is fed from the mechanical oil pump, thereby receiving a rection force of a load when the cam presses the rocker arm; a first electric motor connected to the internal combustion engine; and a second electric motor which is so connected to a drive wheel as to be capable of transmitting torque. When a time during which a rotation angle of the cam in EV travelling remains within a predetermined prescribed angle range is a prescribed time or more (Yes at step S2), the torque is outputted from the first electric motor to drive the mechanical oil pump (step S7).SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a control device for a hybrid vehicle equipped with an oil pressure retaining section to which oil is supplied from a mechanical oil pump connected to an output shaft of an internal combustion engine. [Background technology]

[0002] Patent Document 1 describes a control device for a hybrid vehicle that is configured to supply oil from a mechanical pump connected to an output shaft of an internal combustion engine to a tensioner for adjusting the tension of a chain that transmits power from a crankshaft to an exhaust camshaft or an intake camshaft. This control device is configured to suppress the generation of abnormal noise due to insufficient tension of the chain after the internal combustion engine is started and to suppress the deterioration of PN after the internal combustion engine is started by reducing the hydraulic pressure of the tensioner while an EV mode is set in which the vehicle runs by an electric motor with the internal combustion engine stopped. Specifically, the control device is configured to accumulate the amount of rotation of the crankshaft rotated by the torque acting on the internal combustion engine in the EV mode, and to adjust the hydraulic pressure supplied to the tensioner by multiplying a target hydraulic pressure determined according to the rotation speed of the internal combustion engine by an increase coefficient based on the accumulated amount of rotation of the crankshaft after a predetermined time has elapsed since the internal combustion engine was started. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-032264 A Summary of the Invention [Problem to be solved by the invention]

[0004] The control device described in Patent Document 1 judges that the drop in tensioner oil pressure is large when the rotation amount of the crankshaft in the EV mode is large. On the other hand, even if the crankshaft does not rotate or the rotation amount is small, the tensioner oil pressure may drop due to vibration of the members constituting the tensioner. In such a case, if the drop in tensioner oil pressure is judged based on the rotation amount of the crankshaft in the EV mode as in the control device described in Patent Document 1, the small rotation amount of the crankshaft in the EV mode may result in the tensioner oil pressure being determined to be not dropped or the drop in tensioner oil pressure being determined to be small, and the tensioner may not exert enough pressure when the internal combustion engine is started, causing abnormal noise. In addition, immediately after the internal combustion engine is started, oil may leak from the oil passage between the tensioner and the oil pump, and in that case, the chain may not exert enough pressure when the internal combustion engine is started, causing abnormal noise.

[0005] This invention has been made with attention to the above-mentioned technical problems, and aims to provide a control device for a hybrid vehicle that can keep oil filled in the hydraulic pressure retaining section when the internal combustion engine is started. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the present invention provides a control device for a hybrid vehicle comprising an internal combustion engine, a mechanical oil pump connected to an output shaft of the internal combustion engine, a cam that rotates in conjunction with the output shaft of the internal combustion engine, a rocker arm that is pressed by the cam and swings to drive a valve provided in the internal combustion engine, a lash adjuster that receives a reaction force of a load that causes the cam to press the rocker arm when hydraulic pressure is supplied from the mechanical oil pump, a first electric motor connected to the internal combustion engine so as to be able to transmit torque, and a second electric motor connected to driving wheels so as to be able to transmit torque, the control device detecting a rotation angle of the cam while the internal combustion engine is stopped and driving torque is output from the second electric motor and the vehicle is traveling, and when the time during which the rotation angle of the cam stagnates within a predetermined angle range is equal to or longer than the predetermined time, outputting torque from the first electric motor to rotate the internal combustion engine, thereby driving the mechanical oil pump. Effect of the Invention

[0007] The control device for a hybrid vehicle in this invention rotates the internal combustion engine by the first electric motor and drives a mechanical oil pump when the rotation angle of the cam during the internal combustion engine is stopped and the vehicle is running on the power of the second electric motor and is stagnant within a predetermined angle range where the cam swings and oil may leak from the lash adjuster for a predetermined time or more. Therefore, even if oil leaks from the lash adjuster while the vehicle is running on the power of the second electric motor, the mechanical oil pump can be driven to supply oil to the lash adjuster, and the lash adjuster can be filled with oil at the time when the mode is switched to a mode in which the vehicle is running on the power of the internal combustion engine. Therefore, the generation of abnormal noise caused by the cam colliding with the rocker arm when the internal combustion engine is started can be suppressed. In addition, the opening and closing timing and the opening amount of the valves provided in the internal combustion engine can be appropriately controlled, so that deterioration of fuel efficiency and exhaust emissions can be suppressed. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic diagram for explaining an example of a hybrid vehicle according to an embodiment of the present invention; [Diagram 2] 4 is a schematic diagram for explaining an example of a drive mechanism that transmits power from a crankshaft to an exhaust camshaft and an intake camshaft. FIG. [Diagram 3] 5 is a schematic diagram for explaining an example of an opening and closing mechanism that transmits a load from an exhaust camshaft to an exhaust valve. FIG. [Figure 4] FIG. 4 is a cross-sectional view for explaining an example of a lash adjuster. [Diagram 5] 4 is a flowchart illustrating an example of control in the embodiment of the present invention. [Figure 6] FIG. 4 is a diagram showing the relationship between driven torque and background noise. [Figure 7] FIG. 4 is a diagram showing the amount of torque required to start rotating the crankshaft. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the accompanying drawings. Note that the embodiment described below is merely an example of the implementation of the present invention, and is not intended to limit the present invention.

[0010] FIG. 1 is a schematic diagram for explaining an example of a hybrid vehicle according to an embodiment of the present invention. A hybrid vehicle (hereinafter, simply referred to as a vehicle) Ve shown in FIG. 1 includes an engine 1 and two motors 2 and 3 as driving power sources. The engine 1 can be configured in the same manner as an engine provided as a driving power source for a conventional vehicle. That is, the engine 1 takes in air into a combustion chamber by opening an intake valve (not shown), mixes the air and fuel in the combustion chamber, and burns the mixture to generate power. In addition, exhaust gas generated by burning the mixture is discharged from the combustion chamber by opening an exhaust valve (not shown).

[0011] The first motor 2 and the second motor 3 can be configured in the same manner as motors provided as driving force sources in conventional hybrid vehicles and electric vehicles. That is, in addition to functioning as a motor that outputs driving torque according to the power supplied thereto, they are configured to function as a generator that converts part of the power of the output shaft into electric power by rotating the output shaft. Specifically, they can be configured by a permanent magnet synchronous motor or induction motor. The first motor 2 corresponds to the "first electric motor" in the embodiments of the present invention, and the second motor 3 corresponds to the "second electric motor" in the embodiments of the present invention.

[0012] A power split mechanism 5 is connected to an output shaft (hereinafter referred to as a crankshaft) 4 of the engine 1 shown in Fig. 1. This power split mechanism 5 splits the torque of the engine 1 to the first motor 2 and the driving wheels 6, and is configured so that the engine 1, the first motor 2, and the driving wheels 6 can rotate differentially. In other words, the power split mechanism 5 can be configured by a differential mechanism.

[0013] 1 is configured with a single-pinion type planetary gear mechanism, in which the engine 1 is connected to its carrier C, the first motor 2 is connected to its sun gear S, and the driving wheels 6 are connected to its ring gear R. A second motor 3 is connected in a torque transmission path from the ring gear R to the driving wheels 6 so as to be capable of transmitting torque.

[0014] A first power control unit 7 configured with an inverter and a converter is connected to the first motor 2, and a second power control unit 8 configured with an inverter and a converter is connected to the second motor 3. The first power control unit 7 and the second power control unit 8 are connected to each other, and these power control units 7, 8 are connected to a power storage device 9. Therefore, the first power control unit 7 and the second power control unit 8 are configured to be able to exchange electric power with the power storage device 9, and to exchange electric power between the first power control unit 7 and the second power control unit 8 without going through the power storage device 9.

[0015] The engine 1 is configured such that the intake valves and exhaust valves are opened and closed by the power of the crankshaft 4. Figures 2 and 3 show an example of a drive mechanism 10 for transmitting power from the crankshaft 4 to the intake valves and exhaust valves. Figure 2 shows a schematic side view of the engine 1, and as shown in Figure 2, the power of the crankshaft 4 of the engine 1 is transmitted to an exhaust-side camshaft 12 and an intake-side camshaft 13 via a chain 11. Specifically, a drive-side sprocket 14 is connected to an end of the crankshaft 4, an exhaust-side sprocket 15 is connected to an end of the exhaust-side camshaft 12, and an intake-side sprocket 16 is connected to an end of the intake-side camshaft 13, and the chain 11 is wound around these sprockets 14, 15, and 16.

[0016] 2, a fixed side guide 17 and a drive side guide 18 are provided to maintain the tension of the chain 11 at a predetermined tension and to suppress vibration of the chain 11. Specifically, the chain 11 is provided so that when the engine 1 is running, the chain 11 advances from the drive side sprocket 14 to the exhaust side sprocket 15 and from the intake side sprocket 16 to the drive side sprocket 14. The drive side guide 18 is disposed so as to come into contact with the chain 11 between the drive side sprocket 14 and the exhaust side sprocket 15, and the fixed side guide 17 is provided so as to come into contact with the chain 11 between the intake side sprocket 16 and the drive side sprocket 14.

[0017] In addition, a mechanical oil pump (P) 19 that is driven by the power of the crankshaft 4 is connected to the crankshaft 4. An oil control valve 21 is provided in an oil passage 20 through which the oil output from the mechanical oil pump 19 flows. The oil whose pressure is adjusted by the oil control valve 21 is supplied to a tensioner (not shown) that applies a pressing force to the drive side guide 18, and a lash adjuster 22 (described later).

[0018] 3 is a schematic diagram illustrating an example of an opening / closing mechanism 23 for transmitting a load from the exhaust camshaft 12 to the exhaust valve B, and as shown in FIG. 3, a cam 24 is connected to the exhaust camshaft 12 at the same position in the axial direction as the exhaust valve B. As described above, the crankshaft 4 and the exhaust camshaft 12 are connected by the chain 11, and the cam 24 is connected to the exhaust camshaft 12. Therefore, the cam 24 rotates in conjunction with the crankshaft 4.

[0019] A rocker arm 25 is disposed so as to abut against an outer peripheral surface (cam surface) 24a of the cam 24. The rocker arm 25 is a member that is pressed by the cam 24 to swing and press the exhaust valve B. The rocker arm 25 includes a pressing portion 26, a contact portion 27, and a reaction force portion 28. The pressing portion 26 is one end of the rocker arm 25 and is configured to press the rear end of the exhaust valve B. The contact portion 27 is a central portion in the longitudinal direction of the rocker arm 25, has an outer peripheral surface formed in an arc shape, and is configured to abut against the cam surface 24a. The reaction force portion 28 is the other end of the rocker arm 25 and is configured so that the pressing portion 26 generates a load that presses the exhaust valve B by receiving a reaction force of the load with which the contact portion 27 is pressed.

[0020] In addition, the exhaust valve B is provided with a return spring 29 for generating a spring force against the load received from the pressing portion 26, so that the rear end portion of the exhaust valve B and the pressing portion 26 are in constant contact with each other.

[0021] A lash adjuster 22 is provided for generating a reaction force by the reaction force portion 28. Fig. 4 shows a cross-sectional view for explaining an example of the configuration of the lash adjuster 22. The lash adjuster 22 shown in Fig. 4 includes a bottomed cylindrical body 30 attached to a cylinder head (not shown), and a bottomed cylindrical plunger 31 inserted into the body 30 and reciprocating in the axial direction of the body 30. A low pressure chamber 32 is formed inside the plunger 31. A supply hole 33 communicating with the output side of the oil control valve 21 is formed in the side of the body 30, and a communication hole 34 is formed in the side of the plunger 31 for taking in the oil that has flowed in from the supply hole 33 into the low pressure chamber 32.

[0022] An outlet 35 is formed at the top of the plunger 31, and the rocker arm 25 (reaction portion 28) abuts against the top of the plunger 31 so as to cover the outlet 35. Therefore, excess oil of the oil supplied to the low pressure chamber 32 leaks out from the outlet 35. Also, a high pressure chamber 36 is formed in the lash adjuster 22, which is partitioned by the bottom of the plunger 31 and the inner wall of the body 30. A valve hole 38 that is opened and closed by a check valve 37 is formed at the bottom of the plunger 31. That is, a seating surface portion 39 is connected to the bottom of the plunger 31 with a predetermined gap therebetween, and the check valve 37 is constituted by a spring 40 accommodated between the seating surface portion 39 and the bottom of the plunger 31, and a spherical valve body 41 that is pressed toward the valve hole 38 by the spring 40. Therefore, when the check valve 37 opens, the low pressure chamber 32 and the high pressure chamber 36 are communicated with each other, and oil flows from the low pressure chamber 32 to the high pressure chamber 36 .

[0023] A spring 42 is provided in the high pressure chamber 36, which presses the plunger 31 in a direction protruding from the body 30. Therefore, the reaction portion 28 of the rocker arm 25 and the top of the plunger 31 are constantly in contact with each other, and press the reaction portion 28 of the rocker arm 25 toward the cam 24. Also, as described above, the pressing portion 26 of the rocker arm 25 is pressed toward the cam 24. Therefore, the rocker arm 25 is pressed against the cam 24, and the clearance between the rocker arm 25 and the cam 24 is adjusted to zero.

[0024] 1 is provided with an electronic control unit (hereinafter, referred to as ECU) 43 for controlling the engine 1 and the motors 2 and 3. Like ECUs provided in conventional vehicles, this ECU 43 is mainly composed of a microcomputer and is configured to output command signals to the engine 1 and the motors 2 and 3 based on input signals and pre-stored maps, arithmetic expressions, and the like.

[0025] The ECU 43 receives, for example, a signal from a crank angle sensor that detects the rotation angle of the crankshaft 4, a signal from a vehicle speed sensor that detects the vehicle speed, a signal from an accelerator opening sensor that detects the amount of accelerator operation, a signal from a SOC sensor that detects the remaining charge (SOC) of the storage device 9, a resolver signal that detects the rotation speed (rotation angle) of each of the motors 2, 3, a signal from a motor temperature sensor that detects the temperature of each of the motors 2, 3, and a sensor signal that detects the temperature of the storage device 9.

[0026] Then, the ECU 43 selects a driving mode based on the input signal. Specifically, when the vehicle speed is relatively low or the required driving force based on the accelerator opening is small, the ECU 43 selects the EV driving mode in which the engine 1 is stopped and the vehicle runs only on the power of the second motor 3, and when the vehicle speed is relatively high or the required driving force based on the accelerator opening is large, the ECU 43 selects the HEV driving mode in which the power of the engine 1 and the second motor 3 is transmitted to the drive wheels 6. Alternatively, when the SOC is equal to or greater than a predetermined amount, the ECU 43 selects the EV driving mode, and when the SOC is less than the predetermined amount, the ECU 43 selects the HEV driving mode.

[0027] As described above, while traveling in the EV driving mode, the engine 1 is stopped, and therefore the mechanical oil pump 19 is also stopped. Therefore, oil may leak from the lash adjuster 22, and there is a possibility that the pressing force for reducing the gap between the rocker arm 25 and the cam 24 to zero may be insufficient. For this reason, the control device in this embodiment of the present invention is configured to estimate oil leakage from the lash adjuster 22 in the EV driving mode, and to control the rotation speed of the first motor 2 to drive the mechanical oil pump 19 if oil leakage is estimated.

[0028] A flow chart for explaining one example of this control is shown in Fig. 5. In the control example shown in Fig. 5, first, the crank angle is obtained (step S1). Next, it is determined whether the crank angle has been stagnating within a predetermined angle range for a predetermined period of time or more (step S2). This step S2 is for determining whether or not the plunger 31 of the lash adjuster 22 reciprocates in the axial direction of the body 30 as the crank angle swings, in other words, as the cam 24 swings, there is a possibility that oil is leaking from the lash adjuster 22.

[0029] Therefore, the predetermined angle in step S2 is set to a crank angle range where the nose portion of the cam 24 that is far from the center of rotation comes into contact with the rocker arm 25. The rotation angle (phase) of the cam 24 is uniquely determined based on the crank angle. Therefore, in step S2, it is determined that the crank angle is within the predetermined angle range, but the means for detecting the rotation angle of the cam 24 is not limited to the crank angle, and it is sufficient if it is possible to determine whether the rotation angle of the cam 24 is within the predetermined angle range.

[0030] Furthermore, when the vehicle is traveling in the EV driving mode, a torque (driven torque) λ acts on the crankshaft 4 via the power split mechanism 5, causing the crankshaft 4 to repeatedly rotate forward and backward. In other words, the crankshaft 4 vibrates in the rotational direction. The driven torque λ can be calculated from the equation of motion of the power split mechanism 5 using the following formulas (1) to (3).

number

[0031] In addition, in equation (1), Js represents the moment of inertia of the members including the first motor 2 that rotate together with the sun gear S, θs represents the rotational angle of the first motor 2, and Ts represents the torque of the sun gear S; in equation (2), Jc represents the moment of inertia of the members that rotate together with the carrier C, θc represents the rotational angle of the carrier C (i.e., the crankshaft 4), and Tc represents the torque of the carrier C; in equation (3), Jr represents the moment of inertia of the members that rotate together with the ring gear R, θr represents the rotational angle of the ring gear R, and Tr represents the torque of the ring gear R; and in equations (1) to (3), ρ represents the gear ratio of the power split mechanism 5.

[0032] Therefore, for example, the driven torque λ can be calculated based on the moment of inertia Js of the components including the first motor 2 that rotates integrally with the sun gear S, which is stored in advance in the ECU 43, the rotational angular velocity obtained by twice differentiating the rotational angle θs of the first motor 2 detected by the resolver, the output torque of the first motor 2, which becomes the torque Ts of the sun gear S, and the gear ratio ρ of the power split mechanism 5.

[0033] Therefore, if the crank angle has been held within a predetermined angle range for a predetermined period of time or more and thus a positive determination is made in step S2, the signal of the detected crank angle is subjected to FFT analysis (step S3), and it is determined whether or not the spectrum of a predetermined frequency component is equal to or greater than a predetermined value (step S4). This step S4 is a step for estimating that the vibration of the crank angle (i.e., the pulsation of the driven torque λ) will cause the plunger 31 or the valve body 41 to resonate, causing oil to leak from the lash adjuster 22. Therefore, the predetermined frequency component in step S4 can be set to a frequency component that coincides with a natural frequency based on the spring constant of the spring 42 and the mass of the plunger 31, or a natural frequency based on the spring constant of the spring 40 and the mass of the valve body 41.

[0034] If the answer to step S4 is affirmative because the spectrum of a predetermined frequency component in the crank angle vibration is equal to or greater than a predetermined value, there is a possibility of oil leaking from lash adjuster 22, so mechanical oil pump 19 is driven to fill oil into oil passage 20 leading from mechanical oil pump 19 to lash adjuster 22, and into low pressure chamber 32 and high pressure chamber 36 in lash adjuster 22.

[0035] On the other hand, the operation of the mechanical oil pump 19 inevitably generates abnormal noise. Specifically, the larger the driven torque λ, the larger the background noise due to vibration of the members constituting the engine 1. FIG. 6 shows the relationship between the driven torque λ and the background noise. In the region where the driven torque λ is positive, that is, the region where the driven torque λ acts to rotate the crankshaft 4 in the same direction as when the engine 1 is driven, the background noise increases in proportion to the driven torque λ. In the region where the driven torque λ is negative, that is, the region where the driven torque λ acts to rotate the crankshaft 4 in the opposite direction to when the engine 1 is driven, when the magnitude of the torque is equal to or less than a predetermined torque, the background noise increases at a relatively small rate of change as the driven torque λ increases, whereas in the region where the torque is higher than the predetermined torque, the rate of change increases due to the operation of the brakes of the vehicle Ve.

[0036] Therefore, in the example shown in Fig. 5, the mechanical oil pump 19 is configured to be driven when the background noise becomes large. Specifically, if the spectrum of a predetermined frequency component is equal to or greater than a predetermined value and therefore an affirmative determination is made in step S4, it is then determined whether the driven torque λ is equal to or greater than a predetermined torque (step S5). The predetermined torque in step S5 can be set to a torque at which the background noise shown in Fig. 6 becomes larger than the abnormal noise generated when the mechanical oil pump 19 is driven.

[0037] If the driven torque λ is equal to or greater than the predetermined torque and therefore the answer is YES in step S5, torque is output from the first motor 2 to drive the mechanical oil pump 19 (step S6), and this routine ends for the time being. Specifically, the load torque (resistance torque) of members such as the crankshaft 4 and the carrier C that rotate integrally with the mechanical oil pump 19 and the friction torque of these members are added together, and the torque of the first motor 2 is controlled so that a torque equal to or greater than the torque obtained by subtracting the driven torque λ from the load torque λ is transmitted to the crankshaft 4.

[0038] If the above-mentioned steps S2, S4, and S5 return a negative determination, the possibility of oil leaking from the lash adjuster 22 is low or the situation is not suitable for driving the mechanical oil pump 19, so this routine is temporarily terminated without executing step S6.

[0039] As described above, on the condition that the crank angle remains within a predetermined angle range, the mechanical oil pump 19 is driven to fill the lash adjuster 22 with oil, i.e., keep the cam 24 and the rocker arm 25 in contact, even when the EV driving mode is switched to the HEV driving mode. This makes it possible to suppress the generation of abnormal noise caused by the cam 24 colliding with the rocker arm 25 when the engine is started after switching to the HEV driving mode. In addition, the opening / closing timing and the opening amount of the intake valve and the exhaust valve can be appropriately controlled, making it possible to suppress deterioration of fuel economy and exhaust.

[0040] On the other hand, the torque required to start rotating the crankshaft 4 varies depending on the crank angle at the time of stopping, as shown in Fig. 7. Specifically, the torque required to rotate the crankshaft 4 varies from when the engine is started until the crank angle reaches a predetermined angle, as shown in Fig. 7. In Fig. 7, the torque required to rotate the crankshaft 4 from a state where the crank angle is 0 degrees based on a predetermined reference angle is shown by a solid line, the torque required to rotate the crankshaft 4 from a state where the crank angle is 40 degrees is shown by a dashed line, and the torque required to rotate the crankshaft from a state where the crank angle is 80 degrees is shown by a dashed line.

[0041] Since the torque required to rotate the crankshaft 4 differs depending on the angle of the stopped crankshaft 4 as described above, the output torque of the first motor 2 determined in step S7 may be determined by adding together the load torque of the engine 1 which corresponds to the crank angle, the load torque of the mechanical oil pump 19, and the load torque of components such as the carrier C, and subtracting the driven torque λ.

[0042] As described above, the torque of the first motor 2 for rotating the mechanical oil pump 19 is controlled in accordance with the crank angle and the driven torque λ, thereby allowing the mechanical oil pump 19 to rotate appropriately. Therefore, it is possible to prevent the amount of oil filling the lash adjuster 22 from becoming insufficient due to poor rotation of the mechanical oil pump 19. Alternatively, it is possible to prevent the mechanical oil pump 19 from being driven for a long period of time in order to fill the lash adjuster 22 with sufficient oil, thereby shortening the period during which abnormal noise is generated by driving the mechanical oil pump 19. Therefore, it is possible to shorten the period during which the driver feels uncomfortable by driving the mechanical oil pump 19. Alternatively, it is possible to prevent the mechanical oil pump 19 from rotating excessively, thereby preventing an increase in abnormal noise accompanying an increase in the rotation speed of the mechanical oil pump 19 and the engine 1, thereby preventing the driver from feeling uncomfortable.

[0043] Furthermore, when the SOC of the power storage device 9 drops to an allowable lower limit, the driving mode is switched from the EV driving mode to the HEV driving mode, so it is preferable that the lash adjuster 22 is filled with oil at that point. Therefore, the threshold value for determining the start of driving the mechanical oil pump 19 may be changed according to the SOC. Specifically, the lower the SOC, the smaller the predetermined torque in the above step S5 may be changed to.

[0044] By changing the threshold value for determining when to start driving the mechanical oil pump 19 in accordance with the SOC in this way, the lash adjuster 22 can be filled with oil at the time when the EV driving mode is switched to the HEV driving mode as the SOC drops, and abnormal noises generated when the engine is started can be suppressed. Note that abnormal noises generated when the engine 1 is started without the lash adjuster 22 being filled with oil are louder than abnormal noises generated by driving the mechanical oil pump 19 in the EV driving mode. [Explanation of symbols]

[0045] 1 Engine 2,3 Motor 4 Crankshaft 6 Drive wheels 10 Drive mechanism 11 Chain 12 Exhaust camshaft 13 Intake side camshaft 14 Drive sprocket 15 Exhaust sprocket 16 Intake sprocket 19 Mechanical oil pump 22 Lash adjuster 23 Opening and closing mechanism 24 Cam 24a Cam surface 25 Rocker arm 26 Pressing part 27 Contact part 28 Reaction section 29 Return spring 31 Plunger 32 Low Pressure Room 36 Hyperbaric Chamber 37 Check valve 40,42 Spring 41 Valve body 43 Electronic Control Unit (ECU) B. Exhaust valve C Carrier R ring gear S Sun gear Vehicle

Claims

[Claim 1] A control device for a hybrid vehicle comprising: an internal combustion engine; a mechanical oil pump connected to an output shaft of the internal combustion engine; a cam that rotates in conjunction with the output shaft of the internal combustion engine; a rocker arm that is pressed by the cam to swing and drive a valve provided in the internal combustion engine; a lash adjuster that receives a reaction force of a load that causes the cam to press the rocker arm when hydraulic pressure is supplied from the mechanical oil pump; a first electric motor connected to the internal combustion engine so as to be able to transmit torque; and a second electric motor connected to drive wheels so as to be able to transmit torque, detecting a rotation angle of the cam while the internal combustion engine is stopped and the vehicle is traveling with a drive torque output from the second electric motor; When the time during which the rotation angle of the cam remains within a predetermined angle range is equal to or longer than a predetermined time, a torque is output from the first electric motor to rotate the internal combustion engine, thereby driving the mechanical oil pump. A control device for a hybrid vehicle.

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