JP2014231319A - Vehicular control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress cost and secure line pressure.SOLUTION: A vehicular control device comprises: a power transmission path 52 for coupling a travel motor 12 and a drive wheel 21; a first drive system 51 which is coupled to the power transmission path 52; and a second drive system 69 which is coupled to an engine 11. The vehicular control device further comprises a mechanical pump 41 which is driven by at least one of the power transmission path 52 and the engine 11, and an electrical pump 72 which is driven by an electrical motor 71. A control unit 73 determines discharge pressure shortage of the mechanical pump 41 based on an operation state of the mechanical pump 41, and when it is determined that the mechanical pump 41 is in the discharge pressure shortage state, the electrical pump 72 is driven and the engine 11 is started up.

Description

  The present invention relates to a vehicle control device including an oil pump.

  In recent years, a vehicle incorporating a speed change mechanism such as a continuously variable transmission has been developed as a hybrid vehicle including an engine and a traveling motor. Further, as a travel mode of the hybrid vehicle, there is a motor travel mode in which the engine is stopped and only the travel motor is driven. As described above, even in the motor travel mode in which the engine is stopped, since it is necessary to supply hydraulic oil to the hydraulic system such as the transmission mechanism, the vehicle is equipped with an oil pump that is driven by the travel motor. Yes.

  Further, since the discharge pressure of the oil pump driven by the travel motor is linked to the rotational speed of the travel motor, that is, the vehicle speed, the discharge pressure of the oil pump decreases at low vehicle speeds. Thus, it is necessary to continue supplying hydraulic oil to the hydraulic system even at low vehicle speeds when the discharge pressure of the oil pump decreases. In view of this, a hybrid vehicle equipped with an electric oil pump driven by an electric motor in addition to an oil pump driven by a traveling motor has been proposed (see Patent Document 1). In such a vehicle, the line pressure, which is the basic hydraulic pressure of the hydraulic control system, is secured by driving the electric oil pump at a low vehicle speed.

JP 2011-195102 A

  However, in the hybrid vehicle disclosed in Patent Document 1, when sudden braking or the like is performed and the vehicle speed rapidly decreases, it may be difficult to ensure a minimum line pressure. That is, during sudden braking, the discharge pressure of the oil pump that is linked to the vehicle speed rapidly decreases, so it becomes difficult to ensure the line pressure depending on the discharge capacity of the electric oil pump. For this reason, in order to ensure a line pressure only with an electric oil pump, it was necessary to increase the discharge capacity of the electric oil pump. Thus, increasing the discharge capacity of the electric oil pump is a factor that increases the cost of the hydraulic system, and therefore it is desired to secure the line pressure while suppressing the cost.

  An object of the present invention is to secure a line pressure while suppressing costs.

  The vehicle control device of the present invention includes a power transmission path that connects a traveling motor and drive wheels, a first drive system that is coupled to the power transmission path, and a second drive system that is coupled to an engine, Based on the first oil pump driven by at least one of the power transmission path and the engine, the second oil pump driven by an electric motor, and the operating state of the first oil pump, A pump operation determination unit that determines whether the discharge pressure of the oil pump is insufficient, a pump control unit that drives the second oil pump when the first oil pump is determined to be insufficient discharge pressure, and the first oil pump An engine control unit that starts the engine when it is determined that the discharge pressure is insufficient.

  According to the present invention, when it is determined that the first oil pump is short of discharge pressure, the second oil pump is driven and the engine is started. Thereby, both a 1st oil pump and a 2nd oil pump can be driven, and it becomes possible to ensure a line pressure. And since the engine was started and the 1st oil pump was driven, the enlargement of a 2nd oil pump can be avoided and it becomes possible to suppress cost.

It is the schematic which shows an example of the power unit mounted in a vehicle. It is the schematic which shows the structure of the control apparatus for vehicles which is one embodiment of this invention. It is a flowchart which shows an example of the procedure of the pump operation | movement determination performed by the control unit. It is explanatory drawing which shows the change condition of the rotation speed difference at the time of determining with it being a rapid deceleration state in pump operation | movement determination. It is a flowchart which shows an example of the procedure of the line pressure ensuring control performed by the control unit. It is explanatory drawing which shows the change state of a line pressure when line pressure ensuring control is performed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram showing an example of a power unit 10 mounted on a vehicle. As shown in FIG. 1, the power unit 10 has an engine 11 and a traveling motor 12 as power sources. The power unit 10 is provided with a continuously variable transmission (transmission mechanism) 13, and the continuously variable transmission 13 is provided with a primary pulley 14 and a secondary pulley 15. The engine 11 is connected to one side of the primary pulley 14 via a torque converter 16, while the traveling motor 12 is connected to the other side of the primary pulley 14. A drive wheel output shaft 18 is coupled to the secondary pulley 15 via a fuse clutch 17. Drive wheels 21 are connected to the drive wheel output shaft 18 via a differential mechanism 19 and an axle shaft 20. A motor generator 24 is connected to the crankshaft 22 of the engine 11 via a drive belt 23. The motor generator 24 is a so-called ISG (Integrated Starter Generator) that functions as a generator and an electric motor. The motor generator 24 can be used to start and rotate the crankshaft 22.

  Between the torque converter 16 and the primary pulley 14, an input clutch 30 that is switched between a released state and an engaged state is provided. By switching the input clutch 30 to the released state, the primary pulley 14 and the engine 11 can be disconnected. As a result, the travel mode can be set to the motor travel mode, and the engine 11 can be stopped and only the power of the travel motor 12 can be transmitted to the drive wheels 21. On the other hand, the primary pulley 14 and the engine 11 can be connected by switching the input clutch 30 to the engaged state. As a result, the traveling mode can be set to the parallel traveling mode, and the power of the traveling motor 12 and the engine 11 can be transmitted to the drive wheels 21.

  The continuously variable transmission 13 provided between the traveling motor 12 and the drive wheel 21 has a primary shaft 32 connected to the rotor shaft 31 of the traveling motor 12 and a secondary shaft 33 parallel to the primary shaft 32. ing. A primary pulley 14 is provided on the primary shaft 32, and a primary chamber 34 is defined on the back side of the primary pulley 14. The secondary shaft 33 is provided with a secondary pulley 15, and a secondary chamber 35 is defined on the back side of the secondary pulley 15. Further, a drive chain 36 is wound around the primary pulley 14 and the secondary pulley 15. By adjusting the primary pressure supplied to the primary chamber 34 and the secondary pressure supplied to the secondary chamber 35, the pulley groove width can be changed to change the winding diameter of the drive chain 36. Thereby, continuously variable transmission from the primary shaft 32 to the secondary shaft 33 is possible. As described above, the fuse clutch 17 is provided between the continuously variable transmission 13 and the drive wheel 21. The fuse clutch 17 is a friction clutch that enters a slip state when a set torque is exceeded, and functions as a torque limiter for protecting the continuously variable transmission 13.

  In order to supply hydraulic oil to the hydraulic system such as the continuously variable transmission 13 and the torque converter 16 described above, the power unit 10 is provided with a first oil pump 41 (hereinafter referred to as a mechanical pump) such as a trochoid pump. Yes. Further, the power unit 10 is provided with a valve unit 42 constituted by a plurality of electromagnetic valves and oil passages in order to control the supply destination and pressure of the hydraulic oil. The hydraulic oil discharged from the mechanical pump 41 is supplied to the continuously variable transmission 13, the torque converter 16, and the like through the valve unit 42.

  The mechanical pump 41 includes an outer rotor 43 and an inner rotor 44 incorporated therein. A rotor shaft 45 and a driven sprocket 46 are attached to one end of the inner rotor 44. A drive sprocket 48 is attached to the primary shaft 32 parallel to the rotor shaft 45 via a one-way clutch 47. A chain 49 is wound around the drive sprocket 48 and the driven sprocket 46, and the primary shaft 32 and the inner rotor 44 are connected via a chain mechanism 50. As described above, the mechanical pump 41 is connected to the primary shaft 32 that constitutes a part of the power transmission path 52 via the first drive system 51 configured by the chain mechanism 50. The power transmission path 52 means a power transmission path that connects the traveling motor 12 and the drive wheels 21, that is, a power transmission element group or a power transmission element. In the present embodiment, the power transmission path 52 includes the rotor shaft 31, the primary shaft 32, the secondary shaft 33, the fuse clutch 17, the drive wheel output shaft 18, the differential mechanism 19, the axle shaft 20, and the like.

  A rotor shaft 61 and a driven sprocket 62 are attached to the other end of the inner rotor 44 of the mechanical pump 41. A drive sprocket 66 is attached to a hollow shaft 64 fixed to the pump shell 63 of the torque converter 16 and parallel to the rotor shaft 61 via a one-way clutch 65. A chain 67 is wound around the drive sprocket 66 and the driven sprocket 62, and the hollow shaft 64 and the inner rotor 44 are connected via a chain mechanism 68. Thus, the mechanical pump 41 is connected to the crankshaft 22 of the engine 11 via the second drive system 69 configured by the chain mechanism 68 and the torque converter 16.

  The one-way clutch 47 constituting the first drive system 51 transmits power to the inner rotor 44 from the primary shaft 32 that rotates in the forward rotation direction, while blocking power transmission in the opposite direction. Similarly, the one-way clutch 65 constituting the second drive system 69 transmits power to the inner rotor 44 from the hollow shaft 64 that rotates in the forward rotation direction, while blocking power transmission in the opposite direction. That is, when the primary shaft 32 rotates faster than the hollow shaft 64, the mechanical pump 41 is driven by the primary shaft 32 on the traveling motor 12 side, while the hollow shaft 64 rotates faster than the primary shaft 32. The mechanical pump 41 is driven by the hollow shaft 64 on the engine 11 side. The forward rotation direction of the primary shaft 32 is the rotation direction of the primary shaft 32 during forward travel. The forward rotation direction of the hollow shaft 64 is the rotation direction of the crankshaft 22 when the engine is operating.

  As described above, the primary shaft 32 and the hollow shaft 64 are connected to the inner rotor 44 of the mechanical pump 41. Thus, in the parallel travel mode in which the engine 11 is driven, the mechanical pump 41 can always be driven by the engine 11, and the continuously variable transmission 13 and the like can be hydraulically controlled by the hydraulic oil from the mechanical pump 41. . Even in the motor travel mode in which the engine 11 is stopped, the mechanical pump 41 can be driven by the primary shaft 32 when the vehicle travels with the primary shaft 32 rotating. Thus, the mechanical pump 41 driven by the primary shaft 32 is an oil pump that is rotationally driven by the power transmission path 52. By the way, when the vehicle is stopped in the motor travel mode, the mechanical pump 41 is stopped together with the primary shaft 32. Even when the vehicle is stopped, it is necessary to continue supplying hydraulic oil to the hydraulic system such as the continuously variable transmission 13. is there.

  The vehicle control device 70 is a second oil pump 72 (hereinafter referred to as an electric pump) that is rotationally driven by an electric motor 71 in order to secure a line pressure that is a basic hydraulic pressure of the hydraulic system when the vehicle is stopped in the motor travel mode. ). For example, in the motor travel mode in which the engine 11 is stopped, when the vehicle speed falls below a predetermined value while gradually decreasing, the discharge pressure of the mechanical pump 41 decreases in conjunction with the vehicle speed, so that the mechanical pump 41 is supplemented. The electric pump 72 is driven. Thereby, hydraulic fluid is supplied to the valve unit 42 from both the mechanical pump 41 and the electric pump 72, and it becomes possible to ensure the line pressure of the hydraulic system. By the way, when the vehicle speed rapidly decreases in the motor travel mode, the discharge pressure of the mechanical pump 41 also decreases rapidly. Therefore, there is a possibility that the line pressure is temporarily insufficient only by driving the electric pump 72. Therefore, the vehicle control device 70 performs an operation determination of the mechanical pump 41 (hereinafter referred to as pump operation determination) described later, and when it is determined that the discharge pressure of the mechanical pump 41 is insufficient, the electric pump 72 is driven and the engine 11 is started to execute line pressure securing control for increasing the discharge pressure of the mechanical pump 41.

  Hereinafter, pump operation determination and line pressure ensuring control executed by the vehicle control device 70 will be described. FIG. 2 is a schematic diagram showing a configuration of a vehicle control device 70 according to an embodiment of the present invention. In FIG. 2, the same members as those shown in FIG. 1 are denoted by the same reference numerals and description thereof is omitted. As shown in FIG. 2, the vehicle control device 70 includes a power unit 10 and a control system thereof. The vehicle control device 70 is provided with a control unit 73 that functions as a pump operation determination unit, a pump control unit, and an engine control unit. The control unit 73 includes a wheel speed sensor 74 that detects the rotation speed of the drive wheel 21, a motor rotation sensor 76 that detects the rotation speed of the rotor 75 included in the traveling motor 12, and a brake pedal depression state by the driver. A brake switch 77 or the like is connected. An inverter 79 is connected to the stator 78 of the traveling motor 12, and the control unit 73 controls the traveling motor 12 through the inverter 79. The control unit 73 includes a CPU that calculates control signals and the like, a ROM that stores control programs, arithmetic expressions and map data, and a RAM that temporarily stores data.

  FIG. 3 is a flowchart showing an example of a procedure for determining the pump operation executed by the control unit 73. As shown in FIG. 3, in steps S <b> 1 to S <b> 4, a precondition for performing the pump operation determination is determined. In step S1, it is determined whether or not the current travel mode is a motor travel mode. If the motor travel mode is set, the process proceeds to step S2 and it is determined based on the detection signal from the brake switch 77 whether or not the brake pedal is depressed. In step S2, an ON signal is output from the brake switch 77, and if it is determined that the vehicle is being braked due to depression of the brake pedal, the process proceeds to step S3, and is calculated based on the detection signal of the motor rotation sensor 76. It is determined whether the actual motor rotation speed N1 falls below a predetermined speed threshold value Xa. When the actual motor rotation speed N1 is lower than the speed threshold value Xa, the process proceeds to step S4, and it is determined whether or not the actual motor rotation speed N1 is decelerating. If it is determined in step S4 that the actual motor rotation speed N1 is decelerating, the preconditions in steps S1 to S4 are satisfied, and the process proceeds to step S5, where pump operation determination is started. . If it is determined in any of steps S1 to S4 that the precondition is not satisfied, the routine is exited without performing the pump operation determination.

  In step S5, based on the detection signal from the wheel speed sensor 74, a predicted motor rotation speed N2 that is the rotation speed of the traveling motor 12 is calculated. That is, in step S5, the predicted motor speed N2 of the traveling motor 12 is calculated based on the rotational speed of the axle shaft 20, the final reduction ratio of the differential mechanism 19, and the speed ratio of the continuously variable transmission 13. Subsequently, in step S6, the rotational speed difference ΔN is calculated by subtracting the actual motor rotational speed N1 from the predicted motor rotational speed N2. In step S7, it is determined whether or not the rotational speed difference ΔN exceeds a determination threshold value Xb. Here, the situation where the rotational speed difference ΔN exceeds the determination threshold value Xb is a situation where the rotational speed of the traveling motor 12, that is, the rotational speed of the mechanical pump 41 suddenly decreases as the vehicle suddenly decelerates. That is, in step S7, when the rotational speed difference ΔN exceeds the determination threshold value Xb, the rotational speed of the mechanical pump 41 suddenly decreases and the discharge pressure becomes insufficient. It is determined that the vehicle is in a sudden deceleration state with insufficient pressure.

  Here, FIG. 4 is an explanatory diagram showing a change state of the rotational speed difference ΔN when it is determined that the state is a sudden deceleration state in the pump operation determination. As shown in FIG. 4, when the brake pedal is depressed by the driver in the motor traveling mode, a braking force is applied to the wheels by a hydraulic brake mechanism (not shown). In particular, when a braking operation is performed on a low μ road such as a frozen road surface, the rotational speed N3 of the drive wheel 21 rapidly decreases, so the load on the fuse clutch 17 increases and the fuse clutch 17 slips. Will start. Here, the power transmission path 52 between the traveling motor 12 and the drive wheel 21 is connected to the power transmission path 52a (primary shaft 32 or the like) on the traveling motor 12 side with the fuse clutch 17 as a boundary. The power transmission path 52b (the drive wheel output shaft 18 and the like) on the drive wheel 21 side is considered at the boundary. As described above, when the fuse clutch 17 slips, the power transmission path 52b on the drive wheel 21 side is disconnected from the power transmission path 52a on the traveling motor 12 side. Further, when the brake operation is performed, the traveling motor 12 is controlled to be in a regenerative state, so that a regenerative torque, that is, a braking torque is applied to the power transmission path 52a. That is, when the fuse clutch 17 slips, the power transmission path 52b, which is a rotating mass body, is disconnected from the power transmission path 52a braked by the travel motor 12, so that the deceleration speed of the power transmission path 52a is the power transmission. A phenomenon that exceeds the deceleration speed of the path 52b occurs.

  That is, at the time of braking accompanied by slip of the fuse clutch 17, the actual motor rotational speed N1 calculated based on the rotational speed of the power transmission path 52a is larger than the predicted motor rotational speed N2 calculated based on the rotational speed of the power transmission path 52b. , Will decline rapidly. For this reason, it is possible to quickly detect a braking situation that causes the fuse clutch 17 to slip by determining the magnitude of the rotational speed difference ΔN that is the speed difference between the actual motor rotational speed N1 and the predicted motor rotational speed N2. It becomes. Further, as described above, the braking situation in which the fuse clutch 17 is slipped is a situation in which the rotational speed of the power transmission path 52a, that is, the rotational speed of the mechanical pump 41 is rapidly reduced. In other words, by determining the magnitude of the rotational speed difference ΔN, it is possible to quickly detect a sudden deceleration state that is accompanied by an insufficient discharge pressure of the mechanical pump 41.

  In the above description, it is determined whether or not the engine is in a sudden deceleration state with insufficient discharge pressure of the mechanical pump 41 based on the rotation speed difference ΔN between the actual motor rotation speed N1 and the predicted motor rotation speed N2. The determination method is not limited, and any determination method may be used as long as the determination method is based on the operating state of the mechanical pump 41. For example, when the absolute value of the deceleration speed of the actual motor rotation speed N1 exceeds a predetermined value, it may be determined that the sudden deceleration state is accompanied by insufficient discharge pressure of the mechanical pump 41. In addition, when the absolute value of the deceleration speed of the mechanical pump 41 exceeds a predetermined value, or when the absolute value of the deceleration speed of the rotational speed N3 of the drive wheel 21 exceeds a predetermined value, the discharge pressure of the mechanical pump 41 is insufficient. You may determine with the accompanying sudden deceleration state. Further, by using a hydraulic pressure sensor that detects the discharge pressure of the mechanical pump 41, when the absolute value of the decrease rate of the discharge pressure of the mechanical pump 41 exceeds a predetermined value, it is in a sudden deceleration state with insufficient discharge pressure of the mechanical pump 41. You may judge.

  Next, line pressure securing control that is executed after it is determined that the vehicle is in a sudden deceleration state will be described. FIG. 5 is a flowchart showing an example of the procedure of the line pressure ensuring control executed by the control unit 73. As shown in FIG. 5, in step S <b> 11, it is determined whether it is determined that the vehicle is in a sudden deceleration state. If it is determined in step S11 that the rapid deceleration is determined, the process proceeds to step S12, the electric pump 72 is driven, the process proceeds to step S13, and the engine 11 is started. As described above, when the mechanical pump 41 is suddenly decelerated with insufficient discharge pressure, hydraulic oil is supplied from the electric pump 72 to the valve unit 42 and the engine 11 is started to operate from the mechanical pump 41 to the valve unit 42. Supplying oil. Subsequently, in step S14, it is determined by driving the electric pump 72 and the mechanical pump 41 whether or not the line pressure exceeds a predetermined value for a predetermined time. If it is determined in step S14 that the line pressure is not secured, the process returns to step S12, and the drive state of the electric pump 72 and the mechanical pump 41 is continued. On the other hand, if it is determined in step S14 that the line pressure is secured, the process proceeds to step S15, and the electric pump 72 is stopped.

  Here, FIG. 6 is an explanatory diagram showing a change state of the line pressure PL when the line pressure securing control is executed. In FIG. 6, the symbol PL represents the line pressure, the symbol Np represents the primary rotational speed, the symbol Ne represents the engine rotational speed, the symbol Neop represents the rotational speed of the electric pump 72, and the symbol TNeop represents the electric pump. 72 shows the target rotational speed. As shown in FIG. 6, when it is determined that the vehicle is braked by depressing the brake pedal and the vehicle is suddenly decelerating with insufficient discharge pressure of the mechanical pump 41 (reference A), an activation flag for the electric pump 72 is set. (Code B), the start flag of the engine 11 is set (Code C). In this way, when the start flag of the electric pump 72 and the start flag of the engine 11 are set, the drive of the electric pump 72 with good responsiveness is started (reference D), and then the mechanical pump 41 is driven by the engine 11. Start (reference E).

  In this way, when it is determined that the sudden deceleration state is accompanied by insufficient discharge pressure of the mechanical pump 41, both the electric pump 72 and the mechanical pump 41 are driven to supply sufficient hydraulic oil to the valve unit 42. Therefore, it is possible to avoid the occurrence of insufficient line pressure as indicated by the broken line X. As described above, since both the electric pump 72 and the mechanical pump 41 are driven, it is possible to avoid the occurrence of insufficient line pressure while avoiding the enlargement of the electric pump 72. That is, the line pressure can be secured while suppressing the cost of the hydraulic system. A broken line X indicates a characteristic line when the engine 11 is started and only the mechanical pump 41 is driven. Further, the start flag of the engine 11 is released when the start of the engine 11 is completed.

  6, when it is determined that the line pressure PL has been secured for a predetermined time, the start flag of the electric pump 72 is canceled (reference G), and the electric pump 72 The target rotational speed TNeop is reduced to 0 (symbol H). As described above, when it is confirmed that the line pressure PL is secured after the engine is started, the electric pump 72 is controlled to be in a stopped state while the driving state of the mechanical pump 41 is maintained. As a result, the operating area of the electric pump 72 can be reduced while avoiding the occurrence of insufficient line pressure, and the power consumption of the electric pump 72 can be suppressed and the durability of the electric pump 72 can be increased.

  In the line pressure securing control, not only the mechanical pump 41 and the electric pump 72 are driven, but the amount of hydraulic oil supplied from the valve unit 42 to the hydraulic system such as the torque converter 16 may be limited. Thereby, consumption of the hydraulic fluid supplied from the mechanical pump 41 or the electric pump 72 can be suppressed, and a shortage of line pressure can be avoided. Further, from the viewpoint of securing the clamping force of the continuously variable transmission 13 and protecting the continuously variable transmission 13, it is desirable that the amount of hydraulic oil supplied to the secondary chamber 35 of the secondary pulley 15 is not limited. Further, in the line pressure securing control, the regeneration control of the traveling motor 12 may be prohibited. Thereby, since regenerative braking of the primary shaft 32 and the like by the traveling motor 12 can be prohibited, it is possible to suppress a decrease in the rotational speed of the mechanical pump 41 and to suppress an insufficient discharge pressure of the mechanical pump 41. Become.

  As described above, when performing the pump operation determination, various preconditions are determined along steps S1 to S4 in the flowchart of FIG. In step S1, the pump operation determination is executed during the setting of the motor travel mode by determining the travel mode. When the motor travel mode is not set, that is, when the parallel travel mode is set, the mechanical pump 41 is rotationally driven by the engine 11, so that the discharge pressure of the mechanical pump 41 is not insufficient. In this way, in the parallel travel mode in which there is no shortage of discharge pressure, the pump operation determination is prohibited to prevent erroneous determination. Further, in step S2, the pump operation determination is executed at the time of vehicle braking in which the brake pedal is depressed by determining the signal of the brake switch 77. When the brake operation is not performed, the rotational speed of the mechanical pump 41 does not rapidly decrease due to regenerative braking of the traveling motor 12 or the like. As described above, when the brake operation is not performed, since the discharge pressure of the mechanical pump 41 is not insufficient, the pump operation determination is prohibited to prevent the erroneous determination.

  In step S3, the pump operation determination is performed in the low rotation region of the actual motor rotation speed N1 by determining the magnitude of the actual motor rotation speed N1. When the actual motor rotation speed N1 is not a low rotation area, that is, in the middle and high rotation area of the actual motor rotation speed N1, the discharge pressure of the mechanical pump 41 is sufficiently secured. Will not occur. As described above, in a situation where the actual motor rotation speed N1 exceeds the speed threshold value Xa, there is no occurrence of insufficient discharge pressure of the mechanical pump 41, so that pump operation determination is prohibited to prevent erroneous determination. Further, in step S4, the pump operation determination is executed during the deceleration of the actual motor rotation speed N1 by determining the transition of the actual motor rotation speed N1. When the actual motor rotational speed N1 is maintained or increased, the rotational speed of the mechanical pump 41 does not rapidly decrease due to regenerative braking of the traveling motor 12 or the like. As described above, when the actual motor rotation speed N1 is maintained or increased, a shortage of discharge pressure of the mechanical pump 41 does not occur, so that pump operation determination is prohibited to prevent erroneous determination.

  It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. In the above description, the pump operation determination is executed at the time of vehicle braking by depressing the brake pedal. However, the present invention is not limited to this, and at the time of vehicle braking by the automatic brake that automatically brakes the vehicle according to the inter-vehicle distance or the like. Pump operation determination may be executed. In the above description, the chain drive type continuously variable transmission 13 is used as the speed change mechanism. However, the present invention is not limited to this and may be a belt drive type or traction drive type continuously variable transmission. A planetary gear type or parallel shaft type automatic transmission may also be used. The mechanical pump 41 and the electric pump 72 may be an inscribed gear pump or an outer gear gear pump.

11 Engine 12 Traveling motor 13 Continuously variable transmission (transmission mechanism)
21 Drive wheel 41 Mechanical pump (first oil pump)
51 First Drive System 52 Power Transmission Path 69 Second Drive System 70 Vehicle Control Device 71 Electric Motor 72 Electric Pump (Second Oil Pump)
73 Control unit (pump operation determination unit, pump control unit, engine control unit)

Claims (5)

A power transmission path connecting the driving motor and the drive wheels;
A first oil pump that includes a first drive system coupled to the power transmission path and a second drive system coupled to an engine, and is driven by at least one of the power transmission path and the engine;
A second oil pump driven by an electric motor;
A pump operation determination unit that determines an insufficient discharge pressure of the first oil pump based on an operating state of the first oil pump;
A pump control unit that drives the second oil pump when the first oil pump is determined to have insufficient discharge pressure;
An engine control unit for starting the engine when the first oil pump is determined to have insufficient discharge pressure;
A vehicle control device. The vehicle control device according to claim 1,
The pump control unit is a vehicle control device that stops the second oil pump after the engine is started. The vehicle control device according to claim 1 or 2,
A vehicle control device, wherein a transmission mechanism is provided between the travel motor and the drive wheel, and hydraulic oil is supplied from the first oil pump and the second oil pump to the transmission mechanism. The vehicle control device according to any one of claims 1 to 3,
The said pump operation | movement determination part is a vehicle control apparatus which determines lack of discharge pressure based on the rotational speed of a said 1st oil pump. In the vehicle control device according to any one of claims 1 to 4,
The said pump operation | movement determination part is a control apparatus for vehicles which determines the discharge pressure shortage of a said 1st oil pump at the time of vehicle braking.

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