JP2017128315A - Control device of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform sufficiently, lubrication of a power division mechanism even when a vehicle travels by at least two motors coupled to the power division mechanism formed of a differential mechanism.SOLUTION: A control device for a vehicle: comprises at least two motors, a drive force source different from the motor, and a differential mechanism to which the motors and the drive force source are coupled and which comprises plural rotation elements; and travels by drive force output from the differential mechanism. When the vehicle drives by drive force output by one or more motors out of the at least two motors, the motors are controlled so that an absolute value of a rotation number of each of all rotation elements becomes equal to or more than a predetermined prescribed rotation number (step S4).SELECTED DRAWING: Figure 4

Description

  The present invention relates to an apparatus for controlling a vehicle configured to connect a plurality of driving force sources including a motor or a motor having a power generation function to a differential mechanism and to output a driving force for traveling from the differential mechanism. It is about.

  The differential mechanism has at least three rotation elements, that is, an input element, an output element, and a reaction force element, and the relationship between the rotation speed or torque of the input element and the output element is determined by the rotation speed or torque of the reaction force element. Can be controlled by. An example of this type of differential mechanism is a planetary gear mechanism, which is used as a transmission device such as a vehicle transmission. One example thereof is described in Patent Document 1.

  The apparatus described in Patent Document 1 connects an engine, a first motor / generator, and a second motor / generator to a power split mechanism including a planetary gear mechanism, and mainly uses a driving force output by the engine as a first. The apparatus is configured to be divided into a motor generator side and an output element side (second motor generator side). By controlling the rotational speed of the first motor / generator, the rotational speed of the engine can be controlled. In this case, since the first motor / generator functions as a generator, the electric power generated by the first motor / generator is reduced. The second motor / generator is supplied to the second motor / generator and outputs the driving force. Each motor / generator can also be driven as a motor by the electric power of the power storage device. In this case, the operation of the engine is stopped and the rotation of a member (for example, an input shaft) connected to the engine is stopped by a brake. It is like that.

JP-A-8-295140

  In the device described in Patent Document 1, when the vehicle travels only with the driving force output from the motor / generator, the rotating element to which the engine is connected is fixed, and the first motor / generator is driven to the connected rotating element. Force is input. Then, the driving force is increased or decreased according to the gear ratio of the power split mechanism, and output from the rotating element to which the second motor / generator is connected. Furthermore, the driving force output from the second motor / generator is added, and the driving force output from each of the motor / generators is added to become the driving force for traveling. In such a driving state, the other rotating elements rotate with the rotation of the rotating elements connected to the engine stopped. Therefore, when it is configured to supply lubricating oil to the power split mechanism from a member (for example, an input shaft) that transmits the driving force of the engine to the power split mechanism, each rotating element is rotating relatively. Lubricating oil cannot be sufficiently supplied to the power split mechanism. That is, the power split mechanism described above not only functions to divide the driving force of the engine, but also functions to transmit the driving force of the motor / generator while the engine is stopped. There was no room for improvement in this respect, as the lubrication when running with force was not performed.

  The present invention has been made paying attention to the above technical problem, and has an object to sufficiently lubricate a power split mechanism that is connected to a motor and controlled to various driving states.

  In order to achieve the above object, the present invention includes at least two motors, a driving force source different from the motor, a differential mechanism to which the motor and the driving force source are connected, and a plurality of rotating elements. In the control device for a vehicle that travels with the driving force output from the differential mechanism, when the vehicle travels with the driving force output by any one or more of the at least two motors, all the above The motor is configured to control the motor so that the absolute value of the rotational speed of the rotating element is equal to or greater than a predetermined rotational speed.

  In the present invention, when traveling with the driving force of the motor, the other driving force source does not output the driving force. However, the rotation speeds of all the rotation elements including the rotation element to which the other driving force source is connected are rotated at a speed equal to or higher than a predetermined rotation speed in the positive rotation direction or the negative rotation direction. Therefore, the lubricating oil that adheres or is held by these rotating elements, or that is attached or held by the rotating member connected to these rotating elements, is scattered by centrifugal force. As a result, even when traveling with the driving force of the motor, lubricating oil is actively supplied to the power split mechanism, and the power split mechanism can be sufficiently lubricated. In addition, since each motor is rotating, when the driving force output by any motor is increased, an excessive current flows through any coil in the motor, or overheating is caused accordingly. The situation can be prevented or suppressed in advance.

It is a schematic diagram of the drive system of the vehicle made into object by this invention. It is the schematic diagram which drawn the power split mechanism with the skeleton. It is an alignment chart for demonstrating the operation state of the power split mechanism in each mode. It is a flowchart for demonstrating an example of the control performed by embodiment of this invention. It is a flowchart for demonstrating the other example of the control performed by embodiment of this invention.

  DETAILED DESCRIPTION OF THE INVENTION The present invention will be described based on a specific example. FIG. 1 schematically shows a drive system of a target vehicle in an embodiment of the present invention, and the vehicle 1 shown here has at least two motors as drive power sources. (Or motor / generator: MG) 2 and 3 and another driving force source (for example, engine (ENG), hereinafter referred to as engine) 4 different from these motors 2 and 3 are provided. These motors 2 and 3 and the engine 4 are connected to a power split mechanism 5 comprising a differential mechanism. And it is comprised so that a driving force may be output from this power division mechanism 5 to the driving wheel 6. FIG.

  More specifically, as shown in FIG. 2, in the example shown here, the power split mechanism 5 is constituted by a planetary gear mechanism, and the first motor 2 is attached to the sun gear 5 </ b> S serving as a reaction force rotating element. The second motor 3 is connected via a transmission mechanism 7 to the ring gear 5R that is connected and serves as an output rotation element. Further, the engine 4 is connected to the carrier 5C serving as an input element. The transmission mechanism 7 may be a gear-type speed reducer or a transmission capable of setting a plurality of gear ratios, and outputs a driving force to a drive wheel 6 from a predetermined output member (not shown) in the transmission mechanism 7. It has become.

  The power split mechanism 5, the first motor 2, and the engine 4 are arranged side by side on the same axis, and the input shaft 8 that transmits the driving force output from the engine 4 to the carrier 5C is arranged along the axis. Yes. A sun gear shaft 9 is disposed concentrically with the input shaft 8 on the outer peripheral side of the input shaft 8, and the first motor 2 and the sun gear 5 </ b> S are connected by the sun gear shaft 9. Therefore, the input shaft 8 is arranged on the innermost circumferential side (rotation center side), and the lubricating oil is supplied to the power split mechanism 5 via an oil passage (not shown) formed in the input shaft 8. It is configured. For example, an oil hole (not shown) that opens in a portion of the input shaft 8 located on the inner peripheral side of the power split mechanism 5 is formed by branching from the oil passage, and the lubricating oil that flows out from the oil passage is centrifuged. The power split mechanism 5 is scattered by force to lubricate the power split mechanism 5.

  In the example shown in FIG. 2, a third motor (or motor generator: MG) 10 is provided, and the third motor 10 is connected to the input shaft 8. Therefore, the input shaft 8 can be rotated by the third motor 10 even when the operation of the engine 4 is stopped.

  Said 1st thru | or 3rd motor 2,3,10 is connected to the power supply part 11 containing an inverter and an electrical storage apparatus. An electronic control unit (ECU) 12 is provided for controlling the torque, generated power and the like of each motor 2, 3, 10 via the power supply unit 11. The ECU 12 is mainly composed of a microcomputer, and performs calculations using input data such as vehicle speed and accelerator opening and data stored in advance. The result of the calculation is used as a control command signal for each motor 2. 3 and 10 are output.

  The vehicle 1 includes a hybrid mode (HV mode) using the engine 4 and the first and second motors 2 and 3, and a driving force of at least two motors 2 and 3 (10) without operating the engine 4. It is possible to use an electric vehicle mode (EV mode) that travels alone. Each drive state will be described with reference to a collinear diagram of the planetary gear mechanism constituting the power split mechanism 5 as follows. FIG. 3 is a collinear diagram in which a line labeled “HV” indicates an operating state in the HV mode, and a line labeled “EV” indicates an operating state in the EV mode. . Of the lines labeled “EV”, the solid line indicates a state in which the third motor 10 applies a torque in the positive direction (the direction of the torque output by the engine 4) to the input shaft 8 and rotates the input shaft 8. A broken line indicates a state where the rotation of the input shaft 8 is stopped.

  In the HV mode, the torque output from the engine 4 acts on the carrier 5C as a positive torque, and in this state, the first motor 2 applies a negative torque (a direction opposite to the torque output from the engine 4). When applied, the torque of the ring gear 5R becomes a positive torque. Since the first motor 2 rotates in the positive direction and generates a torque in the negative direction, the first motor 2 functions as a generator, the electric power is supplied to the second motor 3, and the second motor 3 generates the torque in the positive direction. Output. That is, a part of the driving force output from the engine 4 is transmitted to the transmission mechanism 7 and the driving wheel via the power split mechanism 5, and the other driving force is converted into electric power once by the first motor 2. The motor 2 is reconverted into a driving force and added to the driving force transmitted from the power split mechanism 5 toward the driving wheels 6.

  On the other hand, in the EV mode, the first motor 2 functions as a motor by the power of the power supply unit 11, rotates in the negative direction to generate a negative torque, and the second motor 3 functions as a motor by the power of the power supply unit 11. Rotate in the positive direction to generate a positive torque. In that case, the rotation of the input shaft 8 and the carrier 5C connected thereto is stopped by the resistance force caused by the fact that the engine 4 is not operated and the negative torque of the third motor 10 (the state shown by the broken line in FIG. 3). ), The ring gear 5R, which is the output rotation element, is rotated in the forward direction by the driving force of the first motor 2. The driving force output from the second motor 3 is added to this driving force, and the vehicle 1 travels forward. In contrast, in the EV mode, the third motor 10 can output a positive torque to rotate the input shaft 8 and the carrier 5C connected thereto in the positive direction. This state is shown in FIG. 3 by a solid line labeled “EV”.

  In the HV mode, the vehicle travels using the driving force output from the engine 4, so that the vehicle can travel with a larger driving force than the EV mode. Therefore, the selection between the HV mode and the EV mode can be performed based on the required driving amount such as the accelerator opening degree and the vehicle speed. For example, the EV mode region and the HV mode region are determined in advance in the form of a map using the accelerator opening and the vehicle speed as variables, and the EV mode or the HV is determined based on the detected accelerator opening and vehicle speed and the map. Select a mode.

  In the EV mode, the control device according to the embodiment of the present invention controls the motors 2, 3, and 10 so that each rotating element of the power split mechanism 5 rotates. FIG. 4 is a flowchart for explaining an example of the control. First, it is determined whether or not the vehicle is in a power running state in the EV mode (step S1). That is, it is determined whether or not at least two motors 2 and 3 function as motors and each of them outputs a driving force for traveling. This can be determined based on the accelerator opening and the vehicle speed described above.

  If a negative determination is made in step S1, the process returns without performing any particular control. On the other hand, when a positive determination is made in step S1, each of the motors 2, 3, and 10 is controlled to output a driving force that satisfies the required driving amount (step S2). Next, it is determined whether or not the absolute value of the rotational speed of each rotating element (sun gear 5S, ring gear 5R, carrier 5C) of the power split mechanism 5 is equal to or greater than a predetermined first reference value N1 (step S3). This determination can be made based on the number of rotations of the motors 2, 3, and 10.

  If the determination in step S3 is affirmative, the process returns. On the other hand, if a negative determination is made in step S3, the motors 2, 3, and 10 are set such that the absolute value of the rotational speed of each rotary element of the power split mechanism 5 is equal to or greater than the first reference value N1. The rotation speed is controlled (step S4), and then the process returns. The control may be performed by feedback-controlling the rotation speed of any one of the motors and controlling the other motors, for example, by torque. In this way, it is possible to avoid or suppress the output torque of the other motor from becoming excessive. Moreover, it is preferable that the motor for controlling the rotation speed is the first motor 2 which is a motor not connected to the engine 4. In the HV mode, the first motor 2 is controlled at the rotational speed for controlling the engine rotational speed. Therefore, the control for the first motor 2 can be unified to the rotational speed control in both the EV mode and the HV mode. Therefore, the complexity of control can be avoided or suppressed. Further, by controlling the rotation speed of the first motor 2 in both the HV mode and the EV mode, the torque feedback control accuracy can be reduced, and the specifications of the ammeter in the inverter can be simplified accordingly. .

  According to the control device in the embodiment of the present invention, even in the EV mode in which the engine 4 is not operated, all the rotating elements in the power split mechanism 5 rotate in the positive direction or the negative direction at a rotational speed equal to or higher than the predetermined rotational speed N1. Therefore, the lubricating oil that adheres or is held by these rotating elements, or that is attached or held by the rotating members connected to these rotating elements, is scattered by centrifugal force. As a result, the lubricating oil is positively supplied to the power split mechanism 5 even in the EV mode, and the power split mechanism 5 can be sufficiently lubricated.

  The first reference value N1 in the control shown in FIG. 4 described above defines the lower limit rotational speed of each rotating element in the EV mode, and therefore the rotational speed of each motor 2, 3, 10 is controlled in the above step S4. In this case, the first reference value N1 may be controlled as the target rotational speed, or the rotational speed obtained by adding a predetermined correction value to the first reference value N1 may be controlled as the target rotational speed. However, since the rotation speeds of the three rotation elements are different from each other, the control may be performed by setting the upper limit rotation speed in advance instead of performing the control by uniformly setting the target rotation speed. An example of this is shown in the flowchart of FIG.

  In FIG. 5, it is first determined whether or not the vehicle is in a power running state in the EV mode (step S11). If a negative determination is made in step S11, the process returns without performing any particular control. On the other hand, when a positive determination is made in step S11, the motors 2, 3, and 10 are controlled to output a driving force that satisfies the required driving amount (step S12). These Step S11 and Step S12 are the same control as Step S1 and Step S2 shown in FIG. 4 described above.

  Next, it is determined whether or not the absolute value of the rotational speed of each rotary element (in the example shown in FIG. 2, the sun gear 5S and the carrier 5C) other than the output element of the power split mechanism 5 is equal to or smaller than a predetermined second reference value N2. (Step S13). The second reference value N2 is a value (N2> N1) larger than the first reference value N1 described above, and an experiment is conducted in advance as an upper limit rotational speed at which lubricating oil can be scattered by centrifugal force and necessary and sufficient lubrication can be performed. It is a value determined based on this.

  If the determination in step S13 is affirmative, the process returns. On the other hand, if a negative determination is made in step S13, each motor 2 so that the absolute value of the rotational speed of each of the rotating elements other than the output element of the power split mechanism 5 is equal to or less than the second reference value N2. , 3 and 10 are controlled (step S14), and then the process returns. Also in the control in step S14, it is preferable to feedback control the rotational speed of one of the motors, for example, to control the torque of the other motor, and the motor for controlling the rotational speed is not connected to the engine 4. The first motor 2 that is a motor is preferably the same as in the case of the control shown in FIG.

  According to the control shown in FIG. 5, it is avoided or suppressed that the rotational speed of any of the rotating elements becomes excessively high for lubrication, thereby preventing an increase in power loss and a decrease in durability. be able to.

  4 and FIG. 5 described above controls the rotational speeds of the motors 2, 3 and 10 in order to keep the rotational speeds of the rotating elements of the power split mechanism 5 within a predetermined range. Therefore, these controls may be integrated. For example, when an affirmative determination is made at step S3 in the control shown in FIG. 4, the determination at step S13 shown in FIG. 5 may be made, or conversely, an affirmative determination is made at step S13 in the control shown in FIG. In such a case, the determination in step S3 shown in FIG. 4 may be performed. Further, the target vehicle in the present invention is not limited to a hybrid vehicle, and therefore the power split mechanism does not have to be mounted on the hybrid vehicle.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle, 2, 3, 10 ... Motor (motor generator: MG), 4 ... Engine, 5 ... Power split mechanism, 6 ... Drive wheel, 5S ... Sun gear, 5R ... Ring gear, 7 ... Transmission mechanism, 5C ... Carrier 8 ... Input shaft, 9 ... Sun gear shaft, 11 ... Power supply unit, 12 ... Electronic control unit (ECU).

Claims (1)

A drive having at least two motors, a driving force source different from the motor, and a differential mechanism to which the motor and the driving force source are coupled and having a plurality of rotating elements, and output from the differential mechanism In a control device for a vehicle traveling with force,
When traveling with the driving force output by any one or more of the at least two motors, the motors are controlled so that the absolute values of the rotational speeds of all the rotating elements are equal to or higher than a predetermined rotational speed. A control apparatus for a vehicle, characterized by being configured to control.

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