JP2005151699A - VEHICLE CONTROL DEVICE HAVING GENERATOR - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve energy efficiency by recovering kinetic energy at the time of idling of a motor / generator mounted on a vehicle.
A generator that generates an electromotive force by relative rotation between a stator and a rotor can selectively transmit and block power to and from the power transmission system that transmits power to wheels. Control device for vehicles connected in this manner, which occurs in the generator when the generator is cut off from the power transmission system in a state in which the stator and the rotor are rotating relative to each other Regeneration control execution means (step S3) for receiving electric power with a predetermined device is provided.
[Selection] Figure 1

Description

  The present invention relates to a control for vehicles such as an electric vehicle using an electric motor functioning as a generator at the time of regeneration as a power source for traveling, and a hybrid vehicle equipped with this type of electric motor or generator together with an internal combustion engine. It relates to the device.

  A vehicle using an internal combustion engine as a power source is equipped with an alternator (generator) for charging a battery or supplying electric power to an electrical component, which is directly connected to the internal combustion engine. It is common. On the other hand, an electric motor as a power source in an electric vehicle and a generator in the hybrid vehicle described above are used for generating power for traveling, regenerating inertia energy of the vehicle as electric power, and so on. Its capacity is also larger than that of the alternator.

  As an example of a vehicle equipped with this type of generator connected to a power transmission system, Patent Document 1 discloses a hybrid vehicle. The vehicle drive device described in Patent Document 1 is configured to distribute the output torque of the engine to the first motor / generator and the output side by a distribution device mainly composed of a planetary gear mechanism. . Therefore, by applying a reaction force by the first motor / generator, the engine speed can be appropriately controlled, and the first motor / generator generates electric power at that time. On the other hand, a second motor / generator is connected to a drive system from the distributor to the wheels via a clutch, and the first motor / generator is connected to the second motor / generator with the clutch engaged. Driving torque is assisted by supplying electric power and causing the second motor / generator to function as a motor. Furthermore, depending on the running conditions such as the vehicle speed, it may be advantageous in terms of fuel consumption to transmit the engine power to the wheels without converting them into electric power. For this reason, a brake that stops the rotation of the first motor / generator is provided. And is configured to engage the brake and release the clutch.

Patent Document 2 describes a control device for a vehicle including an engine and a motor / generator as power sources, and a torque converter with a lock-up clutch connected to the output side of the power source. The device described in Patent Document 2 is configured to release a lock-up clutch in order to prevent or suppress a shock due to torque fluctuation when a regenerative braking force is generated by a motor / generator. .
JP 2003-104072 A JP 2000-134713 A

  As described in the above-mentioned Patent Document 1, if a motor / generator that assists driving torque and regenerates energy can be selectively disconnected from the power transmission system, for example, It is possible to reduce power loss in a predetermined traveling state such as a low load / high vehicle speed state, to improve fuel consumption and to suppress exhaust gas. The so-called disconnection or disconnection of the motor / generator with respect to the power transmission system is performed in the process of operating the motor / generator as an electric motor or generator, and at the same time, in order to stop the electric control of the motor / generator, Shut off the electrical control system or stop the motor / generator control current. However, when the motor / generator is disconnected or shut off, the motor / generator continues to rotate with its own inertial force, and then the resistance or electrical force due to friction at the bearings, stirring of the lubricating oil, etc. The rotation gradually stops due to iron loss. That is, conventionally, the energy of the motor / generator disconnected or cut off from the power transmission system is wasted as frictional heat, and there is room for improvement in improving energy efficiency.

  The present invention has been made by paying attention to the above technical problem, and an object of the present invention is to provide a control device for a vehicle that can further improve energy efficiency by reducing power loss.

  In order to achieve the above object, the invention according to claim 1 is directed to a power transmission system in which a generator that generates an electromotive force by relative rotation between a stator and a rotor transmits power to wheels. In a vehicle control device connected so that power can be selectively transmitted / cut between the generator and the rotor with respect to the power transmission system with relative rotation between the stator and the rotor. A control device comprising regenerative control execution means for receiving electric power generated by the generator at a predetermined device when it is interrupted. The generator may be a motor / generator having a function as an electric motor or a similar device.

  According to a second aspect of the present invention, in the first aspect of the present invention, when the generator is cut off from the power transmission system while the stator and the rotor are rotating relative to each other, the power generation is performed. Regenerative condition determining means for determining whether a condition for accepting electric power generated in the machine by a predetermined device is further provided, and the regenerative control executing means is configured to generate electric power generated in the generator based on a determination result by the regenerative condition determining means. It is a control apparatus characterized by including the means to perform control which accepts by predetermined equipment.

  Further, the invention according to claim 3 is the invention according to claim 1 or 2, wherein the power transmission system distributes an internal combustion engine as a power source and an output torque of the internal combustion engine to another generator and an output shaft. And a power distribution mechanism, wherein the generator is constituted by an electric motor having a power generation function that is selectively connected to and disconnected from the output shaft.

  Still further, the invention according to claim 4 is the invention according to claim 3, further comprising: shut-off control means for shutting off the electric motor having the power generation function from the power transmission system when the vehicle is in a high speed and / or low load state. The regenerative control execution means further includes a predetermined device for generating electric power generated by the motor when the rotation speed of the motor cut off from the power transmission system by the cutoff control means is equal to or higher than a predetermined rotation speed. A control device comprising a receiving means.

  According to a fifth aspect of the present invention, in the first or second aspect of the present invention, the transmission capable of setting a shift state for setting a predetermined gear ratio and a neutral state for not transmitting power includes the generator and the power transmission system. The control device is configured to shut off the generator from the power transmission system by setting the transmission to a neutral state.

  According to the first aspect of the present invention, when the generator is traveling in a state of being connected to the power transmission system, if the generator is shut off from the power transmission system, the generator is caused by its own inertial force. The electromotive force is generated by the relative rotation between the stator and the rotor. Since the electric power is received by a device such as a battery, a capacitor, or another electric device, and energy regeneration is performed, energy that has been consumed in the past can be effectively used to improve energy efficiency.

  Further, according to the invention of claim 2, in addition to obtaining the same effect as that of the invention of claim 1, even if the generator that is cut off or disconnected from the power transmission system is rotating, If the kinetic energy is not large enough to be regenerated, or if it is expected to be connected to the power transmission system again immediately after being shut off or disconnected, the energy generated by the generator is not met. Regeneration is not performed. That is, it is possible to avoid a situation in which wasteful regenerative control is performed or subsequent control cannot be performed smoothly, thereby improving energy efficiency and improving vehicle running or drivability. Can be.

  Furthermore, according to the invention of claim 3, in addition to obtaining the same effect as the effect of the invention of claim 1 or 2, the output torque of the internal combustion engine is changed between the output shaft and another generator (motor generator). May be applied to a so-called hybrid drive device configured to adjust the torque to the output shaft by the generator. In this case, the state where the torque is applied to the output shaft or the output shaft When the generator is cut off or disconnected from the output shaft in a state where energy is being regenerated through, the kinetic energy at that time is effectively recovered, and the energy efficiency can be improved.

  Furthermore, according to the invention of claim 4, in addition to obtaining the same effect as that of the invention of claim 3, an electric motor having a power generation function when the vehicle speed is high or the load on the vehicle is low. Is cut off or disconnected from the output shaft. That is, when the torque on the output shaft is not required, the electric motor having the power generation function is cut off from the power transmission system, so that the energy efficiency or fuel consumption of the hybrid vehicle as a whole is improved, and at that time, the electric motor Since the kinetic energy of the electric motor is regenerated when the rotational speed of the motor is greater than or equal to a predetermined value, wasteful consumption of energy can be avoided or suppressed, and energy efficiency can be further improved.

  According to the invention of claim 5, in addition to obtaining the same effect as that of the invention of claim 1 or 2, the generator is connected to the power transmission system using a transmission, Moreover, since it can interrupt | block, it is not necessary to provide the new apparatus for connection and interruption | blocking, As a result, it becomes advantageous to size reduction and weight reduction of a power transmission system or a vehicle.

  Next, the present invention will be described based on specific examples. First, FIG. 2 schematically shows a power transmission system in a vehicle to which the present invention can be applied. A transmission 2 is connected to an output side of an internal combustion engine (engine) 1 as a power source. The engine 1 may be an internal combustion engine such as a gasoline engine, a diesel engine, or a gas engine, or a motor using electricity as an energy source. The transmission 2 may be a stepped type or a stepless type, and may be either a manual transmission or an automatic transmission. An output shaft 3 of the transmission 2 is connected to a final reduction gear, that is, a differential gear 4, and is configured to transmit torque from here to the left and right wheels 5.

  A motor / generator 6 corresponding to the generator of the present invention is connected to a power transmission system from the engine 1 to the wheels 5 via a clutch 7. The motor / generator 6 is constituted by a permanent magnet type synchronous motor including a stator (stator) 8 having a coil and a rotor (rotor) 9 having a permanent magnet, for example. An electromotive force is generated by the relative rotation with the. The rotor 9 is connected to the clutch 7. Therefore, when the clutch 7 is engaged, torque is transmitted between the motor generator 6 and the power transmission system, and when the clutch 7 is released, the motor The generator 6 is cut off or disconnected from the power transmission system. On the other hand, the stator 8 is fixed to a predetermined fixing part such as a case or other appropriate member (not shown) or selectively fixed via a clutch mechanism (not shown).

  An inverter 10 and a battery 11 are electrically connected to the motor / generator 6. The battery 11 corresponds to a device that receives power in the present invention. In the example shown in FIG. 2, the power generated by the motor / generator 6 is stored in the battery 11, and the power from the battery 11 to the motor / generator 6 is stored. So that the motor / generator 6 functions as a motor. The motor 10 is controlled by the inverter 10 including the reception and supply of electric power.

  The clutch 7 is a mechanism for mechanically connecting the motor / generator 6 to the output shaft 3 and for releasing the connection, and uses an appropriate type such as a friction clutch or a meshing clutch. Can do. In the example shown in FIG. 2, a hydraulic friction clutch is used, and a hydraulic control device 12 for controlling the engagement / release and the transmission torque capacity is provided. The hydraulic control device 12 includes a plurality of solenoid valves (not shown), and is configured to electrically control supply / discharge of hydraulic pressure and pressure.

  An electronic control unit (ECU) 13 is provided to control the inverter 10 and the hydraulic pressure. The electronic control device 13 is mainly composed of a microcomputer, performs calculation according to input data, prestored data and a control program, and outputs a control signal to the inverter 10 and the hydraulic control device 12. It is like that. The electronic control device 13 receives the rotational speed of the motor / generator 6. That is, a sensor 14 for detecting the rotation speed of the motor / generator 6 is provided, and an output signal thereof is input to the electronic control device 13. As the sensor 14, a resolver attached to the motor / generator 6 can be used. Therefore, since the inertial mass or moment of inertia of the motor / generator 6 can be known in advance, the kinetic energy of the motor / generator 6 can be obtained by detecting the rotational speed.

  An example of control by the control device of the present invention for the above vehicle will be described with reference to FIG. The routine shown in the flowchart of FIG. 1 is repeatedly executed every predetermined short time. First, whether the clutch 7 is disengaged, that is, whether the motor / generator 6 is disconnected or disconnected from the output shaft 3. It is determined whether or not (step S1). If a negative determination is made in step S1, the motor / generator 6 is connected to the output shaft 3 and functions as an electric motor or a generator. Therefore, this routine is performed without any particular control. Exit once.

  On the other hand, if an affirmative determination is made in step S1, it is determined whether or not a regeneration condition is satisfied (step S2). This regenerative condition is a condition as to whether or not it is worth recovering its kinetic energy as electric power in a state where the motor / generator 6 is rotating with inertial force, and an example thereof is a point in time when the motor / generator 6 is disconnected from the output shaft 3. The kinetic energy possessed by the motor / generator 6 is a condition of a predetermined value or more. This can be determined, for example, based on whether or not the rotational speed N of the motor / generator 6 exceeds a predetermined threshold value N1 (N> N1). This is because the kinetic energy of the motor / generator 6 is obtained from the moment of inertia and the rotational speed. The threshold value N1 takes into consideration the regenerative efficiency and the efficiency when driving the motor / generator 6 with the regenerated electric power, and the regenerated energy accelerates the stopped motor / generator 6 to the current rotational speed. It can be set to a value that is larger than the energy required for this.

  Further, as another condition, it can be adopted that the acceleration prediction immediately after the current time is not established. Prediction of acceleration can be obtained, for example, by a navigation system having road information combined with map information, or can be obtained based on road information from a sign post on a road or go-stop information from a traffic light. it can. If acceleration is predicted immediately after that, braking and driving of the motor / generator 6 will be performed continuously, which may reduce the energy efficiency and cause the transient inertial force to be shocked. This can cause discomfort and the regeneration condition is not satisfied. Furthermore, the state of charge (SOC) of the battery 11 can be set as a regeneration condition. In other words, when the charge amount is greater than or equal to a predetermined value, electric power cannot be accepted. Therefore, if the motor / generator 6 is forcibly braked, the electric power for subsequent re-acceleration is more than necessary even though the energy cannot be regenerated. This is because it consumes a large amount of power.

  If a negative determination is made in step S2 because the regeneration condition is not satisfied, this routine is temporarily exited without performing any particular control. On the contrary, if the regenerative condition is satisfied and the determination is affirmative in step S2, regenerative braking (MG regenerative braking) of the motor / generator 6 is executed (step S3). That is, the battery 11 is charged via the inverter 10 with the electric power generated by the motor / generator 6 rotating with its inertial force. As a result, the electric power can be reused as energy when the motor / generator 6 is driven as an electric motor, and wasteful consumption of energy can be suppressed to improve energy efficiency. As a result, the fuel consumption of the vehicle can be improved and the exhaust gas can be reduced.

  An example of another vehicle to which the present invention can be applied is schematically shown in FIG. The example shown here is a vehicle that can be called a mechanical distribution type two-motor hybrid vehicle, and includes an engine, a motor / generator, and a power distribution device as a power source, and the torque output from the power distribution device is The torque is adjusted by the second motor / generator. Specifically, the power distribution device 20 is a mechanism that performs a differential action by three rotating elements. In the example shown in FIG. 3, the power distribution device 20 is configured by a single pinion type planetary gear mechanism. An engine 22 is connected to the carrier 21 so that the carrier 21 serves as an input element, and a first motor / generator 24 is connected to a sun gear 23 that meshes with a pinion gear held by the carrier 21. Is a reaction force element. More precisely, the first motor / generator 24 generates an electromotive force by the relative rotation of the stator (stator) and the rotor (rotor), and energizes the coil of the stator to rotate the rotor. The rotor is connected to the sun gear 23. The stator is fixed to a fixed part such as a casing. A ring gear 25 arranged concentrically with the sun gear 23 and meshing with the pinion gear is connected to an output shaft 26, and this ring gear 25 serves as an output element.

  Further, a clutch 27 is provided between the carrier 21 and the ring gear 25. When the clutch 27 is engaged, the two rotating elements in the power distribution device 20 are integrally connected, so that the entire planetary gear mechanism constituting the power distribution device 20 rotates integrally. Therefore, the clutch 27 is an integrated clutch that integrates the entire planetary gear mechanism.

  Similarly to the example shown in FIG. 2, the output shaft 26 is connected to a final reduction gear, that is, a differential gear 28, and is configured to transmit torque to right and left wheels 29 therefrom. A second motor / generator 30 that adjusts the torque with respect to the output shaft 26 is provided. The second motor / generator 30 corresponds to the generator of the present invention, and a transmission 31 is provided between the second motor / generator 30 and the output shaft 26.

  The transmission 31 sets two reduction ratios (that is, transmission ratios) that reduce the output rotational speed with respect to the input rotational speed, and a neutral state that blocks transmission of torque between the input side and the output side. It is configured to be able to. Specifically, in the example shown in FIG. 3, the transmission is configured by a Ravigneaux planetary gear mechanism having a structure in which a single pinion planetary gear mechanism and a double pinion planetary gear mechanism are combined. That is, the first sun gear 32 with a smaller number of teeth (small diameter) and the second sun gear 33 with a larger number of teeth (large diameter) are arranged adjacent to each other on the same axis, A ring gear 34 is provided on the concentric circles. A short pinion meshes with the first sun gear 32 and a long pinion meshes with the chute pinion and the ring gear 34. The second sun gear 33 meshes with the long pinion. These pinions are held by the carrier 35 so as to rotate and revolve freely.

  Therefore, the transmission 31 has four rotating elements, that is, the sun gears 32 and 33, the ring gear 34, and the carrier 35. The second sun gear 33 is connected to the second motor / generator 30 and input. The carrier 35 is connected to the output shaft 26 and serves as an output element. Accordingly, the first sun gear 32 and the ring gear 34 are reaction force elements (or fixing elements), and in order to make these substantially the reaction force elements, the first sun gear 32 for selectively fixing the first sun gear 32 is used. One brake 36 and a second brake 37 for selectively fixing the ring gear 34 are provided.

  The motor generators 24 and 30 are electrically connected to a battery 39 via an inverter 38, and the motor generators 24 and 30 are controlled by the inverter 38. The motor / generators 24 and 30 are individually controlled independently of each other. Therefore, an inverter may be provided for each motor / generator 24 and 30. On the other hand, the clutch 27 and the brakes 36 and 37 are an engagement device in which engagement / release control is executed by hydraulic pressure, for example, and a hydraulic control device 40 for performing the control is provided. Similar to the hydraulic control device 12 shown in FIG. 2, the hydraulic control device 40 is configured to be able to electrically control the supply and discharge of hydraulic pressure and the pressure. An electronic control device 41 that outputs control signals to the inverter 38 and the hydraulic control device 40 is provided. Further, a rotation speed sensor 42 is provided that detects the rotation speed of the second motor / generator 30 and transmits a detection signal as control data to the electronic control unit 41.

  In the vehicle having the configuration shown in FIG. 3, the engine 22 is operated with good fuel efficiency, and a reaction torque is applied to the torque input from the engine 22 to the carrier 21 by the first motor / generator 24. And the output shaft 26 connected to this is rotated at a predetermined rotational speed. Therefore, as the vehicle speed increases or the load on the vehicle decreases, the rotational speed of the first motor / generator 24 is decreased. When the vehicle speed increases or the load decreases, the first motor The generator 24 is rotated in the opposite direction to the engine 22 and is powered. This is a state in which the first motor / generator 24 is operated as an electric motor and at the same time the second motor / generator 30 functions as a generator, and the second motor / generator 30 is driven by the engine torque transmitted to the output shaft 26. Then, the electric power is supplied to the first motor / generator 24, and the torque is transmitted to the output shaft 26 via the power distribution device 20. That is, power circulation occurs and power loss increases. Therefore, simultaneously with the occurrence of such power circulation, or immediately before that, the clutch 27 is engaged and the engine torque is transmitted to the output shaft 26 as it is, while the brakes 36 and 37 are released and the transmission 31 is in the neutral state. Thus, the second motor / generator 30 is shut off or disconnected from the output shaft 26.

  In this case, if the above-described regenerative condition is satisfied, for example, if the rotational speed of the second motor / generator 30 is equal to or greater than a predetermined value, the regenerative braking control is executed for the second motor / generator 30, and the second motor / generator is performed. Thirty electromotive forces are received by the battery 39. That is, energy regeneration is performed, and the energy is effectively used for driving the second motor / generator 30. Therefore, even when the vehicle having the configuration shown in FIG. 3 is targeted, it is possible to improve energy efficiency, improve fuel efficiency, and reduce exhaust gas.

  The operation of the transmission 31 will be briefly described. When the ring gear 34 is fixed by engaging the second brake 37, a low speed stage having a large gear ratio is set, and the output torque of the second motor / generator 30 is set. The torque increased according to the speed ratio is transmitted to the output shaft 26. Further, when the first brake 36 is engaged instead of the second brake 37, a high speed stage is set in which the speed ratio is somewhat larger than the low speed stage and the speed ratio is less than "1".

  Here, the relationship between the above specific example and the present invention will be briefly described. The functional means of step S3, the inverters 10, 38 or the batteries 11, 39, and the electronic control devices 13, 41 are regenerated. The functional means of step S2 and the electronic control devices 13, 41 correspond to the control execution means, and the regeneration condition judgment means of the present invention. Further, the clutch 7, the brakes 36, 37, or the electronic control device 41 correspond to this. This corresponds to the cutoff control means of the invention.

  In the specific example of the present invention described above, an internal combustion engine is used as a power source. However, the present invention can also be implemented for a so-called electric vehicle using a motor having a power generation function as a power source for traveling. . In that case, when the electric motor is disconnected from the power transmission system and the electric motor is idling, a predetermined condition is satisfied, whereby regenerative braking control for the electric motor is executed.

It is a flowchart for demonstrating the example of control performed with the control apparatus which concerns on this invention. It is a figure which shows typically an example of the power transmission system of the vehicle which can be made into object by this invention. It is a figure which shows typically the other example of the power transmission system of the vehicle which can be made into object by this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine (engine) 3,26 ... Output shaft, 5,29 ... Wheel, 6 ... Motor generator, 7 ... Clutch, 8 ... Stator (stator), 9 ... Rotor (rotor), 11, 39 DESCRIPTION OF SYMBOLS: Battery, 20 ... Power distribution device, 24 ... 1st motor generator, 30 ... 2nd motor generator, 31 ... Transmission, 36 ... 1st brake, 37 ... 2nd brake.

Claims (5)

A generator that generates an electromotive force by the relative rotation of the stator and the rotor is connected to a power transmission system that transmits power to the wheels so that power can be selectively transmitted to and cut off from the power transmission system. In a vehicle control device,
Regenerative control execution means for receiving, with a predetermined device, electric power generated by the generator when the generator is cut off from the power transmission system in a state where relative rotation between the stator and the rotor is occurring. A control device for a vehicle, comprising:   When the generator is cut off from the power transmission system in a state where the stator and the rotor are rotating relative to each other, it is determined whether or not a condition for accepting power generated by the generator with a predetermined device is satisfied. Regenerative condition determining means for performing regenerative control, and the regenerative control executing means includes means for executing control for receiving power generated in the generator by a predetermined device based on a determination result by the regenerative condition determining means. The vehicle control device according to claim 1. The power transmission system includes an internal combustion engine as a power source, and a power distribution mechanism that distributes output torque of the internal combustion engine to another generator and an output shaft,
3. The vehicle control device according to claim 1, wherein the generator is configured by an electric motor having a power generation function that is selectively connected to or disconnected from the output shaft. 4. The vehicle further comprises shut-off control means for shutting off the electric motor having the power generation function from the power transmission system when the vehicle is in a high speed and / or low load state.
The regenerative control execution means is means for receiving, with a predetermined device, electric power generated by the motor when the rotation speed of the electric motor cut off from the power transmission system by the shut-off control means is equal to or higher than a predetermined rotation speed The vehicle control device according to claim 3, further comprising:   A transmission capable of setting a shift state for setting a predetermined gear ratio and a neutral state for not transmitting power is disposed between the generator and the power transmission system, and the transmission is set to a neutral state by setting the transmission to the neutral state. The vehicle control device according to claim 1, wherein the generator is configured to be cut off from the power transmission system.

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