JP2009269537A - Driving device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving device for a vehicle capable of recovering the energy of the vehicle by a simpler constitution than a conventional one. <P>SOLUTION: The driving device 2 is equipped with an input member 10 which rotates by being connected to an internal combustion engine 3, a rotating member 11 to which the input member 10 is connected through a clutch 12, and an automatic transmission 15 for shifting the speed of the rotation of the rotating member 11. The automatic transmission 15 can obtain a plurality of shift stages by changing the connection relation of the rotating member 11 with respect to a plurality of rotary elements of a differential mechanism 18 and can disconnect the rotating member 11 from all of the rotary elements. The rotating member 11 can independently rotate when the rotating member 11 and the input member 10 are disconnected by the clutch 12, and the rotating member 11 and all of the plurality of rotary elements and are disconnected by the automatic transmission 15. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle drive device including a speed change mechanism capable of realizing a plurality of shift speeds.

  A transmission mechanism is provided in the power transmission path from the internal combustion engine to the drive wheels, and a flywheel for energy recovery is provided independently of the transmission mechanism, and this flywheel is clutched to a drive shaft that connects the internal combustion engine and the transmission mechanism. And the drive device of the vehicle connected via the transmission means is known (patent document 1). In addition, there is Patent Document 2 as a prior art document related to the present invention.

Japanese Patent Laid-Open No. 61-192961 JP 2002-349865 A

  The drive device of Patent Document 1 recovers energy to the flywheel by transmitting the rotation of the drive shaft to the flyhole when the vehicle decelerates, and then recovers energy to use the energy recovered by the flywheel during vehicle acceleration, and Its use is realized by operating the clutch. However, since this drive device is provided with a flywheel, a clutch, and a transmission device independently of the transmission mechanism as energy recovery devices, the drive device as a whole is enlarged and the number of parts is increased.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a vehicle drive device that can recover vehicle energy with a simpler configuration than conventional ones.

  The vehicle drive device of the present invention has an input member that rotates by being connected to a drive source, a rotary member to which the input member is connected via a clutch, and a plurality of rotating elements that can be differentially rotated with each other. A transmission mechanism capable of shifting the rotation of the rotation member by connecting the rotation member to at least one of the plurality of rotation elements, and for transmitting the power output from the transmission mechanism to the drive wheels. An output member, and the speed change mechanism can realize a plurality of shift speeds by changing a connection relation of the rotation member to the plurality of rotation elements, and all of the plurality of rotation elements and the rotation member. The input member and the rotating member are separated by the clutch, and all of the plurality of rotating elements and the rotating member are separated from each other. When disconnected by serial transmission mechanism, to solve the problems described above by the rotary member is configured for rotation alone (claim 1).

  According to this drive device, when the input member and the plurality of rotating elements are separated from the rotating member used for realizing the plurality of shift speeds, the rotating member is separated from the input member and the rotating element. Can rotate alone. That is, in this case, the rotating member can freely rotate. Accordingly, in a state where at least one of the input member and the rotating element is connected to the rotating member, the rotating member can be separated from the rotating member after rotating the rotating member, and the rotating member can recover energy. Thereafter, by connecting either the input member or the rotating element to the rotating member, the energy recovered by the rotating member can be used on the drive source side or the drive wheel side. Since this drive device realizes such energy recovery and use by using a rotating member that realizes the gear stage of the speed change mechanism, it is possible to suppress an increase in the size of the device and an increase in the number of parts.

  Energy recovery and utilization by the drive device of the present invention may be realized in various ways. For example, in one aspect of the present invention, an internal combustion engine that performs fuel cut is provided as the drive source so that combustion is interrupted when the vehicle speed reaches a predetermined value in the deceleration process of the vehicle. In conjunction with the execution of the fuel cut, the input member and the rotating member are separated by the clutch, and all of the plurality of rotating elements and the rotating member are separated by the transmission mechanism. When release control means for executing release control for controlling each of the clutch and the speed change mechanism and a restart condition for restarting combustion of the internal combustion engine in which combustion is interrupted by fuel cut are satisfied during execution of the release control And a start control means for controlling the clutch such that the input member and the rotating member are connected to each other (Claim 2).

  In general, when an internal combustion engine is provided as a drive source for a vehicle, if a fuel cut is performed while the vehicle is running, combustion of the internal combustion engine is interrupted. It becomes bigger than the case. For this reason, there is a problem that the engine brake is too effective to perform fuel cut for a long time during the deceleration of the vehicle. Therefore, the fuel cut execution period is limited to a range in which the behavior of the vehicle during deceleration does not become unstable. According to this aspect, since the release control is executed in conjunction with the execution of the fuel cut and the input member and the rotating member are separated from each other, the engine brake can be prevented from being excessively effective. Therefore, since the restriction on the execution period of the fuel cut is relaxed, it is possible to prolong the execution period. Thereby, fuel consumption can be improved.

  Further, in this aspect, the energy recovered by the rotating member by the execution of the release control can be used for restarting the internal combustion engine by operating the clutch that connects the rotating member and the input member after the release control. Therefore, since the energy collected by the rotating member can be used effectively, further improvement in fuel consumption can be expected. Although there are no particular limitations on the structure and shape of the rotating member, it is preferable to increase the moment of inertia as much as possible in order to increase the amount of energy that can be recovered.

  As described above, according to the present invention, when the input member and the plurality of rotating elements are separated from the rotating member used for realizing the plurality of shift speeds, the rotating member rotates with the input member. Can rotate independently of the element. For this reason, after rotating a rotation member in the state in which at least one of an input member and a rotation element was connected with respect to the rotation member, after separating these from a rotation member, energy can be collect | recovered by a rotation member. Thereafter, by connecting either the input member or the rotating element to the rotating member, the energy recovered by the rotating member can be used on the drive source side or the drive wheel side. In this drive device, such energy recovery and use can be realized by using a rotating member that realizes the gear stage of the speed change mechanism, so that the size of the device and the increase in the number of parts can be suppressed. Therefore, the energy of the vehicle can be recovered with a simpler configuration than before.

  FIG. 1 schematically shows the overall configuration of a vehicle to which a drive device according to an embodiment of the present invention is applied. The drive device 2 mounted on the vehicle 1 is provided with an internal combustion engine 3 as a drive source. The power output from the drive device 2 is transmitted to the left and right drive wheels 5 via the differential device 4. The internal combustion engine 3 is configured as a spark ignition type known multi-cylinder internal combustion engine. The internal combustion engine 3 can perform fuel cut and interrupt combustion when a predetermined condition is satisfied. Various controls for the internal combustion engine 3 are performed by an engine control unit (ECU) 6 configured as a computer capable of executing a predetermined program. The ECU 6 receives signals from a vehicle speed sensor 7 for detecting the speed (vehicle speed) of the vehicle 1 and an accelerator opening sensor 8 for detecting the accelerator opening.

  The drive device 2 includes an input member 10 that is connected to the internal combustion engine 3 and rotates, and a rotation member 11 to which the input member 10 is connected via a clutch 12. The input member 10 is connected to a crankshaft (not shown) of the internal combustion engine 3. Note that a damper may be provided between the crankshaft and the input member 10 in order to reduce transmission of torque fluctuation from the internal combustion engine 3. The clutch 12 is configured as a friction clutch that can interrupt power transmission between the input member 10 and the rotating member 11. When the power transmission is interrupted by the clutch 12, the input member 10 is disconnected from the rotating member 11.

As will be described in detail later, the rotating member 11 has a function of recovering the energy of the vehicle 1 during deceleration, and is configured to have as large an inertia moment as possible in order to increase the amount of energy recovered. As an example, the moment of inertia of the rotating member 11 is set to 0.01 [kgcm ² ] or more. When the moment of inertia of the rotating member 11 is set to be large in this way, the rotational inertia of the driving device 2 is increased, so that vibration and noise of the vehicle 1 can be reduced, and the internal combustion engine 3 can be used at a low speed during steady running. Contributes to improved fuel efficiency.

  The drive device 2 is provided with an automatic transmission 15 as a speed change mechanism that can change the rotation of the rotation member 11. The power output from the automatic transmission 15 is transmitted to the propeller shaft 13 as an output member. The propeller shaft 13 is connected to the differential device 4. The automatic transmission 15 includes a differential mechanism 18 in which two sets of single pinion planetary gear mechanisms 16 and 17 are combined. The first planetary gear mechanism 16 rotates a sun gear Su1 that is an external gear, a ring gear Ri1 that is an internal gear coaxially disposed with respect to the sun gear Su1, and a pinion 19 that meshes with these gears Su1 and Ri1. And a carrier Cr1 that is held to revolve freely. On the other hand, the second planetary gear mechanism 17 includes a sun gear Su2 that is an external gear, a ring gear Ri2 that is an internal gear disposed coaxially with the sun gear Su2, and a pinion 20 that meshes with these gears S2 and R2. Has a carrier Cr2 that rotates and revolves. These planetary gear mechanisms 16 and 17 are connected to each other so that the respective sun gears Su1 and Su2 rotate integrally. As a result, the differential mechanism 18 includes, as five rotating elements that can rotate differentially with each other, the first element: a combination of the sun gear Su1 and the sun gear Su2, the second element: the ring gear Ri1, the third element: the carrier Cr1, 4 elements: ring gear Ri2, and 5th element: carrier Cr2.

  The automatic transmission 15 includes a switching device 21 that changes the connection relationship of the rotating member 11 with respect to the rotating elements of the differential mechanism 18 and a vehicle body component of the vehicle 1 in order to realize a plurality of shift stages having different gear ratios. Two brakes 22 and 23 are provided for restraining the rotating element of the differential mechanism 18 so as not to rotate relative to the combined casing 14. The switching device 21 has two clutches 24, 25, and changes the connection relationship with the rotating member 11 by appropriately changing the combination of operating states of these clutches 24, 25. The first clutch 24 can intermittently transmit power between the rotating member 11 and the first element (sun gears Su1 and Su2), and the second clutch 25 can drive power between the rotating member 11 and the second element (ring gear Ri1). Transmission can be interrupted. When both of the clutches 24 and 25 are released and the power transmission is interrupted, each element is separated from the rotating member 11. The first brake 22 switches between a state in which the first element is restrained against rotation with respect to the casing 14 and a state in which the restraint is released. Moreover, the 2nd brake 23 switches the state which restrains a 5th element (carrier Cr2) non-rotatably with respect to the casing 14, and the state which cancels | releases the restraint. The automatic transmission 15 is controlled so as to realize a plurality of shift stages by changing the operating states of the switching device 21 and the brakes 22 and 23 and to select a shift stage suitable for the traveling state of the vehicle 1.

  Control for the automatic transmission 15 is performed by a drive control device 26. The drive control device 26 is configured as a computer for properly controlling the drive device 2. The drive control device 26 acquires information about the running state of the vehicle 1 via the ECU 21 and controls the clutch 12 and the automatic transmission 15 based on the information. The drive control device 26 controls the clutch 12 to be in an engaged state so that the input member 10 and the rotating member 11 rotate integrally when the vehicle 1 starts. Further, the drive control device 26 controls the automatic transmission 15 so that an appropriate gear position is selected based on the vehicle speed of the vehicle 1 and the accelerator opening. These controls are the same as known ones, and are not directly related to the gist of the present invention, so that detailed description will be omitted.

  The drive device 2 according to the present embodiment is characterized by the control executed from the deceleration process of the vehicle 1 to the reacceleration. FIG. 2 is a timing chart for explaining an example of a control result performed by the drive control device 26. The illustrated example shows a process from when the traveling vehicle 1 is decelerated after the clutch 12 and the clutch 25 are in the engaged state (ON) to when they are accelerated again. During this time, the other first clutch 24 of the switching device 21 is controlled to the released state. That is, in the case of FIG. 2, the rotating member 11 is in a state where the first element is separated by the clutch 24.

  As shown in the drawing, when the vehicle speed reaches a predetermined value Vth at time t1 in the deceleration process of the vehicle 1, combustion of the internal combustion engine 3 is interrupted by fuel cut. As described above, the fuel cut is performed by the ECU 6. In conjunction with the execution of the fuel cut, the clutches 12 and 25 are controlled to the released state (OFF). That is, the drive control device 26 performs release control for controlling the clutch 12 and the clutch 25 so that the input member 10 and the second element (ring gear Ri1) are disconnected from the rotating member 11 in conjunction with execution of the fuel cut. When the input member 10 and the second element are separated from the rotating member 11, the rotating member 11 continues to rotate independently. As a result, the energy of the vehicle 1 is recovered by the rotating member 11. As the fuel cut is performed, the clutch 12 is released and the power on the drive wheel 5 side is not transmitted to the internal combustion engine 3. Therefore, the rotational speed of the crankshaft of the internal combustion engine 3, that is, the engine rotational speed (rotation speed) of the internal combustion engine 3 is It becomes 0 immediately.

  Thereafter, when an accelerator pedal (not shown) is depressed at time t2 and the accelerator opening degree rises, the clutch 12 is controlled to be engaged (ON) in conjunction therewith. Thereby, the internal combustion engine 3 is cranked by the energy recovered by the rotating member 11, and the combustion that has been interrupted by the fuel cut is resumed. As a result, the engine speed increases and the energy of the rotating member 11 is consumed, so that the rotating speed of the rotating member 11 decreases. Subsequently, the clutch 25 is controlled to be engaged within a period from time t3 to time t4. As a result, the power of the internal combustion engine 3 is transmitted to the propeller shaft 13 via the automatic transmission 15, so that the rotational speed of the propeller shaft 13 increases and the vehicle 1 shifts to the acceleration state.

  Next, processing executed by the drive control device 26 to realize the control of FIG. 2 will be described. FIG. 3 is a flowchart showing an example of a control routine of drive control executed by the drive control device 26. The program of this routine is held in the storage device of the drive control device 26, read out in a timely manner, and repeatedly executed at predetermined intervals.

  In step S1, it is determined whether or not the fuel cut of the internal combustion engine 3 is being executed. This determination is realized by monitoring a control result executed by the ECU 6 for the internal combustion engine 3, for example, a flag value set during execution of fuel cut. However, whether or not the fuel cut is performed is determined by the drive control device 26 uniquely determining the fuel cut execution condition (for example, when the accelerator speed is 0 and the vehicle speed reaches the predetermined value Vth). You can also If the fuel cut is being executed, the process proceeds to step S2, and if not, the subsequent process is skipped and the current routine is terminated.

  In step S2, the release control shown in FIG. 2 is executed. That is, the drive control device 26 controls the clutch 12 and the switching device 21 such that the input member 10 and the rotation element (at least one of the second element) of the differential mechanism 15 are disconnected from the rotation member 11. . When the drive control device 26 executes the process of step S2, the drive control device 26 functions as a release control unit according to the present invention.

  In step S3, it is determined whether or not a restart condition for resuming the combustion of the internal combustion engine 3 interrupted by the fuel cut is satisfied. Here, it is determined that the restart condition is satisfied when the accelerator opening degree rises from zero. Note that this restart condition can be determined as appropriate, and whether or not the restart condition is satisfied may be determined in consideration of parameters other than the accelerator opening, such as the vehicle speed and the gear position. If the restart condition is satisfied, the process proceeds to step S4. If not, the subsequent process is skipped and the current routine is terminated.

  In step S4, start control of the internal combustion engine 3 is executed. That is, the drive control device 26 controls the clutch 12 so that the input member 10 and the rotating member 11 are connected. In parallel with the control performed by the drive control device 26, the ECU 6 ends the fuel cut and restarts the fuel supply of the internal combustion engine 3. When the drive control device 26 executes the process of step S4, the drive control device 26 functions as a start control unit according to the present invention.

  According to the above embodiment, since the recovery and use of the energy of the vehicle 1 can be realized by using the rotating member 11 that realizes the shift stage of the automatic transmission 15, the increase in the size of the device and the increase in the number of parts are suppressed. be able to. Therefore, the energy of the vehicle can be recovered with a simpler configuration than before. Further, since the release control is executed in conjunction with the execution of the fuel cut and the input member 10 and the rotating member 11 are separated, it is possible to prevent the engine brake from being excessively effective. Therefore, since the restriction on the execution period of the fuel cut is relaxed, it is possible to prolong the execution period. Thereby, fuel consumption can be improved. Furthermore, the energy recovered by the rotation member 11 by the execution of the release control can be used for restarting the internal combustion engine 3 by operating the clutch 12 that connects the rotation member 11 and the input member 10 after the release control. . Therefore, since the energy recovered by the rotating member 11 can be used effectively, an improvement in fuel consumption can be expected.

  This invention is not limited to the above form, It can implement with a various form. The drive source of this embodiment is not limited to an internal combustion engine, and may be an electric motor. A known hybrid unit in which an internal combustion engine and an electric motor are connected via a power split mechanism can also be used as a drive source. The differential mechanism 18 included in the automatic transmission 15 described above is merely an example, and the differential mechanism 18 can be changed to another form that is mechanically equivalent. In addition, realizing the differential mechanism 18 by combining a plurality of planetary gear mechanisms is merely an example. For example, all or part of the planetary gear mechanism of the above-described form may be replaced with a planetary roller mechanism having a friction wheel (roller) that is not a gear as a rotating element.

The figure which showed typically the whole structure of the vehicle to which the drive device which concerns on one form of this invention was applied. The timing chart explaining an example of the control result which a drive control apparatus performs. The flowchart which showed an example of the control routine of the drive control which a drive control apparatus performs.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Drive device 3 Internal combustion engine (drive source)
5 Drive Wheel 10 Input Member 11 Rotating Member 12 Clutch 13 Propeller Shaft (Output Member)
26 Drive control device (release control means, start control means)

Claims (2)

An input member that is connected to a drive source to rotate, a rotary member to which the input member is connected via a clutch, and a plurality of rotating elements that can be differentially rotated with each other, the rotating member being the plurality of rotating elements A speed change mechanism capable of shifting the rotation of the rotation member by being connected to at least one of the rotation elements, and an output member for transmitting power output from the speed change mechanism to the drive wheels,
The speed change mechanism can realize a plurality of shift speeds by changing a connection relation of the rotation members to the plurality of rotation elements, and can disconnect all of the plurality of rotation elements from the rotation members. Configured,
When the input member and the rotating member are separated by the clutch, and all of the plurality of rotating elements and the rotating member are separated by the speed change mechanism, the rotating member can rotate independently. It is comprised in the vehicle drive device characterized by the above-mentioned. As the drive source, an internal combustion engine is provided that performs fuel cut so that combustion is interrupted when the vehicle speed reaches a predetermined value in the deceleration process of the vehicle,
In conjunction with execution of fuel cut of the internal combustion engine, the input member and the rotating member are separated by the clutch, and all of the plurality of rotating elements and the rotating member are separated by the transmission mechanism. The release control means for executing the release control for controlling each of the clutch and the speed change mechanism, and the restart condition for restarting the combustion of the internal combustion engine in which the combustion is interrupted by the fuel cut is during execution of the release control. The drive device according to claim 1, further comprising start control means for controlling the clutch so that the input member and the rotating member are connected when established.

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