JP2013144966A - Control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for a vehicle capable of accurately preventing the generation of a shock caused by the gear hit of a differential gear upon a switching between a drive state and a driven state of a driving source.SOLUTION: A control device 10 for a vehicle is employed in the vehicle 1 in which driving torque generated by an engine 2 is transmitted to drive wheels 5L and 5R via a differential gear 4. Upon switching a drive state that the drive wheels 5L and 5R are driven by the driving torque of the engine 2 and a driven state that the engine 2 is driven by input torque inputted from the drive wheels 5L and 5R, the control device estimates generation torque in the differential gear 4 at the switching and includes an ECU 100 that performs torque control for controlling the driving torque of the engine 2 at the switching on the basis of the estimated generation torque.

Description

  The present invention relates to a vehicle control device, and more particularly to a vehicle control device used in a vehicle that transmits torque generated by a drive source to drive wheels via a differential gear.

  In general, in a vehicle including an internal combustion engine as a drive source, so-called fuel cut at deceleration is performed to stop fuel supply to the internal combustion engine when the vehicle is decelerated in order to improve fuel efficiency. However, at the start of the fuel cut at the time of deceleration, the torque generated by the internal combustion engine suddenly decreases or disappears, and a torque shock due to the torque step occurs.

  Therefore, conventionally, as a vehicle control device for the purpose of reducing such torque shock, the generated torque of the internal combustion engine is limited in advance by gradually retarding the ignition timing, and then the fuel cut during deceleration is cut. Is known (for example, see Patent Document 1). According to this vehicle control device, the torque step at the start of fuel cut during deceleration is reduced, and torque shock is suppressed.

Japanese Patent Laid-Open No. 10-030477

  In the conventional vehicle control device described in Patent Document 1, it is certainly possible to suppress the occurrence of a shock due to a torque step at the start of fuel cut during deceleration by limiting the torque prior to fuel cut during deceleration. .

  However, with this conventional vehicle control device, even if the torque limitation as described above is performed, the occurrence of a shock due to the following factors that occurs at the time of fuel cut transition at the time of deceleration, etc. is accurately suppressed. I can't.

  That is, at the time of shifting to the fuel cut at the time of deceleration, from a driving state in which the driving wheels are driven by the generated torque of the internal combustion engine at a certain time, to a driven state in which the internal combustion engine is driven by the input torque input from the driving wheels. And switch. At the time of this switching, if there is a torque step between the torque generated by the internal combustion engine and the input torque from the drive wheels, the gears of the differential gear provided on the power transmission path between the internal combustion engine and the drive wheels are beaten. Will occur and shock will occur. In this regard, simply decreasing the generated torque of the internal combustion engine prior to the fuel cut during deceleration reduces the generated torque of the internal combustion engine and the input torque from the drive wheels when switching from the driven state to the driven state. The torque step between them cannot be eliminated, and the shock caused by the gear rattling of the differential gear cannot be suppressed accurately.

  Such a problem also occurs when the driving state is switched to the driven state except when the fuel cut at the time of deceleration is not shifted. Further, the shock due to the gearing of the differential gear as described above may also occur at the time of switching from the driven state to the driving state.

  The present invention has been made in view of the above-described circumstances, and can accurately suppress the occurrence of a shock due to the gear rattling at the time of switching between the driving state of the driving source and the driven state. An object of the present invention is to provide a vehicle control device.

  In order to achieve the above object, a vehicle control apparatus according to the present invention includes (1) a differential gear on a power transmission path between a drive source and drive wheels, and the drive torque generated by the drive source is transmitted to the differential gear. The vehicle control device is used for a vehicle that transmits to the driving wheel via the driving state, wherein the driving source is driven by the driving state in which the driving wheel is driven by the driving torque and the input torque input from the driving wheel. Torque control for estimating the generated torque in the differential gear at the time of switching to the driven state and controlling the driving torque at the time of switching based on the estimated generated torque It has the structure provided with the control means which implements.

  With this configuration, the vehicular control apparatus according to the present invention estimates the generated torque in the differential gear at the time of switching between the driving state and the driven state, and uses the estimated generated torque. Based on this, torque control is performed to control the drive torque of the drive source at the time of switching. If this torque control allows the drive torque of the drive source to match or approach the torque generated by the differential gear when switching between the drive state and the driven state, the drive torque of the drive source at the time of the switch And the torque step generated between the input torque from the driving wheel can be suppressed. Therefore, when the driving torque of the driving source is controlled so as to coincide with or approach the torque generated in the differential gear at the time of switching between the driving state and the driven state, the switching between the driving state and the driven state is performed. It is possible to prevent the differential gear from rattling at the time of replacement. Therefore, the vehicle control apparatus according to the present invention can accurately suppress the occurrence of a shock due to the rattling of the differential gear at the time of switching between the driving state and the driven state.

  The vehicle control device according to the present invention is the vehicle control device according to (1), wherein (2) the control means is a drive on the drive source side that meshes with the rotational speed of the differential gear and the differential gear. The driving torque when the rotational speed of the gear becomes equal is estimated as the generated torque.

  With this configuration, in the vehicle control device according to the present invention, the rotational speed of the differential gear is equal to the rotational speed of the drive gear on the drive source side that meshes with the differential gear when switching between the driving state and the driven state. By paying attention to the above, it is possible to estimate an accurate generated torque in the differential gear at the time of switching between the driving state and the driven state.

Further, the vehicle control device according to the present invention is the vehicle control device according to (2), wherein (3) the control means transmits a drive torque Tin transmitted from the drive source side to the differential gear. The value obtained by dividing the differential gear drive source side inertia Iin in the drive system and the input torque Tout transmitted from the drive wheel to the differential gear is the inertia Iout on the drive wheel side of the differential gear in the vehicle drive system. The drive torque required to match the ratio with the value divided by the reduction gear ratio ρ _{def of the} differential gear when the rotational speed of the differential gear and the rotational speed of the drive gear are equal to each other. It has a configuration that is obtained as drive torque.

  With this configuration, the vehicle control device according to the present invention can accurately determine the drive torque when the rotational speed of the differential gear and the rotational speed of the drive gear are equal. Therefore, it is possible to estimate an accurate generated torque in the differential gear at the time of switching between the driving state and the driven state.

  The vehicle control device according to the present invention is the vehicle control device according to any one of (1) to (3), wherein (4) the control means is configured such that the drive torque becomes the estimated generated torque. The torque control is implemented.

  With this configuration, the vehicle control device according to the present invention performs torque control from the time when the drive torque of the drive source becomes the estimated generated torque. On the other hand, the switching between the driving state and the driven state is started at a timing coincident with the torque generated in the differential gear at the time of switching when the driving torque of the driving source is estimated. Therefore, the vehicle control apparatus according to the present invention can perform torque control at an optimal timing.

  The vehicle control device according to the present invention is the vehicle control device according to any one of (1) to (4), wherein (5) the drive source is an internal combustion engine, and the control means A fuel cut of the internal combustion engine is performed at the time of deceleration, and the torque control is performed at the time of switching from the drive state to the driven state prior to the execution of the fuel cut.

  With this configuration, the vehicle control device according to the present invention performs torque control in switching between a driving state and a driven state that occur prior to fuel cut when the vehicle is decelerated. As a result, it is possible to accurately suppress the occurrence of shock due to the gear rattling caused by the switching between the driving state and the driven state that occur prior to the fuel cut when the vehicle is decelerated.

  The vehicle control device according to the present invention is the vehicle control device according to (5), wherein (6) the control means generates a driving torque generated by the internal combustion engine prior to the execution of the fuel cut. It has the structure which implements the torque limitation control which decreases gradually.

  With this configuration, the vehicle control device according to the present invention performs torque limit control that gradually reduces the drive torque of the internal combustion engine prior to the execution of fuel cut, and therefore suppresses torque shock associated with the start of fuel cut. Is possible.

Further, a vehicle control device according to the present invention is the vehicle control device according to any one of (1) to (6) above, (7) having a transmission between the drive source and the differential gear, TQaux is the load torque of auxiliary equipment of the drive source, Iin is inertia on the drive source side of the differential gear in the drive system of the vehicle, Tout is input torque transmitted from the drive wheel to the differential gear, and drive of the vehicle When the inertia on the drive wheel side of the differential gear in the system is Iout, the reduction ratio of the differential gear is ρ _def , the transmission efficiency of the transmission is KETT, and the transmission ratio of the transmission is RATIO The generated torque TQeng is obtained by the following equation (1).

  With this configuration, the vehicle control device according to the present invention can more accurately estimate the generated torque in the differential gear at the time of switching between the driving state and the driven state by the calculation using Expression (1). it can.

  In order to achieve the above object, the vehicle control apparatus according to the present invention includes (8) a differential gear on the power transmission path between the drive source and the drive wheels, and the drive torque generated by the drive source is A vehicle control device used for a vehicle that transmits to a drive wheel via a differential gear, wherein the drive source is driven by a drive state in which the drive wheel is driven by the drive torque and an input torque input from the drive wheel. When switching to the driven state to be driven, the input torque input to the differential gear from the driving wheel at the time of switching is estimated, and based on the estimated input torque, It has the structure provided with the control means which implements the torque control which controls the said drive torque.

  With this configuration, the vehicle control apparatus according to the present invention estimates the input torque that is input to the differential gear from the driving wheel when the control unit switches between the driving state and the driven state, and the estimated input torque Based on the above, torque control for controlling the drive torque of the drive source at the time of switching is performed. If this torque control can make the driving torque of the driving source and the input torque from the driving wheel coincide or approach when switching between the driving state and the driven state, driving of the driving source at the time of switching will be possible. A torque step generated between the torque and the input torque from the drive wheel can be suppressed. Therefore, if the drive torque of the drive source is controlled so that it matches or approaches the input torque from the drive wheels at the time of switching between the drive state and the driven state, switching between the drive state and the driven state is possible. It is possible to prevent the differential gear from rattling at the time of replacement. Therefore, the vehicle control apparatus according to the present invention can accurately suppress the occurrence of a shock due to the rattling of the differential gear at the time of switching between the driving state and the driven state.

  The vehicle control device according to the present invention is the vehicle control device according to (8), wherein (9) the control means is configured to control the torque control from when the driving torque becomes the estimated input torque. It has the structure which implements.

  With this configuration, the vehicle control device according to the present invention performs torque control when the driving torque of the driving source becomes the estimated input torque. On the other hand, switching between the driving state and the driven state is started at a timing coincident with the input torque from the driving wheel at the time of switching when the driving torque of the driving source is estimated. Therefore, the vehicle control apparatus according to the present invention can perform torque control at an optimal timing.

  ADVANTAGE OF THE INVENTION According to this invention, the control apparatus for vehicles which can suppress exactly generation | occurrence | production of the shock by the gearing of a differential gear at the time of the switching of the drive state of a drive source and a driven state can be provided.

1 is a schematic configuration diagram of a vehicle to which a vehicle control device according to an embodiment of the present invention is applied. It is a figure which shows the model of the drive system simplified centering on the differential gear which concerns on embodiment of this invention. It is a flowchart which shows the process sequence of the torque control routine performed with ECU which concerns on embodiment of this invention. It is a time chart which shows an example of the control aspect at the time of the fuel cut at the time of deceleration in embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  In the embodiment of the present invention, an example in which a vehicle control device is applied to a vehicle including an internal combustion engine as a drive source will be described.

  As shown in FIG. 1, a vehicle 1 is constituted by a so-called FR drive vehicle of a front engine / rear drive type, and an engine 2, a transmission 3, and a rear differential as a drive source for generating a drive force of the vehicle 1. The gear 4, the drive wheels 5 </ b> L and 5 </ b> R, and the vehicle control device 10 are configured. The vehicle 1 can transmit the drive torque generated by the engine 2 to the left and right drive wheels 5L and 5R via the transmission 3 and the rear differential gear 4. In the present embodiment, the vehicle control device 10 is applied to the vehicle 1 that is an FR drive vehicle. However, the vehicle control device 10 is not limited to the FR drive vehicle, but other types of vehicles having a differential gear between the engine and the drive wheels. It is also applicable to.

  The engine 2 is configured as an internal combustion engine capable of outputting power using a hydrocarbon fuel such as gasoline or light oil. A compressor (A / C) 21, an alternator (ALT) 22, and an oil pump (O / P) 23 of an air conditioner are drivingly connected to the engine 2 as various auxiliary machines. The engine 2 is connected to the left and right drive wheels 5L and 5R via the transmission 3 and the rear differential gear 4. The engine 2 configured as described above includes a fuel injection device and an ignition device (not shown), and these fuel injection device and ignition device are controlled by an ECU 100 described later.

  The transmission 3 is provided on a power transmission path between the engine 2 and the rear differential gear 4, and changes the rotational speed of the engine 2 and outputs it to the rear differential gear 4 via the propeller shaft 30. Yes. As the transmission 3, a stepped (planetary gear type) automatic transmission that sets a gear stage by using a friction engagement device such as a clutch and a brake and a planetary gear unit, or arbitrarily by a driver's shift operation A manual transmission capable of selecting a gear position, a so-called manual transmission can be used. In addition, a belt-type continuously variable transmission (CVT) that continuously adjusts the gear ratio may be used as the transmission 3.

  The rear differential gear 4 is provided on a power transmission path between the engine 2 and the left and right drive wheels 5L and 5R, and allows the differential of the left and right drive wheels 5L and 5R. The rear differential gear 4 includes a ring gear 41 fixed to the differential case, a pair of pinion gears, and a pair of side gears. The ring gear 41 meshes with a drive pinion gear 31 attached to one end of the propeller shaft 30. The rear differential gear 4 in the present embodiment constitutes a differential gear according to the present invention, and the drive pinion gear 31 constitutes a drive gear according to the present invention.

  The vehicle control device 10 includes a vehicle electronic control device (hereinafter simply referred to as an ECU) 100 and various sensors such as a crank position sensor and an accelerator opening sensor (not shown) connected to the ECU 100. .

  The ECU 100 includes, for example, a microcomputer including a CPU, a RAM, a ROM, an input / output interface, and the like. The CPU uses a temporary storage function of the RAM and performs signal processing according to a program stored in advance in the ROM. It is like that. Various control constants and various maps are stored in advance in the ROM.

  The ECU 100 performs engine control such as ignition timing control and fuel injection control based on inputs from various sensors. In particular, in the present embodiment, as part of the engine control, the ECU 100 performs the deceleration fuel cut control that stops the fuel supply of the engine 2 when a predetermined deceleration fuel cut start condition is satisfied when the vehicle 1 is decelerated. It has become. For example, the deceleration fuel cut start condition is that the rotation speed of the engine 2 is equal to or higher than a predetermined fuel cut reference rotation speed during deceleration and that the accelerator is off. The fuel cut during deceleration in this fuel cut control during deceleration is performed by stopping or limiting fuel injection from an injector (not shown). Note that the ECU 100 determines that the deceleration-time fuel cut end condition is satisfied when the deceleration of the engine 2 becomes less than the deceleration-time fuel-cut reference rotation speed during the deceleration-time fuel cut control or the accelerator pedal is depressed, and the deceleration-time fuel-cut end condition is satisfied. The fuel cut ends. The fuel cut during deceleration in the present embodiment corresponds to the fuel cut in the present invention.

  Further, the ECU 100 generates a drive generated by the engine 2 by gradually retarding the ignition timing of the engine 2 prior to the execution of the fuel cut control at the time of deceleration, in order to suppress a torque shock at the start of the fuel cut at the time of deceleration. Torque limit control for gradually decreasing the torque is performed. The torque limit control may be performed by adjusting the fuel injection amount, the intake air amount, and the like, for example. Further, when the vehicle 1 is a hybrid vehicle, torque limit control may be performed by adjusting the torque of a motor as a drive source.

  Here, when the engine 2 shifts to the fuel cut control during deceleration, the engine 2 uses the input torque input from the drive wheels 5L and 5R from the drive state in which the drive wheels 5L and 5R are driven by the drive torque generated by the engine itself. It switches to the driven state in which it is driven. When switching from such a driven state to a driven state, gears between the gears are generated in the rear differential gear 4, which may cause a shock. In general, such a shock has a torque step between the driving torque of the engine 2 and the input torque from the driving wheels 5L and 5R when the driving state is switched to the driven state. Caused by. Therefore, if the driving torque of the engine 2 can be matched with or brought close to the input torque from the driving wheels 5L and 5R when the driving state is switched to the driven state, the occurrence of such a shock can be suppressed. In other words, if the driving torque of the engine 2 can be matched or brought close to the generated torque generated in the rear differential gear 4 at the time of switching from the driving state to the driven state, the above-described shock is suppressed. it can. Therefore, in order to suppress the occurrence of such a shock, it is necessary to estimate the generated torque of the rear differential gear 4 as described above.

  However, the drive torque of the engine 2 and the input torque from the drive wheels 5L and 5R are not transmitted to the rear differential gear 4 as they are. For example, since various auxiliary machines are drivingly connected to the engine 2, unless considering the load torque of these auxiliary machines or the road surface gradient related to the input torque from the drive wheels 5L and 5R, The torque generated by the rear differential gear 4 at the time of switching from an accurate driving state to a driven state cannot be estimated. For this reason, in order to suppress the occurrence of the shock, it is necessary to estimate the generated torque in more detail. Therefore, in the present embodiment, the driving torque of the engine 2 necessary for suppressing the shock caused by the rattling of the rear differential gear 4 when the driving state is switched to the driven state is estimated, and the estimated driving torque is estimated. Based on the above, torque control for controlling the driving torque of the engine 2 at the time of switching is performed. This torque control is executed by the ECU 100. Further, in this torque control, the driving torque of the engine 2 is controlled so that the driving torque of the engine 2 at the time of the switching is matched with or close to the estimated driving torque.

  Next, with reference to FIG. 1 and FIG. 2, the drive torque estimation logic necessary for suppressing the shock will be described.

FIG. 2 is a model in which the drive system of the vehicle 1 is modeled around the rear differential gear 4. In this model, Iin is the inertia of the drive system on the engine side of the rear differential gear 4, Tin is the drive torque input to the engine gear of the rear differential gear 4, that is, the drive pinion gear 31, and αin is the drive pinion gear. The angular acceleration of 31 is represented. In this model, Iout is the inertia of the drive system on the drive wheel side of the rear differential gear 4, Tout is the input torque input to the drive wheel side gear of the rear differential gear 4, that is, the ring gear 41, and αout is The angular acceleration of the ring gear 41 is represented. The relational expression of torsion in such a model is as the following expressions (2) and (3). Inertia Iin and Iout can be obtained by equivalent inertia calculation centered on the rear differential gear 4.

Here, the drive torque Tin is expressed by the following equation (4). In the following equation (4), TQeng is the driving torque generated by the engine 2, TQac is the load torque of the compressor 21, TQalt is the load torque of the alternator 22, and TQop is the load torque of the oil pump 23. FRcold indicates an increase in friction torque during cold. KETT indicates the transmission efficiency of the transmission 3, and RATIO indicates the transmission ratio of the transmission 3. The KETT is a constant if the transmission efficiency of the transmission 3 is constant. However, when the transmission efficiency changes depending on the gear ratio, the KETT becomes a variable corresponding to the gear ratio.

On the other hand, the input torque Tout is expressed by the following equation (5). In the following equation (5), F _{R / L} is a road load (so-called load load), F _slope is a drag received by the drive wheels 5L and 5R due to the gradient of the road surface, and R _tire is a load of the drive wheels 5L and 5R. Each radius is shown.

Here, when the driving state is switched to the driven state, the rotational speed of the differential gear 4 and the rotational speed of the engine-side drive pinion gear 31 meshing with the differential gear 4 become equal. More specifically, the tooth surface speeds of the ring gear 41 and the drive pinion gear 31 are equal. Therefore, when the gear ratio (reduction ratio) of the rear differential gear 4 is ρ _def , the relationship between the angular accelerations αin and αout of the drive pinion gear 31 and the ring gear 41 is as shown in the following equation (6). (7) is obtained. The following equation (7) shows that the ratio of the value obtained by dividing the drive torque Tin by the inertia Iin and the value obtained by dividing the input torque Tout by the inertia Iout matches the reduction ratio ρ _def .

In the present embodiment, the driving torque of the engine 2 when the tooth surface speeds of the drive pinion gear 31 and the ring gear 41 are equal is the generated torque generated in the rear differential 4 when switching from the driving state to the driven state. Estimated. If the driving torque of the engine 2 can be matched or brought close to the generated torque, it is possible to suppress a shock caused by rattling of the rear differential 4 when the driving state is switched to the driven state. Here, when the driving torque of the engine 2 necessary for suppressing the shock is TQeng, the driving torque TQeng is as shown in the following expression (8) from the above expressions (4) and (7).

Here, regarding the above equation (8), when the various load torques TQac, TQalt, TQop and the friction torque FRcold are summarized as the load torque TQaux of the auxiliary machinery of the engine 2, the following equation (9) is obtained.

  Next, with reference to FIG. 3, the details of the control for suppressing the occurrence of shock at the time of switching from the driving state to the driven state will be described using the above estimation logic. This control is performed through the processing of the torque control routine shown in FIG. The processing of this torque control routine is repeatedly executed at predetermined intervals by the ECU 100 while the vehicle 1 is traveling.

  As shown in FIG. 3, when this routine is started, the ECU 100 first determines whether or not the vehicle is in a state of transition to a fuel cut during deceleration (step S1). For example, the ECU 100 can determine whether or not the deceleration fuel cut start condition is satisfied, thereby determining whether or not the vehicle is in a state of transition to the deceleration fuel cut.

  If it is determined that the ECU 100 is not in the state of transition to the fuel cut at deceleration, the ECU 100 ends the process of this routine without executing the subsequent steps.

  On the other hand, when it is determined that the ECU 100 is in the state of transition to the fuel cut during deceleration, the ECU 100 performs torque limit control of the engine 2 prior to the fuel cut during deceleration (step S2). By this torque limit control, the ignition timing of the engine 2 is gradually retarded, and the drive torque of the engine 2 is gradually reduced.

  Next, the ECU 100 estimates the driving torque TQeng of the engine 2 necessary for suppressing the shock caused by the rattling of the rear differential gear 4 when the driving state is switched to the driven state (step S3). Specifically, the ECU 100 estimates the drive torque TQeng using the above equation (9).

  Next, the ECU 100 determines whether or not the engine 2 is switching from the driving state to the driven state (step S4). Specifically, the ECU 100 determines whether or not the current driving torque of the engine 2 has decreased to the driving torque TQeng estimated in step S3, so that the engine 2 switches from the driving state to the driven state. It is determined whether it is in progress. If the ECU 100 determines that the engine 2 is not switching from the driven state to the driven state, the ECU 100 ends the process of this routine without executing the subsequent steps.

  On the other hand, when it is determined that the engine 2 is being switched from the driving state to the driven state, the ECU 100 controls the driving torque of the engine 2 so as to match or approach the estimated driving torque TQeng. Torque control is performed (step S5). Specifically, ECU 100 adjusts the ignition timing so that the driving torque of engine 2 matches or approaches the estimated driving torque TQeng. The ECU 100 may perform the torque control of the driving torque of the engine 2 by adjusting, for example, the fuel injection amount, the intake air amount, etc. in addition to the adjustment of the ignition timing. Further, when the vehicle 1 is configured by a hybrid vehicle or an electric vehicle, the ECU 100 may perform the torque control of the driving torque of the engine 2 by adjusting the torque of the motor as a driving source.

  Such torque control of the driving torque of the engine 2 is continued while the transition section flag is on. The transition section flag is turned on when the driving torque generated by the engine 2 becomes the estimated driving torque TQeng, and then turned off when a predetermined time has elapsed. The period during which the transition section flag is turned on is set to the time required for switching from the driving state of the engine 2 to the driven state. In the present embodiment, such an on period of the transition section flag is set in consideration of variations in time required for switching from the driving state to the driven state.

  Next, with reference to FIG. 4, the operation of the vehicle control apparatus 10 according to the present embodiment will be described.

  As shown in FIG. 4, when the vehicle 1 is decelerated and shifts to a fuel cut at deceleration, the ignition timing is gradually retarded by torque limit control, and the drive torque of the engine 2 is gradually decreased. Next, at time t1, the driving torque of the engine 2 becomes the estimated driving torque TQeng (indicated by a one-dot chain line in the figure), and when the switching from the driving state of the engine 2 to the driven state is started, the transition is made The section flag is turned on.

  When the transition section flag is turned on, it matches the driving torque TQeng necessary for suppressing the shock caused by the rattling of the rear differential gear 4 when the driving state is switched to the driven state through adjustment of the ignition timing, or The drive torque of the engine 2 is controlled so as to approach (torque control). For example, in the present embodiment, the ignition timing is adjusted to the advance side so that the driving torque of the engine 2 matches or approaches the driving torque TQeng. This torque control of the driving torque of the engine 2 is continued during the switching from the driving state of the engine 2 to the driven state, that is, from the time t1 to the time t2. As described above, when the driving torque of the engine 2 is controlled to the driving torque TQeng, the torque step between the engine side and the driving wheel side of the rear differential gear 4 is eliminated during the switching from the driving state to the driven state. Thus, the shock caused by the rattling of the rear differential gear 4 is effectively suppressed.

  Thereafter, at time t2, when the switching from the driving state of the engine 2 to the driven state is completed and the transition section flag is turned off, the torque limit control is performed again, and the driving torque of the engine 2 has elapsed over time. With gradual decrease. When the driving torque of the engine 2 is sufficiently reduced, the fuel cut at deceleration is started.

  In FIG. 4, the drive torque and ignition timing indicated by dotted lines are not subjected to torque control that causes the drive torque of the engine 2 to match or approach the drive torque TQeng when switching from the drive state to the driven state, respectively. It shows the drive torque and ignition timing when the conventional control is switched. In the conventional control, when switching from the driving state to the driven state, the driving torque TQeng, that is, a relatively large torque between the generated torque generated in the rear differential gear and the actual engine driving torque at the switching. There is a step, which causes the above shock. In contrast, in the present embodiment, as is apparent from FIG. 4, the torque step between the driving torque TQeng and the actual driving torque of the engine 2 at the time of switching from the driving state to the driven state. Since there is no or it is extremely small, the above-mentioned shock is suppressed.

  As described above, when the vehicle control device 10 according to the present embodiment switches between the driving state and the driven state, the ECU 100 estimates the torque generated in the differential gear 4 at the time of switching, And based on this estimated generated torque, torque control for controlling the driving torque of the engine 2 at the time of switching is performed. With this torque control, if the driving torque of the engine 2 can be made to coincide with or close to the torque generated in the differential gear 4 when switching between the driving state and the driven state, the driving of the engine 2 at the time of switching is performed. A torque step generated between the torque and the input torque from the drive wheels 5L and 5R can be suppressed. Therefore, when the driving torque of the engine 2 is controlled so as to coincide with or approach the torque generated in the differential gear 4 at the time of switching between the driving state and the driven state, the driving state and the driven state are changed. The gear teeth of the differential gear 4 at the time of switching can be prevented. Therefore, the vehicle control apparatus 10 according to the present embodiment can accurately suppress the occurrence of a shock due to the rattling of the differential gear 4 at the time of switching between the driving state and the driven state.

  Further, the vehicle control apparatus 10 according to the present embodiment is configured such that the rotational speed of the differential gear 4 and the rotational speed of the engine-side drive pinion gear 31 that meshes with the differential gear 4 at the time of switching between the driving state and the driven state. Focusing on the equality, it is possible to estimate an accurate generated torque in the differential gear 4 when the driving state and the driven state are switched.

Further, the vehicle control apparatus 10 according to the present embodiment determines the ratio of the value obtained by dividing the drive torque Tin by the inertia Iin and the value obtained by dividing the input torque Tout by the inertia Iout as the reduction ratio ρ _def of the rear differential gear 4. The driving torque TQeng of the engine 2 required to match the above is obtained as the driving torque when the rotational speed of the differential gear 4 and the rotational speed of the drive pinion gear 31 are equal. For this reason, the vehicle control apparatus 10 according to the present embodiment can accurately determine the drive torque when the rotational speed of the differential gear 4 and the rotational speed of the drive pinion gear 31 are equal. Therefore, it is possible to estimate an accurate generated torque in the differential gear 4 at the time of switching between the driving state and the driven state.

  Further, the vehicle control device 10 according to the present embodiment performs torque control from the time when the driving torque of the engine 2 becomes the estimated generated torque, that is, the driving torque TQeng. On the other hand, switching between the driving state and the driven state is started at a timing coincident with the torque generated in the differential gear 4 at the time of switching when the driving torque of the engine 2 is estimated, that is, the driving torque TQeng. Therefore, the vehicle control apparatus 10 according to the present embodiment can perform torque control at an optimal timing.

  Further, the vehicle control apparatus 10 according to the present embodiment performs torque control in switching between a driving state and a driven state that occur prior to the execution of a fuel cut during deceleration when the vehicle 1 is decelerated. That is, torque control is performed at the time of switching from the driving state to the driven state prior to the execution of the fuel cut during deceleration. As a result, it is possible to accurately suppress the occurrence of shock due to gear rattling of the differential gear 4 due to switching between the driving state and the driven state that occur prior to the fuel cut during deceleration.

  In addition, since the vehicle control apparatus 10 according to the present embodiment performs torque limit control that gradually reduces the drive torque of the engine 2 prior to the execution of the fuel cut at the time of deceleration, the torque associated with the start of the fuel cut at the time of deceleration. It is possible to suppress the shock.

  Further, the vehicle control apparatus 10 according to the present embodiment calculates the generated torque, that is, the driving torque TQeng in the differential gear 4 at the time of switching between the driving state and the driven state by the calculation using the above equation (8). It can be estimated more accurately.

  In addition, the vehicle control device 10 according to the present embodiment determines the load torque (for example, load torques TQac, TQalt, TQop) of the auxiliary machinery that is drivingly connected to the engine 2, the transmission ratio of the transmission 3, and the transmission efficiency. Considering this, the driving torque TQeng is estimated. Therefore, it is possible to accurately estimate the drive torque TQeng necessary for suppressing the shock regardless of the change in load torque of the auxiliary machinery, the change in the gear ratio of the transmission 3, or the change in transmission efficiency. Further, when the number and types of auxiliary machines connected to the engine 2 are different, if the driving torque TQeng is estimated in consideration of the load torque of each auxiliary machine, as in the present embodiment, The drive torque TQeng necessary for suppressing the shock can be accurately estimated.

  In addition, the vehicle control apparatus 10 according to the present embodiment estimates the drive torque TQeng in consideration of an increase in the friction torque during cold. Therefore, it is possible to accurately estimate the drive torque TQeng necessary for suppressing the shock regardless of the change of the friction torque according to the warm-up state.

  Further, as described above, the vehicle control apparatus 10 according to the present embodiment controls the drive torque of the engine 2 so as to match or approach the drive torque TQeng as described above when switching from the drive state to the driven state. Therefore, it becomes possible to reduce the driving torque of the engine 2 at an early stage as compared with the conventional case in the fuel cut transition section during deceleration other than the switching time. Therefore, the delay time until the fuel cut at the time of deceleration is started can be shortened, and as a result, the fuel consumption of the vehicle 1 is improved.

  Furthermore, the vehicle control device 10 according to the present embodiment can realize the deceleration state of the vehicle 1 according to the driver's accelerator operation by reducing the delay time as described above. That is, conventionally, for example, only control for gradually reducing the driving torque of the engine has been performed, so that the delay time tends to be relatively long. For this reason, even if the driver sets the accelerator operation amount to zero, a situation may occur in which the vehicle does not decelerate easily. In this case, drivability may be deteriorated. On the other hand, the vehicle control apparatus 10 according to the present embodiment can reduce the vehicle 1 earlier than before according to the driver's request by reducing the delay time as described above. It becomes. As a result, drivability is improved.

  In the present embodiment, when the driving torque of the engine 2 has become the driving torque TQeng, the timing of switching from the driving state of the engine 2 to the driven state has been confirmed. This timing may be confirmed by other methods.

  Further, when it is not particularly necessary to suppress the shock caused by the torque step at the start of deceleration fuel cut, the deceleration fuel cut may be performed without performing the torque limit control as described above.

  Further, in the present embodiment, in estimating the drive torque TQeng, the load torque consumed for the speed change operation of the continuously variable transmission is not taken into consideration. For example, when the transmission 3 is configured by a continuously variable transmission, You may consider the load torque spent on the speed change operation of a continuously variable transmission. That is, the drive torque TQeng may be estimated by adding the load torque consumed for the speed change operation of the continuously variable transmission to the equation (8). The load torque includes the torque spent on the primary sheave shifting operation (change of belt wrapping radius) during shifting of the continuously variable transmission, and the secondary sheave shifting operation (belt wrapping radius of the transmission). Torque). Of course, when the influence of such torque can be ignored, it is not necessary to consider these torques.

  Further, in the present embodiment, when the driving torque TQeng is estimated, an increase in the friction torque during the cold time is taken into account. However, when such an increase in the friction torque can be ignored, for example, after the fuel cut during deceleration completes warming up For example, the driving torque TQeng may be estimated without considering the increase in friction torque. That is, the drive torque TQeng may be estimated using the expression (8) excluding the term FRcold.

  Further, in the present embodiment, an example has been described in which the driving torque of the engine 2 at the time of switching from the driving state to the driven state associated with the shift to the fuel cut at the time of deceleration is made coincident with or close to the driving torque TQeng. Of course, when the driving state is switched to the driven state in a situation other than the transition to the fuel cut during deceleration, a similar shock due to the rattling of the rear differential gear 4 may occur. Therefore, even at the time of such switching, if the driving torque of the engine 2 is made equal to or close to the driving torque TQeng, the shock can be suppressed appropriately.

  Further, in the present embodiment, the description has been given of the switching of the engine 2 from the driving state to the driven state. However, the same rattling of the rear differential gear 4 is also performed at the time of switching from the driven state to the driving state. May cause shock. Such a shock can also be suppressed by making the driving torque of the engine 2 at the time of switching coincide with or approach the driving torque TQeng. For example, when the driving torque of the engine 2 is controlled so as to match or approach the driving torque TQeng when the engine 2 is switched from the driven state to the driving state at the time of return from the fuel cut at deceleration, the switching is performed. A shock due to gearing of the rear differential gear 4 due to the replacement can be accurately suppressed.

  In the present embodiment, the example in which the vehicle control device 10 is applied to the vehicle 1 including the engine 2 using the vehicle control device 10 as a drive source has been described. However, the present invention is not limited to this. It is also applicable to.

  Further, in the present embodiment, the driving torque TQeng of the engine 2 at the time of switching between the driving state and the driven state is estimated as the generated torque in the differential gear 4, and the driving torque of the engine 2 at the time of switching Is made equal to or close to the estimated driving torque TQeng. Here, when it can be considered that the driving torque of the engine 2 and the input torque from the driving wheels 5L and 5R are transmitted to the rear differential gear 4 as they are, the switching is performed by performing torque control as follows. It is possible to accurately suppress the shock caused by the rattling of the rear differential gear 4 at that time. That is, the input torque from the drive wheels 5L and 5R at the time of switching between the driving state and the driven state is estimated, and the driving torque of the engine 2 at the time of switching is controlled based on the estimated input torque. Torque control is performed. Specifically, the driving torque of the engine 2 at the time of switching is controlled so that the driving torque of the engine 2 matches or approaches the input torque estimated by the ECU 100. In this case, when the driving torque of the engine 2 becomes the estimated input torque, it is possible to confirm the start of switching between the driving state and the driven state. Therefore, in such an example, torque control can be performed more than when the driving torque of the engine 2 becomes the estimated input torque.

  As described above, the vehicle control device according to the present invention can accurately suppress the occurrence of shock due to the gear rattling when the driving source is switched between the driving state and the driven state. The present invention is useful for a vehicle control device used in a vehicle that transmits torque generated by a drive source to a drive wheel via a differential gear.

1 vehicle 2 engine (drive source, internal combustion engine)
3 Transmission 4 Rear differential gear (Differential gear)
5L, 5R Drive wheel 10 Vehicle control device 21 Compressor (auxiliary equipment)
22 Alternator (auxiliary)
23 Oil pump (auxiliary equipment)
30 Propeller shaft 31 Drive pinion gear (drive gear)
41 Ring gear 100 ECU (control means)

Claims (9)

A vehicle control device used in a vehicle that includes a differential gear on a power transmission path between a drive source and a drive wheel, and that transmits a drive torque generated by the drive source to the drive wheel via the differential gear. And
At the time of switching between a driving state in which the driving wheel is driven by the driving torque and a driven state in which the driving source is driven by an input torque input from the driving wheel, the differential gear at the time of switching And a control means for performing torque control for controlling the driving torque at the time of switching based on the estimated generated torque.   The control means estimates the drive torque when the rotational speed of the differential gear is equal to the rotational speed of the drive gear on the drive source side meshing with the differential gear as the generated torque. The vehicle control device according to claim 1. The control means transmits the drive torque Tin transmitted from the drive source side to the differential gear and a value obtained by dividing the drive torque Tin transmitted from the drive wheel to the differential gear by the inertia Iin on the drive source side of the differential gear in the drive system of the vehicle. The drive torque required to match the ratio of the input torque Tout to the value obtained by dividing the input torque Tout by the inertia Iout on the drive wheel side of the differential gear in the drive system of the vehicle with the reduction ratio ρ _{def of the} differential gear. 3. The vehicle control device according to claim 2, wherein the driving torque is obtained as the driving torque when the rotational speed of the differential gear is equal to the rotational speed of the drive gear.   The vehicle control according to any one of claims 1 to 3, wherein the control means performs the torque control from when the drive torque becomes the estimated generated torque. apparatus. The drive source comprises an internal combustion engine;
The control means performs a fuel cut of the internal combustion engine when the vehicle is decelerated, and performs the torque control when switching from the driving state to the driven state prior to the execution of the fuel cut. The vehicle control device according to any one of claims 1 to 4, characterized in that:   The vehicle control device according to claim 5, wherein the control unit performs torque limit control for gradually decreasing the drive torque generated by the internal combustion engine prior to the execution of the fuel cut. Having a transmission between the drive source and the differential gear;
TQaux is a load torque of auxiliary equipment of the drive source, Iin is inertia on the drive source side of the differential gear in the drive system of the vehicle, Tout is input torque transmitted from the drive wheel to the differential gear, and When the inertia on the drive wheel side of the differential gear in the drive system is Iout, the reduction ratio of the differential gear is ρ _def , the transmission efficiency of the transmission is KETT, and the transmission ratio of the transmission is RATIO, the switching The vehicle control device according to any one of claims 1 to 6, wherein the generated torque TQeng at the time is obtained by the following equation (1).

A vehicle control device used in a vehicle that includes a differential gear on a power transmission path between a drive source and a drive wheel, and that transmits a drive torque generated by the drive source to the drive wheel via the differential gear. And
When switching between a driving state in which the driving wheel is driven by the driving torque and a driven state in which the driving source is driven by an input torque input from the driving wheel, the driving wheel at the time of switching Vehicle control apparatus comprising: a control unit that estimates input torque input to the differential gear, and executes torque control for controlling the drive torque at the time of switching based on the estimated input torque. Control device.   The vehicle control device according to claim 8, wherein the control unit performs the torque control when the driving torque becomes the estimated input torque.

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