JP2008232180A - Shift control device of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmission of a vehicle, which reduces deterioration of drivability of the vehicle. <P>SOLUTION: An ECU 100 performs shift control process in the vehicle 10 equipped with a CVT 300 as the transmission. In the shift control process, the ECU 100 performs shift speed reducing control during relatively slow acceleration or deceleration in which demanded output Pt by a driver is not smaller than the optimum fuel consumption output Pc and is not larger than WOT output Pw. When the shift speed reducing control is performed, a change rate of input rotation speed Vin which is rotation speed of an input shaft 320 of the CVT 300 is set to be smaller as compared with that when the demand output Pt is larger than the WOT output Pw and shift speed is reduced. On the other hand, since a magnitude of inertia torque becomes large according to the shift speed, a torque loss of an engine 200 is reduced with the performance of the shift speed reducing control and the drivability of the vehicle 10 is improved. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technical field of a transmission control device for a vehicle that controls a transmission such as a CVT (Continuously Variable Transmission) provided in the vehicle.

  As this type of apparatus, an apparatus that considers inertia torque has been proposed (see, for example, Patent Document 1). According to the control device for a vehicle with a transmission disclosed in Patent Document 1 (hereinafter referred to as “conventional technology”), for example, the shift speed is determined based on, for example, the difference between the current output and the steady-state output. Thus, the inertia torque at the time of shifting is controlled to a target value in consideration of the driver's intention, and drivability can be improved.

  In addition, when a sudden acceleration request is made in the transmission, if there is a large margin to the high load side fuel consumption deterioration region of the internal combustion engine, a technique for delaying the transmission operation start timing of the transmission has also been proposed (for example, , See Patent Document 2).

JP-A-7-239002 JP 2005-214311 A

  For example, the output required for the internal combustion engine is generally low during steady running or inertia running. Therefore, in the conventional technique, when an acceleration request is made in such a case, for example, even if it is a slight acceleration to maintain the distance from the front vehicle, it is determined that the difference in output is large, There is a possibility that the shift speed is set to be large. On the other hand, such minor acceleration often ends in a relatively short time, and often involves minor deceleration. In such a situation, if the shift speed is set to be large, the engine rotational fluctuation of the internal combustion engine may be remarkably generated, and there is a high possibility that torque loss due to inertia torque becomes obvious and drivability deteriorates. That is, the conventional technique has a technical problem that the drivability of the vehicle may deteriorate in some cases.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a vehicle transmission control device that can suppress deterioration of drivability of the vehicle.

  In order to solve the above-described problems, a first vehicle shift control apparatus according to the present invention includes an internal combustion engine and an input that is rotatably coupled to the engine output shaft of the internal combustion engine as the engine output shaft rotates. An output shaft connected to the shaft and the axle so as to rotate in accordance with the rotation of the axle, and between an input rotational speed representing the rotational speed of the input shaft and an output rotational speed representing the rotational speed of the output shaft A shift control apparatus for a vehicle including a transmission capable of continuously changing a gear ratio, the request output specifying means for specifying a driver's request output, and based on the specified request output Setting means for setting a target input rotation speed representing a target value of the input rotation speed, and shift control means for performing a shift by controlling the transmission so that the input rotation speed becomes the set target input rotation speed And the identified request If the specified output is greater than the maximum output, the shift speed reduction control defined as reducing the shift speed related to the shift is executed when the specified output is greater than the maximum output. And a shift speed control means.

  The “internal combustion engine” in the present invention has, for example, a plurality of cylinders, and in each of the combustion chambers, an explosion force generated when an air-fuel mixture containing various fuels such as gasoline or alcohol burns, for example, pistons This is a concept that encompasses an engine that can be extracted as power through a connecting rod, a crankshaft, and the like as appropriate, and refers to, for example, a 2-cycle or 4-cycle reciprocating engine.

  In the internal combustion engine, for example, the output shaft of the transmission according to the present invention, which can take various known modes such as a pulley type CVT and a toroidal type CVT, is used as the engine output shaft such as a crankshaft. Directly or indirectly, with the fluid transmission means such as a torque converter intervening, or directly or indirectly depending on the engagement state of various engagement means such as a lock-up clutch. Thus, the engine output shaft is rotatably connected with the rotation of the engine output shaft. Accordingly, the rotational speed of the engine output shaft of the internal combustion engine (that is, the engine rotational speed) has a one-to-one relationship with the rotational speed of the input shaft of the transmission (that is, the input rotational speed). In particular, when the engine output shaft of the internal combustion engine and the input shaft of the transmission are directly connected via frictional engagement means such as a lock-up clutch, the input rotational speed and the engine rotational speed coincide with each other. .

  On the other hand, the output shaft of this transmission is, for example, via a propeller shaft (for example, in the case of adopting the FR type drive form or in the case of four-wheel drive) or not (for example, in the case of adopting the FF type drive form). ), And connected to an axle (for example, an axle shaft) that rotates integrally with the drive wheel via a final reduction gear such as a differential, and is configured to be rotatable with the rotation of the axle. The transmission according to the present invention is a physical, mechanical, mechanism that can continuously change the ratio between the input rotational speed described above and the output rotational speed that is the rotational speed of the output shaft, that is, the gear ratio. It is a concept that encompasses a transmission having a mechanical or electrical configuration.

  According to the first vehicle shift control device of the present invention, during operation, for example, various processing units such as an ECU (Electronic Control Unit), various controllers, various computer systems such as a microcomputer device, etc. The required output representing the output required by the driver is specified by the required output specifying means. Here, “specific” according to the present invention refers to, for example, detecting directly or indirectly as a physical numerical value or an electrical signal corresponding to the physical numerical value via some detection means, or appropriate storage means. Select or estimate the corresponding numerical value from a map or the like stored in, etc., according to a preset algorithm or calculation formula from the detected physical numerical value or electrical signal or the selected or estimated numerical value It is a broad concept encompassing deriving as a result of logical operation or numerical operation, or simply acquiring a value detected, selected, estimated or derived as an electric signal or the like. Within the scope of the concept, the required output specifying means is, for example, an operation amount of an accelerator pedal (hereinafter referred to as “accelerator opening” as appropriate) and a vehicle speed (hereinafter referred to as “vehicle speed” as appropriate) that are directly operated by the driver. The required output may be calculated by multiplying the required driving force determined on the basis of the radius of the driving wheel and the vehicle speed.

  On the other hand, according to the first vehicle speed change control device of the present invention, the vehicle speed is controlled by setting means that can take the form of various processing units such as an ECU, various controllers or various computer systems such as a microcomputer device, for example. The target input rotation speed, which is the target value of the input rotation speed described above, is set based on predetermined shift conditions such as the accelerator opening. At this time, as a preferred form of operation of the setting means, for example, in advance, the internal combustion engine can be operated most efficiently based on experiments, empirically, theoretically or based on simulations, in other words, the internal combustion engine. An input rotational speed corresponding to the engine rotational speed adapted to reduce the fuel consumption rate of the engine to a minimum or a level corresponding thereto may be set as the target input rotational speed. At this time, if the input shaft and the engine output shaft are directly connected physically, mechanically, or electrically, the engine rotational speed may be set as the input rotational speed as it is.

  It should be noted that a predetermined condition and a target input rotation speed may be stored in an appropriate storage means in association with each other as a shift map. In this case, the setting means may selectively acquire one value determined according to the current vehicle speed, accelerator opening, etc. from the map and set it as the target input rotation speed. As described above, the required output can also be specified based on the vehicle speed, the accelerator opening, etc. at that time, and the “predetermined condition” related to the target input rotational speed includes this required output. It may be. That is, the requested output and the target input rotation speed may be associated with each other.

  When the target input rotational speed is set in this manner, the input rotational speed is set by the shift control means that can take the form of various processing units such as an ECU, various controllers or various computer systems such as a microcomputer device. The transmission is controlled so as to achieve the input rotation speed, for example, in the form of a gear ratio control or the like, and a shift is performed. Since the output of the internal combustion engine is defined by the engine rotational speed and the output torque, for example, as described above, the required output and the engine rotational speed (that is, have a unique relationship with the target input rotational speed) are determined. For example, the torque value to be output from the internal combustion engine can be determined uniquely. Therefore, when the gear shift is performed, the output torque of the internal combustion engine is naturally controlled through, for example, control of the throttle valve opening (hereinafter referred to as “throttle opening” or the like as appropriate). For example, through such a control process, the operating point defined as a combination of the engine speed and the output torque in the internal combustion engine can be controlled to an optimum operating point corresponding to the required output.

  In particular, when the engine rotational speed is increased by the output torque of the internal combustion engine, such as during acceleration of the vehicle, which may be accompanied by an increase in the engine rotational speed, that is, an increase in the input rotational speed of the transmission, with respect to an increase in the required output In addition, a part of the output torque is lost as an inertia torque, and the output torque that can be used as the driving force of the vehicle is relatively reduced. For this reason, the acceleration performance of the vehicle becomes dull (remarkably, the start of acceleration is delayed), and drivability may be deteriorated.

  Therefore, the first vehicle shift control device according to the present invention includes such a shift speed control means that can take the form of various processing units such as an ECU, various controllers or various computer systems such as a microcomputer device. The deterioration of drivability is suppressed. That is, the shift speed control means executes shift speed reduction control when the required output specified by the required output specifying means is less than or equal to the maximum output allowed in advance. Here, the “shift speed reduction control” is a control including at least reducing the shift speed related to the shift as compared with the case where the specified required output is larger than the maximum output. The “shift speed” is defined as the rate of change of the input rotation speed.

  Here, the “maximum output” is, as a typical example, an output corresponding to the maximum torque that the internal combustion engine can physically output at one engine rotational speed, that is, a WOT (Wide Open Throttle) torque (that is, WOT). Output), or an output that is close to the WOT output to the extent that it can be practically or substantially regarded as a WOT output, and separately from such a physically specified maximum output, for example, economic performance represented by fuel efficiency Alternatively, it may be determined comprehensively in consideration of other performances required for the internal combustion engine, such as environmental performance represented by the amount of emissions.

  For example, as a more specific example, the degree of deterioration of fuel consumption (similarly the degree of emission amount) is defined as exceeding a preset standard with respect to the operating point used for the operation control of the internal combustion engine in normal times. The output corresponding to the output torque that defines the lower limit of the region to be used may be adopted as the maximum output. Such areas where fuel consumption and emissions are remarkably deteriorated are, for example, experimentally, empirically, theoretically, or based on simulation, etc. It may be set so as to ensure reliability to such an extent that no occurrence occurs. As one of the more practical forms, such an operation region (or operation point) that causes deterioration of fuel consumption or emission is preliminarily associated with the engine rotational speed, output torque, etc., or further, the accelerator is opened. The degree and the vehicle speed may be stored as parameters in appropriate storage means and referred to each time.

  When the change in the required output is relatively slight, for example, when the required output changes with a delicate accelerator work that can be performed to maintain the distance between the vehicle and the vehicle during steady running at medium or high speed, etc. In many cases, the accelerator opening frequently repeats increasing and decreasing. Alternatively, even if not repeated, it is easy to follow a process of being temporarily increased and then quickly returned to the original state, and generally, acceleration and deceleration are likely to be repeated regularly or irregularly. When the input rotational speed is converged to the target input rotational speed at a normal shift speed every time such a slight change in required output frequently occurs, the influence of torque loss greatly increases with fluctuations in the engine rotational speed of the internal combustion engine. On the contrary, the fuel consumption may worsen. That is, in this case, the deterioration in drivability is easily manifested as a problem that cannot be overlooked in practice due to the deterioration in fuel efficiency.

  Here, the case where the required output is less than or equal to the maximum output typically represents a situation in which the change in the required output is slight as described above. According to the above-described operation related to the shift speed control means, Shift speed reduction control is performed in a situation where a gentle acceleration request that does not correspond to a transient and intense acceleration request is made. Here, since the inertia torque increases as the shift speed increases, the torque loss due to the inertia torque increases similarly as the shift speed increases. Therefore, since the shift speed is reduced as compared with the case where at least the required output is larger than the maximum output, it is possible to suppress the torque loss somewhat and relatively suppress the deterioration of drivability. . That is, according to the first vehicle shift control device of the present invention, it is possible to efficiently and effectively suppress the deterioration of the drivability of the vehicle.

  At this time, the mode of the shift speed reduction control is not limited as long as the shift speed can be reduced. For example, when the transmission is a pulley-type CVT, the target speed ratio (corresponding to the rotational speed of the drive wheel). The speed change speed may be decreased by decreasing the increase speed or decrease speed of the hydraulic pressure applied to the movable piece of the pulley in order to realize the output rotation speed and the target input rotation speed. Further, the value of the shift speed during the execution period of such shift speed reduction control is, for example, experimentally, empirically, theoretically, or based on simulations, etc. It may be determined so that the fuel consumption is as good as possible without being actualized in practice. Further, when the shift speed is decreased, the target input rotation speed itself may be maintained, or correction may be added. Further, the time characteristic of the shift speed may be linear or a quadratic function.

  In one aspect of the shift control apparatus for a first vehicle according to the present invention, the maximum output is based on a current engine speed of the internal combustion engine and a WOT torque of the internal combustion engine at the current engine speed. WOT output defined as follows.

  According to this aspect, the aforementioned WOT output is adopted as the maximum output. Since the WOT output is the maximum output that can be physically output at one engine rotational speed, the execution range of the shift speed reduction control is substantially maximized in this case. That is, it is possible to obtain the maximum effect related to the suppression of deterioration of drivability.

  In another aspect of the shift control apparatus for a first vehicle according to the present invention, the setting means includes a fuel consumption of the internal combustion engine among operating points defined as a combination of an engine speed and an output torque in the internal combustion engine. The target input rotational speed is set based on the engine rotational speed corresponding to the optimum fuel efficiency operating point determined according to the output of the internal combustion engine as a reduction in the rate.

  According to this aspect, the setting means sets the target input rotation speed based on the engine rotation speed corresponding to the optimum fuel consumption operating point. As already described, when the input rotational speed and the engine rotational speed coincide with each other, the target input rotational speed may be the engine rotational speed itself corresponding to the optimum fuel consumption operating point. Here, the “optimum fuel consumption operating point” is an operating point that is determined according to the output as a fuel efficiency rate that is at least relatively small among the operating points of the internal combustion engine. This includes the minimum operating point of the fuel consumption rate that can minimize the fuel consumption.

  According to this aspect, the internal combustion engine is basically controlled to operate on the optimal fuel consumption line formed by connecting the optimal fuel consumption operating points, so that the fuel consumption of the internal combustion engine can be optimized as much as possible. On the other hand, in a situation where the fuel efficiency tends to deteriorate due to fluctuations in the engine rotation speed (uniquely the input rotation speed) and the deterioration in drivability is relatively obvious, the engine rotation speed can be changed by shift speed reduction control. It is suppressed as much as possible (that is, the period during which the operating point deviates from the optimum fuel consumption line becomes relatively long). That is, according to this aspect, it is possible to provide extremely high profits in practice that both deterioration in fuel consumption and deterioration in drivability can be suppressed.

  In this aspect, the shift speed control means is configured so that the specified required output is not more than the maximum output at the current engine speed of the internal combustion engine and not less than an output corresponding to the optimum fuel consumption operating point. In some cases, the shift speed reduction control may be executed.

  If the requested output is less than the output corresponding to the optimum fuel efficiency operating point at the engine rotational speed at that time, there is a high possibility that a clear deceleration request is made by the driver. Accordingly, when the shift speed reduction control is performed, drivability may be deteriorated due to a decrease in response of the shift. In this way, the speed reduction control is at least preferentially given to the required output belonging to the range corresponding to the optimum fuel efficiency operating point and not more than the maximum output. Only when the vehicle belongs to (that is, when the output is less than the output corresponding to the optimum fuel consumption operating point, the shift is performed at the normal shift speed), the benefit brought about by the shift speed reduction control is efficiently obtained. It can be enjoyed and is useful in practice.

  In view of the fact that the operating point of the internal combustion engine is controlled to the optimum fuel consumption operating point, the case where the shift speed reduction control is performed at the time of deceleration is preferably during the execution period of the shift speed reduction control (notably, This corresponds to the case where a slow deceleration request is made during acceleration.

  In another aspect of the shift control apparatus for a first vehicle according to the present invention, the shift control device further includes actual output specifying means for specifying the actual output of the internal combustion engine, and the shift speed control means includes the specified requested output and The shift speed reduction control is executed so that the shift speed decreases as the deviation from the specified actual output decreases.

  According to this aspect, for example, the actual output specifying means that can take the form of various processing units such as an ECU, various controllers or various computer systems such as a microcomputer device, for example, numerical calculation based on the product of the engine rotational speed and the output torque The actual output representing the output of the internal combustion engine at that time is specified through the above.

  Here, the shift speed reduction control according to the present invention is typically not executed in a situation where the required output is larger than the maximum output (however, as a whole, compared with the shift speed in a situation where the required output is larger than the maximum output). As long as it decreases, the shift speed in a situation where it is larger than the maximum output does not necessarily take a fixed value), and therefore the shift speed may change discontinuously with the maximum output as a boundary. On the other hand, in order to reduce the uncomfortable feeling caused by such discontinuity of the shift speed, the degree of decrease in the shift speed, for example, the decrease amount and the decrease rate with respect to the reference shift speed, are actually realized. If it is suppressed to such an extent that it does not occur, there is a possibility that the benefits brought about by the shift speed reduction control, such as suppressing the deterioration of drivability, may not be fully enjoyed.

  Therefore, according to this aspect, according to the deviation between the actual output as the output of the internal combustion engine and the requested output at the present time, more specifically, the shift speed reduction control is performed so that the shift speed is greatly reduced as the deviation is smaller. Therefore, the benefits of the relative improvement in torque feeling (ie, improved drivability) brought about by the decrease in inertia torque accompanying the decrease in shift speed, and the discontinuity in shift speed with the maximum output as the boundary The benefits associated with suppressing the sense of incongruity caused by gender are compatible with each other and are useful in practice.

  Note that “so that it decreases as the value decreases” does not necessarily mean that the speed change continuously changes, but in advance, experimentally, empirically, theoretically, or based on simulation, etc. The shift speed may be changed step by step so that the shift speed is not changed finely to the extent that the sensitivity of the vehicle is exceeded, and the shift speed is not changed roughly to such an extent that the driver can feel the step of the shift speed. It is the purpose. That is, as a whole, as long as the increase / decrease of the shift speed can correspond to the magnitude of the deviation, the control mode of the shift speed control means can take various modes.

  Further, the value of the shift speed according to the deviation between the actual output and the required output may be variable according to the engine speed, for example. For example, when the internal combustion engine is controlled to operate at an optimal fuel consumption operating point or an operating point equivalent thereto, the actual output and the maximum output in a relatively high output region (generally coincides with the high rotation region). Deviation, i.e., the maximum deviation tends to be small, and if the shift speed is simply determined according to the deviation itself, the discontinuity described above may not be sufficiently resolved. In such a case, for example, the shift speed may be determined continuously or stepwise according to the ratio of the deviation to the maximum deviation. Such control of the shift speed also means that the shift speed decreases as the deviation becomes smaller if one engine rotation speed is observed, and belongs to the category of this aspect.

  In order to solve the above-described problems, a second vehicle shift control device according to the present invention includes an internal combustion engine and an input that is rotatably coupled to the engine output shaft of the internal combustion engine as the engine output shaft rotates. An output shaft connected to the shaft and the axle so as to rotate in accordance with the rotation of the axle, and between an input rotational speed representing the rotational speed of the input shaft and an output rotational speed representing the rotational speed of the output shaft A shift control apparatus for a vehicle including a transmission capable of continuously changing a gear ratio, the request output specifying means for specifying a driver's request output, and based on the specified request output Setting means for setting a target input rotation speed representing a target value of the input rotation speed, and shift control means for performing a shift by controlling the transmission so that the input rotation speed becomes the set target input rotation speed And the identified request Is less than or equal to the WOT output defined based on the current engine rotation speed of the internal combustion engine and the WOT torque of the internal combustion engine at the current engine rotation speed, the specified required output is the WOT output. Shift speed control means for executing a shift speed reduction control defined as reducing the shift speed related to the shift as compared with the case where the output is larger than the output.

  According to the second vehicle shift control device of the present invention, the required output is equal to or less than the WOT output by the shift speed control means, as in the above-described form of the first vehicle shift control device of the present invention. In some cases, shift speed reduction control is executed. Therefore, torque loss due to inertia torque is reduced, and deterioration of drivability of the vehicle can be effectively and effectively suppressed. The second vehicle shift control device according to the present invention is similar to the above-described various aspects related to the first vehicle shift control device according to the present invention (ie, “maximum output” and “WOT output”). Various aspects can be taken (by associating each other).

  Such an operation and other advantages of the present invention will become apparent from the embodiments described below.

Various preferred embodiments of the present invention will be described below with reference to the drawings.
<First Embodiment>
<Configuration of Embodiment>
First, the configuration of the vehicle 10 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic configuration diagram conceptually and schematically showing a main part configuration of the vehicle 10 corresponding to the transmission control apparatus for a vehicle according to the present invention.

  In FIG. 1, a vehicle 10 includes an ECU 100, an engine 200, a torque converter 300, and a CVT 400.

  The ECU 100 is an electronic control unit that includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and controls the entire operation of the vehicle 10. It is an example of “apparatus”. The ECU 100 is configured to execute a shift control process to be described later according to a control program stored in the ROM.

  The engine 200 is a gasoline engine configured to function as a power source for the vehicle 10. Here, the detailed configuration of the engine 200 will be described with reference to FIG. FIG. 2 is a schematic diagram of the engine 200. In the figure, the same reference numerals are given to the same portions as those in FIG. 1, and the description thereof will be omitted as appropriate.

  In FIG. 2, an engine 200 causes an air-fuel mixture to explode by an ignition operation of an ignition device 202 in which a part of a spark plug that is a part of a cylinder 201 is exposed. The reciprocating motion can be converted into the rotational motion of the crankshaft 205 via the connection rod 204. A crank position sensor 206 that detects the rotational position of the crankshaft 205 is installed in the vicinity of the crankshaft 205. The crank position sensor 206 is electrically connected to the ECU 100, and the ECU 100 is configured to control the ignition timing and the like of the ignition device 202 based on the rotational position of the crankshaft 205 detected by the crank position sensor 206. Has been. Further, the ECU 100 is configured to be able to calculate the engine rotational speed NE of the engine 200 (that is, an example of the “engine rotational speed” according to the present invention) based on the rotational position of the crankshaft 205. Below, the principal part structure of the engine 200 is demonstrated with a part of the operation | movement.

  When the fuel in the cylinder 201 is burned, the air sucked from the outside passes through the intake pipe 207 and is mixed with the fuel injected from the injector 214 at the intake port 213 to become the above-mentioned air-fuel mixture. The fuel is stored in the fuel tank 215 and is pumped and supplied to the injector 214 via the delivery pipe 216 by the action of the low pressure pump 217. The injector 214 is electrically connected to the ECU 100, and is configured to be able to inject the supplied fuel into the intake port 213 according to the control of the ECU 100.

  The communication state between the inside of the cylinder 201 and the intake pipe 207 is controlled by opening and closing the intake valve 218. The air-fuel mixture combusted in the cylinder 201 becomes exhaust gas and is guided to the exhaust pipe 221 via the exhaust port 220 when the exhaust valve 219 that opens and closes in conjunction with opening and closing of the intake valve 218 is opened.

  A cleaner 208 is disposed on the intake pipe 207 to purify air sucked from the outside. An air flow meter 209 is disposed on the downstream side (cylinder side) of the cleaner 208. The air flow meter 209 has a form called a hot wire type, and is configured to be able to directly detect the mass flow rate of the sucked air. The air flow meter 209 is electrically connected to the ECU 100, and the detected mass flow rate of the intake air is grasped by the ECU 100 continuously or at a constant or indefinite period.

  On the downstream side of the air flow meter 209 in the intake pipe 207, a throttle valve 210 configured to be able to adjust the intake air amount related to the air sucked into the cylinder 201 is disposed. The throttle position sensor 212 is a sensor configured to be able to detect the throttle opening degree indicating the open / closed state of the throttle valve 210. The throttle position sensor 212 is electrically connected to the ECU 100, and the detected throttle opening is configured to be grasped by the ECU 100 continuously or at a constant or indefinite period.

  The throttle valve motor 211 is a motor configured to be able to control the physical opening / closing operation of the throttle valve 210. The throttle valve motor 211 is a motor driven by power supply from a drive system (not shown), and the drive system is electrically connected to the ECU 100. Therefore, the drive state of the throttle valve motor 211 is controlled to the upper level by the ECU 100. At this time, the ECU 100 basically controls the drive state of the throttle valve motor 211 so that a throttle opening corresponding to an accelerator opening detected by an accelerator position sensor 13 described later can be obtained.

  The throttle valve 210 is an electronically controlled throttle valve that is driven by the driving force of a throttle valve motor 211 whose operation state is controlled by the ECU 100. The throttle opening is determined by the ECU 100 according to the driver's intention (that is, It can be controlled independently of the accelerator opening).

  A three-way catalyst 223 is installed in the exhaust pipe 221. The three-way catalyst 223 is a catalyst capable of purifying CO (carbon monoxide), HC (hydrocarbon), and NOx (nitrogen oxide) discharged from the engine 200, respectively. An air-fuel ratio sensor 222 is disposed upstream of the three-way catalyst 223 in the exhaust pipe 221. Air-fuel ratio sensor 222 is configured to be able to detect the air-fuel ratio of engine 200 from the exhaust gas exhausted through exhaust port 220. The air-fuel ratio sensor 222 is electrically connected to the ECU 100, and the detected air-fuel ratio is grasped by the ECU 100 constantly or at a constant or indefinite period.

  Returning to FIG. 1, the CVT 300 includes two pulleys, and the gear ratio can be continuously changed by changing the groove width of the V groove for winding the endless belt in each pulley. 1 is an electronically controlled automatic transmission that is an example of a “transmission” according to the present invention that is configured to be possible. The configuration of the CVT 300 will be described in detail later with reference to FIG.

  The vehicle 10 further includes a differential 11, a left axle SFL, a right axle SFR, a left front wheel FL, a right front wheel FR, a vehicle speed sensor 12, an accelerator opening sensor 13, and an accelerator pedal 14.

  The differential 11 is a differential gear connected to an output rotation shaft 340, which will be described later, of the CVT 300, and is configured to be able to absorb a rotational difference between the left front wheel FL and the right front wheel FR that are driving wheels and steering wheels. Yes. The differential 11 is configured to be able to decelerate the rotation speed of the output rotation shaft 340 of the CVT 300 (that is, an example of the “output rotation speed” according to the present invention) according to a specific final reduction ratio.

  The left axle SFL and the left axle SFR are rotary shafts connected to the left front wheel FL and the right front wheel FR, respectively, and are configured to be connected to the differential 11. Therefore, in the vehicle 10, the power generated from the engine 200 is transmitted to the left and right front wheels as drive wheels via the crankshaft 205, the CVT 300, the differential 11 and the left and right axles.

  The vehicle speed sensor 12 is a sensor configured to be able to detect the vehicle speed V of the vehicle 10. The vehicle speed sensor 12 is electrically connected to the ECU 100, and the detected vehicle speed V is grasped by the ECU 100 constantly or at a constant or indefinite period.

  The accelerator opening sensor 13 is a sensor configured to be able to detect an accelerator opening Acc that represents the amount of depression of the accelerator pedal 14 that can be depressed by the driver. The accelerator opening sensor 13 is electrically connected to the ECU 100, and the detected accelerator opening Acc is grasped by the ECU 100 constantly or at a constant or indefinite period.

  Here, a detailed configuration of the CVT 300 will be described with reference to FIG. FIG. 3 is a schematic configuration diagram conceptually and schematically showing the configuration of the CVT 300. In the figure, the same reference numerals are given to the same portions as those in FIGS. 1 and 2, and the description thereof is omitted as appropriate.

  3, the CVT 300 includes a power transmission unit 310, an input rotation shaft 320, a transmission unit 330, an output rotation shaft 340, and a hydraulic pressure control unit 350.

  The power transmission unit 310 is connected to the above-described crankshaft 205 of the engine 200, and is a unit for transmitting the rotational power generated by the engine 200 to the input rotation shaft 320. The torque converter 311, the lockup clutch 312, the shaft 313, A forward / reverse switching device 314 is included.

  The torque converter 311 has a pump impeller 311a connected to the crankshaft 205 and a turbine runner 311b connected to the shaft 313, and fluid (for example, ATF) moves between the pump impeller 311a and the turbine runner 311b. It is configured to be able to perform power transmission by energy. The torque converter 311 is configured to amplify the transmitted torque when the lock-up clutch 312 is released.

  The lock-up clutch 312 is a friction engagement means configured to enable power transmission by a friction force between the crankshaft 205 and the shaft 313. When the lockup clutch 312 is engaged, the engine rotational speed NE of the engine 200 matches the input rotational speed Vin, which is the rotational speed of the input rotational shaft 320.

  The forward / reverse switching device 314 is configured such that the input rotation shaft 320 is connected to the output side and the shaft 313 is connected to the input side, and the rotation direction of the input rotation shaft 320 relative to the shaft 313 can be switched between forward and reverse. Planetary gear unit. The forward / reverse switching device 314 includes a planetary gear mechanism having three rotating elements that can be differentially rotated, a brake that stops rotation of the rotating elements of the planetary gear mechanism, and a clutch that selectively connects the rotating elements. Thus, the rotation direction of the input rotation shaft 320 with respect to the rotation direction of the shaft 313 is switched according to the state of engagement and release of the brake and clutch.

  An input rotation shaft (also referred to as a primary shaft) 320 is a rotation shaft as an example of the “input shaft” according to the present invention. The input rotation shaft 320 has a shaft body that can rotate as the shaft 313 rotates, and the input rotation speed Vin, which is the rotation speed, has at least a unique relationship with the engine rotation speed NE of the engine 200.

  The transmission unit 330 includes a drive pulley (also referred to as a primary pulley) 331, an endless belt 332, a driven pulley (also referred to as a secondary pulley) 333, a hydraulic actuator 334, and rotation sensors 335 and 336. It is a unit that defines the gear ratio physically and mechanically. The driving pulley 331 and the driven pulley 333 are arranged with their central axes parallel to each other and at a predetermined interval.

  The drive pulley 331 rotates integrally with the input rotary shaft 320 and is fixed in the axial direction, and the movable pulley piece is configured to rotate integrally with the input rotary shaft 320 and operate in the axial direction. 331b. A hydraulic actuator 334 for operating the movable pulley piece 331b in the axial direction is provided on the back side of the movable pulley piece 331b. The hydraulic actuator 334 further includes a hydraulic chamber (not shown) that applies axial thrust to the movable pulley piece 331b. On the other hand, the opposed surfaces of the fixed pulley piece 331a and the movable pulley piece 331b form a tapered surface having a constant taper angle, and the tapered surface makes a V-shaped groove (hereinafter referred to as “V groove” as appropriate). ") Is formed. The drive pulley 331 is configured to be able to change the groove width related to the V-groove.

  On the other hand, the driven pulley 333 rotates integrally with the output rotation shaft 340 and is fixed in the axial direction, and a movable pulley piece that rotates integrally with the output rotation shaft 340 and operates in the axial direction. 333b. A hydraulic actuator (not shown) for operating the movable pulley piece 333b in the axial direction is provided on the back side of the movable pulley piece 333b. The hydraulic actuator further includes a hydraulic chamber that applies axial thrust to the movable pulley piece 333b. On the other hand, the opposing surfaces of the fixed pulley piece 333a and the movable pulley piece 333b form a tapered surface with a constant taper angle, and a V-groove is formed by the tapered surface in the same manner as the drive pulley 331. .

  The endless belt 332 is a metal and endless belt configured to be able to transmit power between the driving pulley 331 and the driven pulley 333. The endless belt 332 has a configuration in which a large number of metal pieces sandwiched in the V-grooves of the pulleys described above are arranged in an annular shape, and these metal pieces are bound by an annular metal band called a hoop. Have.

  In such a configuration, the total length of the endless belt 332 is limited by the hoop. Therefore, when the endless belt 332 is sandwiched between the pulleys, the taper surface (inclined surface) of the V-groove acts to push the endless belt 332 radially outward, and as a result, tension is applied to the endless belt 332. In addition, contact pressure between the endless belt 332 and each pulley is generated, and torque is transmitted between the endless belt 332 and each pulley by a frictional force determined by the contact pressure and the friction coefficient. The clamping pressure defined as the pressure for clamping the endless belt 332 is controlled according to the hydraulic pressure in the hydraulic chamber of a hydraulic actuator (not shown) on the driven pulley 333 side, for example.

  On the other hand, when the pressure sandwiching the endless belt 332 in either one of the pulleys is relatively increased or decreased, the endless belt 332 is radially outward by the one pulley against the tension of the endless belt 332. Or the other pulley, the endless belt 332 enters the inside in the radial direction, or is pushed out in the radial direction. As a result, a change in the winding radius of the endless belt 332 occurs, and the shift is executed. At this time, for example, by controlling the flow rate of the hydraulic oil supplied to the hydraulic chamber of the hydraulic actuator on the drive pulley 331 side, the gear ratio related to the gear shift is controlled. As described above, the shift in the CVT 300 is executed by changing the above-described groove width in the drive pulley 331 and changing the winding radius of each endless belt 332 around each pulley.

  The rotation sensor 335 is a sensor configured to be able to detect the rotation speed of the input rotation shaft 320, that is, the input rotation speed Vin. The rotation sensor 335 is electrically connected to the ECU 100, and the detected input rotational speed Vin is grasped by the ECU 100 constantly or at a constant or indefinite period.

  The rotation sensor 336 is a sensor configured to be able to detect the rotation speed of the output rotation shaft 340, that is, the output rotation speed Vout. The rotation sensor 336 is electrically connected to the ECU 100, and the detected output rotation speed Vout is grasped by the ECU 100 constantly or at a constant or indefinite period.

  The hydraulic control unit 350 is a control unit for controlling the hydraulic pressure of the hydraulic oil supplied to the hydraulic chamber of the hydraulic actuator 334 on the drive pulley 331 side, and is an upshift arranged in parallel to the hydraulic chamber. A control valve 351 and a downshift control valve 353 are provided.

  The upshift control valve 351 is a valve that controls the supply of hydraulic oil to the hydraulic chamber of the hydraulic actuator 334 on the drive pulley 331 side, and is operated by a signal output from the first solenoid 352 that is electrically connected. It is configured. Specifically, the upshift control valve 351 is configured to supply hydraulic oil to the hydraulic chamber of the hydraulic actuator 334 according to the drive duty ratio in the first solenoid 352.

  The downshift control valve 353 is a valve for discharging hydraulic oil from the hydraulic chamber of the hydraulic actuator 334, and is configured to operate according to a signal output from the second solenoid 354. Specifically, the downshift control valve 353 is configured to discharge hydraulic oil from the hydraulic chamber of the hydraulic actuator 334 in accordance with the drive duty ratio in the second solenoid 354.

  The power transmission unit 310 and the hydraulic control unit 350 are electrically connected to the ECU 100, respectively, and their operating states, for example, the engagement state of the lockup clutch 312, the switching state of the forward / reverse switching device 314, and the first solenoid. The drive duty ratio and the like in each of 352 and second solenoid 354 are controlled by ECU 100. For example, the ECU 100 determines whether or not a shift is necessary based on input signals such as the accelerator opening Acc, the vehicle speed V, and the engine speed NE, and based on the necessity of the shift, the first solenoid 352 and the second solenoid. A driving duty ratio for controlling the energization state of 354 is calculated, and a control signal corresponding to the driving duty ratio is output. The ECU 100 is also configured to control the above-described clamping pressure generated when the driven pulley 333 clamps the endless belt 332 and to control the transmission torque capacity in the CVT 300.

  Under such a configuration, the CVT 300 causes the ECU 100 to control the target gear ratio or the target input rotational speed Vina (uniquely, the target engine speed of the engine 200 based on the traveling state of the vehicle such as the accelerator opening Acc and the vehicle speed V. Speed) is set, and the transmission gear ratio (that is, the ratio between the output rotation speed Vout and the input rotation speed Vin) or the input rotation speed Vin is controlled to match the target value. At this time, the first solenoid 352 or the second solenoid 354 outputs a signal corresponding to the drive duty ratio input from the ECU 100, whereby hydraulic oil is supplied from the upshift control valve 351 to the hydraulic actuator on the drive pulley 331 side. Then, an upshift is executed. Upshift refers to controlling the CVT300 gear ratio to the decreasing side. In contrast, the hydraulic oil is discharged from the hydraulic actuator via the downshift control valve 353, and the downshift is executed. Downshift refers to controlling the gear ratio of CVT 300 to the increasing side. Note that the gear ratio of the CVT 300 can be controlled to be substantially constant by controlling the upshift control valve 351 and the downshift control valve 353.

  The hydraulic control unit 350 is also provided with a solenoid valve for controlling the engagement state (that is, the engagement and disengagement state) of the lockup clutch 312, but the illustration is omitted.

<Operation of Embodiment>
<Basic shift control of CVT300>
The CVT 300 is controlled by the ECU 100 through, for example, control of the hydraulic control unit 350 and operation of the hydraulic actuator 334 (supply and discharge of hydraulic oil) so that the input rotational speed Vin converges to the target input rotational speed Vina. Is done. This target input rotation speed Vina is determined based on a shift map MPVIN stored in advance in the ROM. Here, the details of the shift map MPVIN will be described with reference to FIG. FIG. 4 is a schematic configuration diagram conceptually showing the shift map MPVIN.

  In FIG. 4, the target input rotational speed Vina is determined using the vehicle speed V and the accelerator opening Acc as parameters. More specifically, the target input rotational speed Vina increases as the vehicle speed increases and the accelerator opening Acc increases. Further, the target input rotational speed Vina has an upper limit value and a lower limit value that are determined according to the vehicle speed V, and are respectively defined by an upper limit guard line UPL and a lower limit guard line LWL shown in the drawing. The ECU 100 sets the target input rotation speed Vina by selectively acquiring values corresponding to the vehicle speed V and the accelerator opening Acc detected by the vehicle speed sensor 12 and the accelerator opening sensor 13 from the shift map MPVIN. .

  On the other hand, the engagement state of the lockup clutch 312 is performed based on the clutch control map MPCL stored in the ROM of the ECU 100. Here, the details of the clutch control map MPCL will be described with reference to FIG. FIG. 5 is a schematic configuration diagram conceptually showing the clutch control map MPCL.

  As shown in FIG. 5, the engagement state of the lockup clutch 312 is determined using the accelerator opening Acc and the vehicle speed V as parameters. More specifically, the ECU 100 controls the hydraulic pressure control unit 350 so that the lock-up clutch 312 is released when the position on the map defined by the vehicle speed V and the accelerator opening Acc at that time belongs to the illustrated release region. In addition, the hydraulic control unit 350 is controlled so that the lockup clutch 312 is engaged when it belongs to the illustrated engagement region.

  The target input speed Vina of the CVT 300 is determined based on the above-described shift map MPVIN. The target input speed Vina is set so that the fuel consumption of the engine 200 is the best. Here, if the operating point MV is defined as a combination of the engine rotational speed NE and the output torque Tr of the engine 200, the target input rotational speed Vina can minimize the fuel consumption rate determined by the engine 200 for each output P of the engine 200. It is set to operate at an operating point (hereinafter, referred to as “fuel efficiency minimum operating point” as appropriate). The fuel efficiency minimum operating point is an example of the “optimum fuel efficiency operating point” according to the present invention.

  Here, the fuel efficiency minimum operating point will be described with reference to FIG. FIG. 6 is a schematic diagram of an operating point map MPMV that defines a minimum fuel efficiency operating point.

  In FIG. 6, the minimum fuel consumption rate operating point in the engine 200 can be expressed as an operating point map on a two-dimensional coordinate plane in which the output torque Tr and the engine rotational speed NE are arranged on the vertical axis and the horizontal axis, respectively. The fuel efficiency minimum operating point is an operating point that is experimentally determined in advance for each output P. FIG. 4 shows an operating point MV1 (corresponding to the output P = PWR1 and taking the engine speed NE1 and the output torque Tr1). Operating point MV2 (corresponding to output P = PWR2 (PWR2> PWR1), taking engine speed NE2 (NE2> NE1) and output torque Tr2 (Tr2> Tr1)), operating point MV3 (output P = PWR3 (PWR3>) Corresponding to PWR2), engine speed NE3 (NE3> NE2) and output torque Tr3 (Tr3> Tr2) are adopted, and operating point MV4 (output P = PWR4 (PWR4> PWR3)), engine speed NE4 ( NE4> NE3) and output torque Tr4 (Tr4> Tr3) are adopted).

  Actually, the minimum fuel consumption rate operating point is more precisely defined in accordance with the output P of the engine 200. By connecting all the fuel consumption rate minimum operating points, an operation line that minimizes the fuel consumption rate, that is, shown in the figure. An optimal fuel consumption line MVsfc can be defined. The ECU 100 controls the engine 200 and the CVT 300 so that the engine 200 operates at any operating point on the optimum fuel consumption line MVsfc in accordance with a request output Pt described later. That is, when the required output Pt is determined, the ECU 100 controls the engine rotational speed NE through the control of the input rotational speed Vin (the target input rotational speed Vina is a value corresponding to the engine rotational speed NE at the optimum fuel efficiency operating point). The throttle opening degree of the throttle valve 210 is controlled so that an output torque corresponding to the optimum fuel consumption operating point is obtained. As a result, the fuel efficiency of engine 200 is maintained as optimal as possible. Note that the ECU 100 previously stores data corresponding to the operating point map MPMV (for example, engine speed and output torque data regarding the minimum fuel efficiency operating point) in the ROM (even if the operating point map MPMV itself). Good) I remember.

  The ECU 100 can also use the operating point map MPMV to determine the target input rotation speed Vina of the CVT 300. That is, the engine rotational speed NE has a unique relationship with the input rotational speed Vin, and if the minimum fuel consumption rate operating point corresponding to the required output Pt is determined by the operating point map MPMV, the engine rotational speed NE is inevitably determined. The target value of the output torque Tr can be determined. Therefore, it is possible to set the target input rotational speed Vina, which is the target value of the input rotational speed Vin, based on the target value of the engine rotational speed NE. In the present embodiment, for the purpose of preventing the explanation from becoming complicated, it is assumed that the target input rotational speed Vina set based on the shift map MPVIN coincides with the engine rotational speed NE corresponding to the fuel efficiency minimum operating point. (The lock-up clutch 312 is also fastened). However, the setting mode of the target input rotation speed Vina is not limited to that described here, and appropriate correction may be made in consideration of, for example, transmission loss of the torque converter 311 and response delay of hydraulic oil.

<Details of shift control processing>
By operating the engine 200 at the operating point on the optimal fuel consumption line MVsfc, the engine 200 can basically operate most efficiently. However, when shifting the CVT 300 to change the operating point of the engine 200, for example, During acceleration accompanied by an increase in the engine speed NE, a part of the output torque is lost as an inertia torque (that is, a part of the output torque is used for an increase in the engine speed), and the drivability is reduced by reducing the torque feeling. It may get worse. On the other hand, the required output changes frequently and the amount of change tends to be small. For example, when requesting acceleration / deceleration for maintaining the vehicle speed during steady running, fuel consumption tends to deteriorate due to frequent rotational fluctuations. As a result, the deterioration of drivability may become more obvious. Therefore, in the vehicle 10, the deterioration of the drivability of the vehicle 10 is suppressed by the ECU 100 executing the shift control process. Here, the details of the shift control process will be described with reference to FIG. FIG. 7 is a flowchart of the shift control process.

  In FIG. 7, the ECU 100 calculates a required output Pt (step S101). When calculating the required output Pt, the ECU 100 first acquires the required driving force Ft. The required driving force Ft is a driving force required for the left front wheel FL and the right front wheel FR that are driving wheels. In the ROM of the ECU 100, a driving force map associated with the vehicle speed V and the accelerator opening degree Acc is stored in advance. When acquiring the required driving force Ft, the ECU 100 detects the vehicle speed V and the vehicle speed V detected by the vehicle speed sensor 12. The required driving force Ft is acquired by selectively acquiring a value corresponding to the accelerator opening Acc detected by the accelerator opening sensor 13 from the driving force map. Next, the ECU 100 performs a calculation process “Ft × r × V” based on the required driving force Ft, the vehicle speed V, and the radius r of the driving wheel, and appropriately converts the unit to the result of the calculation process. Finally, the required output Pt is calculated.

  When calculating the required output Pt, the ECU 100 calculates the WOT output Pw (step S102). Here, the WOT torque Pw will be described with reference to FIG. FIG. 8 is another schematic diagram of the operating point map MPMV. In the figure, the same reference numerals are given to the same parts as those in FIG. 6, and the description thereof will be omitted as appropriate.

  The configuration of the operating point map MPMV in FIG. 8 is basically the same as the operating point map MPMV shown in FIG. 6, and a WOT torque line MVwo is added in addition to the optimum fuel consumption line MVsfc. Here, the WOT torque line MVwot is an operating point corresponding to the torque when the throttle valve 210 is controlled to be fully opened for each engine speed NE of the engine 200, that is, the WOT torque Trw (hereinafter referred to as “WOT operation” as appropriate). The operation line is obtained by connecting the points) and represents the physical maximum output (that is, the WOT output) of the engine 200 for each engine speed NE. For example, at the indicated engine speed NE1, the operating point on the optimal fuel consumption line MVsfc (that is, the minimum fuel consumption rate operating point) is MV1, and the operating point on the WOT torque line MVwot is the indicated MVW1 corresponding to the output torque Trw1. is there. That is, at the engine speed NE1, the WOT output of the engine 200 has a value corresponding to “NE1 × Trw1”.

  On the other hand, in the operating point map MPMV, an iso-output line EP obtained by connecting operating points with the same output of the engine 200 can be defined. In FIG. 8, two types of equal output lines EP1 and EP2 respectively corresponding to the outputs PWR1 and PWR2 are shown. Here, in particular, the WOT operating point corresponding to the engine speed NE1 is the operating point on the iso-output line EP2, that is, the WOT output Pw of the engine 200 at the engine speed NE1 is the optimum fuel consumption line at the engine speed NE2. Similar to the output corresponding to the fuel efficiency minimum operating point MV2 on MVsfc, it is PWR2. The ECU 100 previously stores data relating to the WOT operating point (for example, engine speed and output torque (that is, WOT torque) data), that is, data corresponding to the operating point map MPMV shown in FIG. The WOT torque can be specified in accordance with the engine speed NE.

  Returning to FIG. 7, in the process according to step S102, the ECU 100 is based on the WOT torque Trw corresponding to the engine speed NE obtained by time-processing the output signal of the crank position sensor 206 and the engine speed NE ( More specifically, the WOT output Pw is calculated by appropriately performing unit conversion on these products.

  Next, the ECU 100 calculates the optimum fuel consumption output Pc (step S103). As already described, the ECU 100 holds a map (not required to be held individually) corresponding to the operating point map shown in FIGS. 6 and 8 in the ROM, and the engine speed is referred to by referring to the map. It is possible to specify the output torque Tr on the optimum fuel consumption line MVsfc corresponding to NE. Therefore, in the process according to step S103, the ECU 100 can calculate the optimum fuel consumption output Pc by appropriately performing unit conversion on the product of the engine speed NE and the output torque Tr on the optimum fuel consumption line MVsfc.

  When the required output Pt, the WOT output Pw, and the optimum fuel consumption output Pc are calculated by the processing according to steps S101 to S103, the ECU 100 determines whether the required output Pt is equal to or less than the WOT output Pw (step S104). ).

  When the required output Pt is larger than the WOT output Pw (step S104: NO), the ECU 100 controls the engine 200 and the CVT 300 so that the shift is performed at the reference shift speed (step S112). Here, the transmission speed of the CVT 300 is the time change rate of the input rotational speed Vin, and the reference transmission speed is experimentally, empirically, theoretically, or based on simulation or the like in advance. Are determined so that the optimum fuel consumption line MVsfc can be traced to such an extent that practically no deterioration in fuel consumption is manifested.

  Here, when the current engine speed is NE1 described above, the WOT output is PWR2 as shown in FIG. Therefore, for a required output larger than PWR2, a shift is performed at a normal shift speed. For example, when the required output is PWR3 shown in FIG. 6, the engine speed is increased from NE1 to NE3 and the output torque is increased from Tr1 to Tr3 while tracing the optimum fuel consumption line MVsfc (see FIG. 6). For example, the operating point changes while tracing the optimum fuel consumption line MVsfc from the operating point MV1 to the operating point MV3), and the transmission ratio of the CVT 300 and the output torque Tr of the engine 200 are respectively the hydraulic control unit 350 and the throttle opening degree. Controlled through control.

  On the other hand, when the required output Pt is equal to or less than the WOT output Pw (step S104: YES), the ECU 100 determines whether the required output Pt is equal to or greater than the optimum fuel efficiency output Pc (step S105). Here, considering that the operating point of the engine 200 is basically set on the optimum fuel consumption line MVsfc, step S104 is basically a process for determining whether or not an acceleration request is made. In the process of shifting speed reduction control, which will be described later, since the operating point is not necessarily set to the minimum fuel efficiency operating point, it is not always determined in step S104 whether or not there is an acceleration request.

  When the required output Pt is less than the optimum fuel efficiency output Pc (step S105: NO), that is, a remarkable deceleration including a request for deceleration that is typically made in a state where the operating point of the engine 200 is controlled to the minimum operating point of the fuel efficiency rate. When the deceleration is requested, the ECU 100 shifts the process to step S112, and executes the shift process at the normal shift speed as described above.

  When the required output Pt is equal to or greater than the optimum fuel efficiency output Pc (step S105: YES), the ECU 100 indicates the current required output Pt (i) (i is a code that defines a time series, meaning that it is a current value. Is determined to be equal to the request output Pt (i−1) before one detection timing (step S106). When P (t) is equal to P (t-1) (step S106: YES), that is, when there is no change in the required output, the ECU 100 determines whether or not the shift is continuing (step S107). ). When the shift has been completed (including the case where there is no need for the shift originally) (step S107: NO), the ECU 100 returns the process to step S101 and repeatedly executes a series of processes. On the other hand, when shifting is in progress (step S107: YES), the ECU 100 continues shifting while maintaining the shifting speed (step S108), returns the process to step S101, and repeats a series of processes. Note that whether or not the shift has ended is determined based on whether or not the input rotational speed Vin of the CVT 300 has converged to the target input rotational speed Vina.

  On the other hand, when the required output Pt has changed (step S106: NO), the ECU 100 determines whether the required output Pt (i) is larger than the required output Pt (i-1), that is, the required output is increasing. It is determined whether or not there is (step S109). When the required output Pt is increasing (step S109: YES), the ECU 100 executes shift speed reduction control related to the downshift and accelerates the vehicle 10 (step S110). Further, when the required output Pt is decreasing (step S109: NO), the ECU 100 executes shift speed reduction control related to the upshift, and decelerates the vehicle 10 (step S111). In any case, when the required output Pt is equal to or greater than the optimum fuel efficiency output Pc and equal to or less than the WOT output Pw, shift speed reduction control is executed. Here, the shift speed reduction control refers to executing a shift at a shift speed slower than the reference shift speed according to step S112.

  Here, the shift speed can be controlled by controlling the drive duty ratios of the first and second solenoids in the hydraulic control unit 350. That is, qualitatively, if the drive duty ratio is set to be large, the input rotational speed Vin converges in a relatively short time with respect to the target input rotational speed Vina, the speed change speed is increased, and the drive duty ratio is decreased. If set, the input rotational speed Vin converges over a relatively long time with respect to the target input rotational speed Vina, and the shift speed becomes slow. Therefore, the ECU 100 can delay the shift speed with respect to the reference shift speed by setting a small drive duty ratio with respect to the drive duty ratio corresponding to the reference shift speed.

  In this embodiment, it is assumed that the target input rotational speed Vina is unchanged with respect to whether or not the shift speed reduction control is executed. However, as long as the shift speed is decreased, the target input rotational speed Vina is changed. May be.

  Here, the effect of such a shift control process will be described with reference to FIG. FIG. 9 is a timing chart showing time characteristics of the accelerator opening Acc, the required output Pt, and the input rotational speed Vin in the execution process of the shift control process.

  In FIG. 9, the horizontal axis represents time in common, and the vertical axis represents the accelerator opening Acc, the required output Pt, and the input rotation speed Vin of the CVT 300 in order from the top.

  In FIG. 9, in the process of executing the shift control process described above, when the driver depresses the accelerator pedal 14 at time T1, the accelerator opening Acc starts changing from Acc1, and at time T2, Acc2 (Acc2> Acc1 ).

  In this case, as shown in PRF_Pt (see solid line) in the figure, the required output Pt changes while having a unique relationship with the accelerator opening Acc, and changes from the required output PWR1 before time T1 to the required output PWR2 at time T2. To do. Here, before the time T1, the operating point of the engine 200 is controlled to the minimum fuel consumption rate operating point (that is, the operating point MV1) defined on the optimal fuel consumption line MVsfc, and the input rotational speed Vin (engine rotational speed NE). Is equal to NE1. Therefore, the WOT output Pw at time T1 becomes PWR2 as described above. Here, in a period during which a relatively slight acceleration request is made in which the required output Pt is equal to or less than the current WOT output, the processes related to step S104 and step S105 in the shift control process are both “YES”, and the shift speed is increased. Decrease control is executed.

  If the detection cycle of the request output Pt is a period corresponding to, for example, the time T1 to the time T2, the request output Pt changes discontinuously from PWR1 to PWR2 (in this case as well, below the WOT output) Therefore, in actuality, the required output Pt is calculated in a shorter cycle, and the target input rotational speed Vina is constantly obtained during the period from the time T1 to the time T2. , The accompanying control of the input rotational speed Vin and the control of the output torque are performed.

  Here, as a comparative example to be used for comparison with the present embodiment, the time characteristic of the input rotation speed Vin when the shift process according to the reference shift speed is performed is shown as PRF_comp in the drawing (see the one-dot chain line). As shown in PRF_comp, when conforming to the reference shift speed, the input rotational speed Vin increases relatively rapidly as the required output Pt increases, and at time T2 when the required output Pt stabilizes at PWR2, the input rotational speed Vin is also increased. It converges to NE2, which is the value of the engine rotational speed related to the fuel efficiency minimum operating point corresponding to PWR2. Therefore, at time T2, the determination process related to step S107 in the shift control process is “NO”, and the shift is substantially ended. In this case, the average shift speed is a value corresponding to “(NE2−NE1) / (T2−T1)”.

  In contrast to such a comparative example, according to the shift control process according to the present embodiment, if the required output Pt is equal to or less than the WOT output (that is, the illustrated PRF_Pw indicates the characteristic of the WOT output Pw (see the dashed line) As long as it is less than, the shift speed reduction control is executed. As a result, the slope of the illustrated PRF_Vin1 (see the solid line) representing the time characteristic of the input rotational speed Vin becomes gentler than that of PRF_comp according to the comparative example, and when the required output Pt is stabilized at PWR2 at time T2, the input rotation The speed Vin has not yet reached NE2 which is the target input rotation speed Vina. Accordingly, the determination processing related to step S107 in the shift control processing is “YES”, and the input rotational speed Vin is kept until the input rotational speed Vin reaches the engine rotational speed NE2 related to the fuel efficiency minimum operating point MV2 corresponding to the output PWR2. Continue to increase. That is, the shift continues. Following this process, for example, if the input rotational speed Vin reaches NE1 ′ (NE1 <NE1 ′ <NE2) at the time T3 shown in the figure, the speed change speed is “(NE1′−NE1) / (T3−T1)”. ”(Hereinafter referred to as“ speed after decrease control ”), and clearly decreases with respect to the reference shift speed.

  Here, the acceleration request where the required output Pt is equal to or less than the WOT output is often a slight acceleration request for maintaining the vehicle speed, and is inevitably accompanied by frequent and minute accelerator work. As a reflection of such a situation, in FIG. 9, it is assumed that the accelerator opening Acc starts to decrease again at time T3 and decreases to the previous accelerator opening Acc1 at time T4. In this case, the requested output Pt also decreases from RWR2 after time T3, and decreases to the previous PWR1 at time T4.

  On the other hand, as already described, the input rotation speed Vin according to the present embodiment is NE1 'at time T3 due to the shift speed reduction control performed in step S110 in the shift control process. That is, referring to FIG. 8, the operating point of the engine 200 is the minimum fuel consumption rate operating point at the engine speed NE2 from the operating point MVW1 on the WOT torque line MVwo corresponding to the engine speed NE1 on the equal output line EP2. In the section up to MV2, it is controlled to the operating point corresponding to the engine speed NE1 ′.

  Therefore, at time T3, the input rotational speed Vin starts to decrease from NE1 'as the required output Pt decreases. At this time, the required output Pt decreases within the range equal to or greater than the optimum fuel efficiency output Pc at that time (that is, the state in which step S105 in the shift control process is “YES”), and the process related to step S111 in the shift control process Thus, the shift speed reduction control related to the upshift is executed. That is, as a whole, the change characteristic of the input rotation speed Vin according to the present embodiment is moderate, and the fluctuation of the engine rotation speed NE of the engine 200 connected to the input rotation shaft 320 is suppressed. .

  Here, in particular, the magnitude of the inertia torque accompanying the shift in the CVT 300 depends on the shift speed, that is, the change rate of the input rotation speed Vin (uniquely, the change rate of the target input rotation speed Vina), and the shift speed is large. It gets bigger. Therefore, when the shift is performed according to the illustrated characteristic PRF_Vin1, torque loss is suppressed compared to the case where the shift is performed according to the illustrated characteristic PRF_comp according to the comparative example. In terms of sensibility, the comparative example increases the engine speed, that is, realizes the state of “running at the engine output”, whereas in this embodiment, the fluctuation of the engine speed is suppressed and the loss of the output torque Tr is reduced. Reduce and realize “run with torque”. Therefore, according to the present embodiment, the acceleration feeling can be clearly improved as compared with the case where the shift according to the comparative example is performed, which contributes to the improvement of drivability.

  Note that the shift speed when the shift speed reduction control is executed is not limited to the decrease speed according to the present embodiment (that is, the shift speed corresponding to the characteristic PRF_Vin1). Here, with reference to FIG. 10, the aspect which can take the speed change speed is demonstrated. FIG. 10 is another timing chart showing time characteristics of the accelerator opening degree Acc, the required output Pt, and the input rotational speed Vin in the execution process of the shift control process. In the figure, the same reference numerals are given to the same portions as those in FIG. 9, and the description thereof will be omitted as appropriate.

  In FIG. 10, the time characteristic of the input rotation speed Vin is as long as the shift speed can be reduced as compared with the case where the required output Pt is larger than the WOT output Pw (for example, the shift speed defined by PRF_comp described above). , Not limited to the above-described PRF_Vin1. For example, the time characteristic of the input rotational speed Vin may be the illustrated PRF_Vin2 (see the two-dot chain line) or the illustrated PRF_Vin3 (see the broken line). In particular, in the latter case, the change rate of the target input rotation speed Vin is zero, that is, the speed change speed is zero. In this case, unlike the other characteristics, the operating point does not reach the minimum fuel efficiency operating point corresponding to the required output, but as described above, there are many cases where a relatively light acceleration request is accompanied by a deceleration request. , No problem in practice.

Note that when the operating point deviates from the minimum fuel efficiency operating point, the fuel consumption of the engine 200 may decrease when viewed on a regular basis. However, the fluctuation of the engine rotational speed NE in a situation where shift speed reduction control should be executed. In view of the influence of the above, in a transitional manner, the reduction speed reduction control can contribute to the improvement of fuel consumption. At least, the benefits related to improved drivability outweigh the disadvantages related to lower fuel consumption. However, the shift speed should be experimentally, empirically, theoretically or simulated in advance so that fuel efficiency and drivability, which are basically in a trade-off relationship, can be achieved as effectively as possible. Based on this, the operating point of the engine 200 during shifting may be determined as close as possible to the fuel efficiency minimum operating point as long as the deterioration of drivability is not practically manifested.
Second Embodiment
In the first embodiment, the shift speed at the time of execution of the shift speed reduction control is a fixed value, but of course, the shift speed may be variable. Here, a second embodiment of the present invention will be described with reference to FIG. Here, FIG. 11 is a schematic diagram of an operation line of the engine 200 that schematically represents a shift speed determination mode. In the figure, the same reference numerals are given to the same portions as those in FIG. 8, and the description thereof will be omitted as appropriate.

  FIG. 11 shows a state in which the shift speed of the CVT 300 is determined based on the current relative relationship between the engine output P, the WOT output Pw, and the requested output Pt. That is, in the present embodiment, the ECU 100 sets the ratio of the required output Pt when the current output P (here, PWR1) is 0% and the WOT output Pw (here, PWR2) is 100%. Based on this, the shift speed is determined.

  For example, when the operating point where the constant rotation line EP1a corresponding to the required output PWR1a (PWR1 <PWR1a <PWR2) intersects the engine rotational speed NE1 is the illustrated MV1a, the output torque Tr corresponding to the operating point (that is, the required torque) It is assumed that Tr1a (Tr1 <Tr1a <Trw1) shown in the figure is an output torque for outputting the output Pt at the engine speed NE1. If Tr1a is 30% on the scale of the ratio described above, ECU 100 sets the shift speed to 30% of the reference shift speed. Similarly, when the operating point at which the isorotation line EP1b corresponding to the required output PWR1b (PWR1a <PWR1b <PWR2) intersects the engine speed NE1 is the illustrated MV1b, the output torque Tr corresponding to the operating point (that is, Assume that Tr1b (Tr1a <Tr1b <Trw1) shown in the figure is the output torque for outputting the required output Pt at the engine speed NE1. If Tr1b is 70% on the above-described ratio scale, ECU 100 sets the shift speed to 70% of the reference shift speed.

Thus, by setting the shift speed so that the shift speed increases as the deviation from the current engine output increases, control hunting at the WOT operating point is prevented, and the shift speed discontinuity Is resolved. That is, the deterioration of drivability due to newly controlled shift speed is prevented, and more efficient and effective shift is realized.
<Third Embodiment>
In each of the above-described embodiments, the maximum output that defines whether or not to execute the speed reduction control is set as the WOT output Pw. However, the maximum output is not limited to the WOT output. Here, a third embodiment according to the present invention will be described with reference to FIGS. FIG. 12 is a flowchart of the shift control process according to the third embodiment of the present invention. In the figure, the same reference numerals are assigned to the same parts as those in FIG. 7, and the description thereof is omitted as appropriate.

  In FIG. 12, the ECU 100 obtains the upper limit output Pmax after calculating the required output Pt (step S201). Here, the upper limit output Pmax will be described with reference to FIG. FIG. 13 is still another schematic diagram of the operating point map MPMV of the engine 200. In the figure, the same reference numerals are given to the same portions as those in FIG. 8, and the description thereof will be omitted as appropriate.

  In FIG. 13, in the operating point map MPMV, a fuel consumption deterioration region (see the hatched portion in the drawing) is defined in advance as a region where deterioration of the fuel consumption of the engine 200 can manifest. This fuel consumption deterioration area is optimal to such an extent that, for example, experimentally, empirically, theoretically, or based on simulation, it is determined that the disadvantage related to the deterioration of fuel consumption exceeds the profit related to the improvement of drivability. It is a set of operating points that are defined as increasing the degree of deterioration of fuel consumption with respect to fuel consumption on the fuel consumption line MVsfc, and generally exists below the WOT torque line MVwot along the WOT torque line MVwot. The output value corresponding to the operating point that defines the lower limit of the fuel consumption deterioration region is the upper limit output Pmax. For example, for the engine speed NE1, the output corresponding to the illustrated operating point MV1max (ie, greater than PWR1 and The output less than PWR2) is determined as the upper limit output Pmax. The operating point data relating to the fuel efficiency deterioration region is stored in advance as a map in the ROM of the ECU 100, and the ECU 100 selectively acquires the value of the upper limit output Pmax from the map for the current engine speed NE. It is possible.

  Returning to FIG. 12, when the upper limit output Pmax is acquired, it is determined whether or not the required output Pt is equal to or lower than the upper limit output Pmax through the process of calculating the optimum fuel efficiency output Pc as in the first embodiment ( Step S202). The process related to step S202 is the same as the process performed for the WOT output Pw (step S104) in the first embodiment, and when the required output Pt is larger than the upper limit output Pmax (step S202: NO), the speed change is performed. The speed is controlled to the reference shift speed, and when the required output Pt is equal to or lower than the upper limit output Pmax (step S202: YES), the processing after step S105 is executed.

  According to the third embodiment, it is possible to improve drivability while eliminating the possibility of excessive deterioration in fuel consumption at the time of moderate acceleration / deceleration at which shift speed reduction control is to be performed. It is possible to enjoy the profits related to the improvement of efficiency more efficiently and effectively. Further, not only fuel consumption but also a similar region can be defined for the emission amount of the engine 200, for example. Further, these are not mutually exclusive, and it is possible to easily define the fuel consumption deterioration region and the emission deterioration region in advance. In that case, the maximum output for one engine speed NE among the operating points that do not conflict with any region may be set as the maximum output Pmax.

  The present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit or concept of the invention that can be read from the claims and the entire specification. The apparatus is also included in the technical scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram conceptually and schematically showing a main configuration of a vehicle corresponding to a vehicle shift control device according to the present invention according to a first embodiment of the present invention. It is a schematic diagram of the engine in the vehicle of FIG. FIG. 2 is a schematic configuration diagram conceptually and schematically showing a configuration of a CVT provided in the vehicle of FIG. 1. FIG. 4 is a schematic configuration diagram of a shift map used for setting an input rotation speed of the CVT in FIG. 3. FIG. 4 is a schematic configuration diagram of a clutch control map used for determining an engagement state of a lockup clutch in the CVT of FIG. 3. It is a schematic diagram of the operating point map which prescribes | regulates a fuel consumption rate minimum operating point. It is a flowchart of the shift control process performed by ECU. It is another schematic diagram of an operating point map. 6 is a timing chart showing time characteristics of an accelerator opening, a required output, and an input rotation speed in the execution process of the shift control process of FIG. 5. FIG. 6 is another timing chart showing time characteristics of the accelerator opening, the required output, and the input rotation speed in the execution process of the shift control process of FIG. 5. FIG. 10 is a schematic diagram of an operation line according to the second embodiment of the present invention and schematically illustrating a shift speed determination mode. It is a flowchart of the shift control process which concerns on 3rd Embodiment of this invention. It is another schematic diagram of an operating point map.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Vehicle, 100 ... ECU, 200 ... Engine, 210 ... Throttle valve, 300 ... CVT, 310 ... Power transmission part, 320 ... Input rotating shaft, 330 ... Transmission part, 340 ... Output rotating shaft, 350 ... Hydraulic control part.

Claims (6)

An internal combustion engine;
An input shaft rotatably connected to the engine output shaft of the internal combustion engine as the engine output shaft rotates, and an output shaft rotatably connected to the axle according to the rotation of the axle; A transmission control device for a vehicle, comprising: a transmission capable of continuously changing a transmission gear ratio between an input rotation speed representing the rotation speed of the output shaft and an output rotation speed representing the rotation speed of the output shaft. ,
Request output specifying means for specifying the driver's request output;
Setting means for setting a target input rotation speed representing a target value of the input rotation speed based on a predetermined shift condition;
Shift control means for performing a shift by controlling the transmission so that the input rotation speed becomes the set target input rotation speed;
When the specified required output is equal to or less than the maximum allowable output in advance, the shift speed related to the shift is reduced as compared with the case where the specified required output is larger than the maximum output. A shift control device for a vehicle, comprising: a shift speed control means for executing a shift speed reduction control. The maximum output is a WOT output defined based on a current engine rotation speed of the internal combustion engine and a WOT torque of the internal combustion engine at the current engine rotation speed. The vehicle gear shift control device. The setting means is an optimum fuel consumption operation determined according to the output of the internal combustion engine as a fuel efficiency rate of the internal combustion engine, among operating points defined as a combination of engine speed and output torque in the internal combustion engine. The shift control apparatus for a vehicle according to claim 1 or 2, wherein the target input rotation speed is set based on an engine rotation speed corresponding to a point. The shift speed control means is configured to change the shift when the specified required output is not more than the maximum output at the current engine speed of the internal combustion engine and not less than an output corresponding to the optimum fuel consumption operating point. The vehicle speed change control device according to claim 3, wherein speed reduction control is executed. An actual output specifying means for specifying the actual output of the internal combustion engine;
The shift speed control means executes the shift speed reduction control so that the shift speed decreases as the deviation between the specified requested output and the specified actual output decreases. To 5. The vehicle shift control device according to any one of claims 1 to 4. An internal combustion engine;
An input shaft rotatably connected to the engine output shaft of the internal combustion engine as the engine output shaft rotates, and an output shaft rotatably connected to the axle according to the rotation of the axle; A transmission control device for a vehicle, comprising: a transmission capable of continuously changing a transmission gear ratio between an input rotation speed representing the rotation speed of the output shaft and an output rotation speed representing the rotation speed of the output shaft. ,
Request output specifying means for specifying the driver's request output;
Setting means for setting a target input rotation speed representing a target value of the input rotation speed based on a predetermined shift condition;
Shift control means for performing a shift by controlling the transmission so that the input rotation speed becomes the set target input rotation speed;
The specified output is determined when the specified required output is equal to or lower than the WOT output defined based on the current engine speed of the internal combustion engine and the WOT torque of the internal combustion engine at the current engine speed. And a shift speed control means for executing a shift speed reduction control defined as reducing the shift speed related to the shift as compared with a case where the required output is larger than the WOT output. Shift control device.

Images