JP2008202435A - Control device for vehicle equipped with continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for a vehicle equipped with a continuously variable transmission capable of inhibiting drop of driveability and deterioration of practical fuel economy by changing engine sound pressure level proportionally to change of vehicle speed during travel. <P>SOLUTION: The control device controlling speed change ratio of the continuously variable transmission based on target rotation speed of an engine and controlling engine torque based on contents of control of speed change ratio and target output of the engine, is provided with target output calculation means (steps S11 to S13) calculating the target output based on drive demand quantity and vehicle speed, and target rotation speed calculation means (step S14, S15) calculating target rotation speed based on the target output and an engine sound pressure change map predetermined based on relation between engine torque and engine rotation speed with which sound pressure level of engine sound generated when the engine is operated proportionally changes with corresponding to change of vehicle speed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle control device equipped with a continuously variable transmission capable of continuously changing a gear ratio.

  Recently, the rotational speed of an internal combustion engine (engine) for a vehicle such as a gasoline engine diesel engine has been controlled to a rotational speed at which the fuel consumption is optimum (minimum) by a continuously variable transmission connected to the output side thereof. ing. This is due to the fact that the output torque of the engine can be electrically controlled by an electronic throttle valve or the like, in addition to continuously changing the gear ratio in the continuously variable transmission. Therefore, in vehicles equipped with continuously variable transmissions, shift control with an emphasis on fuel efficiency is widely performed. For example, the required driving force is obtained based on the required driving amount represented by the accelerator opening and the vehicle driving state such as the vehicle speed, and the target output is obtained based on the required driving force and the vehicle driving state. Then, a target engine speed (input speed of the continuously variable transmission) that provides the optimum fuel consumption for the target output is calculated, and the continuously variable transmission is controlled so as to achieve the target engine speed. On the other hand, a target output torque of the engine is obtained based on the target output, and an output control device such as an electronic throttle valve is controlled so as to obtain the target output torque.

  In a vehicle equipped with such a continuously variable transmission, when the vehicle is accelerated by the driver's will, the increased state of the vehicle speed and the increased state of the engine speed may not be proportionally linked. That is, the continuously variable transmission can change the speed ratio to an arbitrary value steplessly. For example, the vehicle speed may increase even if the engine speed is constant. In addition, so-called engine sound generated in association with combustion and intake / exhaust when the engine is operated changes in sound pressure level depending on the increase / decrease in engine speed. Therefore, as described above, when the vehicle speed increases while the engine speed is constant, only the vehicle speed increases while the engine sound is maintained constant, which may cause the driver to feel uncomfortable. Therefore, conventionally, it has been proposed to output a sound corresponding to the engine sound changed in accordance with fluctuations in engine speed or vehicle speed from a speaker or the like.

  As an example, an electric-to-sound converter that outputs an audible sound (engine sound) with a frequency proportional to the vehicle speed and a sound pressure proportional to the accelerator depression amount or engine speed from a speaker, accelerates the engine at a constant speed. Patent Document 1 discloses an invention relating to a vehicle with a continuously variable transmission configured to allow a driver to recognize an acceleration state even in a region.

  Further, in Patent Document 2, in a vehicle including a vehicle interior sound control device and a continuously variable transmission, when the vehicle speed is equal to or lower than a predetermined value, a sound in a part of a frequency band of an engine-related sound (engine sound) heard by a driver. An invention relating to a vehicle interior sound control device configured to output an output sound with a changed pressure from a speaker to a vehicle interior is described.

  Patent Document 3 discloses that in a vehicle having a continuously variable transmission, an air intake frequency is adjusted by adjusting a muffler frequency of a resonator provided in an engine intake system based on an increase in vehicle speed regardless of fluctuations in engine speed. An invention relating to an engine sound enhancement device configured to increase the sound is described.

Japanese Patent Laid-Open No. 61-278431 Japanese Patent Application Laid-Open No. 2004-74995 JP 2006-83818 A

  As described above, in a vehicle equipped with a continuously variable transmission, the engine speed and engine torque and the transmission ratio of the continuously variable transmission are controlled based on the optimum fuel consumption line of the engine. At this time, for example, at the time of acceleration that requires a large engine torque, that is, when shifting from a low engine torque state to a high engine torque state, for example, as shown in FIG. Immediately shift to a state where the sound pressure level of the engine sound is high. That is, the sound pressure level of the engine sound rises at a stretch without proportionally increasing with respect to the increase in the engine speed and the accompanying increase in the vehicle speed. As a result, the engine speed and vehicle speed increase according to the amount of depression of the accelerator, as in the case of a vehicle equipped with a conventional manual transmission or a stepped automatic transmission. When driving in the image of a state in which the level also increases, the driver feels uncomfortable, leading to a decrease in so-called drivability. In addition, the driver's accelerator operation and the image of the engine sound are different, so the driver may step on the accelerator too much or return the accelerator too much for the appropriate amount of accelerator operation with an emphasis on fuel efficiency. As a result, the actual fuel consumption may deteriorate.

  On the other hand, as in the invention described in each of the above patent documents, the output sound from the speaker simulating the engine sound or the silencing effect of the resonator according to the fluctuations in the engine speed, the vehicle speed, or the required drive amount By increasing or decreasing the intake sound using the engine, the sound equivalent to the engine sound is changed in proportion to the increase in the vehicle speed, and the driver's uncomfortable feeling caused by the increase in the vehicle speed and the increase in the engine sound can be alleviated. it can. However, none of the inventions described in the above-mentioned patent documents change the engine sound itself based on the actual engine operating state, and the actual engine sound change still remains with respect to vehicle speed fluctuations. There is still room for improvement in order to eliminate the drivability and the practical fuel consumption as described above.

  The present invention has been made paying attention to the above technical problem, and in a vehicle equipped with a continuously variable transmission, the sound pressure level of the engine sound is changed in proportion to the change in the vehicle speed during traveling. Thus, an object of the present invention is to provide a control device that can prevent or suppress a decrease in drivability and a deterioration in practical fuel consumption.

  In order to achieve the above object, the invention of claim 1 controls the speed ratio of a continuously variable transmission connected to the output side of the engine based on the target rotational speed of the engine, and outputs the output torque of the engine. In a vehicle control device equipped with a continuously variable transmission for controlling the transmission ratio based on the control content of the transmission ratio and the target output of the engine, target output calculation for obtaining the target output of the engine based on the requested drive amount and the vehicle speed And the target output obtained by the target output calculating means, and the sound pressure level of the engine sound generated when the engine is operated changes in proportion to the change in the vehicle speed. Target rotational speed calculation means for determining the target rotational speed based on an engine sound pressure change map set in advance based on the relationship between engine output torque and engine rotational speed; A control device which is characterized in that it comprises.

  According to a second aspect of the present invention, in the first aspect of the invention, the target rotational speed calculation means may cause the engine rotational speed when the engine is operated to change in proportion to the change in the vehicle speed. And an engine speed change map set in advance based on the relationship between the engine output torque and the engine speed, and the target engine speed based on the target output and the engine speed change map. A control device including means for obtaining.

  Further, the invention according to claim 3 is the engine according to claim 2, wherein the target speed calculation means obtains the target speed when the sound pressure level of the engine sound is lower than a predetermined value. The control device includes means for relatively increasing the contribution rate of the engine sound pressure change map with respect to the contribution rate of the rotation speed change map.

  The invention according to claim 4 is the invention according to claim 3, further comprising room sound detection means for detecting room sound in the cab of the vehicle, wherein the target rotational speed calculation means is detected by the room sound detection means. The control device includes means for changing the predetermined value in accordance with a sound pressure level of the room sound.

  According to the first aspect of the present invention, a target output for controlling the engine is obtained based on, for example, a requested drive amount and a vehicle speed set according to the driver's accelerator operation. An engine set in advance based on the relationship between the target output and the engine output torque and the engine speed under the condition that the sound pressure level of the engine sound increases proportionally as the vehicle speed increases. From the sound pressure change map, a target engine speed for controlling the running state of the vehicle is obtained. Therefore, the sound pressure level of the engine sound can be proportionally changed with respect to the change in the vehicle speed during traveling based on the driver's accelerator operation. As a result, for example, it is possible to improve the drivability by avoiding an uncomfortable feeling to the driver and an inappropriate accelerator operation by the driver due to, for example, an increase in the vehicle speed and an increase in the sound pressure level of the engine sound. As a result, practical fuel consumption can be improved.

  According to the invention of claim 2, in addition to the engine sound pressure change map, the engine output torque and the engine rotation under the condition that the engine speed increases proportionally as the vehicle speed increases. A preset engine speed change map is set based on the relationship with the number. When the continuously variable transmission and the engine are controlled during traveling, the vehicle running state is determined from the target output obtained based on the requested drive amount and the vehicle speed, the engine sound pressure change map, and the engine speed change map. The target engine speed for controlling the engine is obtained. Therefore, the sound pressure level of the engine sound and the engine speed can be changed in proportion to the change in the vehicle speed during traveling based on the driver's accelerator operation. As a result, drivability and practical fuel consumption can be improved more effectively.

  According to the invention of claim 3, when the engine sound is lower than a predetermined sound pressure level when controlling the running state of the vehicle, the engine sound pressure change map for obtaining the target engine speed is calculated. The contribution rate is made larger than the contribution rate of the engine speed change map. That is, the engine sound is higher than a predetermined sound pressure level that is a threshold value for determining the ratio between the contribution rate of the engine sound pressure change map and the contribution rate of the engine speed change map when determining the target engine speed. When the engine speed is low, the engine sound pressure change map is prioritized over the engine speed change map to obtain the target engine speed. In a state where the sound pressure level of the engine sound is low during traveling, the change in the sound pressure level of the engine sound has a greater influence on the driver than the change in the engine speed. For this reason, when the engine sound is lower than the predetermined sound pressure level, the engine sound pressure level is determined with an emphasis on the engine sound pressure change map. In addition, the engine speed can be changed more appropriately.

  According to the invention of claim 4, room sound such as sound and vibration in the driver's cab is detected, and the predetermined sound pressure level (threshold) is changed according to the sound pressure level of the room sound. Therefore, even if the engine sound generation state changes due to, for example, changes in driving conditions or changes in the vehicle over time, the sound pressure level and engine speed of the engine sound are appropriately set against changes in vehicle speed during driving. Can be changed.

  Next, the present invention will be described based on specific examples. First, a drive mechanism including a continuously variable transmission targeted by the present invention will be described. The present invention can be directed to a continuously variable transmission mounted on a vehicle, and the continuously variable transmission includes a belt. It is a belt-type continuously variable transmission as a transmission member, or a toroidal (traction-type) continuously variable transmission that uses a power roller as a transmission member and transmits torque using the shearing force of oil (traction oil). FIG. 9 schematically shows an example of a vehicle drive mechanism including a belt type continuously variable transmission 1, and the continuously variable transmission 1 is connected to an engine via a forward / reverse switching mechanism 2 and a torque converter 3. 4 is connected to the output side.

  The engine 4 is the same as an engine mounted on a general vehicle, and an internal combustion engine such as a gasoline engine, a diesel engine, or a natural gas engine can be adopted.

  The torque converter 3 connected to the output shaft of the engine 4 has the same structure as that of a conventional torque converter used in general vehicles, and a pump impeller 6 is connected to a front cover 5 to which the output shaft of the engine 4 is connected. A turbine runner 7 that is integrated and faces the pump impeller 6 is disposed adjacent to the inner surface of the front cover 5. The pump impeller 6 and the turbine runner 7 are provided with a large number of blades (not shown). The pump impeller 6 rotates to generate a fluid spiral flow. The spiral runner 7 The turbine runner 7 is rotated by applying torque to the turbine runner 7.

  Further, a stator 8 that selectively changes the flow direction of the fluid fed from the turbine runner 7 and flows into the pump impeller 6 between the pump impeller 6 and the turbine runner 7 on the inner peripheral side thereof. Has been placed. The stator 8 is connected to a predetermined fixing portion 10 via a one-way clutch 9.

  The torque converter 3 includes a lockup clutch 11. The lock-up clutch 11 is arranged in parallel with a substantial torque converter including the pump impeller 6, the turbine runner 7, and the stator 8, and is in a state facing the inner surface of the front cover 5. 7 and is pressed against the inner surface of the front cover 5 by hydraulic pressure, so that torque is directly transmitted from the front cover 5 as an input member to the turbine runner 7 as an output member. The torque capacity of the lockup clutch 11 can be controlled by controlling the hydraulic pressure.

  The forward / reverse switching mechanism 2 is a mechanism that is employed when the rotational direction of the engine 4 is limited to one direction, and outputs the input torque as it is or reversely outputs it. It is configured. In the example shown in FIG. 9, a double pinion type planetary gear mechanism is employed as the forward / reverse switching mechanism 2.

  That is, the ring gear 13 is arranged concentrically with the sun gear 12, and the pinion gear 14 meshed with the sun gear 12 and the pinion gear 14 and another pinion gear 15 meshed with the ring gear 13 are arranged between the sun gear 12 and the ring gear 13. These pinion gears 14 and 15 are held by a carrier 16 so as to rotate and revolve freely. A forward clutch 17 that integrally connects the two rotating elements (specifically, the sun gear 12 and the carrier 16) is provided, and the direction of the torque that is output by selectively fixing the ring gear 13 A reverse brake 18 for reversing is provided.

  The continuously variable transmission 1 has the same configuration as a conventionally known belt-type continuously variable transmission, and has a drive (primary) pulley 19 as an input member and a driven (secondary) as an output member arranged in parallel to each other. Each of the pulleys 20 includes a fixed sheave and a movable sheave that is moved back and forth in the axial direction by hydraulic actuators 21 and 22. Therefore, the groove width of each pulley 19 and 20 is changed by moving the movable sheave in the axial direction, and accordingly, the winding radius of the belt 23 as a transmission member wound around each pulley 19 and 20 (pulley 19, 20 20 effective diameter) changes continuously, and the gear ratio changes steplessly. The drive pulley 19 is connected to a carrier 16 that is an output element in the forward / reverse switching mechanism 2. These pulleys 19 and 20 and the belt 23 constitute a continuously variable transmission.

  The hydraulic actuator 22 in the driven pulley 20 is supplied with a hydraulic pressure (line pressure or its correction pressure) corresponding to the torque input to the continuously variable transmission 1 via a hydraulic pump and a hydraulic control device (not shown). Yes. Therefore, each sheave in the driven pulley 20 sandwiches the belt 23, whereby tension is applied to the belt 23, and a clamping pressure (contact pressure) between the pulleys 19 and 20 and the belt 23 is ensured. . In other words, the torque capacity corresponding to the clamping pressure is set. On the other hand, the hydraulic actuator 21 in the drive pulley 19 is supplied with pressure oil corresponding to the speed ratio to be set, and is set to a groove width (effective diameter) corresponding to the target speed ratio. .

  A driven pulley 20 that is an output member of the continuously variable transmission 1 is connected to a gear pair 24 and a differential 25, and the differential 25 is further connected to left and right drive wheels 26.

  Various sensors are provided to detect the operating state (running state) of a vehicle on which the continuously variable transmission 1 and the engine 4 are mounted. That is, the engine rotation speed sensor 27 that detects the output shaft rotation speed Ne of the engine 4 (the input shaft rotation speed of the lockup clutch 11) Ne and outputs a signal, and the turbine that detects the rotation speed of the turbine runner 7 and outputs the signal. A rotational speed sensor 28, an input shaft rotational speed sensor 29 for detecting the rotational speed Nin of the driving pulley 19 and outputting a signal, an output shaft rotational speed sensor 30 for detecting the rotational speed Nout of the driven pulley 20 and outputting a signal, a driven A hydraulic sensor 31 that detects the hydraulic pressure in the hydraulic actuator 22 on the pulley 20 side and outputs a signal, a wheel speed sensor 32 that detects the rotational speed of the drive wheel 26 and outputs a signal, and the amount of depression of the accelerator pedal by the driver (or Accelerator pedal sensor 33 that detects the angle) and outputs a signal, detects sound and vibration in the driver's cab, Indoor sound sensor 34 for force is provided.

  Control of engagement / release of the forward clutch 17 and reverse brake 18, control of the clamping force of the belt 23, control of torque capacity including engagement / release of the lockup clutch 11, and gear ratio In order to perform the control, a transmission electronic control unit (CVT-ECU) 35 is provided. This electronic control unit 35 is mainly composed of a microcomputer as an example, performs calculations according to a predetermined program based on input data and data stored in advance, and various states such as forward, reverse or neutral, Further, control such as setting of the required clamping pressure and setting of the gear ratio is executed. In addition, an engine electronic control unit (E-ECU) 36 for controlling the engine 4 is provided, and data is communicated between the electronic control units 35 and 36.

  According to the continuously variable transmission 1, the engine speed, which is the input speed, can be controlled steplessly (in other words, continuously), so that the fuel efficiency of a vehicle equipped with the engine speed can be improved. For example, the target driving force is obtained based on the required driving amount represented by the accelerator opening and the vehicle speed, and the target output necessary to obtain the target driving force is obtained based on the target driving force and the vehicle speed. Then, the engine speed for obtaining the target output with the optimum fuel consumption is obtained based on a map prepared in advance. And the gear ratio of the continuously variable transmission 1 is controlled so that it may become the engine speed.

  In order not to impair such an improvement in fuel consumption, the power transmission efficiency in the continuously variable transmission 1 is controlled to a good state. Specifically, the torque capacity of the continuously variable transmission 1, that is, the clamping pressure is such that the target torque determined based on the engine torque can be transmitted and the clamping pressure is as low as possible without causing the belt 23 to slip. Be controlled. For example, in a so-called unsteady traveling state such as when acceleration / deceleration is performed relatively frequently, or when traveling on a rough road with uneven or uneven road surfaces, the clamping pressure is a hydraulic pressure that controls the continuously variable transmission 1. It is set to a relatively high pressure such as the line pressure that is the total source pressure in the system or its correction pressure.

  On the other hand, in steady running conditions such as running on a flat road at a certain speed or above, or in a quasi-steady running condition equivalent to this, the lowest pressure that can transmit input torque without slipping, that is, the limit clamping pressure In order to detect this, the clamping pressure is gradually reduced. The clamping pressure is set to a clamping pressure obtained by adding a predetermined safety factor or a pressure for setting a margin transmission torque for slipping to the detected critical clamping pressure. The clamping pressure in the continuously variable transmission 1 is preferably as low as possible within a range where torque can be transmitted without causing slippage.

  As described above, in a vehicle equipped with the continuously variable transmission 1, when the engine speed and engine torque of the engine 4 and the gear ratio of the continuously variable transmission 1 are controlled based on the optimum fuel consumption line of the engine 4, Conventionally, for example, when a vehicle is accelerated based on a driver's acceleration request, the increase in vehicle speed is proportional to the increase in the sound pressure of so-called engine sound that occurs due to engine combustion and intake / exhaust. There is a state that does not interlock. Therefore, it is difficult for the driver who is operating the accelerator to imagine the relationship between the increase in the vehicle speed and the increase in the sound pressure of the engine sound due to the accelerator operation, or when the driver feels uncomfortable or does not perform the appropriate accelerator operation. was there. Therefore, the control device of the present invention is configured to change the sound pressure level of the engine sound in proportion to the change in the vehicle speed during traveling in a vehicle equipped with the continuously variable transmission 1. A specific example of the control will be described below.

FIGS. 1 to 3 and FIGS. 4 to 8 are flowcharts showing an example of control by the control device of the present invention, and maps used in the control. The routines shown in the flowcharts of FIGS. 1 to 3 are repeatedly executed every predetermined short time.
(First control example)
FIG. 1 is a flowchart for explaining a first control example in the present invention. In FIG. 1, first, the vehicle speed V and the accelerator opening degree θ are read (step S11). The vehicle speed V can be obtained from, for example, the detection value of the wheel speed sensor 32, and the accelerator opening θ can be obtained based on the detection value of the accelerator pedal sensor 33.

  Based on the vehicle speed V and the accelerator opening θ read in step S11, the target driving force Ti for the output shaft of the engine 4, that is, the target driving force Ti required for the input shaft of the continuously variable transmission 1 is obtained. (Step S12). The target driving force Ti can be obtained from a map set in advance corresponding to the change in the accelerator opening θ based on the relationship between the vehicle speed V and the accelerator opening θ as shown in FIG.

Subsequently, based on the vehicle speed V and the target driving force Ti obtained in step S12, a required power Pi required for the engine 4, in other words, a target output Pi for controlling the engine 4 is obtained (step). S13). The target output Pi is obtained from the vehicle speed V and the target driving force Ti.
Pi = V · Ti
Can be calculated as

  Then, the engine sound based on the relationship between the output torque Te of the engine 4 and the engine speed Ne under the condition shown in FIG. 5 where the sound pressure level of the engine sound increases proportionally with the increase of the vehicle speed V. Pressure change map, in other words, an engine sound pressure change map based on the relationship between the output torque Te of the engine 4 and the engine speed Ne so that the sound pressure level of the engine sound changes in proportion to the change in the vehicle speed V Is set (step S14), and based on the engine sound pressure change map and the target output Pi obtained in step S3, the target rotational speed Ni of the output shaft of the engine 4 when the engine 4 is controlled, that is, nothing. A target rotational speed Ni of the input shaft of the step transmission 1 is obtained (step S15).

  When the target output Pi and the target rotational speed Ni are obtained as described above, the engine 4 is controlled based on the target output Pi, and the continuously variable transmission 1 is controlled based on the target rotational speed Ni (step). S16). Thereafter, this routine is once terminated.

  As described above, in the first control example shown in the flowchart of FIG. 1, the target output Pi for controlling the engine 4 is obtained based on the accelerator opening θ and the vehicle speed V. Based on the relationship between the target output Pi and the engine output torque Te and the engine speed Ne under the condition that the sound pressure level of the engine sound increases proportionally as the vehicle speed V increases. From the set engine sound pressure change map, the target rotational speed Ni of the engine 4 when the traveling state of the vehicle is controlled is obtained. Therefore, the sound pressure level of the engine sound can be proportionally changed with respect to the change in the vehicle speed V during traveling based on the accelerator opening θ, that is, the driver's accelerator operation. As a result, for example, the driver feels uncomfortable due to the increase in the vehicle speed V and the increase in the sound pressure level of the engine sound, and an inappropriate accelerator operation by the driver, thereby improving drivability. be able to.

(Second control example)
FIG. 2 is a flowchart for explaining a second control example in the present invention. The control example shown in FIG. 2 is a partial modification of the first control example shown in FIG. 1. The same parts as the first control example shown in FIG. The same reference numerals are assigned and detailed description thereof is omitted.

  2, when the target output (required power) Pi for controlling the engine 4 is obtained from the vehicle speed V and the target driving force Ti in the same manner as in the control example of FIG. 1, the vehicle speed V shown in FIG. The engine sound pressure change map based on the relationship between the output torque Te of the engine 4 and the engine speed Ne under the condition that the sound pressure level of the engine sound increases in proportion to the increase in engine sound, in other words, the engine sound The engine sound pressure change map based on the relationship between the output torque Te of the engine 4 and the engine speed Ne so that the sound pressure level of the engine changes in proportion to the change in the vehicle speed V, and as the vehicle speed V increases. An engine speed change map based on the relationship between the output torque Te of the engine 4 and the engine speed Ne under the condition that the engine speed Ne increases proportionally, in other words, the engine speed Ne changes the vehicle speed V. An engine speed change map based on the relationship between the output torque Te of the engine 4 and the engine speed Ne that changes proportionally in accordance with the engine speed is set (step S21).

Then, the engine 4 is controlled based on the target rotational speed Ni1 obtained from the engine sound pressure change map, the target rotational speed Ni2 obtained from the engine rotational speed change map, and the target output Pi obtained in step S3. The target rotational speed Ni of the output shaft of the engine 4 at the time, that is, the target rotational speed Ni of the input shaft of the continuously variable transmission 1 is obtained (step S22). Here, since the target rotational speed Ni1 and the target rotational speed Ni2 have different characteristics, they cannot be uniquely determined at the same time. Therefore, the target rotational speed Ni is defined by a predetermined coefficient α.
Ni = α · Ni1 + (1-α) · Ni2
Is calculated as That is, the coefficient α is a coefficient for determining the contribution ratio between the target rotational speed Ni1 and the target rotational speed Ni2 when calculating the target rotational speed Ni, and therefore, the target rotational speed obtained from the engine sound pressure change map. When it is desired to place importance on the number Ni1, α is set to a large value with “1” as the upper limit. The lower limit is set to a small value.

  When the target output Pi and the target rotational speed Ni are obtained as described above, the engine 4 is controlled on the basis of the target output Pi as well as on the basis of the target rotational speed Ni as in the control example of FIG. The step transmission 1 is controlled, and then this routine is temporarily terminated.

  As described above, in the second control example shown in the flowchart of FIG. 2, in addition to the engine sound pressure change map described above, the engine speed Ne increases proportionally as the vehicle speed V increases. A predetermined engine speed change map is set based on the relationship between the engine 4 output torque Te and the engine speed Ne. When the continuously variable transmission 1 and the engine 4 are controlled during traveling, the target output Pi obtained based on the accelerator opening θ and the vehicle speed V, the engine sound pressure change map, and the engine speed change map, From this, the target rotational speed Ni of the engine 4 when controlling the running state of the vehicle is obtained. Therefore, the sound pressure level of the engine sound and the engine speed Ne can be changed proportionally with respect to the change in the vehicle speed V during traveling based on the driver's accelerator operation. As a result, drivability can be improved more effectively.

(Third control example)
This third control example is a modification of the second control example shown in FIG. 2 described above, and the target rotational speed obtained from the engine sound pressure change map in steps S21 and S22 in the second control example. When obtaining the target rotational speed Ni from Ni1, the target rotational speed Ni2 obtained from the engine rotational speed change map, and the target output Pi obtained in step S3, the sound pressure level of the engine sound is a predetermined sound pressure level. This is an example of control in which the contribution rate of the target rotational speed Ni1 is increased when the target rotational speed Ni is obtained.

  If the sound pressure level of the engine sound is lower than the predetermined sound pressure level, it is empirically determined that the engine speed does not correspond to the change in the vehicle speed V, which affects the driver (the driver may feel uncomfortable) It has been found that the influence of the sound pressure level of the engine sound on the driver due to the fact that the engine pressure does not correspond to the change in the vehicle speed V is greater. Therefore, in the third control example, when the sound pressure level of the engine sound is lower than the predetermined sound pressure level, the contribution rate of the target rotational speed Ni1 when obtaining the target rotational speed Ni is set to the target rotational speed Ni2. By making the contribution rate relatively large, more appropriate control is performed.

  Specifically, when obtaining the target rotational speed Ni from the target rotational speed Ni1 and the target rotational speed Ni2 in steps S21 and S22 in the second control example, as shown in FIG. In the region L where the level is lower than the predetermined sound pressure level DB0, the coefficient α is made larger than “0.5”. For example, “α = 1” is set. That is, the contribution rate of the target rotational speed Ni1 when determining the target rotational speed Ni is made relatively larger than the contribution rate of the target rotational speed Ni2, and as a result, the target rotational speed Ni1 is emphasized or prioritized. Ni is required.

  The predetermined sound pressure level DB0 set as a threshold value in this control can be set, for example, as a value when the sound pressure level of the engine sound is higher than the sound pressure level of background noise in the cab.

  As described above, in the third control example, when the sound pressure level of the engine sound is lower than the predetermined sound pressure level DB0 when controlling the running state of the vehicle, the target rotational speed Ni of the engine 4 is obtained. The contribution rate of the engine sound pressure change map at the time is larger than the contribution rate of the engine speed change map. In other words, the sound pressure level of the engine sound is a threshold value for determining the ratio between the contribution rate of the engine sound pressure change map and the contribution rate of the engine speed change map when obtaining the target rotation speed Ni of the engine 4. When the sound pressure level DB0 is lower than the engine speed change map, the engine sound pressure change map is prioritized over the engine speed change map to obtain the target engine speed Ni. In a state where the sound pressure level of the engine sound is low during driving, the influence of the engine sound pressure level on the driver is greater than the change of the engine speed, so the engine sound is higher than the predetermined sound pressure level. If the target engine speed Ni of the engine 4 is obtained with an emphasis on the engine sound pressure change map when the engine speed is low, the sound pressure level of the engine sound and the engine speed Ne are more appropriate for changes in the vehicle speed V during travel. Can be changed.

(Fourth control example)
FIG. 3 is a flowchart for explaining a fourth control example in the present invention. The control example shown in FIG. 3 is a partial modification of the second and third control examples described above. The same parts as the second and third control examples shown in FIG. The same reference numerals as those in FIG.

  In FIG. 3, as in the control example of FIG. 2, a target output (required power) Pi for controlling the engine 4 is obtained from the vehicle speed V and the target driving force Ti, and a room sound (darkness) in the cab is obtained. The sound pressure level of (noise) is read (step S31). The sound pressure level of the room sound can be obtained based on the detection value of the room sound sensor 34, for example.

  When the sound pressure level of the room sound is obtained in step S31, the value of the threshold value DB0 is changed based on the sound pressure level of the room sound (step S32). For example, the sound pressure level of the room sound changes according to the traveling environment of the vehicle such as the condition of the traveling road surface and the weather. Further, the engine sound generation state also changes due to changes in the vehicle over time, changes in vehicle state such as in-vehicle state, and the like. Therefore, the control map is fed back by changing the value of the threshold DB0 according to the change of the driving environment, that is, the change of the sound pressure level of the room sound or the change of the vehicle state. Can be learned.

  Then, based on the map in which the threshold value DB0 is changed, the target rotational speed Ni is obtained, and the engine 4 is controlled based on the target output Pi in the same manner as in the control example of FIG. Based on this, the continuously variable transmission 1 is controlled, and then this routine is temporarily terminated.

  As described above, in the fourth control example shown in the flowchart of FIG. 3, room sound such as sound or vibration in the driving room is detected, and the predetermined sound pressure level DB0 is changed according to the sound pressure level of the room sound. Is done. Therefore, for example, even when the generation state of the engine sound changes due to a change in the driving situation or a change with time of the vehicle, the sound pressure level of the engine sound and the engine speed Ne with respect to the change in the vehicle speed V during the driving. Can be changed appropriately.

  Here, the relationship between the above-described specific example and the present invention will be briefly described. Each functional means of steps S11, S12, and S13 described above corresponds to the target output calculation means of the present invention, and steps S14, S15, The functional means C21, S22, and S32 correspond to the target rotational speed calculation means of the present invention. The functional means in step S31 corresponds to the room sound detection means of the present invention.

  The present invention is not limited to the above specific example. In the specific example, the control device for the belt type continuously variable transmission has been described as an example. However, the present invention is not limited to the toroidal continuously variable transmission. The present invention can also be applied to a control device that targets another type of continuously variable transmission such as a machine, and is not limited to the one shown in FIG. For example, the present invention is applied to a control device for a hybrid vehicle that includes an engine and a motor / generator as power sources, and that can continuously output the output torque of the engine as a driving force by controlling the rotation of the motor / generator. You can also

It is a flowchart for demonstrating the 1st control example by the control apparatus of this invention. It is a flowchart for demonstrating the 2nd control example by the control apparatus of this invention. It is a flowchart for demonstrating the 4th example of control by the control apparatus of this invention. It is a figure which shows typically an example of the map used by control in the 1st control example by the control apparatus of this invention. It is a figure which shows typically an example of the map used by control in the 1st control example by the control apparatus of this invention. It is a figure which shows typically an example of the map used by control in the 2nd control example by the control apparatus of this invention. It is a figure which shows typically an example of the map used by control in the 2nd control example by the control apparatus of this invention. It is a figure which shows typically an example of the map used by control in the 3rd control example by the control apparatus of this invention. It is a figure which shows typically an example of the drive system containing the continuously variable transmission made into object by this invention. It is a figure which shows typically the relationship between the optimal fuel consumption line of the conventional continuously variable transmission, and the sound pressure level of an engine sound.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Continuously variable transmission, 4 ... Engine (power source), 33 ... Accelerator pedal sensor, 34 ... Indoor sound sensor, 35 ... Electronic control unit for transmission (CVT-ECU), 36 ... Electronic control unit for engine (E -ECU).

Claims (4)

The transmission ratio of the continuously variable transmission connected to the output side of the engine is controlled based on the target rotational speed of the engine, and the output torque of the engine is controlled based on the control content of the transmission ratio and the target output of the engine. In a vehicle control device equipped with a continuously variable transmission to be controlled,
Target output calculation means for determining the target output of the engine based on the requested drive amount and the vehicle speed;
The engine output such that the target output obtained by the target output calculating means and the sound pressure level of the engine sound generated when the engine is operated change in proportion to the change in the vehicle speed. A continuously variable transmission, comprising: a target rotational speed calculation unit that obtains the target rotational speed based on an engine sound pressure change map set in advance based on a relationship between torque and engine rotational speed. A vehicle control device.   The target rotational speed calculation means is preset based on the relationship between the engine output torque and the rotational speed such that the engine rotational speed when the engine is operated changes proportionally in response to the change in the vehicle speed. 2. The apparatus according to claim 1, further comprising a set engine speed change map, and further comprising means for determining the target speed based on the target output and the engine speed change map. A control device for a vehicle equipped with a step transmission.   The target rotational speed calculation means, when the sound pressure level of the engine sound is lower than a predetermined value, the engine sound pressure change map with respect to the contribution rate of the engine rotational speed change map when obtaining the target rotational speed. The vehicle control device equipped with the continuously variable transmission according to claim 2, further comprising means for relatively increasing the contribution ratio. Further comprising room sound detection means for detecting room sound in the driver's cabin of the vehicle;
The continuously variable transmission according to claim 3, wherein the target rotational speed calculation means includes means for changing the predetermined value in accordance with a sound pressure level of the room sound detected by the room sound detection means. Vehicle control device equipped with.

Images