JP2005061428A - Controller of continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for a continuously variable transmission capable of eliminating the sense of incongruity which the driver feels because the rise in the engine speed with respect to the time axis differs from the rise of the vehicle speed when the driver has operated the accelerator opening to the incremental side and enhancing the fuel economy. <P>SOLUTION: Referring to a fuel economy optimum point searching map, an engine controller 5a determines the engine speed Ne2 and the power Pe2 with which the fuel economy optimizes from the throttle opening TVO. Also the convergence vehicle speed VSP2 at this time is calculated. A transmission controller 6a ties the starting point with the ending point by a straight line, where the ending point consists of a combination of the target input revolving speed Ne2 with the convergence vehicle speed VSP2 while the starting point consists of a combination of the input revolving speed Ne1 stored one cycle before with the vehicle speed VSP1. Controlling the gear ratio R is executed for accomplishing a vehicle speed as to trace the straight line with respect to the rise of the input revolving speed Ne. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to control of a power unit in which a continuously variable transmission such as a V-belt system or a toroidal system and a prime mover composed of an internal combustion engine are combined.
[0002]
[Prior art]
Conventionally, for example, the inventions described in Patent Document 1 and Patent Document 2 are known as inventions for controlling the gear ratio of a continuously variable transmission based on an accelerator operation by a driver.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-141668
[Patent Document 2]
JP 2001-355718 A
[0004]
The control device for a continuously variable transmission described in Patent Document 1 improves speed ratio control and motility to obtain characteristics that minimize the fuel consumption rate based on the accelerator opening and the vehicle speed. It is possible to perform gear ratio control so as to obtain various characteristics, and to control switching between the two using an interpolation coefficient.
[0005]
[Problems to be solved by the invention]
However, the conventional control device has the following problems. In other words, if the accelerator opening degree suddenly increases due to the driver's sudden accelerator operation during the control with the gear ratio that minimizes the fuel consumption rate, the engine speed increases rapidly, Since the vehicle speed increases, the acceleration feeling at the initial stage of acceleration is insufficient.
[0006]
In order to solve this problem, a control device described in Patent Document 2 has been proposed. The control device for a continuously variable transmission described in Patent Document 2 adopts a normal mode shift with emphasis on fuel consumption in the case of a low opening according to the throttle opening TVO of the engine. In that case, the linear mode shift that emphasizes mobility is adopted, and in the linear mode shift, the gear ratio based on the gear ratio immediately before switching to the linear mode is set, thereby eliminating the shortage of acceleration at the initial stage of acceleration. is there.
[0007]
However, in the control device as described in Patent Document 2, since the gear ratio is fixed in the linear mode, the gear ratio suddenly changes to the value of the normal mode immediately after the linear mode is canceled. For example, there is a step in the gear ratio over time, and the driver feels uncomfortable. Further, when releasing the linear mode, it is conceivable that the gear ratio is gradually made asymptotic to the normal mode. However, since the time in the normal mode is reduced, there arises a problem that fuel consumption deteriorates.
[0008]
The present invention proposes a control device for a continuously variable transmission that performs speed ratio control that eliminates a sense of incongruity that is felt by the driver after the entire acceleration range and after the completion of acceleration while placing importance on the fuel consumption rate.
[0009]
[Means for Solving the Problems]
For this purpose, a control device for a continuously variable transmission according to the present invention comprises:
In a control device for a continuously variable transmission that switches a gear ratio of a continuously variable transmission that is drivingly coupled to an engine that is an internal combustion engine,
Based on the driver's accelerator operation and the driving environment of the vehicle, calculate the engine speed that is the best operating point of the fuel consumption rate, the engine speed as the target input speed of the continuously variable transmission,
Based on the driver's accelerator operation and the driving environment of the vehicle, the convergence vehicle speed that is stable at a constant speed after achieving acceleration driving is estimated,
Calculate the target output speed of the continuously variable transmission required to achieve the converged vehicle speed,
The transmission ratio of the continuously variable transmission is set so that the transition is substantially linear from the combination of the input rotation speed and output rotation speed of the continuously variable transmission during acceleration transition to the combination of the target input rotation speed and the target output rotation speed. It is characterized by switching.
[0010]
【The invention's effect】
According to such a configuration of the present invention, in relation to the input rotation speed of the continuously variable transmission, the vehicle speed increases substantially linearly from the vehicle speed before the accelerator increasing operation to the vehicle speed at the constant speed after the accelerator increasing operation without waste. Therefore, it is possible to eliminate the uncomfortable feeling associated with the switching control. Further, the transmission switching control during the acceleration transition can be quickly terminated, and the problem that the fuel consumption deteriorates can be solved.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a simplified plan view showing the overall configuration of a continuously variable transmission including a control device according to an embodiment of the present invention and a drive system from an engine to wheels.
[0012]
A large or small amount of air / fuel mixture is sent to the engine 1 according to the opening of the throttle valve 8, and the engine 1 generates a driving power with a large output or a small output. The throttle drum 9 for adjusting the opening / closing of the throttle valve 8 is mechanically connected to the accelerator pedal 7 via a wire 7w. When the driver depresses the accelerator pedal 7, the throttle valve 8 is opened / closed according to the depression amount. Adjust. As a result, the engine 1 generates a drive power with a large output or a small output according to the accelerator operation of the driver.
[0013]
The engine 1 is drivably coupled to a known V-belt type continuously variable transmission 2 via an input shaft 12 i and transmits drive power to a pump impeller of a torque converter 12 provided in the continuously variable transmission 2. The turbine runner of the torque converter 12 is drivingly coupled to a primary pulley 13 around which a V-belt 15 is stretched through a shaft 12o. On the other hand, the secondary pulley 14 on which the V-belt 15 is stretched is drivingly coupled to the differential gear 3 via the output shaft 14o. The differential gear 3 distributes drive power to the left and right wheels 4 that are partially omitted through the drive shafts 3a and 3b.
[0014]
When the driver depresses the accelerator pedal 7, a throttle sensor 10 provided in the throttle valve 8 detects the opening amount of the throttle valve 8 and transmits a signal of the throttle opening TVO to the engine controller 5. The engine speed sensor 18 provided on the input shaft 12 i detects the speed of the engine 1, that is, the input speed of the continuously variable transmission 2 and transmits it to the transmission controller 6.
[0015]
As part of its function, the engine controller 5 that performs overall control of the engine 1 is based on the throttle opening TVO, and the vehicle operates at a constant speed while maintaining the target input speed tNe with the best fuel consumption rate and the throttle opening TVO. When the vehicle travels at a speed, the convergence vehicle speed tVSP is calculated and output to the transmission controller 6.
[0016]
A vehicle speed sensor 16 provided on the drive shaft 3 a detects the vehicle speed VSP and outputs the vehicle speed VSP to the transmission controller 6.
A transmission controller 6 that performs overall control of the continuously variable transmission 2 outputs a control signal to the hydraulic actuators 13a and 14a to achieve a combination of the target input rotational speed tNe and the convergence vehicle speed tVSP. The gear ratio is continuously switched.
[0017]
The hydraulic actuators 13a and 14a provided on the pulleys 13 and 14 respectively have a V-shaped one of the flanges forming the V-shaped grooves of the pulleys 13 and 14 with one movable flange relatively close to the other fixed flange. The transmission of the continuously variable transmission 2 is executed by narrowing or separating the groove width to widen the V-shaped groove width.
[0018]
FIG. 2 is a functional block diagram showing a control program executed by the engine controller 5a and the transmission controller 6a for executing the above-described shifting. The engine controller 5 a includes a fuel efficiency optimum point calculation unit 51, a gradient resistance estimation unit 52, a convergence vehicle speed estimation unit 53, and a multiplication unit 54. The fuel efficiency optimal point calculation unit 51 stores in advance a fuel efficiency optimal point search map, for example, as shown in FIG. 3, and refers to this map to determine the engine torque Te and engine rotation at which the fuel efficiency is optimal from the throttle opening TVO. The number Ne is obtained. For example, when a driver who desires acceleration traveling depresses the accelerator pedal 7 and performs an accelerator increasing operation, the engine controller 5a determines a new throttle from the throttle opening TVO1 just received before the accelerator increasing operation. The opening degree TVO2 is received. The fuel efficiency optimum point calculation unit 51 refers to the fuel efficiency optimum point search map of FIG. 3 and obtains the engine torque Te2 and the engine speed Ne2 at which the fuel efficiency is optimum from the throttle opening TVO2.
[0019]
The multiplier 54 calculates the product of the engine torque Te2 and the engine speed Ne2, and obtains the power Pe2 that optimizes the fuel consumption.
Pe2 = Te2 × Ne2
The gradient resistance estimator 52 detects the average road surface gradient in the long distance section or the road surface gradient in the short distance section, and the traveling resistance R (independent of the vehicle speed, such as the gradient resistance received when the vehicle travels on the road surface gradient). 0).
[0020]
The convergence vehicle speed estimation unit 53 first obtains a running resistance R (VSP) depending on the vehicle speed, such as rolling resistance of a tire, road surface resistance, and air resistance of a vehicle body, and stores the obtained running resistance R (VSP). In addition, the above R (0) is added together to obtain a vehicle speed-running resistance relationship as shown in FIG. Next, a hyperbolic function Y related to the vehicle speed VSP as shown in FIG. 4 is obtained based on the power Pe2 obtained above.
Y = C × Pe2 / VSP
C is a coefficient determined by the friction coefficient of the tire.
Here, if the power Pe2 is a constant value, the function Y decreases as the vehicle speed VSP increases. The vehicle speed VSP when the total value of the running resistance and the function Y are balanced is defined as a converged vehicle speed VSP2. VSP2 is transmitted to the transmission controller 6.
[0021]
The transmission controller 6 a includes an actual measurement value storage unit 61, a transmission ratio calculation unit 62, and a transmission ratio control unit 63. The actual measurement value storage unit 61 stores the detected and received actual vehicle speed VSP and the engine speed Ne. As shown in FIG. 5, the transmission ratio calculation unit 62 sets a combination of the target input rotational speed Ne2 and the converged vehicle speed VSP2 received from the engine controller 5a on a plane with the vehicle speed on the horizontal axis and the input rotational speed on the vertical axis. Plot as end point. Further, referring to the actual measurement value storage unit 61, the actual vehicle speed VSP stored one time before is VSP1, the engine speed Ne stored one time before is Ne1, and the combination of these values VSP1 and Ne1 is the starting point. Plot on the plane.
[0022]
When the start point and the end point coincide with each other, the current speed ratio R is transmitted to the speed ratio control unit 63 so as to maintain the current speed ratio. The transmission gear ratio R is a linear gradient connecting a point represented by a combination of the origin 0 where the horizontal axis and the vertical axis intersect with the input rotational speed Ne and the vehicle speed VSP.
[0023]
On the other hand, if the origin and the end point do not coincide with each other, the start point and the end point are connected with a straight line as shown by a thick line in FIG. 5, and the input rotational speed Ne and the vehicle speed VSP coincide with the end point along the straight line. Then, a command to change the speed ratio R is transmitted to the speed ratio control unit 63. That is, during the acceleration transition immediately after the accelerator increasing operation and the driver maintains the depression position of the accelerator pedal 7, the input rotational speed of the continuously variable transmission, which is the actual engine rotational speed Ne, is changed from Ne1 to Ne2. In response to the increase, the command to change the speed ratio R is transmitted so that the vehicle speed VSP determined by the output speed of the continuously variable transmission increases from VSP1 to VSP2. For example, when the input rotational speed detected by the engine rotational speed sensor 18 at a certain time during acceleration transition is Nen, a speed ratio R for obtaining a corresponding vehicle speed VSPn with reference to a straight line connecting the start point and the end point, that is, A gradient of a straight line connecting the origin 0 and (VSPn, Nen) is transmitted to the gear ratio control unit 63.
[0024]
The gear ratio control unit 63 outputs a control signal to the hydraulic actuators 13a and 14a based on the received gear ratio command.
[0025]
FIG. 6 is a flowchart showing the control program executed by the engine controller 5a according to the present embodiment. This program is executed by a scheduled interrupt every 10 ms, for example.
In the first step S1, the throttle opening TVO of the throttle 8 is detected.
In the next step S2, based on the throttle opening TVO, an engine torque Te2 and an engine speed Ne2 at which the fuel efficiency is optimized are obtained by referring to a fuel efficiency optimum point search map stored in advance.
In step S3, a vehicle speed dependent running resistance R (VSP) determined based on the vehicle speed VSP, such as an air resistance depending on the shape of the vehicle body and the vehicle speed, is obtained and stored in the convergence vehicle speed estimation unit 53. In step S4, a running resistance R (0) that is unrelated to the vehicle speed, such as a road surface gradient, is calculated. In step S5, a hyperbolic function Y is obtained based on the engine torque Te2 and the engine speed Ne2 at which the fuel efficiency is optimal.
[0026]
In step S6, the intersection of the vehicle speed dependent running resistance R (VSP) and the sum of the running resistance R (0) irrelevant to the vehicle speed and the function Y is obtained by repeated calculation. In step S7, the vehicle speed at the intersection obtained in step S6 is output to the transmission controller 6a as the convergence vehicle speed VSP2. In step S8, the engine speed Ne2 obtained in step S2 is output to the transmission controller 6a.
[0027]
FIG. 7 is a flowchart showing the control program executed by the transmission controller 5a according to the present embodiment. This program is also executed by a scheduled interrupt every 10 ms, for example.
In the first step S9, the target input rotational speed Ne2 and the convergence vehicle speed VSP2 are received, and this combination is read as an end point. In the next step S10, the combination of the actual vehicle speed VSP1 and the input rotational speed Ne1 stored previously is read as the starting point.
[0028]
In step S11, a gear ratio R for increasing the actual vehicle speed VSP is calculated so as to trace the straight line connecting the start point and the end point according to the increase in the input rotational speed Ne. In step S <b> 12, the gear ratio R is output to the gear ratio control unit 63. In step S13, the current vehicle speed VSP and the current input rotational speed Ne are read and stored in memory for use in the next control.
[0029]
Next, another embodiment of the present invention will be described. FIG. 8 is a plan view schematically showing the entire configuration of a continuously variable transmission including a control device according to another embodiment of the present invention and a drive system from the engine to the wheels, and is common to the above embodiment. These parts are denoted by the same reference numerals.
The accelerator pedal 7 is not mechanically connected to the throttle valve 8 and employs a throttle-by-wire system. The accelerator opening sensor 33 detects the operation amount (depression amount) of the accelerator pedal 7 operated by the driver, and transmits the accelerator opening APO to the engine controller 5b.
The throttle control motor 35 receives a command from the engine controller 5b and adjusts the opening of the throttle valve.
[0030]
FIG. 9 is a functional block diagram showing a control program executed by the engine controller 5b and the transmission controller 6b. The transmission controller 6b is almost the same as that shown in FIG. The engine controller 5b that electronically controls the throttle opening of the engine 1 includes a target driving force calculation unit 71, a division unit 72, a fuel efficiency optimum point calculation unit 73, a throttle opening control unit 74, and a gradient resistance estimation unit 52. The vehicle speed estimation unit 53 and the multiplication unit 54 are provided.
[0031]
The target driving force calculation unit 71 stores a search map as shown in FIG. 10 in advance, for example, and refers to this map to obtain the target driving force tF from the accelerator opening APO and the actual vehicle speed VSP.
The convergence vehicle speed estimation unit 53 first stores in advance a running resistance R (VSP) that depends on the vehicle speed, such as tire rolling resistance, road resistance, and air resistance of the vehicle body, or a function of R (VSP) one by one. Then, the above R (0) is added to this to obtain the vehicle speed-running resistance relationship as shown in FIG. Next, the vehicle speed VSP when the total value of the running resistance is equal to the target driving force tF is set as the convergence vehicle speed VSP2. VSP2 is transmitted to the transmission controller 6b.
The multiplier 54 multiplies the convergence vehicle speed VSP2 by the target driving force tF to obtain the convergence power Pw2. The fuel efficiency optimal point calculation unit 73 stores in advance a fuel efficiency optimal point search map as shown in FIG. 12, for example, and refers to the search map to show the equal power line corresponding to the convergence power Pw2 and the performance of the engine 1. The intersection P2 with the fuel efficiency minimum line determined by is obtained. Then, the engine speed Ne2 at the optimum fuel efficiency point P2 is transmitted to the transmission controller 6b.
[0032]
The transmission controller 6 b includes an actual measurement value storage unit 61, a transmission ratio / engine speed calculation unit 82, and a transmission ratio control unit 63. The gear ratio / engine speed calculation unit 82 has a target input speed Ne2 and a converged vehicle speed received from the engine controller 5b on a plane having the horizontal axis as the vehicle speed and the vertical axis as the input speed as shown in FIG. Plot VSP2 combinations as endpoints. Further, referring to the actual measurement value storage unit 61, the actual vehicle speed VSP stored one time before is VSP1, the engine speed Ne stored one time before is Ne1, and the combination of these values VSP1 and Ne1 is the starting point. Plot on the plane.
[0033]
When the start point and the end point coincide with each other, the current speed ratio R is transmitted to the speed ratio control unit 63 so as to maintain the current speed ratio and the engine speed, and the current engine speed is sent to the engine controller 5b. Send.
[0034]
On the other hand, if the origin and the end point do not match, the start point and the end point are connected with a straight line as shown by a thick line in FIG. 13, and the input rotational speed Ne and the vehicle speed VSP are made to match the end point along the straight line. A command to change the gear ratio is transmitted to the gear ratio control unit 63, and an engine speed tNe is transmitted to the engine controller 5b. That is, with reference to a straight line connecting the start point and the end point, in order to achieve a vehicle speed tVSP that is greater than the vehicle speed VSP1 that was previously stored, the engine speed tNe that is greater than the engine speed Ne1 that was previously stored. Is transmitted to the engine controller 5b, and a speed ratio for obtaining the vehicle speed tVSP, that is, a gradient R of a straight line connecting the origin and (tVSP, tNe) is transmitted to the speed ratio control unit 63.
[0035]
FIG. 14 is a flowchart showing the control program executed by the engine controller 5b according to the present embodiment. This program is executed by a scheduled interrupt every 10 ms, for example.
In the first step S21, the detected accelerator opening APO and vehicle speed VSP are read. In the next step S22, the target driving force tF determined from the accelerator opening APO and the actual vehicle speed VSP is obtained by referring to the search map. In step S23, a function of running resistance R (VSP) depending on the vehicle speed is obtained. In step S24, a running resistance R (0) that does not depend on the vehicle speed, such as a gradient resistance, is calculated. In step S25, the vehicle speed VSP2 when the sum of R (VSP) and R (0) is equal to the target driving force tF is calculated.
[0036]
In step S26, the convergence power Pw2 is obtained by multiplying the convergence vehicle speed VSP2 by the target driving force tF. In step S27, an intersection P2 between the equal power line corresponding to the convergence power Pw2 and the fuel efficiency minimum line determined by the performance of the engine 1 is obtained with reference to the fuel efficiency optimum point search map, and the engine speed Ne2 at the fuel efficiency optimum point P2 is obtained. Is output. In step S28, the convergence vehicle speed VSP2 is transmitted to the transmission controller 6b. In step S29, the engine speed Ne2 is transmitted to the transmission controller 6b.
[0037]
FIG. 15 is a flowchart showing the control program executed by the transmission controller 5b according to the present embodiment. This program is also executed by a scheduled interrupt every 10 ms, for example.
In the first step S31, the target input rotational speed Ne2 and the convergence vehicle speed VSP2 of the continuously variable transmission 2 are received, and this combination is read as the end point (VSP2, Ne2). In the next step S32, the combination of the actual vehicle speed VSP and the input rotation speed Ne stored once before the current time is read as the start point (VSP1, Ne1).
[0038]
In step S33, a combination of the engine speed tNe and the vehicle speed tVSP larger than the start point is calculated so as to trace on the straight line connecting the start point and the end point. The relationship of this combination is represented by the following formula.
tNe = Ne1 + (Ne2−Ne1) × (tVSP−VSP1)
/ (VSP2-VSP1)
In step S34, a gear ratio R for achieving the combination (tVSP, tNe) is output. In step S35, the engine speed tNe is transmitted to the engine controller 5b. In step S36, the actual vehicle speed VSP and the current input rotational speed Ne are read and stored in memory for use in the next control.
[0039]
FIG. 16 is a time chart showing the effects of the above-described embodiment of the present invention with respect to the accelerator opening, the vehicle speed, the input rotation speed of the continuously variable transmission, the deviation from the optimum fuel consumption line, and the gear ratio. For comparison, the present invention is indicated by a solid line, the conventional shift described in Patent Document 1 is indicated by a dotted line, and the linear mode shift described in Patent Document 2 is indicated by a one-dot chain line.
[0040]
When the driver depresses the accelerator pedal 7 from time t1 to time t2, in the present invention and the above two conventional examples, the accelerator opening increases substantially from APO1 to APO2. In the present invention and the above two conventional examples, the vehicle speed VSP rises in substantially the same manner while drawing a convex curve upward so as to be the converged vehicle speed VSP2.
[0041]
In the present invention, the input rotational speed Ne of the continuously variable transmission increases while drawing a convex curve upward so as to increase the vehicle speed VSP so that the target input rotational speed Ne2 is reached. And low fuel consumption driving is possible.
On the other hand, in the case of the conventional shift, it can be seen that, similarly to the accelerator opening APO, the vehicle speed increases rapidly in the initial stage and thereafter the vehicle speed VSP slowly increases, which gives the driver a sense of incongruity. In the linear mode shift, the vehicle speed increases while drawing a curve similar to the vehicle speed VSP. However, once the target rotational speed Ne2 is exceeded and the high rotational speed continues for a while, the speed decreases to the target rotational speed Ne2. Worsen.
[0042]
In the present invention, the degree of divergence from the optimum fuel efficiency line deviates greatly from the optimum fuel line until the vehicle speed converges, but does not deviate much after the convergence vehicle speed is achieved. On the other hand, in the linear mode shift, the degree of divergence is large throughout and the fuel efficiency is deteriorated.
[0043]
In the present invention, the gear ratio R gradually changes toward the gear ratio R2 at the converged vehicle speed VSP2, so that the driver does not feel uncomfortable. Further, since the shift transition state is promptly terminated, fuel efficiency can be improved.
On the other hand, in the conventional gear shifting, the gear ratio R is first set to the low gear R4 as the accelerator opening increases, and then the gear shifts to the high gear as the vehicle speed increases. Therefore, the fluctuation range of the gear ratio is large and the driver feels uncomfortable.
Further, in the linear mode speed change, the speed ratio R3 is fixed to the gear ratio R3 slightly lower than the speed ratio R2 at the converged vehicle speed VSP2, but the speed ratio R3 is not a speed ratio that achieves the optimum fuel consumption at the converged vehicle speed VSP2. It is necessary to change the gear ratio to R2 after the linear mode is canceled and shift to the optimum fuel consumption state, and the driver feels uncomfortable.
[0044]
From the above, it can be seen that the present invention, which completes acceleration promptly while reducing the fluctuation range of the gear ratio and has no inferior fuel efficiency, is comprehensively superior.
[0045]
That is, in the present embodiment, based on the throttle opening or the accelerator opening APO, the engine speed Ne2 as the operating point with the best fuel consumption rate and the convergent vehicle speed VSP2 at which the vehicle runs at a constant speed are calculated. The vehicle speed tVSP or the input rotational speed tNe and the vehicle speed tVSP are controlled so as to achieve a substantially linear combination of the converged vehicle speed VSP2 and the target input rotational speed Ne2 from the stored combination of the vehicle speed VSP1 and the input rotational speed Ne1. Therefore, at the time of acceleration, the vehicle speed VSP and the input rotation speed Ne are simultaneously increased to complete the acceleration promptly, and the degree of impairing fuel consumption is small.
[0046]
For this reason, the driver does not feel uncomfortable, can obtain a sense of acceleration with good responsiveness, and can avoid acceleration at the expense of fuel consumption.
[0047]
In the above-described embodiment, the gear ratio is continuously controlled using a V-belt type continuously variable transmission, but in addition to this, even if a toroidal continuously variable transmission is used, the same Of course, there is an effect.
[Brief description of the drawings]
FIG. 1 is a plan view schematically showing an overall configuration of a continuously variable transmission including a control device according to an embodiment of the present invention and a drive system from an engine to wheels.
FIG. 2 is a functional block diagram showing a control program executed by the engine controller and transmission controller 6 provided in the embodiment for executing gear ratio control.
FIG. 3 is a fuel efficiency optimum point search map.
FIG. 4 is a graph showing a vehicle speed-running resistance relationship and a vehicle speed-power relationship used for calculating a converged vehicle speed.
FIG. 5 is a graph showing a gear ratio calculated by the transmission controller according to the embodiment in the relationship between vehicle speed and input rotation speed.
FIG. 6 is a flowchart showing a control program executed by the engine controller according to the embodiment.
FIG. 7 is a flowchart showing a control program executed by the transmission controller according to the embodiment.
FIG. 8 is a plan view schematically showing an overall configuration of a continuously variable transmission including a control device according to another embodiment of the present invention and a drive system from an engine to wheels.
FIG. 9 is a functional block diagram showing a control program executed by the engine controller and the transmission controller provided in the embodiment.
FIG. 10 is a search map.
FIG. 11 is a graph showing a relationship between vehicle speed and running resistance used for calculating a converged vehicle speed.
FIG. 12 is a fuel efficiency optimum point search map.
FIG. 13 is a graph showing a gear ratio calculated by the transmission controller according to the embodiment in the relationship between vehicle speed and input rotation speed.
FIG. 14 is a flowchart showing a control program executed by the engine controller according to the embodiment;
FIG. 15 is a flowchart showing a control program executed by the transmission controller according to the embodiment;
FIG. 16 is a time chart showing the effect of the embodiment with respect to the accelerator opening, the vehicle speed, the input rotation speed of the continuously variable transmission, the deviation from the optimum fuel consumption line, and the gear ratio, together with the conventional example. is there.
[Explanation of symbols]
1 engine
2 continuously variable transmission
3 Differential gear
5 Engine controller
6 Transmission controller
7 Accelerator pedal
8 Throttle valve
9 Throttle drum
10 Throttle sensor
11 Accumulator
12 Torque converter
13, 14 pulley
13a, 14a Hydraulic actuator
16 Vehicle speed sensor
18 Engine speed sensor
33 Accelerator position sensor
35 Throttle control motor
51 Fuel economy optimal point calculation part
52 Gradient resistance estimator
53 Convergence Vehicle Speed Estimator
54 Multiplier
61 Actual value storage
62 Gear ratio calculation unit
63 Gear ratio control unit
71 Target driving force calculation unit
72 Division
73 Fuel Efficiency Optimal Point Calculation Unit
74 Throttle opening controller
82 Gear ratio / engine speed calculator

Claims (6)

In a control device for a continuously variable transmission that switches a gear ratio of a continuously variable transmission that is drivingly coupled to an engine that is an internal combustion engine,
Based on the driver's accelerator operation amount and the driving environment of the vehicle, the engine speed that is the best operating point of the fuel consumption rate is calculated, and the engine speed is set as the target input speed of the continuously variable transmission.
Based on the amount of accelerator operation by the driver and the driving environment of the vehicle, the convergence vehicle speed that is stable at a constant speed after the acceleration is achieved is estimated,
Calculate the target output speed of the continuously variable transmission required to achieve the converged vehicle speed,
The transmission ratio of the continuously variable transmission is set so that the transition is substantially linear from the combination of the input rotation speed and output rotation speed of the continuously variable transmission during acceleration transition to the combination of the target input rotation speed and the target output rotation speed. A continuously variable transmission control device characterized by switching. The control device for a continuously variable transmission according to claim 1,
As the driving environment of the vehicle, the driving resistance based on the vehicle speed and the driving resistance unrelated to the vehicle speed are calculated,
A control device for a continuously variable transmission, wherein a vehicle speed when a driving force based on a sum of both of the running resistances and a driver's accelerator operation amount is balanced is the convergence vehicle speed. 3. The continuously variable transmission control device according to claim 2, wherein the running resistance based on the vehicle speed is calculated based on a rolling resistance of the tire and an air resistance of the vehicle. 4. The continuously variable transmission control device according to claim 2, wherein the running resistance unrelated to the vehicle speed is calculated based on a road gradient. The continuously variable transmission control device according to any one of claims 1 to 4, wherein the driver's accelerator operation amount is mechanically linked to the throttle opening of the engine, and fuel consumption is based on the throttle opening. A control device for a continuously variable transmission, which calculates an engine speed and an engine torque which are operating points having the best rate. The control device for a continuously variable transmission according to any one of claims 1 to 4,
The throttle opening of the engine is controlled independently of the driver's accelerator operation amount, and the required driving force is calculated based on the driver's accelerator operation amount and the vehicle speed immediately before the operation,
Based on the required driving force and the traveling environment of the vehicle, a convergence vehicle speed that is stable at a constant speed after the end of acceleration traveling is estimated,
When maintaining the converged vehicle speed, calculate the engine speed and the engine torque as the operating point with the best fuel consumption rate,
The throttle opening of the engine is controlled so as to achieve the target input torque obtained by dividing the target output torque calculated from the required driving force by the speed ratio determined from the combination of the target input rotational speed and the target output rotational speed. A control device for a continuously variable transmission.

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