WO2014142213A1

WO2014142213A1 - Vehicle provided with belt-type electronically controlled continuously variable transmission

Info

Publication number: WO2014142213A1
Application number: PCT/JP2014/056586
Authority: WO
Inventors: 和利石岡
Original assignee: ヤマハ発動機株式会社
Priority date: 2013-03-12
Filing date: 2014-03-12
Publication date: 2014-09-18

Abstract

This belt-type electronically controlled continuously variable transmission (1) is provided with a primary pulley (10) connected to the input shaft (3) and having a primary sheave (13), a second pulley (11) connected to an output shaft (4) and having a secondary sheave (15), a belt (12) which is wrapped between the primary pulley (10) and the secondary pulley (11), and an actuator (14) which controls the position in the axial direction of the primary sheave (13); this vehicle is provided with said belt-type electronically controlled continuously variable transmission (1), an engine (2), and a controller which calculates a target position in the axial direction of the primary sheave (13) depending on the output of the engine (2) and the target gear ratio of the belt-type electronically controlled continuously variable transmission (1), and controls the actuator (14).

Description

Vehicle with belt-type electronically controlled continuously variable transmission

The present invention relates to a vehicle equipped with a belt-type electronically controlled continuously variable transmission.

In a light-powered vehicle such as a saddle-ride type vehicle represented by a motorcycle, a belt type continuously variable transmission is widely used. A belt-type electronically controlled continuously variable transmission that electronically controls the gear ratio of such a belt-type continuously variable transmission using an actuator is also in practical use.

FIG. 1 is a schematic diagram showing a configuration example of a vehicle 200 provided with a belt-type electronically controlled continuously variable transmission 1. The belt-type electronically controlled continuously variable transmission 1 has a structure in which a V-belt 12 is wound between a primary pulley 10 and a secondary pulley 11, and a movable sheave of the primary pulley 10 (hereinafter referred to as a primary sheave 13). The position in the axial direction is controlled by the actuator 14. Further, the movable sheave of the secondary pulley 11 (hereinafter referred to as the secondary sheave 15) is urged in the direction of sandwiching the V-belt 12 by an elastic body 16 such as a spring. The primary pulley 10 is connected to the input shaft 3 that is the output shaft of the engine 2, and the secondary pulley 11 is connected to the output shaft 4, and transmits power to the drive wheels 6 via the centrifugal clutch 5. A throttle valve 21 is provided in the intake pipe 20 connected to the engine 2.

Furthermore, an ECU (Electric Control Unit) 7 which is a controller for electronically controlling the operation of the entire vehicle 200 is provided. The ECU 7 detects a throttle opening sensor 70 that detects the opening of the throttle valve 21, an input rotational speed sensor 71 that detects the rotational speed of the input shaft 3 that is the rotational speed of the engine 2, and a rotational speed of the output shaft 4. Detection results from the output speed sensor 72 and the vehicle speed sensor 73 that detects the vehicle speed of the vehicle 200 are input. The ECU 7 controls the position of the primary sheave 13 by driving the actuator 14.

In such a vehicle 200, the gear ratio of the belt-type electronically controlled continuously variable transmission 1 is controlled by controlling the position of the primary sheave 13. However, since the slip of the V belt 12 and the primary pulley 10 or the secondary pulley 11 is caused by the load of the belt type electronically controlled continuously variable transmission 1 or the V belt 12 is deformed, the position of the primary sheave 13 is not necessarily limited. And the speed ratio of the belt-type electronically controlled continuously variable transmission 1 does not correspond to 1: 1, and there is a problem that the speed ratio cannot be accurately controlled. Therefore, as shown in FIG. 2, a plurality of curves showing the relationship between the target gear ratio and the position of the primary sheave 13 are prepared, and the throttle is shown as indicating the load of the belt-type electronically controlled continuously variable transmission 1. Attempts have been made to correct the position of the primary sheave 13 by selecting a curve corresponding to the opening θ.

However, the control of the belt-type electronically controlled continuously variable transmission 1 is advanced. For example, kickdown control that temporarily increases the gear ratio, low fuel consumption mode control that selects a gear ratio suitable for low fuel consumption, and high driving force are obtained. When the switching of various operation modes such as power mode control is performed, the throttle opening does not necessarily reflect the load of the belt-type electronically controlled continuously variable transmission 1, and the gear ratio is There is a risk that it cannot be controlled accurately.

The present invention has been made in view of such a viewpoint, and an object thereof is to accurately control a gear ratio in a vehicle including a belt-type electronically controlled continuously variable transmission.

The invention disclosed in the present application has various aspects, and outlines of representative aspects of the aspects are as follows.

(1) A primary pulley connected to an input shaft and having a primary sheave, a secondary pulley connected to an output shaft and having a secondary sheave, a belt wound around the primary pulley and the secondary pulley, and the primary sheave A belt-type electronically controlled continuously variable transmission having an actuator for controlling the position in the axial direction, an engine, and the primary sheave according to an output of the engine and a target speed ratio of the belt-type electronically controlled continuously variable transmission And a controller for controlling the actuator by obtaining a target position in the axial direction of the vehicle.

(2) In (1), the controller obtains the output of the engine based on the target throttle opening or throttle opening and the target engine speed or engine speed.

(3) In (1) or (2), the target position in the axial direction of the primary sheave is after correction by multiplying the target gear ratio by a correction coefficient obtained from the belt tension determined based on the output of the engine. A vehicle that is determined according to the gear ratio.

(4) In (3), the tension of the belt includes the output of the engine, the inertia torque of the belt type electronically controlled continuously variable transmission, the loss of the belt type electronically controlled continuously variable transmission, and the inertial force of the belt. Vehicles determined based on

According to the above aspect (1) of the present invention, the gear ratio can be accurately controlled in the vehicle equipped with the belt-type electronically controlled continuously variable transmission.

According to any one of the aspects (2) to (4) of the present invention, it is possible to correctly estimate the load of the belt type electronically controlled continuously variable transmission.

It is a mimetic diagram showing an example of composition of vehicles provided with a belt type electronically controlled continuously variable transmission. It is a figure which shows the curve which shows the relationship between the target gear ratio and the position of a primary sheave. 1 is a side view of a vehicle according to an embodiment of the present invention. It is a mimetic diagram showing an example of composition of vehicles concerning an embodiment of the present invention. It is a control block diagram showing a part of vehicle control realized by an ECU. It is a figure which shows the example of an engine speed map. It is a figure which shows the example of an engine torque map. It is the control block diagram which showed another part of control of the vehicle implement | achieved by ECU.

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

FIG. 3 is a side view of the vehicle 100 according to the embodiment of the present invention. In addition, although the vehicle 100 shown here is a motorcycle, this is shown as an example of the vehicle 100, and the form will not be specifically limited if it is a vehicle provided with the belt-type electronically controlled continuously variable transmission 1. . In general, the belt type continuously variable transmission including the presence or absence of electronic control is often provided in a light-powered vehicle, and the light-powered vehicle is often a straddle-type vehicle. It can be said that it is suitable for. Here, the saddle-ride type vehicle refers to a motor vehicle having a saddle on which an occupant is seated. Is included. Further, as described above, the belt-type electronically controlled continuously variable transmission refers to a belt-type continuously variable transmission that can electronically control the gear ratio using an actuator.

The vehicle 100 travels by transmitting the rotational power generated by the engine 2 to the driving wheels 6 as rear wheels via the belt-type electronically controlled continuously variable transmission 1. A clutch and a final speed reduction mechanism (not shown) are arranged between the belt-type electronically controlled continuously variable transmission 1 and the drive wheels 6. The output generated by the engine 2 is detected by an accelerator sensor using an accelerator grip rotation operation amount (not shown in FIG. 1) as an accelerator operation amount, and the ECU 7 is provided in the intake pipe of the engine 2 based on the accelerator operation amount and the state of the vehicle 100. It is controlled by adjusting the opening of the electronically controlled throttle valve. The engine 2 is a general reciprocating engine, and its type, for example, 2 strokes or 4 strokes, and the number of cylinders are not particularly limited.

The ECU 7 is a controller that controls the operation of the entire vehicle 100, and is a general computer including a CPU (Central Processing Unit), a memory, a so-called microcontroller, a DSP (Digital Signal Processor), and an FPGA (Field Programmable Gate Array). PLD (Programmable Logic Device) or other electronic circuits may be used. The ECU 7 sends commands to the actuators of the electronically controlled throttle valve and the belt type electronically controlled continuously variable transmission 1 described above, and receives signals from various sensors described later. The electronic board on which the ECU 7 is mounted is disposed at an appropriate position of the vehicle 100, in the illustrated example, below the passenger seat.

FIG. 4 is a schematic diagram showing a configuration example of the vehicle 100 according to the embodiment of the present invention. Since the configuration of vehicle 100 is substantially the same as the configuration shown in FIG. 1, members that are common to each other are assigned the same reference numerals, and redundant descriptions thereof are omitted. The vehicle 100 is provided with an accelerator sensor 74 that detects an accelerator operation amount, and the signal is input to the ECU 7. The intake pipe 20 of the engine 2 is driven by a throttle actuator 22 and is an electronic device that adjusts its opening. A controlled throttle valve 23 is provided.

FIG. 5 is a control block diagram showing a part of the control of the vehicle 100 realized by the ECU 7. In the present embodiment, such control is virtually realized by software executed on the ECU 7, and each block shown in the figure does not physically exist. It can be realized by a typical electric circuit. In the following description, FIG. 4 will be referred to as appropriate.

The control shown in FIG. 5 is based on the target throttle opening and the target speed ratio, which are command values (or converted values) to the throttle actuator 22 and the actuator 14 of the belt-type electronically controlled continuously variable transmission 1 from the accelerator operation amount and the vehicle speed. Is derived. The target throttle opening is the opening of the electronically controlled throttle valve 23 to be realized by the control, and the target speed ratio is the speed ratio of the belt-type electronically controlled continuously variable transmission 1 to be realized by the control. is there.

First, the process for obtaining the target gear ratio will be described. The ECU 7 includes a reference rotation speed calculation unit 7a, a rotation speed correction unit 7b, and a target gear ratio calculation unit 7c shown in FIG. The reference rotational speed calculation unit 7a calculates the reference engine rotational speed based on the accelerator operation amount and the vehicle speed detected by the accelerator sensor 74. Here, the reference engine speed is a target value of the speed of the engine 2 which is uniquely converted from information on the vehicle speed and other information, here information on the accelerator operation amount, that is, the speed of the input shaft 3. In this case, the correction is not made by the rotation speed correction unit 7b described later. The information related to the accelerator operation amount refers to information corresponding to the accelerator operation amount on a one-to-one basis by appropriate conversion, and the information related to the vehicle speed refers to the transmission (in this embodiment, the belt-type electronically controlled continuously variable transmission 1). ) The number of rotations of a member located on the downstream side or information obtained from the number of rotations and corresponding to the vehicle speed on a one-to-one basis by appropriate conversion. The members positioned on the downstream side of the transmission include the output shaft of the clutch 5, an arbitrary gear included in the final reduction mechanism, the drive wheels 6, the axles thereof, and the like. The rotation speed of these members is converted into a vehicle speed on a one-to-one basis by performing appropriate conversion. For example, the rotation speed of the drive wheel 6 is converted into the vehicle speed by multiplying the circumference of the drive wheel 6, and thus corresponds to information on the vehicle speed. Note that the rotation speed of the output shaft 4 and the secondary pulley 11 of the belt-type electronically controlled continuously variable transmission 1 may be handled according to the information on the vehicle speed only when the downstream centrifugal clutch 5 is connected. In the present embodiment, the accelerator operation amount and the vehicle speed are used as the information about the accelerator operation amount and the information about the vehicle speed, respectively, but other information may be used.

The ECU 7 includes an information storage device such as a semiconductor memory, and the information storage device stores a map (hereinafter referred to as an engine speed map) relating the accelerator operation amount, the vehicle speed, and the engine speed. The reference rotation speed calculation unit 7a refers to the engine rotation speed map, obtains the engine rotation speed according to the accelerator operation amount and the vehicle speed, and sets it as the reference engine rotation speed.

FIG. 6 is a diagram showing an example of an engine speed map. The ECU 7 stores data obtained by digitizing the map. In the engine speed map shown here, the horizontal axis represents the vehicle speed, the vertical axis represents the engine speed, and curves Ac1 to Ac3 that are curves corresponding to the accelerator operation amount are illustrated. Here, the curves Ac1 to Ac3 are associated with specific accelerator operation amounts. For example, in a specific state where the accelerator operation amount is large, the curve Ac1 is selected and the specific state where the accelerator operation amount is small. Then, the curve Ac3 is selected, and the curve Ac2 is selected in the middle. Actually, a larger number of curves than those shown in the figure are prepared or an interpolation operation is performed in order to cope with a finer change in accelerator operation amount.

Here, when a curve corresponding to a certain accelerator operation amount, in this case, the curve Ac1 is selected, the engine speed is determined according to the vehicle speed at that time. As can be understood from the figure, even when the vehicle speed is the same, the curve selected when the accelerator operation amount is small is different (the lower curve is selected in the figure), and a smaller engine speed is obtained. It will be.

In this engine speed map, a straight line passing through the origin indicates a state where the gear ratio is constant. In the figure, the straight line indicated by Llow indicates the low gear state in which the belt-type electronically controlled continuously variable transmission 1 has the largest speed ratio, and the straight line indicated by High indicates the highest speed ratio of the belt-type electronically controlled continuously variable transmission 1. A small high gear state is indicated, and a straight line indicated by Lmid indicates an intermediate speed change state. As can be seen from the figure, in this example, each curve increases the engine speed along a straight line Llow (low gear state) while the vehicle speed is low, and gradually reduces the engine speed when the vehicle speed reaches an intermediate value. When the vehicle speed increases, the engine speed increases along a straight line Lhigh (high gear state).

Referring back to FIG. 5, the reference engine speed obtained by the reference speed calculator 7a is transferred to the speed corrector 7b. The rotational speed correction unit 7b can be used in various ways such as kick-down control for temporarily increasing the gear ratio, low fuel consumption mode control for selecting a gear ratio suitable for low fuel consumption, and power mode control for obtaining a high driving force. This is a part that performs a process of appropriately correcting the reference engine speed in order to realize the effect. For example, the reference engine speed is corrected in a direction in which the engine speed is increased in kick down control or power mode control, and is normally decreased in the fuel efficiency mode control. A target engine speed can be obtained by performing correction related to the reference engine speed. Here, the target engine rotational speed is a target value to be controlled as the rotational speed of the output shaft of the engine 2, that is, the rotational speed of the input shaft 3.

The target gear ratio calculation unit 7c calculates the target gear ratio so that the rotational speed of the engine 2 becomes the target engine rotational speed. That is, the target gear ratio calculation unit 7c calculates the target gear ratio based on information regarding the target engine speed and the vehicle speed. In the present embodiment, vehicle speed is used as information related to vehicle speed. In this calculation, for example, the target speed ratio may be obtained by dividing the target engine speed by a value obtained by dividing the vehicle speed by the circumference of the drive wheel 6 and multiplying by the speed reduction ratio of the final speed reduction mechanism 7. When the obtained target speed ratio exceeds the upper limit or lower limit of the speed ratio of the belt-type electronically controlled continuously variable transmission 1, the upper limit or the lower limit may be set as the target speed ratio.

Next, the process for obtaining the target throttle opening will be described. In the following description, torque (engine torque) is used as an amount indicating the power obtained from the engine 2, but instead of this, a so-called output (power). Here, the engine torque is multiplied by the number of revolutions. (Hereinafter referred to as narrowly-defined output) may be used. In this specification, the term “output” is used to indicate some quantitative index indicating kinetic energy obtained from the engine 2 including not only the output in a narrow sense but also the torque. The ECU 7 includes an accelerator operation amount-reference throttle opening conversion unit 7d, a reference engine torque calculation unit 7e, a reference engine torque-reference driving force conversion unit 7f, a driving force correction unit 7g, a target driving force-target engine torque conversion unit 7h, A target throttle opening calculation unit 7i is provided. The accelerator operation amount-reference throttle opening conversion portion 7d is a portion that converts the accelerator operation amount into a throttle opening. Here, the throttle opening obtained by the accelerator operation amount-reference throttle opening conversion unit 7d is referred to as a reference throttle opening. There is a one-to-one relationship between the reference throttle opening and the accelerator operation amount, and the accelerator operation amount is converted into the reference throttle opening by using an arbitrary conversion formula or by referring to a table or a map. The Here, conversion is performed so that the reference throttle opening is also increased if the accelerator operation amount is larger.

The reference engine torque calculator 7e calculates the reference engine torque based on the reference throttle opening and the reference engine speed obtained by the reference speed calculator 7a. The ECU 7 stores a map indicating the relationship between the throttle opening, the engine speed, and the engine torque, which is determined by the output characteristics of the engine 2 (hereinafter, this map is referred to as an engine torque map). The reference engine torque calculation unit 7e uniquely calculates the reference engine torque from the reference throttle opening and the reference engine speed by referring to the engine torque map. As described above, the reference engine speed calculation unit 7a calculates the reference engine speed from the accelerator operation amount and the vehicle speed, and the accelerator operation amount-reference throttle opening conversion unit 7d calculates the accelerator operation amount. Since the reference throttle opening is converted, the reference engine torque calculation unit 7e eventually calculates the reference engine torque based on the accelerator operation amount and the vehicle speed.

FIG. 7 is a diagram showing an example of an engine torque map. In the engine torque map shown here, curves Th1 to Th4, which are curves corresponding to the throttle opening, are illustrated with the horizontal axis representing the engine speed and the vertical axis representing the engine torque. Here, the curves Th1 to Th4 are associated with a specific throttle opening. For example, in a specific state where the throttle opening is large, the curve Th4 is selected and a specific state where the throttle opening is small. Then, the curve Th1 is selected, and in the middle, the curves Th2 and Th3 are selected. Actually, more curves than those shown in the figure are prepared or interpolation calculation is performed in order to cope with a more detailed change in the throttle opening.

The reference engine torque calculation unit 7e refers to the engine torque map and calculates a reference engine torque corresponding to the reference throttle opening and the reference engine speed. That is, if a curve corresponding to a certain reference throttle opening, here, for example, a curve Th4 is selected, the reference engine torque is obtained according to the reference engine speed at that time.

The obtained reference engine torque is converted into a driving force (this is referred to as a reference driving force) by the reference engine torque-reference driving force conversion unit 7f, and necessary correction is performed by the driving force correction unit 7g. Then, it is converted again by the target driving force-target engine torque conversion unit 7h and converted to the target engine torque. The target engine torque is a target value of engine torque obtained by the ECU 7 controlling the engine 2.

The reference engine torque-reference driving force conversion unit 7f subtracts the inertia loss of the engine 2 and the loss of the belt-type electronically controlled continuously variable transmission 1 from the reference engine torque, and then changes the speed of the belt-type electronically controlled continuously variable transmission 1 By multiplying the ratio and the reduction ratio of the final reduction mechanism (referred to as final reduction ratio), it is converted into a reference driving force. The inertia loss of the engine 2 is an inertia loss (or gain) caused by a change in the engine speed, and the loss of the belt type electronically controlled continuously variable transmission 1 is the transmission loss in the belt type electronically controlled continuously variable transmission 1. Thus, it is calculated based on the reference engine speed.

If necessary, the driving force correction unit 7g gives a rider an unnatural impression or discomfort due to the temporal change in the driving force of the vehicle 100 generated by the reference engine torque obtained by the reference engine torque calculation unit 7e. The reference driving force is corrected so as not to impair the operation, and mainly functions as a time filter. As the processing performed here, for example, a waveform shaping process of the reference driving force for shaping a steep change (for example, a step-like change) in the reference driving force into a gentle change can be exemplified. The reason why the driving force correction unit 7g does not directly correct the reference engine torque but corrects the reference driving force obtained by converting the reference engine torque is that the driving force is corrected with respect to the engine torque. This is because the actual behavior of the vehicle 100 is more faithfully reflected because the loss of the engine 2 and the belt-type electronically controlled continuously variable transmission 1 can be taken into account.

The target driving force-target engine torque conversion unit 7h performs reverse conversion of the reference engine torque-reference driving force conversion unit 7f, and divides the target driving force by the final reduction gear ratio and the transmission gear ratio to reduce the inertia loss of the engine 2. The target engine torque is obtained by adding the losses of the belt-type electronically controlled continuously variable transmission 1. The inertia loss of the engine 2 and the loss of the belt-type electronically controlled continuously variable transmission 1 at this time are calculated based on the target engine speed.

The obtained target engine torque is input to the target throttle opening calculation unit 7i together with the target engine speed. Then, the target throttle opening calculator 7i calculates the target throttle opening based on the target engine torque and the target engine speed. This calculation is an inverse conversion of the reference engine torque calculation unit 7e. That is, the target throttle opening calculation unit 7i refers to the engine torque map shown in FIG. 7 again, and a point on the map specified by the target engine torque and the target engine speed is on a curve indicating which throttle opening. The target throttle opening is obtained by checking whether it is located.

In addition, when not correcting the reference driving force in the driving force correcting unit 7g, this may be omitted. Even in this case, after the reference engine torque is converted into the driving force based on the reference engine speed by the reference engine torque-reference driving force converting unit 7f, the driving force is converted by the target driving force-target engine torque converting unit 7h. Is converted into the target engine torque based on the target engine speed, so that a desired driving force can be obtained even when the reference speed is corrected by the speed correction unit 7b. . However, the reference engine torque-reference driving force conversion unit 7f, the driving force correction unit 7g, and the target driving force-target engine torque conversion unit 7h may be omitted, and the reference engine torque may be used as it is as the target engine torque. The engine torque calculation unit 7e, the reference engine torque-reference driving force conversion unit 7f, the driving force correction unit 7g, the target driving force-target engine torque conversion unit 7h, and the target throttle opening calculation unit 7i are all omitted, and the reference throttle opening Can also be used as the target throttle opening as it is.

The ECU 7 converts the target throttle opening obtained in this way into the drive amount of the throttle actuator 22 and sends a signal to the throttle actuator 22 to control the opening of the electronically controlled throttle valve 23. On the other hand, when the target gear ratio is simply converted into the drive amount of the actuator 14 of the belt-type electronically controlled continuously variable transmission 1 and controlled, the correction to the reference engine speed is performed by the rotation speed correction unit 7b. For the reasons described above, the actually obtained gear ratio is different from the target gear ratio.

Therefore, the ECU 7 obtains the target position in the axial direction of the primary sheave 13 from the target gear ratio by taking into account the output of the engine 2 by the processing described below, and thereby the difference between the target gear ratio and the actually obtained gear ratio. Is small.

FIG. 8 is a control block diagram showing another part of the control of the vehicle 100 realized by the ECU 7. The control shown in FIG. 8 determines the engine torque from the throttle opening and the engine speed, and determines the axial target position of the primary sheave 13 according to the engine torque and the target gear ratio. Similar to the control shown in FIG. 5, such control is also virtually realized by software executed on the ECU 7. Of course, some or all of the blocks shown in the figure may be realized by a physical electric circuit.

First, the engine torque calculation unit 7j calculates the current engine torque from the throttle opening and the engine speed. This calculation is performed by referring to the engine torque map shown in FIG. 5 in the same manner as the reference engine torque calculation unit 7e described above. At this time, what is used as the throttle opening is the actual opening of the throttle valve 23 detected by the throttle opening sensor in this embodiment, and what is used as the engine rotational speed is detected by the input rotational speed sensor 71. The rotation speed of the input shaft 3, that is, the actual rotation speed of the engine 2 (see FIG. 4). As described above, the actual engine torque can be accurately calculated by using the actual throttle opening and the actual engine speed as the throttle opening and the engine speed. However, the target engine torque described above may be used as the engine torque. In this case, the engine torque is calculated using the target throttle opening as the throttle opening and the target engine rotation as the engine speed, or the target drive. The target engine torque converted by the force-target engine torque conversion unit 7h may be used. In any case, the engine torque calculator 7j obtains the engine torque based on the target throttle opening or throttle opening and the target engine speed or engine speed.

The corrected gear ratio calculating unit 7k performs correction based on the engine torque calculated by the engine torque calculating unit 7j on the target gear ratio calculated by the target gear ratio calculating unit 7c shown in FIG. The gear ratio is calculated. As described above, even if the actuator 14 is driven so that the primary sheave 13 comes to a position where the transmission ratio of the belt-type electronically controlled continuously variable transmission 1 geometrically becomes the target transmission ratio, the actual transmission ratio is obtained. Deviates from the target gear ratio under the influence of the load. The corrected gear ratio is obtained by appropriately correcting the target gear ratio, and the actuator 14 is driven so that the gear ratio of the belt-type electronically controlled continuously variable transmission 1 geometrically becomes the corrected gear ratio. In this case, the gear ratio is such that the actually obtained gear ratio becomes the target gear ratio or the gear ratio that is practically equivalent to the target gear ratio.

When calculating the corrected gear ratio, the corrected gear ratio calculating unit 7k first determines the tension acting on the belt 12 of the belt-type electronically controlled continuously variable transmission 1 determined based on the engine torque calculated by the engine torque calculating unit 7j. Is calculated. Subsequently, the corrected gear ratio is calculated by multiplying the target gear ratio by a correction coefficient obtained from the tension of the belt 12. The tension of the belt 12 is determined based on the output of the engine, the inertia torque of the belt type electronically controlled continuously variable transmission 1, the loss of the belt type electronically controlled continuously variable transmission 1, and the inertial force of the belt 12. This calculation procedure will be described in detail below.

First, the corrected gear ratio calculation unit 7k calculates the tension F _{belt of the} belt 12 from the following equation.

Here, T _eng is the engine torque, T _inner is the inertia torque of the belt type electronically controlled continuously variable transmission 1, T _loss is the _loss of the belt type electronically controlled continuously variable transmission 1, and F _acc is the acceleration resistance of the belt 12. . The engine torque T _eng is a value obtained by the engine torque calculation unit 7j. For other values, the inertia torque T _inner is a torque generated by a change in angular velocity between the primary pulley 10 of the belt-type electronically controlled continuously variable transmission 1 and the input shaft 3 (including the crankshaft of the engine 2), and the loss T _loss Is a torque generated as a loss due to internal resistance such as friction in the belt type electronically controlled continuously variable transmission 1 or bending of the belt 12. The acceleration resistance F _acc is the inertial resistance of the belt 12 and is obtained by multiplying the weight of the belt 12 by the acceleration of the belt 12. These values can be easily obtained by calculation by measuring the moment of inertia and internal resistance of each part of the belt-type electronically controlled continuously variable transmission 1 in advance.

The primary winding radius R _pri is defined in association with the corrected gear ratio I _cor by the following equation.

Here, ω _pri is the angular velocity of the primary pulley 10, ω _sec is the angular velocity of the secondary pulley 11, and the primary winding radius R _pri and the secondary winding radius R _sec are applied to the belt-type electronically controlled continuously variable transmission 1. When it assumes that there is no deformation | transformation etc., it means the winding radius of the belt 12 with respect to each of the primary pulley 10 and the secondary pulley 11 which implement _| achieves the corrected gear ratio Icor.

The post-correction gear ratio calculation unit 7k further calculates a correction coefficient σ by the following equation.

Here, α is a constant obtained experimentally.

The corrected gear ratio I _cor is obtained from the target gear ratio I _obj and the correction coefficient σ as follows.

By the way, as apparent from

Equations

1 and 2 above, in order to calculate Equation 1, it is necessary to provide the primary winding radius R _pri, that is, the corrected gear ratio I _cor . In this regard, when calculating Equation 1, the primary winding radius R _pri based on the corrected gear ratio I _cor obtained one cycle before in the processing of the ECU 7 may be used. That is, since the ECU 7 repeatedly executes the processes shown in FIGS. 5 and 8 at a preset cycle, the corrected gear ratio I _cor or the primary winding radius R _pri calculated in a certain cycle is stored. It can be used for calculation in the next cycle. Since it is considered that no load is applied to the belt-type electronically controlled continuously variable transmission 1 at the time of the first execution, the gear ratio of the current belt-type electronically controlled continuously variable transmission 1 or the target speed change is set as the corrected gear ratio I _cor. The ratio I _obj can be used.

Finally, the target position conversion unit 7l obtains the target position in the axial direction of the primary sheave 13 according to the corrected gear ratio. Since the target position in the axial direction of the primary sheave 13 corresponds to the drive amount of the actuator 14 on a one-to-one basis, the ECU 7 sends an appropriate drive signal to the actuator 14 so that the position in the axial direction of the primary sheave 13 becomes the target position. Control.

Conversion from the corrected gear ratio to the target position in the axial direction of the primary sheave 13 is based on the assumption that the belt-type electronically controlled continuously variable transmission 1 is not slipped or deformed. A gear ratio after correction is geometrically realized. More specifically, the conversion is performed by performing calculation using an appropriate conversion formula or referring to an appropriate table or map.

Through the control described above, the target position in the axial direction of the primary sheave 13 is controlled according to the corrected gear ratio obtained by taking the output of the engine 2 into account, and thus the target gear ratio and the actual gear ratio are actually obtained. The difference from the gear ratio is small.

The embodiment described above shows a specific example of the vehicle according to the present invention, and the present invention is not limited to the illustrated specific example. A person skilled in the art may arbitrarily change the detailed shape and arrangement of each member and the number thereof as necessary. In addition, the functional block diagram or control block diagram shown as a specific example shows an example, and any modification can be made as long as the configuration exhibits the same function.

Claims

A primary pulley connected to the input shaft and having a primary sheave;
A secondary pulley connected to the output shaft and having a secondary sheave;
A belt hung between the primary pulley and the secondary pulley;
An actuator for controlling the axial position of the primary sheave, and a belt-type electronically controlled continuously variable transmission,
Engine,
And a controller that controls the actuator by obtaining a target position in the axial direction of the primary sheave in accordance with an output of the engine and a target gear ratio of the belt-type electronically controlled continuously variable transmission.
2. The vehicle according to claim 1, wherein the controller obtains an output of the engine based on a target throttle opening or throttle opening and a target engine speed or engine speed.
The target position in the axial direction of the primary sheave is determined according to a corrected gear ratio obtained by multiplying the target gear ratio by a correction coefficient obtained from the belt tension determined based on the output of the engine. Vehicle.
The tension of the belt is determined based on an output of the engine, an inertia torque of the belt-type electronically controlled continuously variable transmission, a loss of the belt-type electronically controlled continuously variable transmission, and an inertial force of the belt. Vehicle.