JP2000346169A - Control device of vehicle continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the change of input and output speed ratio as much as possible in a device having a transmission mechanism having a stepwise transmission and a continuously variable transmission serially arranged on the output side of a driving force source by providing a speed ratio control means for changing the speed ratio of the continuously variable transmission in the gear shifting transition of the stepwise transmission. SOLUTION: A transmission accelerator 2 provided on the output side of an engine 1 has a transmission mechanism 3 and a final gear 4, and the transmission mechanism 3 has a stepwise transmission 8 in the power transmitting passage between an input shaft 5 and a counter shaft 6 and a continuously variable transmission 9 in the powder transmitting passage between the counter shaft 6 and an output shaft 7. An electronic control unit(ECU) is provided in order to control the stepwise transmission 8 and the continuously variable transmission 9, and the ECU controls the speed ratio of the continuously variable transmission 9 in the shifting of the stepwise transmission 9 so as to minimize the change quantity of the input and output ratio showing the ratio of the input-side rotating speed of the transmission mechanism 3 to the output- side rotating speed of the transmission mechanism 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a continuously variable transmission for a vehicle in which a stepped transmission and a continuously variable transmission are arranged in series on the output side of a driving force source.

[0002]

2. Description of the Related Art Generally, a continuously variable transmission for a vehicle includes a belt type and a toroidal type. A belt-type continuously variable transmission has a plurality of pulleys whose groove width can be changed, and a belt wound around these pulleys. By controlling at least one of the groove widths of the respective pulleys, it is possible to continuously control the ratio between the input rotation speed and the output rotation speed, that is, the gear ratio.

Incidentally, in order to improve the starting performance of the vehicle, it is desirable to set the maximum speed ratio of the continuously variable transmission large. On the other hand, the thermal efficiency of a normal engine is high in the low / medium rotation range and in the relatively high torque range, so the maximum speed of the continuously variable transmission is required to improve fuel efficiency and reduce emissions. It is desirable to set the ratio smaller on the speed increasing side. Therefore, in order to achieve both the improvement of the starting performance of the vehicle and the improvement of the fuel efficiency, the control range of the speed ratio of the continuously variable transmission may be set wide.

In the belt type continuously variable transmission, as a specific configuration for widening the speed ratio width, the distance between the input shaft and the output shaft of the continuously variable transmission is increased, and
There are a first configuration for increasing the diameter of the pulley and a second configuration for reducing the winding radius of the belt. However, when the first configuration is used, there is a problem that the continuously variable transmission becomes larger and heavier, and when the second configuration is used, there is a possibility that the radius of curvature of the belt is reduced and its durability is reduced. There is.

[0005] An example of a continuously variable transmission for a vehicle which can cope with such a problem is disclosed in Japanese Patent Laid-Open No. 60-374.
No. 55 is described. That is, the vehicle continuously variable transmission described in this publication includes an input shaft and an output shaft arranged in parallel with each other, and a gear transmission mechanism (a stepped transmission) provided on the input shaft side or the output shaft side. ), And a continuously variable transmission provided over the input shaft and the output shaft. This gear transmission mechanism has a friction engagement device such as a clutch or a brake, and the gear ratio is controlled by controlling engagement / disengagement of the friction engagement device.

On the other hand, the continuously variable transmission includes an input pulley provided on an input shaft, an output pulley provided on an output shaft,
A belt wound around the input side pulley and the output side pulley. The input pulley is mounted so that one of the pulleys can move in the axial direction with respect to the input shaft, and the output pulley is mounted so that one of the pulleys can move in the axial direction with respect to the output shaft. In this continuously variable transmission, the gear ratio is controlled by changing the groove width of at least one of the input side pulley and the output side pulley. By controlling the speed ratio of the gear transmission mechanism to compensate for the control range of the speed ratio that is not sufficient with the continuously variable transmission alone, the ratio between the input shaft speed and the output shaft speed, that is, the input / output speed ratio Can be increased as much as possible.

[0007]

During gear shifting by the gear transmission mechanism, torque fluctuations due to engine inertia are absorbed by slippage of the friction engagement device.
When the change width of the gear ratio of the gear transmission mechanism is large, the inertia torque may not be completely absorbed and the torque fluctuation of the output shaft may increase. As a result, the ride comfort may be reduced due to a shift shock, or the durability of the friction engagement device may be reduced. For this reason, the change width of the gear ratio of the gear transmission mechanism cannot be set so large. Therefore, if the change width of the gear ratio of the gear transmission mechanism is set small in order to suppress shift shock, the shift width of the input / output gear ratio will be narrowed, achieving both improved start-up performance, improved fuel economy, and reduced emissions. Can not. As described above, the conventional control device for a continuously variable transmission for a vehicle achieves both suppression of the shift shock of the gear transmission mechanism and increasing the control width of the input / output gear ratio as much as possible. Was difficult.

The present invention has been made in view of the above circumstances, and can suppress shift shock.
Further, it is an object of the present invention to provide a control device for a continuously variable transmission for a vehicle, which can increase a control width of an input / output speed ratio of a stepped transmission and a continuously variable transmission as much as possible.

[0009]

In order to achieve the above-mentioned object, according to the first aspect of the present invention, a stepped transmission and a continuously variable transmission are arranged in series on the output side of a driving force source. A control device for a continuously variable transmission for a vehicle having a speed change mechanism, wherein a speed ratio control means for changing a speed ratio of the continuously variable transmission during a shift transition of the stepped transmission is provided. Is what you do.

According to the first aspect of the present invention, the change in the input / output speed ratio is suppressed as much as possible by controlling the speed ratio of the continuously variable transmission during the speed change of the stepped transmission. Therefore,
The fluctuation of the inertia torque due to the change in the rotation speed of the driving force source is suppressed.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the speed ratio control means is configured to determine a speed of the input side of the speed change mechanism and a speed of the speed change mechanism during a speed change of the stepped transmission. The speed ratio of the continuously variable transmission is controlled so as to reduce the amount of change in the input / output ratio indicating the ratio to the output-side rotation speed. Here, the change amount of the input / output ratio includes the gradient of the input / output ratio characteristic line in the input / output ratio diagram showing the ratio of the change rate, the change rate, the degree of change, and the rotation speed on the output side of the transmission mechanism. Slope).

According to the second aspect of the present invention, in addition to the same effect as the first aspect of the present invention, the input / output indicating the ratio of the number of revolutions on the input side of the transmission mechanism to the number of revolutions on the output side of the transmission mechanism. The speed ratio of the continuously variable transmission is controlled so that the amount of change in the speed ratio is less than the maximum value.

According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, the continuously variable transmission is mounted on two mutually parallel power transmission shafts, and an axis of the power transmission shaft is provided. Pulleys constituted by a set of sheaves that can move relative to each other in the direction, a belt wound around the two pulleys, and the power transmission shaft for controlling the groove width between the sheaves of each pulley. And an actuator that operates in the axial direction.

According to the third aspect of the invention, the same operation as the first or second aspect of the invention is produced, and the control range of the speed ratio of the continuously variable transmission can be reduced. Therefore, it is possible to suppress the distance between the two power transmission shafts and the amount of operation of the actuator in the axial direction of the power transmission shafts, which are factors for setting the control width of the speed ratio of the continuously variable transmission.

[0015]

Next, the present invention will be specifically described with reference to the drawings. FIG. 1 shows an embodiment in which the control device of the present invention is used in an FF vehicle (vehicle with front-wheel drive with an engine). More specifically, FIG. 1 is a skeleton diagram of a power transmission path. In FIG. 1, reference numeral 1 denotes an engine as a driving force source of a vehicle. As the engine 1, an internal combustion engine, specifically, a gasoline engine, a diesel engine, an LPG engine, or the like is used. Here, for convenience, a case where a gasoline engine is mounted as the engine 1 will be described.
Is a suction and exhaust device, a lubrication device, a cooling device, a fuel injection device,
A known device having an ignition device, a starting device, and the like can be used, and its crankshaft (not shown) is arranged in the width direction of the vehicle.

On the output side of the engine 1, a transaxle 2 is provided. The transaxle 2 has a speed change mechanism 3 and a final gear 4. First, the structure of the speed change mechanism 3 will be described. The speed change mechanism 3 has an input shaft 5, a counter shaft 6, and an output shaft 7. Here, the rotation center axis X1 of the input shaft 5
And the rotation center axis Y1 of the counter shaft 6 and the rotation center axis Z1 of the output shaft 7 are arranged in parallel with each other. Further, the power between the input shaft 5 and the counter shaft 6 (in other words, torque)
A stepped transmission 8 is provided on the transmission path, and a continuously variable transmission (CVT) 9 is provided on a power transmission path between the counter shaft 6 and the output shaft 7.

The input shaft 5, the counter shaft 6, and the output shaft 7 are arranged in the width direction of the vehicle so that the output of the engine 1 is transmitted to the input shaft 5. Stepped transmission 8
Has a forward gear transmission mechanism 10 for setting a forward gear, and a reverse gear transmission mechanism 11 for setting a reverse gear. First, the forward gear transmission mechanism 10 will be described. A first hollow shaft 12 is attached to the outer periphery of the input shaft 5 so as to be rotatable relative to the input shaft 5. A second hollow shaft 13 is attached to the outer periphery so as to be rotatable relative to the first hollow shaft 12.

A first drive gear 14 is formed on the first hollow shaft 12, and a second drive gear 15 is formed on the second hollow shaft 13. The outer diameter of the first drive gear 14 is set smaller than the outer diameter of the second drive gear 15. Furthermore, the input shaft 5
A first clutch C1 for controlling a power transmission state between the input shaft 5 and the first hollow shaft 12, and a second clutch C2 for controlling a power transmission state between the input shaft 5 and the second hollow shaft 13. Is provided. Each of the first clutch C1 and the second clutch C2 is a known clutch including a piston (not shown) operating in the axial direction of the input shaft 5, a return spring (not shown), and the like.

A first driven gear 16 and a second driven gear 17 are formed on the counter shaft 6. The outer diameter of the first driven gear 16 is set larger than the outer diameter of the second driven gear 17. Also,
The first driven gear 16 and the first drive gear 14 mesh with each other, and the second driven gear 17 and the second drive gear 15 mesh with each other.

The forward gear change mechanism 10 having the above-described structure is for setting the forward gear, and includes a first clutch C1.
Is engaged and the second clutch C2 is released, the power of the input shaft 5 is transmitted to the first drive gear 14
And the state where the speed is transmitted to the countershaft 6 via the first driven gear 16 in a reduced speed, that is, a low speed stage (low gear).
Is set. On the other hand, when the second clutch C2 is engaged and the first clutch C1 is released, the power of the input shaft 5 is transmitted through the second drive gear 15 and the second driven gear 17 to the countershaft. 6
, That is, a high gear (high gear) is set.

All the clutches of the stepped transmission 8 are released when the vehicle is stopped, but when the vehicle starts moving, a predetermined clutch is gradually engaged while slip control is performed (so-called friction control). And start the vehicle smoothly. Note that when the vehicle is stopped, so-called hill hold control is performed to maintain the stopped state by maintaining the hydraulic pressure of the wheel cylinder of the braking device regardless of the depressed state of the brake pedal.

On the other hand, the reverse gear transmission mechanism 11 is mounted on the outer periphery of the input shaft 5 so as to be rotatable relative to the input shaft 5, and the third drive gear 1.
8 and a third driven gear 20 formed on the countershaft 6. An intermediate shaft 21 parallel to the input shaft 5 and the counter shaft 6 is provided, and an intermediate gear 22 is formed on the intermediate shaft 21. Further, the intermediate gear 22, the third drive gear 18, and the third driven gear 20 are meshed. Further, the input shaft 5 and the third hollow shaft 1
9 is provided with a reverse clutch CR for controlling the state of power transmission between the clutch 9 and the clutch 9. This reverse clutch CR is a piston (not shown) that operates in the axial direction of the input shaft 5.
And a return spring (not shown).

With the above configuration, the first clutch C1
When the second clutch C2 is disengaged and the reverse clutch CR is engaged, the power of the input shaft 5 is transmitted to the counter shaft 6 via the third drive gear 18, the intermediate gear 22, and the third driven gear 20. The state is transmitted and the counter shaft 6 is rotated in the opposite direction to the input shaft 5, that is, the reverse gear is set. Thus, in the stepped transmission 8,
The gear ratio can be controlled stepwise (discontinuously). As described above, the stepped transmission 8 is a so-called constant mesh transmission.

The continuously variable transmission 9 includes a countershaft 6
And a driven pulley 24 provided on the output shaft 7 side. The driving pulley 23 has a fixed sheave 25 fixed to the counter shaft 6 and a movable sheave 26 configured to be movable in the axial direction of the counter shaft 6. By operating the movable sheave 26 in the axial direction of the counter shaft 6, the movable sheave 26
A hydraulic actuator 27 is provided for moving the fixed sheave 25 closer to and away from the fixed sheave 25. This hydraulic actuator 2
Reference numeral 7 denotes a piston (not shown) that operates in the axial direction of the counter shaft 6 and a return spring (not shown).
It is a publicly known one provided with such as.

On the other hand, the driven pulley 24 has a fixed sheave 28 fixed to the output shaft 7 and a movable sheave 29 configured to be movable in the axial direction of the output shaft 7. Further, a hydraulic actuator 30 is provided for moving the movable sheave 29 in the axial direction of the output shaft 7 so as to approach / separate the movable sheave 29 and the fixed sheave 28. The hydraulic actuator 30 is a known hydraulic actuator including a piston (not shown) that operates in the axial direction of the output shaft 7 and a return spring (not shown). Further, a belt 31 is wound around the driving pulley 23 and the driven pulley 24.

In the continuously variable transmission 24 having the above structure, the distance between the fixed sheave 25 and the movable sheave 26 is controlled by controlling the hydraulic pressure acting on the hydraulic actuator 27.
That is, the groove width is adjusted. As a result, the driving pulley 2
3, the winding radius of the belt 31 changes, and the speed ratio of the continuously variable transmission 9 is controlled steplessly (continuously). In addition, by controlling the hydraulic pressure acting on the hydraulic actuator 30 in accordance with this, the groove width between the fixed sheave 28 and the movable sheave 29 is adjusted, and the tension of the belt 31 is controlled. As described above, in this embodiment, the stepped transmission 8 and the continuously variable transmission 9 are arranged in series in the power transmission path on the output side of the engine 1.

Between the output shaft 7 and the final gear 4, there is provided a transmission (not shown) constituted by gears and the like. As the final gear 4, a known gear having a ring gear, a pinion gear, a side gear, and the like can be used. The output side of the final gear 4 is connected to the front wheels (not shown) of the vehicle. The final gear 4 also has a function as a differential.

Next, a control system of the FF vehicle having the above hardware configuration will be described with reference to the block diagram of FIG. First, an electronic control unit (ECU) 32 that controls the engine 1, the stepped transmission 8, and the continuously variable transmission 9 is provided. The electronic control unit 32 includes an arithmetic processing unit (CPU
Or MPU) and storage device (RAM and ROM)
And a microcomputer mainly including an input / output interface. For the electronic control unit 32, a signal of an engine speed sensor 33, a signal of an accelerator opening sensor 34, a throttle opening sensor 35
, A signal of a brake switch 36, a signal of a shift position sensor 37 for detecting an operation state of a shift lever (not shown), a signal of an input rotation speed sensor 38 for detecting the rotation speed of the driving pulley 23, a driven pulley For example, a signal of an output rotation speed sensor 39 for detecting the rotation speed of 24 is input.

By operating the shift lever, a driving position (for example, a drive position or a reverse position) for setting a state for transmitting the driving force of the engine 1 to the wheels, and a state where the driving force of the engine 1 is not transmitted to the wheels. A non-drive position to be set (for example, a neutral position, a parking position) can be selected. When the drive position is selected, the forward gear can be set by the stepped transmission 8, and when the reverse position is selected, the reverse gear can be set by the stepped transmission 8. Further, the vehicle speed can be calculated based on the signal of the output rotation speed sensor 39.

The electronic control unit 32 stores various data in advance for controlling the engine 1, the stepped transmission 8, and the continuously variable transmission 9 based on various signals. For example, the engine speed controls the gear ratio of the stepped transmission 8 and the continuously variable transmission 9 based on the vehicle state such as the accelerator opening, the vehicle speed, and the engine speed, so that the optimal operating state of the engine 1 is obtained. Is stored.

Further, a fuel injection device 40, an ignition timing control device 41, and a hydraulic control device 42 are connected to the electronic control device 32 so that data communication is possible. The hydraulic control device 42 controls the first clutch C of the stepped transmission 8.
By operating various solenoid valves 42A for controlling the hydraulic pressure acting on the first and second clutches C2 and the shift lever (not shown), the first clutch C1, the second clutch C2, and the third clutch CR are operated. It has a manual valve 42B for controlling the hydraulic pressure acting thereon, and various solenoid valves 42C for controlling the hydraulic pressure acting on the hydraulic actuators 27, 30 of the continuously variable transmission 9. Then, based on various input signals and data, the electronic control unit 32 outputs control signals to the fuel injection device 40, the ignition timing control device 41, the hydraulic control device 42, and the like.

Here, the correspondence between the configuration of the above embodiment and the configuration of the present invention will be described. That is, the engine 1
Correspond to the driving force source of the present invention, and the counter shaft 6 and the output shaft 7 correspond to the power transmission shaft of the present invention.

An example of control of the vehicle having the above hardware configuration will be described with reference to the flowchart of FIG. First, the engine 1, the stepped transmission 8, and the continuously variable transmission 9 are controlled based on a signal input to the electronic control unit 32.
Then, based on the above-mentioned signal, it is determined whether or not the speed change of the stepped transmission 8 should be performed (step S1). If a negative determination is made in step S1, the process returns. On the other hand, if a positive determination is made in step S1, control is performed to change the gear ratio of the continuously variable transmission 9 during the shifting of the stepped transmission 8 (step S1).
2), is returned. Here, the method of determining the shift progress state (transition transition state) of the stepped transmission 8 includes a method based on whether the engine speed is synchronized with the speed after the shift, and a solenoid based on the hydraulic control device 42. The method includes a method based on a duty ratio of a current value supplied to the valve 42A and a method of measuring a time from a start of shifting of the stepped transmission 8 by a timer.

Here, the correspondence between the functional means shown in FIG. 3 and the configuration of the present invention will be described.
Step S2 corresponds to the speed ratio control means of the present invention. Then, an example of the control contents corresponding to step S1 and step S2 will be described based on the diagram of FIG.
In the diagram of FIG. 4, the continuously variable transmission 9 corresponding to the two-stage speed ratio of the stepped transmission 8 (that is, the low gear and the high gear) is shown.
(Ie, the value obtained by dividing the number of revolutions of the counter shaft 6 by the number of revolutions of the output shaft 7) and the input / output speed ratio of the transmission mechanism 3 (specifically, the input number of revolutions (engine number of revolutions)). The relationship with the number of rotations (the value divided by the number of rotations of the driven pulley 24) is shown.

In the control example of FIG. 3, the stepped transmission 8
For example, when the speed ratio of the low gear is changed from the low gear to the high gear, the point A1 on the low gear side and the point on the high gear side are changed so that the change amount (change width or change rate) of the input / output speed ratio is as small as possible. It is controlling to B1 or point D1. On the other hand, when the gear ratio of the stepped transmission 8 is changed from, for example, a high gear to a low gear, the change in the input / output gear ratio is made as small as possible from the point E1 on the high gear side to the low gear side. Is controlled to the point F1 or the point G1. In other words, in FIG. 4, the speed ratio of the continuously variable transmission 9 is controlled such that the gradient (inclination) of the arrow indicating the change trajectory of the speed ratio of the continuously variable transmission 9 becomes as steep as possible. .

The gradient of the arrow indicating the change locus of the speed ratio of the continuously variable transmission 9 in FIG. 4 is the input / output speed ratio substantially equal to the change amount of the input / output speed ratio of the automatic transmission having the torque converter. It is desirable to be set as follows.

As described above, according to this embodiment, at the time of shifting of the stepped transmission 8, the input / output transmission ratio can be changed as much as possible by cooperatively controlling the transmission ratio of the continuously variable transmission 9. Is suppressed. Therefore, at the time of gear shifting of the stepped transmission 8, torque fluctuation due to inertia of the engine 1 is suppressed as much as possible, so that shift shock can be suppressed, and the riding comfort of the vehicle is improved. Further, the continuously variable transmission 9 is provided between the stepped transmission 8 and the final gear 4, but the load acting on the belt 31 because the torque fluctuation is suppressed in advance by the stepped transmission 8. Is reduced and its durability is improved.

Further, since the shift shock is small, the control width of the input / output gear ratio can be set as wide as possible (that is, wide step). Therefore, the power performance at the time of starting the vehicle can be ensured, and the engine 1 can be operated in a region where the combustion efficiency is high in response to the change in the vehicle state. That is, it is possible to achieve both improvement in the startability of the vehicle, improvement in fuel efficiency, and reduction in emissions.

Note that the gear ratio of the continuously variable transmission 9 can be controlled so that the input / output gear ratio does not change during a gear shift transition in which the stepped transmission 8 switches between the low gear and the high gear. . If the width of the gear ratio between the low gear and the high gear is further widened by such control, the width of control of the input / output gear ratio can be further expanded, and the degree of freedom in flavoring power performance and fuel efficiency is further increased. there is a possibility.
When such control is performed, for example, it is more effective to improve the responsiveness of the continuously variable transmission 9 by using an electric oil pump as the hydraulic pressure source for supplying the hydraulic pressure to the hydraulic control device 42.

Further, according to this embodiment, since the control width of the input / output gear ratio can be increased by increasing the gear ratio width of the stepped transmission 8, the speed of the continuously variable transmission 9 can be increased. The control width of the ratio is made as small as possible, in other words, the inter-axis distance between the countershaft 6 and the output shaft 7 which is a component for setting the control width of the speed ratio of the continuously variable transmission 9 is made as small as possible. And the piston strokes of the hydraulic actuators 27 and 30 can be made as short as possible, and the size and weight of the system can be reduced.

In this embodiment, the change width of the input / output gear ratio is equal to or larger than the change width of the input / output gear ratio in a structure in which a so-called torque converter and a continuously variable transmission are arranged in series. It can be designed to be

Further, the embodiment of FIG. 1 automatically stops the engine when a predetermined engine stop condition is satisfied, and automatically starts the engine when the engine stop condition is released during the automatic stop of the engine. To return to the operating state,
The invention can also be applied to a vehicle having a so-called eco-run system.

In the embodiment shown in FIG. 1, the positions of the stepped transmission and the continuously variable transmission in the power transmission path can be reversed. That is, the power of the engine is first input to the continuously variable transmission, and the power output from the continuously variable transmission is transmitted to the continuously variable transmission.
In the case of such a configuration, the clutch of the stepped transmission is released at the time of rapid deceleration, so that the change in the belt winding radius with respect to the pulley is hardly hindered, so that the durability of the belt can be improved.

FIG. 5 is a skeleton diagram showing another embodiment in which the present invention is applied to an FF vehicle. FIG. 5 is different from the embodiment shown in FIG. 1 in that a planetary gear type stepped transmission is used instead of the constant mesh type stepped transmission. That is, the transaxle 50 is provided on the output side of the engine 1. This transaxle 50
Has a transmission mechanism 51 and a final gear 52.

First, the structure of the transmission mechanism 51 will be described. The transmission mechanism 51 includes an input shaft 53, an intermediate shaft 54, and an output shaft 5
Five. Here, the rotation center axis X2 of the input shaft 53 and the rotation center axis Y of the intermediate shaft 54
2 and the rotation center axis Z2 of the output shaft 55 are arranged in parallel with each other. Further, in the power transmission path between the input shaft 53 and the intermediate shaft 54, a continuously variable transmission 9 is provided.
A stepped transmission 56 is provided in a power transmission path between the output shaft 4 and the output shaft 55.

The input shaft 53, the intermediate shaft 54 and the output shaft 55 are arranged in the width direction of the vehicle so that the output of the engine 1 is transmitted to the input shaft 53. The continuously variable transmission 9 has an input shaft 60, and the input shaft 60 and the input shaft 53 are arranged on the same axis. An input clutch C3 is provided between the input shaft 53 and the input shaft 60 of the continuously variable transmission 9.

The continuously variable transmission 9 has the same configuration as the continuously variable transmission 9 shown in FIG. 1, and the fixed sheave 25 of the continuously variable transmission 9 is fixed to the input shaft 60. Further, the movable sheave 26 is configured to be movable in the axial direction of the input shaft 60. further,
Another fixed sheave 28 of the continuously variable transmission 9 is an intermediate shaft 54.
, And the other movable sheave 29 is configured to be movable in the axial direction of the intermediate shaft 54.

The stepped transmission 56 is a planetary gear type transmission for setting a forward step or a reverse step. The stepped transmission 56 is provided on the outer peripheral side of the intermediate shaft 54. This stepped transmission 56 has a first sun gear 57 formed on an intermediate shaft 54, and a first hollow shaft 58 mounted on the outer periphery of the intermediate shaft 54 so as to be rotatable relative to the intermediate shaft 54. are doing. A second sun gear 59 is formed in the first hollow shaft 58, and a pitch circle diameter of the second sun gear 59 is set to be larger than a pitch circle diameter of the first sun gear 57. Further, a clutch C4 for controlling a power transmission state between the intermediate shaft 54 and the first hollow shaft 58 is provided. Further, on a casing (not shown) side of the transaxle 50, a brake B1 for stopping rotation of the first hollow shaft 58 is provided.

On the other hand, outside the intermediate shaft 54, a ring gear 61 is disposed concentrically with the intermediate shaft 54, and a first pinion gear 62 meshing with the ring gear 61 and the second sun gear 59 is provided. Further, a second pinion gear 63 meshing with the first pinion gear 62 and the first sun gear 57 is provided. Further, a second hollow shaft 64 is provided on the outer periphery of the intermediate shaft 54 so as to be rotatable relative to the intermediate shaft 54. The carrier 65 of the first pinion gear 62 and the carrier 66 of the second pinion gear 63 are connected to the second hollow shaft 64. Further, a reverse brake BR for stopping rotation of the ring gear 61 is provided on the casing side of the transaxle 50. Further, a drive gear 67 is formed on the second hollow shaft 64.

Here, the input clutch C3 and the clutch C
4. The engagement / release control of the brake B1 and the reverse brake BR will be described based on the operation chart of FIG. This figure 6
, The mark “○” means that the friction engagement device is engaged, and the blank space means that the friction engagement device is released. That is, when the low gear of the forward gear is selected, the input clutch C3 and the brake B1 are engaged,
The clutch C4 and the reverse brake BR are released. Therefore, the torque of the input shaft 53 is transmitted to the intermediate shaft 54 by the continuously variable transmission 9 and reduced by the action of the sun gear 57, the second pinion gear 63, the first pinion gear 62 and the sun gear 59 to the second hollow shaft 64. The power is transmitted to the driven gear 68 via the drive gear 67.

On the other hand, when the forward gear is selected, the input clutch C3 and the clutch C4 are engaged, and the brake B1 and the reverse brake BR are released. Therefore, the rotation of the intermediate shaft 54 and the first
The hollow shaft 58 and the second hollow shaft 64 rotate integrally,
The torque is transmitted to the driven gear 68 via the drive gear 67. When the reverse gear is selected, the input clutch C3 and the reverse brake BR are engaged, and the clutch C4 and the brake B1 are released. Therefore, the drive gear 67 rotates in a direction opposite to that in the case of the forward gear.

On the other hand, a driven gear 68 and a final drive gear 69 are formed on the output shaft 55, and the drive gear 67 and the driven gear 68 are engaged with each other. The final gear 52 has a ring gear 71 formed on the outer periphery of the differential case 70, a pinion gear 72 mounted inside the differential case 70, and side gears 73 and 74 meshed with the pinion gear 72. This side gear 7
Drive shafts 75 and 76 are connected to 3 and 74, respectively. The ring gear 69 and the final drive gear 69 are meshed.

Also in the case of the embodiment of FIG. 5, the control system can be configured in the same manner as the embodiment of FIG. That is, based on the signal input to the electronic control unit, the engagement / disengagement of the friction engagement devices such as the input clutch C3, the clutch C4, the brake B1, and the reverse brake BR is controlled, and the operation of the continuously variable transmission 9 is controlled. Hydraulic actuator 2
7, 30 are controlled. In the embodiment of FIG. 5, a signal from a sensor (not shown) for detecting the rotation speed of the drive gear 67 is input to the electronic control unit.
Thus, when comparing the embodiment of FIG. 1 and the embodiment of FIG. 5, the arrangement positions of the stepped transmission and the continuously variable transmission in the power transmission path are reversed. That is, the power of the engine 1 is input to the continuously variable transmission 9 first, and the power output from the continuously variable transmission 9 is transmitted to the continuously variable transmission 50.

Here, the correspondence between the configuration of the above embodiment of FIG. 5 and the configuration of the present invention will be described. That is, the input shaft 56 and the intermediate shaft 54 correspond to the power transmission shaft of the present invention. Also, in the embodiment shown in FIG. 5, by applying the control shown in FIG. 3, the same effect as that of the embodiment shown in FIG. 1 can be obtained. This figure 5
In the embodiment, the input / output speed ratio of the speed change mechanism 50 is
This is a value obtained by dividing the engine speed by the speed of the drive gear 67.

Further, the present invention can be used as a continuously variable transmission of a toroidal type continuously variable transmission having a disk having an arc-shaped friction surface and a power roller in contact with the disk. Further, in the present invention, an electric motor may be employed as the driving force source.

[0056]

As described above, according to the first aspect of the invention, the input / output speed ratio can be changed by cooperatively controlling the speed ratio of the continuously variable transmission during the shift transition of the stepped transmission. As much as possible. Therefore, when shifting the stepped transmission,
The torque fluctuation due to the inertia of the driving force source is suppressed as much as possible, so that the shift shock can be suppressed, and the riding comfort of the vehicle is improved. Further, since there is little shift shock due to the shift of the stepped transmission, the control width of the input / output gear ratio can be set as wide as possible, and the power performance at the time of starting the vehicle can be secured, and the driving force The source can be operated in an efficient area. That is, it is possible to achieve both improvement in the startability of the vehicle, improvement in fuel efficiency, and reduction in emissions.

According to the second aspect of the present invention, the speed ratio of the continuously variable transmission is controlled such that the amount of change in the input / output speed ratio is less than the maximum value, and the same effect as that of the first aspect is obtained. be able to.

According to the third aspect of the present invention, the same effects as those of the first or second aspect can be obtained, and the change width of the input / output speed ratio can be increased. The control width of the ratio can be made as small as possible. For this reason, the distance between the power transmission shafts, which is a component for setting the control ratio of the transmission ratio of the continuously variable transmission, is reduced as much as possible, and the operation amount of the actuator in the axial direction of the power transmission shaft is reduced. By making it as short as possible, the size and weight of the system can be reduced.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram showing an embodiment of a power transmission path of an FF vehicle using the present invention.

FIG. 2 is a block diagram showing a control system corresponding to the system of FIG.

FIG. 3 is a flowchart illustrating a control example of the present invention.

FIG. 4 is a diagram showing control contents performed in the control example of FIG. 3;

FIG. 5 is a skeleton diagram showing another embodiment of the power transmission path of the FF vehicle using the present invention.

6 is a chart showing engagement / disengagement of the friction engagement device shown in FIG. 5;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine, 3 ... 50 Transmission mechanism, 6 ... Counter shaft, 7 ... Output shaft, 8, 56 ...
Stepped transmission, 9: continuously variable transmission, 23: drive side pulley, 24: driven side pulley, 25, 28: fixed sheave, 26, 29: movable sheave, 31: belt, 2
7, 30: hydraulic actuator, 54: intermediate shaft, 56: input shaft, X1, X2, Y
1, Y2, Z1 ... axis.

Claims (3)

[Claims] 1. A control device for a continuously variable transmission for a vehicle comprising a transmission mechanism in which a stepped transmission and a continuously variable transmission are arranged in series on an output side of a driving force source, wherein the stepped transmission is provided. A control device for a continuously variable transmission for a vehicle, comprising: a speed ratio control unit that changes a speed ratio of the continuously variable transmission during a shift transition of the vehicle. 2. An input / output gear ratio indicating a ratio between an input-side rotational speed of the speed change mechanism and an output-side rotational speed of the speed change mechanism during a speed change of the stepped transmission. The control device for a continuously variable transmission for a vehicle according to claim 1, wherein a speed ratio of the continuously variable transmission is controlled so as to reduce a variation amount of the continuously variable transmission. 3. The continuously variable transmission is constituted by a set of sheaves attached to two mutually parallel power transmission shafts and capable of relatively moving in the axial direction of the power transmission shaft. It is characterized by comprising two pulleys, a belt wound around the two pulleys, and an actuator that operates in the axial direction of the power transmission shaft to control a groove width between sheaves of each pulley. The control device for a continuously variable transmission for a vehicle according to claim 1 or 2, wherein