JP4200569B2 - Control device for continuously variable transmission with starting clutch - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device for a continuously variable transmission in a vehicle including a continuously variable transmission with a starting clutch.
[0002]
[Prior art]
2. Description of the Related Art A power transmission device including a continuously variable transmission in which a belt is stretched between an input pulley and an output pulley whose groove width can be changed is known (see Japanese Patent No. 2651810). In such a power transmission device, a start clutch is provided between the continuously variable transmission and the drive wheel side so as to absorb torque fluctuation on the engine side and not transmit torque fluctuation to the drive wheel side. The start clutch is slip-controlled by adjusting the engagement state of the start clutch.
[0003]
In a vehicle equipped with a continuously variable transmission with a starting clutch as described above, it is general that the transmission ratio is not controlled while the transmission ratio is fixed to the maximum (Low) while the starting clutch is slipping. That is, when the starting clutch is slipping, the vehicle speed does not match the rotation speed on the output pulley side, and if the gear ratio is controlled by setting the target rotation speed of the input pulley according to the vehicle speed, The gear ratio does not match the rotational speed on the pulley side. If the starting clutch is engaged in this state and the vehicle speed matches the rotational speed on the output pulley side, the result is a gear ratio that does not match the vehicle speed. For this reason, since the target rotational speed of the input pulley cannot be set appropriately while the starting clutch is slipping, the speed ratio is not controlled.
[0004]
[Problems to be solved by the invention]
In a conventional vehicle equipped with a continuously variable transmission with a starting clutch, gear shifting control is not performed while the starting clutch is slipping. Therefore, if the vehicle speed increases, the rotational speed on the input side may increase excessively. It was.
[0005]
The present invention has been made in view of the above-described situation. Even when the start clutch is in a slip state, the continuously variable transmission with a start clutch capable of controlling the gear ratio by appropriately setting the target rotational speed of the input pulley. An object is to provide a control device.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, there is provided a continuously variable transmission with a starting clutch provided with a starting clutch in a continuously variable transmission that continuously adjusts a gear ratio between an input pulley and an output pulley. When the start clutch slips, the state control means maintains the slip state in a predetermined state, and the transmission ratio control means sets the target rotational speed of the input pulley based on the rotational speed of the output pulley and the required load, and the input pulley The gear ratio of the continuously variable transmission is controlled so as to achieve the target rotational speed. For this reason, even if the starting clutch is in the slip state, the rotational speed of the output pulley is stable with respect to the vehicle speed, and the target rotational speed of the input pulley is appropriately set to control the gear ratio of the continuously variable transmission.
[0007]
In order to achieve the above object, according to the second aspect of the present invention, there is provided a continuously variable transmission with a starting clutch provided with a starting clutch in a continuously variable transmission that continuously adjusts a gear ratio between an input pulley and an output pulley. The transmission ratio control means sets the target rotation speed of the input pulley based on the rotation speed of the output pulley and the required load, and controls the transmission ratio of the continuously variable transmission so that the input pulley becomes the target rotation speed. Further, when the slip state of the starting clutch is detected by the clutch slip detecting means, the target rotational speed of the input pulley is set so as to maintain the target gear ratio at that time. For this reason, even if the starting clutch is in the slip state, the rotational speed of the output pulley is stabilized, the target rotational speed of the input pulley is set appropriately, and the speed ratio of the continuously variable transmission is controlled.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic diagram of a vehicle equipped with a control device for a continuously variable transmission with a starting clutch according to an embodiment of the present invention, FIG. 2 is a block diagram of the control device, and FIG. 3 is a flowchart of gear ratio control. Is shown. The vehicle shown in the figure is described by taking as an example a hybrid vehicle that uses both an electric motor and an engine to obtain driving force. However, any vehicle other than a hybrid vehicle may be used as long as it has a continuously variable transmission with a starting clutch. The present invention can also be applied to other vehicles.
[0009]
As shown in FIG. 1, the output shaft 2 of the engine 1 is connected to the input side of a continuously variable transmission (CVT) 5 via a clutch 3 and a double pinion planetary gear mechanism 4 for forward / reverse switching. . An electric motor / generator (M / G) 6 also serving as an engine starter motor is connected to the input side of the CVT 5. The output side of the CVT 5 is connected to the differential 8 via the starting clutch 7, and the driving force is transmitted to the driving wheels 9. Incidentally, reference numeral 41 in the figure denotes a brake for stopping the ring gear of the planetary gear mechanism 4. The CVT 5 is configured by a belt 13 being stretched between an input pulley 11 and an output pulley 12 whose groove widths can be changed, and by changing the groove widths of the input pulley 11 and the output pulley 12 by the CVT operating means 14, A predetermined gear ratio can be obtained.
[0010]
A primary rotational speed sensor (NP sensor) 15 for detecting the rotational speed of the input pulley 11 of the CVT 5 is provided, and the rotational speed on the input side of the CVT 5 is detected by the NP sensor 15. A secondary rotational speed sensor (NS sensor) 16 is provided on the output pulley 12 side of the CVT 5 as an output pulley rotational speed detecting means for detecting the rotational speed of the rotary shaft 12a of the output pulley 12. The rotational speed on the output side is detected.
[0011]
In addition, a drive shaft rotation speed sensor (rotation sensor) 18 for detecting the rotation speed of the drive axle 17 of the drive wheel 9 is provided, and the rotation speed corresponding to the vehicle speed of the drive axle 17 on the downstream side of the start clutch 7 by the rotation sensor 18. Is detected. By comparing the detection information of the NS sensor 16 and the detection information of the rotation sensor 18, the slip state of the starting clutch 7 can be detected. On the other hand, an accelerator position sensor (APS) 19 is provided as a required load detecting means for detecting a driver's required load, and the depression state of the accelerator pedal is detected by the APS 19.
[0012]
Detection information of the NP sensor 15, NS sensor 16, rotation sensor 18 and APS 19 is input to the control device 20, and the control device 20 outputs an operation command to the CVT actuating means 14 based on the detection information of various sensors to output CVT 5. Control the gear ratio. Further, the control device 20 controls the torque of the engine 1 or M / G 6 based on the detection information of the NS sensor 16 and the rotation sensor 18, that is, the slip state of the start clutch 7, and sets the slip state of the start clutch 7 to a predetermined state. The feedback control is performed so as to be maintained (slip state control means).
[0013]
Note that the slip state control means for maintaining the slip state of the start clutch 7 in a predetermined state is a feedback control of the clutch capacity of the start clutch 7 based on the detection information of the NS sensor 16 and the rotation sensor 18, and the engagement of the start clutch 7. The combined state may be adjusted.
[0014]
In the hybrid vehicle described above, the driving force 9 is transmitted to the input side of the CVT 5 only by the M / G 6 by driving the driving wheel 9 by turning the clutch 3 on / off and driving the engine 1 as needed. Thus, the engine 1 is driven and the M / G 6 and the engine 1 are used together to transmit driving force to the input side of the CVT 5 to drive the drive wheels 9. That is, if the motor of the M / G 6 is operated with the clutch 3 turned off and the brake 41 turned off, the motor alone traveling mode is set, and at the time of deceleration, the regenerative braking mode is set by operating the M / G 6 generator. . When the clutch 3 is turned on and the brake 41 is turned off, the planetary gear mechanism 4 rotates together with the output shaft of the engine 1, and if the M / G 6 is idled, the engine independent traveling mode, M / G If the motor 6 is operated, the engine / motor combined driving mode is selected. If the M / G 6 is operated for power generation, the engine / generator combined driving mode is selected. The engine 1 is started by transmitting the motor output of the M / G 6 to the output shaft of the engine 1 in this state. In the state where the clutch 3 is turned off and the brake 41 is turned on, the carrier of the planetary gear mechanism 4 is reversely rotated with respect to the output shaft of the engine 1 so that the reverse movement by the engine output is possible.
[0015]
In a hybrid vehicle equipped with the CVT 5 with the starting clutch 7, during the operation with the starting clutch 7 coupled, the rotational speed (target NP) of the target input pulley 11 based on the vehicle speed and the detected information of the APS 19 And the gear ratio of the CVT 5 is controlled so that the rotational speed of the input pulley 11 becomes the target NP.
[0016]
On the other hand, in a hybrid vehicle equipped with the CVT 5 with the starting clutch 7, for example, when the engine 1 is started while the engine 1 is stopped and the M / G 6 is running, torque fluctuation occurs when the engine 1 is started. Then, the engagement state of the start clutch 7 is adjusted to cause the start clutch 7 to slip so as to absorb the torque fluctuation at the start of the engine 1 and not transmit the torque fluctuation to the drive wheel 9 side.
[0017]
A block configuration for controlling the transmission ratio of the CVT 5 will be described with reference to FIG.
[0018]
As shown in the figure, the control device 20 sets the target rotational speed (target NP) of the input pulley 11 based on the rotational speed (NS) of the output pulley 12 and the required load (AP), and the input pulley 11 A gear ratio control means 21 is provided for feedback control of the gear ratio of the CVT 5 so as to be the target NP.
[0019]
That is, the gear ratio control means 21 is provided with a target NP setting means 22 and a CVT operation command means 23, and detection information of the NS sensor 16 and the APS 19 is input to the target NP setting means 22. In the target NP setting means 22, a target NP is set based on the detection information of the NS sensor 16 and the APS 19, and the target NP is input to the CVT operation command means 23. Further, detection information of the NP sensor 15 is input to the CVT operation command means 23. The CVT operation command means 23 outputs an operation command to the CVT operation means 14 based on the target NP and the detection information of the NP sensor 15. Thereby, the CVT 5 is shifted so that the rotational speed of the input pulley 11 becomes the target NP, and the gear ratio of the CVT 5 is feedback-controlled.
[0020]
On the other hand, the control device 20 includes slip state control means 24 for controlling the slip state to be maintained in a predetermined state when the start clutch 7 slips. Detection information of the NS sensor 16 and the rotation sensor 18 is input to the slip state control means 24, and the slip state control means 24 compares the detection information of the NS sensor 16 with the detection information of the rotation sensor 18, thereby A slip state is detected. Information on the slip state is sent to the gear ratio control means 21. When the slip state of the starting clutch is detected by the slip state control means 24, the torque of the engine 1 or M / G 6 is feedback controlled to keep the slip speed of the starting clutch 7 at a constant value.
[0021]
The flow of control of the gear ratio of CVT 5 will be described with reference to FIG.
[0022]
As shown in the figure, it is determined whether or not slip has occurred in the starting clutch 7 in step S1, and slip occurs when the difference between the detected value of the NS sensor 16 and the detected value of the rotation sensor 18 is more than a predetermined value. It is judged that If it is determined that no slip has occurred in the starting clutch 7, a target NP is set based on the rotational speed NS of the output pulley 12 and the required load AP based on the detection information of the NS sensor 16 and the APS 19 in step S2. When the target NP is set, the CVT 5 is shifted in step S3 based on the set target NP, and the gear ratio is controlled so that the rotational speed of the input pulley 11 becomes the target NP.
[0023]
On the other hand, if it is determined in step S1 that the starting clutch 7 is slipping, the torque of the engine 1 or M / G 6 is feedback controlled in step S4 so that the slip speed of the starting clutch 7 is maintained at a constant value. To do. After the slip state of the starting clutch 7 is kept constant in step S4, the process proceeds to step S2, and the gear ratio is controlled as in the case where no slip occurs.
[0024]
In the above-described control device for the continuously variable transmission with a starting clutch, when the starting clutch 7 is not slipped, the target NP of the input pulley 11 is determined based on the rotational speed on the output pulley 12 side correlated with the vehicle speed and the required load. The transmission ratio of the CVT 5 is controlled so that the input pulley 11 becomes the target NP. Further, when slip has occurred in the starting clutch 7, after maintaining the slip state in a predetermined state, the input pulley 11 is based on the rotational speed on the output pulley 12 side and the required load in the same manner as when slip does not occur. Target NP is set, and the gear ratio of the CVT 5 is controlled so that the input pulley 11 becomes the target NP.
[0025]
That is, even if the starting clutch 7 is in the slip state, the slip state is maintained in a predetermined state, so that the rotational speed of the output pulley 12 is stabilized with respect to the vehicle speed, and the control using the rotational speed of the output pulley 12 as an input parameter remains. However, the target NP of the input pulley 11 can be set appropriately to control the transmission ratio of the CVT 5, and the speed change control using the output pulley rotational speed and the required load as input parameters is common regardless of the start clutch 7 slip state. Can be applied.
[0026]
A control device for a continuously variable transmission with a starting clutch according to another embodiment of the present invention will be described with reference to FIGS. FIG. 4 shows a block configuration of the control device, and FIG. 5 shows a flowchart of the gear ratio control. In addition, since the schematic structure of a vehicle is the same as FIG. 1, the overlapping description is abbreviate | omitted.
[0027]
The control device for a continuously variable transmission with a start clutch according to this embodiment includes an NS sensor 16 and a rotation sensor 18 as clutch slip detection means. The speed ratio control means 21 of the control device 20 includes a start clutch 7. When a slip state exceeding a predetermined value is detected, target maintenance setting means 31 is provided for setting the target NP of the input pulley 11 while maintaining the target gear ratio at that time.
[0028]
A block configuration for controlling the transmission ratio of the CVT 5 according to another embodiment will be described with reference to FIG.
[0029]
As shown in the figure, the control device 20 sets the target rotational speed (target NP) of the input pulley 11 based on the rotational speed (NS) of the output pulley 12 and the required load (AP), and the input pulley 11 A gear ratio control means 21 is provided for feedback control of the gear ratio of the CVT 5 so as to be the target NP. Further, in the gear ratio control means 21, when a slip state of a predetermined level or more of the start clutch 7 is detected, the target NP of the input pulley 11 is set while maintaining the target gear ratio at that time.
[0030]
That is, the gear ratio control means 21 is provided with a target NP setting means 22 and a CVT operation command means 23 as in the configuration shown in FIG. 2, and the target NP setting means 22 detects the NS sensor 16 and the APS 19. A target NP is set based on the information, and the target NP is input to the CVT operation command means 23. Further, the CVT operation command means 23 outputs an operation command to the CVT operation means 14 based on the target NP and the detection information of the NP sensor 15, and the CVT 5 performs a speed change operation so that the rotational speed of the input pulley 11 becomes the target NP. Then, the gear ratio of CVT 5 is feedback controlled.
[0031]
On the other hand, the gear ratio control means 21 has a target maintenance setting means 31 for setting the target NP of the input pulley 11 in a state where the target gear ratio at that time is maintained when a slip state greater than a predetermined value of the start clutch 7 is detected. The target maintenance setting means 31 is supplied with detection information from the NS sensor 16 as clutch slip detection means. The target NP set by the target maintenance setting means 31 is input to the CVT operation command means 23, and the CVT operation command means 23 outputs an operation command to the CVT operation means 14 based on the detection information of the target NP and the NP sensor 15. To do. Then, the CVT 5 is shifted so that the rotational speed of the input pulley 11 becomes the target NP set by the target maintenance setting means 31, and the target gear ratio when the slip state of the start clutch 7 is detected is maintained. Thus, the gear ratio of CVT 5 is feedback controlled.
[0032]
The target NP applied when the operation command is output from the CVT operation command means 23 to the CVT operation means 14 is prioritized by the information from the target maintenance setting means 31, and the information from the target maintenance setting means 31 is input. If not, the information from the target NP setting means 22 is applied.
[0033]
The flow of control of the transmission ratio of CVT 5 will be described with reference to FIG.
[0034]
As shown in the figure, it is determined whether or not slip has occurred in the starting clutch 7 in step S11, and slip occurs when the difference between the detected value of the NS sensor 16 and the detected value of the rotation sensor 18 is more than a predetermined value. It is judged that If it is determined that no slip has occurred in the starting clutch 7, the target NP setting means 22 sets the target NP based on the rotational speed NS of the output pulley 12 and the required load AP based on the detection information of the NS sensor 16 and the APS 19 in step S12. Is set. When the target NP is set, the CVT 5 is shifted in step S13 based on the target NP set by the target NP setting means 22, and the gear ratio is controlled so that the rotational speed of the input pulley 11 becomes the target NP. The
[0035]
On the other hand, if it is determined in step S11 that the starting clutch 7 has slipped, the rotational speed NS of the output pulley 12 based on the detection information of the NS sensor 16 is maintained in step S14 so as to maintain the target gear ratio at the time of occurrence of the slip. Based on this, the target NP is set by the target maintenance setting means 31. When the target NP is set, the CVT 5 is shifted in step S13 based on the target NP set by the target maintenance setting means 31, and the gear ratio is controlled so that the rotational speed of the input pulley 11 becomes the target NP. The
[0036]
In the above-described control device for the continuously variable transmission with a starting clutch, when the starting clutch 7 is not slipped, the target NP of the input pulley 11 is determined based on the rotational speed on the output pulley 12 side correlated with the vehicle speed and the required load. The transmission ratio of the CVT 5 is controlled so that the input pulley 11 becomes the target NP. Further, when the start clutch 7 is slipped, the target NP of the input pulley 11 is set so as to maintain the target gear ratio at that time, and the gear ratio of the CVT 5 is controlled so that the input pulley 11 becomes the target NP. Is done.
[0037]
For this reason, even if the starting clutch 7 is in a slip state greater than or equal to a predetermined value, the rotational speed of the output pulley 12 is stabilized, the target NP of the input pulley 11 is appropriately set, the gear ratio of the CVT 5 is controlled, and the starting clutch Stable shift control is possible regardless of the slip state 7.
[0038]
【The invention's effect】
The control device for a continuously variable transmission with a starting clutch according to the first aspect of the invention maintains the slip state in a predetermined state when the starting clutch slips by the slip state control means, and the rotational speed and request of the output pulley by the speed ratio control means. The target rotational speed of the input pulley is set based on the load, and the gear ratio of the continuously variable transmission is controlled so that the input pulley is at the target rotational speed, so even if the starting clutch is in the slip state The rotational speed of the output pulley is stable with respect to the vehicle speed, and the target rotational speed of the input pulley is set appropriately, so that the speed ratio of the continuously variable transmission can be controlled. As a result, it is possible to perform stable shift control of the continuously variable transmission while applying gear ratio control based on the rotation speed of the output pulley and the required load in common regardless of the slip state of the starting clutch.
[0039]
According to a second aspect of the present invention, the control device for the continuously variable transmission with a starting clutch sets the target rotational speed of the input pulley based on the rotational speed of the output pulley and the required load by the transmission ratio control means, The gear ratio of the continuously variable transmission is controlled so that the pulley has the target rotational speed, and when the slip state of the starting clutch is detected by the clutch slip detection means, the target gear ratio at that time is maintained. Since the target rotational speed of the input pulley is set to the input pulley, the target rotational speed of the input pulley is set appropriately to control the gear ratio of the continuously variable transmission even when the starting clutch slips beyond a predetermined level. be able to. As a result, stable shift control of the continuously variable transmission is possible regardless of the slip state of the starting clutch.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a vehicle including a continuously variable transmission with a starting clutch according to an embodiment of the present invention.
FIG. 2 is a block configuration diagram of a control device.
FIG. 3 is a flowchart of gear ratio control.
FIG. 4 is a block diagram of a control device for a continuously variable transmission with a starting clutch according to another embodiment of the present invention.
FIG. 5 is a flowchart of gear ratio control.
[Explanation of symbols]
1 Engine 3 Clutch 4 Planetary gear mechanism 5 Continuously variable transmission (CVT)
6 Electric motor / generator (M / G)
7 Starting clutch 9 Drive wheel 11 Input pulley 12 Output pulley 15 Primary rotational speed sensor (NP sensor)
16 Secondary rotational speed sensor (NS sensor)
18 Drive axle rotation speed sensor (rotation sensor)
19 Accelerator position sensor (ASP)
20 control device 21 gear ratio control means 22 target NP setting means 24 slip state control means 31 target maintenance setting means

Claims (2)

A continuously variable transmission capable of continuously adjusting a gear ratio between an input pulley to which a driving force from a driving force source of the vehicle is input and an output pulley that outputs a driving force to the wheel side;
A starting clutch interposed between the output pulley and the wheel side;
Slip state control means for controlling to maintain the slip state in a predetermined state when the starting clutch slips;
Output pulley rotation speed detection means for detecting the rotation speed of the output pulley;
A required load detecting means for detecting a required load of the driver;
A shift that sets a target rotational speed of the input pulley based on the rotational speed of the output pulley and the required load, and controls a transmission ratio of the continuously variable transmission so that the input pulley becomes the target rotational speed. A control device for a continuously variable transmission with a starting clutch, comprising: a ratio control means. A continuously variable transmission capable of continuously adjusting a gear ratio between an input pulley to which a driving force from a driving force source of the vehicle is input and an output pulley that outputs a driving force to the wheel side;
A starting clutch interposed between the output pulley and the wheel side;
Clutch slip detecting means for detecting a slip state of the starting clutch;
Output pulley rotation speed detection means for detecting the rotation speed of the output pulley;
A required load detecting means for detecting a required load of the driver;
While setting the target rotational speed of the input pulley based on the rotational speed of the output pulley and the required load, and controlling the gear ratio of the continuously variable transmission so that the input pulley becomes the target rotational speed, The continuously variable transmission with a starting clutch further comprising a speed ratio control means for maintaining a target speed ratio when the clutch slip detecting means detects a slip state of the starting clutch. Control device.

Images