Control device for lock-up clutch and method for controlling lock-up clutch
The control device addresses unintended vehicle behaviors and discomfort by reducing hydraulic pressure to the lock-up clutch based on vehicle speed and gear ratio, enhancing slip control to manage torque fluctuations.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- JATCO LTD
- Filing Date
- 2021-03-08
- Publication Date
- 2026-07-08
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Existing lock-up clutch control systems do not adequately consider the vehicle's state, leading to unintended vehicle behaviors and driver discomfort when the accelerator is turned on while the lock-up clutch is engaged and the vehicle is running with the accelerator off.
A control device and method that reduce hydraulic pressure to the lock-up clutch when the accelerator is off, vehicle speed is below a predetermined speed, and the gear ratio is lower than a certain threshold, increasing the slip amount of the lock-up clutch to mitigate torque fluctuations.
Suppresses unintended vehicle behaviors and reduces driver discomfort by managing slip control based on vehicle state, particularly when the accelerator is turned on with the lock-up clutch engaged.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to a control device for a lock-up clutch and a control method for a lock-up clutch.
Background Art
[0002] Patent Document 1 discloses a lock-up control device for an automatic transmission that engages a lock-up clutch while the vehicle is coasting with the accelerator off.
[0003] When the accelerator is turned on while the lock-up clutch is engaged and the vehicle is running with the accelerator off, the lock-up control device prohibits complete engagement of the lock-up clutch and reduces the output of the engine through the engine output control means for a predetermined time. According to this, it is possible to reduce the shock generated by the torque fluctuation of the engine when the accelerator is turned on.
Prior Art Documents
Patent Documents
[0004]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0005] However, in Patent Document 1, it cannot be said that the state of the vehicle when executing the above control is sufficiently considered. Therefore, depending on the state of the vehicle, there may be a behavior of the vehicle that the driver does not intend, which may give the driver a sense of discomfort.
[0006] The present invention has been made in view of such technical problems, and an object thereof is to suppress the occurrence of a behavior of the vehicle that the driver does not intend when the accelerator is turned on in a state where the lock-up clutch is engaged and the vehicle is running with the accelerator off, and to reduce the sense of discomfort given to the driver. [Means for solving the problem]
[0007] According to one aspect of the present invention, a control device for controlling a lock-up clutch provided between an engine and a transmission mechanism mounted on a vehicle is provided, wherein when the lock-up clutch is engaged, the accelerator is off, the vehicle speed is below a predetermined vehicle speed, and the gear ratio of the transmission mechanism is lower than the predetermined gear ratio, the control device for the lock-up clutch reduces the hydraulic pressure supplied to the lock-up clutch to increase the amount of slip of the lock-up clutch when the accelerator is turned on.
[0008] According to another aspect of the present invention, a control method is provided for controlling a lock-up clutch provided between an engine and a transmission mechanism mounted on a vehicle, wherein when the accelerator is turned on while the lock-up clutch is engaged, the accelerator is off, the vehicle speed is below a predetermined vehicle speed, and the gear ratio of the transmission mechanism is lower than the predetermined gear ratio, the hydraulic pressure supplied to the lock-up clutch is reduced to increase the slip amount of the lock-up clutch. [Effects of the Invention]
[0009] In these embodiments, when the lock-up clutch is engaged, the accelerator is off, the vehicle speed is below a predetermined speed, and the gear ratio of the transmission mechanism is lower than the predetermined gear ratio, the hydraulic pressure supplied to the lock-up clutch is reduced to increase the amount of slip of the lock-up clutch. When the vehicle speed is below a predetermined speed and the gear ratio of the transmission mechanism is lower than the predetermined gear ratio, the torque fluctuation of the engine when the accelerator is turned on may cause the vehicle to behave in a way that the driver did not intend. Therefore, when the vehicle speed is below a predetermined speed and the gear ratio of the transmission mechanism is lower than the predetermined gear ratio, increasing the amount of slip of the lock-up clutch when the accelerator is turned on can suppress the occurrence of the vehicle's behavior that the driver did not intend. Thus, according to these embodiments, when the lock-up clutch is engaged and the vehicle is moving with the accelerator off, the occurrence of the vehicle's behavior that the driver did not intend can be suppressed when the accelerator is turned on, and the discomfort caused to the driver can be reduced. [Brief explanation of the drawing]
[0010] [Figure 1] Figure 1 is a schematic diagram of a vehicle equipped with a control device for a lock-up clutch according to an embodiment of the present invention. [Figure 2] Figure 2 is a time chart showing the vehicle's behavior while slip control is being performed. [Figure 3] Figure 3 is a flowchart showing the processes performed by the lock-up clutch control unit. [Figure 4] Figure 4 is a diagram illustrating the conditions under which slip control is performed. [Modes for carrying out the invention]
[0011] Embodiments of the present invention will be described below with reference to the attached drawings. In the following, a large gear ratio (reduction ratio) will be referred to as Low, and a small gear ratio (reduction ratio) will be referred to as High. Furthermore, changing the gear ratio to the Low side will be called downshifting, and changing it to the High side will be called upshifting.
[0012] Figure 1 is a schematic diagram of a vehicle 100 equipped with a transmission controller 40 as a control device for a lock-up clutch 2a according to an embodiment of the present invention. As shown in Figure 1, the vehicle 100 includes an engine 10 as a drive source, an automatic transmission 20, a torque converter 2 provided between the engine 10 and the automatic transmission 20, an engine controller 30, a transmission controller 40, and an air conditioner 80.
[0013] An exhaust passage 11 is connected to the engine 10. The exhaust passage 11 is equipped with a catalytic converter 12, a gasoline particulate filter (GPF) 13, and a muffler 14.
[0014] The catalytic converter 12 incorporates an exhaust gas purification catalyst such as a three-way catalytic converter and is positioned upstream of the GPF 13. The catalytic converter 12 purifies the exhaust gas by oxidizing unburned components such as HC and CO contained in the exhaust gas of the engine 10, and by reducing oxidizing components such as NOx.
[0015] The GPF13 is a filter that captures particulate matter (PM) in the exhaust of engine 10.
[0016] The muffler 14 is located downstream of the GPF 13 and reduces the exhaust noise of the exhaust passing through it.
[0017] With the above configuration, exhaust from the engine 10 flows through the exhaust passage 11, is purified by the catalytic converter 12, and after PM is removed by the GPF 13, it is discharged to the outside through the muffler 14.
[0018] The torque converter 2 is provided with a lock-up clutch 2a. The lock-up clutch 2a is engaged when the vehicle 100 is traveling at a speed equal to or higher than a predetermined lock-up vehicle speed. When the lock-up clutch 2a is engaged, the input shaft 2b as an input element of the torque converter 2 and the output shaft 2c as an output element are directly connected, and the input shaft 2b and the output shaft 2c rotate at the same speed. Therefore, in the state where the lock-up clutch 2a is engaged, the rotation of the output shaft 10a of the engine 1 is directly transmitted from the output shaft 2c of the torque converter 2 to the automatic transmission 20 as it is.
[0019] The automatic transmission 20 includes a forward and reverse switching mechanism 3 as a power transmission mechanism, a variator 4 as a speed change mechanism, a hydraulic control circuit 5, and an oil pump 6.
[0020] In the vehicle 100, the rotation generated by the engine 10 is transmitted to the drive wheels 50 through the torque converter 2, the forward and reverse switching mechanism 3, the variator 4, the gear set 7, and the differential gear device 8.
[0021] The forward and reverse switching mechanism 3 has a double pinion planetary gear set as a main component, its sun gear is coupled to the engine 10 via the torque converter 2, and the carrier is coupled to the input shaft 4d (primary pulley 4a) of the variator 4. The forward and reverse switching mechanism 3 further includes a forward clutch 3a that directly connects between the sun gear and the carrier of the double pinion planetary gear set, and a reverse brake 3b that fixes the ring gear. When the forward clutch 3a is engaged, the input rotation from the engine 10 via the torque converter 2 is directly transmitted to the primary pulley 4a as it is, and when the reverse brake 3b is engaged, the input rotation from the engine 10 via the torque converter 2 is reversely decelerated and transmitted to the primary pulley 4a.
[0022] The variator 4 is a continuously variable transmission mechanism that changes the rotation of the engine 10 transmitted to the input shaft 4d and transmits it from the output shaft 4e to the drive wheels 50. The variator 4 includes a primary pulley 4a provided on the engine 10 side in the power transmission path, a secondary pulley 4b provided on the drive wheel 50 side, and a belt 4c as an endless member wound around the primary pulley 4a and the secondary pulley 4b.
[0023] In the variator 4, by controlling the hydraulic pressure supplied to the primary pulley 4a and the hydraulic pressure supplied to the secondary pulley 4b, the contact radius between each pulley 4a, 4b and the belt 4c is changed, and the transmission ratio Rv is changed.
[0024] The oil pump 6 is a mechanical oil pump that is driven by inputting the rotation of the engine 10 and utilizing a part of the power of the engine 10. The oil discharged from the oil pump 6 is supplied to the hydraulic control circuit 5.
[0025] The hydraulic control circuit 5 includes a regulator valve 5a that regulates the pressure of the hydraulic oil supplied from the oil pump 6 to generate the required hydraulic pressure, a primary solenoid valve 5b that adjusts the hydraulic pressure supplied to the primary pulley 4a, a secondary solenoid valve 5c that adjusts the hydraulic pressure supplied to the secondary pulley 4b, a lock-up solenoid valve 5d that adjusts the hydraulic pressure (hereinafter referred to as LU pressure) supplied to the lock-up clutch 2a, a select solenoid valve 5e that adjusts the hydraulic pressure supplied to the forward clutch 3a and the reverse brake 3b, a manual valve 5f that switches the supply path of the hydraulic pressure to the forward clutch 3a and the reverse brake 3b, etc.
[0026] Based on the control signal from the transmission controller 40, the hydraulic control circuit 5 supplies the adjusted hydraulic pressure to each part of the torque converter 2, the forward and reverse switching mechanism 3, and the variator 4.
[0027] <The engine controller 30 consists of a microcomputer equipped with a CPU, RAM, ROM, input / output interfaces, etc. The engine controller 30 performs various processes by having the CPU read and execute programs stored in the ROM. The engine controller 30 can also be composed of multiple microcomputers.
[0028] The engine controller 30 controls the rotational speed Ne (hereinafter referred to as engine rotational speed Ne) and engine torque Te of the engine 10 based on signals from various sensors that detect the status of each part of the vehicle 100. The engine controller 30 also receives signals indicating the operating status of the air conditioner 80.
[0029] The transmission controller 40 consists of a microcomputer equipped with a CPU, RAM, ROM, input / output interface, etc. The transmission controller 40 and the engine controller 30 are connected in a communicative manner, and information is shared as needed. The transmission controller 40 performs various processes by having the CPU read and execute programs stored in the ROM. The transmission controller 40 can also be composed of multiple microcomputers. The transmission controller 40 and the engine controller 30 may also be integrated into a single controller.
[0030] The transmission controller 40 controls the engagement state of the lock-up clutch 2a, the gear ratio Rv of the variator 4, the engagement state of the forward clutch 3ab and the reverse brake 3b, etc., based on signals from various sensors that detect the condition of each part of the vehicle 100.
[0031] The transmission controller 40 receives signals from an accelerator position sensor 61 that detects the accelerator position APO corresponding to the amount of operation of the accelerator pedal 41, a brake fluid pressure sensor 62 that detects the brake fluid pressure BRP corresponding to the amount of operation of the brake pedal 42, a signal from an inhibitor switch 64 that detects the position of the shifter 63, a signal from a turbine rotation speed sensor 65 that detects the rotation speed Nt (hereinafter referred to as turbine rotation speed Nt) of the output shaft 2c of the torque converter 2, a signal from a primary rotation speed sensor 66 that detects the rotation speed Np (hereinafter referred to as primary rotation speed Np) of the input shaft 4d (primary pulley 4a) of the variator 4, a signal from a secondary rotation speed sensor 67 that detects the rotation speed Ns of the output shaft 4e (secondary pulley 4b) of the variator 4, a signal from a primary hydraulic pressure sensor 68 that detects the primary hydraulic pressure Pp supplied to the primary pulley 4a, a signal from a secondary hydraulic pressure sensor 69 that detects the secondary hydraulic pressure Ps supplied to the secondary pulley 4b, and a signal from an engine rotation speed sensor 70 that detects the engine rotation speed Ne.
[0032] In this embodiment, the transmission controller 40 performs coast lock-up control, which engages the lock-up clutch 2a when the vehicle 100 is coasting with the accelerator off (accelerator opening APO = 0). This allows engine braking to be applied to the vehicle 100 while coasting. Hereafter, coasting with the lock-up clutch 2a engaged by coast lock-up control will be referred to as coast lock-up driving.
[0033] Incidentally, if the accelerator is turned on while coast lock-up driving, a shock may occur in the vehicle 100 due to torque fluctuations in the engine 10. Therefore, when the accelerator is turned on while coast lock-up driving, the transmission controller 40 performs slip control by lowering the LU pressure and increasing the slip amount of the lock-up clutch 2a. This reduces the shock caused by torque fluctuations in the engine 10. In other words, it can suppress the occurrence of unintended behavior of the vehicle 100 by the driver.
[0034] The slip control will be explained below with reference to Figure 2. Figure 2 is a time chart showing the state of vehicle 100 under the execution of slip control.
[0035] Prior to time t1, vehicle 100 was traveling at a speed exceeding the lock-up speed, and the lock-up clutch 2a was fully engaged.
[0036] When the accelerator is released at time t1 (accelerator opening APO=0), the LU pressure decreases, and the lock-up clutch 2a slips. This increases the difference in rotational speed between the engine speed Ne and the turbine speed Nt. In Figure 2, the amount of slip of the lock-up clutch 2a increases from time t1 to time t3, reaching a predetermined slip amount at time t3.
[0037] At time t2, fuel injection to engine 10 is stopped, and the engine torque Te becomes negative. Since power from engine 10 is not needed during coasting, fuel efficiency can be improved by stopping fuel injection to engine 10.
[0038] At time t3, the slip amount of the lock-up clutch 2a becomes a predetermined amount. From time t3 onward, the LU pressure is controlled so that the slip amount of the lock-up clutch 2a becomes a predetermined amount.
[0039] When the accelerator is turned on at time t4 (accelerator opening APO ≠ 0), slip control is initiated, the LU pressure decreases, and the amount of slip of the lock-up clutch 2a increases.
[0040] At time t5, fuel injection to engine 10 resumes. The LU pressure also increases.
[0041] At time t5, the slip amount of the lock-up clutch 2a increases until just before it is released. Therefore, even if fuel injection to the engine 10 is restarted at time t5 and the engine torque Te increases, no major shock occurs to the vehicle 100.
[0042] From time t5 onward, the LU pressure increases, and at time t6, the LU pressure becomes the engagement pressure. As a result, the lock-up clutch 2a is fully engaged, and the engine rotational speed Ne matches the turbine rotational speed Nt.
[0043] The time from when the accelerator is turned on at time t4, causing the LU pressure to decrease and then increase, and the time from when the accelerator is turned on at time t4, causing the engine torque Te to increase, are predetermined based on the specifications of vehicle 100 and experimental results. Therefore, the timing of increasing the LU pressure and the timing of increasing the engine torque Te may be different.
[0044] In the example shown in Figure 2, coast slip control is performed between time t1 and time t4, keeping the lock-up clutch 2a in a slipping state. By performing coast slip control, if the drive wheels 50 lock up due to sudden braking during coasting, the lock-up clutch 2a can be quickly released to prevent engine stalling. However, it is not necessary to perform coast slip control.
[0045] Furthermore, in the example shown in Figure 2, fuel cut control is performed to stop fuel injection between time t2 and time t4. Fuel efficiency can be improved by stopping fuel injection during coasting. Note that it is not necessary to perform fuel cut control.
[0046] Incidentally, by performing slip control according to the state of the vehicle 100, it is possible to effectively suppress the occurrence of unintended behavior of the vehicle 100 by the driver.
[0047] Therefore, the transmission controller 40 of this embodiment performs slip control according to the state of the vehicle 100 by performing the process shown in Figure 3. The process performed by the transmission controller 40 will be described below with reference to Figure 3. The process shown in Figure 3 is performed at regular intervals.
[0048] In step S11, the transmission controller 40 determines whether the accelerator is off.
[0049] If the transmission controller 40 determines that the accelerator is off, it proceeds to step S12. If the transmission controller 40 determines that the accelerator is not off, it terminates the process.
[0050] In step S12, the transmission controller 40 determines whether the lock-up clutch 2a is engaged. Specifically, the transmission controller 40 determines whether the lock-up clutch 2a is engaged based on the LU pressure. Alternatively, the determination may be made based on the difference in rotational speed between the engine rotational speed Ne and the turbine rotational speed Nt.
[0051] If the transmission controller 40 determines that the lock-up clutch 2a is engaged, it proceeds to step S13. If the transmission controller 40 determines that the lock-up clutch 2a is not engaged, it terminates the process. Note that the engaged state includes not only the fully engaged state but also the slipped state. In other words, any state other than the released state is considered engaged.
[0052] In step S13, the transmission controller 40 determines whether the engine rotational speed Ne is greater than or equal to the lower limit rotational speed NeL and less than or equal to the upper limit rotational speed NeH.
[0053] If the transmission controller 40 determines that the engine rotational speed Ne is greater than or equal to the lower limit rotational speed NeL and less than or equal to the upper limit rotational speed NeH, it proceeds to step S14. If the transmission controller 40 determines that the engine rotational speed Ne is not greater than or equal to the lower limit rotational speed NeL and less than or equal to the upper limit rotational speed NeH, it terminates the process.
[0054] The lower limit rotational speed NeL is set to a value such that the engine rotational speed Ne does not fall below a certain level when the variator 4 is shifted along the coastline in a pre-set shift map based on the vehicle specifications and experimental results. The lower limit rotational speed NeL is, for example, set to 1000 [rpm] to 1200 [rpm].
[0055] The upper limit rotational speed NeH is set to a value such that, even without executing slip control when the engine rotational speed Ne is higher than the upper limit rotational speed NeH, the vehicle 100 will not exhibit behavior that would cause discomfort to the driver. Specifically, the upper limit rotational speed NeH is set based on the specifications of the vehicle 100 and experimental results. Furthermore, when the engine rotational speed Ne is high, it can be said that accelerating the vehicle 100 quickly by pressing the accelerator without executing slip control is more in line with the driver's intentions. The upper limit rotational speed NeH is set to, for example, 3000 [rpm] to 4000 [rpm].
[0056] In step S14, the transmission controller 40 determines whether the regeneration process of the GPF13 is being performed.
[0057] Because the GPF13 can become clogged if PM accumulates, it is necessary to regenerate the GPF13 by burning off the accumulated PM at the appropriate time. The GPF13 is regenerated by operating the engine 10 in a GPF regeneration mode with a higher load than normal. Therefore, during the GPF13 regeneration process, there is a higher possibility that the vehicle 100 will behave in a way that is not intended by the driver when the accelerator is pressed. For this reason, the transmission controller 40 determines whether the GPF13 regeneration process is being performed so that it can perform appropriate slip control according to the state of the vehicle 100.
[0058] If the transmission controller 40 determines that the GPF13 regeneration process is being performed, it proceeds to step S15. If the transmission controller 40 determines that the GPF13 regeneration process is not being performed, it proceeds to step S19.
[0059] In step S15, the transmission controller 40 determines whether the vehicle speed Vsp is less than or equal to the third vehicle speed Vspg. The third vehicle speed Vspg will be described later.
[0060] If the transmission controller 40 determines that the vehicle speed Vsp is less than or equal to the third vehicle speed Vspg, it proceeds to step S16. If the transmission controller 40 determines that the vehicle speed Vsp is not less than or equal to the third vehicle speed Vspg, it terminates the process.
[0061] In step S16, the transmission controller 40 determines whether the gear ratio Rv of the variator 4 is greater than the third gear ratio Rvg. In other words, it determines whether the gear ratio Rv is lower than the third gear ratio Rvg. The third gear ratio Rvg will be explained later.
[0062] If the transmission controller 40 determines that the gear ratio Rv of the variator 4 is greater than the third gear ratio Rvg, it proceeds to step S17. If the transmission controller 40 determines that the gear ratio Rv of the variator 4 is not greater than the third gear ratio Rvg, it terminates the process.
[0063] In step S17, the transmission controller 40 determines whether the accelerator is pressed.
[0064] If the transmission controller 40 determines that the accelerator is pressed, it proceeds to step S18. If the transmission controller 40 determines that the accelerator is not pressed, it returns to step S12.
[0065] In step S18, the transmission controller 40 performs slip control (see time t4 onwards in Figure 2).
[0066] In step S19, the transmission controller 40 determines whether the air conditioner 80 of the vehicle 100 is operating.
[0067] When the air conditioner 80 is operating, the load on the engine 10 increases, so the output fluctuation of the engine 10 when the accelerator is pressed is greater than when the air conditioner 80 is not operating. Therefore, when the air conditioner 80 is operating, there is a higher possibility that the vehicle 100 will behave in a way that is not intended by the driver when the accelerator is pressed. For this reason, the transmission controller 40 determines whether the air conditioner 80 is operating so that it can perform appropriate slip control according to the state of the vehicle 100.
[0068] If the transmission controller 40 determines that the air conditioner 80 is operating, it proceeds to step S20. If the transmission controller 40 determines that the air conditioner 80 is not operating, it proceeds to step S23.
[0069] In step S20, the transmission controller 40 determines whether the vehicle speed Vsp is less than or equal to the second vehicle speed Vspa. The second vehicle speed Vspa will be explained later.
[0070] If the transmission controller 40 determines that the vehicle speed Vsp is less than or equal to the second vehicle speed Vspa, it proceeds to step S21. If the transmission controller 40 determines that the vehicle speed Vsp is not less than or equal to the second vehicle speed Vspa, it terminates the process.
[0071] In step S21, the transmission controller 40 determines whether the gear ratio Rv of the variator 4 is greater than the second gear ratio Rva. In other words, it determines whether the gear ratio Rv is lower than the second gear ratio Rva. The second gear ratio Rva will be explained later.
[0072] If the transmission controller 40 determines that the gear ratio Rv of the variator 4 is greater than the second gear ratio Rva, it proceeds to step S17. If the transmission controller 40 determines that the gear ratio Rv of the variator 4 is not greater than the second gear ratio Rva, it terminates the process.
[0073] In step S23, the transmission controller 40 determines whether the vehicle speed Vsp is less than or equal to the first vehicle speed Vspr. The first vehicle speed Vspr will be described later.
[0074] If the transmission controller 40 determines that the vehicle speed Vsp is less than or equal to the first vehicle speed Vspr, it proceeds to step S24. If the transmission controller 40 determines that the vehicle speed Vsp is not less than or equal to the first vehicle speed Vspr, it terminates the process.
[0075] In step S24, the transmission controller 40 determines whether the gear ratio Rv of the variator 4 is greater than the first gear ratio Rvr. In other words, it determines whether the gear ratio Rv is lower than the first gear ratio Rvr. The first gear ratio Rvr will be described later.
[0076] If the transmission controller 40 determines that the gear ratio Rv of the variator 4 is greater than the first gear ratio Rvr, it proceeds to step S17. If the transmission controller 40 determines that the gear ratio Rv of the variator 4 is not greater than the first gear ratio Rvr, it terminates the process.
[0077] Next, we will explain the conditions for performing slip control, referring to Figure 4.
[0078] Region A in Figure 4 shows the region in which slip control is performed when the vehicle 100 is coasting in a state where the GPF13 regeneration process is not being performed and the air conditioner 80 is not operating (hereinafter referred to as the normal state).
[0079] In other words, when vehicle 100 is in normal coast lock-up mode, slip control is executed when the accelerator is pressed if the following conditions are met: engine speed Ne is greater than or equal to the lower limit speed NeL and less than or equal to the upper limit speed NeH, vehicle speed Vsp is less than or equal to the first vehicle speed Vspr, and the gear ratio Rv of variator 4 is greater than the first gear ratio Rvr (on the low side).
[0080] If the accelerator is turned on while vehicle 100 is coasting, the lower the vehicle speed Vsp and the larger the gear ratio Rv, the more likely it is that vehicle 100 will behave in a way that was not intended by the driver.
[0081] Therefore, the first vehicle speed Vspr and the first gear ratio Rvr are set so that slip control is performed in a region where it is thought that unintended behavior of the vehicle 100 may occur when the accelerator is turned on while the vehicle 100 is driving in coast lock-up mode under normal conditions. Specifically, the first vehicle speed Vspr and the first gear ratio Rvr are set based on the specifications of the vehicle 100 and experimental results. The first vehicle speed Vspr is, for example, set to 50 km / h to 60 km / h.
[0082] Region B in Figure 4 shows the region in which slip control is performed in addition to region A when the vehicle 100 is coasting in a state where the GPF13 regeneration process is not being performed and the air conditioner 80 is operating (hereinafter referred to as the A / C operating state).
[0083] In other words, when vehicle 100 is running with the A / C activated and coasting in lock-up mode, slip control is performed when the accelerator is pressed if the following conditions are met: engine speed Ne is greater than or equal to the lower limit speed NeL and less than or equal to the upper limit speed NeH, vehicle speed Vsp is less than or equal to the second vehicle speed Vspa, and the gear ratio Rv of variator 4 is greater than the second gear ratio Rva (on the low side).
[0084] As mentioned above, the load on the engine 10 increases when the air conditioner 80 is operating, so the output fluctuation of the engine 10 when the accelerator is pressed is greater than when the air conditioner 80 is not operating.
[0085] Therefore, if the accelerator is pressed while the vehicle 100 is coasting with the A / C operating and the vehicle is locked up, the vehicle 100 is more likely to exhibit unintended behavior compared to normal conditions, even in the range where the vehicle speed Vsp is higher. Similarly, the vehicle 100 is more likely to exhibit unintended behavior compared to normal conditions, even in the range where the gear ratio Rv is lower.
[0086] Therefore, the second vehicle speed Vspa is set to a higher value than the first vehicle speed Vspr, and the second gear ratio Rva is set to a lower value (higher value) than the first gear ratio Rvr. Specifically, the second vehicle speed Vspa and the second gear ratio Rva are set based on the specifications and experimental results of vehicle 100.
[0087] Region C in Figure 4 shows the region in which slip control is performed in addition to regions A and B when the vehicle 100 is coast-locked while the GPF13 regeneration process is being executed (hereinafter referred to as the GPF regeneration state).
[0088] In other words, when vehicle 100 is in coast lock-up mode with GPF regeneration, slip control is executed when the accelerator is pressed if the following conditions are met: engine speed Ne is greater than or equal to the lower limit speed NeL and less than or equal to the upper limit speed NeH, vehicle speed Vsp is less than or equal to the third vehicle speed Vspg, and the gear ratio Rv of variator 4 is greater than the third gear ratio Rvg (on the low side).
[0089] As described above, the GPF13 is regenerated by operating the engine 10 in GPF regeneration mode, which is under a higher load than usual. In addition, in GPF regeneration mode, the load on the engine 10 may be higher than when the air conditioner 80 is operating.
[0090] Therefore, if the accelerator is turned on while vehicle 100 is coasting with GPF regeneration in progress, unintended behavior of vehicle 100 is more likely to occur even in the range where the vehicle speed Vsp is higher compared to when the A / C is operating. Similarly, unintended behavior of vehicle 100 is more likely to occur even in the range where the gear ratio Rv is on the low side compared to when the A / C is operating.
[0091] Therefore, the third vehicle speed Vspg is set to a higher value than the first vehicle speed Vspr and the second vehicle speed Vspa, and the third gear ratio Rvg is set to a lower value (higher value) than the first gear ratio Rvr and the second gear ratio Rva. Specifically, the third vehicle speed Vspg and the third gear ratio Rvg are set based on the specifications and experimental results of vehicle 100.
[0092] The main effects and benefits of the transmission controller 40 configured as described above will be summarized below.
[0093] (1)(6) The transmission controller 40 controls the lock-up clutch 2a provided between the engine 10 and the variator 4 mounted on the vehicle 100. When the accelerator is turned on while the lock-up clutch 2a is engaged, the accelerator is off, the vehicle speed Vsp is less than or equal to a predetermined vehicle speed (Vspr, Vspa, Vspg), and the gear ratio Rv of the variator 4 is lower than a predetermined gear ratio (Rvr, Rva, Rvg), the hydraulic pressure (LU pressure) supplied to the lock-up clutch 2a is reduced to increase the slip amount of the lock-up clutch 2a.
[0094] When the vehicle speed Vsp is below a predetermined speed and the gear ratio Rv of the variator 4 is lower than the predetermined gear ratio, the torque fluctuation of the engine 10 when the accelerator is turned on may cause unintended vehicle behavior 100. Therefore, when the vehicle speed Vsp is below a predetermined speed and the gear ratio Rv of the variator 4 is lower than the predetermined gear ratio, increasing the slip amount of the lock-up clutch 2a when the accelerator is turned on can suppress the occurrence of unintended vehicle behavior 100. Thus, this suppresses the occurrence of unintended vehicle behavior 100 when the vehicle 100 is running with the lock-up clutch 2a engaged and the accelerator off, and reduces the discomfort felt by the driver. Note that increasing the slip amount of the lock-up clutch 2a includes moving the lock-up clutch 2a from a fully engaged state to a slipped state.
[0095] (2) When the air conditioner 80 of the vehicle 100 is not operating, the predetermined gear ratio is the first gear ratio Rvr, and when it is operating, the predetermined gear ratio is the second gear ratio Rva, which is higher than the first gear ratio Rvr.
[0096] According to this, even if the accelerator is turned on while the air conditioner 80 is operating, the lock-up clutch 2a is engaged, and the vehicle 100 is moving with the accelerator off, it is possible to suppress the occurrence of unintended behavior of the vehicle 100 and reduce the discomfort felt by the driver.
[0097] (3) When the air conditioner 80 of vehicle 100 is not operating, the predetermined vehicle speed is the first vehicle speed Vspr, and when it is operating, the predetermined vehicle speed is the second vehicle speed Vspa, which is higher than the first vehicle speed Vspr.
[0098] According to this, even if the accelerator is turned on while the air conditioner 80 is operating, the lock-up clutch 2a is engaged, and the vehicle 100 is moving with the accelerator off, it is possible to suppress the occurrence of unintended behavior of the vehicle 100 and reduce the discomfort felt by the driver.
[0099] (4) When the GPF13 of vehicle 100 has not undergone regeneration treatment, the predetermined gear ratio is the first gear ratio Rvr, and when it has undergone regeneration treatment, the predetermined gear ratio is the third gear ratio Rvg, which is higher than the first gear ratio Rvr.
[0100] According to this, even if the accelerator is turned on while the vehicle 100 is running with the vehicle 100 in motion and the lock-up clutch 2a is engaged during the regeneration process of the GPF13, it is possible to suppress the occurrence of unintended behavior of the vehicle 100 and reduce the discomfort felt by the driver.
[0101] (5) When the GPF13 of vehicle 100 is not regenerated, the predetermined vehicle speed is the first vehicle speed Vspr, and when it is regenerated, the predetermined vehicle speed is the third vehicle speed Vspg, which is higher than the first vehicle speed Vspr.
[0102] According to this, even if the accelerator is turned on while the vehicle 100 is running with the vehicle 100 in motion and the lock-up clutch 2a is engaged during the regeneration process of the GPF13, it is possible to suppress the occurrence of unintended behavior of the vehicle 100 and reduce the discomfort felt by the driver.
[0103] Although embodiments of the present invention have been described above, these embodiments represent only a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.
[0104] For example, the above embodiment described the case where the gear shift mechanism is a variator 4. However, the gear shift mechanism may be any other gear shift mechanism.
[0105] Furthermore, in the above embodiment, the conditions for executing slip control are set corresponding to the normal state, the A / C operating state, and the GPF regeneration state, respectively. However, it is not always necessary to provide the conditions corresponding to the A / C operating state and the GPF regeneration state. [Explanation of Symbols]
[0106] 100 vehicles 10 Engines 2a Lock-up clutch 4. Variator (gear shifting mechanism) 13. Gasoline Particulate Filter 40. Transmission controller (control device) 80 Air Conditioner
Claims
1. A control device for controlling a lock-up clutch installed between the engine and the transmission mechanism of a vehicle, When the lock-up clutch is engaged, the accelerator is off, the vehicle speed is below a predetermined vehicle speed, and the gear ratio of the transmission mechanism is lower than the predetermined gear ratio, and the accelerator is turned on, the hydraulic pressure supplied to the lock-up clutch is reduced to increase the amount of slip of the lock-up clutch. A control device for the lock-up clutch.
2. A control device according to claim 1, When the vehicle's air conditioner is not operating, the predetermined gear ratio is the first gear ratio, and when it is operating, the predetermined gear ratio is the second gear ratio, which is higher than the first gear ratio. A control device for the lock-up clutch.
3. A control device according to claim 1, When the vehicle's air conditioner is not operating, the predetermined vehicle speed is the first vehicle speed, and when it is operating, the predetermined vehicle speed is a second vehicle speed that is higher than the first vehicle speed. A control device for the lock-up clutch.
4. A control device according to claim 1, When the vehicle's gasoline particulate filter is not regenerated, the predetermined gear ratio is the first gear ratio, and when it is regenerated, the predetermined gear ratio is the third gear ratio, which is higher than the first gear ratio. A control device for the lock-up clutch.
5. A control device according to claim 1, The predetermined vehicle speed when the vehicle's gasoline particulate filter is not being regenerated is the first vehicle speed, and the predetermined vehicle speed when the regeneration process is being performed is a third vehicle speed that is higher than the first vehicle speed. A control device for the lock-up clutch.
6. A control method for controlling a lock-up clutch provided between the engine and transmission mechanism mounted on a vehicle, When the lock-up clutch is engaged, the accelerator is off, the vehicle speed is below a predetermined vehicle speed, and the gear ratio of the transmission mechanism is lower than the predetermined gear ratio, and the accelerator is turned on, the hydraulic pressure supplied to the lock-up clutch is reduced to increase the amount of slip of the lock-up clutch. Control method for the lock-up clutch.