JP4013530B2 - Lockup clutch control device for power transmission device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lockup clutch control device for a power transmission device including a fluid coupling, a lockup clutch, and a transmission, and more particularly to a lockup clutch control device that prevents a connection shock of the lockup clutch. is there.
[0002]
[Prior art]
The present inventors have proposed a power transmission device including a fluid coupling, a lock-up clutch, and a transmission as shown in Japanese Patent Application No. 2001-099737.
[0003]
This power transmission device is used in a vehicle, and includes a fluid coupling connected to an output shaft of an engine, a lockup clutch that mechanically connects and disconnects the fluid coupling, and a fluid coupling and a manual transmission. And a shift clutch connected to.
[0004]
When the vehicle starts, the shift clutch is engaged and the fluid coupling starts to creep, and then the lockup clutch is engaged and the fluid coupling is integrated to run without slipping. When the driver indicates the intention to perform the shift operation, the shift clutch is automatically disconnected, and when the shift operation is completed, the shift clutch is reconnected. For this reason, the driver can perform a shift operation without operating the clutch pedal. If the vehicle speed decreases, the lock-up clutch is disengaged to prevent knocking or engine stall.
[0005]
Here, while the lock-up clutch is disengaged, slippage occurs in the fluid coupling and transmission efficiency loss occurs, causing problems such as deterioration in fuel consumption and engine braking force. Yes. Specifically, the rotational speed of the input shaft of the transmission is detected, and when the detected value is equal to or higher than the contact rotational speed set in advance for each gear stage (contact condition is established), the lockup clutch is engaged. I am doing so. Further, the lockup clutch is disengaged when the rotational speed of the input shaft is equal to or lower than the pre-rotation speed preset for each gear stage (satisfaction condition is established).
[0006]
[Problems to be solved by the invention]
By the way, in this power transmission device, when the above contact condition is established and the lockup clutch is connected, the lockup clutch is suddenly connected, that is, the valve that supplies pressure oil to the lockup clutch is controlled to be fully opened at once. As a result, it was found that a connection shock occurred depending on the driver's accelerator operation.
[0007]
Specifically, when the driver shows an intention to accelerate when the lockup clutch is connected, that is, when the accelerator is depressed, the torque on the engine side is large. A connection shock does not occur because the connection is loose with slip. However, when the lockup clutch is connected, if the driver keeps the accelerator constant or performs an operation to return the accelerator, the torque on the engine side becomes smaller than the torque transmission capacity of the lockup clutch and the lockup is performed. The up clutch is momentarily connected. As a result, a connection shock that causes the vehicle to be pushed forward occurs.
[0008]
This connection shock causes the driver to feel the opposite movement of the vehicle being pushed forward while maintaining or slowing down the vehicle speed. Is essential.
[0009]
In the case of a normal AT vehicle, a shift operation (shift-up) is usually performed when the accelerator is returned, so the driver is less likely to feel a lock-up clutch connection shock. Since the power transmission device is a manual transmission that is manually operated by the driver, the gear is not shifted unless the driver performs the shifting operation by himself / herself. For this reason, the connection shock of the lockup clutch is easily detected by the driver.
[0010]
Accordingly, an object of the present invention is to provide a lockup clutch control device for a power transmission device that solves the above-described problems and prevents a lockup clutch connection shock.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the present invention includes a pump unit connected to an output shaft of an engine and a turbine unit connected to an input shaft on a transmission side. Power transmission comprising: a fluid coupling adapted to transmit to a part; a lock-up clutch provided on the fluid coupling, wherein the pump part and the turbine part are connected and rotated integrally when in contact; and a transmission An input for detecting the rotational speed of the input shaft of the transmission in a lockup clutch control device that controls the lockup clutch so that the lockup clutch is connected when a contact condition is established. A shaft rotation sensor, an engine rotation sensor that detects the rotation speed of the engine, and an accelerator sensor that detects an accelerator opening of an accelerator pedal The contact conditions, the accelerator opening detected by the accelerator sensor Opening that can be regarded as a driver's acceleration The quick contact condition that is satisfied when Opening degree that the driver can be considered to be accelerating When the lock-up clutch is engaged, when the lock-up clutch is engaged, the lock-up clutch loose-connection control is started, and the quick-contact condition is satisfied. When this occurs, the sudden contact control of the lockup clutch is started, and further, the accelerator opening detected by the accelerator sensor is controlled during the slow engagement control of the lockup clutch. Opening degree that the driver can be considered to be accelerating When it increases above, switch to the quick contact control, and the accelerator opening is reduced during the quick contact control of the lockup clutch. Opening degree that the driver can be considered to be accelerating When the rotational speed is reduced to less than, the control is switched to the slow contact control, and when the rotational speed of the transmission input shaft detected by the input shaft rotational sensor matches the rotational speed of the engine detected by the engine rotational sensor, Ends lock-up clutch quick or slow control The lockup clutch is controlled to be connected / disconnected in accordance with a duty pulse output from the electronic control unit. When the lockup clutch is controlled to be loosely connected, a predetermined step duty with respect to the previous output duty is determined every predetermined time. The output duty is gradually increased to the maximum duty on the contact side, and when the lockup clutch is suddenly controlled, the maximum duty is output first and held. To do.
[0012]
According to this, when the driver performs an accelerator operation that causes a connection shock, the loose engagement condition is established and the lockup clutch is gently connected, so that the connection shock does not occur.
[0017]
The value of the step duty at the time of the slow contact control may be determined according to the difference in the rotational speed between the output shaft of the engine and the input shaft of the transmission.
[0018]
The value of the step duty at the time of the slow contact control may be determined according to the accelerator opening.
[0019]
The value of the step duty at the time of the slow contact control may be determined according to the change speed of the accelerator opening.
[0020]
Further, the transmission may be a manual transmission that is manually operated by a driver.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.
[0022]
First, the structure of the power transmission device of this embodiment will be described with reference to FIGS.
[0023]
As shown in FIG. 1, the power transmission device includes a fluid coupling (fluid coupling) 2 connected to an output shaft (crankshaft) 1 of an engine E, and a lock-up clutch that mechanically connects and disconnects the fluid coupling 2. 7 and a shift clutch (wet multi-plate clutch) 3 connected between the fluid coupling 2 and the transmission T / M. In addition, the fluid coupling here is a broad concept including a torque converter, and the torque converter is actually used also in this embodiment.
[0024]
The fluid coupling 2 includes a pump unit 4 that rotates integrally with a casing 18 connected to the output shaft 1 of the engine E, a turbine unit 5 that is provided in the casing 18 so as to face the pump unit 4, and a turbine unit 5. And a stator section 6 interposed between the pump section 4 and the pump section 4.
[0025]
The lock-up clutch 7 is operated by pressure oil supplied from the hydraulic circuit 19 and mechanically connects and disconnects the pump portion 4 and the turbine portion 5 of the fluid coupling 2.
[0026]
The input side of the transmission clutch (wet multi-plate clutch) 3 is connected to the turbine section 5 of the fluid coupling 2 via the input shaft 3a, and the output side is connected to the input shaft 8 of the transmission T / M. The transmission clutch 3 is urged by a spring (not shown) in a direction in which clutch plates, which will be described later, do not frictionally engage with each other, and when pressure oil is supplied from the hydraulic circuit 19, the clutch plates are frictionally engaged with each other. It becomes.
[0027]
Here, the details of the fluid coupling 2, the lockup clutch 7, and the transmission clutch 3 will be described with reference to FIG. 2 that are the same as those in FIG. 1 represent the same members.
[0028]
As shown, a casing 18 connected to the output shaft 1 of the engine is integrally provided with a bowl-shaped pump portion 4, and the pump portion 4 is connected to the outer periphery of the input shaft 3 a of the transmission clutch 3 via a bearing 80. Is rotatably supported by the shaft. A casing-like turbine section 5 is disposed in the casing 18 so as to face the pump section 4, and the turbine section 5 is integrally connected to the input shaft 3 a of the transmission clutch 3. In FIG. 2, the stator portion 6 is omitted for convenience of explanation.
[0029]
A clutch disk 31 is connected to the turbine unit 5 via a damper spring 30. The clutch disk 31 is provided on the outer peripheral portion of the turbine hub 32 of the turbine portion 5 so as to be rotatable and slidable in the axial direction, and one side surface thereof faces the inner surface of the casing 18. A clutch facing 33 is mounted on the outer peripheral portion of the clutch disk 31 facing the casing 18. The clutch disk 31, the casing 18, and the clutch facing 33 constitute the lockup clutch 7.
[0030]
An outer chamber 34 is formed between the casing 18 and the clutch disk 31 by the clutch disk 31, and an inner chamber 35 is formed between the turbine unit 5 and the clutch disk 31. Further, an inner passage 36 that is continuous with the outer chamber 34 is formed in the input shaft 3 a of the transmission clutch 3, and the outer periphery of the input shaft 3 a is continuous with the turbine portion 5 and the pump portion 4 through the bearing 80. An outer passage 37 is formed.
[0031]
When the lockup clutch 7 is disengaged, as shown in the upper half of the figure, the pressure oil from the hydraulic circuit 19 (see FIG. 1) is supplied to the outer chamber 34 through the inner passage 36 in the input shaft 3a. . By this hydraulic pressure, the frictional engagement between the casing 18 and the clutch disc 31 is released and the clutch 18 is disconnected. The pressure oil supplied to the outer chamber 34 flows through the turbine unit 5 and the pump unit 4 as shown by an arrow 38 to transmit the rotation of the pump unit 4 to the turbine unit 5, and a part thereof passes through the bearing 80. It flows to the outer passage 37.
[0032]
When the lock-up clutch 7 is engaged, the flow of pressure oil is switched in the reverse manner to the case of disconnection. That is, as shown in the lower half of the drawing, the pressure oil from the hydraulic circuit 19 passes through the bearing 80 from the outer passage 37 and flows through the pump section 4 and the turbine section 5 as indicated by the arrow 39 to the inner chamber. 35. The clutch disk 31 is pressed toward the casing 18 by the pressure oil in the inner chamber 35, and the clutch facing 33 and the casing 18 are frictionally engaged. As a result, the rotation of the casing 18 is transmitted to the turbine unit 5 via the clutch disk 31 and the damper spring 30, and the pump unit 4 and the turbine unit 5 rotate integrally.
[0033]
Next, the shift clutch (wet multi-plate clutch) 3 includes a plurality of clutch plates 41a and 41b that are spline-engaged on the input side and the output side in a clutch casing 40 filled with oil. It is configured. The clutch plates 41a and 41b are pressed against each other by the clutch piston 42 or released so that the clutch can be connected and disconnected. The clutch piston 42 is urged by a clutch spring 43 in a disconnecting direction (left side in the figure) in which the clutch plates 41a and 41b are not frictionally engaged with each other. When pressure oil from the hydraulic circuit 19 is supplied to the speed change clutch 3, the clutch piston 42 is pressed to the right side in the figure in opposition to the urging force of the clutch spring 43, and the clutch plates 41a and 41b are frictionally engaged with each other. As a result, the transmission clutch 3 is engaged.
[0034]
Now, returning to FIG. 1, the transmission T / M has an input shaft 8, an output shaft 9 disposed coaxially therewith, and a countershaft 10 disposed in parallel thereto.
[0035]
An input main gear 11 is fixed to the input shaft 8 and rotates integrally.
[0036]
A first-speed main gear M1, a second-speed main gear M2, a third-speed main gear M3, a fourth-speed main gear M4, and a reverse main gear MR are rotatably supported on the output shaft 9 with respect to the output shaft 9, respectively. . A 6-speed main gear M6 that rotates integrally with the output shaft 9 is fixed to the output shaft 9.
[0037]
The countershaft 10 includes an input subgear 12 that meshes with the input main gear 11, a first speed subgear C1 that meshes with the first speed main gear M1, a second speed subgear C2 that meshes with the second speed main gear M2, and 3 A third speed sub gear C3 meshing with the speed main gear M3, a fourth speed sub gear C4 meshing with the fourth speed main gear M4, and a reverse sub gear CR meshing with the reverse main gear MR via the idle gear IR are fixed. Has been. Further, a sixth speed sub gear C6 that meshes with the sixth speed main gear M6 is rotatably supported on the sub shaft 10.
[0038]
According to this transmission T / M, when the sleeve S / R1 spline-engaged with the hub H / R1 fixed to the output shaft 9 is spline-engaged with the dog DR of the reverse main gear MR, the output shaft 9 is reversely rotated. When the sleeve S / R1 is spline-engaged with the dog D1 of the first speed main gear M1, the output shaft 9 rotates at a speed equivalent to the first speed. Then, when the sleeve S / 23 spline-engaged with the hub H / 23 fixed to the output shaft 9 is spline-engaged with the dog D2 of the second-speed main gear M2, the output shaft 9 rotates at the second speed, and the sleeve When S / 23 is spline-engaged with the dog D3 of the third-speed main gear M3, the output shaft 9 rotates at a speed equivalent to the third speed. Further, when the sleeve S / 45 spline-engaged with the hub H / 45 fixed to the output shaft 9 is spline-engaged with the dog D4 of the 4-speed main gear M4, the output shaft 9 rotates at a speed equivalent to 4th speed, and the sleeve When the S / 45 is spline-engaged with the dog D5 of the input main gear 11, the output shaft 9 rotates at the fifth speed (direct connection). Further, when the sleeve S6 spline-engaged with the hub H6 fixed to the auxiliary shaft 10 is spline-engaged with the dog D6 of the sixth-speed auxiliary gear C6, the output shaft 9 rotates at the sixth speed.
[0039]
The transmission T / M is of a manual type, and the sleeve S is operated via a shift fork and a shift rod (not shown) when the driver operates the shift lever 21 in the cab.
[0040]
In the present embodiment, a knob switch 20 is provided on the shift lever 21 in order to automatically disengage the shift clutch 3 by detecting the driver's intention to shift. That is, the shift knob of the shift lever 21 is attached to the lever so as to be slightly swingable in the speed change operation direction, and the knob switch 20 is provided between the lever and the shift knob. When the driver operates the shift lever 21 to perform the shift operation, the shift knob swings before the operation of the shift lever 21 and the knob switch 20 is turned on. It has become.
[0041]
The transmission T / M is provided with a gear position sensor 21s for detecting the current gear position. Data detected by the knob switch 20 and the gear position sensor 21 s is input to the electronic control unit 22.
[0042]
Further, the depression amount of the accelerator pedal 23 (accelerator opening) and the presence or absence of depression of the brake pedal 25 are detected by the accelerator sensor 24 and the brake switch 26, respectively, and the data is input to the electronic control unit 22.
[0043]
An input shaft rotation sensor 27 for detecting the rotation speed of the input shaft 8 of the transmission T / M is provided in the input sub gear 12 of the transmission T / M. The rotation speed of the sub shaft 10 is detected by the input shaft rotation sensor 27 and input to the electronic control unit 22, and the transmission T / M of the transmission T / M is based on the detected value and the gear ratio between the input main gear 11 and the input sub gear 12. The rotational speed of the input shaft 8 is calculated.
[0044]
Further, a turbine part rotation sensor 28 for detecting the rotational speed of the turbine part 5 of the fluid coupling 2 is provided on the input side of the transmission clutch 3, and the casing 18 connected to the output shaft 1 of the engine E has a rotation of the engine E. An engine rotation sensor 29 for detecting the number is provided, and a vehicle speed sensor 74 for detecting the vehicle speed is provided on the output shaft 9 of the transmission T / M. Detection values of these sensors 28, 29 and 74 are input to the electronic control unit 22.
[0045]
Next, details of the hydraulic circuit 19 for operating the lockup clutch 7 and the transmission clutch 3 will be described with reference to FIG.
[0046]
As shown in the figure, the oil in the oil tank 45 is sucked and discharged by the hydraulic pump OP through the filter F, and the discharge pressure is adjusted by the relief valve 47 so that the pressure oil supply line 46 has a predetermined pressure. Oil is supplied.
[0047]
A lock-up five-way valve 49 that connects and disconnects the lock-up clutch 7 by switching the direction of the pressure oil flowing to the fluid coupling 2 is connected to the pressure oil supply line 46 via a line 48. A pressure oil return line 50 that returns pressure oil to the oil tank 45 is connected to the lockup five-way valve 49, and a throttle valve 51, a cooler 52, and an on-off valve 53 are connected to the pressure oil return line 50. ing. The on-off valve 53 is normally closed and is opened when pilot hydraulic pressure is supplied from a pilot line 54 connected to the pressure oil supply line 46.
[0048]
The lock-up five-way valve 49 is switched and controlled by a pilot control three-way solenoid valve 56 connected to a pilot line 55 of the pressure oil supply line 46.
[0049]
When the pilot control three-way solenoid valve 56 is turned OFF, the pilot control three-way solenoid valve 56 is closed as shown in the figure. As a result, the pilot hydraulic pressure is not supplied to the lock-up five-way valve 49, and the pressure oil from the line 48 is supplied to the outer chamber 34 from the inner passage 36 described with reference to FIG. 5 and after flowing into the pump section 4, returns from the outer passage 37 through the line 58 to the pressure oil return line 50 through the lock-up five-way valve 49. Therefore, the lockup clutch is disengaged.
[0050]
When the pilot control three-way solenoid valve 56 is turned ON, the pilot control three-way solenoid valve 56 is opened, and the pilot hydraulic pressure from the pilot line 55 is supplied to the lock-up five-way valve 49 so that the lock-up five-way valve is turned on. 49 is switched, and the pressure oil from the line 48 flows from the line 58 to the outer passage 37, passes through the pump unit 4 and the turbine unit 5, and is then supplied to the inner chamber 35. The clutch disc 31 is pressed toward the casing 18 by the hydraulic pressure and frictionally engaged with the casing 18, and the lockup clutch 7 is brought into contact. On the other hand, the oil in the outer chamber 34 is pushed out from the inner passage 36 to the line 57 and is returned from the oil return line 60 to the oil tank 45 via the lock-up five-way valve 49.
[0051]
The pilot control three-way solenoid valve 56 is duty-controlled according to the duty pulse output from the electronic control unit 22 so that the magnitude of the pilot hydraulic pressure supplied to the lockup five-way valve 49 can be changed. By changing the magnitude of the pilot oil pressure, the lock-up five-way valve 49 is adjusted steplessly, and the amount of pressure oil flowing toward the disengagement side and the contact side of the lockup clutch 7 can be controlled steplessly. That is, as a result, the lockup clutch 7 is connected / disconnected in accordance with the duty pulse output from the electronic control unit 22. When the duty output to the pilot control three-way solenoid valve 56 is 0%, the pilot control three-way solenoid valve 56 is turned OFF, and all the pressure oil supplied from the lock-up five-way valve 49 flows to the disconnected side. The lockup clutch 7 is disengaged. As the duty increases, the amount of pressure oil supplied to the contact side of the lockup clutch 7 increases, and when the output duty is 100%, the pilot control three-way solenoid valve 56 is fully opened (ON) and all the pressure oil is contacted. Will be supplied to.
[0052]
A clutch switching three-way valve 61 for switching the supply of pressure oil to the transmission clutch 3 is connected to the pressure oil supply line 46 via a line 68. The clutch switching three-way valve 61 is controlled to be switched by a pilot control three-way solenoid valve 63 connected to a pilot line 62 of the pressure oil supply line 46.
[0053]
When the pilot control three-way solenoid valve 63 is turned off, the pilot control three-way solenoid valve 63 is opened as shown. As a result, the pilot hydraulic pressure is supplied to the clutch switching three-way valve 61, and the clutch switching three-way valve 61 is opened. Accordingly, pressure oil is supplied to the transmission clutch 3 and is operated in the contact direction. The figure shows a state when the engine is stopped. Since the oil pump is stopped and no pressure oil is supplied to the pressure oil supply line 46, the clutch switching three-way valve 61 is closed.
[0054]
When the pilot control three-way solenoid valve 63 is turned ON, the pilot control three-way solenoid valve 63 is closed, the pilot hydraulic pressure is not supplied, and the clutch switching three-way valve 61 is closed. Therefore, no pressure oil is supplied to the speed change clutch 3 and it is actuated in the disconnection direction by the urging force of the spring 42.
[0055]
The pilot control three-way solenoid valve 63 that switches the clutch switching three-way valve 61 is also duty-controlled according to the duty pulse output from the electronic control unit 22, but here it is not directly related to the present invention. The description is omitted.
[0056]
The control at the time of traveling in the power transmission device described so far is as follows.
[0057]
First, it is assumed that when the vehicle is stopped in gear neutral, the driver tries to start and operates the shift lever to the start stage. Then, prior to the operation of the shift lever, the shift knob swings and the knob switch 20 is turned on. With this as a signal, the transmission clutch 3 is disconnected. When the shift lever is subsequently operated, the transmission T / M is geared into the starting stage, and when this is detected by the gear position sensor 21s, the transmission clutch 3 is connected. By this connection, the turbine unit 5 is stopped by a brake from the drive wheel side, so that the pump unit 4 slides with respect to the turbine unit 5 and a creep force is generated. Therefore, after that, if the brake pedal 25 is released or the accelerator pedal 23 is depressed, the vehicle starts to move. This is the same as a normal AT car.
[0058]
After starting, when it is determined that a predetermined contact condition, which will be described later, is satisfied, the lock-up clutch 7 is engaged, and the pump unit 4 and the turbine unit 5 of the fluid coupling 2 are integrated and travel without slipping. Then, basically, the lockup clutch 7 is always engaged during traveling, and the shift clutch 3 is automatically connected and disconnected when the driver performs a shift operation of the transmission T / M. If it is determined that a predetermined disconnection condition is satisfied while traveling with the lock-up clutch 7 in contact, the lock-up clutch 7 is disconnected and travel is performed with the creep force of the fluid coupling 2.
[0059]
The gist of the present invention resides in that a connection shock is prevented from occurring when the contact condition is established and the lock-up clutch 7 is connected, which will be described in detail below. Since the disconnection condition is not directly related to the present invention, the description is omitted here.
[0060]
In the present invention, two types of connection control are performed by starting the connection of the lockup clutch 7 or by the driver's accelerator operation when the lockup clutch 7 is connected. Specifically, they are the slow contact control and the quick contact control, which are executed when the slow contact condition and the quick contact condition are satisfied, respectively.
[0061]
First, the quick contact condition and the quick contact control will be described.
・ Quick contact conditions
No.1 The disconnect condition is not satisfied.
No. 2 The lock-up five-way valve 49 and the pilot control three-way solenoid valve 56 are normal.
No.3 The gear position is 2nd or higher.
No.4 Shifting clutch 3 is engaged.
No.5 Engine E speed is 1000rpm or more.
No. 6 The rotational speed of the input shaft 8 of the transmission T / M is equal to or higher than the predetermined rotational speed.
No.7 ABS is not operating.
No.8 The emergency switch is OFF.
No.9 Emergency judgment is not in progress.
No.10 The accelerator opening is 70% or more (accelerator opening ≧ 70%).
[0062]
If all of the above conditions are met (No.1, No.2, No.3, No.4, No.5, No.6, No.7, No.8, No.9, and No.10), it is determined that the quick contact condition is satisfied, and the lockup clutch 7 is suddenly connected. Be controlled.
[0063]
Here, conditions No. 5 and No. 6 are conditions for guaranteeing that no knocking or rattling noise (tooth rattling noise) or the like occurs in the transmission T / M even when the lock-up clutch 7 is connected. The predetermined rotational speed of the input shaft 8 of the transmission T / M is selected from a map that is set in advance for each gear and input to the electronic control unit 22.
[0064]
The most important condition in the present invention is condition No. 10. That is, that the accelerator opening is 70% or more means that the accelerator is depressed to such an extent that it can be considered that the driver is willing to accelerate. Even if the lock-up clutch 7 is suddenly engaged, the torque on the engine side is large. This means that no connection shock occurs. Accordingly, when the quick contact condition is satisfied, the quick contact control is executed.
[0065]
The quick contact control will be described with reference to FIG. 4A shows the engine speed Ne detected by the engine speed sensor 29 and the speed Ni of the input shaft 8 detected by the input shaft speed sensor 27. FIG. 4B shows the electronic control unit 22. 4 shows the output duty that is output to the pilot control three-way solenoid valve 56 that operates the lockup clutch 7, and FIG. 4C shows the accelerator opening detected by the accelerator sensor 24.
[0066]
First, at time T0 to T1, since the rotational speed Ni of the input shaft 8 is equal to or lower than a predetermined rotational speed (900 rpm in this case), the contact condition is not satisfied, and the lockup clutch 7 is in a disconnected state. Therefore, there is a difference between the engine speed Ne and the input shaft speed Ni by the amount of slip in the fluid coupling 2.
[0067]
At T1, since the rotational speed Ni of the input shaft 8 is equal to or higher than the predetermined rotational speed (900 rpm) and the accelerator opening is 70% or higher, the quick contact condition is satisfied and the quick contact control is executed.
[0068]
In the rapid contact control, as shown in FIG. 4B, the maximum duty (100%) on the contact side is first output to the pilot control three-way solenoid valve 56 and is maintained thereafter. Accordingly, the pilot control three-way solenoid valve 56 is fully opened (ON), and all the pressure oil is supplied to the contact side. As a result, the lockup clutch 7 is operated toward the contact side at the maximum speed of the mechanism.
[0069]
However, when the rapid contact condition is satisfied, the accelerator opening is 70% or more and the engine torque is large. Therefore, as shown in FIG. 4A, the engine speed Ne and the input shaft speed Ni Do not synchronize immediately, but are loosely connected with some slippage. That is, the lockup clutch 7 is completely connected at T2 when the connection (synchronization) period Tc1 has elapsed from the start of the rapid contact control T1, and the engine speed Ne and the input shaft speed Ni coincide. In this way, if the sudden contact condition is satisfied, the lockup clutch 7 is gently connected even if the lockup clutch 7 is suddenly controlled. In other words, since the slopes of the line Ne and the line Ni in the period Tc1 in FIG. 4A become gentle, no connection shock occurs.
[0070]
In addition, when the later-described slow contact condition is satisfied during the quick contact control, the mode is immediately switched to the slow contact control.
[0071]
Next, the slow contact condition and the slow contact control will be described.
・ Loose contact condition
No.1 The disconnect condition is not satisfied.
No. 2 The lock-up five-way valve 49 and the pilot control three-way solenoid valve 56 are normal.
No.3 The gear position is 2nd or higher.
No.4 Shifting clutch 3 is engaged.
No.5 Engine E speed is 1000rpm or more.
No. 6 The rotational speed of the input shaft 8 of the transmission T / M is equal to or higher than the predetermined rotational speed.
No.7 ABS is not operating.
No.8 The emergency switch is OFF.
No.9 Emergency judgment is not in progress.
No.10 The accelerator opening is less than 70% (accelerator opening <70%).
[0072]
If all the above conditions are met (No.1, No.2, No.3, No.4, No.5, No.6, No.7, No.8, No.9, and No.10), it is determined that the loose connection condition has been established, and the lockup clutch 7 is loosely connected. Be controlled.
[0073]
Conditions No. 1 to No. 9 are the same as the quick contact conditions, and only condition No. 10 is different.
[0074]
That is, if the accelerator opening is less than 70%, it means that the engine torque is small and there is a possibility that a connection shock may occur if the lock-up clutch 7 is suddenly engaged. The clutch 7 is controlled to be loosely connected to prevent the occurrence of a connection shock.
[0075]
The slow contact control will be described with reference to FIG. FIG. 5A shows the engine rotational speed Ne detected by the engine rotational sensor 29 and the rotational speed Ni of the input shaft detected by the input shaft rotational sensor 27. FIG. FIG. 5C shows the output duty output to the pilot control three-way solenoid valve 56 that operates the lock-up clutch 7. FIG. 2 The accelerator opening detected by 4 is shown.
[0076]
First, at time T0 to T1, since the rotational speed Ni of the input shaft 8 is equal to or lower than a predetermined rotational speed (900 rpm in this case), the contact condition is not satisfied, and the lockup clutch 7 is in a disconnected state. Therefore, there is a difference between the engine speed Ne and the input shaft speed Ni by the amount of slip in the fluid coupling 2.
[0077]
At T1, the rotational speed Ni of the input shaft 8 is equal to or higher than the predetermined rotational speed (900 rpm) and the contact condition is satisfied. At this time, since the accelerator opening is 70% or more, the rapid contact condition is satisfied and the above-described condition is satisfied. Rapid contact control is executed. Therefore, the maximum duty (100%) on the contact side is output to the pilot control three-way solenoid valve 56.
[0078]
After that, it is assumed that the driver performs an operation of returning the accelerator at T2, and the accelerator opening degree is less than 70% and the loose contact condition is satisfied. Then, switching from the rapid contact control to the slow contact control is performed.
[0079]
In the loose connection control, the output duty is gradually changed to the contact side so that the lockup clutch 7 is gently connected to prevent the connection shock. First, at the control start time T2, the start duty Dst And the end duty De is selected. The start duty Dst is a duty value that is output relatively large initially, and is set to such a value that the lock-up clutch 7 is brought into contact near the torque point (position at which connection starts). On the other hand, the end duty De is set to a value at which the lockup clutch 7 is substantially connected. When the output duty reaches the end duty De, 100% of the duty is output.
[0080]
In this embodiment, the start duty Dst and the end duty De are set in advance according to the accelerator opening (horizontal axis) and the gear position (vertical axis) of the transmission T / M, respectively, as shown in FIGS. And selected from the map input to the electronic control unit 22. In the present embodiment, the start duty Dst and the end duty De are always set to be constant regardless of the accelerator opening and the gear position.
[0081]
When selection of the start duty Dst and the end duty De is completed, the start duty Dst is first output for a predetermined period (T2 to T3). However, in the illustrated embodiment, since the quick contact control is switched to the slow contact control at T2, the start duty Dst is output by subtracting from the previous output duty (100%). In this way, by outputting the start duty Dst for a predetermined period, for example, in the case where the loose connection control is performed from the connection start time T1, the ineffective stroke (play) of the lock-up clutch 7 is suddenly contacted to shorten the connection time. Can do.
[0082]
After the start duty Dst is output, a step duty Dsp corresponding to the vehicle condition is selected from the map every predetermined period t (hereinafter referred to as a slow contact period), and the value obtained by adding the step duty Dsp to the previous output duty The duty is output.
[0083]
In the present embodiment, the step duty Dsp is the difference in rotational speed between the output shaft 1 of the engine E and the input shaft 8 of the transmission T / M, the gear position, the accelerator opening and the gear position, and the changing speed of the accelerator opening. And the gear position are set in advance and input to the electronic control unit 22.
[0084]
In the present embodiment, according to the map shown in FIG. 8, the rotational speed difference between the output shaft 1 of the engine E and the input shaft 8 of the transmission T / M (horizontal axis) and the gear position (vertical axis) are determined. The first step duty Dsp1 is selected, and the second step duty Dsp2 corresponding to the accelerator opening (horizontal axis) and the gear position (vertical axis) is selected from the map shown in FIG. 9, and from the map shown in FIG. The third step duty Dsp3 is selected according to the change rate (horizontal axis) of the accelerator opening and the gear position (vertical axis). The step duty Dsp is calculated by adding all of the first, second and third step duties Dsp1, Dsp2 and Dsp3 (Dsp = Dsp1 + Dsp2 + Dsp3).
[0085]
The step duty Dsp is calculated every slow contact cycle t, and a new output duty is output every slow contact cycle t. In this way, the lockup clutch 7 is gradually connected gradually by gradually increasing the value of the duty output to the pilot control three-way solenoid valve 56 at each slow engagement cycle t, and the engine speed Ne and the input shaft rotational speed Ni are gradually synchronized. When the output duty reaches the end duty De, a duty of 100% is output, and the lockup clutch 7 is completely connected at T4. At this time, the engine rotational speed Ne coincides with the input shaft rotational speed Ni.
[0086]
As described above, when the accelerator opening is small and the engine torque is small, the loose engagement condition is established, and the lockup clutch 7 is controlled so that the lockup clutch 7 is not instantaneously connected. Connect gently. In other words, since the slopes of the line Ne and the line Ni in the period Tc2 in FIG. 5A become gentle, it is possible to prevent a connection shock from occurring.
[0087]
Further, since the period Tc2 from the connection start T1 of the lockup clutch 7 to the connection (synchronization) end T4 is substantially equal to the connection (synchronization) period Tc1 in the sudden contact control, the connection feeling of the lockup clutch 7 is suddenly contacted. Regardless of control or slow contact control, it is always constant.
[0088]
If the quick contact condition is satisfied while the slow contact control is being performed, the control is immediately switched to the quick contact control.
[0089]
The loose contact period t may be equal to or different from the duty output period. When the slow contact cycle t is longer than the duty output cycle, the same duty is output until a new step duty Dsp is determined.
[0090]
Thus, in the present invention, since the connection shock does not occur when the driver depresses the accelerator, the lock-up clutch 7 is suddenly controlled, and the driver performs an operation of holding the accelerator constant or returning it. In this case, the lockup clutch 7 is controlled to be loosely connected to prevent the connection shock.
[0091]
As a result, a connection shock can be always prevented regardless of the driver's accelerator operation when the lockup clutch 7 is connected. Therefore, even if it is a power transmission device provided with the manual transmission which a driver performs manual operation, a driver does not sense a connection shock.
[0092]
【The invention's effect】
In short, according to the present invention, in a power transmission device including a fluid coupling, a lock-up clutch, and a transmission clutch, an excellent effect of preventing a connection shock of the lock-up clutch is exhibited.
[Brief description of the drawings]
FIG. 1 is a skeleton diagram of a power transmission device according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a power transmission device according to an embodiment of the present invention.
FIG. 3 is an explanatory diagram of the hydraulic circuit of FIG. 1;
FIG. 4A is a time chart showing an engine speed and an input shaft speed at the time of rapid contact control.
(B) is a time chart which shows the output duty at the time of rapid contact control.
(C) is a time chart which shows the accelerator opening at the time of rapid contact control.
FIG. 5A is a time chart showing an engine speed and an input shaft speed at the time of slow contact control.
(B) is a time chart which shows the output duty at the time of slow contact control.
(C) is a time chart which shows the accelerator opening at the time of slow contact control.
FIG. 6 is a map used for selecting a start duty.
FIG. 7 is a map used for selecting an end duty.
FIG. 8 is a map used for selecting a step duty according to a difference in rotation between an engine output shaft and a transmission input shaft.
FIG. 9 is a map used for selecting a step duty according to the accelerator opening.
FIG. 10 is a map used for selecting a step duty according to a change speed of an accelerator opening.
[Explanation of symbols]
2 Fluid coupling
3 Shifting clutch
7 Lock-up clutch
8 Input shaft of transmission
22 Electronic control unit
E engine
T / M transmission

Claims (5)

A fluid coupling having a pump section connected to the output shaft of the engine and a turbine section connected to the input shaft on the transmission side, and transmitting the rotation of the pump section to the turbine section via a fluid; When the contact condition is satisfied, provided in the fluid coupling and provided in a power transmission device including a lockup clutch that connects the pump unit and the turbine unit to rotate integrally when contacting, and a transmission. In the lockup clutch control device for controlling the lockup clutch so that the lockup clutch is connected to
An input shaft rotation sensor for detecting the rotation speed of the input shaft of the transmission, an engine rotation sensor for detecting the rotation speed of the engine, and an accelerator sensor for detecting the accelerator opening of the accelerator pedal,
The contact conditions includes a Kyuse' conditions satisfied when the accelerator opening detected by the accelerator sensor is not less than the opening degree can be regarded that there is an acceleration intention of the driver, opening the accelerator opening can be regarded that there is an acceleration intention of the driver consists of a gradual connection conditions to be satisfied when less than degrees,
When contacting the lock-up clutch,
When the loosely connected condition is satisfied, the lockup clutch is slowly controlled. When the suddenly connected condition is satisfied, the lockup clutch is suddenly controlled.
In addition, when the accelerator opening detected by the accelerator sensor increases more than the opening that can be regarded as the driver's intention to accelerate during the slow-release control of the lock-up clutch, the control is switched to the quick-contact control and the lock When the accelerator opening decreases to less than the opening that can be considered to be the driver's acceleration intention during the up-clutch rapid contact control, switch to slow connection control,
When the rotational speed of the input shaft of the transmission detected by the input shaft rotational sensor matches the rotational speed of the engine detected by the engine rotational sensor, the sudden contact control or the slow contact control of the lockup clutch is terminated. And
The lock-up clutch is connected / disconnected in accordance with a duty pulse output from the electronic control unit,
When the lockup clutch is loosely controlled, the output duty is gradually increased to the maximum duty on the contact side by adding a predetermined step duty to the previous output duty every predetermined time,
A lockup clutch control device for a power transmission device, wherein when the lockup clutch is suddenly controlled, the maximum duty is first output and held . 2. The lockup clutch control device for a power transmission device according to claim 1 , wherein a value of a step duty at the time of the slow contact control is determined in accordance with a difference in rotational speed between an output shaft of the engine and an input shaft of the transmission. . The lockup clutch control device for a power transmission device according to claim 1 or 2 , wherein a value of a step duty at the time of the gentle contact control is determined according to an accelerator opening . The lockup clutch control device for a power transmission device according to any one of claims 1 to 3, wherein a value of a step duty at the time of the slow contact control is determined according to a change speed of an accelerator opening . The lockup clutch control device for a power transmission device according to any one of claims 1 to 4, wherein the transmission is a manual transmission that is manually operated by a driver .

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