JP2001108055A - Torque limiter device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent, with an easy control, an abnormal torque such as an excessive torque or periodic torque variation from causing damage or reduction of durability, in a vehicle having no fluid coupling such as a torque converter in a power transmission route. SOLUTION: Engaging torques of clutches C1, C2 are controlled so that the clutches C1, C2 slip before a belt of a belt-type continuously variable transmission 12 starts to slip. The engaging torque of the clutches C1, C2 is decreased during an operation of an antilock brake device 90, and a peak value of torque variation following the operation of the antilock brake device 90 is decreased to suppress low-cycle fatigue. When an engine 14 is cranked and started by engaging a brake B1 and reversely rotating a motor generator 16, an engaging torque of a brake B1 is set so that the brake B1 slips upon occurrence of an abnormal torque by resonance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque limiter device for a vehicle, and more particularly to a torque limiter device suitably applied to a vehicle having no fluid coupling such as a torque converter in a power transmission path.

[0002]

2. Description of the Related Art Vehicles without a fluid coupling such as a torque converter in a power transmission path have been proposed in recent years. For example, (a) an engine that generates power by burning fuel, and (b)
Some hybrid vehicles having an electric motor and (c) a combining and distributing device that mechanically combines and distributes power between the engine, the electric motor, and the output member, without a fluid coupling There is. In such a vehicle, when excessive torque is input to the power transmission path due to wheel lock or the like at the time of sudden braking, there is no function to absorb the torque unlike a torque converter, so that it directly acts on a drive source such as an engine. As a result, a large impact is generated, and there is a possibility that a shaft for transmitting power is broken or a gear of each part is damaged. Further, when a belt-type continuously variable transmission is provided, the belt may slip.

On the other hand, a starting clutch is provided between the belt-type continuously variable transmission and the driving wheels, and when an excessive torque is input during braking or the like, the starting clutch slips. Preventing belt slippage is described, for example, in "HONDA R & D Technical Review" (VOL.
8 1996).

[0004]

However, when a clutch is provided between the belt-type continuously variable transmission and the drive wheels and used as a torque limiter, a large transmission torque capacity (engagement torque) is required. In addition, since it is necessary to control the engagement torque in a wide range according to the belt pressing force of the belt-type continuously variable transmission, it is difficult to obtain high control accuracy, particularly when a hydraulic clutch is used. Was.

In the case where an anti-lock brake device for controlling the braking force so that the driving wheels do not lock is provided, excessive torque is periodically applied when the device is operated. Durability may be reduced.

An engine is connected to the first rotating element and an electric motor is connected to the second rotating element.
In a vehicle provided with a mechanical compound dispensing device in which a rotating element is connected to a case via a friction engagement type brake, the engine is cranked and started by engaging the brake and operating an electric motor. However, since a spring-mass system that uses the shaft of an engine or an electric motor or a damper as a spring is configured, it resonates when the engine rotation speed passes through its resonance point, causing excessive torque fluctuation. May be broken or large vibrations may occur.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. It is an object of the present invention to provide a vehicle in which a power transmission path is not provided with a fluid coupling such as a torque converter or an excessive torque or a periodic torque. It is an object of the present invention to prevent damage or deterioration in durability due to abnormal torque such as fluctuation by relatively simple control.

[0008]

According to a first aspect of the present invention, there is provided a vehicle in which power is transmitted from a power source for traveling to driving wheels via a transmission. (B) a frictional engagement device disposed between the power source and the transmission and involved in power transmission, and (b) the frictional engagement when a predetermined abnormal torque is generated between the power source and the drive wheels. Engagement torque control means for controlling the engagement torque of the friction engagement device so that the device slips.

According to a second aspect of the present invention, there is provided a vehicle in which power is transmitted from a driving power source to driving wheels via a belt-type continuously variable transmission. (B) a frictional engagement device disposed between the frictional engagement devices for power transmission;
The engagement torque of the friction engagement device is determined based on the belt pressing force of the belt-type continuously variable transmission so that the friction engagement device slips before the belt of the belt-type continuously variable transmission slips. And controlling engagement torque control means.

According to a third aspect of the present invention, (a) a frictional engagement device for transmitting power is provided between a driving power source and a driving wheel, while (b) the driving wheel is not locked. In a vehicle provided with an anti-lock brake device for controlling a braking force of a braking device provided on the drive wheel, (c)
When the braking force of the braking device is controlled by the anti-lock brake device, an engagement torque control means for reducing the engagement torque of the friction engagement device is provided.

According to a fourth aspect of the present invention, (a) an engine that generates power by burning fuel and an electric motor are provided, while (b) the engine is connected to a first rotating element and a second rotating element is connected to the second rotating element. In a vehicle provided with a mechanical combining and distributing device in which the electric motor is connected and a third rotating element is connected to a case via a friction engagement type brake, (c) the brake is engaged and (D) by operating an electric motor to crank and start the engine, and (d) when an abnormal torque is generated when the engine is started by the engine starting means, the brake slips. And engagement torque control means for controlling the engagement torque of the brake.

[0012]

According to the first aspect, the engagement torque of the friction engagement device is controlled so that the friction engagement device slips when a predetermined abnormal torque is generated between the power source and the drive wheels. Therefore, even in vehicles that do not have a fluid coupling such as a torque converter in the power transmission path, abnormalities such as excessive torque input due to wheel lock during sudden braking and excessive torque cycle fluctuations due to the operation of the antilock brake device Damage to each member of the power transmission path and reduction in durability due to the torque are suppressed. In addition, since the friction engagement device is disposed between the power source and the transmission, the transmission torque is generally smaller than that of the transmission on the driving wheel side, so that the control is easy and the change in the torque is easy. Even when the engagement torque is continuously controlled based on the predetermined physical quantity, the control range is narrowed, and high control accuracy is obtained.

The second invention substantially corresponds to an embodiment of the first invention, and the same operation and effect as those of the first invention can be obtained. That is, in the second aspect, the slippage of the friction engagement device prevents slippage of the belt of the belt-type continuously variable transmission, thereby improving durability. Further, it is necessary to continuously control the engagement torque according to the belt pressing force of the belt type continuously variable transmission. However, a friction engagement device is disposed between the power source and the belt type continuously variable transmission. Therefore, the engagement torque to be controlled is relatively small and the control range is narrow, so that control is easy and high control accuracy can be obtained.

According to the third aspect of the present invention, when the braking force of the braking device is controlled by the anti-lock braking device, the engagement torque of the friction engagement device is reduced. Even in a vehicle that does not have the same, the peak value of the torque fluctuation due to the operation of the antilock brake device is reduced due to the slip of the friction engagement device, and the decrease in durability of each member of the power transmission path due to low cycle fatigue is suppressed. .

In the fourth invention, when the engine is cranked and started by engaging the brake and operating the electric motor, a spring-mass system having a shaft and a damper of the engine and the electric motor as springs is constituted. Therefore, if a fluid coupling such as a torque converter is not provided, resonance occurs when the engine rotation speed passes through the resonance point, and there is a possibility that excessive torque fluctuation and large vibration may occur. If abnormal torque is generated when the engine starts, the brake slips, so the abnormal torque is absorbed by the brake slip and excessive torque fluctuations and large vibrations due to such resonance are suppressed. Is done.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is suitably applied to a vehicle having no fluid coupling such as a torque converter in a power transmission path. The first to third inventions are suitably applied to a case where a power source having a large inertia capable of receiving an excessive input torque is provided, such as an engine that generates power by burning fuel.

[0017] As a vehicle not provided with a fluid coupling such as a torque converter or the like and provided with an engine which generates power by burning fuel as a power source, a series type, a parallel type and the like having an engine and a motor generator are provided. Hybrid vehicles are widely known. For example, (a) an engine that generates power by burning fuel, (b) a motor generator, and (c) a composite distributor that mechanically combines and distributes power between the engine, the motor generator, and an output member. Is an example of such a hybrid vehicle. The motor generator is used, for example, as an electric motor and a generator, but may be an electric motor or a generator having only one of the functions. Of course, it is also possible to use a motor generator as the electric motor of the fourth invention. Power is mechanically synthesized,
As the combining and distributing device for distributing, a bevel gear type differential device and a planetary gear device are preferably used.

The friction engagement device involved in power transmission includes a clutch interposed in a power transmission path for transmitting and disconnecting power, as well as a predetermined reaction force receiving member required to output power to the transmission. The brake which fixes an element to a case may be sufficient. As the friction engagement device, a hydraulic friction clutch of a single-plate type, a multi-plate type, or the like, which is frictionally engaged by a hydraulic actuator, or a hydraulic friction brake is preferably used, but an electromagnetic friction engagement device may also be used. it can.

The transmission transmits the power to the drive wheels by decelerating (torque amplifying) at least during general traveling. A belt-type continuously variable transmission is preferably used as in the second invention. It is also possible to use another continuously variable transmission such as a toroidal type or a stepped transmission. Further, a reduction gear that reduces the rotation speed at a constant reduction ratio may be used.

The engagement torque control means of the first invention is configured to continuously control the engagement torque based on a predetermined physical quantity as in the second invention, for example. Control (adjustment) to a constant engagement torque so as to cause slippage with torque may be performed.

The engagement torque control means of the third invention determines whether or not the antilock brake device is operating, and during the operation, for example, reduces the engagement torque of the friction engagement device by a predetermined value. However, it is desirable that the pressure is gradually reduced at a predetermined reduction rate. If the torque is reduced at a predetermined rate, the peak value of the periodically changing torque gradually decreases due to slippage of the friction engagement device, so that a torque of a certain magnitude (peak value) acts periodically and repeatedly. Compared with the case, low cycle fatigue is more effectively suppressed. When the engagement torque is reduced by a predetermined value, the reduction width may be a constant value, but the reduction width is set from a map or an arithmetic expression using a predetermined physical quantity such as the rotation speed of the drive source as a parameter. You can also.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram illustrating a hybrid drive device 10 to which the present invention is applied. FIG. 2 is a skeleton diagram including a transmission 12, and the hybrid drive device 10 includes a fluid coupling such as a torque converter. Engine 14, which generates power by burning fuel,
It comprises a motor generator 16 used as an electric motor and a generator, and a double pinion type planetary gear set 18. The engine 14 is connected to the sun gear 18s of the planetary gear set 18, the motor generator 16 is connected to the carrier 18c, and the ring gear 18r is connected to the case 20 via the first brake B1. The carrier 18c is connected to the input shaft 22 of the transmission 12 via a first clutch C1, and the ring gear 18r is connected to the input shaft 22 via a second clutch C2. Engine 14
Is a damper device 15 having an elastic member such as a spring or rubber,
And a shaft 17 connected to a sun gear 18s. The planetary gear device 18 corresponds to the combining and distributing device of the fourth invention. The sun gear 18s corresponds to a first rotating element, the carrier 18c corresponds to a second rotating element, and the ring gear 18r corresponds to a third rotating element. The input shaft 22 of the transmission 12 corresponds to an output member.

Each of the clutches C1 and C2 and the first brake B1 is a wet-type multi-plate hydraulic friction engagement device that is frictionally engaged by a hydraulic actuator, and is frictionally engaged by hydraulic oil supplied from a hydraulic control circuit 24. It is adapted to be combined. FIG. 3 is a diagram showing a main part of the hydraulic control circuit 24. The original pressure PC generated by the electric hydraulic pressure generating device 26 including the electric pump is connected to the manual valve 2.
The power is supplied to the clutches C1 and C2 and the brake B1 via the control lever 8 in accordance with the operation range of the shift lever 30 (see FIG. 1). The shift lever 30 is a shift operation member operated by the driver. In this embodiment, the shift lever 30 is selectively operated in five ranges of “B”, “D”, “N”, “R”, and “P”. The manual valve 28 is connected to the shift lever 30 via a cable or a link.
, And can be mechanically switched in accordance with the operation of the shift lever 30.

The "B" range indicates that the transmission 12
The operation range in which a relatively large power source brake is generated due to a downshift or the like, and the "D" range is an operation range in which the vehicle travels forward. Is supplied. The original pressure PC is supplied to the first clutch C1 via the shuttle valve 31. "N"
The range is an operation range that cuts off the transmission of power from the power source, and the “R” range is an operation range that runs backward, and “P”
The range is an operation range in which power transmission from the power source is cut off and the rotation of the drive wheels is mechanically prevented by a parking lock device (not shown). In these operation ranges, the original pressure is supplied from the output port 28b to the first brake B1. A PC is provided. Original pressure PC output from output port 28b
Is also input to the return port 28c. In the "R" range, the original pressure PC is supplied from the shuttle valve 31 to the first clutch C1 from the return port 28c via the output port 28d.

The clutches C1, C2 and the brake B1
Are provided with control valves 32, 34 and 36, respectively, so that the oil pressures P _C1 , P _C2 and P _B1 thereof are controlled. ON for hydraulic pressure P _C1 of clutch C1
The pressure is regulated by the -OFF valve 38, and the pressure of the clutch C2 and the brake B1 is regulated by the linear solenoid valve 40.

Each running mode shown in FIG. 4 is established according to the operating states of the clutches C1, C2 and the brake B1. That is, in the "B" range or the "D" range, any one of the "ETC mode", the "direct connection mode", and the "motor running mode (forward)" is established. In the "ETC mode", the second clutch C2 is engaged. The first clutch C1 and the first brake B
When the vehicle 1 is open, the engine 14 and the motor generator 16 are operated together to make the vehicle travel forward.
In the “direct connection mode”, the engine 1 is engaged with the clutches C1 and C2 engaged and the first brake B1 released.
4 is operated to move the vehicle forward. In the “motor running mode (forward)”, the motor generator 16 is operated to cause the vehicle to run forward with the first clutch C1 engaged and the second clutch C2 and the first brake B1 released. The “ETC mode” is an electric torque converter mode corresponding to an engine / motor running mode, and the “direct connection mode” corresponds to an engine direct connection mode.

FIG. 5 is an alignment chart showing the operating state of the planetary gear set 18 in the forward mode, where "S" indicates the sun gear 18s, "R" indicates the ring gear 18r, and "C" indicates the carrier 18c. , Their spacing is the gear ratio ρ
(= Number of teeth of sun gear 18s / number of teeth of ring gear 18r)
Is determined by Specifically, assuming that the interval between “S” and “C” is 1, the interval between “R” and “C” becomes ρ, and in this embodiment, ρ is about 0.6. Further, the torque ratio in the ETC mode of (a) is engine torque Te: CVT input shaft torque Tin: motor torque Tm = ρ: 1: 1−ρ, and the motor torque Tm can be smaller than the engine torque Te. In a steady state, the torque obtained by adding the motor torque Tm and the engine torque Te is CV
It becomes T input shaft torque Tin. CVT means a continuously variable transmission. In this embodiment, a belt-type continuously variable transmission is provided as the transmission 12.

Returning to FIG. 4, "N" range or "P"
In the range, either “neutral” or “charge / eng start mode” is established, and “neutral”
Then, all of the clutches C1, C2 and the first brake B1 are released. In the “charging / Eng start mode”, the clutches C1 and C2 are released, the first brake B1 is engaged, the motor generator 16 is rotated in the reverse direction to start the engine 14, and the planetary gear device 1
The motor 42 is rotated and driven via the motor 8, the regenerative control of the motor generator 16 is performed to generate electric power, and the battery 42 (see FIG. 1) is charged.

In the "R" range, "motor traveling mode (reverse)" or "friction traveling mode" is established. In "motor traveling mode (reverse)", the first clutch C1 is engaged and the second clutch is engaged. With C2 and the first brake B1 released, the motor generator 16 is operated in the reverse rotation direction to cause the vehicle to travel backward.
In the "friction running mode", the first clutch C1 is engaged and the second clutch C2 is released.
By operating the motor generator 16 in the reverse rotation direction to cause the vehicle to travel backward, the engine 14 is operated and the first brake B1 is slip-engaged in a state where the ring gear 18r is rotated in the forward direction. Is to apply a reverse assist force to the input shaft 22.

The transmission 12 is a belt-type continuously variable transmission.
Speed ratio γ (= input shaft rotation speed Nin / output shaft rotation speed Nou
t) is greater than 1.0 in a predetermined gear ratio range.
Is reduced (torque amplification) and output to the output shaft 44. The power output to the output shaft 44 is transmitted to the ring gear 50 of the differential device 48 via the reduction gear 46,
The gears are distributed to the left and right drive wheels 52 by the differential device 48.

The hybrid drive device 10 of the present embodiment is
It is controlled by the HVECU 60 shown in FIG. HVECU 60 includes a CPU, a RAM, and a ROM.
And the like while using the temporary storage function of the RAM.
By executing signal processing according to a program stored in the OM in advance, the electronic throttle ECU 62, the engine ECU 64, the M / GECU 66, the T / MECU 68,
It controls the ON-OFF valve 38, the linear solenoid valve 40 of the hydraulic control circuit 24, the starter 70 of the engine 14, and the like. The electronic throttle ECU 62 controls opening and closing of an electronic throttle valve 72 of the engine 14.
The CU 64 controls the engine output based on the fuel injection amount of the engine 14, the variable valve timing mechanism, the ignition timing, and the like, and the M / GECU 66 controls the power running torque, the regenerative braking torque, and the like of the motor generator 16 via the inverter 74. The T / MECU 68 determines the transmission ratio γ of the transmission 12 (= input shaft rotation speed Nin / output shaft rotation speed Nou).
t) and the belt pressing force are controlled. The transmission 12 has a transmission ratio γ and a belt pressing force controlled by a hydraulic actuator. The hydraulic control circuit 24 includes a circuit for controlling the transmission ratio γ and the belt pressing force of the transmission 12. The starter 70 is an electric motor, and a pinion provided on a motor shaft is engaged with a ring gear provided on a flywheel or the like of the engine 14 so that the engine 1
4 is to be cranked.

The HVECU 60 is supplied with a signal indicating the operation amount θac of an accelerator pedal 78 as an accelerator operation member from an accelerator operation amount sensor 76.
A signal indicating the operation range (shift position) of the shift lever 30 is supplied from the shift position sensor 80. Further, from the engine rotation speed sensor 82, the motor rotation speed sensor 84, the input shaft rotation speed sensor 86, and the output shaft rotation speed sensor 88, respectively, the engine rotation speed (rotation speed) Ne, the motor rotation speed (rotation speed) Nm, the input shaft Signals representing the rotation speed (the rotation speed of the input shaft 22) Nin and the output shaft rotation speed (the rotation speed of the output shaft 44) Nout are supplied. The output shaft rotation speed Nout corresponds to the vehicle speed V. In addition, an anti-lock brake device (A) that controls the braking force of the braking device so that the drive wheels 52 do not lock.
BS) 90 supplies a signal indicating the operating state, and various signals indicating the operating state, such as the state of charge SOC of the battery 42, are supplied. The anti-lock brake device 90 controls the brake oil pressure according to the slip state of the wheels. During operation, the brake oil pressure, that is, the brake force changes periodically. Storage amount SO
C may be simply the battery voltage, or may be obtained by sequentially integrating the charge / discharge amount.

The HVECU 60 basically has the functions shown in FIG. 6, and is adapted to execute the running mode shown in FIG. The ETC mode control means 100 in FIG. 6 implements the “ETC mode”, the direct connection mode control means 102 implements the “direct connection mode”, and the motor forward means 104 implements the “motor traveling mode (forward)”. The charging control means 106 implements a “charging / Eng start mode”, the motor reversing means 108 implements a “motor traveling mode (reverse)”, and the engine assist reversing means 110 performs “friction traveling”. The mode is implemented, and the ETC mode control means 100 and the direct connection mode control means 102 constitute an engine forward means 112. The mode determination means 114 determines the traveling mode based on the accelerator operation amount θac, the vehicle speed V (output shaft rotation speed Nout), the stored power SOC, the shift position of the shift lever 30, the coolant temperature of the engine 14, and the like. The respective means are switched so that the operation is performed in the determined traveling mode.

The HVECU 60 also executes signal processing in accordance with the flowchart of FIG. 7 so that the engagement torques T _C1 and T _C2 of the clutches C1 and C2 are prevented so that the belt of the belt-type continuously variable transmission 12 is prevented from slipping. Control. That is, the clutches C1 and C2 are connected to the belt-type continuously variable transmission 1.
It also functions as a torque limiter for preventing the slip of the second belt.

In step S1-1, the clutches C1, C
2 oil pressures P _C1 and P _C2 , specifically, the ON-OFF valve 3
Based on the hydraulic command value for the linear solenoid valve 8 and the linear solenoid valve 40, the friction coefficient of the friction material, the friction area, the radius, and the like, the engagement torques T _C1 and T _C2 of the clutches C1 and _C2 are calculated. The hydraulic pressures P _C1 and P _C2 are set to a predetermined margin so that the engagement torques T _C1 and T _C2 required for power transmission can be obtained based on, for example, the driving mode, the engine torque Te, and the motor torque Tm shown in FIG. Is controlled by

In step S1-2, a belt transmission torque T _CVT that can be transmitted without causing the belt to slip is calculated based on the belt pressing force of the belt-type continuously variable transmission 12. Specifically, it is calculated based on a hydraulic pressure command value for controlling the belt pressing force, a friction coefficient, a gear ratio γ, and the like.

In step S1-3, a belt type
Before the belt of the continuously variable transmission 12 slips, the clutch C
1 or C2 so that the belt transmission
Luc T_CVTTorque T based on_C1, T_C2The upper limit of
Set the engagement torque T_C1, T _C2Is over the upper limit
In this case, the ON-OFF valve 38 or
Oil pressure P by linear solenoid valve 40_C1, P_C2Pressure regulation
Correct your control. In this step S1-3, the engagement control
Engagement torque of the engaged clutch C1 and / or C2
T_C1, T_C2The upper limit of the clutch C1 and the clutch C1
If both C2 and C2 are engaged,
Only the upper limit may be limited.

In this way, the driving wheels 5 can be used during sudden braking or the like.
When the torque of the clutch C1 or C2 slips before the belt of the belt-type continuously variable transmission 12 slips when an excessive torque is input to the power transmission path due to, for example, the locking of the torque converter 2, the torque converter Belt type continuously variable transmission 1
The belt 2 is prevented from slipping and durability is improved.

On the other hand, since the clutches C1 and C2 are disposed closer to the power source than the belt-type continuously variable transmission 12, the gear ratio γ of the belt-type continuously variable transmission 12 is smaller than that of the drive wheels 52.
Control of engagement torques T _C1 and T _C2 ,
Specifically, the ON-OFF valve 38 and the linear solenoid valve 4
0 pressure-regulating control of the hydraulic P _C1, P _C2 is easy due. Also, while the upper limit guard is being performed, the engagement torques T _C1 and T _C2 need to be continuously controlled in accordance with the belt pressing force of the belt-type continuously variable transmission 12. However, since the control range is relatively narrow, the High control accuracy can be obtained irrespective of the response delay of the pressure control.

The control shown in FIG. 7 is performed by the clutch C1,
This is particularly effective in a “direct connection mode” in which the engine 14 is directly connected to the input shaft 22 by engaging the C2 together.

The control shown in FIG. 7 corresponds to the first and second embodiments of the present invention. In the series of signal processing performed by the HVECU 60, the steps for executing steps S1-1 to S1-3 in FIG. The ON-OFF valve 38 and the linear solenoid valve 40 constitute the engagement torque control means of the first invention and the second invention.

The HVECU 60 also executes signal processing in accordance with the flow chart of FIG. 8 so that the engagement torque T of the clutches C1 and C2 when the antilock brake device 90 is operated.
_C1, by reducing T _C2, suppresses low cycle fatigue due to the control of anti-lock brake system 90.
That is, the clutches C1 and C2 also function as torque limiters for suppressing low cycle fatigue caused by control of the antilock brake device 90.

In step S2-1, a signal supplied from the anti-lock brake device 90 indicates whether or not the anti-lock brake device 90 is operating, that is, whether or not the braking force is being controlled to prevent locking of the wheels. When the control is being performed, the clutch C1,
The engagement torques T _C1 and T _C2 are reduced by forcibly reducing the oil pressures P _C1 and P _C2 of _C2 . The hydraulic pressures P _C1 and P _C2 of the clutches C1 and C2 are reduced by a fixed amount each time Step S2-2 is repeatedly executed at a predetermined cycle time when the antilock brake device 90 is operated, and gradually decreased at a predetermined reduction rate. Let me do. In step S2-2, the hydraulic pressure P _{C1 of} the clutch C1 and / or C2 whose engagement is controlled,
It is only necessary to lower P _C2 , and when both clutches C1 and C2 are engaged, it is only necessary to lower either one of the oil pressures P _C1 or P _C2 .

In this way, when the braking force is controlled by the anti-lock brake device 90,
Since the engagement torques T _C1 and T _{C2 of} the clutches C 1 and C ₂ , specifically, the hydraulic pressures P _C1 and P _C2 are reduced at a predetermined reduction rate, the power transmission path is not provided with a fluid coupling such as a torque converter. Also in the vehicle, the clutch C1 or C2
Due to the slip, the peak value of the torque fluctuation due to the operation of the antilock brake device 90 is reduced, and the decrease in the durability of each member of the power transmission path due to low cycle fatigue is suppressed.

In this embodiment, since the hydraulic pressures P _C1 and P _C2 are gradually reduced at a predetermined reduction rate, the peak value of the periodically changing torque gradually decreases due to slippage of the clutches C1 and C2. And a certain size (peak value)
In comparison with the case where the torque of
Low cycle fatigue is more effectively suppressed.

Since the clutches C1 and C2 are disposed closer to the power source than the belt-type continuously variable transmission 12, the gear ratio γ of the belt-type continuously variable transmission 12 is smaller than that of the drive wheels 52.
Control of engagement torques T _C1 and T _C2 ,
Specifically, the ON-OFF valve 38 and the linear solenoid valve 4
0 pressure-regulating control of the hydraulic P _C1, P _C2 is easy due.

The control of FIG. 8 is performed by the clutch C1,
This is particularly effective in a “direct connection mode” in which the engine 14 is directly connected to the input shaft 22 by engaging the C2 together.

The control shown in FIG. 8 corresponds to the first and third embodiments of the present invention. In the series of signal processing performed by the HVECU 60, the steps for executing steps S2-1 to S2-2 in FIG. The ON-OFF valve 38 and the linear solenoid valve 40 constitute the engagement torque control means of the first invention and the third invention.

[0049] HVECU60 further, at the start of the engine 14 by the charging control unit 106, by controlling the engagement torque T _B1 of the first brake B1 in accordance with the flowchart of FIG. 9, suppressing the occurrence of abnormal torque due to resonance. That is, the first brake B1 also functions as a torque limiter for suppressing occurrence of abnormal vibration due to resonance when the engine is started.

In step S3-1, the charge control means 10
6, the clutches C1, C2 are released, the first brake B1 is engaged, and the engine 14 is cranked by rotating the motor generator 16 in the reverse direction. For example, the determination is made from the command signal of the mode determination unit 114 or the operation state of the motor generator 16. When the start control of the engine 14 is performed by the charge control means 106, step S3-2 is executed, and the first brake B
When starting a predetermined one of the engagement torque T _B1 based like cranking torque of the engine 14 engaging torque T _B1
Adjust to ^* . The starting engagement torque T _B1 ^* is
The torque required for starting, such as cranking of No. 4, is fixed to the case 20 by the ring gear 18r, which is a reaction force receiving element, so that the torque is transmitted from the motor generator 16 to the engine 14 via the planetary gear device 18. When an abnormal torque more than necessary is generated by the first brake B1
Is a predetermined value determined in advance by experiments or the like so that the slip may occur. However, the starting engagement torque T _B1 ^* may be learned and corrected when the engine 14 is started. The adjustment of the engagement torque T _B1 is performed by the linear solenoid valve 40.
The control is performed by the pressure control of the hydraulic pressure P _B1 .

When the engine 14 is started by releasing the clutches C1 and C2, engaging the first brake B1, and reversely rotating the motor generator 16, the engine 14 is started. In this vehicle which does not have a fluid coupling such as a torque converter, resonance occurs when the engine rotation speed Ne passes through the resonance point of the vehicle, since a spring-mass system having the spring 17 and the damper device 15 as springs is configured. However, in this control, if an abnormal torque is generated when the engine 14 is started, the first torque may be generated.
Since the brake B1 slips, the abnormal torque is absorbed by the slip of the first brake B1, and the occurrence of excessive torque fluctuation and large vibration due to such resonance is suppressed.

The control shown in FIG. 9 corresponds to the fourth embodiment of the present invention.
Steps S3-1 to S3-2 form an engagement torque control unit of the fourth invention together with the linear solenoid valve 40. Further, the charge control means 1 shown in FIG.
06 corresponds to the engine starting means of the fourth invention.

The embodiments of the present invention have been described in detail with reference to the drawings. However, these embodiments are merely examples, and the present invention is based on the knowledge and knowledge of those skilled in the art. Can be implemented.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating a hybrid drive device to which the present invention is applied.

FIG. 2 is a skeleton view showing a power transmission system of the hybrid drive device of FIG. 1;

FIG. 3 is a circuit diagram showing a part of the hydraulic control circuit of FIG. 1;

FIG. 4 is a diagram for explaining a relationship between some traveling modes established in the hybrid drive device of FIG. 1 and operating states of a clutch and a brake.

FIG. 5 is a collinear chart showing a relationship between rotation speeds of respective rotating elements of the planetary gear device in the ETC mode, the direct connection mode, and the motor traveling mode (forward) in FIG.

FIG. 6 is a block diagram showing some functions of the HVECU of FIG. 1;

FIG. 7 is a flowchart illustrating an operation of a torque limiter for preventing a belt of a belt-type continuously variable transmission from slipping in the hybrid drive device of FIG. 1;

8 is a flowchart illustrating an operation of a torque limiter for suppressing low cycle fatigue caused by control of the antilock brake device in the hybrid drive device of FIG.

FIG. 9 is a flowchart illustrating an operation of a torque limiter for suppressing occurrence of abnormal vibration due to resonance when the engine is started in the hybrid drive device of FIG. 1;

[Explanation of symbols]

10: Hybrid drive unit 12: Belt-type continuously variable transmission 14: Engine 16: Motor generator (electric motor) 18: Planetary gear unit (combined distribution unit) 18s: Sun gear (first rotating element) 18
r: Carrier (second rotating element) 18r: Ring gear (third rotating element) 38: ON-OFF valve 40: Linear solenoid valve 52: Drive wheel 60: HVECU
90: Anti-lock brake device 106: Charge control means (engine starting means) C1: First clutch (friction engagement device) C2: Second clutch (friction engagement device) B1: First brake (brake) Step S1-1 S1-3: Engagement torque control means (first invention, second invention) Steps S2-1, S2-2: Engagement torque control means (first invention, third invention) Steps S3-1, S3-2 : Engagement torque control means (fourth invention)

Continued on the front page (72) Inventor Hideaki Komada 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Mitsuhiro Umeyama 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation

Claims (4)

[Claims] 1. A vehicle in which power is transmitted from a driving power source to driving wheels via a transmission, a frictional engagement disposed between the power source and the transmission and involved in power transmission. Device, such that the friction engagement device slips when a predetermined abnormal torque is generated between the power source and the drive wheel,
A torque limiter device for a vehicle, comprising: engagement torque control means for controlling an engagement torque of the friction engagement device. 2. A vehicle in which power is transmitted from a power source for traveling to drive wheels via a belt-type continuously variable transmission, wherein the power source is disposed between the power source and the belt-type continuously variable transmission. A frictional engagement device involved in power transmission, and a belt pressing force of the belt-type continuously variable transmission so that the frictional engagement device slips before the belt of the belt-type continuously variable transmission slips. And torque control means for controlling the engagement torque of the friction engagement device. 3. A braking device provided between a driving power source and a driving wheel, the friction engaging device being involved in power transmission, and a braking device provided on the driving wheel so that the driving wheel is not locked. A vehicle provided with an anti-lock brake device for controlling the braking force of the vehicle, wherein the engagement torque of the friction engagement device is reduced when the braking force of the braking device is controlled by the anti-lock brake device. A torque limiter device for a vehicle, comprising a torque control unit. 4. An engine which generates power by combustion of fuel and an electric motor, wherein the engine is connected to a first rotating element and the electric motor is connected to a second rotating element, and In a vehicle provided with a mechanical combining and distributing device in which a rotating element is connected to a case via a friction engagement type brake, the engine is closed by engaging the brake and operating the electric motor. An engine starting means for starting by ranking, and an engagement torque control means for controlling an engagement torque of the brake so that the brake slips when an abnormal torque is generated when the engine is started by the engine start means. And a torque limiter device for a vehicle.