JP2000291695A - Power transmission system protecting device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power transmission system protecting device for vehicle capable of properly preventing a power transmission member of each part forming a power transmission path from being damaged even when the excess positive torque is generated on a power transmission system caused by the quick reduction of the speed of rotation of a wheel caused by the running-on of the wheel. SOLUTION: In a case when it is judged by a judging means 64 that at least one of the speed of rotations NFL, NFR, NRL, NRR of a plurality of wheels of a vehicle is quickly raised or reduced to a degree causing the damage of a power transmission member forming a power transmission path of the vehicle, an automatic clutch 14 is released with priority by a preferential automatic clutch releasing mans 66, so that the automatic clutch 14 is released with priority when the excess positive torque is generated by the quick reduction of the speed of rotation of one of the wheels or when the excess negative torque is generated by the quick rise of the speed of rotation of one of the wheels, and the power transmission member of each part forming the power transmission path of the vehicle can be properly prevented from being damaged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission system protection device for a hybrid vehicle.

[0002]

2. Description of the Related Art When a relatively large negative torque is suddenly generated in a power transmission system of a vehicle due to a braking operation during a slip period while the vehicle is running, a clutch provided in series with the power transmission system is operated. A device has been proposed in which the power transmission member of each part constituting the power transmission path is prevented from being damaged by being released. For example, JP
This is the device described in US Pat. According to this, when the occurrence of wheel slip is detected based on the rotational speed difference between the wheels, the slip increases the apparent vehicle speed, thereby prohibiting the lock-up clutch from being engaged. By preferentially releasing the lock-up clutch, engine stall due to the brake operation during the slip period is suitably prevented.

[0003]

However, when the vehicle is running on a rough road, the rotational speed of the wheels is suddenly reduced, such as when the wheels ride on a rock, and an excessive torque or torque change occurs in the power transmission system. It may occur rapidly. However, in the above-described conventional apparatus, when the occurrence of wheel slip is detected, the lock-up clutch of the vehicle is uniformly preferentially released, and the power is reduced due to the sudden generation of negative torque due to the brake operation during the slip period. Since the transmission path is protected, it is impossible to cope with the generation of excessive positive torque due to the rapid decrease in the rotation speed of the wheels as described above, and the power transmission members of the respective parts constituting the power transmission path are damaged. There was a disadvantage.

The present invention has been made in view of the above circumstances, and an object of the present invention is to generate an excessive positive torque or a torque change in a power transmission system due to a rapid decrease in the number of rotations of a wheel caused by the running of a wheel. It is an object of the present invention to provide a power transmission system protection device that can appropriately prevent damage to power transmission members of each part constituting the power transmission path even if the power transmission path is prevented.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, a gist of a first invention is to provide a power transmission system protection device for a vehicle for protecting a power transmission path from a prime mover to driving wheels. (A) an automatic clutch inserted in series in a power transmission path of the vehicle, and (b) at least one of the rotation speeds of a plurality of wheels provided in the vehicle defines a power transmission path of the vehicle. Determining means for determining that the power transmission member constituting the power transmission member has rapidly risen or decreased to such an extent as to cause damage; and (c) at least one of the rotation speeds of each of the wheels constitutes a power transmission path of the vehicle by the determination means. Automatic clutch priority release means for preferentially releasing the automatic clutch if it is determined that the power transmission member suddenly rises or falls to such an extent as to cause damage to the power transmission member.
To include.

[0006]

According to this structure, the determining means causes at least one of the rotational speeds of the plurality of wheels provided in the vehicle to rise so rapidly as to cause damage to the power transmission member constituting the power transmission path of the vehicle. Alternatively, if it is determined that the automatic clutch has suddenly dropped, the automatic clutch is preferentially released by the automatic clutch priority releasing means, so that an excessive positive torque or torque change due to a sudden decrease in the rotation speed of at least one wheel, or When an excessive negative torque or torque change due to a sudden rise occurs, the automatic clutch is preferentially disengaged, and damage to the power transmission members of each part constituting the power transmission path is preferably prevented.

[0007]

According to a second aspect of the present invention, there is provided a belt type in which a transmission belt is wound around a pair of variable pulleys having a variable effective diameter. A power transmission system protection device for protecting a belt-type continuously variable transmission in a vehicle in which a continuously variable transmission is provided in a power transmission path from a prime mover to a drive wheel, comprising:
Determining means for determining that at least one of the rotation speeds of the plurality of wheels provided in the vehicle has rapidly increased or decreased to such an extent that slippage of the transmission belt has occurred; When it is determined that at least one of the rotation speeds has rapidly increased or decreased to such an extent as to cause slippage of the transmission belt, a clamping pressure increasing means for increasing the clamping pressure of the variable pulley on the transmission belt, It is in.

[0008]

In this way, when it is determined by the determining means that the rotation of each wheel has rapidly increased or decreased to such an extent that the transmission belt slips, the clamping pressure increasing means is provided. Since the clamping pressure of the variable pulley against the transmission belt is increased, when an excessive positive torque or torque change due to a sudden decrease in the rotation speed of the wheel or an excessive negative torque or torque change due to a sudden increase occurs, the variable pulley The clamping pressure on the power transmission belt is increased, so that damage to the belt-type continuously variable transmission inserted in the power transmission path is preferably prevented.

Here, in the first invention and the second invention, preferably, a wheel rotation number detecting device for detecting each rotation number of a plurality of wheels provided in the vehicle, and the wheel rotation number detecting device thereof And a rotation determination reference range calculating means for calculating a rotation determination reference range based on the average value of the rotation speeds of the respective wheels detected by the control unit. It is determined whether or not at least one of the rotation speeds of each of the wheels has rapidly increased or decreased to such an extent as to cause damage to a power transmission member constituting the power transmission path, based on whether or not the rotation has deviated from a reference range. . According to this configuration, based on whether at least one of the rotation speeds of each wheel is out of the rotation determination reference range, at least one of the rotation speeds of each wheel is transmitted to the power transmission member configuring the power transmission path. The automatic clutch is preferentially released even when an excessive positive torque is generated due to a sudden decrease in the rotation speed of the wheels, and it is determined that the automatic clutch has been rapidly increased or decreased to such an extent as to cause damage. The clamping pressure is increased.

In the first invention and the second invention, preferably, a wheel rotation number detecting device for detecting each rotation number of a plurality of wheels provided in the vehicle, and the wheel rotation number detecting device, A wheel acceleration calculating means for calculating each wheel acceleration corresponding to the vehicle acceleration from the detected rotation speed of each wheel, an acceleration sensor for detecting an actual acceleration of the vehicle, and a vehicle acceleration detected by the acceleration sensor. Acceleration determination reference range calculation means for calculating an acceleration determination reference range based on actual acceleration, wherein the determination means includes at least one of the wheel accelerations.
One of them determines whether the rotation of each wheel has rapidly increased or decreased to the extent that the power transmission member constituting the power transmission path may be damaged, that is, a torque change, based on whether or not one of the power transmission members has deviated from the acceleration determination reference range. Things.
With this configuration, the determination means can be performed even when the vehicle running on the rough road jumps and all the wheels of the vehicle run at the same time, or when the wheels of the vehicle running on the frozen road or the snowy road run at the same time. , The automatic clutch is preferentially released by the automatic clutch priority releasing means, or the clamping pressure on the transmission belt of the variable pulley is increased by the clamping pressure increasing means.

In the first invention and the second invention, preferably, a wheel rotation number detecting device for detecting each rotation number of a plurality of wheels provided in the vehicle, and the wheel rotation number detecting device, A wheel acceleration calculating means for calculating each wheel acceleration corresponding to the vehicle acceleration from the detected number of rotations of each wheel, wherein the judging means includes a performance of the vehicle in which at least one of the wheel accelerations is set in advance. The rotation of each of the wheels rapidly rises or falls to such an extent as to cause damage to a power transmission member constituting the power transmission path, based on whether or not an acceleration determination reference range corresponding to an acceleration range that can be raised can be obtained. That is, the torque change is determined. If you do this,
Even when a vehicle running on a rough road jumps and its wheels idle at the same time, or when each wheel of a vehicle running on a frozen road or a snow-covered road idles at the same time, based on the determination result by the determination means, The automatic clutch is preferentially released by the automatic clutch priority releasing means, or the clamping pressure on the transmission belt of the variable pulley is increased by the clamping pressure increasing means.

[0012]

FIG. 1 shows a power transmission system of a vehicle and a control device thereof. The driving force output from the engine 10 functioning as a prime mover is transmitted to the belt-type continuously variable transmission 12 and the automatic clutch 1 forming a power transmission path.
4. The gears are transmitted to the drive wheels, ie, a pair of front left wheels 20 and front right wheels 22, via a pair of axles 18 and a differential gear unit 16. In the present embodiment, the automatic clutch 14 is used to protect each power transmission member constituting the power transmission path, for example, the belt-type continuously variable transmission 12, the differential gear device 16, and a joint (not shown) from a sudden change in torque. Functions as a protective clutch.

The belt-type continuously variable transmission 12 is wound around a pair of an input-side variable pulley 24 and an output-side variable pulley 26 whose effective diameters are variable, and is wound around the input-side variable pulley 24 and the output-side variable pulley 26. A transmission belt 28 is provided, for example, and a squeezing pressure applied to the output-side variable pulley 26 from an output-side hydraulic cylinder (not shown) is adjusted based on the speed ratio and the transmission torque.
6, the tension of the transmission belt 28, that is, the tension of the transmission belt 28 is controlled so as to be as low as possible within a range where no slip occurs. The belt-type continuously variable transmission 12 is
For example, the effective diameter of the input-side variable pulley 24, that is, the gear ratio determined by the operating position of the input-side hydraulic cylinder (not shown) is adjusted so that the engine 10 operates along the optimum fuel efficiency curve. That is, the target input shaft rotation speed is determined based on the throttle valve opening and the accelerator pedal operation amount and the vehicle speed V that reflect the actual engine output torque from the relationship stored in advance. The gear ratio is adjusted so that the actual input shaft rotation speed matches the target input shaft rotation speed.

The belt-type continuously variable transmission 12 has a belt clamping pressure regulating valve 29 for regulating the operating oil pressure, for example, the line pressure, of the output hydraulic cylinder for applying the clamping force of the output variable pulley 26, and an input variable valve. A hydraulic control circuit 31 including a speed ratio control valve device 30 for supplying hydraulic oil to or discharging hydraulic oil from an input hydraulic cylinder that changes the effective diameter of the pulley 24 is provided.

The automatic clutch 14 is provided in series in a power transmission path from the engine 10 to the driving wheels, that is, the left front wheel 20 and the right front wheel 22, and is described in, for example, Japanese Patent Application Laid-Open No. 1-233127. like,
The clutch is automatically engaged or disengaged by a clutch actuator (not shown) operated by a hydraulic pressure, an electromagnet, an electric motor, or the like.

In the vehicle, the rotation speeds (rotational speeds: left front wheel 20, right front wheel 22, left rear wheel 32, right rear wheel 34) are provided.
rpm), the rotation detection plates 36, 38, 40, 42 that rotate together with the left front wheel 20, the right front wheel 22, the left rear wheel 32, and the right rear wheel 34, and the rotation detection plates 36, 3
8, 40, and 42 are provided with a front left wheel rotation sensor 44, a front right wheel rotation sensor 46, a rear left wheel rotation sensor 48, and a rear right wheel rotation sensor 50 that output pulse signals corresponding to the irregularities provided on the respective wheels. A signal indicating the number of rotations of each wheel is supplied from each of the rotation sensors to the electronic control unit 52.

The electronic control unit 52 includes a CPU, a RAM,
A so-called microcomputer including an OM, an input / output interface, and the like. The CPU processes the input signal according to a program stored in the ROM in advance while using the temporary storage function of the RAM, and controls the automatic clutch 14.

FIG. 2 is a functional block diagram for explaining a main control function of the electronic control unit 52. As shown in FIG. In the figure,
The wheel rotation speed detecting device 60 including the rotation sensors 44, 46, 48, and 50 includes a plurality of wheels 20 provided in the vehicle.
The rotational speeds N _FL , N _FR , N _RL , and N _RR of 22, 32, and 34 are sequentially detected. Rotation determination reference range calculation means 62
Are the rotation speeds N _FL , N _FR , N _{RL of} the wheels 20, 22, 32, 34 detected by the wheel rotation speed detection device 60.
The average value of N _RR , for example, the moving average value N _FLAV of the rotation speeds N _FL , N _FR , N _RL , and N _RR of the wheels 20, 22, 32, and 34 in a predetermined moving range of several seconds to several tens of seconds,
_{Based on} the average value N _AV of N _FRAV , N _RLAV , and N _RRAV , the rotation determination reference range A is sequentially calculated at a predetermined cycle. The rotation determination reference range A is such that at least one of the rotation speeds N _FL , N _FR , N _RL , and N _RR of each of the wheels 20, 22, 32, and 34 damages each power transmission member constituting the power transmission path of the vehicle. In order to judge that the temperature has risen or fallen to such an extent that it occurs, for example, the upper limit value and the lower limit value are set to the average value N _AV.
Is set up and down by a margin value or margin ratio that is set in advance.

The judging means 64 determines whether each of the wheels 20, 22,
Number of rotations N of 32, 34_FL, N_FR, N _RL, N_RRAt least
Is also determined based on whether or not one of the
Power transmission units of the respective components constituting the power transmission path of the vehicle
The wheel speed soars enough to cause damage to the material or
It is determined that the temperature has dropped sharply. In other words, smell on rough road
The number of rotations of the wheel, such as when the wheel rides on a rock
Is suddenly reduced and excessive torque is suddenly applied to the power transmission system.
On the road or the wheels float on the ground on rough roads
The wheel speed suddenly rises, as in the case of an idle
When the power transmission system is
That is, it is determined that a crack occurs rapidly. Self
The dynamic clutch priority releasing means 66
Of each wheel 20, 22, 32, 34_FL, N_FR,
N_RL, N_RRAt least one out of the rotation judgment reference range A
That constitutes the power transmission path of the vehicle
The number of rotations N is sufficient to cause damage to any of the power transmission members.
_FL, N_FR, N_RL, N_RRAt least one of the soaring or
If it is determined that the speed has dropped sharply, the automatic clutch 1
4 is preferentially temporarily released for a predetermined period. This place
During a fixed period, a sudden increase or decrease in transmission torque is
Release of the delivery route, that is, release of the automatic clutch 14
This is a period to avoid
Does not damage any of the constituent power transmission members
As far as possible so as not to interfere with the continuation of the vehicle.
Set short.

FIG. 3 is a flowchart for explaining a main part of the control operation of the electronic control unit 52, and shows a protection clutch control routine. In FIG. 3, in step (hereinafter, step is omitted) SA1, input signal processing is executed, and the rotation sensors 44, 46, 48, and 50 are processed.
20, 22, 32, 34 output from
The signals representing the rotation speeds N _FL , N _FR , N _RL , and N _RR are read. Subsequently, the rotation determination reference range calculating means 62
In SA2 corresponding to, each wheel 20, 22, 32, 34
Of the rotation speeds N _FL , N _FR , N _RL , N _RR of the respective wheels 20, 22, 32, 34, for example, the rotation speeds N _FL , N _FR , N _RL ,
Based on the average value N _AV of the moving average values N _FLAV , N _FRAV , N _RLAV , and N _RRAV within a predetermined moving section of several seconds to several tens of seconds of N _RR , each wheel 20, 22, 32, 34 A rotation determination reference range A for sequentially determining, at a predetermined cycle, a rotation determination reference range A for determining that any rotation has rapidly increased or decreased to such an extent as to cause damage to each of the power transmission members constituting the power transmission path of the vehicle.

Next, the SA corresponding to the determination means 64
3, the rotation speeds N _FL , N of the wheels 20, 22, 32, 34
_It is determined whether at least one of _FR , _NRL , and _NRR has deviated from the rotation determination reference range A. Since the determination of SA3 is denied in normal traveling, release of the hydraulic clutch 14, that is, release of the power transmission path, is prohibited in SA4. However, if the determination in SA3 is affirmative due to the wheels climbing on a rock on a rough road or floating on the ground and the wheels spinning, SA5 corresponding to the automatic clutch priority release means 66 is determined. , The automatic clutch 14 is temporarily released for a predetermined period.

As described above, according to the present embodiment, the determination means 64 (SA3) determines the rotation speeds N _FL , N _FR , N _RL , N _FL , of the plurality of wheels 20, 22, 32, 34 provided on the vehicle. N
If it is determined that at least one of the _RRs has risen or dropped sharply enough to cause damage to the power transmission member constituting the power transmission path of the vehicle, the automatic clutch priority release means 66 (SA5) uses the automatic clutch 14 Is released preferentially, when an excessive positive torque is generated due to a sudden decrease in the rotational speed of any of the wheels, or when an excessive negative torque is generated due to a rapid increase in the rotational speed of any of the wheels. The automatic clutch 14 is preferentially disengaged, so that damage to the power transmission members of the components constituting the power transmission path of the vehicle is preferably prevented.

That is, in the present embodiment, a wheel rotation speed detecting device 60 for detecting the rotation speed of each of the plurality of wheels 20, 22, 32, and 34 provided in the vehicle, and the wheel rotation speed detecting device 60 detects the rotation speed. Each wheel 20,22,3
Average value N _AV of rotation speeds N _FL , N _FR , N _RL and N _RR of 2, 34
A rotation determination reference range calculation means 62 for calculating a rotation determination reference range A is provided on the basis of the determination means 64, the rotational speed N _FL of the wheels 20,22,32,34, N _FR, N
_RL, at least one of N _RR based on whether outside the rotation determination reference range A, the rotational speed N _FL of the wheels, N _FR,
Since it is determined that at least one of N _RL and N _RR has risen or dropped sharply enough to cause damage to the power transmission member constituting the power transmission path,
Number of rotations N _FL , N _FR , N _RL , N _{RR of 0} , 22, 32, 34
The automatic clutch 14 is also preferentially released when excessive positive torque is generated due to at least one of the sudden drops.

Next, another embodiment of the present invention will be described. In the following description, the same parts as those in the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 4 is a diagram showing a power transmission system of a vehicle and a control device therefor according to another embodiment of the present invention. In the vehicle of the present embodiment, an acceleration sensor 76 for detecting the acceleration in the front-rear direction of the vehicle is provided.
1 in that a signal representing the actual acceleration output from the electronic control unit 6 is supplied to the electronic control unit 52.
Are different from the embodiment shown in FIG.

FIG. 5 is a functional block diagram for explaining the main control functions of the electronic control unit 52 provided in the vehicle shown in FIG. In FIG. 5, the wheel acceleration calculating means 68
Are the rotation speeds N _FL , N _FR , N of the respective wheels 20, 22, 32, 34 detected by the wheel rotation speed detection device 60, respectively.
_RL, N Based on the _RR, the wheel acceleration G _FL corresponding the difference between the values read in the values and the current control cycle read in the change value, for example, a predetermined time before the control cycle the vehicle acceleration, G _FR , G _RL , and G _RR are calculated. The acceleration determination reference range calculating means 70 calculates the actual acceleration G _{V of} the vehicle detected by the acceleration sensor 76.
Is calculated on the basis of the above. The acceleration determination reference range B is such that at least one of the rotation speeds N _FL , N _FR , N _RL , and N _RR of each of the wheels 20, 22, 32, and 34 damages each power transmission member constituting the power transmission path of the vehicle. to determine that jumped or dips to an extent of generating, for example, those that the upper limit and the lower limit was set vertically for a preset margin value or margin percentage therefrom around the actual acceleration G _V above is there. The determination means 72 determines the rotation of each of the wheels 20, 22, 32, and 34 based on whether at least one of the wheel accelerations G _FL , G _FR , G _RL , and G _RR is out of the acceleration determination reference range B. It is determined that at least one of the numbers N _FL , N _FR , N _RL , and N _RR has risen or fallen sharply enough to cause damage to the power transmission member constituting the power transmission path of the vehicle. The automatic clutch priority release means 66 _activates the automatic clutch 14 when the determination means 72 determines that at least one of the wheel accelerations G _FL , G _FR , G _RL , G _RR is out of the acceleration determination reference range B. It is released temporarily for a predetermined period.

FIG. 6 shows a main part of the control operation of the electronic control unit 52 provided in the vehicle shown in FIG. 4, that is, a protection clutch control routine. In SB1 of FIG.
After the input signal processing is performed in the same manner as in A1, in SB2 corresponding to the wheel acceleration calculating means 68, the rotation speed N of each of the wheels 20, 22, 32, and 34 read in SB1.
_{Based on FL} , N _FR , N _RL , and N _RR , respective wheel accelerations G _FL , G _FR , G _RL , and G _RR corresponding to the vehicle acceleration are calculated, respectively. Next, the acceleration determination reference range calculating means 70
In SB3 corresponding to the following, based on the actual acceleration G _V of the vehicle detected by the acceleration sensor 76, each wheel 20,
It is determined that at least one of the rotational speeds N _FL , N _FR , N _RL , and N _RR of 22, 32, and 34 has risen or fallen sharply enough to cause damage to each power transmission member constituting the power transmission path of the vehicle. An acceleration determination reference range B is calculated. At SB4 corresponding to the determination means 72, it is determined whether at least one of the wheel accelerations G _FL , G _FR , G _RL , and G _RR is out of the acceleration determination reference range B.

In normal running, the determination at SB4 is negative, so that the release of the automatic clutch 14, that is, the release of the power transmission path, is prohibited at SB5. However, if the determination in SB4 is affirmative due to the wheels climbing on rocks or floating off the ground and the wheels spinning on rough roads, the automatic clutch priority release means 6
At SB6 corresponding to No. 6, the automatic clutch 14 is temporarily released for a predetermined period.

As described above, according to the present embodiment, the wheel rotation for detecting the rotation speeds N _FL , N _FR , N _RL , and N _RR of the plurality of wheels 20, 22, 32, and 34 provided in the vehicle, respectively. The respective wheel accelerations corresponding to the vehicle acceleration from the number detection device 60 and the rotation speeds N _FL , N _FR , N _RL , and N _{RR of the} wheels 20, 22, 32, and 34 respectively detected by the wheel rotation speed detection device 60. Wheel acceleration calculating means 68 (SB2) for calculating G _FL , G _FR , G _RL , G _RR , an acceleration sensor 76 for detecting the actual acceleration of the vehicle, and an actual vehicle detected by the acceleration sensor 76 Acceleration determination reference range calculation means 70 (SB3) for calculating an acceleration determination reference range B based on the acceleration Gv of
2 (SB4), the wheel accelerations G _FL , G _FR , G
_At least one of _RL and G _RR is the acceleration determination reference range B
, The rotation speed N _{FL of} each wheel,
If it is determined that N _FR , N _RL , N _RR has risen or dropped sharply enough to cause damage to the power transmission member constituting the power transmission path of the vehicle, that is, if it is determined that the torque has changed, the automatic clutch release means 66 (SB6) The automatic clutch 14 is immediately disengaged, so that a vehicle running on a rough road jumps and its wheels idle at the same time,
Even when the wheels of the vehicle running on the snow-covered road run idle at the same time, the automatic clutch 14 is preferentially disengaged, and it is preferable that the drive devices of the respective components constituting the power transmission path of the vehicle are damaged. Is prevented.

Further, according to the present embodiment, even when a vehicle running on a rough road jumps and all the wheels spin at the same time, or when all the wheels run on the rock at the same time, the determination means 72 determines Each wheel acceleration G _FL , G _FR , G _RL ,
There is an advantage that the automatic clutch 14 is immediately released when it is determined that at least one of the _GRRs has deviated from the acceleration determination reference range B.

FIG. 7 is a functional block diagram illustrating another control function of the electronic control device 52 of FIG. 4, and FIG. 8 is a flowchart illustrating the control operation of the electronic control device 52. In FIG. 7, the acceleration determination reference value storage means 78
Is provided, for example, in the ROM or RAM of the electronic control unit 52, and stores in advance an acceleration determination reference range C corresponding to an acceleration range that can be obtained in terms of vehicle performance based on a setting input. The acceleration determination reference range C includes a vehicle engine output, a transmission gear ratio, a vehicle body weight, a wheel diameter,
It is obtained in advance based on the braking performance and the like.

In SC1 of FIG.
After input signal processing is performed in the same manner as in B1, the wheel acceleration
In SC2 corresponding to the degree calculating means 68, the same as SB2 is used.
Similarly, each wheel 20, 22, read in SC1
Number of rotations N of 32, 34_FL, N _FR, N_RL, N_RRBased on
And each wheel acceleration G corresponding to the vehicle acceleration_FL, G_FR, G
_RL, G_RRAre calculated respectively. Next, in SC3,
The vehicle stored in the acceleration determination reference value storage means 78
Acceleration judgment that roughly corresponds to the vehicle acceleration range that can be obtained in the performance of
The disconnection reference range C is read. And the determination means 7
In SC4 corresponding to No. 4, each wheel acceleration G_FL, G_FR, G
_RL, G_RRIs at least one of the acceleration determination reference rotation ranges.
It is determined whether or not the box C has been removed.

In the normal running, since the determination at SC4 is denied, the release of the automatic clutch 14, that is, the release of the power transmission path, is prohibited at SC5. However, if the determination of SC4 is affirmative due to the wheels climbing on rocks or floating off the ground and the wheels spinning on rough roads, the automatic clutch priority release means 6
In SC6 corresponding to 6, the automatic clutch 14 is temporarily released for a predetermined period. According to the present embodiment, the automatic clutch 14 is automatically disengaged when the torque of the power transmission system changes suddenly, so that the same effect as the embodiment of FIG. 6 can be obtained.

FIG. 9 is a functional block diagram for explaining a main part of the control function of another embodiment of the electronic control unit 52 provided in the vehicle of FIG. 1, and FIG.
6 is a flowchart for explaining a main part of the control operation of FIG. In FIG. 9, instead of the automatic clutch priority releasing means 66 in the functional block diagram of FIG. 2, a belt clamping pressure regulating valve 29 is used to clamp the transmission belt 28 of the belt type continuously variable transmission 12 so as not to slip. The difference is that a clamping pressure increasing means 84 for temporarily increasing the pressure is provided, and the other components are the same. The squeezing pressure increasing means 84 determines the rotation speeds N _FL , N _FR , N N of the wheels 20, 22, 32, 34 by the determining means 64.
_The rotation speeds N _FL , N _FR , and N _RL are such that at least one of _RL and N _RR has deviated from the rotation determination reference range A, that is, damage to one of the power transmission members constituting the power transmission path of the vehicle. , _NRR has suddenly increased or decreased, the output hydraulic pressure provided on the output variable pulley 26 of the belt type continuously variable transmission 12 using the belt clamping pressure regulating valve 29. By increasing the hydraulic pressure supplied to the cylinder and increasing the clamping pressure of the output-side variable pulley 26 on the transmission belt 28 for a predetermined period, slippage of the transmission belt 28 due to a sudden change in transmission torque is prevented.

In FIG. 10, SA in the flowchart of FIG.
4 and SA5 are provided in place of SD4 for inhibiting the temporary increase of the belt clamping pressure and SD5 corresponding to the clamping pressure increasing means 84, and the other components are the same. In this SD5, each wheel 20 in SD3,
When it is determined that at least one of the rotation speeds N _FL , N _FR , N _RL , and N _RR of the rotation speeds 22, 32, and 34 is out of the rotation determination reference range A, the output-side variable pulley 26 of the belt-type continuously variable transmission 12 is rotated. The operating hydraulic pressure supplied to the output side hydraulic cylinder provided in the motor is increased, and the clamping pressure of the output side variable pulley 26 on the transmission belt 28 is increased only for a predetermined period. Also in the present embodiment, similarly to the embodiment of FIGS. 1 to 3, when an excessive positive torque is generated due to a sudden decrease in the rotational speed of one of the wheels, or excessively increased due to a sudden increase in the rotational speed of any of the wheels. When a large negative torque is generated, the belt-type continuously variable transmission 12 provided in the power transmission path of the vehicle is protected from damage.

FIG. 11 is a functional block diagram for explaining a main part of the control function of another embodiment of the electronic control unit 52 provided in the vehicle shown in FIG. 4, and FIG.
4 is a flowchart illustrating a main part of a control operation of No. 2;
In FIG. 11, instead of the automatic clutch priority releasing means 66 in the functional block diagram of FIG. 5, a belt clamping pressure regulating valve 29 is used to clamp the transmission belt 28 of the belt type continuously variable transmission 12 so as not to slip. The difference is that a clamping pressure increasing means 84 for temporarily increasing the pressure is provided, and the other components are the same. The pinching force increasing means 84 determines that at least one of the wheel accelerations G _FL , G _FR , G _RL , and G _RR has deviated from the acceleration determination reference range B by the determining means 72, that is, the power of the vehicle. The number of rotations N is large enough to cause damage to any of the power transmission members constituting the transmission path.
_When it is determined that at least one of _FL , N _FR , N _RL , and N _RR has rapidly increased or decreased, the output side variable pulley 26 of the belt type continuously variable transmission 12 is controlled using the belt clamping pressure regulating valve 29. By increasing the working oil pressure supplied to the output hydraulic cylinder provided in the transmission belt, and increasing the clamping pressure of the output variable pulley 26 on the transmission belt 28 for a predetermined period, the transmission belt due to a sudden change in the transmission torque is increased. 28 is prevented from slipping.

In FIG. 12, SB of the flowchart of FIG.
5 and SB6 are provided in place of SE5 for inhibiting a temporary increase in belt clamping pressure and SE6 corresponding to the clamping pressure increasing means 84, and the other components are the same. In SE6, when it is determined in SE4 that at least one of the wheel accelerations G _FL , G _FR , G _RL , and G _RR is out of the acceleration determination reference range B, the output variable of the belt type continuously variable transmission 12 is changed. The operating oil pressure supplied to the output side hydraulic cylinder provided on the pulley 26 is increased, and the clamping force of the output side variable pulley 26 on the transmission belt 28 is increased only for a predetermined period. Also in this embodiment, similarly to the embodiment of FIGS. 5 and 6, when a sudden change in torque occurs due to a sudden decrease in the rotation speed of any of the wheels, or abruptly due to a sudden increase in the rotation speed of any of the wheels. When a large torque change occurs, the belt-type continuously variable transmission 12 provided in the power transmission path of the vehicle is protected from damage.

FIG. 13 is a functional block diagram for explaining a main part of a control function of another embodiment of the electronic control unit 52 provided in the vehicle shown in FIG. 4, and FIG.
4 is a flowchart illustrating a main part of a control operation of No. 2;
In FIG. 13, a belt clamping pressure regulating valve 29 is used in place of the automatic clutch priority releasing means 66 in the functional block diagram of FIG. 7 to prevent the transmission belt 28 of the belt type continuously variable transmission 12 from slipping. The difference is that a clamping pressure increasing means 84 for temporarily increasing the pressure is provided, and the other components are the same. The squeezing pressure increasing means 84 determines that at least one of the wheel accelerations G _FL , G _FR , G _RL , and G _RR has deviated from the acceleration determination reference range C by the determining means 74, that is, the power of the vehicle. The number of rotations N is large enough to cause damage to any of the power transmission members constituting the transmission path.
_When it is determined that at least one of _FL , N _FR , N _RL , and N _RR has rapidly increased or decreased, the output side variable pulley 26 of the belt type continuously variable transmission 12 is controlled using the belt clamping pressure regulating valve 29. By increasing the working oil pressure supplied to the output hydraulic cylinder provided in the transmission belt, and increasing the clamping pressure of the output variable pulley 26 on the transmission belt 28 for a predetermined period, the transmission belt due to a sudden change in the transmission torque is increased. 28 is prevented from slipping.

In FIG. 14, SC in the flowchart of FIG.
5 and SC6, except that SF5 for inhibiting a temporary increase in the belt clamping pressure and SF6 corresponding to the clamping pressure increasing means 84 are provided, and the other components are the same. In SF6, if it is determined in SF4 that at least one of the wheel accelerations G _FL , G _FR , G _RL , G _RR is out of the acceleration determination reference range C, the output variable of the belt type continuously variable transmission 12 is changed. The operating oil pressure supplied to the output side hydraulic cylinder provided on the pulley 26 is increased, and the clamping force of the output side variable pulley 26 on the transmission belt 28 is increased only for a predetermined period. Also in this embodiment, similarly to the embodiment of FIGS. 7 and 8, when a sudden change in torque occurs due to a sudden decrease in the rotational speed of one of the wheels, or suddenly due to a sudden increase in the rotational speed of any of the wheels. When a large torque change occurs, the belt-type continuously variable transmission 12 provided in the power transmission path of the vehicle is protected from damage.

Although the embodiment of the present invention has been described with reference to the drawings, the present invention can be applied to other embodiments.

For example, the embodiments shown in FIGS. 1 to 3, the embodiments shown in FIGS. 4 and 6, the embodiments shown in FIGS. 7 and 8, the embodiments shown in FIGS. 9 and 10, the embodiments shown in FIGS. FIG.
Although the embodiments of FIGS. 3 and 14 have been described, at least two selected from those embodiments are provided in a common vehicle in order to increase the reliability of protection of a power transmission member constituting a power transmission path. You may. In this case, the determination conditions for releasing the automatic clutch 14 may be parallel or serial.

The rotation determination reference range A, the acceleration determination reference range B, and the acceleration determination reference range C used in the above-described embodiment have their areas set by the upper limit value and the lower limit value. Even if the area is set by one of the upper limit value and the lower limit value, a certain effect can be obtained.

In the vehicle shown in FIG. 1 or FIG.
The front wheel drive system in which the drive wheels are the front wheels 20 and 22, that is, F
Although the F system has been adopted, a rear wheel drive system, that is, an FR system in which the drive wheels are the rear wheels 32 and 34 may be employed. In the vehicle shown in FIG. 1 or FIG. 4, an electric motor functioning as a prime mover may be provided instead of the engine 10 or for assisting the engine, or a plurality of electric motors may be provided instead of the belt-type continuously variable transmission 12. A stepped manual transmission or an automatic transmission that can be switched to the shift speed may be provided.

Further, in the vehicle of the above-described embodiment, a fluid coupling such as a torque converter or a fluid coupling may be provided between the engine 10 and the belt-type continuously variable transmission 12. When the fluid coupling is provided with a lock-up clutch for directly connecting the input-side rotary member and the output-side rotary member, power is supplied using the lock-up clutch instead of the automatic clutch 14. The power transmission member constituting the transmission path can be protected.

Further, the automatic clutch 14 of the above-described embodiment is used.
May be controlled by, for example, a computer for performing a shift control of the belt-type continuously variable transmission 12, or an engine controlling computer for performing a combustion control of the engine 10.

The above description is merely an embodiment of the present invention, and the present invention can be variously modified without departing from the gist thereof.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a power transmission system of a vehicle and an electronic control device thereof according to an embodiment of the present invention.

FIG. 2 is a functional block diagram illustrating a main part of a control function of the electronic control device of FIG. 1;

FIG. 3 is a flowchart illustrating a main part of a control operation of the electronic control device of FIG. 1, and is a diagram illustrating a protection clutch control routine.

FIG. 4 is a diagram illustrating a configuration of a power transmission system of a vehicle and an electronic control device thereof according to another embodiment of the present invention.

FIG. 5 is a functional block diagram illustrating a main part of a control function of the electronic control device of FIG. 4;

FIG. 6 is a flowchart illustrating a main part of a control operation of the electronic control device of FIG. 5, and is a diagram illustrating a protection clutch control routine.

FIG. 7 is a functional block diagram illustrating a main part of another example of the control function of the electronic control device of FIG. 4;

8 is a flowchart illustrating a main part of a control operation of the electronic control device of FIG. 7, and is a diagram illustrating a protection clutch control routine.

FIG. 9 is a functional block diagram illustrating a main part of another example of the control function of the electronic control device of FIG. 1;

FIG. 10 is a flowchart illustrating a main part of a control operation of the electronic control device of FIG. 9, and is a diagram illustrating a protection clutch control routine.

FIG. 11 is a functional block diagram illustrating a main part of another example of the control function of the electronic control device in FIG. 4;

12 is a flowchart illustrating a main part of a control operation of the electronic control device of FIG. 11, and is a diagram illustrating a protection clutch control routine.

FIG. 13 is a functional block diagram illustrating a main part of another example of the control function of the electronic control device of FIG. 4;

14 is a flowchart illustrating a main part of a control operation of the electronic control device in FIG. 13, and is a diagram illustrating a protection clutch control routine.

[Explanation of symbols]

 10: Engine (motor) 12: Belt-type continuously variable transmission 14: Automatic clutch (protection clutch) 20, 22: Front wheel (drive wheel) 24: Variable input pulley 26: Variable output pulley 28: Transmission belt 64, 72 74: determination means 66: automatic clutch priority release means 84: clamping pressure increasing means

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) F16H 63:06 F term (reference) 3J052 AA09 DB10 GC46 HA11 LA01 LA20 3J057 AA01 AA02 AA03 GA02 GB36 GB40 GE01

Claims (2)

[Claims] 1. A power transmission system protection device for a vehicle for protecting a power transmission path from a prime mover to a drive wheel, comprising: an automatic clutch inserted in series in a power transmission path of the vehicle; Determining means for determining that at least one of the rotation speeds of the plurality of wheels provided has rapidly increased or decreased to such an extent as to cause damage to a power transmission member constituting a power transmission path of the vehicle; and When it is determined that at least one of the rotation speeds of each wheel has rapidly increased or decreased to such an extent as to cause damage to the power transmission member constituting the power transmission path of the vehicle, the automatic clutch is preferentially released. And a power transmission system protection device for a vehicle, comprising: 2. A vehicle in which a belt-type continuously variable transmission in which a transmission belt is wound between a pair of variable pulleys whose effective diameter is variable is provided in a power transmission path from a prime mover to driving wheels. A power transmission system protection device for protecting a continuously variable transmission, wherein at least one of the rotation speeds of a plurality of wheels provided in the vehicle rapidly rises or falls to such an extent that the transmission belt slips. When the determination unit determines that at least one of the rotation speeds of each of the wheels has rapidly increased or decreased to the extent that slippage of the transmission belt occurs, the transmission of the variable pulley is determined. A power transmission system protection device for a vehicle, comprising: a squeezing force increasing means for increasing a squeezing force on the belt.