JPH11157355A - Control method of four-wheel drive vehicle mounted with rotation transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of vibration caused by the repetition of lock and release of a two-way clutch at the time of low temperature start. SOLUTION: A transfer 5 housing a rotation transmission device A is provided with a temperature sensor 32 for detecting the oil temperature of internal lubricating oil. When the measured value of oil temperature measured by the temperature sensor 42 is the set value or lower in the case of traveling in a 2WD mode at the time of low temperature start, a hub clutch 2 is engaged. The idling speed of a two-way clutch 10 is therefore reduced so as to prevent the abnormal lock of the two-way clutch 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method for a 4WD vehicle provided with a rotation transmission device for switching between transmission and interruption of a driving force on a driving path of the vehicle.
The present invention relates to a control method that enables a function to be maintained when a vehicle is started at a low temperature.

[0002]

2. Description of the Related Art When a 4WD vehicle having directly connected front and rear wheels turns on a paved road, a so-called tight corner braking phenomenon occurs. As a means for solving this problem, the present applicant has filed Japanese Patent Application No. 8-172598. And Japanese Patent Application No. 9-28001
Proposed a rotation transmission device using a roller type two-way clutch and an electromagnetic coil.

[0003] As shown in FIGS. 5 and 6, this rotation transmitting device A is provided in a FR-based 4WD vehicle in which a hub clutch 2 is mounted at each end of a front wheel 1 in a transmission 4 connected to an engine 3. The output is transmitted directly to the propulsion shaft 8 of the rear wheel 7 via the input shaft 6 inside the transfer 5, and inside the transfer 5, the input shaft 6 and a chain sprocket 9 mounted coaxially with the input shaft 6 so as to be relatively rotatable.
Mechanism 22 for synchronizing and rotating input shaft 6
A two-way clutch 10 of a roller engagement type for transmitting and blocking the rotation of the sprocket 9 and the input shaft 6, and an electromagnetic clutch 11 for controlling locking and free of the two-way clutch 10; Typical part-time 4WD driving mode (2WD, 4WD-
Hi, 4WD-L ₀ ), and a 4WD control mode is added.

FIG. 7 shows a specific structure of the two-way clutch 10 and the electromagnetic clutch 11 in the rotation transmitting device A. The two-way clutch 10 includes an inner member 12 and an outer ring 1.
3 are rotatably fitted coaxially via a bearing, a plurality of cam surfaces 14 are provided on one of the inner member 12 and the outer ring 13, and a cylindrical surface 15 is provided on the other, and a wedge-shaped space is formed between both surfaces. Then, a retainer 16 is provided in the wedge-shaped space, and a roller 17 as an engaging element is incorporated into a plurality of pockets formed in the retainer 16 to a neutral position where the roller 17 does not engage with the cylindrical surface 15 and the cam surface 14. Switch spring 18 for supporting and biasing retainer 16
Is locked between the retainer 16 and the inner member 12 or the outer ring 13 having the cam surface 14.

The electromagnetic clutch 11 includes a friction flange 19 fixed to the outer race 13 or the inner member 12 and an armature 20 fitted to the end of the cage 16 so as to be slidable with the cage 16 but not to rotate relative thereto. Are overlapped with an appropriate gap therebetween, and an electromagnetic coil 21 for pressing the friction flange 19 and the armature 20 by magnetic force is provided. By turning on and off the current of the electromagnetic coil 21, the roller 17 is engaged or idled. It has become.

[0006] By the way, the 4WD vehicle exerts its power in a low-temperature snowfall area, but when the vehicle is started at a low temperature, the oil filled in the transfer is also low in temperature and its viscosity is large.

[0007] The above 4WD vehicle has a mode changeover switch 2
When the vehicle travels with the 2WD mode or AUTO mode selected by 3, the hub clutch 2 is turned off, the front drive system is stopped from rotating, and the two-way clutch 10 is idle.

[0008]

As described above, when the vehicle is started at a low temperature, the oil in the transfer is also low in temperature and high in viscosity, so that the two-way clutch 10 is inwardly moved with respect to the stop of the outer wheel 13 when the 2WD mode is selected. During idle rotation of the member 12, the roller 17 may lock due to drag resistance of the oil.

After locking, the two-way clutch 10
The relative rotation between the outer ring 13 and the inner member 12 is lost, and the lock is released again without being affected by the oil.

That is, the two-way clutch 10 repeatedly locks and frees, which causes a problem that vibration is generated.

SUMMARY OF THE INVENTION It is an object of the present invention to reduce the number of idle rotations of the two-way clutch or reduce the viscosity of oil at the time of starting the vehicle at a low temperature, thereby preventing the two-way clutch from being locked and free from vibration. It is an object of the present invention to provide a control method for a 4WD vehicle equipped with a rotation transmission device capable of being mounted.

[0012]

According to a first aspect of the present invention, an output from a transmission is transmitted directly to a rear wheel propulsion shaft via an input shaft inside a transfer. A method for controlling a 4WD vehicle in which power is branched to a front wheel propulsion shaft via a rotation transmission device and a hub clutch or a front wheel axle engagement / disengagement means, wherein a temperature sensor for measuring an internal oil temperature is provided in a transfer. Even when the driver selects 2WD driving, the hub clutch or the front wheel axle disengaging means is engaged when the temperature based on the signal of the temperature sensor is equal to or lower than the set temperature.

According to a second aspect of the present invention, the output from the transmission is directly transmitted to the rear wheel propulsion shaft via the input shaft inside the transfer, and the power is branched to the front wheel propulsion shaft via the rotation transmission device. A method for controlling a 4WD vehicle using a hub clutch or a front wheel axle engagement / disengagement means, wherein a temperature sensor for measuring an internal oil temperature is provided in a transfer, and a signal from the temperature sensor is used even when the driver selects 2WD traveling. When the temperature is equal to or lower than the set temperature I, the hub clutch or the front wheel axle engagement / disengagement means is engaged. In addition, a configuration is adopted in which both set temperatures are provided with hysteresis and the set temperature II is set higher than the set temperature I. .

According to a third aspect of the present invention, the output from the transmission is directly transmitted to the rear wheel propulsion shaft via the input shaft inside the transfer, and the power is branched to the front wheel propulsion shaft via the rotation transmission device. A method of controlling a 4WD vehicle using a hub clutch or a front wheel axle engagement / disengagement means, wherein a temperature sensor for measuring an internal oil temperature is provided in a transfer, and when a temperature based on a signal from the temperature sensor is lower than a set temperature, rotation transmission is performed. In this configuration, a current is applied to an electromagnetic coil of the device to increase the internal temperature of the rotation transmitting device.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

A first embodiment of the control method shown in FIGS. 1 to 3 is a transfer method in which a rotation transmitting device A is accommodated.
A temperature sensor 32 for detecting the oil temperature of the lubricating oil 31 housed therein.

An oil temperature detection signal from the temperature sensor 32 is input to an ECU (controller) 33,
Numeral 3 is for operating the actuator of the hub clutch 2.

At the time of starting the vehicle at low temperature, when the driver travels with the mode changeover switch 23 selected to the 2WD mode, a signal of the measured oil temperature in the transfer 5 by the temperature sensor 32 is input to the ECU 33, If the measured value is lower than the preset temperature set in the ECU 33, the hub clutch 2 or the front wheel axle disengaging means is engaged.

When the 2WD mode is selected, in the conventional rotation transmitting device A, the inner member 12 idles with respect to the outer ring 13 to be stopped. At this time, the hub clutch 2 or the front wheel axle engaging / disengaging means is engaged. In this case, the rotation of the front wheel 1 is transmitted to the outer wheel 13, and the outer wheel 13 rotates in the same direction as the inner member 12, whereby the number of idle rotations of the inner member 12 and the outer wheel 13 decreases, and the lubricating oil 31 is removed. Even when the viscosity increases at low temperatures, it is possible to prevent the two-way clutch 10 from locking due to drag resistance of the oil.

When the oil temperature in the transfer 5 rises as the vehicle travels and the oil temperature measured by the temperature sensor 32 exceeds the set temperature, the hub clutch 2 or the front axle engagement / disengagement means is disengaged, and the front wheels are driven. Stop the system and normal 2W
Set to D mode.

When the oil temperature of the lubricating oil 31 in the transfer 5 rises above a set value, the viscosity of the oil decreases and the drag resistance decreases. Therefore, the front wheel drive system is stopped and the outer wheel 13 and the inner member 12 are stopped. , The two-way clutch 10 does not engage,
It is possible to effectively prevent the two-way clutch 10 from repeatedly generating a vibration by repeatedly locking and freeing at a low temperature start.

Next, in the control method according to the second embodiment shown in FIG. 4, the rotation transmitting device A is mounted on the front wheel output shaft 34 in the lower portion of the transfer 5, and the synchronization mechanism 22, the two-way clutch 10 and the electromagnetic clutch 11 Are arranged so as to be immersed in the lubricating oil 31, and a temperature sensor 32 for detecting the oil temperature of the internal lubricating oil 31 is attached to the transfer 5.

In the second embodiment, at the time of starting the vehicle at a low temperature, when the driver selects the mode changeover switch 23 to the 2WD mode and travels, the temperature sensor 3
The signal of the oil temperature measurement value in the transfer 5 due to the
When the oil temperature is input to U33 and the measured oil temperature is lower than the preset temperature preset in the ECU 33, as shown in FIG.
The electromagnetic coil 21 of the electromagnetic clutch 11 and / or the electromagnetic coil 24 of the synchronizing mechanism 22 are energized. The lubricating oil 31 is instantaneously raised, thereby reducing the viscosity of the lubricating oil 31 and preventing the two-way clutch 10 from locking due to drag resistance of the oil 31.

In the second embodiment, the voltage when the electromagnetic coil 21 is energized when the AUTO mode is selected depends on the friction flange 1 generated when the electromagnetic coil 21 is energized.
The frictional force between the armature 9 and the armature 20 is set to a value that does not exceed the torque of the switch spring 18 so that the two-way clutch 10 is not locked.

In each of the above embodiments, the control of the hub clutch 2 and the electromagnetic coils 21 and 24 by the oil temperature measurement signal of the temperature sensor 32 is performed by setting the set temperature I and the set temperature II in the ECU 33, With hysteresis,
When the set temperature II is set higher than the set temperature I and the measured temperature of the temperature sensor 32 is equal to or lower than the set temperature I, the engagement of the hub clutch 2 or the energization of the electromagnetic coils 21 and 24 is performed. If it exceeds II, the hub clutch 2 is disengaged or the electromagnetic coils 21 and 24 are turned off.

In the first embodiment, the engagement and disengagement of the hub clutch 2 is performed.
Although the energization to 4 is turned on and off independently, both embodiments may be used in combination.

[0027]

As described above, according to the first aspect of the present invention, the hub clutch is engaged when the vehicle runs in the 2WD or AUTO mode at the time of low-temperature start, so that the two-way clutch in the rotation transmitting device is idled. Even when the number can be reduced and the lubricating oil has a high viscosity due to a low temperature and has a large drag resistance, the lock of the two-way clutch can be prevented from occurring, and the vibration due to the repetition of lock and free of the two-way clutch can be prevented.

The invention according to claim 2 is characterized in that at the time of low temperature starting,
When driving in the WD or AUTO mode, the electromagnetic coil of the rotation transmission device is energized, so the heat of the electromagnetic coil raises the oil temperature of the lubricating oil and reduces its viscosity. Lock of the two-way clutch due to the above can be prevented.

[Brief description of the drawings]

FIG. 1 is a plan view showing a layout of a 4WD drive vehicle showing a first embodiment of a control method.

FIG. 2 is a block diagram of a control method.

FIG. 3 is a flowchart showing the operation of the control method.

FIG. 4 is a plan view showing a layout of a 4WD drive vehicle in which a rotation transmission device is mounted on a lower output shaft.

FIG. 5 is a plan view showing a layout of a 4WD drive vehicle incorporating a rotation transmission device.

FIG. 6 is a cross-sectional view of a transfer incorporating a rotation transmitting device.

7A is a longitudinal sectional view of a rotation transmitting device, and FIG. 7B is a longitudinal sectional view of the same.

[Explanation of symbols]

 Reference Signs List 5 Transfer 6 Input shaft 10 Two-way clutch 11 Electromagnetic clutch 12 Inner member 14 Cam surface 15 Cylindrical surface 16 Cage 17 Roller 18 Switch spring 21 Electromagnetic coil 22 Synchro mechanism 23 Mode switch 31 Lubricating oil 32 Temperature sensor 33 ECU

Claims (3)

[Claims] An output from a transmission is directly transmitted to a rear wheel propulsion shaft via an input shaft inside a transfer, and power is branched to a front wheel propulsion shaft via a rotation transmission device. A method for controlling a 4WD vehicle by means of a front wheel axle engagement / disengagement means, wherein a temperature sensor for measuring an internal oil temperature is provided in a transfer, and a temperature according to a signal of the temperature sensor is equal to or lower than a set temperature even when a driver selects 2WD traveling. Wherein the hub clutch or the front wheel axle engaging / disengaging means is engaged at the time of the control. 2. The output from the transmission is transmitted directly to the rear wheel propulsion shaft via an input shaft inside the transfer, and power is branched to the front wheel propulsion shaft via a rotation transmission device. A method for controlling a 4WD vehicle by means of a front wheel axle engagement / disengagement means, wherein a temperature sensor for measuring an internal oil temperature is provided in a transfer, and even when a driver selects 2WD traveling, a temperature based on a signal from the temperature sensor is set to a set temperature I. At the following time, the hub clutch or the front wheel axle engagement / disengagement means is engaged, and when the temperature of the vehicle rises above the set temperature II due to the running of the vehicle, the hub clutch or the front wheel axle engagement / disengagement means is disengaged. , A hysteresis is provided for both set temperatures, and the set temperature I
A method for controlling a 4WD vehicle equipped with a rotation transmission device, wherein the set temperature II is set higher. 3. The output from the transmission is transmitted directly to the rear wheel propulsion shaft via the input shaft inside the transfer, and the power is branched to the front wheel propulsion shaft via the rotation transmission device. A method for controlling a 4WD vehicle using front wheel axle engagement / disengagement means, wherein a temperature sensor for measuring an internal oil temperature is provided in a transfer, and when a temperature according to a signal of the temperature sensor is equal to or lower than a set temperature, an electromagnetic coil of a rotation transmission device is provided. A method for controlling a 4WD vehicle equipped with a rotation transmitting device, characterized by flowing an electric current to increase an internal temperature of the rotation transmitting device.