JP2008089092A - Torque transmission control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a sense of incongruity from being given to a driver with respect to operation for differential lock release by the driver. <P>SOLUTION: The torque transmission control device equipped with a differential device 1 interposed between rear wheels 2 and 3 and capable of performing differential lock by engaging a dog clutch 25 by operation of an operation switch 31 by the driver is provided with a first controller 29 and engine speed sensors 35 and 37 as differential rotation speed detection devices for detecting a differential rotation speed between the rear wheels 2 and 3 when the driver operates differential lock release of the dog clutch 25, and a second controller 41 as a brake control device for suitably operating brakes 47 and 49 of the rear wheels 2 and 3 and forcibly releasing differential lock when the differential rotation speed is equal to or lower than a set value. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a torque transmission control device capable of forcibly releasing a differential lock device.

  2. Description of the Related Art Conventionally, some automobile differential devices are provided with a differential lock device. Some of these differential devices can be differentially locked by engaging the dog clutch when the operating switch is operated to the differential lock position when traveling on a rough road or the like. Such differential lock can improve the running performance of rough roads.

  However, even if the operation switch is returned to the differential / unlocked position after exiting a rough road, the differential / lock state may continue if the torque is applied between the dog and clutch meshing. There was a problem that the operation was uncomfortable.

Japanese Patent Laid-Open No. 10-96461

  The problem to be solved is that it gives an uncomfortable feeling to the driver's operation for unlocking the differential.

  The present invention provides a differential that can be differentially locked by engaging a meshing clutch that is interposed between wheels and that is interposed between wheels so as not to give a sense of incongruity to the operation of the driver for unlocking the differential lock. In the torque transmission control device provided with a device, a differential rotation detection device that detects differential rotation between the wheels when the driver performs differential / unlock operation of the meshing clutch, and when the differential rotation is equal to or less than a set value The most important feature is that a brake control device for forcibly releasing the differential lock by appropriately operating the brake of the wheel is provided.

  The torque transmission control device according to the present invention is a torque transmission control device including a differential device that is interposed between wheels and that can be differentially locked by engaging a meshing clutch by a driver's operation. A differential rotation detection device that detects a differential rotation between the wheels when a differential lock release operation is performed, and a brake that forcibly releases the differential lock by appropriately operating the brakes of the wheels when the differential rotation is less than a set value Since the control device is provided, it is possible to forcibly release the diff lock so as to match the operation of the driver, and it is possible to suppress a sense of discomfort with respect to the operation of the driver.

  The purpose of preventing the driver's operation for unlocking the differential from being uncomfortable was realized by controlling the brakes on the wheels.

[Four-wheel drive vehicle]
1 and 2 are simplified plan views of a four-wheel drive vehicle that is an automobile to which a torque transmission control device according to a first embodiment of the present invention is applied. FIG. 1 shows a straight traveling time, and FIG. 2 shows a turning traveling time.

  As shown in FIGS. 1 and 2, the four-wheel drive vehicle (automobile) according to the first embodiment includes a rear differential device 1 as a differential device between rear wheels 2 and 3 as wheels, and between front wheels 5 and 7. A front differential device 9 is provided.

  Torque is input to the rear differential device 1 sequentially from an engine (not shown) through a transmission (not shown), a transfer 11 having a center differential device disposed therein, a propeller shaft 13 and the like. It has become so. Torque is transmitted from the rear differential device 1 to the left and right rear wheels 1 and 3 via left and right axle shafts 15 and 17.

  Torque is input to the front differential device 9 from the engine through the transmission, transmission 11, transfer 11, propeller shaft 19 and the like sequentially. Torque is transmitted from the front differential device 9 to the left and right front wheels 5 and 7 via the left and right axle shafts 21 and 23.

The rear differential device 1 can be differentially locked by meshing a dog clutch 25 that is a meshing clutch by an operation of the driver.
The dog clutch 25 engages with the energization control of the solenoid 27 to bring the rear differential device 1 into the differential lock state. When the energization control of the solenoid 27 is stopped, the differential spring is released by the biasing force of the return spring.

  The solenoid 27 is energized and controlled by the output signal of the first controller 29. When the operation signal of the operation switch 31 is input to the first controller 29 and the driver operates the operation switch 31 to input a signal (ON signal) for differential lock, the solenoid 27 is energized and controlled. . When the driver operates the operation switch 31 to input a signal (OFF signal) for diff / lock release, the energization control of the solenoid 27 is stopped. The operation switch 31 is disposed in the driver's seat instrument or the center console.

  Connected to the first controller 29 are a differential lock detection switch 33, rotation speed sensors 34, 35, 36, 37 for detecting the rotation speeds of the front and rear wheels 5, 72, 3 and a steering angle sensor 39 for detecting a steering angle. Has been.

  The first controller 29 determines the differential lock position of the dog clutch 25 based on the input signal from the differential lock detection switch 33. The differential lock position determination result is displayed on a differential lock indicator on the instrument panel of the driver's seat.

  The first controller 29 detects differential rotation between the front wheels 5, 7 and between the rear wheels 2, 3 based on input signals from the wheel speed sensors 34, 35, 36, 37. Therefore, the first controller 29 and the rotation speed sensors 35 and 37 constitute a differential rotation detection device that detects the differential rotation between the rear wheels 2 and 3.

  The first controller 29 determines the vehicle turning state based on an input signal from the rudder angle sensor 39. Other methods and means for detecting and judging the turning state of the vehicle include the following. That is, the above-mentioned vehicle sensor 34, 35 or 36, 37 may detect the differential rotation of the left and right wheels, and may determine the turning state from the wheel speed difference. You may judge by detecting the signal of each sensor.

  The output signal of the first controller 29 is input to the second controller 41 as a brake control device. The second controller 41 can control the brakes 43, 45, 47, 49 of the front and rear wheels 5, 7, 2, 3. The second controller 41 controls the brakes 47 of the rear wheels 2 and 3 when the differential rotation between the rear wheels 2 and 3 is equal to or less than a set value when the dog clutch 25 is differentially unlocked by operating the operation switch 31 of the driver. Actuate 49 properly to forcibly release differential lock.

  In this embodiment, as shown in FIG. 1, the second controller 41 alternately operates the brakes 47 and 49 of the rear wheels 2 and 3 during straight traveling, releases the meshing force between the dog and clutch 25,・ The differential lock is forcibly released by the urging force of the return spring that releases the clutch 25.

  In this embodiment, the release operation of the dog clutch 25 is performed mainly based on the return spring (release means), but the function of the release means can be performed more smoothly by performing the brake operation of the present invention. .

  Further, as shown in FIG. 2, the second controller 41 operates the brakes 47 and 49 of the rear wheels 2 and 3 on the side where the input rotational speed to the dog clutch 25 is fast when turning, and similarly, the differential lock Is forcibly released. In FIG. 2, the brake 47 of the left rear wheel 2 on the outside of the turn is operated.

  The differential / unlock release by the operation of the brakes 47 and 49 is performed by appropriately operating the brakes 47 and 49. In this case, the proper operation is such that the straight traveling and the turning traveling are not affected.

[Differential lock release brake operation]
FIG. 3 is a control flow chart of the torque transmission control device.

The flow chart of FIG. 3 is executed by the operation of the operation switch 31. In step S1, a determination process of “Differential / unlock determination?” Is executed. In this process, the first controller 29 determines whether or not the differential lock position of the dog clutch 25 is the differential / release position based on an input signal from the differential lock detection switch 33.
When it is determined that the dog clutch 25 is not in the differential / unlock position (NO), the process proceeds to step S2, and when it is determined that the dog clutch 25 is in the differential / unlock position, the process returns.

  In step S2, a determination process of “vehicle speed ≠ 0” is executed. In this process, it is determined whether or not the vehicle speed is zero based on the input signals from the rotational speed sensors 35 and 37. If the vehicle speed is not zero (YES), the process proceeds to step S3, and if the vehicle speed is zero ( NO), the process returns.

  In step S3, a “turn determination” determination process is executed. In this process, the vehicle turning state is determined by the input signal from the rudder angle sensor 39 or the other example described above, and between the front wheels 5 and 7 and the rear wheel by the input signal from the rotation speed sensors 34, 35, 36, and 37. A differential rotation between 2 and 3 is detected, and it is determined whether each differential rotation is equal to or less than a set value. If it is determined from the input signal from the rudder angle sensor 39 that the vehicle is not in a turning state, and each differential rotation between the front wheels 5 and 7 and between the rear wheels 2 and 3 is determined to be equal to or less than a set value (NO), If the diff / lock non-release state during straight running is estimated and the process proceeds to step S4, and if the diff / lock non-release state during travel in a turning state is estimated (YES), the process proceeds to step S5.

  In step S4, a process of “applying a brake for a predetermined time alternately on the left and right rear wheels” is executed. In this process, the second controller 41 that has received a signal from the first controller 29 operates the brakes 47 and 49 of the left and right rear wheels 2 and 3 alternately for a certain period of time to forcibly release the diff lock and the process is performed. Return.

  In step S5, a “turn determination” determination process is executed. In this process, the first controller 29 determines whether the vehicle is turning right or left based on a signal from the steering angle sensor 39. If the vehicle is turning right (YES), the process proceeds to step S6. If (NO), the process proceeds to step S7.

  In step S6, a process of “applying a brake to the left rear wheel for a certain period of time” is executed. In this process, the second controller 41 receiving the signal from the first controller 29 operates the brake 47 of the left rear wheel 2 for a certain period of time, forcibly releases the differential lock, and the process returns.

In step S7, a process of “applying a brake to the right rear wheel for a certain period of time” is executed. In this process, the second controller 41 receiving the signal from the first controller 29 operates the brake 49 of the right rear wheel 3 for a certain period of time, forcibly releases the differential lock, and the process returns.
[Effects of Example 1]
In the embodiment of the present invention, in the torque transmission control device provided with the differential device 1 that is interposed between the rear wheels 2 and 3 and can be differentially locked by engaging the dog clutch 25 by operating the operation switch 31 of the driver, A first controller 29 serving as a differential rotation detection device and rotational speed sensors 35 and 37 for detecting differential rotation between the rear wheels 2 and 3 when the driver performs differential / unlock operation of the dog clutch 25; Since the second controller 41 is provided as a brake control device that appropriately operates the brakes 47 and 49 of the rear wheels 2 and 3 and forcibly releases the differential lock when the differential rotation is equal to or less than a set value, the driver The diff lock can be forcibly released so as to match the operation of the driver, and the driver's uncomfortable feeling can be suppressed.
[Others]
By providing the first controller 29 in a part of the second controller 41, both controllers can be integrated and function as one controller. That is, a control box that incorporates and controls differential lock control as a function of the brake control controller may be used.
The differential device that can be differentially locked can be the front differential device 9 or the center differential device. In the center differential device, the difference between the average rotation speed between the left and right front wheels and the average rotation speed between the left and right rear wheels is estimated based on whether or not both rotation speeds are below a certain value. Is done.

(Example 1) which is a skeleton top view at the time of the straight running of the four-wheel drive vehicle to which the torque transmission control apparatus is applied. (Example 1) which is a skeleton top view at the time of the turning driving | running | working of the four-wheel drive vehicle to which a torque transmission control apparatus is applied. 1 is a flowchart of a torque transmission control device (Example 1).

Explanation of symbols

1 Rear differential device (differential device)
2,3 Rear wheels (wheels)
29 First controller (differential rotation detection device)
35, 37 Speed sensor (Differential rotation detector)
41 Second controller (brake control device)

Claims (3)

In the torque transmission control device provided with a differential device that is interposed between the wheels and can be differentially locked by engaging the meshing clutch by the operation of the driver,
A differential rotation detection device that detects differential rotation between the wheels when the driver performs a differential / unlock operation of the meshing clutch;
A torque transmission control device, comprising: a brake control device that appropriately operates a brake of the wheel and forcibly releases differential lock when the differential rotation is equal to or less than a set value. The torque transmission control device according to claim 1,
The brake control device alternately operates the brakes of the wheels during straight traveling. The torque transmission control device according to claim 1,
The torque transmission control device, wherein the brake control device operates a brake of a wheel on a side having a higher input rotational speed to the meshing clutch during turning.

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