JP2009029215A - Control device of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device of a vehicle suitably suppressing generation of abnormal sound when a vehicle starts turning. <P>SOLUTION: This control device includes front and rear wheel driving force distribution control means 80 for controlling an electronic control coupling 26 so that driving force may be transmitted with a distribution ratio fixed in advance to a differential device 28 for rear wheels on a side without a differential limiting mechanism when starting of turning of the vehicle is decided. The driving force therefore is released to the differential device 28 for rear wheels on the side without the differential limiting mechanism when the vehicle starts turning and the driving force inputted into a differential device 18 for front wheels with a differential limiting mechanism is reduced. As a result, generation of abnormal sound caused by a stick slip, etc. in the differential limiting mechanism can be suppressed, while securing the driving force requiring the starting. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a front-rear wheel drive vehicle control device including a front-rear wheel drive force distribution device that controls the distribution of drive force to front and rear wheels, and more particularly, to an improvement for suppressing the generation of abnormal noise when turning. .

  In a vehicle having front wheels and rear wheels as drive wheels, for example, a four-wheel drive state and a two-wheel drive state are selectively established, or a driving force between the front wheels and the rear wheels in the four-wheel drive state. There is known a front-rear wheel driving force distribution device that controls distribution of the driving force generated by a driving force source to the front wheels and the rear wheels, such as controlling the distribution rate. For example, an electromagnetic clutch device disposed in series with the propeller shaft is the same. In a vehicle equipped with such a front and rear wheel driving force distribution device, the amount of driving force distribution to each wheel is determined based on information detected by various sensors provided in the vehicle regarding the control of the front and rear wheel driving force distribution device. Be controlled.

  In vehicles equipped with the front and rear wheel driving force distribution device as described above, it has been pointed out that there is a problem that vibration occurs when starting in a high rudder angle state, and a technique for solving such a problem has been proposed. . For example, this is the vehicle control apparatus described in Patent Document 1. According to this technique, when it is determined that the vehicle is starting at a high steering angle state, the differential of the differential device as the front and rear wheel driving force distribution device is limited, thereby sticking the differential device. It is said that the occurrence of slip can be prevented in advance, and the occurrence of vibration due to the stick slip can be suitably suppressed.

JP 2006-88763 A

  By the way, in general, in a vehicle, a differential device (differential) that divides an input driving force into left and right driving wheels is used. As an example of such a differential device, one having a differential limiting mechanism that limits the differential between the left and right wheels is known, and is used in various vehicles. In a vehicle including a differential device having such a differential limiting mechanism, a problem has been pointed out that abnormal noise is generated when the vehicle starts turning. However, although the conventional technique can prevent vehicle vibration at the time of starting in a high rudder angle state, the above-mentioned abnormal noise is not considered at all, and the abnormal noise cannot be suppressed. There wasn't. For this reason, there has been a demand for the development of a vehicle control device that suitably suppresses the generation of abnormal noise when turning.

  The present invention has been made against the background of the above circumstances, and an object of the present invention is to provide a vehicle control device that suitably suppresses the generation of abnormal noise when turning.

  In order to achieve such an object, the gist of the present invention includes a pair of left and right front wheels, a front wheel differential device that divides an input driving force into the left and right front wheels, and a pair of left and right rear wheels. A differential device for rear wheels that divides the input driving force into the left and right rear wheels, and a differential that restricts the differential between the left and right wheels corresponding to the front wheel differential device or the rear wheel differential device. A vehicle control device comprising: a limiting mechanism; and a front and rear wheel driving force distribution device that controls distribution of input torque of the driving force generated by the driving force source to the front wheel differential device and the rear wheel differential device When it is determined that the vehicle starts to turn, the front and rear wheels are configured so that the driving force is transmitted at a predetermined distribution ratio to the differential device on the side not provided with the differential limiting mechanism. An input torque to the front wheel differential and the rear wheel differential through the driving force distribution device. It is characterized in that a driving force distribution control means for controlling the distribution.

  In this way, when it is determined that the vehicle starts to turn, the driving force is transmitted at a predetermined distribution ratio to the differential device on the side not provided with the differential limiting mechanism. Since it includes driving force distribution control means for controlling input torque distribution to the front wheel differential device and the rear wheel differential device via the front and rear wheel driving force distribution device, the differential limiting mechanism is provided at the start of turning. The differential limiting mechanism while securing the driving force necessary for starting by reducing the driving force input to the differential apparatus having the differential limiting mechanism by releasing the driving force to the differential apparatus on the side not equipped The generation of abnormal noise due to stick-slip or the like can be suppressed. That is, it is possible to provide a vehicle control device that suitably suppresses the generation of abnormal noise when turning.

  Here, preferably, the driving force distribution control means is provided on the condition that the steering angle is not less than a predetermined angle and the driving force generated by the driving force source is not less than a predetermined value. The vehicle starts to turn. In this way, it is possible to determine the turning start of the vehicle in a practical manner.

  Preferably, the differential device on the side provided with the differential limiting mechanism is provided integrally with a final gear for transmitting a driving force to a corresponding driving wheel and an axle of the driving wheel. A torque proportional differential gear device having a plurality of worm wheels between a helical gear. In this way, regarding a vehicle equipped with a differential limiting mechanism that is likely to generate abnormal noise due to stick-slip or the like at the start of turning, the generation of abnormal noise at the start of turning can be suitably suppressed.

  Preferably, the front and rear wheel driving force distribution device is provided in series with a propeller shaft for transmitting a driving force generated by the driving force source to the rear wheel, and generates a magnetic force generated by a coil. Accordingly, it is an electronically controlled coupling that controls transmission of driving force from the propeller shaft to the rear wheel. If it does in this way, generation | occurrence | production of the noise at the time of turning start can be suppressed suitably regarding the vehicle provided with the front-and-rear wheel driving force distribution apparatus of the practical aspect.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a skeleton diagram illustrating the configuration of a front and rear wheel drive vehicle based on a front engine front wheel drive (FF) having a driving force transmission device 10 to which the present invention is preferably applied. In FIG. 1, the torque generated by the engine 12 as a driving force source is a pair of left and right via a torque converter 14, a transmission 16, a front wheel differential 18, and a pair of left and right front axles 20. While being transmitted to the front wheel 22, a propeller shaft 24 as a driving force transmission shaft, an electronically controlled coupling 26 (hereinafter simply referred to as a coupling 26) as a front and rear wheel driving force distribution device, a rear wheel differential device 28, and It is transmitted to a pair of left and right rear wheels 32 via a pair of left and right rear axles 30. Further, an electronic control unit 34 for controlling the coupling 26 is provided. That is, the driving force transmission device 10 shown in FIG. 1 is an electronically controlled torque split type four-wheel drive vehicle driving system that distributes torque generated by the engine 12 as a driving force source to the front and rear wheels in accordance with the traveling state. It is an example.

  The engine 12 is, for example, an internal combustion engine such as a gasoline engine or a diesel engine that generates driving force by combustion of fuel injected in a cylinder. The torque converter 14 includes, for example, a pump impeller coupled to the crankshaft of the engine 12, a turbine impeller coupled to the input shaft of the transmission 16, and a transmission case via a one-way clutch. And a stator impeller fixed to the hydrodynamic power transmission device that transmits power through the fluid between the pump impeller and the turbine impeller. The transmission 16 includes, for example, a plurality of friction engagement elements, and selectively establishes a plurality of transmission ratios according to a combination of engagement or release of the friction engagement elements, and inputs from the input shaft. This is an automatic transmission that shifts and outputs the generated driving force.

  The electronic control unit 34 is a so-called microcomputer that includes a CPU, a ROM, a RAM, an input / output interface, and the like, and executes signal processing according to a program stored in advance in the ROM while using a temporary storage function of the RAM. Yes, for example, various control related to front and rear wheel driving by the driving force transmission device 10 such as transmission torque control of the coupling 26 by controlling the command value of the current supplied to the coil 50 provided in the coupling 26 Execute. In order to execute such control, the power transmission device 10 includes a wheel speed sensor 36 that detects an actual rotational speed of the rear wheel 32 corresponding to a vehicle speed, and a steering angle that detects a steering angle of a steering wheel (not shown). Various sensors such as a sensor 38 and an accelerator opening sensor 40 for detecting an accelerator opening corresponding to the amount of depression of an accelerator pedal (not shown) are provided, and a signal indicating a vehicle speed and a signal indicating a steering angle from each sensor. , And a signal representing the accelerator opening are supplied to the electronic control unit 34.

  FIG. 2 is a cross-sectional view illustrating a configuration example of the coupling 26. As shown in FIG. 2, the coupling 26 is configured to be coaxial with the propeller shaft 24 serving as an input shaft and integrally rotated about an axis C common to the propeller shaft 24. 46, a second housing 48 including a coil (electromagnetic solenoid) 50 fixed to the inner peripheral side of the first housing 46, and coaxially with the first housing 46 so as to be relatively rotatable around its axis C. The disposed output shaft 52, the control cam 54 disposed coaxially with the output shaft 52 so as to be relatively rotatable about the axis C, and the relative rotation of the first housing 46 and the control cam 54 are prevented. A control clutch 56 having a plurality of clutch plates 58a, 58b, which are engaging elements, for alternately engaging and slipping, and the second housing 48. An armature 60 which is an annular iron piece disposed coaxially with the output shaft 52 so as to be relatively movable in the direction of the axis C in order to clamp the clutch plates 58a and 58b constituting the control clutch 56 between A main clutch 62 configured to alternately include a plurality of clutch plates 64a and 64b, which are engaging elements, in order to prevent or slip relative rotation between the first housing 46 and the output shaft 52, and the first clutch In order to clamp the clutch plates 64a and 64b constituting the main clutch 62 between the housing 46 and the output shaft 52, the clutch plates 64a and 64b are arranged coaxially with the output shaft 52 so that they cannot rotate about the axis C and can move in the axial direction. The main cam 66 is provided. The output shaft 52 is connected to an input shaft (input gear) of the rear wheel differential device 28. In addition, a plurality of recesses corresponding to the respective cam surfaces are formed on opposite sides of the control cam 54 and the main cam 66, and a corresponding recess is provided between the control cam 54 and the main cam 66. A plurality of balls 68 are arranged so as to be fitted between them.

  In the coupling 26 configured as described above, when the coil 50 is in a non-excited state, both the control clutch 56 and the main clutch 62 are in a non-engaged state. The driving force (torque) of the propeller shaft 24 is not transmitted to the output shaft 52. However, when the coil 50 is in an excited state, magnetic flux is generated around the coil 50, so that the armature 60 is in the second housing. The clutch plates 58a and 58b are clamped between the second housing 48 and the armature 60 by being attracted to the side 48, and the control clutch 56 is engaged or slipped according to the control current to the coil 50. When the control clutch 56 is engaged or slipped in this manner and a relative rotational speed difference is generated between the control cam 54 and the main cam 66, the ball 68 is placed on the slope of the recess in the control cam 54. The main cam 66 is pushed and pressed to the main cam 66 side, and the main cam 66 is pushed to the propeller shaft 24 side. As a result, the clutch plates 64a and 64b are pinched between the first housing 46 and the main cam 66 to engage or slip the main clutch 62, and the driving force of the propeller shaft 24 is increased at a predetermined rate. It is transmitted to the output shaft 52.

  The transmission torque transmitted by the coupling 26 is proportionally determined by a control current supplied to the coil 50, for example, as shown in FIG. That is, when the current supplied to the coil 50 is relatively small, the force with which the armature 60 is attracted to the second housing 48 side is relatively weak, and the engagement force of the control clutch 56 is relatively small. Although the relative rotational speed difference between the control cam 54 and the main cam 66 is reduced, the force with which the main cam 66 is pressed against the propeller shaft 24 is relatively weak and the transmission torque is relatively small. When the current supplied to the coil 50 is relatively large, the force with which the armature 60 is attracted to the second housing 48 side is relatively strong and the engagement force of the control clutch 56 is relatively large. The rotational speed difference between the main cam 66 and the main cam 66 becomes large, so that the main cam 66 is connected to the propeller shaft 2. Transmission torque force pressed to the side becomes relatively strong is relatively large. When the current supplied to the coil 50 exceeds a predetermined value, the driving force is transmitted to the front and rear wheels in a state close to a directly connected four-wheel drive vehicle. With the above configuration, the ratio of the driving force transmitted to the rear wheel 32 with respect to the total driving force output from the transmission 16 is continuously controlled within a range of zero to 0.5.

  FIG. 4 is a diagram for explaining the configuration of the front wheel differential 18 in detail. As shown in FIG. 4, the front wheel differential unit 18 includes a final gear 70 for transmitting the driving force output from the transmission 16 to the front wheel 22 as a driving wheel, and left and right corresponding respectively. A pair of left and right helical gears (worm gears) 72 provided integrally with the front wheel axle 20 and rotated integrally around a common shaft center with each front wheel axle 20, screw teeth on the cylindrical surface, and spur gears at both ends. And a torque proportional differential gear device (Torsen differential) provided with a plurality of (for example, three) worm wheels 74 corresponding to the respective helical gears 72 so as to be capable of rotating about respective axis centers. It is. The plurality of worm wheels 74 are meshed with the corresponding helical gears 72 with screw-like tooth traces formed on the cylindrical surface, and are paired with worm wheels 74 (the other helical gear 72) with spur gears provided at both ends. Is meshed with a spur gear of a worm wheel 74) provided corresponding to the above. The plurality of worm wheels 74 corresponding to the helical gear 72 on the final gear 70 side cannot rotate relative to the final gear 70 between the final gear 70 and the helical gear 72 and can rotate about their respective axis centers. Is provided. In the front wheel differential device 18 configured as described above, when rotational torque is output from the transmission 16 and the final gear 70 is rotated, the differential 18 is provided between the final gear 70 and the helical gear 72. The rotational torque is transmitted to the corresponding front wheel axle 20 through the plurality of worm wheels 74. Further, the rotation (autorotation) torque of each worm wheel 74 is transmitted to the plurality of worm wheels 74 provided corresponding to the other helical gear 72 via the spur gear, and the other helical gear 72 is also rotated by the worm wheel 74 in the same rotation. Rotated by number. As described above, in the front wheel differential device 18, the differential between the left and right front wheel axles 20 or the front wheels 22 is limited mainly by the friction of the tooth surfaces. That is, in the front wheel differential device 18 shown in FIG. 4, a differential limiting mechanism that limits the differential between the left and right wheels from the final gear 70, the helical gear 72, and the worm wheel 74 is configured.

  FIG. 5 is a functional block diagram for explaining the main part of the control function provided in the electronic control unit 34. The front and rear wheel driving force distribution control means 80 shown in FIG. 5 controls the operation of the coupling 26 to thereby control the front wheel differential 18 and the rear wheels of the driving force (torque) generated by the engine 12. The distribution of input torque to the differential unit 26 is controlled. Specifically, by controlling the control current to the coil 50 provided in the coupling 26, the engagement force of the main clutch 62 in the coupling 26 is controlled, and thereby output from the transmission 16. The ratio of the driving force transmitted to the rear wheel 32 with respect to the total driving force is controlled steplessly within a range of zero to 0.5.

  Here, the front and rear wheel driving force distribution control means 80 includes a turning start determination means 82 for control at the time of turning start, and the turning start determination means 82 determines the turning start of the vehicle. Specifically, from a predetermined relationship, the vehicle speed detected by the wheel speed sensor 36, the steering angle detected by the steering angle sensor 38, the accelerator opening detected by the accelerator opening sensor 40, and the like. The turning start of the vehicle is determined based on the condition that the rudder angle is not less than a predetermined angle and the driving force generated by the engine 12 is not less than a predetermined value. Note that a torque sensor that directly detects the output torque of the engine 12 or the input torque to the front wheel differential 18 or the like is provided, and the above determination is made based on the torque detected by the torque sensor. Good.

  The front / rear wheel driving force distribution control means 80, when the turning start determination means 82 determines the turning start of the vehicle, the differential device on the side where the differential limiting mechanism is not provided, that is, for the rear wheel. The operation of the coupling 26 is controlled so that the driving force is transmitted to the differential device 28 at a predetermined distribution rate. This distribution ratio is preferably a ratio as small as possible within a limit in which stick slip does not occur in the differential device having a differential limiting mechanism when the vehicle starts to turn beyond a predetermined rudder angle, that is, the front wheel differential device 18. It has been experimentally obtained in advance. When it is determined that the vehicle starts to turn, the electronic control unit 34 according to the present embodiment is predetermined to the rear wheel differential device 28 on which the differential limiting mechanism is not provided as shown in FIG. The coupling 26 is controlled so that the driving force is transmitted at the distribution rate. When the driving force is transmitted to the rear wheel differential device 28 as described above, the driving force (input torque) input to the front wheel differential device 18 provided with the differential limiting mechanism is correspondingly increased. Reduced. FIG. 7 is a diagram illustrating a relationship between input torque and vibration input to a differential device having a differential limiting mechanism. As shown in FIG. C. As the components are reduced, A. C. Ingredients are also reduced. Therefore, the occurrence of vibrations in the differential device can be suppressed by suppressing the torque input to the differential device including the differential limiting mechanism to a predetermined value or less. In the present embodiment, the occurrence of stick-slip in the front wheel differential 18 is suppressed as described above, and the occurrence of abnormal noise due to the stick-slip or the like is preferably prevented.

  FIG. 8 is a flowchart for explaining a main part of the front and rear wheel driving force distribution control by the electronic control unit 34, and is repeatedly executed at a predetermined cycle.

First, in step (hereinafter, step is omitted) S1, the vehicle speed corresponding to the wheel speed of the rear wheel 32 from the wheel speed sensor 36, the steering angle from the rudder angle sensor 38, the accelerator opening sensor 40, and so on. , The accelerator opening is detected (input). Next, in S2 corresponding to the operation of the turning start determination means 82, the turning start of the vehicle is determined. Specifically, greater than the detected value steering angle theta is predetermined theta _v at S1, and the input torque to the front wheel differential device 18 which is calculated based on the vehicle speed and the accelerator opening or the like T or not greater than the value T _v the predetermined (the value in the state of not performing torque transmission by the coupling 26) is determined. If the determination in S2 is affirmative, in S3, after the coupling command torque is calculated so that the torque is transmitted to the rear wheel differential device 28 at a predetermined predetermined distribution rate, If the determination at S2 is negative, the coupling command torque at the time of non-turning start (during normal control) is calculated at S4, and then at S5, S4 or S5 is executed. The command current is supplied to the coil 50 of the coupling 26 in accordance with the command torque calculated in (5), and after the operation of the coupling 26 is controlled, this routine is terminated. In the above control, S2 to S5 correspond to the operation of the front and rear wheel driving force distribution control means 80.

  As described above, according to the present embodiment, when it is determined that the vehicle starts to turn, the vehicle is driven at a predetermined distribution rate to the rear wheel differential device 28 on which the differential limiting mechanism is not provided. Since it includes front and rear wheel driving force distribution control means 80 (S2 to S5) for controlling the coupling 26 so that force is transmitted, the differential for the rear wheel on the side not provided with the differential limiting mechanism at the time of turning start. Stick slip in the differential limiting mechanism while securing the driving force required for starting by reducing the driving force input to the front wheel differential device 18 provided with the differential limiting mechanism by releasing the driving force to the device 28. It is possible to suppress the occurrence of abnormal noise caused by the above. That is, it is possible to provide a vehicle control device that suitably suppresses the generation of abnormal noise when turning.

  The front and rear wheel driving force distribution control means 80 is provided on the condition that the rudder angle is not less than a predetermined angle and the driving force generated by the engine 12 as a driving force source is not less than a predetermined value. Therefore, the turning start of the vehicle can be determined in a practical manner.

  The front wheel differential device 18 on the side provided with the differential limiting mechanism is integrated with the final gear 70 for transmitting the driving force to the corresponding front wheel 22 and the front wheel axle 20 corresponding to each front wheel 22. A vehicle equipped with a differential limiting mechanism that easily generates noise due to stick-slip or the like when turning, since it is a torque proportional differential gear device having a plurality of worm wheels 74 between the helical gear 72 provided. With respect to the above, it is possible to suitably suppress the occurrence of abnormal noise when the vehicle starts turning.

  The front and rear wheel driving force distribution device is provided in series with the propeller shaft 24 for transmitting the driving force generated by the engine 12 to the rear wheel 32, and according to the magnetic force generated by the coil 50. Since the vehicle is provided with a coupling 26 for controlling the transmission of driving force from the propeller shaft 24 to the rear wheel 32, a vehicle having a front and rear wheel driving force distribution device of a practical aspect is different during turning. Sound generation can be suitably suppressed.

  The preferred embodiments of the present invention have been described in detail with reference to the drawings. However, the present invention is not limited to these embodiments, and may be implemented in other modes.

  For example, in the above-described embodiment, the example in which the torque proportional differential gear device is provided as the front wheel differential device 18 on the side provided with the differential limiting mechanism has been described, but the present invention is limited to this. Rather than, for example, a Thornton power-lock differential limiting device having a plurality of differential small gears, a Borgwarner spin resistant that has a preload spring and a multi-plate clutch or cone clutch, and generates friction torque by a pressing force caused by a spring load. Type differential limiter, Gleason type differential limiter with a split small gear shaft divided into two and a cam mechanism inserted between them, or rotational speed sensitive differential using viscous coupling The present invention may be applied to a vehicle provided with a limiting device or the like, that is, a vehicle provided with a differential limiting mechanism according to a differential device, and abnormal noise is generated when the vehicle starts turning. As long as it can stiffness, prima facie effect by application of the present invention is obtained.

  In the above-described embodiment, the example in which the electronic control coupling 26 is provided as the front and rear wheel driving force distribution device has been described. However, the front wheel differential device 18 and the rear wheel driving force generated by the driving force source are described. As long as the input torque distribution to the differential device 28 can be controlled, other types of devices may be used.

  In addition, although not illustrated one by one, the present invention is implemented with various modifications within a range not departing from the gist thereof.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a skeleton diagram illustrating a configuration of a front and rear wheel drive vehicle based on a front engine front wheel drive having a driving force transmission device to which the present invention is preferably applied. It is a schematic sectional drawing explaining the structural example of the electronically controlled coupling with which the driving force transmission apparatus of FIG. 1 was equipped. It is a graph which shows the relationship between the control current supplied to the coil with which the electronic control coupling for vehicles of FIG. 2 was provided, and transmission torque. It is a figure explaining in detail the structure of the differential for front wheels with which the driving force transmission apparatus of FIG. 1 was equipped. It is a functional block diagram explaining the principal part of the control function with which the electronic control apparatus of FIG. 1 was equipped. FIG. 2 is a diagram illustrating a state in which a driving force is released to a rear wheel differential device when the vehicle of FIG. 1 starts turning. It is a figure which illustrates the relationship between the input torque and vibration which are input into the differential gear provided with the differential limiting mechanism. It is a flowchart explaining the principal part of the front-and-rear wheel driving force distribution control by the electronic controller of FIG.

Explanation of symbols

12: Engine (drive power source)
18: Front wheel differential 22: Front wheel 24: Propeller shaft 26: Electronically controlled coupling (front and rear wheel driving force distribution device)
28: Rear wheel differential device 32: Rear wheel 50: Coil 70: Final gear 72: Helical gear 74: Worm wheel 80: Front and rear wheel driving force distribution control means

Claims (4)

A pair of left and right front wheels, a front wheel differential that divides the input driving force into the left and right front wheels, a pair of left and right rear wheels, and a rear wheel that divides the input driving force into the left and right rear wheels A differential device, a differential limiting mechanism for limiting the differential between the left and right wheels corresponding to the front wheel differential device or the rear wheel differential device, and the front wheel difference in driving force generated by a driving force source A vehicle control device comprising a front and rear wheel driving force distribution device for controlling input torque distribution to a moving device and a differential device for rear wheels,
When it is determined that the vehicle starts to turn, the front and rear wheel driving force distribution device is configured such that the driving force is transmitted at a predetermined distribution rate to the differential device on the side not provided with the differential limiting mechanism. And a driving force distribution control means for controlling input torque distribution to the front wheel differential and the rear wheel differential through the vehicle.   The driving force distribution control means determines turning of the vehicle on the condition that the steering angle is not less than a predetermined angle and the driving force generated by the driving force source is not less than a predetermined value. The vehicle control device according to claim 1, which is a vehicle.   The differential device on the side provided with the differential limiting mechanism is provided between a final gear for transmitting a driving force to a corresponding driving wheel and a helical gear provided integrally with the axle of the driving wheel. The vehicle control device according to claim 1, which is a torque proportional differential gear device including a plurality of worm wheels.   The front and rear wheel driving force distribution device is provided in series with a propeller shaft for transmitting the driving force generated by the driving force source to the rear wheel, and from the propeller shaft according to the magnetic force generated by the coil. The vehicle control device according to any one of claims 1 to 3, wherein the control device is an electronically controlled coupling that controls transmission of driving force to the rear wheels.

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