Controllable differential system and vehicle having controllable differential system

Abstract

A controllable differential system for a vehicle includes a differential that can be disengaged or engaged, and can also be locked when engaged. A differential lock switch has three positions for sending a command to an actuator to disengage or engage the differential, and for sending a command to a controller to unlock and lock the differential. The vehicle includes a motor, a transmission continuously connected to a rear drivetrain, and a differential mounted in a front drivetrain. When the differential is disengaged, the vehicle can be driven in rear-wheel drive mode, or when the differential is engaged, the vehicle can be driven in four-wheel drive mode. When the differential is locked and a manual override control is not activated, the vehicle can enforce vehicle speed limiting or engine speed limiting. The vehicle can implement an anti-lock braking system (ABS), which can be disabled when the differential is locked.

Description

[0001] Cross-references

[0002] This application claims priority to U.S. Provisional Application Serial No. 62 / 928,793, filed October 31, 2019, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This technology relates to controllable differential systems and to vehicles having controllable differential systems. Background Technology

[0004] All-terrain vehicles (ATVs), side-by-side vehicles (SSVs), and similar vehicles are used for practical and recreational purposes. These ATVs and SSVs are typically equipped with a transmission that can direct power from the internal combustion engine (ICE) to the rear drivetrain for rear-wheel drive (or two-wheel drive) operation, or to both the rear and front drivetrains for all-wheel drive (or four-wheel drive) operation.

[0005] Certain driving conditions, especially when the vehicle is being driven off-road, can cause wheel slippage, even in all-wheel drive mode. A locking differential can be installed in either or both of the front and / or rear drivetrains. Conventional controllers for locking and unlocking differentials are quite cumbersome. Some controllers require the vehicle to be stopped to lock or unlock the vehicle's differential.

[0006] Therefore, a controllable differential system and vehicle are needed to address the aforementioned shortcomings. Summary of the Invention

[0007] The purpose of this technology is to improve at least some of the inconveniences existing in the prior art.

[0008] According to one aspect of the present technology, a controllable differential system for a vehicle is provided, the controllable differential system comprising: a differential having a disengaged engagement mode and an engaged mode, the differential being selectively locked when in the engaged mode; a differential lock switch having a first position, a second position, and a third position, the second position being intermediate between the first and third positions, the differential lock switch being biased to return to the second position when released from the third position, the differential lock switch being operatively connected to the differential for placing the differential in the disengaged engagement mode when the differential lock switch is in the first position, and placing the differential in the engaged mode when the differential lock switch is in the second position; and a controller operatively connected to the differential and to the differential lock switch, the controller being adapted to control the differential to selectively change the differential from one of an unlocked state and a locked state to another of an unlocked state and a locked state when the differential lock switch is in the third position.

[0009] In some implementations of this technology, the controller is also adapted to control the differential to change from one of the unlocked and locked states to another of the unlocked and locked states when the differential lock switch is held in the third position for a predetermined time.

[0010] In some implementations of this technology, the controller is also adapted to control the differential to change from one state of unlocked state to another state of unlocked state and locked state when the differential lock switch is released from the third position after being held for more than a predetermined time.

[0011] In some implementations of this technology, the controllable differential system further includes: an actuator electrically connected to a differential lock switch and adapted to receive commands from the differential lock switch to engage and disengage the differential, the actuator also electrically connected to a controller and adapted to receive commands from the controller to lock and unlock the differential; and a mechanical lock adapted to be driven by the actuator to selectively engage and disengage the differential and selectively lock and unlock the differential.

[0012] In some implementations of this technology, the actuator includes an electric motor driven by an integrated circuit; and the mechanical lock includes a rod driven by the electric motor and a lever driven by the rod, the lever being adapted to engage a sleeve in the differential to selectively disengage, engage, or engage and lock the differential.

[0013] In some implementations of this technology, the actuator is adapted to provide electronic feedback signals of a locked or unlocked state to the controller.

[0014] In some implementations of this technology, the differential is a front differential suitable for installation in the front drivetrain of a vehicle.

[0015] According to another aspect of the present technology, a vehicle is provided, the vehicle including a frame, a motor connected to the frame, a rear drivetrain connected to the frame, a front drivetrain connected to the frame, and a transmission. The front drivetrain includes a controllable differential system, the controllable differential system including: a differential having a disengaged engagement mode and an engaged mode, the differential being selectively lockable in the engaged mode; a differential lock switch having a first position, a second position, and a third position, the second position being intermediate between the first and third positions, the differential lock switch being biased to return to the second position when released from the third position, the differential lock switch being operated... The transmission is operatively connected to the differential for disengaging the differential in a first position and engaging the differential in a second position; and a controller operatively connected to the differential and the differential lock switch, the controller being adapted to control the differential to selectively change the differential from one of an unlocked state and a locked state to another of an unlocked state and a locked state when the differential lock switch is in a third position; the transmission is adapted to direct power from the motor to the rear drivetrain and, when the differential is in the engaged mode, to direct power from the motor to the front drivetrain.

[0016] According to another aspect of the present technology, a vehicle is provided, the vehicle including a frame, a motor connected to the frame, a rear drivetrain connected to the frame, a front drivetrain connected to the frame, a transmission, a controller, and a differential lock switch, the front drivetrain including a front differential capable of being selectively configured into one of the following modes: (i) a disengaged engagement mode for rear-wheel drive operation of the vehicle, (ii) an engaged and unlocked mode, and (iii) an engaged and locked mode, wherein when the front differential is engaged, the vehicle is capable of operating in all-wheel drive; the transmission is adapted to: direct power from the motor to the rear drivetrain, and when the front differential is engaged, direct power from the motor to the rear drivetrain. The controller is operatively connected to the front differential; the differential lock switch is operatively connected to the front differential and to the controller, the differential lock switch being adapted to: provide a disengagement command to the front differential for placing the front differential in a disengagement mode; provide an engagement command to the front differential for placing the front differential in an engagement and unlock mode; provide a locking command to the controller, which, upon receiving the locking command, selectively changes the front differential from an engagement and unlock mode to an engagement and lock mode; and provide an unlock command to the controller, which, upon receiving the unlock command, changes the front differential from an engagement and lock mode to an engagement and unlock mode.

[0017] In some implementations of this technology, the vehicle also includes an actuator operatively connected to the front differential and controlled by a controller, the actuator being adapted to: receive a disengagement command from a differential lock switch; receive an engagement command from a differential lock switch; receive a locking command via the controller; receive an unlocking command via the controller; and, in response to receiving one of the disengagement command, engagement command, locking command, and unlocking command, selectively place the front differential in a disengagement mode, an engagement and unlocking mode, and an engagement and locking mode.

[0018] In some implementations of this technology, the differential lock switch has a first position, a second position, and a third position, with the second position located between the first and third positions. When released from the third position, the differential lock switch is biased to return to the second position. The differential lock switch is adapted to: provide a disengagement command when in the first position; provide an engagement command when moving from the first position to the second position; provide a locking command when in the third position and the front differential is in an engaged and unlocked mode; and provide an unlock command when in the third position and the front differential is in an engaged and locked mode.

[0019] In some implementations of this technology, when the differential lock switch remains in the third position for a predetermined time, the differential lock switch provides a locking command and a locking instruction.

[0020] In some implementations of this technology, the vehicle also includes a brake control unit that implements an anti-lock braking system (ABS); the controller is also adapted to disable the ABS by the brake control unit when the current differential is engaged and locked.

[0021] In some implementations of this technology, the vehicle is an off-road vehicle selected from all-terrain vehicles and side-by-side vehicles.

[0022] In some implementations of this technology, the vehicle also includes a handlebar that is pivotally connected to the frame and operatively connected to the front drivetrain, with a differential lock switch mounted on the handlebar.

[0023] In some implementations of this technology, the vehicle also includes a manual overtaking control device; the controller is also adapted to control the motor to limit the vehicle speed when the front differential is engaged and locked and the manual overtaking control device is not enabled.

[0024] In some implementations of this technology, the vehicle also includes a manual overtaking control device; the controller is also adapted to control the motor to limit the motor speed when the front differential is engaged and locked and the manual overtaking control device is not enabled.

[0025] In some implementations of this technology, the vehicle also includes a handlebar that is pivotally connected to the frame and operatively connected to the front drivetrain, with a hand-operated overtaking control device mounted on the handlebar.

[0026] In some implementations of this technology, the vehicle further includes: a steering assembly operatively connected to the front drivetrain; and a steering angle sensor operatively connected to the steering assembly; the controller is also operatively connected to the steering angle sensor and is also adapted to delay or prevent the front differential from changing from an engaged and unlocked mode to an engaged and locked mode when the steering angle indicated by the steering angle sensor exceeds a predetermined angle threshold.

[0027] In some implementations of this technology, the vehicle also includes a vehicle speed sensor operatively connected to one of the front drivetrain and the rear drivetrain; the controller is also operatively connected to the vehicle speed sensor and is also adapted to delay or prevent the front differential from changing from an engaged and unlocked mode to an engaged and locked mode when the vehicle speed indicated by the vehicle speed sensor exceeds a predetermined angle threshold.

[0028] In some implementations of this technology, the vehicle also includes an engine speed sensor operatively connected to the motor; the controller is also operatively connected to the engine speed sensor and is also adapted to delay or prevent the front differential from changing from an engaged and unlocked mode to an engaged and locked mode when the speed of the motor indicated by the engine speed sensor exceeds a predetermined angle threshold.

[0029] In some implementations of this technology, the vehicle also includes a gearbox sensor operatively connected to the transmission; the controller is also operatively connected to the gearbox sensor and is also adapted to delay or prevent the front differential from changing from an engaged and unlocked mode to an engaged and locked mode when the gearbox sensor indicates that the transmission is not in a predetermined state.

[0030] In some implementations of this technology, the vehicle also includes: a throttle operator operatively connected to the throttle and to a motor; a throttle opening sensor; the controller is also operatively connected to the throttle opening sensor and is also adapted to delay or prevent the front differential from changing from an engaged and unlocked mode to an engaged and locked mode when the throttle opening reported by the throttle opening sensor exceeds a predetermined opening threshold.

[0031] In some implementations of this technology, the vehicle also includes: a controller area network (CAN) bus operatively connected to the controller; an indicator of the status of the CAN bus; the controller is also operatively connected to the CAN bus status indicator and is also adapted to delay or prevent the front differential from changing from an engaged and unlocked mode to an engaged and locked mode when the integrity of the CAN bus status indication signal reported by the CAN bus status indicator is lost.

[0032] In some implementations of this technology, the vehicle also includes a vision display operatively connected to a controller that is also adapted to: display an indication on the vision display when the current differential is prevented from changing from an engaged and unlocked mode to an engaged and locked mode; and display an indication on the vision display when the change from the engaged and unlocked mode to the engaged and locked mode is delayed.

[0033] In some implementations of this technology, the vehicle also includes a vision display operatively connected to the controller and adapted to display the current disengaged, engaged and unlocked, or engaged and locked mode of the front differential.

[0034] In some implementations of this technology, the visual display includes a cluster of vehicles.

[0035] In some implementations of this technology, the visual display includes an icon that appears next to the differential lock switch.

[0036] According to another aspect of the present technology, a vehicle is provided, the vehicle comprising: a frame; a motor connected to the frame; a rear drivetrain connected to the frame; a front drivetrain connected to the frame, the front drivetrain including a lockable front differential; a manual overrunning control device; and a controller operatively connected to the front differential and the manual overrunning control device, the controller being adapted to control the motor to limit the speed of the motor when the front differential is locked and the manual overrunning control device is not activated.

[0037] According to another aspect of the present technology, a vehicle is provided, the vehicle comprising: a frame; a motor connected to the frame; a rear drivetrain connected to the frame; a front drivetrain connected to the frame, the front drivetrain including a lockable front differential; a manual overtaking control device; and a controller operatively connected to the lockable front differential and to the manual overtaking control device, the controller being adapted to control the motor to limit the speed of the vehicle when the front differential is locked and the manual overtaking control device is not activated.

[0038] In some implementations of this technology, the vehicle also includes a handlebar that is pivotally connected to the frame and operatively connected to the front drivetrain, with a hand-operated overtaking control device mounted on the handlebar.

[0039] According to another aspect of the present technology, a vehicle is provided, the vehicle comprising: a frame; a motor connected to the frame; a rear drivetrain connected to the frame; a front drivetrain connected to the frame, the front drivetrain including a lockable front differential; a brake control unit that implements an anti-lock braking system (ABS); and a controller operatively connected to the front differential and to the brake control unit, the controller being adapted to disable the ABS by the brake control unit when the front differential is locked.

[0040] In some implementations of this technology, the front differential can be configured in one of the following modes: (i) disengagement mode, (ii) engagement and unlocking mode, and (iii) engagement and locking mode. The vehicle also includes a transmission adapted to direct power from the motor to the rear drivetrain and, optionally, to the front drivetrain.

[0041] In some implementations of this technology, the vehicle also includes a differential lock switch operatively connected to the front differential and to a controller. The differential lock switch is adapted to: provide a disengagement command to the front differential to place the front differential in a disengagement mode; provide an engagement command to the front differential to place the front differential in an engagement and unlock mode; provide a locking command to the controller, which, upon receiving the locking command, selectively changes the front differential from an engagement and unlock mode to an engagement and lock mode; and provide an unlock command to the controller, which, upon receiving the unlock command, changes the front differential from an engagement and lock mode to an engagement and unlock mode.

[0042] For the purposes of this application, when referring to a vehicle and vehicle-related components, terms related to spatial orientation, such as “forward,” “backward,” “left,” “right,” “above,” and “below,” mean as would be understood by a driver of the vehicle in an upright driving position while the vehicle is moving forward.

[0043] The embodiments of this technology each have at least one of the above-described objectives and / or aspects, but not necessarily all of them. It should be understood that some aspects of this technology obtained in an attempt to achieve the above objectives may not satisfy those objectives and / or may satisfy other objectives not specifically described herein.

[0044] Additional and / or alternative features, aspects, and advantages of embodiments of the present technology will become apparent from the following description, drawings, and appended claims. Attached Figure Description

[0045] To better understand this technology, as well as other aspects and additional features thereof, reference is made to the following description used in conjunction with the accompanying drawings, in which:

[0046] Figure 1 This is a three-dimensional view taken from the left rear side of an all-terrain vehicle;

[0047] Figure 2 yes Figure 1 A left-side front view of the chassis, engine, continuously variable transmission, seat, steering assembly, front suspension assembly, and rear suspension assembly of an all-terrain vehicle.

[0048] Figure 3 From Figure 1 A three-dimensional view of the steering assembly, front drive system, rear drive system, and braking assembly of an all-terrain vehicle, viewed from the left rear side.

[0049] Figure 4 yes Figure 1 Right-side front view of the steering assembly, front drivetrain, rear drivetrain, and braking assembly of an all-terrain vehicle.

[0050] Figure 5 yes Figure 1 Top plan view of the steering assembly, front drive system, rear drive system, and braking assembly of an all-terrain vehicle.

[0051] Figure 6 According to the implementation method Figure 1 A 3D view of the vehicle's engageable and lockable front differential;

[0052] Figure 7A for Figure 6 A perspective view of the differential, in which the cover has been removed to show the mechanical lock driven by the actuator;

[0053] Figure 7B schematically shown Figure 7A Details of the actuator;

[0054] Figure 8A , Figure 8B and Figure 8C They are respectively Figure 6 Cross-sectional views of the differential in disengaged mode, engaged and unlocked mode, and engaged and locked mode;

[0055] Figure 9 According to the implementation method Figure 1 The right switch control housing of the vehicle and the connection of the right switch control housing to Figure 6 Rear-view perspective view of the differential and the wiring connecting it to the controller;

[0056] Figure 10A , Figure 10B and Figure 10C for Figure 9 A detailed rear perspective view of the housing of the right switch control device, showing the differential lock switch in the first, second, and third positions respectively;

[0057] Figure 11 For use according to the implementation method Figure 1 Rear view of the housing of the left switch control unit of the vehicle;

[0058] Figure 12 To illustrate the implementation method Figure 1 A block diagram showing the connection between the vehicle's front differential and electrical components;

[0059] Figure 13 To illustrate the implementation method Figure 12 A block diagram of the internal components of the controller; and

[0060] Figure 14 This is an enlarged top plan view of the brake control unit. Detailed Implementation

[0061] This technology will be described with reference to a four-wheeled straddle-mounted all-terrain vehicle (ATV) 9. However, it is conceivable that aspects of this technology can be used in other types of vehicles, such as side-by-side vehicles (SSVs), ATVs, and other off-road vehicles.

[0062] Reference Figures 1 to 5 The ATV 9 has a front end 2 and a rear end 4 aligned with its forward direction of travel. The ATV 9 has a frame, such as a tubular frame 12. An internal combustion engine 16, used to power the ATV 9, is connected to the frame. It is conceivable that the ATV 9 could be powered by other types of motors, such as electric motors.

[0063] The ATV 9 has a front drivetrain 6 and a rear drivetrain 8, both of which are connected to the frame 12. The front drivetrain 6 has two front wheels 18, and the rear drivetrain 8 has two rear wheels 18, although a rear drivetrain with a single wheel 18 or four wheels 18 is also conceivable. Each wheel 18 is fitted with a low-pressure wide tire, which is suitable for off-road conditions and for traversing rough terrain.

[0064] Wheels 18 are operatively connected to engine 16 via a transmission, which in the illustrated example includes a continuously variable transmission (CVT) 17 that receives power from engine 16 and a gearbox 19 operatively connected to CVT 17. The driver uses a shifter 34 located below the right side of handlebar 32 to position gearbox 19 in one of the following positions: high-speed transmission, low-speed transmission, neutral transmission, or reverse transmission. When the front differential 76 of the current drivetrain 6 is disengaged, CVT 17 and gearbox 19 direct power from engine 16 to the rear wheels 18 only, allowing ATV 9 to operate in rear-wheel drive (or two-wheel drive) mode. When the front differential 76 is engaged, CVT 17 and gearbox 19 direct power from engine 16 to both rear and front wheels 18, allowing ATV 9 to operate in all-wheel drive (or four-wheel drive) mode.

[0065] like Figure 1 As illustrated, the ATV 9 also includes a fairing 60, which includes a front trim panel 62 at the front end 2 of the ATV 9 and several side panels 64 extending along the lateral sides of the ATV 9. Mudguards 66 are provided above each wheel 18 to protect the driver and / or passenger from dirt, water, and other debris sprayed by the rotating wheels 18. The ATV 9 also includes a straddle-mounted seat 28, which is mounted to the frame 12 to accommodate the driver of the ATV 9. Footrests 50 are provided on both sides of the seat 28 and are configured to be lower than the seat 28 in the vertical direction to support the driver's feet.

[0066] The front wheel 18 is suspended on the frame 12 via the left front suspension assembly 24 and the right front suspension assembly 24, while the rear wheel 18 is suspended on the frame 12 via the left rear suspension assembly 26 and the right rear suspension assembly 26.

[0067] The steering assembly 30, operatively connected to the front wheels 18, is rotatably supported by the frame 12, enabling the driver to operate the ATV 9. The steering assembly 30 includes handlebars 32, each with a handle grip 33 at each end. The handlebars 32 are pivotally connected to the frame 12 and operatively connected to the front wheels 18 via a steering column 74. Operation of the handlebars 32 actuates the steering linkage 70, which includes a power steering gearbox 31 assisted by an electric motor 29, and is operatively connected to the left and right front wheels 18. It is conceivable that the power steering electric motor 29 may be omitted. Other vehicles may include a steering wheel instead of the handlebars 32.

[0068] The ATV 9 can operate in rear-wheel drive mode or all-wheel drive mode. (See reference...) Figure 3 , Figure 4 and Figure 5 The front drivetrain 6 of the ATV 9 includes a front differential 76, a pair of half-shafts 78 connected to constant velocity (CV) joints 128 and 88, and shafts extending between CV joints 88 and hubs 86, each of which is supported by a corresponding pivot pin 85. The front differential 76 is connected to a corresponding CV joint 128 on each of its left and right sides, with each CV joint 128 connected to one end of a corresponding half-shaft 78. Another CV joint 88 is connected to the opposite end of each half-shaft 78. Each CV joint 88 and 128 is protected by a respective boot-shaped cover 102. The front wheel 18 and front disc 82 are mounted to each hub 86 and supported by corresponding pivot pins 85. On each side of the front differential 76, the front wheel 18, front disc 82, CV joint 88, half-shafts 78, and CV joint 128 are operably connected to rotate together at a common speed.

[0069] The left and right front brake assemblies include a front disc 82 and a front caliper 84 mounted on a pivot pin 85. The left and right front calipers 84 are connected to hoses 95L and 95R, respectively. Each front caliper 84 includes a pair of brake pads 87 positioned on opposite sides of the respective front disc 82. The front calipers 84 are actuated by applying fluid pressure in hoses 95L and / or 95R, causing the brake pads 87 to apply pressure to the respective front disc 82.

[0070] The rear drivetrain 8 of the ATV 9 includes a rear long gear 96 enclosed within a housing 97, an input shaft 100 of the long gear 96, CV joints 130 and 132, half shafts 98, and a shaft extending between CV joint 132 and a hub 104. The input shaft 100 is operably connected to the rear drive shaft 101 via a universal joint 81. The rear drive shaft 101 is connected to the gearbox 19 via another universal joint 81 to receive power from the engine 16. The long gear 96 is connected to the CV joint 130 on each of its left and right sides, the CV joints being connected to one end of the corresponding half shaft 98. Another CV joint 132 is connected to the opposite end of each half shaft 98. CV joints 130 and 132 are protected by their respective boot-shaped covers 102. The hub 104 is supported by the lower end of the rear suspension assembly 26. Rear wheels 18 are mounted to each hub 104.

[0071] The long gear 96 transmits the torque received from the engine 16 to the left rear wheel 18 and the right rear wheel 18. The long gear 96 causes the CV joint 130, half shaft 98, CV joint 132, wheel axle 104 and rear wheel 18, as well as the single rear disc 106, located on both the left and right sides of the ATV 9, to rotate together at a common speed.

[0072] A single rear brake assembly includes a single rear disc 106 mounted to the right hub 104 and a single rear caliper 108. Although the single rear disc 106, as illustrated, is located on the right-hand side of the ATV 9, it is also conceivable to mount the single rear disc 106 on the left-hand side of the ATV 9. The single rear caliper 108 is supported by the right rear suspension assembly 26. The single rear caliper 108 is connected to a hose 116. The single rear caliper 108 includes a pair of rear brake pads (not shown) positioned on opposite sides of the single rear disc 106. The single rear caliper 108 is actuated by applying fluid pressure in the hose 116, causing the rear brake pads to apply pressure to the single rear disc 106. There is no rear brake assembly on the left-hand side of the ATV 9, where the left rear wheel 18 is supported by the left rear suspension assembly 26. It is also conceivable to provide rear brake assemblies on both sides of the rear drivetrain 8 of the ATV 9.

[0073] The user of the ATV 9 can actuate either or both of two user-actuated braking input devices, such as the lever 90 and the foot lever 110, to transmit braking commands independently or jointly for slowing or stopping the ATV 9. The lever 90 and the front master cylinder 92 are mounted on the handlebars 32. The front master cylinder 92 may be directly filled with brake fluid. Actuating the lever 90 causes the front master cylinder 92 to transmit braking commands to the brake control unit 124. In the implementation shown, the braking command from the lever 90 is in the form of fluid pressure in a hose 94 connecting the front master cylinder 92 and the brake control unit 124. In another implementation, actuation of the lever 90 can apply tension to the cable to transmit braking commands to the brake control unit 124. When the lever 90 is actuated, a signal is sent to activate the brake lights.

[0074] The foot lever 110 and the rear master cylinder 112 are mounted on a bracket 114, which is supported by the lower portion of the frame 12. The rear master cylinder 112 receives brake fluid from the reservoir 120 via a hose 118. Actuating the foot lever 110 causes fluid pressure to be applied to the rear master cylinder 112 in the hose 126, which in turn causes a braking command to be transmitted to the brake control unit 124. As in the case of the hand lever 90, it is also conceivable that the foot lever 110 can be used to apply a braking command to the brake control unit 124 by applying tension to the cable. The braking command is proportional (linearly or non-linearly) to the pressure applied to the foot lever 110. When the foot lever 110 is actuated, a signal is sent to activate the brake lights.

[0075] The brake control unit 124 can receive braking commands from the front master cylinder 92 via hose 94, or from the rear master cylinder 112 via hose 126, or receive braking commands from both master cylinders 92 and 112 and apply front and / or rear braking to the ATV 9 accordingly. Figure 14 As shown above, the brake control unit 124 includes an electronic controller 156 that commands the motor 157 of the hydraulic pump 158 to direct pressure in hoses 95L, 95R, and 116. The brake control unit 124 can implement an anti-lock braking system (ABS), wherein wheel speed sensors (not shown) report the speed of each of the wheels 18 or the speed of each of the half-shafts 78 and 98 to the electronic controller 156 of the brake control unit 124. To prevent wheel 18 lock-up, the brake control unit 124 can temporarily release the pressure applied by one or both of the front caliper 84 and / or rear caliper 108 to the corresponding front disc 82 and / or rear disc 106 of wheel 18 when the wheel 18 is found to be rotating at a significantly lower speed than the other wheels 18.

[0076] The front differential 76 can be controlled to operate in either a disengaged or engaged mode. When the front differential 76 is disengaged, the ATV 9 operates in rear-wheel drive mode, and when the front differential 76 is engaged, it operates in all-wheel drive mode. Furthermore, the front differential can be selectively locked or unlocked when in engaged mode. When engaged, whether locked or unlocked, the front differential 76 receives torque from the engine 16 at its input shaft 140 via the front driveshaft 80, which is operatively connected to the gearbox 19. In turn, the front differential 76 transmits torque to the front wheels 18 via CV joint 128, the front half-shaft 78, and CV joint 88. When unlocked, the front differential 76 can send unequal torque to the two front wheels 18, allowing the left and right front wheels 18 to rotate at different speeds. When locked, the front differential 76 sends equal torque to both front wheels 18, causing them to rotate at the same speed.

[0077] Turn now Figure 6 , Figure 7A , Figure 7B as well as Figures 8A to 8C The front differential 76 is housed in a housing 136 having a cover 138, the cover 138 being in Figure 7A The upper part has been removed. The front differential 76 has an input shaft 140 operatively connected to the front drive shaft 80. The left and right output shafts 142 of the front differential 75 are operatively connected to corresponding half-shafts 78 via corresponding CV joints 128. An actuator 144 actuates a mechanical lock 146 for selectively disengaging, engaging, or engaging and locking the front differential 76. The actuator 144 has a pair of electrical connectors 148 for receiving commands to disengage, engage, or engage and lock the front differential 76. Figure 7BAs shown above, actuator 144 includes an electric motor 147 driven by integrated circuit 149, which receives commands from electrical connector 148. It is conceivable that actuator 144 could be implemented as a solenoid.

[0078] Within the front differential 76, a ring gear 300 is operatively connected to and rotates with the input shaft 140 via a gear (not shown) on the input shaft 140. The planetary gear housing 302 also rotates with the ring gear 300 and the input shaft 140. When the front differential 76 is disengaged, the left planetary gear 302L, housed in the planetary gear housing 302, is disengaged from the left output shaft 142, and no torque is transmitted to the left front wheel 18. The right planetary gear 302R is connected to the right output shaft 142, but the disengagement between the left planetary gear 302L and the left output shaft 142 results in no torque being transmitted from the front differential 76 to the right output shaft 142. The output shaft 142, the front half-shaft 78, and the front wheel 18 thus rotate independently of the input shaft 140. When the front differential 76 is engaged, torque from the input shaft 140 is transmitted to the output shaft 142 via the left planetary gear 302L and the right planetary gear 302R. As long as the front differential 76 is engaged and not locked, the left planetary gear 302L and the right planetary gear 302R can transmit torque unevenly between the left front output shaft 142 and the right front output shaft 142 according to the driving conditions of the ATV 9. When the front differential 76 is engaged and locked, the relative movement between the left output shaft 142 and the right output shaft 142 is prevented or completely eliminated.

[0079] More specifically, the mechanical lock 146 includes a rod 150 that actuates the lever 152. For example... Figure 8A As shown above, when the front differential 76 is disengaged, lever 152 is held in a first angular position by actuator 144 and rod 150 to position sleeve 154 away from ring gear 300. In this position, left planetary gear 302L is disengaged from intermediate shaft 304 connected to left output shaft 142. No torque is transmitted to intermediate shaft 304 and left output shaft 142, thereby disengaging the front differential 76. Figure 8B The diagram shows rod 150 rotated to a second angular position via actuator 144, causing rod 152 to move closer to ring gear 300 and sleeve 154. In this position, sleeve 154 connects intermediate shaft 304 to left planetary gear 302L. Depending on the torque received from the ground on each front wheel 18, torque received on input shaft 140 is transmitted by front differential 76 to one or both front wheels 18. In this position, front differential 76 is engaged but not locked. Figure 8CThe rod 150 is shown to be further rotated to a third angle position via the actuator 144. In this third position, the sleeve 154 directly engages the ring gear 300 to lock the intermediate shaft 304 to the ring gear 300, thereby locking the front differential 76.

[0080] When the differential 76 is disengaged, there is no connection between the input shaft 140 and the output shaft 142, therefore no torque is transmitted from the engine 16, CVT 17, and gearbox 19 to the output shaft 142; in this case, no torque is applied to the front wheels 18, and the ATV 9 operates in two-wheel drive mode, more specifically, rear-wheel drive mode. When the differential 76 is engaged in the unlocked state, torque is received at the input shaft 140 and transmitted to the output shaft 142; in this case, the ATV 9 operates in all-wheel drive mode. In this mode, unequal torque can be transmitted through the front differential 76 to the left and right wheels 18, which can rotate at unequal speeds depending on driving conditions. When the differential 76 is engaged in the locked state, torque is received at the input shaft 40, and equal torque is transmitted to the output shaft 142; in this case, the ATV 9 operates in all-wheel drive mode, and no speed difference is allowed between the front wheels 18.

[0081] A command from the differential lock switch 160, located on the right-hand side of the handlebars 32 and housed in the right-hand switch control housing 162, selectively disengages or engages the front differential 76. This command is received at actuator 144 and is generated by the user of the ATV 9 actuating the differential lock switch 160. A command from a controller, such as an engine control unit (ECU) 200, to change the front differential 76 between an unlocked and locked state is received at actuator 144, which converts another actuation of the differential lock switch 160 by the user of the ATV 9. (See reference...) Figure 9The right-side switch control housing 162 supports the differential lock switch 160, the throttle operator 164, and a visual display including icons 166, 168, and 170, which allows visualization of the current operating mode of the front differential 76. The throttle operator 164 is connected to the throttle body (not shown) of the engine 16 via a cable 173, which extends within a wire sheath 172. It is conceivable that the cable 173 connecting the throttle operator 164 to the throttle body could be replaced by a drive-by signal, wherein commands from the throttle operator 164 can be electronically transmitted to the throttle body. The differential lock switch 160 is connected to a connector 175 via cable 174, which extends from the right-side switch control housing 162. The connector 175 connects to another connector 176. Two wires 177 and 178 extend from connector 176. Cable 177 transmits the control signal from differential lock switch 160 directly to actuator 144 (in Figure 9 (illustrated above), and wire 178 transmits the control signal from differential lock switch 160 to ECU 200 (also shown above). Figure 9 (Illustrative diagram above). Cables 174, 177, and 178 enable the Controller Area Network (CAN) bus. Cable 179 connects the ECU 200 to other systems of the ATV 9.

[0082] The differential lock switch 160 can be placed in three different positions. Figure 10A , Figure 10B and Figure 10C The image shows the first, second, and third positions of the differential lock switch 160. The second position is between the first and third positions, and the differential lock switch 160 is biased to return to the second position when released from the third position. Thus, the driver can place the differential lock switch 160 in one of the first and second positions, and then the differential lock switch 160 remains in the position selected by the driver. If the driver presses the differential lock switch 160 to place it in the third position and then releases it, the differential lock switch 160 returns to the second position.

[0083] When the differential lock switch 160 is in the first position, it sends a disengagement command to the actuator 144 to place the front differential 76 in the disengagement mode. When the differential lock switch 160 is in the second position, it sends an engagement command to the actuator 144 to place the front differential 76 in the engagement mode. Therefore, moving the differential lock switch 160 from the first position to the second position places the front differential 76 in the engagement mode without locking it. It can be noted that the disengagement and engagement commands are sent directly from the differential lock switch 160 to the actuator 144 without passing through the ECU 200.

[0084] Moving the differential lock switch 160 from the second position to the third position selectively changes the front differential 76 between an unlocked and locked state. Assuming the third position is accessible from the second position, the front differential 76 is expected to be in an engaged mode when the differential lock switch 160 is in the third position. In the third position, the differential lock switch 160 can send a lock command or unlock command to the ECU 200, requesting that the front differential 76 be changed from an unlocked state to a locked state or vice versa. To this end, when the differential lock switch 160 is in the third position, a signal is sent from the differential lock switch 160 to the ECU 200, and the signal ends when the differential lock switch 160 is released from the third position and returns to the second position. Depending on the current state of the front differential 76, the ECU 200 converts this signal into a lock command or unlock command. In an embodiment, the ECU 200 can immediately convert the signal received when the differential lock switch 160 is in the third position into a lock command or unlock command.

[0085] Optionally, the ECU 200 may detect that the differential lock switch 160 has remained in the third position for at least a predetermined time before converting the signal into a lock or unlock command. In one embodiment, the ECU 200 sends a control signal to the actuator 144 to lock the front differential 76, which was previously in an unlocked state, or to unlock the front differential, which was previously in a locked state. In this embodiment, the ECU 200 causes the actuator 144 to change the unlocked or locked state of the front differential 76 when the differential lock switch 160 remains in the third position after a predetermined time, or once the differential lock switch 160 has been released and returned to the second position after being held for at least the predetermined time.

[0086] In another embodiment, changing the front differential 76 from an unlocked state to a locked state may be conditional. One or more additional conditions may cause the ECU 200 to delay responding to the locking command, or may completely prevent the ECU 200 from responding to the locking command. Some of these additional conditions are based on inputs provided to the ECU 200 by other components of the ATV 9. For example, Figure 11 A left-hand switch control housing 180, mounted on the left side of the handlebar 32, is shown. The left-hand switch control housing 180 supports an on / off button 182, a stop switch 184, an override button 186, and a headlight switch 190. The on / off button 182, stop switch 184, and override button 186 are operatively connected to the ECU 200 and operated by the driver of the ATV 9 to turn on the ATV 9, ignite the engine 16, enforce the maximum speed limit of the ATV 9, and disable the maximum speed limit. The headlight switch 190 controls the headlights directly or via the ECU 200.

[0087] Figure 12 This illustrates how the ECU 200 interacts with actuator 144, differential lock switch 160 held by right switch control housing 162, throttle operator 164, and icons 166, 168, 170, as well as other components of the ATV 9, to control the front differential 76. The ECU 200 and... Figure 12Some of the interactions between the other components shown above can be performed via CAN bus 216. ECU 200 is connected to differential lock switch 160, actuator 144, front differential 76, engine 16, brake control unit 124, and override button 186, all of which have been described above. ECU 200 may also be connected to: engine speed sensor 202, operatively connected to engine 16; vehicle speed sensor 204, operatively connected to at least one of front drivetrain 6 and rear drivetrain 8; throttle opening sensor 206, operatively connected to throttle operator 164, cable 173, or throttle valve (not shown) of engine 16; gearbox sensor 208, operatively connected to gearbox 19 or shifter 34; CAN bus status indicator 210, which tracks signal integrity on CAN bus 216; and steering angle sensor 212, operatively connected to steering assembly 30. In this implementation, the throttle opening sensor 206 and / or the CAN bus status indicator 210 may be implemented as software functions within the ECU 200, assuming that the information required for the ECU 200 to determine the throttle opening and the status of the CAN bus 216 may already be available within the ECU 200.

[0088] ECU 200 can also be connected to a visual display, such as cluster 214 installed in the driver's field of vision of the ATV 9, which is suitable for displaying various information elements to the driver. Alternatively or additionally, ECU 200 can be connected to icons 166, 168, and 170 on the right switch control housing 162.

[0089] The differential lock switch 160 sends a command 220 to the actuator 144 for engaging and disengaging the front differential 76. The differential lock switch 160 also sends a signal 222 to the ECU 200 as a command to lock or unlock the differential 76 when the differential lock switch 160 is in the third position. In one embodiment, signal 222 is sent once the differential lock switch 160 is in the third position, and the ECU 200 immediately interprets signal 222 as a command to engage or disengage the front differential 76. In another embodiment, signal 222 is continuously sent while the differential lock switch 160 remains in the third position, and the ECU 200 interprets signal 222 as a command to engage or disengage the front differential when the differential lock switch 160 has been in the third position for at least a predetermined time, or when the differential lock switch 160 is released after being in the third position for at least a predetermined time. In another embodiment, the differential lock switch 160 sends signal 222 only after it has been held in the third position for a predetermined time. Actuator 144 sends digital feedback information 224 to cluster 214 to allow cluster 214 to display the current state of front differential 76. When ECU 200 determines that conditions for locking or unlocking front differential 76 are met, ECU 200 sends a corresponding control signal 226 to actuator 144. In response, actuator 144 may send electronic feedback signal 228 to ECU 200 to indicate whether front differential 76 is in an unlocked or locked state. It is also conceivable that mechanical feedback may be sent from front differential 76 to ECU 200 to indicate whether front differential 76 is in an unlocked or locked state. ECU 200 may compare the information contained in electronic feedback signal 228 with the most recent control signal 226 to determine whether the most recent control signal 226 has been effectively and appropriately acted upon by actuator 144. The ECU 200 can send information 230 related to the general operation of the ATV 9 or the operation of the front differential 76 to the cluster 214. The driver can input commands on the cluster 214, which are relayed to the ECU 200 via signal 232.

[0090] When ECU 200 detects a locking command provided by differential lock switch 160, ECU 200 can check values ​​provided by one or more of the engine speed sensor 202, vehicle speed sensor 204, throttle opening sensor 206, gearbox sensor 208, CAN bus status indicator 210, and steering angle sensor 212. In some cases, ECU 200 can delay or block the transmission of control signal 226, thereby requesting the actuator to lock the front differential 76. Control signal 226 can be delayed or blocked when the engine speed reported by engine speed sensor 202 exceeds a predetermined engine speed threshold, such as 4000 RPM. Control signal 226 can also be delayed or blocked when the vehicle speed reported by vehicle speed sensor 204 exceeds a predetermined vehicle speed threshold, such as 40 km / h.

[0091] When the throttle opening reported by throttle opening sensor 206 exceeds a predetermined opening threshold, such as 30% of the throttle opening, the control signal 226 may be further delayed or blocked. The control signal 226 may also be delayed or blocked when gearbox sensor 208 indicates that CVT 17 is not in a predetermined state, such as reverse or low-speed forward gear. The ECU 200 may also delay or block the transmission of control signal 226 when the status of CAN bus 216 reported by CAN bus status indicator 210 indicates a loss of signal integrity on CAN bus 216. The ECU 200 may also delay or block the transmission of control signal 226 when the steering angle indicated by steering angle sensor 212 exceeds a predetermined angle threshold, such as 25 degrees. When none of these conditions are present, the ECU 200 provides control signal 226 to request the actuator to lock the front differential 76 to actuator 144. In this embodiment, any of the above conditions may cause the ECU 200 to abandon the request to lock the front differential 76. In another embodiment, when the conditions preventing locking no longer exist, the ECU 200 may delay the request to lock the front differential 76 and send a control signal 226 to the actuator 144, thereby requesting the actuator to lock the front differential 76.

[0092] Locking the front differential 76 allows the ECU 200 to adapt to other driving conditions of the ATV 9. For example, when the front differential 76 is engaged and locked, the ECU 200 can disable the ABS control unit 124. When the front differential 76 is engaged and locked, the ECU 200 can implement the engine speed limiting function and control the engine 16 to limit its speed. The driver can increase the engine speed limit implemented by the engine speed limiting function by pressing the override button 186. Continuously pressing the override button 186 will cause the engine speed limit to increase continuously. Instead of the override button 186, it is also conceivable to use another equivalent manual override control device. When the front differential 76 is engaged and locked, the ECU 200 can also implement the vehicle speed limiting function and control the engine 16 to limit the speed of the ATV 9 unless the driver has pressed the override button 186 to disable the vehicle speed limiting function.

[0093] The ECU 200 provides a feedback signal 234 to the right-hand switch control housing 162 regarding the current state of the front differential 76, allowing... Figure 10A , Figure 10B and Figure 10C Icons 166, 168, and 170 shown above provide the driver with visual feedback regarding the current operating mode of the front differential 76. When the current differential 76 is disengaged, icon 166 is illuminated, and the ATV 9 operates in rear-wheel drive mode. When the current differential 76 is engaged and unlocked, icon 168 is illuminated, and the ATV 9 operates in all-wheel drive mode. When the current differential 76 is engaged and locked, icon 170 is illuminated. Icon 170 may flash when the driver has requested to lock the front differential 76, while other conditions of the ATV 9 described above prevent or delay locking the front differential 76. The ECU 200 controls the illumination of icons 166, 168, and 170 based on the current state of the front differential 76. Instead of the visual display provided by icons 166, 168, and 170, or in addition to the visual display provided by icons 166, 168, and 170, ECU 200 may enable cluster 214 to display one or more icons that provide the same or equivalent information.

[0094] like Figure 13 As shown above, the ECU 200 includes a processor 240 (or multiple cooperating processors 240), which is operatively connected to a storage device 242 (or multiple cooperating storage devices 242), an input device 244, and an output device 246, allowing the ECU 200 to interact with... Figure 12The ECU 200 communicates with other components of the ATV 9 shown above. Although one input device 244 and one output device 246 are shown, the ECU 200 may include multiple input devices and multiple output devices, or be adapted to communicate with one or more input / output devices for other components of the ATV 9. The storage device 242 includes a non-transitory memory 248 that stores computer instructions that, when executed by the processor 240, allow the ECU 200 to control the locking and unlocking of the front differential 76. The storage device 240 may also store a table 250 that includes various parameters, such as a predetermined time for the third position of the differential lock switch 160, a predetermined throttle opening threshold, a predetermined state of the CVT 17, and a predetermined steering angle threshold for the steering assembly 30.

[0095] The ATV 9 includes other components such as the intake system, exhaust system, radiator, air tank, battery, starter, etc. Since it is believed that those skilled in the art will readily identify these components, further explanation and description of these components will not be provided herein.

[0096] Modifications and improvements to the above embodiments of this technology may be apparent to those skilled in the art. The foregoing description is intended to be exemplary and not restrictive. Therefore, the scope of this technology is intended to be defined only by the scope of the appended claims.

Claims

1. A controllable differential system for a vehicle, comprising: A differential, the differential having: Disconnection mode, and Joining mode, The differential can be selectively locked when in the engagement mode; Differential lock switch, the differential lock switch having: First position, Second position, and Third position, The second position is between the first position and the third position, and the differential lock switch is biased to return to the second position when released from the third position. The differential lock switch is operatively connected to the differential for: When the differential lock switch is in the first position, the differential is in the disengaged engagement mode, and When the differential lock switch is in the second position, the differential is in the engagement mode; as well as A controller, operatively connected to the differential and to the differential lock switch, is adapted to control the differential to: When the differential lock switch is in the third position, the differential is selectively changed from one of the unlocked state and the locked state to the other of the unlocked state and the locked state.

2. The controllable differential system according to claim 1, wherein, The controller is also adapted to control the differential to change from one of the unlocked state and the locked state to the other of the unlocked state and the locked state when the differential lock switch is held in the third position for a predetermined time.

3. The controllable differential system according to claim 1, wherein, The controller is also adapted to control the differential to change from one of the unlocked state and the locked state to the other of the unlocked state and the locked state when the differential lock switch is released from the third position after being held for more than a predetermined time.

4. The controllable differential system according to any one of claims 1 to 3, further comprising: An actuator electrically connected to the differential lock switch and adapted to receive from the differential lock switch commands to engage and disengage the differential, the actuator also electrically connected to the controller and adapted to receive from the controller commands to lock and unlock the differential; as well as A mechanical lock, which is adapted to be driven by the actuator to selectively engage and disengage the differential and to selectively lock and unlock the differential.

5. The controllable differential system according to claim 4, wherein: The actuator includes an electric motor driven by an integrated circuit; and The mechanical lock includes a rod driven by the electric motor and a lever driven by the rod, the lever being adapted to engage a sleeve in the differential to selectively disengage, engage, or engage and lock the differential.

6. The controllable differential system according to claim 4, wherein, The actuator is adapted to provide the controller with an electronic feedback signal of the locked state or the unlocked state.

7. The controllable differential system according to any one of claims 1 to 3, wherein, The differential is a front differential suitable for installation in the front drivetrain of the vehicle.

8. A vehicle comprising: Frame; A motor connected to the frame; The rear drivetrain is connected to the vehicle frame; A front drivetrain connected to the frame, the front drivetrain comprising a controllable differential system as described in any one of claims 1 to 7; as well as A transmission adapted to direct power from the motor to the rear drivetrain, and, when the differential is engaged, to direct power from the motor to the front drivetrain.

9. A vehicle comprising: Frame; A motor connected to the frame; The rear drivetrain is connected to the vehicle frame; A front drivetrain connected to the frame, the front drivetrain including a front differential that can be configured in one of the following modes: (i) a disengaged mode for rear-wheel drive operation of the vehicle, (ii) an engaged and unlocked mode, and (iii) an engaged and locked mode in which the vehicle can operate in all-wheel drive when the front differential is engaged. The transmission is suitable for: Power is directed from the motor to the rear drivetrain, and When the front differential engages, power is directed from the motor to the front drivetrain. A controller, operatively connected to the front differential; as well as A differential lock switch, operatively connected to the front differential and to the controller, the differential lock switch being adapted to: Provide a disengagement command to the front differential to place the front differential in the disengagement mode; Provide an engagement command to the front differential to place the front differential in the engaged and unlocked mode; A locking command is provided to the controller, which, upon receiving the locking command, selectively changes the front differential from the engaged and unlocked mode to the engaged and locked mode; as well as An unlock command is provided to the controller, and upon receiving the unlock command, the controller changes the front differential from the engaged and locked mode to the engaged and unlocked mode. The differential lock switch has the following features: First position, Second position, and Third position, The second position is located between the first position and the third position, and the differential lock switch is biased to return to the second position when released from the third position; and The differential lock switch is suitable for: When the differential lock switch is in the first position, the disengagement command is provided; The engagement command is provided when the differential lock switch moves from the first position to the second position; When the differential lock switch is in the third position and the front differential is in the engaged and unlocked mode, the differential lock switch provides the locking command; as well as When the differential lock switch is in the third position and the front differential is in the engaged and locked mode, the differential lock switch provides the unlock command.

10. The vehicle of claim 9, further comprising an actuator operatively connected to the front differential and controlled by the controller, the actuator being adapted to: Receive the disengagement command from the differential lock switch; Receive the engagement command from the differential lock switch; The locking command is received via the controller; The unlock command is received via the controller; as well as In response to receiving one of the disconnect engagement command, the engagement command, the locking command, and the unlocking command, the front differential is selectively placed in a corresponding mode of the disconnect engagement mode, the engagement and unlocking mode, and the engagement and locking mode.

11. The vehicle according to claim 9 or 10, wherein, When the differential lock switch remains in the third position for a predetermined time, the differential lock switch provides the locking command and the unlocking command.

12. The vehicle according to claim 9 or 10, further comprising: A brake control unit that implements an anti-lock braking system (ABS); The controller is also adapted to disable the ABS by the brake control unit when the front differential is in the engaged and locked mode.

13. The vehicle according to claim 9 or 10, wherein, The vehicle is an off-road vehicle selected from all-terrain vehicles and side-by-side vehicles.

14. The vehicle according to claim 9 or 10, further comprising a handlebar pivotally connected to the frame and operatively connected to the front drivetrain, wherein the differential lock switch is mounted on the handlebar.

15. The vehicle according to claim 9 or 10, further comprising: Manual overtaking control device; The controller is also adapted to control the motor to limit the speed of the vehicle when the front differential is in the engaged and locked mode and the manual overtaking control is not enabled.

16. The vehicle according to claim 9 or 10, further comprising: Manual overtaking control device; The controller is also adapted to control the motor to limit the speed of the motor when the front differential is in the engaged and locked mode and the manual overrun control device is not enabled.

17. The vehicle of claim 15, further comprising a handlebar pivotally connected to the frame and operatively connected to the front drivetrain, wherein the hand-operated overtaking control is mounted on the handlebar.

18. The vehicle of claim 16, further comprising a handlebar pivotally connected to the frame and operatively connected to the front drivetrain, wherein the hand-operated overdrive control is mounted on the handlebar.

19. The vehicle according to claim 9 or 10, further comprising: A steering assembly operatively connected to the front drivetrain; as well as A steering angle sensor, operatively connected to the steering assembly; The controller is also operatively connected to the steering angle sensor and is adapted to delay or prevent the front differential from changing from the engaged and unlocked mode to the engaged and locked mode when the steering angle indicated by the steering angle sensor exceeds a predetermined angle threshold.

20. The vehicle according to claim 9 or 10, further comprising: A vehicle speed sensor, operatively connected to one of the front drivetrain and the rear drivetrain; The controller is also operatively connected to the vehicle speed sensor and is adapted to delay or prevent the front differential from changing from the engaged and unlocked mode to the engaged and locked mode when the vehicle speed indicated by the vehicle speed sensor exceeds a predetermined angle threshold.

21. The vehicle according to claim 9 or 10, further comprising: An engine speed sensor, operatively connected to the motor; The controller is also operatively connected to the engine speed sensor and is adapted to delay or prevent the front differential from changing from the engaged and unlocked mode to the engaged and locked mode when the speed of the motor indicated by the engine speed sensor exceeds a predetermined angle threshold.

22. The vehicle according to claim 9 or 10, further comprising: A gearbox sensor, operatively connected to the transmission; The controller is also operatively connected to the gearbox sensor and is further adapted to delay or prevent the front differential from changing from the engaged and unlocked mode to the engaged and locked mode when the gearbox sensor indicates that the transmission is not in a predetermined state.

23. The vehicle according to claim 9 or 10, further comprising: A throttle valve operator, operatively connected to the throttle valve and to the motor; Throttle opening sensor; The controller is also operatively connected to the throttle opening sensor and is further adapted to delay or prevent the front differential from changing from the engaged and unlocked mode to the engaged and locked mode when the throttle opening reported by the throttle opening sensor exceeds a predetermined opening threshold.

24. The vehicle according to claim 9 or 10, further comprising: Operablely connected to the controller's Controller Area Network (CAN) bus; The indicator of the status of the CAN bus; The controller is also operatively connected to the CAN bus status indicator and is further adapted to delay or prevent the front differential from changing from the engaged and unlocked mode to the engaged and locked mode when the integrity of the CAN bus status indication signal reported by the CAN bus status indicator is lost.

25. The vehicle of claim 9 or 10, further comprising a vision display operatively connected to the controller, the controller being adapted to: When the front differential is prevented from changing from the engaged and unlocked mode to the engaged and locked mode, the visual display shows an indication; and When the change from the engaged and unlocked mode to the engaged and locked mode is delayed, the visual display shows an indication.

26. The vehicle of claim 9 or 10 further includes a visual display operatively connected to the controller and adapted to display the current disengaged mode, engaged and unlocked mode, or engaged and locked mode of the front differential.

27. The vehicle according to claim 25, wherein, The visual display includes a cluster of vehicles.

28. The vehicle according to claim 26, wherein, The visual display includes a cluster of vehicles.

29. The vehicle according to claim 25, wherein, The visual display includes an icon that appears next to the differential lock switch.

30. The vehicle according to claim 26, wherein, The visual display includes an icon that appears next to the differential lock switch.

Images