A multifunctional wheelchair

Abstract

The present invention relates to a multifunctional wheelchair, comprising a seat, a walking mechanism and a driving unit, wherein the seat comprises a deformable chair frame, an adjustable seat surface, a backrest and a front and rear telescopic adjustment support rod; the deformable chair frame comprises an upper beam, a bottom beam and front and rear columns, and the front and rear columns are respectively hinged with the upper beam and the bottom beam through a connecting shaft; the walking mechanism comprises front and rear wheels, front and rear crawler assemblies and a self-locking device for a flat-ground walking mode; the front and rear crawler assemblies rotate coaxially at the connection; a front telescopic adjustment support rod is connected between the front column and the bottom beam, a rear telescopic adjustment support rod is connected between the upper beam and the rear crawler assembly, a mode conversion joystick is connected at the adjoining part of the front column and the front and rear crawler assemblies, and a seat surface angle stabilizing regulator is connected between the mounting frame of the upper beam and the rear crawler assembly; the driving unit comprises a power unit, a speed transmission mechanism, a speed clutch mechanism and a mode conversion clutch. The present invention has the ability to walk on the ground, climb stairs and go off-road, and has good comfort and safety, and enhances the indoor and outdoor independent mobility of people with mobility difficulties, improves their quality of life, and reduces the burden of service personnel.

Description

Technical Field

[0001] The invention relates to a wheelchair, in particular to a multifunctional wheelchair. Background Art

[0002] Existing wheelchairs include ordinary push wheelchairs and electric wheelchairs that can walk on flat ground, electric wheelchairs / stair climbers that can climb stairs, high-tech fully intelligently controlled wheelchairs that can travel on flat ground and climb stairs, and full-track wheelchairs with certain complex terrain off-road capabilities.

[0003] The wheelchairs / stair climbing mechanisms currently on the market that have both the functions of walking on the ground and climbing stairs use a track mounted under the chair or behind the chair, a telescopic rod to control the mode conversion, and no automatic seat balance adjustment device. The biggest disadvantages of this type of wheelchair are:

[0004] A. To smoothly ascend and descend stairs, a healthy person must be responsible for the operation, so that when reaching the last step or descending the first step, the operator can manually ensure the smooth transition of the seat angle. Otherwise, the passenger will experience a sudden change in angle and sudden touchdown when reaching the last step.

[0005] B. From the moment the stair and stairs mode is selected, the passenger can no longer sit flat on the seat comfortably, but half-lying on the wheelchair and constantly changing the lying position to a larger angle as the passenger goes up and down the stairs and the angle of the stairs changes.

[0006] C. When going up and down stairs, the telescopic rod extends out from the front of the seat and tilts upward, and the angle is turned until the rear wheel exceeds the track height. This causes the front of the seat to be higher than the steps and the ground, and the legs of the passengers are suspended in the air. The seat is only supported by the telescopic rod, and the shaking between the steps greatly increases the sense of insecurity of the passengers.

[0007] D. Direction control cannot be performed when going up or down the stairs; the power device has a single function and the control is too simple.

[0008] In recent years, some patented technical designs have improved the seat balance and corresponding structure when climbing stairs, but comprehensive analysis still has the following problems:

[0009] A. Some seats have unstable balance structures, such as suspension type: when walking, encountering obstacles, braking or sudden changes in posture, the seat will rush forward and shake back and forth. Most of them adopt independent seat balance control, which not only increases the cost, but also increases a lot of weight and control difficulty.

[0010] B. These existing technologies require manual operation for the transition from up to down to the last step. Some of them even require stopping the vehicle first and then operating the transition mechanism, which increases the difficulty and unsafe factors of operation for the disabled and cannot achieve automatic and smooth transition.

[0011] C. These prior arts all rely on the elasticity of the crawler tracks and the design of the patterns to achieve driving on steps, which lacks safety guarantees. Summary of the invention

[0012] The technical problem to be solved by the present invention is to overcome the deficiencies of the above-mentioned prior art and provide a multifunctional wheelchair that has the ability to walk on flat ground, climb stairs and have certain complex terrain off-road capabilities. It has good comfort and safety, and can significantly enhance the ability of people with limited mobility to move independently indoors and outdoors, improve their quality of life, and reduce the burden on the personnel serving them.

[0013] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0014] A multifunctional wheelchair is designed, including a seat, a walking mechanism and a driving unit, wherein the seat includes a deformable seat frame, an adjustable seat surface and a backrest, and a front and rear telescopic adjustment support rod; wherein the deformable seat frame includes an upper beam, a bottom beam and front and rear columns arranged in pairs on the left and right, and the left and right front and rear columns are respectively hinged to the upper beam and the bottom beam through a connecting shaft;

[0015] The walking mechanism includes front and rear wheels, front and rear crawler assemblies, and a self-locking device for the flat ground walking mode; wherein the front wheel is hinged on the front column, the rear wheel is rotatably connected to the rear column, and the connection of the front and rear crawler assemblies is rotatably connected to the connecting shaft between the rear column and the bottom beam;

[0016] A front telescopic adjustment support rod is connected between the front column and the bottom beam, a rear telescopic adjustment support rod is connected between the upper beam and the rear crawler assembly, a mode conversion joystick is connected at the junction of the front column and the front and rear crawler assemblies, and a seat angle stabilization adjuster is connected between the mounting frame where the upper beam is located and the rear crawler assembly;

[0017] The driving unit comprises a power unit, a speed change transmission mechanism, a speed change clutch mechanism and a mode conversion clutch.

[0018] Preferably, in the above-mentioned multifunctional wheelchair, the rear end of the adjustable seat surface is hinged on the upper beam, and a seat surface angle adjuster is provided between the front end and the upper beam; the seat surface angle adjuster includes a mounting frame, an adjusting screw rod and a screw nut, and an adjusting hand wheel / motor; an adjustable connecting shaft is provided between the adjustable backrest and the upper beam;

[0019] It also includes a front foot pedal, on which a movable shaft, a rubber block and a rubber roller are arranged, and a shock-absorbing spring is arranged between the front foot pedal and the rubber roller; a flat-ground running shock-absorbing spring is also arranged between the bottom beam and the rear pillar, and in the flat-ground running mode, the shock-absorbing spring is in contact with the rear pillar.

[0020] Preferably, in the above multifunctional wheelchair, the axial distance between the front column and the center of the connecting axis corresponding to the upper beam and the bottom beam is greater than the axial distance between the rear column and the center of the connecting axis corresponding to the upper beam and the bottom beam, so that when the wheelchair is in the stair mode, the front of the seat is higher than the back, with a certain slope, which can encourage the occupant to lie back and move the center of gravity backward to prevent the accident of tipping forward;

[0021] The rear column is provided with a spring sheet for shock absorption. In the stair mode, the rear column portion where the spring sheet is located contacts the upper beam to provide support;

[0022] The mounting frame where the upper beam is located is equipped with a stair mode horizontal measurement and control tube; the adjustable seat surface is also equipped with a stair mode safety detection horizontal tube; the stair mode horizontal measurement and control tube and the stair mode safety detection horizontal tube are both V-shaped structures.

[0023] Preferably, in the above-mentioned multifunctional wheelchair, the self-locking device for the ground-walking mode comprises a front and rear wheel walking mode locking mechanism and a front crawler assembly reset locking mechanism; wherein the front wheel walking mode locking mechanism comprises a ground-walking locking spring and a limit locking plate, wherein the fixed end of the ground-walking locking spring is mounted on the mounting arm where the front wheel is located, and the free end of the ground-walking locking spring is plugged and matched with the limit locking plate provided on the bottom beam to realize locking and positioning;

[0024] The rear wheel walking mode locking mechanism and the front crawler assembly reset locking mechanism include a steel cable, a rear wheel flat ground mode safety lock hook, a front crawler assembly reset safety lock hook, a bottom beam and a front crawler track locking hook, a locking opening block and a locking reset spring; wherein one end of the steel cable is connected to the mode conversion joystick, and the other end thereof passes through the connecting shaft at the rear side of the bottom beam, and is successively connected to the locking reset spring, the rear wheel flat ground mode safety lock hook, and the front crawler track assembly reset safety lock hook; at the same time, the rear wheel flat ground mode safety lock hook and the front crawler track assembly reset safety lock hook are hinged on the bottom beam, the rear wheel flat ground mode safety lock hook cooperates with the boss on the rear column for locking, the front end bent hook portion of the front crawler track assembly reset safety lock hook cooperates with the front wheel axle of the front crawler track assembly, and a protrusion is provided at the rear end thereof to cooperate with the locking opening block provided on the front crawler track assembly to realize locking or opening.

[0025] Preferably, in the above-mentioned multifunctional wheelchair, the power unit is a power motor;

[0026] The speed transmission mechanism includes a clutch gearbox located on the rear column, and the clutch gearbox is provided with a stair speed fixing convex strip, an off-road speed fixing convex strip, a stair off-road mode fixing convex platform, a flat mode fixing convex platform and corresponding clutch plates and driving gears;

[0027] The speed change clutch mechanism includes a switching lever, a speed change wheel connected to the front and rear speed adjustment disks, a stair speed boss, an off-road speed adjustment boss, and a tension spring connected to the rear column to provide downward pressure for the speed change wheel;

[0028] The mode conversion clutch includes a conversion pressure column, a flat mode clutch switching movable boss, a stair / off-road mode clutch switching boss, a clutch plate mounting shaft, and a tension spring fixed on the gearbox to provide tension for switching the stair mode.

[0029] Preferably, in the above-mentioned multifunctional wheelchair, the bottom beam is provided with a manual wheelchair / electric drive selection knob, a selection cam and a top column, wherein the selection cam is rotatably connected to the bottom beam via a wheel shaft, the selection knob is embedded on the wheel shaft, the top column is embedded on the bottom beam and is located directly above the selection cam, and the surface of the selection cam is in conflict with the lower end surface of the top column;

[0030] When the wheelchair is to be pushed manually in the flat ground mode, the selection knob is in a horizontal state and the cam protrusions are on the same level. Under the action of the tension spring, the conversion pressure column and the top column are pressed down, driving the flat ground mode clutch switching boss and the flat ground mode fixed convex strip to separate, driving the corresponding clutch plate to disengage the drive gear, and realizing the hand-pushing function;

[0031] When electric drive is required, the hand-pushed wheelchair and the electric drive selection knob selection cam are rotated to a vertical state, the conversion is pressed, and the top column is lifted up, causing the flat mode clutch switching boss and the flat mode fixed convex strip to overlap, pushing the corresponding clutch plate to engage with the drive gear to realize the electric drive function.

[0032] Preferably, in the above-mentioned multifunctional wheelchair, an anti-rollover mechanism is provided at the lower end of the rear column; the anti-rollover mechanism comprises an anti-rollover bar, one end of which is provided with an anti-rollover wheel, the other end of which is provided with a flipping drive mechanism, and a stowage locking knob is provided at the end;

[0033] Among them, the flip driving mechanism includes a driving gear, a speed change gear, and a speed increasing gear, wherein the speed change gear and the driving gear are coaxially arranged, and the speed increasing gear and the speed change gear are matched and meshed for transmission; the driving gear and the gear provided by the bottom beam are matched and meshed for transmission.

[0034] Preferably, in the above-mentioned multifunctional wheelchair, the instantaneous regulator comprises a cylinder with an open end, in which an adjustment and shock-absorbing spring and a trigger magnet are installed, and a magnetically controlled Hall switch is installed on the surface of the cylinder; the closed end of the cylinder is hinged to the rear track assembly, the open end of the cylinder is slidably fitted with the end of the seat angle stabilizing regulator, and the trigger magnet is arranged between the shock-absorbing spring and the end of the rod-shaped seat angle stabilizing regulator.

[0035] Preferably, in the above-mentioned multifunctional wheelchair, the front track assembly includes inner and outer side guard plates of the front track, a front track driving gear, a front track driving pair of wheels, a rubber wheel rotating with the pair of wheels, a front track driving passive wheel, and a front track speed regulating disc;

[0036] The rear crawler assembly includes inner and outer rear crawler guard plates, rear crawler drive driven wheels and a rear crawler speed regulating disc; relative to the front and rear crawler speed regulating discs, two pairs of front and rear crawler speed regulating disc clutch separation grooves are respectively provided on the crawler guard plates;

[0037] The front and rear crawler speed regulating plates rotate with the front and rear crawler tracks. When the front crawler tracks are horizontal to the ground and the rear crawler tracks are retracted and vertical to the ground, the clutch separation grooves of one pair of speed regulating plates overlap, and the speed change wheel of the speed change clutch mechanism is stuck in the clutch separation grooves of the pair of speed regulating plates under the action of the tension spring. The stair boss and the off-road boss are driven by the switching rod to separate from the stair fixed convex strip and the off-road fixed convex strip, causing the front and rear crawler tracks to be disengaged from the drive.

[0038] When the front crawler track is horizontal to the ground and the rear crawler track is also horizontal to the ground, the other pair of clutch separation grooves of the speed regulating disc overlap, so that the stair boss is separated from the stair fixed convex strip and the off-road boss is combined with the off-road fixed convex strip to complete the off-road speed switching;

[0039] When the front and rear crawlers do not form the above conditions, the clutch separation grooves of the two pairs of speed regulating discs do not overlap, and the speed change wheel is on the outer periphery of one or both of the front and rear crawler speed regulating discs, causing the stair boss to overlap with the stair fixed convex strip and the off-road boss to separate from the off-road fixed convex strip to complete the speed switching in the stair mode;

[0040] The front end of the front crawler assembly is provided with a pair of deceleration sensors and deceleration triggering magnetic blocks, which cooperate with electrical control to provide a settable fixed safety speed when the terrain and road surface change and transition.

[0041] Preferably, in the above-mentioned multifunctional wheelchair, the front and rear track assemblies are respectively provided with front and rear auxiliary wheels; wherein, the front auxiliary wheel extension arm and the extension arm extension spring are hingedly connected to the protruding end of the front auxiliary wheel, and the front auxiliary wheel is provided with a damping spring drive block, a forced reset shaft when driving on flat ground, a front auxiliary wheel extension torsion spring, a front auxiliary wheel damping spring and a front auxiliary wheel turning angle damping limit block;

[0042] The rear auxiliary wheel comprises a driving wheel, a ground contact support wheel and a transmission belt; wherein the transmission belt is also provided with an auxiliary support wheel, and the rear auxiliary wheel is also provided with a rear auxiliary wheel rotation torsion spring, a rear auxiliary wheel adjustable damping spring, a rear auxiliary wheel independent support positioning groove, a rear auxiliary wheel retracting reset groove, a rear auxiliary wheel independent support positioning key, a damping spring starting point limit block and an in-position limit block, and the ground contact support wheel is provided with a pair of magnetic control sensors and magnetic control sensor triggering magnetic blocks, which cooperate with the circuit to provide safety alarm prompts and safety protection control;

[0043] The transmission belts of the front and rear crawler assemblies are also provided with angle-adjustable crawler auxiliary support wheels respectively.

[0044] The beneficial technical effects of the technical solution of the present invention are:

[0045] Structurally, the multifunctional wheelchair of the present invention adopts a variable chair frame structure that keeps the seat angle unchanged and allows the front and rear height positions of the wheelchair to be deformed according to different functions and driving requirements; it adopts front and rear two-section coaxial drive tracks, front and rear auxiliary wheels, pneumatic telescopic adjustment support rods, and an electric adjuster to stabilize the seat angle to achieve adaptive crossing driving on various complex road terrains; utilizing the different functional characteristics of the wheelchair itself, a mode conversion clutch and a speed change clutch mechanism are used in conjunction with the speed regulating clutch grooves on the front and rear track guard plates to automatically control the driving requirements of four speeds when driving on different roads and stairs in different modes, namely flat ground driving, stair and step driving, off-road beach driving, and step obstacle transition speed; a deceleration sensor is used to achieve a smooth transition of automatic descent without special operation, thereby improving safety.

[0046] Moreover, the present invention adopts a simple mechanical structure and a small amount of electrical control components in structure, which reduces the production cost, realizes the use function, can meet the needs of a large number of users, and is easy to promote and popularize.

[0047] In summary, the present invention greatly improves the range of motion, travel and independent self-care conditions of the disabled, the physically challenged and the elderly, improves their quality of life, reduces the burden on families and society, and has significant social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The specific embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings, wherein:

[0049] Figure 1 It is a schematic diagram of the structure of the multifunctional wheelchair of the present invention in the flat ground mode;

[0050] Figure 2 It is a schematic diagram of the structure of the multifunctional wheelchair of the present invention in the stair climbing mode;

[0051] Figure 2-1 It is a structural schematic diagram of the multifunctional wheelchair of the present invention in the transition state 1 of going up and down stairs;

[0052] Figure 2-2 It is a structural schematic diagram of the multifunctional wheelchair of the present invention in the second transition state of going up and down stairs;

[0053] Figure 3 It is a schematic diagram of the structure of the multifunctional wheelchair of the present invention in off-road mode or lying flat function;

[0054] Figure 4 It is a schematic structural diagram of the multifunctional wheelchair of the present invention in an obstacle-crossing state;

[0055] Figure 5 It is a structural schematic diagram of a speed change clutch mechanism;

[0056] Figure 6 is a schematic diagram of the structure of the mode conversion clutch;

[0057] Figure 7 It is a principle block diagram of the control part of the multifunctional wheelchair of the present invention; DETAILED DESCRIPTION

[0058] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the present invention. It is obvious that the described embodiments are only some exemplary specific implementation methods of the present invention and are not intended to limit the scope of the present invention. Any equivalent changes and modifications made by any technician in this field without departing from the concept and principle of the present invention should fall within the scope of protection of the present invention. Example

[0059] See also Figure 1-7 , Figure 2-1 In the figure, the multifunctional wheelchair of the present invention comprises a seat that is kept horizontal during normal driving (or 0-5 degrees high at the front and 0-10 degrees low at the rear), and automatically adjusted to a set angle of 5-10 degrees high at the front and 0-10 degrees low at the rear when driving on steps; a chair frame structure composed of a deformable frame with a variable height of 0-10 cm up and down and a movable height of 0-40 cm front and back; a walking mechanism in different modes composed of a front small wheel, a rear large wheel, a front crawler track, and a rear crawler track; a power motor, a clutch, and a speed transmission mechanism to meet the needs of different driving functions; an electric telescopic adjuster, a pneumatic rod, a linkage guide rod, a damping spring, a torsion spring, a reset spring, and Limit devices and other devices complete the mechanical control of different mode conversions and various driving states; the electric adjuster that stabilizes the seat angle, the pneumatic automatic telescopic rod, the rear auxiliary wheel, the instantaneous adjuster and the level detection tube complete the front and rear seat balance adjustment guarantee system when switching between different modes and on stairs with different angles and different slopes; the front and rear wheel self-locking devices, front and rear track reset locking mechanisms, anti-roll wheels, front auxiliary wheels, rear auxiliary wheels, electromagnetic brakes and automatic balancing control as well as magnetic control, light control, and micro-motion sensor switches form a safety guarantee and alarm system for smooth driving; and a monitoring and control system composed of a single-chip microcomputer, a control main board, etc.

[0060] Specifically, the axis spacing of the front column 2 from the center of the upper shaft 101 to the center of the lower shaft 205 is about 2 cm longer than the axis spacing of the rear column 3 from the center of the upper shaft 102 to the center of the lower shaft (integrated with the clutch gearbox) 402. Therefore, in the stair mode, the seat is higher in front and lower in the back, forming a 5-9 degree balance adjustment controlled at a slope of 6-8 degrees. Its function is to ensure that the seat surface can be adjusted to a horizontal position when driving in the flat mode. When driving in the stair mode, due to the weight of the person, the weight ratio of the upper body to the lower body, the different sitting postures, and the sudden change of sitting posture, the center of gravity of the seat surface may be moved forward, causing the front and rear to lose balance and cause a forward tipping accident on the steps. Therefore, when switching to the stair mode, the high front and low back slope of the seat can prompt the occupant to lie back and move the center of gravity backward to prevent this accident.

[0061] The spring sheet 301 of the rear column 3 provides a vertical force support point for the upper beam 1 of the chair frame when in stair mode, and increases the stability and shock absorption of the chair frame.

[0062] The installation angle of the horizontal measuring and controlling tube 43 should be in a horizontal state when the chair frame rotates about 22 degrees, so as to avoid that when entering the automatic balancing adjustment program, the rear trigger point 432 is too low, causing the seat angle stabilizing regulator 8 to continuously extend, causing the front end of the chair frame bottom beam 4 to touch the ground and lift the main shaft 402. The front trigger point 431 is lower than the rear point 432 at about 20 degrees to ensure that the rear crawler 30 is restored to its original position when switching from the stair mode to the flat ground mode. And after completing the mode conversion, the horizontal angle between the front end 431 and the midpoint of the horizontal tube 43 cannot be higher than 4 degrees.

[0063] The installation angle requirement of the front and rear points of the safety detection horizontal tube 42 in the stair mode is that the front point 421 is higher than the rear point, not less than 4 degrees and not more than 5 degrees. The first function is to maintain an angle greater than 1 degree when the angle of the adjustable seat surface 40 designed for the lying function and the off-road function is parallel to the upper beam of the chair frame. Secondly, when the adjustment is out of control or the sitting posture changes, the front point 421 is lower than the rear point 422, causing an alarm. The alarm not only reminds people to lie back quickly, but also interrupts the drive motor 10, which needs to be eliminated and manually restored.

[0064] Anti-rollover mechanism 16 and implementation process: At the beginning of mode conversion, the driving gear 163 integrated with the clutch and speed change acts as a moving tooth and meshes with the gear 403 fixed on the bottom beam as a stationary tooth, and the moving tooth rotates around the stationary tooth. When rotating downward, the moving tooth 163 and the coaxial speed change gear 162 rotate clockwise, and the speed increase gear 161 meshed with the speed change gear rotates counterclockwise, thereby driving the anti-rollover bar 164 fixed on the coaxial axis to rotate upward.

[0065] Front and rear tracks: The front pneumatic support rod 9, under the control of the seat angle stabilizer 8, makes the front track automatically press against the steps or the ground at various angles, thus supporting the front end of the wheelchair. The rear track 30 is mainly supported by the seat angle stabilizer 8, and the rear pneumatic support rod 17 is auxiliary supported and plays a shock-absorbing role together with the spring 123 in the instantaneous regulator. The front and rear track auxiliary support wheels 25 and 35 have the ability to adjust small angles. When the track is pressed on the step angle, the track auxiliary wheel close to the angle rotates upward due to different forces, and the other auxiliary wheel farther away rotates downward, so that an S-shaped shape is formed on the track surface, and a wrap angle appears at the top angle of the step, preventing the wheelchair from sliding down, improving the stability of the wheelchair on the steps, and protecting the top angle of the steps.

[0066] Specifically, the front auxiliary wheel: The main function is to ensure that the wheelchair will not automatically slide down from the steps under any circumstances. When the front track 20 is horizontal to the ground, the reset shaft 234 of the front auxiliary wheel 23 is pressed down by the bottom beam 4, forcing the front auxiliary wheel to be retracted above the front track without affecting its driving on flat ground, beach, grass and other terrains. When the front track rotates downward, the front auxiliary wheel is extended downward under the action of the front auxiliary wheel extension torsion spring 235. When there is no obstacle, the damping spring drive block 233 touches the starting point of the damping block and then performs corresponding actions according to the steps up or down.

[0067] Specifically, the rear auxiliary wheel: the main function is that when the wheelchair reaches the last step, the rear section of the crawler 30 will lose its support point, and the wheelchair will gradually lose balance and flip backwards. When the rear crawler shaft of the rear auxiliary wheel 32 is 15-18 cm off the ground, the rear auxiliary wheel independent support groove 326 is stuck in the rear auxiliary wheel independent support key 331 under the action of the rear auxiliary wheel extension torsion spring 325, and its ground contact support wheel 324 contacts the ground to support a smooth transition, so that the wheelchair can smoothly adapt to the change of the step. Secondly, when the wheelchair goes down the step, under the action of the rear auxiliary wheel adjustable damping spring 333, the rear auxiliary wheel and the ground contact support wheel 324 hook the step to prevent the wheelchair from sliding down, which also plays a role in smooth transition.

[0068] Specifically, the speed regulating mechanism is composed of a clutch gearbox 13 and a speed clutch mechanism 15, and front and rear track outer guard plates 21, 31 both of which are connected to one end of the main shaft 402 and have speed regulating disks 27, 37.

[0069] The speed regulating plates 27 and 37 rotate with the front and rear crawler tracks 20 and 30. When the front crawler track is horizontal to the ground and the rear crawler track is retracted and vertical to the ground, the clutch separation grooves 271 and 371 of the speed regulating plate overlap. The speed change wheel 152 of the speed change clutch mechanism 15 is stuck in the clutch separation grooves 271 and 371 of the speed regulating plate under the action of the tension spring 155. The switching rod 151 drives the stair boss 153 and the off-road boss 154 to separate from the stair fixed ridge 131 and the off-road fixed ridge 132, driving their respective clutch plates to separate, causing the front and rear crawler tracks to disengage from the drive.

[0070] When the front crawler 20 and the rear crawler 30 are horizontal to the ground, the clutch separation grooves 272 and 372 of the speed regulating plate overlap, so that the stair boss 153 separates from the stair fixed protrusion 131, driving the clutch plate to separate, and the off-road boss 154 combines with the off-road fixed protrusion 132 to push the clutch plate to engage and complete the off-road speed switching.

[0071] When the front and rear tracks do not form the above conditions, the clutch separation grooves 271, 371 and 272, 372 of the speed regulating disc will not overlap, and the speed change wheel 152 must be on the outer periphery of one or two of the front and rear speed regulating discs 27 and 37, causing the stair boss 153 to overlap with the stair fixed ridge 131 and push the clutch plate to engage, causing the off-road boss 154 to separate from the off-road fixed ridge 132, driving the clutch plate to separate and completing the speed switching in the stair mode.

[0072] Specifically, the mode conversion clutch is composed of a mode conversion clutch 14 in the clutch gearbox 13, a conversion pressure column 141 and a top column in the chair frame bottom beam 4, a hand-pushed wheelchair and an electric drive selection knob 405 selection cam 406, etc.

[0073] Flat-land driving mode: When the flat-land mode hand-pushing wheelchair is required, the selection knob is in a horizontal state, and the cam 406 protrusions are in the same horizontal state. Under the action of the tension spring 145, the conversion pressing 141 and the top column 407 are pressed down to drive the flat-land mode clutch switching boss 142 and the flat-land mode fixed protrusion 134 to separate, drive the clutch plate to disengage the drive gear, and realize the hand-pushing function. In this state, although the stair off-road mode switching boss 143 overlaps with the stair mode fixed protrusion, the off-road boss 154 in the speed clutch and mechanism, the stair boss 153 and the fixed protrusions 131 and 132 are all in a separated state. Therefore, even if the motor 10 is started by mistake, only the gears in the clutch gearbox will be idle, and no accident will occur.

[0074] When electric drive is required, the hand-pushed wheelchair and the electric drive selection knob 405 selection cam 406 are rotated to a vertical state, the conversion pressing 141 and the top column 407 are both lifted up, causing the flat mode clutch switching boss 142 and the flat mode fixed convex strip 134 to overlap, pushing the clutch plate to engage with the drive gear to realize the electric drive function.

[0075] Driving in stair or off-road mode: When in stair or off-road mode, the clutch gearbox 13 is horizontally separated from the bottom beam 4, and the conversion pressing 141 is pressed to the bottom under the action of the tension spring 145, the flat ground mode clutch conversion movable boss 142 and the flat ground mode fixed boss 134 are separated, and the stair and off-road mode clutch switching boss 143 and the stair and off-road mode fixed boss 133 overlap, so that the mode conversion clutch is in stair mode.

[0076] Specifically, the instantaneous regulator: when the last step is completed, the front and rear balance points of the wheelchair are uncertain, and the distance between the rear auxiliary wheel 32 and the ground is uncertain due to the different angles between the stair steps and the ground, and the larger the angle, the larger the distance between the rear auxiliary wheel 32 and the ground. After passing the balance point, the wheelchair will flip backwards, and the adjustment length of the seat surface and the rear track is limited by the adjustment speed of the seat surface angle stability regulator 8 and cannot be adjusted instantaneously, which causes the wheelchair to flip backwards at a large angle and cause insecurity. The function of the instantaneous regulator 12 is that when the rear track of the wheelchair loses its support point and flips backwards, the spring 123 in the regulator 12 and the rear pneumatic strut 10 quickly extend by about 1 to 3 cm to allow the rear auxiliary wheel to touch the ground in time to achieve a smooth transition and a soft landing.

[0077] Specifically, the deceleration sensor: after being triggered, the wheelchair's speed is forced to drop to 2-5cm per second, and after being triggered, it is automatically released after a delay of 10 seconds.

[0078] When used specifically, the multifunctional wheelchair of the present invention can realize the functions of at least the following three modes: A, flat ground mode; B, stair mode; C, off-road mode.

[0079] 1. Flat ground mode: The operation panel is equipped with a (flat ground) button; it has the functions of an ordinary push wheelchair and an electric wheelchair, and is suitable for driving indoors and outdoors on flat ground and small slopes.

[0080] 2. Stairs mode: The operation panel is equipped with a (Stairs) button; in this mode, the front and rear tracks change with the gradient of the steps, so that the seat always maintains a balanced state. It is suitable for independent operation of steps not exceeding 40 degrees, and with the assistance of someone, it can cope with various angles of stairs indoors and outdoors. This mode can also be used to escape from difficulties and overcome road obstacles.

[0081] 3. Off-road mode: The operation panel is set to the (off-road) button: (same as the stair mode, just manually retract the rear auxiliary wheels) In this mode, the front and rear tracks are level with the ground and automatically shift to high gear. It is mainly used for driving on beaches, grass, ice and snow, and muddy roads.

[0082] The specific mode conversion process of the present invention during driving is as follows:

[0083] 1. Conversion from flat ground to staircase mode: (combined with the attached Figure 1 , Figure 2-1 )

[0084] It is mainly completed by the mode conversion rod 7, the balance seat angle stabilization regulator 8 and the horizontal measurement and control tube 11. When the mode is converted, the rear auxiliary wheel retracting reset groove 327 needs to be pulled out from the independent support positioning key 331, otherwise (the magnetic control sensor triggers the magnetic block 329 and the magnetic control sensor 311 overlaps) an alarm is sounded and the conversion is stopped.

[0085] Conversion process: Press the stair mode operation key to start the mode conversion rod 7 to retract and the seat angle stability regulator 8 to extend. The mode conversion rod 7 retracts and pulls the steel cable 191 of the self-locking device 19, driving the rear large wheel safety lock 29 and the front crawler reset lock 28 to unlock, and the chair frame rear column 3, the chair frame upper beam 1, the rear large wheel 6, the clutch transmission 13, and the rear crawler 30 rotate backward with the main shaft 402 as the center, and at the same time drive the chair frame front column 2 and the front small wheel 5 to rotate with the front column and the bottom beam connecting shaft 205 as the center, until the mode conversion rod 7 triggers the self-contained retraction limit switch when reaching 45~50 degrees, and the conversion process ends.

[0086] The state after completing the stair mode conversion:

[0087] The conversion rod 7 retracts into place, the self-locking shock absorber 19 is pulled out, the front track safety lock 28 and the rear wheel safety lock 29 are unlocked, and the force on the spring 301 in the rear column 3 disperses and reduces the supporting force of the conversion rod 7, protects the self-locking mechanism of the conversion rod 7, and at the same time plays a shock-absorbing role in this mode.

[0088] The front crawler 20 is horizontal to the ground, the forced reset shaft 234 is forced to reset when the front auxiliary wheel 23 is traveling on flat ground, the independent support positioning groove 326 of the rear auxiliary wheel 32 is in the positioning key 311, and the rear crawler 30 has an angle of about 20 degrees with the ground.

[0089] 2. Switch from stair mode to ground mode: (combined with the attached Figure 2 , 2-2 )

[0090] Press the ground mode conversion lever 7 to extend, the wheelchair frame and related components rotate forward, and the seat angle stability regulator 8 performs automatic balance control as it changes, until the center of gravity of the seat is forward after the front and rear balance points, and the midpoint of the front point of the horizontal measurement and control tube 43 is horizontal, the rear track 30 is separated from the support point, and the horizontal measurement and control tube 43 will no longer be controlled by the extension and contraction of the seat angle stability regulator 8. When the mode is converted to about 20 degrees, the front point 431 will always be lower than the midpoint 433, so the seat angle stability regulator 8 can only retract until the limit switch 11 is triggered to stop. The mode conversion lever 7 is extended to the self-contained limit switch, the front column limit shock-absorbing rubber block is pressed, and the front small wheel 5 and the locking spring 501 are locked, and the mode conversion is completed. At this time, the spring in the self-locking shock-absorbing protection 19 is pressed back and the control cable 191 of the rear wheel and front track reset safety is released. Under the action of the locking reset spring 17, the front track safety lock 28 and the rear wheel safety lock 29 are in a safe locking state.

[0091] 3. Off-road mode conversion (combined with the attached Figure 3 ):

[0092] When the off-road mode button is pressed, the retracted reset groove 327 of the rear auxiliary wheel 32 should be manually locked in the positioning key 331, and the magnetic control sensor 311 is in the same position as the magnetic control trigger magnet 329. Otherwise, an alarm is sounded and the conversion is stopped.

[0093] 4. Lying flat function: (to prevent the front support rod from lifting and the main shaft from tilting up)

[0094] Manually lock the rear auxiliary wheel folding groove 327 of the rear auxiliary wheel 32 in the positioning key 331, so that the magnetic control sensor 311 overlaps with the magnetic control trigger magnet 329. Select the off-road mode, adjust the adjustable temporary adjustable bed surface 38 to a horizontal level or select an angle, and adjust the chair back 46 to a suitable angle. Whether in the stair mode or the off-road mode, when the passenger leaves the chair vehicle, the main shaft 402 must first be stepped on to the horizontal limit rod to lock the bottom beam 4 and the front track. (When a person leaves, the weight is reduced, and under the action of the front gas strut 9, the rear end of the front track, i.e., the main shaft, will be forced to arch upward to raise the seat surface, causing inconvenience for short people to use it again.) When using this function, the power must be turned off to prevent the wheelchair from being moved by accident.

[0095] See also Figure 1-7 and Figure 2-1 2-2, the control process during the specific driving process of the present invention is as follows:

[0096] 1. Normal driving on flat roads (see Figure 1 ): Same as ordinary electric wheelchair.

[0097] 2. Stairway driving (see Figure 2 , 2-1 , 2-2):

[0098] a. Going up the stairs: When changing on the flat ground, the independent support groove 326 of the rear auxiliary wheel is stuck in the positioning key 331, and the ground contact wheel 324 rotates in the same direction as the wheelchair driven by the transmission belt 34. When the auxiliary support wheel 323 touches the step, the rear auxiliary wheel 326 is moved out of 331. When the rear auxiliary wheel 32 encounters resistance, it rotates in the opposite direction of the wheelchair. When there is no resistance, it rotates in the same direction under the action of the rotating torsion spring 325 (this elastic force only allows the rear auxiliary wheel to extend freely and slide until the independent support positioning key 331 of the rear auxiliary wheel is stuck when there is no obstacle). Therefore, the resistance is very small when going up the stairs, and the impact is not great. After each step, the rear auxiliary wheel will be gradually pressed forward and then gradually extended backward to provide safety for the wheelchair. As the angle of the step changes, the seat surface angle stabilization regulator 8 adjusts the horizontal state of the seat surface. On the steps, the front auxiliary wheel 23 cooperates with the rear auxiliary wheel 32 to provide safety.

[0099] The conversion is completed when you lean on the steps to switch to stair mode. As long as the joystick is pulled back, the wheelchair will go up the steps.

[0100] b. Go up to the last step (see Figure 2-1): The rear crawler tracks rise gradually above the ground, and the rear auxiliary wheels extend until they are caught by the rear auxiliary wheel independent support positioning keys 331. After the balance point is passed according to the weight and sitting posture of the person, the wheelchair is smoothly transferred to the flat ground under the action of the pneumatic support rod 10 behind the instantaneous regulator 12 of the rear auxiliary wheel 32.

[0101] c. Continuous climbing stairs: Repeat steps a and b. The corner platform is large. When changing the direction of the stairs, use the joystick to change the direction just like driving on the ground. If the corner platform is small, you can retract one or both sides of the front small wheels to reduce the length of the wheelchair. If it is too small, you can switch modes to adjust the angle first and then switch the mode to stair mode.

[0102] d. When you have completed the steps, switch to the corresponding mode according to the purpose.

[0103] e. Go down the steps; (regardless of the way of going down the steps, the retracting and resetting groove 327 of the rear auxiliary wheel must be moved out of the rear auxiliary wheel independent support positioning key 331 to unlock)

[0104] After switching to stair mode, push the joystick forward to the step. When the front track passive wheel 223 approaches the edge of the step, the front track extends downward and the front auxiliary wheel 23 extends together with it under the action of the front pneumatic support rod 9. When the front track trigger magnet 211 triggers the deceleration sensor 18 to decelerate the wheelchair drive motor, if the body weight is too light, the front track will extend downward and drive the wheelchair to move forward suddenly and touch the rubber wheel 222 rotating with the opposite wheel. Since the rotation direction of 222 is opposite (clockwise), the wheelchair is forced to buffer backward (to prevent excessive forward rush) to ensure the safety of the passengers. As the wheelchair moves forward, the rear track and the seat angle stabilizing regulator 8 cooperate to make the wheelchair slowly transition to the step.

[0105] f. Safety guarantee for downward travel: Due to the structure of the front and rear tracks supporting the auxiliary wheels, which forms a wrap angle on the top angle of the step and the damping effect of the front and rear auxiliary wheels, the depression at the junction of the front and rear tracks, and the lowering and backward shifting of the center of gravity of the wheelchair, plus the safety level monitoring tube designed for this purpose, the deceleration design of the transition section provides multiple safety guarantees for the wheelchair.

[0106] g. Go down to the last step (see Figure 2-2 ): When the front track reaches the last step, the angle between the front track and the ground gradually decreases. When it reaches about 15 degrees, the extension arm 231 of the front auxiliary wheel is gradually pressed forward. When it reaches about 10 degrees, the forced reset shaft 234 touches the bottom beam. As the angle decreases, the front auxiliary wheel gradually returns to the top of the track and resets. When the rear track 30 passes the edge of the last step, the damping spring start block of the rear auxiliary wheel 32 turns the torsion of the damping spring 325 to a limit, so that the ground contact support wheel 324 of the rear auxiliary wheel can hook the step to make the rear track land slowly.

[0107] h. Continuously go down the stairs: Repeat items e and g of this paragraph.

[0108] j. Go up the stairs again: At this time, the rear auxiliary wheels have been moved backwards by 180 degrees. If the passenger is light, the wheelchair can be operated to move backwards. When the ground contact support wheels 324 touch the stairs and are blocked, the rear auxiliary wheels will arch upwards due to the angle design to reach the state of going up stairs. If the passenger is too heavy, this cannot be achieved and a new mode needs to be switched to achieve this.

[0109] 3. Off-road mode driving instructions (see Figure 3 ):

[0110] Driving on beach, grass, ice and snow, muddy roads: The conversion method of this mode is the same as that of the stair mode, but the retracted reset groove 327 of the rear auxiliary wheel needs to be pushed into the independent support positioning key 331 to lock it, otherwise the alarm will stop driving. When the front and rear tracks are horizontal to the ground, the speed regulating discs 272 and 372 overlap, the stair speed fixed convex strip 131 and the stair speed boss 153 separate, and the off-road speed fixed convex strip 132 and the off-road speed boss 154 overlap, so that the clutch transmission 15 is adjusted to the speed of the off-road mode.

[0111] The seat angle can be adjusted by the hand wheel 412 in the regulator 41. In this mode, the safety level monitoring tube 42 is closed.

[0112] 4. Ability to cross obstacles (see Figure 4 ): width not less than 60cm (can withstand the crushing of the left and right tracks), such as door sills, tree trunks, steps, curbstones and other obstacles with a height and length not exceeding 30cm. It can also cross other obstacles with a height of less than 25cm and ditches with a width not exceeding 35cm.

[0113] Obstacle crossing operation: move the rear track close to the obstacle, select the off-road mode (if the distance to the obstacle is too close, the wheelchair will automatically move forward when the mode is switched), operate the joystick to drive slowly in sequence (the process is the same as going up to the last step). When the main shaft 402 of the wheelchair is suspended, it will not sink due to the joint action of the front gas strut fixed part, the mode switching electric rod 7, the seat angle stabilizing regulator 8 and the rear telescopic adjusting rod 17. When the front track leaves the obstacle, the rubber roller 454 or rubber block 452 of the front foot pedal 45 plays a supporting role. At this time, the front track extends downward and also passes through the deceleration process of the sensor 18 and the magnetic block 211 to ensure safety. When the front track touches the foot pedal 45 and leaves the obstacle, the front end of the chair sinks and the seat angle stabilizing regulator 8 adjusts the balance, and the front and rear tracks slowly touch the ground horizontally to complete the crossing. When crossing the ditch, it is necessary to drive forward, the front track passes first, and the bottom beam and the front track locking hook 39 are stepped on and locked to prevent the front end of the track 20 from extending downward.

[0114] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Many modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A multifunctional wheelchair, comprising a seat, a walking mechanism and a driving unit, characterized in that: The chair comprises a deformable chair frame, an adjustable seat and backrest, and a front and rear telescopic adjustable support rod; wherein the deformable chair frame comprises an upper beam, a bottom beam, and front and rear columns arranged in pairs on the left and right, and the left and right front and rear columns are respectively hinged to the upper beam and the bottom beam through a connecting shaft; The walking mechanism includes front and rear wheels, front and rear crawler assemblies, and a self-locking device for the flat ground walking mode; wherein the front wheel is hinged on the front column, the rear wheel is rotatably connected to the rear column, and the connection of the front and rear crawler assemblies is rotatably connected to the connecting shaft between the rear column and the bottom beam; A front telescopic adjustment support rod is connected between the front column and the bottom beam, a rear telescopic adjustment support rod is connected between the upper beam and the rear crawler assembly, a mode conversion joystick is connected at the junction of the front column and the front and rear crawler assemblies, and a seat angle stabilization adjuster is connected between the mounting frame where the upper beam is located and the rear crawler assembly; The drive unit includes a power unit, a speed transmission mechanism, a speed clutch mechanism and a mode conversion clutch; The rear end of the adjustable seat is hinged on the upper beam, and a seat angle adjuster is provided between the front end and the upper beam; the seat angle adjuster includes a mounting frame, an adjusting screw rod and screw nut, and an adjusting hand wheel / motor; an adjustable connecting shaft is provided between the adjustable backrest and the upper beam; It also includes a front foot pedal, on which a movable shaft, a rubber block and a rubber roller are arranged, and a shock-absorbing spring is arranged between the front foot pedal and the rubber roller; a flat-ground running shock-absorbing spring is also arranged between the bottom beam and the rear pillar, and in the flat-ground running mode, the shock-absorbing spring contacts the rear pillar; The axis spacing between the front column and the upper beam and the bottom beam corresponding to the connecting axis center is greater than the axis spacing between the rear column and the upper beam and the bottom beam corresponding to the connecting axis center, so that when the wheelchair is in the stair mode, the front of the seat is higher than the back, with a certain slope, which can encourage the occupant to lie back and move the center of gravity backward to prevent the occurrence of forward rollover accidents; The rear column is provided with a spring sheet for shock absorption. In the stair mode, the rear column portion where the spring sheet is located contacts the upper beam to provide support; The mounting frame where the upper beam is located is equipped with a stair mode horizontal measurement and control tube; the adjustable seat surface is also equipped with a stair mode safety detection horizontal tube; the stair mode horizontal measurement and control tube and the stair mode safety detection horizontal tube are both V-shaped structures; The instantaneous regulator includes a cylinder with an open end, in which an adjustment and shock-absorbing spring and a trigger magnet are installed, and a magnetically controlled Hall switch is installed on the surface of the cylinder; the closed end of the cylinder is hinged on the rear track assembly, the open end of the cylinder is slidably mounted on the end of the seat angle stabilizing regulator, and the trigger magnet is arranged between the shock-absorbing spring and the end of the rod-shaped seat angle stabilizing regulator.

2. The multifunctional wheelchair according to claim 1, characterized in that: The self-locking device for the flat-ground walking mode includes front and rear wheel walking mode locking mechanisms and a front crawler assembly reset locking mechanism; wherein the front wheel walking mode locking mechanism includes a flat-ground walking locking spring and a limit locking plate, wherein the fixed end of the flat-ground walking locking spring is installed on the mounting arm where the front wheel is located, and the free end of the flat-ground walking locking spring is plugged and matched with the limit locking plate provided on the bottom beam to achieve locking and positioning; The rear wheel walking mode locking mechanism and the front crawler assembly reset locking mechanism include a steel cable, a rear wheel flat ground mode safety lock hook, a front crawler assembly reset safety lock hook, a bottom beam and a front crawler track locking hook, a locking opening block and a locking reset spring; wherein one end of the steel cable is connected to the mode conversion joystick, and the other end thereof passes through the connecting shaft at the rear side of the bottom beam, and is successively connected to the locking reset spring, the rear wheel flat ground mode safety lock hook, and the front crawler track assembly reset safety lock hook; at the same time, the rear wheel flat ground mode safety lock hook and the front crawler track assembly reset safety lock hook are hinged on the bottom beam, the rear wheel flat ground mode safety lock hook cooperates with the boss on the rear column for locking, the front end bent hook portion of the front crawler track assembly reset safety lock hook cooperates with the front wheel axle of the front crawler track assembly, and a protrusion is provided at the rear end thereof to cooperate with the locking opening block provided on the front crawler track assembly to realize locking or opening.

3. The multifunctional wheelchair according to claim 1, characterized in that: The power unit is a power motor; The speed transmission mechanism includes a clutch gearbox located on the rear column, and the clutch gearbox is provided with a stair speed fixing convex strip, an off-road speed fixing convex strip, a stair off-road mode fixing convex platform, a flat mode fixing convex platform and corresponding clutch plates and driving gears; The speed change clutch mechanism includes a switching lever, a speed change wheel connected to the front and rear speed adjustment disks, a stair speed boss, an off-road speed adjustment boss, and a tension spring connected to the rear column to provide downward pressure for the speed change wheel; The mode conversion clutch includes a conversion pressure column, a flat mode clutch switching movable boss, a stair / off-road mode clutch switching boss, a clutch plate mounting shaft, and a tension spring fixed on the gearbox to provide tension for switching the stair mode.

4. The multifunctional wheelchair according to claim 3, characterized in that: The bottom beam is provided with a manual wheelchair / electric drive selection knob, a selection cam and a top column, wherein the selection cam is rotatably connected to the bottom beam through a wheel shaft, the selection knob is embedded on the wheel shaft, and the top column is embedded on the bottom beam and located directly above the selection cam, and the surface of the selection cam is in conflict with the lower end surface of the top column; When the wheelchair is to be pushed manually in the flat ground mode, the selection knob is in a horizontal state and the cam protrusions are on the same level. Under the action of the tension spring, the conversion pressure column and the top column are pressed down, driving the flat ground mode clutch switching boss and the flat ground mode fixed convex strip to separate, driving the corresponding clutch plate to disengage the drive gear, and realizing the hand-pushing function; When electric drive is required, the hand-pushed wheelchair and the electric drive selection knob selection cam are rotated to a vertical state, the conversion is pressed, and the top column is lifted up, causing the flat ground mode clutch switching boss and the flat ground mode fixed convex strip to overlap, pushing the clutch plate to engage with the drive gear to realize the electric drive function.

5. The multifunctional wheelchair according to claim 1, characterized in that: The lower end of the rear pillar is provided with an anti-rollover mechanism; the anti-rollover mechanism includes an anti-rollover bar, one end of the anti-rollover bar is provided with an anti-rollover wheel, the other end of the anti-rollover bar is provided with a flipping drive mechanism, and a stowage locking knob is provided at the end; Among them, the flip driving mechanism includes a driving gear, a speed change gear, and a speed increasing gear, wherein the speed change gear and the driving gear are coaxially arranged, and the speed increasing gear and the speed change gear are matched and meshed for transmission; the driving gear and the gear provided by the bottom beam are matched and meshed for transmission.

6. The multifunctional wheelchair according to claim 3, characterized in that: The front crawler assembly includes inner and outer guard plates of the front crawler, a front crawler driving gear, a front crawler driving wheel pair, a rubber wheel rotating with the wheel pair, a front crawler driving driven wheel, and a front crawler speed regulating plate; The rear crawler assembly includes inner and outer rear crawler guard plates, rear crawler drive driven wheels and rear crawler speed regulating discs; relative to the front and rear crawler speed regulating discs, two pairs of front and rear crawler speed regulating disc clutch separation grooves are respectively provided on the crawler guard plates; The front and rear crawler speed regulating plates rotate with the front and rear crawler tracks. When the front crawler tracks are horizontal to the ground and the rear crawler tracks are retracted and vertical to the ground, the clutch separation grooves of one pair of speed regulating plates overlap, and the speed change wheel of the speed change clutch mechanism is stuck in the clutch separation grooves of the pair of speed regulating plates under the action of the tension spring. The stair boss and the off-road boss are driven by the switching rod to separate from the stair fixed convex strip and the off-road fixed convex strip, causing the front and rear crawler tracks to be disengaged from the drive. When the front crawler track is horizontal to the ground and the rear crawler track is also horizontal to the ground, the other pair of clutch separation grooves of the speed regulating disc overlap, so that the stair boss is separated from the stair fixed convex strip and the off-road boss is combined with the off-road fixed convex strip to complete the off-road speed switching; When the front and rear crawlers do not form the above conditions, the clutch separation grooves of the two pairs of speed regulating discs do not overlap, and the speed change wheel is on the outer periphery of one or both of the front and rear crawler speed regulating discs, causing the stair boss to overlap with the stair fixed convex strip and the off-road boss to separate from the off-road fixed convex strip to complete the speed switching in the stair mode; The front end of the front crawler assembly is provided with a pair of deceleration sensors and deceleration triggering magnetic blocks, which cooperate with electrical control to provide a settable fixed safety speed when the terrain and road surface change and transition.

7. The multifunctional wheelchair according to claim 1, characterized in that: The front track assembly and the rear track assembly are respectively provided with a front auxiliary wheel and a rear auxiliary wheel; wherein, the front auxiliary wheel extension arm and the extension arm extension spring are hinged at the extended end of the front auxiliary wheel, and the front auxiliary wheel is provided with a damping spring drive block, a forced reset shaft when driving on flat ground, a front auxiliary wheel extension torsion spring, a front auxiliary wheel damping spring and a front auxiliary wheel turning angle damping limit block; The rear auxiliary wheel comprises a driving wheel, a ground contact support wheel and a transmission belt; wherein the transmission belt is also provided with an auxiliary support wheel, the rear auxiliary wheel is also provided with a rear auxiliary wheel rotation torsion spring, a rear auxiliary wheel adjustable damping spring, a rear auxiliary wheel independent support positioning groove, a rear auxiliary wheel retracting reset groove, a rear auxiliary wheel independent support positioning key, a damping spring starting point limit block and an in-position limit block, and the ground contact support wheel is provided with a pair of magnetic control sensors and magnetic control sensor triggering magnetic blocks; The transmission belts of the front crawler assembly and the rear crawler assembly are respectively provided with angle-adjustable crawler auxiliary support wheels.

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