Steering mechanism and electric mobility

Abstract

To provide a steering mechanism that can realize a smooth spin-turn.SOLUTION: A steering mechanism is configured to steer a pair of front wheels 10 of an electric mobility, and with respect to the steering angle difference between an inner wheel steering angle, which is a steering angle of the inner ring, and an outer wheel steering angle, which is a steering angle of the outer ring, when the inner wheel steering angle is at a first angle as any angle in the range of 40° to 45°, the steering mechanism can steer the inner ring and the outer ring such that the steering angle difference when the inner ring steering angle is at a second angle as any angle in the range of 90° or more is five times or more.SELECTED DRAWING: Figure 21

Description

[Technical field]

[0001] The present invention relates to electric mobility and its steering mechanism. [Background technology]

[0002] A known steering mechanism for such electric mobility vehicles includes a pitman arm, left and right knuckles, and rods connecting the pitman arm to the left and right knuckles, see Patent Document 1, for example. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2022 / 0396309 Summary of the Invention [Problem to be solved by the invention]

[0004] The electric mobility vehicle has a steering mechanism for making pivot turns or super pivot turns, but with the configuration of the electric mobility vehicle, it is actually difficult to have the central axes of the pair of front wheels intersect with the central axes of the pair of rear wheels at the midpoint or center position between the pair of rear wheels, making it difficult to achieve smooth super pivot turns.

[0005] In view of the above circumstances, a steering mechanism capable of realizing smooth pivot turning is desired. [Means for solving the problem]

[0006] One aspect of the present invention is a steering mechanism that steers a pair of front wheels of an electric mobility vehicle, and is configured to be able to steer the inner wheel and the outer wheel so that the steering angle difference between the inner wheel steering angle and the outer wheel steering angle when the inner wheel steering angle is at a first angle that is any angle in the range of 40° to 45° is five times or more when the inner wheel steering angle is at a second angle that is any angle in the range of 90° or more. Another aspect of the present invention is a steering mechanism for steering the right and left front wheels of an electric mobility vehicle, the steering mechanism including a center shaft that is rotatable at least about a first axis extending in a vertical direction and that rotates by operating a handlebar; a pitman arm fixed to the center shaft; a right knuckle that is rotatable at least about a second axis on the right side that extends in a vertical direction and that supports the right front wheel; a right knuckle arm provided on the right knuckle; and a left knuckle that is rotatable at least about a second axis on the left side that extends in a vertical direction and that supports the left front wheel. The electric vehicle further comprises a left knuckle arm provided on the left knuckle, a right rod having one end connected to the right knuckle arm and the other end connected to the pitman arm, and a left rod having one end connected to the left knuckle arm and the other end connected to the pitman arm, wherein when the right and left front wheels are positioned at a straight-ahead steering angle for driving the electric mobility straight, each of the rods is tilted so that the difference in height between the other end and the one end is 15 mm or more, and when the steering angle of the inner wheel is 90° or more, the difference in height is 4 mm or more smaller than at the straight-ahead steering angle. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a front view of an electric mobility device according to one embodiment. [Diagram 2] FIG. 2 is a rear perspective view of the electric mobility device of the present embodiment. [Diagram 3] FIG. 2 is a side view of the electric mobility of the present embodiment. [Figure 4] FIG. 2 is a bottom view of the electric mobility of the present embodiment. [Diagram 5]FIG. 2 is a plan view of a rear wheel side vehicle body of the electric mobility device of the present embodiment. [Figure 6] FIG. 2 is a partial cross-sectional view of a rear wheel side vehicle body of the electric mobility device of the present embodiment. [Figure 7] 7 is a cross-sectional view taken along line VII-VII in FIG. 5. [Figure 8] FIG. 2 is a bottom view of the rear wheel side vehicle body of the electric mobility device of the present embodiment. [Figure 9] FIG. 2 is a perspective view of a main portion of a rear wheel side vehicle body of the electric mobility device of the present embodiment. [Figure 10] FIG. 2 is a rear view of the swing base of the electric mobility device according to the present embodiment and the swing control unit according to the first modified example. [Figure 11] FIG. 2 is a perspective view of a main part of a rear-wheel side vehicle body of the electric mobility device according to the present embodiment and a swing control unit according to a first modified example. [Figure 12] FIG. 11 is a rear view of the swing base of the electric mobility device of the present embodiment and the swing control unit of the second modified example. [Figure 13] FIG. 13 is a rear view of the swing base of the electric mobility device of the present embodiment and the swing control unit of the third modified example. [Figure 14] FIG. 13 is a rear view of the swing base of the electric mobility device of the present embodiment and the swing control unit of the fourth modified example. [Figure 15] 13 is a rear view of a swing base of a modified example of the electric mobility device of the present embodiment and a swing control unit of a fifth modified example. FIG. [Figure 16] FIG. 13 is a rear view of a swing base of another modified example of the electric mobility device of the present embodiment and a swing control unit of a sixth modified example. [Figure 17] FIG. 2 is a front view of a main part of the electric mobility device of the present embodiment. [Figure 18] FIG. 4 is a plan view showing the operation of the steering mechanism of the present embodiment. [Figure 19] FIG. 4 is a plan view showing the operation of the steering mechanism of the present embodiment. [Figure 20] FIG. 4 is a plan view showing the operation of the steering mechanism of the present embodiment. [Figure 21] FIG. 4 is a plan view showing the operation of the steering mechanism of the present embodiment. [Figure 22] FIG. 2 is an exploded perspective view of a main portion of the front wheel side frame of the present embodiment. [Figure 23] 2 is a cross-sectional view of a main portion of a front wheel side frame of the present embodiment. FIG. [Figure 24] 4 is a cross-sectional view of the angle adjustment mechanism of the present embodiment. FIG. [Diagram 25] 4 is a cross-sectional view of a main part of the angle adjustment mechanism of the present embodiment. FIG. [Figure 26] FIG. 2 is a front view of a main part of the angle adjustment mechanism of the present embodiment. [Figure 27] FIG. 2 is a cross-sectional view of a main part of the electric mobility of the present embodiment. [Figure 28] FIG. 2 is a cross-sectional view of a main part of the electric mobility of the present embodiment. [Figure 29] FIG. 2 is a side view of the electric mobility device in a stored state according to the present embodiment. [Diagram 30] FIG. 2 is a block diagram of a control unit for the electric mobility device of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] An electric mobility device 1 according to an embodiment of the present invention will be described below with reference to the drawings. As shown in Figs. 1 to 4, this electric mobility 1 has a mobility body 30. The mobility body 30 has a pair of front wheels 10, a pair of rear wheels 20, and a body 31 supported by the front wheels 10 and the rear wheels 20. This electric mobility 1 also has a seat unit 40 detachably attached to the mobility body 30. The electric mobility 1 of this embodiment is one in which one person sits on the seat unit 40. Such a vehicle may be called a personal mobility vehicle. In the following description, the vehicle front-rear direction may be simply described as the front-rear direction, and the vehicle width direction may be simply described as the width direction. Furthermore, the vehicle front-rear direction and the mobility body 30 or the body 31 are aligned, and the vehicle width direction and the mobility body 30 or the body 31 are aligned. Furthermore, the following description is basically given of the electric mobility 1 placed on a horizontal plane in an unloaded state or in a state in which a predetermined load is applied. An example of a state in which a predetermined load is applied is a state in which an object or person of the permissible weight of the electric mobility 1, or an object or person of ⅔ the permissible load, is placed on the seat unit 40.

[0009] 6 and 7, in this embodiment, an output shaft 51 of a motor 50 is connected to each of a pair of rear wheels 20, and each of the motors 50 can drive the two rear wheels 20. In this embodiment, the output shaft 51 of the motor 50 functions as the axle of the rear wheels 20. However, the driving force of the motor 50 may be configured to be transmitted to the pair of front wheels 10 via a power transmission member such as a belt, a gear, a shaft, or the axle of the rear wheels 20.

[0010] Each front wheel 10 is supported by a body 31. In this embodiment, the pair of front wheels 10 includes an axle 11, a hub 12 attached to the axle 11, and an outer peripheral member 13 provided on the outer periphery of the hub 12 and having an outer periphery made of a material having rubber-like elasticity such as rubber or silicone. The front wheels 10 are configured to be rotatable by bearings such as bearings (not shown).

[0011] In this embodiment, each rear wheel 20 has an axle, such as the output shaft 51 of the motor 50, a hub 22 attached to the axle, and an outer circumferential member 23 provided on the outer periphery of the hub 22, the outer circumferential surface of which is formed from a material having rubber-like elasticity, such as rubber or silicone.

[0012] In this embodiment, the front wheel 10 and the rear wheel 20 may be pneumatic tires, or may be solid tires formed from a material having rubber-like elasticity even to the inside.

[0013] The mobility body 30 has a front-wheel side body 110 and a rear-wheel side body 120 detachably connected to the front-wheel side body 110. The front-wheel side body 110 has a front-wheel side frame (body frame) 111 formed so that the front end side extends along the ground, and to which the axle of the front wheel 10 is attached via a front-wheel suspension 160. The rear end side of the front-wheel side frame 111 is a vertical frame 111a extending upward, and the seat unit 40 is attached to the upper end side of the vertical frame 111a. As shown in FIG. 1, the front-wheel suspension 160 has a base 172 that supports the pair of front wheels 10 at both ends in the vehicle width direction via knuckles 173, 174, and a pair of springs 161 attached to the base 172. The base 172 supports the front-wheel side frame (body frame) 111 via the pair of springs 161. In addition, the front-wheel side body 110 has a front-wheel side cover 110a, which is arranged to cover at least a portion of the front-wheel side frame 111 and is used to protect the front-wheel side frame 111, as a portion for the feet of a passenger sitting in the seat unit 40, as a luggage carrying area, a mudguard, etc.

[0014] The front wheel side frame 111 is made of a material suitable for obtaining strength, such as metal.

[0015] 2, 4, etc., the rear-wheel-side body 120 has a rear-wheel-side frame (body frame) 121 and a rear-wheel-side cover 120a that is provided to cover at least a portion of the rear-wheel-side frame 121 and is used to protect the rear-wheel-side frame 121, as a mudguard, etc. The front-wheel-side frame 111 and the rear-wheel-side frame 121 form the entire body frame of the mobility main body 30.

[0016] The rear wheel side frame 121 is made of a material suitable for obtaining strength, such as metal.

[0017] As shown in FIG. 2 and other figures, the rear wheel side frame 121 is provided with a pair of anti-toppling members 126 in a detachable manner in the width direction to prevent the electric mobility 1 from tipping backward.

[0018] As shown in FIGS. 2, 3, 5, etc., a rechargeable battery BA is detachably attached to the rear wheel side body 120.

[0019] The seat unit 40 has a seat surface portion 41 on which a passenger sits, and a backrest portion 42. A center shaft 171 is rotatably attached to the front end side of the front wheel side frame 111, and a handle shaft 181 is attached to the upper end of the center shaft 171 so as to be swingable in the front-rear direction. The handle shaft 181 can be fixed to an upper swing position shown in Figs. 1 to 3 etc. by an angle adjustment mechanism described later, and can swing to a lower swing position shown in Fig. 29. A handle 180 is fixed to the upper end of the handle shaft 181, and the handle includes a first operating unit 180a and a second operating unit 180b, each of which is an operating lever, a button, etc. A rider can displace the operating units 180a, 180b toward the rear of the vehicle.

[0020] When the handle shaft 181 is not in a rotation position for making a pivot turn, described below, if the operation unit 180a is operated, the control device 80, described below, rotates the pair of rear wheels 20 in the forward direction by both motors 50. Also, when the handle shaft 181 is not in a rotation position for making a pivot turn, if the operation unit 180b is operated, the control device 80 rotates the pair of rear wheels 20 in the backward direction by both motors 50. When the handle shaft 181 is in a rotation position for making a pivot turn, if the operation unit 180a or 180b is operated, the control device 80, described below, rotates the pair of rear wheels 20 in opposite directions by both motors 50. It is also possible for the control device 80 to drive the electric mobility 1 in an automatic manner based on a program, without the rider operating the handlebars 180, the operation units 180a, 180b, etc.

[0021] A signal corresponding to the amount of displacement of the operating portions 180a and 180b is transmitted to a control unit 60, which will be described later, and each of the motors 50 is driven in response to the signal.

[0022] As shown in FIG. 30, the control unit 60 has a motor driver 70 that drives each motor 50, and a control device 80.

[0023] The control device 80 includes a processor 81 having, for example, a CPU, a RAM, etc., a storage device 82 having a non-volatile memory, a ROM, etc., and a transmitter / receiver 83. A program for controlling the electric mobility 1 is stored in the storage device 82, and the processor 81 operates based on the program and transmits drive signals for driving each motor 50 to the motor driver 70.

[0024] Each rear wheel 20 is attached to the rear-wheel-side vehicle body 120 via a rear-wheel suspension. As shown in FIG. 7, each rear-wheel suspension has a swing base 131 and a spring 140 made of a metal such as steel. The swing base 131 is formed using a material suitable for obtaining strength, such as aluminum or other metal materials. A part of the swing base 131 may be made of plastic. The electric mobility 1 of this embodiment has a swing unit 2 including the swing base 131 and a motor 50 fixed to the swing base 131. The swing unit 2 is a part that swings together with the swing base 131, and the swing unit 2 may further have other configurations.

[0025] The base end side of the oscillating base 131 is attached to the rear-wheel side frame 121 of the rear-wheel side body 120 so as to be able to oscillate in the vertical direction, and when the oscillating base 131 oscillates, the tip of the oscillating base 131 moves in the vertical direction. The base end side of the oscillating base 131 is disposed on the center side in the width direction of the lower surface of the rear-wheel side frame 121, and the tip portion of the oscillating base 131 is disposed outside in the width direction of the rear-wheel side frame 121. In this embodiment, the base end, base end portion, and base end side of the oscillating part 2 are the base end, base end portion, and base end side of the oscillating base 131, and the tip, tip portion, and tip side of the oscillating part 2 are the tip, tip portion, and tip side of the oscillating base 131.

[0026] More specifically, a pair of shaft support parts are provided on the lower surface of the rear wheel side frame 121, and each shaft support part is provided with a through hole extending in the front-rear direction. Meanwhile, as shown in Fig. 4, a shaft 150 extending in the front-rear direction is fixed to the base end side of the swing base 131.

[0027] A bearing such as a plain bearing is provided between the shaft 150 and the shaft support portion.

[0028] With the above-mentioned configuration, the oscillating base 131 oscillates around an oscillating axis 150a (FIGS. 4, 7, etc.) which is the central axis of the shaft 150. Alternatively, a shaft support portion may be provided on the base end side of the oscillating base 131 , and the shaft 150 may be fixed to the lower surface of the rear wheel side frame 121 .

[0029] As shown in Fig. 6 and Fig. 7, a rear wheel support member 132 is provided at the tip of the oscillating base 131. The rear wheel support member 132 is a member provided at the tip of the oscillating base 131. In this embodiment, the oscillating base 131 and the rear wheel support member 132 are integrally formed by performing press processing (bending, cutting, etc.), welding, etc. on a steel plate. When the rear wheel support member 132 is fixed to the oscillating base 131, the rear wheel support member 132 is a part of the oscillating base 131. As shown in Fig. 6 and Fig. 7, the rear wheel support member 132 extends upward from the tip of the oscillating base 131, and in this embodiment, a housing of the motor 50 is fixed to the rear wheel support member 132 by a plurality of bolts.

[0030] The hub 22 of the rear wheel 20 is fixed to the output shaft 51 of the motor 50. As a result, the motor 50 and the rear wheel 20 are supported at the tip of the swing base 131. In other words, the rear wheel support member 132 supports the rear wheel 20 on the oscillating base 131 via the motor 50. Other mechanical elements such as bearings, axles, other members, etc. may be fixed to the rear wheel support member 132, and the rear wheel support member 132 may support the rear wheel 20 via the other mechanical elements, axles, other members, etc. There may also be cases where the housing of the motor 50 is fixed to the tip, middle, or other portion of the oscillating base 131. In this case, even if the rear wheel support member 132 is not provided, the rear wheel 20 is supported by the oscillating base 131 via the motor 50. Also, other mechanical elements such as bearings, axles, other members, etc. may be fixed to the tip of the oscillating base 131, and the tip of the oscillating base 131 may support the rear wheel 20 via the other mechanical elements, axles, other members, etc. In either case, the rear wheel 20 is disposed on the tip side of the oscillating base 131 and is supported by the oscillating base 131 so as to move up and down together with the tip side of the oscillating base 131.

[0031] 7, stopper portions 128a and 128b are provided on the underside of the rear-wheel side frame 121, and when the tip end of the oscillating base 131 moves downward, the base end of the oscillating base 131 abuts against the rear-wheel side frame 121 from below via the stopper portion 128a. This position is the lower limit swing position of the oscillating base 131. On the other hand, when the tip end of the oscillating base 131 moves upward, the base end of the oscillating base 131 abuts against the rear wheel side frame 121 from below via the stopper portion 128b.

[0032] Incidentally, even if the tip end of the oscillating base 131 swings downward, the base end of the oscillating base 131 may not come into contact with the rear wheel side frame 121 or the like, and the downward or upward swing of the oscillating base 131 may be stopped by the force of the spring 140. In this case, the position where the downward or upward swing of the oscillating base 131 stops due to the support of the spring 140 becomes the lower limit swing position or the upper limit swing position.

[0033] The rear wheel width W1 (FIG. 7), which is the widthwise distance between the outer end of one rear wheel 20 and the outer end of the other rear wheel 20, is, for example, 450 to 650 mm. In this embodiment, the rear wheel width W1 is 530 to 550 mm. In contrast, the support shaft width W2 (FIG. 7), which is the widthwise distance between one oscillation axis 150a and the other oscillation axis 150a, is, for example, 50 to 200 mm. In this embodiment, the support shaft width W2 is 120 to 130 mm or less.

[0034] In this embodiment, the distance from the swing axis 150a to the outer end of the rear wheel 20 is about 210 mm, and when the swing base 131 swings from the upper limit swing position to the lower limit swing position, the rear wheel 20 moves up and down by 25 mm or more. To improve passenger comfort, it is preferable that the rear wheel 20 is configured to move up and down relative to the body frame by 15 mm or more, and more preferably by 20 mm or more, but it is not limited to these numerical values ​​as long as the required suspension function is realized.

[0035] 6, one end of a spring 140 is attached to the tip of the oscillating base 131. In this embodiment, one end of the spring 140 is attached to the tip of the oscillating base 131 via a rear wheel support member 132. Note that one end of the spring 140 may be attached to another part of the oscillating base 131.

[0036] On the other hand, the other end of the spring 140 is attached to the rear wheel side frame 121 .

[0037] In this embodiment, the angle that the extension direction of the spring 140 forms with the width horizontal line is 20° or less. In one example, the width horizontal line is parallel to a line passing through the center point of the axle of one rear wheel 20 and the center point of the axle of the other rear wheel 20. In another example, the width horizontal line is parallel to a line passing through the radial center point of the axle of one front wheel 10 and the center point of the axle of the other front wheel 10.

[0038] In one example, the extension direction of the spring 140 is a straight line passing through the radial center of one end of the spring 140 and the radial center of the other end. For example, the angle is set in the range of 5° to 20°. If the angle is 50° or less, there is a possibility that the same function as when the angle is 20° will be achieved.

[0039] It is also preferred to use a known non-linear spring as spring 140. One example of a non-linear spring has a winding pitch that is different at one end of the spring than at the other, which results in a higher spring rate as the spring is compressed than as it begins to compress. Other types of non-linear springs may also be used.

[0040] In this manner, in this embodiment, the spring 140 extends in the vehicle width direction and also extends obliquely downward from the inside to the outside in the vehicle width direction.

[0041] When a force is applied to each rear wheel 20 from below and each rear wheel 20 moves upward relative to the rear wheel side frame 121, each spring 140 is compressed. At this time, since the springs 140 are arranged as described above, the ratio of the horizontal force component to the vertical force component in the force applied from the other end of each spring 140 to the rear wheel side frame 121 becomes large. In other words, it becomes difficult for the vertical force to be transmitted from each spring 140 to the rear wheel side frame 121. It is also possible to further provide a damper arranged in parallel with the spring 140. In one example, a known damper such as an oil damper may be arranged in the spring 140. In another example, instead of the spring (biasing member) 140, another biasing member such as an air cylinder may be provided. In this case, a biasing system can be configured having an air cylinder capable of supplying air to the base end side and the tip end side of the cylinder portion, a pump that supplies air to the cylinder portion, electronic control valves provided on the base end side and the tip end side of the cylinder portion, and a control device. By controlling the pump and the electronically controlled valve with the control device, it is possible to realize an appropriate suspension function according to the weight of the rider. The biasing member may be any member that can apply a downward force to the rocking part 2 when the tip side of the rocking part 2 moves upward.

[0042] The electric mobility 1 is required to be small, lightweight, have a simple structure, be durable, etc. For this reason, the space available for arranging the suspension, springs, dampers, etc. is relatively small, and it is often not possible to make the suspension, springs, dampers, etc. large. The above configuration is useful for effectively cushioning the downward force applied to the rear wheel 20 in a limited space. The force from below includes the force that the rear wheel 20 receives from the ground when a passenger sits on the seat unit 40, and the force that the rear wheel 20 receives from unevenness in the ground when the electric mobility 1 is traveling.

[0043] In this embodiment, the oscillating base 131 of the oscillating unit 2 extends from the oscillating axis 150a outward in the vehicle width direction, and also extends from the oscillating axis 150a in a substantially horizontal direction. In this embodiment, when the angle that the extending direction of the oscillating base 131 or the oscillating unit 2 in the vehicle width direction forms with the horizontal direction is 35° or less, it can be said that the oscillating base 131 extends from the oscillating axis 150a in a substantially horizontal direction. The angle is preferably 25° or less, more preferably 10° or less, and even more preferably 5° or less.

[0044] In one example, the extension direction of the oscillating base 131 (oscillating section 2) is a direction passing through the centroid of the cross section of the base end of the oscillating base 131 and the centroid of the cross section of the tip end of the oscillating base 131. The cross section is a cross section cut by a plane extending in the front-rear direction and the up-down direction of the vehicle. In another example, the extension direction of the oscillating base 131 is a direction in which the lower surface or the upper surface of the oscillating base 131 substantially extends.

[0045] In this embodiment, when no passenger is seated on the seat unit 40, the rocking base 131 extends slightly downward from the rocking axis 150a relative to the horizontal direction. When a passenger sits on the seat unit 40, the rocking base 131 rocks upward against the reaction force of the spring 140, and the rocking base 131 extends slightly upward from the rocking axis 150a relative to the horizontal direction. When the passenger is light, the rocking base 131 extends horizontally from the rocking axis 150a or slightly downward from the horizontal direction.

[0046] In this state, one end of the spring 140 is attached to the tip of the rocking base 131 via the rear wheel support member 132, and the spring 140 extends in the vehicle width direction as described above. Therefore, as the rocking position of the rocking base 131 approaches the upper limit rocking position, the compression amount of the spring 140 per unit rocking amount of the rocking base 131 increases. With this configuration, when a light passenger is on the vehicle, the compression amount of the spring 140 per unit rocking amount of the rocking base 131 becomes smaller than when a heavy passenger is on the vehicle.

[0047] Alternatively, spring 140 may be a non-linear spring whose spring rate increases as compression progresses. In one example, spring 140 is a non-linear spring whose spring rate after the increase is 1.3 times or more, and preferably 1.5 times or more, of the spring rate before the increase. In other words, the spring rate of the entire rear wheel suspension changes in response to the weight of the rider. Note that the effect of changing the spring rate of the entire rear wheel suspension in response to the weight of the rider can be obtained simply by using spring 140 as a non-linear spring.

[0048] In this way, the spring rate of the entire rear wheel suspension changes according to the weight of the rider, so that excessive rocking of the rocking base 131 is prevented when a heavy rider rides on the vehicle. This configuration that provides a spring rate according to the rider's weight not only reduces vibrations but also protects each frame of the mobility body 30. Furthermore, when the electric mobility 1 turns or turns, a large force is applied to one spring 140 of the pair of rear wheels 20. Here, the spring rate of the spring 140 becomes high when a large force is applied. For example, when the electric mobility 1 is stationary or moving straight with a light rider on board, the spring rate has not yet become high, but when the electric mobility 1 turns or turns, the spring rate of the outer rear wheel suspension becomes high. This suppresses the roll angle when turning or turning, stabilizing the posture of the electric mobility 1 and the rider.

[0049] In addition, in this embodiment, a swing control unit 3 is provided which suppresses or restricts the different vertical movements of the base ends of a pair of swing parts 2, thereby preventing the tip side of one of the pair of swing parts 2 from becoming higher than the tip side of the other, or restricts it to a predetermined range. 9 and other figures, the swing control unit 3 of this embodiment has a first member 310 and a second member 320 made of metal, hard plastic, or the like. More preferably, the first member 310 and the second member 320 are formed of a spring material such as stainless steel or spring steel used in the manufacture of springs such as coil springs.

[0050] The first member 310 has a main body 310a fixed to the base end of one (right side) of a pair of oscillating bases 131 by a bolt or the like, and the second member 320 has a main body 320a fixed to the base end of the other (left side) of the pair of oscillating bases 131 by a bolt or the like. The first member 310 has a plurality of upper contact portions 311 arranged at intervals from each other in the vehicle front-rear direction, and a plurality of lower contact portions 312 arranged at intervals from each other in the vehicle front-rear direction.

[0051] In this embodiment, each of the contact portions 311, 312 extends from the main body 310a toward the inside in the vehicle width direction, and each of the contact portions 311, 312 is fixed to the main body 310a. Alternatively, each of the contact portions 311, 312 is formed integrally with the main body 310a. As shown in Figures 8 and 9, the multiple upper contact portions 311 and the multiple lower contact portions 312 are arranged alternately in the vehicle front-rear direction. The multiple upper contact portions 311 are disposed above the multiple lower contact portions 312.

[0052] The second member 320 also has a plurality of upper contact portions 321 arranged at intervals from each other in the vehicle front-rear direction, and a plurality of lower contact portions 322 arranged at intervals from each other in the vehicle front-rear direction. Further, each of the contact portions 321, 322 extends from the main body 320a toward the inside in the vehicle width direction, and each of the contact portions 321, 322 is fixed to the main body 320a. Alternatively, each of the contact portions 321, 322 is formed integrally with the main body 320a. As shown in Figures 8 and 9, the upper contact portions 321 and the lower contact portions 322 are arranged alternately in the vehicle front-rear direction. The upper contact portions 321 are disposed above the lower contact portions 322.

[0053] The first member 310 and the second member 320 are fixed to a pair of swing bases 131 so that the upper contact parts 311 of the first member 310 and the lower contact parts 322 of the second member 320 are aligned in the vertical direction, and the lower contact parts 312 of the first member 310 and the upper contact parts 321 of the second member 320 are aligned in the vertical direction (FIG. 9). When the left and right rear wheels 20 that can move in the vertical direction are arranged at the same height position with respect to the vehicle body frame as described above, that is, when the tip sides of the pair of swing bases 131 (swinging parts 2) are arranged at the same height position with respect to the vehicle body frame, the first member 310 and the second member 320 do not come into contact with each other, or the first member 310 and the second member 320 are lightly in contact with each other without engaging with each other in the vertical direction. The tip side of the swing base 131 (swinging part 2) is, for example, a specific part at the tip of the swing base 131.

[0054] Here, the height position can be measured relative to a reference plane (reference height position) based on a reference element, a reference shape, a reference position, etc. of the rear-wheel-side body 120. The reference element is, for example, a part or all of the underside of the rear-wheel-side frame 121 in the body frame, a pair of tip-over prevention members 126, their central axes, etc. The reference shape is, for example, a single or multiple shapes that are characteristic of the rear-wheel-side frame 121. The reference position is, for example, the height position of the specific part of the rear wheel 20 or the oscillating base 131 relative to the body frame, measured with the electric mobility 1 at rest with no load.

[0055] For example, in the case of a reference element, a reference plane (reference height position) can be set based on a single or multiple grooves, protrusions, flat surfaces, etc. extending horizontally in the vehicle width direction on the underside of the rear-wheel side frame 121, or holes, grooves, protrusions, flat surfaces, etc. aligned in the vehicle width direction on the underside of the rear-wheel side frame 121. The reference shape and reference position can be set in a similar manner.

[0056] When the electric mobility 1 makes a turn, centrifugal force acts on the electric mobility 1, and a large load may be applied to the rear wheel 20 on the outside of the turn, out of the pair of rear wheels 20. In this case, the electric mobility 1 may tilt toward the outside of the turn, as shown by the arrow in FIG. 3. This behavior may also be called rolling. This tilting behavior may also be caused by a passenger putting their weight on one side in the width direction of the vehicle. For example, a passenger sitting on a stopped electric mobility 1 may put their weight on one side in the width direction of the vehicle to pick up an item next to the electric mobility 1.

[0057] This tilting behavior also occurs when a passenger puts their weight on one side in the vehicle width direction while standing on the footrest. As mentioned above, when a soft rear wheel suspension is used to improve passenger comfort, this leaning behavior is more likely to occur. This tilting behavior can also be said to be a rotational behavior about an axis extending in the front-rear direction of the vehicle.

[0058] In this embodiment, the tilting behavior causes the height position of one of the pair of oscillating parts 2 to be higher than the height position of the tip side of the other oscillating part 2. For example, when the difference between the two height positions becomes a predetermined difference of 10 mm, the upper contact parts 311 and the lower contact parts 322 come into contact in the vertical direction. At this time, in this embodiment, the lower contact parts 312 of the first member 310 and the upper contact parts 321 of the second member 320 also come into contact in the vertical direction. This contact restricts the vertical movement of the first member 310 and the second member 320 relative to each other. In other words, the difference between the height position of one of the pair of oscillating parts 2 and the height position of the tip side of the other oscillating part 2 is suppressed or restricted from exceeding the predetermined difference. More specifically, the difference between the height position of one of the pair of oscillating parts 2 and the height position of the tip side of the other oscillating part 2 is restricted to a predetermined range of 10 mm.

[0059] The predetermined range can be set appropriately. Specific values ​​vary depending on factors such as the size of the electric mobility 1, but for example, if the predetermined range is set to a relatively small range of 2 to 10 mm, the electric mobility 1 will be less likely to roll. If the predetermined range is set to a relatively large range exceeding 10 mm, the degree of freedom in tilting the electric mobility 1 when turning will be increased.

[0060] This configuration makes it possible to reduce the tilting behavior while realizing a soft rear wheel suspension for improving passenger comfort as described above. This leads to improved driving performance of the electric mobility 1 and further improved passenger comfort. In addition, when the first member 310 and the second member 320 are formed using a spring material as described above, a configuration can be adopted in which, when the upper contact portion 311 and the lower contact portion 322 come into contact with each other in the vertical direction, the upper contact portion 311 and / or the lower contact portion 322 can deform within a range of elastic deformation according to the force applied in the vertical direction to the contact portion. In this case, for example, a force of 500N, 1000N, etc. is applied to the contact portion in the vertical direction, and the tip of the upper contact portion 311 and / or the tip of the lower contact portion 322 can displace in the vertical direction by 0.3mm or more, 0.5mm or more, or 1mm or more. With this configuration, it is expected that the restriction of the displacement of the oscillating portion 2 becomes softer, and the members 310, 320 become less likely to wear out (become less likely to permanently deform).

[0061] Alternatively, a single upper contact portion 311 and a single lower contact portion 312 may be provided on the first member 310, and a single upper contact portion 321 and a single lower contact portion 322 may be provided on the second member 320. Even in this case, the above-described advantageous effects can be similarly achieved.

[0062] Also, for example, it is possible to omit the second member 320 and achieve the above effect using only the first member 310. In this case, a part of the base end of one oscillating base 131 is disposed below a plurality of upper contact parts 311 of the first member 310 fixed to the base end of the other oscillating base 131. Also, a part of the base end of the other oscillating base 131 is disposed above a plurality of lower contact parts 312 of the first member 310. When the part of the base end functions in the same manner as the second member 320, the above effect is achieved.

[0063] A part or the whole of the first member 310 and the second member 320 can be part of the base end of the oscillating base 131. For example, the upper contact portion 311 and the lower contact portion 312 may be integrally provided on the base end side of one oscillating base 131, and the upper contact portion 322 and the lower contact portion 322 may be integrally provided on the base end side of the other oscillating base 131.

[0064] Alternatively, a hole or a notch may be formed on the base end side of one of the oscillating bases 131, and a protrusion inserted into the hole or notch may be formed on the base end side of the other oscillating base 131. The upper end surface of the hole or notch functions as an upper contact portion that contacts the protrusion from above, and the lower end surface of the hole or notch functions as a lower contact portion that contacts the protrusion from below.

[0065] As described above, in order to regulate different directional swinging in which one of the base ends of a pair of oscillating parts 2 swings in a different vertical direction relative to the other, it is sufficient that the base end side of at least one of the oscillating parts 2 is provided with an upper contact portion that contacts the base end side of the other oscillating part 2 from above and a lower contact portion that contacts it from below.

[0066] It is also possible to use a swing control section 4 shown in FIGS. 10 and 11 in place of the swing control section 3 of this embodiment. The swing control unit 4 has a connection member 400 in which a first fixing part 410 is fixed to the base end side of one of the pair of swing bases 131 by a bolt or the like and a second fixing part 420 is fixed to the base end side of the other of the pair of swing bases 131 by a bolt or the like. The swing control unit 4 may have other members in addition to the connection member 400.

[0067] The connecting member 400 has a force generating portion 430 made of metal, hard plastic, or the like that connects the first fixed portion 410 and the second fixed portion 420, and the force generating portion 430 has an elastically deformable shape. One end of the force generating portion 430 is a connecting portion with the first fixed portion 410, and the other end of the force generating portion 430 is a connecting portion with the second fixed portion 420.

[0068] An example of an elastically deformable shape is a shape disposed over a range of 170° or more around axis 431 extending in the vehicle front-rear direction, as shown in Fig. 10. Axis 431 is disposed within a range surrounded by force generating unit 430, and extends in the vehicle front-rear direction. For this reason, the elastically deformable shape is usually a shape disposed over a range of 180° or more around axis 430.

[0069] The cross-sectional shape of the force generating unit 430 may be, for example, a shape consisting of a single arc, a shape made by connecting multiple arcs, a shape made by connecting a single or multiple arcs with a single or multiple straight lines, a shape obtained by removing some sides of a polygon, or the like. The cross-sectional shape is a cross-sectional shape cut by a plane perpendicular to the vehicle longitudinal direction. Some or all of the arcs may be arcs having a center of curvature outside the force generating unit 430. The force generating unit 430 in FIG. 10 has a cross-sectional shape made by connecting multiple arcs. Moreover, the force generating unit 440 in FIG. 12, which is a swing control unit 4' of a modified example, has a cross-sectional shape made by connecting multiple arcs having a center of curvature outside the force generating unit 440.

[0070] Since the force generating units 430, 440 have the above-mentioned configuration, when the base ends of the pair of oscillating bases 131 both oscillate upward or downward in the same direction, a first deformation occurs in which one end and the other end of the force generating units 430, 440 are displaced horizontally relative to each other. When the pair of oscillating bases 131 oscillate in the same direction in this way, the force generating units 430, 440 having the above-mentioned shape apply a relatively small reaction force to the base ends of the pair of oscillating bases 131.

[0071] On the other hand, in the case of different direction swing in which one base end side of the pair of swing bases 131 swings upward or downward relative to the other base end side, a second deformation occurs in which one end and the other end of the force generating units 430, 440 are displaced in the up-down direction relative to each other. In this way, the force generating units 430, 440 deform in a mode different from that in the case of same direction swing. In this embodiment, the ratio (second spring constant) between the force from the force generating units 430, 440 and the deformation amount of the second deformation during different direction swing is 3 times or more, more preferably 5 times or more, compared to the ratio (first spring constant) between the force from the force generating units 430, 440 and the deformation amount of the first deformation during same direction swing. The ratio may be 1.5 times or more. The ratio of the second spring constant to the first spring constant is not limited to the above value, and may be any value that can reduce the tilting behavior as described above. The same applies to the following description.

[0072] Therefore, the swing control units 4, 4' suppress different-direction swinging, in which one of the base ends of the pair of swinging units 2 swings in a different vertical direction relative to the other. This configuration can suppress or restrict the difference between the height position of the tip end side of one of the pair of swinging units 2 relative to the vehicle body frame and the height position of the tip end side of the other of the pair of swinging units 2 relative to the vehicle body frame from becoming larger than the predetermined range. In the case of suppression, the force generating units 430, 440 generate a sufficiently large force before the difference exceeds the predetermined range, thereby making it difficult for the difference to exceed the predetermined range. The same applies to the other force generating units.

[0073] It is also possible to use a swing control section 4'' shown in FIG. 13, which has a modified shape of the force generating section 430 of the swing control section 4 described above in this embodiment. The swing control unit 4'' and the force generating unit 430'' have an elastically deformable shape. The force generating unit 430'' is also shaped to be disposed over a range of 170° or more around the axis 431, and has a cross-sectional shape formed by connecting multiple circular arcs.

[0074] It is also possible to use a swing control section 5 shown in FIG. 14 in place of the swing control section 3 of this embodiment. The swing control unit 5 has a connection member 500 in which a first fixing part 510 is fixed to the base end side of one of the pair of swing bases 131 by a bolt or the like and a second fixing part 520 is fixed to the base end side of the other of the pair of swing bases 131 by a bolt or the like. The swing control unit 5 may have other members in addition to the connection member 500.

[0075] The connecting member 500 has a force generating section 530 consisting of a thread-like member, a string-like member, a band-like member, or the like that connects the first fixing section 510 and the second fixing section 520. The force generating section 530 of this embodiment is formed by winding a thread consisting of polyester fiber, nylon fiber, aramid fiber, or the like multiple times around the first fixing section 510 and the second fixing section 520. The thread-like member or the string-like member can be made using chemical fibers such as polyester fiber, nylon fiber, aramid fiber, natural fiber, metal fiber, or the like. The band-like member can be made using metal, plastic, rubber, or the like. The force generating section 530 of this embodiment may be provided with a rubber-like elasticity that covers the force generating section 530.

[0076] Since the connecting member 500 has the above-mentioned configuration, during the same-direction swing, a first deformation occurs in the force generating part 530, in which the first fixed part 510 side and the second fixed part 520 side of the force generating part 530 are displaced horizontally relative to each other. The length of the force generating part 530 between the first fixed part 510 and the second fixed part 520 is set so that a strong tension is not generated during the deformation.

[0077] On the other hand, during the different direction swing, a second displacement occurs in the force generating unit 530, in which the first fixed unit 510 side and the second fixed unit 520 side of the force generating unit 530 are displaced in the up-down direction relative to each other. The ratio (second spring constant) of the force (tension) from the force generating unit 530 to the deformation amount of the first deformation during the same direction swing is 3 times or more, more preferably 5 times or more in this embodiment. The ratio may be 1.5 times or more. As described above, the ratio is not limited to these values. The deformation amount can also be said to be the displacement amount (change in distance) of the first fixed unit 510 relative to the second fixed unit 520.

[0078] For this reason, the swing control unit 5 suppresses or regulates different direction swinging in which one of the base ends of the pair of swinging units 2 swings in a different direction in the up-down direction relative to the other. This configuration suppresses or regulates the difference in height between the tip end side of one of the pair of swinging units 2 relative to the vehicle body frame and the tip end side of the other of the pair of swinging units 2 relative to the vehicle body frame from exceeding the predetermined difference.

[0079] It is also possible to provide the swing control unit 6 on the swing base 131' in Fig. 15. In Fig. 15, the same components as those in the above embodiment are denoted by the same reference numerals. In Fig. 15, the shaft 150 fixed to the base end side of the right swing base 131' is disposed to the left of the shaft 150 fixed to the base end side of the left swing base 131'. The swing control section 6 has a connection member 600 that connects the base end side of the right swing base 131' to the base end side of the left swing base 131'. In addition to the connection member 600, the swing control section 6 may have other members.

[0080] The connecting member 600 can also be said to be a force generating unit made of a thread-like member, string-like member, band-like member, or the like that connects the base end side of the right oscillating base 131′ and the left oscillating base 131′. The force generating unit can be made of the same material as the force generating unit 530.

[0081] Since the connecting member 600 has the above-mentioned configuration, the change in the distance between both ends of the force generating portion in the up-down direction (first deformation) is small during the same-direction swing. The length of the force generating portion is set so that a strong tension is not generated at this time.

[0082] On the other hand, during the different direction swing, the distance between both ends of the force generating unit in the up-down direction changes significantly (second deformation). The ratio (second spring constant) between the force (tension) from the force generating unit during the same direction swing and the deformation amount of the first deformation is 3 times or more, and more preferably 5 times or more, in this embodiment, compared to the ratio (first spring constant) between the force (tension) from the force generating unit during the different direction swing and the deformation amount of the second deformation. The ratio may be 1.5 times or more. As mentioned above, the ratio is not limited to these values. The deformation amount can also be said to be the displacement amount (change in distance) of the upper end of the force generating unit relative to the lower end.

[0083] For this reason, the swing control unit 6 suppresses or restricts different directional swing in which one of the base ends of the pair of swinging units 2 swings in a different vertical direction relative to the other. This configuration suppresses or restricts the difference in height between the tip end side of one of the pair of swinging units 2 relative to the vehicle body frame and the tip end side of the other swinging unit 2 relative to the vehicle body frame from exceeding the predetermined difference.

[0084] The swing control unit 7 can be provided on the swing base 131'' in FIG. 16. In FIG. 16, the same reference numerals are used for the components equivalent to those in the above embodiment. In FIG. 16, the shaft 150 fixed to the base end of the right swing base 131'' and the shaft 150 fixed to the base end of the left swing base 131'' are spaced apart from each other by a predetermined distance in the vehicle width direction. In FIG. 16, the rear wheel support member 132 is fixed to the swing base 131'', but the lower end of the rear wheel support member 132 may be connected to the swing base 131'' so as to be swingable in the vehicle width direction, as in a double wishbone suspension. In this case, the upper end of the rear wheel support member 132 is connected to an upper swing base (not shown) so as to be swingable in the vehicle width direction, as necessary.

[0085] The swing control unit 7 has a connecting member 700 in which a first fixing portion 710 is fixed to the base end side of one of the pair of swing bases 131'' by a bolt or the like and a second fixing portion 720 is fixed to the base end side of the other of the pair of swing bases 131'' by a bolt or the like. The swing control unit 7 may have other members in addition to the connecting member 700. In one example, the fixing portions 710, 720 are each a pulley fixed to the swing base 131'' coaxially with the swing axis 150a. The connecting member 700 also functions as a force generating portion.

[0086] The connecting member 700 has force generating portions 731, 732 consisting of a thread-like member, a string-like member, a band-like member, or the like that connects the first fixing portion 710 and the second fixing portion 720. The force generating portions 731, 732 of this embodiment are band-like members that can be created in the same manner as the force generating portion 530. One end of the force generating portion 731 is fixed to the upper end portion of the fixing portion 710, and the other end of the force generating portion 731 is fixed to the lower end portion of the fixing portion 720. One end of the force generating portion 732 is fixed to the lower end portion of the fixing portion 710, and the other end of the force generating portion 732 is fixed to the upper end portion of the fixing portion 720.

[0087] Since the connecting member 700 has the above-mentioned configuration, during the same-direction swing, the first fixed portion 710 and the second fixed portion 720 rotate in different directions from each other, and a first deformation occurs in the force generating portions 731, 732 in response to the rotation. The lengths of the force generating portions 731, 732 between the first fixed portion 710 and the second fixed portion 720 are set so that a strong tension is not generated during the deformation.

[0088] On the other hand, during the different direction swing, for example, first fixed portion 710 and second fixed portion 720 rotate in the same direction, and this rotation generates a second displacement in which one of force generating portions 731, 732 is stretched more than the first deformation.

[0089] Therefore, the swing control unit 7 suppresses or restricts the rotation of the first fixed part 710 and the second fixed part 720 about the swing axis 150a with a force larger than that of the first deformation during the second deformation. This suppresses or restricts the different direction swing in which one of the base ends of the pair of swing parts 2 swings in a different direction in the up-down direction relative to the other. This configuration suppresses or restricts the difference in height between the tip end side of one of the pair of swing parts 2 relative to the vehicle body frame and the tip end side of the other of the pair of swing parts 2 from becoming larger than the predetermined difference.

[0090] In the swing control unit 7, the first fixed portion 710 and the second fixed portion 720 may be gears such as spur gears instead of pulleys, and the first fixed portion 710 and the second fixed portion 720, which are gears, may be meshed with each other. In this case, the first fixed portion 710 and the second fixed portion 720 meshing with each other allow swinging in the same direction and restrict swinging in different directions. It is also possible to provide a single or multiple gears between the first fixed part 710 and the second fixed part 720. In this case, the rotation of the first fixed part 710 can be transmitted to the second fixed part 720 via a single or multiple gears, and the single or multiple gears can be configured to allow swinging in the same direction and restrict swinging in different directions. Also, instead of the single or multiple gears, it is also possible to provide a member such as a rod or plate extending in the vertical direction, and to provide rack gears extending in the vertical direction on both the left and right ends of the member. In this case, when the member is attached to the body frame by a linear guide or the like so as to be movable only in the vertical direction, the member allows swinging in the same direction and restricts swinging in different directions.

[0091] As mentioned above, each of the rocking control units controls the tilting behavior when the user stands on the footrest while driving, and contributes to stabilizing the vehicle posture, so they can also be called stabilizers.

[0092] When the swing control section is configured to connect a pair of swing sections 2 like the connecting member 400 of the swing control section 4, the spring constants of the force generating sections 430, 430'', 440 during swing in the same direction can be adjusted to supplement or replace the spring 140. In other words, the swing control section has the function of a stabilizer as well as the function of a suspension spring.

[0093] The pair of front wheels 10 are steered by a steering mechanism. As shown in Figures 1, 4, etc., the steering mechanism of this embodiment has a center shaft 171, a base 172, a right knuckle 173 attached to the right side of the base 172 in the vehicle width direction, a left knuckle 174 attached to the left side of the base 172 in the vehicle width direction, and a pair of kingpins 175. The base 172 is composed of a single member or multiple members.

[0094] Center shaft 171 is attached to front-wheel-side frame 111 to be rotatable about first axis 101, and center shaft 171 has a pitman arm 171a extending in a direction intersecting first axis 101. In this embodiment, pitman arm 171a extends in a direction substantially perpendicular to first axis 101, but is not limited to this and can be set appropriately as long as at least one of the effects described below is achieved. In this embodiment, a base end of pitman arm 171a is fixed to center shaft 171 by bolts, welding, or the like.

[0095] The right knuckle 173 and the left knuckle 174 are attached to the base 172 rotatably around the second axis 102, which is the central axis of the kingpin 175, and the right knuckle 173 and the left knuckle 174 have a right knuckle arm 173a and a left knuckle arm 174a, respectively, extending in a direction intersecting the second axis 102. In this embodiment, the knuckle arms 173a, 174a extend in a direction substantially perpendicular to the second axis 102, but are not limited to this and may be appropriately set within a range in which at least one of the effects described below is achieved. In this embodiment, the base ends of the knuckle arms 173a, 174a are fixed to the knuckles 173, 174 by bolts, welding, or the like.

[0096] The steering mechanism has a right rod 176 connecting the tip of pitman arm 171a to the tip of right knuckle arm 173a, and a left rod 177 connecting the tip of pitman arm 171a to the tip of left knuckle arm 174a.

[0097] With the above configuration, a link mechanism is formed having at least four joints: a first connection portion between the center shaft 171 having the pitman arm 171a and the front wheel side frame 111, a second connection portion between the base 172 and the right knuckle 173, a third connection portion between the tip of the right knuckle arm 173a and one end of the right rod 176, and a fourth connection portion between the other end of the right rod 176 and the tip of the pitman arm 171a.

[0098] Also, a link mechanism is configured having at least four joints: a fifth connecting portion between center shaft 171 having pitman arm 171a and front-wheel-side frame 111, a sixth connecting portion between base 172 and left knuckle 174, a seventh connecting portion between the tip of left knuckle arm 174a and one end of left rod 177, and an eighth connecting portion between the other end of left rod 177 and the tip of pitman arm 171a. The fifth connecting portion is the same as the first connecting portion.

[0099] As shown in FIG. 17, one end of the rods 176, 177 is a joint part 176a, 177a such as a universal joint typically being a ball joint, and the rods 176, 177 are connected to the knuckle arms 173a, 174a via the joint parts 176a, 177a. The other end of the rods 176, 177 is a joint part 176b, 177b such as a universal joint typically being a ball joint, and the rods 176, 177 are connected to the pitman arm 171a via the joint parts 176b, 177b. The length of the rod 176 is the distance between the center point of the spherical part of the joint part 176a (the swing center of the joint) and the center point of the spherical part of the joint part 176b (the swing center of the joint), and the length of the rod 177 is the same. In this embodiment, the rods 176, 177 are 165 to 175 mm, but the present disclosure is not limited thereto. In this embodiment, the third connecting portion is the center point of the spherical portion of the joint part 176a (the swing center of the joint), and the fourth connecting portion is the center point of the spherical portion of the joint part 176b (the swing center of the joint), as are the seventh connecting portion and the eighth connecting portion.

[0100] In this embodiment, as shown in Figs. 1, 17, etc., the joint parts 176b and 177b overlap in the vertical direction. More specifically, the joint parts 176b and 177b are aligned in the extension direction of the first axis line 101. The other ends of the rods 176 and 177 may overlap in the vertical direction, or the other ends of the rods 176 and 177 may be aligned in the extension direction of the first axis line 101. This configuration is useful for increasing the amount of pressure by changing the rod angle, which will be described later.

[0101] In this embodiment, as shown in FIG. 3, the kingpin 175 is inclined in the vehicle longitudinal direction. In this embodiment, the inclination angle (caster angle) α1 of the second axis 102 of the kingpin 175 in the vehicle longitudinal direction is 2 to 4°. In order to reduce the operating force of the handle 180 for elderly people and the like, the inclination angle α1 is preferably about 0° to 6°, and more preferably 4° or less. When straight-line stability is taken into consideration, the inclination angle α1 may be set in the range of 12° or less. The inclination angle α1 may be set to an angle other than the above depending on the conditions and required performance. In this embodiment, the second axis 102 is inclined toward the rear of the vehicle, but the present disclosure is not limited thereto.

[0102] In this embodiment, as shown in Figs. 1 and 17, the kingpin 175 is inclined in the vehicle width direction. In this embodiment, the inclination angle α2 of the second axis 102 of the kingpin 175 in the vehicle width direction is 9 to 10°. Because of an increase in the pushing amount due to a change in the rod angle described later, the inclination angle α2 is 3° or more, preferably 5° or more, and more preferably 8° or more. The inclination angle α2 may be set to an angle other than the above depending on the conditions and required performance. In this embodiment, the second axis 102 is inclined inward in the width direction, but the present disclosure is not limited to this. The inclination angle α2 is preferably 1° or more larger than the inclination angle α1, more preferably 3° or more larger, and further preferably 5° or more larger.

[0103] As shown in FIG. 17, the axle 11 of the right front wheel 10 is fixed to the right knuckle 173, and the axle 11 of the left front wheel 10 is fixed to the left knuckle 174. In this embodiment, when both front wheels 10 are arranged at a steering angle for forward travel with a tilt angle α2, the camber angle is configured to be smaller than the tilt angle α2. In other words, if the camber angle of the front wheels 10 is set to the same as the tilt angle α2, the front wheels 10 will have a negative camber angle equal to the tilt angle α2, but in this embodiment, the front wheels 10 have a positive camber angle or a negative camber angle of a small predetermined angle. The small predetermined angle is preferably 3° or less, and more preferably 2° or less. In this embodiment, the front wheels 10 have a positive camber angle of 1° or less or 0.5° or less. With the above configuration, when both front wheels 10 are arranged at a steering angle for forward travel, the axle 11 extends obliquely downward rather than perpendicularly to the second axis 102.

[0104] It can be said that the second axis 102 extends mainly in the vertical direction with an inclination arrangement of inclination angles α1 and α2. In addition, the second axis 102 extends slightly in the vehicle front-rear direction and the vehicle width direction, and also extends mainly in the vertical direction, so it can be said that the second axis 102 extends at least in the vertical direction.

[0105] In this embodiment, the center shaft 171 is inclined in the vehicle front-rear direction as shown in Fig. 3. The inclination angle β of the first axis 101 of the center shaft 171 in the vehicle front-rear direction is 5° or more, preferably 8° or more, and more preferably 10° or more. In this embodiment, the inclination angle β is set in the range of 8° or more and 12° or less, and in Fig. 3, the inclination angle β is 10° to 11°.

[0106] It can be said that the first axis 101 extends mainly in the vertical direction with an inclination angle β. In addition, since the inclination angle β extends slightly in the vehicle front-rear direction and mainly extends in the vertical direction, it can be said that the first axis 101 extends at least in the vertical direction. The inclination angle α1 is preferably smaller than the inclination angle β by 1° or more, more preferably by 3° or more, and further preferably by 5° or more. In this embodiment, the first axis 101 is inclined toward the rear of the vehicle, but the present disclosure is not limited to this.

[0107] 18, when the steering angle of both front wheels 10 is 0° or approximately 0°, or when both front wheels 10 are positioned at a straight steering angle for going straight, pitman arm 171a extends forward of the vehicle from center shaft 171, and knuckle arms 173a, 174a also extend forward of the vehicle from knuckles 173, 174. At this time, in this embodiment, the third connecting portion is positioned outboard of the second connecting portion in the vehicle width direction, and the seventh connecting portion is positioned outboard of the sixth connecting portion in the vehicle width direction.

[0108] In addition, in this state, the height positions of the joint parts 176b, 177b (the fourth connecting part and the eighth connecting part) are higher than the height positions of the joint parts 176a, 177a (the third connecting part and the seventh connecting part). In other words, the rods 176, 177 are inclined so that the other end is higher than one end. In this embodiment, the seventh connecting part is higher than the third connecting part by the height difference between the eighth connecting part and the fourth connecting part so that the inclination of the right rod 176 and the inclination of 177 are equal. In addition, because of the height difference, the length of the right rod 176 and the length of the left rod 177 differ by 1 mm or more. In this embodiment, the length of the right rod 176 and the length of the left rod 177 differ by 2 mm or more.

[0109] Each component is designed, set, etc. so that the above numerical values ​​are obtained when the electric mobility 1 is placed on a horizontal plane and in an unloaded state or when the specified load is applied.

[0110] 19 and 20 , when the rider turns the handle 180 and the handle shaft 181 so that the electric mobility 1 moves forward and left, the pitman arm 171a rotates to the left about the first axis 101. At this time, the height positions of the fourth and eighth connectors of the pitman arm 171a change in accordance with the leftward rotation and the inclination angle β. In this embodiment, since the first axis 101 is inclined toward the rear of the vehicle, the height positions of the fourth and eighth connectors move downward in accordance with the leftward rotation.

[0111] At this time, the tip end (seventh connecting portion) of the left knuckle arm 174a is pushed outward in the vehicle width direction by the left rod 177, and the left knuckle arm 174a rotates to the left about the second axis 102. At this time, the height position of the seventh connecting portion of the left knuckle arm 174a changes in accordance with the left rotation and the inclination angle α2. In this embodiment, since the second axis 102 is inclined inward in the vehicle width direction, the left rotation and the inclination angle α2 act to move the height position of the seventh connecting portion upward.

[0112] For this reason, in this embodiment, in response to the rotation to the left, the difference in height between the eighth connecting portion and the seventh connecting portion decreases, causing a decrease in the inclination of the left rod 177. In addition, in response to the amount of this decrease, the amount by which the left rod 177 pushes the tip end portion (seventh connecting portion) of the left knuckle arm 174a outward in the vehicle width direction increases.

[0113] In this embodiment, as the amount of rotation of the pitman arm 171a to the left increases, the amount of downward movement of the height positions of the fourth and eighth connecting parts per unit angle of rotation increases. In this embodiment, as the amount of rotation of the left knuckle arm 174a to the left increases, the height position of the seventh connecting part moves upward. For this reason, in this embodiment, it is possible to set the amount of pressing to be increased when the amount of rotation to the left increases.

[0114] During the left rotation, the tip end (third connecting portion) of the right knuckle arm 173a is pulled inward in the vehicle width direction by the right rod 176, causing the right knuckle arm 173a to rotate to the left about the second axis 102. At this time, the height position of the third connecting portion of the right knuckle arm 173a changes in accordance with the left rotation and the inclination angle α2. In this embodiment, since the second axis 102 is inclined inward in the vehicle width direction, the left rotation and the inclination angle α2 act to move the height position of the third connecting portion downward.

[0115] For this reason, in this embodiment, during the rotation to the left, the amount of decrease in inclination of the right side rod 176 caused by a decrease in the difference in height positions between the first and third connecting parts is smaller than or is nonexistent relative to the amount of decrease in inclination of the left side rod 177 caused by a decrease in the difference in height positions between the eighth and seventh connecting parts. For this reason, the increase in the amount of pulling by the right side rod 176 to pull the tip end (third connecting part) of the right knuckle arm 173a inward in the vehicle width direction is smaller than or is nonexistent relative to the increase in the amount of pushing by the left side rod 177 to the tip end (seventh connecting part) of the left knuckle arm 174a outward in the vehicle width direction. In order to differentiate the amount of inclination reduction of the left and right rods 176, 177 as described above, it is also possible to arrange the kingpin 175 so that the upper side of the second axis 102 is arranged outward in the vehicle width direction relative to the lower side. In this case, the rods 176, 177 are arranged at an incline so that the other end is lower than one end during a straight steering angle.

[0116] Depending on the degree of increase in the pushing amount and the pulling amount, the steering angle difference between the left and right when the amount of rotation of the pitman arm 171a to the left is large can be made significantly larger than the steering angle difference when the amount of rotation of the pitman arm 171a to the left is small. The steering angle difference is the difference between the inner wheel steering angle of the inner wheel (left front wheel 10) and the outer wheel steering angle of the outer wheel (right front wheel 10). When the pitman arm 171a is rotated to the right, the inner wheel steering angle of the inner wheel (right front wheel 10) becomes larger than the outer wheel steering angle of the outer wheel (left front wheel 10), just like in the case of rotation to the left. Also, the steering angle difference when the amount of rotation of the pitman arm 171a to the right is large can be made significantly larger than the steering angle difference when the amount of rotation of the pitman arm 171a to the right is small.

[0117] Using the above configuration, it is possible to obtain an example of the following steering characteristic, in which the steering angle difference when the amount of rotation of the pitman arm 171a to the right or left is large is significantly larger than the steering angle difference when the amount of rotation of the pitman arm 171a to the right or left is small. An example of the steering characteristic includes the following: when the steering angle of the inner wheel (inner wheel steering angle) is about 20°, the steering angle of the outer wheel (outer wheel steering angle) is about 20°, and the steering angle difference is 0° (Figure 19). When the steering angle of the inner wheel is about 45°, the steering angle of the outer wheel is about 42°, and the steering angle difference is about 3° (Figure 20). When the steering angle of the inner wheel is about 102°, the steering angle of the outer wheel is about 78°, and the steering angle difference is about 24° (Figure 21). In this example of the steering characteristic, the steering angle difference is as described above both when the right front wheel 10 is the inner wheel and when the left front wheel 10 is the inner wheel.

[0118] In FIG. 21, in a plan view, the intersection point between the central axis A1 of the inner wheel (left front wheel 10) and the axis A3 passing through the center of the pair of rear wheels 20 and the intersection point between the central axis A2 and the axis A3 of the outer wheel (right front wheel 10) are approximately aligned. "Approximately aligned" refers to a case where the distance between the two intersection points is 4 cm or less. In addition, in the vehicle width direction, the two intersection points are disposed between the two rear wheels 20. More specifically, in the vehicle width direction, the two intersection points are disposed at a middle position between the two rear wheels 20. The middle position is preferably a completely central position, but also includes a position separated from the completely central position by a distance of 20 cm or less in the vehicle width direction, preferably a position separated by a distance of 15 cm or less, and more preferably a position separated by a distance of 10 cm or less. In addition, it is preferable that the two intersection points are aligned or approximately aligned, but it is sufficient that the two intersection points are disposed at a middle position. The distance between the two intersection points is preferably 15 cm or less, more preferably 10 cm or less, and even more preferably 5 cm or less.

[0119] The above state is in accordance with the theory of Ackermann steering geometry, and is useful for smoothly turning the electric mobility 1 around the intersection. In order to turn, in the above state, the control device 80 drives the motor 50 so that the left and right rear wheels 20 rotate in opposite directions relative to each other. In this embodiment, such turning is called a pivot turn. It is preferable that the rotation speeds of the left and right rear wheels 20 are the same, but this can be changed as appropriate depending on the conditions. For smooth turning, it is preferable that the two intersections are located at or near the exact center position.

[0120] The above configuration is useful because the arrangement of the intersections allows the steering angle difference when the amount of rotation of the pitman arm 171a to the right or left to be significantly larger than the steering angle difference when the amount of rotation of the pitman arm 171a to the right or left to be small. For example, as shown in FIG. 21, when the steering angle of the inner wheel (left front wheel 10) is close to 90° or 100°, it becomes difficult to apply a rotational force to the left knuckle arm 174a by the pushing force of the left rod 177. In this embodiment, a setting can be realized that increases the pushing force when the amount of rotation to the right or left becomes large, which is useful for firmly applying a rotational force to the knuckle arms 173a, 174a of the inner wheel when the steering angle of the inner wheel is close to 90° or 100°.

[0121] As a comparative example, the results of a simplified calculation of steering characteristics based on the theory of Ackermann geometry are shown. The simplified calculation is performed using the formula tan α=1 / ((1 / tan β)-(T / W)). α is the steering angle of the inner wheel, β is the steering angle of the outer wheel, T is the tread dimension, and W is the wheelbase dimension. In this simplified calculation of steering characteristics, as an example, the wheelbase dimension is set to 2.2 times the tread dimension.

[0122] The steering characteristics of the comparative example include the following: When the steering angle of the inner wheel is about 20°, the steering angle of the outer wheel is about 17.5°, resulting in a steering angle difference of 2.5°. When the steering angle of the inner wheel is about 45°, the steering angle of the outer wheel is about 35°, resulting in a steering angle difference of about 10°. When the steering angle of the inner wheel is about 102°, the steering angle of the outer wheel is about 77°, resulting in a steering angle difference of about 25°.

[0123] The theory of Ackermann geometry is a theory that makes the positions of the two intersections completely coincident. Therefore, when the steering angle of the inner wheel of the comparative example is about 102°, the positions of the two intersections completely coincide at the midpoint between the two rear wheels 20. In this way, the example of the steering characteristics of the present embodiment described above is useful for smooth pivot turning, similar to the comparative example.

[0124] Normally, the positions of the two intersections are aligned at the midpoint between the two rear wheels 20, so when the theory of Ackermann geometry is used, the steering angle difference gradually increases from when the steering angle of the inner wheel is small, as described above. In contrast, in this embodiment, the amount of increase in the steering angle difference after the steering angle of the inner wheel exceeds 45° is significantly greater than that of the theory of Ackermann geometry, as described above. This configuration is useful for applying a strong rotational force from the rods 176, 177 to the knuckle arms 173a, 174a of the inner wheel when the steering angle of the inner wheel becomes large, as described above.

[0125] In this embodiment, the kingpin 175 is inclined inward in the vehicle width direction. The inner wheel is disposed rearward of the kingpin 175 as the steering angle increases. At this time, the positive camber angle of the inner wheel increases. That is, the inner wheel tilts in a direction in which the lower side of the inner wheel goes under the axle 11. Due to this movement, the part supported by the inner wheel moves downward due to gravity. For example, in FIG. 21, the left front wheel 10 (inner wheel) tilts in a direction in which the lower side goes under the axle 11, and the left knuckle 174 moves downward due to gravity. Since gravity tries to move an object lower, this configuration can help to set the steering angle of the inner wheel to a deep angle such as 90° or 100° by the pushing force of the rods 176 and 177.

[0126] In addition, in the above-described example of the steering characteristic of this embodiment, the steering angle difference when the steering angle of the inner wheel is 20°, 45°, etc. does not conform to the theory of Ackermann geometry. It can also be said that the front wheels 10 become close to a parallel steering geometry when turning right or left at a low speed. In this embodiment, as the steering angle increases, the part supported by the inner wheel moves downward due to gravity. This configuration acts in the direction of increasing the steering angle of the inner wheel. Because there is play due to gaps between the components of the steering mechanism and elastic deformation of each component, the above-mentioned gravity-related movement tends to increase the steering angle of the inner wheel within the range of the play when turning right or left with a steering angle of the inner wheel of 45° or less. This contributes to smooth driving of the electric mobility 1 when turning right or left at low speed.

[0127] In the above-mentioned example of the steering characteristic of this embodiment, when the steering angle of the inner wheel is a first angle that is any angle in the range of 40° to 45°, the steering angle difference is about 3° or less than 3°. Also, when the steering angle of the inner wheel is 102° (second angle) that is any angle in the range of 90° or more, the steering angle difference is about 24°. At this time, the two intersections are located between the two rear wheels 20. At this time, for example, when the simplified calculation of the Ackermann geometry theory is calculated for a narrow vehicle body in which W is three times T, the steering angle difference is about 16° when the positions of the two intersections coincide.

[0128] Therefore, the steering angle difference at the second angle is five times or more than the steering angle difference at the first angle, and in the above example of the steering characteristic, it is seven times or more or eight times or more. This configuration means that when the steering angle of the inner wheel increases in the steering angle range close to 90° as described above, the increase in the steering angle difference per unit steering angle change of the inner wheel (when the steering angle of the inner wheel changes by 1°) is large. This configuration is useful for applying a strong rotational force from the rods 176, 177 to the knuckle arms 173a, 174a of the inner wheel when the steering angle of the inner wheel increases.

[0129] In this embodiment, the rods 176, 177 are inclined so that the other end is higher than the one end when the pair of front wheels 10 are arranged at a straight steering angle. In this case, when the electric mobility 1 is viewed from the front as in Fig. 1, in this embodiment, the difference in height position between the third connecting part and the fourth connecting part and the difference in height position between the seventh connecting part and the eighth connecting part are set between 32 and 38 mm. The difference in height position at the time of the straight steering angle is preferably 15 mm or more, more preferably 20 mm or more, and further preferably 25 mm or more. In addition, the height position of each connecting part can also be measured using the position of the center point of the spherical part of the joint parts 176a, 176b, 177a, 177b (the swing center of the joint), or it can be measured using the position of a specific part of a fixing member such as a bolt that fixes the joint parts 176a, 176b, 177a, 177b to the pitman arm 171a or the knuckle arms 173a, 174a.

[0130] In this embodiment, when the steering angle of the inner wheel is 102°, the height difference decreases by 9 to 10 mm in the rod 176 of the inner wheel, and does not change or increases within a range of 5 mm or less in the rod 177 of the outer wheel. In other words, when the steering angle of the inner wheel changes from a straight steering angle to 102°, the difference in height position between the third connecting portion and the fourth connecting portion of the rod 176 of the inner wheel decreases by 9 to 10 mm. The decrease is preferably 4 mm or more, more preferably 6 mm or more, and even more preferably 8 mm or more. In this way, when the inner wheel steering angle is the second angle, the difference in height between the right rod or the left rod corresponding to the inner wheel becomes obviously smaller, and the inclination angle of the inner wheel rods 176, 177 becomes smaller accordingly. This configuration is extremely useful for applying a rotational force firmly from the rods 176, 177 to the knuckle arms 173a, 174a of the inner wheel when the steering angle of the inner wheel becomes large.

[0131] When the length of the rod 176 is 170 mm, the rod 176 is inclined at an angle (rod angle) of about 12° with respect to the horizontal plane when the difference in height position is 35 mm, and when the difference in height position is 25 mm, the rod 176 is inclined at an angle (rod angle) of about 8.5° with respect to the horizontal plane. At the time of the straight steering angle, the rods 176, 177 are preferably inclined at an angle (rod angle) of 5° or more with respect to the horizontal plane, more preferably 8° or more, and even more preferably 10° or more. In order to apply a rotational force from the rods 176, 177 to the knuckle arms 173a, 174a firmly, the angle at the time of the straight steering angle is 40° or less, preferably 30° or less, and more preferably 20° or less.

[0132] In this embodiment, the right second axis 102 is inclined so that its upper side is disposed inward in the vehicle width direction relative to its lower side. In addition, at the time of a straight steering angle, the right knuckle arm 173a extends from the right knuckle 173 toward the front of the vehicle, and one end of the right rod 176 is connected to the tip of the right knuckle arm 173. With this configuration, the height position of one end of the right rod 176 changes as the steering angle of the right front wheel 10 as the inner wheel increases. This configuration realizes the above steering characteristics without using a complex configuration, and is useful for firmly applying a rotational force from the rods 176, 177 to the knuckle arms 173a, 174a of the inner wheel when the steering angle of the inner wheel increases.

[0133] In this embodiment, the first axis 101 is inclined so that its upper side is disposed rearward of the vehicle relative to its lower side. In addition, when the steering angle is straight ahead, the pitman arm 171a extends from the center shaft 171 toward the front of the vehicle, and the other end of the right rod 176 is connected to the tip of the pitman arm 171a. With this configuration, the height position of the other end of the right rod 176 changes as the steering angle of the right front wheel 10 as the inner wheel increases. This configuration realizes the above steering characteristics without using a complex configuration, and is useful for firmly applying a rotational force from the rods 176 and 177 to the knuckle arms 173a and 174a of the inner wheel when the steering angle of the inner wheel increases.

[0134] For example, in a state where the steering angle of the inner wheel is 90° or more and the amount of rotation of the knuckle arms 173a, 174a of the inner wheel is also 90° or more as shown in Fig. 21, in order to apply a strong rotational force to the knuckle arms 173a, 174a of the inner wheel from the rods 176, 177, a configuration may be considered in which the tip of the pitman arm 171a is disposed considerably forward of the knuckle arms 173a, 174a. However, this configuration is an obstacle to reducing the dimension of the electric mobility 1 in the front-rear direction.

[0135] In this embodiment, the above configuration makes it possible to apply a rotational force firmly to the knuckle arms 173a, 174a of the inner wheels when the steering angle of the inner wheels becomes large from the rods 176, 177. Therefore, this embodiment is also useful for reducing the dimension of the electric mobility 1 in the front-rear direction. In recent years, there has been an increase in cases where the electric mobility vehicle 1 is used within facilities and luxury cruise ships, and in such cases, miniaturization of the electric mobility vehicle 1 is particularly important. For example, if the electric mobility vehicle 1 cannot turn smoothly within an elevator, it will be necessary to reverse the electric mobility vehicle 1 when entering or exiting the elevator. This will lead to a situation in which it will take a long time for the electric mobility vehicle 1 to exit the elevator, which is undesirable for users of the electric mobility vehicle 1 and elevator passengers. For this reason, miniaturization and turning performance of the electric mobility vehicle 1 are important.

[0136] The front-wheel side frame 111 has a longitudinal frame 111b manufactured by extrusion molding of a metal such as aluminum. As shown in FIG. 22, the longitudinal frame 111b has a single or multiple partition walls 111c that divide the internal space into upper and lower parts. Meanwhile, the vertical frame 111a is also manufactured by extrusion molding, and the same extrusion molding material as the longitudinal frame 111b can be used. This configuration is useful for reducing manufacturing costs, weight, etc.

[0137] Furthermore, in this embodiment, the swing control unit is employed, which can reduce the tilting behavior. This configuration reduces the tilting behavior of the electric mobility 1 during a pivot turn or immediately before the start of a pivot turn. This is useful for making the movements of the rods 176, 177 as intended or as close as possible to the intended movements, and can also be said to be useful for allowing the electric mobility 1 to perform a smooth pivot turn.

[0138] One end of a curved member 112 made of a metal such as aluminum is fixed to the rear end of the longitudinal frame 111b by a fixing structure. As the fixing structure, one end of the curved member 112 is provided with one or more protrusions 113 extending toward the front of the vehicle. The protrusion 113 has an upper surface that fits along the lower surface of the partition wall 111c, and a plurality of through holes 113a are formed in the protrusion 113 at intervals in the longitudinal direction of the vehicle. Each of the through holes 113a penetrates the protrusion in the vertical direction.

[0139] The vertical dimension of the protrusion 113 is equal to the distance between the bottom wall 111d of the front-rear frame 111b and the partition wall 111c. For example, the protrusion 113 is inserted into the space between the partition wall 111c and the bottom wall 111d until one end of the curved member 112 comes into contact with the rear end of the front-rear frame 111b.

[0140] The partition wall 111c has a plurality of holes formed at positions corresponding to the plurality of through holes 113a of the inserted protrusion 113. The lower wall 111d also has a plurality of holes formed at positions corresponding to the plurality of through holes 113a of the inserted protrusion 113. The fixing structure also includes a nut member 114 disposed on the partition wall 111c. The nut member 114 is formed with female threads 114a at positions corresponding to the plurality of through holes 113a of the protrusion 113.

[0141] With the protrusion 113 inserted into the space and the nut member 114 placed on the partition wall 111c as described above, a plurality of bolts 115 are inserted into the plurality of holes in the partition wall 111c, respectively, and the plurality of bolts 115 are screwed into the female threads 114a, thereby fixing one end of the curved member 112 to the rear end of the front-rear frame 111b. The end of the vertical frame 111a is fixed to the other end of the curved member 112 by a similar fixing structure.

[0142] An angle adjustment mechanism is provided that adjusts the angle of the swing position of the handle shaft 181 in the front-rear direction about the axis 181a in Fig. 2. As shown in Figs. 24 and 25, the angle adjustment mechanism has a first engagement member 183 fixed to the lower end of the handle shaft 181, and a second engagement member 184 fixed to the center shaft 171. When the first engagement member 183 rotates about the axis 181a relative to the second engagement member 184, the inclination of the handle shaft 181 in the front-rear direction changes.

[0143] A contact surface 183a of the first engaging member 183 with the second engaging member 184 is, for example, a concave-convex contact surface having a plurality of radially extending protrusions, and a contact surface 184a of the second engaging member 184 with the first engaging member 183 is a contact surface having a shape complementary to the contact surface 183a. A clamp lever 185 is in contact with the surface opposite to the contact surface 183a of the first engagement member 183. The clamp lever 185 is attached to one end of a fastening shaft 186, and the clamp lever 185 is capable of swinging up and down around an axis 185a of its base end.

[0144] The clamp lever 185 has a first swing position where the tip end is located almost directly above the base end as shown in Fig. 24, and a second swing position where it is rotated (swung) a predetermined angle from the clamp position as shown in Fig. 25, which is the release position. A known clamp lever having a cam surface formed on its base end can be used as the clamp lever 185. The fastening shaft 186 extends in a direction along the axis 181a, and in this embodiment, the central axis of the fastening shaft 186 coincides with the axis 181a. The fastening shaft 186 is movable relative to the first engagement member 183 and the second engagement member 184 in a direction along the central axis.

[0145] A flanged bush 186a, a nut 186b, etc. are fixed to the other end of the fastening shaft 186, and a plurality of disc springs are arranged on the outer circumferential surface of the other end side of the fastening shaft 186 in a direction along the central axis of the fastening shaft 186. The plurality of disc springs are spring members 187, and other spring members such as coil springs can be used instead of the plurality of disc springs. The spring member 187 is disposed sandwiched between the flanged bush 186a and the center shaft 171. The flanged bush 186a and the nut 186b are members that move together with the fastening shaft 186 when the fastening shaft 186 moves toward the clamp lever 185, thereby pushing the spring member 187 toward the center shaft 171.

[0146] When clamp lever 185 is placed in the clamping position, and clamping shaft 186 moves toward clamp lever 185, spring member 187 is compressed to a first compressed state. When clamp lever 185 is placed in the release position, clamping shaft 186 moves in the opposite direction to clamp lever 185, and spring member 187 is in a second compressed state in which the amount of compression is smaller than the first compressed state. In the second compressed state, spring member 187 is compressed to a certain degree. In another example, spring member 187 is not compressed at all.

[0147] In this state, in order for the contact surface 183a to move around the axis 181a relative to the contact surface 184a, a climbing action is required in which the spring member 187 moves in a direction along the central axis to a position where the engagement of the projections and recesses with the contact surface 184a is released. In this embodiment, the spring member 187 is configured to be compressed during the climbing action. Therefore, when the inclination of the handle shaft 181 in the front-rear direction changes, the spring member 187 is compressed every time the engagement of the projections and recesses between the contact surface 183a and the contact surface 184a is climbed over. In this configuration, the user can change the position of the handle shaft 181 in the front-rear direction in a stepwise manner. In addition, the user can make the adjustment by simply setting the clamp lever 185 to the release position.

[0148] After the handle shaft 181 is placed in the desired swing position, when the user swings the clamp lever 185 to the clamping position, the spring member 187 is compressed to a first compressed state. In this state, the remaining compression of the spring member 187 is less than the amount of movement required for the overriding operation. This configuration is useful for preventing unintended changes in the swing position of the handle shaft 181, which is subject to large forces.

[0149] The portion of the first engagement member 183 that comes into contact with the base end of the clamp lever 185 has a first contact portion 183b made of a metal material and a second contact portion 183c made of a resin material. It is preferable to select a resin material with a low coefficient of friction as the resin material. The first contact portion 183b and the second contact portion 183c are aligned in the swing direction of the clamp lever 185. When the direction along the central axis is the up-down direction of the clamp, the second contact portion 183c is located directly below the axis 185a.

[0150] With this configuration, when the clamp lever 185 is in the fastening position, the base end of the clamp lever 185 comes into contact with the first contact portion 183b and the second contact portion 183c. This ensures that the fastened state is maintained in the fastening position. On the other hand, when the clamp lever 185 moves from the fastening position to the release position, the base end of the clamp lever 185 comes into contact only with the second contact portion 183c. This allows the clamp lever 185 to move smoothly from the fastening position to the release position.

[0151] The front-wheel side body 110 is removably connected to the rear-wheel side body 120. As shown in FIG. 22, in this embodiment, an upper engaging portion 191 and a lower engaging portion 192 arranged below the upper engaging portion 191 are provided at the rear end of the front-wheel side frame 111 of the front-wheel side body 110. The lower engaging portion 192 is an engaging portion that opens downward. As shown in FIGS. 27 and 28, the rear-wheel side frame 121 of the rear-wheel side body 120 has an upper engaged portion 193 and a lower engaged portion 194 arranged at height positions corresponding to the upper engaging portion 191 and the lower engaging portion 192. In this embodiment, the engaged portions 193, 194 are frame parts such as pipes or rods extending in the vehicle width direction, for example.

[0152] The lower engaging portion 192, which is open downward, approaches the lower engaged portion 194 from diagonally forward, thereby engaging with the lower engaged portion 194 from above. Conversely, when disengaging the lower engaging portion 192 from the lower engaged portion 194, it is necessary to move the lower engaging portion 192 diagonally forward relative to the lower engaged portion 194.

[0153] As shown in Fig. 22, a locking projection 192a protruding in the vehicle width direction is provided at an end of the lower engaging portion 192 in the vehicle width direction. Meanwhile, a locking rotating member 195 is attached to, for example, a part of the rear-wheel-side frame 121 of the rear-wheel-side body 120. In this embodiment, the rotating member 195 is rotatable about an axis 195c extending in the vehicle width direction, but the rotating member 195 may be rotatable about an axis extending in another direction. In this embodiment, the rotating member 195 is rotatably attached to the pipe-shaped frame of the lower engaged portion 194.

[0154] The rotating member 195 has a battery contact portion 195a that protrudes in the radial direction from one part of its circumference, and a lock portion 195b that protrudes in the radial direction from another part of its circumference. The rotating member 195 is urged to rotate in a predetermined direction (counterclockwise in FIG. 28) by a urging member such as a torsion spring (not shown). As a result, in an unloaded state, the rotating member 195 is disposed at the position shown in FIG. 28. At this position, the battery contact portion 195a is disposed at a position where it can come into contact with the battery BA attached to the battery housing portion 196. Then, in the process of attaching the battery BA to the battery housing portion 196 as shown in FIG. 27, the battery contact portion 195a is pressed by the battery BA in the direction opposite to the urging direction by the urging member. Then, when the battery BA is attached to the predetermined position, the rotating member 195 rotates to the position shown in FIG. 27.

[0155] In this state, the locking portion 195b of the rotating member 195 is disposed at least in front of the locking projection 192a, and is configured so that the locking portion 195b restricts at least the forward movement of the locking projection 192a. This prevents the lower engaging portion 192 from moving diagonally forward relative to the lower engaged portion 194. In other words, unless the battery BA is removed from the battery housing portion 196, the engagement between the lower engaging portion 192 and the lower engaged portion 194 cannot be released.

[0156] In this way, the rotating member 195 rotatably attached to the rear-wheel side frame 121 rotates to a predetermined rotation position when the battery BA is attached. At the predetermined rotation position, the rotating member 195 comes into contact with a part of the front-wheel side frame 111 that is engaged with the engaged portion of the rear-wheel side frame 121, and this contact restricts movement of the lower engaging portion (engaging portion) 192 of the front-wheel side frame 111 in a direction in which the engagement is released.

[0157] As shown in Fig. 2 etc., a stand member 197 is attached to the rear end of the electric mobility 1. The stand member 197 has a support part 197a that is fixed to the seat unit 40 and extends rearward from the seat unit 40, and a widthwise extending part 197b that has a central part fixed to the support part 197a and extends in the vehicle width direction. Both ends of the widthwise extending part 197b are located further rearward than the central side of the vehicle, and anti-slip members 197c made of a material having rubber-like elasticity may be attached to both ends.

[0158] 29 while using the tip-over prevention members 126 as a fulcrum, and then the electric mobility 1 can stand on its own thanks to the tip-over prevention members 126 and the width-direction extending portions 197b. This state is useful for reducing the storage space required for the electric mobility 1. Furthermore, the user can store the electric mobility 1 without having to perform operations such as folding it.

[0159] The central axis of the spring 140 is disposed on the vehicle front side relative to the rotation axis of the rear wheel 20. This configuration is advantageous for reducing the dimension of the electric mobility 1 in the front-rear direction.

[0160] In addition, in the rear-wheel-side cover 120a, it is preferable that the fender 120b (FIG. 5) of the right rear wheel 20 is fixed to the right swinging portion 2. The same is true for the left fender 120b. For example, the fender 120b is fixed to the rear wheel support member 132 of the swinging portion 2, the motor 50, etc., using a plurality of bolts (not shown).

[0161] In this case, the fender 120b moves up and down together with the swinging part 2 and the rear wheel 20. For this reason, even if the rear wheel 20 moves significantly up and down around the swing axis 150a, the change in shape of the electric mobility vehicle 1 appears small when viewed from the rear, side, etc. This configuration improves the function of the rear wheel suspension while maintaining the appearance of the electric mobility vehicle 1, thereby lifting the spirits of the rider of the electric mobility vehicle 1.

[0162] Even if two or more pairs of front wheels 10 are provided on the front-wheel-side vehicle body 110, the various effects of the rear wheel suspension, the stabilizer, and the steering mechanism described above can be similarly achieved. Furthermore, even if the electric mobility 1 is not provided with the rear wheel suspension, the stabilizer, etc., the various effects of the steering mechanism described above can be similarly achieved. Furthermore, even if other wheels are provided between the front wheels 10 and the rear wheels 20, or if other wheels are provided behind the rear wheels 20, the various effects of the rear wheel suspension and the stabilizer described above can be similarly achieved. Furthermore, even if the electric mobility 1 is not provided with the rear wheel suspension and the stabilizer, and a single or multiple rear wheels 20 are provided instead of a pair of rear wheels 20, the various effects of the steering mechanism described above and similar effects can be achieved.

[0163] Furthermore, even if the front-wheel side body 110 and the rear-wheel side body 120 are connected in a non-detachable manner, the above-mentioned various effects of the rear-wheel suspension, the stabilizer, and the steering mechanism can be achieved. In this case, the front-wheel side frame 111 and the rear-wheel side frame 121 are, for example, integrated, and the front-wheel side frame 111 and the rear-wheel side frame 121 form the body frame of the electric mobility 1.

[0164] Furthermore, when the rear wheel support member 132 is not provided at the tip of the oscillating base 131, one end of the spring 140 may be fixed to another member such as the housing of the motor 50, or may be fixed to another member fixed to or provided on the oscillating base 131. In this case, one end of the spring 140 is attached to the tip of the oscillating base 131 via the above-mentioned member. Alternatively, one end of the spring 140 may be directly attached to the tip of the oscillating base 131 . Even in these cases, the various effects of the rear wheel suspension described above can be achieved.

[0165] It is also possible to attach two (or more) seat units 40 aligned in the front-to-rear direction to the electric mobility 1. In this case, two (or more) people will be seated aligned in the front-to-rear direction on the electric mobility 1. Even in such a case, the various effects of the rear wheel suspension, the stabilizer, and the steering mechanism described above can be achieved. [Explanation of symbols]

[0166] 1. Electric Mobility 2 Swinging part 3,4,4',4'',5,6,7 Swing control section 10 Front wheel 20 Rear wheel 110 Front wheel side body 111 Front wheel frame 120 Rear wheel side body 121 Rear wheel frame 131 Swinging Base 132 Rear wheel support member 171 Center shaft 171a Pitman Arm 172 Base 173 Right Knuckle 173a Right knuckle arm 174 Left knuckle 174a Left knuckle arm 175 Kingpin 176 Right Rod 177 Left Rod 140 Spring BA Battery

Claims

1. A steering mechanism for steering a pair of front wheels of an electric mobility vehicle, A steering mechanism configured to be able to steer the inner wheel and the outer wheel so that the steering angle difference between the inner wheel steering angle and the outer wheel steering angle when the inner wheel steering angle is at a first angle that is any angle in the range of 40° to 45° is 5 times or more when the inner wheel steering angle is at a second angle that is any angle in the range of 90° or more.

2. the pair of front wheels includes a right front wheel and a left front wheel, a center shaft that is rotatable about at least a first axis extending in the vertical direction and that rotates by operating a handle; A pitman arm fixed to the center shaft; a right knuckle that is rotatable about at least a right second axis that extends in the vertical direction and supports the right front wheel; a right knuckle arm provided on the right knuckle; a left knuckle that is rotatable about at least a left second axis that extends in the vertical direction and supports the left front wheel; a left knuckle arm provided on the left knuckle; a right rod having one end connected to the right knuckle arm and the other end connected to the pitman arm; a left rod having one end connected to the left knuckle arm and the other end connected to the pitman arm, 2. The steering mechanism according to claim 1, wherein when the pair of front wheels are positioned at a straight-ahead steering angle for straight-ahead driving of the electric mobility, each of the rods is positioned at an angle such that the difference in height position between the other end and the one end is 15 mm or more, and when the inner wheel steering angle is at the second angle, the difference in height position is 4 mm or more smaller than at the straight-ahead steering angle.

3. A steering mechanism for steering right and left front wheels of an electric mobility vehicle, a center shaft that is rotatable about at least a first axis extending in the vertical direction and that rotates by operating a handle; A pitman arm fixed to the center shaft; a right knuckle that is rotatable about at least a right second axis that extends in the vertical direction and supports the right front wheel; a right knuckle arm provided on the right knuckle; a left knuckle that is rotatable about at least a left second axis that extends in the vertical direction and supports the left front wheel; a left knuckle arm provided on the left knuckle; a right rod having one end connected to the right knuckle arm and the other end connected to the pitman arm; a left rod having one end connected to the left knuckle arm and the other end connected to the pitman arm, a steering mechanism in which, when the right and left front wheels are positioned at a straight-ahead steering angle for driving the electric mobility vehicle in a straight line, each of the rods is positioned at an angle such that the difference in height position between the other end and the one end is 15 mm or more, and when the steering angle of the inner wheel is 90° or more, the difference in height position is 4 mm or more smaller than at the straight-ahead steering angle.

4. 4. The steering mechanism according to claim 2 or 3, wherein the right second axis is inclined in a vehicle width direction, the right knuckle arm extends from the right knuckle toward a front of the vehicle during the straight-ahead steering angle, and the one end of the right rod is connected to a tip portion of the right knuckle arm, so that the height position of the one end of the right rod changes as the steering angle of the right front wheel as the inner wheel increases.

5. 4. The steering mechanism according to claim 2, wherein the first axis is inclined toward the rear of the vehicle, the pitman arm extends from the center shaft toward the front of the vehicle during the straight-ahead steering angle, and the other end of the right side rod is connected to a tip portion of the pitman arm, so that the height position of the other end of the right side rod changes as the steering angle of the right front wheel serving as the inner wheel increases.

6. 4. The steering mechanism according to claim 2, wherein the other end of the right rod and the other end of the left rod are arranged to be aligned in the vertical direction.

7. A pair of front wheels, A steering mechanism according to any one of claims 1 to 3; A pair of rear wheels; A vehicle body frame, A pair of swinging parts is provided, When one end of each of the swinging parts in the vehicle width direction is defined as a base end and the other end of the swinging part in the vehicle width direction is defined as a tip end, the base end side of each of the swinging parts is supported by the vehicle body frame so as to be swingable in the up-down direction about a swing axis extending in the front-rear direction of the vehicle, and each of the rear wheels is supported by the swinging parts so as to move in the up-down direction together with the tip end side of each of the swinging parts, a biasing member that applies a downward force to each of the swinging portions when the tip end side of the swinging portion moves upward; An electric mobility comprising: a swing control unit that suppresses or restricts, within a predetermined range, different directional swing in which one of the base ends of the pair of swing parts swings in a different direction in the vertical direction relative to the other.

Images