Small electric vehicle

Abstract

To provide a small electric vehicle in which a suspension device is attached to a highly rigid portion.SOLUTION: A small electric vehicle includes: a vehicle body frame extending over the front and the rear of a vehicle body; a seat post extending upward from an intermediate part of the vehicle body frame; an upper frame connecting an intermediate part of the seat post with a rear part of the vehicle body frame; and suspension devices each including an arm part for supporting a rear wheel in a manner that allows vertical movement. A part of the arm part is disposed within a frame-like part enclosed by the vehicle body frame, the seat post, and the upper frame and fixed to the frame-like part.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a small electric vehicle. [Background technology]

[0002] Patent Document 1 discloses a small electric vehicle powered by battery power. The small electric vehicle includes a body frame and wheels attached to the body frame. The body frame includes a pair of left and right main pipes extending in the longitudinal direction of the vehicle, and multiple cross members connecting the two main pipes.

[0003] In the small electric vehicle of Patent Document 1, each of the left and right rear wheels is supported in a cantilevered manner on the body frame by a pivot shaft extending in the vehicle width direction. The pivot shaft allows each rear wheel to move up and down. In addition, a rear suspension that reduces the up and down movement of the rear wheels is supported on the body frame. It is believed that the pivot shaft and the upper ends of the rear suspension are both attached to a cross member of the body frame. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-76477 Summary of the Invention [Problem to be solved by the invention]

[0005] If the rigidity of the portion of the small electric vehicle to which the suspension device is attached is low, the ride comfort of the small electric vehicle may deteriorate.

[0006] One object of the present invention is to provide a small electric vehicle in which a suspension device is attached to a highly rigid portion. [Means for solving the problem]

[0007] <1> A small electric vehicle according to one aspect of the present invention includes a body frame extending across the front and rear of a vehicle body, a seat post extending upward from a middle portion of the body frame, an upper frame connecting the middle portion of the seat post to a rear portion of the body frame, and a suspension device including an arm portion that supports a rear wheel so that the rear wheel can move up and down. A portion of the arm portion is disposed inside a frame-shaped portion surrounded by the body frame, the seat post, and the upper frame, and is fixed to the frame-shaped portion.

[0008] <2> the above <1> In the small electric vehicle described in the above, the suspension device may include a shock absorber, and may further include a shock absorber mounting bracket that is fixed to the upper frame and fixes an upper end of the shock absorber. [Effects of the Invention]

[0009] the above <1> In the configuration described in the document, the body frame, seat post, and upper frame are connected in a frame-like manner to support each other. Therefore, the frame-like portion consisting of the body frame, seat post, and upper frame has extremely high rigidity. A portion of the arm portion of the suspension device is disposed inside this highly rigid frame-like portion, and a portion of the arm portion is fixed to the frame-like portion, thereby stabilizing the mounting state of the suspension device. Furthermore, because the seat post is firmly supported by the body frame and the upper frame, the mounting state of the seat attached to the seat post is also stable. As a result, the ride comfort of the small electric vehicle is improved.

[0010] the above <2> In the configuration described in [2], the shock absorber mounting bracket that secures the upper end of the shock absorber is fixed to the upper frame of the frame-shaped part, which has high rigidity, so the shock absorber is mounted in a stable state. In addition, by disposing the upper end of the shock absorber above the upper frame, the stroke length of the shock absorber is increased, improving the ride comfort of the small electric vehicle. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic side view of a small electric vehicle according to an embodiment. [Figure 2] FIG. 2 is a schematic perspective view of the area near the seat of the small electric vehicle of FIG. 1, as viewed obliquely from behind. [Figure 3] FIG. 3 is a schematic perspective view of a body frame of the small electric vehicle of FIG. [Figure 4] 4 is a schematic perspective view of the configuration in the vicinity of the suspension device in the small electric vehicle of FIG. 1, as viewed obliquely from behind. [Figure 5] FIG. 5 is a schematic side view of the configuration in the vicinity of the suspension device in the small electric vehicle of FIG. 1, as viewed from the side. [Figure 6] FIG. 6 is a schematic rear view of the configuration in the vicinity of the suspension device in the small electric vehicle of FIG. 1, as seen from behind. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] An example of an embodiment of a small electric vehicle according to the present invention will be described below with reference to the drawings. The dimensions of components shown in the drawings are for clarity of description and do not necessarily represent actual dimensions. In the drawings, "UP" indicates the top of the vehicle, "LWR" indicates the bottom, "FR" indicates the front, "RR" indicates the rear, "RH" indicates the right, and "LH" indicates the left. In the following description, "up," "down," "front," "rear," "right," and "left" respectively correspond to the "up," "down," "front," "rear," "right," and "left" of the vehicle. Note that the present invention is not limited to the following examples, but is defined by the claims, and includes all modifications within the meaning and scope of the claims.

[0013] <Embodiment 1> <Overall structure> A small electric vehicle 1 according to an embodiment will be described with reference to FIG. 1. The small electric vehicle 1 according to the embodiment will be described using a single-seater mobility scooter as an example. Mobility scooters are also called senior cars. In the following description, the small electric vehicle 1 may be simply referred to as a vehicle 1.

[0014] The small electric vehicle 1 includes a body frame 2 indicated by a dashed line. Attached to the body frame 2 are a power system including a battery (not shown), a drive system including wheels 10 and a suspension device 5 (see FIGS. 4 to 6 ), a seat system including a seat 13 where an occupant sits, an operation system including a handle 15 operated by the occupant, and a brake system including an electromagnetic brake 6 that decelerates the vehicle 1. The electromagnetic brake 6 not only functions to decelerate the vehicle 1, but also includes a locking mechanism 60 that locks the drive wheels when the vehicle 1 is stopped, and an unlocking switch 65 that unlocks the locking mechanism 60. The drive wheels in this example are the rear wheels 10B. Most of these components are covered by a body 9 made of metal, resin, or the like. The operation system may include a joystick instead of the handle 15.

[0015] The body 9 is provided with a seat post cover 90 that covers the seat post 3 that supports the seat 13 from below. As shown in FIG. 2, a recess 90c is formed in the rear surface of the seat post cover 90. Inside the recess 90c, an unlock switch 65 (see FIGS. 4 to 7) for unlocking the lock mechanism 60 (see FIG. 1) is disposed.

[0016] A suspension device 5 (see FIGS. 4 to 6) that supports the rear wheel 10B, which is the drive wheel, is disposed inside this seat post cover 90. One of the features of the small electric vehicle 1 of the embodiment is the configuration of the suspension device 5 that supports the rear wheel 10B. Each component of the vehicle 1 will be described below in order.

[0017] <Body frame> Fig. 3 is a schematic perspective view of the vehicle body frame 2. Fig. 3 also shows a seat post 3, an upper frame 4, and a steering column 8 attached to the vehicle body frame 2. The seat post 3 is part of a seat system. The steering column 8 is part of an operating system.

[0018] The body frame 2 includes a pair of left and right side members 21, 22 extending in the front-rear direction of the vehicle body, and cross members 23, 24 extending in the vehicle width direction and connecting the two side members 21, 22.

[0019] The side members 21, 22 have a front portion 2F, a middle portion 2M, and a rear portion 2B. The front portion 2F extends upward as it extends forward. The front end of the front portion 2F sandwiches the steering column 8. The middle portion 2M extends almost horizontally from the rear end of the front portion 2F toward the rear, and then extends diagonally upward. The rear portion 2B extends almost horizontally from the rear end of the middle portion 2M toward the rear. At the rear end of the rear portion 2B, the side members 21, 22 are spaced apart.

[0020] The cross member 23 is arranged to connect the front sections 2F. In this example, the cross member 23 is a pipe-shaped member. On the other hand, the cross member 24 is arranged to connect the slanted sections in the middle section 2M. In this example, the cross member 24 is a plate-shaped member with a hat-shaped cross section. The cross member 24 is arranged so that the opening of the hat shape faces downward.

[0021] The seat post 3 extends upward and is disposed in the middle of the cross member 24 in the width direction. In this example, the seat post 3 is tilted rearward as it extends upward. The seat 13 shown in FIG. 1 is attached to the upper end of the seat post 3.

[0022] <Upper frame> The compact electric vehicle 1 of this example further includes an upper frame 4. The upper frame 4 is disposed above the rear portions 2B of the side members 21, 22 of the vehicle body frame 2. The upper frame 4 connects the middle portion 3M of the seat post 3 in the height direction to the rear portions 2B of the side members 21, 22. The upper frame 4 of this example includes a frame main body 40 extending rearward from the middle portion 3M of the seat post 3, and a bridge portion 45 spanning between the two side members 21, 22. The frame main body 40 and the bridge portion 45 of this example are separate members and are integrated by welding or the like. Unlike this example, the bridge portion 45 may be omitted. In this case, the upper frame 4 is composed of only the frame main body 40. The rear end of the frame main body 40 is directly connected to the rear portions 2B of both side members 21, 22.

[0023] As shown in FIG. 5, the bridge portion 45 of this example includes a front leg plate 45F disposed forward, a rear leg plate 45B disposed rearward of the front leg plate 45F, and a top plate 45U connecting the upper ends of the front leg plate 45F and the rear leg plate 45B. The front leg plate 45F and the rear leg plate 45B of this example are inverted C-shaped plate members that open downward (see FIGS. 3 and 4). The front leg plate 45F and the rear leg plate 45B have a thickness that extends substantially along the longitudinal direction of the vehicle 1. The top plate 45U is a rectangular plate member that is long in the longitudinal direction of the vehicle 1. The top plate 45U has a thickness that extends substantially along the vertical direction of the vehicle 1.

[0024] When viewed from the side of the vehicle 1, the frame main body 40 includes a rectangular portion 40F located in the front and a triangular portion 40B located in the rear. The triangular portion 40B tapers toward the rear. The cross section of the frame main body 40 is hat-shaped and opens downward. The front end of the rectangular portion 40F is fixed to a portion of the circumferential surface of the seat post 3 that faces rearward. The lower end of the triangular portion 40B is fixed to the upper surface of the top plate 45U of the bridge portion 45. A step 40S is formed at the boundary between the rectangular portion 40F and the triangular portion 40B at the bottom of the frame main body 40. This step 40S abuts against the front surface of the front leg plate 45F. Therefore, even if a stress that tilts the seat post 3 backward acts on the seat post 3, the seat post 3 is supported by the frame main body 40, which is fixed to the circumferential surface of the seat post 3, and the bridge portion 45, on which the step 40S of the frame main body 40 is hooked. Since the bridge portion 45 is fixed to the body frame 2, the seat post 3 hardly bends.

[0025] As described above, in the vehicle 1 of this example, the body frame 2, seat post 3, and upper frame 4 are connected in a frame-like manner and support each other. Therefore, the frame-like portion 1F made up of the body frame 2, seat post 3, and upper frame 4 has extremely high rigidity. Because the body frame 2, seat post 3, and upper frame 4 support each other and are not easily bent, the vehicle 1 of this example provides excellent riding comfort when sitting in the seat 13 and when driving.

[0026] As shown in Fig. 3, a base portion 41 is fixed to the middle portion of the frame main body 40 in the vehicle length direction. The base portion 41 is a gate-shaped member including a left wall portion 41L, a right wall portion 41R, and an upper surface portion 41U. The middle portion of the frame main body 40 is sandwiched between the left wall portion 41L and the right wall portion 41R. The base portion 41 has a rectangular shape when viewed from the side of the vehicle 1.

[0027] A shock absorber mounting bracket (hereinafter referred to as SA bracket) 42 is attached to the base portion 41. The SA bracket 42 includes a mounting portion 42F to which a shock absorber 55 is attached and a front wall portion 42W that extends downward from the front end of the mounting portion 42F. The SA bracket 42 is formed by bending a single plate material. A notch is formed in the middle of the SA bracket 42 in the vehicle width direction, facing toward the rear of the vehicle. The notch is formed to divide the front wall portion 42W into left and right halves and extends halfway through the mounting portion 42F. The base portion 41 is fitted into the notch, so that the front wall portion 42W sandwiches the base portion 41 from the left and right. The front wall portion 42W and the mounting portion 42F are fixed to the base portion 41 by welding or the like. The left and right portions of the mounting portion 42F each have a portion that slopes upward as it moves outward in the vehicle width direction. An upper end 55U of a shock absorber 55, which will be described later, is fixed to this inclined portion.

[0028] As shown in FIGS. 3 to 5, a switch mounting bracket (hereinafter referred to as SW bracket) 43 is further attached to the rear end of the mounting portion 42F. The SW bracket 43 in this example is a member independent of the SA bracket 42, and as shown in FIGS. 4 to 6, is a plate-shaped member including a vertical wall portion 43W and a mounting portion 43F. The SW bracket 43 is integrated with the rear portion of the SA bracket 42 by welding or the like. Furthermore, the vertical wall portion 43W of the SW bracket 43 is fixed to the rear end of the base portion 41 and the upper surface of the upper frame 4 by welding or the like. Unlike this example, the SW bracket 43 and the SA bracket 42 may be a seamless, integrated member. An unlocking switch 65, which will be described later, is disposed on the SW bracket 43.

[0029] <Suspension device> In this example, the suspension device 5 that supports the rear wheel 10B will be described with reference to Figures 4 to 6. A description of the suspension device (not shown) that supports the front wheel 10F will be omitted.

[0030] As shown in Fig. 4, the vehicle 1 of this example is equipped with a suspension device 5 that supports the left rear wheel 10B and a suspension device 5 that supports the right rear wheel 10B. The left and right suspension devices 5, 5 are independent. Each suspension device 5 includes an arm portion 50, a pivot shaft 51, a motor 52, a coil spring 53, and a shock absorber 55. In the drawing of this example, the coil spring 53 is shown simplified as a cylindrical shape.

[0031] The arm portion 50 is a member that supports the rear wheel 10B so that it can move up and down. In this example, the arm portion 50 is a box-shaped body that includes a front portion 50F (FIG. 5), a rear portion 50B, a top portion 50U, and side portions 50S, and is open at the bottom. The front portion 50F and the rear portion 50B are plate members that have an inverted trapezoidal shape when viewed from the rear. The inner ends of the front portion 50F and the rear portion 50B are attached to the bridge portion 45 by pivot shafts 51. The inner ends are ends that face the center of the vehicle 1 in the vehicle width direction. The pivot shafts 51 that support the arm portion 50 extend in the front-to-rear direction of the vehicle 1. Therefore, the outer ends of the arm portion 50 are configured to be able to swing up and down around the axis of the pivot shafts 51. The outer ends are ends that face away from the center of the vehicle 1 in the vehicle width direction.

[0032] The top portion 50U is a rectangular plate member that connects the upper end of the front portion 50F with the upper end of the rear portion 50B. The side portion 50S is a rectangular plate member that connects the outer end of the front portion 50F with the outer end of the rear portion 50B. A through hole 50h is formed in the side portion 50S.

[0033] As described above, the inner end of the arm portion 50 is disposed inside the bridge portion 45, which is part of the frame portion 1F, which has excellent rigidity, and is supported by the frame portion 1F. By attaching the arm portion 50 to the frame portion 1F, which has excellent rigidity, the arm portion 50 is firmly held to the body frame 2 and does not wobble. The arm portion 50, which is firmly held to the body frame 2, improves the ride comfort of the vehicle 1.

[0034] The motor 52 rotates the rear wheel 10B using power from a battery (not shown). In this example, the motor 52 is disposed inside the box-shaped arm portion 50 and is fixed to the arm portion 50. In a configuration in which the left and right suspension devices 5 are independent, the left and right rear wheels 10B rotate independently. Unlike this example, the motor 52 may be an in-wheel motor disposed inside the rear wheel 10B. A rotation shaft 52s of the motor 52 passes through the through hole 50h. The rear wheel 10B (see FIG. 1) is attached to this rotation shaft 52s.

[0035] The coil spring 53 is a member that absorbs input from the ground. A known configuration can be used for the coil spring 53. In this example, the coil spring 53 is disposed on the outer periphery of the shock absorber 55. In other words, the shock absorber 55 is inserted inside the coil spring 53. Unlike this example, the coil spring 53 may be disposed at a position away from the shock absorber 55.

[0036] The shock absorber 55 is a member that damps the vibration of the coil spring 53. A known configuration can be used for the shock absorber 55. The lower end 55D of the shock absorber 55 is attached to the top portion 50U of the arm portion 50 so as to be able to swing freely. Meanwhile, the upper end 55U of the shock absorber 55 is fixed to the mounting portion 42F of the SA bracket 42. The SA bracket 42 is fixed to the frame main body 40 of the upper frame 4, which has excellent rigidity. Therefore, the shock absorber 55 is firmly held to the vehicle frame 2 and does not wobble. Such a shock absorber 55 can effectively damp the vibration of the coil spring 53, improving the ride comfort of the vehicle 1.

[0037] The SA bracket 42, to which the upper end 55U of the shock absorber 55 is fixed, is disposed above the upper frame 4. Therefore, the vehicle 1 of this example can employ a shock absorber 55 with a long stroke length. The shock absorber 55 with a long stroke length can quickly damp the vibration of the coil spring 53.

[0038] In this example, the arm portions 50, 50 of the left and right suspension devices 5, 5 are configured independently, but unlike this example, the left and right arm portions 50, 50 may be connected in series. In this case, the middle portions of the connected arm portions 50, 50 are supported on the bridge portion 45 by a pivot shaft 51. A motor 52, a coil spring 53, and a shock absorber 55 are each arranged on the left and right sides.

[0039] <Unlock switch> From the perspective of safety, in the vehicle 1 of this example, the locking mechanism 60 is activated when the vehicle is stopped, locking the rear wheels 10B. The locking mechanism 60 is, for example, a non-excitation-activated electromagnetic brake. A non-excitation-activated electromagnetic brake is an electromagnetic brake that locks the rear wheels 10B when not energized and unlocks the rear wheels 10B when energized. The locking mechanism 60 maintains the vehicle 1 in a stopped state, ensuring the safety of occupants when getting on and off the seat 13. The locking mechanism 60 is automatically released, for example, when the occupant operates the accelerator. With such a vehicle 1, there are situations where it is desirable to move the vehicle 1 manually. For example, if the vehicle 1 runs off the road, there is a need to manually lift part of the vehicle 1 to move the vehicle 1. The lock release switch 65 meets such needs.

[0040] To ensure the safety of passengers getting in and out of the seat 13, the unlock switch 65 must be located in a position that is not easily accessible to passengers seated in the seat 13. The unlock switch 65 in this example is located on the upper surface of the recess 90c, as shown in FIG. 7, which is a cross-sectional view taken along the line VII-VII in FIG. 2. The unlock switch 65 includes a button 65b that can be pressed with a finger. The unlock switch 65 in the recess 90c is located in a position where the button 65b can be touched with a user's finger when the user stands to the side of the vehicle 1 with their palm facing up and inserts their finger into the recess 90c. In other words, the button 65b of the unlock switch 65 faces downward, and the button 65b is pressed upward. The lock mechanism 60 is released only while the button 65b of the unlock switch 65 is pressed, and the lock mechanism 60 is locked when the user releases their finger from the button 65b of the unlock switch 65. If the vehicle 1 having this configuration goes off the road, for example, the user holds the handlebars 15 with one hand and grabs the recessed portion 90c with the other hand to lift the seat post cover 90 upward. At this time, because the direction in which the seat post cover 90 is lifted and the direction in which the button portion 65b is pressed are the same, the user can press the button portion 65b of the lock release switch 65 with their fingertip at the same time as lifting the vehicle 1. In other words, the lock mechanism 60 can be released through a series of actions in which the small electric vehicle 1 is lifted, allowing the vehicle 1 to be moved easily.

[0041] In this embodiment, heavy components such as the motor 52 and the suspension system 5 are concentrated in the rear of the vehicle 1, making the rear of the vehicle 1 very heavy. To lift this heavy rear of the vehicle 1, a portion that can be grasped with the hand during lifting must have sufficient rigidity. The unlock switch 65 in this embodiment is fixed to the SW bracket 43. The SW bracket 43 is fixed to the upper frame 4, which has excellent rigidity, via the SA bracket 42 and the base 41. Therefore, when a user grasps the recess 90c with their hand and lifts the seat post cover 90 while pressing the button 65b of the unlock switch 65 to move the vehicle 1, the SW bracket 43 can share the stress generated during lifting. Therefore, the seat post cover 90 is unlikely to be damaged when lifted. Furthermore, even if a strong stress is applied to the unlock switch 65, the unlock switch 65 is unlikely to rattle or come off. [Explanation of symbols]

[0042] 1. Small electric vehicles 1F frame part 10 wheels, 10B rear wheels, 10F front wheels 13 seat, 15 handle 2 Body frame 2B rear, 2F front, 2M middle 21,22 Side members, 23,24 Cross members 3 seatpost 3M middle part 4 Upper frame 40 Frame body 40B triangular section, 40F rectangular section, 40S step 41 Base 41L left wall, 41R right wall, 41U top 42 Shock absorber mounting bracket (SA bracket) 42F mounting part, 42W front wall part 43 Switch mounting bracket (SW bracket) 43F mounting section, 43W vertical wall section 45 Bridge section 45B rear leg plate, 45F front leg plate, 45U top plate 5. Suspension device 50 Arm section 50h through hole, 50B rear, 50F front, 50S side, 50U top 51 Pivot axis 52 Motor 52s Rotating Axis 53 Coil spring 55 shock absorber 55D bottom edge, 55U top edge 6 Electromagnetic brake 60 Locking mechanism 65 Unlock switch, 65b Button 8. Steering column 9 Body 90 seatpost cover, 90c recess

Claims

1. a body frame extending across the front and rear of the vehicle body; a seat post extending upward from a middle portion of the body frame; an upper frame connecting an intermediate portion of the seat post and a rear portion of the body frame; a suspension device including an arm portion that supports the rear wheel so that the rear wheel can move up and down; a portion of the arm portion is disposed inside a frame-shaped portion surrounded by the body frame, the seat post, and the upper frame, and is fixed to the frame-shaped portion; Small electric vehicle.

2. the suspension device includes a shock absorber; The small electric vehicle according to claim 1 , further comprising a shock absorber mounting bracket fixed to the upper frame and for fixing an upper end of the shock absorber.

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