JP2020179685A - Steering structure of electric vehicle - Google Patents

Abstract

To ensure a space, where driver's feet are placed, without blocking a driver's field of vision.SOLUTION: An electric vehicle (1) includes a seat cushion (90) on which a driver is seated, a steering wheel unit (4) which is located ahead of the seat cushion and used by the driver to steer front wheels (10), a steering shaft (6) that bears the steering wheel unit at one end so that the steering wheel unit can integrally rotate about the shaft, a steering post (7) that bears the other end of the steering shaft so that the steering shaft can rotate about its axis, a steering angle sensor (50) that detects a steering angle of the steering wheel unit, a power steering mechanism (15) that varies the steering angle of the front wheels according to the steering angle of the steering wheel unit, and a controller (16) that controls the power steering mechanism. One end of the steering post is fixed to a vehicle body frame (2) and the other end of the steering post bears the other end of the steering shaft at a position higher than the seat surface of the seat cushion.SELECTED DRAWING: Figure 3

Description

The present invention relates to a steering structure of an electric vehicle.

Human-powered wheelchairs and electric wheelchairs that can be self-propelled by the driving operation of the user have been proposed as means of transportation for elderly people who have difficulty walking and persons with physical disabilities who have difficulty walking. For example, Patent Document 1 shown below describes a small electric vehicle in which a pair of left and right front wheels are arranged in front of a vehicle body frame and a pair of left and right rear wheels are arranged behind the vehicle body frame. The small electric vehicle is equipped with a drive motor for driving the rear wheels. A seat on which the driver sits is provided above the drive motor.

In addition, a steering shaft for steering the front wheels is erected upward in front of the floor. The steering shaft is provided with a leg shield as a protective cover that protects the driver's suspension.

JP-A-2010-200961

However, in Patent Document 1, there is a problem that the provision of the leg shield obstructs the driver's view of the front of the front wheel and limits the space on which the driver's foot rests.

The present invention has been made in view of the above points, and one of the objects of the present invention is to provide a steering structure for an electric vehicle capable of securing a space on which the driver's feet can be placed without obstructing the driver's field of view. To do.

The steering structure of the electric vehicle according to one aspect of the present invention includes a seat on which the driver sits, a steering wheel arranged in front of the seat and for the driver to steer the front wheels, and one end side around the steering wheel. A steering shaft that rotatably supports the steering shaft, a steering post that rotatably supports the other end side of the steering shaft, a steering angle sensor that detects the steering angle of the steering wheel, and a steering angle of the steering wheel. The steering post includes a power steering mechanism that changes the steering angle of the front wheels according to the steering angle, and a control device that controls the power steering mechanism. One end of the steering post is fixed to the vehicle body frame, and the other end is the seat surface of the seat. It is characterized in that the other end side of the steering shaft is supported at a higher position.

According to the present invention, it is possible to secure a space on which the driver's feet are placed without obstructing the driver's field of vision.

It is a perspective view which looked at the electric vehicle which concerns on this embodiment from the right front. It is a perspective view which looked at the electric vehicle which concerns on this embodiment from the right rear. It is a left side view of the electric vehicle which concerns on this embodiment. It is a front view of the electric vehicle which concerns on this embodiment. It is a top view of the handle unit which concerns on this embodiment. It is a perspective view of the steering structure which concerns on this embodiment. It is another perspective view of the steering structure which concerns on this embodiment. It is a functional block diagram of the steering structure which concerns on this embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following, the electric vehicle to which the present invention is applied will be described by taking a senior citizen car as an example, but the application target is not limited to this and can be changed. For example, the present invention may be applied to other types of electric vehicles such as electric wheelchairs for persons with physical disabilities. The direction is based on the driver, with arrow FR for the front of the vehicle, arrow RE for the rear of the vehicle, arrow UP for the upper part of the vehicle, arrow LO for the lower part of the vehicle, arrow L for the left side of the vehicle, and arrow R for the right side of the vehicle. Shown. That is, the direction indicated by the arrow FR is the forward direction of the vehicle.

First, the schematic configuration of the electric vehicle according to the present embodiment will be described with reference to FIGS. 1 to 5. FIG. 1 is a perspective view of the electric vehicle according to the present embodiment as viewed from the front right. FIG. 2 is a perspective view of the electric vehicle according to the present embodiment as viewed from the rear right. FIG. 3 is a left side view of the electric vehicle according to the present embodiment. FIG. 4 is a front view of the electric vehicle according to the present embodiment. FIG. 5 is a plan view of the handle unit according to the present embodiment. The electric vehicle is not limited to the configuration shown below, and can be changed as appropriate.

As shown in FIGS. 1 to 4, the electric vehicle 1 is composed of a senior car traveling on a sidewalk. The driver of the electric vehicle 1 is often an elderly person, and the electric vehicle 1 is treated as a pedestrian under the law. Specifically, the electric vehicle 1 includes a vehicle body in which the exterior cover 3 is attached to the vehicle body frame 2.

The vehicle body frame 2 constitutes the entire skeleton portion, and is formed by welding, for example, a metal pipe or a sheet metal member. The body frame 2 includes a body pipe 20 in which a metal pipe is bent in a U shape in a plan view. The body pipe 20 is composed of a pair of left and right sidebars 21 extending in the front-rear direction and a rear bar 22 connecting the rear ends of the pair of left and right sidebars 21.

The sidebar 21 has an obtuse-angled V-shaped bend when viewed from the side. Specifically, the sidebar 21 is bent at a substantially central portion in the front-rear direction of the vehicle. The sidebar 21 is inclined upward from the bent portion toward the front and extends forward, and is inclined upward from the bent portion toward the rear.

The rear bar 22 extends in the left-right direction, which is the vehicle width direction, behind the vehicle. Further, as will be described in detail later, a front bar 23 is provided in front of the vehicle so as to project forward in a U-shape in a plan view. A pair of left and right front wheels 10 are arranged on the front side of the vehicle body frame 2. The front bar 23 is provided at a position higher than that of the front wheel 10. A pair of left and right rear wheels 11 are arranged on the rear side of the vehicle body frame 2. The rear bar 22 is provided at a position higher than that of the rear wheel 11.

Further, the electric vehicle 1 according to the present embodiment is a rear-wheel drive vehicle, and includes an electric motor 12 for driving, a battery 13, and an inverter 14. The electric motor 12, the battery 13, and the inverter 14 are arranged in the vicinity of the rear wheels 11. The electric motor 12 drives the rear wheels 11 via a differential device (not shown). The electric motor 12 is driven by the electric power of the battery 13. The inverter 14 converts the direct current from the battery 13 into an alternating current and supplies it to the electric motor 12.

The exterior cover 3 includes a front cover 30 arranged on the front side of the vehicle body, an electrical cover 31 and a rear cover 32 arranged on the rear side of the vehicle body, and a step floor 33 that defines a footrest space for the driver. The cover. The front cover 30 is formed so as to cover above the pair of left and right front wheels 10. The front cover 30 functions as a mudguard for the front wheels 10. The front bar 23 penetrates the front cover 30 and projects forward and upward. Inside the front cover 30, a power steering mechanism 15 for changing the steering angle of the front wheels 10 is provided. Although not particularly shown, the power steering mechanism 15 includes a plurality of link mechanisms and actuators such as a steering motor (both not shown).

The electrical cover 31 is formed so as to cover the front upper part of the rear wheel 11. The front end of the electrical cover 31 is located at the bent portion of the sidebar 21. The electric motor 12, the battery 13, and the inverter 14 described above are covered with an electrical cover 31. Further, in addition to the above configuration, various electrical components such as a control device 16 that collectively controls the electric vehicle 1 are arranged inside the electrical cover 31.

The control device 16 is composed of a processor, a memory, and the like that execute various processes. The memory is composed of a storage medium such as a ROM (Read Only Memory) or a RAM (Random Access Memory) depending on the application. A control program or the like that controls the above-mentioned various configurations is stored in the memory. The main functions of the control device 16 in this embodiment will be described later.

The rear cover 32 is formed so as to cover the upper part of the pair of left and right rear wheels 11 so as to be connected to the rear end of the electrical cover 31. Like the front cover 30, the rear cover 32 also functions as a mudguard for the rear wheels 11. The electrical cover 31 and the rear cover 32 are arranged so as to be sandwiched between the pair of sidebars 21.

The step floor 33 is formed so as to cover a part of a pair of left and right sidebars 21 extending in the front-rear direction. The step floor 33 is arranged between the rear cover 32 and the front cover 30. Specifically, the step floor 33 is formed by a flat portion 34 extending flatly from the bent portion of the sidebar 21 toward the front wheel 10, and an inclined portion 35 that is connected to the tip of the flat portion 34 and is inclined upward toward the front. It is composed. That is, the flat portion 34 and the front cover 30 are connected by the inclined portion 35.

A steering wheel unit 4 (hereinafter, may be simply referred to as a steering wheel) that enables the vehicle to be steered is arranged above the front cover 30 and the step floor 33. The steering wheel unit 4 is attached to the vehicle body via the steer-by-wire mechanism 5. The steer-by-wire mechanism 5 includes a steering shaft 6 to which the steering wheel unit 4 is attached, and a steering post 7 that rotatably supports the steering shaft 6 around an axis. Further, the vicinity of the connecting portion between the steering shaft 6 and the steering post 7 is covered with the steering cover 8.

One end side of the steering post 7 is fixed to the vehicle body frame 2. The other end side of the steering post 7 supports the lower end side of the steering shaft 6. Specifically, the steering post 7 is configured by welding a metal fixing member to the upper and lower ends of a hollow pipe 70 bent in a substantially L-shape in a side view.

As shown in FIGS. 1 to 3, the hollow pipe 70 is inclined so that the apex of the bent portion 71 is located at the foremost end. Specifically, the hollow pipe 70 includes a first post portion 72 that inclines backward from the bent portion 71 as the starting point, and a second post portion 73 that inclines backward from the bent portion 71 as the starting point. have. The angle formed by the first post portion 72 and the second post portion 73 is a substantially right angle.

A block-shaped steering bracket 74 extending in the vehicle width direction is welded to the upper end of the first post portion 72. The opening of the first post portion 72 is exposed on the upper surface of the steering bracket 74 (see FIGS. 6 and 7). The steering shaft 6 and the first post portion 72 are arranged so that their axial directions are parallel to each other (see FIG. 3). More specifically, the central axis of the steering shaft 6 and the central axis of the first post portion 72 are deviated from each other, and the central axis of the steering shaft 6 is provided at a position higher than the central axis of the first post portion 72 ( (See FIG. 3).

A frame fixing portion 75 for fixing the hollow pipe 70 to the vehicle body frame 2 is welded to the second post portion 73 (see FIGS. 1 to 4). The frame fixing portion 75 is formed by bending a metal plate into a U shape in a front view so as to cover the upper part of the second post portion 73 (see FIG. 2). The lower end of the frame fixing portion 75 is welded to the vehicle body frame 2 directly below. In the side view, the frame fixing portion 75 is located substantially directly above the center of the front wheel 10. Further, the steering bracket 74 is arranged behind the frame fixing portion 75. The detailed configuration of the handle unit 4 and the steer-by-wire mechanism 5 will be described later.

A driver's seat 9 is arranged above the electrical cover 31. The seat 9 has a seat cushion 90 on which the driver sits, a seat back 91 constituting the backrest of the driver, and a pair of left and right armrests 92. The seat back 91 extends upward from the rear end of the seat cushion 90. Armrests 92 are provided on both sides of the seat back 91. The seat height of the seat cushion 90 is lower than the connection portion between the steering shaft 6 and the steering post 7.

Next, the detailed configuration of the handle unit 4 will be described. The steering wheel unit 4 is for the driver to steer the front wheels, and is configured to be rotated by the driver seated on the seat 9. The handle unit 4 is fixed to a handle bracket 60 provided at the upper end of the steering shaft 6. As shown in FIG. 5, the steering wheel unit 4 includes a pair of left and right handlebars 40 gripped by the driver, and a switch box 41 in which various operation switches are arranged.

The pair of handlebars 40 project from the left and right side surfaces of the switch box 41 and are bent in a substantially U-shape in a plan view. Rearview mirrors 42 are arranged at the left and right corners of the switch box 41, respectively.

The switch box 41 is arranged in the center of the entire handle unit 4. The switch box 41 is equipped with operating devices, display devices, and the like necessary for running the electric vehicle 1.

A pair of accelerator levers 43 are provided on the right side surface of the switch box 41. The accelerator lever 43 can be operated by pushing it down from the initial position in a predetermined direction. The accelerator lever 43 performs an accelerator operation in the traveling direction selected by the forward / backward switching lever 46 described later. When the accelerator lever 43 is pushed down, the electric vehicle 1 advances in a predetermined direction, and when the accelerator lever 43 is released, the electric motor 12 is braked and the electric vehicle 1 is braked.

A brake lever 44 is provided on the side surface of the front left corner of the switch box 41. The brake lever 44 projects to the left and is configured to be rotatable rearward from the initial position starting from the proximal end side. The brake lever 44 functions as a brake when the electric vehicle 1 is pushed by hand, and functions as a parking brake when parked.

On the upper surface of the switch box 41, a maximum speed setting knob 45, a forward / backward switching lever 46, a display unit 47, a blinker switch 48, and an alarm switch 49 are provided.

The maximum speed setting knob 45 is a dial-type operation unit, and is arranged substantially in the center of the upper surface of the switch box 41. By operating the maximum speed setting knob 45, it is possible to adjust the maximum speed when moving forward within a predetermined speed range. For example, the maximum speed of the electric vehicle 1 can be adjusted in the range of 1 km / h to 6 km / h.

The forward / backward switching lever 46 is composed of a switch that can slide in the front-rear direction. The forward / backward switching lever 46 is for switching the traveling direction of the vehicle between forward and reverse. The forward / backward switching lever 46 is slidable between a forward position instructing forward movement and a reverse movement position instructing reverse movement.

The display unit 47 includes a display that displays predetermined information on the electric vehicle 1 in a timely manner. The display unit 47 displays, for example, the charging status of the battery 13.

A pair of blinker switches 48 are provided on the left and right sides. A pair of left and right turn signal indicators 48a are arranged in the vicinity corresponding to the pair of left and right turn signal switches 48. For example, when the left turn signal switch 48 is operated, the left turn signal indicator light 48a blinks to signal a left turn. On the other hand, when the right turn signal switch 48 is operated, the right turn signal indicator light 48a blinks to signal a right turn.

The alarm switch 49 is composed of a push button type switch. The alarm switch 49 is arranged between the pair of blinker switches 48. By pressing the alarm switch 49, an alarm sound is emitted from the speaker (not shown).

By the way, in the wheelchair type small electric vehicle as described above, the one adopting the steer-by-wire system in which the steering control of the front wheels is realized by the power steering device without using human power has been proposed. For example, as this type of electric vehicle, there is a vehicle equipped with a steering actuator such as an electric motor, a power steering device composed of gears and links, and a joystick type controller for inputting steering force.

The operation of the joystick type electric vehicle is complicated, unlike the conventional steering wheel type electric vehicle. Specifically, in a joystick type electric vehicle, the speed system and the steering system are configured by the same detection device. On the other hand, in a steering wheel type electric vehicle, the speed system and the steering system are composed of separate detection devices. For this reason, it is expected that the joystick type electric vehicle will take longer to master the operation than the steering wheel type.

In addition, the drivers who use electric vehicles are often people with weak muscles and elderly people with weak reflexes. Therefore, it is preferable that the driver supports his / her weight when boarding the electric vehicle. In this respect, in the steering wheel type electric vehicle, the steering wheel is provided at a relatively high position of the electric vehicle. Therefore, the driver can utilize the steering wheel as a support when riding.

On the other hand, since the joystick type electric vehicle does not have the above-mentioned configuration that supports the driver when riding, there is a problem that it is difficult for the driver to ride while supporting the weight.

Further, in a conventional steering wheel type electric vehicle, a large protective cover is attached around the steering shaft that supports the steering wheel. For this reason, there is a possibility that the driver's field of view toward the front of the front wheels is obstructed and it becomes difficult to grasp the position of the front wheels. In addition, there may be a problem that the space on which the driver's foot is placed is limited.

Therefore, the present inventor came up with the present invention by paying attention to the positional relationship between the arrangement location of the steer-by-wire mechanism and the seating surface of the seat when adopting the steer-by-wire mechanism in the steering wheel type electric vehicle. As described above, in the present embodiment, the steering wheel unit 4 arranged in front of the seat 9 is attached to the vehicle body via the steer-by-wire mechanism 5. The steer-by-wire mechanism 5 includes a steering shaft 6 to which the steering wheel unit 4 is attached, and a steering post 7 that rotatably supports the steering shaft 6 around an axis. The steering shaft 6 supports the steering wheel unit 4 so as to be integrally rotatable around the axis on the upper end side. Further, one end side of the steering post 7 is fixed to the vehicle body frame 2, and the other end side supports the other end side of the steering shaft 6 at a position higher than the seating surface of the seat cushion 90.

According to this configuration, with the connection portion between the steering shaft 6 and the steering post 7 as a boundary, a movable portion that moves in conjunction with the rotation of the steering wheel unit 4 and a fixed portion that is fixed without being linked to the rotation of the steering wheel unit 4. It can be divided into parts and parts. In this case, the steering shaft 6 corresponds to the movable portion and the steering post 7 corresponds to the fixed portion. That is, the movable portion is provided at a position higher than the seat surface of the seat cushion 90, and the fixed portion is provided at a position lower than the seat surface of the seat cushion 90. Therefore, it is not necessary to provide a protective cover such as a leg shield around the steering post 7 located at the driver's feet. As a result, there are no obstacles that obstruct the view of the driver seated on the seat 9, and it is possible to secure a space for the driver's feet. Further, since the steering post 7 does not move in conjunction with the rotation of the steering wheel unit 4, it is possible to prevent clothes and luggage from being caught in the driver's suspension.

Next, the details of the steering-by-wire mechanism will be described with reference to FIGS. 1 to 8. FIG. 6 is a perspective view of the steering structure according to the present embodiment. FIG. 7 is another perspective view of the steering structure according to the present embodiment. FIG. 8 is a functional block diagram of the steering structure according to the present embodiment. In the functional block diagram shown in FIG. 8, the mechanical connection relationship is shown by a solid line, and the electrical connection relationship is shown by a broken line.

As shown in FIGS. 1 to 8, the electric vehicle 1 according to the present embodiment does not mechanically transmit the steering amount of the steering wheel unit 4 directly to the front wheels 10 which are steering wheels, but steers the steering wheel unit 4. A so-called steer-by-wire mechanism 5 that electrically detects the amount and controls the steering angle of the front wheels 10 is adopted. Steering-by-wire refers to a technology that replaces conventional mechanical control and controls mechanical operation with an electric signal via a wire. According to the steer-by-wire, since a gear box or the like connecting the steering shaft 6 and the axle is not required, the weight of the electric vehicle 1 can be reduced and the space can be expanded. In addition, the degree of freedom in vehicle design is greatly increased.

The steer-by-wire mechanism 5 detects the steering angle of the steering wheel unit 4 with the steering angle sensor 50, and the control device 16 controls the power steering mechanism 15 according to the steering angle to change the steering angle of the front wheels 10. It is configured (see FIG. 8).

Here, with reference to FIGS. 6 and 7, a detailed configuration of the steer-by-wire mechanism 5 for detecting the steering angle of the steering wheel unit 4, particularly a configuration of a connecting portion between the steering shaft 6 and the steering post 7 will be described in detail.

As shown in FIGS. 6 and 7, side posts 51 are provided at both left and right ends of the steering bracket 74 that forms a part of the steering post 7. The pair of left and right side posts 51 are composed of hollow pipes extending rearward and upward from the end of the steering bracket 74. The pair of left and right side posts 51 are arranged substantially parallel to the first post portion 72. The upper end of the side post 51 is located at substantially the same height as the armrest 92 in a side view (see FIG. 3).

The upper ends of the pair of side posts 51 are connected to each other by a connecting plate 51a. The connecting plate 51a is formed of a metal plate having a thickness in the front-rear direction and extending in the left-right direction. The connecting plate 51a is joined from the back side of the pair of side posts 51 by, for example, welding.

Further, a steering support 52 that rotatably supports the steering shaft 6 is provided between the pair of side posts 51 on the upper end side of the side posts 51. The steering support 52 is formed of a metal block body and has a through hole 52a penetrating vertically in the center. A steering support 52 is inserted through the through hole 52a. A bearing (not shown) is provided inside the through hole 52a. The steering support 52 is arranged in front of the connecting plate 51a and is fixed to the connecting plate 51a by bolts B and nuts N.

A bearing portion 53 that rotatably supports the steering shaft 6 and a sensor pedestal 54 for attaching the steering angle sensor 50 described above are provided between the steering support 52 and the steering bracket 74 in the axial direction. ..

The bearing portion 53 is formed in a substantially cylindrical shape. The steering shaft 6 extends downward until it reaches the bearing portion 53. The lower end of the steering shaft 6 is rotatably supported by a bearing (not shown) provided in the bearing portion 53. The sensor pedestal 54 extends to the left and right, and each end is welded to the side post 51. The sensor pedestal 54 is arranged at substantially the same height as the bearing portion 53, and is located slightly in front of the bearing portion 53. The bearing portion 53 and the sensor pedestal 54 are integrally fixed by bolting or welding.

A steering angle sensor 50 is provided on the upper surface of the sensor pedestal 54 via a sensor bracket 55. The sensor bracket 55 is formed by, for example, bending a metal plate. The steering angle sensor 50 is configured to detect the steering angle of the steering wheel unit 4 as described above. Specifically, the steering angle sensor 50 has a shaft portion 50a that penetrates the sensor bracket 55 from the lower surface and projects toward the sensor pedestal side. The shaft portion 50a is provided with a sensor-side gear portion 50b that meshes with the gear portion 57 on the steering shaft 6 side, which will be described later. The shaft portion 50a and the sensor side gear portion 50b are integrally rotatably connected to each other.

Above the bearing portion 53, the steering shaft 6 is provided with a stopper 56 that regulates the rotation angle range and a gear portion 57 that meshes with the sensor side gear portion 50b. The stopper 56 is formed of a plate-like body having a predetermined thickness in the axial direction. The stopper 56 projects radially outward from the outer surface of the steering shaft 6 toward the rear, and is formed in a substantially fan shape when viewed from the axial direction of the steering shaft 6. The gear portion 57 is located below the stopper 56 in the axial direction. The stopper 56 and the gear portion 57 are fixed so as to be rotatable integrally with the steering shaft 6.

The steering angle sensor 50 transmits the rotation of the steering shaft 6 to the sensor side gear portion 50b via the gear portion 57, and detects the rotation angle of the sensor side gear portion 50b to detect the rotation angle of the steering shaft 6, that is, the steering wheel unit. The steering angle of 4 is detected. A connector 50d of the wire harness 50c is connected to the front surface of the steering angle sensor 50. The wire harness 50c is routed downward from the front of the steering angle sensor 50 and is housed in the opening on the upper end side of the first post portion 72. Although not shown, the wire harness 50c is routed to the lower vehicle body frame 2 and further to the control device 16 behind the vehicle via the hollow pipe 70.

One end of the return spring 58 is engaged with each of the left and right corners of the stopper 56 formed in a fan shape. The return spring 58 is composed of, for example, a tension coil spring. Rod-shaped spring support portions 59 project from the left and right side surfaces of the sensor pedestal 54, respectively. The spring support portion 59 is formed by bending a rod member a plurality of times, and the other end of the return spring 58 is engaged with the tip thereof. The side post 51 is surrounded by the stopper 56, the return spring 58, and the spring support portion 59. The stopper 56 is pulled by a pair of return springs 58 and is held at the original position (direction in which the front wheels 10 face forward and backward) at which the steering angle becomes zero.

In the steer-by-wire mechanism 5 configured in this way, when the driver steers the steering wheel unit 4 in a predetermined direction, the steering shaft 6 rotates a predetermined angle around the axis. The rotation of the steering shaft 6 is transmitted to the sensor-side gear portion 50b via the gear portion 57 at the lower end. The steering angle sensor 50 can detect the rotation angle of the steering shaft 6 (steering angle of the steering wheel unit 4) by detecting the rotation of the gear portion 50b on the sensor side.

The rotation angle of the steering shaft 6 detected by the steering angle sensor 50 is output to the control device 16 via the wire harness 50c. The control device 16 issues a command to the power steering mechanism 15 to change the steering angle of the front wheels 10 according to the rotation angle of the steering shaft 6. The power steering mechanism 15 adjusts the steering angle of the front wheels 10 in response to a command from the control device 16. As a result, it is possible to control the steering of the front wheels 10 according to the steering angle of the steering wheel unit 4.

Further, the range of the steering angle of the steering wheel unit 4 is regulated by the stopper 56. Specifically, when the end of the fan-shaped stopper 56 comes into contact with the outer surface of the side post 51, further rotation of the steering shaft 6 is restricted. Thereby, it is possible to regulate the excessive rotation of the handle unit 4.

Further, the steering angle sensor 50 is arranged in front of the steering shaft 6. According to this configuration, since relatively large parts that obstruct the driver's field of vision are not located on the driver's side, it is possible to realize the steer-by-wire mechanism 5 without obstructing the driver's field of vision.

As described above, in the steering mechanism of the electric vehicle 1 according to the present embodiment, one end side of the steering post 7 is fixed to the vehicle body frame 2, and the other end side is steered at a position higher than the seat surface of the seat cushion 90. The other end side of the shaft 6 is rotatably supported. More specifically, the steering angle sensor 50 is provided at a position higher than the seat surface of the seat cushion 90. In this way, by arranging the boundary between the movable portion and the fixed portion constituting the steer-by-wire mechanism 5 at a position higher than the seating surface of the seat cushion 90, the movable portion of the steer-by-wire mechanism 5 is placed around the driver's suspension. It does not exist and it is possible to secure the leg space of the driver. There are no obstacles obstructing the driver's view of the vicinity of the front of the front wheel 10, and the visibility is improved.

Further, the steering wheel unit 4 is arranged at a high position on the front upper side of the seat 9, and the steering wheel unit 4 can be firmly fixed to the vehicle body frame 2 via the steering shaft 6 and the steering post 7. Therefore, the steering wheel unit 4 can be used as a support when the driver gets on the vehicle, and the convenience when getting on the vehicle is improved.

Further, the steering post 7 has a bent portion 71 arranged at the foremost end, a first post portion 72 that inclines backward from the bent portion 71 as a starting point, and a rearward portion that is inclined downward from the bent portion 71 as a starting point. It has a second post portion 73 that is inclined toward the surface. The second post portion 73 side is fixed to the vehicle body frame 2. According to this configuration, since the steering post 7 is bent in a side view, it is possible to increase the space for putting the foot above the step floor 33 and improve the comfort. Further, the steering post 7 can be formed so as to pass through a position farther from the viewpoint of the driver seated on the seat 9. As a result, it is possible to reduce the range of visibility toward the front of the front wheel 10 blocked by the steering post 7.

Further, the electric vehicle 1 includes a front bar arranged in front of the front wheel 10, and at least a part of the bent portion 71 is located in front of the center of the front wheel 10 and behind the front bar 23. .. According to this configuration, since the front bar 23 is located in front of the steering post 7, it is possible to prevent an obstacle or the like from colliding with the steering shaft 6. Further, by locating the bent portion in front of the center of the front wheel 10, it is possible to secure a sufficient field of view in the vicinity of the front of the front wheel 10 and to secure a wide footrest space for the driver.

Further, the steering post 7 is formed by a hollow pipe 70, and a wire harness 50c for the steering angle sensor 50 is arranged inside the hollow pipe 70. For example, when the wire harness 50c is arranged outside the steering post 7, it is necessary to provide a protective cover for protecting the wire harness 50c. Providing a protective cover around the steering post 7 can be an obstacle for the driver to block the view of the front wheels 10 toward the front. According to the above configuration, the wire harness 50c can be protected by the hollow pipe 70 without using the protective cover. Therefore, it is possible to prevent obstruction of the field of view.

Further, the step floor 33 provided as the exterior cover 3 that covers a part of the vehicle body frame 2 has an inclined portion 35 that is inclined upward toward the front and connected to the front cover 30. The steering post 7 is fixed to the vehicle body frame 2 in front of the extension line L of the inclined portion 35 in the side view. That is, the frame fixing portion 75 is arranged in front of the extension line L of the inclined portion 35. According to this configuration, even if the driver's foot protrudes from the inclined portion 35 when getting on and off, it is possible to prevent accidentally touching the steering post 7.

Further, the steer-by-wire mechanism 5 includes a pair of side posts 51 that connect the steering shaft 6 and the steering post 7, a stopper 56 that regulates the steering angle of the steering wheel unit 4, a sensor pedestal 54 to which the steering angle sensor 50 is attached, and one end. A return spring 58 that engages with the stopper 56 and the other end engages with the sensor pedestal 54 side. The stopper 56 and the sensor pedestal 54 are arranged between the pair of side posts 51. The stopper 56 regulates the steering angle of the steering wheel unit 4 by abutting on the outer surface of the side post 51. According to this configuration, it is possible to arrange the rotation regulation configuration and the in-position return configuration within the width of the pair of side posts. As a result, it is possible to prevent the steering-by-wire mechanism 5 from becoming large in size, further improving the visibility of the driver and securing a space under the feet.

In the above-described embodiment, the steering post 7 is formed in an L-shape in a side view, but the present invention is not limited to this configuration. For example, the steering post 7 may have a C-shaped or J-shaped curved shape.

Further, in the above-described embodiment, since the steering shaft 6 is not directly mechanically coupled to the front wheels 10, a degree of freedom can be obtained in the installation angle of the steering shaft 6. Therefore, a tilt mechanism may be added to the steering shaft 6. As a result, it is possible to realize a shaft shape that ensures visibility in front of the front wheel 10.

Further, in the above-described embodiment, the steering shaft 6 is preferably formed of a hollow pipe. According to this configuration, the wire harness from the handle unit 4 can be arranged in the hollow pipe, and the dedicated protective cover can be omitted. By forming the housing parts such as the vehicle body frame 2 with hollow pipes in this way, it is possible to secure a space for arranging the wire harness, and protect the wire harness without using a dedicated protective cover. It is possible. As a result, the number of exterior covers 3 can be reduced, and it is possible to secure a sufficient space for the driver's foot while preventing the driver's view from being obstructed.

Further, in the above-described embodiment, the case where the return spring 58 is composed of the tension coil spring has been described, but the present invention is not limited to this configuration. The return spring 58 may be composed of other types of urging members such as torsion springs and leaf springs.

Moreover, although the present embodiment and the modified example have been described, as another embodiment of the present invention, the above-described embodiment and the modified example may be combined in whole or in part.

Further, the embodiment of the present invention is not limited to the above-described embodiment, and may be variously modified, replaced, or modified without departing from the spirit of the technical idea of the present invention. Furthermore, if the technical idea of the present invention can be realized in another way by the advancement of the technology or another technology derived from it, it may be carried out by using that method. Therefore, the scope of claims covers all embodiments that may be included within the scope of the technical idea of the present invention.

As described above, the present invention has the effect of securing a space on which the driver's feet rest without obstructing the driver's field of vision, and is particularly useful for electric vehicles such as senior cars.

1: Electric vehicle 2: Body frame 3: Exterior cover 4: Steering by wire mechanism 6: Steering shaft 7: Steering post 8: Steering cover 9: Seat 10: Front wheels 11: Rear wheels 12: Electric motor 13: Battery 14: Inverter 15: Power steering mechanism 16: Control device 20: Body pipe 21: Sidebar 22: Rear bar 23: Front bar 30: Front cover 31: Electrical cover 32: Rear cover 33: Step floor 34: Flat part 35: Inclined part 40: Handlebar 41: Switch box 42: Back mirror 43: Accelerator lever 44: Brake lever 45: Maximum speed setting knob 46: Forward / backward switching lever 47: Display 48: Winker switch 48a: Winker indicator light 49: Alarm switch 50 : Steering angle sensor 50a: Shaft 50b: Sensor side gear 50c: Wire harness 50d: Connector 51: Side post 51a: Connecting plate 52: Steering support 52a: Through hole 53: Bearing 54: Sensor pedestal 55: Sensor bracket 56 : Stopper 57: Gear part 58: Return spring 59: Spring support part 60: Handle bracket 70: Hollow pipe 71: Bending part 72: First post part 73: Second post part 74: Steering bracket 75: Frame fixing part 90: Seat cushion 91: Seat back 92: Armrest B: Bolt N: Nut

Claims (7)

The seat on which the driver sits and
A steering wheel arranged in front of the seat for the driver to steer the front wheels,
A steering shaft that supports the handle so that it can rotate integrally around the axis on one end side,
A steering post that rotatably supports the other end of the steering shaft and
A steering angle sensor that detects the steering angle of the steering wheel and
A power steering mechanism that changes the steering angle of the front wheels according to the steering angle of the steering wheel,
A control device for controlling the power steering mechanism is provided.
The steering structure of an electric vehicle is characterized in that one end side of the steering post is fixed to a vehicle body frame and the other end side supports the other end side of the steering shaft at a position higher than the seat surface of the seat. The steering structure of an electric vehicle according to claim 1, wherein the steering angle sensor is provided at a position higher than the seat surface of the seat. The steering post
The bent part placed at the front end and
A first post portion that inclines backward from the bent portion as a starting point,
It has a second post portion that inclines rearward from the bent portion as a starting point toward the bottom.
The steering structure of an electric vehicle according to claim 1 or 2, wherein the second post portion side is fixed to the vehicle body frame. Further provided with a front bar located in front of the front wheels
The steering structure for an electric vehicle according to claim 3, wherein at least a part of the bent portion is located in front of the center of the front wheels and behind the front bar. The steering post is formed by a hollow pipe
The steering structure of an electric vehicle according to any one of claims 1 to 4, wherein a wire harness for the steering angle sensor is arranged inside the hollow pipe. Further provided with an exterior cover that covers a part of the vehicle body frame,
The exterior cover is
The front cover that covers the upper part of the front wheel and
It has a step floor that defines the footrest space for the driver.
The step floor has an inclined portion that is inclined upward toward the front and is connected to the front cover.
The steering structure for an electric vehicle according to any one of claims 1 to 5, wherein the steering post is fixed to the vehicle body frame in front of an extension line of the inclined portion in a side view. A pair of side posts connecting the steering shaft and the steering post,
A stopper that regulates the steering angle of the steering wheel,
The sensor pedestal to which the steering angle sensor is attached and
A return spring, one end of which engages the stopper and the other end of which engages the sensor pedestal side, is further provided.
The stopper and the sensor pedestal are arranged between the pair of side posts.
The steering structure of an electric vehicle according to any one of claims 1 to 6, wherein the stopper regulates the steering angle of the steering wheel by abutting on the outer surface of the side post.

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