JP2016120747A - Electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable easy and safe maintenance of internal components, in an electric vehicle having three or more wheels, an electric motor, and a battery.SOLUTION: An electric vehicle 1 includes: electric motors serving as power sources, for driving some or all of provided three or more wheels; and a battery for supplying electric power to the electric motors. The electric vehicle 1 includes: a lower unit 10 having the electric motors and the battery; and an upper unit 11 provided above the lower unit 10, for storing components. The electric vehicle has a clamshell structure where the upper unit 11 can be opened to a predetermined angle equal to or under a right angle with respect to the lower unit 10, around a hinge portion 12 provided at the lower unit 10 and the upper unit 11, on the rear side or the front side of the electric vehicle 1. Of the rear side and the front side of the electric vehicle 1, the electric motors are disposed at one side where the hinge portion 12 is not provided, and the battery is disposed at the other side where the hinge portion 12 is provided.SELECTED DRAWING: Figure 1A

Description

  The present invention relates to an electric vehicle, and more particularly to an electric vehicle having a battery and using an electric motor as a power source.

  Some vehicles are configured to be able to run on alternative fuels such as electricity, hydrogen, and biofuel in addition to petroleum fuel. If electricity, hydrogen, or the like is used, it is possible to eliminate CO2 emission during traveling than when petroleum fuel is used. In particular, if the battery is used, the vehicle can be more easily downsized and the mobility can be improved than when a fuel cell or the like is used. For this reason, the demand for battery-driven electric vehicles is increasing in various applications such as transport vehicles, care vehicles, and monitoring vehicles. However, electric vehicles driven by fuel cells are also expected to be used, and further miniaturization is expected. Many battery-driven electric vehicles use an electric motor as a power source.

  As a kind of vehicle, Patent Document 1 discloses that a rear body frame is connected to a rear portion of a front body frame so as to be relatively rotatable around a vertical axis, and an engine for driving a vehicle and driving a work machine is mounted on the rear body frame. A wheel loader is disclosed. In this wheel loader, the upper part of the engine and its surroundings is covered with a bonnet hood, and an operation seat is provided on the upper surface of the bonnet hood, and the rear end side of the bonnet hood can be freely opened and closed around a rotation axis along the lateral direction of the body It is connected to the rear part of the rear body frame.

JP 2000-73401 A

  As described above, in an electric vehicle, downsizing is required to improve mobility, but in order to reduce the size, it is necessary to increase the density of components inside the electric vehicle. On the other hand, when trying to increase the density of parts, the number of parts that require much time for removal increases, so it cannot be said that maintenance of internal parts can be easily performed.

  Of course, such a problem similarly occurs in a wheel loader having a mechanism for opening a hood hood (hood-like hood) as described in Patent Document 1 and a passenger car having a mechanism for opening a hood. In particular, these bonnets basically serve as a lid that covers a part of the vehicle's internal parts (mainly the engine), and other parts that need to be opened during maintenance. Since there are many (for example, a steering system and various control boards), it cannot be said that maintenance of internal components can be easily performed.

  In addition, a device for facilitating maintenance work when reducing the size of an electric vehicle needs to consider the safety of the maintenance work. In particular, the electric vehicle may be maintained with the battery removed, and it is necessary to ensure safety during the maintenance work even in such a state.

  The present invention has been made in view of the above circumstances, and its object is to facilitate maintenance work of internal components easily and safely in an electric vehicle including three or more wheels, an electric motor, and a battery. It aims to be able to be executed.

  In order to solve the above-described problem, the first technical means of the present invention includes three or more wheels, an electric motor serving as a power source for driving part or all of the three or more wheels, An electric vehicle including a battery for supplying electric power to the electric motor, wherein the electric vehicle includes a lower unit including the electric motor and the battery, and an upper unit provided on an upper portion of the lower unit and housing components. The upper unit is opened to a predetermined angle that is equal to or less than a right angle with respect to the lower unit, with a hinge portion provided in the lower unit and the upper unit at the rear side or the front side of the electric vehicle. The electric motor is disposed on the rear side or the front side of the electric vehicle where the hinge part is not provided, and the hinge part is provided. It is obtained by wherein the said battery on the side that is being arranged.

  According to a second technical means, in the first technical means, the horizontal position of the center of gravity of the upper unit is on the front side or the rear side of the electric vehicle on the side where the hinge portion is not provided. It is what.

  According to a third technical means, in the first or second technical means, a lock mechanism is provided for locking at least one rotation of the wheel when the upper unit is opened with respect to the lower unit. It is characterized by.

  According to a fourth technical means, in any one of the first to third technical means, the upper unit has a plurality of removable subunits, and the more frequently the maintenance unit is, the more the electric vehicle It is arrange | positioned in the side in which the said hinge part is not provided among the front side or back side of this.

  According to a fifth technical means, in any one of the first to fourth technical means, the electric motor and the battery are accommodated in a bottom surface portion of the lower unit.

  Sixth technical means is characterized in that, in any one of the first to fifth technical means, among the wheels, a wheel on the front side of the electric vehicle and a wheel on the rear side are arranged close to each other. It is a thing.

  According to the present invention, maintenance work of internal parts can be easily and safely performed in an electric vehicle including three or more wheels, an electric motor, and a battery.

1 is a perspective view illustrating a configuration example of an electric vehicle according to a first embodiment of the present invention. It is a side view of the electric vehicle of FIG. 1A. It is a figure which shows a mode that it saw from the arrow CC direction of the electric vehicle of FIG. 1B. It is a figure which shows an example of the gravity center of the electric vehicle of FIG. 1A, and the weight ratio of each component, and is also a figure which shows the example of 1 structure of the electric vehicle which concerns on the 2nd Embodiment of this invention. It is a figure which shows a mode that it saw from the arrow BB direction of the electric vehicle of FIG. 2A. It is a figure which shows the example of 1 structure of the lock mechanism provided in the electric vehicle which concerns on the 3rd Embodiment of this invention. It is a figure which shows the mode at the time of the lock | rock by the lock mechanism of FIG. 3A. It is a figure which shows the mode at the time of unlocking by the locking mechanism of FIG. 3A. It is sectional drawing which shows one structural example of the electric vehicle which concerns on the 4th Embodiment of this invention.

  The electric vehicle according to the present invention is a vehicle having a battery (storage battery), a fuel cell or the like and using an electric motor as a power source, and is particularly suitable for autonomous driving. Of course, the present invention can also be applied to an electric vehicle in which a seat is provided in the upper portion and driven by a wireless controller or the like. Various types of batteries such as lithium ion secondary batteries and nickel metal hydride batteries can be used as the battery. Hereinafter, various embodiments of the present invention will be described in detail with reference to the drawings. Hereinafter, a battery will be described as an example of a battery, but a battery such as a fuel cell can be similarly applied.

(First embodiment)
An electric vehicle according to a first embodiment of the present invention will be described with reference to FIGS. 1A to 2B. 1A is a perspective view showing an example of the configuration of an electric vehicle according to the present embodiment, FIG. 1B is a side view of the electric vehicle of FIG. 1A, and FIG. 1C is from the direction CC of the electric vehicle of FIG. 1B. It is a figure which shows a mode that it saw. 2A is a diagram showing an example of the center of gravity of the electric vehicle and the weight ratio of each component in FIG. 1A, and FIG. .

  The electric vehicle 1 illustrated in FIGS. 1A to 1C can function as a traveling unit of an autonomous traveling robot equipped with, for example, a camera. In addition, the electric vehicle 1 includes a control unit (not shown) such as a CPU (Central Processing Unit) board, which will be described later based on a signal from the outside and a detection result of the camera. It controls the rotation speed and direction of the electric motor, the brake amount and timing of the front and rear wheels.

  The electric vehicle 1 includes four wheels (the right front wheel 21 and the rear wheel 22 and the left front wheel 31 and the rear wheel 32), and electric motors 41L and 41R serving as a power source for driving the wheels. And a battery 40 for supplying electric power to the electric motors 41L and 41R. In this example, four wheels are provided, but three or more wheels may be provided. Moreover, although the example which provided the wheel in the side surface of the below-mentioned lower unit 10 is given, it can also be provided so that it may be covered with the lower unit 10. In FIGS. 1B and 2B, the wheels 21, 22, 31, and 32 are indicated by chain lines.

  The electric motors 41L and 41R are an example of an electric motor that serves as a power source for driving part or all of the wheels (three or more wheels) provided in the electric vehicle 1. The illustrated electric motor 41R drives the right front wheel 21 and also drives the right rear wheel 22 indirectly (to be driven). Similarly, the illustrated electric motor 41L drives the left front wheel 31 and also drives the left rear wheel 32 indirectly. Further, for such indirect driving, the electric vehicle 1 may be provided with a power transmission member that transmits power between the front wheels and the rear wheels provided as a pair. The electric vehicle 1 may be provided with wheels that rotate only when the electric vehicle 1 is driven forward or backward by driving other wheels, that is, wheels that are not directly or indirectly connected to the electric motor.

  As one of the main features of the present invention, the electric vehicle 1 includes a lower unit 10 including electric motors 41L and 41R and a battery 40, and an upper unit 11 provided on the upper portion of the lower unit 10. It is assumed that parts are stored in the upper unit 11. The storage method may be any method including attachment with screws or the like. Therefore, the upper unit 11 is not a simple lid. The shape of the upper unit 11 is not limited to the rectangular shape shown in the drawing, and various electronic boards and other components that constitute the control unit can be included therein. These internal components may be mounted in a state where they can be taken out from the upper unit 11 as one subunit 13 (or a plurality of subunits), for example.

  The electric vehicle 1 opens the upper unit 11 to a predetermined angle equal to or less than a right angle with respect to the lower unit 10 around the hinge portion 12 provided in the lower unit 10 and the upper unit 11 on the rear side of the electric vehicle 1. It has a clamshell type structure. Although the example in which the hinge part 12 was provided in the back side of the electric vehicle 1 is given, it may be provided in the front side. When provided on the front side, the upper unit 11 is opened from the rear of the electric vehicle 1.

  Further, in FIG. 1B, the angle when the upper unit 11 is opened with respect to the lower unit 10 is illustrated as θ. Of course, in the open state, it is necessary to prevent the upper unit 11 from descending. For this purpose, a support portion (not shown) for supporting the upper unit 11 may be provided on the lower unit 10. This support part is preferably provided with a damper such as a gas damper. As a result, it is possible to prevent a hand from being caught during manual opening and closing.

  By adopting the structure as described above, compared to the conventional vehicle provided with a simple lid-like body or bonnet, not only the parts seen from the upper side of the lower unit 10 in the opened state but also the lower part of the upper unit 11 The parts visible from the side are also added, and the internal parts visible on the surface can be doubled. In other words, compared with the conventional vehicle, it is possible to improve the component density while ensuring the take-out property of the internal components. Therefore, with such a structure, many internal parts can be easily taken out, and maintenance becomes easy. In addition, what is necessary is just to implement maintenance of the components provided in the exteriors, such as a wheel, from the side.

  Here, the lower unit 10 will be described. The lower unit 10 is formed in a rectangular shape as illustrated. Of course, it is not limited to a rectangular shape. The lower unit 10 in the present configuration example includes a front surface 14F and a rear surface 14B that face each other in the traveling direction indicated by an arrow, and a right side surface 14R and a left side surface 14L that face each other in the direction intersecting the traveling direction. As described above, the electric vehicle 1 has four wheels. The right front wheel 21 and the rear wheel 22 are protruded from the right side surface 14R, and the left front wheel 31 and the rear wheel 32 are protruded from the left side surface 14L. Have.

  The length of the right side surface 14R and the left side surface 14L (the total length of the lower unit 10) is, for example, about 1 m, and the length of the front surface 14F and the rear surface 14B (also referred to as the width of the lower unit 10) is, for example, 0.8 to 0.9 m. The electric vehicle 1 can be configured as a degree. Further, by setting the distance between the axes of the right front wheel 21 and the rear wheel 22 or the left front wheel 31 and the rear wheel 32 (also referred to as a wheel base) to be as short as about 0.8 m, for example, the electric vehicle 1 It is possible to provide mobility that can turn even in a narrow place. Further, the outer diameters of the front wheels 21 and 31 and the rear wheels 22 and 32 are all about 0.4 m, for example. Of course, the dimensions of the electric vehicle 1 are not limited to those illustrated here.

  A band-shaped cover 18 is installed on each of the side surfaces 14R and 14L of the lower unit 10 and extends along the front-rear direction of the lower unit 10. Below the cover 18 are provided axles 21a, 31a and axles 22a, 32a that rotatably support the front wheels 21, 31 and the rear wheels 22, 32, respectively. Each axle 21a, 31a, 22a, 32a is independently rotatable when not coupled by a power transmission member.

  As a power transmission member in this configuration example, a sprocket 21b is provided on the axle 21a of the right front wheel 21, and a sprocket 22b is provided on the axle 22a of the rear wheel 22. Between the sprocket 22b, for example, a belt 23 provided with a protrusion that meshes with the sprocket is provided on the inner surface side. Similarly, a sprocket 31b is provided on the axle 31a of the left front wheel 31, and a sprocket 32b is provided on the axle 32a of the rear wheel 32, and between the front wheel sprocket 31b and the rear wheel sprocket 32b. A belt 33 similar to the belt 23 is wound around.

  With this configuration, the left and right pair of front wheels and rear wheels function as driven wheels that are driven without slipping by a belt that is a power transmission member when one wheel is a driving wheel. To do. As a power transmission member that connects a pair of left and right front wheels and rear wheels, in addition to using a sprocket and a belt provided with a projection that meshes with the sprocket, for example, a sprocket and a chain that meshes with the sprocket may be used. . Furthermore, if slip is acceptable, a pulley and a belt having a large friction may be used as the power transmission member. However, the power transmission member needs to be configured so that the rotational speeds of the driving wheel and the driven wheel are the same.

  In the present configuration example, the right sprockets 21b, 22b and the belt 23, which are power transmission members, are arranged outside the right side surface 14R and below the cover 18, and the left sprockets 31b, 32b and the belt 33 is arranged outside the left side surface 14L and below the cover 18, but the cover 18 may be omitted and the power transmission member may be arranged inside the lower unit 10.

  The electric motor 41R and the electric motor 41L are provided on the front wheels 21 and 31 side of the bottom surface 15 of the lower unit 10. Thus, by arranging the electric motor on the front side in the traveling direction, sufficient air cooling can be easily performed even if the electric motor generates a large amount of heat. A gear box 43R is provided as a part of the power transmission mechanism between the motor shaft 42R of the right electric motor 41R and the axle 21a of the right front wheel 21. Similarly, a gear box 43L is provided as a part of the power transmission mechanism between the motor shaft 42L of the left electric motor 41L and the axle 31a of the left front wheel 31. In the present configuration example, the two electric motors 41R and 41L are arranged in parallel so as to be symmetric with respect to the center line in the traveling direction of the electric vehicle 1, and the gear boxes 43R and 43L are also the electric motors 41R and 41L, respectively. It is arranged on the left and right outside.

  The gear boxes 43R and 43L are composed of a plurality of gears, shafts, and the like, and are assembly parts that transmit the power from the electric motor to the axle that is the output shaft by changing the torque, the rotation speed, and the rotation direction. A clutch for switching the shutoff may be included. The left and right rear wheels 22 and 32 are pivotally supported by bearings 44R and 44L, respectively, and the bearings 44R and 44L are disposed close to the right side surface 14R and the left side surface 14L of the bottom surface 15 of the lower unit 10, respectively. Yes.

  In this configuration example, the pair of front and rear wheels 21 and 22 on the right side in the traveling direction and the left and right front and rear wheels 31 and 32 can be independently driven in this manner. That is, the power of the right electric motor 41R is transmitted to the gear box 43R through the motor shaft 42R, and the rotational speed, torque, or rotational direction is changed by the gear box 43R and transmitted to the axle 21a. The wheel 21 is rotated by the rotation of the axle 21a, and the rotation of the axle 21a is transmitted to the axle 22a via the sprocket 21b, the belt 23, and the sprocket 22b, and the rear wheel 22 is rotated. The transmission of power from the left electric motor 41L to the front wheels 31 and the rear wheels 32 is the same as that on the right side described above, and a description thereof will be omitted.

  In addition, the configuration of the drive system of the electric vehicle 1 in this configuration example is a well-balanced vehicle because the left and right configurations are the same with respect to the center line in the traveling direction. Further, since the driving force from the electric motors 41R and 41L is a four-wheel drive that is transmitted to all the wheels, there is no problem in traveling on rough roads such as rough terrain.

  When the rotation speeds of the two electric motors 41R and 41L are the same, the electric vehicle 1 moves forward or backward if the gear ratios (reduction ratios) of the gear boxes 43R and 43L are the same. When changing the speed of the electric vehicle 1, the gear ratios of the gear boxes 43R and 43L may be changed while maintaining the same value. Further, when changing the traveling direction, the gear ratio of each gear box 43R, 43L is changed so that the rotational difference between the rotational speed of the right front wheel 21 and the rear wheel 22 and the rotational speed of the left front wheel 31 and the rear wheel 32 is obtained. It becomes possible by having. Furthermore, by changing the rotation direction of the output from each gear box 43R, 43L, the turning direction of the left and right wheels can be reversed to enable stationary turning around the center of the electric vehicle 1.

  The electric vehicle 1 may be provided with a steering mechanism that makes the angle of the front and rear wheels variable by remote operation or on-site operation, or a skid steer mechanism that rotates the left and right wheels in opposite directions. However, such a mechanism is not provided in this configuration example. Therefore, when the electric vehicle 1 is turned stationary, the larger the wheel base, the greater the resistance applied to the wheels, and a larger driving torque is required for turning. However, by making the gear ratios in the gear boxes 43R and 43L variable as in this configuration example, a large torque can be applied to the wheels if the rotational speed of the wheels during turning is lowered.

  For example, when the gear ratio in the gear box 43R is 10 for the number of gear teeth on the motor shaft 42R, 20 for the number of teeth on the intermediate gear, and 40 for the gear on the side of the axle 21b, the rotational speed of the axle 21b Is ¼ of the rotational speed of the motor shaft 42R, but four times the torque is obtained. And, by selecting a gear ratio that further reduces the rotation speed, a larger torque can be obtained, so that it is possible to turn even on road surfaces with large resistance related to wheels such as rough terrain and sand. .

  In this configuration example, since the gear boxes 43R and 43L are provided between the motor shafts 42R and 42L and the axles 21a and 31a, vibrations from the wheels 21 and 31 are not directly transmitted to the motor shaft. Further, clutches for transmitting and disconnecting (cutting off) power are provided in the gear boxes 43R and 43L, and when the electric motors 41R and 41L are not energized, the electric motors 41R and 41L side and the axles 21a and 31a serving as drive shafts It is desirable to block power transmission between the two. Thus, even if a force is applied to the lower unit 10 at the time of stop and the wheels rotate, the rotation is not transmitted to the electric motors 41R and 41L. Therefore, no back electromotive force is generated in the electric motors 41R and 41L. There is no risk of damaging the circuits of the motors 41R and 41L.

  Thus, in this configuration example, the pair of front and rear front and rear wheels on the left and right are connected by the power transmission member, and the four wheels are driven so as to be driven by the two electric motors arranged on the front wheel side. Therefore, there is no need to provide an electric motor dedicated to the rear wheel, and a gear box dedicated to the rear wheel required between the electric motor and the rear wheel. Can be reduced. As described above, the two electric motors 41R and 41L are arranged on the front wheels 21 and 31 side of the bottom surface 15 of the lower unit 10 on the left and right sides in the traveling direction, and further on the left and right sides of the electric motors 41R and 41L. Although the gear boxes 43R and 43L are arranged, only the bearings 44R and 44L are arranged on the rear wheels 22 and 32 side of the bottom surface 15. Therefore, the bottom surface 15 of the lower unit 10 has a central position. For example, a wide accommodation space 16 can be secured over the end of the rear surface 14B.

  The battery 40 can be installed in the accommodation space 16. Examples of the battery 40 include a lithium ion battery. The battery 40 has, for example, a rectangular parallelepiped shape, and can be placed from the rear side to the center of the bottom surface 15 as shown in FIG. 1C. Thereby, a large-capacity battery 40 for realizing long-time running can be mounted in the accommodation space 16 of the lower unit 10.

  Further, the battery 40 can be removed by opening the upper unit 11 with respect to the lower unit 10, but an opening / closing mechanism and a slide mechanism (not shown) are separately provided on the rear surface 14B of the lower unit 10. It is preferable to make the battery 40 into and out of the accommodating space 16 easier. Thereby, operations such as replacement, charging, and inspection of the battery 40 can be easily performed from the rear surface 14B.

  As described above, the electric vehicle 1 adopts a clamshell type structure. Therefore, the electric vehicle 1 is particularly accompanied by opening / closing of the upper unit 11 with the battery 40 removed (or removal of the battery 40 in the open state). The movement of the center of gravity can cause a risk of falling, and the risk increases when working on slopes or in an unstable scaffold. Therefore, it is necessary to reduce the risk of the electric vehicle 1 falling during the maintenance work. Actually, the electric motors 41L and 41R are often attached so as to be difficult to remove from the lower unit 10, but the battery 40 is often attached easily as in this configuration example. Therefore, it can be beneficial to reduce the risk of falling.

  Therefore, the following arrangement relationship is adopted as one of the main features of the present invention. That is, of the rear side or the front side of the electric vehicle 1, the electric motors 41L and 41R are arranged on the side where the hinge part 12 is not provided, and the battery 40 is arranged on the side where the hinge part 12 is provided. . Of course, the electric motors 41L and 41R are arranged so as not to overlap the battery 40 in the vertical direction.

  The effect of such an arrangement relationship will be described. The horizontal position of the center of gravity of the electric vehicle 1 moves to the hinge portion 12 side when the upper unit 11 is opened compared to the closed state. If the battery 40 is attached, it is easy to design so that the upper unit 11 will not fall over even if the weight of the upper unit 11 is slightly higher than the weight of the lower unit 10. However, in consideration of the removed state, the horizontal position of the center of gravity of the electric vehicle 1 moves to the side opposite to the hinge portion 12 side when the battery 40 is removed. Design is difficult.

  However, in the present invention, the arrangement relationship as described above is adopted, and the electric motors 41L and 41R, which are heavy components other than the battery 40, are provided on the side opposite to the hinge portion 12, so that the battery 40 is removed. In addition, when the upper unit 11 is opened, the movement of the center of gravity of the electric vehicle 1 due to each state is in a canceling direction. Therefore, according to the present invention, the risk of the electric vehicle 1 falling can be reduced, safety during maintenance work can be ensured, and such design is facilitated. In particular, in an electric vehicle in which the weight of the upper unit 11 is large or an electric vehicle having a short wheel base, for example, an electric vehicle in which the distance between the wheels is less than twice the diameter of the wheel or 1.5 times or less, Such an arrangement relationship in consideration of the center of gravity is particularly useful.

  In this way, the electric motors 41L and 41R (and other heavy components such as the gear boxes 43R and 43L) are arranged on the side opposite to the position of the battery 40 occupying a large specific gravity among all the components in the electric vehicle 1. Thus, in the state in which the upper unit 11 is closed, the horizontal position of the center of gravity of the electric vehicle 1 can be moved to the vicinity of the center, and traveling performance can be ensured. Of course, when the upper unit 11 is opened with the battery 40 attached, the center of gravity of the electric vehicle 1 does not approach the hinge portion 12 as much as possible due to such an arrangement.

  Next, a more preferable example of the center of gravity of the electric vehicle 1 will be described with reference to FIGS. 2A and 2B. In FIG. 2A and FIG. 2B, an example of the ratio of the weight of each component in the electric vehicle 1 is shown in color, and the darker color indicates that the ratio is higher.

  First, the horizontal position of the center of gravity G of the electric vehicle 1 is near the center of the electric vehicle 1 with the upper unit 11 closed with respect to the lower unit 10 (near the center of the region where the electric vehicle 1 is projected on the horizontal plane). It is preferable for traveling.

  In the electric vehicle 1, the vertical position of the center of gravity G of the electric vehicle 1 is preferably on the lower unit 10 side regardless of the open / closed state of the lower unit 10 and the upper unit 11. In order to keep the center of gravity G low in this way, for example, heavy parts (driving parts such as gears, electric motors, and bearings) are collected in the lower unit 10 and an electronic board or the like is arranged in the upper unit 11.

  Moreover, the electric motors 41L and 41R and the battery 40 are housed in the bottom surface of the lower unit 10 as in this configuration example, so that the center of gravity of the lower unit 10 can be lowered, and the center of gravity G of the electric vehicle 1 is thereby lowered. It can be said that it is preferable because an electric vehicle capable of running stably can be obtained.

  Of the provided wheels, it is preferable that the wheels on the front side of the electric vehicle 1 (that is, the front wheels 21 and 31) and the wheels on the rear side (that is, the rear wheels 22 and 32) are arranged close to each other. By shortening the wheel base in this way, it is possible to improve the mobility as described above, and even if the battery 40 is removed and the upper unit 11 is opened due to the above arrangement relationship, it does not fall down. That is, since the vehicle with a short wheel base has a structure that easily falls over, the effect of preventing the fall due to the arrangement relationship is more beneficial. Furthermore, as in this configuration example, the stability can be further increased by forming all the wheels with the same diameter.

  In this configuration example, the pair of front and rear front wheels and rear wheels are connected by a sprocket and a belt so that the power from the electric motor is transmitted to the front and rear wheels, but each wheel (front wheels 21, 31 and rear wheels). 22 and 32) and an axle 21a, 31a, 22a, 32a, for example, an electromagnetic clutch is provided as a power transmission member, and only the front wheels 21, 31 or only the rear wheels 22, 32 are driven, Further, only one wheel may be driven. In this case, independent rotation control of the four wheels becomes possible, and even if the friction coefficient with a frozen road surface or a muddy road surface is small by switching power transmission and interruption at high speed by an electromagnetic clutch, respectively. It is possible to maintain a stable traveling direction by controlling the rotation of the wheels. In addition, it is possible to use the rotating disk provided in the electromagnetic clutch as a brake by holding it with a fixed member.

  In this configuration example, power from the electric motors 41R and 41L is transmitted to the axles of the drive wheels via the gear boxes 43R and 43L, and the power from the electric motors 41R and 41L is transmitted to the torque and the gear boxes 43R and 43L. By changing the rotation speed and the rotation direction, the electric vehicle 1 is accelerated, decelerated, changed direction, and turned. As an alternative configuration, the power from the electric motors 41R and 41L is transmitted to the axles of the drive wheels simply through a fixed ratio (predetermined constant ratio) gear, and the magnitude and frequency of the drive voltage to the electric motor are changed. Accordingly, the rotation direction and speed of the left and right drive shafts may be changed. As a result, it is not necessary to provide a gear box (transmission), which is a complicated mechanical mechanism, but simply through a gear, so that mechanical troubles and maintenance burdens are reduced and the gear box is not required. Thus, the weight of the electric vehicle can be reduced.

(Second Embodiment)
The second embodiment of the present invention will be described again with reference to FIG. 2A, focusing on the differences from the first embodiment, but various application examples of the first embodiment can be similarly applied. .

  In the electric vehicle 1 according to the present embodiment, the horizontal position of the center of gravity Gu of the upper unit 11 is assumed to be on the front side or the rear side of the electric vehicle 1 on the side where the hinge portion 12 is not provided. In the example of FIG. 2A and the like, since the hinge portion 12 is provided on the rear side, the horizontal position of the center of gravity Gu of the upper unit 11 is on the front side of the electric vehicle 1. Here, the open / close state is not particularly relevant. Since the opening angle is less than a right angle, whether the upper unit 11 is closed or opened, if the center of gravity Gu is provided on the front side, the horizontal position of the center of gravity Gu will be on the front side of the upper unit 11. become.

  Thus, the center of gravity G of the electric vehicle 1 is excessively set in a state where the upper unit 11 is opened with respect to the lower unit 10 by moving the horizontal position of the center of gravity Gu of the upper unit 11 to the side opposite to the hinge portion 12. It is possible not to move backward, and to prevent the upper unit 11 from falling due to opening and closing. Also in this embodiment, it can be said that the effect in the state which removed the battery 40 is especially remarkable.

(Third embodiment)
An electric vehicle according to a third embodiment of the present invention will be described with reference to FIGS. 3A to 3C. FIG. 3A is a diagram showing a configuration example of a lock mechanism provided in the electric vehicle according to the present embodiment, FIG. 3B is a diagram showing a state when the lock mechanism of FIG. 3A is locked, and FIG. 3C is a diagram of the lock of FIG. It is a figure which shows the mode at the time of unlocking by a mechanism. Although the present embodiment will be described focusing on differences from the first embodiment, various application examples of the first and second embodiments can be similarly applied.

  The electric vehicle 1 according to the present embodiment is provided with a lock mechanism for locking at least one rotation of the wheel when the upper unit 11 is opened with respect to the lower unit 10 in order to prevent movement during maintenance. Of course, it can be said that it is more preferable in terms of safety to provide a lock mechanism on a larger number of wheels.

  The lock mechanism illustrated in FIG. 3A is a tire lock mechanism that is interlocked with opening and closing, and mechanically detects the opening and closing of the upper unit 11, and locks the front wheels 21 and 31 (to prevent rotation of the tire). In addition, although the locking mechanism with respect to the front wheel 21 and the front wheel 31 which are drive wheels is shown in figure, you may provide also with respect to the rear wheels 22 and 32.

  More specifically, the front wheels 21 and 31 are provided with arc-shaped holes 51 centering on the axles 21a and 31a. The hole 51 may be made in a disk provided inside the front wheels 21 and 31. Hereinafter, the lock mechanism of the front wheel 21 will be described as a representative. The locking mechanism includes an arm portion 54 that rotates about a fixed rotation shaft 54a, an arm portion 55 that is rotatably attached to one end of the arm portion 54 by a rotation shaft 54b, and a rotation shaft 54c that is connected to the other end of the arm portion 54. The arm part 53 attached so that rotation was possible, and the pin part 52 are provided.

  The rotation shaft 55a of the hinge portion 12 is attached to the end of the arm portion 55 opposite to the rotation shaft 54b, and the arm portion 55 is moved in the direction of the arrow by the operation of the hinge portion 12 by opening and closing the upper unit 11. It is designed to rotate. This rotation is transmitted as a parallel motion to the arm portion 53 via the arm portion 54. The wheel 21 side of the arm portion 54 has an inclined portion as illustrated in FIG. 3B. As illustrated in FIGS. 3B and 3C, the pin portion 52 includes a cylindrical pin body 52 a disposed so as to contact the inclined portion, a support column 52 b attached to the lower unit 10, and a spring 52 c.

  With such a configuration, when the upper unit 11 is opened, the arm portion 53 moves parallel to the wheel 21 side with the operation of the hinge portion 12, and as shown in FIG. By pressing the surface, the pin body 52a moves toward the wheel 21 with respect to the support column 52b and fits into the hole 51, and the wheel 21 is locked. On the other hand, when the upper unit 11 is closed, the arm portion 53 moves parallel to move away from the wheel 21 as the hinge portion 12 is operated, and the inclined portion is the surface of the pin main body 52a as shown in FIG. 3C. The pin main body 52a moves away from the wheel 21 with respect to the column 52b and comes out of the hole 51, and the wheel 21 is unlocked. In addition, when it provides in the rear wheels 22 and 32 close to the hinge part 12, the length of the arm part mentioned later can be shortened compared with the case where it provides in the front wheels 21 and 31.

  In this embodiment, such a lock mechanism prevents the electric vehicle 1 from moving during the maintenance work, so that an accident during the work can be prevented. This effect is particularly remarkable when the battery 40 is removed and the upper unit 11 is opened. In this configuration example, an example of the automatic lock mechanism has been described. However, other than the automatic / manual lock mechanism, such as a lock mechanism using a brake that sandwiches the disk, other lock mechanisms may be provided.

(Fourth embodiment)
An electric vehicle according to a fourth embodiment of the present invention will be described with reference to FIG. FIG. 4 is a cross-sectional view showing a configuration example of the electric vehicle according to the present embodiment. Although this embodiment is described centering on differences from the first embodiment, various application examples of the first to third embodiments can be similarly applied.

  As illustrated in FIG. 4, the upper unit 11 in the present embodiment has a plurality of removable subunits (in this example, three subunits 13a, 13b, and 13c). And as a main feature of this embodiment, a subunit with a high maintenance frequency shall be arrange | positioned in the side by which the hinge part 12 is not provided among the front side or the back side of the electric vehicle 1. FIG.

  As the subunit 13a, for example, an optional board is mounted and frequently replaced depending on the application. In addition, as the subunit 13b, for example, a control unit such as a CPU board for controlling an autonomous traveling vehicle can be cited. When a malfunction occurs, the board is replaced with a new one, and the degree of maintenance is moderate. I can say that. As the subunit 13c, for example, a primary circuit component, a cooling fan, a heat sink, and the like, which are generally heavy because they are close to the battery 40 and the like, are arranged. Examples of the circuit components on the primary side include a transformer, a choke coil, and ferrite. These parts are replaced rather than repaired at the time of failure, that is, parts need not be removed except during replacement, and it can be said that the maintenance frequency is low.

  The classification of the subunits 13a, 13b, and 13c may be grouped for each control target, for example, which facilitates the subunitization for each frequency. Moreover, the subunits may be arranged in the front-rear direction as shown, or a plurality of subunits may be arranged in the left-right direction.

  With such a configuration, for example, when only the subunit 13a is to be maintained, it is only necessary to take out the subunit 13a for maintenance as shown in the figure, and the subunit with higher maintenance frequency is closer to the front side as viewed from the front surface 14F. Therefore, it can be said that workability can be improved.

  Furthermore, it is preferable to provide a support (not shown) for supporting the upper unit 11 with respect to the lower unit 10 and to have a mechanism (and a damper) that can fix the angle θ in stages. As a result, the angle θ can be changed stepwise for each of the subunits 13a, 13b, and 13c during maintenance. That is, a part with a high maintenance frequency can be maintained with a small opening / closing angle θ, and a part with a low frequency can be opened for maintenance. As described above, by providing several steps in the opening / closing angle θ and making it unnecessary to open as much as possible, it is possible to further prevent the fall due to the movement of the center of gravity accompanying the opening / closing of the upper unit 11.

  Here, the example which applies 2nd Embodiment to this embodiment is given. As can be seen from the fact that a part having a large weight is given as the subunit 13c in the above-described example, it cannot be said that the weight having a higher maintenance frequency is actually larger. Therefore, when such an application is performed, it is preferable to determine the arrangement of each subunit based on a predetermined function with the maintenance frequency and weight as variables.

(Other)
As an electric vehicle according to the present invention, a four-wheel vehicle has been mainly described as an example, but a case where an odd number of wheels such as three wheels are provided will be supplementarily described. For example, when three wheels are provided, it can be said that it is preferable to provide left and right wheels as front wheels and one wheel at the center in the left and right direction as rear wheels in terms of ease of arrangement of the electric motor. However, when three wheels are provided, left and right wheels may be provided as rear wheels and one wheel may be provided at the center in the left and right direction as front wheels. Regardless of how many wheels are provided, the electric vehicle according to the present invention may drive at least one of the wheels.

DESCRIPTION OF SYMBOLS 1 ... Electric vehicle, 10 ... Lower unit, 11 ... Upper unit, 12 ... Hinge part, 13 ... Substrate unit, 13, 13a, 13b, 13c ... Sub unit, 14R ... Right side, 14L ... Left side, 14F ... Front 14B ... rear surface, 15 ... bottom surface, 16 ... storage space, 18 ... cover, 21, 31 ... wheel (front wheel), 22, 32 ... wheel (rear wheel), 21a, 22a, 31a, 32a ... axle, 21b, 22b, 31b, 32b ... sprocket, 23, 33 ... belt, 40 ... battery, 41R, 41L ... electric motor, 42R, 42L ... motor shaft, 43R, 43L ... gear box, 44R, 44L ... bearing, 51 ... hole, 52 ... pin Part 52a... Pin body 52b.

Claims (6)

An electric vehicle comprising three or more wheels, an electric motor serving as a power source for driving part or all of the three or more wheels, and a battery for supplying electric power to the electric motor. ,
The electric vehicle includes a lower unit including the electric motor and the battery, and an upper unit that is provided on an upper part of the lower unit and stores components. And a clamshell type structure capable of opening the upper unit to a predetermined angle equal to or less than a right angle with respect to the lower unit, with a hinge portion provided in the upper unit as a center,
The electric motor is arranged on a side where the hinge part is not provided, of the rear side or the front side of the electric vehicle, and the battery is arranged on the side where the hinge part is provided. Electric vehicle to do.   2. The electric vehicle according to claim 1, wherein the horizontal position of the center of gravity of the upper unit is located on a front side or a rear side of the electric vehicle on a side where the hinge portion is not provided.   The electric vehicle according to claim 1, wherein a lock mechanism is provided for locking at least one rotation of the wheel when the upper unit is opened with respect to the lower unit.   The upper unit has a plurality of removable subunits, and the subunit having a higher maintenance frequency is arranged on the front side or the rear side of the electric vehicle where the hinge portion is not provided. The electric vehicle according to claim 1, wherein the electric vehicle is a vehicle.   The electric vehicle according to any one of claims 1 to 4, wherein the electric motor and the battery are accommodated in a bottom surface portion of the lower unit. The electric vehicle according to any one of claims 1 to 5, wherein a wheel on a front side and a wheel on a rear side of the electric vehicle among the wheels are arranged in proximity to each other.

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