Modular electric vehicle

A modular electric vehicle includes a first body module having a lateral connecting side, a second body module having a lateral connecting side, two first wheels mounted to the first body module, two second wheels mounted to the second body module, and a connection unit. The connection unit includes a first electrical connector disposed at the lateral connecting side of the first body module, and a second electrical connector disposed at the lateral connecting side of the second body module. The first electrical connector is operable to be selectively and electrically coupled to the second electrical connector, so that the first and second body modules can be selectively assembled to form a relatively light electric vehicle.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority of Taiwanese Patent Application No. 105101671, filed on Jan. 20, 2016, and Taiwanese Patent Application No. 105118677, filed on Jun. 15, 2016.

FIELD

The disclosure relates to an electric vehicle, and more particularly to a modular electric vehicle.

BACKGROUND

For an electric vehicle, the energy consumption thereof is closely related to the weight thereof. To reduce the weight of a conventional electric vehicle, several parts of the conventional electric vehicle were designed to be made of specific materials, such as aluminum alloy. However, the weight of the conventional electric vehicle cannot be effectively reduced simply by material selection.

SUMMARY

Therefore, an object of the disclosure is to provide a modular electric vehicle that can alleviate the drawback of the prior art.

According to the disclosure, the modular electric vehicle includes a vehicle body unit, a wheel unit, a driving unit, a power source unit, a connection unit and a controller. The vehicle body unit includes a first body module and a second body module. The first body module has a lateral connecting side. The second body module has a lateral connecting side. The wheel unit includes two first wheels that are mounted to the first body module and that are arranged in a front-rear direction, and two second wheels that are mounted to the second body module and that are arranged in the front-rear direction. The driving unit includes a first driving motor for driving rotation of one of the first wheels, and a second driving motor for driving rotation of one of the second wheels. The power source unit provides electrical power for driving the modular electric vehicle, and includes a first battery that is disposed on the first body module. The connection unit includes a first electrical connector that is disposed at the lateral connecting side of the first body module, and a second electrical connector that is disposed at the lateral connecting side of the second body module, that corresponds in position to the first electrical connector, and that is electrically coupled to the second driving motor. The controller is disposed at the first body module, and is electrically coupled to the first driving motor, the first battery and the first electrical connector. The first electrical connector is operable to be selectively and electrically coupled to the second electrical connector, so that the controller is able to be electrically coupled to the second driving motor by virtue of the first and second electrical connectors, and that the first battery provides electrical power to the controller and the first and second driving motors for driving the one of the first wheels and the one of the second wheels.

DETAILED DESCRIPTION

Referring toFIGS. 1 to 4, the embodiment of the modular electric vehicle according to the disclosure includes a vehicle body unit10, a wheel unit5, a driving unit6, a power source unit7, a connection unit8and a controller9.

The vehicle body unit10includes a first body module1, a second body module2, a body module3and a fourth body module4.

The first body module1has a first roof11, a first chassis12that is spaced apart from the first roof11in a top-bottom direction, a lateral connecting side15, a rear connecting side16, a lateral wall13that is opposite to the lateral connecting side15in a lateral direction and that interconnects the first roof11and the first chassis12, a slide groove121that is formed in the first chassis12and that opens at the lateral connecting side15, and a first back plate14that is pivotally connected to an end of the first roof11proximate to the rear connecting side16. In one embodiment, the lateral wall13may be provided with a side door.

The second body module2has a second roof21, a second chassis22that is spaced apart from the second roof21in the top-bottom direction, a lateral connecting side25, a rear connecting side26, a lateral wall23that is opposite to the lateral connecting side25in the lateral direction and that interconnects the second roof21and the second chassis22, a slide rod221that is connected to the second chassis22and that extends from the lateral connecting side25and away from the lateral wall23, and a second back plate24that is pivotally connected to an end of the second roof21proximate to the rear connecting side26. The slide rod221of the second body module2slidably and removably engages the slide groove121of the first body module1. In one embodiment, the lateral wall23may be provided with a side door.

The third body module3has a third roof31, a third chassis32that is spaced apart from the third roof31in the top-bottom direction, a first lateral connecting side34, a second lateral connecting side35that is opposite to the first lateral connecting side34in the lateral direction, a rear connecting side36, and a third back plate33that is pivotally connected to an end of the third roof31proximate to the rear connecting side36.

The fourth body module4has a fourth chassis41, two lateral walls42that respectively and upwardly extend from two opposite lateral edges of the fourth chassis41, a rear wall43that extends upwardly from an rear edge of the fourth chassis41and that interconnects the lateral walls42, and a front connecting side44that is opposite to the rear wall43. In one embodiment, each of the lateral walls42may be provided with a side door.

The vehicle body unit10can be selectively assembled into a basic configuration (seeFIGS. 16 to 18), a first augmented configuration (seeFIGS. 19 to 21) or a second augmented configuration (seeFIGS. 3 to 7 and 22).

Referring toFIGS. 1, 3 and 6, the wheel unit5includes two first wheels51that are mounted to the first body module1and that are arranged in a front-rear direction, two second wheels52that are mounted to the second body module2and that are arranged in the front-rear direction, two third wheels53that are mounted to the fourth body module4and that are spaced apart from each other in the lateral direction, a first auxiliary wheel54that is mounted to the first body module1and that is non-collinear with the first wheels51, a second auxiliary wheel55that is mounted to the second body module2and that is non-collinear with the second wheels52, three third auxiliary wheels56that are mounted to the third body module3and that are non-collinear with each other, a fourth auxiliary wheel57that is mounted to the fourth body module4, and six suspension mechanisms58(only one is shown inFIG. 8). Each of the first, second and third wheels51,52,53is mounted to the corresponding one of the first, second and forth body modules1,2,4by virtue of a respective one of the suspension mechanisms58.

Each of the suspension mechanisms58is operable to adjust the position of the corresponding one of the first, second and third wheels51,52,53relative to the corresponding one of the first, second and forth body modules1,2,4. For the sake of brevity, one of the third wheels53and the corresponding suspension mechanism58are exemplified inFIG. 8. Note that each of the other suspension mechanisms58is similar to the exemplified suspension mechanism58. The suspension mechanism58includes a bracket81that is fixedly mounted to the fourth body module4, an upper arm582that is pivoted to an upper portion of the bracket81, a lower arm583that is pivoted to a lower portion of the bracket81and that is longer than the upper arm582, a support member584that is connected between the upper and lower arms582,583and that is mounted with an axle portion531of the third wheel53, and a resilient rod member585that has opposite ends respectively pivoted to the upper portion of the bracket81and the lower arm583. In one embodiment, the resilient rod member585is configured as an adjustable shock absorber, and is adjustable in length. The lower arm583pivots relative to the bracket81upon the lengthwise adjustment of the resilient rod member585, so as to move the support member584and the third wheel53relative to the fourth body module4.

In more detail, the suspension mechanism58is operable to switch among an unfolded state (seeFIG. 9), a semi-folded state (seeFIG. 10) and a folded state (seeFIG. 11) upon the lengthwise adjustment of the resilient rod member585. When the suspension mechanism58is in the unfolded state, the third wheel53is closer to a ground (G) than the fourth auxiliary wheel57. For example, the third wheel53is in contact with the ground (G) and the fourth auxiliary wheel57is spaced apart from the ground (G) (seeFIG. 9). When the suspension mechanism58is in the semi-folded state, lower ends of the third wheel53and the fourth auxiliary wheel57are at the same level. For example, both of the third wheel53and the fourth auxiliary wheel57are in contact with the ground (G) (seeFIG. 10). When the suspension mechanism58is in the folded state, the fourth auxiliary wheel57is closer to the ground (G) than the third wheel53. For example, the fourth auxiliary wheel57is in contact with the ground (G) and the third wheel53is spaced apart from the ground (G) (seeFIG. 11). It should be noted that each of the other suspension mechanisms58functions like the suspension mechanism58exemplified inFIGS. 9 to 11.

Referring toFIGS. 4 and 8, the driving unit6includes two first driving motors61that are respectively for driving rotations of the first wheels51, two second driving motors62that are respectively for driving rotations of the second wheels52, and two third driving motors63that are respectively for driving rotations of the third wheels53. In a variation of the embodiment, the driving unit6may include only one first driving motor61that is for driving rotation of one of the first wheels51, only one second driving motor62that is for driving rotation of one of the second wheels52, and only one third driving motor63that is for driving rotation of one of the third wheels53. In this embodiment, each of the first, second and third driving motors61,62,63is configured as a wheel hub motor, and is disposed between the corresponding one of the first, second and third wheels51,52,53and the corresponding suspension mechanism58.

Referring toFIGS. 3 and 4, the power source unit7provides electrical power for driving the modular electric vehicle, and includes a first battery71that is disposed on the first body module1, a second battery72that is disposed on the second body module2, a third battery73that is disposed on the third body module3, and a fourth battery74that is disposed on the fourth body module4.

Referring toFIGS. 1 to 3, the connection unit8includes two first electrical connectors, two second electrical connectors, two third electrical connectors, two fourth electrical connectors, a fifth electrical connector, a sixth electrical connector, six first non-electrical connectors, six second non-electrical connectors, six third non-electrical connectors, six fourth non-electrical connectors, nine fifth non-electrical connectors, nine sixth non-electrical connectors, two first back plate connectors, two first chassis connectors, two second back plate connectors, two second chassis connectors, two third back plate connectors, two third chassis connectors, a plurality of connecting blocks85and a plurality of connecting grooves86.

The first electrical connectors are disposed at the lateral connecting side15of the first body module1. The second electrical connectors are disposed at the lateral connecting side25of the second body module2, correspond respectively in position to the first electrical connectors, and are electrically coupled to the second driving motors62and the second battery72. The third electrical connectors are disposed at the first lateral connecting side34of the third body module3, and correspond respectively in position to the first electrical connectors. The fourth electrical connectors are disposed at the second lateral connecting side35of the third body module3, correspond respectively in position to the second electrical connectors, and are electrically coupled to the third electrical connectors and the third battery73. The fifth electrical connector is disposed at the rear connecting side16of the first body module1. The sixth electrical connector is disposed at the front connecting side44of the fourth body module4, corresponds in position to the fifth electrical connector, and is electrically coupled to the third driving motors62and the fourth battery74.

In this embodiment, each of the first, fourth and sixth electrical connectors is configured as a male electrical connector81, and each of the second, third and fifth electrical connectors is configured as a female electrical connector82that is able to be coupled to the male electrical connector81. The locations of each corresponding pair of the male and female electrical connectors81,82are interchangeable. Note that, inFIGS. 1 and 2, each of the male electrical connectors81is expressed by a hemisphere, and each of the female electrical connectors82is expressed by a circle.

For the sake of brevity, only the fifth and sixth electrical connectors are described in the following paragraphs. Referring toFIGS. 1, 2, 12 and 13, the sixth electrical connector (i.e., the male electrical connector81) includes an inner terminal seat811, and an outer connecting seat that is rotatably sleeved on the inner terminal seat811. The inner terminal seat811is fixedly disposed on the front connecting side44of the fourth body module4, and is formed with a recess811a. The sixth electrical connector further includes a plurality of current terminals811b(i.e., conductive terminals) extending from a recess-defining-surface that defines the recess811a, and a plurality of signal terminals811c(i.e., conductive terminals) extending from the recess-defining-surface and surrounding the current terminals811b. The outer connecting seat includes a rotating section812, a casing section813and two wing sections814. The rotating section812is rotatably sleeved on the inner terminal seat811. The casing section813is co-rotatably sleeved on the rotating section812. The wing sections814respectively extend radially and outwardly from two diametrically opposite sides of the casing section813.

The fifth electrical connector (i.e., the female electrical connector82) includes a mounting seat821that is disposed in the rear connecting side16of the first body module1. The mounting seat821has a retaining groove822that is formed in an outer surface of the mounting seat821and that is shaped to be substantially complementary to the sixth electrical connector, and a protrusion821athat is disposed in the retaining groove822and that is able to engage the recess811aof the inner terminal seat811of the sixth electrical connector. The protrusion821ais formed with a plurality of current terminal holes821b(i.e., terminal holes) that are in spatial communication with the retaining groove822and that are respectively for being inserted by the current terminals811bof the sixth electrical connector, and a plurality of signal terminal holes821c(i.e., terminal holes) that are respectively for being inserted by the signal terminals811cof the sixth electrical connector. The fifth electrical connector further includes a plurality of electrical contacts (not shown) that are respectively disposed in the current terminal holes821band the signal terminal holes821c. The retaining groove822has two extending groove portions822athat are respectively located at two diametrically opposite sides of the protrusion821aand extend about the protrusion821a.

To couple the fifth and sixth electrical connectors together, the outer connecting seat of the sixth electrical connector is inserted into the retaining groove822of the fifth electrical connector, so that the current terminals811band the signal terminals811care respectively inserted into the current terminal holes821band the signal terminal holes821c, and are respectively in contact with the electrical contacts to permit electrical power transmission and signal transmission between the fifth and sixth electrical connectors. Then, the outer connecting seat is rotated by an electromechanical control manner to respectively engage the wing sections814with the extending groove portions822a, so as to maintain the electrical connection between the fifth and sixth electrical connectors.

Referring toFIGS. 1 to 3, the first non-electrical connectors are disposed at the lateral connecting side15of the first body module1. The second non-electrical connectors are disposed at the lateral connecting side25of the second body module2, and correspond respectively in position to the first non-electrical connectors. The third non-electrical connectors are disposed at the first lateral connecting side34of the third body module3, and correspond respectively in position to the first non-electrical connectors. The fourth non-electrical connectors are disposed at the second lateral connecting side35of the third body module3, and correspond respectively in position to the second non-electrical connectors. The fifth non-electrical connectors are disposed at the rear connecting side16of the first body module1, at the rear connecting side26of the second body module2and at the rear connecting side36of the third body module3. The sixth non-electrical connectors are disposed at the front connecting side44of the fourth body module4, and correspond respectively in position to the fifth non-electrical connectors. The first back plate connectors are disposed at the first back plate14. The first chassis connectors are disposed at the first chassis12, and correspond respectively in position to the first back plate connectors. The second back plate connectors are disposed at the second back plate24. The second chassis connectors are disposed at the second chassis22, and correspond respectively in position to the second back plate connectors. The third back plate connectors are disposed at the third back plate33. The third chassis connectors are disposed at the third chassis32, and correspond respectively in position to the third back plate connectors.

In this embodiment, each of the first, fourth and sixth non-electrical connectors and the first, second and third back plate connectors is configured as a male non-electrical connector83, and each of the second, third and fifth non-electrical connectors and the first, second and third chassis connectors is configured as a female non-electrical connector84that is able to be coupled to the male non-electrical connector83. The locations of each corresponding pair of the male and female non-electrical connectors83,84are interchangeable. Note that, inFIGS. 1 and 2, each of the male non-electrical connectors83is expressed by a hemisphere, and each of the female non-electrical connectors84is expressed by a circle.

For the sake of brevity, only one of the first non-electrical connectors and one of the third non-electrical connectors are described in the following paragraphs. Referring toFIGS. 1, 2, 14 and 15, the first non-electrical connector (i.e., the male non-electrical connector83) includes an inner seat831, and an outer connecting seat that is rotatably sleeved on the inner seat831. The inner seat811is fixedly disposed on the lateral connecting side15of the first body module1, and is formed with a recess831a. The outer connecting seat includes a rotating section832, a casing section833and two wing sections834. The rotating section832is rotatably sleeved on the inner seat831. The casing section833is co-rotatably sleeved on the rotating section832. The wing sections834respectively extend radially and outwardly from two diametrically opposite sides of the casing section833.

The third non-electrical connector (i.e., the female non-electrical connector84) includes a mounting seat841that is disposed in the first lateral connecting side34of the third body module3. The mounting seat841has a retaining groove842that is formed in an outer surface of the mounting seat841and that is shaped to be substantially complementary to the first non-electrical connector, and a protrusion841athat is disposed in the retaining groove842and that is able to engage the recess831aof the inner seat831of the first non-electrical connector. The retaining groove842has two extending groove portions842athat are respectively located at two diametrically opposite sides of the protrusion841aand extend about the protrusion841a.

To couple the first and third non-electrical connectors together, the outer connecting seat of the first non-electrical connector is inserted into the retaining groove842of the third non-electrical connector, so that the protrusion841ais inserted into the recess831aof the inner seat831of the first non-electrical connector. Then, the outer connecting seat is rotated by an electromechanical control manner to respectively engage the wing sections834with the extending groove portions842a, so as to maintain the connection between the first and third non-electrical connectors.

Referring toFIGS. 1 to 3, the connecting blocks85are disposed at the lateral connecting side25of the second body module2, the first lateral connecting side34of the third body module3and the front connecting side44of the fourth body module4. The connecting grooves86are disposed at the lateral connecting side15of the first body module1, the second lateral connecting side35of the third body module3, the rear connecting side16of the first body module1, the rear connecting side26of the second body module2and the rear connecting side36of the third body module3.

The connecting blocks85disposed at the lateral connecting side25of the second body module2respectively correspond in position to the connecting grooves86disposed at the lateral connecting side15of the first body module1. The connecting blocks85disposed at the first lateral connecting side34of the third body module3respectively correspond in position to the connecting grooves86disposed at the lateral connecting side15of the first body module1. The connecting grooves86disposed at the second lateral connecting side35of the third body module3respectively correspond in position to the connecting blocks85disposed at the lateral connecting side25of the second body module2. The connecting blocks85disposed at the front connecting side44of the fourth body module4respectively correspond in position to the connecting grooves86disposed at the rear connecting side16of the first body module1, the rear connecting side26of the second body module2and the rear connecting side36of the third body module3. The locations of each corresponding pair of the connecting block85and the connecting groove86are interchangeable.

Referring toFIGS. 3 and 4, the controller9is disposed at the first body module1, and is electrically coupled to the first driving motors61, the first battery71and the first and fifth electrical connectors. When the vehicle body unit10is assembled into the second augmented configuration, the controller9is electrically coupled to the second and third driving motors61and the second, third and fourth batteries72,73,74by virtue of the first to sixth electrical connectors, so as to control the first, second and third driving motors61,62,63to drive rotation of each of the first, second and third wheels51,52,53. In this embodiment, the controller9includes a steering wheel (not shown), and an engine control unit (ECU) for control each of the first, second and third driving motors61,62,63. It should be further noted that each of the suspension mechanisms58may cooperate with an independent steering mechanism (not shown) that is electrically coupled to the controller9for independently steering the corresponding wheel51,52,53in a desired direction.

To assemble the vehicle body unit10into the basic configuration (seeFIGS. 16 to 18), each of the suspension mechanisms58(seeFIG. 1) that are mounted to the first and second body modules1,2is switched into the semi-folded state, so that the first wheels51and the first auxiliary wheel54cooperatively support the first body module1, and the second wheels52and the second auxiliary wheel55cooperatively support the second body module2. Then, each of the first electrical connectors is operated to be electrically coupled to the corresponding one of the second electrical connectors, each of the first non-electrical connectors is operated to be coupled to the corresponding one of the second non-electrical connectors, the connecting blocks85disposed at the lateral connecting side25of the second body module2are respectively coupled to the connecting grooves86disposed at the lateral connecting side15of the first body module1, and the slide rod221of the second body module2engages the slide groove121of the first body module1, so that the first and second body modules1,2are electrically and firmly interconnected. The first back plate connectors are operated to be respectively coupled to the first chassis connectors, and the second back plate connectors are operated to be respectively coupled to the second chassis connectors. Finally, each of the suspension mechanisms58mounted to the first and second body modules1,2is switched into the unfolded state, so that the first and second wheels51,52cooperatively support the first and second body modules1,2, and the first and second auxiliary wheels54,55are spaced apart from the ground (G). At this time, the first and second body modules1,2cooperatively define a first retaining space (S1) therebetween that is suitable for only one passenger and that may be provided with a car seat (not shown). The controller9is electrically coupled to the second battery72and the second driving motors62by virtue of the first and second electrical connectors. In this embodiment, when the vehicle body unit10is assembled into the basic configuration, the first and second batteries71,72are connected in parallel to provide electrical power to the controller9and the first and second driving motors61,62for driving the first and second wheels51,52. Note that the basic configuration of the vehicle body unit10is much lighter than the total weight of the first to fourth body modules1,2,3,4, so that the energy consumption of the basic configuration is considerably reduced.

To assemble the vehicle body unit10into the first augmented configuration (seeFIGS. 19 to 21), each of the suspension mechanisms58(seeFIG. 10) that are mounted to the first and second body modules1,2is switched into the semi-folded state, so that the first wheels51and the first auxiliary wheel54cooperatively support the first body module1, and the second wheels52and the second auxiliary wheel55cooperatively support the second body module2. At this time, a distance between the first body module1and the ground (G) is the same to that between the second body module2and the ground (G) and that between the third body module3and the ground (G). Then, each of the first electrical connectors is operated to be electrically coupled to the corresponding one of the third electrical connectors, each of the fourth electrical connectors is operated to be electrically coupled to the corresponding one of the second electrical connectors, each of the first non-electrical connectors is operated to be coupled to the corresponding one of the third non-electrical connectors, each of the fourth non-electrical connectors is operated to be coupled to the corresponding one of the second non-electrical connectors, the connecting blocks85disposed at the lateral connecting side25of the second body module2are respectively coupled to the connecting grooves86disposed at the second lateral connecting side35of the third body module3, the connecting blocks85disposed at the first lateral connecting side34of the third body module3are respectively coupled to the connecting grooves86disposed at the lateral connecting side15of the first body module1, and the slide rod221of the second body module2partially engages the slide groove121of the first body module1and is partially retained in the third body module3, so that the first, second and third body modules1,2,3are electrically and firmly interconnected. The first back plate connectors are operated to be respectively coupled to the first chassis connectors, the second back plate connectors are operated to be respectively coupled to the second chassis connectors, and the third back plate connectors are operated to be respectively coupled to the third chassis connectors. Finally, each of the suspension mechanisms58mounted to the first and second body modules1,2is switched into the unfolded state, so that the first and second wheels51,52cooperatively support the first, second and third body modules1,2,3, and the first, second and third auxiliary wheels54,55,56are spaced apart from the ground (G). At this time, the first, second and third body modules1,2,3cooperatively define a second retaining space (S2) thereamong that is suitable for two passengers and that may be provided with at least one car seat (not shown). The controller9is electrically coupled to the second and third batteries72,73and the second driving motors62by virtue of the first to fourth electrical connectors. In this embodiment, when the vehicle body unit10is assembled into the first augmented configuration, the first, second and third batteries71,72,73are connected in parallel to provide electrical power to the controller9and the first and second driving motors61,62for driving the first and second wheels51,52. Note that the first augmented configuration of the vehicle body unit10is also apparently lighter than the total weight of the first to fourth body modules1,2,3,4, so that the energy consumption of the first augmented configuration is considerably reduced.

To assemble the vehicle body unit10from the first augmented configuration (seeFIGS. 19 to 21) into the second augmented configuration (seeFIG. 22), each of the suspension mechanisms58(seeFIG. 10) that are mounted to the first and second body modules1,2is switched into the semi-folded state, so that the first wheels51and the first auxiliary wheel54cooperatively support the first body module1, and the second wheels52and the second auxiliary wheel55cooperatively support the second body module2. Each of the suspension mechanisms58that are mounted to the fourth body modules4is switched into the semi-folded state, so that the third wheels53and the third auxiliary wheel56cooperatively support the fourth body module4. At this time, a distance between the first body module1and the ground (G) is the same to that between the second body module2and the ground (G), that between the third body module3and the ground (G) and that between the fourth body module4and the ground (G). Then, the sixth electrical connector is operated to be electrically coupled to the fifth electrical connectors, each of the sixth non-electrical connectors is operated to be coupled to the corresponding one of the fifth non-electrical connectors, the connecting blocks85disposed at the front connecting side44of the fourth body module4are respectively coupled to the connecting grooves86disposed at the rear connecting side16of the first body module1, the rear connecting side26of the second body module2and the rear connecting side36of the third body module3, so that the fourth body module4is electrically and firmly connected to the first, second and third body modules1,2,3. Finally, Referring further toFIG. 7, the suspension mechanisms58mounted with one of the first wheels51that is distal from the fourth body module4is switched into the unfolded state, the suspension mechanisms58mounted with the other one of the first wheels51that is proximate to the fourth body module4is switched into the folded state, the suspension mechanisms58mounted with one of the second wheels52that is distal from the fourth body module4is switched into the unfolded state, the suspension mechanisms58mounted with the other one of the second wheels52that is proximate to the fourth body module4is switched into the folded state, each of the suspension mechanisms58mounted to the fourth body module4is switched into the unfolded state, so that the one of the first wheels51distal from the fourth body module4, the one of the second wheels52distal from the fourth body module4and the third wheels53cooperatively support the first, second, third and fourth body modules1,2,3,4, and the first, second and third auxiliary wheels54,55,56, the other one of the first wheels51proximate the fourth body module4and the other one of the second wheels52proximate the fourth body module4are spaced apart from the ground (G). The first back plate14of the first body module1, the second back plate24of the second body module2, the third back plate33of the third body module3, and the lateral and rear walls42,43of the fourth body module4cooperatively define a third retaining space (S3) thereamong that opens upwardly and that is for retaining goods. The controller9is electrically coupled to the second, third and fourth batteries72,73,74, and the second and third driving motors62,63by virtue of the first to sixth electrical connectors. In this embodiment, when the vehicle body unit10is assembled into the second augmented configuration, the first, second, third and fourth batteries71,72,73,74are connected in parallel to provide electrical power to the controller9and the first, second and third driving motors61,62,63for driving the one of the first wheels51, the one of the second wheels52and the third wheels53. In a variation of the embodiment, the suspension mechanisms58mounted with the other one of the first wheels51may not be switched into the folded state, and the suspension mechanisms58mounted with the other one of the second wheels52may not be switched into the folded state. The other one of the first wheels51and the other one of the second wheels52may be driven by the corresponding driving motors.

Referring further toFIG. 5, before the fourth body module4being connected to the first, second and third body modules1,2,3, the first back plate14of the first body module1can be rotated to be flush with the first roof11, the second back plate24of the second body module2can be rotated to be flush with the second roof21, and the third back plate33of the third body module3can be rotated to be flush with the third roof31, so that after the vehicle body unit10is assembled into the second augmented configuration, the first, second, third and fourth body modules1,2,3,4cooperatively define a fourth retaining space (S4) thereamong that is suitable for four passengers and that may be provided with at least one car seat (not shown).

To sum up, since the vehicle body unit10of this disclosure includes the first, second, third and fourth body modules1,2,3,4that can be selectively assembled into different configurations for different demands. The base configuration and the first augmented configuration of the vehicle body unit10are apparently lighter than the total weight of the first to fourth body modules1,2,3,4, so that the energy consumption of the basic configuration and the first augmented configuration is considerably reduced.