Electric vehicle

Abstract

To provide an electric vehicle that can provide vehicle traveling performance, balance in loading capability of stably loading cargo, durability of a load-carrying platform, and light-weight of the load-carrying platform in a compatible manner.SOLUTION: An electric vehicle 1 includes: a vehicle body frame including a pair of left and right main frames 31 extending in the front-rear direction of the electric vehicle 1; a pair of left and right driven wheels 5 arranged to sandwich the pair of main frames 31 from both sides; a pair of left and right drive wheels 6 arranged to sandwich the pair of main frames 31 from both sides; and a load-carrying platform frame 101 detachably mounted on the main frames 31. The load-carrying platform frame 101 includes: a pair of left and right load-carrying platform main frames 111 that overlap at least partially with the pair of main frames 31 in a plan view of the electric vehicle 1 and are supported by the main frames 31; and an outer frame 112 that is supported by the pair of load-carrying platform main frames 111 to define an outer edge of the load-carrying platform frame 101.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments according to the present invention relate to electric vehicles.

Background Art

[0002] The separable mounting platform for a carriage includes a mounting platform body, a tray installed on the mounting platform body via a vibration isolator, and an opening / closing fixture attached to a side surface portion of the mounting platform body.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An electric vehicle used in a field is required to achieve both high running performance on rough roads such as soft ground, hard ground, and uneven ground, and an excellent balance that enables stable loading of a load on a loading platform.

[0005] In addition, the loading platform of an electric vehicle used in a field is required to have durability capable of supporting a load, light weight, simplicity, and the ability to allocate as much of the vehicle's transportation capacity to the load loading amount as possible.

[0006] Therefore, an object of the present invention is to provide an electric vehicle capable of achieving both running performance of the vehicle, a balance enabling stable loading of a load, durability of the loading platform, and light weight of the loading platform.

Means for Solving the Problems

[0007] To solve the above problems, an electric vehicle according to an embodiment of the present invention includes a vehicle body frame having a pair of left and right main frames extending in the longitudinal direction of the vehicle, a pair of left and right driven wheels arranged so as to sandwich the pair of main frames from left and right, a pair of left and right drive wheels arranged so as to sandwich the pair of main frames from left and right, and a loading platform frame detachably mounted on the vehicle body frame. The loading platform frame includes a pair of left and right loading platform main frames that at least partially overlap the pair of main frames in a plan view of the vehicle and are supported by the pair of main frames, and an outer frame frame supported by the pair of loading platform main frames and defining an outer edge of the loading platform frame.

Advantages of the Invention

[0008] According to the present invention, it is possible to provide an electric vehicle capable of achieving excellent ride comfort, a stable loading balance for the load, durability of the loading platform, and light weight of the loading platform.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Mode for Carrying Out the Invention

[0010] Hereinafter, the electric vehicle according to the present invention will be described with reference to FIGS. 1 to 11. In a plurality of drawings, the same or corresponding components are denoted by the same reference numerals.

[0011] FIG. 1 is a perspective view of an electric vehicle according to an embodiment of the present invention.

[0012] FIG. 2 is an exploded perspective view of an electric vehicle according to an embodiment of the present invention.

[0013] FIG. 3 is a plan view of a vehicle body of an electric vehicle according to an embodiment of the present invention.

[0014] FIG. 4 is a side view of a vehicle body of an electric vehicle according to an embodiment of the present invention.

[0015] FIG. 5 is a front view of a vehicle body of an electric vehicle according to an embodiment of the present invention.

[0016] FIG. 6 is a rear view of a vehicle body of an electric vehicle according to an embodiment of the present invention.

[0017] For convenience of explanation, the solid arrow F shown in FIG. 3 is defined as the front and forward direction of the electric vehicle 1 according to the present embodiment, and the solid arrow B shown in FIG. 3 is defined as the rear and reverse direction of the electric vehicle 1 according to the present embodiment. Further, the solid arrow L shown in FIG. 3 is defined as the left direction of the electric vehicle 1 according to the present embodiment, and the solid arrow R shown in FIG. 3 is defined as the right direction of the electric vehicle 1 according to the present embodiment.

[0018] As shown in FIGS. 1 to 6, the electric vehicle 1 according to the present embodiment includes a vehicle body 2, a loading platform 3 detachably mounted on the vehicle body 2, a driven wheel 5 as a front wheel, and a drive wheel 6 as a rear wheel.

[0019] Note that the electric vehicle 1 can also be operated by reversing the front and rear in the traveling direction. That is, the electric vehicle 1 may include a drive wheel 6 as a front wheel and a driven wheel 5 as a rear wheel. In this case, the front, rear, left, and right of the electric vehicle 1 are reversed.

[0020] The electric vehicle 1 includes a vehicle body frame 7 as a chassis and a plurality of wheels 8 that support the vehicle body frame 7 so as to be able to travel. The plurality of wheels 8 include a pair of left and right driven wheels 5 and a pair of left and right drive wheels 6.

[0021] Further, the electric vehicle 1 includes a pair of left and right first suspension devices 11 that support each of the pair of driven wheels 5 so as to be steerable, a steering device 12 that electrically steers the pair of driven wheels 5, a pair of left and right second suspension devices 15 that support each of the pair of drive wheels 6, a pair of left and right electric motors 16 that output the driving force of each of the pair of drive wheels 6, and a pair of left and right transmission devices 17 that transmit the driving force of each of the pair of electric motors 16 to each of the pair of drive wheels 6.

[0022] Furthermore, the electric vehicle 1 includes a first storage box 21, a first control device 22 that is housed in the first storage box 21 and controls each of the pair of electric motors 16, a second storage box 25, a second control device 26 that is housed in the second storage box 25 and controls the steering device 12, and a plurality of batteries 28 that can supply power to the electric motors 16, the steering device 12, the first control device 22, and the second control device 26.

[0023] The electric vehicle 1 also includes an input device that can operate forward, reverse, left turn, and right turn. The input device may be, for example, a combination of a steering wheel, an accelerator, and a shift lever, or a joystick that can be operated by tilting a lever.

[0024] Note that the electric vehicle 1 has a substantially symmetrical structure. Therefore, regarding the components such as the devices, mounted equipment, and wheels provided in a pair on the left and right, only the components on the left side will be described, and the description of the components on the right side will be omitted.

[0025] The vehicle body frame 7 includes a pair of main frames 31 extending in the longitudinal direction of the electric vehicle 1, a plurality of sub-frames 32 extending in the lateral direction of the electric vehicle 1 and connecting the pair of main frames 31, and a pair of side extension frames 33 sandwiching the pair of main frames 31 from the left and right sides of the electric vehicle 1.

[0026] Further, the vehicle body frame 7 includes an appropriate reinforcing frame 35 provided below the pair of main frames 31, the plurality of sub-frames 32, and the pair of side extension frames 33 to reinforce the vehicle body frame 7, and a plurality of gussets 38 provided at connection locations of the various frames 31, 32, 33, 35.

[0027] Note that a frame with its longitudinal direction oriented in the front-rear direction of the electric vehicle 1 may be referred to as a longitudinal frame, and a frame with its longitudinal direction oriented in the width direction, lateral direction of the electric vehicle 1 may be referred to as a transverse frame. For example, the pair of main frames 31 are longitudinal frames, and the plurality of sub-frames 32 are transverse frames.

[0028] The vehicle body frame 7 functions as a main structure for suspending and mounting various components of the vehicle body 2. The upper surface 7t of the vehicle body frame 7 functions as a loading surface of the loading platform 3. The upper surface 7t of the vehicle body frame 7 may be inclined within a range suitable for loading on the loading platform 3, and is preferably substantially horizontal.

[0029] The upper surface 7t of the vehicle body frame 7 is a plane including the upper surfaces 31t of the respective main frames 31 and the upper surfaces 33t of the respective side extension frames 33. In other words, the upper surfaces 31t of the respective main frames 31 and the upper surfaces 33t of the respective side extension frames 33 are aligned in the same plane, that is, the upper surface 7t of the vehicle body frame 7. The upper surfaces 32t of the plurality of sub-frames 32 may be aligned with the upper surface 7t of the vehicle body frame 7, or may be below the upper surface 7t of the vehicle body frame 7.

[0030] The vehicle body frame 7 supports the steering device 12, the first suspension device 11, the second suspension device 15, the first storage box 21, the second storage box 25, and a plurality of batteries 28 in a suspended manner. All the components of the vehicle body 2 supported by the vehicle body frame 7 are arranged at positions lower than the upper surface 7t of the vehicle body frame 7. In other words, all the components of the electric vehicle 1 are arranged at positions lower than the respective upper surfaces 31t of the pair of main frames 31 and the respective upper surfaces 33t of the pair of side extension frames 33. By doing so, the center of gravity position of the electric vehicle 1 approaches the road surface on which the driven wheels 5 and the drive wheels 6 are grounded, that is, the center of gravity of the electric vehicle 1 is lowered. The lower the center of gravity position, the more improved the running stability of the electric vehicle 1.

[0031] The pair of main frames 31 are arranged at the center in the left - right direction of the vehicle body frame 7 so as to penetrate the vehicle body frame 7 in the front - rear direction. The pair of main frames 31 may be linear or curved, but it is preferably mirror - symmetric with the plane that bisects the vehicle body frame 7 into left and right of the electric vehicle 1 as the mirror plane. The mirror - symmetric main frames 31 are excellent in the rigidity of the vehicle body frame 7 and the left - right balance of the vehicle body frame 7. The linear main frame 31 has a shorter total extension than the curved main frame 31 and is excellent in weight reduction of the vehicle body frame 7.

[0032] Each main frame 31 may be an integrally - molded product or a joined body in which a plurality of members are joined together. The integrally - molded main frame 31 has no joint part and is thus more excellent in weight reduction than the joined - body main frame 31. Among the components of the electric vehicle 1, the weight reduction of the relatively heavy main frame 31 enables the electric vehicle 1 to run without damaging the road surface such as a farm field.

[0033] The steering device 12, the first suspension device 11, the second suspension device 15, the first storage box 21, the second storage box 25, and the plurality of batteries 28 supported by the vehicle body frame 7 are supported solely by the main frames 31.

[0034] One end 31f of the main frame 31 in the front-rear direction is the front end 31f of the main frame 31, close to the pair of driven wheels 5 and far from the pair of drive wheels 6. The front end 31f of the main frame 31 protrudes more than the pair of driven wheels 5 in the direction away from the pair of drive wheels 6. That is, the main frame 31 has a length that protrudes forward of the axle 41 of the driven wheels 5 in the front-rear direction of the electric vehicle 1, so-called front overhang. The front overhang of the main frame 31 is also the front overhang of the vehicle body frame 7.

[0035] The other end 31b of the main frame 31 in the front-rear direction is the rear end 31b of the main frame 31, far from the pair of driven wheels 5 and close to the pair of drive wheels 6. The rear end 31b of the main frame 31 protrudes more than the pair of drive wheels 6 in the direction away from the pair of driven wheels 5. That is, the main frame 31 has a length that protrudes rearward of the axle 42 of the drive wheels 6 in the front-rear direction of the electric vehicle 1, so-called rear overhang. The rear overhang of the main frame 31 is also the rear overhang of the vehicle body frame 7.

[0036] By making the rear overhang of the vehicle body frame 7 larger than the front overhang, the weight of the electric vehicle 1 borne by the drive wheels 6 increases. This increase in the shared load of the drive wheels 6 effectively acts on the improvement of the traction of the drive wheels 6. The improvement of the traction of the drive wheels 6 prevents the drive wheels 6 from slipping on rough roads such as fields.

[0037] The main frame 31 has an upper surface 31t that is disposed above the top of the steering device 12, the top of the first suspension device 11, the top of the second suspension device 15, the upper surface 32t of the first storage box 21, the upper surface 25t of the second storage box 25, and the upper surface 28t of the plurality of batteries 28, and supports the steering device 12, the first suspension device 11, the second suspension device 15, the first storage box 21, the second storage box 25, and the plurality of batteries 28.

[0038] The plurality of sub - frames 32 extend in the left - right direction of the electric vehicle 1. The plurality of sub - frames 32 include, for example, a sub - frame 32 spanned between the front end portions 31f of a pair of main frames 31, a sub - frame 32 spanned between the rear end portions 31b, and a sub - frame 32 spanned between the intermediate portions of the front end portion 31f and the rear end portion 31b in the front - rear direction of the main frame 31.

[0039] A pair of driven wheels 5 are disposed below the respective upper surfaces 31t of the pair of main frames 31 and are arranged so as to sandwich the main frames 31 from the left and right in a plan view (FIG. 3) of the electric vehicle 1. The top of each driven wheel 5 is disposed below the respective upper surface 31t of the pair of main frames 31.

[0040] Each driven wheel 5 has an axle 41. For the sake of convenience of explanation, the axle 41 of the driven wheel 5 is referred to as the front - wheel axle 41. Also, the width dimension obtained by adding the tire width of one driven wheel 5 to the tread width of the pair of driven wheels 5 is referred to as the outermost - edge width of the pair of driven wheels 5.

[0041] A pair of drive wheels 6 are disposed below the respective upper surfaces 31t of the pair of main frames 31 and are arranged so as to sandwich the pair of main frames 31 from the left and right in a plan view (FIG. 3) of the electric vehicle 1. The top of each drive wheel 6 is disposed below the respective upper surface 31t of the pair of main frames 31.

[0042] Each drive wheel 6 has an axle 42. For the sake of convenience of explanation, the axle 42 of the drive wheel 6 is referred to as the rear - wheel axle 42. Also, the width dimension obtained by adding the tire width of one drive wheel 6 to the tread width of the pair of drive wheels 6 is referred to as the outermost - edge width of the pair of drive wheels 6.

[0043] The main frame 31 sandwiched between the pair of drive wheels 6 and between the pair of driven wheels 5 is disposed closer to the center in the width direction of the electric vehicle 1, specifically at the center of the electric vehicle 1. Therefore, the left and right balance of the electric vehicle 1 is likely to be balanced, and thus the load sharing of the left and right drive wheels 6 is also likely to be balanced. The balance of the load sharing of the left and right drive wheels 6 effectively acts on the stability of the traction of the left and right drive wheels 6. The stability of the traction of the left and right drive wheels 6 prevents the drive wheels 6 from spinning on rough roads such as farm fields. Also, if the traction of the left and right drive wheels 6 is stable on rough roads such as farm fields, the electric vehicle 1 can run stably without damaging the road surface.

[0044] In the width direction of the electric vehicle 1, the pair of side extension frames 33 are provided inside the larger one of the outermost edge widths of the pair of driven wheels 5 and the outermost edge widths of the pair of drive wheels 6. In the width direction of the electric vehicle 1, it is more preferable that the pair of side extension frames 33 are provided inside the smaller one of the outermost edge widths of the pair of driven wheels 5 and the outermost edge widths of the pair of drive wheels 6. Therefore, the electric vehicle 1 can easily avoid contact between surrounding obstacles and the vehicle body frame 7 including the side extension frames 33 during both running and turning. Also, since the pair of side extension frames 33 are located inside the running tracks of the left and right driven wheels 5 and the left and right drive wheels 6, the widthwise size of the vehicle body frame 7 that supports the loading platform 3 is expanded without limiting the running performance and turning performance of the electric vehicle 1.

[0045] The pair of side extension frames 33 have a center of gravity Gsf that is between the front wheel axle 41 and the rear wheel axle 42 and close to the rear wheel axle 42 and far from the front wheel axle 41 in the front-rear direction of the electric vehicle 1. That is, the center of gravity of the vehicle body frame 7 including the side extension frames 33 is close to the rear wheel axle 42 and far from the front wheel axle 41. Therefore, the load sharing of the drive wheels 6 is larger than the load sharing of the driven wheels 5. This increase in the load sharing of the drive wheels 6 effectively acts on the improvement of the traction of the drive wheels 6. The improvement of the traction of the drive wheels 6 prevents the drive wheels 6 from spinning on rough roads such as farm fields.

[0046] In addition, in the plan view of the electric vehicle 1 (Fig. 3), the side expansion frame 33 has a first portion 45 arranged to be sandwiched between the driven wheels 5 and the drive wheels 6, and a second portion 46 arranged to be sandwiched between the main frame 31 and the drive wheels 6. In the plan view of the electric vehicle 1 (Fig. 3), the pair of side expansion frames 33 avoid the upper sides of the pair of driven wheels 5 and the pair of drive wheels 6. By doing so, even when the driven wheels 5 and the drive wheels 6 swing greatly in the vertical direction of the electric vehicle 1, that is, when the vehicle body frame 7 sinks deeply, the contact between the vehicle body frame 7 and the driven wheels 5 and the contact between the vehicle body frame 7 and the drive wheels 6 can be prevented. In other words, the electric vehicle 1 can keep the ground clearance of the vehicle body frame 7 supporting the loading platform 3 low. The vehicle body frame 7 with a low ground clearance can contribute to lowering the center of gravity of the electric vehicle 1.

[0047] The first portion 45 has a pair of front and rear expansion frames 51 that project from one of the pair of main frames 31 to either the left or the right so as to expand the width of the vehicle body frame 7, and an outer edge frame 52 that is spanned between the protruding ends of the pair of expansion frames 51 and extends in the front-rear direction of the electric vehicle 1. The pair of expansion frames 51 are spaced apart from each other in the front-rear direction of the electric vehicle 1, parallel to each other, and extend orthogonally to the main frame 31. The outer edge frame 52 extends parallel to the main frame 31 and is orthogonal to the pair of expansion frames 51. The pair of expansion frames 51 are vertical frames, and the outer edge frame 52 is a horizontal frame.

[0048] The second part 46 includes a sub-expansion frame 55 that protrudes from one of the pair of main frames 31 to either the left or right to expand the width of the vehicle body frame 7, and a sub-outside edge frame 56 that is spanned between the middle part of the expansion frame 51 on the rear side of the first part 45 and the protruding end of the sub-expansion frame 55 and extends in the longitudinal direction of the electric vehicle 1. The sub-expansion frame 55 is parallel to the expansion frame 51 of the first part 45, is disposed closer to the drive wheel 6 than the expansion frame 51 on the rear side of the first part 45, and extends orthogonally to the main frame 31. In a plan view (FIG. 3) of the electric vehicle 1, the sub-expansion frame 55 has a protruding end closer to the main frame 31 than the drive wheel 6, and the extension line of the sub-expansion frame 55 crosses the drive wheel 6. The sub-outside edge frame 56 extends parallel to the main frame 31 and is orthogonal to the expansion frame 51 and the sub-expansion frame 55. The sub-outside edge frame 56 is a vertical frame, and the sub-expansion frame 55 is a horizontal frame.

[0049] The side expansion frame 33 having the first part 45 and the second part 46 expands the function of supporting the loading platform 3 borne by the main frame 31 disposed closer to the center of the vehicle body frame 7. Further, the second part 46 expands the function of supporting the loading platform 3 borne by the vehicle body frame 7 in a region sandwiched between the drive wheel 6 and the main frame 31 where the expansion by the first part 45 alone is insufficient, and brings the center of gravity Gsf of the side expansion frame 33 closer to the drive wheel 6 to increase the shared load of the drive wheel 6, which effectively acts on improving the traction of the drive wheel 6.

[0050] Note that the second part 46 may be disposed so as to be sandwiched between the main frame 31 and the driven wheel 5.

[0051] Each gusset 38 is provided at each butt joint portion of longitudinal-shaped members such as the main frame 31, the sub-frame 32, the side expansion frame 33, and the reinforcing frame 35 to connect a plurality of members that merge at the butt joint portion.

[0052] The electric vehicle 1 includes a pair of fixtures 62 provided at the front and rear of the electric vehicle 1 and a pair of stoppers 63 provided on the left and right of the electric vehicle 1.

[0053] The fixture 62 detachably connects and fixes the loading platform 3 disposed on the upper surface 7t of the vehicle body frame 7 to the vehicle body 2. The electric vehicle 1 loads a loading platform 3 suitable for various uses, such as fruit tree harvesting operations and transportation operations of harvested fruit trees, on the vehicle body frame 7 of the vehicle body 2 and fixes it with the fixture 62. By doing so, the electric vehicle 1 can provide flexible and suitable convenience according to various uses.

[0054] The fixture 62 restricts the relative displacement (misalignment) between the vehicle body 2 and the loading platform 3 in the longitudinal and vertical directions of the electric vehicle 1. The stopper 63 restricts the relative displacement (misalignment) between the vehicle body 2 and the loading platform 3 in the left - right and width directions of the electric vehicle 1. That is, the fixture 62 and the stopper 63 cooperate to integrate the vehicle body 2 and the loading platform 3.

[0055] When traveling on an unstable road surface such as a farm field, if the vehicle body 2 and the loading platform 3 rattle in the vertical direction of the electric vehicle 1, there is a risk of damaging the load. Therefore, it is preferable that the fixture 62 and the stopper 63 are arranged such that the interval between the pair of fixtures 62 is longer than the interval between the pair of stoppers 63. Since the overall length of the electric vehicle 1 in this embodiment is longer than the overall width, it is preferable that the pair of fixtures 62 are arranged in the front - rear direction of the electric vehicle 1 and the pair of stoppers 63 are arranged in the left - right direction of the electric vehicle 1. Such an arrangement relationship between the fixture 62 and the stopper 63 integrally and firmly combines the vehicle body 2 and the loading platform 3 in the vertical direction of the electric vehicle 1. If the vehicle body 2 and the loading platform 3 are integrally and firmly combined, the center - of - gravity position of the electric vehicle 1 is stable without being affected by the rattling between the vehicle body 2 and the loading platform 3, improving the running performance and stability of the electric vehicle 1.

[0056] The first suspension device 11 is fixed to the vehicle body frame 7 so as to be suspended from the main frame 31 via a driven wheel support vehicle body frame 71 provided at the front end of the main frame 31. The first suspension device 11 supports the driven wheel 5, that is, the front wheel, so as to be swingable in the vertical direction of the electric vehicle 1. The first suspension device 11 includes a first swing arm 72 supported by the driven wheel support vehicle body frame 71 around a swing axis extending in the front-rear direction of the electric vehicle 1 and swingable in the vertical direction of the electric vehicle 1, and a first damper 73 spanned between the first swing arm 72 and the driven wheel support vehicle body frame 71 to buffer the swing of the first swing arm 72.

[0057] In a plan view of the electric vehicle 1 (Figure 3), the steering device 12 is disposed between the front end portions 31f of the pair of main frames 31. The steering device 12 is fixed to the vehicle body frame 7 so as to be suspended from the main frame 31 via the driven wheel support vehicle body frame 71 together with the first suspension device 11. The steering device 12 includes a second electric motor 75 that converts the electric power stored in the plurality of batteries 28 and outputs a steering force of the driven wheel 5 as a steering wheel, and a pair of tie rods 76 that distribute and transmit the steering force of the second electric motor 75 to each of the pair of driven wheels 5. The steering device 12 imparts a steering angle to the driven wheel 5 by pushing and pulling the pair of tie rods 76 left and right by the steering force generated by the second electric motor 75.

[0058] The second suspension device 15 integrally supports the drive wheel 6, the electric motor 16, and the transmission device 17. The second suspension device 15 supports the drive wheel 6, that is, the rear wheel, so as to be swingable in the vertical direction of the electric vehicle 1. The second suspension device 15 is provided on the rear side of the center of the main frame 31 and is fixed to the vehicle body frame 7 so as to be suspended from the main frame 31 via a drive wheel support frame 81 extending in the left-right direction of the main frame 31. The drive wheel support frame 81 is located directly below a pair of extension frames 51 closer to the drive wheel 6, that is, a pair of rear extension frames 51, and extends in the left-right direction of the electric vehicle 1 parallel to them. The vehicle body frame 7 includes a pair of left and right drive wheel support reinforcing frames 82 extending in the vertical direction of the electric vehicle 1 and bridging between the drive wheel support frame 81 and the respective extension frames 51. The drive wheel support frame 81 and the pair of extension frames 51 integrated by the pair of drive wheel support reinforcing frames 82 firmly support the second suspension device 15 that swings the drive wheel 6, the electric motor 16, and the transmission device 17 together.

[0059] The second suspension device 15 includes a second swing arm 83 supported by the drive wheel support frame 81 around a swing axis extending in the left-right direction of the electric vehicle 1 and enabling the drive wheel 6 to swing in the vertical direction of the electric vehicle 1, and a second damper 85 bridged between the second swing arm 83 and a second part 46 of the side extension frame 33 to buffer the swing of the second swing arm 83.

[0060] The swing axis of the second swing arm 83 overlaps the drive wheel support frame 81 in a plan view of the electric vehicle 1. That is, the swing axis of the second swing arm 83 is located between the front wheel axle 41 and the rear wheel axle 42 in the front-rear direction of the electric vehicle 1, close to the rear wheel axle 42 and far from the front wheel axle 41. The second swing arm 83 houses the transmission device 17. In the width direction of the electric vehicle 1, the second swing arm 83 supports the drive wheel 6 on the side closer to the main frame 31 than the drive wheel 6 and supports the electric motor 16 on the side farther from the main frame 31 than the electric motor 16. In other words, the second suspension device 15 supports the drive wheel 6 on the outer side of the electric vehicle 1 and the electric motor 16 on the inner side of the electric vehicle 1 with the second swing arm 83 as the center.

[0061] In the longitudinal direction of the electric vehicle 1, the electric motor 16 is located between the axle 42 of the drive wheel 6 and the axle 41 of the driven wheel 5, close to the axle 42 of the drive wheel 6 and far from the axle 41 of the driven wheel 5. Also, in the longitudinal direction of the electric vehicle 1, the electric motor 16 is located between the swing axis of the second swing arm 83 and the axle 42 of the drive wheel 6, close to the swing axis of the second swing arm 83 and far from the axle 42 of the drive wheel 6. In other words, the electric motor 16 is disposed near the base of the second swing arm 83, and the drive wheel 6 is disposed near the protruding end of the second swing arm 83.

[0062] The electric motor 16 has an output shaft 16o that outputs the driving force of the drive wheel 6. The output shaft 16o of the electric motor 16 and the axle 42 of the drive wheel 6 are parallel. The electric motor 16 is disposed inside the second swing arm 83 in the width direction of the electric vehicle 1 and is fixed to the second swing arm 83. The electric motor 16 has a cylindrical outer cylinder, and this outer cylinder extends so as to face the center of the electric vehicle 1 in the width direction of the electric vehicle 1. The left and right second suspension devices 15 can be close to each other in the width direction of the electric vehicle 1 within a range where the outer cylinders of the left and right electric motors 16 do not overlap. That is, the minimum value of the tread width of the left and right drive wheels 6 depends on the sizes of the left and right electric motors 16.

[0063] The transmission device 17 is housed in the corresponding second swing arm 83. The transmission device 17 is a speed reducer that decelerates and transmits the driving force from the output shaft 16o of the electric motor 16 to the rear wheel axle 42.

[0064] In the longitudinal direction of the electric vehicle 1, the center of gravity Gbatt of the plurality of batteries 28 is arranged so as to sandwich a virtual line VL1 passing through the axle 42 of the drive wheels 6. That is, the center of gravity Gbatt of the front battery 28F and the center of gravity Gbatt of the rear battery 28B are arranged so as to sandwich the virtual line VL1 passing through the axle 42 of the drive wheels 6. Generally, the battery 28 is a relatively heavy mounted device among all the components of the electric vehicle 1. By arranging the center of gravity Gbatt of the plurality of such heavy batteries 28 so as to sandwich the virtual line VL1 passing through the axle 42 of the drive wheels 6, the weight of the plurality of batteries 28 effectively acts to improve the traction of the drive wheels 6. Improving the traction of the drive wheels 6 prevents the drive wheels 6 from spinning on rough roads such as farm fields.

[0065] In the longitudinal direction of the electric vehicle 1, the center of gravity Gbatt of the plurality of batteries 28 is arranged so as to sandwich a virtual line VL2 passing through the output shaft 16o of the electric motor 16. That is, the center of gravity Gbatt of the front battery 28F and the center of gravity Gbatt of the rear battery 28B are arranged so as to sandwich the virtual line VL2 passing through the output shaft 16o of the electric motor 16. Generally, the electric motor 16 is a relatively heavy mounted device among all the components of the electric vehicle 1 like the battery 28. By arranging the center of gravity Gbatt of the heavy battery 28 among all the components of the electric vehicle 1 so as to sandwich the virtual line VL2 passing through the output shaft 16o of the similarly heavy electric motor 16, the weight of the plurality of batteries 28 and the weight of the electric motor 16 act effectively in superposition to improve the traction of the drive wheels 6. Improving the traction of the drive wheels 6 prevents the drive wheels 6 from spinning on rough roads such as farm fields.

[0066] In other words, in the longitudinal direction of the electric vehicle 1, the plurality of batteries 28 are biased closer to the drive wheels 6 than to the driven wheels 5.

[0067] Each battery 28 is, for example, a lead-acid battery with a voltage of 12 volts. The plurality of batteries 28 includes at least two batteries 28 that are electrically connected in series. Here, the battery 28 disposed between the driven wheel 5 as the front wheel and the drive wheel 6 as the rear wheel is called the front battery 28F, and the battery 28 disposed closer to the rear end portion 31b of the main frame 31 than the front battery 28F is called the rear battery 28B.

[0068] In a plan view of the electric vehicle 1 (FIG. 3), the front battery 28F is disposed so as to be sandwiched between the central portions of the pair of main frames 31. The front battery 28F is fixed to the vehicle body frame 7 so as to be suspended from the main frame 31 via the front battery support frame 91.

[0069] In a plan view of the electric vehicle 1 (FIG. 3), the rear battery 28B is disposed so as to be sandwiched between the rear end portions 31b of the pair of main frames 31. The rear battery 28B is fixed to the vehicle body frame 7 so as to be suspended from the main frame 31 via the rear battery support frame 92.

[0070] The vehicle body frame 7 supports the front battery 28F, which is disposed between the drive wheel 6 and the driven wheel 5 among the plurality of batteries 28, so that it can be detached by moving it in either the left or right direction of the electric vehicle 1 (solid arrow α shown in FIG. 3), and supports the rear battery 28B (other batteries) among the plurality of batteries 28 so that it can be detached by approaching or moving away from the virtual line VL1 passing through the axle 42 of the drive wheel 6 (solid arrow β shown in FIG. 3). That is, the front battery support frame 91 supports the front battery 28F so that it can be detached by moving it in either the left or right direction of the electric vehicle 1. The rear battery support frame 92 supports the rear battery 28B so that it can be detached by approaching or moving away from the virtual line VL1 passing through the axle 42 of the drive wheel 6.

[0071] Such a battery 28 attachment / detachment structure extremely improves the ease of attachment / detachment work and replacement work of the battery 28 of the electric vehicle 1. Further, since the battery 28 attachment / detachment structure of the electric vehicle 1 includes a plurality of batteries 28 with different attachment / detachment directions, whether it is a case of handling the mounting positions of the plurality of batteries 28 in a limited manner or a case of alternately changing the mounting positions of the plurality of batteries 28 for each opportunity, it is possible to easily prevent confusion of the mounting positions of the batteries 28.

[0072] If the ground height Hbatt of the battery 28, which is relatively heavy among all the components of the electric vehicle 1, is set low, it contributes to the electric vehicle 1. However, if the ground height Hbatt of the battery 28 is made too low, when the electric vehicle 1 is driven on a road surface with unevenness such as a farm field, the battery 28 may come into contact with the road surface and be damaged. On the other hand, the running performance of the electric vehicle 1 depends on the diameters of the driven wheels 5 and the drive wheels 6. Therefore, the ground height Hbatt of the bottom surface 28b of each battery 28 is set higher than one-third of the diameter of the drive wheel 6. By doing so, the running performance of the electric vehicle 1 can be enhanced, and the center of gravity of the electric vehicle 1 can be lowered, that is, the running stability can be achieved within a range where damage to the battery 28 can be avoided.

[0073] The first control device 22 is housed in the first storage box 21 and controls the plurality of electric motors 16.

[0074] In a plan view of the electric vehicle 1 (FIG. 3), the first storage box 21 that houses the first control device 22 is arranged so as to overlap above either the plurality of batteries 28 or the plurality of electric motors 16. The first storage box 21 is sandwiched between a pair of main frames 31 and is arranged below the respective upper surfaces 31t of the pair of main frames 31. In the front-rear direction of the electric vehicle 1, the first storage box 21 is located between the axles 41 of the pair of driven wheels 5 and the axles 42 of the pair of drive wheels 6, close to the axles 42 of the pair of drive wheels 6 and far from the axles 41 of the pair of driven wheels 5. Also, in the front-rear direction of the electric vehicle 1, the first storage box 21 is arranged so as to straddle a virtual line VL1 passing through the axles 42 of the pair of drive wheels 6.

[0075] By arranging the first storage box 21 near the battery 28, the cable length of the power cable connecting from the plurality of batteries 28 to the plurality of electric motors 16 via the first storage box 21 can be easily shortened. Generally, the power cable has a small wire number, a thick diameter of the individual wire, and a weight per unit length heavier than that of the signal line. The shorter the cable length of such a power cable, the more it contributes to the weight reduction of the electric vehicle 1. Also, by stacking the first storage box 21 on the battery 28, the electric vehicle 1 can easily prevent contact between the surrounding obstacles and the first storage box 21 and can reliably protect the first control device 22 accommodated in the first storage box 21. Further, by sandwiching the first storage box 21 between the pair of main frames 31, the electric vehicle 1 can easily prevent contact between the surrounding obstacles and the first storage box 21 and contact between the loading platform 3 loaded on the vehicle body frame 7 and the first storage box 21, and can reliably protect the first control device 22 accommodated in the first storage box 21. Also, by arranging the first storage box 21 near the battery 28, the weight of the electric vehicle 1 borne by the drive wheels 6 further increases. This increase in the shared load of the drive wheels 6 effectively acts to improve the traction of the drive wheels 6. The improvement in the traction of the drive wheels 6 prevents the drive wheels 6 from spinning on a rough road such as a farm field.

[0076] The second control device 26 is accommodated in the second storage box 25 and controls the second electric motor 75.

[0077] In the plan view (FIG. 3) of the electric vehicle 1, the second storage box 25 that houses the second control device 26 is arranged so as to overlap at least one of the plurality of batteries 28 and the plurality of electric motors 16. The second storage box 25 is sandwiched between the pair of main frames 31 and is arranged below the respective upper surfaces 31t of the pair of main frames 31. In the front-rear direction of the electric vehicle 1, the second storage box 25 is between the axles 41 of the pair of driven wheels 5 and the axles 42 of the pair of drive wheels 6, close to the axles 42 of the pair of drive wheels 6 and far from the axles 41 of the pair of driven wheels 5. The second storage box 25 is closer to the axles 41 of the pair of driven wheels 5 than the first storage box 21 and is provided adjacent to the front of the first storage box 21. The second storage box 25 is arranged substantially directly above the front battery 28F.

[0078] By arranging the second storage box 25 in front of the first storage box 21, the cable length of the power cable connecting from the plurality of batteries 28 to the second electric motor 75 via the second storage box 25 can be easily shortened. Also, by stacking the second storage box 25 on the battery 28, the electric vehicle 1 can easily prevent contact between the surrounding obstacles and the second storage box 25, and can reliably protect the second control device 26 accommodated in the second storage box 25. Further, by sandwiching the second storage box 25 between the pair of main frames 31, the electric vehicle 1 can easily prevent contact between the surrounding obstacles and the second storage box 25, and contact between the loading platform 3 loaded on the vehicle body frame 7 and the second storage box 25, and can reliably protect the second control device 26 accommodated in the second storage box 25. Also, by arranging the second storage box 25 in the vicinity of the battery 28, the weight of the electric vehicle 1 borne by the drive wheels 6 further increases. This increase in the load borne by the drive wheels 6 effectively acts to improve the traction of the drive wheels 6. The improvement in the traction of the drive wheels 6 prevents the drive wheels 6 from spinning on rough roads such as farm fields.

[0079] The electric vehicle 1 travels straight forward or backward by making the outputs of the left and right electric motors 16 substantially the same, that is, making the torques of the left and right drive wheels 6 the same, and making the steering angle of the pair of driven wheels 5 zero with the output of the second electric motor 75, that is, aligning the front wheel axle 41 in the left - right direction of the electric vehicle 1. Also, the electric vehicle 1 turns left or right by making the outputs of the left and right electric motors 16 different, that is, making the torques of the left and right drive wheels 6 different, and giving a steering angle to the pair of driven wheels 5 with the output of the second electric motor 75 according to the output difference between the left and right electric motors 16. The forward movement, backward movement, left turn, and right turn of the electric vehicle 1 are controlled by the first control device 22 and the second control device 26 based on the operation signal output by the input device.

[0080] Next, the loading platform 3 will be described in detail.

[0081] FIG. 7 is a plan view of the loading platform frame of the electric vehicle according to the embodiment of the present invention.

[0082] FIG. 8 is a front view of the loading platform frame of the electric vehicle according to the embodiment of the present invention.

[0083] FIG. 9 is a side view of a loading platform frame of an electric vehicle according to an embodiment of the present invention.

[0084] As shown in FIGS. 7 to 9 in addition to FIGS. 1 and 2, the loading platform 3 of the electric vehicle 1 according to the present embodiment includes a loading platform frame 101 detachably mounted on a vehicle body frame 7 of the vehicle body 2.

[0085] The loading platform frame 101 is the main structure of the loading platform 3 and supports the loading platform 3 and the cargo loaded on the loading platform 3. The loading platform frame 101 may correspond to a mount for loading a work machine.

[0086] The upper surface 101t of the loading platform frame 101 functions as a loading surface for the cargo of the electric vehicle 1. The upper surface 101t of the loading platform frame 101 may be inclined within a range suitable for loading the cargo, and is preferably substantially horizontal. The loading platform 3 may include a flat plate as a loading surface provided on the upper surface 101t of the loading platform frame 101.

[0087] Note that the loading platform frame 101 has a substantially symmetrical structure. Therefore, regarding the components provided in a pair on the left and right, only the components on the left side will be described, and the description of the components on the right side will be omitted.

[0088] The loading platform frame 101 includes a pair of loading platform main frames 111 supported by a pair of main frames 31 of the vehicle body 2, and an outer frame frame 112 supported by the pair of loading platform main frames 111 and defining the outer edge of the loading platform frame 101.

[0089] In addition, the loading platform frame 101 includes at least one loading platform sub-frame 113 spanned between the pair of loading platform main frames 111 or spanned between the loading platform main frame 111 and the outer frame frame 112.

[0090] Furthermore, the loading platform frame 101 includes a plurality of loading platform gussets 115 provided at connection portions of various frames 111, 112, 113.

[0091] The pair of cargo bed main frames 111 overlap at least partially with the pair of main frames 31 of the vehicle body 2 in a plan view of the electric vehicle 1. In other words, the pair of cargo bed main frames 111 overlap all or part of the pair of main frames 31 of the vehicle body 2 in the vertical direction of the electric vehicle 1. The overlap between the cargo bed main frame 111 and the main frame 31 may be continuous in the longitudinal direction of the cargo bed main frame 111 and the main frame 31, or may be discrete in the longitudinal direction of the cargo bed main frame 111 and the main frame 31.

[0092] The pair of cargo bed main frames 111 are arranged at the center in the left-right direction of the cargo bed frame 101 so as to penetrate the cargo bed frame 101 in the front-rear direction. The pair of cargo bed main frames 111 may have a straight shape or a curved shape, but it is preferably mirror-symmetric with the plane that bisects the cargo bed frame 101 into left and right of the electric vehicle 1 as the mirror plane. The mirror-symmetric cargo bed main frames 111 are excellent in the rigidity of the cargo bed frame 101 and the balance between the left and right of the cargo bed frame 101. The straight-shaped cargo bed main frame 111 has a shorter total length than the curved-shaped cargo bed main frame 111 and is excellent in weight reduction of the cargo bed frame 101.

[0093] Each cargo bed main frame 111 may be an integrally molded product or a joined body in which a plurality of members are joined together. The integrally molded cargo bed main frame 111 does not have a joint part and is excellent in weight reduction compared to the joined body cargo bed main frame 111. Among the components of the electric vehicle 1, weight reduction of the relatively heavy cargo bed main frame 111 enables the electric vehicle 1 to travel without damaging the road surface such as a farm field. In addition, weight reduction of the cargo bed main frame 111 contributes to weight reduction of the cargo bed 3 and contributes to an increase in the maximum load capacity (the maximum weight of the load that can be loaded on the cargo bed) of the load. In addition, weight reduction of the cargo bed 3 improves the handleability of the cargo bed 3 alone.

[0094] In addition, the cargo bed main frame 111 that overlaps all or part of the pair of main frames 31 of the vehicle body 2 in the plan view of the electric vehicle 1 exhibits sufficient rigidity to support the load in cooperation with the main frame 31 of the vehicle body 2. The force acting on the load of the electric vehicle 1 traveling in the field is greater than the force acting on the load of a vehicle traveling on a flat and stable road surface. The cargo bed main frame 111 and the main frame 31 of the electric vehicle 1 according to the present embodiment cooperate to firmly and stably support a large force acting on the load by overlapping in the vertical direction of the electric vehicle 1. Further, compared with the case where the cargo bed main frame 111 and the main frame 31 function independently without overlapping in the vertical direction of the electric vehicle 1, the cargo bed main frame 111 and the main frame 31 of the electric vehicle 1 according to the present embodiment are easy to reduce their total weight and easy to improve their durability.

[0095] The outer frame 112 includes a pair of left and right vertical frame frames 121 extending in the front-rear direction of the electric vehicle 1, a pair of front and rear horizontal frame frames 122 extending in the left-right direction of the electric vehicle 1, and a reinforcing portion 123 capable of supporting the cargo bed frame 101 in a plane.

[0096] The pair of cargo bed main frames 111 and the pair of vertical frame frames 121 are arranged in parallel. The pair of horizontal frame frames 122 are arranged in parallel and orthogonal to the pair of cargo bed main frames 111 and the pair of vertical frame frames 121. That is, the outer frame 112 depicts a rectangular shape in the plan view of the electric vehicle 1.

[0097] Note that the outer frame 112 may depict a circular shape or an elliptical shape in the plan view of the electric vehicle 1. Further, the outer frame 112 may depict a non-rectangular polygon such as a triangular shape or a hexagonal shape in the plan view of the electric vehicle 1.

[0098] The outer frame 112 may be contained within a rectangular region having the overall length of the electric vehicle 1, substantially the overall length of the vehicle body frame 7, as the long side and the overall width of the electric vehicle 1, substantially the outermost edge width of the pair of drive wheels 6, as the short side in a plan view of the electric vehicle 1, or may extend outside this region. Further, the loading platform 3 may be biased toward the side of the pair of drive wheels 6, i.e., the rear side of the electric vehicle 1, or toward the side of the pair of driven wheels 5, i.e., the front side of the electric vehicle 1, within this rectangular region.

[0099] In other words, the loading platform 3 may be contained within a rectangular region having the overall length of the electric vehicle 1, substantially the overall length of the vehicle body frame 7, as the long side and the overall width of the electric vehicle 1, substantially the outermost edge width of the pair of drive wheels 6, as the short side in a plan view of the electric vehicle 1, or may extend outside this region. Further, the loading platform 3 may be biased toward the side of the pair of drive wheels 6, i.e., the rear side of the electric vehicle 1, or toward the side of the pair of driven wheels 5, i.e., the front side of the electric vehicle 1, within this rectangular region. Further, the loading platform 3 may depict a circular shape, an elliptical shape, or a non-rectangular polygon such as a triangular shape or a hexagonal shape in a plan view of the electric vehicle 1.

[0100] The loading platform 3 contained within the rectangular region formed by the overall length and overall width of the electric vehicle 1 in a plan view of the electric vehicle 1 stabilizes the left-right balance of the electric vehicle 1 during both straight running and turning of the electric vehicle 1.

[0101] The reinforcing portion 123 is preferably provided at the end of the vertical frame 121 or at the end of the horizontal frame 122. The reinforcing portion 123 corresponds to the legs of the loading platform 3 and is capable of supporting the loading platform 3 alone on a plane. Therefore, the reinforcing portion 123 is preferably provided in the vicinity of all the corners of the outer frame 112.

[0102] Further, the reinforcing portion 123 may be spanned between the vertical frame 121 and the horizontal frame 122. That is, the reinforcing portion 123 may be provided at the corner of the outer frame 112 where the vertical frame 121 and the horizontal frame 122 intersect. In this case, the reinforcing portion 123 and the loading platform gusset 115 cooperate to connect the vertical frame 121 and the horizontal frame 122 and reinforce the corner of the outer frame 112. The reinforcing portion 123 and the loading platform gusset 115 may be separate parts or integrally formed.

[0103] In addition to the reinforcing portion 123, the loading platform 3 may be provided with legs that cooperate with the reinforcing portion 123 to support the loading platform 3 on a plane.

[0104] The loading platform sub-frame 113 at least partially overlaps the lateral frame of the vehicle body 2 in a plan view of the electric vehicle 1. In other words, the loading platform sub-frame 113 entirely or partially overlaps the pair of lateral frames of the vehicle body 2 in the vertical direction of the electric vehicle 1. The overlap between the loading platform sub-frame 113 and the lateral frame may be continuous in the longitudinal direction of the loading platform sub-frame 113 and the lateral frame, or may be discrete in the longitudinal direction of the loading platform sub-frame 113 and the lateral frame.

[0105] The lateral frame is, for example, a sub-frame 32 that is spanned between the pair of main frames 31 of the vehicle body 2 and extends in the width direction of the electric vehicle 1, an extension frame 51 provided to sandwich the pair of main frames 31 from the left and right and extend in the width direction of the electric vehicle 1, and a sub-extension frame 55. That is, the loading platform sub-frame 113 is provided so as to at least partially overlap any one of the sub-frame 32, the extension frame 51, and the sub-extension frame 55 of the vehicle body 2 in a plan view of the electric vehicle 1.

[0106] Incidentally, it is preferable that the loading platform frame 101 is mirror-symmetrical with the mirror plane being the plane that bisects the loading platform frame 101 into left and right sides of the electric vehicle 1. Therefore, when the loading platform frame 101 includes the loading platform sub-frame 113, the loading platform frame 101 may include at least one loading platform sub-frame 113 spanned between a pair of main loading platform frames 111, or a pair of left and right loading platform sub-frames 113 spanned between the main loading platform frame 111 and the outer frame 112. FIGS. 7 to 9 illustrate a loading platform frame 101 including a pair of left and right loading platform sub-frames 113 corresponding to a pair of left and right extension frames 51 of the vehicle body 2.

[0107] By the way, the vehicle body frame 7 of the vehicle body 2 includes a plurality of sub-frames 32 spanned between a pair of main frames 31 in the region sandwiched between the pair of main frames 31, and includes a side extension frame 33 between the driven wheels 5 arranged in the front and rear. At the same time, a space for the wheels 8 to move up and down is secured directly above the pair of driven wheels 5 and the pair of drive wheels 6. Therefore, the support rigidity of the loading platform frame 101 is firm at the center in the left-right direction of the vehicle body frame 7 and is void in the region directly above the wheels 8. Therefore, it is preferable that the loading platform frame 101 includes a pair of left and right loading platform sub-frames 113 spanned between the main loading platform frame 111 and the outer frame 112 rather than the loading platform sub-frame 113 spanned between the pair of main loading platform frames 111. The loading platform frame 101 that preferentially includes a pair of left and right loading platform sub-frames 113 spanned between the main loading platform frame 111 and the outer frame 112 exhibits sufficient rigidity to support the load in cooperation with the vehicle body frame 7 of the vehicle body 2 at the center in the left-right direction of the loading platform frame 101, while the rigidity of the four corners of the loading platform frame 101 in the front, rear, left, and right directions can be ensured by the loading platform sub-frame 113. Also, by not installing the loading platform sub-frame 113 spanned between the pair of main loading platform frames 111, the weight of the entire loading platform frame 101 is reduced.

[0108] The upper surface 101t of the loading platform frame 101 is a plane including the upper surfaces 111t of the pair of main loading platform frames 111, the upper surface 112t of the outer frame 112, and the upper surface 113t of the auxiliary loading platform frame 113. In other words, the upper surfaces 111t of the pair of main loading platform frames 111, the upper surface 112t of the outer frame 112, and the upper surface 113t of the auxiliary loading platform frame 113 are aligned on the same plane, that is, the upper surface 111t of the loading platform frame 101. The upper surface 112t of the outer frame 112 is preferably aligned with the upper surface 101t of the loading platform frame 101. The upper surface 113t of the auxiliary loading platform frame 113 may be aligned with the upper surface 101t of the loading platform frame 101, or may be below the upper surface 101t of the loading platform frame 101.

[0109] The lower surface 101b of the loading platform frame 101 is a plane including the lower surfaces 111b of the pair of main loading platform frames 111, the lower surface 112b of the outer frame 112, and the lower surface 113b of the auxiliary loading platform frame 113. In other words, the lower surfaces 111b of the pair of main loading platform frames 111, the lower surface 112b of the outer frame 112, and the lower surface 113b of the auxiliary loading platform frame 113 are aligned on the same plane, that is, the lower surface 111b of the loading platform frame 101.

[0110] The lower surface 101b of the loading platform frame 101 is supported by the upper surface 7t of the vehicle body frame 7 of the vehicle body 2. Therefore, among the loading platform frames 101, it is preferable that at least a pair of loading platform main frames 111 are supported by a pair of main frames 31 of the vehicle body 2 directly or indirectly via a vibration damping member 125, such as a rubber plate. The pair of loading platform main frames 111 may be supported by a pair of main frames 31 of the vehicle body 2 in all or part of the area where they overlap the pair of main frames 31 of the vehicle body 2 in a plan view of the electric vehicle 1. When the vibration damping member 125 is sandwiched between the loading platform main frame 111 and the main frame 31, the vibration damping member 125 may be sandwiched in all or part of the area where the loading platform main frame 111 and the main frame 31 overlap. When the loading platform main frame 111 and the main frame 31 are in direct contact, that is, in a so-called metal touch state, the loading platform main frame 111 and the main frame 31 may be in contact in all or part of the area where they overlap.

[0111] By supporting the lower surface 111b of the loading platform main frame 111 with the upper surface 31t of the main frame 31, the loading platform main frame 111 and the main frame 31 can cooperate to firmly and stably support the force acting on the load loaded on the loading platform 3 and the force acting on the loading platform 3 itself.

[0112] The lower surface 112b of the outer frame frame 112 may be aligned with the lower surface 101b of the loading platform frame 101, may be above the lower surface 101b of the loading platform frame 101, or may be below the lower surface 101b of the loading platform frame 101.

[0113] The lower surface 113b of the auxiliary cargo bed frame 113 may be flush with the lower surface 101b of the cargo bed frame 101, or may be above the lower surface 101b of the cargo bed frame 101. When the auxiliary cargo bed frame 113 cooperates with the main cargo bed frame 111 to support the cargo bed 3 on the vehicle body 2, it is preferable that the auxiliary cargo bed frame 113 is supported on the side frame of the vehicle body 2 directly or indirectly via a vibration damping member 125, such as a rubber plate. The auxiliary cargo bed frame 113 may be supported on the side frame of the vehicle body 2 in the entire area or a partial area of the portion overlapping the side frame of the vehicle body 2 in a plan view of the electric vehicle 1. When a vibration damping member 125 is sandwiched between the auxiliary cargo bed frame 113 and the side frame, the vibration damping member 125 may be sandwiched in the entire area or a partial area where the auxiliary cargo bed frame 113 and the side frame overlap. When the auxiliary cargo bed frame 113 and the side frame are in direct contact, i.e., in a so-called metal touch state, the auxiliary cargo bed frame 113 and the side frame may be in contact in the entire area or a partial area where the two overlap.

[0114] By supporting the lower surface 113b of the auxiliary cargo bed frame 113 on the upper surface of the side frame, the auxiliary cargo bed frame 113 and the main side frame can cooperate to firmly and stably support the force acting on the load loaded on the cargo bed 3 and the force acting on the cargo bed 3 itself.

[0115] FIG. 10 is a perspective view of a fixture of an electric vehicle according to an embodiment of the present invention.

[0116] As shown in FIG. 10, the electric vehicle 1 according to the present embodiment includes a fixture 62 that detachably fixes the cargo bed frame 101 of the cargo bed 3 and the vehicle body frame 7 of the vehicle body 2. A pair of fixtures 62 are provided at the front and rear of the electric vehicle 1. The pair of fixtures 62 detachably fix the portion sandwiched between the pair of main cargo bed frames 111 of the outer frame 112 and the vehicle body frame 7.

[0117] Each fixture 62 is, for example, a catch clip. The fixture 62 includes a hook portion 131 provided on the loading platform frame 101 and a main body portion 132 provided on the vehicle body 2.

[0118] The main body portion 132 includes a hook portion 133 that can be hooked onto the hook portion 131, and an operation lever 135 for a fixing operation of pulling the hooked hook portion 133 toward the vehicle body 2 and a release operation of pushing the hooked hook portion 133 away from the vehicle body 2.

[0119] When the operation lever 135 is tilted in a direction away from the loading platform 3 with the hook portion 133 hooked onto the hook portion 131, the hook portion 133 is pulled toward the vehicle body 2, pulling the hook portion 131 toward the vehicle body 2, and the loading platform frame 101 of the loading platform 3 and the vehicle body frame 7 of the vehicle body 2 are fixed.

[0120] Also, when the operation lever 135 is lifted in a direction approaching the loading platform 3 with the hook portion 133 hooked onto the hook portion 131 and pulled toward the vehicle body 2, the hook portion 133 is pushed out toward the loading platform 3, the engagement with the hook portion 131 is loosened, and the fixing between the loading platform frame 101 of the loading platform 3 and the vehicle body frame 7 of the vehicle body 2 is released.

[0121] The electric vehicle 1 having such a fixture 62 can easily connect and fix the vehicle body 2 and the loading platform 3, and can easily separate the vehicle body 2 and the loading platform 3.

[0122] FIG. 11 is a perspective view of another example of the fixture of the electric vehicle according to the embodiment of the present invention.

[0123] As shown in FIG. 11, the electric vehicle 1 according to this embodiment includes a fixture 62A that detachably fixes the loading platform frame 101 of the loading platform 3 and the vehicle body frame 7 of the vehicle body 2. A pair of fixtures 62A are provided in a pair before and after the electric vehicle 1. The pair of fixtures 62 detachably fix the portion sandwiched between the pair of loading platform main frames 111 of the outer frame frame 112 and the vehicle body frame 7.

[0124] Each fixture 62A is, for example, a clamp. The fixture 62A includes a receiving plate portion 141 provided on the loading platform frame 101 and a swing fastening portion 142 provided on the vehicle body 2.

[0125] The swing fastening portion 142 includes a bolt portion 143 that can swing in the vertical direction of the electric vehicle 1 and a nut portion 145 that can be tightened to the bolt portion 143.

[0126] The receiving plate portion 141 has a notch that can dispose the bolt portion 143 and can regulate the passage of the nut portion 145.

[0127] When the nut portion 145 is tightened with the bolt portion 143 disposed in the notch of the receiving plate portion 141, the receiving plate portion 141 is drawn toward the vehicle body 2, and the loading platform frame 101 of the loading platform 3 and the vehicle body frame 7 of the vehicle body 2 are fixed.

[0128] Further, when the nut portion 145 is loosened with the receiving plate portion 141 drawn toward the vehicle body 2, the restraint of the receiving plate portion 141 is released, and the bolt portion 143 can be retracted from the notch of the receiving plate portion 141, and the fixing between the loading platform frame 101 of the loading platform 3 and the vehicle body frame 7 of the vehicle body 2 is released.

[0129] The electric vehicle 1 having such a fixture 62A can easily connect and fix the vehicle body 2 and the loading platform 3, and can easily separate the vehicle body 2 and the loading platform 3.

[0130] As described above, the electric vehicle 1 according to the present embodiment includes a pair of left and right main frames 31 extending in the front-rear direction of the electric vehicle 1, a pair of left and right driven wheels 5 disposed below the upper surfaces 31t of the respective main frames 31 and arranged to sandwich the pair of main frames 31 from the left and right, and a pair of left and right drive wheels 6 disposed below the upper surfaces 31t of the respective main frames 31 and arranged to sandwich the pair of main frames 31 from the left and right. Therefore, the left-right balance of the electric vehicle 1 is easily balanced, and as a result, the load sharing of the left and right drive wheels 6 is also easily balanced. The balance of the load sharing of the left and right drive wheels 6 effectively acts on the stability of the traction of the left and right drive wheels 6. The stability of the traction of the left and right drive wheels 6 prevents the drive wheels 6 from spinning on a rough road such as a field. Therefore, the electric vehicle 1 can easily achieve both high running performance and running performance that does not damage the road surface.

[0131] Further, the electric vehicle 1 according to the present embodiment includes a main frame 31 having one end portion 31f that protrudes more than the pair of driven wheels 5 in a direction away from the pair of drive wheels 6. Therefore, the electric vehicle 1 can stably support a larger loading platform 3 by making the front overhang of the vehicle body frame 7 larger than the rear overhang.

[0132] Furthermore, the electric vehicle 1 according to the present embodiment includes a main frame 31 having the other end portion 31b that protrudes more than the pair of drive wheels 6 in a direction away from the pair of driven wheels 5. Therefore, the electric vehicle 1 increases the load sharing of the drive wheels 6 to improve the traction of the drive wheels 6 and can stably support a larger loading platform 3 by making the rear overhang of the vehicle body frame 7 larger than the front overhang.

[0133] Further, the electric vehicle 1 according to the present embodiment includes a pair of electric motors 16 that each output the driving force of a pair of drive wheels 6, a first control device 22 that controls the pair of electric motors 16, and a first storage box 21 that is disposed so as to overlap at least one of the plurality of batteries 28 and the plurality of electric motors 16 and houses the first control device 22. The first storage box 21 is sandwiched between a pair of main frames 31 and disposed below the upper surfaces 31t of the respective pair of main frames 31, and is located between the axle 41 of the pair of driven wheels 5 and the axle 41 of the pair of drive wheels 6 in the front-rear direction of the electric vehicle 1, close to the axle 42 of the pair of drive wheels 6 and far from the axle 41 of the pair of driven wheels 5. Therefore, the power cable connecting the plurality of batteries 28 to the plurality of electric motors 16 in the electric vehicle 1 is shortened, and the weight of the electric vehicle 1 is reduced. The weight reduction of the electric vehicle 1 improves the running performance on rough roads. Further, the electric vehicle 1 can easily prevent contact between surrounding obstacles and the first storage box 21 and reliably protects the first control device 22 housed in the first storage box 21. Furthermore, the electric vehicle 1 increases the shared load of the drive wheels 6 by concentrating the weight of components in the vicinity of the plurality of batteries 28, achieving both weight reduction of the total weight and high traction of the drive wheels 6.

[0134] Furthermore, the electric vehicle 1 according to the present embodiment is provided so as to sandwich the pair of main frames 31 from the left and right inside the larger one of the outermost edge widths of the pair of driven wheels 5 and the outermost edge widths of the pair of drive wheels 6, and has a left-right pair of side extension frames 33 having a center of gravity Gsf that is located between the axle 41 of the pair of driven wheels 5 and the axle 42 of the pair of drive wheels 6 in the front-rear direction of the electric vehicle 1, close to the axle 42 of the pair of drive wheels 6 and far from the axle 41 of the pair of driven wheels 5. The pair of side extension frames 33 increases the shared load of the drive wheels 6 and effectively acts to improve the traction of the drive wheels 6. The improvement in the traction of the drive wheels 6 prevents the drive wheels 6 from spinning on rough roads such as farm fields and improves the running performance of the electric vehicle 1.

[0135] In addition, the electric vehicle 1 according to the present embodiment includes a pair of left and right side extension frames 33 each having a second portion 46 disposed so as to be sandwiched between a pair of main frames 31 and a pair of driven wheels 5. Therefore, the electric vehicle 1 extends the function of the loading platform of the vehicle frame 7 to the area sandwiched between the drive wheels 6 and the main frame 31 where the expansion is insufficient only by the first portion 45, and moves the center of gravity Gsf of the side extension frame 33 closer to the drive wheels 6 to increase the shared load of the drive wheels 6 and improve the traction of the drive wheels 6.

[0136] Furthermore, the electric vehicle 1 according to the present embodiment includes a pair of left and right side extension frames 33 that avoid a pair of driven wheels 5 and a pair of drive wheels 6 in a plan view of the electric vehicle 1 (FIG. 3). Therefore, the electric vehicle 1 can keep the ground clearance of the vehicle frame 7 as a loading platform low. The vehicle frame 7 with a low ground clearance can contribute to lowering the center of gravity of the electric vehicle 1.

[0137] In addition, the electric vehicle 1 according to the present embodiment includes a pair of main frames 31 and a pair of side extension frames 33 each having upper surfaces 31t and 33t disposed in the same plane. Therefore, the center of gravity position of the electric vehicle 1 approaches the road surface where the driven wheels 5 and the drive wheels 6 are in contact with the ground, that is, the center of gravity of the electric vehicle 1 is lowered. The lower the center of gravity position, the better the running stability of the electric vehicle 1.

[0138] Furthermore, the electric vehicle 1 according to the present embodiment includes a pair of left and right loading platform main frames 111 that at least partially overlap a pair of main frames 31 of the vehicle body 2 in a plan view of the electric vehicle 1 and are supported by the pair of main frames 31, and an outer frame 112 that is supported by the pair of loading platform main frames 111 and defines the outer edge of the loading platform frame 101. Therefore, the left and right balance of the electric vehicle 1 is easily balanced, and thus the shared load of the left and right drive wheels 6 is also easily balanced. The balance of the shared load of the left and right drive wheels 6 effectively acts on the stability of the traction of the left and right drive wheels 6. The stability of the traction of the left and right drive wheels 6 prevents the drive wheels 6 from spinning on a rough road such as a field. Therefore, the electric vehicle 1 can easily achieve both high cross-country performance and running performance without damaging the road surface.

[0139] Further, the electric vehicle 1 can firmly and stably support the forces acting on the load loaded on the loading platform 3 and the forces acting on the loading platform 3 itself by the loading platform main frame 111 and the main frame 31 that overlap in the vertical direction of the electric vehicle 1 in cooperation. Compared with the case where the loading platform main frame 111 and the main frame 31 function separately and independently without overlapping in the vertical direction of the electric vehicle 1, the loading platform main frame 111 and the main frame 31 of the electric vehicle 1 are likely to reduce their total weight and are likely to improve their durability. The weight reduction of the loading platform main frame 111, which is the main structure of the loading platform 3, and the main frame 31, which is the main structure of the vehicle body 2, increases the ratio of the maximum loading capacity in the carrying capacity of the electric vehicle 1.

[0140] Furthermore, the electric vehicle 1 according to the present embodiment includes at least one sub-loading platform frame 113 that is bridged between a pair of loading platform main frames 111 with at least a part thereof overlapping the lateral frame of the vehicle body 2 in a plan view of the electric vehicle 1, and that is bridged between the loading platform main frame 111 and the outer frame frame 112 with at least a part thereof overlapping the lateral frame in a plan view of the electric vehicle 1. Therefore, the left and right balance of the electric vehicle 1 is easily balanced, and thus the load sharing of the left and right drive wheels 6 is also easily balanced. The balance of the load sharing of the left and right drive wheels 6 effectively acts on the stability of the traction of the left and right drive wheels 6. The stability of the traction of the left and right drive wheels 6 prevents the drive wheels 6 from spinning on a rough road such as a field. Therefore, the electric vehicle 1 can easily achieve both high running performance and running performance that does not damage the road surface.

[0141] In addition, the electric vehicle 1 can firmly and stably support the forces acting on the cargo loaded on the cargo bed 3 and the forces acting on the cargo bed 3 itself through the cooperation of the cargo bed sub-frame 113 and the cross-frame that overlap in the vertical direction of the electric vehicle 1. Compared with the case where the cargo bed sub-frame 113 and the cross-frame function independently without overlapping in the vertical direction of the electric vehicle 1, the cargo bed sub-frame 113 and the cross-frame of the electric vehicle 1 are likely to reduce their total weight and improve their durability. The weight reduction of the cargo bed sub-frame 113 and the cross-frame increases the proportion of the maximum load capacity in the transportation capacity of the electric vehicle 1.

[0142] Note that the cargo bed frame 101, which preferentially includes a pair of left and right cargo bed sub-frames 113 spanned between the cargo bed main frame 111 and the outer frame 112 and excludes the cargo bed sub-frame 113 spanned between the pair of cargo bed main frames 111, exhibits sufficient rigidity to support the cargo in cooperation with the vehicle body frame 7 at the center in the left-right direction of the cargo bed frame 101, while the rigidity at the four corners of the front, rear, left, and right of the cargo bed frame 101 can be ensured by the cargo bed sub-frame 113. In addition, by not installing the cargo bed sub-frame 113 spanned between the pair of cargo bed main frames 111, the weight of the entire cargo bed frame 101 is reduced.

[0143] Further, the electric vehicle 1 according to the present embodiment includes a pair of fixtures 62, 62A provided at the front and rear of the electric vehicle 1 that detachably fix the portion sandwiched between the pair of cargo bed main frames 111 of the outer frame 112 and the vehicle body frame 7. When traveling on an unstable road surface such as a farm field, if the vehicle body 2 and the cargo bed 3 rattle in the vertical direction of the electric vehicle 1, there is a risk of damaging the cargo. Therefore, the fixtures 62, 62A have a total length longer than the total width of the electric vehicle 1, that is, they are arranged at the front and rear of the electric vehicle 1. Therefore, the electric vehicle 1 firmly and robustly integrates the vehicle body 2 and the cargo bed 3 in the vertical direction. If the vehicle body 2 and the cargo bed 3 are firmly and robustly integrated, the center of gravity position of the electric vehicle 1 is stable without being affected by the rattling between the vehicle body 2 and the cargo bed 3, and the driving performance and stability of the electric vehicle 1 are improved.

[0144] Furthermore, the electric vehicle 1 according to the present embodiment includes fixtures 62 and 62A that detachably fix the loading platform frame 101 of the loading platform 3 and the vehicle body frame 7 of the vehicle body 2, and a pair of left and right vertical frame frames 121 extending in the longitudinal direction of the electric vehicle 1 and a pair of front and rear horizontal frame frames 122 extending in the lateral direction of the electric vehicle 1. It has an outer frame frame 112 and a reinforcing portion 123 that is bridged between the vertical frame frame 121 and the horizontal frame frame 122 and can support the loading platform frame 101 on a plane. The electric vehicle 1 having the fixtures 62 and 62A can easily connect and fix the vehicle body 2 and the loading platform 3, and can easily separate the vehicle body 2 and the loading platform 3. Further, the electric vehicle 1 can easily place the loading platform 3 separated from the vehicle body 2 on a roughly flat surface such as the ground of a field. The loading platform 3 separated from the vehicle body 2 cannot receive the strength and rigidity benefits of the vehicle body frame 7, but the reinforcing portion 123 improves the strength and rigidity of the loading platform 3 when the loading platform 3 is handled alone. Note that the load conditions applied to the loading platform 3 when the loading platform 3 is handled alone are generally milder than when the electric vehicle 1 is mounted and travels in the field.

[0145] The electric vehicle 1 according to the present embodiment includes a vibration damping member 125 sandwiched between a pair of main frames 31 and the loading platform frame 101. Therefore, the electric vehicle 1 can sufficiently dampen the vibration of the loading platform 3 while firmly integrating the vehicle body 2 and the loading platform 3.

[0146] As described above, the electric vehicle 1 according to the embodiment of the present invention can achieve the running performance of the vehicle, the balance that allows stable loading of the load, the durability of the loading platform 3, and the light weight of the loading platform 3 in parallel.

[0147] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.

Description of Signs

[0148] 1... Electric vehicle, 2... Vehicle body, 3... Loading platform, 5... Driven wheel, 6... Driving wheel, 7... Vehicle body frame, 7t... Upper surface, 8... Wheel, 11... First suspension device, 12... Steering device, 15... Second suspension device, 16... Electric motor, 16o... Output shaft, 17... Transmission device, 21... First storage box, 22... First control device, 25... Second storage box, 25t... Upper surface, 26... Second control device, 28... Battery, 28F... Front battery, 28B... Rear battery, 28t... Upper surface, 28b... Bottom surface, 31... Main frame, 31t... Upper surface, 31f... One end, front end, 31b... The other end, rear end, 32... Sub-frame, 32t... Upper surface, 33... Lateral extension frame, 33t... Upper surface, 35... Reinforcement frame, 38... Gusset, 41... Axle of driven wheel, front wheel axle, 42... Axle of driving wheel, rear wheel axle, 45... First part, 46... Second part, 51... Extension frame, 52... Outer edge frame, 55... Sub-extension frame, 56... Sub-outer edge frame, 62, 62A... Fixture, 63... Fastener, 71... Driven wheel support frame, 72... First swing arm, 73... First damper, 75... Second electric motor, 76... Tie rod, 81... Driving wheel support frame, 82... Driving wheel support reinforcement frame, 83... Second swing arm, 85... Second damper, 91... Front battery support frame, 92... Rear battery support frame, 101... Loading platform frame, 101t... Upper surface, 101b... Lower surface, 111... Main loading platform frame, 111t... Upper surface, 111b... Lower surface, 112... Outer frame, 112t... Upper surface, 112b... Lower surface, 113... Sub-loading platform frame, 113t... Upper surface, 113b... Lower surface, 115... Loading platform gusset, 121... Vertical frame, 122... Horizontal frame, 123... Reinforcement part, 125... Vibration damping member, 131... Hook part, 132... Body part, 133... Hanging part, 135... Operating lever, 141... Receiving plate part, 142... Swing fastening part, 143... Bolt part, 145... Nut part.

Claims

1. A vehicle body frame having a pair of left and right main frames extending in the longitudinal direction of the vehicle, A pair of left and right driven wheels arranged to sandwich the pair of main frames from the left and right, A pair of left and right drive wheels arranged to sandwich the pair of main frames from the left and right, A loading platform frame detachably mounted on the vehicle body frame, comprising: The loading platform frame, In a plan view of the vehicle, a pair of left and right loading platform main frames at least partially overlapping the pair of main frames and supported by the pair of main frames, An outer frame frame supported by the pair of loading platform main frames and defining an outer edge of the loading platform frame, an electric vehicle.

2. At least one lateral frame that is spanned between the pair of main frames and extends in the width direction of the vehicle and that is provided to sandwich the pair of main frames from the left and right and extends in the width direction of the vehicle, In a plan view of the vehicle, at least one loading platform lateral frame that at least partially overlaps the lateral frame and is spanned between the pair of loading platform main frames and that at least partially overlaps the lateral frame in a plan view of the vehicle and is spanned between the loading platform main frame and the outer frame frame, the electric vehicle according to claim 1.

3. The electric vehicle according to claim 1 or 2, comprising a pair of fixing tools provided at the front and rear of the vehicle for detachably fixing a portion of the outer frame frame sandwiched between the pair of loading platform main frames and the vehicle body frame.

4. Comprising a fixing tool for detachably fixing the loading platform frame and the vehicle body frame, The outer frame frame, A pair of left and right vertical frame frames extending in the longitudinal direction of the vehicle, A pair of front and rear lateral frame frames extending in the left and right direction of the vehicle, A reinforcing portion spanned between the vertical frame frame and the lateral frame frame and capable of supporting the loading platform frame in a plane, the electric vehicle according to claim 1 or 2.

5. The electric vehicle according to claim 1 or 2, comprising a vibration damping member sandwiched between the pair of main frames and the loading platform frame.

Images