Traveling body and snow removal machine comprising same

Abstract

Provided is a traveling body in which quietness, a tight turning radius (maneuverability), a simplified and compact configuration, reduced cost, a good level difference climb-over function, and good ground contact can be achieved in unmanned work at an indefinite timing by automated control, such as for snow removal. The traveling body comprises: a front frame having a pair of front wheels; a rear frame having a pair of rear wheels; a coupling shaft which is located on the back side of a boundary part between the front frame and the rear frame and which couples the front frame and the rear frame so as to allow the front frame and the rear frame to rotate about an axis independently of each other; and coil springs as a pair of elastic members which are respectively disposed on both sides of the coupling shaft between the front frame and the rear frame and which impart a restoring force to return to an original state when one or both of the front frame and the rear frame rotate about an axis S. Each of the front and rear wheels is independently driven by a respective motor.

Description

Traveling body and snow removal machine equipped with the same

[0001] The present invention relates to a traveling body suitable for constituting a work vehicle such as a snow removal machine or a lawn mower, and particularly to a traveling body suitable for embodying an unmanned configuration by automatic control and a snow removal machine equipped with the same.

[0002] For snow removal in snowy areas, snow removal machines have been conventionally used. For example, there is a walking type snow removal machine in which an operator walks while holding the grip portion of the handle to perform operations, and proposals regarding this have also been made so far (see, for example, Patent Document 1).

[0003] Patent Document 2 discloses a control system for a work vehicle such as a tractor used in a farm field. In paragraph "0100" of the same document, it is described that the work vehicle may be a work vehicle that performs automatic driving without a driver. In that case, components necessary only for manned driving, such as a cabin, a driver's seat, a steering wheel, and an operation terminal, may not be provided on the work vehicle. In paragraph "0117", it is described that it can also be applied to a snow removal vehicle. That is, it can be said that it is described that the control target may be a work vehicle in which a snow removal unit is added to an unmanned configuration such as a tractor.

[0004] Japanese Patent Application Laid-Open No. 2002-180431 Japanese Patent Application Laid-Open No. 2024-94537

[0005] However, conventional snow removal machines including walking type snow removal machines are those in which an operator walks while operating to perform snow removal work. Therefore, for example, before a large amount of snow accumulates in earnest, it is impossible to meet the demand for automatically removing snow without a driver by automatic control in a relatively narrow area such as a private land at night.

[0006] Furthermore, in unmanned operations with undefined timeframes using such automated control, quiet operation is particularly required at night. Additionally, maneuverability (mobility) to accommodate narrow areas, a simple and compact design, low costs, good obstacle-climbing capabilities, and ground contact are also necessary. However, even if tractors and other work vehicles are redesigned for unmanned operation, they fundamentally retain their engines, complex transmissions, and suspensions, making it impossible to meet these requirements. In other words, while high-horsepower engine configurations are suitable for removing large amounts of snow accumulated over wide areas such as public roads, their robust and powerful design may actually be a hindrance in initial snowfall operations in relatively narrow areas.

[0007] The present invention has been made in view of the above-mentioned points, and its purpose is to provide a vehicle capable of satisfying the above-mentioned requirements in an unmanned configuration with automatic control for low-load work such as the initial stages of snowfall or grass cutting, and a snow removal machine equipped therewith.

[0008] To achieve the above objective, the running body (4) of the present invention is characterized by comprising: a front frame (12) having a pair of front wheels (10); a rear frame (16) having a pair of rear wheels (14); a connecting shaft (18) that connects the front frame (12) and the rear frame (16) so that they can each rotate independently around their axis; and a pair of elastic members (20, 20) disposed on both sides of the connecting shaft (18) between the front frame (12) and the rear frame (16) to provide a restoring force that returns either or both of the front frame (12) and the rear frame (16) to their original state when they rotate around their axes.

[0009] The vehicle according to the present invention has a minimal configuration suitable for unmanned work with automatic control, thus providing excellent maneuverability (mobility) for use in narrow areas, a simple and compact configuration, low cost, good obstacle-climbing capabilities, and good ground contact.

[0010] Furthermore, in the above-described vehicle body (4), a pair of elastic members (20, 20) may be detachably provided to the front frame (12) and the rear frame (16). This configuration allows the strength of the restoring force to be easily changed by replacing the elastic members, and the suspension function can be optimized according to the operating environment and conditions.

[0011] Furthermore, in the above-described vehicle body (4), the pair of elastic members (20, 20) may be configured as coil springs installed between the front frame (12) and the rear frame (16). This allows for the selection of springs with standardized spring constants, making it easier to optimize the suspension function according to the operating environment and conditions.

[0012] Furthermore, in the above-described vehicle (4), each front wheel (10) and each rear wheel (14) is unitized including a drive motor (38) that drives each of them, so that each front wheel (10) and each rear wheel (14) is driven independently. This allows for a skid steering function to be obtained with a simple configuration, and also simplifies the manufacturing process and reduces costs by modularizing the drive configuration into a common unit.

[0013] Furthermore, in the above-described vehicle (4), the battery that supplies power to each motor (38) may be configured to be located at the outer ends of the front frame (12) and rear frame (16) in the direction of travel, and in the center of the width direction perpendicular to the direction of travel. This configuration allows for stable driving performance.

[0014] Furthermore, the above-mentioned vehicle (4) may be configured with a lead-acid battery (22). This configuration allows for stable driving performance even off-road, and also provides a stable power supply even when the environment or usage conditions change.

[0015] Furthermore, in the above-described vehicle (4), the front frame (12) and rear frame (16) may be configured to allow adjustment of the mounting position of each front wheel (10) and each rear wheel (14) and each motor (38) in the direction of travel and / or in the width direction perpendicular to the direction of travel. This allows the wheelbase and tread of the vehicle (4) to be variable, and the configuration can be optimized according to the type of work and environmental conditions.

[0016] Furthermore, in the above-mentioned vehicle body (4), the connecting shaft (18) may be provided in a manner that allows for adjustment of its length in the axial direction. This allows for adjustment of the vehicle body length, thereby improving the ability to travel on slopes and overcome obstacles.

[0017] Furthermore, the snowblower (2) of the present invention may be configured to include a traveling body (4) having any of the above configurations and a snow removal unit (8) for snow removal. This configuration makes it possible to realize a snowblower that is simple, low-cost, highly maneuverable, strong against uneven surfaces, and has excellent ground contact, suitable for snow removal in relatively narrow areas such as private property during the initial stages of snowfall.

[0018] According to the present invention, it is possible to provide a vehicle that enables a simple and low-cost unmanned work vehicle configuration with good maneuverability, strong resistance to uneven surfaces, and excellent ground contact, as well as a snowplow equipped with the same.

[0019] Figure 2 is a perspective view of a snowblower equipped with a vehicle according to one embodiment of the present invention. Figure 1 is a perspective view of the snowblower shown in Figure 1 with the weather-resistant cover removed (vehicle with the snow removal unit attached). Figure 2 is an exploded perspective view of the vehicle shown in Figure 2. Figure 2 is an enlarged perspective view of the vehicle shown in Figure 2 from a different angle. Figure 2 is an enlarged plan view of the vehicle shown in Figure 2. Figure 2 is a bottom view of the vehicle shown in Figure 2. Figure 2 is an enlarged perspective view of the connecting shaft portion as seen from the bottom side of the vehicle shown in Figure 2. Figure 2 is an enlarged perspective view showing the coil spring mounting configuration on the left side of the vehicle shown in Figure 2. Figure 2 is a schematic exploded perspective view to explain the simplification and low center of gravity stability of the vehicle shown in Figure 2. Figure 1 shows the step-climbing function of the vehicle shown in Figure 1. Figure 2 is an enlarged perspective view of the snow removal unit portion of the vehicle shown in Figure 2. Figure 1 is a control block diagram of the snowblower shown in Figure 1. Figure 1 is a front view of the controller for controlling the snowblower shown in Figure 1. Figure 13 shows the snow removal area specified on the display screen of the controller shown in Figure 13. Figure 1 shows the snow removal travel line of the specified snow removal area of ​​the snowblower shown in Figure 1.

[0020] Embodiments of the present invention will be described in detail below with reference to the attached drawings.

[0021] Figure 1 shows a four-wheel drive snowblower 2 equipped with a vehicle 4 according to this embodiment, which is suitable for automatically controlling snow removal in the initial stages of snowfall in relatively narrow areas such as private property. The snowblower 2 has the top surface of the vehicle 4 covered with a weather-resistant cover 6, and a snow removal unit 8 is provided at the front of the vehicle 4. The snowblower 2 can also be called an unmanned ground vehicle (UGV) for the purpose of snow removal.

[0022] As shown in Figures 2 to 6, the vehicle body 4 comprises a front frame 12 having a pair of front wheels 10 on each side, a rear frame 16 separate from the front frame 12 and having a pair of rear wheels 14 on each side, a connecting shaft 18 (see Figure 6 viewed from the bottom) positioned on the back side of the boundary between the front frame 12 and the rear frame 16, which connects the front frame 12 and the rear frame 16 so that they can each rotate independently around the axis S, and a pair of coil springs 20, 20 as elastic members, which are positioned on both sides of the connecting shaft 18 between the front frame 12 and the rear frame 16, and which provide a restoring force to return either or both of the front frame 12 and the rear frame 16 to their original state when they rotate around the axis S. Hereinafter, the front frame 12 and the rear frame 16 together will also be referred to as the "vehicle body".

[0023] Each front wheel 10 and each rear wheel 14 consists of a wheel and a rubber tire, and the shape of the tire tread is actually a lug type, similar to that of a tractor tire. In Figure 2, arrow Y indicates the longitudinal direction (direction of travel) of the vehicle 4, and arrow X indicates the width direction (left-right direction). Also, arrow Y1 indicates the front side (forward or forward direction), arrow Y2 indicates the rear side (rearward or reverse direction), arrow X1 indicates the left side (left side when facing forward direction), and arrow X2 indicates the right side (right side when facing forward direction). Other figures will also be explained based on this.

[0024] As shown in Figure 5, the front frame 12 and the rear frame 16 have a C-shaped or U-shaped symmetrical shape (shared shape for front and rear) with housing recesses 12a and 16a for housing lead-acid batteries 22 as batteries. In Figure 5, reference numeral 24 denotes the contact line between the front frame 12 and the rear frame 16 due to the biasing force of the coil springs 20, 20, and 12b and 16b indicate bolt insertion holes formed in a number of aligned positions around the housing recesses 12a and 16a in the front, rear, left, and right directions. The fixing configuration of the rectangular parallelepiped lead-acid battery 22 is described in terms of the front frame 12, where a support plate 26 is placed on the bottom surface, and two long bolts 28 are inserted through the bolt insertion holes of the support plate 26 and the bolt insertion holes 12b of the front frame 12, and the long bolts 28 are fixed to the front frame 12 by inserting a strip plate 30 from above and tightening it with nuts (see Figure 2). The lead-acid battery 22 in the rear frame 16 is fixed in a similar manner (some details omitted).

[0025] As shown in Figure 2, a support frame 32 for supporting the weather-resistant cover 6 is fixed to the rear frame 16. The support frame 32 consists of a rear support frame 32a with four legs fixed to the rear frame 16, and a narrow, rectangular front support frame 32b extending from the front upper end of the rear support frame 32a toward the front frame 12. As described above, the front frame 12 and the rear frame 16 can rotate relative to each other around the axis S via a connecting shaft 18, so to avoid interference (collision between members) due to rotation, the front support frame 32b is not fixed to the front frame 12, and as shown in Figure 1, the weather-resistant cover 6 also has a shape that narrows towards the front in accordance with this.

[0026] As shown in Figures 6 and 7, the connecting shaft 18 has an extendable double-shaft structure consisting of a front shaft 18A rotatably supported by a bottom-open box-shaped bearing 34A bolted to the lower surface of the front frame 12, and a rear shaft 18B which has a smaller diameter than the front shaft 18A, is slidably inserted into the front shaft 18A, and is rotatably supported by a bottom-open box-shaped bearing 34B.

[0027] As shown in Figure 7, bearing 34A consists of a fixing plate 34A1 bolted to the front frame 12 via bolt insertion holes 12b, a pair of front and rear side plates 34A2, 34A2 fixed to the lower surface of fixing plate 34A1 by welding or the like, and a pair of left and right side plates 34A3, 34A3 also fixed to the lower surface of fixing plate 34A1 by welding or the like. Support holes for the front shaft 18A are formed in the front and rear side plates 34A2, 34A2. Similarly, bearing 34B consists of a fixing plate 34B1 bolted to the rear frame 16 via bolt insertion holes 16b, a pair of front and rear side plates 34B2, 34B2 fixed to the lower surface of fixing plate 34B1 by welding or the like, and a pair of left and right side plates 34B3, 34B3 also fixed to the lower surface of fixing plate 34B1 by welding or the like. Support holes for the rear shaft 18B are formed in the front and rear side plates 34B2, 34B2. In this embodiment, the front shaft 18A and the rear shaft 18B are directly supported by box-shaped bearings 34A and 34B, but they may also be supported via bearings.

[0028] Although not shown in the diagram, the rear axle 18B can be fixed in position relative to the front axle 18A by a locking mechanism such as bolt tightening at an appropriate sliding position. In other words, the connecting shaft 18 is provided so that its length in the axial direction can be adjusted. By extending the connecting shaft 18 to separate the front and rear of the vehicle, that is, by increasing the length in the direction of travel of the vehicle, the effective contact area is increased, making it possible to travel stably without slipping even on slopes of 30° or more.

[0029] As shown in Figure 8, the left coil spring 20 is detachably mounted between a spring receiving plate 34 fixed to the lower left end of the front frame 12 and the rear frame 16 by welding or the like. The spring receiving plate 34 has multiple insertion holes 34a formed at intervals in the front-rear direction, and an axle pin 36 that engages the hook 20a of the coil spring 20 is inserted through the insertion holes 34a. Although detailed illustrations are omitted, the right coil spring 20 has a similar mounting configuration. When the coil springs 20 are the same, the spring force (restoring force) can be changed by changing the insertion position of the axle pin 36 and thereby changing the distance between the axle pins 36. It is also possible to set coil springs 20 with different spring constants according to the usage conditions and environment by changing the distance between the axle pins 36. In other words, the tension (preload) can be easily changed by changing the stiffness (spring constant) and mounting position of the two coil springs 20 connecting the front frame 12 and the rear frame 16, and the setting can be easily changed according to the environment and usage conditions. In the height direction of the running body 4, the coil springs 20, 20 are set to a position higher than the connecting shaft 18.

[0030] As shown in Figures 6 and 9, each front wheel 10 and rear wheel 14 is independently driven by a motor 38 powered by a lead-acid battery 22. Each front wheel 10 and rear wheel 14 is unitized as a tire motor unit 42, which includes a reduction gearbox (not shown) and a fixing plate 40 that constitute the motor mount. Each tire motor unit 42 is detachably attached to the front frame 12 and rear frame 16 by bolts via a fixing plate 40 with bolt insertion holes. In other words, as shown in Figure 9, the vehicle body is divided into front and rear units, which are common to both front and rear. Therefore, there is no steering mechanism or suspension mechanism, which are complex, have many parts, and incur maintenance costs. That is, it is a concrete configuration with a minimal design that is symmetrical front and rear and left and right, limited to the minimum configuration necessary for unmanned operation.

[0031] The front frame 12 and rear frame 16 are configured to allow adjustment of the mounting position of the tire motor unit 42, which is a unitized configuration of each front wheel 10, each rear wheel 14 and each motor 38, in the direction of travel (front-rear direction) and / or in the width direction perpendicular to the direction of travel. Therefore, by appropriately changing the front-rear and left-right fixing positions of the tire motor unit 42 relative to the front frame 12 and rear frame 16, the wheelbase and tread can be varied and adjusted according to the application. This also contributes to cost reduction during mass production and reduction of maintenance costs.

[0032] Furthermore, in the vehicle 4 or snowblower 2 of this embodiment, for example, when the connecting shaft 18 is not extended, the dimensions are 90 cm in length, 64 cm in width, and 60 cm in height, and the minimum turning radius due to the skid steering function can be 30 cm. In that case, the maximum diameter of the connecting shaft 18 can be 48 mm. By adopting such a dimensional configuration, it is possible to realize a vehicle that is robust and has high load-bearing capacity (high durability) despite being intended for low-load work vehicles.

[0033] As described above, each of the front wheels 10 and rear wheels 14 of the vehicle body 4 according to this embodiment is independently driven using separate motors 38. This allows for skid steering, which changes the direction of travel of the vehicle by changing the rotational speed and direction of rotation of the left and right wheels, thereby improving maneuverability. In this embodiment, from the viewpoint that increasing the weight increases the moment and improves stability when heavy objects are placed at the ends of the vehicle body, and that increasing the weight improves road grip, two relatively heavy lead-acid batteries 22 are placed at the outer ends (front and rear ends) in each direction of travel (front and rear) of the vehicle body, in the center of the width direction perpendicular to the direction of travel, to improve stability. Although lithium-ion batteries are generally known to be lightweight and energy-efficient as the power source for the motors 38, relatively heavy lead-acid batteries 22 are used after considering resistance to temperature changes and weight balance.

[0034] While a skid steering function can also be obtained with a crawler-type system, experiments by the inventors have confirmed that the belt may freeze and fail to operate in snow removal applications. Furthermore, crawler-type systems have a large number of parts, a complex mechanism, and small wheels that make them vulnerable to uneven surfaces. For this reason, this embodiment employs four-wheel independent drive. As shown in Figure 2, the lower half of the lead-acid battery 22 is fixed so that it is located below the front frame 12 and the rear frame 16, resulting in a low center of gravity and four-wheel drive, which allows it to exert powerful driving and traction forces on any surface (off-road), such as paved roads, grass, and gravel.

[0035] As described above, the vehicle body 4 according to this embodiment is divided into front and rear sections and integrated into a common unit, and is rotatable relative to each other around the axis S of the connecting shaft 18, so it can also be called a rolling rigid frame system.

[0036] Figure 10 shows the rolling function of the vehicle 4 (snowblower 2) to overcome obstacles, specifically an example where the right front wheel 10 rides onto a step 54 about 20 cm high. In this case, the front frame 12 rotates (rolls) to the left around the axis S of the connecting shaft 18 and rides onto the step 54, but the two rear wheels 14 of the rear frame 16 and the left front wheel 10 remain in contact with the ground. In other words, even with a step 54, all four wheels, including the surface on top of the step 54, can always maintain contact with the ground, allowing the vehicle to travel without reducing the driving force of the four-wheel drive (without slipping). As described above, the front support frame 32a of the support frame 32 is not fixed to the front frame 12, and the front of the weatherproof cover 6 is narrower, so the front frame 12 does not interfere with the weatherproof cover 6 even when it rolls.

[0037] When passing over a step, the elastic force of the pair of coil springs 20, 20 causes the front frame 12 to rotate around the axis S and return to its original position. The same applies when the rear wheels 14 of the rear frame 16 pass over a step. In this way, the vehicle 4 according to this embodiment achieves a suspension function that is resistant to steps and a vehicle body restoration function after rolling with a relatively simple and low-cost configuration of simply mounting coil springs 20 on both sides of the connecting shaft 18, without using the complex suspension mechanism that existing vehicles have. This simplification of the configuration is based on the idea that ride comfort can be reduced because it is unmanned, while prioritizing drivability and off-road capability.

[0038] As shown in Figure 11, the snow removal unit 8 includes a snow removal plow 44 and a support mechanism 46 that supports the plow 44. The support mechanism 46 consists of vertical brackets 48 fixed to both front sides of the front frame 12, a support bracket 50 fixed to the vertical brackets 48 by bolt fastening, and a pair of upper and lower arms 52 extending forward from the support bracket 50 and connected to the plow 44. Each vertical bracket 48 and support bracket 50 has multiple bolt insertion holes formed at intervals in the vertical direction, allowing the position of the support bracket 50 relative to the vertical bracket 48, i.e., the position of the plow 44, to be adjusted. The vertical position of the plow 44 may also be adjusted by moving the support bracket 50 up and down with an electric actuator.

[0039] The automatic control of the snowblower 2 will be explained with reference to Figures 12 to 15. As shown in Figure 12, the snowblower 2 is equipped with a motor 38, an electronic control unit 60 which is a microcomputer, a GPS compass 62 which determines the position of the snowblower 2, an emergency stop button 64 which forcibly stops the operation of the snowblower 2 in an emergency, an obstacle sensor 66 which detects obstacles by emitting ultrasonic waves, and a plurality of contact sensors 68 such as touch sensors which are provided on the front, back, left, right, left and right sides of the snowblower 2 and on both sides and detect when the snowblower 2 comes into contact with an obstacle (omitted in Figure 1, etc.). The operator controls the snowblower 2 with a portable controller 70.

[0040] When the controller 70 specifies a predetermined snow removal area on the map, the electronic control unit 60 controls the snowblower 2 to remove snow from the specified area unmanned, while avoiding obstacles, based on the position information of the snowblower 2 obtained by GPS (Global Positioning System).

[0041] As shown in Figure 13, the controller 70 is equipped with a display screen 71 that displays map information and location information on a map obtained from GPS signals, various operation buttons 72 to 76, antennas 77 and 78, and application software that calculates the route to take for snow removal in a designated snow removal area. Note that the configuration of the controller 70 is just one example, and it is also possible to use a mobile communication terminal device (smartphone) with application software for remotely controlling the snowblower 2 installed as the controller 70.

[0042] Next, we will explain the process of automatically controlling snowblower 2 to remove snow from a designated area without human intervention.

[0043] First, when map information is displayed on the controller 70's display screen 71, the operator specifies the area (area on the map) that they want to clear snow from unattended (snow removal area specification step). Specifically, as shown in Figure 14, the operator specifies the area to be cleared on the map displayed on the controller 70's display screen 71, indicating the corners of the area with the numbers "1", "2", "3", and "4". That is, in the example shown in Figure 14, the operator touches the snow removal area corner setting mode button 71a and taps the four corners of the snow removal area in the order of the numbers "1", "2", "3", and "4". Note that the points of the four corners of the snow removal area, which are displayed with the numbers "1", "2", "3", and "4", can also be modified later by dragging those points on the display screen 71.

[0044] When the snow removal area is designated as described above, touch the snow removal driving line (automatically calculated display) mode button 71b on the display screen 71 shown in FIG. 14. Then, the moving path of the snow remover 2 in the designated snow removal area is calculated by dedicated application software (moving path calculation step). An example thereof is shown in FIG. 15.

[0045] According to the moving path shown in FIG. 15, a total of 12 linear driving lines L1 to L12 extending in the vertical direction of FIG. 15 are set horizontally parallel and at equal intervals within the designated snow removal area. The snow remover 2 evenly removes snow in the designated snow removal area while moving along these driving lines L1 to L12 (snow removal step).

[0046] That is, first, with the plow 44 arranged at the above-described snow removal position, the snow remover 2 is moved (driven) from point a, which is the starting point, to point b, which is the ending point (toward the upper side of FIG. 15) along the linear driving line (first driving line) L1 (first step). By this movement, the snow on the driving line L1 is scraped and removed by the snow remover 2. After that, the snow remover 2 is reversed from point b to point a along the driving line L1 (second step). In the case of a configuration in which the plow 44 is vertically moved by an electric actuator, it is reversed with the plow 44 raised.

[0047] In the process of the snow remover 2 reversing from point b to point a along the driving line L1 shown in FIG. 15, when the snow remover 2 reaches point c (a position near point a) in the middle of the driving line L1, the snow remover 2 moves forward along the driving line M1 that extends substantially linearly obliquely forward from point c to the next adjacent driving line (second driving line) L2 and reaches point d on the next adjacent linear driving line L2. After that, the snow remover 2 reverses from point d to point e, which is the starting point, along the driving line L2 (third step).

[0048] From the above state, the snow remover 2 advances while removing snow from point e on the travel line L2 to point f which is the end point along the travel line L2 (the fourth step). Thereafter, the same operation is repeated in this order, and the snow remover 2 repeats snow removal while sequentially traveling on the travel lines L1 to L12, whereby the designated snow removal area is snow-removed by the snow remover 2. In this embodiment, when explaining the example of retreating the snow remover 2 along the travel line L1, the example of retreating to point c in the middle of the travel line L1 has been described, but in addition to this, the snow remover 2 may be retreated to point a which is the starting point of the travel line L1.

[0049] In this embodiment, the method is such that the operator controls the operation of the snow remover 2 while looking at the display screen 71 of the controller 70, but when the automatic control start button of the controller 70 is pressed, thereafter, the snow remover 2 may be made to operate according to a snow removal program pre-installed in the electronic control unit 60 automatically.

[0050] As described above, the embodiments of the present invention have been explained, but the present invention is not limited to the above embodiments, and various modifications are possible within the scope of the technical idea described in the claims, the specification, and the drawings. For example, in the above embodiment, the coil spring 20 is exemplified as the elastic member, but it is not limited to this, and other configurations such as a rubber rod member may be used as long as it can exhibit a restoring force after rolling. Further, in the above embodiment, the snow remover 2 is exemplified, but it may be a work vehicle provided with a lawn mowing unit or a turf mowing unit instead of the snow removal unit 8, or it may be a luggage carrier vehicle equipped with a luggage compartment or a luggage placement table. Further, since the traveling body 4 according to the above embodiment can exhibit strong traveling performance and traction while being small, it may be used in a form of towing a cart carrying people or objects. Furthermore, by replacing the snow removal unit 2 with a unit for construction machinery, it is also possible to make it a work vehicle for construction and civil engineering that can transport earth and sand, stones, concrete blocks, etc.

[0051] Furthermore, if necessary, cushions or springs can be added to the tire motor unit 42 to add a suspension function, and a steering mechanism can also be added to the tire motor unit 42 by providing a mechanism that rotates the wheels (front or rear wheels) left or right (steering).

Claims

1. A running body comprising: a front frame having a pair of front wheels; a rear frame having a pair of rear wheels; a connecting shaft that connects the front frame and the rear frame so that they can each rotate independently around an axis; and a pair of elastic members disposed on both sides of the connecting shaft between the front frame and the rear frame, which provide a restoring force to return either or both of the front frame and the rear frame to their original state when they rotate around the axis.

2. The traveling body according to claim 1, characterized in that the pair of elastic members are detachably provided with respect to the front frame and the rear frame.

3. The traveling body according to claim 1, characterized in that the pair of elastic members are coil springs installed between the front frame and the rear frame.

4. The vehicle according to claim 1, characterized in that each of the front wheels and each of the rear wheels is unitized with a drive motor that drives each of them, so that each of the front wheels and each of the rear wheels is driven independently.

5. The traveling body according to claim 4, characterized in that the battery that supplies power to each of the motors is located at the outer end of the front frame and the rear frame in the direction of travel, and at the center of the width direction perpendicular to the direction of travel.

6. The vehicle according to claim 5, characterized in that the battery is a lead-acid battery.

7. The vehicle according to claim 4, characterized in that the front frame and the rear frame are configured to allow adjustment of the mounting position of the integrated configuration of each front wheel and each rear wheel and each motor in the direction of travel and / or in the width direction perpendicular to the direction of travel.

8. The traveling body according to claim 1, characterized in that the connecting shaft is provided so that its length in the axial direction can be adjusted.

9. A snowblower comprising a traveling body according to any one of claims 1 to 8 and a snow removal unit for snow removal.

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