Electrically-assisted trailer

Abstract

The invention discloses an electric power-assisted trailer which comprises a controller which is at least electrically connected with a driving motor so as to control rotation of the driving motor; wherein the electrically assisted trailer further comprises: a parameter detection module configured to sense an operating force applied to the handle device; the electric power-assisted trailer comprises a power-assisted mode, and the controller is configured in the mode that in the power-assisted mode, the controller controls the power-assisted state provided by the driving motor to the driving wheels according to the operating force. And the user feels more comfortable in the power-assisted state.

Description

[0001] This application is a divisional application of the application with the application date of November 24, 2023, the national application number of 202311586479.7, and the invention title of "Electric-Assist Trailer". Technical Field

[0002] This application relates to a vehicle for transportation, and more particularly to an electric-assist trailer. Background Art

[0003] With the continuous improvement of people's living standards, various outdoor activities have gradually become the top choice for people to relax, such as outdoor picnics or camping. Generally, when carrying out the above activities, a lot of things need to be carried, which is inconvenient. To meet the above needs, outdoor picnic trailers on the market are widely welcomed. However, the outdoor play areas are generally not as smooth as urban roads, and it is relatively laborious to push and pull when the trailer is transporting heavy things.

[0004] This section provides background information related to this application, and these background information are not necessarily prior art. Summary of the Invention

[0005] One object of this application is to solve or at least mitigate part or all of the above problems. The purpose of this application is to provide an electric trailer that can provide electric energy assistance.

[0006] To achieve the above object, this application adopts the following technical solutions: An electric-assist trailer, comprising: a trailer main body, at least including a foldable frame; a handle device, connected to the trailer main body; a walking assembly, at least including driving wheels; a driving motor, configured to drive the driving wheels to rotate; a power supply access part, for accessing a power supply, and the power supply at least powers the driving motor; a controller, at least electrically connected to the driving motor to control the rotation of the driving motor; wherein, the electric-assist trailer further includes: a parameter detection module, configured to sense the operating force applied to the handle device; the electric-assist trailer includes an assistance mode, and the controller is configured to: in the assistance mode, the controller controls the assistance state provided by the driving motor to the driving wheels according to the operating force.

[0007] In one embodiment, the parameter detection module is arranged on the handle device or at the connection between the handle device and the trailer main body.

[0008] In one embodiment, it further includes: a control board, at least provided with the controller; An energy recovery circuit is arranged on the control board; The power supply includes a battery pack, and the energy of the battery pack is greater than or equal to 40 Wh; The energy recovery circuit recovers electric energy when the driving motor decelerates to charge the battery pack.

[0009] In one embodiment, the parameter detection module is further configured to detect the running state of the electric-assisted trailer; The controller is configured to: when the running state is a downhill state, control the drive motor to change the assistance state to reduce the rotational speed of the drive motor.

[0010] In one embodiment, it further includes: a mode selection switch, which is arranged on the handle device and is at least electrically connected to the controller, and the mode selection switch is used to control the working mode of the electric-assisted trailer.

[0011] In one embodiment, when the mode selection switch is in the on state, the electric-assisted trailer is in the assistance mode, and the controller is configured to control the drive motor to provide assistance; when the mode selection switch is in the non-conductive state, the electric-assisted trailer is in the non-assistance mode, and the controller is configured to control the drive motor to stop providing assistance.

[0012] In one embodiment, when the mode selection switch is in the first switch state, the drive motor does not work; When the mode selection switch is in the second switch state, it has multiple switch gears; The controller is set to control the drive motor to output power at a corresponding output rotational speed or output torque according to different switch gears.

[0013] In one embodiment, it further includes: a safety switch, which is arranged on the handle device and is at least electrically connected to the controller; The controller is configured not to respond to changes in the switch state of the mode selection switch when the safety switch is turned on.

[0014] An electric-assisted trailer includes: a trailer main body, which at least includes a foldable frame; a handle device, which is connected to the trailer main body; a running assembly, which at least includes drive wheels; a drive motor, which is arranged to drive the drive wheels to rotate; a power access part, which is arranged to access a battery pack to supply power to the drive motor; a controller, which is at least electrically connected to the drive motor to control the rotation of the drive motor; the electric-assisted trailer further includes: a mode selection switch, which at least has a first switch state and a second switch state; the controller is configured to: Control the drive motor to provide assistance or not provide assistance according to the switch state of the mode selection switch.

[0015] In one embodiment, the trailer main body further includes an enclosure member, and the enclosure member is detachably connected to the frame to form a storage space.

[0016] In one embodiment, the power access part is arranged to detachably access a battery pack or an external power supply device.

[0017] In one embodiment, the power access part at least includes an enclosed battery compartment or an outdoor power access part.

[0018] In one embodiment, the drive motor is a hub motor.

[0019] In one embodiment, it further includes: a control board, which is at least provided with a controller; An energy recovery circuit is provided on the control board; The energy recovery circuit recovers electric energy to charge the battery pack when the drive motor decelerates.

[0020] In one embodiment, it further includes: a safety switch, which is provided on the handle device and is at least electrically connected to the controller; The controller is configured not to respond to changes in the switch state of the mode selection switch when the safety switch is turned on.

[0021] In one embodiment, it further includes a parameter detection module; The parameter detection module is set to detect the trailer parameters of the electric assisted trailer; The controller is configured to adjust the assistance state of the drive motor according to the trailer parameters.

[0022] In one embodiment, the controller is configured to identify the operation intention of the user operating the electric assisted trailer according to the trailer parameters, and adjust the assistance state of the drive motor according to the operation intention.

[0023] In one embodiment, the trailer parameters include the working parameters of the drive motor, or the state parameters of the handle device relative to the trailer body, or the magnitude and direction of the force applied by the user on the handle device, or the walking speed of the user.

[0024] In one embodiment, the assistance state includes the output torque of the drive motor or the output speed of the drive motor.

[0025] In one embodiment, the mode selection switch includes a self-resetting structure. When the mode selection switch is triggered, the mode selection switch is in one of the first switch state or the second switch state. When the mode selection switch is released, the mode selection switch resets to the other switch state of the first switch state or the second switch state.

[0026] In one embodiment, it further includes a status indication part, which indicates the assistance state of the drive motor through sound and light display.

[0027] An electric-assisted trailer, comprising: a trailer main body, at least including a foldable frame; a handle device connected to the trailer main body; a traveling assembly, at least including a driving wheel; a driving motor configured to drive the driving wheel to rotate; a power supply access part configured to access a battery pack to supply power to the driving motor; a controller electrically connected to at least the driving motor to control the rotation of the driving motor; the electric-assisted trailer further includes: a parameter detection module configured to detect trailer parameters of the electric-assisted trailer; the controller is configured to adjust the assistance state of the driving motor according to the trailer parameters.

[0028] In one embodiment, the controller is configured to identify the operation intention of the user operating the electric-assisted trailer according to the trailer parameters, and adjust the assistance state of the driving motor according to the operation intention.

[0029] In one embodiment, the trailer parameters include the operating parameters of the driving motor, or the state parameters of the handle device relative to the trailer main body, or the magnitude and direction of the force applied by the user on the handle device, or the walking speed of the user.

[0030] In one embodiment, the assistance state includes the output torque of the driving motor or the output rotational speed of the driving motor.

[0031] In one embodiment, the parameter detection module is further configured to detect operation information input by the user, and the controller is configured to adjust the assistance state of the driving motor according to the operation information.

[0032] The advantages of the present application are as follows: The electric trailer is powered by a battery pack to supply power to the driving motor, and the driving motor drives the traveling assembly to move, realizing the assisted walking of the electric trailer. Through the mode selection switch, the user can select the assisted mode and the non-assisted mode according to actual needs. By detecting the operating force applied to the handle device through the parameter detection module, the controller can adaptively adjust the assistance state of the driving motor, so that the user obtains a more comfortable assistance state. Description of the Drawings

[0033] Figure 1 is a schematic structural diagram of the electric trailer in the unfolded state in the embodiment of the present application; Figure 2 is a schematic structural diagram of the electric trailer in another perspective in the unfolded state in the embodiment of the present application; Figure 3 is a schematic structural diagram of the electric trailer with the trailer main body in the folded state in the embodiment of the present application; Figure 4 is a schematic structural diagram of the power supply access part and the battery pack in the embodiment of the present application; Figure 5 is a schematic structural diagram of the battery pack and an electric tool using the battery pack in the embodiment of the present application; Figure 6It is a schematic diagram of the control circuit structure of the electric trailer in the embodiment of the present application; Figure 7 It is a schematic diagram of the structure of the drive motor and the transmission mechanism of the electric trailer in the embodiment of the present application; Figure 8 It is Figure 7 A schematic diagram of the structure from another perspective; Figure 9 It is Figure 8 A cross-sectional view along the G-G section in; Figure 10 It is a schematic diagram of the structure of the clutch mechanism in the second state in the embodiment of the present application; Figure 11 It is a schematic diagram of the structure of the clutch mechanism in the first state in the embodiment of the present application; Figure 12 It is Figure 10 A schematic diagram of the structure of the half cross-sectional view of; Figure 13 It is a schematic diagram of the structure of the handle device and the passive wheel in the embodiment of the present application; Figure 14 It is Figure 13 A schematic diagram of the partial structure from another perspective; Figure 15 It is Figure 13 A schematic diagram of the force direction detection part and the connecting rod in; Figure 16 It is Figure 13 A schematic diagram of the structure of the holding part in; Figure 17 It is Figure 13 An exploded view of the structure of the angle detection part in; Figure 18 It is a schematic diagram of the structure of another kind of drive wheel and drive motor; Figure 19 It is a schematic diagram of the structure of the electric trailer for construction sites in the embodiment of the present application; Figure 20 It is a schematic diagram of the structure of the electric trailer for warehouses in the embodiment of the present application. Detailed implementation manners

[0034] Before explaining in detail any embodiment of the present application, it should be understood that the present application is not limited to the structural details and component arrangements set forth in the following description or shown in the above drawings.

[0035] In this application, the terms "comprise", "include", "have" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or apparatus comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or apparatus. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising that element.

[0036] In this application, the term "and / or" describes the associative relationship between associated objects and indicates that three relationships may exist. For example, A and / or B may represent three cases: A exists alone, A and B exist simultaneously, and B exists alone. Additionally, in this application, the character " / " generally indicates that the associated objects before and after are in an "and / or" relationship.

[0037] In this application, the terms "connect", "combine", "couple", "mount" may be direct connection, combination, coupling or mounting, or may be indirect connection, combination, coupling or mounting. For example, direct connection means that two parts or components are connected together without the need for an intermediate member, and indirect connection means that two parts or components are respectively connected to at least one intermediate member, and these two parts or components are connected through the intermediate member. In addition, "connect" and "couple" are not limited to physical or mechanical connection or coupling and may include electrical connection or coupling.

[0038] In this application, those of ordinary skill in the art will understand that relative terms used in connection with a quantity or condition (such as "about", "approximately", "substantially", etc.) are intended to include the stated value and have the meaning indicated by the context. For example, such relative terms include at least the degree of error associated with the measurement of a particular value, tolerances resulting from manufacturing, assembly, use, etc. associated with a particular value. Such terms should also be considered to disclose a range defined by the absolute values of two endpoints. Relative terms may refer to a plus or minus a certain percentage (such as 1%, 5%, 10% or more) of the indicated value. A numerical value without the use of a relative term should also be disclosed as a particular value having a tolerance. In addition, when expressing a relative angular positional relationship (such as substantially parallel, substantially perpendicular), "substantially" may refer to a plus or minus a certain number of degrees (such as 1 degree, 5 degrees, 10 degrees or more) from the indicated angle.

[0039] In this application, those of ordinary skill in the art will understand that the functions performed by a component may be performed by one component, multiple components, one part, or multiple parts. Similarly, the functions performed by a part may also be performed by one part, one component, or a combination of multiple parts.

[0040] In this application, the directional terms such as "upper", "lower", "left", "right", "front", and "rear" are described based on the orientation and positional relationship shown in the drawings, and should not be construed as limiting the embodiments of this application. In addition, in the context, it should also be understood that when it is mentioned that one component is connected "above" or "below" another component, it can not only be directly connected "above" or "below" another component, but also be indirectly connected "above" or "below" another component through an intermediate component. It should also be understood that the directional terms such as the upper side, lower side, left side, right side, front side, and rear side not only represent the positive direction, but can also be understood as the side direction. For example, the lower side can include directly below, lower left, lower right, lower front, and lower rear, etc.

[0041] In this application, the terms "controller", "processor", "central processor", "CPU", and "MCU" can be interchanged. When using the units "controller", "processor", "central processor", "CPU", or "MCU" to perform specific functions, unless otherwise specified, these functions can be performed by a single one of the above units or multiple of the above units.

[0042] In this application, the terms "device", "module", or "unit" can be implemented in the form of hardware or software in order to achieve specific functions.

[0043] In this application, the terms "calculate", "judge", "control", "determine", "identify", etc. refer to the operations and processes of a computer system or a similar electronic computing device (such as a controller, a processor, etc.).

[0044] To clearly illustrate the technical solution of this application, the upper side, lower side, left side, right side, front side, and rear side as shown Figures 1 - 2 are also defined.

[0045] The electric trailer 100 introduced in the embodiments of this application can be a family outdoor camping trailer, or a construction trailer, or a warehouse trailer, or a trailer used in other scenarios.

[0046] The following takes an outdoor camping trailer as an example for illustration: Refer to Figure 1As shown, the electric trailer 100 is an outdoor camping electric trailer. In this embodiment, the electric trailer 100 is mainly used for users to use when camping or playing outdoors, and is used to use the electric trailer 100 to transport tools used for outdoor camping, such as tents, cooking utensils, food, lamps, tableware, electric equipment, tableware, brackets, etc., and can even carry babies and children. In this way, the weight carried by the electric trailer 100 is relatively large. In this embodiment, the electric trailer 100 can optionally travel by electric power, which can reduce the force applied to the electric trailer 100 by the user and facilitate the user's operation. Therefore, the electric trailer 100 can also be understood as an electric power trailer.

[0047] In this embodiment, the electric trolley 100 does not restrict the user's operating direction. In some embodiments, the user operates the electric trolley 100 in a dragging manner, that is, the user is located in front of the electric trolley 100 in the direction of travel, and the electric trolley 100 follows the user. In some embodiments, the user operates the electric trolley 100 in a pushing manner, that is, the user is located behind the electric trolley 100 in the direction of travel, the electric trolley 100 is in front of the user, and the user walks behind the electric trolley 100.

[0048] In some embodiments, the electric trailer 300 can also be a trailer used on a construction site, in which case the electric trailer 300 can transport construction materials, construction tools, construction equipment, etc. on the construction site.

[0049] In some embodiments, the electric trailer 400 can also be a trailer used in a warehouse, in which case the electric trailer 400 can transport some shelves, goods, tools, equipment, etc.

[0050] In this embodiment, if Figures 1 - 4 As shown, the electric trailer 100 includes a trailer body 11, a handle device 12, a travel assembly 17 and a power supply access portion 14. The spatial orientation in the following description is based on Figure 1 and Figure 2 The coordinate system shown in the figure shall prevail. In the present embodiment, the trailer body 11 includes a frame 111 and an enclosure 112 detachably connected to the frame 111. The handle device 12 includes a gripping portion 121 and a connecting rod 122 connected between the gripping portion 121 and the trailer body 11. The walking assembly 17 includes at least a driving wheel 171 and a passive wheel 172. In the present embodiment, at least one set of the driving wheel 171 and the passive wheel 172 adopts a universal wheel structure. Optionally, at least one of the driving wheel 171 and the passive wheel 172 has a locking function to achieve parking.

[0051] Optionally, the vehicle frame 111 is a rigid structural member, and the enclosure member 112 is a flexible structural member. For example, the vehicle frame 111 is formed by welding or hinging metal plates or metal rods, and the enclosure member 112 can be made of waterproof canvas, Oxford cloth, or other flexible materials of other materials. In this embodiment, the vehicle frame 111 includes a bottom 1111, an end 1112, and a side 1113. Among them, the bottom 1111 serves as the main load-bearing part. The ends 1112 are arranged at both ends in the front-rear direction. The sides 1113 are respectively arranged on both sides in the left-right direction, and the sides 1113 on the left and right sides are respectively connected to the ends 1112. The ends 1112 and the sides 1113 form a frame structure that basically surrounds the bottom 1111 on all sides. In some embodiments, the ends 1112 and the sides 1113 are formed by connecting components of the same structure or are integrally formed components.

[0052] In this embodiment, the vehicle frame 111 is a detachable or foldable frame. Exemplarily, as Figure 3 shown, the foldable frame can be folded by gathering towards the middle of the frame, or by gathering towards any side or any face of the frame. In one embodiment, the foldable vehicle frame 111 and the enclosure member 112 together can form a three-dimensional storage space 13 or a towing space. Generally, the storage space 13 can be a cubic space with an upper opening. In other embodiments, the above storage space 13 can also be a three-dimensional space of other shapes. In some embodiments, the storage space 13 can also be a closed three-dimensional space. As Figures 1 - 2 shown, the vehicle frame 111 has an unfolded state. As Figure 3 shown, the vehicle frame 111 has a folded state. When the vehicle frame 111 is in the folded state, the space occupied by the electric trailer 100 is smaller, which is convenient for storage. When the vehicle frame 111 is in the unfolded state, the storage space 13 formed by the trailer body 11 of the electric trailer 100 becomes larger, which is convenient for the user to tow more items. It should be explained that, as Figure 3 shown is the folded state of the vehicle frame 111, and it is not necessarily the storage state of the electric trailer 100. In some embodiments, the electric trailer 100 has a smaller storage state, for example, the traveling assembly 17 and the handle device 12 are respectively folded and stored.

[0053] The handle device 12 is installed at one end of the storage space 13. In this embodiment, the handle device 12 is arranged at the front end of the storage space 13, and the handle device 12 is rotatably connected to the trailer body 11. As Figure 1 and Figure 2 shown, the included angle between the handle device 12 and the trailer body 11 is greater than or equal to 70°. In this embodiment, the included angle between the handle device 12 and the bottom 1111 is greater than or equal to 70°. Among them, Figure 1When the included angle between the handle device 12 shown by the solid line and the trailer body 11 is greater than or equal to 70° and less than or equal to 90°, the electric trailer 100 may be in a pushing state. When the included angle between the handle device 12 shown by the dotted line and the trailer body 11 is greater than 90°, the electric trailer 100 may be in a pulling or dragging state.

[0054] In one embodiment, the connecting rod 122 on the handle device 12 includes a telescopic rod or a folding rod. When the frame 111 is in a folded state, the handle device 12 can also be retracted, thus greatly reducing the storage volume of the electric trailer 100. In one embodiment, the ratio of the volume of the electric trailer 100 when the frame 111 is in a folded state to the volume of the electric trailer 100 when the frame 111 is in an unfolded state is greater than or equal to 0.1 and less than or equal to 0.6. For example, it can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, etc.

[0055] In one embodiment, as Figures 4 - 5 shown, the power access part 14 is used to access a power supply. Optionally, the power access part 14 is used to detachably access the battery pack 141. Optionally, the power access part 14 is used to access an external power device. Among them, the external power device can be an outdoor mobile power source that can output direct current and alternating current, and the outdoor mobile power source also has a variety of different output interfaces to serve as a power distribution station to meet different needs of users.

[0056] As Figure 5As shown, the battery pack 141 can also be adapted to other types of power tools 200, such as handheld power tools, such as drills, pruning machines, screwdrivers, nail guns, etc. Or bench tools, such as table saws, miter saws, etc. Or walk-behind power tools, such as walk-behind lawn mowers, walk-behind snow blowers. Or ride-on power tools, such as ride-on lawn mowers, ride-on vehicles, all-terrain vehicles, etc. Or robotic tools, such as lawn mowing robots, snow sweeping robots, etc. In some embodiments, the power tools that the battery pack 141 can be adapted to can also be gardening tools, such as pruning machines, blowers, lawn mowers, chain saws, etc. In some embodiments, the power tools that the battery pack 141 can be adapted to can also be vegetation care tools, such as string trimmers, etc. Or, the power tools can also be sawing tools, such as reciprocating saws, jigsaws, circular saws, etc. Or, the power tools can also be grinding tools, such as angle grinders, sanders, etc. Or, the power tools can also be other tools, such as lights, fans, etc. In this way, when the battery pack 141 of the electric trailer 100 has insufficient power, the battery pack of the power tool can be borrowed for continuous power supply. Or, when the power tool has insufficient power, the battery pack of the electric trailer 100 can be borrowed for power supply. Or, the battery pack 141 of the electric trailer 100 can be charged by borrowing the charger 201 of the power tool 200. The applicability and endurance of the electric trailer 100 are improved. In this way, when the user is working in the garden or using the power tool 200, the user can use the electric trailer 100 to tow the power tool 200 or workpieces, etc.

[0057] In this embodiment, the power access part 14 can at least include a positive connection end 14a and a negative connection end 14b, which can be docked with the positive and negative poles of the battery pack 141. In some embodiments, the power access part 14 can also include a communication connection end 14c, and the communication connection end 14c is connected to the communication terminal of the battery pack 141 to communicate with the battery pack 141.

[0058] In some embodiments, the power access part 14 can be arranged on the handle device 12, or at the front end, rear end or lower end of the storage space 13. In some embodiments, the power access part 14 can include a battery compartment 142 for accommodating the battery pack 141, and the battery compartment 142 can be a closed battery compartment. A positive connection end 14a and a negative connection end 14b for docking with the electrical terminals of the battery pack 141 are provided in the battery compartment 142. Optionally, a positive connection end 14a, a negative connection end 14b and a communication connection end 14c for docking with the electrical terminals of the battery pack 141 are provided in the battery compartment 142. In this embodiment, the battery compartment 142 can include a battery compartment cover 1421 and a battery compartment body 1422. After the battery pack 141 is installed in the battery compartment body 1422, a substantially closed battery compartment 142 can be obtained by closing the battery compartment cover 1421, which can play a role in dust and water protection.

[0059] In this embodiment, the battery pack 141 is pluggably connected to the power access unit 14. For example, a coupling portion 1423 for connecting the battery pack 141 is provided in the battery compartment 142. A first guide rail 1424 is formed on the coupling portion 1423, and the battery pack 141 is provided with a second guide rail 1411 that can be matched with the first guide rail 1424 so that the battery pack 141 slides along the first guide rail 1424. The structure of the coupling portion 1423 in the battery compartment 142 is substantially the same as the structure of the coupling portion formed on the power tool for connecting the battery pack 141.

[0060] A locking structure and an ejection structure are further provided at the battery compartment 142. The locking structure is used to lock the battery pack in the battery compartment 142 to prevent the battery pack 141 from shaking and ensure the electrical connection between the battery pack 141 and the power interface. The ejection structure is used to eject the battery pack 141 when the locking of the battery pack 141 by the locking structure is released, so as to facilitate the user to remove the battery pack. Since the working principle and structure of the mechanical battery pack locking and ejection are already fully disclosed to those skilled in the art, detailed description is omitted here for the purpose of brevity of the specification.

[0061] In one embodiment, the power access unit 14 may include an outdoor power access terminal capable of accessing an outdoor power device. Exemplarily, the outdoor power access terminal may be an electrical interface similar to the interface on a power strip, and the electric trailer 100 can be electrically connected to an external power device through a power cord. In one embodiment, the outdoor power access terminal may further include a protective cover that can cover the outdoor power interface to play a role in dust and water protection. In this way, the user can also prepare an outdoor power device, connect it to the outdoor power device through the interface on the power access unit 14 or the power cord connected to the interface, and then place the outdoor power device in the storage space so that the user can tow the electric trailer 100 and the outdoor power device together.

[0062] In this embodiment, the battery pack 141 is used to supply power to the electric trailer 100. The battery pack 141 may be a battery pack with cylindrical battery cells. Alternatively, the battery pack may also be a soft pack with multiple stacked pouch-shaped battery cells.

[0063] In some embodiments, the battery pack 141 may be a battery pack with lithium battery units. Alternatively, the battery pack may also be a battery pack with lithium iron phosphate battery units. Alternatively, the battery pack may also be a battery pack that has both lithium battery units and lithium iron phosphate battery units.

[0064] In one embodiment, the electric trailer 100 may further be provided with a power output interface, which can output the electric energy of the battery pack 141 or an external power supply device to supply power to other electric devices. For example, the power output interface is a USB type-A interface or a USB type-C interface, etc., and can supply power to intelligent devices, lighting fixtures, picnic utensils, etc. of the user with a USB interface. In one embodiment, the power output interface may be disposed at an adjacent position around the power access part 14. For example, it is disposed on the battery compartment body 1422 of the battery compartment 142. In one embodiment, the power output interface may also be disposed on the handle device 12. In one embodiment, the power output interface may also be disposed at the front end, rear end, left side, right side, lower side, etc. of the storage space 13.

[0065] In one embodiment, the electric trailer 100 may be provided with a battery compartment 142 for accessing the battery pack 141 and an external power access terminal for accessing an external power supply device at the same time. Exemplarily, the battery pack 141 can be used for power supply when the electric trailer 100 is towed or pushed. When the power output interface 15 on the electric trailer 100 is used to supply power to an external electrical device, an external power supply device can be used for power supply.

[0066] In one embodiment, the electric trailer 100 may have at least two battery compartments. That is to say, the electric trailer 100 can be powered by at least two battery packs 141, so as to increase the endurance time of the electric trailer 100. In this embodiment, at least two battery packs 141 can supply power to the electric trailer 100 at the same time, or supply power to the electric trailer 100 in a time-sharing manner, or supply power to the electric trailer 100 in an interleaved manner, that is, one battery pack 141 supplies power for a period of time and then another battery pack 141 is used for power supply. In other embodiments, the controller 10 in the electric trailer 100 can determine the power supply time or sequence of the battery packs 141 according to the power, voltage, temperature, etc. of multiple battery packs 141. In some embodiments, the number of battery packs included in the electric trailer 100 can be 1, 2, 3, 4, 5 or 6. In some embodiments, the electric trailer 100 may include at least three batteries. In some embodiments, the electric trailer 100 may include at least four battery packs. In some embodiments, the electric trailer 100 may include two power interfaces respectively electrically connected to two battery packs 141, and may also include a spare storage compartment for storing spare batteries.

[0067] In some embodiments, the electric trailer 100 includes a built-in battery. Among them, the built-in battery can be understood as a battery that is generally not disassembled, or a battery that is inconvenient for the user to quickly disassemble.

[0068] In this embodiment, the energy of the battery pack 141 that powers the electric trailer 100 is greater than or equal to 40 Wh. In one embodiment, the energy of the battery pack 141 that powers the electric trailer 100 is greater than or equal to 40 Wh and less than or equal to 800 Wh. In one embodiment, the battery pack 141 can be a lithium-ion battery, a lithium iron phosphate battery, a capacitor battery, a sodium-ion battery, or a hybrid-core battery, that is, the battery pack 141 contains battery cells made of multiple different materials.

[0069] In this embodiment, the ratio of the energy of the battery pack 141 that powers the electric trailer 100 to the weight of the electric trailer 100 is greater than or equal to 5 Wh / Kg and less than or equal to 100 Wh / Kg. For example, the ratio of the energy of the battery pack 141 that powers the electric trailer 100 to the weight of the electric trailer 100 is 5 Wh / Kg, 10 Wh / Kg, 13 Wh / Kg, 15 Wh / Kg, 20 Wh / Kg, 30 Wh / Kg, 40 Wh / Kg, 50 Wh / Kg, 60 Wh / Kg, 70 Wh / Kg, 80 Wh / Kg, 90 Wh / Kg, 100 Wh / Kg, etc.

[0070] Reference Figures 1 - 4 and Figure 6 Referring to the structure of the electric trailer 100 and its control system shown, the electric trailer 100 further includes a mode selection switch 16, a controller 10, a drive motor 20, a parameter detection module 30, and a power display device. In one embodiment, a safety switch (not shown) may also be included. Among them, the controller 10 can be arranged on a control board. The controller 10 is arranged on a circuit board, and the circuit board includes: a printed circuit board (Printed Circuit Board, PCB) and a flexible printed circuit (Flexible Printed Circuit, FPC). The control board can generally be encapsulated in a closed electric control box or electric control module, and the position of the control board can be understood as the position of the electric control box or electric control module. In this embodiment, the controller 10 uses a dedicated control chip, for example, a single-chip microcomputer, a microcontroller unit (Microcontroller Unit, MCU). In one embodiment, the control board can be arranged at an adjacent position close to the power access part 14, for example, adjacent to the periphery of the battery compartment, or arranged on any outer surface of the battery compartment, or arranged inside the battery compartment. In this embodiment, the control board is powered by the battery pack 141.

[0071] In this embodiment, both the control board and the battery pack 141 are arranged at the rear end of the electric trailer 100. The control board and the battery pack 141 can also be arranged at the rear side of the axle of the rear wheel set in the traveling assembly 17. Among them, the rear wheel set is the drive wheel 171 in this embodiment.

[0072] In one embodiment, the control system of the electric trailer 100 may further include an energy recovery circuit 40. The energy recovery circuit 40 is arranged on the control board and is electrically connected to at least the controller 10 and the drive motor 20. In this embodiment, the energy recovery circuit 40 can convert the potential energy or kinetic energy generated by the electric trailer 100 into electrical energy, and reversely charge the battery pack 141. During the operation of the energy recovery circuit 40, the drive motor 20 acts as a generator to generate charging electrical energy. Exemplarily, during the deceleration of the drive motor 20, the controller 10 can control the energy recovery circuit 40 to recover electrical energy to charge the battery pack 141. In one embodiment, during the downhill process of the electric trailer 100, the electric trailer 100 is subjected to gravity, and the rotation speed of the travel component 17 of the electric trailer 100 becomes faster. Optionally, during the downhill process of the electric trailer 100, the drive motor 20 may decelerate or brake. When the electric trailer 100 is downhill, the energy recovery circuit 40 can generate charging electrical energy to charge the battery pack 141.

[0073] In one embodiment, when the electric trailer 100 has at least two battery packs 141 , the controller 10 can control the battery packs 141 to supply power to the drive motor 20 in a time-sharing manner, and can charge the charging energy generated by the energy recovery circuit 40 to the battery packs 141 with lower energy.

[0074] In the related art, when the charging electric energy generated by the energy recovery circuit 40 is used to charge the battery pack, if the battery pack is fully charged at this time, there is a risk of damaging the battery pack. On the other hand, in the control scheme of the drive motor 20 using vector control, the current of the drive motor 20 can be equivalent to: the current that forms the magnetic field and the current that provides the torque. When the speed of the drive motor 20 decelerates too fast, the charging current generated by the drive motor 20 will also increase. If the current is too large when charging the battery pack, the battery pack will also be damaged.

[0075] In this embodiment, when it is determined that the energy recovery circuit 40 generates a current for the drive motor 20 to charge the battery pack 141, when the preset conditions are met, the current for providing torque is reduced to reduce the charging current and voltage. At the same time, the current for forming the magnetic field is increased to maintain the torque for deceleration or braking. The preset conditions include the battery pack voltage meeting a threshold, the current-related parameters of the drive motor 20 meeting a threshold, the speed-related parameters of the drive motor 20 meeting a threshold, or any one of the user's manual operation requirements.

[0076] In some embodiments, when it is determined that the energy recovery circuit 40 generates a current for charging the battery pack 141 by driving the motor 20, when a preset condition is satisfied, the utilization of the charging current generated by the driving motor 20 is enabled. The current utilization method includes recovering and utilizing the current using a power resistor. In this embodiment, the power resistor is disposed near the battery compartment 142. In some embodiments, the current utilization method includes supplying the charging current generated by the driving motor 20 to, for example, a lighting lamp, an indicator lamp, and an additional driving motor 20 to avoid damage to the battery pack. Among them, the preset conditions include any one of the battery pack voltage satisfying a threshold value, the driving motor 20 current-related parameter satisfying a threshold value, the driving motor 20 rotation speed-related parameter satisfying a threshold value, or a user manual operation requirement.

[0077] In this embodiment, the electric trailer 100 may further include a parameter detection module 30 capable of detecting the traveling state of the electric trailer 100. Among them, the traveling state of the electric trailer 100 at least includes: a traveling state, a stop state, an uphill state, a downhill state, an acceleration state, and a deceleration state. The controller 10 may control whether the energy recovery circuit 40 operates according to the above traveling state. For example, when the electric trailer 100 is in a deceleration state or a downhill state, the controller 10 controls the energy recovery circuit 40 to generate charging electric energy to charge the battery pack 141.

[0078] In one embodiment, the parameter detection module 30 detects the rotation speed or operating current of the driving motor 20. In one embodiment, the parameter detection module 30 detects the forward direction of the electric trailer 100. In one embodiment, the parameter detection module 30 detects the included angle between the handle device 12 and the trailer main body 11. In one embodiment, the parameter detection module 30 detects the inclination angle between the trailer main body 11 and the horizontal plane. In one embodiment, the parameter detection module 30 detects the magnitude and direction of the force applied by the user to the handle device 12. In one embodiment, the parameter detection module 30 detects the speed or acceleration of the user's walking, etc. The present application does not limit the specific type or quantity of the parameter detection module 30 or the parameter acquisition form, etc.

[0079] In one embodiment, the parameter detection module is further configured to detect operation information input by the user, and the controller is configured to adjust the assistance state of the driving motor according to the operation information. For example, the parameter detection module is a module having a human-computer interaction interface, such as a button, a knob, or a screen, and the user generates different operation instructions by different operations on the human-computer interaction interface.

[0080] Such as Figures 7 - 12As shown, in one embodiment, the drive motor 20 is installed between two drive wheels 171 and drives at least one of the drive wheels 171 to rotate. In this embodiment, the drive motor 20 can drive both drive wheels 171 to rotate simultaneously. In this embodiment, the drive wheels 171 are the rear wheels of the electric trailer 100, that is, the traveling wheels arranged on the side away from the handle device 12. Among them, the drive wheels 171 include a left drive wheel 1711 and a right drive wheel 1712 arranged in the left-right direction. In this embodiment, one wheel is provided for each of the left drive wheel 1711 and the right drive wheel 1712. Optionally, two or more wheels are provided for each of the left drive wheel 1711 and the right drive wheel 1712. The specific number of the left drive wheel 1711 and the right drive wheel 1712 does not affect the substantial content of this application.

[0081] As Figure 7 shown, the drive motor 20 is arranged on the vehicle frame 111. Optionally, the drive motor 20 is connected to the bottom 1111 of the vehicle frame 111. The drive motor 20 is arranged on the side close to the power access part 14.

[0082] As Figures 7 - 12 shown, the electric trailer 100 further includes a transmission mechanism 50 for transmitting the power of the drive motor 20 to the drive wheels 171. Optionally, the electric trailer 100 further includes a clutch mechanism 54 for connecting or disconnecting the power transmission of the drive motor 20 to the drive wheels 171. It should be noted that the drive motor 20, the transmission mechanism 50, and the clutch mechanism 54 can share some structures. At the same time, the transmission mechanism 50 and the clutch mechanism 54 can be selectively arranged according to the actual requirements of different products. In some embodiments, the electric trailer 100 includes the drive motor 20 and the transmission mechanism 50. In some embodiments, the electric trailer 100 includes the drive motor 20 and the clutch mechanism 54. In some embodiments, the electric trailer 100 includes the drive motor 20, the transmission mechanism 50, and the clutch mechanism 54. In some embodiments, the electric trailer 100 includes the drive motor 20.

[0083] In this embodiment, the transmission mechanism 50 includes a speed reduction assembly 51 and a differential assembly 53. The drive motor 20 includes a drive shaft 21 that rotates around a first axis 101. The speed reduction assembly 51 and the differential assembly 53 connect the drive shaft 21 and the drive wheels 171.

[0084] As Figures 9 - 10As shown, the speed reduction assembly 51 includes: a first driving wheel 511, a first driven wheel 512, a second driving wheel 513, and a second driven wheel 514. When in transmission connection, the first driving wheel 511 is formed on or connected to the driving shaft 21 of the driving motor. Optionally, the first driving wheel 511 is coaxially connected to the output end of the driving shaft 21. Therefore, the first driving wheel 511 rotates about the first axis 101. The first driven wheel 512 meshes with the first driving wheel 511 to form a speed reduction transmission with a certain transmission ratio. Optionally, the transmission ratio is greater than 1. The first driven wheel 512 and the second driving wheel 513 rotate substantially coaxially. The second driving wheel 513 meshes with the second driven wheel 514 to form a speed reduction transmission with a certain transmission ratio. In this embodiment, the second driven wheel 514 rotates about the central axis 171a of the driving wheel 171. Among them, the second driven wheel 514 is disposed inside the driving wheel 171. Exemplarily, the left driving wheel 1711 and the right driving wheel 1712 are connected by a coupling assembly 52. The two ends of the coupling assembly 52 are respectively provided with the second driving wheel 513. The left driving wheel 1711 and the right driving wheel 1712 are respectively provided with the second driven wheel 514. Thus, the output power of the driving motor 20 drives the driving wheel 171 of the electric trailer 100 to rotate. In this embodiment, the first driven wheel 512 is externally meshed with the first driving wheel 511. The first driven wheel 512 and the first driving wheel 511 are respectively cylindrical gears. The second driven wheel 514 is externally meshed with the second driving wheel 513. The first driven wheel 512 and the first driving wheel 511 are respectively cylindrical gears. In some alternative embodiments, the speed reduction assembly 51 adopts one or a combination of bevel gear transmission, worm transmission, and planetary gear transmission. It can be understood that in the connection and power transmission of gears and rotating shafts, setting the connection structure of the support bearing and the vehicle frame, as well as the dust-proof protection housing according to requirements, all belong to the well-known technologies of those skilled in the art and have been fully disclosed.

[0085] In this embodiment, in order to achieve the speed difference between the inner wheel and the outer wheel when the electric trailer 100 turns, so as to achieve a smooth turn. In this embodiment, a differential assembly 53 is provided to enable the driving wheels 171 of the electric drive to travel at different speeds. As Figure 12As shown in the figure, the differential assembly 53 includes: a first bevel gear 531, a first connecting shaft 532, a second bevel gear 533, a third bevel gear 534, a second connecting shaft 521, a fourth bevel gear 535 and a third connecting shaft 522. Among them, the first connecting shaft 532 connects the first bevel gear 531 and the second bevel gear 533. The first bevel gear 531 and the second bevel gear 533 respectively rotate around the first connecting shaft 532. The center line of the first connecting shaft 532 is set as the second axis 102. The first bevel gear 531 and the second bevel gear 533 are respectively located at both ends of the first connecting shaft 532 and have no meshing relationship. Optionally, the first bevel gear 531 and the second bevel gear 533 are arranged in parallel. The third bevel gear 534 is respectively meshed and connected with the first bevel gear 531 and the second bevel gear 533. The fourth bevel gear 535 is respectively meshed and connected with the first bevel gear 531 and the second bevel gear 533. Among them, the third bevel gear 534 is connected to the second driving wheel 513 through the second connecting shaft 521. Further, the third bevel gear 534 is connected to a driving wheel 171. In this embodiment, the third bevel gear 534 is connected to the right driving wheel 1712. The fourth bevel gear 535 is connected to the third connecting shaft 522, and the fourth bevel gear 535 is connected to the right driving wheel 1712. The second connecting shaft 521 and the third connecting shaft 522 are substantially parallel. The second connecting shaft 521 and the third connecting shaft 522 are respectively substantially perpendicular to the first connecting shaft 532.

[0086] To ensure the smooth power transmission path of the drive motor 20, the differential assembly 53 further includes a first transmission connection portion 536 for connecting the first driven wheel 512 and the first connecting shaft 532. The first transmission connection portion 536 is embedded inside the first driven wheel 512, and both ends of the first connecting shaft 532 are connected to the first transmission connection portion 536. In this embodiment, when the first driven wheel 512 is driven to rotate, the first transmission connection portion 536 drives the first bevel gear 531 and the second bevel gear 533 on the first connecting shaft 532 to rotate around the axis of the first driven wheel 512 respectively. The first bevel gear 531 and the second bevel gear 533 respectively drive the third bevel gear 534 and the fourth bevel gear 535 meshing with them to rotate. In this embodiment, the first driven wheel 512, the first transmission connection portion 536, and the second connecting shaft 521 are coaxial, so that the first driven wheel 512 and the second driving wheel 513 rotate coaxially. The rotation axes of the first driven wheel 512, the first transmission connection portion 536, the second connecting shaft 521, and the second driving wheel 513 are set as the third axis 103. The third axis 103 is parallel but not coincident with the central axis 171a of the driving wheel. In this embodiment, the first bevel gear 531 and the second bevel gear 533 rotate around the third axis 103, and then drive the third bevel gear 534 and the fourth bevel gear 535 to rotate, thereby transmitting the rotational driving force of the drive motor 20 to the left driving wheel 1711 and the right driving wheel 1712, that is, the first bevel gear 531 and the second bevel gear 533 transmit power through "revolution". When the electric trailer 100 turns, a speed difference is generated between the inner wheel and the outer wheel. In this embodiment, the rotation speeds of the third bevel gear 534 and the fourth bevel gear 535 are different. Since the first bevel gear 531 and the second bevel gear 533 are also configured with "rotation" around the second axis 102, the rotation speed of the inner traveling wheel is slowed down, and the rotation speed of the outer traveling wheel is increased. The cost of using the differential assembly 53 is low, and the weight of the components is light.

[0087] In this embodiment, using the differential assembly 53 enables it to be used and achieve functions regardless of whether the rotation direction of the driving wheel is forward (forward) or reverse (backward). When the electric trailer 100 is in a downhill state, due to gravity, the speed of the traveling wheels of the electric trailer 100 increases. The differential actively decelerates to buffer the acceleration of the traveling wheels due to gravity, so that the rotation speed of the driving wheel can basically be maintained within the rotation speed range driven by the drive motor 2020.

[0088] In this embodiment, the third bevel gear 534, the second connecting shaft 521, the fourth bevel gear 535, and the third connecting shaft 522 are part of the coupling assembly 52. Optionally, the third connecting shaft 522 includes a left shaft and a right shaft connected coaxially, so that the connection between the left driving wheel 1711 and the right driving wheel 1712 has flexibility.

[0089] Such as Figures 10 - 12As shown, a clutch mechanism 54 may also be provided in the electric trailer 100. The clutch mechanism 54 generally has two states. When the clutch mechanism 54 is in the first state, the transmission between the drive motor 20 and the drive wheel 171 can be disconnected. When it is in the second state, power is transmitted between the drive motor 20 and the drive wheel 171. In some embodiments, the electric trailer 100 is switched between two states of electric assist and non-assist through the clutch mechanism 54. It can be understood that electric assist means that the controller 10 can control the drive motor 20 to drive the drive wheel 171 to rotate to assist the user in dragging or pushing the trailer, and non-electric assist means that it is pushed by manpower like an ordinary picnic cart. In some embodiments, by using the clutch mechanism 54, the drive wheel will not drive the drive motor to rotate in the reverse direction when there is no electric assist, so as to prevent damage to the drive motor.

[0090] As Figures 9 - 11 shown, the clutch mechanism 54 includes a fork 541, a clutch control part, and a clutch body 545. In this embodiment, the clutch body 545 is arranged in the torque transmission path between the first driven wheel 512 and the drive wheel 171. Optionally, the clutch body 545 is arranged in the torque transmission path between the first driven wheel 512 and the second driving wheel 513. In some embodiments, the clutch body 545 is arranged in the torque transmission path between the first driven wheel 512 and the differential assembly 53.

[0091] The clutch body 545 includes: an engaging portion 5451, a connecting groove portion 5453, and a limiting projection 5454. Among them, the engaging portion 5451 is selectively connected to the first driven wheel 512. As Figures 10 - 11 shown, the engaging portion 5451 includes an external tooth portion 5452, and the first driven wheel 512 is provided with an internal tooth portion 5121 that cooperates with the external tooth portion 5452. When the clutch mechanism 54 is in the second state, as Figure 10 shown, the external tooth portion 5452 is meshed and connected with the internal tooth portion 5121. When the clutch mechanism 54 is in the first state, as Figure 11 shown, the external tooth portion 5452 is disengaged from the internal tooth portion 5121. The second driving wheel 513 is connected with a second transmission connection portion 537. The second transmission connection portion 537 drives the second driving wheel 513 to rotate. The second transmission connection portion 537 is provided with a limiting groove 5371, and the limiting groove 5371 cooperates with the limiting projection 5454 to circumferentially limit the second driving wheel 513 and the clutch body 545, that is, the second driving wheel 513 and the clutch body 545 rotate together, but the clutch body 545 and the second transmission connection portion 537 have an axial relative displacement, so that the clutch body 545 can be switched between the first state and the second state. The external tooth portion 5452 is meshed and connected with the internal tooth portion 5121, and the rotation of the first driven wheel 512 is transmitted to the second driving wheel 513 through the clutch body 545. As Figure 11As shown, the external tooth part 5452 disengages from the internal tooth part 5121, and the rotation of the first driven wheel 512 cannot be transmitted to the clutch body 545. Furthermore, the power transmission path between the first driven wheel 512 and the second driving wheel 513 is disconnected.

[0092] The fork 541 is engaged with the connection groove part 5453 of the clutch body 545. The fork 541 rotates around the fourth axis 104 to drive the clutch body 545 to move axially along the third axis 103 repeatedly, so as to realize the switching of the clutch body 545 between the first state and the second state. The fork 541 is connected to the connection groove part 5453 and the clutch control part respectively on both sides of the fourth axis 104. In this embodiment, the clutch control part includes a control rope 542 and a reset part 544. The fork 541 is toggled by the control rope 542 to make the clutch body 545 move towards the first state position. In this embodiment, the control rope 542 is controlled by the user operation. Optionally, the control rope 542 is connected to the mode selection switch 16. Optionally, the electric trailer 100 is provided with a separate operating element to drive the control rope 542. The reset part 544 includes a spiral spring when the auxiliary clutch body 545 moves from the position of the first state to the position of the second state. In some embodiments, the reset part 544 is also used to provide a holding force for the clutch body 545 to hold it at the position of the second state. In this embodiment, for dust prevention and protection of the control rope 542, a protective sleeve 543 is sleeved outside the control rope 542.

[0093] In some embodiments, the clutch mechanism further includes other mechanical clutch mechanisms. For example, ratchet clutches, centrifugal clutches, friction clutches, and hydraulic clutches. The above mechanical clutches can be used as the clutch mechanism of the present application after simple deformation or combination. On the premise of being able to complete the function of the clutch mechanism of the present application, the specific form of the structure does not affect the substantive content of the present application.

[0094] In some alternative embodiments, the clutch may be a one-way bearing or an overrunning clutch.

[0095] In some embodiments, the clutch mechanism further includes an electronic clutch. For example, an electromagnetic clutch. For example, a dry single-plate electromagnetic clutch, a dry multi-plate electromagnetic clutch, a wet multi-plate electromagnetic clutch, a magnetic powder clutch, and a slip-ring electromagnetic clutch.

[0096] In some embodiments, the mechanical clutch mechanism and the electronic clutch can be coupled and used simultaneously.

[0097] Such as Figure 13As shown, in this embodiment, the passive wheel 172 is the front wheel set of the electric trailer 100, that is, the traveling wheels arranged on the side close to the handle device 12. Among them, the passive wheel 172 includes a left passive wheel 1721 and a right passive wheel 1726 arranged in the left-right direction. In this embodiment, one wheel 1722 is respectively arranged on the left passive wheel 1721 and the right passive wheel 1726. Optionally, two or more wheels are respectively arranged on the left passive wheel 1721 and the right passive wheel 1726. The specific number of the left passive wheel 1721 and the right passive wheel 1726 does not affect the substantial content of this application. Among them, the left passive wheel 1721 includes a wheel 1722, a wheel axle 1723, and a left wheel frame 1724. The right passive wheel 1726 includes a wheel 1722, a wheel axle 1723, and a right wheel frame 1727. Taking the left passive wheel 1721 as an example, the wheel 1722 is installed on the left wheel frame 1724 through the wheel axle 1723. The wheel 1722 rotates around the wheel axle 1723. The left wheel frame 1724 is connected to the vehicle frame 111 through a rotating shaft 1725. Among them, the left wheel frame 1724 rotates relative to the vehicle frame 111 around the center line of the rotating shaft 1725 to achieve steering.

[0098] A pull rod linkage assembly 173 is arranged between the left passive wheel 1721 and the right passive wheel 1726, which is used to actively drive the passive wheel 172 to turn when the electric trailer 100 turns. The pull rod linkage assembly 173 includes a first connecting rod 1731, a second connecting rod 1732, and a first steering rod 1733. In this embodiment, the first connecting rod 1731 connects the rotating shaft 1725 of the left passive wheel 1721 and the first steering rod 1733. The second connecting rod 1732 connects the rotating shaft 1725 of the right passive wheel 1726 and the first steering rod 1733. Among them, the first connecting rod 1731 is respectively rotatably connected to the rotating shaft 1725 of the left passive wheel 1721 and the first steering rod 1733. The second connecting rod 1732 is respectively rotatably connected to the rotating shaft 1725 of the right passive wheel 1726 and the first steering rod 1733. The first steering rod 1733 is connected to the handle device 12. In this embodiment, the first steering rod 1733 moves in the same direction as the handle device 12. In this embodiment, the first steering rod 1733 is rotatably connected to the vehicle frame 111 to ensure the stable fixation of the pull rod linkage assembly 173.

[0099] Taking a left turn as an example, when the driving handle device 12 moves to the left, the first steering rod 1733 is connected to the handle device 12. The handle device 12 drives the first steering rod 1733 to rotate, driving the first link 1731 and the second link 1732 to swing accordingly. The first link 1731 drives the left wheel carrier 1724 to rotate, and the second link 1732 drives the right wheel carrier 1727 to rotate, thereby converting the rotation of the handle device 12 into the corresponding steering of the left driven wheel 1721 and the right driven wheel 1726. Thus, the left driven wheel 1721 and the right driven wheel 1726 are actively steered by the applied force, rather than being steered by the friction of the ground or passive dragging. The turning is more labor-saving.

[0100] In this embodiment, the drive motor 20 can be an outer rotor drive motor 20. In some embodiments, the drive motor can also be an inner rotor drive motor 20. In one embodiment, the rated output power of the outer rotor drive motor 20 is greater than or equal to 100W and less than or equal to 800W. For example, it can be 100W, 200W, 300W, 400W, 500W, 600W, 700W, 800W, etc.

[0101] In some alternative embodiments, as Figure 18 shown, the drive motor 20' can be integrated in the drive wheel 171', that is, the drive motor 20' is a hub drive motor. In this embodiment, the total rated output power of the hub drive motor 20' is greater than or equal to 100W and less than or equal to 800W. For example, it can be 100W, 200W, 300W, 400W, 500W, 600W, 700W, 800W, etc.

[0102] In one embodiment, the length of the hub drive motor 20' along the radial direction D of the drive wheel 171 is greater than or equal to 100mm and less than or equal to 250mm. For example, it can be 100mm, 120mm, 130mm, 150mm, 200mm, 230mm, 250mm, etc. In this embodiment, one hub drive motor 20' is provided in each of the two drive wheels 171, and the rated output power of each hub drive motor 20' is greater than or equal to 50W and less than or equal to 400W. By using the hub drive motor 20', the structure of the transmission mechanism can be simplified and the number of components can be reduced.

[0103] In one embodiment, the controller 10 can control the assistance state of the drive motor 20 according to the switch state of the mode selection switch 16, such as providing assistance or not. Exemplarily, when the mode selection switch 16 is in the conducting state, i.e., the second switch state, the controller 10 can control the drive motor 20 to provide assistance; when the mode selection switch 16 is in the non-conducting state, i.e., the first switch state, the controller 10 can control the drive motor 20 not to provide assistance. For example, when towing or pushing a trailer to move, the mode selection switch 16 can be triggered to be in the conducting state, so that the drive motor 20 provides assistance; when the trailer stops moving, the mode selection switch 16 is triggered to disconnect again, so that the drive motor 20 stops providing assistance. In one embodiment, the triggering method of the mode selection switch 16 is related to the type of the switch. For example, when the mode selection switch 16 is a toggle switch or a push switch, the triggering method is toggling or pressing. In one embodiment, the mode selection switch 16 can be manually triggered by the user or automatically triggered. For example, when the electric trailer 100 is pushed or towed to generate displacement or is about to generate displacement, the mode selection switch 16 can be automatically triggered to conduct, so that the drive motor 20 can provide assistance; when the electric trailer 100 stops or is about to stop, the mode selection switch 16 can be automatically triggered to disconnect, so that the drive motor 20 no longer provides assistance.

[0104] In some embodiments, the mode selection switch 16 includes an automatic reset component. When triggered by the user, it is in one state, such as conducting or non-conducting. When the user releases it, it is in another state. Optionally, the initial state or the released state of the mode selection switch is the conducting state, that is, it is default to provide assistance. When triggered by the user, it is in the non-conducting state, that is, the user can turn off the assistance according to the actual usage situation. Optionally, the mode selection switch is a self-resetting switch.

[0105] In one embodiment, the mode selection switch 16 can have multiple switch positions in the second switch state, and the output speed or output torque of the drive motor 20 is different under different switch positions. Exemplarily, the controller 10 can control the drive motor 20 to output the corresponding torque or speed according to the size of the switch position where the mode selection switch 16 is located in the second switch state, so as to adapt to the target requirements in this position. In one embodiment, different switch positions can include a power-saving position, a labor-saving position, a smooth road position, a grassland position, a ramp position, an uphill position, a downhill position, etc.

[0106] In one embodiment, the mode selection switch 16 can be prevented from being accidentally triggered by setting a safety switch. For example, when the safety switch is not closed, regardless of whether the mode selection switch 16 is conducting or not, the drive motor 20 does not provide assistance.

[0107] In one embodiment, as Figures 1 - 3As shown, the mode selection switch 16 is a toggle switch. In some embodiments, the mode selection switch 16 is a micro switch, a rocker switch, a touch switch, a voice control switch, or the like.

[0108] As Figure 13 and Figure 16 As shown, as an embodiment of manual control of the drive motor 20, a first trigger switch 1121 is provided on the holding portion 121. Optionally, the holding portion 121 is provided with a grasping area, and the first trigger switch 1121 is provided within the grasping area. Optionally, the first trigger switch 1121 is provided within the operating area of the user's four fingers. When the first trigger switch 1121 is triggered, the controller 10 controls the drive motor 20 to start and provides assistance. When the first trigger switch 1121 is not triggered or is released, the controller 10 controls the drive motor 20 to decelerate or gradually decelerate to a stop.

[0109] As Figure 14 and Figure 15 As shown, as another embodiment of manual control of the drive motor, a force direction detection unit 30b is provided on the handle device 12. The force direction detection unit 30b can send a corresponding signal when the handle device 12 is dragged or pushed, so that the parameter detection module 30 can identify whether the force applied by the user is a pulling force or a pushing force. In this embodiment, the force direction detection unit 30b is provided on the connecting rod 122. Optionally, the force direction detection unit 30b includes a displacement sensor 1224. The connecting rod 122 includes an upper rod 1221 and a lower rod 1222 that generate relative displacement along the axis. Among them, a reset structure 1223 is connected between the upper rod 1221 and the lower rod 1222. When the user applies a pulling force or a pushing force to the handle device 12, relative displacement in different directions will occur between the upper rod 1221 and the lower rod 1222. The displacement sensor 1224 includes a Hall sensor. Any one of the Hall sensor and the magnet 1225 moves with the upper rod 1221, and the other does not move with the upper rod 1221. The reset structure 1223 is used to provide a reset force to the upper rod 1221 when the upper rod 1221 is operated to generate an axial displacement. In this embodiment, when the displacement sensor 1224 determines that the upper rod 1221 is operated and approaches the lower rod 1222, a signal for controlling the drive motor 20 to decelerate is sent to the controller 10.

[0110] Alternatively, in some embodiments, the parameter detection module of the electric trailer 100 may include a speed control switch. The user can control the traveling speed of the electric trailer 100 through the speed control switch. For example, the user can control the electric trailer 100 to travel at different speed gears, or can also control the traveling speed of the electric trailer 100 steplessly. Optionally, the adjustment switch includes a rotary operating member and a position sensor. Optionally, the position sensor is a Hall sensor. The magnet is disposed on the rotary operating member, and the Hall sensor is disposed within the holding portion 121 without rotational movement. The user operates the rotary operating member to cause an angular change between the magnet and the Hall sensor. The Hall sensor sends different analog signals to control different rotational speeds of the drive motor. Optionally, when the rotary operating member rotates counterclockwise, the drive motor 20 controls the electric trailer 100 to move forward, and the greater the rotation angle, the higher the rotational speed of the drive motor 20. When the rotary operating member rotates clockwise, the controller 10 controls the drive motor 20 to reverse and controls the drive motor 20 to move at a constant speed to achieve constant-speed reverse. When the rotary operating member rotates in the reset direction, the trailer decelerates and brakes when reset to the initial position.

[0111] As another embodiment of the manual control of the drive motor 20, as Figure 14 shown, a reset detection portion 124 of the handle device 12 is provided on the trailer body 11. When the reset detection portion 124 detects that the handle device 12 returns to the preset state, the drive motor 20 stops or does not respond to startup. Optionally, the reset detection portion 124 includes a contact switch. Optionally, a fixing portion is provided on the trailer body 11. The fixing portion includes a card slot 1241, a one-way buckle 1242 disposed within the card slot 1241, and a contact switch. When the connecting rod 122 is engaged in the card slot 1241, the connecting rod 122 abuts against the contact switch (such as a membrane switch, a rocker switch, etc.) to change its state and send a signal to the controller 10. The one-way buckle 1242 confines the connecting rod 122 engaged in the card slot 1241 within the card slot 1241. In some embodiments, an unlocking portion connected to the one-way buckle 1242 is further provided to release the connecting rod 122 from the card slot 1241. In some embodiments, the holding and releasing of the connecting rod 122 can be achieved through the elastic deformation of the card slot 1241.

[0112] In one embodiment, the trailer parameters of the electric trailer 100 detected by the parameter detection module 30 include the operating parameters of the drive motor 20, or the state parameters of the handle device 12 relative to the trailer body 11, or the magnitude and direction of the force applied by the user to the handle device 12, or the walking speed of the user. The controller 10 can adaptively adjust the boosting state of the drive motor 20 according to the above trailer parameters. Among them, the boosting state can include not only boosting or not boosting, but also the output torque or output speed of the drive motor 20 when boosting. In this embodiment, regardless of the working condition, the user can control the trailer to move while maintaining a substantially constant walking speed or a substantially constant driving force or towing force, so that the user can obtain a relatively comfortable following state. The so-called comfortable following state can be understood as that the controller 10 controls the drive motor 20 to increase or decrease the output torque, so that the force applied by the user to the handle device 12, the driving force of the motor, and the resistance of the ground or the wheels reach a balanced state, or the controller 10 makes the walking speed of the walking assembly 17 substantially consistent with the walking speed of the user by controlling the output speed of the drive motor 20.

[0113] In some embodiments, when the controller 10 determines that the electric trailer 100 is in a downhill walking state according to the angle between the electric trailer 100 and the horizontal plane and the magnitude and direction of the force applied by the user to the handle device 12, it can control the drive motor 20 to reduce the driving force or change the direction of the driving force, or make the trailer decelerate, so as to prevent the user from being unable to keep up with the downhill speed of the trailer. Alternatively, when the controller 10 determines that the electric trailer 100 is in an uphill walking state according to the angle between the electric trailer 100 and the horizontal plane and the magnitude and direction of the force applied by the user to the handle device 12, it can control the drive motor 20 to increase the driving force, so that the user can tow the electric trailer 100 uphill without increasing the towing force applied to the handle device 12.

[0114] In some embodiments, the parameter detection module 30 may include a pressure sensor for the user to detect the force applied to the handle device 12.

[0115] Reference Figures 13 - 14 , the parameter detection module 30 includes an angle detection part 30a provided at the connection between the handle device 12 and the trailer body 11 for detecting the rotation angle of the handle device 12 relative to the trailer body 11. As Figure 17As shown, the angle detection unit 30a includes a target member connected to the handle device 12 and a position sensor 32. Optionally, the position sensor 32 includes a linear Hall sensor. The linear Hall sensor is fixed and connected to the trailer body 11 through a bracket 31 without relative movement. The target member includes a magnet 1225. Optionally, the handle device 12 is provided with a bushing 125. The handle device 12 is rotatably connected to the trailer body 11 through the bushing 125. The target member further includes a fixing seat 311 for fixing the magnet 1225. The fixing seat 311 is connected to the bushing 125 and rotates synchronously. In this embodiment, when it is detected that the angle between the handle device 12 and the trailer body 11 reaches the first preset value, the angle detection unit 30a sends a corresponding signal, and the controller 10 controls the driving motor 20 to decelerate. When it is detected that the angle between the handle device 12 and the trailer body 11 reaches the second preset value, the angle detection unit 30a sends a corresponding signal, and the controller 10 controls the driving motor 10 to stop.

[0116] In some embodiments, the force applied by the user on the handle device 12 is determined based on the angle information detected by the angle detection unit 30a. In one embodiment, the electric trailer 100 includes: an angle detection unit 30a and a force direction detection unit 30b. When the angle detection unit 30a determines that the included angle between the handle device 12 and the trailer body 11 is substantially 90°, the force direction detection unit 30b is automatically triggered, so that the controller 10 can determine that the electric trailer 100 may be in a state of being pushed and walking. In one embodiment, the force direction detection unit 30b can calculate the force applied to the handle device 12 based on the relative displacement value between the upper rod 1221 and the lower rod 1222. The controller 10 can determine the magnitude and direction of the user's force based on the detection results of the angle detection unit 30a and the force direction detection switch 30b, and then control the driving motor 20 to change the current assist state to enable the user to obtain a comfortable walking state. In one embodiment, the parameter detection module 30 may not directly detect the magnitude and direction of the force applied by the user on the handle device 12, but can detect parameters such as the walking speed or acceleration of the electric trailer 100 and the included angle of the electric trailer 100 relative to the horizontal plane. The controller 10 can estimate the magnitude and direction of the force applied by the user based on the above parameters, and then determine the walking state of the electric trailer 100, or control the assist state of the driving motor 20 according to the estimated force.

[0117] In one embodiment, the controller 10 can also identify the user's operation intention based on the parameters detected by the parameter detection module 30, and then adaptively adjust the assist state of the driving motor 20 according to the identified operation intention to enable the user to obtain a more comfortable walking state. The so-called operation intention may include a forward dragging intention, or a forward approaching stop intention, or a backward pushing intention, or a backward approaching stop intention, or a forward acceleration intention, or a forward deceleration intention, or a backward acceleration intention, or a backward deceleration intention, etc.

[0118] In this embodiment, a drive circuit 41 is provided between the controller 10 and the drive motor 20. The drive circuit 41 may include a plurality of switching elements Q1-Q6. Each gate terminal of the switching element is electrically connected to the controller 10 for receiving a control signal from the controller 10. Each drain or source of the switching element is connected to the stator winding of the drive motor 20. The switching elements Q1-Q6 receive control signals from the controller 10 to change their respective conduction states, thereby changing the current applied to the stator winding of the motor by the battery pack 141. In one embodiment, the drive circuit 41 may be a three-phase bridge driver circuit including six controllable semiconductor power devices (such as Field Effect Transistor (FET), Bipolar Junction Transistor (BJT), Insulated Gate Bipolar Transistor (IGBT), etc.). It can be understood that the above switching elements may also be any other type of solid-state switch, such as Insulated Gate Bipolar Transistor (IGBT), Bipolar Junction Transistor (BJT), etc. To rotate the motor, the drive circuit 41 has multiple drive states, and the rotation state of the motor is different under different conduction states.

[0119] In one embodiment, the controller 10 may output a square wave control signal to control the rotation of the motor. In one embodiment, the controller 10 may also adopt the FOC control method to control the rotation of the motor. This application does not limit the control method adopted by the controller 10.

[0120] In one embodiment, the electric trailer 100 may further be provided with a power display device capable of displaying the current power of the battery pack 141. Exemplarily, the power display device may be provided on the handle device 12 or on the hatch of the battery compartment or on the body of the battery compartment. The power display device may be an LED lamp.

[0121] In one embodiment, the electric trailer 100 may further be provided with a lighting device. The lighting device may be provided on the battery compartment, or at the periphery of the storage space 13, or on the handle device 12, or suspended on the trailer body 11.

[0122] In some embodiments, the status indicating unit indicates the assistance status of the driving motor through acoustic and optical displays. Optionally, the status indicating unit includes a status indicator light for prompting the assistance status of the driving motor. For example, it lights up when in the assistance state and does not light up when in the non-assistance state. Alternatively, more assistance states are characterized by different colors, blinking and constant lighting, different blinking frequencies, or different breathing light frequencies. Optionally, the status indicating unit includes a sound prompter, such as a buzzer, for indicating the assistance status of the driving motor.

[0123] As Figure 19 shown, the electric trailer can also be a construction site trailer 300. The trailer frame 31 of the construction site trailer 300 is mainly used to transport construction materials for the construction site, such as cement, mortar, bricks, steel bars, etc. The construction site trailer 300 includes a trailer handle 302, walking wheels 303, and a power access unit 304. Since the things transported by the construction site trailer 300 are generally heavy, the walking wheels 303 of the trailer can be internally provided with hub drive motors 20 to drive the drive wheels to walk to assist the operation of the trailer 300. And in order to supply power to the hub drive motors 20, the power access unit 304 can be connected to at least one battery pack. In this embodiment, the battery pack connected by the power access unit 304 can be the same as the battery pack described in the above embodiment, and the relevant features of the electric trailer 100 for outdoor picnic in the above embodiment can also be applied to the construction site trailer 300 in this embodiment. For example, the way of the controller in the construction site trailer 300 to adaptively assist, the type of the battery pack, the power supply method, etc. will not be elaborated here one by one.

[0124] As Figure 20 shown, the electric trailer can also be a warehouse trailer 400. The warehouse trailer 400 can also include the battery pack, the hub drive motor 20, and the adaptive assistance mode involved in the outdoor picnic trailer or the construction site trailer.

[0125] The foregoing has shown and described the basic principles, main features, and advantages of the present application. Those skilled in the art should understand that the above embodiments do not limit the present application in any form. Any technical solutions obtained by means of equivalent replacement or equivalent transformation fall within the protection scope of the present application.

Claims

1. An electric-assisted trailer, comprising: a trailer body, at least including a foldable frame; a handle device connected to the trailer body; a traveling assembly, at least including drive wheels; a drive motor configured to drive the drive wheels to rotate; a power supply access part for accessing a power supply, and the power supply at least supplies power to the drive motor; a controller electrically connected to at least the drive motor to control the rotation of the drive motor; a speed control switch for controlling the traveling speed of the electric-assisted trailer; wherein, the speed control switch includes a rotary operating member, when the rotary operating member rotates counterclockwise, the drive motor drives the electric-assisted trailer to move forward; when the rotary operating member rotates clockwise, the controller controls the drive motor to reverse, and the electric-assisted trailer reverses.

2. The electric-assisted trailer according to claim 1, wherein, the speed control switch further includes a position sensor, and the position sensor is a Hall sensor.

3. The electric-assisted trailer according to claim 2, wherein, a magnet is provided on the rotary operating member, and by operating the rotary operating member, an angular change occurs between the magnet and the Hall sensor, and the Hall sensor sends different analog signals to control different rotation speeds of the drive motor.

4. The electric-assisted trailer according to claim 1, wherein, the controller controls the drive motor to reverse and controls the drive motor to move at a constant speed to achieve constant-speed reverse.

5. The electric-assisted trailer according to claim 1, wherein, when the rotary operating member rotates in the reset direction, the electric-assisted trailer decelerates, and when the rotary operating member resets to the initial position, the electric-assisted trailer brakes.

6. The electric-assisted trailer according to claim 1, wherein, the electric-assisted trailer includes different speed gears.

7. The electric-assisted trailer according to claim 1, wherein, the controller steplessly controls the traveling speed of the electric-assisted trailer.

8. The electric-assisted trailer according to claim 1, wherein, the trailer body further includes an enclosure member, and the enclosure member is detachably connected to the frame to form a storage space.

9. The electric-assisted trailer according to claim 1, wherein, further comprising: the power supply access part is detachably connected to a battery pack, the power supply access part is provided with a coupling part connected to the battery pack, and the structure of the coupling part is substantially the same as the coupling part of an electric tool adapted to the battery pack for coupling the battery pack, so that after the battery pack is detached from the trailer body, it can be coupled to the electric tool to supply power to the electric tool.

10. An electric-assisted trailer, comprising: a trailer body, at least including a foldable frame; a handle device connected to the trailer body; a traveling assembly, at least including drive wheels; a drive motor configured to drive the drive wheels to rotate; a power supply access part for accessing a power supply, and the power supply at least supplies power to the drive motor; a controller electrically connected to at least the drive motor to control the rotation of the drive motor; A speed control switch that controls the traveling speed of the electric assist trailer; wherein, the speed control switch includes a rotary operating member, and when the rotary operating member rotates, the drive motor drives the electric assist trailer to move forward or backward.

11. The electric assist trailer according to claim 10, characterized in that the speed control switch further includes a position sensor, and the position sensor is a Hall sensor.

12. The electric assist trailer according to claim 11, characterized in that a magnet is provided on the rotary operating member, and by operating the rotary operating member, an angular change occurs between the magnet and the Hall sensor, and the Hall sensor sends different analog signals to control different rotational speeds of the drive motor.

13. The electric assist trailer according to claim 11, characterized in that the controller controls the drive motor to reverse and controls the drive motor to move at a constant speed to achieve constant speed reverse.

14. The electric assist trailer according to claim 11, characterized in that when the rotary operating member rotates in the reset direction, the electric assist trailer decelerates, and when the rotary operating member resets to the initial position, the electric assist trailer brakes.

15. The electric assist trailer according to claim 11, characterized in that further comprising: The power supply access part is detachably connected to the battery pack. The power supply access part is provided with a coupling part connected to the battery pack. The structure of the coupling part is basically the same as the coupling part of the electric tool adapted to the battery pack for coupling the battery pack, so that after the battery pack is detached from the trailer body, it can be coupled to the electric tool to supply power to the electric tool.

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