Electric trailer

Abstract

The utility model discloses an electric trailer which comprises a trailer body at least comprising a foldable frame. The handle device is connected to the trailer body; the walking assembly at least comprises a driving wheel; the driving motor is configured to drive the driving wheel to rotate; the power supply access part is used for being detachably connected into the battery pack to supply power to the driving motor; and the controller is at least electrically connected with the driving motor to control the driving motor to rotate. The driving motor drives the walking assembly to move, and power-assisted walking of the electric trailer is achieved.

Description

[0001] This application is a divisional application of an application with a filing date of November 24, 2023, a national application number of 202323191893.6, and a utility model name of “Electric Trailer”. Technical Field

[0002] The present application relates to a shipping vehicle, and in particular to an electric trailer. Background Art

[0003] As people's living standards continue to improve, various outdoor activities have gradually become people's first choice for relaxation, such as outdoor picnics or camping. Generally, when carrying out the above activities, you need to carry a lot of things, which is inconvenient to carry. In order to meet the above needs, outdoor picnic trailers on the market are widely welcomed. However, outdoor playgrounds are generally different from the smoothness of urban roads. When transporting heavy things on the trailer, it is more laborious to push and pull.

[0004] This section provides background information related to the present application which is not necessarily prior art. Utility Model Content

[0005] An object of the present application is to solve or at least alleviate part or all of the above problems. The object of the present application is to provide an electric trailer capable of providing electric power assistance.

[0006] In order to achieve the above objectives, this application adopts the following technical solutions:

[0007] An electric trailer comprises: a trailer body, comprising at least a frame; a handle device connected to the trailer body; a travel assembly, comprising at least a drive wheel; a drive motor, configured to drive the drive wheel to rotate; a power access portion, configured to detachably access a battery pack to power the drive motor; and a controller, at least electrically connected to the drive motor to control the rotation of the drive motor; wherein the energy of the battery pack is greater than or equal to 40Wh.

[0008] In one embodiment, the power supply input portion is provided with a coupling portion connected to the battery pack, and the structure of the coupling portion is substantially the same as the coupling portion of the electric tool adapted to the battery pack for coupling to the battery pack.

[0009] In one embodiment, the trailer body further comprises an enclosure member which is detachably connected to the frame to form a storage space.

[0010] In one embodiment, the battery pack is disposed at the front end, rear end, lower end, left side, or right side of the storage space.

[0011] In one embodiment, the vehicle frame is a rigid structural member and the enclosure comprises a flexible structural member.

[0012] In one embodiment, it further includes a parameter detection module; the parameter detection module is configured to detect trailer parameters of the electric trailer; and the controller is configured to adjust the assist state of the drive motor according to the trailer parameters.

[0013] In one embodiment, the controller is configured to identify the user's operating intention of operating the electric trailer according to the trailer parameters, and adjust the power assist state of the drive motor according to the operating intention.

[0014] In one embodiment, the trailer parameters include operating parameters of the drive motor, or state parameters of the handle device relative to the trailer body, or the magnitude and direction of the force applied by the user to the handle device, or the walking speed of the user.

[0015] In one embodiment, the assist state includes the output torque of the drive motor or the output speed of the drive motor.

[0016] In one embodiment, the drive motor is a wheel hub motor.

[0017] In one embodiment, the outer diameter of the hub motor is greater than or equal to 100 mm and less than or equal to 250 mm.

[0018] An electric trailer comprises: a trailer body, comprising at least a frame; a handle device connected to the trailer body; a travel assembly, comprising at least a drive wheel; a drive motor, driving the drive wheel to rotate; a power access portion, used for detachably accessing a battery pack and at least supplying power to the drive motor; a controller, at least electrically connected to the drive motor to control the rotation of the drive motor; the power access portion is provided with a coupling portion connected to the battery pack, the structure of the coupling portion being substantially the same as the coupling portion of an electric tool adapted to the battery pack for coupling to the battery pack, so that the battery pack can be coupled to the electric tool to supply power to the electric tool after being removed from the trailer body.

[0019] An electric trailer comprises: a trailer body, comprising at least a foldable frame; a handle device connected to the trailer body; a travel assembly, comprising at least a drive wheel; a drive motor, configured to drive the drive wheel to rotate; a power supply access portion, for detachably accessing a battery pack to supply power to the drive motor; and a controller, at least electrically connected to the drive motor to control the rotation of the drive motor.

[0020] In one embodiment, the power supply input portion is arranged on the handle device.

[0021] In one embodiment, the trailer body further comprises an enclosure, which is detachably connected to the foldable frame to form a storage space.

[0022] In one embodiment, the power supply access portion is arranged at the front end, rear end, lower end, left side or right side of the storage space.

[0023] In one embodiment, the vehicle frame is a rigid structural member and the enclosure comprises a flexible structural member.

[0024] In one embodiment, the power input portion includes at least two independently arranged power interfaces.

[0025] In one embodiment, at least two independently arranged power interfaces include at least one enclosed battery compartment.

[0026] In one embodiment, the power supply access portion further includes an outdoor power supply access terminal configured to access an external power supply device.

[0027] In one embodiment, it also includes: a power output interface that can be connected to an external power-consuming device to output electrical energy; the power output interface is arranged on the handle device or at the front end or rear end of the storage space.

[0028] In one embodiment, it further includes: a control board, which is at least provided with a controller; the control board is arranged adjacent to the power supply access part.

[0029] In one embodiment, an energy recovery circuit is provided on the control board; the energy recovery circuit recovers electrical energy to charge the battery pack when the drive motor decelerates.

[0030] In one embodiment, it also includes a parameter detection module; the parameter detection module is at least used to detect the walking state of the electric trailer; the controller is configured to: when the walking state is a downhill state, control the energy recovery circuit to recover electric energy.

[0031] In one embodiment, the parameter detection module is further used to detect trailer parameters of the electric trailer; and the controller is configured to adjust the power assist state of the drive motor according to the trailer parameters.

[0032] In one embodiment, the controller is configured to identify the user's operating intention of operating the electric trailer according to the trailer parameters, and adjust the power assist state of the drive motor according to the operating intention.

[0033] In one embodiment, the trailer parameters include operating parameters of the drive motor, or state parameters of the handle device relative to the trailer body, or the magnitude and direction of the force applied by the user to the handle device, or the walking speed of the user.

[0034] In one embodiment, the assist state includes the output torque of the drive motor or the output speed of the drive motor.

[0035] In one embodiment, it further includes: a power display device, which is arranged on the handle device or in an adjacent area around the power supply input portion.

[0036] 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 controller is configured to control the operation of the drive motor according to the switch state of the mode selection switch.

[0037] In one embodiment, when the mode selection switch is in a first switching state, the drive motor does not work; when the mode selection switch is in a second switching state, it has multiple switch positions; the controller is configured to control the drive motor to output power at a corresponding output speed or output torque according to different switch positions.

[0038] 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; and the controller is configured not to respond to the change of the switch state of the mode selection switch when the safety switch is turned on.

[0039] In one embodiment, the ratio of the volume of the electric trailer when the frame is in a folded state to the volume of the electric trailer when the frame is in an unfolded state is greater than or equal to 0.1 and less than or equal to 0.6.

[0040] The benefit of the present application is that the electric trailer uses a battery pack to power the drive motor, which drives the travel assembly to move, thereby achieving power-assisted travel of the electric trailer, which can reduce the force applied to the electric trailer by the user and facilitate the user's operation. The use of a universal battery pack improves the applicability and endurance of the electric trailer. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is a schematic structural diagram of an electric trailer in an unfolded state in an embodiment of the present application;

[0042] Figure 2 is a structural schematic diagram of the electric trailer in the unfolded state from another perspective in the embodiment of the present application;

[0043] Figure 3 is a structural schematic diagram of an electric trailer in which the trailer body is in a folded state in an embodiment of the present application;

[0044] Figure 4 It is a schematic diagram of the structure of the power supply access part and the battery pack in the embodiment of the present application;

[0045] Figure 5 is a schematic diagram of the structure of a battery pack and an electric tool using the battery pack in the embodiment of the present application;

[0046] Figure 6 is a schematic diagram of the control circuit structure of the electric trailer in the embodiment of the present application;

[0047] Figure 7 is a schematic diagram of the structure of the driving motor and transmission mechanism of the electric trailer in the embodiment of the present application;

[0048] Figure 8 yes Figure 7 A schematic diagram of the structure from another perspective;

[0049] Fig. 9 yes Figure 8 A cross-sectional view along section GG;

[0050] Fig.10 is a schematic diagram of the structure of the clutch mechanism in the embodiment of the present application when it is in the second state;

[0051] Fig.11 is a schematic diagram of the structure of the clutch mechanism in the embodiment of the present application when it is in the first state;

[0052] Fig.12 yes Fig.10 A structural schematic diagram of a half-section view;

[0053] Fig.13 is a schematic diagram of the structure of the handle device and the passive wheel of the embodiment of the present application;

[0054] Fig.14 yes Fig.13 A schematic diagram of part of the structure from another perspective;

[0055] Fig.15 yes Fig.13 Structural schematic diagram of the neutral force direction detection unit and the connecting rod;

[0056] Fig.16 yes Fig.13 A schematic diagram of the structure of the middle grip portion;

[0057] Fig.17 yes Fig.13 Structural explosion diagram of the mid-angle detection unit;

[0058] Fig.18 is a schematic diagram of another drive wheel and drive motor structure;

[0059] Fig.19 It is a schematic diagram of the structure of an electric trailer for construction sites in the embodiment of the present application;

[0060] Fig. 20 It is a schematic diagram of the structure of an electric trailer for warehouse in the embodiment of the present application. DETAILED DESCRIPTION

[0061] Before any embodiments of the application are explained in detail, it is to be understood that the application is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the above drawings.

[0062] In this application, the terms "comprises", "includes", "has" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device that includes the element.

[0063] In this application, the term "and / or" is a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects before and after are in an "and / or" relationship.

[0064] In the present application, the terms "connect", "combine", "couple", and "install" may refer to direct connection, combination, coupling, or installation, or indirect connection, combination, coupling, or installation. For example, direct connection refers to two parts or components being connected together without the need for an intermediate piece, and indirect connection refers to two parts or components being connected to at least one intermediate piece respectively, and the two parts or components being connected via the intermediate piece. In addition, "connect" and "couple" are not limited to physical or mechanical connections or couplings, and may include electrical connections or couplings.

[0065] In this application, it will be understood by those of ordinary skill in the art that relative terms (e.g., "about," "approximately," "substantially," etc.) used in conjunction with quantities or conditions include the values ​​and have the meaning indicated by the context. For example, the relative terms include at least the degree of error associated with the measurement of a specific value, the tolerances caused by manufacturing, assembly, and use associated with a specific value, etc. Such terms should also be considered to disclose a range defined by the absolute values ​​of the two endpoints. Relative terms may refer to plus or minus a certain percentage (e.g., 1%, 5%, 10% or more) of the indicated value. Numerical values ​​that do not use relative terms should also be disclosed as specific values ​​with tolerances. In addition, "substantially" may refer to plus or minus a certain degree (e.g., 1 degree, 5 degrees, 10 degrees or more) on the basis of the indicated angle when expressing a relative angular position relationship (e.g., substantially parallel, substantially perpendicular).

[0066] In this application, it will be understood by those skilled in the art that the function performed by a component can be performed by one component, multiple components, one part, or multiple parts. Similarly, the function performed by a part can also be performed by one part, one component, or a combination of multiple parts.

[0067] In the present application, the terms "upper", "lower", "left", "right", "front", "back" and other directional words are described based on the orientation and positional relationship shown in the accompanying drawings, and should not be understood as limiting the embodiments of the present application. In addition, in the context, it is also necessary to understand that when it is mentioned that an element is connected to another element "upper" or "lower", it can not only be directly connected to another element "upper" or "lower", but also indirectly connected to another element "upper" or "lower" through an intermediate element. It should also be understood that directional words such as upper side, lower side, left side, right side, front side, back side, etc. not only represent the positive orientation, but can also be understood as the lateral orientation. For example, the bottom can include directly below, lower left, lower right, lower front, and lower back, etc.

[0068] In this application, the terms "controller", "processor", "central processing unit", "CPU", and "MCU" are interchangeable. When a unit "controller", "processor", "central processing unit", "CPU", or "MCU" is used to perform a specific function, unless otherwise specified, these functions can be performed by a single unit or multiple units.

[0069] In the present application, the terms “device”, “module” or “unit” may be implemented in the form of hardware or software to achieve specific functions.

[0070] In this application, the terms "calculate", "judge", "control", "determine", "identify", etc. refer to the operations and processes of a computer system or similar electronic computing device (e.g., controller, processor, etc.).

[0071] In order to clearly explain the technical solution of this application, the following is also defined: Figure 1-Figure 2 Upper side, lower side, left side, right side, front side and back side shown.

[0072] The electric trailer 100 introduced in the embodiment of the present application can be a family outdoor camping trailer, or a construction trailer, a warehouse trailer, or a trailer used in other occasions.

[0073] The following is an example of an outdoor camping trailer:

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] In this embodiment, if Figures 1 to 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.

[0079] Optionally, the frame 111 is a rigid structural member, and the enclosure 112 is a flexible structural member. For example, the frame 111 is welded or hinged by metal plates or metal rods, and the enclosure 112 can be made of waterproof canvas or Oxford cloth or other flexible materials. In this embodiment, the 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 end 1112 is arranged at both ends in the front and rear directions. The side 1113 is respectively arranged on both sides in the left and right directions, and the side 1113 on the left and right sides is respectively connected to the end 1112. The end 1112 and the side 1113 form a frame structure that basically surrounds the bottom 1111. In some embodiments, the end 1112 and the side 1113 are connected by parts of the same structure or are integrally formed parts.

[0080] In this embodiment, the frame 111 is a detachable or foldable frame. Figure 3 As shown, the foldable frame can be gathered toward the middle of the frame to be folded, or can be gathered toward any side or any surface of the frame to be folded. In one embodiment, the foldable frame 111 and the enclosure 112 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 storage space 13 can also be a three-dimensional space of other shapes. In some embodiments, the storage space 13 can also be a three-dimensional space that can be closed. Figure 1 to Figure 2 As shown, the frame 111 is in an expanded state. Figure 3 As shown, the frame 111 has a folded state. When the frame 111 is in the folded state, the electric trailer 100 occupies a smaller space, which is convenient for storage. When the 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 users to check in more items. Figure 3 The frame 111 is shown in a folded state, which is not necessarily the stowed state of the electric trailer 100. In some embodiments, the electric trailer 100 has a smaller stowed state, such as the travel assembly 17 and the handle device 12 are folded and stowed respectively.

[0081] 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. Figure 1 and Figure 2 As shown, the angle between the handle device 12 and the trailer body 11 is greater than or equal to 70°. In this embodiment, the angle between the handle device 12 and the bottom 1111 is greater than or equal to 70°. Figure 1When the 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 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.

[0082] 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 the folded state, the handle device 12 can also be retracted, thereby 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 the folded state to the volume of the electric trailer 100 when the frame 111 is in the 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.

[0083] In one embodiment, Figures 4 to 5 As shown, the power access part 14 is used to access the 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 supply device. Among them, the external power supply device can be an outdoor mobile power supply that can output direct current and alternating current. The outdoor mobile power supply also has a variety of different output interfaces to serve as a power discharge station to meet the different needs of users.

[0084] like 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-type tools, such as table saws, miter saws, etc. Or hand-push power tools, such as hand-push lawn mowers, hand-push snow blowers. Or riding power tools, such as riding lawn mowers, riding vehicles, all-terrain vehicles, etc. Or robot tools, such as mowing robots, snow sweeping robots, etc. In some embodiments, the power tools that the battery pack 141 can adapt to can also be garden tools, such as pruning machines, hair dryers, lawn mowers, chain saws, etc. In some embodiments, the power tools that the battery pack 141 can adapt to can also be vegetation care tools, such as lawn mowers, etc. Alternatively, the power tools can also be sawing tools, such as reciprocating saws, jigsaws, circular saws, etc. Alternatively, the power tools can also be grinding tools, such as angle grinders, sanders, etc. Alternatively, 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 is insufficient, the battery pack of the electric tool can be used for continuous power supply. Alternatively, when the power of the electric tool is insufficient, the battery pack of the electric trailer 100 can be used for power supply. Alternatively, the battery pack 141 of the electric trailer 100 can be charged by the charger 201 of the electric 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 electric tool 200 to work, the user can use the electric trailer 100 to transport the electric tool 200 or a workpiece.

[0085] In this embodiment, the power supply connection part 14 may include at least a positive connection terminal 14a and a negative connection terminal 14b, which can be connected to the positive and negative electrodes of the battery pack 141. In some embodiments, the power supply connection part 14 may also include a communication connection terminal 14c, which is connected to the communication terminal of the battery pack 141 to communicate with the battery pack 141.

[0086] In some embodiments, the power access portion 14 may be provided 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 portion 14 may include a battery compartment 142 for accommodating a battery pack 141, and the battery compartment 142 may be a closed battery compartment. A positive connection terminal 14a and a negative connection terminal 14b are provided in the battery compartment 142 for docking with the electrical terminals of the battery pack 141. Optionally, a positive connection terminal 14a, a negative connection terminal 14b, and a communication connection terminal 14c are provided in the battery compartment 142 for docking with the electrical terminals of the battery pack 141. In this embodiment, the battery compartment 142 may 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, the battery compartment 142 may be substantially closed by covering the battery compartment cover 1421, which can play a role in dustproof and waterproof.

[0087] In this embodiment, the battery pack 141 is pluggably connected to the power supply input part 14. For example, a coupling part 1423 for connecting the battery pack 141 is provided in the battery compartment 142, and the coupling part 1423 is formed with a first guide rail 1424, and the battery pack 141 is provided with a second guide rail 1411 that can match with the first guide rail 1424 so that the battery pack 141 slides along the first guide rail 1424. The coupling part 1423 in the battery compartment 142 has a structure that is substantially the same as the coupling part formed on the power tool for connecting the battery pack 141.

[0088] The battery compartment 142 is also provided with a locking structure and an ejection structure. The locking structure is used to lock the battery pack in the battery compartment 142 to prevent the battery pack 141 from shaking, and to 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 structure releases the battery pack 141, thereby facilitating the user to remove the battery pack. Because the working principle and structure of the mechanical battery pack locking and ejection have been fully disclosed to professionals in this field, a detailed description is omitted here for the purpose of brevity of the specification.

[0089] In one embodiment, the power access portion 14 may include an outdoor power access terminal that can be connected to an outdoor power supply device. Exemplarily, the outdoor power access terminal may be an electrical interface similar to the interface on a socket strip, and the electric trailer 100 can be electrically connected to an external power supply device through a power cord. In one embodiment, the outdoor power access terminal may also include a protective cover that can be covered on the outdoor power interface to prevent dust and water. In this way, the user can also prepare an outdoor power supply device, connect to the outdoor power supply device through the interface on the power access portion 14 or the power cord connected to the interface, and then place the outdoor power supply device in the storage space so that the user can drag the electric trailer 100 and the outdoor power supply device together.

[0090] In this embodiment, a battery pack 141 is used to power the electric trailer 100. The battery pack 141 may be a battery pack having cylindrical cells. Alternatively, the battery pack may be a soft pack having a plurality of stacked bag-shaped cells.

[0091] In some embodiments, the battery pack 141 may be a battery pack having lithium battery cells. Alternatively, the battery pack may also be a battery pack having lithium iron phosphate battery cells. Alternatively, the battery pack may also be a battery pack having both lithium battery cells and lithium iron phosphate battery cells.

[0092] In one embodiment, the electric trailer 100 may also be provided with a power output interface, which can output the power of the battery pack 141 or an external power supply device to power other electric devices. For example, the power output interface is a USB type-A interface or a USB type-C interface, etc., which can power the user's smart device or lighting fixture or picnic utensils with a USB interface. In one embodiment, the power output interface can be set at an adjacent position around the power access part 14, for example, on the battery compartment body 1422 of the battery compartment 142. In one embodiment, the power output interface can also be set on the handle device 12. In one embodiment, the power output interface can also be set at the front end or rear end or left side or right side or bottom side of the storage space 13.

[0093] In one embodiment, the electric trailer 100 may be provided with a battery compartment 142 for receiving a battery pack 141, and an external power supply access terminal for receiving an external power supply device. For example, the battery pack 141 may be used to supply power when the electric trailer 100 is being towed or pushed. When the power output interface 15 on the electric trailer 100 is used to supply power to an external power device, the external power supply device may be used to supply power.

[0094] In one embodiment, the electric trailer 100 may have at least two battery compartments. That is, the electric trailer 100 may be powered by at least two battery packs 141, thereby increasing the battery life of the electric trailer 100. In this embodiment, at least two battery packs 141 may power the electric trailer 100 at the same time, or may power the electric trailer 100 in a time-sharing manner, or may power 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 supplies power. In other embodiments, the controller 10 in the electric trailer 100 may determine the power supply time or sequence of the battery packs 141 according to the power, voltage, or temperature of the multiple battery packs 141. In some embodiments, the number of battery packs included in the electric trailer 100 may 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 electrically connected to the two battery packs 141 respectively, and may also include a spare storage compartment for storing spare batteries.

[0095] In some embodiments, the electric trailer 100 includes a built-in battery, wherein the built-in battery can be understood as a battery that is generally not disassembled, or a battery that is not convenient for users to quickly disassemble.

[0096] In this embodiment, the energy of the battery pack 141 for powering the electric trailer 100 is greater than or equal to 40Wh. In one embodiment, the energy of the battery pack 141 for powering the electric trailer 100 is greater than or equal to 40Wh and less than or equal to 800Wh. In one embodiment, the battery pack 141 can be a lithium-ion battery or a lithium iron phosphate battery or a capacitor battery or a sodium-ion battery or a mixed-core battery, that is, the battery pack 141 contains cells of multiple different materials.

[0097] In this embodiment, the ratio of the energy of the battery pack 141 for powering the electric trailer 100 to the weight of the electric trailer 100 is greater than or equal to 5Wh / Kg and less than or equal to 100Wh / Kg. For example, the ratio of the energy of the battery pack 141 for powering the electric trailer 100 to the weight of the electric trailer 100 is 5Wh / Kg, 10Wh / Kg, 13Wh / Kg, 15Wh / Kg, 20Wh / Kg, 30Wh / Kg, 40Wh / Kg, 50Wh / Kg, 60Wh / Kg, 70Wh / Kg, 80Wh / Kg, 90Wh / Kg, 100Wh / Kg, etc.

[0098] refer to Figures 1 to 4 and Figure 6 The electric trailer 100 structure and its control system shown in the figure, the electric trailer 100 also 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 may 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 circuit board (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 the electric control module. In this embodiment, the controller 10 uses a dedicated control chip, such as a single-chip microcomputer, a microcontroller unit (Microcontroller Unit, MCU)

[0099] In one embodiment, the control board can be arranged at an adjacent position close to the power supply input portion 14, for example, arranged adjacent to the periphery of the battery compartment or arranged on any outer surface of the battery compartment or arranged in the battery compartment. In this embodiment, the control board is powered by the battery pack 141.

[0100] In this embodiment, the control board and the battery pack 141 are both 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 group in the travel assembly 17. Among them, the rear wheel group is the driving wheel 171 in this embodiment.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] In some embodiments, 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 charging current generated by the drive motor 20 is enabled. The current utilization method includes using a power resistor to recover the current. In this embodiment, the power resistor is arranged near the battery compartment 142. In some embodiments, the current utilization method includes supplying the charging current generated by the drive motor 20 to, for example, a lighting lamp, an indicator light, or an additional drive motor 20. To avoid damage to the battery pack. Among them, the preset conditions include the battery pack voltage meeting a threshold, the drive motor 20 current-related parameters meeting a threshold, the drive motor 20 speed-related parameters meeting a threshold, or any one of the user's manual operation requirements.

[0106] In this embodiment, the electric trailer 100 may further include a parameter detection module 30, which can detect the walking state of the electric trailer 100. The walking state of the electric trailer 100 at least includes: walking state, stop state, uphill state, downhill state, acceleration state and deceleration state. The controller 10 can control whether the energy recovery circuit 40 works according to the above walking 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 energy to charge the battery pack 141.

[0107] In one embodiment, the parameter detection module 30 detects the rotation speed or working current of the drive 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 angle between the handle device 12 and the trailer body 11. In one embodiment, the parameter detection module 30 detects the inclination angle between the trailer 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. This application does not limit the specific type or number of parameter detection modules 30 or the parameter collection form, etc.

[0108] 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 power assist state of the drive motor according to the operation information. For example, the parameter detection module is a module with a human-computer interaction interface, such as a button, a dial or a screen, and the user generates different operation instructions by performing different operations on the human-computer interaction interface.

[0109] like Figures 7 to 12As shown, in one embodiment, the drive motor 20 is installed between the two drive wheels 171 to drive at least one of the drive wheels 171 to rotate. In this embodiment, the drive motor 20 can drive the two drive wheels 171 to rotate at the same time. In this embodiment, the drive wheel 171 is the rear wheel of the electric trailer 100, that is, the running wheel arranged on the side away from the handle device 12. Among them, the drive wheel 171 includes a left drive wheel 1711 and a right drive wheel 1712 arranged in the left and right directions. In this embodiment, the left drive wheel 1711 and the right drive wheel 1712 are respectively provided with one wheel. Optionally, the left drive wheel 1711 and the right drive wheel 1712 are respectively provided with two or more wheels. The specific number of the left drive wheel 1711 and the right drive wheel 1712 does not affect the substantive content of this application.

[0110] like Figure 7 As shown, the driving motor 20 is disposed on the frame 111. Optionally, the driving motor 20 is connected to the bottom 1111 of the frame 111. The driving motor 20 is disposed on a side close to the power supply input portion 14.

[0111] like Figures 7 to 12 As shown, the electric trailer 100 also includes a transmission mechanism 50 for transmitting the power of the drive motor 20 to the drive wheel 171. Optionally, the electric trailer 100 also includes a clutch mechanism 54 for connecting or disconnecting the power of the drive motor 20 to the drive wheel 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 set according to the actual needs of different products. In some embodiments, the electric trailer 100 includes a drive motor 20 and a transmission mechanism 50. In some embodiments, the electric trailer 100 includes a drive motor 20 and a clutch mechanism 54. In some embodiments, the electric trailer 100 includes a drive motor 20, a transmission mechanism 50 and a clutch mechanism 54. In some embodiments, the electric trailer 100 includes a drive motor 20.

[0112] In this embodiment, the transmission mechanism 50 includes a reduction assembly 51 and a differential assembly 53. The driving motor 20 includes a driving shaft 21 rotating around a first axis 101. The reduction assembly 51 and the differential assembly 53 connect the driving shaft 21 and the driving wheel 171.

[0113] like Figures 9 and 10As shown, the 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 the transmission is connected, the first driving wheel 511 is formed 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 is meshed with the first driving wheel 511 to form a reduction transmission with a certain transmission ratio. Optionally, the transmission ratio is greater than 1. The first driven wheel 512 rotates substantially coaxially with the second driving wheel 513. The second driving wheel 513 is meshed with the second driven wheel 514 to form a 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. Wherein, the second driven wheel 514 is arranged in 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 a second driving wheel 513. The left driving wheel 1711 and the right driving wheel 1712 are respectively provided with a second driven wheel 514. Then, 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 cylindrical gears respectively. 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 cylindrical gears respectively. In some alternative embodiments, the 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 between the gears and the rotating shaft, the connection structure of the support bearing and the frame, as well as the dust protection housing are set according to the needs, which are all well-known technologies for those skilled in the art and have been fully disclosed.

[0114] In this embodiment, in order to achieve a speed difference between the inner wheel and the outer wheel when the electric trailer 100 turns, so as to achieve a smooth turn, a differential assembly 53 is provided in this embodiment to enable the electric drive wheels 171 to travel at different speeds. Fig.12As shown, 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 rotate around the first connecting shaft 532 respectively, and 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 meshed and connected with the first bevel gear 531 and the second bevel gear 533 respectively. The fourth bevel gear 535 is meshed and connected with the first bevel gear 531 and the second bevel gear 533 respectively. The third bevel gear 534 is connected to the second driving wheel 513 through the second connecting shaft 521, and then 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 is substantially parallel to the third connecting shaft 522. The second connecting shaft 521 and the third connecting shaft 522 are substantially perpendicular to the first connecting shaft 532.

[0115] To make the power transmission path of the drive motor 20 unobstructed. The differential assembly 53 also includes a first transmission connection portion 536. It is used to connect the first driven wheel 512 and the first connecting shaft 532. The first transmission connection portion 536 is embedded in 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, and the first bevel gear 531 and the second bevel gear 533 respectively drive the third bevel gear 534 and the fourth bevel gear 535 meshed therewith to rotate. In this embodiment, the first driven wheel 512, the first transmission connection part 536 and the second connecting shaft 521 are coaxial, so that the first driven wheel 512 rotates coaxially with the second driving wheel 513, and the rotation axis of the first driven wheel 512, the first transmission connection part 536, the second connecting shaft 521 and the second driving wheel 513 is set as the third axis 103. The third axis 103 is parallel to the central axis 171a of the driving wheel but does not overlap. In this embodiment, the first bevel gear 531 and the second bevel gear 533 rotate around the third axis 103, thereby driving the third bevel gear 534 and the fourth bevel gear 535 to rotate and then transmit the rotational driving force of the driving 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 is turning, the speed difference between the inner wheel and the outer wheel is generated. In this embodiment, the third bevel gear 534 and the fourth bevel gear 535 have different rotation speeds. Since the first bevel gear 531 and the second bevel gear 533 are also configured to rotate around the second axis 102, the speed of the inner running wheel is slowed down and the speed of the outer running wheel is accelerated. The cost of using the differential assembly 53 is low and the weight of the components is light.

[0116] In this embodiment, the differential assembly 53 is used so that the driving wheel can be used and function can be realized 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 running wheel of the electric trailer 100 increases, and the differential is actively decelerated to buffer the acceleration of the running wheel due to gravity, so that the speed of the driving wheel can be basically maintained within the speed range driven by the driving motor 2020.

[0117] 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 shaft 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 is flexible.

[0118] like Figures 10 to 12As shown, the electric trailer 100 may also be provided with a clutch mechanism 54. 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, there is power transmission between the drive motor 20 and the drive wheel 171. In some embodiments, the electric trailer 100 is switched between the two states of electric power-assisted and non-power-assisted by the clutch mechanism 54. It can be understood that the electric power-assisted 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 the non-electric power-assisted means that it is pushed by manpower like an ordinary picnic car. In some embodiments, by using the clutch mechanism 54, the drive wheel will not reversely drive the drive motor to rotate when it is not electric-assisted, so as to damage the drive motor.

[0119] like Figures 9 to 11 As shown, the clutch mechanism 54 includes a shift fork 541, a clutch control unit 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 driving 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.

[0120] The clutch body 545 includes: a meshing portion 5451, a connecting groove portion 5453 and a limiting protrusion 5454. The meshing portion 5451 can be selectively connected to the first driven wheel 512. Figure 10 to Figure 11 As shown, the meshing portion 5451 includes an outer tooth portion 5452, and the first driven wheel 512 is provided with an inner tooth portion 5121 that matches the outer tooth portion 5452. When the clutch mechanism 54 is in the second state, as shown in FIG. Fig.10 As shown, the outer tooth portion 5452 is meshed with the inner tooth portion 5121. When the clutch mechanism 54 is in the first state, as shown in FIG. Fig.11 As shown, the outer tooth portion 5452 is meshed and disengaged from the inner tooth portion 5121. The second driving wheel 513 is connected to 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 protrusion 5454 to limit the second driving wheel 513 and the clutch body 545 circumferentially, 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 switches between the first state and the second state. The outer tooth portion 5452 is meshed and connected with the inner 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 shown Fig.11As shown, the outer tooth portion 5452 is disengaged from the inner tooth portion 5121, and the rotation of the first driven wheel 512 cannot be transmitted to the clutch body 545, and thus the power transmission path between the first driven wheel 512 and the second driving wheel 513 is disconnected.

[0121] The shift fork 541 cooperates with the connection groove 5453 of the clutch body 545. The shift fork 541 rotates around the fourth axis 104 to drive the clutch body 545 to repeatedly move along the axial direction of the third axis 103, so as to realize the switching of the clutch body 545 between the first state and the second state. The shift fork 541 is connected to the connection groove 5453 and the clutch control part 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 shift fork 541 is shifted by the control rope 542 to make the clutch body 545 move to the first state position. In this embodiment, the control rope 542 is controlled by the user, and 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 coil 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 to the clutch body 545 to keep it in the position of the second state. In this embodiment, in order to prevent dust and protect the control rope 542, a protective cover 543 is provided on the outer side of the control rope 542.

[0122] In some embodiments, the clutch mechanism also includes other mechanical clutch mechanisms. For example, a ratchet clutch, a centrifugal clutch, a friction clutch, and a hydraulic clutch. The above mechanical clutches can be used as the clutch mechanism of the present application in simple deformation or combination. Under 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.

[0123] In some alternative embodiments, the clutch may be a one-way bearing or an overrunning clutch.

[0124] In some embodiments, the clutch mechanism further includes an electronic clutch, such as an electromagnetic clutch, such as a dry single-plate electromagnetic clutch, a dry multi-plate electromagnetic clutch, a wet multi-plate electromagnetic clutch, a magnetic powder clutch, or a slip electromagnetic clutch.

[0125] In some embodiments, both a mechanical clutch mechanism and an electronic clutch coupling may be used simultaneously.

[0126] like Fig.13As shown, in this embodiment, the passive wheel 172 is the front wheel group of the electric trailer 100, that is, the walking wheel 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 and right directions. In this embodiment, the left passive wheel 1721 and the right passive wheel 1726 are respectively provided with a wheel 1722. Optionally, the left passive wheel 1721 and the right passive wheel 1726 are respectively provided with two or more wheels. The specific number of the left passive wheel 1721 and the right passive wheel 1726 does not affect the substantive content of this application. Among them, the left passive wheel 1721 includes a wheel 1722, an axle 1723 and a left wheel frame 1724. The right passive wheel 1726 includes a wheel 1722, an 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 axle 1723. The wheel 1722 rotates around the wheel axle 1723. The left wheel frame 1724 is connected to the frame 111 through the rotating shaft 1725. The left wheel frame 1724 rotates around the center line of the rotating shaft 1725 relative to the frame 111 to achieve steering.

[0127] A pull rod linkage assembly 173 is provided between the left passive wheel 1721 and the right passive wheel 1726, and 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 rotatably connected to the rotating shaft 1725 of the left passive wheel 1721 and the first steering rod 1733 respectively. The second connecting rod 1732 is rotatably connected to the rotating shaft 1725 of the right passive wheel 1726 and the first steering rod 1733 respectively. 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 frame 111 to ensure stable fixation of the pull rod linkage assembly 173.

[0128] Taking left turning as an example, the handle device 12 is driven to move to the left, the first steering rod 1733 is connected to the handle device 12, and the handle device 12 drives the first steering rod 1733 to rotate, driving the first connecting rod 1731 and the second connecting rod 1732 to swing accordingly. The first connecting rod 1731 drives the left wheel frame 1724 to rotate, and the second connecting rod 1732 drives the right wheel frame 1727 to rotate, thereby converting the rotation of the handle device 12 into the corresponding steering of the left passive wheel 1721 and the right passive wheel 1726. As a result, the left passive wheel 1721 and the right passive wheel 1726 are actively steered by force, rather than being steered by the friction of the ground or passive drag. Turning is more labor-saving.

[0129] In this embodiment, the drive motor 20 may be an outer rotor drive motor 20. In some embodiments, the drive motor may 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 100 W and less than or equal to 800 W, for example, 100 W, 200 W, 300 W, 400 W, 500 W, 600 W, 700 W, 800 W, etc.

[0130] In some alternative embodiments, such as Fig.18 As shown, the drive motor 20' can be integrated into 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.

[0131] In one embodiment, the length of the hub drive motor 20' along the radial direction D of the driving wheel 171 is greater than or equal to 100 mm and less than or equal to 250 mm. For example, it can be 100 mm, 120 mm, 130 mm, 150 mm, 200 mm, 230 mm, 250 mm, etc. In this embodiment, a hub drive motor 20' is respectively provided in the two driving wheels 171, and the rated output power of each hub drive motor 20' is greater than or equal to 50 W and less than or equal to 400 W. By using the hub drive motor 20', the structure of the transmission mechanism can be simplified and the number of components can be reduced.

[0132] In one embodiment, the controller 10 can control the power-assisting state of the drive motor 20, such as power-assisting or non-power-assisting, according to the switch state of the mode selection switch 16. Exemplarily, when the mode selection switch 16 is in the on state, i.e., the second switch state, the controller 10 can control the drive motor 20 to provide power-assisting, and when the mode selection switch 16 is in the non-conductive state, i.e., the first switch state, the controller 10 can control the drive motor 20 not to provide power-assisting. For example, when dragging or pushing a trailer, the mode selection switch 16 can be triggered to be in the on state, so that the drive motor 20 provides power-assisting; and when the trailer stops walking, the mode selection switch 16 is triggered again to be disconnected, so that the drive motor 20 stops power-assisting. In one embodiment, the triggering mode of the mode selection switch 16 is related to the type of switch, for example, when the mode selection switch 16 is a toggle switch or a push switch, the triggering mode is to toggle or press. In one embodiment, the mode selection switch 16 can be manually triggered by the user or automatically triggered. For example, when the electric trolley 100 is pushed or dragged to generate displacement or is about to generate displacement, the mode selection switch 16 can be automatically triggered to be turned on, so that the drive motor 20 can provide assistance; when the electric trolley 100 stops or is about to stop, the mode selection switch 16 can be automatically triggered to be turned off, so that the drive motor 20 no longer provides assistance.

[0133] In some embodiments, the mode selection switch 16 includes an automatic reset member. When triggered by the user, it is in one state, such as conduction or non-conduction, and when released by the user, it is in another state. Optionally, the initial state or release state of the mode selection switch is a conduction state, that is, the default is to provide power assistance. When triggered by the user, it is in a non-conduction state, that is, the user can turn off the power assistance according to actual usage. Optionally, the mode selection switch is a self-reset switch.

[0134] In one embodiment, the mode selection switch 16 may have a plurality of switch gears in the second switch state, and the output speed or output torque of the drive motor 20 may be different in different switch gears. Exemplarily, the controller 10 may control the drive motor 20 to output a corresponding torque or speed according to the size of the switch gear in the second switch state of the mode selection switch 16, so as to adapt to the target demand in the gear. In one embodiment, the different switch gears may include a power saving gear or a labor saving gear or a smooth road gear or a grass gear or a ramp gear or an uphill gear or a downhill gear, etc.

[0135] In one embodiment, a safety switch can be provided to prevent the mode selection switch 16 from being triggered by mistake. For example, when the safety switch is not closed, the drive motor 20 does not provide assistance regardless of whether the mode selection switch 16 is turned on or not.

[0136] In one embodiment, Figures 1 to 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-activated switch, etc.

[0137] like Fig.13 and Fig.16 As shown, as an embodiment of manual control of the drive motor 20, a first trigger switch 1121 is provided on the gripping portion 121. Optionally, the gripping portion 121 is provided with a gripping area, and the first trigger switch 1121 is provided in the gripping area. Optionally, the first trigger switch 1121 is provided in the user's four-finger operation area. 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 released, the controller 10 controls the drive motor 20 to decelerate or gradually decelerate to stop.

[0138] like Fig.14 and Fig.15 As shown, as another embodiment of manual control of the driving motor, a force direction detection unit 30b is provided on the handle device 12, and 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 identifies 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 axial direction. Among them, a reset structure 1223 is connected between the upper rod 1221 and the lower rod 1222, and when the user applies a pulling force or a pushing force to the handle device 12, a relative displacement in different directions occurs between the upper rod 1221 and the lower rod 1222. The displacement sensor 1224 includes a Hall sensor. Any 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 cause 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.

[0139] Alternatively, in some embodiments, the parameter detection module of the electric trailer 100 may include a speed regulating switch, and the user can control the travel speed of the electric trailer 100 through the speed regulating switch, for example, the electric trailer 100 can be controlled to travel at different speed gears, or the travel speed of the electric trailer 100 can be infinitely controlled. Optionally, the regulating switch includes a rotating operating member and a position sensor. Optionally, the position sensor is a Hall sensor, the magnet is arranged on the rotating operating member, and the Hall sensor is arranged in the grip 121 without rotating. The user operates the rotating operating member to change the angle between the magnet and the Hall sensor, and the Hall sensor sends different analog signals to control different speeds of the drive motor. Optionally, when the rotating operating member rotates counterclockwise, the drive motor 20 controls the electric trailer 100 to move forward, and the larger the rotation angle, the higher the speed of the drive motor 20. The rotating operating member rotates clockwise, and the controller 10 controls the drive motor 20 to reverse and control the drive motor 20 to move at a constant speed to achieve constant speed reversing. The rotating operating member rotates in the reset direction to slow down the trailer, and brakes when it is reset to the initial position.

[0140] As another embodiment of manually controlling the drive motor 20, Fig.14 As shown, the trailer body 11 is provided with a reset detection unit 124 of the handle device 12. When the reset detection unit 124 detects that the handle device 12 returns to a preset state, the drive motor 20 stops or does not respond to the start. Optionally, the reset detection unit 124 includes a contact switch. Optionally, a fixing unit is provided on the trailer body 11. The fixing unit includes a slot 1241, a one-way buckle 1242 provided in the slot 1241, and a contact switch. When the connecting rod 122 is inserted into the slot 1241, the connecting rod 122 contacts 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 inserted into the slot 1241 in the slot 1241. In some embodiments, an unlocking unit connected to the one-way buckle 1242 is also provided, and the connecting rod 122 is released from the slot 1241 through the unlocking unit. In some embodiments, the connection rod 122 can be retained and released by elastic deformation of the locking slot 1241 .

[0141] In one embodiment, the trailer parameters of the electric trailer 100 detected by the parameter detection module 30 include the working 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 power-assisting state of the drive motor 20 according to the above trailer parameters. Among them, the power-assisting state includes not only power-assisting or no power-assisting, but also the output torque or output speed of the drive motor 20 when power-assisting. In this embodiment, no matter what working conditions, the user can maintain a basically unchanged walking speed or a basically unchanged driving force or dragging force to control the walking of the trailer, so that the user can obtain a more 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 reaches a balanced state with the driving force of the motor and the resistance of the ground or wheels, or the controller 10 controls the output speed of the drive motor 20 so that the walking speed of the walking component 17 is basically consistent with the walking speed of the user.

[0142] In some embodiments, when the controller 10 determines that the electric trailer 100 is in a downhill travel 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, the controller 10 can control the drive motor 20 to reduce the driving force or change the direction of the driving force, or slow down the trailer to avoid the user from not being able to keep up with the speed of the trailer going downhill. Alternatively, when the controller determines that the electric trailer 100 is in an uphill travel 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, the drive motor 20 can be controlled to increase the driving force, so that the user can drag the electric trailer 100 uphill without increasing the dragging force applied to the handle device 12.

[0143] In some embodiments, the parameter detection module 30 may include a pressure sensor for detecting a force applied by a user to the handle assembly 12 .

[0144] refer to Figure 13 to Figure 14 The parameter detection module 30 includes an angle detection unit 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. Fig.17As shown, the angle detection unit 30a includes a target part 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, and does not move relative to each other. The target part includes a magnet 1225. Optionally, the handle device 12 is provided with a sleeve 125. The handle device 12 is rotatably connected to the trailer body 11 through the sleeve 125. The target part also includes a fixed seat 311 for fixing the magnet 1225. The fixed seat 311 is connected to the sleeve 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 a first preset value, the angle detection unit 30a sends a corresponding signal, and the controller 10 controls the drive motor 20 to decelerate. When it is detected that the angle between the handle device 12 and the trailer body 11 reaches a second preset value, the angle detection unit 30a sends a corresponding signal, and the controller 10 controls the drive motor 10 to stop.

[0145] In some embodiments, the force applied by the user to the handle device 12 is determined by 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 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 drive motor 20 to change the current power-assisting state, so that the user can 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 to the handle device 12, but can detect parameters such as the walking speed or acceleration of the electric trailer 100 and the 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 power assist state of the drive motor 20 based on the estimated force.

[0146] In one embodiment, the controller 10 can also identify the user's operation intention according to the parameters detected by the parameter detection module 30, and then adaptively adjust the power state of the drive motor 20 according to the identified operation intention, so that the user can get a more comfortable walking state. The so-called operation intention can include forward dragging intention, forward stop intention, backward pushing intention, backward stop intention, forward acceleration intention, forward deceleration intention, backward acceleration intention, or backward deceleration intention, etc.

[0147] In this embodiment, a drive circuit 41 is provided between the controller 10 and the drive motor 20, and the drive circuit 41 may include a plurality of switch elements Q1-Q6. Each gate terminal of the switch element is electrically connected to the controller 10 for receiving a control signal from the controller 10. Each drain or source of the switch element is connected to the stator winding of the drive motor 20. The switch elements Q1-Q6 receive control signals from the controller 10 to change their respective conduction states, thereby changing the current loaded on 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 (e.g., field effect transistors (FET), bipolar junction transistors (BJT), insulated gate bipolar transistors (IGBT), etc.). It is understandable that the above-mentioned switch element may also be any other type of solid-state switch, such as an insulated gate bipolar transistor (IGBT), a bipolar junction transistor (BJT), etc. In order to make the motor rotate, the driving circuit 41 has a plurality of driving states. In different conduction states, the rotation state of the motor is different.

[0148] In one embodiment, the controller 10 can output a square wave control signal to control the motor to rotate. In one embodiment, the controller 10 can also use FOC control to control the motor to rotate. This application does not limit the control method used by the controller 10.

[0149] In one embodiment, the electric trailer 100 may also be provided with a power display device, which can display 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 light.

[0150] In one embodiment, the electric trailer 100 may also be provided with a lighting device, which may be arranged on the battery compartment, or on the weekend of the storage space 13, or on the handle device 12, or hung on the trailer body 11.

[0151] In some embodiments, the status indicator indicates the power-assisting state of the drive motor through sound and light display. Optionally, the status indicator includes a status indicator light for indicating the power-assisting state of the drive motor, for example, it is on when it is in the power-assisting state and it is off when it is in the non-power-assisting state. Or more power-assisting states can be represented by different colors, flashing and always on, different flashing frequencies or different breathing light frequencies. Optionally, the status indicator includes a sound prompter, such as a buzzer, for indicating the power-assisting state of the drive motor.

[0152] like Fig.19 The electric trailer shown can also be a construction site trailer 300, and 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, a running wheel 303, and a power supply access part 304. Because the things transported by the construction site trailer 300 are generally heavy, the running wheel 303 of the trailer can be built with a hub drive motor 20 to drive the drive wheel to travel as a running assist for the trailer 300, and in order to power the hub drive motor 20, the power supply access part 304 can be connected to at least one battery pack. In this embodiment, the battery pack connected to the power supply access part 304 can be consistent with the battery pack described in the above embodiment, and the relevant features of the electric trailer 100 for outdoor picnics in the above embodiment can also be applied to the construction site trailer 300 in this embodiment, for example, the way in which the controller in the construction site trailer 300 is adaptive to assist, the type of battery pack, the power supply method, etc., are not repeated here one by one.

[0153] like Fig. 20 The electric trailer shown may also be a warehouse trailer 400 , which may also include a battery pack, a hub drive motor 20 , and an adaptive power assist mode, etc., which are used in an outdoor picnic trailer or a construction site trailer.

[0154] The above shows and describes 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, and any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present application.

Claims

1. An electric trailer, characterized in that: include The trailer body includes at least a frame; a handle device connected to the trailer body; A traveling assembly, comprising at least a driving wheel; A driving motor drives the driving wheel to rotate; A power supply access portion, used for detachably accessing a battery pack to at least supply power to the driving motor; a controller, at least electrically connected to the drive motor to control the rotation of the drive motor; The power access portion is provided with a coupling portion connected to the battery pack, and the structure of the coupling portion is basically the same as the coupling portion of the electric tool adapted to the battery pack for coupling the battery pack, so that the battery pack can be coupled to the electric tool to power the electric tool after being removed from the trailer body.

2. The electric trailer according to claim 1, characterized in that: The power supply access portion is arranged on the handle device.

3. The electric trailer according to claim 1, characterized in that: The trailer body also includes an enclosure member that is detachably connected to the foldable frame to form a storage space.

4. The electric trailer according to claim 3, characterized in that: The power supply access portion is arranged at the front end, rear end, lower end, left side or right side of the storage space.

5. The electric trailer according to claim 3, characterized in that: The vehicle frame is a rigid structural member, and the enclosure member includes a flexible structural member.

6. The electric trailer according to claim 1, characterized in that: The power supply input portion includes at least two independently arranged power supply interfaces.

7. The electric trailer according to claim 6, characterized in that: At least two independently arranged power supply interfaces include at least one enclosed battery compartment.

8. The electric trailer according to claim 1, characterized in that: The power supply access part also includes an outdoor power supply access terminal, which is configured to access an external power supply device.

9. The electric trailer according to claim 3, characterized in that: Also includes: Power output interface, which can be connected to external power-consuming equipment to output electrical energy; The power output interface is arranged on the handle device or at the front end or the rear end of the storage space.

10. The electric trailer according to claim 1, characterized in that: Also includes: A control board is provided with at least the controller; the control board is arranged adjacent to the power supply access part.

11. The electric trailer according to claim 10, characterized in that: The control board is provided with an energy recovery circuit; The energy recovery circuit recovers electrical energy to charge the battery pack when the drive motor decelerates.

12. The electric trailer according to claim 11, characterized in that: Also includes parameter detection module; The parameter detection module is at least used to detect the walking state of the electric trailer; The controller is configured to control the energy recovery circuit to recover electric energy when the walking state is a downhill state.

13. The electric trailer according to claim 12, characterized in that: The parameter detection module is also used to detect the trailer parameters of the electric trailer; The controller is configured to adjust the assist state of the drive motor according to the trailer parameter.

14. The electric trailer according to claim 13, characterized in that: The controller is configured to identify the user's operation intention of operating the electric trailer according to the trailer parameters, and adjust the power assist state of the drive motor according to the operation intention.

15. The electric trailer according to claim 13, characterized in that: The trailer parameters include working parameters of the drive motor, or state parameters of the handle device relative to the trailer body, or the magnitude and direction of the force applied by the user to the handle device, or the walking speed of the user.

16. The electric trailer according to claim 13, characterized in that: The assist state includes the output torque of the drive motor or the output speed of the drive motor.

17. The electric trailer according to claim 1, characterized in that: Also includes: The power display device is arranged on the handle device or in an adjacent area around the power supply input portion.

18. The electric trailer according to claim 1, characterized in that: It also includes: a mode selection switch, which is arranged on the handle device and is at least electrically connected to the controller; The controller is configured to control the driving motor to operate according to a switch state of the mode selection switch.

19. The electric trailer according to claim 18, characterized in that: 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 configured to control the drive motor to output power at a corresponding output speed or output torque according to different switch gears.

20. The electric trailer according to claim 18, characterized in that: It also 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 a change in a switch state of the mode selection switch when the safety switch is turned on.

21. The electric trailer according to claim 1, characterized in that: The ratio of the volume of the electric trailer when the frame is in the folded state to the volume of the electric trailer when the frame is in the unfolded state is greater than or equal to 0.1 and less than or equal to 0.6.

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