Lawn edge trimmer and electric tool

Abstract

The invention discloses a lawn edge trimmer and an electric tool, and belongs to the technical field of electric tools. The lawn edge trimmer comprises an output shaft, a protective cover, a front shell, a rear shell, a motor, a connecting assembly and a transmission assembly, the output shaft is used for installing blades for cutting grass, and the protective cover is used for surrounding at least part of the blades; the front shell accommodates at least part of the output shaft; a combination part for combining the battery pack is formed on the rear shell; the motor is mounted to the rear shell to drive the output shaft; the connecting assembly is used for connecting the front shell and the rear shell; the transmission assembly is used for realizing power transmission between the motor and the output shaft; when the motor is in the maximum efficiency state, the ratio of the output power of the motor to the weight of the lawn edge trimmer is larger than or equal to 180 W / kg. The electric tool comprises a motor, and when the motor is in the maximum efficiency state, the ratio of the output power of the motor to the weight of the electric tool is larger than or equal to 180 W / kg. And the power density is high, so that the machine performance is improved, the weight of the whole machine is kept in a light state, and user operation is facilitated.

Description

Technical Field

[0001] The present application relates to the technical field of electric tools, and in particular to a lawn trimmer and an electric tool. Background Art

[0002] A lawn edger in the related art, as a commonly used gardening tool, generally includes a long pole assembly for users to operate, one end of the long pole assembly is connected to a working head, and the other end of the long pole assembly is connected to an operating assembly for easy operation by users. For lawn edgers, the overall performance is relatively low. If the performance is further improved on this basis, the overall machine needs to be made larger and heavier, which will make the machine heavier and difficult to hold. Users need to swing it when operating it, which is easy to get tired.

[0003] This section provides background information related to the present application which is not necessarily prior art. Summary of the invention

[0004] One object of the present application is to solve or at least alleviate part or all of the above problems. To this end, one object of the present application is to provide a lawn edge trimmer and an electric tool.

[0005] In order to achieve the above objectives, this application adopts the following technical solutions:

[0006] A lawn trimmer comprises: an output shaft for mounting a blade for cutting grass; a guard for surrounding at least part of the blade; a front housing for accommodating at least part of the output shaft; a rear housing formed with a coupling portion for coupling with a battery pack; a motor mounted to the rear housing to drive the output shaft; a connecting assembly for connecting the front housing and the rear housing; a transmission assembly for achieving power transmission between the motor and the output shaft; when the motor is in a state of maximum efficiency, the ratio of the output power of the motor to the weight of the lawn trimmer is greater than or equal to 180 W / kg.

[0007] In some embodiments, when the motor is in a state of maximum efficiency, a ratio of the output power of the motor to the weight of the lawn edge trimmer is greater than or equal to 200 W / kg.

[0008] In some embodiments, the output power of the motor is greater than or equal to 1000W.

[0009] In some embodiments, the output power of the motor is greater than or equal to 1200W.

[0010] In some embodiments, the lawn edge trimmer weighs less than or equal to 5.5 kg.

[0011] In some embodiments, the connection assembly includes a connection tube, which is used to connect the front shell and the rear shell, and at least a portion of the connection tube is bent and extended.

[0012] In some embodiments, the transmission assembly includes: a first transmission shaft, used to connect to the motor and arranged at the rear end of the connecting tube; a second transmission shaft, used to drive the output shaft; a connecting shaft, connecting the first transmission shaft and the second transmission shaft, and the connecting shaft is at least partially arranged in the connecting tube, and the connecting shaft is a flexible shaft.

[0013] In some embodiments, the connecting pipe includes a straight pipe portion and a curved pipe portion connected to each other, the straight pipe portion is connected to the rear shell, and the curved pipe portion is connected to the front shell, and the bending angle of the curved pipe portion relative to the straight pipe portion is greater than or equal to 135° and less than or equal to 155°.

[0014] In some embodiments, the radius of curvature of the curved pipe portion is greater than or equal to 400 mm and less than or equal to 500 mm.

[0015] In some embodiments, along a direction parallel to the straight pipe portion, the length of the connecting pipe is greater than or equal to 1400 mm.

[0016] In some embodiments, it also includes: a first communication unit; a terminal device, including a second communication unit, the first communication unit is wirelessly connected to the second communication unit, and the terminal device can display the status information of the lawn trimmer.

[0017] In some embodiments, the first communication unit and the second communication unit are both Bluetooth units.

[0018] In some embodiments, it also includes: a detection module for detecting the operating parameters or electrical parameters of the motor; a control module for determining whether the motor is in a stalled operating state based on the operating parameters or electrical parameters, and controlling the motor to stop when in the stalled operating state.

[0019] In some embodiments, the connecting assembly includes a connecting pipe, which includes a straight pipe portion and a curved pipe portion connected to each other, the straight pipe portion is connected to the rear shell, the curved pipe portion is connected to the front shell, and the rotation axis of the output shaft is basically perpendicular to the extension direction of the straight pipe portion.

[0020] In some embodiments, the connection assembly includes a connection tube, and the connection tube is a carbon fiber tube.

[0021] An electric tool comprises: an output shaft for mounting a blade for cutting grass; a guard for surrounding at least part of the blade; a front housing for accommodating at least part of the output shaft; a rear housing formed with a coupling portion for coupling with a battery pack; a motor mounted to the rear housing to drive the output shaft; a connecting assembly comprising a connecting tube for connecting the front housing and the housing; a transmission assembly for achieving power transmission between the motor and the output shaft; wherein the transmission assembly comprises: a first transmission shaft for connecting to the motor and disposed at the rear end of the connecting tube; a second transmission shaft for driving the output shaft; a connecting shaft connecting the first transmission shaft and the second transmission shaft, and the connecting shaft is at least partially disposed in the connecting tube; when the motor is in a state of maximum efficiency, the ratio of the output power of the motor to the weight of the electric tool is greater than or equal to 180W / kg.

[0022] In some embodiments, when the motor is in a state of maximum efficiency, a ratio of the output power of the motor to the weight of the power tool is greater than or equal to 200 W / kg.

[0023] In some embodiments, the output power of the motor is greater than or equal to 1000W.

[0024] In some embodiments, the weight of the power tool is less than or equal to 5.5 kg.

[0025] In some embodiments, it also includes: a first communication unit; a terminal device, including a second communication unit, the first communication unit is wirelessly connected to the second communication unit, and the terminal device can display status information of the power tool.

[0026] The benefit of the present application lies in that the motor drives the output shaft to rotate, which in turn can drive the blade to rotate to achieve the function of cutting grass. When the motor is in the maximum efficiency state, the ratio of the motor's output power to the weight of the lawn trimmer is greater than or equal to 180W / kg, indicating that the motor has a large output power and a small mass, and has a high power density, so that the performance of the machine is improved while the weight of the entire machine is kept light, which is convenient for user operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of a lawn trimmer provided by the present application;

[0028] Figure 2 This is a partial structural diagram of a lawn trimmer provided by the present application. Figure 1 ;

[0029] Figure 3 is a side view of a lawn edge trimmer provided by the present application;

[0030] Figure 4 This is a partial structural diagram of a lawn trimmer provided by the present application. Figure 2 ;

[0031] Figure 5 This is a partial structural diagram of a lawn trimmer provided by the present application. Figure 3 ;

[0032] Figure 6 It is a partial structural schematic diagram of the connection assembly provided by this application;

[0033] Figure 7 is a partial structural cross-sectional view of a connection assembly provided in the present application;

[0034] Figure 8 yes Figure 7 A partial enlarged view of

[0035] Fig. 9 It is a circuit block diagram of a lawn trimmer provided by the present application;

[0036] Fig.10 This is a partial structural diagram of a lawn trimmer provided by the present application. Figure 4 ;

[0037] Fig.11 yes Fig.10 A magnified image of point A;

[0038] Fig.12 This is a partial structural diagram of a lawn trimmer provided by the present application. Figure 5 ;

[0039] Fig.13 This is a partial structural diagram of a lawn trimmer provided by the present application. Figure 6 ;

[0040] Fig.14 is a characteristic curve diagram of the motor provided by the present application;

[0041] Fig.15 It is a structural schematic diagram of another lawn edge trimmer provided in the present application. DETAILED DESCRIPTION

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] In the present 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, and the like. 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).

[0047] 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.

[0048] 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.

[0049] See also Figure 1 The present application provides an electric tool 100, which is a mechanical tool for trimming lawns, plants, etc. It can be a long-pole trimmer. The electric tool 100 is described as a lawn edger.

[0050] See also Figures 1 to 5 The lawn trimmer includes an output shaft 110, a front housing 210, a rear housing 220, a connecting assembly 300, a motor 400 and a transmission assembly 500. The output shaft 110 is used to install a blade 120 for cutting grass, the front housing 210 accommodates at least part of the output shaft 110, the rear housing 220 is formed with a coupling portion 221 for coupling with a battery pack 600, the connecting assembly 300 is used to connect the front housing 210 and the rear housing 220, and the motor 400 is installed to the rear housing 220. The transmission assembly 500 is used to realize power transmission between the motor 400 and the output shaft 110, so that the motor 400 can drive the output shaft 110 to rotate, so that the blade 120 rotates to achieve cutting.

[0051] In some embodiments, the connection assembly 300 includes a connection tube 310 for connecting the front housing 210 and the rear housing 220 , and the transmission assembly 500 includes a transmission shaft at least partially disposed in the connection tube 310 , and the connection tube 310 protects the transmission shaft.

[0052] In other embodiments, the connection assembly 300 includes a connection tube 310, and the connection tube 310 is used to connect the front housing 210 and the rear housing 220. The transmission assembly 500 includes a first transmission shaft 510, a second transmission shaft 520, and a connection shaft 530, wherein the first transmission shaft 510 is used to connect with the motor 400 and is disposed at the rear end of the connection tube 310, the second transmission shaft 520 is used to drive the output shaft 110, and the connection shaft 530 connects the first transmission shaft 510 and the second transmission shaft 520, and the connection shaft 530 is at least partially disposed in the connection tube 310.

[0053] The first transmission shaft 510 is connected to the motor 400 through a gear mechanism, a first gear is provided on the motor shaft 410 of the motor 400, a second gear is provided on the first transmission shaft 510, and the first gear is meshed with the second gear. The first gear and the second gear may be spur gears. The first transmission shaft 510 is connected to the connecting shaft 530 through a first joint, and the second transmission shaft 520 is connected to the connecting shaft 530 through a second joint. The second transmission shaft 520 is connected to the output shaft 110 through a gear mechanism, a third gear is provided on the second transmission shaft 520, a fourth gear is provided on the output shaft 110, and the third gear is meshed with the fourth gear. The third gear and the fourth gear may be helical gears.

[0054] The lawn edge trimmer further includes a main handle 710 and an auxiliary handle 720. The main handle 710 is mounted to the connection assembly 300 for the user to hold, and the main handle 710 is located between the rear housing 220 and the auxiliary handle 720. Both the main handle 710 and the auxiliary handle 720 are connected to the connection pipe 310. In this embodiment, the auxiliary handle 720 extends to the upper side of the connection pipe 310. When the operator is operating, one hand holds the main handle 710 and the other hand holds the auxiliary handle 720, which is convenient for holding.

[0055] In one embodiment, at least a portion of the connecting tube 310 is bent and extended so that the blade 120 is away from the operator to ensure operational safety. Since the connecting tube 310 is bent, the connecting shaft 530 located in the connecting tube 310 also needs to be bent, so the connecting shaft 530 is set as a flexible shaft, and the torque is transmitted through the flexible shaft, and the flexible shaft can withstand a larger torque.

[0056] like Figure 1 , Figures 6 to 8 As shown, the connecting tube 310 includes a straight tube portion 311 and a curved tube portion 312 connected to each other, the straight tube portion 311 is connected to the rear shell 220, and the curved tube portion 312 is connected to the front shell 210. Among them, the main handle 710 and the auxiliary handle 720 are both arranged at the rear end of the connecting tube 310. This arrangement of the straight tube portion 311 at the rear and the curved tube portion 312 at the front is convenient for the user to operate at the rear end, so that the blade 120 at the front end is away from the operator. Generally, the operator stands on the left side of the connecting tube 310 to hold the main handle 710 and the auxiliary handle 720, so the bending direction of the connecting tube 310 is toward the right side of the connecting tube 310, so that the blade 120 at the front end is away from the operator.

[0057] The bending angle of the curved tube portion 312 relative to the straight tube portion 311 is greater than or equal to 135° and less than or equal to 155°. In some embodiments, the bending angle of the curved tube portion 312 relative to the straight tube portion 311 is greater than or equal to 140° and less than or equal to 150°. In some embodiments, the bending angle of the curved tube portion 312 relative to the straight tube portion 311 is equal to 150°. By bending smoothly, vibration and noise are reduced. Figure 6 α represents the bending angle of the curved tube portion 312 relative to the straight tube portion 311 .

[0058] The radius of curvature of the curved tube portion 312 is greater than or equal to 400 mm and less than or equal to 500 mm. In some embodiments, the radius of curvature of the curved tube portion 312 is greater than or equal to 420 mm and less than or equal to 480 mm. In one embodiment, the radius of curvature of the curved tube portion 312 is 450 mm.

[0059] When the bending angle of the curved tube portion 312 relative to the straight tube portion 311 is equal to 150° and the curvature radius of the curved tube portion 312 is 450 mm, it can meet the use requirements and effectively reduce noise and vibration.

[0060] Along the direction parallel to the straight tube portion 311, the length of the connecting tube 310 is greater than or equal to 1400 mm. With a greater length, the blade 120 is farther away from the operator and the operating range is larger. In one embodiment, the connecting shaft 530 can withstand at least 27 N·m of torque. The diameter of the connecting shaft 530 is greater than or equal to 5 mm and less than or equal to 7 mm. In some embodiments, the diameter of the connecting shaft 530 can be 6 mm. The length of the connecting shaft 530 is greater than or equal to 1350 mm and less than or equal to 1500 mm. In some embodiments, the length of the connecting shaft 530 is greater than or equal to 1400 mm and less than or equal to 1450 mm.

[0061] The rotation axis of the output shaft 110 is substantially perpendicular to the extension direction of the straight tube portion 311 , so that the blade 120 is as far away from the operator as possible and the blade 120 is convenient for cutting in a vertical plane.

[0062] In some embodiments, the connecting tube 310 may be a carbon fiber tube. Carbon fiber is an existing material, and the carbon fiber tube has the advantages of high strength, long life, corrosion resistance, light weight, low density, etc. It can not only reduce weight, but also maintain high strength when bent. In other embodiments, the connecting tube 310 includes an aluminum tube and a nylon tube, the nylon tube is inserted into the aluminum tube, and the connecting shaft 530 is at least partially disposed in the nylon tube.

[0063] In some embodiments, see Fig. 9, the lawn trimmer also includes a first communication unit 610 and a terminal device 620. The first communication unit 610 is a wireless communication unit, which can send information to the terminal device 620 or receive information from the terminal device 620. The terminal device 620 includes a second communication unit 621, and the first communication unit 610 is connected to the second communication unit 621 by wireless communication, and the terminal device 620 can display the status information of the lawn trimmer. By displaying the status information of the lawn trimmer on the terminal device 620, it is convenient for users to understand the working status of the lawn trimmer in time without being restricted by location. Through the terminal device 620, users can understand the machine information on the APP, monitor the working status of the machine, and upgrade and update the machine. In some embodiments, the first communication unit 610 and the second communication unit 621 are both Bluetooth units. In some embodiments, the first communication unit 610 and the second communication unit 621 are both ZigBee units. In other embodiments, the first communication unit 610 and the second communication unit 621 are both WIFI units. The working principle of the wireless communication connection is a prior art and will not be repeated here. Among them, the terminal device 620 can be a mobile phone, a tablet or a computer.

[0064] The lawn trimmer also includes a detection module 630 and a control module 640. The detection module 630 is used to detect the operating parameters or electrical parameters of the motor 400. The control module 640 is used to determine whether the motor 400 is in a stalled operating state according to the operating parameters or electrical parameters, and control the motor 400 to stop rotating when in the stalled operating state. The detection module 630 and the control module 640 cooperate to realize the brake protection function. After the blade 120 is stalled, the motor 400 can be stopped immediately in time, and the motor 400 will not continue to rotate with the flexible shaft, thereby preventing the flexible shaft from twisting off.

[0065] The operating parameter may be a rotation speed, including but not limited to the rotation speed of the motor 400 and the rotation speed of the output shaft 110. When the rotation speed of the motor 400 is greater than or equal to a first set value, and the rotation speed of the output shaft 110 is less than or equal to a second set value, the control module 640 determines that the motor 400 is in a stalled operation state. The electrical parameter may be the current of the motor 400. The detection module 630 detects the current current value of the motor 400, and the control module 640 determines whether the current current value is greater than a preset current threshold value. If so, it is determined that the motor 400 is in a stalled operation state.

[0066] like Fig.10 and Fig.11 As shown, the lawn trimmer also includes a display component 810, which at least displays the speed information of the lawn trimmer, so that the user can intuitively obtain the current speed information, and even if the speed information changes due to accidental contact, it can be processed in time, which is convenient to operate and improves work efficiency.

[0067] The speed information may be the speed information of the output shaft 110, so that the user can obtain the speed of the blade 120 in a timely manner. The speed information may also be the speed information of the motor 400, so that the user can obtain the state of the motor 400 in a timely manner. It is understood that the lawn trimmer also includes a speed sensor for detecting the speed of the motor 400 or the output shaft 110.

[0068] In some embodiments, the display component 810 includes a display screen. Information is displayed on the display screen for intuitive observation. The display screen can be a touch screen for adjusting the speed. In other embodiments, the display component 810 includes a display light. Information is displayed by the display light, and the failure rate is low. Different colors of lights can represent different speed gears, for example, red represents the first gear, orange represents the second gear, and green represents the third gear. It is also possible to set multiple speed display lights 811, and several of the multiple speed display lights 811 are lit to indicate the speed of the lawn trimmer. For example, in this embodiment, the lawn trimmer has three speed gears, namely low speed gear, medium speed gear and high speed gear. Correspondingly, the display component 810 includes three speed display lights 811, and if one speed display light 811 is on, it means that the lawn trimmer is in low speed gear, if two speed display lights 811 are on, it means that the lawn trimmer is in medium speed gear, and if three speed display lights 811 are on, it means that the lawn trimmer is in high speed gear. For example, when in low gear, the rotation speed of blade 120 is greater than or equal to 3800 rpm and less than or equal to 4200 rpm, when in medium gear, the rotation speed of blade 120 is greater than or equal to 5300 rpm and less than or equal to 5700 rpm, and when in high gear, the rotation speed of blade 120 is greater than or equal to 6800 rpm and less than or equal to 7200 rpm.

[0069] In some embodiments, the speed information includes a speed gear or a speed value. The speed gear can be divided into a low speed gear, a medium speed gear and a high speed gear.

[0070] In some embodiments, the display component 810 can display the remaining power of the battery pack 600 to facilitate timely charging. For example, the display component 810 includes a power display light 812, and different colors of the power display light 812 represent different power levels, such as red represents little power, orange represents less power, and green represents sufficient power.

[0071] In some embodiments, the display component 810 can display the current efficiency or current or torque.

[0072] The display assembly 810 includes a display interface, and the display interface can display speed information. For example, in the present embodiment, the three speed display lights 811 can be considered as the display interface. Of course, the display interface can also be considered to include a power display light 812 and a Bluetooth display light 813 described below. A speed regulating member 820 is provided on one side of the display interface, and the display interface and the speed regulating member 820 are provided at a position close to each other, so as to facilitate observation while adjusting the speed. Specifically, the distance between the speed regulating member 820 and the display interface is less than or equal to 10 cm. The speed regulating member 820 can be a speed regulating button, and the speed can be adjusted by pressing. The speed can be changed once per pressing, or the speed can be switched by pressing different durations. For example, in the present embodiment, the speed regulating member 820 can be operated so that the lawn trimmer switches cyclically between a low gear, a medium gear, and a high gear.

[0073] The display assembly 810 is disposed on the housing of the main handle 710. The housing of the main handle 710 is sleeved on the connecting tube 310, the display assembly 810 is disposed on the upper side of the housing of the main handle 710, and the speed regulating member 820 and the display assembly 810 are disposed on the same side of the main handle 710, so as to facilitate observation while adjusting the speed. Specifically, the speed regulating member 820 is located at the rear end of the display interface, and the display interface will not be blocked when the speed regulating member 820 is operated.

[0074] See also Figure 3 The housing of the main handle 710 is also provided with a trigger 830, and the trigger 830 and the display assembly 810 are provided on opposite sides of the main handle 710. The trigger 830 is provided on the lower side of the housing of the main handle 710 and is located at the rear end of the main handle 710. Generally, the thumb of the right hand can operate the speed regulating member 820 when the main handle 710 is held by the right hand, and the other four fingers of the right hand can operate the trigger 830. The speed regulating member 820 and the trigger 830 can be operated by one hand.

[0075] The display component 810 also includes a display unit for displaying the connection status of the first communication unit 610. For example, the display unit includes a Bluetooth display light 813. When the Bluetooth display light 813 flashes, the first communication unit 610 is in a waiting state, and when the Bluetooth display light 813 is always on, the first communication unit 610 is in a connected state. The first communication unit 610 can be a Bluetooth unit or a WIFI unit. The first communication unit 610 is used to send information to the terminal device 620 or receive information from the terminal device 620.

[0076] See also Figure 1 , Figure 2 and Fig.12 The lawn edge trimmer further comprises a guard 130, which is used to surround at least part of the blade 120. It can not only prevent the blade 120 from hurting the operator, but also prevent the grass fragments from splashing.

[0077] See also Fig.12 The blade 120 rotates around a rotation axis in a cutting plane, and a guide protrusion 131 is circumferentially provided on the outer circumference of the shield 130, and the guide protrusion 131 is located in the cutting plane. By providing the guide protrusion 131 and the guide protrusion 131 being located in the cutting plane, it is convenient for the user to align the blade according to the guide protrusion 131 on the shield 130, so that the user can align the curb more clearly, and the cost and weight can be reduced.

[0078] In the process of disassembling and assembling the blade 120 of the existing lawn trimmer, a large force is required to clamp the gear box, so the gear box may crack.

[0079] See also Fig.13 The output shaft 110 is provided with a flange 140, a notch 141 is provided on the flange 140, and a shield hole 132 is provided on the shield 130, and the shield hole 132 is communicated with the notch 141. When removing the blade 120, one end of the tool 150 passes through the shield hole 132 and is inserted into the notch 141 to fix the output shaft 110, so that the blade 120 can be easily removed. The tool 150 is stuck on the shield 130 instead of the gear box to avoid damaging the gear box, thereby protecting the gear box from cracking.

[0080] Specifically, a limiting rib is provided on the shield 130, and the shield hole 132 is opened on the limiting rib, or the limiting rib surrounds the shield hole 132. The tool 150 can be an existing wrench.

[0081] See also Figure 1 , Figure 2 , Fig.12 and Fig.13 The lawn edge trimmer further includes a support assembly, which includes a running wheel 160 for supporting the lawn edge trimmer on the ground. Specifically, the running wheel 160 is rotatably arranged on the shield 130. The running wheel 160 supports the lawn edge trimmer. When in use, the running wheel 160 can be placed on the ground to push the lawn edge trimmer forward to achieve cutting, saving manpower.

[0082] The support assembly further includes a support plate 170 disposed on one side of the guard 130. When the lawn edge trimmer is placed on the ground, the support plate 170 supports the lawn edge trimmer to prevent the lawn edge trimmer from tipping over.

[0083] When the motor 400 is in the state of maximum efficiency, the ratio of the output power of the motor 400 to the weight of the lawn edge trimmer is greater than or equal to 180W / kg, indicating that the output power of the motor 400 is large and the mass is small, and it has a high power density, so that the performance of the machine is improved while the weight of the whole machine is kept in a light state, which is convenient for users to operate. In some embodiments, when the motor 400 is in the state of maximum efficiency, the ratio of the output power of the motor 400 to the weight of the lawn edge trimmer is greater than or equal to 200W / kg. In some embodiments, when the motor 400 is in the state of maximum efficiency, the ratio of the output power of the motor 400 to the weight of the lawn edge trimmer is greater than or equal to 250W / kg. In some embodiments, when the motor 400 is in the state of maximum efficiency, the ratio of the output power of the motor 400 to the weight of the lawn edge trimmer can be 200W / kg, 220W / kg, 240W / kg, 250W / kg, 260W / kg, 280W / kg.

[0084] The output power of the motor 400 is greater than or equal to 1000 W. In some embodiments, the output power of the motor 400 is greater than or equal to 1200 W. In some embodiments, the output power of the motor 400 is greater than or equal to 1400 W. In some embodiments, the output power of the motor 400 is 1000 W, 1100 W, 1200 W, 1300 W, 1400 W, 1500 W.

[0085] The nominal voltage of the battery pack 600 is greater than or equal to 40V, which improves the performance of the machine and is suitable for more working conditions, such as cutting harder stones. In some embodiments, the nominal voltage of the battery pack 600 is greater than or equal to 56V. In some embodiments, the nominal voltage of the battery pack 600 is greater than or equal to 80V.

[0086] Among them, the output power of the motor 400 when the motor 400 is in the maximum efficiency state is: the characteristic curve of the motor 400 is obtained by measurement, and the maximum efficiency point of the motor 400 is found from the characteristic curve. The output power corresponding to the maximum efficiency point is the output power when the motor 400 is in the maximum efficiency state.

[0087] Fig.14 The characteristic curve diagram of the motor 400 is shown in the figure, in which multiple curves are shown with different lines, wherein the horizontal coordinate of each curve is torque, represented by T, and the unit is N·m, and the vertical coordinate of each curve is different. For the convenience of distinction, different line types and letters are used to represent it. Each curve is specifically: N represents the speed, the unit is r / min, Pout represents the output power, the unit is W, Pin represents the input power, the unit is W, U represents the voltage, the unit is V, I represents the current, the unit is A, η represents the efficiency percentage, and η1 represents the maximum efficiency point in the figure. In this embodiment, the efficiency at the maximum efficiency point is 83.8%, and the corresponding output power is 1284.48W.

[0088] The weight of the lawn edge trimmer is less than or equal to 5.5 kg. In some embodiments, the weight of the lawn edge trimmer is less than or equal to 5 kg. In some embodiments, the weight of the lawn edge trimmer is less than or equal to 4.8 kg. In some embodiments, the weight of the lawn edge trimmer can be 5.5 kg, 5.0 kg, 4.8 kg, 4.5 kg, 3.5 kg, 3.0 kg.

[0089] The weight of the lawn edge trimmer refers to the weight of the main body of the lawn edge trimmer, excluding the battery pack 600 but including the blade 120 and the auxiliary handle 720 .

[0090] In another embodiment, if Fig.15 As shown, as another lawn edge trimmer 900, it is Figure 1 The lawn edge trimmers in FIG. 1 have substantially the same structure, the main difference being that the connecting pipe 910 extends in a straight line. Figure 1 All lawn trimmers are suitable for Fig.14 The structures of the lawn edge trimmer 900 in the above description can all be applied to the lawn edge trimmer 900, and will not be described in detail.

[0091] 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. A lawn trimmer, comprising: An output shaft for mounting a blade that cuts the grass; a guard for surrounding at least a portion of the blade; A front housing, accommodating at least a portion of the output shaft; A rear housing having a coupling portion for coupling with a battery pack; a motor mounted to the rear housing to drive the output shaft; A connecting assembly, used to connect the front housing and the rear housing; A transmission assembly, used to realize power transmission between the motor and the output shaft; It is characterized in that, when the motor is in a state of maximum efficiency, the ratio of the output power of the motor to the weight of the lawn trimmer is greater than or equal to 180 W / kg.

2. The lawn edge trimmer according to claim 1, characterized in that: When the motor is in a state of maximum efficiency, the ratio of the output power of the motor to the weight of the lawn trimmer is greater than or equal to 200 W / kg.

3. The lawn edge trimmer according to claim 1, characterized in that: The output power of the motor is greater than or equal to 1000W.

4. The lawn edge trimmer according to claim 3, characterized in that: The output power of the motor is greater than or equal to 1200W.

5. The lawn edge trimmer according to claim 1, characterized in that: The weight of the lawn edge trimmer is less than or equal to 5.5 kg.

6. The lawn edge trimmer according to claim 1, characterized in that: The connecting assembly comprises a connecting pipe, and the connecting pipe is used to connect the front shell and the rear shell, and at least a part of the connecting pipe is bent and extended.

7. The lawn edge trimmer according to claim 6, characterized in that: The transmission assembly comprises: A first transmission shaft, used to be connected to the motor and arranged at the rear end of the connecting pipe; A second transmission shaft, used to drive the output shaft; A connecting shaft connects the first transmission shaft and the second transmission shaft, and the connecting shaft is at least partially disposed in the connecting tube, and the connecting shaft is a flexible shaft.

8. The lawn edge trimmer according to claim 6, characterized in that: The connecting pipe includes a straight pipe portion and a curved pipe portion connected to each other, the straight pipe portion is connected to the rear shell, the curved pipe portion is connected to the front shell, and the bending angle of the curved pipe portion relative to the straight pipe portion is greater than or equal to 135° and less than or equal to 155°.

9. The lawn edge trimmer according to claim 8, characterized in that: The curvature radius of the curved pipe portion is greater than or equal to 400 mm and less than or equal to 500 mm.

10. The lawn edge trimmer according to claim 8, characterized in that: Along a direction parallel to the straight pipe portion, the length of the connecting pipe is greater than or equal to 1400 mm.

11. The lawn edge trimmer according to claim 1, characterized in that: Also includes: a first communication unit; The terminal device comprises a second communication unit, the first communication unit is connected to the second communication unit by wireless communication, and the terminal device can display the status information of the lawn trimmer.

12. The lawn edge trimmer according to claim 11, characterized in that: The first communication unit and the second communication unit are both Bluetooth units.

13. The lawn edge trimmer according to claim 1, characterized in that: Also includes: A detection module, used for detecting operating parameters or electrical parameters of the motor; The control module is used to determine whether the motor is in a stalled operation state according to the operation parameters or electrical parameters, and control the motor to stop when in the stalled operation state.

14. The lawn edge trimmer according to claim 1, characterized in that: The connecting assembly includes a connecting pipe, which includes a straight pipe portion and a curved pipe portion connected to each other. The straight pipe portion is connected to the rear housing, and the curved pipe portion is connected to the front housing. The rotation axis of the output shaft is substantially perpendicular to the extension direction of the straight pipe portion.

15. The lawn edge trimmer according to claim 1, characterized in that: The connection assembly comprises a connection tube, and the connection tube is a carbon fiber tube.

16. An electric tool comprising: An output shaft for mounting a blade that cuts the grass; a guard for surrounding at least a portion of the blade; A front housing, accommodating at least a portion of the output shaft; A rear housing having a coupling portion for coupling with a battery pack; a motor mounted to the rear housing to drive the output shaft; A connecting assembly, comprising a connecting pipe for connecting the front housing and the housing; A transmission assembly, used to realize power transmission between the motor and the output shaft; Wherein, the transmission assembly comprises: A first transmission shaft, used to be connected to the motor and arranged at the rear end of the connecting pipe; A second transmission shaft, used to drive the output shaft; a connecting shaft, connecting the first transmission shaft and the second transmission shaft, wherein the connecting shaft is at least partially disposed in the connecting tube; It is characterized in that, when the motor is in a state of maximum efficiency, a ratio of the output power of the motor to the weight of the electric tool is greater than or equal to 180 W / kg.

17. The electric tool according to claim 16, characterized in that: When the motor is in a state of maximum efficiency, a ratio of the output power of the motor to the weight of the electric tool is greater than or equal to 200 W / kg.

18. The electric tool according to claim 16, characterized in that: The output power of the motor is greater than or equal to 1000W.

19. The electric tool according to claim 16, characterized in that: The weight of the electric tool is less than or equal to 5.5 kg.

20. The electric tool according to claim 16, characterized in that Also includes: a first communication unit; The terminal device includes a second communication unit, the first communication unit is wirelessly connected to the second communication unit, and the terminal device can display status information of the electric tool.

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