Electric tool

Abstract

The invention provides an electric tool, a connecting pipe used by the electric tool is at least provided with a first material layer made of a carbon fiber material and a second material layer made of a non-carbon fiber material in the radial direction of the connecting pipe, the rigidity of the second material layer is smaller than that of the first material layer, and the toughness of the second material layer is larger than that of the first material layer. According to the connecting pipe, on one hand, the weight is small, so that the electric tool is lighter, and an operator can work more easily; and on the other hand, due to the fact that the connecting pipe has good rigidity and toughness, the connecting pipe has good impact resistance and buffering resistance, when the connecting pipe transversely falls off and collides with a ground protruding structure, the connecting pipe is not prone to breakage or large deformation damage, and the hand feeling of a user is better in the using process.

Description

A power tool

[0001] This application claims priority to Chinese patent application filed on May 25, 2023, with application number 202310601918.0, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present application, including the embodiments of the present invention, relates to the technical field of power tools, and more particularly to a power tool. Background Art

[0003] In some power tools, such as lawn mowers and high-branch saws, the connecting pipes connecting the working head assembly (such as the cutting unit) and the grip assembly are generally metal pipes (such as aluminum pipes). Based on users' strong demand for lightweight power tools, some manufacturers are currently considering using connecting pipes made of lightweight all-carbon fiber to replace traditional metal pipes. However, although the connecting pipes made of all-carbon fiber material are light in weight, their vibration absorption and anti-buffering properties are poor, resulting in unsatisfactory performance of the power tool. In addition, the use of all-carbon fiber material directly increases the cost of the entire connecting pipe, which brings great trouble to manufacturers.

[0004] Summary of the Invention

[0005] In order to overcome the defects of the prior art, the problem to be solved by the embodiments of the present disclosure is to provide an electric tool with a connecting pipe that is light in weight, has satisfactory impact resistance and anti-buffering performance, and is low in cost.

[0006] In order to achieve the above-mentioned purpose, the embodiment of the present disclosure provides the following technical solutions: an electric tool, comprising a working head assembly, wherein the working head assembly includes a working head; a power assembly, wherein the power assembly drives the working head; a battery pack, wherein the battery pack supplies power to the power assembly; a grip assembly for a user to grip; a connecting tube, arranged between the working head assembly and the grip assembly, wherein the connecting tube is arranged with at least a first material layer made of carbon fiber material and a second material layer made of non-carbon fiber material, wherein the stiffness of the second material layer is less than the stiffness of the first material layer, and the toughness of the second material layer is greater than the toughness of the first material layer.

[0007] In one embodiment, the total thickness of the second material layers accounts for 50% to 80% of the total wall thickness of the connecting pipe.

[0008] In one embodiment, the second material layer is a glass fiber layer.

[0009] In one embodiment, the second material layer includes axial fiber bundles extending along the axial direction of the connecting tube, and the total thickness of the axial fiber bundles in the radial direction of the connecting tube accounts for greater than or equal to 80% of the total thickness of the second material layer.

[0010] In one embodiment, the outermost layer of the connecting tube in the radial direction is a carbon fiber outer layer formed by the first material layer.

[0011] In one embodiment, the carbon fiber outer layer and the adjacent material layer have different fiber arrangement directions.

[0012] In one embodiment, the first material layer includes axial fiber bundles extending along the axial direction of the connecting tube, and the total thickness of the axial fiber bundles in the radial direction of the connecting tube accounts for greater than or equal to 40% of the total thickness of the first material layer.

[0013] In one embodiment, the number of the first material layers is configured as one layer, and the carbon fiber outer layer is a woven structure composed of multiple fiber bundles; or, the number of the first material layers is configured as greater than or equal to two layers, and the carbon fiber outer layer is a woven structure composed of multiple fiber bundles, and the remaining first material layers are arranged on the inner side of the carbon fiber outer layer in the radial direction of the connecting tube to form a carbon fiber inner layer, and the carbon fiber inner layer includes the axial fiber bundles arranged and extended along the axial direction of the connecting tube, and the ratio of the total layer thickness of the axial fiber bundles to the total layer thickness of the carbon fiber inner layer is greater than or equal to 50%.

[0014] In one embodiment, the total weight of the power tool is less than or equal to 7 kg, the wall thickness of the connecting tube is 1.5 mm to 2.0 mm, and the ratio of the impact energy that the connecting tube can withstand to the wall thickness of the connecting tube is greater than or equal to 58 J / mm.

[0015] In one embodiment, the electric tool is a lawn mower, the total weight of the lawn mower is less than or equal to 7 kg, the battery pack is arranged at one end of the connecting tube located at the grip assembly, the power assembly is arranged at one end of the connecting tube located at the working head assembly, and the wall thickness of the connecting tube is 1.5 mm to 1.8 mm.

[0016] In one embodiment, the weight of the bare power tool, i.e., after removing the battery pack, is 4.2 kg to 5.5 kg. The power tool is a high-branch saw, which includes a connecting assembly, one end of the connecting assembly is provided with the working head assembly, and the other end is provided with the battery pack, the power assembly and the grip assembly. The connecting assembly includes a telescopic tube and a handle tube, and the handle tube is connected to the grip assembly. The telescopic tube includes an inner tube and an outer tube, and the inner tube is at least partially coaxially slidably nested in the outer tube and one end of which is connected to the working head assembly. A locking member is also provided between the inner tube and the outer tube to keep the two relatively fixed. The outer tube is arranged between the inner tube and the handle tube, and the connecting tube is configured as the outer tube.

[0017] In order to overcome the defects of the prior art, the problem to be solved by the embodiments of the present disclosure is to provide an electric tool with a connecting pipe that is light in weight, has satisfactory impact resistance and anti-buffering performance, and is low in cost.

[0018] In order to achieve the above-mentioned objectives, the embodiments of the present disclosure provide the following technical solutions: an electric tool, comprising a working head assembly, the working head assembly comprising a working head; a power assembly, the power assembly driving the working head; a battery pack, the battery pack supplying power to the power assembly; a grip assembly for a user to grip; a connecting tube, arranged between the working head assembly and the grip assembly, the connecting tube having at least a first material layer and a second material layer arranged in its radial direction, the first material layer being a carbon fiber layer, and the second material layer being a glass fiber layer.

[0019] In one embodiment, the total thickness of the glass fiber layers accounts for 50% to 80% of the total wall thickness of the connecting pipe.

[0020] In one embodiment, the glass fiber layer includes axial fiber bundles extending along the axial direction of the connecting tube, and the total thickness of the axial fiber bundles in the radial direction of the connecting tube accounts for more than or equal to 80% of the total thickness of the glass fiber layer.

[0021] In one embodiment, the outermost layer of the connecting pipe in the radial direction is a carbon fiber outer layer formed by the carbon fiber layer.

[0022] In one embodiment, the carbon fiber outer layer and the adjacent material layer have different fiber arrangement directions.

[0023] In one embodiment, the carbon fiber layer includes axial fiber bundles extending along the axial direction of the connecting tube, and the total thickness of the axial fiber bundles of the carbon fiber layer in the radial direction of the connecting tube accounts for a ratio of greater than or equal to 40% of the total layer thickness of the carbon fiber layer.

[0024] In one embodiment, the number of carbon fiber layers is configured as one layer, and the carbon fiber outer layer is a woven structure composed of multiple fiber bundles; or, the number of carbon fiber layers is configured as greater than or equal to two layers, and the carbon fiber outer layer is a woven structure composed of multiple fiber bundles, and the remaining carbon fiber layers are arranged on the inner side of the carbon fiber outer layer in the radial direction of the connecting tube to form a carbon fiber inner layer, and the carbon fiber inner layer includes the axial fiber bundles arranged and extended along the axial direction of the connecting tube, and the ratio of the total layer thickness of the axial fiber bundles to the total layer thickness of the carbon fiber inner layer is greater than or equal to 50%.

[0025] In one embodiment, the total weight of the power tool is less than or equal to 7 kg, the wall thickness of the connecting tube is 1.5 mm to 2.0 mm, and the ratio of the impact energy that the connecting tube can withstand to the wall thickness of the connecting tube is greater than or equal to 58 J / mm.

[0026] In one embodiment, the electric tool is a lawn mower, the total weight of the lawn mower is less than or equal to 7 kg, the battery pack is arranged at one end of the connecting tube located at the grip assembly, the power assembly is arranged at one end of the connecting tube located at the working head assembly, and the wall thickness of the connecting tube is 1.5 mm to 1.8 mm.

[0027] In one embodiment, the weight of the bare power tool, i.e., after removing the battery pack, is 4.2 kg to 5.5 kg. The power tool is a high-branch saw, which includes a connecting assembly, one end of the connecting assembly is provided with the working head assembly, and the other end is provided with the battery pack, the power assembly and the grip assembly. The connecting assembly includes a telescopic tube and a handle tube, and the handle tube is connected to the grip assembly. The telescopic tube includes an inner tube and an outer tube, and the inner tube is at least partially coaxially slidably nested in the outer tube and one end of which is connected to the working head assembly. A locking member is also provided between the inner tube and the outer tube to keep the two relatively fixed. The outer tube is arranged between the inner tube and the handle tube, and the connecting tube is configured as the outer tube.

[0028] In order to overcome the defects of the prior art, the problem to be solved by the embodiments of the present disclosure is to provide an electric tool with a split connecting pipe that is light in weight, has satisfactory impact resistance and anti-buffering performance, and is low in cost.

[0029] In order to achieve the above-mentioned purpose, the embodiment of the present disclosure provides the following technical solutions: an electric tool, comprising a working head assembly, wherein the working head assembly includes a working head; a power assembly, wherein the power assembly drives the working head; a battery pack, wherein the battery pack supplies power to the power assembly; a grip assembly for a user to grip; a connecting tube, wherein the connecting tube includes a first connecting tube connected to the working head assembly and a second connecting tube connected to the grip assembly, wherein the first connecting tube and / or the second connecting tube are arranged in a radial direction with at least a first material layer made of carbon fiber material and a second material layer made of non-carbon fiber material, wherein the stiffness of the second material layer is less than the stiffness of the first material layer, and the toughness of the second material layer is greater than the toughness of the first material layer.

[0030] In one embodiment, the total thickness of the second material layers in the first connecting tube accounts for 50% to 80% of the total wall thickness of the first connecting tube.

[0031] In one embodiment, the second material layer of the first connecting pipe is a glass fiber layer.

[0032] In one embodiment, the second material layer of the first connecting tube includes an axial fiber bundle extending along the axial direction of the first connecting tube, and the ratio of the total thickness of the axial fiber bundle in the radial direction of the first connecting tube to the total layer thickness of the second material layer is greater than or equal to 80%.

[0033] In one embodiment, the outermost layer of the first connecting tube in the radial direction is a carbon fiber outer layer formed by the first material layer.

[0034] In one embodiment, the carbon fiber outer layer of the first connecting tube and the adjacent material layer have different fiber arrangement directions.

[0035] In one embodiment, the first material layer of the first connecting tube includes axial fiber bundles extending along the axial direction of the first connecting tube, and the total thickness of the axial fiber bundles in the radial direction of the first connecting tube accounts for a ratio of greater than or equal to 40% of the total layer thickness of the first material layer.

[0036] In one embodiment, the number of the first material layers of the first connecting tube is configured as one layer, and the carbon fiber outer layer of the first connecting tube is a woven structure composed of multiple fiber bundles; or, the number of the first material layers of the first connecting tube is configured as greater than or equal to two layers, and the carbon fiber outer layer of the first connecting tube is a woven structure composed of multiple fiber bundles, and the remaining first material layers are arranged on the inner side of the carbon fiber outer layer in the radial direction of the first connecting tube to constitute a carbon fiber inner layer, and the carbon fiber inner layer of the first connecting tube includes the axial fiber bundles arranged and extended along the axial direction of the first connecting tube, and the ratio of the total layer thickness of the axial fiber bundles to the total layer thickness of the carbon fiber inner layer is greater than or equal to 50%.

[0037] In one embodiment, the total thickness of the second material layers in the second connecting pipe accounts for 50% to 80% of the total wall thickness of the second connecting pipe.

[0038] In one embodiment, the second material layer of the second connecting pipe is a glass fiber layer.

[0039] In one embodiment, the second material layer of the second connecting tube includes axial fiber bundles extending along the axial direction of the second connecting tube, and the total thickness of the axial fiber bundles in the radial direction of the second connecting tube accounts for greater than or equal to 80% of the total layer thickness of the second material layer.

[0040] In one embodiment, the outermost layer of the second connecting pipe in the radial direction is a carbon fiber outer layer composed of the carbon fiber layer.

[0041] In one embodiment, the carbon fiber outer layer of the second connecting tube has a different fiber arrangement direction from that of the adjacent material layer.

[0042] In one embodiment, the first material layer of the second connecting tube includes an axial fiber bundle extending along the axial direction of the second connecting tube, and the total thickness of the axial fiber bundle in the radial direction of the second connecting tube accounts for a ratio of greater than or equal to 40% of the total layer thickness of the first material layer.

[0043] In one embodiment, the number of the first material layers of the second connecting tube is configured as one layer, and the carbon fiber outer layer is a woven structure composed of multiple fiber bundles; or, the number of the first material layers of the second connecting tube is configured as greater than or equal to two layers, the carbon fiber outer layer of the second connecting tube is a woven structure composed of multiple fiber bundles, and the remaining first material layers are arranged on the inner side of the carbon fiber outer layer in the radial direction of the second connecting tube to form a carbon fiber inner layer, and the carbon fiber inner layer of the second connecting tube includes the axial fiber bundles arranged and extended along the axial direction of the second connecting tube, and the ratio of the total layer thickness of the axial fiber bundles to the total layer thickness of the carbon fiber inner layer is greater than or equal to 50%.

[0044] The problem to be solved by the embodiments of the present disclosure is to provide an electric tool with an outer tube that is light in weight, has satisfactory impact resistance and anti-buffering performance, and is low in cost, and an inner tube that is light in weight, has satisfactory impact resistance and anti-bending performance.

[0045] The technical solution adopted by the embodiment of the present disclosure to solve the problems of the prior art is: an electric tool, the electric tool comprising: a working head assembly, the working head assembly comprising a working head; a power assembly, the power assembly driving the working head; a battery pack, the battery pack supplying power to the power assembly; a grip assembly for a user to grip; a connecting assembly, arranged between the working head assembly and the grip assembly; one end of the connecting assembly is provided with the working head assembly, the other end is provided with the battery pack, the power assembly and the grip assembly, the connecting assembly comprises a first connecting tube, a second connecting tube and a handle tube, the handle tube is connected to the grip assembly The first connecting tube is close to the working head assembly relative to the second connecting tube, the second connecting tube is connected to the first connecting tube, and the second connecting tube is close to the holding assembly relative to the first connecting tube, and is characterized in that: the first connecting tube is arranged with at least a carbon fiber layer made of carbon fiber material in its radial direction, and the second connecting tube is arranged with at least a carbon fiber layer made of carbon fiber material in its radial direction, wherein the proportion of the total layer thickness of the carbon fiber layers in the first connecting tube to the total wall thickness of the first connecting tube is greater than the proportion of the total layer thickness of the carbon fiber layers in the second connecting tube to the total wall thickness of the second connecting tube.

[0046] In one embodiment, the first connecting tube and the second connecting tube constitute a telescopic tube, the first connecting tube is configured as the inner tube of the telescopic tube, the second connecting tube is configured as the outer tube of the telescopic tube, the inner tube is at least partially coaxially slidably nested in the outer tube and one end of which is connected to the working head assembly, and a locking member is further provided between the inner tube and the outer tube to keep the two relatively fixed, and the outer tube is arranged between the inner tube and the handle tube.

[0047] In one embodiment, the total thickness of the carbon fiber layers in the inner tube accounts for 100% of the total wall thickness of the inner tube.

[0048] In one embodiment, the inner tube is provided with at least two carbon fiber layers in its radial direction, the carbon fiber layer located on the outermost radial layer of the inner tube is a woven structure composed of multiple fiber bundles, and the remaining carbon fiber layers are unidirectional structures composed of multiple fiber bundles.

[0049] In one embodiment, the unidirectional structure includes an axial structure and a circumferential structure, a plurality of fiber bundles extending axially along the inner tube constitute the axial structure, and a plurality of fiber bundles extending circumferentially along the inner tube constitute the circumferential structure, wherein the ratio of the total layer thickness of the carbon fiber layer adopting the axial structure to the total layer thickness of the carbon fiber layer adopting the circumferential structure is 3:2.

[0050] In one embodiment, the outer tube is further provided with one or at least two glass fiber layers made of glass fiber material in the radial direction, and the total thickness of the glass fiber layers accounts for 50% to 80% of the total wall thickness of the outer tube.

[0051] In one embodiment, the glass fiber layer of the outer tube includes axial fiber bundles extending along the axial direction of the outer tube, and the total thickness of the axial fiber bundles in the radial direction of the outer tube accounts for greater than or equal to 80% of the total layer thickness of the glass fiber layer.

[0052] In one embodiment, the outermost layer of the outer tube in the radial direction is a carbon fiber outer layer composed of the carbon fiber layer.

[0053] In one embodiment, the carbon fiber outer layer of the outer tube and the adjacent material layer have different fiber arrangement directions.

[0054] In one embodiment, the carbon fiber layer of the outer tube includes axial fiber bundles extending along the axial direction of the outer tube, and the total thickness of the axial fiber bundles in the radial direction of the outer tube accounts for greater than or equal to 40% of the total thickness of the carbon fiber layer.

[0055] In one embodiment, the number of the carbon fiber layers of the outer tube is configured as one layer, and the carbon fiber outer layer is a woven structure composed of multiple fiber bundles; or, the number of the carbon fiber layers of the outer tube is configured as greater than or equal to two layers, the carbon fiber outer layer of the outer tube is a woven structure composed of multiple fiber bundles, and the remaining carbon fiber layers are arranged on the inner side of the carbon fiber outer layer in the radial direction of the outer tube to constitute a carbon fiber inner layer, and the carbon fiber inner layer of the outer tube includes the axial fiber bundles extending along the axial direction of the outer tube, and the total thickness of the axial fiber bundles in the radial direction of the outer tube accounts for a ratio of greater than or equal to 60% of the total layer thickness of the carbon fiber layers.

[0056] In one embodiment, the handle tube is a metal tube.

[0057] Compared with the prior art, in the above-mentioned preferred embodiment of the present invention, under the premise that the connecting tube uses carbon fiber material, by adding glass fiber and controlling the thickness ratio of the glass fiber layer and the carbon fiber layer, the ratio of the glass fiber and carbon fiber usage is controlled, so that the connecting tube has the advantages of both toughness and stiffness, and has better impact resistance when it falls. Compared with the connecting tube made of all carbon fiber, it has better toughness, lower vibration feel during use, good anti-buffering performance, and lower material cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0059] FIG1 is a schematic structural diagram of a material layer adopting a woven structure;

[0060] FIG2 is a schematic structural diagram of an axial structure in which the fiber extension direction of the material layer is parallel to the axial direction of the tube body in a unidirectional structure;

[0061] FIG3 is a cross-sectional view of one structure of a connecting pipe when the number of the first material layer, i.e., the carbon fiber layer, and the second material layer, i.e., the glass fiber layer, are both configured as one layer;

[0062] FIG4 is a cross-sectional view of another structure of the connecting pipe when the number of the first material layer, i.e., the carbon fiber layer, and the second material layer, i.e., the glass fiber layer, are both configured as one layer;

[0063] FIG5 is a cross-sectional view of one structure of a connecting pipe when the number of the first material layer, i.e., the carbon fiber layer, is configured as one layer and the number of the second material layer, i.e., the glass fiber layer, is configured as two or more layers;

[0064] FIG6 is a cross-sectional view of another structure of the connecting pipe when the number of the first material layer, i.e., the carbon fiber layer, is configured as one layer and the number of the second material layer, i.e., the glass fiber layer, is configured as two or more layers;

[0065] FIG7 is a cross-sectional view of one structure of a connecting pipe when the number of first material layers, i.e., carbon fiber layers, is configured to be two or more layers, and the number of second material layers, i.e., glass fiber layers, is configured to be one layer;

[0066] FIG8 is a cross-sectional view of another structure of the connecting pipe when the number of the first material layer, i.e., the carbon fiber layer, is configured to be two or more layers, and the number of the second material layer, i.e., the glass fiber layer, is configured to be one layer;

[0067] FIG9 is a cross-sectional view of another structure of the connecting pipe when the number of the first material layer, i.e., the carbon fiber layer, is configured to be two or more layers, and the number of the second material layer, i.e., the glass fiber layer, is configured to be one layer;

[0068] FIG10 is a cross-sectional view of one structure of a connecting pipe when the number of the first material layer, i.e., the carbon fiber layer, and the second material layer, i.e., the glass fiber layer, are both configured to be greater than or equal to two layers;

[0069] FIG11 is a cross-sectional view of another structure of the connecting pipe when the number of the first material layer, i.e., the carbon fiber layer, and the second material layer, i.e., the glass fiber layer, are both configured to be greater than or equal to two layers;

[0070] FIG12 is a cross-sectional view of a preferred structure of a connecting pipe provided in the present application;

[0071] FIG13 is a schematic diagram of a limiting structure protruding from the inner wall of the connecting pipe;

[0072] FIG14 is a schematic structural diagram of the cooperation between the limiting structure and the lining of FIG13;

[0073] FIG15 is a schematic structural diagram of a clamp having a C-shaped portion;

[0074] FIG16 is a schematic structural diagram of a clamp having a U-shaped portion;

[0075] FIG17 is a schematic structural diagram of a front-mounted grass trimmer using the connecting pipe provided by the present application;

[0076] FIG18 is a schematic structural diagram of an existing rear-mounted grass trimmer;

[0077] FIG19 is a schematic structural diagram of a high-branch saw using the telescopic tube provided by the present application;

[0078] FIG20 is a schematic structural diagram of a multi-working head electric tool using the split connecting pipe provided in this application. DETAILED DESCRIPTION

[0079] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0080] In the field of power tools, most power tools require users to hold them for a long time to operate. Therefore, it is important to minimize the weight of the power tools, especially for power tools with a connecting tube 10, such as lawn mowers, high-branch saws, and brush cutters. Typically, the power tools 100, 200, 300, and 400 with a connecting tube 10 include a working head assembly 20, a power assembly, a battery pack 30, and a grip assembly 40, wherein the working head assembly 20 includes a working head 201, the power assembly includes a motor that provides driving force for the power tool and a control board that controls the rotation of the motor, and the battery pack 30 supplies power to the motor. The battery pack 30 is preferably a lithium battery pack and is detachably mounted on the connecting tube 10 at one end of the grip assembly 40. The grip assembly 40 is for the user to hold and is provided with an operating switch for the user to operate the tool.

[0081] The connecting tube 10 can serve as a connecting component to connect the working head assembly 20 and the grip assembly 40 of the power tool. In some power tools 100, 200, and 300, the connecting tube 10 is a single-piece tube structure. In some multi-working head power tools 400, the connecting tube 10 can be a split tube, including a first connecting tube 107 and a second connecting tube 108. The first connecting tube 107 is connected to the various working head assemblies 20, and the second connecting tube 108 is connected to the grip assembly 40. The working head assembly 20 and the grip assembly 40 of the power tool 400 are connected through the first connecting tube 107 and the second connecting tube 108. For ease of understanding, taking the lawn mower 100, 200 or the electric tool 400 with a grass trimmer working head as an example, one end of the connecting tube 10 or the second connecting tube 108 in the connecting tube 10 can be connected to the gripping assembly 40 of the lawn mower 100, 200 or the electric tool 400 with a multi-tool head (the gripping assembly 40 is used to be held and manipulated by the operator at one end) and the other end of the connecting tube 10 or the first connecting tube 107 in the connecting tube 10 can be connected to the working head assembly 20 of the lawn mower 100, 200 or the electric tool 400 with a multi-tool head (the working head assembly 20 is the end that performs the grass trimming task). Taking the high-branch saw 300 as an example, the connecting pipe 10 can be used as a part of the connecting component connecting the gripping assembly 40 of the high-branch saw 300 (the gripping assembly 40 is the end of the high-branch saw 300 used by the operator to hold and manipulate and adjust the height of the working head assembly 20 relative to the ground) and the working head assembly 20 (the working head assembly 20 is the end that performs trimming of high trees).

[0082] At present, the technical route of reducing the weight of the connecting tube 10 can be used to meet the demand for lightweight. However, based on the actual use scenarios of such tools, the connecting tube 10 must have good impact resistance to prevent the connecting tube from breaking due to the tool falling, causing the parts connected to the connecting tube 10 to fly out and cause injuries. In order to solve the above problems, some manufacturers have tried to use all-carbon fiber materials to make the connecting tube 10. Although it takes into account the requirements of lightweight and impact resistance, some new problems have arisen in the actual process for some specific power tools. For example, the lawn mowers 100 and 200, although the all-carbon fiber connecting tube 10 meets the requirements of lightweight and impact resistance, during use, the connecting tube 10 will transmit the vibration of the working head assembly 20 during the cutting process to the grip assembly 40, and the user will experience numbness in the hands and poor physical sensation. Another example is the high-branch saw 300. The connecting tube 10 of this type of product generally adopts a telescopic tube 10 consisting of an inner tube 101 and an outer tube 102. Based on the usage scenario and usage method of the high-branch saw 300, the inner tube 101 is connected to the working head assembly 20 and when it falls, it is usually the inner tube 101 that collides with the ground or a sharp object, and the outer tube 102 is closer to the user's grip. Therefore, the stiffness requirement of the outer tube 102 relative to the inner tube 101 does not need to be particularly strict. Instead, relative to the inner tube 101, the outer tube 102 needs to have better usage comfort, that is, to reduce the numbness of the user's hands. The outer tube 102 made of all-carbon fiber material has redundant impact resistance and poor anti-buffering performance, and the use of all-carbon fiber solution further leads to increased costs and low cost performance.

[0083] In this application, by improving the structure, material and other aspects of the connecting tube 10 to meet the requirements of lightweight, impact resistance and anti-buffering performance, the comprehensive mechanical properties are improved, so that the power tools 100, 200, 300, 400 using the connecting tube 10 have a better user experience, and the material cost can also be further reduced.

[0084] This connecting tube 10 is made of a composite of different types of fibers. Its main structure includes a first material layer 103 made of carbon fiber material and a second material layer 104 made of non-carbon fiber material arranged in the radial direction. The main components of the first material layer 103 and the second material layer 104 are both fibers, but the fiber types are different. Furthermore, the difference between the second material layer 104, which uses a different fiber type from the first material layer 103 made of carbon fiber material, is that the stiffness of the second material layer 104 is less than the stiffness of the first material layer 103, that is, the elastic modulus of the fibers used to make the second material layer 104 is less than the elastic modulus of the carbon fiber, and the toughness of the second material layer 104 is greater than the toughness of the first material layer 103, that is, the fracture strain of the fibers used to make the second material layer 104 is greater than the fracture strain of the carbon fiber. This material selection allows the connecting tube 10 to achieve lightweight compared to existing aluminum tubes while also meeting the requirements of toughness and stiffness.

[0085] In the present application, the material of the first material layer 103 is carbon fiber, and the material of the second material layer 104 is glass fiber or Kevlar fiber, preferably glass fiber, that is, the connecting tube 10 is a composite tube composed of glass fiber and carbon fiber. Among them, the reason why the material of the second material layer 104 is preferably glass fiber is because glass fiber has good toughness and a certain degree of rigidity, which can significantly improve the toughness of the entire connecting tube 10, and the reason why the material of the first material layer 103 is preferably carbon fiber is because carbon fiber has high rigidity and a certain degree of rigidity, which can ensure the rigidity of the entire connecting tube 10, so that the connecting tube 10 can better meet the working requirements of connection, support, and force. In this way, the second material layer 104 of glass fiber mainly enhances the toughness and supplements the rigidity, while the first material layer 103 of carbon fiber mainly enhances the rigidity and supplements the toughness, so that the toughness and rigidity of the connecting tube 10 are both excellent, so that the comprehensive mechanical properties of the connecting tube 10 are improved.

[0086] At the same time, the present application also limits the proportion of carbon fiber and glass fiber, that is, the number of the second material layer 104 is configured as one layer or at least two layers, and the total layer thickness of the second material layer 104 accounts for 50% to 80% of the total wall thickness of the connecting tube 10. Correspondingly, the number of the first material layer 103 is configured as one layer or at least two layers, and the total layer thickness of the first material layer 103 accounts for 20% to 50% of the total wall thickness of the connecting tube 10. For example, the total layer thickness of the second material layer 104 accounts for 55% of the total wall thickness of the connecting tube 10, the total layer thickness of the first material layer 103 accounts for 45% of the total wall thickness of the connecting tube 10, or the total layer thickness of the second material layer 104 accounts for 55% of the total wall thickness of the connecting tube 10. The total thickness of the first material layer 103 accounts for 60% of the total wall thickness of the connecting tube 10, and the total thickness of the first material layer 103 accounts for 40% of the total wall thickness of the connecting tube 10, or the total thickness of the second material layer 104 accounts for 65% of the total wall thickness of the connecting tube 10, and the total thickness of the first material layer 103 accounts for 35% of the total wall thickness of the connecting tube 10, or the total thickness of the second material layer 104 accounts for 70% of the total wall thickness of the connecting tube 10, and the total thickness of the first material layer 103 accounts for 30% of the total wall thickness of the connecting tube 10, or the total thickness of the second material layer 104 accounts for 75% of the total wall thickness of the connecting tube 10, and the total thickness of the first material layer 103 accounts for 25% of the total wall thickness of the connecting tube 10, etc. If the total thickness of the first material layer 103 of carbon fiber is too large, it means that the total thickness of the second material layer 104 of glass fiber is too small, which will make the stiffness of the connecting tube 10 meet the requirements, but the overall toughness is poor; if the total thickness of the first material layer 103 of carbon fiber is too small, it means that the total thickness of the second material layer 104 of glass fiber is too large, which will make the toughness of the connecting tube 10 meet the requirements, but the overall stiffness is low. Therefore, by limiting the proportion of the total thickness of the first material layer 103 and the second material layer 104, the toughness and stiffness of the connecting tube 10 can be better matched, meeting the requirements of anti-buffering performance and impact resistance, further optimizing the comprehensive mechanical properties of the connecting tube 10, and having good vibration absorption characteristics and excellent anti-buffering performance during use. At the same time, in order to be similar to the mechanical properties of existing aluminum tubes, it is preferred that the total thickness of the second material layer 104 accounts for 75% of the total wall thickness of the connecting tube 10, and the total thickness of the first material layer 103 accounts for 25% of the total wall thickness of the connecting tube 10.

[0087] By setting the wall thickness of the connecting tube 10 within the range of 1.5 mm to 2.0 mm, such as 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, etc., it can be close to or the same as the wall thickness of the existing aluminum tube, so that it can replace the aluminum tube and be directly connected to the working head assembly 20 and the gripping assembly 40.

[0088] When the above-mentioned connecting tube 10 is used as the connecting tube 10 of the power tools 100, 200, 300, 400 such as the lawn mower 100, 200 to connect the gripping assembly 40 and the working head assembly 20, on the one hand, its weight is reduced compared with the aluminum tube, so that the power tools 100, 200, 300, 400 are lighter, and the operator can more easily load the power tools 100, 200, 300, 400 to work; on the other hand, because the connecting tube 10 has good rigidity and toughness, the overall impact resistance and anti-buffering performance of the connecting tube 10 are better.

[0089] When the connecting tube 10 falls horizontally, the raised structure on the ground will impact the middle part of the connecting tube 10 in the axial direction. In order to prevent the connecting tube 10 from breaking or deforming significantly, it is preferred to set the outermost layer of the connecting tube 10 in its radial direction to be a carbon fiber outer layer 105 composed of the first material layer 103.

[0090] Specifically, in the radial direction of the connecting tube 10, the first material layer 103 and the second material layer 104 are arranged sequentially, and the outermost layer of the connecting tube 10 in the radial direction is provided as a carbon fiber outer layer 105 composed of the first material layer 103. The number of first material layers 103 is configured as one, and this first material layer 103 serves as the carbon fiber outer layer 105. The remaining second material layers 104 are all wrapped, nested within, and connected to the carbon fiber outer layer 105, and the second material layers 104 form the inner sidewall of the connecting tube 10. Alternatively, the number of first material layers 103 is configured as two or more, and the outermost layer of the connecting tube 10 in the radial direction is the carbon fiber outer layer 105 composed of the first material layer 103. The remaining first material layers 103 and second material layers 104 are arranged sequentially as required and are wrapped, nested within, and connected to the carbon fiber outer layer 105. One of the remaining first material layers 103 or the second material layers 104 forms the inner sidewall of the connecting tube 10. Because the stiffness of the first material layer 103 is greater than that of the second material layer 104, the present application sets the radial outermost layer of the connecting tube 10 as the carbon fiber outer layer 105 composed of the first material layer 103. Compared with the connecting tube 10 with the second material layer 104 made of glass fiber as the radial outermost layer, when the connecting tube 10 falls and collides with the raised structure on the ground, even if it is bumped, the damage will be less, so that the connecting tube 10 has excellent vertical axial impact resistance and good surface appearance performance.

[0091] In the present application, the basic shape of the fiber is filamentous or linear, that is, the basic component units of the first material layer 103 and the second material layer 104 are fiber filaments, a large number of fiber filaments are assembled to form a fiber bundle 106, and multiple fiber bundles 106 are arranged in different ways to form different fiber structures.

[0092] On this basis, the first material layer 103 includes axial fiber bundles extending along the axial direction of the connecting tube 10, wherein the total thickness of the axial fiber bundles in the radial direction of the connecting tube 10 is controlled to be greater than 40% of the total layer thickness of the first material layer 103, so that the connecting tube 10 has the required stiffness performance.

[0093] Further, in an optional embodiment, the number of first material layers 103 is configured to be one layer, which is the carbon fiber outer layer 105, and the carbon fiber outer layer 105 is a woven structure composed of multiple fiber bundles 106; or, the number of first material layers 103 is configured to be greater than or equal to two layers, wherein one first material layer 103 constitutes the carbon fiber outer layer 105, and the carbon fiber outer layer 105 is a woven structure composed of multiple fiber bundles 106, and the remaining first material layers 103 are arranged on the inner side of the carbon fiber outer layer 105 in the radial direction of the connecting tube 10 to constitute a carbon fiber inner layer 103, and these carbon fiber inner layers 103 can be a unidirectional structure or a woven structure composed of multiple fiber bundles 106.

[0094] As shown in Figure 1, the molding structure of the carbon fiber outer layer 105 or part of the carbon fiber inner layer 103 is a woven structure, that is, during the molding process, multiple parallel fiber filaments are gathered into a fiber bundle 106, and then half of all the fiber bundles 106 are extended along the first direction, and the remaining half are extended along the second direction. There is a certain angle between the first direction and the second direction, such as 60 degrees, 90 degrees or 120 degrees, and then the fiber bundles 106 along the first direction and the fiber bundles 106 along the second direction are cross-extended to form a woven structure (this process is similar to the weaving process of cloth), that is, the fiber bundles 106 in the first direction and the fiber bundles 106 in the second direction are cross-woven. Such a setting can make the fiber bundles 106 of the carbon fiber outer layer 105 and part of the carbon fiber inner layer 103 extend and connect along different directions (i.e., the first direction and the second direction), so that the stiffness of the carbon fiber outer layer 105 and part of the carbon fiber inner layer 103 is improved, and at the same time, the impact resistance of the carbon fiber outer layer 105 and part of the carbon fiber inner layer 103 is also improved, thereby further improving the mechanical properties of the carbon fiber outer layer 105 and part of the carbon fiber inner layer 103.

[0095] As shown in Figure 2, the molding structure of part of the carbon fiber inner layer 103 is a unidirectional structure in which the fiber bundles 106 extend in the same direction, for example, extending axially along the connecting tube 10. That is to say, a carbon fiber inner layer 103 includes a circumferential axial structure composed of axial fiber bundles 106 extending along the axial direction of the connecting tube 10. Such an arrangement can further improve the bending stiffness and axial strength of the connecting tube 10, thereby further improving the impact resistance of the connecting tube 10. At the same time, it can also improve the rigidity of the carbon fiber inner layer 103 and optimize the mechanical properties of the carbon fiber inner layer 103.

[0096] In the above optional embodiment, the number of the first material layer 103 is configured to be greater than or equal to two layers, the carbon fiber outer layer 105 adopts a woven structure, and the remaining carbon fiber inner layers 103 can all adopt a unidirectional structure or partially adopt a unidirectional structure and partially adopt a woven structure. Among them, the unidirectional structure preferably adopts an axial structure in which the fiber bundles 106 are extended and arranged along the axial direction of the connecting tube 10. By controlling the ratio of the total layer thickness of the carbon fiber inner layer 103 adopting the axial structure to the total layer thickness of the carbon fiber inner layer 103 to be greater than or equal to 50%, the connecting tube 10 can have better impact resistance and ensure the continuity of the overall strength of the connecting tube 10.

[0097] In an optional embodiment, the second material layer 104 can be arranged according to the same principle as in the above embodiment, that is, the number of the second material layer 104 is configured as one layer, and the second material layer 104 is a woven structure or a unidirectional structure composed of multiple fiber bundles 106. If a unidirectional structure is selected, it is preferred to use an axial structure in which the fiber bundles 106 are all arranged parallel to the axial direction of the connecting tube 10; or, the number of the second material layer 104 is configured as more than two layers, and the second material layer 104 can all adopt a unidirectional structure or partially adopt a unidirectional structure and partially adopt a woven structure. In the unidirectional structure, the fiber bundles 106 are all arranged parallel to the axial direction of the connecting tube 10. The axial structure formed by the parallel arrangement is mainly, or it can be understood that the second material layer 104 includes an axial fiber bundle 106 extending and arranged along the axial direction of the connecting tube 10. By controlling the ratio of the total layer thickness of the second material layer 104 adopting the axial structure to the total layer thickness of the second material layer 104, that is, the total thickness of the axial fiber bundle 106 in the radial direction of the connecting tube 10 accounts for the total layer thickness of the second material layer 104. The ratio is greater than or equal to 80%, so that the elongation at break δ of the connecting tube 10 is ≥2.5%, so as to have good toughness and vibration absorption performance. Compared with aluminum tubes with the same wall thickness, under the same operating conditions, the connecting tube 10 of the present application has less vibration and better feel to use.

[0098] In the present application, as shown in FIG1 , the weaving direction of the weaving structure refers to the extension direction of each of the two intersecting fiber bundles 106, and the bisector of the angle b between the two fiber bundles 106 is also made to extend along the axial direction of the connecting tube 10. In other words, the angle c between the two fiber bundles 106 and the axis of the connecting tube 10 is the same in size and is half of the angle b between the two fiber bundles 106. In this way, by making the bisector of the angle between the first direction and the second direction parallel to the axial direction of the connecting tube 10, the weaving structure forming the connecting tube 10 can be made into a symmetrical structure. When the connecting tube 10 is subjected to an impact perpendicular to the axial direction (i.e., radial direction), the symmetrical structure can further enhance the impact resistance of the connecting tube 10. Therefore, it is preferred that the weaving structure is arranged symmetrically about the axial direction.

[0099] It should be noted that the angle between the first and second directions and the axial direction should not be too large or too small. If the angle between the first and second directions and the axial direction is too large, the fiber layer will have low toughness but high stiffness. If the angle between the first and second directions and the axial direction is too small, the fiber layer will have high toughness but low stiffness. Preferably, the angle between the first and second directions and the axial direction is 45 degrees.

[0100] Furthermore, the extension direction of the fiber bundle 106 in the unidirectional structure is the same as the axial direction of the connecting tube 10 (the extension direction of the fiber bundle 106 in this case is shown in FIG2 ) to form an axial fiber bundle 106, that is, the fiber bundle 106 constituting the unidirectional structure extends along the axial direction of the connecting tube 10 to form an axial structure. Alternatively, the extension direction of the fiber bundle 106 in the unidirectional structure can be made the same as the circumferential direction of the connecting tube 10, that is, the fiber bundle 106 constituting the unidirectional structure and the axial direction of the connecting tube 10 are perpendicular to each other in the horizontal plane. Since the unidirectional structure in which the fiber bundle 106 extends in a single direction is more suitable for a single force direction (this force direction is, for example, a direction perpendicular to the axial direction), the toughness of the connecting tube 10 can be further improved by setting the extension direction of the fiber bundle 106 in the unidirectional structure along the axial direction of the connecting tube 10.

[0101] Alternatively, the fiber bundle 106 of the unidirectional structure may no longer extend in a straight line, but may be extended in a spiral, specifically, extended in a spiral around the axis of the connecting tube 10, so that the extension direction of the fiber bundle 106 of the unidirectional structure and the axial direction of the connecting tube 10 have an angle greater than 0 degrees and less than 90 degrees. The angle greater than 0 degrees and less than 90 degrees refers to dividing the spiral structure into a plurality of spiral segments of smaller lengths. Since the length of each spiral segment is small, the spiral segment can be approximately regarded as a straight segment. The angle between the straight segment and the axis of the connecting tube 10 ranges from 0 degrees to 90 degrees, for example, it can be 30 degrees, 45 degrees or 60 degrees, etc. The larger the angle, the smaller the pitch of the spiral structure. The unidirectional structure formed in this way can also make the connecting tube 10 have good comprehensive performance in all directions, so that when it is used as the connecting tube 10 of the power tool, it can improve the performance of the power tool.

[0102] Furthermore, based on the above two embodiments, the arrangement direction of the fiber bundle 106 of the carbon fiber outer layer 105, which is the radially outermost layer of the connecting tube 10, is set to be different from the fiber arrangement direction of the material layer adjacent to it. It is preferred that the carbon fiber outer layer 105, which is the radially outermost layer of the connecting tube 10, adopts a woven structure, and the remaining first material layers 103 and / or second material layers 104 can select fiber arrangement directions that meet the setting requirements.

[0103] For example, the number of the first material layer 103 is configured as one layer, and the number of the second material layer 104 is also configured as one layer. The first material layer 103 is the carbon fiber outer layer 105, and the carbon fiber outer layer 105 adopts a woven structure, and the arrangement direction of the fiber bundles 106 of the woven structure (see FIG1 for the arrangement direction) is different from the arrangement direction of the fiber bundles 106 of the second material layer 104, that is, the second material layer 104 adopts a unidirectional structure, and no matter whether the fiber bundles 106 of the unidirectional structure extend along the axial direction, the circumferential direction or the spiral direction around the axis of the connecting tube 10, they are all in the same direction as the woven structure of the carbon fiber outer layer 105. The braiding directions of the first material layer 103, i.e., the carbon fiber outer layer 105, are different. For example, as shown in FIG3 , the first material layer 103, i.e., the carbon fiber outer layer 105, adopts a braided structure, and the second material layer 104 adopts a unidirectional structure, and its fiber bundles 106 extend along the axial direction of the connecting tube 10. Alternatively, the second material layer 104 adopts a braided structure, and the braiding direction of the second material layer 104 is different from that of the carbon fiber outer layer 105. For example, as shown in FIG4 , the angle between the braiding direction of the second material layer 104 and the axial direction of the connecting tube 10 is 30 degrees, and the angle between the braiding direction of the carbon fiber outer layer 105 and the axial direction of the connecting tube 10 is 45 degrees. This arrangement can make the mechanical properties of the outer first material layer 103 and the inner second material layer 104 more prominent and more consistent.

[0104] For example, the number of first material layers 103 is configured as one layer, and the number of second material layers 104 is configured as two or more layers. The first material layer 103 is a carbon fiber outer layer 105, which adopts a woven structure, and the arrangement direction of the fiber bundles 106 of the woven structure (see FIG1 for the arrangement direction) is different from the arrangement direction of the fiber bundles 106 of the adjacent second material layer 104, that is, the second material layer 104 adjacent to the carbon fiber outer layer 105 adopts a unidirectional structure, and regardless of whether the fiber bundles 106 of the unidirectional structure extend along the axial direction, the circumferential direction, or the spiral direction around the axis of the connecting tube 10, they are all different from the weaving direction of the woven structure of the carbon fiber outer layer 105. The remaining second material layers 104 can all adopt a woven structure, or all adopt a unidirectional structure, or partially adopt a woven structure and partially adopt a unidirectional structure, wherein the unidirectional structure mainly selects an axial structure, and the total layer thickness of the second material layers 104 adopting the axial structure accounts for a ratio of greater than or equal to 80% of the total layer thickness of the second material layers 104. For example, as shown in FIG5 , the connecting tube 10 is radially arranged from the inside to the outside in the order of a second material layer 104 of a woven structure, a second material layer 104 of a unidirectional structure and a fiber bundle 106 extending axially along the connecting tube 10, and a first material layer 103 of a woven structure, i.e., a carbon fiber outer layer 105; or, the second material layer 104 adjacent to the carbon fiber outer layer 105 adopts a woven structure, and the weaving direction of the second material layer 104 is different from the weaving direction of the carbon fiber outer layer 105. For example, the angle between the weaving direction of the second material layer 104 and the axial direction of the connecting tube 10 is 30 degrees, and the angle between the weaving direction of the carbon fiber outer layer 105 and the axial direction of the connecting tube 10 is 45 degrees. The remaining second material layers 104 can all adopt a woven structure, or all adopt a unidirectional structure, or partially adopt a woven structure and partially adopt a unidirectional structure, wherein the unidirectional structure mainly selects an axial structure, and the total layer thickness of the second material layers 104 of the axial structure accounts for a ratio of greater than or equal to 80% of the total layer thickness of the second material layers 104. For example, referring to Figure 6, in the radial direction from the inside to the outside of the connecting tube 10, there are successively a second material layer 104 with a unidirectional structure and fiber bundles 106 extending along the axial direction of the connecting tube 10, a second material layer 104 with a unidirectional structure and fiber bundles 106 extending along the axial direction of the connecting tube 10, a second material layer 104 with a woven structure, and a first material layer 103 with a woven structure, i.e., a carbon fiber outer layer 105.

[0105] For example, the number of first material layers 103 is configured to be greater than two layers, and the number of second material layers 104 is configured to be one layer, wherein one first material layer 103 constitutes the radially outermost carbon fiber outer layer 105 of the connecting tube 10, and the remaining first material layers 103 are arranged radially inward of the carbon fiber outer layer 105 to constitute the carbon fiber inner layer 103. If one of the carbon fiber inner layers 103 is arranged adjacent to the carbon fiber outer layer 105, the carbon fiber outer layer 105 adopts a woven structure, and the arrangement direction of the fiber bundles 106 of the woven structure (see FIG. 1 for the arrangement direction) is different from the arrangement direction of the fiber bundles 106 of the carbon fiber inner layer 103. That is, the carbon fiber inner layer 105 adjacent to the carbon fiber outer layer 105 adopts a unidirectional structure, and no matter the fiber bundle 106 of the unidirectional structure extends along the axial direction, circumferential direction or spiral direction around the axis of the connecting tube 10, it is different from the weaving direction of the weaving structure of the carbon fiber outer layer 105. The remaining carbon fiber inner layers 103 can all adopt a woven structure, or all adopt a unidirectional structure, or partially adopt a woven structure and partially adopt a unidirectional structure, among which the unidirectional structure mainly selects the axial structure, and the total layer thickness of the carbon fiber inner layer 103 adopting the axial structure accounts for more than or equal to 50% of the total layer thickness of the carbon fiber inner layer 103, and the second material layer 104 with only one layer adopts the axial structure in the unidirectional structure. For example, as shown in Figure 7, in the radial direction of the connecting tube 10 From the inside to the outside, they are the first material layer 103 with a unidirectional structure and the fiber bundles 106 extending along the axial direction of the connecting tube 10, the second material layer 104 with a unidirectional structure and the fiber bundles 106 extending along the axial direction of the connecting tube 10, the first material layer 103 with a unidirectional structure and the fiber bundles 106 extending along the axial direction of the connecting tube 10, and the first material layer 103 with a woven structure, namely the carbon fiber outer layer 105; or, the carbon fiber inner layer 103 adjacent to the carbon fiber outer layer 105 adopts a woven structure, and the weaving direction of the carbon fiber inner layer 103 is different from the weaving direction of the carbon fiber outer layer 105, for example, the angle between the weaving direction of the carbon fiber inner layer 103 and the axial direction of the connecting tube 10 is 30 degrees, and the angle between the weaving direction of the carbon fiber outer layer 105 and the axial direction of the connecting tube 10 is 45 degrees. The remaining carbon fiber inner layers 103 can all adopt a woven structure, or all adopt a unidirectional structure, or partially adopt a woven structure and partially adopt a unidirectional structure, among which the unidirectional structure mainly selects an axial structure, and the total layer thickness of the carbon fiber inner layer 103 adopting the axial structure accounts for a ratio greater than or equal to 50% of the total layer thickness of the carbon fiber inner layer 103, and the second material layer 104 with only one layer adopts a unidirectional structure. For example, as shown in Figure 8, in the radial direction of the connecting tube 10, from the inside to the outside, there are the first material layer 103 with a unidirectional structure and the fiber bundle 106 extending along the axial direction of the connecting tube 10, the second material layer 104 with a unidirectional structure and the fiber bundle 106 extending along the axial direction of the connecting tube 10, the first material layer 103 with a woven structure, and the first material layer 103 with a woven structure, namely the carbon fiber outer layer 105.If the second material layer 104 is set to be adjacent to the carbon fiber outer layer 105, the carbon fiber outer layer 105 adopts a woven structure, the second material layer 104 adopts a unidirectional structure, and the fiber bundles 106 of the unidirectional structure extend in the axial direction, circumferential direction or spiral direction around the axis of the connecting tube 10, which are different from the weaving direction of the woven structure of the carbon fiber outer layer 105. For example, as shown in Figure 9, in the radial direction of the connecting tube 10, from the inside to the outside, there are the first material layer 103 with a unidirectional structure and the fiber bundles 106 extending in the axial direction of the connecting tube 10, the first material layer 103 with a unidirectional structure and the fiber bundles 106 extending in the axial direction of the connecting tube 10, the second material layer 104 with a unidirectional structure and the fiber bundles 106 extending in the axial direction of the connecting tube 10, and the first material layer 103 with a woven structure, namely the carbon fiber outer layer 105.

[0106] For example, the number of first material layers 103 is configured to be greater than or equal to two layers, and the number of second material layers 104 is configured to be greater than or equal to two layers, wherein one first material layer 103 constitutes the radially outermost carbon fiber outer layer 105 of the connecting tube 10, and the remaining first material layers 103 are arranged radially inward of the carbon fiber outer layer 105 in the connecting tube 10 to constitute the carbon fiber inner layer 103. If one of the carbon fiber inner layers 103 is arranged adjacent to the carbon fiber outer layer 105, the carbon fiber outer layer 105 adopts a woven structure, and the arrangement direction of the fiber bundles 106 of the woven structure (see FIG. 1 for the arrangement direction) is different from the arrangement direction of the fiber bundles 106 of the carbon fiber inner layer 103. That is, the carbon fiber inner layer 103 adjacent to the carbon fiber outer layer 105 adopts a unidirectional structure, and regardless of whether the fiber bundles 106 of the unidirectional structure extend in the axial direction, circumferential direction, or spiral direction around the axis of the connecting tube 10, they are all different from the weaving direction of the braided structure of the carbon fiber outer layer 105. The remaining carbon fiber inner layers 103 can all adopt a braided structure, or all adopt a unidirectional structure, or partially adopt a braided structure and partially adopt a unidirectional structure, wherein the unidirectional structure is mainly an axial structure, and the total layer thickness of the carbon fiber inner layers 103 adopting the axial structure accounts for greater than or equal to 50% of the total layer thickness of the carbon fiber inner layers 103. The second material layer 104 can all adopt a unidirectional structure, or partially adopt a braided structure and partially adopt a unidirectional structure, wherein the unidirectional structure is mainly an axial structure, and the total layer thickness of the second material layers 104 with the axial structure accounts for greater than or equal to 80% of the total layer thickness of the second material layers 104. For example, referring to Figure 10, in the radial direction of the connecting tube 10, from the inside to the outside, there are successively a first material layer 103 with a unidirectional structure and fiber bundles 106 extending along the axial direction of the connecting tube 10, a second material layer 104 with a unidirectional structure and fiber bundles 106 extending along the axial direction of the connecting tube 10, the first material layer 103 with a unidirectional structure and fiber bundles 106 extending along the axial direction of the connecting tube 10, the second material layer 104 with a unidirectional structure and fiber bundles 106 extending along the axial direction of the connecting tube 10, the first material layer 103 with a unidirectional structure and fiber bundles 106 extending along the axial direction of the connecting tube 10, and the first material layer 103 with a woven structure, namely the carbon fiber outer layer 105; or the carbon fiber inner layer 103 adjacent to the carbon fiber outer layer 105 adopts a woven structure, and the weaving direction of the carbon fiber inner layer 103 is different from the weaving direction of the carbon fiber outer layer 105, for example, the angle between the weaving direction of the carbon fiber inner layer 103 and the axial direction of the connecting tube 10 is 30 degrees, and the angle between the weaving direction of the carbon fiber outer layer 105 and the axial direction of the connecting tube 10 is 45 degrees. The remaining carbon fiber inner layers 103 can all adopt a woven structure, or all adopt a unidirectional structure, or partially adopt a woven structure and partially adopt a unidirectional structure, among which the unidirectional structure mainly selects an axial structure, and the total layer thickness of the carbon fiber inner layer 103 adopting the axial structure accounts for a ratio greater than or equal to 50% of the total layer thickness of the carbon fiber inner layer 103.The second material layer 104 may be entirely unidirectional, or partially woven and partially unidirectional. The unidirectional structure is primarily an axial structure, and the ratio of the total thickness of the second material layer 104 in the axial direction to the total thickness of the second material layer 104 is greater than or equal to 80%. For example, as shown in FIG11 , in the radial direction of the connecting tube 10, from the inside to the outside, the second material layer 104 in a unidirectional structure with fiber bundles 106 extending in the axial direction of the connecting tube 10, the second material layer 104 in a unidirectional structure with fiber bundles 106 extending in the axial direction of the connecting tube 10, the first material layer 103 in a unidirectional structure with fiber bundles 106 extending in the axial direction of the connecting tube 10, the second material layer 104 in a unidirectional structure with fiber bundles 106 extending in the axial direction of the connecting tube 10, the first material layer 103 in a woven structure, and the first material layer 103 in a woven structure, i.e., the carbon fiber outer layer 105.

[0107] At the same time, under the premise that the wall thickness range of the connecting tube 10 is determined, the thickness of each first material layer 103 and each second material layer 104 is further limited to 0.15mm~0.25mm, for example, 0.16mm, 0.18mm, 0.20mm, 0.22mm, 0.24mm, etc. Within this range, when the total thickness ratio of the first material layer 103 and the second material layer 104 remains unchanged, the number of the first material layer 103 or the second material layer 104 can be increased by reducing the thickness of a single first material layer 103 or the second material layer 104, thereby improving the impact toughness and stiffness of the connecting tube 10.

[0108] Such a setting can ensure that the strength of the outermost layer of the connecting tube 10 is high, while reducing the impact energy transmission in the radial direction of the connecting tube 10. Even when it falls and contacts the raised structure on the ground, the carbon fiber outer layer 105 can withstand most of the impact capacity, and avoid the remaining first material layer 103 or second material layer 104 wrapped by the carbon fiber outer layer 105 from being impacted as much as possible, causing cracks or breakage inside the connecting tube 10.

[0109] When the number of layers of the first material layer 103 and the second material layer 104 is greater than or equal to two, the most basic setting principle is that the outermost layer in the radial direction of the connecting tube 10 is formed of the first material layer 103 to form the carbon fiber outer layer 105, and the radial arrangement order of the remaining first material layers 103 and second material layers 104 on the connecting tube 10 is not particularly required. It is only necessary to ensure that the arrangement direction of the fiber bundles 106 of the carbon fiber outer layer 105 is different from the arrangement direction of the fiber bundles 106 of the adjacent material layers. For example, all the first material layers 103 can be concentrated on the outer side of the connecting tube 10 in the radial direction, and all the second material layers 104 can be concentrated on the inner side of the connecting tube 10 in the radial direction, or the carbon fiber outer layer 105, all the second material layers 104 and the remaining first material layers 103 can be arranged in sequence from the outside to the inside of the connecting tube 10 in the radial direction, or the carbon fiber outer layer 105, the second material layer 104 and the remaining first material layers 103 can be arranged alternately in sequence from the outside to the inside of the connecting tube 10 in the radial direction, etc.

[0110] On the basis of the above embodiments, a preferred structure is to arrange all the second material layers 104 together along the radial direction of the connecting tube 10, and the number of the second material layers 104 is five layers, of which two layers of the second material layers 104 adopt a woven structure, and three layers of the second material layers 104 adopt a unidirectional structure, and the two layers of the second material layers 104 adopting the woven structure are adjacent to the connecting tube 10 in the radial direction, and the three layers of the second material layers 104 adopting the unidirectional structure are adjacent to the connecting tube 10 in the radial direction, that is, the five layers of the second material layers 104 are arranged from the outside to the inside in the radial direction of the connecting tube 10 as the second material layer 104 with a woven structure, the second material layer 104 with a woven structure, the second material layer 104 with a unidirectional structure, the second material layer 104 with a unidirectional structure, and the second material layer 104 with a unidirectional structure, or the second material layer 104 with a unidirectional structure, the second material layer 104 with a unidirectional structure, the second material layer 104 with a woven structure, and the second material layer 104 with a woven structure. This arrangement can maximize the improvement of the toughness and vibration absorption performance of the connecting pipe 10 , and is therefore used as the preferred arrangement of the second material layer 104 of the connecting pipe provided in this application.

[0111] Furthermore, in combination with the above-described embodiments, a preferred structure for the entire connecting tube 10 can be obtained, namely, multiple second material layers 104 are arranged sequentially from the inside to the outside in the radial direction of the connecting tube 10 to form five fiber layers A, B, C, D, and E, and multiple first material layers 103 are arranged sequentially from the inside to the outside in the radial direction of the connecting tube 10 to form three fiber layers F, G, and H, wherein the fiber layer H located in the radially outermost layer of the connecting tube 10 adopts a twill weave structure. For example, the second material layers A, B, C, D, and E all adopt a unidirectional structure, and the fiber bundles 106 all extend in the axial direction of the connecting tube 10. The first material layer G adjacent to the first material layer H, i.e., the carbon fiber outer layer H, can adopt a unidirectional structure, or a woven structure, and the angle formed between its weaving direction and the axial direction of the connecting tube 10 is different from the angle formed between the weaving direction of the carbon fiber outer layer H and the axial direction of the connecting tube 10. The first material layer F can adopt a woven structure or a unidirectional structure. Alternatively, part of the second material layer A, the second material layer B, the second material layer C, the second material layer D and the second material layer E adopt a unidirectional structure, and part of them adopt a woven structure. By superimposing the unidirectional structure and the woven structure in the radial direction of the connecting tube 10, specifically, referring to Figure 12, the second material layer A, the second material layer B, and the second material layer C can adopt a unidirectional structure and the fiber bundle 106 extends along the axial direction of the connecting tube 10, the second material layer D and the second material layer E can adopt a woven structure, the first material layer F and the first material layer G can adopt a unidirectional structure and the fiber bundle 106 extends along the axial direction of the connecting tube 10, and the outermost carbon fiber outer layer H adopts a twill woven structure and the woven direction has an angle of, for example, 45 degrees with the axial direction of the connecting tube 10.

[0112] Specifically, the number of first material layers 103 is one or more than two, the number of second material layers 104 is one or more than two, and each fiber layer of the connecting tube 10 comprises epoxy resin. During the manufacturing process of the connecting tube 10, each fiber layer is immersed in a prepreg containing epoxy resin. This allows the connecting tube 10 to cure smoothly during the molding process, ensuring that each fiber layer is molded according to the preset structure, thereby more reliably improving the mechanical properties of the connecting tube 10. In the present application, the glass transition temperature of the epoxy resin in the connecting tube 10 is 140°C to 210°C. Manufacturing the connecting tube 10 within this temperature range ensures that the connecting tube 10 has good heat resistance, thereby helping to improve its mechanical properties. If the glass transition temperature of the epoxy resin is too high, the cost of the connecting tube 10 will increase; if the glass transition temperature of the epoxy resin is too low, the heat resistance of the connecting tube 10 will be poor. Preferably, the glass transition temperature of the epoxy resin is 170°C to 210°C.

[0113] The connecting tube 10 provided in this application is over 30% lighter than conventional aluminum tubes, and boasts an axial modulus of 60 GPa to 90 GPa, achieving stiffness comparable to aluminum tubes. Furthermore, it can pass a 1-meter drop test without bending, demonstrating superior impact resistance. Under the same operating conditions, power tools using this connecting tube 10 experience lower vibration and better cushioning performance than those using aluminum tubes.

[0114] As shown in FIG13 , a limiting structure 50 is protruding from the inner sidewall of the connecting tube 10. In some types of power tools, the working head assembly 20 and the power assembly are respectively disposed at either end of the connecting tube 10. For example, the power assembly driving the working head assembly 20 of a rear-mounted lawn mower 200 is located in the grip assembly 40. Therefore, a transmission structure is required within the connecting tube 10. To prevent radial vibration of the transmission structure within the connecting tube 10, an inner liner 60 is typically provided within the connecting tube 10. Furthermore, to prevent circumferential rotation of the inner liner 60 within the connecting tube 10, a limiting structure 50 is also provided on the inner sidewall of the connecting tube 10 and is mounted in conjunction with the inner liner 60. This limiting structure 50 can be a protrusion, as shown in FIG14 . The protrusion is embedded in the groove of the liner 60 to achieve circumferential positioning of the liner 60 within the connecting tube 10. The protrusion can extend in the axial direction of the connecting tube 10 to form a ridge, thereby more effectively positioning the liner 60 along the entire axial length of the connecting tube 10. As shown in FIG13 , the cross-sectional shape of the protrusion is trapezoidal or rectangular, and the width d of the protruding end of the protrusion away from the inner sidewall of the connecting tube 10 is less than 10 mm. At the same time, multiple protrusions can be arranged at equal intervals around the circumference of the connecting tube 10, such as 2, 3, or 4. The material of the limiting structure 50 can be the glass fiber or carbon fiber mentioned above, and its material is not limited to the material of the fiber layer forming the inner sidewall of the connecting tube 10. In other words, the material of the limiting structure 50 can be the same as or different from the material of the fiber layer forming the inner sidewall of the connecting tube 10. Alternatively, the limiting structure 50 can also be a groove opened in the inner sidewall of the connecting tube 10. In addition, the limiting structure 50 may not be provided on the inner side wall of the connecting pipe 10 . The connecting pipe 10 with such a structure can meet the working requirements of a front-mounted grass trimmer in which the motor is provided at the working head assembly 20 .

[0115] In addition, the connection between the connecting tube 10 and the housing of the grip assembly 40 is generally achieved by using a clamp 70. Referring to Figures 15 and 16 , the clamp 70 includes a C-shaped portion 701 or two U-shaped portions 702, with connecting portions 703 provided at the opening of the C-shaped portion 701 or on both sides of the opening of the two U-shaped portions 702. The connecting portions 703 are provided with through-holes 704 for screws to pass through. When connecting to the housing of the grip assembly 40, the connecting tube 10 is inserted into the housing of the grip assembly 40, and the clamp 70 is sleeved onto the connecting tube 10. The screws passing through the through-holes 104 are tightened onto the housing of the grip assembly 40, thereby tightening the clamp 70 to the connecting tube 10 and connecting the clamp 70 to the housing of the grip assembly 40, thereby achieving the connection between the connecting tube 10 and the grip assembly 40. Among them, the inner surface arc length of the C-shaped part 701 or the two U-shaped parts 702 is 30mm~50mm, the length of the connecting tube 10 wrapped therein is 15mm~90mm, and the connecting tube 10 is firmly connected to the holding assembly 40 through 2~6 clamps 70 arranged in its axial direction.

[0116] Furthermore, the connecting tube 10 is provided with a positioning hole (not shown in the figure) or a positioning groove (not shown in the figure) for positioning the clamp 70. When the structure provided on the connecting tube 10 is a positioning groove, the positioning groove is an annular groove extending along the axial direction of the connecting tube 10, and the width of the positioning groove matches the width of the C-shaped portion 701 or the U-shaped portion 702, so as to more firmly achieve the connection between the connecting tube 10 and the clamp 70; when the structure provided on the connecting tube 10 is a positioning hole, a fixing member such as a pin or a screw is passed through the C-shaped portion 701 or the U-shaped portion 702 and fixedly connected to the positioning hole, so as to more firmly achieve the connection between the connecting tube 10 and the clamp 70. The diameter of the positioning hole is 5mm to 8mm, and multiple positioning holes are provided in the circumferential direction of the connecting tube 10. At the same time, the distance between the positioning hole closest to the end of the connecting tube 10 and the end is not greater than 40mm, so as to further improve the connection firmness.

[0117] Normally, the weight of the entire power tool 100, 200, 300, 400 using the above-mentioned connecting tube 10 (including the weight of the battery pack) is less than or equal to 7 kg. Based on factors such as the type of tool, the operating conditions of the corresponding tool, and possible safety risks, there is a corresponding need to improve the weight, impact resistance, and anti-buffering performance of the connecting tube 10. For this reason, the connecting tube 10 provided in this application has the following characteristics: the ratio of the impact energy that the connecting tube 10 can withstand to its wall thickness is greater than or equal to 58 J / mm. Among them, the impact energy E is calculated by E=mgh, m represents the total mass of the power tool after assembly with the battery pack 30, g represents the gravity coefficient, and h represents the drop height of the entire machine. Compared with aluminum tubes of the same wall thickness, length, and diameter and in the same drop scenario, this connecting tube 10 can withstand greater impact energy.

[0118] In order to clearly and intuitively understand the connecting pipe 10 provided in the present application, a front-mounted grass trimmer 100 that meets the above-mentioned whole machine weight requirement, i.e., the whole machine weight is less than or equal to 7 kg and the motor is arranged at the working head assembly 20, is described in detail below.

[0119] As shown in Figure 17, the front-mounted mower 100 includes a working head assembly 20, a power assembly, a battery pack 30, and a grip assembly 40. The working head assembly 20 includes a mowing head 201; the power assembly includes a motor that provides driving force for the mowing head 201 and a control panel that controls the motor's rotation. The battery pack 30 is a lithium-ion battery pack and is removably mounted on the connecting tube 10 at one end of the grip assembly 40. The grip assembly 40 is for the user to hold and is equipped with corresponding operating switches. The connecting tube 10 serves as a connecting component to connect the working head assembly 20 and the grip assembly 40 of the front-mounted mower 100. The wall thickness of the connecting tube 10 is set to be between 1.5 mm and 1.8 mm, so that it can directly replace existing aluminum tubes. For example, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, etc. are all possible. In the usage scenario of the front-mounted lawn mower 100, the connecting tube 10 meets the requirement that the ratio of the bare metal mass of the electric tool, that is, the mass after removing the battery pack 30, to the wall thickness of the connecting tube 10 is within the range of 1.5kg / mm ​​to 1.9kg / mm. Compared with the existing aluminum tube, under the premise of using the same wall thickness, tube diameter, length and the same drop height, the impact-resistant equivalent bare metal mass of the electric tool using the connecting tube 10 can be heavier, that is, the applicable product range of the connecting tube 10 is larger, and under the premise of the same bare metal mass and the same drop height, the wall thickness of the connecting tube 10 can be thinner, and the weight reduction effect is better.

[0120] Because the front-mounted mower 100 weighs less than or equal to 7 kg, compared to other heavy power tools, such as mowers weighing more than 7 kg, as shown in FIG18 , most of these mowers are rear-mounted mowers 200 with the motor mounted on the grip assembly 40. Compared to the front-mounted mower 100, the weight of the connecting tube 10 is relatively balanced at both ends. The connecting tube 10 of the rear-mounted mower 200 has a grip assembly 40, a power assembly, and a battery pack 30 at one end, and a working head assembly 20 at the other end. This imbalance in weight places a significantly higher stiffness requirement on the connecting tube 10 than in the front-mounted mower 100. Since the front-mounted mower 100 does not require particularly stringent stiffness requirements for the connecting tube 10, using an all-carbon fiber material for the connecting tube 10 would increase costs and create redundant performance, resulting in a poor cost-effectiveness ratio. Furthermore, users would experience a noticeable numbness in their hands during use, resulting in a poor user experience. To this end, the present connecting tube 10 is made of carbon fiber and has a toughening material, namely glass fiber, added thereto, so that the connecting tube 10 is arranged radially with at least a carbon fiber layer (i.e., a first material layer) 103 and a glass fiber layer (i.e., a second material layer) 104. The glass fiber layer 104 primarily enhances toughness and supplements stiffness, while the carbon fiber layer 103 primarily enhances stiffness and supplements toughness, so that the connecting tube 10 has both excellent toughness and stiffness, thereby improving the overall mechanical properties of the connecting tube 10, reducing material costs and increasing cost-effectiveness. The addition of tough glass fiber improves the vibration absorption performance of the connecting tube 10 and reduces the numbness during use.

[0121] At the same time, the proportion of glass fiber and carbon fiber is also limited, that is, the total thickness of the glass fiber layer 104 accounts for 50% to 80% of the total wall thickness of the connecting tube 10, and correspondingly, the total thickness of the carbon fiber layer 103 accounts for 20% to 50% of the total wall thickness of the connecting tube 10. By limiting the proportion of the total thickness of the carbon fiber layer 103 and the glass fiber layer 104, the toughness and stiffness of the connecting tube 10 can be better coordinated to meet the requirements of anti-buffering performance and impact resistance. In order to further optimize the comprehensive mechanical properties of the connecting tube 10, it is preferred that the total thickness of the glass fiber layer 104 accounts for 75% of the total wall thickness of the connecting tube 10 and the total thickness of the carbon fiber layer 103 accounts for 25% of the total wall thickness of the connecting tube 10. In actual use, the cutting effect of the front mower 100 using this connecting tube 10 is equivalent to the cutting effect of the front mower 100 using an aluminum tube, and the use effect of the connecting tube 10 is also equivalent to or better than that of the aluminum tube.

[0122] Furthermore, under the premise that the wall thickness range of the connecting tube 10 is 1.5mm to 2.0mm and the thickness ratio of the glass fiber layer 104 to the carbon fiber layer 103 is determined, the thickness of each carbon fiber layer 103 and each glass fiber layer 104 is further limited to the range of 0.15mm to 0.25mm. By selecting appropriate layer thickness to adjust the number of carbon fiber layers 103 and glass fiber layers 104, the connecting tube 10 can have excellent impact resistance and anti-buffering performance.

[0123] If the front mower 100 falls, the raised structure on the ground will first contact the outermost layer of the connecting tube 10 and generate an impact force. The impact force will be transmitted radially inward along the connecting tube 10, destroying the multiple fiber layers in the radial direction of the connecting tube 10 one by one. For this reason, the carbon fiber layer 103 is preferably selected as the outermost layer of the connecting tube 10, that is, the carbon fiber outer layer 105. Because the stiffness of carbon fiber is greater than that of glass fiber, such a setting can ensure that the outermost layer of the connecting tube 10 has high strength, can reduce bump damage when falling, can resist friction during transportation, and the performance of the connecting tube 10 is not affected in high and low temperature and rainy environments, and has good surface appearance performance. At the same time, the fiber arrangement direction of the carbon fiber layer 103 as the outermost layer of the connecting tube 10 is set to be different from the fiber arrangement direction of the adjacent carbon fiber layer 103 or glass fiber layer 104, so as to reduce the radial transmission effect of the impact force on the connecting tube 10. The carbon fiber layer 103 as the outermost layer of the connecting tube 10 adopts a 3K twill weave structure, so the adjacent carbon fiber layer 103 or glass fiber layer 104 may adopt a unidirectional structure or a weave structure with different weaving angles.

[0124] The carbon fiber layer 103 and the glass fiber layer 104 may be constructed in a woven structure or a unidirectional structure. However, the carbon fiber layer 103 and the glass fiber layer 104 of the connecting tube 10 of this embodiment are primarily constructed in an axial structure within the unidirectional structure, i.e., the ratio of the total thickness of the glass fiber layer 104 in the axial structure to the total thickness of the glass fiber layers 104 is greater than or equal to 80%, and the carbon fiber layer 103 includes a carbon fiber outer layer 105 constituting the outermost layer of the connecting tube and at least one carbon fiber inner layer 103, wherein the ratio of the total thickness of the carbon fiber inner layer 103 in the axial structure to the total thickness of all carbon fiber inner layers 103 is greater than or equal to 50%. Alternatively, the ratio of the total thickness of the glass fiber layer 104 in the axial structure to the total thickness of the glass fiber layers 104 is greater than or equal to 80%, and the ratio of the total thickness of the carbon fiber layer 103 in the axial structure to the total thickness of all carbon fiber layers 103 is greater than or equal to 40%. Such an arrangement can ensure that the connecting pipe 10 has excellent impact resistance while ensuring the consistency of performance at various locations of the connecting pipe 10 and the continuity of the overall strength.

[0125] As shown in Figure 12, a more preferred connecting tube 10 structure is provided for use on a front-mounted lawn mower 100, wherein a plurality of glass fiber layers 104 are arranged in sequence from the inside to the outside along the connecting tube diameter 10 to form five glass fiber layers 104 of A, B, C, D and E, and then a plurality of carbon fiber layers 103 are stacked in sequence from the inside to the outside along the radial direction of the connecting tube 10 on the glass fiber layer E to form three carbon fiber layers 103 of F, G and H, wherein the carbon fiber layer H located at the radial outermost layer of the connecting tube 10, that is, the carbon fiber outer layer H, adopts a twill weaving structure, the glass fiber layer A, the glass fiber layer B, and the glass fiber layer C adopt a unidirectional structure and the fiber bundles 106 extend along the axial direction of the connecting tube 10, the glass fiber layer D and the glass fiber layer E adopt a weaving structure, the carbon fiber layer F and the carbon fiber layer G adopt a unidirectional structure and the fiber bundles 106 extend along the axial direction of the connecting tube 10, the outermost carbon fiber layer H, that is, the carbon fiber outer layer H adopts a twill weaving structure and the weaving direction has an angle of 45 degrees with the axial direction of the connecting tube 10, for example.

[0126] In order to verify that the connecting tube 10 provided in this application is equivalent to or better than the impact resistance of the aluminum tube, a drop test was performed on the connecting tube 10 to simulate the normal drop of the connecting tube 10 during the use of the front mower 100. Before the drop test, a suitable battery pack 30 was first assembled on the front mower 100, and then the front mower 100 was lifted horizontally to a height of 1m from the curb (the curb was 15cm to 20cm from the ground and the curb was 15cm wide) and then released, allowing the front mower 100 to fall freely. The curb impacted the weakest position of the connecting tube 10, that is, the axial center. The drop test required that there should be no cracks at the impacted position of the connecting tube 10. In addition, by observing whether the connecting tube 10 and the aluminum tube were bent after the drop test, the impact resistance of the connecting tube 10 and the aluminum tube was further compared. Furthermore, in order to reduce the safety risks of the front mower 100 using the connecting tube 10, a blade edge test is added to simulate the extreme situation where the sharp blade of the front mower 100 impacts the connecting tube 10 after it falls. Before the blade edge test, a suitable battery pack 30 is first installed on the front mower 100. The front mower 100 is then lifted horizontally to a height of 1m above the blade and released. The blade edge impacts the weakest point of the connecting tube 10, i.e., the axial center. The blade edge test requires that there must be no cracks at the impacted position of the connecting tube 10, or the cracks must be less than 10mm wide in the axial direction of the connecting tube 10, and the crack width must not expand after being hit 1,000 times with a wooden stake. For a clearer comparison, Table 1 below shows the test results of a front mower using a connecting tube within the above-mentioned specification parameter range, a front mower not using a connecting tube within the above-mentioned specification parameter range, and a front mower using an existing aluminum tube of the same specification.

[0127] Table 1

[0128] By comparison, it can be seen that the connecting tube 10 provided by the present application, provided that it is the same length and wall thickness as the aluminum tube, has a significantly lower mass than the entire mower 100 using the connecting tube 10. Both the connecting tube 10 provided by the present application and existing aluminum tubes can pass the 1m drop test and blade edge test, meaning that the impact resistance of the connecting tube 10 provided by the present application is equivalent to that of the aluminum tube. Furthermore, by comparing the bending conditions of the connecting tube 10 provided by the present application and the aluminum tube after passing the 1m drop test, it can be seen that the impact resistance of the connecting tube 10 provided by the present application is superior to that of the aluminum tube.

[0129] In other power tools that use a connecting assembly, such as a high-pole saw 300 with a bare weight of 4.2 kg to 5.0 kg, a working head assembly 20 is located at one end of the connecting assembly, and a battery pack 30, a power assembly, and a grip assembly 40 are located at the other end. The connecting assembly includes a telescopic tube 10 and a handle tube 80, which is connected to the grip assembly 40. The working head assembly 20 includes at least a housing, a guide plate 202, and a chainsaw. Part of the guide plate 202 is located in the housing. During cutting, the chainsaw slides at high speed on the guide plate 202. The grip assembly 40 typically includes a main handle and an auxiliary handle. The main handle is generally equipped with control buttons such as a control switch to facilitate user operation of the machine. The telescopic tube 10 includes an inner tube 101 and an outer tube 102. The inner tube 101 is at least partially coaxially slidably nested within the outer tube 102 and connected at one end to the working head assembly 20. A locking member 90 is provided between the inner and outer tubes 101, 102 to maintain relative fixation between the two. The outer tube 102 is disposed between the inner tube 101 and the handle tube 80. The transmission structure of the power assembly is disposed within the inner and outer tubes 101, 102 and is drivingly connected to the front working head assembly 20.

[0130] When the high-branch saw 300 is used to prune branches, the inner tube 101 is stretched to an appropriate length relative to the outer tube 102 and the two are kept relatively fixed by the locking member 90. The user holds the main handle and the auxiliary handle in both hands, and lifts the working head assembly 20 connected to the front end of the inner tube 101 to an appropriate height, hangs it on the branch to be pruned, and pulls the grip assembly 40 to cause the connecting assembly to move back and forth, so that the working head assembly 20 located at the front end of the inner tube 101 can complete the precise sawing operation of the branch. Generally, the overall length of the telescopic tube 10 of the high-branch saw 300 can reach more than 3 meters. In addition, after the inner tube 101 is connected to the working head assembly 20, the distance from the working head assembly 20 to the user's grip is relatively long. In order to prevent the inner tube 101 from bending and deformation so that the user can accurately lift the working head assembly 20 to the designated position, the rigidity and toughness of the inner tube 101 are prioritized, and the inner tube 101 must have greater rigidity to improve its bending resistance. In the event of a fall, the working head assembly 20 falls in an arc shape with the user's gripping end as the center point and the length of the telescopic tube 10 or the sum of the lengths of the telescopic tube 10 and the handle tube 80 as the radius. The raised structure on the ground is likely to directly impact the inner tube 101, while the outer tube 102 is closer to the user's grip and is less likely to be impacted. Therefore, the impact resistance requirements for the inner tube 101 need to be higher than the impact resistance requirements for the outer tube 102. Since the outer tube 102 is closer to the user's grip, the anti-buffering performance requirements for the outer tube 102 need to be higher than the anti-buffering performance requirements for the inner tube 101. Based on the different performance requirements for the inner tube 101 and the outer tube 102, the connecting tube provided in the above embodiment can be configured as the outer tube 102 in the high-branch saw 300 that meets the weight requirements, while the inner tube 101 needs to use a connecting tube with stronger rigidity.

[0131] To this end, the present application further provides a power tool having a lightweight, low-cost outer tube 102 with satisfactory impact resistance and cushioning performance, and an inner tube 101 with lightweight, high-impact resistance, and high-bending performance. For ease of understanding, a pole saw 300 will be used as an example for detailed description.

[0132] FIG19 shows an electric tool, typically a high-branch saw 300, comprising a working head assembly 20, a power assembly, a battery pack 30, a grip assembly 40, and a connecting assembly. The working head assembly 20 comprises at least a housing, a guide plate 202, and a chainsaw, with the guide plate 202 partially disposed within the housing. During cutting, the chainsaw slides at high speed on the guide plate 200 to cut branches. The connecting assembly has the working head assembly 20 at one end and the battery pack 30, power assembly, and grip assembly 40 at the other. The bare metal weight of this type of high-branch saw 300, excluding the battery pack 30, is typically 4.2 kg to 5.0 kg.

[0133] The grip assembly 40 generally includes a main handle and an auxiliary handle, wherein the main handle is generally provided with control buttons such as a control switch to facilitate user operation of the machine. The connecting assembly includes a telescopic tube 10 and a handle tube 80, and the handle tube 80 is connected to the grip assembly 40. The telescopic tube 10 includes an inner tube 101 and an outer tube 102. The inner tube 101 is at least partially coaxially slidably nested in the outer tube 102 and one end thereof is connected to the working head assembly 20. A locking member 90 is also provided between the inner tube 101 and the outer tube 102 to keep the two relatively fixed. The outer tube 102 is provided between the inner tube 101 and the handle tube 80. The handle tube 80 is the same as the handle tube 80 in the existing high-branch saw 300 and is made of a metal tube.

[0134] The transmission structure of the power assembly is arranged in the inner tube 101 and the outer tube 102 and is driven and connected to the front working head assembly 20. A liner 60 is provided between the inner side wall of the inner tube 101 and the outer tube 102 and the transmission structure to reduce radial vibration of the transmission structure. At the same time, a limiting structure 50 is provided on the inner side wall of the inner tube 101 and the outer tube 102, which is installed in conjunction with the liner 60 inside the tube to further limit the liner 60 from rotating circumferentially along the inner tube 101 or the outer tube 102. The limiting structure 50 can be a ridge extending in the axial direction of the inner tube 101 or the outer tube 102, a single protrusion, or a groove. One is provided on the circumference of the inner side wall of the inner tube 101 and the outer tube 102, or multiple linings, such as 2, 3, or 4, are provided at equal intervals. The material of the limiting structure 50 can be the same as or different from the material constituting the inner side wall of the inner tube 101 or the outer tube 102.

[0135] Because the working head assembly 20 of the high-branch saw 300 is used at a relatively high height, the inner tube 101 must not only ensure that it does not bend or deform after being connected to the working head assembly 20, but also ensure that the inner tube 101 can withstand the impact of the raised structure on the ground after a drop, without breaking the tube body or generating cracks on the tube body surface. The impact resistance of the inner tube 101 needs to be significantly higher than that of the outer tube 102, and it also needs to have better bending resistance. The outer tube 102 is closer to the user's grip than the inner tube 101. In the event of a drop, the probability of the outer tube 102 being impacted by the raised structure on the ground is lower than the probability of the inner tube 101 being impacted by the raised structure on the ground. Since it is closer to the user's grip, it needs to have better vibration absorption performance to transmit less vibration generated during the cutting process of the tool to the user's grip, so that the user has a better grip feel.

[0136] Based on this, the structure of the telescopic tube 10, namely the inner tube 101 and the outer tube 102, used in the high-branch saw 300 provided in the present application is that the inner tube 101 is arranged with at least a carbon fiber layer 103 made of carbon fiber material in its radial direction, and the outer tube 102 is arranged with at least a carbon fiber layer 103 made of carbon fiber material in its radial direction, wherein the proportion of the sum of the layer thickness of the carbon fiber layer 103 in the inner tube 101 to the total wall thickness of the inner tube 101 is greater than the proportion of the sum of the layer thickness of the carbon fiber layer 103 in the outer tube 102 to the total wall thickness of the outer tube 102, thereby achieving that the stiffness of the inner tube 101 is greater than the stiffness of the outer tube 102.

[0137] Subsequently, it is preferred to set the ratio of the total thickness of the carbon fiber layers 103 in the inner tube 101 to 100% of the total wall thickness of the inner tube 101. That is, the inner tube 101 is made entirely of carbon fiber. This not only achieves lightweighting, but also meets the required stiffness performance of the inner tube 101. Furthermore, the wall thickness of the inner tube 101 is set within a range of 1.6 mm to 2.3 mm, for example, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, etc. This setting makes the wall thickness of the inner tube 101 similar to or the same as that of the inner tube in the existing metal telescopic tube, allowing for direct replacement.

[0138] When a fall occurs, the raised structure on the ground first impacts the outer wall of inner tube 101, and the impact energy is then transferred radially toward the interior of inner tube 101. To further reduce the radial impact energy transfer effect of inner tube 101, the radially outermost carbon fiber layer 103 of inner tube 101 is configured as a carbon fiber outer layer 105. This carbon fiber outer layer 105 utilizes a woven structure composed of multiple fiber bundles 106, and the fiber bundles 106 of the adjacent carbon fiber layers 103 are arranged in a different direction. The remaining carbon fiber layers 103 utilize a unidirectional structure composed of multiple fiber bundles 106. This arrangement enhances the mechanical properties of the woven carbon fiber outer layer 105 and the unidirectional carbon fiber layers 103.

[0139] Furthermore, during the forming process of the braided structure, multiple parallel fiber filaments are converged into fiber bundles 106, and then half of all the fiber bundles 106 are extended along the first direction, and the remaining half are extended along the second direction. There is a certain angle between the first direction and the second direction, such as 60 degrees, 90 degrees or 120 degrees, and then the fiber bundles 106 along the first direction and the fiber bundles 106 along the second direction are cross-extended to form a braided structure (this process is similar to the weaving process of cloth), that is, the fiber bundles 106 in the first direction and the fiber bundles 106 in the second direction are cross-woven. By such an arrangement, the fiber bundles 106 of the carbon fiber outer layer 105 located in the radial outermost layer of the inner tube 101 can be extended and connected in different directions (i.e., the first direction and the second direction), so that the stiffness and impact resistance of the carbon fiber outer layer 105 are improved.

[0140] As shown in FIG1 , the braiding direction in the braided structure refers to the extension direction of each of the two intersecting fiber bundles 106, and the bisector of the angle b between the two fiber bundles 106 extends along the axial direction of the inner tube 101. That is, the angle c between the two fiber bundles 106 and the axis of the inner tube 101 is the same in size and is half of the angle b between the two fiber bundles 106. In this way, by making the bisector of the angle between the first direction and the second direction parallel to the axial direction of the inner tube 101, the formed braided structure can be made symmetrical. When the inner tube 101 is subjected to an impact perpendicular to the axial direction (i.e., radial direction), the symmetrical structure can further enhance the impact resistance of the inner tube 101. Therefore, it is preferred that the braided structure be arranged symmetrically about the axial direction.

[0141] The unidirectional structure includes an axial structure and a circumferential structure. The fiber bundles 106 in the axial structure extend in the same direction as the axial direction of the inner tube 101 (the extending direction of the fiber bundles 106 in this case is shown in FIG2 ), i.e., the axial fiber bundles 106 constituting the axial structure extend along the axial direction of the inner tube 101. The fiber bundles 106 in the circumferential structure extend in the same direction as the circumferential direction of the inner tube 101, i.e., the fiber bundles 106 constituting the circumferential structure are perpendicular to the axis of the inner tube 101 in a horizontal plane. In this embodiment, the ratio of the total thickness of the carbon fiber layers 103 in the inner tube 101 with the axial structure to the total thickness of the carbon fiber layers 103 with the circumferential structure is 3:2, i.e., the total thickness of the carbon fiber layers 103 in the axial structure accounts for 60% of the total thickness of the carbon fiber layers 103 in the unidirectional structure, and the total thickness of the carbon fiber layers 103 in the circumferential structure accounts for 40% of the total thickness of the carbon fiber layers 103 in the unidirectional structure. Such an arrangement ensures that the inner tube 101 uses a unidirectional carbon fiber inner layer 103 to ensure the consistency of stiffness and reduce the transmission effect of impact energy in the radial direction of the inner tube 101 .

[0142] As for the outer tube 102, while meeting the rigidity requirements, it also needs to have better vibration absorption performance than the inner tube 101. The outer tube 102 can utilize the connecting tube structure described in the embodiment of the front-mounted mower 100. The outer tube 102 also includes one or at least two fiberglass layers 104 arranged radially along its length. A preferred structure is shown in FIG12 . Fiberglass has good toughness and a certain degree of rigidity, significantly enhancing the toughness of the outer tube 102. Carbon fiber also has high rigidity and a certain degree of toughness, ensuring the rigidity of the outer tube 102, enabling the outer tube 102 to better meet operational requirements for connection, support, and load bearing. This arrangement allows the fiberglass layer 104 to primarily enhance toughness and supplement rigidity, while the carbon fiber layer 103 primarily enhances rigidity and supplements toughness. This ensures that the outer tube 102 possesses both excellent toughness and rigidity, meeting practical operational requirements.

[0143] At the same time, the proportions of glass fiber and carbon fiber are limited, that is, the total thickness of the glass fiber layer 104 accounts for 50% to 80% of the total wall thickness of the outer tube 102, and correspondingly, the total thickness of the carbon fiber layer 103 accounts for 20% to 50% of the total wall thickness of the outer tube 102. Under the premise that the wall thickness of the outer tube 102 is certain, if the total thickness of the carbon fiber layer 103 is too large, it means that the total thickness of the glass fiber layer 103 is too small, which will make the stiffness of the outer tube 102 meet the requirements, but the overall toughness is poor; if the total thickness of the carbon fiber layer 103 is too small, it means that the total thickness of the glass fiber layer 104 is too large, which will make the toughness of the outer tube 101 meet the requirements, but the overall stiffness is low. Therefore, by limiting the combined thickness ratio of the carbon fiber layer 103 and the glass fiber layer 104, the toughness and stiffness of the outer tube 102 can be better balanced, meeting the requirements for cushioning and impact resistance, further optimizing the overall mechanical properties of the outer tube 102, and providing excellent vibration absorption and cushioning performance during use. Preferably, the combined thickness of the glass fiber layer 104 accounts for 75% of the total wall thickness of the outer tube 102, and the combined thickness of the carbon fiber layer 103 accounts for 25% of the total wall thickness of the outer tube 102.

[0144] Similar to the inner tube 101 described above, it is preferred that the outermost layer of the outer tube 102 in its radial direction be a carbon fiber outer layer 105 composed of a carbon fiber layer 103, and that the carbon fiber outer layer 105 be a woven structure to resist the impact of protrusions on the ground on the outer wall of the outer tube 102 that may be caused by a fall. Secondly, the arrangement direction of the fiber bundles 106 of the carbon fiber outer layer 105 and the adjacent material layers are set to be different, thereby reducing the impact energy transmission effect in the radial direction of the outer tube 102. Alternatively, it is also possible to consider that the outermost layer of the outer tube 102 in its radial direction be a carbon fiber outer layer 105 composed of a carbon fiber layer 103, and the weaving direction of the carbon fiber outer layer 105 and the arrangement direction of the fiber bundles 106 of the adjacent material layers are set to be different, wherein the carbon fiber layer 103 includes axial fiber bundles extending in the axial direction of the outer tube 102, and the ratio of the total thickness of the axial fiber bundles in the radial direction of the outer tube 102 to the total thickness of the carbon fiber layer 103 is greater than or equal to 40%, which can also meet the use requirements of the outer tube 102.

[0145] Specifically, during the forming process, the braided structure of the carbon fiber outer layer 105 is formed by converging multiple parallel fiber filaments into fiber bundles 106, and then half of all the fiber bundles 106 are extended along the first direction, and the remaining half are extended along the second direction. There is a certain angle between the first direction and the second direction, such as 60 degrees, 90 degrees or 120 degrees, and then the fiber bundles 106 along the first direction and the fiber bundles 106 along the second direction are cross-woven to form a braided structure (this process is similar to the weaving process of cloth), that is, the fiber bundles 106 in the first direction and the fiber bundles 106 in the second direction are cross-woven. By such an arrangement, the fiber bundles 106 of the carbon fiber outer layer 105 located in the radial outermost layer of the outer tube 102 can be extended and connected in different directions (i.e., the first direction and the second direction), so that the stiffness and impact resistance of the carbon fiber outer layer 105 are improved.

[0146] As shown in FIG1 , the braiding direction in the braided structure refers to the extension direction of each of the two intersecting fiber bundles 106, and the bisector of the angle b between the two fiber bundles 106 extends along the axial direction of the outer tube 102. In other words, the angle c between the two fiber bundles 106 and the axis of the outer tube 102 is the same in magnitude and is half of the angle b between the two fiber bundles 106. In this way, by making the bisector of the angle between the first direction and the second direction parallel to the axial direction of the outer tube 102, the formed braided structure can be made symmetrical. When the outer tube 102 is subjected to an impact perpendicular to the axial direction (i.e., radial direction), the symmetrical structure can further enhance the impact resistance of the outer tube 102. Therefore, it is preferred that the braided structure be arranged symmetrically about the axial direction.

[0147] Secondly, the carbon fiber outer layer 105 utilizes a 3K twill weave, and the adjacent material layers have a weave direction that differs from that of the carbon fiber outer layer 105. For example, the adjacent carbon fiber layer 103 or glass fiber layer 104 utilizes a unidirectional structure, and whether the fiber bundles 106 of the unidirectional structure extend in the axial direction, circumferential direction, or helical direction around the outer tube 102, they all have a weave direction that differs from that of the carbon fiber outer layer 105. Alternatively, the adjacent carbon fiber layer 103 or glass fiber layer 104 utilizes a woven structure, but the weave direction of the woven structure differs from that of the carbon fiber outer layer 105. For example, the weave direction of the carbon fiber layer 103 or glass fiber layer 104 adjacent to the carbon fiber outer layer 105 may be at a 40-degree angle to the axial direction of the outer tube 102, while the weave direction of the carbon fiber outer layer 105 may be at a 60-degree angle to the axial direction of the outer tube 102. This arrangement can reduce the effect of impact energy transmission in the radial direction of the outer tube 102. The remaining carbon fiber layer 103, i.e., the carbon fiber inner layer 103, can entirely adopt a unidirectional structure, or partially adopt a unidirectional structure and partially adopt a woven structure, wherein the unidirectional structure mainly adopts an axial structure in which the fiber bundles 106 extend and are arranged in the axial direction of the outer tube 102, and the ratio of the total layer thickness of the carbon fiber inner layer 103 adopting the axial structure to the total layer thickness of the carbon fiber inner layer 103 is greater than or equal to 60%. This arrangement is to ensure the consistency of the overall strength of the outer tube 102. Similarly, the glass fiber layer 104 can entirely adopt a woven structure, or entirely adopt a unidirectional structure, or partially adopt a woven structure and partially adopt a unidirectional structure, wherein the unidirectional structure mainly adopts an axial structure in which the fiber bundles 106 extend and are arranged in the axial direction of the outer tube 102, and the ratio of the total layer thickness of the glass fiber layer 104 adopting the axial structure to the total layer thickness of the glass fiber layer 104 is greater than or equal to 80%, so that the outer tube 102 has good toughness and vibration absorption performance.

[0148] To verify that the impact resistance of the telescopic tube 10 provided herein is equivalent to or superior to that of an aluminum tube, a tipping test was performed on the telescopic tube 10 to simulate the typical tipping condition of the telescopic tube 10 during use with a pole saw 300. Prior to the tipping test, the pole saw 300 was assembled with a suitable battery pack 30. The inner tube 101 was pulled out of the outer tube 102 and locked relative to each other using the locking member 90. The front end of the inner tube 101 was connected to the working head assembly 20. Then, hold the main handle and auxiliary handle with both hands and raise the telescopic tube 10 at a 60° angle relative to the ground, so that the working head assembly 20 at the front end of the inner tube 101 is 4 meters away from the curb (the curb is 15cm to 20cm high from the ground and the curb is 15cm wide). Let go and let the working head assembly 20 fall naturally. The curb will impact the weakest point of the inner tube 101, that is, the axial center. The tipping test requires that there should be no cracks at the impacted position of the inner tube 101. In addition, by observing whether the inner tube 101 and the aluminum tube are bent after the tipping test, the impact resistance of the inner tube 101 and the aluminum tube can be further compared. Furthermore, in order to reduce the safety risks of the high-branch saw 300 using the telescopic tube 100, a blade edge test is added to simulate the extreme situation where the sharp blade of the high-branch saw 300 impacts the inner tube 101 after the high-branch saw 300 is tipped over. Before the blade edge test, the appropriate battery pack 30 was first assembled on the pole saw 300. The inner tube 101 was pulled out of the outer tube 102 and locked with the locking member 90 to keep the two relatively fixed. The front end of the inner tube 101 was then assembled with the working head assembly 20. The pole saw 300, equipped with the grip assembly 40, battery pack 30, and power assembly, was then placed on the ground. The inner tube 101 was then grasped and the working head assembly 20 was raised to a height of 1.5 meters above the blade. The blade edge struck the inner tube 101 at its weakest point, i.e., the axial center. The blade edge test required that the impacted location of the inner tube 101 must not have cracks, or that the cracks generated must be less than 8 mm wide in the axial direction of the inner tube 101, and that the crack width must not expand after 1,000 hits with a wooden stake. For a clearer comparison, Table 2 below shows the test results of a pole saw using an inner tube within the aforementioned specification parameter range, a pole saw not using an inner tube within the aforementioned specification parameter range, and an existing pole saw with an aluminum tube of the same specification.

[0149] Table 2

[0150] By comparison, it can be seen that the overall weight of a high-branch saw 300 using the telescopic tube 10 provided by the present application is less than that of a high-branch saw using an existing aluminum telescopic tube. Assuming that the telescopic tube 10 provided by the present application and the aluminum telescopic tube have the same length and outer tube wall thickness, the inner tube 101 of the telescopic tube 10 provided by the present application and the inner tube of the aluminum telescopic tube can both pass the 4m tipping test and the blade edge test, meaning that the impact resistance of the inner tube 101 of the telescopic tube 10 provided by the present application is equivalent to that of the inner tube of the aluminum telescopic tube. Furthermore, by comparing the bending conditions of the inner tube 101 of the telescopic tube 10 provided by the present application and the inner tube of the aluminum telescopic tube after passing the 4m tipping test, it can be seen that the impact resistance of the inner tube 101 of the telescopic tube 10 provided by the present application is superior to that of the inner tube of the aluminum telescopic tube.

[0151] The telescopic tube 10 provided herein is over 30% lighter than conventional aluminum tubes. The axial modulus of its inner tube 101 can reach 90 GPa to 120 GPa, achieving stiffness comparable to aluminum tubes. Furthermore, its impact resistance surpasses that of aluminum tubes, surpassing even aluminum tubes by withstanding a 4m tipping test without bending. Under the same operating conditions, a high-pole saw 300 using this telescopic tube 10 exhibits lower vibration and improved cushioning compared to a high-pole saw using an aluminum tube.

[0152] Furthermore, in some power tools that can use multiple working head assemblies, as shown in Figure 20, the power tool 400 is a lawn mower or a high-branch saw using a split connecting pipe, and the connecting pipe 10 includes a first connecting pipe 107 and a second connecting pipe 108, wherein the first connecting pipe 107 is connected to the front-end working head assembly 20, and the second connecting pipe 108 is connected to the grip assembly 40, the battery pack 30 and other universal components, and the different working head assemblies 20 are connected to the universal components at the rear end through the first connecting pipe 107 and the second connecting pipe 108. The split connecting tube 10 of this type of electric tool 400 also has the need for being lightweight and having good impact resistance and anti-buffering performance. The first connecting tube 107 and the second connecting tube 108 can be configured as follows: the first connecting tube 107 adopts the same configuration as the connecting tube 10 in the embodiment of the above-mentioned front mower 100 or the outer tube 101 in the embodiment of the above-mentioned high-branch saw 300, and the second connecting tube 108 adopts the same configuration as the inner tube 101 in the above-mentioned high-branch saw 300 or a metal tube in the prior art; or, the first connecting tube 107 adopts The second connecting tube 108 may adopt the same configuration as the inner tube 101 in the above-mentioned high-branch saw 300 or a metal tube in the prior art; the second connecting tube 108 may adopt the same configuration as the connecting tube 10 in the above-mentioned front mower 100 embodiment or the outer tube 102 in the above-mentioned high-branch saw 300 embodiment; or the first connecting tube 107 and the second connecting tube 108 may both adopt the same configuration as the connecting tube 10 in the above-mentioned front mower 100. The specific configuration scheme and the technical effect achieved are the same as those in the above-mentioned front mower 100 or high-branch saw 300 embodiment, and will not be repeated here.

[0153] The above description of the disclosed embodiments will enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An electric tool, comprising: A working head assembly, the working head assembly comprising a working head for an operation; A power assembly, the power assembly drives the working head; A battery pack, the battery pack providing power to the power assembly; A grip component for a user to hold; The connecting pipe is arranged between the working head assembly and the holding assembly, and is characterized in that: The connecting pipe is at least arranged with a first material layer made of carbon fiber material and a second material layer made of non-carbon fiber material, the stiffness of the second material layer is smaller than the stiffness of the first material layer, and the toughness of the second material layer is greater than the toughness of the first material layer.

2. The electric tool according to claim 1, characterized in that: The total thickness of the second material layers accounts for 50% to 80% of the total wall thickness of the connecting pipe.

3. The electric tool according to claim 2, characterized in that: The second material layer is a glass fiber layer.

4. The electric tool according to claim 2, characterized in that: The second material layer includes axial fiber bundles extending along the axial direction of the connecting tube, and the ratio of the total thickness of the axial fiber bundles in the radial direction of the connecting tube to the total layer thickness of the second material layer is greater than or equal to 80%.

5. The electric tool according to claim 2, characterized in that: The outermost layer of the connecting pipe in the radial direction is a carbon fiber outer layer formed by the first material layer.

6. The electric tool according to claim 5, characterized in that: The carbon fiber outer layer and the adjacent material layer have different fiber arrangement directions.

7. The electric tool according to claim 5 or 6, characterized in that: The first material layer includes axial fiber bundles extending and arranged along the axial direction of the connecting tube, and the ratio of the total thickness of the axial fiber bundles in the radial direction of the connecting tube to the total layer thickness of the first material layer is greater than or equal to 40%.

8. The electric tool according to claim 7, characterized in that: The number of the first material layers is configured as one layer, and the carbon fiber outer layer is a woven structure composed of multiple fiber bundles; or, the number of the first material layers is configured as greater than or equal to two layers, and the carbon fiber outer layer is a woven structure composed of multiple fiber bundles, and the remaining first material layers are arranged on the inner side of the carbon fiber outer layer in the radial direction of the connecting tube to form a carbon fiber inner layer, and the carbon fiber inner layer includes the axial fiber bundles extending and arranged along the axial direction of the connecting tube, and the ratio of the total layer thickness of the axial fiber bundles to the total layer thickness of the carbon fiber inner layer is greater than or equal to 50%.

9. The electric tool according to claim 8, characterized in that: The total weight of the electric tool is less than or equal to 7 kg, the wall thickness of the connecting pipe is 1.5 mm to 2.0 mm, and the ratio of the impact energy that the connecting pipe can withstand to the wall thickness of the connecting pipe is greater than or equal to 58 J / mm.

10. The electric tool according to claim 9, characterized in that: The electric tool is a lawn mower, the total weight of which is less than or equal to 7 kg, the battery pack is arranged at one end of the connecting tube located at the grip assembly, the power assembly is arranged at one end of the connecting tube located at the working head assembly, and the wall thickness of the connecting tube is 1.5 mm to 1.8 mm.

11. The electric tool according to claim 8, characterized in that: The weight of the bare body of the electric tool, i.e., after removing the battery pack, is 4.2 kg to 5.5 kg. The electric tool is a high-branch saw, which includes a connecting assembly. The working head assembly is provided at one end of the connecting assembly, and the battery pack, the power assembly and the grip assembly are provided at the other end. The connecting assembly includes a telescopic tube and a handle tube. The handle tube is connected to the grip assembly. The telescopic tube includes an inner tube and an outer tube. The inner tube is at least partially coaxially slidably nested in the outer tube and one end of which is connected to the working head assembly. A locking piece is also provided between the inner tube and the outer tube to keep the two relatively fixed. The outer tube is arranged between the inner tube and the handle tube, and the connecting tube is configured as the outer tube.

12. An electric tool, comprising: A working head assembly, the working head assembly comprising a working head for an operation; A power assembly, the power assembly drives the working head; A battery pack, the battery pack providing power to the power assembly; A grip component for a user to hold; The connecting pipe is arranged between the working head assembly and the holding assembly, and is characterized in that: The connecting pipe is at least arranged with a first material layer and a second material layer in the radial direction thereof, wherein the first material layer is a carbon fiber layer, and the second material layer is a glass fiber layer.

13. The electric tool according to claim 12, characterized in that: The total thickness of the glass fiber layers accounts for 50% to 80% of the total wall thickness of the connecting pipe.

14. The electric tool according to claim 13, characterized in that: The glass fiber layer includes axial fiber bundles extending and arranged along the axial direction of the connecting tube, and the ratio of the total thickness of the axial fiber bundles in the radial direction of the connecting tube to the total layer thickness of the glass fiber layer is greater than or equal to 80%.

15. The electric tool according to claim 14, characterized in that: The outermost layer of the connecting pipe in the radial direction is a carbon fiber outer layer formed by the carbon fiber layer.

16. The electric tool according to claim 15, characterized in that: The carbon fiber outer layer and the adjacent material layer have different fiber arrangement directions.

17. The electric tool according to claim 15 or 16, characterized in that: The carbon fiber layer includes axial fiber bundles extending and arranged along the axial direction of the connecting tube, and the ratio of the total thickness of the axial fiber bundles of the carbon fiber layer in the radial direction of the connecting tube to the total layer thickness of the carbon fiber layer is greater than or equal to 40%.

18. The electric tool according to claim 17, characterized in that: The number of the carbon fiber layers is configured as one layer, and the carbon fiber outer layer is a woven structure composed of multiple fiber bundles; or the number of the carbon fiber layers is configured as greater than or equal to two layers, and the carbon fiber outer layer is a woven structure composed of multiple fiber bundles, and the remaining carbon fiber layers are arranged on the inner side of the carbon fiber outer layer in the radial direction of the connecting tube to form a carbon fiber inner layer, and the carbon fiber inner layer includes the axial fiber bundles extending and arranged along the axial direction of the connecting tube, and the ratio of the total layer thickness of the axial fiber bundles to the total layer thickness of the carbon fiber inner layer is greater than or equal to 50%.

19. The electric tool according to claim 18, characterized in that: The total weight of the electric tool is less than or equal to 7 kg, the wall thickness of the connecting pipe is 1.5 mm to 2.0 mm, and the ratio of the impact energy that the connecting pipe can withstand to the wall thickness of the connecting pipe is greater than or equal to 58 J / mm.

20. The electric tool according to claim 19, characterized in that: The electric tool is a lawn mower, the total weight of which is less than or equal to 7 kg, the battery pack is arranged at one end of the connecting tube located at the grip assembly, the power assembly is arranged at one end of the connecting tube located at the working head assembly, and the wall thickness of the connecting tube is 1.5 mm to 1.8 mm.

21. The electric tool according to claim 18, characterized in that: The weight of the bare body of the electric tool, i.e., after removing the battery pack, is 4.2 kg to 5.5 kg. The electric tool is a high-branch saw, which includes a connecting assembly. The working head assembly is provided at one end of the connecting assembly, and the battery pack, the power assembly and the grip assembly are provided at the other end. The connecting assembly includes a telescopic tube and a handle tube. The handle tube is connected to the grip assembly. The telescopic tube includes an inner tube and an outer tube. The inner tube is at least partially coaxially slidably nested in the outer tube and one end of which is connected to the working head assembly. A locking piece is also provided between the inner tube and the outer tube to keep the two relatively fixed. The outer tube is arranged between the inner tube and the handle tube, and the connecting tube is configured as the outer tube.

22. An electric tool, comprising: A working head assembly, the working head assembly comprising a working head for an operation; A power assembly, the power assembly drives the working head; A battery pack, the battery pack providing power to the power assembly; A grip component for a user to hold; The connecting pipe comprises a first connecting pipe connected to the working head assembly and a second connecting pipe connected to the holding assembly, characterized in that: The first connecting tube and / or the second connecting tube are at least arranged with a first material layer made of carbon fiber material and a second material layer made of non-carbon fiber material in the radial direction, the stiffness of the second material layer is smaller than the stiffness of the first material layer, and the toughness of the second material layer is greater than the toughness of the first material layer.

23. The electric tool according to claim 22, characterized in that: The total thickness of the second material layers in the first connecting pipe accounts for 50% to 80% of the total wall thickness of the first connecting pipe.

24. The electric tool according to claim 23, characterized in that: The second material layer of the first connecting pipe is a glass fiber layer.

25. The electric tool according to claim 23, characterized in that: The second material layer of the first connecting tube includes an axial fiber bundle extending and arranged along the axial direction of the first connecting tube, and the ratio of the total thickness of the axial fiber bundle in the radial direction of the first connecting tube to the total layer thickness of the second material layer is greater than or equal to 80%.

26. The electric tool according to claim 23, characterized in that: The outermost layer of the first connecting tube in the radial direction is a carbon fiber outer layer formed by the first material layer.

27. The electric tool according to claim 26, characterized in that: The carbon fiber outer layer of the first connecting tube has a different fiber arrangement direction from that of the adjacent material layer.

28. The electric tool according to claim 26 or 27, characterized in that: The first material layer of the first connecting tube includes axial fiber bundles extending along the axial direction of the first connecting tube, and the ratio of the total thickness of the axial fiber bundles in the radial direction of the first connecting tube to the total layer thickness of the first material layer is greater than or equal to 40%.

29. The electric tool according to claim 28, characterized in that: The number of the first material layers of the first connecting tube is configured as one layer, and the carbon fiber outer layer of the first connecting tube is a woven structure composed of multiple fiber bundles; or, the number of the first material layers of the first connecting tube is configured as greater than or equal to two layers, and the carbon fiber outer layer of the first connecting tube is a woven structure composed of multiple fiber bundles, and the remaining first material layers are arranged on the inner side of the carbon fiber outer layer in the radial direction of the first connecting tube to constitute a carbon fiber inner layer, and the carbon fiber inner layer of the first connecting tube includes the axial fiber bundles arranged and extended along the axial direction of the first connecting tube, and the ratio of the total layer thickness of the axial fiber bundles to the total layer thickness of the carbon fiber inner layer is greater than or equal to 50%.

30. The electric tool according to claim 22, characterized in that: The total thickness of the second material layers in the second connecting pipe accounts for 50% to 80% of the total wall thickness of the second connecting pipe.

31. The electric tool according to claim 30, characterized in that: The second material layer of the second connecting pipe is a glass fiber layer.

32. The electric tool according to claim 30, characterized in that: The second material layer of the second connecting tube includes axial fiber bundles extending along the axial direction of the second connecting tube, and the ratio of the total thickness of the axial fiber bundles in the radial direction of the second connecting tube to the total layer thickness of the second material layer is greater than or equal to 80%.

33. The electric tool according to claim 30, characterized in that: The outermost layer of the second connecting pipe in the radial direction is a carbon fiber outer layer formed by the carbon fiber layer.

34. The electric tool according to claim 33, characterized in that: The carbon fiber outer layer of the second connecting tube has a different fiber arrangement direction from that of the adjacent material layer.

35. The electric tool according to claim 33 or 34, characterized in that: The first material layer of the second connecting tube includes axial fiber bundles extending along the axial direction of the second connecting tube, and the ratio of the total thickness of the axial fiber bundles in the radial direction of the second connecting tube to the total layer thickness of the first material layer is greater than or equal to 40%.

36. The electric tool according to claim 35, characterized in that: The number of the first material layers of the second connecting tube is configured as one layer, and the carbon fiber outer layer is a woven structure composed of multiple fiber bundles; or, the number of the first material layers of the second connecting tube is configured as greater than or equal to two layers, the carbon fiber outer layer of the second connecting tube is a woven structure composed of multiple fiber bundles, and the remaining first material layers are arranged on the inner side of the carbon fiber outer layer in the radial direction of the second connecting tube to form a carbon fiber inner layer, and the carbon fiber inner layer of the second connecting tube includes the axial fiber bundles arranged and extended along the axial direction of the second connecting tube, and the ratio of the total layer thickness of the axial fiber bundles to the total layer thickness of the carbon fiber inner layer is greater than or equal to 50%.

37. An electric tool, comprising: A working head assembly, the working head assembly comprising a working head for an operation; A power assembly, the power assembly drives the working head; A battery pack, the battery pack providing power to the power assembly; A grip component for a user to hold; A connecting assembly, disposed between the working head assembly and the holding assembly; The working head assembly is arranged at one end of the connecting assembly, and the battery pack, the power assembly and the grip assembly are arranged at the other end. The connecting assembly comprises a first connecting tube, a second connecting tube and a handle tube, the handle tube is connected to the grip assembly, the first connecting tube is closer to the working head assembly than the second connecting tube, the second connecting tube is connected to the first connecting tube, and the second connecting tube is closer to the grip assembly than the first connecting tube, and is characterized in that: The first connecting tube is provided with at least one carbon fiber layer made of carbon fiber material in its radial direction, and the second connecting tube is provided with at least one carbon fiber layer made of carbon fiber material in its radial direction, wherein the ratio of the sum of the layer thicknesses of the carbon fiber layers in the first connecting tube to the total wall thickness of the first connecting tube is greater than the ratio of the sum of the layer thicknesses of the carbon fiber layers in the second connecting tube to the total wall thickness of the second connecting tube.

38. The electric tool according to claim 37, characterized in that: The first connecting tube and the second connecting tube constitute a telescopic tube, the first connecting tube is configured as the inner tube of the telescopic tube, the second connecting tube is configured as the outer tube of the telescopic tube, the inner tube is at least partially coaxially slidably nested in the outer tube and one end of the inner tube is connected to the working head assembly, a locking piece is also provided between the inner tube and the outer tube to keep the two relatively fixed, and the outer tube is arranged between the inner tube and the handle tube.

39. The electric tool according to claim 38, characterized in that: The ratio of the total thickness of the carbon fiber layers in the inner tube to the total wall thickness of the inner tube is 100%.

40. The electric tool according to claim 39, characterized in that: The inner tube has at least two carbon fiber layers arranged in the radial direction thereof, the carbon fiber layer located at the outermost layer in the radial direction of the inner tube is a woven structure composed of multiple fiber bundles, and the remaining carbon fiber layers are unidirectional structures composed of multiple fiber bundles.

41. The electric tool according to claim 40, characterized in that: The unidirectional structure includes an axial structure and a circumferential structure. A plurality of fiber bundles extend axially along the inner tube to form the axial structure, and a plurality of fiber bundles extend circumferentially along the inner tube to form the circumferential structure, wherein the ratio of the total layer thickness of the carbon fiber layer using the axial structure to the total layer thickness of the carbon fiber layer using the circumferential structure is 3:

2.

42. The electric tool according to claim 38, characterized in that: The outer tube is further provided with one or at least two glass fiber layers made of glass fiber material in the radial direction, and the total thickness of the glass fiber layers accounts for 50% to 80% of the total wall thickness of the outer tube.

43. The electric tool according to claim 42, characterized in that: The glass fiber layer of the outer tube includes axial fiber bundles extending and arranged along the axial direction of the outer tube, and the ratio of the total thickness of the axial fiber bundles in the radial direction of the outer tube to the total layer thickness of the glass fiber layer is greater than or equal to 80%.

44. The electric tool according to claim 43, characterized in that: The outermost layer of the outer tube in the radial direction is a carbon fiber outer layer composed of the carbon fiber layer.

45. The electric tool according to claim 44, characterized in that: The carbon fiber outer layer of the outer tube and the adjacent material layer have different fiber arrangement directions.

46. ​​The electric tool according to claim 44 or 45, characterized in that: The carbon fiber layer of the outer tube includes axial fiber bundles extending and arranged along the axial direction of the outer tube, and the ratio of the total thickness of the axial fiber bundles in the radial direction of the outer tube to the total thickness of the carbon fiber layer is greater than or equal to 40%.

47. The electric tool according to claim 46, characterized in that: The number of the carbon fiber layers of the outer tube is configured as one layer, and the carbon fiber outer layer is a woven structure composed of multiple fiber bundles; or, the number of the carbon fiber layers of the outer tube is configured as greater than or equal to two layers, and the carbon fiber outer layer of the outer tube is a woven structure composed of multiple fiber bundles, and the remaining carbon fiber layers are arranged on the inner side of the carbon fiber outer layer in the radial direction of the outer tube to constitute a carbon fiber inner layer, and the carbon fiber inner layer of the outer tube includes the axial fiber bundles extending and arranged along the axial direction of the outer tube, and the total thickness of the axial fiber bundles in the radial direction of the outer tube accounts for a ratio of greater than or equal to 60% of the total thickness of the carbon fiber layers.

48. The electric tool according to claim 37, characterized in that: The handle tube is a metal tube.

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