Electric tool

Abstract

The utility model 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

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

[0002] The present application, including the embodiments of the present utility model, relates to the technical field of electric tools, and specifically to an electric tool. Background Art

[0003] In some power tools, such as lawn mowers and high-branch saws, the connecting pipes that connect 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. Utility Model Content

[0004] 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.

[0005] In order to achieve the above objectives, the present disclosure provides the following technical solutions:

[0006] An electric tool, comprising:

[0007] A working head assembly, the working head assembly comprising a working head for an operation;

[0008] A power assembly, the power assembly drives the working head;

[0009] A battery pack, the battery pack providing power to the power assembly;

[0010] A grip component for a user to hold;

[0011] A connecting pipe, arranged between the working head assembly and the holding assembly;

[0012] 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.

[0013] 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.

[0014] In one embodiment, the second material layer is a glass fiber layer.

[0015] 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 more than or equal to 80% of the total thickness of the second material layer.

[0016] 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.

[0017] In one embodiment, the carbon fiber outer layer and the adjacent material layer have different fiber arrangement directions.

[0018] 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 a total thickness of the first material layer of greater than or equal to 40%.

[0019] 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, 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%.

[0020] In one embodiment, the total weight of the electric 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.

[0021] 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.

[0022] In one embodiment, 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.

[0023] 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.

[0024] In order to achieve the above objectives, the present disclosure provides the following technical solutions:

[0025] An electric tool, comprising:

[0026] A working head assembly, the working head assembly comprising a working head for an operation;

[0027] A power assembly, the power assembly drives the working head;

[0028] A battery pack, the battery pack providing power to the power assembly;

[0029] A grip component for a user to hold;

[0030] A connecting pipe is provided between the working head assembly and the holding assembly.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] In one embodiment, the carbon fiber outer layer and the adjacent material layer have different fiber arrangement directions.

[0036] 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 total thickness of the carbon fiber layer of greater than or equal to 40%.

[0037] 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, 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%.

[0038] In one embodiment, the total weight of the electric 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.

[0039] 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.

[0040] In one embodiment, 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.

[0041] 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 which is light in weight, has satisfactory impact resistance and anti-buffering performance, and is low in cost.

[0042] In order to achieve the above objectives, the present disclosure provides the following technical solutions:

[0043] An electric tool, comprising:

[0044] A working head assembly, the working head assembly comprising a working head for an operation;

[0045] A power assembly, the power assembly drives the working head;

[0046] A battery pack, the battery pack providing power to the power assembly;

[0047] A grip component for a user to hold;

[0048] A connecting pipe, the connecting pipe includes a first connecting pipe connected to the working head assembly and a second connecting pipe connected to the holding assembly,

[0049] 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.

[0050] 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.

[0051] In one embodiment, the second material layer of the first connecting pipe is a glass fiber layer.

[0052] 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 total thickness of the axial fiber bundle in the radial direction of the first connecting tube accounts for greater than or equal to 80% of the total layer thickness of the second material layer.

[0053] 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.

[0054] In one embodiment, the carbon fiber outer layer of the first connecting tube has a different fiber arrangement direction from that of an adjacent material layer.

[0055] In one embodiment, the first material layer of the first connecting tube includes an axial fiber bundle extending along the axial direction of the first connecting tube, and the total thickness of the axial fiber bundle in the radial direction of the first connecting tube accounts for a total layer thickness of the first material layer greater than or equal to 40%.

[0056] 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, 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%.

[0057] 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.

[0058] In one embodiment, the second material layer of the second connecting pipe is a glass fiber layer.

[0059] In one embodiment, the second 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 80% of the total layer thickness of the second material layer.

[0060] In one embodiment, the outermost layer of the second connecting pipe in the radial direction is a carbon fiber outer layer formed by the carbon fiber layer.

[0061] In one embodiment, the carbon fiber outer layer of the second connecting tube has a different fiber arrangement direction from that of an adjacent material layer.

[0062] 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 total layer thickness of the first material layer greater than or equal to 40%.

[0063] 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 constitute 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%.

[0064] 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.

[0065] The technical solution adopted by the embodiments of the present disclosure to solve the problems of the prior art is:

[0066] An electric tool, comprising:

[0067] A working head assembly, the working head assembly comprising a working head for an operation;

[0068] A power assembly, the power assembly drives the working head;

[0069] A battery pack, the battery pack providing power to the power assembly;

[0070] A grip component for a user to hold;

[0071] A connecting assembly, disposed between the working head assembly and the holding assembly;

[0072] The working head assembly is disposed at one end of the connecting assembly, and the battery pack, the power assembly and the grip assembly are disposed at the other end. The connecting assembly includes 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.

[0073] 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.

[0074] 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 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.

[0075] 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.

[0076] In one embodiment, 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.

[0077] 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.

[0078] 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.

[0079] 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 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%.

[0080] In one embodiment, the outermost layer of the outer tube in the radial direction is a carbon fiber outer layer formed by the carbon fiber layer.

[0081] In one embodiment, the carbon fiber outer layer of the outer tube and its adjacent material layer have different fiber arrangement directions.

[0082] 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 a total thickness of the carbon fiber layer of greater than or equal to 40%.

[0083] 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 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.

[0084] In one embodiment, the handle tube is a metal tube.

[0085] Compared with the prior art, in the above-mentioned preferred embodiment of the utility model, 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 usage ratio of glass fiber and carbon fiber can be 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

[0086] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and the description thereof are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0087] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0088] Figure 1 A schematic diagram of a structure in which a material layer adopts a woven structure;

[0089] Figure 2 It is a structural schematic 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;

[0090] Figure 3 A cross-sectional view of one structure of the connecting tube when the number of the first material layer, i.e., the carbon fiber layer, and the number of the second material layer, i.e., the glass fiber layer, are both configured as one layer;

[0091] Figure 4 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 number of the second material layer, i.e., the glass fiber layer, are both configured as one layer;

[0092] Figure 5 A cross-sectional view of one structure of the connecting tube 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 greater than or equal to two layers;

[0093] Figure 6 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;

[0094] Figure 7 A cross-sectional view of one structure of the connecting tube when the number of the first material layer, i.e., the carbon fiber layer, is configured to be greater than or equal to two layers and the number of the second material layer, i.e., the glass fiber layer, is configured to be one layer;

[0095] Figure 8 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 greater than or equal to two layers, and the number of the second material layer, i.e., the glass fiber layer, is configured to be one layer;

[0096] Fig. 9 A cross-sectional view of another structure of the connecting tube when the number of the first material layer, i.e., the carbon fiber layer, is configured to be greater than or equal to two layers, and the number of the second material layer, i.e., the glass fiber layer, is configured to be one layer;

[0097] Fig.10 A cross-sectional view of one structure of the connecting tube 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;

[0098] Fig.11 A cross-sectional view of another structure of the connecting tube 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;

[0099] Fig.12 A cross-sectional view of a preferred structure of a connecting pipe provided in the present application;

[0100] Fig.13 It is a schematic diagram of a limiting structure protruding on the inner side wall of the connecting pipe;

[0101] Fig.14 for Fig.13 A schematic diagram of the structure of the limiting structure and the lining;

[0102] Fig.15 It is a schematic diagram of the structure of a clamp having a C-shaped part;

[0103] Fig.16 It is a schematic diagram of the structure of a clamp with a U-shaped part;

[0104] Fig.17 A schematic diagram of the structure of a front-mounted grass trimmer using the connecting pipe provided in the present application;

[0105] Fig.18 It is a structural schematic diagram of an existing rear-mounted grass trimmer;

[0106] Fig.19 A schematic diagram of the structure of a high-branch saw using the telescopic tube provided in the present application;

[0107] Fig. 20 A schematic structural diagram of a multi-working head electric tool using the split connecting pipe provided in the present application.

[0108] Reference numerals and component descriptions in the drawings:

[0109] 100, front-mounted mower; 200, rear-mounted mower; 300, high-branch saw; 400, multi-working head power tool;

[0110] 10. Connecting tube / telescopic tube; 20. Working head assembly; 30. Battery pack; 40. Grip assembly; 50. Limiting structure; 60. Lining; 70. Clamp; 80. Handle tube; 90. Locking piece;

[0111] 101, inner tube; 102, outer tube; 103, first material layer / carbon fiber layer / carbon fiber inner layer; 104, second material layer / glass fiber layer; 105, carbon fiber outer layer; 106, fiber bundle; 107, first connecting tube; 108, second connecting tube;

[0112] 201, working head / grass cutting head;

[0113] 701, C-shaped part; 702, U-shaped part; 703, connecting part; 704, through hole;

[0114] A, B, C, D, E, second material layer / glass fiber layer; F, G, first material layer / carbon fiber layer / carbon fiber inner layer;

[0115] H. Carbon fiber outer layer. DETAILED DESCRIPTION

[0116] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described implementation is a partial implementation of the utility model, not all implementations. Based on the implementation of the utility model, all other implementations obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0117] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0118] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0119] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0120] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0121] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0122] In the field of electric tools, most electric tools need to be held for a long time by the user to operate. Therefore, it is important to suppress the maximum weight of the electric tool, especially for electric tools with a connecting tube 10, such as lawn mowers, high-branch saws, brush cutters, etc. Usually, the electric tools 100, 200, 300, 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 electric tool, and a control panel 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 installed at one end of the connecting tube 10 located at the grip assembly 40 in a detachable manner. The grip assembly 40 is for the user to hold and is provided with an operating switch for the user to operate the tool.

[0123] The connecting tube 10 can be used 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, 300, the connecting tube 10 is an integral tube structure, and 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 various types of working head assemblies 20, and the second connecting tube 108 is connected to the grip assembly 40, and the working head assembly 20 and the grip assembly 40 of the power tool 400 are connected by connecting 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 the end for being gripped and manipulated by the operator) 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 holding assembly 40 of the high-branch saw 300 (the holding assembly 40 is the end of the high-branch saw 300 used by the operator to hold and operate the working head assembly 20 relative to the ground) and the working head assembly 20 (the working head assembly 20 is the end for trimming high trees).

[0124] 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 fall of the tool, 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 the requirements of lightweight and impact resistance are taken into account, some new problems have arisen in the actual process for some specific power tools. For example, the lawn mowers 100 and 200, the all-carbon fiber connecting tube 10 meets the requirements of lightweight and impact resistance, but 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 composed of an inner tube 101 and an outer tube 102. Based on the usage scenario and 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 comfort in use, that is, to reduce the numbness of the user's hands. The outer tube 102 made of all carbon fiber has redundant impact resistance and poor anti-buffering performance. The use of all-carbon fiber solution further increases costs and has a low cost-performance ratio.

[0125] In the present 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 electric tools 100, 200, 300, 400 using the connecting tube 10 have a better user experience, and the material cost can also be further reduced.

[0126] This connecting tube 10 is made of composite fibers of different types, and 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 types of fibers are different. Furthermore, the difference between the second material layer 104 using a fiber type different 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 fiber used to prepare 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 fiber used to prepare the second material layer 104 is greater than the fracture strain of the carbon fiber. By selecting materials in this way, the connecting tube 10 can be lightweight compared to the existing aluminum tube while also meeting the requirements of toughness and stiffness.

[0127] 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 stiffness, 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 stiffness and a certain toughness, which can ensure the stiffness of the entire connecting tube 10, so that the connecting tube 10 can better meet the working requirements of connection, support, force, etc., so that the second material layer 104 of glass fiber mainly enhances toughness and supplements stiffness, and the first material layer 103 of carbon fiber mainly enhances stiffness and supplements toughness, so that the toughness and stiffness of the connecting tube 10 are excellent, so that the comprehensive mechanical properties of the connecting tube 10 are improved.

[0128] At the same time, the present application also limits the proportion of carbon fiber and glass fiber, that is, the number of second material layers 104 is configured as one layer or at least two layers, and the total layer thickness of the second material layers 104 accounts for 50% to 80% of the total wall thickness of the connecting tube 10. Correspondingly, the number of first material layers 103 is configured as one layer or at least two layers, and the total layer thickness of the first material layers 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, the total thickness of the second material layer 104 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, 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, 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, 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 sum of the thickness of the first material layer 103 of the carbon fiber is too large, it means that the sum of the thickness of the second material layer 104 of the 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 sum of the thickness of the first material layer 103 of the carbon fiber is too small, it means that the sum of the thickness of the second material layer 104 of the 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 sum of the 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 to meet the requirements of anti-buffering performance and impact resistance, and further optimize the comprehensive mechanical properties of the connecting tube 10, which has 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 the existing aluminum tube, it is preferred that the sum of the thickness of the second material layer 104 accounts for 75% of the total wall thickness of the connecting tube 10, and the sum of the thickness of the first material layer 103 accounts for 25% of the total wall thickness of the connecting tube 10.

[0129] 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 directly connect to the working head assembly 20 and the gripping assembly 40.

[0130] When the above-mentioned connecting tube 10 is used as the connecting tube 10 of the electric 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 electric tools 100, 200, 300, 400 are lighter, and the operator can more easily load the electric 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.

[0131] When the connecting tube 10 falls laterally, the raised structure on the ground will impact the middle axial part of the connecting tube 10. 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 a carbon fiber outer layer 105 composed of the first material layer 103.

[0132] Specifically, in the radial direction of the connecting tube 10, the first material layer 103 and the second material layer 104 are arranged in sequence, and the outermost layer of the connecting tube 10 in the radial direction is set as a carbon fiber outer layer 105 composed of the first material layer 103. The number of the first material layer 103 is configured as one layer, and the first material layer 103 is the carbon fiber outer layer 105, and the remaining second material layers 104 are all wrapped by the carbon fiber outer layer 105, nested in the carbon fiber outer layer 105 and connected to the carbon fiber outer layer 105, and the second material layer 104 forms the inner side wall of the connecting tube 10. Alternatively, the number of the first material layer 103 is configured as more than or equal to two layers, 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, and the remaining first material layers 103 and second material layers 104 are arranged in sequence as needed and are wrapped, nested in and connected to the carbon fiber outer layer 105, and one of the remaining first material layers 103 or the second material layer 104 forms the inner side wall 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.

[0133] In the present application, the basic shape of the fiber is filament-type or linear-type, 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.

[0134] 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.

[0135] Further, in an optional embodiment, the number of first material layers 103 is configured as 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 as 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.

[0136] See also Figure 1 As shown, 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, a plurality of parallel fiber filaments are converged 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, and 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 configuration 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.

[0137] See also Figure 2As shown, 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, extend 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 a configuration 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, the rigidity of the carbon fiber inner layer 103 can also be improved, and the mechanical properties of the carbon fiber inner layer 103 can be optimized.

[0138] 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, wherein the unidirectional structure preferably adopts an axial structure in which the fiber bundles 106 are 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.

[0139] In an optional embodiment, the second material layer 104 can be arranged in 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 arranged in parallel along 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 arranged in parallel along the axial direction of the connecting tube 10. The axial structure formed by parallel arrangement is mainly adopted, 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 with an 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.

[0140] In this application, if Figure 1As shown, 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 also extends along the axial direction of the connecting tube 10, that is, the angle c between the two fiber bundles 106 and the axis of the connecting tube 10 is the same and is one-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 of the connecting tube 10 can be made into a symmetrical structure. When the connecting tube 10 is impacted perpendicular to the axial direction (i.e., radial direction), the symmetrical structure can further enhance the impact resistance of the connecting tube 10, so it is preferred to set the weaving structure symmetrically about the axial direction.

[0141] It should be noted that the angle between the first direction and the second direction and the axial direction should not be too large or too small. If the angle between the first direction and the second direction and the axial direction is too large, the fiber layer will have a smaller toughness and a larger stiffness. If the angle between the first direction and the second direction and the axial direction is too small, the fiber layer will have a larger toughness and a smaller stiffness. Preferably, the angle between the first direction and the second direction and the axial direction is 45 degrees.

[0142] Furthermore, the extending direction of the fiber bundle 106 in the unidirectional structure is the same as the axial direction of the connecting tube 10 (in this case, the extending direction of the fiber bundle 106 is as shown in FIG. Figure 2 The unidirectional structure is a structure in which the fiber bundle 106 is arranged along the axial direction of the connecting tube 10 to form an axial fiber bundle 106. Alternatively, the extending direction of the fiber bundle 106 of the unidirectional structure can be the same as the circumferential direction of the connecting tube 10, that is, the fiber bundle 106 of the unidirectional structure is perpendicular to the axial direction of the connecting tube 10 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 extending direction of the fiber bundle 106 in the unidirectional structure is arranged along the axial direction of the connecting tube 10, which can further improve the toughness of the connecting tube 10.

[0143] 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 extending 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 line segment. The angle between the straight line segment and the axis of the connecting tube 10 ranges from 0 degrees to 90 degrees, for example, 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 enable the connecting tube 10 to have good comprehensive performance in all directions, so that when it is used as the connecting tube 10 of the electric tool, it can improve the performance of the electric tool.

[0144] Furthermore, on the basis of the above two embodiments, the arrangement direction of the fiber bundle 106 of the radially outermost carbon fiber outer layer 105 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 radially outermost carbon fiber outer layer 105 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.

[0145] 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 a carbon fiber outer layer 105. The carbon fiber outer layer 105 adopts a woven structure, and the fiber bundles 106 of the woven structure are arranged in a direction (see the arrangement direction). Figure 1 The fiber bundles 106 of the second material layer 104 are arranged in a different direction, that is, the second material layer 104 adopts a unidirectional structure, and no matter the fiber bundles 106 of the unidirectional structure extend in the axial direction, the circumferential direction or the spiral direction around the axis of the connecting tube 10, they are all different from the braiding direction of the braided structure of the carbon fiber outer layer 105, for example, see Figure 3 As shown, the first material layer 103, i.e., the carbon fiber outer layer 105, adopts a woven 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;

[0146] Alternatively, the second material layer 104 adopts a woven structure, and the woven direction of the second material layer 104 is different from the woven direction of the carbon fiber outer layer 105. Figure 4 As shown, 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. In this way, the mechanical properties of the outer first material layer 103 and the inner second material layer 104 can be more prominent and more consistent.

[0147] For example, the number of the first material layer 103 is one layer, the number of the second material layer 104 is greater than or equal to two layers, the first material layer 103 is a carbon fiber outer layer 105, the carbon fiber outer layer 105 adopts a woven structure, and the fiber bundles 106 of the woven structure are arranged in a direction (see the arrangement direction). Figure 1 The fiber bundles 106 of the second material layer 104 adjacent to the carbon fiber outer layer 105 are arranged in a different direction, that is, the second material layer 104 adjacent to the carbon fiber outer layer 105 adopts a unidirectional structure, and no matter 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 second material layers 104 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 mainly selects an axial structure, and the total layer thickness of the second material layer 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 layer 104. For example, see Figure 5 As shown, radially from the inside to the outside of the connecting tube 10 are the second material layer 104 of the woven structure, the second material layer 104 of the unidirectional structure with the fiber bundle 106 extending axially along the connecting tube 10 , and the first material layer 103 of the woven structure, i.e. the carbon fiber outer layer 105 .

[0148] Alternatively, 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 that 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 layer 104 with an axial structure accounts for a ratio of greater than or equal to 80% of the total layer thickness of the second material layer 104. For example, see Figure 6 As shown, 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.

[0149] 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 on the inner side of the carbon fiber outer layer 105 in the radial direction of the connecting tube 10 to constitute the carbon fiber inner layer 103.

[0150] 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 fiber bundles 106 of the woven structure are arranged in a direction (see the arrangement direction for details). Figure 1 The arrangement direction of the fiber bundles 106 of the carbon fiber inner layer 103 is different. 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 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 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 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 of 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 the axial structure in the unidirectional structure, for example, see Figure 7 As shown, 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, a first material layer 103 with a unidirectional structure and fiber bundles 106 extending along the axial direction of the connecting tube 10, and a first material layer 103 with a woven structure, i.e., a carbon fiber outer layer 105.

[0151] Alternatively, 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 that 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, wherein 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 of 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, see Figure 8As shown, 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, a first material layer 103 with a woven structure, and the first material layer 103 with a woven structure, i.e., a carbon fiber outer layer 105.

[0152] If the second material layer 104 is arranged 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, the circumferential direction, or the spiral direction around the axis of the connecting tube 10, which are different from the woven direction of the woven structure of the carbon fiber outer layer 105, for example, see Fig. 9 As shown, 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 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, and the first material layer 103 with a woven structure, i.e., a carbon fiber outer layer 105.

[0153] 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 greater than two layers, one of the first material layers 103 constitutes the radially outermost carbon fiber outer layer 105 of the connecting tube 10, 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 the carbon fiber inner layer 103.

[0154] 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 fiber bundles 106 of the woven structure are arranged in a direction (see the arrangement direction for details). Figure 1The arrangement direction of the fiber bundles 106 of the carbon fiber inner layer 103 is different. That is, the carbon fiber inner layer 103 adjacent to the carbon fiber outer layer 105 adopts a unidirectional structure, and no matter 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 weaving structure of the carbon fiber outer layer 105. The remaining carbon fiber inner layers 103 can all adopt a weaving structure, or all adopt a unidirectional structure, or partly adopt a weaving structure and partly adopt a unidirectional structure, wherein 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 of greater than or equal to 50% of the total layer thickness of the carbon fiber inner layer 103. The second material layer 104 can all adopt a unidirectional structure, or partly adopt a weaving structure and partly adopt a unidirectional structure, wherein the unidirectional structure mainly selects an axial structure, and the total layer thickness of the second material layer 104 with an axial structure accounts for a ratio of greater than or equal to 80% of the total layer thickness of the second material layer 104. For example, see Fig.10 As shown, 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, 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, a first material layer 103 with a unidirectional structure and fiber bundles 106 extending along the axial direction of the connecting tube 10, and a first material layer 103 with a woven structure, i.e., a carbon fiber outer layer 105.

[0155] Alternatively, 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 that 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 may all adopt a woven structure, or all adopt a unidirectional structure, or partly adopt a woven structure and partly adopt a unidirectional structure, wherein the unidirectional structure mainly selects an axial structure, and the total layer thickness of the carbon fiber inner layer 103 with an axial structure accounts for a ratio of greater than or equal to 50% of the total layer thickness of the carbon fiber inner layer 103. The second material layer 104 may all adopt a unidirectional structure, or partly adopt a woven structure and partly adopt a unidirectional structure, wherein the unidirectional structure mainly selects an axial structure, and the total layer thickness of the second material layer 104 with an axial structure accounts for a ratio of greater than or equal to 80% of the total layer thickness of the second material layer 104. For example, see Fig.11As shown, in the radial direction of the connecting tube 10, from the inside to the outside, 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 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, a first material layer 103 with a woven structure, and the first material layer 103 with a woven structure, i.e., a carbon fiber outer layer 105.

[0156] 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 first material layers 103 or second material layers 104 can be increased by reducing the thickness of a single first material layer 103 or second material layer 104, thereby improving the impact toughness and stiffness of the connecting tube 10.

[0157] Such a configuration can ensure that the strength of the outermost layer of the connecting tube 10 is high, while reducing the impact energy transfer in the radial direction of the connecting tube 10. Even when it falls and contacts a 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.

[0158] When the number of layers of the first material layer 103 and the second material layer 104 is greater than or equal to two layers, 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 specially required, and it is only necessary to ensure that the arrangement direction of the fiber bundle 106 of the carbon fiber outer layer 105 is different from the arrangement direction of the fiber bundle 106 of the adjacent material layer. 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 are 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 are arranged alternately from the outside to the inside of the connecting tube 10 in the radial direction, and so on.

[0159] On the basis of the above embodiments, a preferred structure is that all the second material layers 104 are arranged together along the radial direction of the connecting tube 10, and the number of the second material layers 104 is five, 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 a second material layer 104 with a woven structure, a second material layer 104 with a woven structure, a second material layer 104 with a unidirectional structure, a second material layer 104 with a unidirectional structure, and a second material layer 104 with a unidirectional structure, or are a second material layer 104 with a unidirectional structure, a second material layer 104 with a unidirectional structure, a second material layer 104 with a unidirectional structure, a second material layer 104 with a woven structure, and a second material layer 104 with a woven structure. This arrangement can maximize the improvement of the toughness and vibration absorption performance of the connecting tube 10 , and is therefore used as the preferred arrangement of the second material layer 104 of the connecting tube provided in the present application.

[0160] Further, in combination with the above-mentioned embodiments, a preferred structure of the entire connecting tube 10 can be obtained, that is, multiple second material layers 104 are arranged in sequence from inside to 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 in sequence from inside to 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 radial outermost layer of the connecting tube 10 adopts a twill weaving structure. Among them, for example: 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 all adopt a unidirectional structure, and the extension direction of the fiber bundle 106 all extends along 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 by its weaving direction and the axial direction of the connecting tube 10 is different from the angle formed by the weaving direction of the carbon fiber outer layer H and the axial direction of the connecting tube 10, and the first material layer F can adopt a woven structure or a unidirectional structure. Alternatively, 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 partially adopt a unidirectional structure and partially adopt a braided structure, and the unidirectional structure and the braided structure are superimposed in the radial direction of the connecting tube 10. For details, see Fig.12As shown, 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 can adopt a twill woven structure and the weaving direction has an angle of 45 degrees with the axial direction of the connecting tube 10, for example.

[0161] Specifically, the number of layers of the first material layer 103 is one layer or more than or equal to two layers, the number of layers of the second material layer 104 is one layer or more than or equal to two layers, and each fiber layer of the connecting tube 10 includes epoxy resin. In the process of manufacturing the connecting tube 10, each fiber layer is immersed in a prepreg containing epoxy resin, so that the connecting tube 10 can be smoothly cured during the molding process, ensuring that each fiber layer can be molded according to a preset structure, so that the mechanical properties of the connecting tube 10 can be more reliably improved. 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 can make the connecting tube 10 have good heat resistance, thereby helping to improve the mechanical properties of the connecting tube 10. If the glass transition temperature of the epoxy resin is too large, the cost of the connecting tube 10 will increase; if the glass transition temperature of the epoxy resin is too small, the heat resistance of the connecting tube 10 is poor. Preferably, the glass transition temperature of the epoxy resin is 170°C to 210°C.

[0162] The connecting tube 10 provided by the present application can reduce weight by more than 30% compared to the aluminum tube in the prior art, and the axial modulus can reach 60GPa to 90GPa, so as to have a stiffness close to that of the aluminum tube, and can pass the 1m drop test without bending, and has better impact resistance than the aluminum tube. Under the same use conditions, the power tool using the connecting tube 10 has lower hand vibration and better anti-buffering performance than the power tool using the aluminum tube.

[0163] See also Fig.13 As shown, a limiting structure 50 is protrudingly provided on the inner side wall of the connecting tube 10. In some types of electric tools, the working head assembly 20 and the power assembly are respectively arranged at the two ends of the connecting tube 10. For example, the power assembly of the rear-mounted lawn mower 200 driving the working head assembly 20 is arranged at the grip assembly 40. Therefore, it is necessary to set a transmission structure inside the connecting tube 10. In order to prevent the transmission structure from radially vibrating in the connecting tube 10, an inner liner 60 is generally provided inside the connecting tube 10. In order to prevent the inner liner 60 from circumferentially rotating inside the connecting tube 10, a limiting structure 50 is also provided on the inner side wall of the connecting tube 10 and is installed in coordination with the inner liner 60. This limiting structure 50 can be a protrusion, see Fig.14As shown, the protrusion is embedded in the groove of the liner 60 to achieve the circumferential positioning of the liner 60 in the connecting pipe 10. The protrusion can extend in the axial direction of the connecting pipe 10 to form a convex strip to achieve more adequate positioning of the liner 60 over the entire axial length of the connecting pipe 10, and see Fig.13 As shown, the cross-sectional shape of the projection is a trapezoid or a rectangle, and the width d of the protruding end of the projection away from the inner side wall of the connecting tube 10 is less than 10 mm, and at the same time, a plurality of projections can be arranged at equal intervals on the circumference of the connecting tube 10, such as 2, 3 or 4. The material of the limiting structure 50 can be the above-mentioned glass fiber or carbon fiber, and its material is not limited to the material of the fiber layer forming the inner side wall of the connecting tube 10, that is, the material of the limiting structure 50 can be the same as or different from the material of the fiber layer of the inner side wall of the connecting tube 10. Alternatively, the limiting structure 50 can also be a groove provided on the inner side wall of the connecting tube 10. In addition, the limiting structure 50 may not be provided on the inner side wall of the connecting tube 10, and the connecting tube 10 of this structure can meet the working requirements of the front mower in which the motor is arranged at the working head assembly 20.

[0164] In addition, the connection between the connecting pipe 10 and the housing of the gripping assembly 40 is generally connected by a clamp 70. Fig.15 and Fig.16 As shown, the clamp 70 includes a C-shaped part 701 or two U-shaped parts 702, and a connecting part 703 is provided at the opening of the C-shaped part 701 or on both sides of the opening of the two U-shaped parts 702. The connecting part 703 is provided with a through hole 704 for the screw to pass through. When connected with the shell of the gripping component 40, the connecting pipe 10 is extended into the shell of the gripping component 40, and the clamp 70 is sleeved on the connecting pipe 10. The screw passing through the through hole 104 is tightened onto the shell of the gripping component 40 to achieve the clamping of the connecting pipe 10 by the clamp 70 and the connection between the clamp 70 and the shell of the gripping component 40, thereby realizing the connection between the connecting pipe 10 and the gripping component 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 wrapped around the connecting tube 10 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.

[0165] Furthermore, the connecting pipe 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 pipe 10 is a positioning groove, the positioning groove is an annular groove extending along the axial direction of the connecting pipe 10, and the width of the positioning groove matches the width of the C-shaped part 701 or the U-shaped part 702, so as to more stably realize the connection between the connecting pipe 10 and the clamp 70; when the structure provided on the connecting pipe 10 is a positioning hole, a fixing member such as a pin or a screw is passed through the C-shaped part 701 or the U-shaped part 702 and fixedly connected to the positioning hole, so as to more stably realize the connection between the connecting pipe 10 and the clamp 70, the diameter of the positioning hole is 5mm to 8mm, and a plurality of positioning holes are provided in the circumferential direction of the connecting pipe 10, and the distance between the positioning hole closest to the end of the connecting pipe 10 and the end is not more than 40mm, so as to further improve the connection firmness.

[0166] Normally, the weight of the entire power tool 100, 200, 300, 400 (including the weight of the battery pack) using the above-mentioned connecting tube 10 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 are corresponding improvement needs for 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 whole machine. Compared with aluminum tubes with the same wall thickness, length, and tube diameter and in the same drop scenario, the present connecting tube 10 can withstand greater impact energy.

[0167] In order to clearly and intuitively understand the connecting pipe 10 provided in the present application, a front mower 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 taken as an example for specific description.

[0168] See also Fig.17As shown, the front mower 100 includes 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 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 rotation of the motor. The battery pack 30 is a lithium battery pack and is installed at one end of the connecting pipe 10 located at the grip assembly 40 in a detachable manner. The grip assembly 40 is for the user to hold and is provided with a corresponding operating switch. The connecting pipe 10 is used as a connecting component to connect the working head assembly 20 and the grip assembly 40 of the front mower 100. The wall thickness of the connecting pipe 10 is set to be within 1.5mm to 1.8mm so that it can directly replace the existing aluminum tube, for example, 1.5mm, 1.6mm, 1.7mm, 1.8mm, etc.

[0169] In the usage scenario of the front 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 tubes, 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.

[0170] Since the weight of the front mower 100 is less than or equal to 7 kg, compared with other heavy electric tools, such as mowers weighing more than 7 kg, refer to Fig.18 As shown, most of this type of mowers are rear-mounted mowers 200 in which the motor is arranged at the grip assembly 40. Compared with the front-mounted mower 100, the weight of the two ends of the connecting pipe 10 is relatively balanced. One end of the connecting pipe 10 of the rear-mounted mower 200 is provided with the grip assembly 40, the power assembly and the battery pack 30, and the other end is provided with the working head assembly 20. The weight of the two ends of the connecting pipe 10 is unbalanced, and the rigidity requirement for the connecting pipe 10 is significantly higher than that of the connecting pipe 10 in the front-mounted mower 100. Since the rigidity requirement for the connecting pipe 10 of the front-mounted mower 100 does not need to be particularly strict, if the connecting pipe 10 is made of all carbon fiber material, it will increase the cost and have redundant performance, and the cost performance is not high. At the same time, the user will feel obvious numbness in the hand when using it, and the hand feeling is not good.

[0171] To this end, the present connecting tube 10 adds a toughening material, namely glass fiber, on the basis of the carbon fiber material, so that the connecting tube 10 is arranged with at least a carbon fiber layer (i.e., the first material layer) 103 and a glass fiber layer (i.e., the second material layer) 104 in its radial direction. The glass fiber layer 104 mainly enhances toughness and supplements stiffness, and the carbon fiber layer 103 mainly enhances stiffness and supplements toughness, so that the toughness and stiffness of the connecting tube 10 are both excellent, so that the comprehensive mechanical properties of the connecting tube 10 are improved, the material cost is lower, and the cost performance is higher. The addition of tough glass fiber improves the vibration absorption performance of the connecting tube 10 and reduces the numbness during use.

[0172] 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 matched 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 the present connecting tube 10 is equivalent to the cutting effect of the front mower 100 using the aluminum tube, and the use effect of the connecting tube 10 is also equivalent to or better than the use effect of the aluminum tube.

[0173] Furthermore, under the premise that the wall thickness range of the connecting tube 10 is 1.5 mm to 2.0 mm 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 0.15 mm to 0.25 mm. 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.

[0174] 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 strength of the outermost layer of the connecting tube 10 is high, and can reduce bump damage when falling, and can resist friction during transportation. In high and low temperature and rainy environments, the performance of the connecting tube 10 is not affected, and it 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.

[0175] Based on the carbon fiber layer 103 and the glass fiber layer 104, a braided structure or a unidirectional structure can be selected, but the carbon fiber layer 103 and the glass fiber layer 104 of the connecting tube 10 of the present embodiment are still mainly based on the axial structure in the unidirectional structure, that is, the ratio of the total layer thickness of the glass fiber layer 104 using the axial structure to the total layer thickness of the glass fiber layer 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 layer thickness of the carbon fiber inner layer 103 using the axial structure to the total layer thickness of all carbon fiber inner layers 103 is greater than or equal to 50%. Alternatively, the ratio of the total layer thickness of the glass fiber layer 104 using the axial structure to the total layer thickness of the glass fiber layer 104 is greater than or equal to 80%, and the ratio of the total layer thickness of the carbon fiber layer 103 using the axial structure to the total layer 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.

[0176] See also Fig.12As shown, a preferred connecting tube 10 structure is provided for application on a front mower 100, wherein a plurality of glass fiber layers 104 are arranged in sequence from inside to outside in the connecting tube diameter 10 upward 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 inside to outside in 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, i.e., 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 bundle 106 extends 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 bundle 106 extends along the axial direction of the connecting tube 10, the outermost carbon fiber layer H, i.e., 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.

[0177] In order to verify that the connection tube 10 provided in the present application is equivalent to or better than the impact resistance of the aluminum tube, a drop test is performed on the connection tube 10 to simulate the normal drop of the connection tube 10 during the use of the front mower 100. Before the drop test, a suitable battery pack 30 is first installed on the front mower 100, and then the front mower 100 is lifted horizontally to a height of 1m from the curb (the height of the curb from the ground is 15cm to 20cm, and the curb is 15cm wide) and then released, so that the front mower 100 falls freely. The curb impacts the weakest position of the connection tube 10, that is, the axial center. The drop test requires that there should be no cracks at the position where the connection tube 10 is impacted. In addition, by observing whether the connection tube 10 and the aluminum tube are bent after the drop test, the impact resistance of the connection tube 10 and the aluminum tube can be further compared.

[0178] Furthermore, in order to reduce the safety risk of the front mower 100 using the connecting tube 10, a blade 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 test, a suitable battery pack 30 is first installed on the front mower 100, and then the front mower 100 is lifted horizontally to a height of 1m above the blade and released. The blade of the blade impacts the weakest position of the connecting tube 10, that is, the axial center. The blade test requires that there should be no cracks at the impacted position of the connecting tube 10 or the cracks generated should be less than 10mm in width in the axial direction of the connecting tube 10, and the crack width should not expand after 1,000 hits with wooden stakes.

[0179] For a clearer comparison, the following Table 1 shows the test results of a front mower using a connecting pipe within the above-mentioned specification parameter range, a front mower not using a connecting pipe within the above-mentioned specification parameter range, and a front mower using an existing aluminum tube of the same specification.

[0180]

[0181] Table 1

[0182] By comparison, it can be seen that the connecting tube 10 provided by the present application has the same length and wall thickness as the aluminum tube, and the mass of the front mower 100 using the connecting tube 10 is significantly less than the mass of the entire mower using the aluminum tube. The connecting tube 10 provided by the present application and the existing aluminum tube can both pass the 1m drop test and the blade test, that is, the impact resistance of the connecting tube 10 of the present application is equivalent to that of the aluminum tube. Furthermore, by comparing the bending conditions of the connecting tube 10 of 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 of the present application is better than that of the aluminum tube.

[0183] In some other power tools using connection components, such as a high-branch saw 300 with a bare machine mass of 4.2 kg to 5.0 kg, a working head component 20 is provided at one end of the connection component, and a battery pack 30, a power component and a grip component 40 are provided at the other end, wherein the connection component includes a telescopic tube 10 and a handle tube 80, and the handle tube 80 is connected to the grip component 40. The working head component 20 includes at least a housing, a guide plate 202, a chain saw, etc., wherein a portion of the guide plate 202 is disposed in the housing, and during the cutting process, the chain saw slides at high speed on the guide plate 202. The grip component 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, so that the user can operate the machine easily. 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 of the inner tube 101 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 transmission structure of the power assembly is provided in the inner tube 101 and the outer tube 102 and is drivingly connected to the front working head assembly 20.

[0184] When the high branch saw 300 is used to prune branches, the inner tube 101 is stretched to a suitable 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 with both hands respectively, and lifts the working head assembly 20 connected to the front end of the inner tube 101 to a suitable height and hangs it against the branch to be pruned. The grip assembly 40 is pulled to make the connecting assembly 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 branches. Generally, the overall length of the telescopic tube 10 of the high branch saw 300 can reach more than 3m. 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 deforming so that the user can accurately lift the working head assembly 20 to the specified position, the rigidity and toughness of the inner tube 101 should be given priority to make it have stronger rigidity to improve the bending resistance. Once a fall occurs, the working head assembly 20 falls in an arc shape with the user's grip 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, while the outer tube 102 is closer to the user's grip, and 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.

[0185] In this regard, the present application also provides an electric tool having an outer tube 102 with light weight, satisfactory impact resistance and anti-buffering performance and low cost, and an inner tube 101 with light weight, satisfactory impact resistance and anti-bending performance. For ease of understanding, a high-branch saw 300 is taken as an example for detailed description.

[0186] See also Fig.19 As shown, an electric tool is a high-branch saw 300, which includes a working head assembly 20, a power assembly, a battery pack 30, a grip assembly 40 and a connecting assembly, wherein the working head assembly 20 at least includes a housing, a guide plate 202, a chain saw, etc., wherein a portion of the guide plate 202 is arranged in the housing, and during the cutting process, the chain saw slides at high speed on the guide plate 200 to cut branches. The working head assembly 20 is arranged at one end of the connecting assembly, and the battery pack 30, the power assembly and the grip assembly 40 are arranged at the other end. The bare machine mass of such a high-branch saw 300, that is, the weight after removing the battery pack 30, is generally 4.2 kg to 5.0 kg.

[0187] 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 the user to operate the machine. The connection 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, wherein 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, and a locking member 90 is also provided between the inner tube 101 and the outer tube 102 to keep the two relatively fixed, and the outer tube 102 is provided between the inner tube 101 and the handle tube 80, and the handle tube 80 is the same as the handle tube 80 in the existing high-branch saw 300, and both are made of metal tubes.

[0188] The transmission structure of the power assembly is arranged in the inner tube 101 and the outer tube 102 and is drivingly connected to the front working head assembly 20. The inner tube 101 and the outer tube 102 are provided with a liner 60 between the inner side wall and the transmission structure to reduce the radial vibration of the transmission structure. At the same time, a limiting structure 50 is protrudingly arranged on the inner side wall of the inner tube 101 and the outer tube 102, and is installed in conjunction with the liner 60 in the tube to further limit the liner 60 from rotating circumferentially along the inner tube 101 or the outer tube 102 in the tube. The limiting structure 50 can be a convex strip extending in the axial direction of the inner tube 101 or the outer tube 102, a single convex block or a groove, and one is arranged in the circumferential direction of the inner side wall of the inner tube 101 and the outer tube 102, or multiple liner 60 can be arranged at equal intervals, such as 2, 3 or 4. 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.

[0189] Since the working head assembly 20 of the high branch saw 300 is used at a relatively high height, the inner tube 101 must ensure that it does not bend or deform after being connected to the working head assembly 20, and must also ensure that the inner tube 101 can withstand the impact of the raised structure on the ground after a fall occurs, and that the tube body does not break and that cracks do not appear on the surface of the tube body. The impact resistance of the inner tube 101 needs to be significantly higher than that of the outer tube 102, and it also needs better bending resistance. The outer tube 102 is closer to the user's grip than the inner tube 101, and in the event of a fall, the probability that the outer tube 102 is impacted by the raised structure on the ground is lower than the probability that the inner tube 101 is 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, so that less vibration generated during the tool cutting process is transmitted to the user's grip, so that the user has a better grip feel.

[0190] Based on this, the structure of the telescopic tube 10, i.e., 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 ratio 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 ratio 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.

[0191] Afterwards, it is preferred to set the ratio of the total thickness of the carbon fiber layer 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 of all carbon fiber materials, which, on the one hand, achieves the purpose of lightweight, and on the other hand, can also meet the performance requirements of the stiffness of the inner tube 101. In addition, the wall thickness of the inner tube 101 is set within 1.6 mm to 2.3 mm, such as 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, etc., so that it is similar to or the same as the wall thickness of the inner tube in the existing metal telescopic tube, so that it can be directly replaced.

[0192] When a fall occurs, the protruding structure on the ground first impacts the outer wall of the inner tube 101, and then the impact energy is transferred to the inside of the inner tube 101 along the radial direction of the inner tube 101. In this way, in order to further reduce the impact energy transfer effect in the radial direction of the inner tube 101, the carbon fiber layer 103 located at the outermost layer in the radial direction of the inner tube 101 is formed into a carbon fiber outer layer 105, and the carbon fiber outer layer 105 adopts a woven structure composed of multiple fiber bundles 106, and the arrangement direction of the fiber bundles 106 of the adjacent carbon fiber layer 103 is different. The remaining carbon fiber layer 103 adopts a unidirectional structure composed of multiple fiber bundles 106. Such an arrangement can make the mechanical properties of the carbon fiber outer layer 105 with a woven structure and the carbon fiber layer 103 with a unidirectional structure more prominent.

[0193] Furthermore, during the forming process of the above-mentioned woven 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, and 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. Through such an arrangement, the fiber bundles 106 of the carbon fiber outer layer 105 located at the outermost layer in the radial direction 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.

[0194] See also Figure 1 As shown, 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 is also extended 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 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 a symmetrical structure. When the inner tube 101 is impacted perpendicular to the axial direction (i.e., radial direction), the symmetrical structure can further enhance the impact resistance of the inner tube 101, so it is preferred that the braided structure is arranged symmetrically about the axial direction.

[0195] The above-mentioned unidirectional structure includes an axial structure and a circumferential structure, wherein the extending direction of the fiber bundle 106 in the axial structure is the same as the axial direction of the inner tube 101 (in this case, the extending direction of the fiber bundle 106 is as follows: Figure 2As shown), the axial fiber bundles 106 constituting the axial structure are arranged to extend along the axial direction of the inner tube 101. The extending direction of the fiber bundles 106 in the circumferential structure is the same as the circumferential direction of the inner tube 101, that is, the fiber bundles 106 constituting the circumferential structure are perpendicular to the axis of the inner tube 101 in the horizontal plane. The ratio of the total layer thickness of the carbon fiber layer 103 with an axial structure to the total layer thickness of the carbon fiber layer 103 with a circumferential structure in the inner tube 101 in this embodiment is 3:2, that is, the total layer thickness of the carbon fiber layer 103 with an axial structure accounts for 60% of the total layer thickness of the carbon fiber layer 103 with a unidirectional structure, and the total layer thickness of the carbon fiber layer 103 with a circumferential structure accounts for 40% of the total layer thickness of the carbon fiber layer 103 with a unidirectional structure. With such a configuration, on the one hand, the carbon fiber inner layer 103 with a unidirectional structure in the inner tube 101 can ensure the consistency of stiffness and reduce the transmission effect of the impact energy in the radial direction of the inner tube 101.

[0196] The outer tube 102, under the premise of meeting the rigidity requirement, also needs to have better vibration absorption performance than the inner tube 101. The outer tube 102 can use the connecting tube structure in the embodiment of the front mower 100 described above. The outer tube 102 is also arranged with one or at least two glass fiber layers 104 made of glass fiber material in its radial direction. The preferred structure can be seen in Fig.12 As shown. Glass fiber has good toughness and a certain degree of rigidity, which can significantly improve the toughness of the entire outer tube 102. Carbon fiber has high rigidity and a certain degree of rigidity, which can ensure the rigidity of the entire outer tube 102, so that the outer tube 102 can better meet the working requirements of connection, support, force, etc. In this way, the glass fiber layer 104 mainly enhances the toughness and supplements the rigidity, and the carbon fiber layer 103 mainly enhances the rigidity and supplements the toughness, so that the outer tube 102 has both excellent toughness and rigidity, so that the outer tube 102 meets the actual use requirements.

[0197] At the same time, the proportion of glass fiber and carbon fiber is 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 proportion of the total thickness of the carbon fiber layer 103 and the glass fiber layer 104, the toughness and stiffness of the outer tube 102 can be better matched, the requirements of anti-buffering performance and impact resistance can be met, and the comprehensive mechanical properties of the outer tube 102 can be further optimized, and it has good vibration absorption characteristics and excellent anti-buffering performance during use. Preferably, the total thickness of the glass fiber layer 104 accounts for 75% of the total wall thickness of the outer tube 102, and the total thickness of the carbon fiber layer 103 accounts for 25% of the total wall thickness of the outer tube 102.

[0198] Similar to the above-mentioned inner tube 101, it is preferred that the outermost layer of the outer tube 102 in the radial direction is a carbon fiber outer layer 105 composed of a carbon fiber layer 103, and the carbon fiber outer layer 105 adopts a woven structure to resist the impact of the protruding structure on the ground on the outer wall of the outer tube 102 when falling, and secondly, the arrangement direction of the fiber bundles 106 of the carbon fiber outer layer 105 and the adjacent material layer is set to be different, so as to reduce 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 the radial direction is a carbon fiber outer layer 105 composed of a carbon fiber layer 103, and the woven direction of the carbon fiber outer layer 105 is set to be different from the arrangement direction of the fiber bundles 106 of the adjacent material layer, wherein the carbon fiber layer 103 includes axial fiber bundles extending and arranged along the axial direction of the outer tube 102, and the total thickness of the axial fiber bundles in the radial direction of the outer tube 102 accounts for a ratio of the total thickness of the carbon fiber layer 103 greater than or equal to 40%, which can also meet the use requirements of the outer tube 102.

[0199] Specifically, during the forming process of the braided structure of the carbon fiber outer layer 105, multiple parallel fiber filaments are converged 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, and 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. Through such an arrangement, the fiber bundles 106 of the carbon fiber outer layer 105 located at the outermost layer in the radial direction 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.

[0200] See also Figure 1 As shown, the braiding direction in the braided structure refers to the extension direction of the two intersecting fiber bundles 106, and the bisector of the angle b between the two fiber bundles 106 is also extended along the axial direction of the outer tube 102, that is, the angle c between the two fiber bundles 106 and the axis of the outer tube 102 is the same 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 a symmetrical structure. When the outer tube 102 is impacted perpendicular to the axial direction (i.e., radial direction), the symmetrical structure can further enhance the impact resistance of the outer tube 102, so it is preferred that the braided structure is arranged symmetrically about the axial direction.

[0201] Secondly, the carbon fiber outer layer 105 adopts a 3K twill weaving structure, and the weaving direction of the material layer adjacent to it is set to be different from the weaving direction of the carbon fiber outer layer 105.

[0202] For example, the adjacent carbon fiber layer 103 or glass fiber layer 104 adopts a unidirectional structure, and no matter the fiber bundle 106 of the unidirectional structure extends in the axial direction, circumferential direction or spiral direction around the axis of the outer tube 102, it is different from the weaving direction of the weaving structure of the carbon fiber outer layer 105. Alternatively, the adjacent carbon fiber layer 103 or glass fiber layer 104 adopts a woven structure, but the weaving direction of the woven structure 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 layer 103 or glass fiber layer 104 adjacent to the carbon fiber outer layer 105 and the axial direction of the outer tube 102 is 40 degrees, and the angle between the weaving direction of the carbon fiber outer layer 105 and the axial direction of the outer tube 102 is 60 degrees. Such a setting can reduce the impact energy transmission effect in the radial direction of the outer tube 102. The remaining carbon fiber layer 103, i.e., the carbon fiber inner layer 103, can all 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 are arranged along the axial direction of the outer tube 102, and the ratio of the total layer thickness of the carbon fiber inner layer 103 with the axial structure to the total layer thickness of the carbon fiber inner layer 103 is greater than or equal to 60%, and this arrangement is used to ensure the continuity of the overall strength of the outer tube 102.

[0203] Similarly, the glass fiber layer 104 can be entirely woven, or entirely unidirectional, or partially woven and partially unidirectional. The unidirectional structure mainly adopts an axial structure in which the fiber bundles 106 are arranged along the axial direction of the outer tube 102, and the ratio of the total layer thickness of the glass fiber layer 104 with 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.

[0204] In order to verify that the impact resistance of the telescopic tube 10 provided by the present application is equivalent to or better than that of the aluminum tube, a tipping test is performed on the telescopic tube 10 to simulate the normal tipping of the telescopic tube 10 during the use of the high-branch saw 300. Before the tipping test, a suitable battery pack 30 is first assembled on the high-branch saw 300, the inner tube 101 is pulled out of the outer tube 102 and locked by the locking member 90 to keep the two relatively fixed, and the front end of the inner tube 101 is connected to the working head assembly 20. Then, hold the main handle and the auxiliary handle with both hands and lift the telescopic tube 10 at an angle of 60° relative to the ground, so that the working head assembly 20 at the front end of the inner tube 101 is 4m away from the curb (the height of the curb from the ground is 15cm to 20cm, and the curb is 15cm wide). Let go and let the working head assembly 20 fall naturally. The curb impacts the weakest position of the inner tube 101, which is the axial center. The dumping 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 dumping test, the impact resistance of the inner tube 101 and the aluminum tube can be further compared.

[0205] Furthermore, in order to reduce the safety risk of the high-branch saw 300 using the telescopic tube 10, a blade 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 falls over. Before the blade test, a suitable battery pack 30 is first assembled on the high-branch saw 300, the inner tube 101 is pulled out of the outer tube 102 and locked by the locking member 90 to keep the two relatively fixed, and the front end of the inner tube 101 is assembled with the working head assembly 20. Thereafter, the high-branch saw 300 provided with the grip assembly 40, the battery pack 30 and one end of the power assembly is placed on the ground, and then the inner tube 101 is held by hand to lift the working head assembly 20 to a height of 1.5m above the blade and let go. The blade edge impacts the weakest position of the inner tube 101, i.e., the axial center. The blade edge test requires that there shall be no cracks at the impacted position of the inner tube 101 or the width of the crack in the axial direction of the inner tube 101 shall be less than 8mm, and the crack width shall not expand after 1000 wooden stake knocking tests are performed on the crack.

[0206] For a clearer comparison, Table 2 below shows the test results of a high-branch saw using an inner tube within the above-mentioned specification parameter range, a high-branch saw not using an inner tube within the above-mentioned specification parameter range, and a high-branch saw with an existing aluminum tube of the same specification.

[0207]

[0208]

[0209] Table 2

[0210] By comparison, it can be seen that the weight of the high-branch saw 300 using the telescopic tube 10 provided by the present application is less than the weight of the high-branch saw using the existing aluminum telescopic tube. Under the premise 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 of the present application and the inner tube of the aluminum telescopic tube can both pass the 4m tipping test and the blade edge test, that is, the impact resistance of the inner tube 101 in the telescopic tube 10 of 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 of 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 of the present application is better than that of the inner tube of the aluminum telescopic tube.

[0211] The telescopic tube 10 provided by the present application can reduce weight by more than 30% compared to the aluminum telescopic tube in the prior art, and the axial modulus of the inner tube 101 can reach 90GPa to 120GPa, so as to have a stiffness close to that of the aluminum tube, and its impact resistance can be tested by a 4m tipping test without bending, and its impact resistance is better than that of the aluminum tube. Under the same use conditions, the high branch saw 300 using the telescopic tube 10 has lower hand vibration and better anti-buffering performance than the high branch saw using the aluminum telescopic tube.

[0212] Further, in some power tools that can use multiple working head assemblies, see Fig. 20 As shown, the electric tool 400 is a grass trimmer 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 working head assembly 20, and the second connecting pipe 108 is connected to the common components such as the grip assembly 40 and the battery pack 30, and the different working head assemblies 20 are connected to the common components at the rear end through the first connecting pipe 107 and the second connecting pipe 108. The split connecting pipe 10 of this type of electric tool 400 also has a demand for being lightweight and having good impact resistance and anti-buffering performance. The first connecting pipe 107 and the second connecting pipe 108 can be configured as follows: the first connecting pipe 107 adopts the same configuration as the connecting pipe 10 in the above-mentioned front grass trimmer 100 embodiment or the outer tube 101 in the above-mentioned high-branch saw 300 embodiment, and the second connecting pipe 108 adopts the same configuration as the inner tube 101 in the above-mentioned high-branch saw 300 or adopts a metal pipe in the prior art; or the first connecting pipe 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, and 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.

[0213] The above description of the disclosed embodiments enables professionals in the field to implement or use the utility model. Various modifications to these embodiments will be apparent to professionals in the field, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the utility model. Therefore, the utility model will not be limited to the embodiments shown herein, but will conform to the widest range 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; 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 tube has at least one first material layer made of carbon fiber material and one second material layer made of non-carbon fiber material arranged in its 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.

2. The electric tool according to claim 1, characterized in that: The second material layer is a glass fiber layer, and the total thickness of the second material layer 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 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%.

4. The electric tool according to claim 2, characterized in that: The outermost layer of the connecting tube in the radial direction is a carbon fiber outer layer formed by the first material layer, and the fiber arrangement direction of the carbon fiber outer layer is different from that of the adjacent material layer.

5. The electric tool according to claim 4, characterized in that: The first material layer comprises an axial fiber bundle extending and arranged along the axial direction of the connecting tube, and the ratio of the total thickness of the axial fiber bundle 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%; The number of the first material layer is configured as one layer, and the carbon fiber outer layer is a woven structure composed of multiple fiber bundles; Alternatively, the number of the first material layers is configured to be greater than or equal to two layers, 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, the carbon fiber inner layer includes the axial fiber bundles extending 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%.

6. The electric tool according to claim 1, 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.

7. The electric tool according to claim 6, 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.

8. The electric tool according to claim 1, 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.

9. 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.

10. The electric tool according to claim 9, characterized in that: The total layer thickness of the glass fiber layer accounts for 50% to 80% of the total wall thickness of the connecting tube; 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 a ratio greater than or equal to 80% of the total layer thickness of the glass fiber layer.

11. The electric tool according to claim 10, 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, and the fiber arrangement direction of the carbon fiber outer layer is different from that of the adjacent material layer.

12. The electric tool according to claim 11, characterized in that: The carbon fiber layer comprises 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 thickness of the carbon fiber layer is greater than or equal to 40%; 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%.

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