Grass trimming head and handheld electric tool

Abstract

The utility model discloses a grass trimming head and a handheld electric tool. Wherein the grass trimming head comprises a cutting assembly and a contact piece which is rotatably mounted at the end part of the cutting assembly, the cutting assembly can be driven to rotate around a rotating axis, and the contact piece can independently rotate around the rotating axis relative to the cutting assembly; and when the cutting assembly is driven to rotate around the rotating axis, the contact piece has a non-driven state in which the contact piece does not rotate along with the cutting assembly. When the grass trimming head is used for trimming the grass close to the ground, the contact piece can make contact with the ground, and the contact piece can independently rotate relative to the cutting assembly and further has a non-driven state which does not rotate along with the cutting assembly. Therefore, in the state, the rotating speed of the contact piece is reduced or the contact piece stops rotating due to interference with the ground, and the cutting assembly can be continuously driven to rotate without being influenced and is kept at the set rotating speed, so that the efficiency of pruning operation is ensured.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of gardening tools, and particularly relates to a grass cutting head and a handheld electric tool. BACKGROUND

[0002] The grass cutter is a kind of electric handheld tool, which is mainly used for trimming lawns, weeds and other plants. The grass cutter comprises a grass cutting head. The flexible line is driven to rotate by driving the grass cutting head to rotate, so as to complete the trimming and cutting work on the plants. During use, when the grass cutting head is close to the ground for trimming work, it may collide with and rub against the ground. Such contact may cause the rotation speed of the grass cutting head to decrease, thereby affecting the efficiency of the trimming work.

[0003] Therefore, in view of the above technical problems, it is necessary to provide a grass cutting head and a handheld electric tool. CONTENT OF THE UTILITY MODEL

[0004] The application aims to provide a grass cutting head and a handheld electric tool, which can solve the problem that the rotation speed of the grass cutting head decreases when the grass cutting head collides with the ground, thereby affecting the cutting efficiency.

[0005] In order to achieve the above-mentioned purpose, a specific embodiment of the application provides a grass cutting head, and the technical scheme is as follows:

[0006] The grass cutting head comprises a cutting assembly and a contact piece rotatably installed at the end of the cutting assembly. The cutting assembly is driven to rotate around a rotation axis, and the contact piece is independently rotatable around the rotation axis relative to the cutting assembly. When the cutting assembly is driven to rotate around the rotation axis, the contact piece has a non-driven state of not rotating with the cutting assembly.

[0007] In one or more embodiments of the application, there is a gap between the cutting assembly and the contact piece. A through hole is formed in the contact piece and penetrates the contact piece. The through hole communicates the gap between the contact piece and the cutting assembly.

[0008] In one or more embodiments of the application, the minimum opening diameter of the through hole is greater than the gap between the contact piece and the cutting assembly.

[0009] In one or more embodiments of the application, a plurality of through holes are uniformly distributed around the rotation axis.

[0010] In one or more embodiments of the application, the contact piece comprises a protruding portion protruding in a direction away from the cutting assembly. The vertical projection of the end surface of the contact piece is in the shape of a circular ring. The circular ring-shaped protruding portion is coaxially arranged with the rotation axis.

[0011] In one or more embodiments of the present application, the protrusion is metal and is embedded on the contact piece.

[0012] In one or more embodiments of the present application, the contact piece has a vertical projection area on its end face that is less than or equal to 30% of a vertical projection area of the cutting assembly on the end face of the contact piece.

[0013] In one or more embodiments of the present application, the contact piece includes a sheet-shaped body and a ring-shaped body that extends from a peripheral edge of the sheet-shaped body, the sheet-shaped body and the ring-shaped body enclosing a receiving space, at least part of the cutting assembly being assembled in the receiving space, and the contact piece has a vertical projection area on its end face that is greater than or equal to 100% of a vertical projection area of the cutting assembly on the end face of the contact piece.

[0014] In one or more embodiments of the present application, the cutting assembly includes an end cover adjacent to the contact piece, the contact piece includes a contact sheet and a transfer rod fixedly connected, the end cover is provided with a mounting hole, a bearing is fixed in the mounting hole, the transfer rod is provided with a retainer ring at an end away from the contact sheet, the transfer rod is rotatably inserted into the bearing, and the bearing is located between the retainer ring and the contact sheet.

[0015] One specific embodiment of the present application also provides a handheld electric power tool, and the technical scheme is as follows:

[0016] A handheld electric power tool includes the above-described grass trimming head and a driving assembly that drives the grass trimming head to rotate.

[0017] Compared with the prior art, the grass trimming head disclosed in the present application can contact the ground when performing ground trimming work, and the contact piece can rotate independently relative to the cutting assembly and also has a non-driven state in which the contact piece does not rotate with the cutting assembly. Therefore, in this state, the contact piece will slow down or stop rotating due to interference with the ground, while the cutting assembly can continue to be driven to rotate without being affected and maintain a set rotation speed, thereby ensuring the efficiency of the trimming work. In addition, since the contact piece can avoid direct friction and impact of the cutting assembly with the ground during work, the service life of the grass trimming head is prolonged. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical schemes in the embodiments of the present application or the prior art, the drawings needed in the embodiments or the prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments described in the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the explosion of the grass trimmer head in Example 1 of the present application;

[0020] Figure 2 This is a schematic cross-sectional view of a grass trimmer head in Example 1 of the present application;

[0021] Figure 3 for Figure 2 A in the middle is an enlarged schematic diagram;

[0022] Figure 4 This is a schematic structural diagram of the contact member, bearing, and retaining ring in Example 1 of the present application;

[0023] Figure 5 This is a schematic cross-sectional view of a grass trimmer head in Example 2 of the present application;

[0024] Figure 6 for Figure 5 Enlarged schematic diagram of point B in the middle.

[0025] Description of main reference numerals:

[0026] 1. Cutting assembly; 11. End cap; 111. Mounting hole; 12. Cutting head seat; 13. Positioning frame; 14. Wire drum; 15. Elastic member; 16. Cover body; 2. Contact member; 21. Through hole; 22. Protrusion; 23. Contact piece; 24. Adapter rod; 25. Sheet body; 26. Ring body; 3. Bearing; 4. Retaining ring. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0028] Example 1

[0029] Reference Figure 1 and Figure 2 This embodiment discloses a grass trimmer head, including a cutting assembly 1 and a contact member 2 rotatably mounted on the end of the cutting assembly 1. The cutting assembly 1 can be driven to rotate around a rotation axis, and the contact member 2 can rotate independently relative to the cutting assembly 1 around the rotation axis; wherein, when the cutting assembly 1 is driven to rotate around the rotation axis, the contact member 2 has a non-driven state that does not rotate with the cutting assembly 1.

[0030] When the lawn mower head is used for ground trimming, the contact member 2 can be in contact with the ground. The contact member 2 can rotate independently relative to the cutting assembly 1 and can also be in a non-driven state without rotating with the cutting assembly 1. Therefore, in this state, the contact member 2 can be reduced in rotation speed or stopped due to the interference with the ground, while the cutting assembly 1 can continue to be driven to rotate without being affected and maintain the set rotation speed, thereby ensuring the efficiency of the trimming operation.

[0031] With reference to Figure 2 and Figure 3 , there is a gap between the cutting assembly 1 and the contact member 2, and the contact member 2 is provided with a through hole 21 (see Figure 4 ) penetrating the contact member 2. The through hole 21 communicates the gap between the contact member 2 and the cutting assembly 1. Since there is a gap between the cutting assembly 1 and the contact member 2, the cutting assembly 1 and the contact member 2 will not rub against each other. The above structure helps to reduce the adverse effects on the rotation speed of the cutting assembly 1 when the lawn mower head is used for ground trimming. However, when the lawn mower head is working, dirt, grass and other impurities can enter the gap between the cutting assembly 1 and the contact member 2. With the accumulation of impurities in the gap, the function of the contact member 2 can be lost. The through hole 21 can timely discharge the impurities, thereby ensuring that the rotation speed of the cutting assembly 1 is maintained at the set speed and is not affected by the accumulation of impurities.

[0032] Further, the minimum opening diameter of the through hole 21 is greater than the gap between the contact member 2 and the cutting assembly 1. The diameter of the through hole 21 is set so that the impurities entering the gap between the contact member 2 and the cutting assembly 1 can be better discharged. In the present embodiment, a plurality of through holes 21 are uniformly distributed around the rotation axis. By increasing the number of through holes 21, the probability of discharging impurities can be increased, and the uniform distribution of the through holes 21 can ensure that the center of gravity of the contact member 2 does not deviate, thereby ensuring the stability of the contact member 2 during rotation.

[0033] With reference to Figure 4 , in the present embodiment, four through holes 21 are provided in the contact member 2, but this is not a limitation on the number of through holes 21 in the present embodiment. In other embodiments, the number of through holes 21 can be set according to actual conditions.

[0034] With reference to Figure 3 and Figure 4 , the contact member 2 includes a protruding portion 22 protruding away from the cutting assembly 1; the vertical projection of the protruding portion 22 on the end surface of the contact member 2 is in the shape of a circular ring, and the circular ring-shaped protruding portion 22 is coaxially arranged with the rotation axis. The protruding portion 22 can reduce the contact area between the contact member 2 and the ground, thereby reducing the friction between the contact member 2 and the ground and further improving the service life of the contact member 2. In the present embodiment, the circular ring-shaped protruding portion 22 is coaxially arranged with the adapter rod 24, which can ensure the stability of the contact member 2 during rotation.

[0035] In an optional embodiment, the through hole 21 is arranged on the protruding part 22, so that the contact area of the protruding part 22 with the ground is further reduced, the friction between the contact piece 2 and the ground is reduced, and the service life of the contact piece 2 is ensured.

[0036] With reference to Figure 3 , the protruding part 22 is metal, and the protruding part 22 is embedded on the contact piece 2. When the grass head is used, the protruding part 22 preferentially hits the ground, and the use intensity, hardness, rigidity, and wear resistance of the relatively good metal can further prolong the service life of the contact piece 2. It can be understood that the other part of the contact piece 2 except the protruding part 22 can be a metal matrix or a plastic matrix, and the protruding part 22 and the other part of the contact piece 2 are produced by integral molding.

[0037] With reference to Figure 2 , the vertical projection area of the contact piece 2 at the end surface is less than or equal to 30% of the vertical projection area of the cutting assembly 1 at the end surface of the contact piece 2. By reducing the area of the contact piece 2, the weight of the grass head can be reduced and the production cost can be reduced. At the same time, when the cutting assembly 1 is struck to extend the cutting wire inside the cutting assembly 1, the other part of the grass head can be operated to contact the ground, so that the stress probability of the contact piece 2 with the ground can be reduced, and the service life thereof can be improved.

[0038] With reference to Figure 3 and Figure 4 , the cutting assembly 1 includes an end cover 11 adjacent to the contact piece 2, and the contact piece 2 includes a contact sheet 23 and an adapter rod 24 fixedly connected. The end cover 11 is provided with a mounting hole 111, the bearing 3 is fixed in the mounting hole 111, the adapter rod 24 is provided with a retainer 4 at an end away from the contact sheet 23, the adapter rod 24 is rotatably inserted into the bearing 3, and the bearing 3 is located between the retainer 4 and the contact sheet 23. In this embodiment, the protruding part 22 is arranged on the contact sheet 23, and a gap exists between the contact sheet 23 and the end cover 11.

[0039] Specifically, the adapter rod 24 is provided with an assembly hole, the retainer 4 is fixedly installed in the assembly hole, and the end surface of the retainer 4 abuts against the end surface of the bearing 3 to limit the displacement of the contact piece 2 in the axial direction of the bearing 3, so as to avoid the contact piece 2 from being separated from the end cover 11. By fixing the contact piece 2 through the cooperation of the bearing 3 and the retainer 4, the assembly steps can be simplified, and the assembly efficiency can be improved.

[0040] With reference to Figure 1 and Figure 2The cutting assembly 1 in the embodiment further comprises a cutter head seat 12, a positioning frame 13 matched with the cutter head seat 12, a wire reel 14 installed in the cutter head seat 12, and an elastic member 15 and a cover 16 matched with the wire reel 14, and a flexible cutting wire is wound on the wire reel 14. When the cutting assembly 1 is driven to rotate by an external driving assembly, the cutting wire can be driven to rotate to complete the trimming work of plants. The cutting assembly 1 is a conventional structure in the art, and thus the embodiment of the application does not make a detailed description thereof.

[0041] Embodiment 2

[0042] With reference to Figure 5 and Figure 6 The difference between the embodiment and the embodiment 1 is that the contact member 2 in the embodiment comprises a sheet-shaped body 25 and a ring-shaped body 26 bent and extended from the periphery of the sheet-shaped body 25, the sheet-shaped body 25 and the ring-shaped body 26 enclose a receiving space, and at least part of the cutting assembly 1 is assembled in the receiving space. The vertical projection area of the end surface of the contact member 2 is greater than or equal to 100% of the vertical projection area of the cutting assembly 1 on the end surface of the contact member 2. Therefore, the cutting assembly 1 can be protected by setting the shape and size of the contact member 2.

[0043] In the embodiment, since the contact member 2 fully covers the end portion of the cutting assembly 1, dirt such as soil and weeds is not easy to enter between the cutting assembly 1 and the contact member 2, and thus the contact member 2 in the embodiment is not provided with the through hole 21.

[0044] The application further discloses a handheld electric power tool comprising the above-described grass trimming head and a driving assembly for driving the grass trimming head to rotate. When the handheld electric power tool is used, the driving assembly can drive the grass trimming head to rotate, so that the trimming work of plants such as grass can be completed. It can be understood that, since the handheld electric power tool of the application is provided with the above-described grass trimming head, the ground trimming work can be performed, and the working efficiency of the grass trimming head is not affected. The driving assembly is a common structure in the art, and thus the specific structure thereof is not described in detail in the embodiment.

[0045] It is apparent for those skilled in the art that the application is not limited to the details of the above-described exemplary embodiments, and the application can be implemented in other specific forms without departing from the spirit or essential characteristics of the application. Therefore, the embodiments should be regarded as exemplary and non-limiting, and the scope of the application is defined by the appended claims rather than the above description, and all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the application. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0046] Furthermore, it should be understood that although the specification is described in terms of embodiments, not every embodiment includes every feature described. The specification can include implicit combinations of explicitly mentioned features and / or explicit combinations of implicitely mentioned features. Each embodiment depends on the explicit combinations of features and / or the implicit combinations of features made specifically within that embodiment, and each such embodiment can be combined with every other such embodiment to create further embodiments.

Claims

1. A grass trimmer head, characterized in that: The invention comprises a cutting assembly (1) and a contact member (2) rotatably mounted on the end of the cutting assembly (1), wherein the cutting assembly (1) can be driven to rotate around a rotation axis, and the contact member (2) can rotate independently relative to the cutting assembly (1) around the rotation axis; wherein, when the cutting assembly (1) is driven to rotate around the rotation axis, the contact member (2) has a non-driven state in which it does not rotate with the cutting assembly (1).

2. The grass trimmer head according to claim 1, characterized in that: There is a gap between the cutting assembly (1) and the contact piece (2), and a through hole (21) is provided on the contact piece (2) that penetrates the contact piece, and the through hole (21) communicates with the gap between the contact piece (2) and the cutting assembly (1).

3. The grass trimmer head according to claim 2, characterized in that: The minimum opening diameter of the through hole (21) is larger than the gap between the contact piece (2) and the cutting assembly (1).

4. The grass trimmer head according to claim 2, characterized in that: The plurality of through holes (21) are evenly distributed around the rotation axis.

5. The mowing head according to claim 1, characterized in that: The contact member (2) comprises a protruding portion (22) protruding in a direction away from the cutting assembly (1); the protruding portion (22) is annular in shape when vertically projected onto the end face of the contact member (2), and the annular protruding portion (22) is coaxially arranged with the rotation axis.

6. The grass trimmer head according to claim 5, characterized in that: The protrusion (22) is made of metal, and the protrusion (22) is embedded in the contact piece (2).

7. The mowing head according to claim 2, characterized in that: The vertical projection area of ​​the contact piece (2) on its end surface is less than or equal to 30% of the vertical projection area of ​​the cutting component (1) on the end surface of the contact piece (2).

8. The mowing head according to claim 1, characterized in that: The contact member (2) comprises a sheet-like body (25) and an annular body (26) bent and extended from the periphery of the sheet-like body (25); the sheet-like body (25) and the annular body (26) enclose an accommodating space; at least a portion of the cutting assembly (1) is assembled in the accommodating space; and the vertical projection area of ​​the contact member (2) on its end face is greater than or equal to 100% of the vertical projection area of ​​the cutting assembly (1) on the end face of the contact member (2).

9. The mowing head according to claim 1, characterized in that: The cutting assembly (1) comprises an end cap (11) adjacent to the contact member (2), and the contact member (2) comprises a fixedly connected contact piece (23) and a transfer rod (24); The end cover (11) is provided with a mounting hole (111), a bearing (3) is fixed in the mounting hole (111), a retaining ring (4) is provided at one end of the transfer rod (24) away from the contact piece (23), the transfer rod (24) is rotatably inserted into the bearing (3), and the bearing (3) is located between the retaining ring (4) and the contact piece (23).

10. A handheld power tool, characterized in that: The utility model comprises a grass trimmer head as claimed in any one of claims 1 to 9 and a driving component for driving the grass trimmer head to rotate.

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