Electric tool

Abstract

The utility model discloses an electric tool. The electric tool comprises a gearbox, a cutting mechanism, a transmission mechanism, a rolling piece and a driving mechanism. The cutting mechanism comprises a blade; the transmission mechanism is movably mounted in the gear box and comprises a connecting piece connected with the blade; the rolling piece is movably propped between the inner wall of the gearbox and the connecting piece, and the peripheral surface of the rolling piece is in line contact or point contact with the connecting piece; the driving mechanism is connected with the transmission mechanism so as to drive the connecting piece to drive the blade to move. According to the electric tool, the rolling piece movably abuts against the position between the inner wall of the gear box and the connecting piece, a friction plate fixed to the inner wall of the gear box in the prior art is replaced, namely sliding friction in the prior art is replaced with rolling friction, surface contact at the contact position is changed into line contact or point contact, friction force is reduced, and the service life of the electric tool is prolonged. Heat generation is reduced, the service life of the rolling piece is prolonged, and the use cost of the electric tool is reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electric tools, and particularly relates to an electric tool. BACKGROUND

[0002] The hedge trimmer is a kind of electric tool, which is a machine specially used for trimming hedges, lawn edges and other greening projects, and is suitable for trimming various types of hedges and lawn edges.

[0003] The existing cutter bar (also referred to as a blade, etc.) of the hedge trimmer is connected with a connecting piece in the gear box, and the cutter bar is driven to make reciprocating linear motion through the movement of the connecting piece, so as to realize trimming of the hedges and the lawn edges. A friction plate is generally arranged between the connecting piece and the inner wall of the gear box, which serves to support the connecting piece and protect the gear box. The connecting piece will rub against the surface of the friction plate during movement. Since the friction plate and the connecting piece are in surface contact, a large amount of heat will be generated, which will cause the local temperature in the gear box to be too high. In addition, the friction plate is thin and not wear-resistant, and has a short service life, so it needs to be frequently replaced, resulting in high material and labor costs.

[0004] The information disclosed in this section of the background art is only intended to increase the understanding of the overall background of the application, and should not be regarded as acknowledging or implying in any form that the information constitutes prior art known to those skilled in the art. CONTENT OF THE UTILITY MODEL

[0005] The purpose of the application is to provide an electric tool which can prolong the service life of the rolling member and reduce the heat generated by friction.

[0006] In order to achieve the above purpose, the technical scheme provided by an embodiment of the application is as follows: an electric tool, comprising:

[0007] a gear box;

[0008] a cutting mechanism comprising a cutter bar;

[0009] a transmission mechanism movably installed in the gear box, the transmission mechanism comprising a connecting piece connected with the cutter bar;

[0010] a rolling member movably abutting between the inner wall of the gear box and the connecting piece, and the outer peripheral surface of the rolling member being in linear contact or point contact with the connecting piece;

[0011] a driving mechanism connected with the transmission mechanism to drive the connecting piece to move the cutter bar.

[0012] In one or more embodiments of the present application, the cutting mechanism comprises two stacked blades, the transmission mechanism comprises two stacked connecting members, each of the blades is connected with one of the connecting members, and the power tool comprises two rolling members arranged at opposite sides of the gear box respectively, and the stacked connecting members are arranged between the two rolling members.

[0013] In one or more embodiments of the present application, the rolling members are rod-shaped or spherical.

[0014] In one or more embodiments of the present application, the gear box is provided with a limiting groove on an inner wall thereof, the rolling members are arranged in the limiting groove and partially protrude from the limiting groove and abut against the connecting members.

[0015] In one or more embodiments of the present application, the limiting groove comprises a bottom wall and side walls arranged on opposite sides of the bottom wall along a movement direction of the blade, and the side walls are in clearance fit with the rolling members.

[0016] In one or more embodiments of the present application, the rolling members are rod-shaped, and along an axial direction of the rolling members, axial end portions of the rolling members are in clearance fit with the inner wall of the gear box.

[0017] In one or more embodiments of the present application, the gear box is provided with a protruding structure on an inner wall thereof, and the limiting groove is arranged on the protruding structure.

[0018] In one or more embodiments of the present application, the protruding structure comprises a first protruding rib and a plurality of second protruding ribs arranged perpendicularly to each other, and the limiting groove is arranged at a connection between the first protruding rib and the second protruding ribs.

[0019] In one or more embodiments of the present application, the gear box is provided with a plurality of spherical rolling members arranged at intervals.

[0020] In one or more embodiments of the present application, the cutting mechanism comprises a support member, a blade and a pin assembly arranged in a stacked manner, the support member is provided with a socket, the blade is provided with a sliding groove arranged therethrough, and the pin assembly is inserted into the socket and the sliding groove.

[0021] The transmission mechanism comprises an eccentric wheel rotatably arranged in the gear box and connected with the driving mechanism, the eccentric wheel is rotatably connected with the connecting member, and the connecting member is rotatably connected with the blade.

[0022] Compared with the prior art, the electric tool of the application uses the rolling piece movably abutting between the inner wall of the gear box and the connecting piece, instead of the friction plate fixed on the inner wall of the gear box in the prior art, that is, the rolling friction is used instead of the sliding friction in the prior art, the contact is changed from surface contact to line contact or point contact, the friction is reduced, the heat generation and the service life of the rolling piece are reduced, and the use cost of the electric tool is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments described in the application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0024] Figure 1 It is a partial perspective view of the electric tool in an embodiment of the application;

[0025] Figure 2 It is an exploded view of part of the structure of the electric tool in an embodiment of the application;

[0026] Figure 3 It is a partial cross-sectional view of the electric tool in an embodiment of the application;

[0027] Figure 4 It is a partial perspective view of the gear box in an embodiment of the application;

[0028] Figure 5 It is a perspective view of the eccentric wheel in an embodiment of the application.

[0029] Main drawing reference explanation:

[0030] 1, gear box; 11, box body; 12, accommodating cavity; 13, limiting groove; 14, protruding structure; 141, first protruding rib; 142, second protruding rib; 2, cutting mechanism; 21, cutter bar; 211, sliding groove; 22, supporting piece; 23, bolt assembly; 231, bolt; 232, nut; 3, transmission mechanism; 31, connecting piece; 32, eccentric wheel; 321, body part; 322, protruding part; 323, shaft part; 33, bearing; 34, connecting pin; 4, rolling piece. DETAILED DESCRIPTION

[0031] In order for those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described in the following with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should fall within the scope of protection of the present application.

[0032] As described in the background, in the existing hedge trimmer, a swing rod structure (equivalent to the transmission mechanism in the present application) is used to drive the blade to move, the connecting piece in the swing rod structure is connected with the blade, the connecting piece will move in the gear box to drive the blade to reciprocate, and a friction plate will be arranged between the inner wall of the gear box and the connecting piece to support the connecting piece and protect the gear box; the connecting piece will rub against the surface of the friction plate when moving, and the friction plate and the connecting piece are in surface contact, so a large amount of heat will be generated, resulting in a local temperature in the gear box being too high, in addition, the friction plate is thin and not wear-resistant, has a short service life and needs to be frequently replaced, resulting in high material cost and labor cost.

[0033] To solve the above problems, the present application provides an electric tool, which comprises a gear box, a cutting mechanism, a transmission mechanism, a rolling piece and a driving mechanism; the cutting mechanism comprises a blade; the transmission mechanism is movably installed in the gear box, and comprises a connecting piece connected with the blade; the rolling piece is movably arranged between the inner wall of the gear box and the connecting piece, and the outer circumferential surface of the rolling piece is in linear or point contact with the connecting piece; and the driving mechanism is connected with the transmission mechanism to drive the connecting piece to move the blade.

[0034] The electric tool scheme uses the rolling piece movably arranged between the inner wall of the gear box and the connecting piece to replace the friction plate fixed on the inner wall of the gear box in the prior art, that is, the rolling friction is used to replace the sliding friction in the prior art, the contact is changed from surface contact to linear or point contact, the friction is reduced, the heat generation and the service life of the rolling piece are reduced, and the use cost of the electric tool is reduced.

[0035] As shown in FIG. 1, Figures 1-4 The electric tool of one embodiment of the present application comprises a gear box 1, a cutting mechanism 2, a transmission mechanism 3, two rolling pieces 4 and a driving mechanism, the cutting mechanism 2 comprises two blades 21 arranged in layers, the transmission mechanism 3 comprises two connecting pieces 31 arranged in layers, each blade 21 is connected with a connecting piece 31, the two rolling pieces 4 are respectively arranged on opposite sides of the connecting pieces 31 arranged in layers and movably abut between the inner wall of the gear box 1 and the corresponding connecting pieces 31.

[0036] The drive mechanism drives two connecting parts 31 to move via the transmission mechanism 3. Each connecting part 31 drives the corresponding blade 21 to perform linear reciprocating motion, and the two blades 21 move in opposite directions, thereby enabling the cutting mechanism 2 to complete the pruning and cutting of the plant. The gearbox 1 may include two connected housings 11, which form a receiving cavity 12. The transmission mechanism 3 and the rolling element 4 are installed in the receiving cavity 12, and the cutting mechanism 2 and the drive mechanism are partially located in the receiving cavity 12.

[0037] like Figure 2 and 3 As shown, in this embodiment, the rolling element 4 is a rod-shaped rolling element 4, which can also be called a rolling rod or rolling pin, etc. Since the rolling element 4 can movably abut against the inner wall of the gearbox 1 and the connecting member 31, when the connecting member 31 moves, the rolling element 4 can rotate along its own axial direction, making the friction between the rolling element 4 and the connecting member 31 rolling friction. Furthermore, the outer peripheral surface of the rod-shaped rolling element 4 is curved, and the outer peripheral surface is in line contact with the connecting member 31. The movable abutment of the rolling element 4 against the inner wall of the gearbox 1 and the connecting member 31 also serves to support the connecting member 31.

[0038] Since the contact between the rolling element 4 and the connecting element 31 is point contact or point contact, the size of the rolling element 4 is larger than the thickness of the friction plate, while having the same material volume as the friction plate in the prior art. Figure 3 Up and down direction (i.e.) Figure 3 (The stacking direction of the two connecting parts 31) The size of the rolling element 4 is greater than the thickness of the friction plate, which can further increase the service life of the rolling element 4 and extend the continuous working time of the power tool.

[0039] In other embodiments, the rolling element 4 is a spherical rolling element 4 (not shown in the figure), which can be called a rolling ball or rolling bead, etc. In this case, the outer peripheral surface of the rolling element 4 is in point contact with the connecting element 31. In order to better support the connecting element 31, each connecting element 31 can hold multiple rolling elements 4 between itself and the inner wall of the gearbox 1.

[0040] like Figures 2-4 As shown, a limiting groove 13 is provided on the inner wall of the gearbox 1. The rolling element 4 is located in the limiting groove 13 and partially protrudes from the limiting groove 13 and abuts against the connecting element 31. The limiting groove 13 serves to limit the position and range of motion of the rolling element 4 in the receiving cavity 12, and can also facilitate the installation and positioning of the rolling element 4 when producing power tools.

[0041] Specifically, the limiting groove 13 comprises a bottom wall and side walls arranged on opposite sides of the bottom wall along the movement direction of the cutter strip 21, and the side walls are in clearance fit with the rolling member 4. In this way, when the connecting member 31 moves and the rolling member 4 rotates along the axial direction, the rolling member 4 can not only rotate, but also roll between the two side walls in the limiting groove 13. When the rolling member 4 is in the form of a rod, the clearance between the side walls and the rolling member 4 can make the rolling member 4 adapt to the movement of the connecting member 31, rotate around the axial direction and reciprocate in the axial direction, reduce the friction in the axial direction and the direction perpendicular to the axial direction, and prolong the service life of the rolling member 4.

[0042] It can be understood that the clearance fit between the side walls and the rolling member 4 means that there is a clearance between any one of the side walls and the rolling member 4.

[0043] In the embodiment, the axial end of the rolling member 4 is in clearance fit with the inner wall of the gear box 1 along the axial direction of the rolling member 4. In this way, a certain space for movement of the rolling member 4 can be provided.

[0044] The inner wall of the gear box 1 is provided with a protruding structure 14, and the limiting groove 13 is arranged on the protruding structure 14. In this way, the rolling member 4 can be closely abutted with the connecting member 31, the thickness of the inner wall can be increased, and the inner wall of the gear box 1 can be protected.

[0045] Further, the protruding structure 14 comprises a first protruding rib 141 and a plurality of second protruding ribs 142 arranged perpendicularly to each other, and the limiting groove 13 is arranged at the connection between the first protruding rib 141 and the second protruding rib 142. In this way, the strength of the box body 11 of the gear box 1 can be enhanced, the material can be saved, and the weight of the box body 11 of the gear box 1 can be reduced.

[0046] The cutting mechanism 2 comprises a support member 22, a cutter strip 21 and a plug assembly 23 arranged in layers, the support member 22 is provided with a plug hole, the cutter strip 21 is provided with a sliding groove 211 arranged in a penetrating manner, and the plug assembly 23 is inserted into the plug hole and the sliding groove 211. Figure 2 and 3 As shown in the drawings, in the embodiment, the cutter strip 21 is two, the plug assembly 23 can comprise a plug 231 and a nut 232, the plug 231 comprises a plug cap and a plug shaft, the size of the plug cap is greater than the size of the plug hole and the sliding groove 211, the size of the plug shaft is less than or equal to the size of the plug hole and the sliding groove 211, the plug shaft sequentially penetrates the sliding groove 211 of one cutter strip 21, the sliding groove 211 of the other cutter strip 21 and the plug hole of the support member 22, and is threadedly connected with the nut 232, the plug cap is abutted with the cutter strip 21 along the axial direction of the plug shaft, so that the fixed assembly process of the cutting mechanism 2 is realized, in addition, the box body 11 of the gear box 1 can be provided with a threaded hole, and the support member 22 and the cutter strip 21 are partially inserted into the gear box 1, at this time, the plug shaft can be threadedly connected with the threaded hole in the box body 11, so that the support member 22 and the box body 11 are fixedly connected.

[0047] It can be understood that since the pin shaft is inserted into the sliding groove 211, the blade 21 can slide along the sliding groove 211 relative to the pin shaft.

[0048] One end of the blade 21 is provided with a hole, and the connecting piece 31 is also provided with a corresponding hole. The one end of the blade 21 is placed in a point of the connecting piece 31 in a stack, and the corresponding holes are coaxial. Then, the connecting pin 34 is inserted into the holes of the blade 21 and the connecting piece 31. In addition, the connecting position of the blade 21 and the connecting piece 31 is located in the gear box 1, which limits the connecting pin 34 from exiting the holes of the blade 21 and the connecting piece 31, thereby achieving the connection of the blade 21 and the connecting piece 31.

[0049] As shown in FIGS. Figure 2 , 3 and 5, the transmission mechanism 3 in the embodiment includes an eccentric wheel 32 rotatably installed in the gear box 1 and connected with the driving mechanism. The eccentric wheel 32 is rotatably connected with the connecting piece 31, and the connecting piece 31 is rotatably connected with the blade 21. The eccentric wheel 32 includes a body part 321, two protruding parts 322 protruding on both axial sides of the body part 321, and two shaft parts 323. The shaft part 323 is rotatably installed on the inner wall of the gear box 1, and the axis of the shaft part 323 is the rotation axis of the eccentric wheel 32. The two protruding parts 322 are centrally symmetrically arranged on both axial sides of the body part 321, and the axes of the two protruding parts 322 are parallel but not coincident. The axis of any protruding part 322 is parallel but not coincident with the axis of the shaft part 323. The two connecting pieces 31 are respectively sleeved on one protruding part 322, and the connecting piece 31 is rotatably connected with the protruding part 322.

[0050] The driving mechanism can be an existing motor and a gear installed on the output shaft of the motor. The body part 321 can be a gear. That is, the gear in the driving mechanism can be arranged in the gear box 1 and engaged with the body part 321. The gear is driven to rotate by the motor, thereby driving the body part 321 to rotate.

[0051] Specifically, the connecting piece 31 can be provided with a hole for sleeving the protruding part 322. In order to reduce the friction between the connecting piece 31 and the protruding part 322, the connecting piece 31 and the protruding part 322 can be provided with a bearing 33.

[0052] It is apparent for those skilled in the art that the present application is not limited to the details of the above-described exemplary embodiments, but rather can be implemented in other specific forms without departing from the spirit or essential characteristics of the application. The embodiments should therefore be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the above description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. No limitation is intended to the details of the illustrated embodiments which can include known components or steps not specifically recited herein.

[0053] Furthermore, it should be understood that although the specification is described in terms of embodiments, not every embodiment includes only one independent technical solution, and the specification is described in this way only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that those skilled in the art can understand.

Claims

1. A power tool characterized by comprising: The utility model relates to a cutting mechanism (2) of a power tool, which comprises a gear box (1), a cutting mechanism (2) comprising a blade (21), a transmission mechanism (3) movably mounted in the gear box (1), the transmission mechanism (3) comprising a connecting piece (31) connected with the blade (21), a rolling piece (4) movably arranged between the inner wall of the gear box (1) and the connecting piece (31), the outer circumferential surface of the rolling piece (4) being in linear or point contact with the connecting piece (31), and a driving mechanism connected with the transmission mechanism (3) to drive the connecting piece (31) to move the blade (21). The cutting mechanism (2) comprises two stacked blades (21), the transmission mechanism (3) comprises two stacked connecting pieces (31), each blade (21) is connected with a connecting piece (31), and the power tool comprises two rolling pieces (4) arranged on opposite sides of the gear box (1), and the stacked connecting pieces (31) are arranged between the two rolling pieces (4). The rolling piece (4) is rod-shaped or spherical. The inner wall of the gear box (1) is provided with a limiting groove (13), the rolling piece (4) is arranged in the limiting groove (13) and protrudes from the limiting groove (13) and abuts against the connecting piece (31). The limiting groove (13) comprises a bottom wall and side walls arranged on opposite sides of the bottom wall along the movement direction of the blade (21), and the side walls are in clearance fit with the rolling piece (4). The rolling piece (4) is rod-shaped, and the axial end of the rolling piece (4) is in clearance fit with the inner wall of the gear box (1) along the axial direction of the rolling piece (4).

2. The power tool of claim 1, wherein, The inner wall of the gear box (1) is provided with a protruding structure (14), and the limiting groove (13) is arranged on the protruding structure (14).

3. The power tool of claim 1, wherein, The protruding structure (14) comprises a first convex rib (141) and a plurality of second convex ribs (142) arranged perpendicularly to each other, and the limiting groove (13) is arranged at the connection position of the first convex rib (141) and the second convex rib (142).

4. The power tool of claim 3, wherein, A plurality of spherical rolling pieces (4) are arranged in the gear box (1).

5. The power tool of claim 4, wherein, The cutting mechanism (2) comprises a support (22), a blade (21) and a bolt assembly (23) stacked, the support (22) has a insertion hole, the blade (21) is provided with a sliding groove (211) arranged through the blade (21), and the bolt assembly (23) is inserted into the insertion hole and the sliding groove (211).

6. The power tool of claim 5, wherein, The transmission mechanism (3) comprises an eccentric wheel (32) rotatably mounted in the gear box (1) and connected with the driving mechanism, the eccentric wheel (32) is rotatably connected with the connecting piece (31), and the connecting piece (31) is rotatably connected with the blade (21).

7. The power tool of claim 4, wherein, ​ 8. The power tool of claim 7, wherein, ​ 9. The power tool of claim 3, wherein, ​ 10. The power tool of claim 1, wherein, ​ ​

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