A work head and a trimming machine

Abstract

The application relates to the field of electric tools, and particularly discloses a working head and a trimming machine, wherein the working head comprises a blade arranged on an output shaft, clamping pieces clamped on both sides of the blade, a fastener fastened on the output shaft and locking the clamping pieces, and a fixing piece arranged on one side of the fastener, wherein the fixing piece comprises an inner extension part and an outer extension part; the output shaft is provided with a positioning part, the inner extension part is matched with the positioning part, so that the fixing piece and the output shaft are circumferentially positioned; the locking piece is provided with a limiting part, and the outer extension part is matched with the limiting part, so that the fixing piece and the locking piece are circumferentially limited. Through the double circumferential interlocking of the inner and outer extension parts of the fixing piece and the positioning part of the output shaft and the limiting part of the locking piece, the risk of loosening of the screw pair of the locking piece caused by bidirectional rotation operation is completely eliminated, the risk of relative sliding of the blade and the output shaft or even the falling of the blade is significantly reduced, and the operation safety is improved.

Description

Technical Field

[0001] This application relates to the field of power tools, specifically to a working head and a trimming machine. Background Technology

[0002] As the core actuator of gardening tools such as trimmers and lawnmowers, the reliability of the locking structure of the rotating blade directly affects the equipment's operating efficiency and safety. Existing rotating blades are typically fixed to the output shaft using a "pressure plate clamping + end locking" method. The specific structure generally includes the blade, output shaft, pressure plate, and locking element (such as a nut). The locking element axially fixes the pressure plate and blade to the output shaft, enabling power transmission. However, existing technology has the following shortcomings: trimmers need to frequently switch between clockwise and counterclockwise rotation (e.g., alternating trimming and ditching operations), and trimmers are prone to severe vibrations from impacts with hard objects when cutting weeds. Existing locking structures mostly rely on a single thread preload or simple pressure plate constraint. When the output shaft rotates in both directions or vibrates for extended periods, the locking element is prone to loosening due to reverse torque or vibration, causing the blade to slide relative to the output shaft, and even posing a safety hazard of blade detachment. Utility Model Content

[0003] The purpose of at least one specific embodiment of this utility model is to overcome the defects of the prior art and provide a working head and a trimming machine.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0005] A working head, comprising:

[0006] The blade is mounted on the output shaft;

[0007] A clamping element, which passes through the output shaft and clamps the blade on both sides;

[0008] A locking element, which is fastened to the output shaft and locks the clamping element;

[0009] A fixing member is provided on one side of the locking member, and the fixing member includes an inner extension and an outer extension;

[0010] The output shaft has a positioning part, and the inner extension part is adapted to the positioning part so that the fixing part and the output shaft are circumferentially positioned.

[0011] The locking member has a limiting part, and the outer extension part is adapted to the limiting part so that the fixing member and the locking member are circumferentially limited.

[0012] Furthermore, the clamping components include an upper pressure plate and a lower pressure plate that are sleeved on the output shaft and respectively clamp the two sides of the blade;

[0013] The lower pressure plate has a support part on one side. The support part is sleeved on the outside of the output shaft and supported on the boss side of the output shaft surface. When the locking part is locked on the output shaft, one side of it abuts against the upper pressure plate, so that the upper pressure plate and the lower pressure plate form opposing clamping forces on the blade.

[0014] Furthermore, the locking component also includes a mounting portion, which is sleeved on the outside of the output shaft and supported between the locking component and the clamping component.

[0015] Furthermore, the positioning part is a positioning groove provided on the surface of the output shaft. When the fixing member is sleeved on the output shaft, the inner extension part extends into the positioning groove, so that the fixing member and the output shaft form circumferential positioning.

[0016] Furthermore, the positioning groove extends along the length of the output shaft, and the extension direction of the positioning groove defines the movement direction of the fixing member on the output shaft.

[0017] Furthermore, the limiting part is a limiting groove provided on the surface of the locking part. When the locking part is in the fastened position on the output shaft, the outer extension of the fixing part can be pressed into the limiting groove, so that the fixing part and the locking part can achieve circumferential positioning.

[0018] Furthermore, the outer extension is a deformable protrusion structure that undergoes plastic deformation and embeds into the limiting groove when subjected to pressure.

[0019] Furthermore, both the outer extension and the limiting part are configured as multiple parts.

[0020] Furthermore, the upper and lower pressure plates are mutually circumferentially limited, and the upper and / or lower pressure plates are circumferentially limited relative to the output shaft.

[0021] The beneficial effects of this utility model are as follows: This application completely eliminates the risk of loosening of the locking thread pair caused by bidirectional rotation operation (clockwise / counterclockwise switching of the trimmer) by double circumferential interlocking of the inner and outer extensions of the fixing part with the positioning part of the output shaft and the limiting part of the locking part through the double circumferential interlocking of the inner and outer extensions of the fixing part with the positioning part of the output shaft and the limiting part of the locking part. It significantly reduces the risk of relative sliding between the blade and the output shaft or even the blade falling off, and improves the safety of operation.

[0022] Another solution adopted in this application is: a trimming machine, comprising:

[0023] Connecting rod;

[0024] A drive assembly, which is mounted at the end of the connecting rod;

[0025] The aforementioned working head;

[0026] The drive assembly includes a motor, a gearbox connected to the motor, and a power output end of the gearbox connected to an output shaft.

[0027] The trimming machine is equipped with the aforementioned working head and has the corresponding technical effects of the aforementioned working head. Attached Figure Description

[0028] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0029] Figure 1 This is a three-dimensional schematic diagram of the working head in Embodiment 1 of this application.

[0030] Figure 2 This is a schematic diagram of the working head explosion in Embodiment 1 of this application.

[0031] Figure 3 This is a front view of the working head in Embodiment 1 of this application.

[0032] Figure 4 for Figure 3 A schematic diagram of the cross section along line AA.

[0033] Figure 5 for Figure 4 Enlarged view of area B in the image.

[0034] Figure 6 This is a schematic diagram of the structure after the fastening component and the blade are assembled in Embodiment 1 of this application.

[0035] Figure 7 This is a schematic diagram of the assembly of the fastening component and the blade in Embodiment 1 of this application.

[0036] Figure 8 This is a schematic diagram of the assembly of the pressure plate and the output shaft in Embodiment 1 of this application.

[0037] Figure 9 This is a schematic diagram of the upper pressure plate in Embodiment 1 of this application.

[0038] Figure 10 This is a schematic diagram of the trimming machine in Example 2 of the application. Detailed Implementation

[0039] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0040] Reference Figure 1 , Figure 2This embodiment provides a working head 100, which includes a protective cover 120, an output shaft 30, a blade 10 passing through the output shaft 30, and a fastening assembly for fastening the blade 10. The end of the output shaft 30 is connected to a drive assembly, which includes a motor 110 and a gearbox 130 that is poweredly connected to the motor shaft of the motor 110. The power output end of the gearbox 130 is connected to the output shaft 30.

[0041] Reference Figure 3 , Figure 4 , Figure 5 The protective cover 120 is a protective component with an opening 121, used to block debris and foreign objects during operation; the motor 110 is fixed to the outside of the protective cover 120, and its motor shaft is connected to the power input end of the gearbox 130 to provide power; the power output end of the gearbox 130 is connected to the output shaft 30 to realize power transmission and speed regulation; one end of the output shaft 30 is connected to the gearbox 130, and the other end extends through the opening 121 of the protective cover 120 to the inside of the protective cover 120. The blade 10 is sleeved on the output shaft 30 and fixed on the output shaft 30 by a fastening assembly; the fastening assembly includes an upper pressure plate 50, a lower pressure plate 40, a locking member 60, and a fixing member 70. Through the cooperation of multiple components, the blade is clamped, prevented from loosening, and rotated synchronously. The upper pressure plate 50 and the lower pressure plate 40 can form a clamping member for holding the blade 10 after clamping each other.

[0042] Reference Figure 8 The lower pressure plate 40 is sleeved on the output shaft 30, and its inner side is provided with an axially extending planar mating part 402, which mainly realizes the effect of circumferential torque transmission. Specifically, the shape of the planar mating part 402 is perfectly adapted to the torque transmission plane 301 on the outer circumference of the output shaft 30. During assembly, the planar mating part 402 and the torque transmission plane 301 radially abut against each other, forming a circumferential positioning constraint to ensure that the lower pressure plate 40 can rotate synchronously with the output shaft 30.

[0043] The lower pressure plate 40 also has a support part 403 on one side. The support part 403 passes through the opening 121 of the protective cover 120 and extends into the gearbox 130. At the same time, the support part 403 is sleeved on the outside of the output shaft 30 and supported on the boss side of the surface of the output shaft 30, further enhancing the connection stability between the lower pressure plate 40 and the output shaft 30.

[0044] Reference Figure 8 , Figure 9The lower pressure plate 40 has a boss 401 on the side surface near the blade 10; the upper pressure plate 50 has a corresponding groove 501 on the side surface near the blade 10. The groove 501 is adapted to the shape of the boss 401. In this embodiment, the boss 401 is square. When the lower pressure plate 40 and the upper pressure plate 50 are spliced, the boss 401 extends into the groove 501, and the two form a circumferential limit. As mentioned above, after the lower pressure plate 40 is sleeved on the output shaft 30, it forms a circumferential positioning constraint with the output shaft 30. Therefore, after the lower pressure plate 40 and the upper pressure plate 50 are spliced, the clamping member formed by the lower pressure plate 40 and the upper pressure plate 50 also maintains a circumferential limit with the output shaft 30. The lower pressure plate 40 and the upper pressure plate 50 are clamped on both sides of the blade 10 and rotate synchronously with the output shaft 30.

[0045] Reference Figure 2 , Figure 7 , Figure 8 When the blade 10 is installed, the inner hole 101 of the blade 10 passes through the output shaft 30 and is sleeved on the outer edge of the boss 401 of the lower pressure plate 40, and its side is in close contact with the support surface 404 of the lower pressure plate 40. During assembly, the upper pressure plate 50 is installed on one side of the blade 10, and the boss 401 of the lower pressure plate 40 is embedded in the groove 501 of the upper pressure plate 50. The lower pressure plate 40 and the upper pressure plate 50 are mutually circumferentially limited and clamped on both sides of the blade 10 to ensure that the blade 10 rotates synchronously with the upper and lower pressure plates (to avoid slippage during cutting).

[0046] The locking member 60 is used to axially fix the upper pressure plate 50, the lower pressure plate 40 and the blade 10 on the output shaft 30. The end of the output shaft 30 away from the gearbox 130 is provided with an external thread section 302. In this embodiment, the locking member 60 is implemented as a locking nut structure with an open slot. Its inner side is provided with an internal thread that matches the external thread section. It is fixed to the end of the output shaft 30 by thread engagement and abuts against the side of the upper pressure plate 50 to achieve axial pre-tightening.

[0047] Reference Figure 6 , Figure 7 The fixing member 70 includes a mounting part 701, an inner extension part 702 and an outer extension part 703 connected to the mounting part 701. The fixing member 70 is sleeved on the outside of the output shaft 30 through the mounting part 701. After the locking member 60 is threadedly connected to the output shaft 30, the mounting part 701 supports the locking member 60 and the upper pressure plate 50 and acts as a gasket. In addition, the output shaft 30 has a positioning part 303, and the inner extension part 702 can be adapted to the positioning part 303 so that the fixing member 70 and the output shaft 30 can be circumferentially positioned.

[0048] The locking member 60 has a limiting part 601, and the outer extension 703 can be adapted to the limiting part 601 so that the fixing member 70 and the locking member 60 are circumferentially limited.

[0049] Specifically, the positioning part 303 is a positioning groove provided on the surface of the output shaft 30. When the fixing member 70 is sleeved on the output shaft 30, the inner extension part 702 extends into the positioning groove, so that the fixing member 70 and the output shaft 30 form circumferential positioning. In this embodiment, the positioning groove extends along the length direction of the output shaft 30, and the extension direction of the positioning groove limits the movement direction of the fixing member 70 on the output shaft 30.

[0050] The limiting part 601 is a limiting groove provided on the surface of the locking member 60. When the locking member 60 is in the fastened position on the output shaft 30, the outer extension 703 of the fixing member 70 can be pressed into the limiting groove, so that the fixing member 70 and the locking member 60 are circumferentially positioned. In this embodiment, the outer extension 703 is a deformable protrusion structure, which undergoes plastic deformation and embeds into the limiting groove when pressed.

[0051] Furthermore, multiple extension portions 703 and limiting portions 601 are provided. On the one hand, the extension portions 703 and limiting portions 601 can be arbitrarily paired, which facilitates assembly. On the other hand, multiple sets of connections can be realized between the extension portions 703 and limiting portions 601, which increases the stability of the assembly of the locking member 60 and the fixing member 70.

[0052] In some embodiments, the retainer 70 may be implemented as a stop washer. When the retainer 70 is configured as a stop washer, it prevents the locking member 60 from rotating relative to the output shaft 30 by physical locking, thus preventing the threaded pair from loosening.

[0053] After the fastener 70 and the locking element 60 are assembled, the output shaft 30 will not rotate in either the forward or reverse direction. There is no relative rotational tendency between the locking element 60 and the fastener 70, thus completely eliminating the risk of loosening caused by bidirectional rotation.

[0054] Reference Figures 2 to 7 The assembly process of the working head 100 is as follows: The lower pressure plate 40 is sleeved on the outside of the output shaft 30, so that the planar mating part 402 of the lower pressure plate 40 is aligned with the torque transmission plane 301 of the output shaft 30 (the torque transmission plane 301 is a virtual plane formed by the positioning groove), ensuring that the lower pressure plate 40 and the output shaft 30 transmit torque in the circumferential direction without slippage. The support part 403 of the lower pressure plate 40 extends into the gearbox 130 through the opening 121 of the protective cover 120 and is pushed to the preset position. At the same time, one end of the support part 403 abuts against the boss on the surface of the output shaft 30.

[0055] Then, the blade 10 is fitted onto the outside of the boss 401 of the lower pressure plate 40, so that the side of the blade 10 fits against the support surface 404 of the lower pressure plate 40; the upper pressure plate 50 is installed, so that the groove 501 of the upper pressure plate 50 fits into the boss 401 of the lower pressure plate 40, ensuring that the upper pressure plate 50 and the side of the blade 10 are in close contact; the mounting part 701 of the fixing member 70 is fitted onto the outside of the output shaft 30, and the inner extension part 702 is aligned with the positioning groove (positioning part 303) on the output shaft 30. The fixing member 70 is pushed in along the extension direction of the positioning groove until the mounting part 701 contacts the side of the upper pressure plate 50, and the fixing member 70 is installed in place and circumferentially limited on the output shaft 30.

[0056] Screw the locking member 60 into the output shaft 30. The locking member 60 is screwed into the external thread section 302 until it abuts against the side of the upper pressure plate 50, completing the axial pre-tightening. At the same time, press the outer extension 703 on the fixing member 70 into the corresponding limiting part 601 (limiting groove) on the locking member 60. This achieves circumferential positioning between the fixing member 70 and the locking member 60. Since the fixing member 70 is circumferentially positioned relative to both the output shaft 30 and the locking member 60, the output shaft 30, the locking member 60, and the fixing member 70 form a tightly bound whole, and no relative rotation will occur between any two of them.

[0057] After the motor 110 starts, the power is transmitted to the output shaft 30 through the gearbox 130. The output shaft 30 drives the lower pressure plate 40 to rotate through the cooperation of the planar mating part 402 and the torque transmission plane 301. The lower pressure plate 40 drives the upper pressure plate 50 and the blade 10 to rotate synchronously through the fitting structure of the boss 401 and the groove 501, so as to realize the cutting operation.

[0058] When the output shaft 30 rotates clockwise or counterclockwise, the inner and outer extensions of the fixing part 70 are double circumferentially interlocked with the output shaft positioning part and the locking part limiting part, which completely eliminates the risk of the locking part 60 thread pair loosening caused by bidirectional rotation operation (clockwise / counterclockwise switching of the trimmer), significantly reduces the risk of relative sliding between the blade and the output shaft or even the blade falling off, and improves the safety of operation.

[0059] Example 2

[0060] Reference Figure 10 This embodiment provides an edge trimming machine 200, which includes a connecting rod 210, an operating component 220, and a working head 100 as described in Embodiment 1 above. The working head 100 is mechanically connected to the connecting rod 210.

[0061] Since the trimming machine 200 needs to frequently switch the rotation direction of the blades during trimming, the blades will rotate clockwise / counterclockwise (if trimming along a corner, the blades need to be adjusted in the opposite direction). Through the design of the working head 100 in the above embodiment, the blades do not come loose, which improves the safety of operation.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A working head, comprising: The blade is mounted on the output shaft; A clamping element, which passes through the output shaft and clamps both sides of the blade; A locking element, which is fastened to the output shaft and locks the clamping element; The locking member is characterized in that a fixing member is provided on one side, and the fixing member includes an inner extension and an outer extension; The output shaft has a positioning part, and the inner extension part is adapted to the positioning part so that the fixing member and the output shaft are circumferentially positioned. The locking member has a limiting portion, and the outer extension portion is adapted to the limiting portion so that the fixing member and the locking member are circumferentially limited.

2. The working head according to claim 1, characterized in that, The clamping component includes an upper pressure plate and a lower pressure plate sleeved on the output shaft and respectively clamping both sides of the blade; The lower pressure plate has a support portion on one side. The support portion is sleeved on the outside of the output shaft and supported on one side of the boss on the surface of the output shaft. When the locking member is locked on the output shaft, one side of it abuts against the upper pressure plate, so that the upper pressure plate and the lower pressure plate form opposing clamping forces on the blade.

3. The working head according to claim 1, characterized in that, The locking member also includes a mounting part, which is sleeved on the outside of the output shaft and supported between the locking member and the clamping member.

4. The working head according to claim 1 or 2, characterized in that, The positioning part is a positioning groove provided on the surface of the output shaft. When the fixing member is sleeved on the output shaft, the inner extension part extends into the positioning groove, so that the fixing member and the output shaft form a circumferential positioning.

5. The working head according to claim 4, characterized in that, The positioning groove extends along the length of the output shaft, and the extension direction of the positioning groove defines the movement direction of the fixing member on the output shaft.

6. The working head according to claim 1 or 2, characterized in that, The limiting part is a limiting groove provided on the surface of the locking member. When the locking member is in the fastened position on the output shaft, the outer extension of the fixing member can be pressed into the limiting groove, so that the fixing member and the locking member are circumferentially positioned.

7. The working head according to claim 6, characterized in that, The outer extension is a deformable protrusion that undergoes plastic deformation when compressed and embeds itself into the limiting groove.

8. The working head according to claim 1, characterized in that, Both the outer extension and the limiting portion are provided in multiples.

9. The working head according to claim 2, characterized in that, The upper pressure plate and the lower pressure plate are mutually circumferentially limited, and the upper pressure plate and / or the lower pressure plate are circumferentially limited relative to the output shaft.

10. A trimming machine, characterized in that, include: Connecting rod; A drive assembly, which is mounted at the end of the connecting rod; The working head according to any one of claims 1-9; The drive assembly includes a motor, a gearbox connected to the motor, and the power output end of the gearbox is connected to the output shaft.

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