Pruning machine

Abstract

Provided is a pruner that does not increase weight and cost and can reduce damage to a gear when a blade is jammed with a simple configuration. The pruner includes an electric motor (50), a blade drive gear (61) that is rotationally driven by the electric motor (50), an eccentric cam (62) provided on the gear (61), and a pair of blades that are in a relatively slidable manner. The pair of blades are reciprocated in opposite directions along their longitudinal directions by the eccentric cam (62), so that cutting edges (24) that are spaced apart from each other and are provided in a protruding manner on the pair of blades are ground against each other. An impact absorbing structure (70) is provided between a connecting structure (28) of the eccentric cam (62) and the cutting edges (24) of the blades.

Description

Technical Field

[0001] This invention relates to a pruning machine. Background Technology

[0002] Hedge trimmers and pruning shears used for pruning and trimming hedges and garden plants include a blade drive gear driven to rotate by a drive source inside the main body, a cam (eccentric cam) consisting of two eccentric discs located on one side of the gear, and upper and lower paired blades that slide freely together. The eccentric cam causes the two long blades to reciprocate in opposite directions along their longitudinal direction, so that the cutting edges arranged in a comb-like pattern on them move back and forth, thereby performing pruning and trimming operations (see, for example, Patent Document 1).

[0003] Among existing pruning machines, there are those that reciprocate by having a drive shaft rotatably supported in the transmission housing of the main body shell (the main body of the working machine) and driven by the crankshaft of an internal combustion engine as the drive source through a centrifugal clutch, thereby causing the upper and lower blades to move back and forth (see, for example, Patent Document 2).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2019-193598

[0007] Patent Document 2: Japanese Patent Application Publication No. H11-009089 Summary of the Invention

[0008] Technical problem solved by the present invention

[0009] In the pruning machine with a clutch mechanism as described above, when the blade gets stuck on a thick branch or hard object such as a fence or steel bar during pruning, the rotational force of the engine and the impact (huge torque) when stuck are released due to the failure of the clutch mechanism. Therefore, the impact when stuck is difficult to be directly transmitted to the gears, thereby reducing the damage to the gears.

[0010] In addition, in electric pruning machines that use an electric motor (hereinafter sometimes referred to as "motor") as the driving source, if a clutch mechanism is not used, when the machine jams during the pruning process, the rotational force of the motor and the impact (huge torque) when jamming cannot be released through the clutch mechanism. Therefore, the impact when jamming will be directly transmitted to the gears, which may cause damage to the gears (such as missing teeth).

[0011] As a countermeasure, one could consider, for example, using the same clutch mechanism as an engine-driven pruning machine. However, this would lead to problems such as reduced operability due to increased weight, increasing the burden on the user, and also increasing costs.

[0012] The present invention addresses the aforementioned problems and aims to provide a pruning machine that does not increase weight or cost and can reduce damage to gears when the blade jams with a simple construction.

[0013] Technical means to solve the problem

[0014] To solve the above problems, the pruning machine of the present invention basically includes: an electric motor; a blade drive gear driven by the electric motor; an eccentric cam disposed on the gear; and a pair of blades that are slidably connected to each other, wherein the eccentric cam causes the pair of blades to reciprocate in opposite directions along their longitudinal direction, thereby causing the cutting edges with spaced protrusions on the pair of blades to move relative to each other, characterized in that an impact absorption structure is provided between the connecting structure of the eccentric cam and the cutting edge of the blade.

[0015] In a preferred aspect, the pruning machine may include a connecting rod connecting the eccentric cam and the blade, and the impact absorbing structure may be disposed between the connecting structure of the connecting rod and the cutting edge of the blade.

[0016] In other preferred aspects, the impact-absorbing structure may include a vulnerable portion.

[0017] In other preferred aspects, the impact-absorbing structure may include a slit portion extending in a direction perpendicular to the reciprocating motion direction of the blade.

[0018] In other preferred aspects, the width of the impact-absorbing structure including the slit portion along the vertical direction may be wider than the width of the blade along the vertical direction between the connecting structure and the impact-absorbing structure and / or the width of the blade along the vertical direction between the impact-absorbing structure and the cutting edge.

[0019] In other preferred aspects, the width of the impact-absorbing structure including the slit portion along the vertical direction may be narrower than the width of the cutting edge protruding from the blade along the vertical direction.

[0020] In other preferred aspects, the slit portion may have a vulnerable section.

[0021] In other preferred aspects, the vulnerable portion may be formed by at least one of a notch, cut, groove, or trench.

[0022] In other preferred aspects, the slit portion may be self-contained as an elongated hole for inserting a component that holds the pair of blades into which a reciprocating motion can be performed in opposite directions along its longitudinal direction, extending in a direction perpendicular to the reciprocating motion direction of the blades.

[0023] In other preferred aspects, the slit portion may extend from a position different from the elongated hole into which the component for holding the pair of blades to be able to reciprocate in opposite directions along their longitudinal direction is inserted, in a direction perpendicular to the reciprocating direction of the blades.

[0024] Invention Effects

[0025] According to the present invention, since only an impact absorption structure needs to be provided between the blade connection structure and the cutting edge, it will not lead to an increase in weight or cost, and can reduce the damage to the gear when the blade jams with a simple structure. Attached Figure Description

[0026] Figure 1 This is a perspective view of a hedge trimmer according to one embodiment of the present invention.

[0027] Figure 2 This is a side view of a hedge trimmer according to one embodiment of the present invention.

[0028] Figure 3 This is a side sectional view of a hedge trimmer according to one embodiment of the present invention.

[0029] Figure 4 This is a bottom view of a hedge trimmer according to one embodiment of the present invention. The figure shows the state after the bottom plate of the drive transmission mechanism housing has been removed.

[0030] Figure 5 This diagram illustrates the operation of the upper and lower blades, which are engaged by an eccentric cam and a movable plate.

[0031] Figure 6 This is an enlarged bottom view of the main part (proximal part) of the lower blade of a hedge trimmer according to an embodiment of the present invention.

[0032] Figure Labels

[0033] 1. Hedge trimmer (branch pruner)

[0034] 10 Main body shell

[0035] 15 Battery mounting structure

[0036] 20 Blade Assembly

[0037] 21. Blade

[0038] 22 blades

[0039] 23 Cover plate

[0040] 24 cutting edge

[0041] 25 long holes

[0042] 26 Square cylindrical gasket

[0043] 27. Bolt

[0044] 28 Connection Structure

[0045] 30 front handle

[0046] 31 Front shield

[0047] 40 years old handle

[0048] 41 Connection Structure

[0049] 42 Grip Structure

[0050] 43 Trigger Link

[0051] 44 Unlock Link

[0052] 45 Power Switch

[0053] 50 electric motors

[0054] 60 Drive transmission mechanism

[0055] 61 Blade Drive Gear

[0056] 62 Eccentric Cam

[0057] 63. Movable piece (connecting rod)

[0058] 64 Support Shaft

[0059] 65 bearing

[0060] 66. Outer shell

[0061] 67 Top Plate

[0062] 68 base plate

[0063] 70 Impact Absorption Structure

[0064] 71. Slit section

[0065] 72 Vulnerable Parts

[0066] 100 batteries

[0067] 110 Joint Structure

[0068] 120 connecting rod

[0069] L axis of rotation Detailed Implementation

[0070] Hereinafter, embodiments of the present invention will be described in detail with appropriate reference to the accompanying drawings. In the following description, a hedge trimmer, as one type of pruning machine, will be used as an example. Furthermore, in this specification, the side with the blade (cutting edge) is the front side or the distal side, the side with the main body casing is the rear side or the proximal side, the side with the protruding front handle for the operator to grip is the upper side, and the opposite side is the lower side. However, the arrangement of the up, down, front, back, left, and right directions is intended to facilitate the description of the hedge trimmer of this embodiment and does not limit the construction or use of the hedge trimmer.

[0071] The hedge trimmer 1 in this embodiment is as follows: Figure 1 As shown, this is a handheld, small-scale cutting machine used for pruning and trimming hedges and garden plants. It is powered by an internal battery 100. The hedge trimmer 1 is shown... Figure 2 As shown, it includes an electric motor 50 as a drive source, a blade assembly 20 disposed in front of the electric motor 50, and a main body housing 10 that houses the electric motor 50.

[0072] The main outer casing 10 is a resin box with its top surface inclined relative to its bottom surface. The top surface of the main outer casing 10 slopes gradually downwards from back to front. That is, the main outer casing 10 is formed such that the front part is lower than the rear part. In addition, the main outer casing 10 is formed in a roughly triangular shape when viewed from the side.

[0073] A battery mounting structure 15 for mounting the battery 100 is provided on the top surface of the main body casing 10. The battery mounting structure 15 is inclined from back to front, gradually downward, along with the top surface of the main body casing 10.

[0074] Battery 100 is a well-known type of battery, which houses a secondary battery such as a lithium-ion rechargeable battery within a rectangular casing extending in the front-to-back direction. At the rear end of the bottom surface of battery 100, as... Figure 2 and Figure 3 As shown, the engagement structure 110, which engages with the battery mounting structure 15, protrudes outward.

[0075] When mounting the battery 100 onto the battery mounting structure 15, the battery 100 is slid from back to front relative to the battery mounting structure 15, while simultaneously engaging the bottom of the battery 100 with the battery mounting structure 15. Furthermore, when the front end of the battery 100 moves to a position where it is supported by the front end of the battery mounting structure 15, the engagement structure 110 of the battery 100 engages with the battery mounting structure 15, thereby securing the battery 100 to the battery mounting structure 15.

[0076] The top surface of the battery mounting structure 15 has a metal connector (not shown). The connector is electrically connected to the control circuit board (not shown) and the electric motor 50. Furthermore, by connecting the connector of the battery 100 to the connector of the battery mounting structure 15, the battery 100 supplies power to the control circuit board and the electric motor 50.

[0077] When the battery 100 is removed from the battery mounting structure 15, the connecting rod 120 located at the rear end of the battery 100 is pulled up. Figure 3 The battery mounting structure 15 and the engagement structure 110 are disengaged, thereby allowing the battery 100 to slide backward relative to the battery mounting structure 15.

[0078] like Figure 1 As shown, a front handle 30 is provided at the front of the main body housing 10. The front handle 30 is located in front of the battery 100 mounted on the battery mounting structure 15. The front handle 30 is formed in a door-shaped manner when viewed from the front, and has a horizontal member extending in the left-right direction, and two vertical members extending downward from the left and right ends of the horizontal member. The lower ends of the two vertical members are fixed to the front end of the main body housing 10. A front cover 31 is provided between the lower ends of the two vertical members of the front handle 30. The front cover 31 is formed in a manner that covers the blade assembly 20 (proximal end).

[0079] A rear handle 40 is provided at the rear of the main body housing 10. The rear handle 40 has a connecting structure 41 that connects to the rear of the main body housing 10, and a gripping structure 42 with an opening extending in the left-right direction. When the operator holds the hedge trimmer 1, they grip the rear handle 40 by inserting their hand into the opening of the gripping structure 42. The connecting structure 41 of the rear handle 40 is as follows... Figure 3 As shown, the rear handle 40 is connected in a manner that allows it to rotate freely about a front-rear axis relative to the rear end face of the main body housing 10. Thus, the rear handle 40 as a whole can rotate freely about a front-rear axis relative to the main body housing 10.

[0080] The inner circumference of the rear handle 40 grip structure 42 is as follows Figure 1 As shown, a trigger link 43 is provided, which is an operating device for driving the blade assembly 20 by rotating the electric motor 50 when the operator holds it. In addition, a power switch 45 is provided on the top surface of the grip structure 42, in addition to an unlocking link 44 for unlocking the trigger link 43.

[0081] Furthermore, the shape of the main casing 10, the configuration and installation of the battery 100, etc., are of course not limited to the examples shown in the figure.

[0082] Furthermore, although the control circuit board and electric motor 50 in the hedge trimmer 1 of this embodiment are powered by the battery 100, for example, the battery 100 may not be used, and the control circuit board and electric motor 50 may be powered by an external power source via a power cord.

[0083] Blade assembly 20 Figure 2 As shown, it extends forward in a straight line relative to the electric motor 50 and protrudes forward from the front end of the main body housing 10. The blade assembly 20 is a cutting tool that includes an upper blade 21 and a lower blade 22 made of metal and a cover plate 23 made of resin.

[0084] The upper blade 21 and lower blade 22 are long, strip-shaped blades that overlap each other. The upper blade 21 and lower blade 22 are joined together in a manner that allows them to slide freely relative to each other, and they form a pair. The upper blade 21 and lower blade 22 are as follows... Figure 1 As shown, multiple cutting blades 24 protrude to the left and right at certain intervals along its longitudinal direction. The cover plate 23 is a protective component used to prevent the operator's hands from contacting the upper blade 21 and the lower blade 22, and covers the top surface of the upper blade 21.

[0085] Upper blade 21 and lower blade 22 as follows Figure 4 As shown, a required number of elongated holes (longer holes in the longitudinal direction) 25 are formed at certain intervals along its longitudinal direction. The length of the elongated holes 25 is the allowable length for the reciprocating motion of the upper blade 21 and the lower blade 22. Furthermore, a square prism-shaped washer 26, which is rectangular in plan view and has a circular insertion hole, is slidably inserted into the elongated holes 25 (overlapping elongated holes) of the upper blade 21 and the lower blade 22. A pin 27, as a fastener, is inserted into and secured in the circular insertion hole of the square prism-shaped washer 26 (depending on the longitudinal position, it also includes a through hole provided on the cover plate 23). In this way, the upper blade 21 and the lower blade 22 are held in a state where they can slide freely relative to each other and are securely fixed in a predetermined position along the longitudinal direction.

[0086] The rear ends (proximal ends) of the upper blade 21 and the lower blade 22 are as follows: Figure 3 and Figure 4 As shown, a connection structure 28 is formed to connect with the movable piece 63. In this embodiment, the connection structure 28 is formed as a short cylindrical protrusion, and the upper blade 21 and the lower blade 22 are connected to the movable piece 63 by inserting into the distal opening of the movable piece 63. However, the construction of the connection structure 28, i.e., the connection construction of the upper blade 21 and the lower blade 22 with the movable piece 63, is not limited to the example shown in the figure. For example, circular openings as connection structures may be formed on the upper blade 21 and the lower blade 22, and the connection can be achieved by inserting the cylindrical protrusion formed on the movable piece 63 into the opening.

[0087] The rear ends of the upper blade 21 and the lower blade 22 are as follows Figure 3 and Figure 4 As shown, it is inserted into the main body housing 10. The rear ends of the upper blade 21 and the lower blade 22 are connected to the electric motor 50 through the drive transmission mechanism 60.

[0088] The drive transmission mechanism 60 includes a blade drive gear 61, two upper and lower eccentric cams (hereinafter referred to as cams) 62, 62 disposed on the blade drive gear 61, and two upper and lower movable plates (also referred to as connecting rods) 63, 63.

[0089] The blade drive gear 61 is a disc-shaped gear with a support shaft 64 protruding vertically from its center. The upper and lower ends of the support shaft 64 are supported by two bearings 65 located inside the main housing 10, which are rotatable. That is, the blade drive gear 61 rotates around the axis of the support shaft 64.

[0090] Two cams 62, 62, formed by an eccentric disc, protrude from the top and bottom surfaces of the blade drive gear 61, respectively. The two cams 62, 62 are positioned eccentrically to one side and the other side relative to the rotation center (center of the support shaft 64) of the blade drive gear 61. In this embodiment, the two cams 62, 62 are integrally formed with the gear 61 by form grinding.

[0091] The upper cam 62 engages by inserting into the rear end opening of the upper movable plate 63, and the rear end connecting structure 28 of the upper blade 21 is connected by inserting into the distal end opening of the upper movable plate 63. The lower cam 62 engages by inserting into the rear end opening of the lower movable plate 63, and the rear end connecting structure 28 of the lower blade 22 is connected by inserting into the distal end opening of the lower movable plate 63.

[0092] The drive transmission mechanism 60 is constructed such that the upper and lower cams 62, 62 rotate and move with the rotation of the blade drive gear 61, thereby causing the upper and lower movable blades 63, 63 to reciprocate in the front-back direction. The upper blade 21 and lower blade 22 reciprocate in opposite directions in the front-back direction (that is, along their longitudinal direction, they reciprocate in opposite directions for a predetermined stroke) (see...). Figure 4 and Figure 5 In other words, its structure allows the rotational motion of the electric motor 50 to be converted into the reciprocating motion of the upper blade 21 and the lower blade 22 in the longitudinal direction through the two movable plates 63 of the drive transmission mechanism 60.

[0093] The aforementioned blade drive gear 61, cams 62 and 62, movable plates 63 and 63, etc., are housed within the housing 66 of the drive transmission mechanism 60. The housing 66 includes a top plate 67 and a bottom plate 68. The top plate 67 and bottom plate 68 of the housing 66 are formed such that the blade drive gear 61, cams 62 and 62, movable plates 63 and 63, etc., are covered together from the upper and lower sides of the blade assembly 20. The blade assembly 20 protrudes forward from the front end of the housing 66.

[0094] Furthermore, although this embodiment employs a linkage-type connection that indirectly connects the upper and lower cams 62, 62 to the upper blade 21 and lower blade 22 (connection structure 28, 28) via the upper and lower movable pieces 63, 63, it is also reasonable to form, for example, an elongated hole (a hole that is longer in the left-right direction) as a connection structure at the rear end (proximal end) of the upper blade 21 and lower blade 22, and make the upper blade 21 and lower blade 22 reciprocate in the front-back direction by inserting the upper and lower cams 62, 62 into the elongated hole (connection structure). In other words, an elongated hole-type connection that directly connects the upper and lower cams 62, 62 to the upper blade 21 and lower blade 22 (connection structure) is adopted.

[0095] The electric motor 50 is located above the rear of the drive transmission mechanism 60. The electric motor 50 includes a stator 51, an outer rotor 52, an output shaft 53, and a base 54.

[0096] The stator 51 is provided with multiple coils 51a. The lower end of the base 54 located on the inner periphery of the stator 51 is fixed to the top plate 67 of the housing 66 of the drive transmission mechanism 60.

[0097] The output shaft 53 is inserted into a bearing located on the inner circumferential surface of the base 54. In this way, the output shaft 53 is supported on the base 54 in a rotatable manner. An output gear 53a is provided at the lower end of the output shaft 53. The output gear 53a meshes with the blade drive gear 61 of the drive transmission mechanism 60.

[0098] The outer rotor 52 has a cylindrical annular wall 52a surrounding the stator 51 and each coil 51a, and a top 52b that blocks the opening on the top surface of the annular wall 52a. Although the outer rotor 52 in this embodiment is made of iron, there are no limitations on the material of the outer rotor as a rotating wheel. A plurality of magnets 52c are mounted on the inner circumferential surface of the annular wall 52a.

[0099] The upper end of the output shaft 53 is connected to the center portion of the top 52b of the outer rotor 52. In this way, the stator 51 is supported on the outer rotor 52 in a rotatable manner, and the output shaft 53 rotates in conjunction with the outer rotor 52. The rotation axis L of the outer rotor 52 and the output shaft 53 extends in a vertical direction perpendicular to the extension direction (front-back direction) of the blade assembly 20.

[0100] The outer rotor 52 is formed such that its diameter (lateral) is greater than its length in the direction of the rotation axis L (vertical direction). In other words, the outer rotor 52 is formed in a flat shape with a lateral width greater than its height when viewed in the lateral direction (perpendicular to the rotation axis L).

[0101] The outer rotor 52 is rotatably supported on the stator 51 and is connected to the rear end of the blade assembly 20 via a drive transmission mechanism 60. Furthermore, when the battery 100 energizes the coils 51a of the stator 51, the outer rotor 52 and the output shaft 53 begin to rotate, and this driving force is transmitted to the blade assembly 20 via the drive transmission mechanism 60, causing the upper blade 21 and the lower blade 22 to reciprocate in opposite directions (see...). Figure 4 and Figure 5 In other words, the cams 62 and 62 of the drive transmission mechanism 60 cause the long, paired upper and lower blades 21 and 22 to reciprocate in opposite directions along their longitudinal direction, thereby causing the serrated cutting edges 24 on them to move in opposite directions to achieve operations such as pruning and trimming of hedges and garden plants.

[0102] In the electrically driven hedge trimmer 1 that uses the electric motor 50 with the above-described structure as the drive source, without a clutch mechanism, when jamming occurs during the trimming or pruning process, the rotational force of the motor 50 and the impact (huge torque) when jamming cannot be released through the clutch mechanism. Therefore, the impact when jamming will be directly transmitted to the gear 61, which may cause damage to the gear 61 (such as missing teeth).

[0103] Therefore, in this embodiment, in order to reduce the damage to the gear 61 when the blades (upper blade 21, lower blade 22) jam, an impact absorption structure 70 is provided between the connecting structure 28 of the blades (upper blade 21, lower blade 22) and the cutting edge 24 (more specifically, the cutting edge 24 located on the side closest to the proximal end or on the side of the connecting structure 28).

[0104] Furthermore, the impact absorption structure 70 can be provided on both the upper blade 21 and the lower blade 22, or it can be provided on only one of them. In the following detailed description, the case where the impact absorption structure 70 is provided on the lower blade 22 will be used as an example.

[0105] The impact absorption structure 70 is the weakest part of the lower blade 22, and it is also designed to reduce (absorb) the impact transmitted to the gear 61 via the moving plate 63, etc., during jamming through deformation or damage. In this embodiment, if combined with Figure 4 refer to Figure 6 It is evident that the impact-absorbing structure 70 is constructed to include a slit portion 71 and a vulnerable portion 72.

[0106] The slit portion 71 is formed extending in the left-right direction (perpendicular to the reciprocating motion direction). Furthermore, the ends of the slit portion 71 in the left-right direction are formed into approximately circular shapes, slightly wider than the central portion (slightly wider in the front-back direction). In this embodiment, the width (Ls) of the impact-absorbing structure 70 including the slit portion 71 in the left-right direction is wider than the width of the lower blade 22 in the left-right direction. That is, the width (Ls) of the impact-absorbing structure 70 including the slit portion 71 in the left-right direction is wider than the width (La) of the lower blade 22 between the connecting structure 28 and the impact-absorbing structure 70 in the left-right direction and / or the width (Lb) of the lower blade 22 between the impact-absorbing structure 70 and the cutting edge 24 in the left-right direction. Additionally, the width (Ls) of the impact-absorbing structure 70 including the slit portion 71 in the left-right direction is narrower than the width (Lc) of the cutting edge 24, which protrudes from the lower blade 22 in the left-right direction. In other words, the impact absorption structure 70 containing the slit portion 71 is formed such that it is located inside the cutting edge 24 protruding on the lower blade 22 in the left-right direction and does not protrude to the outside of the cutting edge 24 protruding on the lower blade 22 in the left-right direction.

[0107] The vulnerable portion 72 is formed by notches, cuts, grooves, or channels. In this embodiment, the vulnerable portion 72 is formed at the end of the slit portion 71 in the left-right direction (that is, the part of the slit portion 71 furthest from the center of the lower blade 22).

[0108] With this structure, when jamming occurs during pruning or trimming, the impact-absorbing structure 70 will deform due to the impact of the jamming. Furthermore, if the impact of the jamming cannot be completely absorbed solely by the deformation of the impact-absorbing structure 70 (the slit portion 71), the vulnerable portion 72 (notch, etc.) provided on the impact-absorbing structure 70 will be damaged. Thus, through the deformation or damage of the impact-absorbing structure 70, the impact of jamming transmitted to the gear 61 via the movable piece 63, etc., can be suppressed (absorbed).

[0109] In this embodiment, for space considerations, the slit portion 71 of the impact-absorbing structure 70 is formed to extend in the left-right direction from the elongated hole 25 into which the square columnar gasket 26 is inserted. However, the slit portion 71 of the impact-absorbing structure 70 may also be formed to extend in the left-right direction from a position other than the elongated hole 25 into which the square columnar gasket 26 is inserted. For example, in the latter case, assuming that the slit portion 71 of the impact-absorbing structure 70 deforms under the action of tensile force in the front-back direction when jammed, the elongated hole 25 adjacent to the slit portion 71 of the impact-absorbing structure 70 will deform in a way that widens in the left-right direction, thereby achieving the effect of allowing the upper blade 21 and the lower blade 22 to slide smoothly relative to each other (in other words, without hindering the sliding of the upper blade 21 and the lower blade).

[0110] Furthermore, in this embodiment, the impact-absorbing structure 70 is disposed at one position between the blade (upper blade 21, lower blade 22) connecting structure 28 and the cutting edge 24. However, naturally, the impact-absorbing structure 70 may also be disposed at multiple positions between the blade (upper blade 21, lower blade 22) connecting structure 28 and the cutting edge 24. Moreover, the shape of the impact-absorbing structure 70 is certainly not limited to the example shown in the figure.

[0111] As described above, the hedge trimmer 1 of this embodiment includes an electric motor 50, a blade drive gear 61 driven by the electric motor 50, an eccentric cam 62 provided on the gear 61, and a pair of blades that are connected in a relatively free sliding manner. The eccentric cam 62 causes the pair of blades to reciprocate in opposite directions along their longitudinal direction, thereby causing the cutting edges 24, which are spaced apart on the pair of blades, to shift relative to each other. Furthermore, an impact absorption structure 70 is provided between the connection structure 28 between the blade and the eccentric cam 62 (in this embodiment, the connection structure 28 with the movable piece connecting the cam and the blade) and the cutting edge 24 (specifically, the cutting edge 24 located on the side closest to the proximal end or the side of the connection structure 28). Thus, when the blade gets stuck due to the cutting edge catching on a thick branch, fence, steel bar, or other hard object during trimming or pruning (during the stuck period), the impact and other shocks can be released by the deformation of the impact absorption structure 70, thereby reducing damage to the gear 61.

[0112] Furthermore, the impact absorption structure 70 includes a vulnerable portion 72 (such as a notch). Thus, even if an impact occurs that the impact absorption structure 70 cannot completely absorb, damage to the gear 61 can be reduced by damaging the vulnerable portion 72 (such as the notch). Additionally, because the vulnerable portion 72 exists between the connecting structure and the cutting edge, the blade will not break at the cutting edge 24, thus enhancing safety.

[0113] Furthermore, since the blade is usually a replacement part that needs to be replaced after wear, it is easier to replace even if it needs to be replaced due to the aforementioned deformation or damage than when the gear 61 needs to be replaced due to damage, and the cost can be reduced (that is, the cost advantage is greater).

[0114] Furthermore, the impact-absorbing structure 70 includes a slit portion 71 extending in a direction perpendicular to the reciprocating motion direction (longitudinal) of the blade (lateral). The width of the impact-absorbing structure 70 including the slit portion 71 in the vertical direction is wider than the width of the blade between the connecting structure 28 and the impact-absorbing structure 70 in the vertical direction, and / or the width of the blade between the impact-absorbing structure 70 and the cutting edge 24 in the vertical direction. Thus, for example, a user can force the blade to slide by gripping a portion of the impact-absorbing structure 70, thereby facilitating the removal of cutting debris and other debris adhering between the upper blade 21 and the lower blade 22, which is beneficial for maintenance.

[0115] Furthermore, the width of the impact-absorbing structure 70, including the slit portion 71, along the vertical direction is narrower than the width of the cutting edge 24, which protrudes along the left and right direction. Thus, during operation, the impact-absorbing structure 70 is less likely to snag on branches or other objects, thereby maintaining workability.

[0116] As described above, according to this embodiment, since only the impact absorption structure 70 needs to be provided between the blade connection structure and the cutting edge, it will not lead to an increase in weight or cost, and the damage to the gear 61 when the blade jams can be reduced with a simple structure.

[0117] Although an example of an embodiment of the present invention has been described above, the present invention is not limited to the described embodiment and can be appropriately modified without departing from the spirit of the present invention.

[0118] Although the blade assembly 20 of the hedge trimmer 1 in this embodiment is as follows Figure 1 The blade assembly shown extends forward in a straight line and has a structure that allows the upper blade 21 and lower blade 22 to reciprocate in the front-back direction. However, the structure of the blade assembly is not limited. For example, as an example of the blade assembly, a T-shaped blade can also be used, in which a blade extending in the left-right direction is provided at the far end of the straight extension portion extending forward from the electric motor 50 and the blade reciprocates in the left-right direction. Furthermore, although the blade assembly 20 of the hedge trimmer 1 in this embodiment belongs to the type that performs trimming, pruning, and other operations by causing the upper blade 21 and lower blade 22 to reciprocate in opposite directions along their longitudinal direction using two eccentric cams 62 (that is, the type in which both the upper blade 21 and lower blade 22 move), it is of course possible to use a type in which one of the upper blade 21 and lower blade 22 does not move.

Claims

1. A pruning machine, characterized in that, include: Electric motor; The blade-driven gear is rotated by the electric motor; A pair of blades are formed to extend longitudinally and be joined to each other in a relatively slidable manner, wherein each of the pair of blades is formed with a connecting structure and a transversely protruding cutting edge formed at intervals from the longitudinal direction of the pair of blades. An eccentric cam, operably connected to the blade drive gear and the connection structure of the pair of blades, is used to convert the rotational motion of the blade drive gear into reciprocating motions of the pair of blades in opposite directions along their longitudinal direction, thereby causing the cutting edges to grind against each other; and An impact-absorbing structure is disposed between the connecting structure and the cutting edge of each of the pair of blades, wherein the impact-absorbing structure is configured to include a slit portion extending in a direction perpendicular to the reciprocating motion direction of the blades and a vulnerable portion, wherein the impact occurring when the pair of blades jams can be absorbed by damage to the vulnerable portion of the impact-absorbing structure.

2. The pruning machine as described in claim 1, characterized in that, The pruning machine also includes a connecting rod that connects the eccentric cam and the pair of blades to the connecting structure.

3. The pruning machine as described in claim 1, characterized in that, The width of the impact-absorbing structure, including the slit portion, along the vertical direction is narrower than the width of the cutting edge protruding from the blade along the vertical direction.

4. The pruning machine as described in claim 1, characterized in that, The vulnerable portion is composed of at least one of a notch, cut, groove, or trench.

5. The pruning machine as described in claim 1, characterized in that, The slit portion extends from an elongated hole in a direction perpendicular to the reciprocating motion direction of the blades, the elongated hole being used for inserting a component that holds the pair of blades in a position to reciprocate in opposite directions along their longitudinal direction.

6. The pruning machine as described in claim 1, characterized in that, The slit portion extends from a position different from an elongated hole in a direction perpendicular to the reciprocating motion direction of the blades, the elongated hole being used for inserting a component that holds the pair of blades in a position to reciprocate in opposite directions along their longitudinal direction.

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