Cutting tools

Abstract

To provide a technology which enables improvement of users' convenience in a cutting tool provided with a hand guard.SOLUTION: A cutting tool disclosed by the specification includes: a cutting unit; a prime mover configured to drive the cutting unit; a housing including a housing body for holding the cutting unit and housing the prime mover, and a grip which extends from the housing body and is configured to be grasped by a user's hand; and a hand guard attached to the housing, configured to protect fingers of the user's hand grasping the grip, and being more deformable than the housing.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The technology disclosed herein relates to cutting tools. [Background technology]

[0002] Patent Document 1 discloses a cutting tool including a housing including a cutting unit, a motor for driving the cutting unit, a housing main body for holding the cutting unit and accommodating the motor, a grip extending from the housing main body and held by a user's hand, and a finger guard attached to the housing for protecting the user's fingers when holding the grip. The finger guard is seamlessly formed integrally with the housing. Therefore, the finger guard is easily deformed to the same extent as the housing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-209581 Summary of the Invention [Problem to be solved by the invention]

[0004] The cutting tool of Patent Document 1 is provided with a finger guard (corresponding to the hand guard of the present application) to protect the user's fingers when holding the grip. However, providing a hand guard on a cutting tool can sometimes impair user convenience. For example, when a user uses the cutting tool to perform cutting work (e.g., pruning tree branches), the hand guard may mechanically interfere with an obstacle (e.g., a tree trunk), preventing the cutting tool from being positioned or oriented as desired, thereby hindering the cutting work. This specification provides a technology that can improve user convenience in a cutting tool provided with a hand guard. [Means for solving the problem]

[0005] The cutting tool disclosed in this specification includes a housing including a cutting unit, a motor for driving the cutting unit, a housing main body for holding the cutting unit and accommodating the motor, a grip extending from the housing main body and held by a user's hand, and a hand guard attached to the housing, which is more easily deformed than the housing and protects the user's fingers when holding the grip. Note that "hand guard deformation" as used herein refers to reversible deformation. For example, "hand guard deformation" can refer to elastic deformation of the hand guard itself. Furthermore, "hand guard deformation" can also refer to the swinging of a hand guard from a closed state to an open state in a hand guard configured like a swing door. Furthermore, "hand guard deformation" can also refer to a change in the position of the hand guard relative to the housing, in a hand guard that is translatable between a first position and a second position relative to the housing.

[0006] According to the above configuration, when a load is applied to the hand guard while the hand guard is in contact with an obstacle, the hand guard deforms relative to the housing. Therefore, when a user performs cutting work using the cutting tool, even if the hand guard interferes with an obstacle, the cutting tool can be placed in a desired position or posture. Therefore, the convenience of the cutting tool provided with the hand guard can be improved. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a perspective view of a chainsaw T1 according to a first embodiment, viewed from above on the front left. [Figure 2] 1 is a perspective view of the chainsaw T1 according to the first embodiment, viewed from above and rear right, with the battery pack B1 removed from the battery interface 160. FIG. [Figure 3] 1 is a bottom view of the chainsaw T1 according to the first embodiment as viewed from below. FIG. [Figure 4]1 is a perspective view of the chainsaw T1 according to the first embodiment, with a sprocket cover 18 removed from a housing body 14, as viewed from above and behind the left. [Figure 5] 2 is a cross-sectional view of the internal structure of the chainsaw T1 according to the first embodiment, seen from the left, in the vicinity of the base end of the grip 16. FIG. [Figure 6] 2 is a cross-sectional view of the internal structure of the housing 4 of the chainsaw T1 according to the first embodiment, as viewed from the right. FIG. [Figure 7] 1 is a diagram of the electric motor 64, motor shaft 80, cooling fan 82, power transmission mechanism 70, oil pump 68, sprocket 26, and working unit 10 of the chainsaw T1 according to the first embodiment, viewed from above and to the front right. [Figure 8] 1 is a view of the inside of a housing body 14 of a chainsaw T1 according to a first embodiment, viewed from the front along a direction perpendicular to an axis A1 of a motor shaft 80. FIG. [Figure 9] FIG. 10 is a perspective view of the chainsaw T2 according to the second embodiment, seen from above and rear right, with the battery pack B2 removed from the battery interface 160. [Figure 10] 10 is a cross-sectional view of the internal structure of a housing 4 of a chainsaw T2 according to a second embodiment, as viewed from the right. FIG. [Figure 11] FIG. 11 is a perspective view of the chainsaw T3 according to the third embodiment, seen from above and rear right, with the battery pack B3 removed from the battery interface 360. [Figure 12] 10 is a cross-sectional view of the internal structure of the housing 4 of the chain saw T3 according to the third embodiment, as viewed from the right. FIG. [Figure 13] FIG. 11 is a perspective view of the chainsaw T4 according to the fourth embodiment, seen from above and rear right, with the battery pack B4 removed from the battery interface 360. [Figure 14] 10 is a cross-sectional view of the internal structure of the housing 4 of the chainsaw T4 according to the fourth embodiment, as viewed from the right. FIG. [Figure 15]FIG. 10 is a perspective view of a chainsaw T1 according to a modified example, seen from above rear right, with a battery pack B1 removed from a battery interface 160. DETAILED DESCRIPTION OF THE INVENTION

[0008] Representative, non-limiting embodiments of the present invention are described in detail below with reference to the drawings. This detailed description is intended simply to provide those skilled in the art with details for implementing preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Additionally, the additional features and inventions disclosed can be used separately or in conjunction with other features and inventions to provide further improved cutting tools.

[0009] Furthermore, the combinations of features and steps disclosed in the following detailed description are not essential to practicing the invention in its broadest sense, but are described solely to specifically illustrate exemplary embodiments of the invention. Furthermore, the various features of the following exemplary embodiments and those described in the claims do not necessarily have to be combined in the exact embodiments described herein or in the exact order listed to provide additional and useful embodiments of the invention.

[0010] All features described in this specification and / or claims are intended to be disclosed individually and independently of one another as limitations to the specific features described in the original disclosure and claims, apart from the configuration of features described in the examples and / or claims. Furthermore, all numerical ranges and group or aggregate descriptions are intended to disclose intermediate configurations thereof as limitations to the specific features described in the original disclosure and claims.

[0011] In one or more embodiments, the housing may be formed from a material having a Young's modulus greater than 100 MPa. The hand guard may be formed from a material having a Young's modulus in the range of 1 MPa to 100 MPa.

[0012] When the hand guard is deformed by elastic deformation, the greater the Young's modulus of the material used for the hand guard, the greater the load required to deform the hand guard by a predetermined amount. With the above configuration, the user can sufficiently deform the hand guard with a relatively small load. This further improves user convenience.

[0013] In one or more embodiments, the housing may be made of a plastic material, and the hand guard may be made of a rubber material.

[0014] Rubber materials can undergo greater elastic deformation than other materials (e.g., plastic materials). With the above configuration, the user can cause the hand guard to undergo greater elastic deformation. This further improves user convenience.

[0015] In one or more embodiments, the hand guard may include a first end located near a proximal end of the grip, a second end located near a distal end of the grip, and a guard body extending continuously between the first end and the second end. Note that, in this specification, the end of the grip closest to the housing body is referred to as the "proximal end of the grip," and the end away from the housing body is referred to as the "distal end of the grip."

[0016] According to the above configuration, the hand guard is disposed so as to cover the grip from its base end to its tip end, thereby reliably protecting the fingers of the user when holding the grip.

[0017] In one or more embodiments, the housing may further include a first mounting portion to which the first end of the hand guard is attached and a second mounting portion to which the second end of the hand guard is attached, and at least one of the first end and the second end may be rotatably mounted relative to the corresponding at least one of the first mounting portion and the second mounting portion.

[0018] When a hand guard is supported by a housing at two points, a first end and a second end, both the first end and the second end may be fixed to the corresponding first and second mounting portions. In this case, the hand guard can be considered a beam fixed at both ends, so a large load is required to deform the hand guard (guard body) by a predetermined amount. In contrast, with the above configuration, at least one of the first end and the second end is rotatably attached to at least one of the corresponding first and second mounting portions. In this case, the hand guard can be considered a beam fixed at one end and simply supported (pin-supported) at the other end, or a beam simply supported (pin-supported) at both ends, so a user can sufficiently deform the hand guard with a relatively small load.

[0019] In one or more embodiments, the guard body may include a plate portion formed in a plate shape.

[0020] According to the above configuration, the thin and wide plate portion allows the plate portion to be easily deformed, and the plate portion can protect a wide area of ​​the user's fingers. Therefore, it is possible to realize a hand guard that is easily deformed while maintaining the protective function of the hand guard.

[0021] In one or more embodiments, the guard body may have a rib portion that protrudes from the surface of the plate portion at a position opposite the grip and extends in a direction from the first end toward the second end.

[0022] If the plate portion is excessively deformed at the position facing the grip (the plate portion bends excessively), the gap between the grip and the plate portion becomes too narrow, and the plate portion may be pressed against the fingers of the user holding the grip. In this case, it becomes difficult for the user to change the position of their fingers, which reduces user convenience. According to the above configuration, the rib portion increases the rigidity of the plate portion at the position facing the grip. This makes it possible to prevent the plate portion from being excessively deformed at the position facing the grip (the plate portion bends excessively). This makes it possible to prevent the plate portion from being pressed against the fingers of the user holding the grip. This improves user convenience.

[0023] In one or more embodiments, the rib portion may protrude from a surface of the plate portion opposite a surface facing the grip.

[0024] If the rib portion protrudes from the surface of the plate portion facing the grip, there is a possibility that the rib portion will come into contact with the user's fingers when the user moves their fingers between the grip and the plate portion. This may be irritating to the user and reduce user convenience. In contrast, with the above configuration, the rib portion protrudes from the surface of the plate portion opposite the surface facing the grip. This prevents the rib portion from coming into contact with the user's fingers when the user moves their fingers between the grip and the plate portion. This improves user convenience.

[0025] In one or more embodiments, the cutting tool may further include a trigger lever provided near the base end of the grip and configured to activate the prime mover when pulled toward the grip by a user's finger. The guard body may include a first extension connected to the first end and extending away from the grip from the base end toward the tip end, a second extension connected to the second end and extending away from the grip from the tip end toward the base end, and a bent portion connecting the first extension and the second extension. The length of the first extension may be shorter than the length of the second extension.

[0026] When the guard main body deforms, if the guard main body is pressed against the user's fingers that are engaged with the trigger lever, this may result in erroneous operation of the trigger lever. In contrast, with the above configuration, the guard main body has high rigidity near the bent portion. Furthermore, the bent portion has a shape that protrudes outward when viewed from the grip. As a result, when the guard main body is pressed against the grip, the bent portion ensures a space between the grip and the guard main body. Furthermore, because the bent portion is located closer to the base end of the grip, a space is ensured near the trigger lever when the guard main body is pressed against the grip. Therefore, with the above configuration, it is possible to prevent the guard main body from being pressed against the user's fingers that are engaged with the trigger lever, thereby preventing erroneous operation of the trigger lever.

[0027] Example 1 As shown in Fig. 1, the cutting tool of this embodiment is a chainsaw T1. The chainsaw T1 is a so-called pruning chainsaw that is mainly used for cutting lumber, tree branches, etc. The weight of the entire chainsaw T1 is relatively light, at most about 2000g. This allows the chainsaw T1 to be carried in one hand.

[0028] The chainsaw T1 includes a housing 4, a guide bar 6, a saw chain 8, a hand guard 20, and a battery pack B1. The guide bar 6 is a long, thin, plate-like member attached to the housing 4 so as to protrude forward from the housing 4. The guide bar 6 is made of a metal material such as iron. The saw chain 8 includes a plurality of interconnected cutters (not shown) and is attached along the periphery of the guide bar 6. A battery pack B1 having a substantially rectangular parallelepiped shape is attached to the housing 4. The chainsaw T1 runs the saw chain 8 along the periphery of the guide bar 6 using power supplied from the battery pack B1.

[0029] Various guide bars 6 can be attached depending on the type of cutting work. The radius of curvature of the tip of the guide bar 6 is, for example, 15 mm. In the chainsaw T1 of this embodiment, the saw chain 8 travels along the periphery of the guide bar 6 at a speed of, for example, 8 m / s. In this specification, the guide bar 6 and the saw chain 8 are sometimes collectively referred to as the "working unit 10." In this embodiment, the weight of the working unit 10 is, for example, approximately 180 g. The housing 4 is also provided with a work cover 12 that covers a portion of the working unit 10. Therefore, the user performs cutting work by pressing the portion of the working unit 10 that is not covered by the work cover 12 against the object to be cut (e.g., a tree branch). In this case, it is assumed that the load applied by the user to the chainsaw T1 is at most approximately 20 N.

[0030] In the following description, in the longitudinal direction of the guide bar 6, the direction from the housing 4 toward the guide bar 6 is referred to as the forward direction, and the direction from the guide bar 6 toward the housing 4 is referred to as the rearward direction. The direction perpendicular to the front-to-rear direction, that is, the direction from the working unit 10 toward the work cover 12, is referred to as the upward direction, and the direction from the work cover 12 toward the working unit 10 is referred to as the downward direction. The direction perpendicular to the front-to-rear direction and the up-down direction is referred to as the left-to-right direction. Note that in Figures 1 to 15, the saw chain 8 is shown as a ring-shaped member that is flush with the guide bar 6 for ease of illustration.

[0031] The housing 4 includes a housing main body 14, a grip 16, a first mounting portion 22, and a second mounting portion 24. The housing main body 14 has a generally rectangular parallelepiped shape that slopes upward from the front to the rear in the front-to-rear direction. The housing main body 14 holds the working unit 10 together with a sprocket cover 18 at the front. The grip 16 is connected to the lower front portion of the housing main body 14. The grip 16 has a generally cylindrical shape that slopes downward from the front to the rear in the front-to-rear direction. The first mounting portion 22 protrudes downward from the housing 4 and is located near the base end of the grip 16. The second mounting portion 24 protrudes downward from the housing 4 and is located near the tip end of the grip 16. A hand guard 20 is attached to the first mounting portion 22 and the second mounting portion 24. The housing 4 (housing body 14, grip 16, first mounting portion 22, and second mounting portion 24) is made of a material with a Young's modulus greater than 100 MPa. In this embodiment, the housing 4 is made of a plastic material such as polyamide. The Young's modulus of polyamide may vary depending on the surrounding environment, but it is generally greater than 5000 MPa. The portions where the user's fingers are placed (head portion 14a of housing body 14 and the area around grip 16) are coated with a rubber material such as nitrile butadiene rubber.

[0032] The battery pack B1 contains a rechargeable secondary battery, such as a lithium-ion battery. The output voltage of the battery pack B1 is, for example, 10 V. The battery capacity of the battery pack B1 is, for example, 1.5 Ah. The weight of the battery pack B1 is, for example, approximately 215 g. As shown in FIG. 3, a display unit 166 is provided on the bottom surface of the battery pack B1. The display unit 166 notifies the user of the remaining battery power of the battery pack B1 by changing the display in accordance with the remaining battery power of the battery pack B1.

[0033] As shown in FIG. 2, a battery interface 160 for detachably receiving a battery pack B1 is provided at the tip of the grip 16. The battery pack B1 is attached to the battery interface 160 by sliding it from the upper rear to the lower front. The battery interface 160 also has a connection terminal 162 for connecting to a terminal (not shown) provided on the battery pack B1. The connection terminal 162 is electrically connected to a control unit 62 (see FIG. 6) and a trigger switch 52 (see FIG. 6), which will be described later. When the battery pack B1 is attached to the battery interface 160, the terminal provided on the battery pack B1 and the connection terminal 162 are electrically connected. This allows power to be supplied from the battery pack B1 to the control unit 62 and the trigger switch 52.

[0034] 1, when the battery pack B1 is attached to the battery interface 160, the battery pack B1 and the grip 16 have a smooth connection with each other on their outer surfaces. The battery pack B1 can be removed by pushing in the hooks 164 provided on the battery pack B1 and sliding it from the lower front to the upper rear relative to the battery interface 160.

[0035] As shown in Figure 4, the sprocket cover 18 includes a sprocket cover body 36 and a locking member 42. The sprocket cover body 36 includes a sleeve 38. The locking member 42 includes a locking member body 44, a nut 46, and a claw portion 48. Inside the sprocket cover 18, the sprocket 26 is exposed to the outside of the housing body 14. A saw chain 8 is stretched over the sprocket 26 from a guide bar 6. The guide bar 6 also includes a notch 6a extending in the front-to-rear direction. The pins 28, 30 and bolt 32, which protrude and are fixed from the left side surface of the housing body 14, are fitted into the notch 6a from the right.

[0036] 4 , the sprocket cover 18 can be attached to the housing main body 14 by inserting the bolt 32 into the sleeve 38 of the sprocket cover main body 36 and tightening the nut 46 of the locking member 42 onto the bolt 32 that passes through the sleeve 38. With the nut 46 tightened onto the bolt 32, the guide bar 6 is sandwiched and fixed between the housing main body 14 and the sprocket cover 18. With the bolt 32 and nut 46 loosened, the user can slide the guide bar 6 forward or backward relative to the housing main body 14 to change the distance between the guide bar 6 and the sprocket 26 and adjust the tension of the saw chain 8.

[0037] The user can tighten or loosen the bolt 32 and the nut 46 by rotating the claw 48, which stands upright to the left relative to the locking member body 44, around the axis of the bolt 32. This allows the user to fasten the nut 46 to the bolt 32 with sufficient tightening torque without using any special tools. Note that, as shown in FIG. 1, the claw 48 is normally held in a lying state along the locking member body 44 by a torsion spring (not shown).

[0038] As shown in FIG. 2, a trigger lever 50 is disposed on the underside of the grip 16 near its base end, allowing the user to operate the working unit 10. As shown in FIG. 5, the trigger lever 50 is supported by the housing 4 so as to be rotatable about a rotation axis 50a extending in the left-right direction. The user can operate the trigger lever 50 by pulling it up toward the grip 16. In this specification, the front end of the portion of the trigger lever 50 that is exposed outside the grip 16 will be simply referred to as the "front end 50f." The rear end of the portion of the trigger lever 50 that is exposed outside the grip 16 will be simply referred to as the "rear end 50r."

[0039] A trigger switch 52 that detects when the user pulls up the trigger lever 50 is provided inside the housing 4. The trigger switch 52 is located directly above the trigger lever 50 and straddles the gap between the grip 16 and the housing main body 14. The trigger switch 52 is electrically connected to a control unit 62 (see FIG. 6 ), which will be described later. The trigger switch 52 outputs a trigger-on signal to the control unit 62 while the trigger lever 50 is being pulled up. A locking member 54 that switches between a state that permits and a state that prohibits operation of the trigger lever 50 by the user is also provided inside the housing 4. The locking member 54 is located directly above the trigger lever 50 and in front of the trigger switch 52. The locking member 54 is supported by the housing 4 so as to be rotatable about a rotation shaft 54a that extends in the left-right direction.

[0040] When the locking member 54 is rotated upward, the locking member 54 mechanically interferes with the trigger lever 50, prohibiting the trigger lever 50 from rotating upward. When the locking member 54 is rotated downward, the locking member 54 no longer interferes with the trigger lever 50, allowing the trigger lever 50 to rotate upward.

[0041] As shown in FIG. 1, the locking member 54 has a left locking lever 58a that protrudes outside the housing 4 through a through-hole 56a provided on the left side surface of the housing 4. As shown in FIG. 2, the locking member 54 has a right locking lever 58b that protrudes outside the housing 4 through a through-hole 56b provided on the right side surface of the housing 4. Hereinafter, the left locking lever 58a and the right locking lever 58b will be collectively referred to as the "locking levers 58." The user can rotate the locking member 54 via the locking lever 58.

[0042] The trigger lever 50 and the locking member 54 are connected to each other by a torsion spring 60 (see FIG. 5). The torsion spring 60 biases the trigger lever 50 in a direction that rotates it downward, and biases the locking member 54 in a direction that rotates it upward. Therefore, when the user releases his / her hand from the trigger lever 50, the biasing force of the torsion spring 60 causes the trigger lever 50 to rotate downward. Furthermore, when the user releases his / her hand from the locking lever 58, the biasing force of the torsion spring 60 causes the locking member 54 to rotate upward.

[0043] For example, when using the chainsaw T1, the user holds the chainsaw T1 by grasping the grip 16 with the right hand and placing the left hand on the head 14a. From this state, when the user presses down on the lock lever 58 with the thumb of the right hand, the user is permitted to operate the trigger lever 50. In this state, the user can pull up the trigger lever 50 with the index finger of the right hand, thereby driving the working unit 10.

[0044] (Handguard 20 configuration) The hand guard 20 shown in FIG. 1 is a protective device for protecting the user's hands gripping the grip 16. If the saw chain 8 breaks while the user is performing a cutting operation (while the working unit 10 is being driven), the broken saw chain 8 may fly out from the guide bar 6 while maintaining its momentum during travel. In such a case, the hand guard 20 can prevent the saw chain 8 flying out from the guide bar 6 from coming into contact with the user's hands gripping the grip 16 (see FIG. 1). The hand guard 20 is made of a material having a Young's modulus in the range of 1 MPa to 100 MPa, for example. The hand guard 20 of this embodiment is made of a rubber material such as nitrile butadiene rubber. The Young's modulus of nitrile butadiene rubber may vary depending on the surrounding environment, but it can be said to be in the range of 1 MPa to 10 MPa.

[0045] The hand guard 20 includes a first end 202, a second end 204, and a guard body 206 that extends continuously between the first end 202 and the second end 204. The first end 202 is attached to a first mounting portion 22 so as to be rotatable about a rotation axis 22a that extends in the left-right direction. By being attached to the first mounting portion 22, the first end 202 is positioned near the base end of the grip 16. Furthermore, the second end 204 is attached to a second mounting portion 24 so as to be rotatable about a rotation axis 24a (see FIG. 2) that extends in the left-right direction. By being attached to the second mounting portion 24, the second end 204 is positioned near the tip end of the grip 16.

[0046] The guard body 206 includes a plate portion 208 formed in a plate shape and a plurality of rib portions 210 (see FIG. 3) protruding downward from the lower surface of the plate portion 208. The plate portion 208 is disposed so that its upper surface faces the grip 16. In this embodiment, the thickness of the plate portion 208 (thickness in a direction perpendicular to the upper and lower surfaces of the plate portion 208) is, for example, approximately 5 mm.

[0047] As shown in Figure 3, when the chainsaw T1 is viewed from below, the plate portion 208 has a generally rectangular shape. The plate portion 208 has a width of, for example, about 29 mm to the left of the left surface of the guide bar 6. The plate portion 208 has a width of, for example, about 30 mm to the right of the right surface of the guide bar 6. The plate portion 208 also has a width of, for example, about 30 mm to the left of the left surface of the grip 16 (see Figure 1). The plate portion 208 has a width of, for example, about 0.5 mm to the right of the right surface of the grip 16.

[0048] The multiple rib portions 210 include a first rib portion 212 extending in the front-rear direction along the underside of the plate portion 208, a second rib portion 214 extending in the left-right direction along the underside of the plate portion 208, and a third rib portion 216 extending along the peripheral edge of the underside of the plate portion 208. Four first rib portions 212 are arranged in the left-right direction. When viewed from below, each of the first rib portions 212 extends in a substantially straight line between the first end 202 and the second end 204. Three second rib portions 214 are arranged in the front-rear direction. The first rib portion 212 and the second rib portion 214 are connected at portions where they intersect at right angles. The second rib portion 214 is connected to the third rib portion 216 at its left and right ends.

[0049] As shown in FIG. 6, the plate portion 208 is composed of a first extending portion 220 that extends away from the grip 16 from the base end toward the tip end, a second extending portion 222 that extends away from the grip 16 from the tip end toward the base end, and a bent portion 224 that connects the first extending portion 220 and the second extending portion 222. The length of the first extending portion 220 in the extension direction is shorter than the length of the second extending portion 222 in the extension direction. The bending angle of the bent portion 224 is, for example, 100°. The radius of curvature of the bent portion 224 is, for example, 18 mm. As a result, in a natural state (a state in which no external force is applied to the hand guard 20), the hand guard 20 has a shape that protrudes outward when viewed from the grip 16.

[0050] The hand guard 20 configured as described above is more susceptible to elastic deformation than the housing 4. The hand guard 20 is configured to begin to deform when a predetermined load of 5 N or less is applied from a direction facing the underside of the plate portion 208, for example. Note that "begins to deform" here means that the elastic strain of the hand guard 20 exceeds 1%. This allows the user to deform the hand guard 20 with a relatively small load.

[0051] (Internal structure of the Chainsaw T1) As shown in FIG. 6, the housing body 14 accommodates a control unit 62, an electric motor 64, an oil tank 66, an oil pump 68, a reducer 72, and a cooling fan 82 therein.

[0052] As shown in Fig. 7, the electric motor 64 is an inner rotor type DC brushless motor. The electric motor 64 includes a stator 76 around which a coil 74 is wound, and a rotor 78 that is disposed inside the stator 76 and includes a permanent magnet (not shown). In this embodiment, the weight of the electric motor 64 (the coil 74, the stator 76, and the rotor 78) is, for example, approximately 180 g. A motor shaft 80 is fixed to the rotor 78 and is disposed so as to pass through the centers of the stator 76 and the rotor 78. Therefore, the electric motor 64 is configured to rotate the motor shaft 80.

[0053] The cooling fan 82 is fixed to the motor shaft 80 below the rotor 78. The cooling fan 82 rotates in conjunction with the rotation of the motor shaft 80. When the cooling fan 82 rotates, an air flow is formed from below to above along the axis A1 (see FIG. 6) of the motor shaft 80. At this time, air is drawn from the outside of the housing 4 to the inside through the left air intake 140 (see FIG. 1) and the right air intake 142 (see FIG. 2). Air is also exhausted from the inside of the housing 4 to the outside through the left air exhaust 144 (see FIG. 1) and the right air exhaust 146 (see FIG. 2). This allows the cooling fan 82 to cool the electric motor 64 as the electric motor 64 is driven.

[0054] The reducer 72 includes a first bevel gear 72a fixed to the motor shaft 80 below the cooling fan 82, and a second bevel gear 72b that meshes with the first bevel gear 72a. The second bevel gear 72b is fixed to a drive shaft 84. The drive shaft 84 is supported by the housing 4 (see FIG. 1) so as to be rotatable about an axis of rotation extending in the left-right direction. A sprocket 26 is fixed to the drive shaft 84 on the left side of the second bevel gear 72b. Therefore, when the electric motor 64 is driven, the rotational motion of the motor shaft 80 is transmitted to the saw chain 8 via the reducer 72, the drive shaft 84, and the sprocket 26. This causes the saw chain 8 to rotate around the sprocket 26 and the guide bar 6.

[0055] The oil tank 66 shown in FIG. 6 is a tank for storing lubricating oil for lubricating the saw chain 8. The oil tank 66 can store a maximum of approximately 50 cc of lubricating oil. The oil tank 66 is provided with a filler port (not shown) for refilling the oil tank 66 with lubricating oil. A cap 660 is detachably attached to the filler port. The oil tank 66 is disposed near the front end of the housing body 14. As shown in FIG. 2, the cap 660 and the filler port of the oil tank 66 are exposed to the outside of the housing body 14. Therefore, the user can remove the cap 660 from the filler port and fill oil into the oil tank 66 without disassembling the housing body 14.

[0056] As shown in FIG. 7, a worm gear 84a is fixed to the drive shaft 84 to the right of the second bevel gear 72b. The worm gear 84a meshes with the worm wheel 68a of the oil pump 68. Therefore, when the electric motor 64 is driven, the rotational motion of the motor shaft 80 is transmitted to the oil pump 68 via the reducer 72, the drive shaft 84, the worm gear 84a, and the worm wheel 68a. This drives the oil pump 68. When the oil pump 68 is driven, lubricating oil is sucked into the oil supply passage 682 via the suction portion 680 disposed inside the oil tank 66 (see FIG. 6). The lubricating oil is then supplied from the oil supply passage 682 to the guide bar 6 and the saw chain 8 via the discharge portion 684.

[0057] In this specification, the mechanism composed of the reducer 72, the drive shaft 84, and the worm gear 84a may be referred to as the "power transmission mechanism 70." As shown in FIG. 6, the power transmission mechanism 70 is disposed in the central portion of the housing main body 14. The power transmission mechanism 70 is disposed in front of and below the electric motor 64. The power transmission mechanism 70 is disposed rearward of the oil tank 66. In this embodiment, the weight of the power transmission mechanism 70 is, for example, approximately 110 g.

[0058] The control unit 62 is disposed directly below the head 14a of the housing main body 14. The control unit 62 is disposed above and behind the electric motor 64. A wiring space S is formed below the control unit 62 and behind the electric motor 64. Although not shown, most of the conductors electrically connecting the control unit 62, electric motor 64, and other components are routed through the wiring space S.

[0059] The control unit 62 includes a control board (not shown) on which an inverter circuit having a plurality of switching elements and a control circuit for controlling the operation of each switching element are mounted, and a substantially rectangular parallelepiped controller case 620 that houses the control board. The controller case 620 is made of a metal material such as aluminum. In this embodiment, the weight of the control unit 62 is, for example, approximately 60 g.

[0060] While a trigger-on signal is being output from the trigger switch 52, the control unit 62 converts the DC power supplied from the battery pack B1 into three-phase AC power and supplies it to the electric motor 64. When the trigger-on signal is no longer being output from the trigger switch 52, the control unit 62 cuts off the power supply from the battery pack B1 to the electric motor 64. The control unit 62 also controls the drive of the electric motor 64 so that the saw chain 8 travels in a predetermined traveling direction. The predetermined traveling direction here refers to a direction in which the saw chain 8 travels forward above the guide bar 6 and travels backward below the guide bar 6.

[0061] (Positional relationship of main components to axis A1) The axis A1 of the motor shaft 80 (see FIG. 7) is disposed on a plane extending in the front-rear and up-down directions. The axis A1 is inclined relative to the up-down direction, from rear to front as it moves from top to bottom. In this embodiment, the angle of inclination of the axis A1 relative to the up-down direction is 41°. The control unit 62 is disposed on the axis A1. The control unit 62 (controller case 620) is disposed along a plane substantially perpendicular to the axis A1. The distance from the axis A1 to the front end 62f of the control unit 62 (which coincides with the front end of the controller case 620) is shorter than the distance from the axis A1 to the rear end 62r of the control unit 62 (which coincides with the rear end of the controller case 620). In addition, the drive shaft 84 of the power transmission mechanism 70 is disposed so as to be substantially perpendicular to the axis A1.

[0062] As shown in Figure 8, when the interior of the housing main body 14 (see Figure 1) is viewed from the front along a direction perpendicular to the axis A1, the control unit 62, the electric motor 64, the cooling fan 82, the power transmission mechanism 70 and the sprocket 26, and the oil tank 66 are arranged in a substantially straight line, in that order from above. When viewed from the front along a direction perpendicular to the axis A1, the center of gravity 62G of the control unit 62, the center of gravity 64G of the electric motor 64, and the center of gravity 82G of the cooling fan 82 are all located on the axis A1.

[0063] When viewed from the front along a direction perpendicular to the axis A1, the control unit 62, the electric motor 64, and the cooling fan 82 each have a substantially symmetrical shape (substantially line-symmetrical with respect to the axis A1). Although not shown, the grip 16 (see FIG. 1) and the battery pack B1 (see FIG. 1) also have a substantially symmetrical shape (substantially line-symmetrical with respect to the axis A1). The sprocket 26 is disposed to the left of the axis A1. The oil tank 66, the oil pump 68, the second bevel gear 72b, and the worm gear 84a are disposed to the right of the axis A1.

[0064] (Positional relationship of main components to trigger lever 50) FIG. 6 shows a straight line A2 that passes through the front end 50f of the trigger lever 50 and extends in the vertical direction, and a straight line A3 that passes through the rear end 50r of the trigger lever 50 and extends in the vertical direction.

[0065] A front end 62f of the control unit 62 is disposed rearward of the rear end 50r of the trigger lever 50. A front end 64f of the electric motor 64 is disposed rearward of the front end 50f of the trigger lever 50 and forward of the rear end 50r of the trigger lever 50. A rear end 70r of the power transmission mechanism 70 (coincident with the rear end of the first bevel gear 72a) is disposed rearward of the front end 50f of the trigger lever 50 and forward of the rear end 50r of the trigger lever 50. A front end B1f of the battery pack B1 is disposed rearward of the rear end 50r of the trigger lever 50. A center of gravity 62G of the control unit 62 is disposed rearward of the rear end 50r of the trigger lever 50. A center of gravity 64G of the electric motor 64 is disposed rearward of the rear end 50r of the trigger lever 50. A center of gravity 82G of the cooling fan 82 is disposed rearward of the front end 50f of the trigger lever 50 and forward of the rear end 50r of the trigger lever 50. The center of gravity BG1 of the battery pack B1 is located behind the rear end 50r of the trigger lever 50.

[0066] In the chainsaw T1 configured as described above, the center of gravity TG1 of the chainsaw T1 is located inside the housing 4, between the lines A2 and A3. The center of gravity TG1 can also be said to be located at a position overlapping with the locking member 54. The distance from the line A2 to the center of gravity TG1 is approximately the same as the distance from the line A3 to the center of gravity TG1. In this embodiment, the center of gravity TG1 is determined when the oil tank 66 is filled with lubricating oil, the battery pack B1 is attached to the battery interface 160, and all other components are attached.

[0067] Example 2 9, the cutting tool of this embodiment is a chainsaw T2. The chainsaw T2 has substantially the same configuration as the chainsaw T1 of embodiment 1, except that it includes a battery pack B2 instead of the battery pack B1. The following describes only the differences between the chainsaw T2 and the chainsaw T1.

[0068] The battery pack B2 contains a rechargeable secondary battery, such as a lithium-ion battery. The output voltage of the battery pack B2 is, for example, 10 V. The battery capacity of the battery pack B2 is, for example, 4.0 Ah. The weight of the battery pack B2 is, for example, approximately 375 g. The battery pack B2 is detachably attached to the battery interface 160, similar to the battery pack B1.

[0069] Battery pack B2 has a larger width in the extension direction of grip 16 than battery pack B1 (see FIG. 2). The width of battery pack B2 in the left-right direction is approximately the same as that of battery pack B1. The width of battery pack B2 in the extension direction of grip 16 and in a direction perpendicular to the left-right direction is approximately the same as that of battery pack B1. As a result, the volume of battery pack B2 is larger than the volume of battery pack B1.

[0070] 10, the front end B2f and the center of gravity BG2 of the battery pack B2 are located rearward of the rear end 50r of the trigger lever 50. The center of gravity TG2 of the chainsaw T2 is located inside the housing 4, between the lines A2 and A3. The center of gravity TG2 can also be said to be located near the front end of the trigger switch 52. The distance from the line A2 to the center of gravity TG2 is greater than the distance from the line A3 to the center of gravity TG2.

[0071] Example 3 11, the cutting tool of this embodiment is a chainsaw T3. The chainsaw T3 has substantially the same configuration as the chainsaw T1 of embodiment 1, except that it includes a battery pack B3 instead of the battery pack B1 and a battery interface 360 ​​instead of the battery interface 160. The following describes only the differences between the chainsaw T3 and the chainsaw T1.

[0072] Battery pack B3 houses a rechargeable secondary battery, such as a lithium-ion battery. The output voltage of battery pack B3 is, for example, 18 V. The battery capacity of battery pack B3 is, for example, 2.0 Ah. The weight of battery pack B3 is, for example, approximately 375 g. The width of battery pack B3 in the extension direction of grip 16 is approximately the same as that of battery pack B1 (see FIG. 2). Battery pack B3 has a larger width in the left-right direction than battery pack B1. Battery pack B3 has a larger width in the extension direction of grip 16 and in a direction perpendicular to the left-right direction than battery pack B1. As a result, the volume of battery pack B3 is larger than the volume of battery pack B1.

[0073] The battery pack B3 is attached to the battery interface 360 ​​by sliding it from the upper rear to the lower front. The battery interface 360 ​​also has a connection terminal 362 for connecting to a terminal (not shown) provided on the battery pack B3. The connection terminal 362 is electrically connected to the control unit 62 (see FIG. 12) and the trigger switch 52 (see FIG. 12). When the battery pack B3 is attached to the battery interface 360, the terminal provided on the battery pack B3 and the connection terminal 362 are electrically connected. This allows power to be supplied from the battery pack B3 to the control unit 62 and the trigger switch 52.

[0074] 12, when the battery pack B3 is attached to the battery interface 360, the battery pack B3 is smoothly connected to the outer surface of the grip 16. The battery pack B3 can be removed by sliding it from the front lower side to the rear upper side relative to the battery interface 360 ​​while pushing in the hook 364 (see FIG. 11) provided on the battery pack B3.

[0075] The front end B3f and center of gravity BG3 of the battery pack B3 are located rearward of the rear end 50r of the trigger lever 50. The center of gravity TG3 of the chainsaw T3 is located inside the housing 4, between the lines A2 and A3. The center of gravity TG3 can also be said to be located near the front end of the trigger switch 52. The distance from the line A2 to the center of gravity TG3 is greater than the distance from the line A3 to the center of gravity TG3. The center of gravity TG3 of the chainsaw T3 is located at approximately the same position as the center of gravity TG2 of the chainsaw T2 of the second embodiment.

[0076] Example 4 As shown in Fig. 13, the cutting tool of this embodiment is a chainsaw T4. The chainsaw T4 has substantially the same configuration as the chainsaw T3 of embodiment 3, except that it includes a battery pack B4 instead of battery pack B3. The following describes only the differences between the chainsaw T4 and the chainsaw T3.

[0077] The battery pack B4 contains a rechargeable secondary battery, such as a lithium-ion battery. The voltage of the battery pack B4 is, for example, 18 V. The battery capacity of the battery pack B4 is, for example, 6.0 Ah. The weight of the battery pack B4 is, for example, approximately 670 g. The battery pack B4 is detachably attached to the battery interface 360, similar to the battery pack B3.

[0078] The width of battery pack B4 in the extension direction of grip 16 is larger than that of battery pack B3 (see FIG. 11). The width of battery pack B4 in the left-right direction is approximately the same as that of battery pack B3. The width of battery pack B4 in the extension direction of grip 16 and in a direction perpendicular to the left-right direction is approximately the same as that of battery pack B3. As a result, the volume of battery pack B4 is larger than that of battery pack B3.

[0079] 14, the front end B4f and the center of gravity BG4 of the battery pack B4 are located rearward of the rear end 50r of the trigger lever 50. The center of gravity TG4 of the chainsaw T4 is located inside the housing 4 and rearward of the line A3. The center of gravity TG3 can also be said to be located near the rear end of the trigger switch 52.

[0080] Hereinafter, the chainsaw T1, the chainsaw T2, the chainsaw T3, and the chainsaw T4 may be collectively referred to as "chainsaw T."

[0081] (Variation) In the above embodiment, the cutting tool is a chainsaw T having a guide bar 6 and a saw chain 8 as the working unit 10. In another embodiment, the cutting tool may be a reciprocating saw having a saw blade as the working unit 10. In yet another embodiment, the cutting tool may be electric scissors having shears as the working unit 10. Note that if the cutting tool is a reciprocating saw or electric scissors, the cutting tool does not need to be equipped with the oil tank 66 and the oil pump 68.

[0082] In the above embodiment, the chainsaw T is a pruning chainsaw designed to be carried with one hand. In another embodiment, the chainsaw T may be a large chainsaw designed to be carried with both hands, equipped with a handle to be held with the other hand other than the hand that holds the grip (corresponding to the grip 16). In this case, the handle to be held with the other hand may be provided above the housing (corresponding to the housing 4) or on the side of the housing.

[0083] In the above embodiment, the electric motor 64 is an inner rotor type DC brushless motor. In another embodiment, the electric motor 64 may be an outer rotor type DC brushless motor. Alternatively, the electric motor 64 may be a brushed motor or another type of electric motor.

[0084] In the above embodiment, the chainsaw T (an example of a cutting tool) may be provided with an internal combustion engine instead of the electric motor 64 as the prime mover for rotating the sprocket 26. In this case, the drive shaft 84 fixed to the sprocket 26 may be rotated by the drive of the engine.

[0085] In the above embodiment, a configuration has been described in which a plastic material such as polyamide is used for the housing 4. In another embodiment, a plastic material other than polyamide (e.g., polycarbonate) may be used for the housing 4 as long as the material has a Young's modulus greater than 100 MPa. In yet another embodiment, a material other than a plastic material (e.g., a metal material such as aluminum) may be used for the housing 4 as long as the material has a Young's modulus greater than 100 MPa.

[0086] In the above embodiment, a rubber material such as nitrile butadiene rubber is used for the hand guard 20. In another embodiment, a rubber material other than nitrile butadiene rubber (e.g., ethylene propylene rubber) may be used for the hand guard 20 as long as the material has a Young's modulus within a range of 1 MPa to 100 MPa.

[0087] In the above embodiment, at least one of the first end 202 and the second end 204 of the hand guard 20 may be non-rotatably attached to at least one of the corresponding first mounting portion 22 and the second mounting portion 24.

[0088] In the above embodiment, the plurality of rib portions 210 of the hand guard 20 may not include at least one of the first rib portion 212, the second rib portion 214, and the third rib portion 216.

[0089] In the above embodiment, the hand guard 20 is formed from a material (rubber material) with a relatively low Young's modulus, thereby being more susceptible to elastic deformation than the housing 4. In another embodiment, the hand guard 20 may be configured to be swingable relative to the housing 4, like a swing door. In this case, when a load is applied to the hand guard 20 while the hand guard 20 is in contact with an obstacle, the hand guard 20 deforms from a closed state to an open state. In yet another embodiment, the hand guard 20 may be configured to be translatable between a first position and a second position relative to the housing 4. In this case, when a load is applied to the hand guard 20 while the hand guard 20 is in contact with an obstacle, the hand guard 20 translates between the first position and the second position, thereby changing the position of the hand guard 20 relative to the housing 4. Note that if the hand guard 20 is deformed by a method other than elastic deformation, the hand guard 20 may be made of a material other than rubber (for example, a plastic material such as polyamide) or a material with a Young's modulus greater than 100 MPa.

[0090] In the above embodiment, the chainsaw T (an example of a cutting tool) may not include the power transmission mechanism 70. In this case, for example, the sprocket 26 may have a plurality of teeth formed thereon, and the plurality of teeth of the sprocket 26 may mesh with a first bevel gear 72a fixed to the motor shaft 80. Furthermore, the worm wheel 68a of the oil pump 68 may mesh with the first bevel gear 72a fixed to the motor shaft 80.

[0091] In the above embodiment, a configuration has been described in which a metal material such as aluminum is used for the controller case 620. In another embodiment, a metal material other than aluminum (for example, iron) may be used for the controller case 620. In yet another embodiment, a material other than a metal material (for example, a plastic material such as polyamide) may be used for the controller case 620.

[0092] As shown in FIG. 15, a chainsaw T1 (an example of a cutting tool) may be provided with an exhaust port 544 instead of the exhaust ports 144, 146 in the above-described embodiment. The exhaust port 544 is provided in the head 14a of the housing main body 14. In this case, when the cooling fan 82 rotates, air is discharged from the inside of the housing 4 to the outside through the exhaust port 544 instead of the exhaust ports 144, 146. In this case, the cooling fan 82 can also cool the electric motor 64 as the electric motor 64 is driven. The above configuration may be applied to the chainsaws T2, T3, and T4.

[0093] (Correspondence) As described above, in one or more embodiments, the chainsaw T (an example of a cutting tool) comprises a housing 4 including a working unit 10 (an example of a cutting unit), an electric motor 64 (an example of a prime mover) that drives the working unit 10, a housing main body 14 that holds the working unit 10 and houses the electric motor 64, and a grip 16 that extends from the housing main body 14 and is held by a user's hand, and a hand guard 20 that is attached to the housing 4 and protects the user's fingers when holding the grip 16, and is more easily deformed than the housing 4.

[0094] According to the above configuration, when a load is applied to the hand guard 20 while the hand guard 20 is in contact with an obstacle, the hand guard 20 deforms relative to the housing 4. Therefore, when a user performs cutting work using the chainsaw T, even if the hand guard 20 interferes with an obstacle, the chainsaw T can be placed in a desired position or posture. Therefore, the chainsaw T provided with the hand guard 20 can be made more convenient for the user.

[0095] In one or more embodiments, the housing 4 is made of a material having a Young's modulus greater than 100 MPa. The handguard 20 is made of a material having a Young's modulus in the range of 1 MPa to 100 MPa.

[0096] When the hand guard 20 is deformed by elastic deformation, the greater the Young's modulus of the material used for the hand guard 20, the greater the load required to deform the hand guard 20 by a predetermined amount. With the above configuration, the user can sufficiently deform the hand guard 20 with a relatively small load. This further improves user convenience.

[0097] In one or more embodiments, the housing 4 is made of a plastic material, and the handguard 20 is made of a rubber material.

[0098] Rubber materials can undergo greater elastic deformation than other materials (for example, plastic materials). With the above configuration, the user can cause greater elastic deformation of the hand guard 20. This further improves user convenience.

[0099] In one or more embodiments, the hand guard 20 includes a first end 202 located near the proximal end of the grip 16, a second end 204 located near the distal end of the grip 16, and a guard body 206 extending continuously between the first end 202 and the second end 204.

[0100] According to the above configuration, the hand guard 20 is disposed so as to cover the grip 16 from its base end to its tip end. This ensures that the fingers of the user holding the grip 16 are protected.

[0101] In one or more embodiments, the housing 4 further includes a first mounting portion 22 to which a first end 202 of the handguard 20 is attached, and a second mounting portion 24 to which a second end 204 of the handguard 20 is attached. At least one of the first end 202 and the second end 204 is rotatably mounted relative to the corresponding at least one of the first mounting portion 22 and the second mounting portion 24.

[0102] When the hand guard 20 is supported by the housing 4 at two points, the first end 202 and the second end 204, both the first end 202 and the second end 204 may be fixed to the corresponding first mounting portion 22 and second mounting portion 24. In this case, the hand guard 20 can be considered a beam fixed at both ends, so a large load is required to deform the hand guard 20 (guard main body 206) by a predetermined amount. In contrast, with the above configuration, at least one of the first end 202 and the second end 204 is rotatably attached to at least one of the corresponding first mounting portion 22 and second mounting portion 24. In this case, the hand guard 20 can be considered a beam fixed at one end and simply supported (pin-supported) at the other end, or a beam simply supported (pin-supported) at both ends, so the user can sufficiently deform the hand guard 20 with a relatively small load.

[0103] In one or more embodiments, the guard body 206 includes a plate portion 208 formed in a plate shape.

[0104] According to the above configuration, by forming plate portion 208 into a thin, wide shape, plate portion 208 can be easily elastically deformed, and can protect a wide range of the user's fingers with plate portion 208. Therefore, it is possible to realize a hand guard 20 that is easily deformed while ensuring the protective function of hand guard 20.

[0105] In one or more embodiments, the guard body 206 has a first rib portion 212 (an example of a rib portion) that protrudes from the surface of the plate portion 208 at a position opposite the grip 16 and extends in a direction from the first end 202 toward the second end 204.

[0106] If the plate portion 208 is excessively deformed at the position facing the grip 16 (the amount of deflection of the plate portion 208 becomes excessive), the distance between the grip 16 and the plate portion 208 becomes excessively narrow, and there is a risk that the plate portion 208 will be pressed against the fingers of the user holding the grip 16. In this case, it will be difficult for the user to change the posture of their fingers, which will impair user convenience. According to the above configuration, the first rib portion 212 increases the rigidity of the plate portion 208 at the position facing the grip 16. This makes it possible to prevent the plate portion 208 from being excessively deformed at the position facing the grip 16 (the amount of deflection of the plate portion 208 becoming excessive). This makes it possible to prevent the plate portion 208 from being pressed against the fingers of the user holding the grip 16. This improves user convenience.

[0107] In one or more embodiments, the first rib portion 212 protrudes from the underside of the plate portion 208 (an example of the surface of the plate portion opposite the grip-facing surface).

[0108] If the first rib portion 212 protrudes from the upper surface of the plate portion 208 (an example of the surface of the plate portion facing the grip), there is a possibility that the first rib portion 212 will come into contact with the user's fingers when the user moves their fingers between the grip 16 and the plate portion 208. This may be irritating to the user and reduce user convenience. In contrast, with the above configuration, the first rib portion 212 protrudes from the lower surface of the plate portion 208. This prevents the first rib portion 212 from coming into contact with the user's fingers when the user moves their fingers between the grip 16 and the plate portion 208. This improves user convenience.

[0109] In one or more embodiments, the chainsaw T further includes a trigger lever 50 located near the base end of the grip 16 and operable to activate the electric motor 64 when pulled toward the grip 16 by a user's finger. The guard body 206 includes a first extension 220 connected to the first end 202 and extending away from the grip 16 from the base end toward the tip end, a second extension 222 connected to the second end 204 and extending away from the grip 16 from the tip end toward the base end, and a bent portion 224 connecting the first extension 220 and the second extension 222. The length of the first extension 220 is shorter than the length of the second extension 222.

[0110] When the guard main body 206 deforms, if the guard main body 206 is pressed against the user's fingers that are hanging on the trigger lever 50, this could result in erroneous operation of the trigger lever 50. In contrast, with the above configuration, the guard main body 206 has high rigidity near the bent portion 224. Furthermore, the bent portion 224 has a shape that protrudes outward when viewed from the grip 16. As a result, when the guard main body 206 is pressed against the grip 16, the bent portion 224 ensures a space between the grip 16 and the guard main body 206. Furthermore, because the bent portion 224 is located closer to the base end of the grip 16, a space is ensured near the trigger lever 50 when the guard main body 206 is pressed against the grip 16. Therefore, with the above configuration, it is possible to prevent the guard main body 206 from being pressed against the user's fingers that are hanging on the trigger lever 50, thereby preventing erroneous operation of the trigger lever 50. [Explanation of symbols]

[0111] 4: Housing 6: Guide bar 6a: Notch 8: Saw chain 10: Working section 12: Work cover 14: Housing body 14a:Head 16: Grip 18: Sprocket cover 20: Handguard 22: First mounting part 22a: Rotating shaft 24: Second mounting part 24a: Rotating shaft 26: Sprocket 28, 30: pin 32: Bolt 36: Sprocket cover body 38: Sleeve 42:Locking member 44: Locking member body 46: Nut 48: Claw part 50: Trigger lever 50a: Rotating shaft 50f: Front end of trigger lever 50r: Rear end of trigger lever 52: Trigger switch 54: Locking member 54a: Rotating shaft 56a: Through hole 56b: Through hole 58a: Left lock lever 58b: Right lock lever 60: Torsion spring 62: Control unit 62G: Center of gravity of control unit 62f: Front end of control unit 62r: Rear end of control unit 64: Electric motor 64G: Center of gravity of electric motor 64f: Front end of electric motor 66: Oil tank 68: Oil pump 68a: Worm wheel 70: Power transmission mechanism 70r: Rear end of power transmission mechanism 72:Reducer 72a: 1st bevel gear 72b: 2nd bevel gear 74: Coil 76: Stator 78: Rotor 80: Motor shaft 82: Cooling fan 82G: Cooling fan center of gravity 84: Drive shaft 84a: Worm gear 140: Left air intake 142: Right air intake 144: Left exhaust port 146: Right exhaust port 160: Battery interface 162: Connection terminal 164: Hook 166:Display section 202: First end 204:Second end 206: Guard body 208: Plate section 210: Rib section 212: First rib section 214: Second rib section 216: Third rib section 220: 1st extension part 222:Second extension part 224: Bend 360: Battery interface 362: Connection terminal 364: Hook 544: Exhaust port 620: Controller case 660: Cap 680: Intake section 682: Oil supply passage 684:Discharge part B1, B2, B3, B4: Battery pack B1f, B2f, B3f, B4f: Front end of battery pack BG1, BG2, BG3, BG4: Center of gravity of battery pack S: Wiring space T1, T2, T3, T4: Chainsaw TG1, TG2, TG3, TG4: Chainsaw center of gravity

Claims

1. A cutting operation unit; a prime mover that drives the cutting unit; a housing including a housing main body that holds the cutting unit and houses the motor, and a grip that extends from the housing main body and is held by a user's hand; a hand guard attached to the housing, protecting the user's fingers when the user is holding the grip, and the hand guard is more easily deformed than the housing, The housing is made of a plastic material, A cutting tool, wherein the hand guard is made of a rubber material.

2. the housing is formed of a material having a Young's modulus greater than 100 MPa; 2. The cutting tool of claim 1, wherein the hand guard is made of a material having a Young's modulus in the range of 1 MPa to 100 MPa.

3. The device further includes a trigger lever provided on the grip, which is pulled toward the grip by a user's finger to activate the prime mover, The cutting operation unit includes: a guide bar extending in the front-rear direction; a saw chain provided on the periphery of the guide bar and running along the periphery of the guide bar by being driven by the prime mover, 2. The cutting tool of claim 1, wherein the prime mover is disposed above the trigger lever when a direction perpendicular to the front-to-rear direction, the direction along which the trigger lever is pulled, is defined as an upward direction and the opposite direction is defined as a downward direction.

4. The hand guard is a first end portion disposed near a base end of the grip; a second end portion disposed near the tip of the grip; 2. The cutting tool of claim 1, further comprising a guard body extending continuously between said first end and said second end.

5. The housing includes: a first mounting portion to which the first end of the hand guard is attached; a second mounting portion to which the second end of the hand guard is attached, The cutting tool of claim 4 , wherein at least one of the first end and the second end is rotatably mounted relative to at least one of the corresponding first mounting portion and the second mounting portion.

6. The cutting tool according to claim 4 , wherein the guard body includes a plate portion formed in a plate shape.

7. 7. The cutting tool according to claim 6, wherein the guard body has a rib portion that protrudes from the surface of the plate portion at a position facing the grip and extends in a direction from the first end toward the second end.

8. The cutting tool according to claim 7 , wherein the rib portion protrudes from a surface of the plate portion opposite to a surface facing the grip.

9. a trigger lever provided near the base end of the grip and configured to activate the prime mover when pulled toward the grip by a user's finger, The guard body is a first extension portion connected to the first end portion and extending away from the grip from the base end side toward the tip end side; a second extension portion connected to the second end portion and extending away from the grip as it moves from the distal end side toward the proximal end side; a bending portion connecting the first extension portion and the second extension portion, The cutting tool of claim 4 , wherein the length of the first extension is shorter than the length of the second extension.

Images