chain saw

Abstract

A chain saw is provided, and a technique capable of inhibiting the accumulation of chips in a space formed between at least a brake drum, a main body case main body, and a guide bar is disclosed. The chain saw is provided with: a saw chain; a guide bar extending in a front-rear direction, the saw chain being attached to the guide bar; a sprocket that causes the saw chain to travel along the periphery of the guide bar; a prime mover; a brake drum that rotates integrally with the sprocket; a main body case that houses the prime mover; a sprocket cover that covers the sprocket; and a cover member that is provided between the main body case and the guide bar. When viewed in an upper side cross section that extends in the front-rear direction and a left-right direction and that includes an upper side rear end portion of the guide bar, the cover member is in contact with or close to a surface of the guide bar that is opposite the main body case, and a rear end of the cover member is located at a position that is rearward of a rear end of the guide bar.

Description

Technical Field

[0001] The technology disclosed in this specification relates to chainsaws. Background Technology

[0002] A chainsaw is disclosed in Japanese Patent Application Publication No. 2011-025470. The chainsaw includes: a saw chain; a guide bar extending in a front-rear direction, on which the saw chain is mounted; a sprocket that causes the saw chain to travel along the periphery of the guide bar; a prime mover that causes the sprocket to rotate about a rotation axis extending in a left-right direction; a main body housing that houses the prime mover; and a sprocket cover that covers the sprocket. Summary of the Invention

[0003] The problem the invention aims to solve

[0004] Chainsaws like the one described above sometimes have a brake drum. In this case, when using the chainsaw for cutting operations, chips may enter the space formed by the brake drum, the main body housing, and the guide rod, causing the chips to obstruct the rotation of the saw chain. This specification discloses a technique that can suppress the entry of chips into the space formed between at least the brake drum, the main body housing, and the guide rod.

[0005] Solution for solving the problem

[0006] This specification discloses a chainsaw. The chainsaw includes: a saw chain; a guide bar extending in a front-rear direction, on which the saw chain is mounted; a sprocket that causes the saw chain to travel along the periphery of the guide bar; a prime mover that causes the sprocket to rotate about a rotation axis extending in a left-right direction; a brake drum that rotates integrally with the sprocket; a main body housing that houses the prime mover; a sprocket cover that covers the sprocket; and a cover member disposed between the main body housing and the guide bar. When viewed in an upper cross-section extending in both the front-rear and left-right directions and including the upper rear end portion of the guide bar, the cover member is in contact with or close to the surface of the guide bar opposite to the main body housing, and the rear end of the cover member is located further rearward than the rear end of the guide bar.

[0007] In the above structure, it is possible to prevent chips from entering the space formed by at least the brake drum, the main body housing, and the guide rod. Attached Figure Description

[0008] Figure 1 This is a perspective view of chainsaw 2 in the embodiment.

[0009] Figure 2 This is a right-side view of chainsaw 2 in the embodiment.

[0010] Figure 3 This is a perspective view of the state in which the battery pack BT has been removed from the battery pack mounting part 22c of the embodiment of the chainsaw 2.

[0011] Figure 4This is a left view of the chainsaw 2 of the embodiment with the side handle 14, handguard 16 and left side housing 10 removed.

[0012] Figure 5 This is a cross-sectional view near the motor 36 of the chainsaw 2 in the embodiment.

[0013] Figure 6 This is a longitudinal sectional view near the control device 42 of the chainsaw 2 in the embodiment.

[0014] Figure 7 This is a right view of the chainsaw 2 of the embodiment with the sprocket cover 20 removed.

[0015] Figure 8 This is a right view of the chainsaw 2 of the embodiment with the sprocket cover 20 and outer cover plate 72 removed.

[0016] Figure 9 This is a right view of the chainsaw 2 of the embodiment with the sprocket cover 20, outer cover plate 72, guide rod 6, inner cover plate 70, brake cover 18, and brake drum cover 98 removed.

[0017] Figure 10 This is a cross-sectional view near the guide rod 6 when viewing the chainsaw 2 of the embodiment in an upper cross-section including the upper rear end 6c of the guide rod 6.

[0018] Figure 11 This is a cross-sectional view near the guide rod 6 when viewing the chainsaw 2 of the embodiment in a lower cross-section including the lower rear end 6d of the guide rod 6.

[0019] Figure 12 This is a perspective view of the chainsaw 2 of the embodiment with the sprocket cover 20, outer cover plate 72, guide rod 6, inner cover plate 70, and brake cover 18 removed.

[0020] Figure 13 This is a perspective view of the inner sprocket cover 21a of the chainsaw 2 in the embodiment.

[0021] Figure 14 This is a right view of the chainsaw 2 of the embodiment placed on the mounting surface P. Detailed Implementation

[0022] Hereinafter, representative, non-limiting examples of the invention will be described in detail with reference to the accompanying drawings. This detailed description is merely intended to present to those skilled in the art the details of preferred embodiments for carrying out the invention, and is not intended to limit the scope of the invention. Furthermore, in order to provide a further improved chainsaw, the disclosed additional features and inventions can be used separately from or together with other features and inventions.

[0023] Furthermore, the features and combinations of processes disclosed in the following detailed description are not essential for carrying out the invention in the broadest sense, but are described only to illustrate representative specific examples of the invention. Moreover, when providing additional and useful embodiments of the invention, the various features of the following representative specific examples and the various features of the technical solutions described in the claims are not necessarily combined as in the specific examples described herein or in the order listed.

[0024] All features recited in this specification and / or claims are intended to be disclosed separately and independently of the structure of the features recited in the embodiments and / or claims, as a disclosure of the original application and as a limitation of the specific matters recited in the claims. Furthermore, all numerical ranges and descriptions relating to groups or sets are intended to disclose their intermediate structures as a disclosure of the original application and as a limitation of the specific matters recited in the claims.

[0025] In one or more embodiments, the rear end of the cover member may also be located near the sprocket.

[0026] Typically, the sprocket is positioned behind the guide rod and also behind the aforementioned space. Therefore, in the above structure, it is possible to further suppress chips from entering the aforementioned space.

[0027] In one or more embodiments, when viewed in a cross-section extending in the front-back and left-right directions and located below the upper rear end of the guide rod, the cover member is in contact with or close to the surface of the guide rod opposite to the main body shell, and the rear end of the cover member is located behind the rear end of the guide rod.

[0028] In the above structure, compared to a structure in which the cover member and the guide rod are in contact or close to each other on the surface opposite to the main body shell when viewed only from the upper side section, and the rear end of the cover member is located in front of the rear end of the guide rod, it is possible to suppress the entry of chips into the space described above.

[0029] In one or more embodiments, the cover component may also be composed of components independent of the main body shell.

[0030] In the above structure, compared to a structure where the cover component and the main shell are integrated, the chainsaw can be easily assembled.

[0031] In one or more embodiments, a second cover member may also be provided between the sprocket cover and the guide rod. Alternatively, when viewed in a top cross-section, the second cover member may be in contact with or close to the surface of the guide rod opposite the sprocket cover, and the rear end of the second cover member may be located further rearward than the rear end of the guide rod.

[0032] In the above structure, it is possible to prevent chips from entering the space formed by at least the sprocket cover, the sprocket, and the guide rod.

[0033] In the above embodiments, the rear end of the second cover component may also be located near the sprocket.

[0034] Typically, the sprocket is positioned behind the guide rod and also behind the aforementioned space. Therefore, in the above structure, it is possible to further suppress chips from entering the aforementioned space.

[0035] In one or more embodiments, when viewed in a cross-section extending in the front-back and left-right directions and located below the upper rear end of the guide rod, the second cover member is in contact with or close to the surface of the guide rod opposite the sprocket cover, and the rear end of the second cover member is located behind the rear end of the guide rod.

[0036] In the above structure, compared to a structure in which the second cover member is in contact or close to the surface opposite to the sprocket cover of the guide rod when viewed only from the upper cross section, and the rear end of the second cover member is located in front of the rear end of the guide rod, it is possible to suppress the entry of chips into the space described above.

[0037] (Example)

[0038] like Figure 1 , Figure 2 As shown, the chainsaw 2 of this embodiment includes a main body 4, a guide bar 6, and a saw chain 8. The guide bar 6 is an elongated, plate-shaped member that extends in the front-rear direction and is mounted on the main body 4, protruding forward from the main body 4. The saw chain 8 has multiple interconnected blades and is mounted along the periphery of the guide bar 6. A battery pack BT is mounted on the main body 4. The battery pack BT contains multiple secondary battery cells (not shown) and is configured to be repeatedly charged by external power. The chainsaw 2 uses the power supplied from the battery pack BT to drive a motor 36 (see reference 1). Figure 5 This causes the saw chain 8 to travel along the periphery of the guide rod 6, thereby cutting the workpiece such as wood. Furthermore, in the following description, the length direction of the guide rod 6 is referred to as the front-back direction of the chainsaw 2, the direction orthogonal to the front-back direction is referred to as the vertical direction of the chainsaw 2, and the direction orthogonal to both the front-back and vertical directions is referred to as the left-right direction of the chainsaw 2. It should also be noted that, for clarity, the saw chain 8 is omitted from some of the accompanying drawings.

[0039] The main body 4 includes a left side housing 10, a right side housing 12, a side handle 14, a hand guard 16, a brake cover 18, and a sprocket cover 20. The left side housing 10 and the right side housing 12 form the main body housing 22 and the top handle 24. The left side housing 10 forms the shape of the left half of the main body housing 22 and the top handle 24, and the right side housing 12 forms the shape of the right half of the main body housing 22 and the top handle 24. The sprocket cover 20 includes an inner sprocket cover 21a and an outer sprocket cover 21b disposed in contact with the outer surface of the inner sprocket cover 21a.

[0040] The main body shell 22 includes a lower main body shell 22a having a generally rectangular parallelepiped shape in the longitudinal direction of the main body 4, and an upper main body shell 22b extending from the upper rear part of the lower main body shell 22a toward the upper rear side. For example... Figure 3 As shown, a battery pack mounting portion 22c is formed on the rear surface of the upper main body housing 22b. This battery pack mounting portion 22c allows the battery pack BT to be installed and removed by sliding it left-right. The user can install the battery pack BT into the battery pack mounting portion 22c by holding the top handle 24 with their right hand and sliding the battery pack BT to the right with their left hand. Conversely, the user can remove the battery pack BT from the battery pack mounting portion 22c by holding the top handle 24 with their right hand and sliding the battery pack BT to the left with their left hand.

[0041] like Figure 1 As shown, the top handle 24 includes: a generally prismatic support portion 24a extending upward from the front upper surface of the lower main body housing 22a; and a grip portion 24b extending downward from the rear upper part of the support portion 24a and connecting to the upper front surface of the upper main body housing 22b. The grip portion 24b has a generally circular cross-sectional shape. A recess 24c is formed on the upper surface of the support portion 24a. Inside the recess 24c is a power switch 26 for switching the power on / off of the chainsaw 2 by the user and a power indicator 28 for displaying the power on / off status of the chainsaw 2. A front grip portion 24d extending in a straight line is provided at the front end of the grip portion 24b, and a trigger switch 30 for the user to operate the rotation drive of the saw chain 8 is arranged on the lower surface of the front grip portion 24d. A trigger locking lever 32 is disposed on the upper part of the grip 24b. The trigger locking lever 32 switches between a state that allows the user to operate the trigger switch 30 and a state that prohibits the user from operating the trigger switch 30. A locking pin 34 is rotatably supported on the trigger locking lever 32, and a portion of the locking pin 34 protrudes from the upper surface of the trigger locking lever 32.

[0042] The side handle 14 has a generally U-shaped profile that connects the upper rear left surface of the support portion 24a of the top handle 24 to the lower rear left surface of the lower main body housing 22a. The cross-sectional shape of the side handle 14 is generally circular. When using the chainsaw 2, the user holds the top handle 24 with their right hand and the side handle 14 with their left hand to hold the chainsaw 2. From this state, when the user rotates the locking pin 34 of the top handle 24 to press it into the trigger locking lever 32, and presses the trigger locking lever 32 with the palm of their right hand, the user is allowed to operate the trigger switch 30. In this state, the user pushes the trigger switch 30 with the index finger of their right hand, thereby driving the saw chain 8 to rotate.

[0043] like Figure 4 As shown, the lower main housing 22a houses the motor 36, oil tank 38, oil pump 40, and control device 42. The oil tank 38 is positioned forward of the motor 36 and oil pump 40. The control device 42 is positioned rearward of the motor 36 and oil pump 40.

[0044] When viewed from the rear, the oil tank 38 partially overlaps with the motor 36, control device 42, and battery pack BT. When viewed from the rear, the motor 36 partially overlaps with the control device 42 and battery pack BT. When viewed from the rear, the battery pack BT partially overlaps with the trigger switch 30.

[0045] When viewed from below, the oil tank 38 does not overlap with the motor 36, control device 42, or battery pack BT. When viewed from below, the motor 36, control device 42, and battery pack BT do not overlap. When viewed from below, the control device 42 and battery pack BT partially overlap.

[0046] like Figure 5 As shown, motor 36 is an external rotor type DC brushless motor. Motor 36 rotates about a rotation axis AX extending in the left-right direction. Motor 36 includes: a stator 46 with a coil 44 wound around it; a rotor 48 disposed radially outside the stator 46; a cooling fan 50 fitted into the rotor 48; and an output shaft 52 disposed through the center of the stator 46 and rotor 48, and fitted into the cooling fan 50. The coil 44, stator 46, rotor 48, and cooling fan 50 are housed in a motor housing 37. The motor housing 37 and stator 46 are fixed to the main body housing 22. The coil 44 of the stator 46 is connected to a control device 42. The output shaft 52 is disposed along the left-right direction of the chainsaw 2 and is rotatably supported on the main body housing 22 by means of bearings 54 and 56.

[0047] like Figure 6As shown, the control device 42 is fixed to the lower main body housing 22a. The control device 42 includes a circuit board 58, a housing 60, and a potting compound 62. The circuit board 58 is housed within the housing 60. The circuit board 58 includes multiple switching elements (not shown) and a microcomputer (not shown). The switching elements are, for example, IGBTs or MOSFETs. The microcomputer controls the drive of the motor 36 by switching the on and off states of the switching elements. The housing 60 has a box-shaped shape with an upward opening. The housing 60 includes multiple heat sinks 60a arranged along the front-rear and left-right directions of the housing 60. Each of the multiple heat sinks 60a has a prism shape and protrudes downward from the lower surface of the housing 60 in a manner orthogonal to the lower surface of the housing 60. The potting compound 62 is made of, for example, resin material. The potting compound 62 is injected into the interior of the housing 60 in a molten state and solidifies, thereby being disposed inside the housing 60. The circuit board 58 is embedded inside the potting compound 62.

[0048] Next, the airflow when the cooling fan rotates at 50 degrees Celsius will be explained. Figure 5 , Figure 6 In the diagram, airflow is illustrated by arrows. (For example...) Figure 6 As shown, when the cooling fan 50 rotates, air from outside the main housing 22 flows into the interior of the main housing 22 through the air supply port 22d. The air flowing into the interior of the main housing 22 passes through the gaps between the heat sinks 60a and flows towards the front of the control device 42. As the air passes between the heat sinks 60a, heat from the control device 42 is dissipated from the heat sinks 60a to the air. In this embodiment, the main housing 22 is provided with a front rib 22e and a rear rib 22f extending inward from the wall surface of the main housing 22. The front rib 22e and the rear rib 22f each have a generally flat plate shape. In the direction in which the heat sinks 60a extend, the front ends of the front rib 22e and the rear rib 22f are located between the front end portion and the root portion of the heat sink 60a (i.e., the junction of the heat sink 60a and the lower surface of the housing 60). Thus, air passes through the area near the root portion of the heat sink 60a. The root of the heat sink 60a is located near the circuit board 58, so the heat of the control device 42 is dissipated from the root of the heat sink 60a to the air, thereby effectively cooling the control device 42.

[0049] like Figure 5As shown, air flowing to the front of the control device 42 flows into the interior of the motor housing 37 through the air supply opening 37a. The air flowing into the interior of the motor housing 37 flows in the gap between the stator 46 and the rotor 48, cooling the stator 46 and the rotor 48 before reaching the cooling fan 50. The air reaching the cooling fan 50 flows radially outward along the blades 50a, then flows circumferentially along the inner surface of the motor housing 37, and flows out to the outside of the main housing 22 through the exhaust opening 37b of the motor housing 37 and the exhaust port 22g of the main housing 22.

[0050] like Figure 5 As shown, a sprocket 64 and a brake base 66 are fixed near the right end of the output shaft 52. The sprocket 64 and brake base 66 are positioned to the right of the bearing 56. A brake drum 68 is fitted into the brake base 66. The brake drum 68 includes a base 68a and a protrusion 68b protruding outward from the base 68a (i.e., to the right of the chainsaw 2). The base 68a has a cylindrical portion 68c and a flange portion 68d disposed outside the cylindrical portion 68c and tapering in diameter from the cylindrical portion 68c. The protrusion 68b has: a cylindrical portion 68e having an outer diameter smaller than that of the cylindrical portion 68c; and a flange portion 68f disposed outside the cylindrical portion 68e and tapering in diameter from the cylindrical portion 68e. The flange portion 68f of the protrusion 68b contacts the sprocket 64.

[0051] The sprocket 64 protrudes to the outside of the right-side housing 12. Saw chain 8 (see reference) Figure 1 The guide rod 6 is mounted on the sprocket 64. When the motor 36 is driven, the sprocket 64 and the output shaft 52 rotate together around the rotation axis AX of the motor 36, thereby moving the saw chain 8 (refer to...) Figure 1 It travels along the periphery of sprocket 64 and guide rod 6. In this embodiment, the rotation axis AX of sprocket 64 is aligned with the rotation axis AX of motor 36.

[0052] like Figure 7 As shown, the guide rod 6 is fixed to the right housing 12 in a clamped state by the inner cover plate 70 and the outer cover plate 72. The inner cover plate 70 has a shape that bends inward (i.e., to the left side of the chainsaw 2) near its upper and lower ends. The outer cover plate 72 has a shape that bends outward (i.e., to the right side of the chainsaw 2) near its upper and lower ends. Figure 8 As shown, an elongated hole 6a is formed in the guide rod 6 along its length (i.e., the front-to-back direction of the chainsaw 2). The guide rod 6 is held to the main body housing 22 by means of a support pin 74 and a support bolt 76 passing through the elongated hole 6a. The support bolt 76 passes through the outer cover plate 72 (see reference). Figure 7 ) and sprocket cover 20 (refer to) Figure 2 ), protruding outwards from the sprocket cover 20. For example... Figure 2As shown, a nut 78 is installed on the support bolt 76 and fastened from the outside of the sprocket cover 20. With the nut 78 loosened, the user can slide the guide rod 6 in the back-and-forth direction, thereby changing the distance between the guide rod 6 and the sprocket 64 and adjusting the tension of the saw chain 8.

[0053] like Figure 8 As shown, the guide rod 6 has an engagement hole 82 that engages with the engagement claw 80. Figure 9 As shown, the engaging jaw 80 is connected to the adjusting screw 86 via a rotary-to-linear conversion mechanism 84. The rotary-to-linear conversion mechanism 84 converts the rotational motion of the adjusting screw 86 into linear motion along the direction (i.e., the front-to-back direction) of the elongated hole 6a of the engaging jaw 80. Figure 8 As shown, the adjusting screw 86 passes through the elongated hole 6a without contacting its inner circumferential surface. When the user rotates the adjusting screw 86, the engaging pawl 80 moves in the back-and-forth direction, and the guide rod 6 slides in the back-and-forth direction of the chainsaw 2. In this way, the back-and-forth position of the guide rod 6 can be adjusted relative to the sprocket 64.

[0054] like Figure 2 As shown, the sprocket 64, inner cover plate 70, outer cover plate 72, and support pin 74 are covered by the sprocket cover 20. A recess 20a is formed in the sprocket cover 20. A fastening opening 20b for the support bolt 76 to pass through and an adjustment opening 20c for accessing the adjusting screw 86 from the outside are formed in the recess 20a. The nut 78 is fastened to the support bolt 76 from the outside of the recess 20a. The user can tighten or loosen the nut 78 while the sprocket cover 20 is installed. Furthermore, while the sprocket cover 20 is installed, the user can adjust the tension of the saw chain 8 by rotating the adjusting screw 86 through the adjustment opening 20c.

[0055] like Figure 9 As shown, the handguard 16 is connected to the brake band 90 via a linkage mechanism 88. A portion of the linkage mechanism 88 and the brake band 90 are covered by a brake cover 18 (see...). Figure 2 The handguard 16 is capable of swinging about its axis of rotation in the left-right direction along the chainsaw 2. The brake band 90 surrounds the cylindrical portion 68c of the brake drum 68 (see reference). Figure 5 The linkage mechanism 88 causes the brake band 90 to narrow when the handguard 16 tilts forward and to widen when the handguard 16 is upright backward. When the brake band 90 narrows, the inner circumferential surface of the brake band 90 abuts against the outer circumferential surface of the cylindrical portion 68c of the brake drum 68, and the friction between the two brakes the rotation of the output shaft 52.

[0056] exist Figure 1The oil tank 38 shown stores lubricating oil for lubricating the saw chain 8. The oil tank 38 is provided with a cover 92 that can be removed through a replenishment opening for adding lubricating oil to the oil tank 38. The cover 92 of the oil tank 38 protrudes to the outside of the left side of the housing 10 and is located on the left surface of the front part of the main housing 22.

[0057] like Figure 4 As shown, the rotation of the oil pump 40 and the motor 36 is linked, drawing lubricating oil from inside the oil tank 38 through the inlet pipe 94, and guiding the guide rod 6 and saw chain 8 through the outlet pipe 96 (see reference). Figure 1 Lubricating oil is supplied from the oil tank 38 to the guide rod 6 and saw chain 8 via the oil pump 40. Figure 1 The amount of lubricating oil supplied can be adjusted using adjusting pin 97.

[0058] like Figure 10 , Figure 11 As shown, a space SP1 is formed by the main housing 22, the brake drum 68, the sprocket 64, and the guide rod 6. A wall 22h extending in the left-right direction of the main housing 22 is arranged in front of the space SP1. A wall 22i extending in the front-back direction of the main housing 22 and the flange portion 68d of the brake drum 68 are arranged on the left side of the space SP1. The cylindrical portion 68e of the brake drum 68 and the outer peripheral surface 64a of the sprocket 64 are arranged behind the space SP1. The guide rod 6 is arranged on the right side of the space SP1. With such a space SP1, when the chainsaw 2 is used for cutting operations, as the saw chain 8 rotates, chips enter the space SP1, and these chips may accumulate within the space SP1.

[0059] Regarding the above aspects, in this embodiment, the inner cover plate 70 inhibits chips from entering the space SP1. For example... Figure 10 , Figure 11 As shown, the inner cover plate 70 is disposed between the main body shell 22 and the guide rod 6.

[0060] like Figure 8 As shown, the rear end 6b of the guide rod 6 has: an upper rear end portion 6c, which protrudes rearward above the center of the guide rod 6 in the vertical direction; a lower rear end portion 6d, which protrudes rearward below the center of the guide rod 6 in the vertical direction; and a middle rear end portion 6e, which is recessed forward between the upper rear end portion 6c and the lower rear end portion 6d. In the guide rod 6 of this embodiment, the position of the upper rear end portion 6c in the front-rear direction is approximately the same as the position of the lower rear end portion 6d in the front-rear direction.

[0061] like Figure 10 , Figure 11As shown, in this embodiment, when viewed in any cross-section extending along the front-back and left-right directions and including the rear end 6b of the guide rod 6 (i.e., the upper rear end 6c, the lower rear end 6d, or the middle rear end 6e), the inner cover plate 70 contacts the surface of the guide rod 6 opposite to the main body housing 22 (i.e., the left surface of the guide rod 6), and the rear end 70a of the inner cover plate 70 is located further rearward than the rear end 6b of the guide rod 6. For example, as Figure 10 As shown, when viewed in an upper cross-section extending along both the front-rear and left-right directions and including the upper rear end 6c of the guide rod 6, the inner cover plate 70 contacts the left surface of the guide rod 6, and the rear end 70a of the inner cover plate 70 is located further rearward than the rear end 6b of the guide rod 6 (here, the upper rear end 6c). Furthermore, as... Figure 11 As shown, when viewed in a lower cross-section extending in both the front-rear and left-right directions and including the lower rear end 6d of the guide rod 6, the inner cover plate 70 contacts the left surface of the guide rod 6, and the rear end 70a of the inner cover plate 70 is located further rearward than the rear end 6b of the guide rod 6 (here, the lower rear end 6d). By configuring the structure in this way, it is possible to suppress the entry of chips into the space SP1.

[0062] like Figure 8 As shown, the rear end 70a of the inner cover plate 70 is located further back than the rear end 6b of the guide rod 6 and near the sprocket 64. In this specification, "near the sprocket 64" means, for example, a distance of less than 1 mm in the radial direction of the rotation axis AX of the sprocket 64, or, for example, a distance of less than 0.5 mm in the radial direction of the rotation axis AX of the sprocket 64.

[0063] like Figure 12 As shown, a brake drum cover 98 is fixed to the right surface of the main housing 22. The brake drum cover 98 is disposed below the brake cover 18. The brake drum cover 98 includes: a circular portion 98a that surrounds the protrusion 68b of the brake drum 68 (see reference). Figure 5 The area surrounding the circular portion 98a; and a protrusion 98b, which is located at the front end of the circular portion 98a and protrudes outward from the circular portion 98a. For example... Figure 10 , Figure 11 As shown, the brake drum cover 98 is positioned further inward than the inner cover 70 (i.e., on the left side of the inner cover 70). The protrusion 98b contacts the left surface of the inner cover 70. The rear end 98c of the protrusion 98b is positioned approximately the same in the longitudinal direction as the rear end 70a of the inner cover 70.

[0064] like Figure 12 As shown, the lower middle end 18a of the brake cover 18 is disposed between the main body housing 22 and the protrusion 98b of the brake drum cover 98. Figure 10As shown, the brake cover 18 is positioned further inward than the inner cover 70 (i.e., on the left side of the inner cover 70). The lower middle end 18a contacts the left surface of the inner cover 70.

[0065] like Figure 10 , Figure 11 As shown, the rear end portion 70b of the inner cover plate 70, a portion of the circular portion 98a and the protrusion 98b of the brake drum cover 98, and the middle lower end portion 18a of the brake cover 18 are disposed within the space SP1. The space SP1 is filled by the rear end portion 70b of the inner cover plate 70, a portion of the circular portion 98a and the protrusion 98b of the brake drum cover 98, and the middle lower end portion 18a of the brake cover 18, thereby suppressing the entry of chips into the space SP1 and / or the accumulation of chips within the space SP1. In this embodiment, the distance 98c of the rear end portion 70b of the inner cover plate 70 and the protrusion 98b of the brake drum cover 98 from the outer peripheral surface 64a of the sprocket 64 in the front-rear direction is 6 mm or less, and the distance 98b of the inner cover plate 70 and the protrusion 98b of the brake drum cover 98 from the left surface of the guide rod 6 in the left-right direction is 3 mm or less. Therefore, the entry of chips into the space SP1 and / or the accumulation of chips within the space SP1 can be effectively suppressed. Furthermore, in a modified example, the distance in the front-rear direction between the rear end 70b of the inner cover plate 70 or the rear end 98c of the protrusion 98b of the brake drum cover 98 and the outer peripheral surface 64a of the sprocket 64 can also be 6 mm or less. Alternatively, the distance in the left-right direction between the protrusion 98b of the inner cover plate 70 or the brake drum cover 98 and the left surface of the guide rod 6 can be 3 mm or less. In such a structure, it is also possible to suppress the entry of chips into the space SP1 and / or the accumulation of chips in the space SP1.

[0066] The circular portion 98a of the brake drum cover 98 covers a portion of the base 68a (i.e., the cylindrical portion 68c and the flange portion 68d) and the cylindrical portion 68e of the brake drum 68. This suppresses the accumulation of chips near the outer peripheral surface of the brake drum 68. Furthermore, the brake drum cover 98 is detachably fixed to the main housing 22. Therefore, if chips enter the space SP1, they can be easily removed by removing the brake drum cover 98 from the main housing 22.

[0067] like Figure 13 As shown, the stepped portion 20d of the sprocket cover 20 protrudes inward from the wall 20e that forms the outer shape of the sprocket cover 20. For example... Figure 10 , Figure 11 As shown, the step portion 20d is arranged parallel to the guide rod 6.

[0068] like Figure 10 , Figure 11 As shown, by support pin 74 (refer to) Figure 5The sprocket cover 20, sprocket 64, and guide rod 6 form a space SP2. A support pin 74 is positioned in front of the space SP2, and the guide rod 6 is positioned to the left of the space SP2. The outer peripheral surface 64a of the sprocket 64 is positioned behind the space SP2, and the stepped portion 20d of the sprocket cover 20 is positioned to the right of the space SP2. With such a space SP2, when the chainsaw 2 is used for cutting operations, as the saw chain 8 rotates, chips enter the space SP2, and the chips may accumulate inside the space SP2.

[0069] Regarding the above aspects, in this embodiment, the outer cover plate 72 inhibits chips from entering the space SP2. For example... Figure 10 , Figure 11 As shown, the outer cover plate 72 is disposed between the sprocket cover 20 and the guide rod 6. The outer cover plate 72 is fixed to the sprocket cover 20.

[0070] In this embodiment, when viewed in any cross-section extending along the front-rear and left-right directions and including the rear end 6b of the guide rod 6, the outer cover 72 contacts the surface of the guide rod 6 opposite to the sprocket cover 20 (i.e., the right surface of the guide rod 6), and the rear end 72a of the outer cover 72 is located further rearward than the rear end 6b of the guide rod 6. For example, as Figure 10 As shown, when viewed in an upper cross-section extending along both the front-rear and left-right directions and including the upper rear end 6c of the guide rod 6, the outer cover 72 contacts the right surface of the guide rod 6, and the rear end 72a of the outer cover 72 is located further rearward than the rear end 6b of the guide rod 6 (here, the upper rear end 6c). Furthermore, as... Figure 11 As shown, when viewed in a lower cross-section extending in both the front-to-back and left-to-right directions and including the lower rear end 6d of the guide rod 6, the outer cover plate 72 contacts the right surface of the guide rod 6, and the rear end 72a of the outer cover plate 72 is located further rearward than the rear end 6b of the guide rod 6 (here, the lower rear end 6d). By configuring it in this way, it is possible to suppress the entry of chips into the space SP2.

[0071] like Figure 7 As shown, the rear end 72a of the outer cover plate 72 is located behind the rear end 6b of the guide rod 6 and near the sprocket 64.

[0072] like Figure 13 As shown, an abutment rib 20f is provided in the sprocket cover 20. The abutment rib 20f protrudes inward from the step portion 20d or the wall 20e and has a shape that is substantially the same as the outer cover plate 72. The abutment rib 20f abuts against the entire outer surface of the outer cover plate 72.

[0073] like Figure 10 , Figure 11As shown, the rear end portion 72b of the outer cover plate 72 and the abutment rib 20f of the sprocket cover 20 are disposed within the space SP2. The space SP2 is filled by the rear end portion 72b of the outer cover plate 72 and the abutment rib 20f of the sprocket cover 20, thereby suppressing the entry of chips into the space SP2 and / or the accumulation of chips within the space SP2. In this embodiment, the distance in the left-right direction between the outer cover plate 72 and the right surface of the guide rod 6 is 3 mm or less. This effectively suppresses the entry of chips into the space SP2 and / or the accumulation of chips within the space SP2. Furthermore, in a modified example, the distance in the left-right direction between the stepped portion 20d of the sprocket cover 20 and the right surface of the guide rod 6 may be 3 mm or less, based on or replacing the outer cover plate 72. In this case, the stepped portion 20d of the sprocket cover 20 may contact or approach the right surface of the guide rod 6. In such a structure, the entry of chips into the space SP2 and / or the accumulation of chips within the space SP2 can also be suppressed.

[0074] like Figure 8 As shown, when viewing chainsaw 2 from the right, the lower end BU of battery pack BT is positioned above the center line CL1 of guide rod 6. The center line CL1 refers to the line extending from the center of guide rod 6 in the vertical direction along the front-back direction. Figure 9 As shown, when viewing the chainsaw 2 from the right, the distance L from the reference line RL, extending from the center line CL2 of the front end grip portion 24d of the top handle 24, to the lower end BU of the battery pack BT, is less than 2.6 times the width W of the front end grip portion 24d of the top handle 24 in the direction orthogonal to the center line CL2. The center line CL2, as referred to here, is a line passing through the center of the upper and lower surfaces (excluding the protrusion 31) of the front end grip portion 24d of the top handle 24 at the location where the protrusion 31 is formed on the lower surface of the front end grip portion 24d of the top handle 24. The protrusion 31 is located behind the trigger switch 30. Therefore, in a chainsaw 2 without this protrusion 31, the aforementioned center line CL2 can also be defined as a line passing through the center of the upper and lower surfaces of the front end grip portion 24d of the top handle 24 at a location directly behind the trigger switch 30 on the lower surface of the front end grip portion 24d of the top handle 24 (for example, 1 mm behind the trigger switch 30).

[0075] like Figure 14 As shown, with the chainsaw 2 mounted on the mounting surface P, the height H1 of the center of gravity GR of the battery pack BT from the mounting surface P in the vertical direction is more than half of the height H2 of the upper end of the top handle 24 from the mounting surface P in the vertical direction. Here, the upper end of the top handle 24 refers to the position with the greatest vertical height from the mounting surface P among the support portion 24a and the grip portion 24b formed by the left housing 10 and the right housing 12. That is, when determining the upper end of the top handle 24, the trigger locking lever 32 and the locking pin 34 are not considered.

[0076] (Modified example)

[0077] The chainsaw 2 can also replace the motor 36 by having an engine, including an internal combustion engine, as the prime mover to rotate the sprocket 64. In this case, it can also be configured such that the output shaft 52 connected to the sprocket 64 is rotated by the engine.

[0078] The brake drum 68 can also be integrally formed with the sprocket 64.

[0079] Alternatively, when viewed in an upper cross-section extending in both the front-rear and left-right directions and including the upper rear end 6c of the guide rod 6, the inner cover plate 70 is close to the surface of the guide rod 6 opposite to the main body housing 22. In this specification, "a component is close to the surface of the guide rod 6 opposite to the main body housing 22 (or sprocket cover 20)" means, for example, that the distance between the surface of a component opposite to the guide rod 6 and the surface of the guide rod 6 opposite to the main body housing 22 (or sprocket cover 20) is within 3 mm, and that the distance between the surface of a component opposite to the guide rod 6 and the surface of the guide rod 6 opposite to the main body housing 22 (or sprocket cover 20) is within 2 mm.

[0080] The chainsaw 2 may also be without the inner cover plate 70. In this case, when viewed in an upper cross-section extending in both the front-rear and left-right directions and including the upper rear end 6c of the guide rod 6, the protrusion 98b of the brake drum cover 98 may be in contact with or close to the surface of the guide rod 6 opposite to the main body housing 22, and the rear end 98c of the protrusion 98b may be located further back than the rear end 6b of the guide rod 6.

[0081] The chainsaw 2 may also be without the inner cover plate 70 and the brake drum cover 98. In this case, when viewed in an upper cross-section extending in both the front-rear and left-right directions and including the upper rear end 6c of the guide rod 6, the lower middle end 18a of the brake cover 18 may be in contact with or close to the surface of the guide rod 6 opposite to the main body housing 22, and the rear end of the lower middle end 18a may be located further back than the rear end 6b of the guide rod 6.

[0082] The rear end 70a of the inner cover plate 70 may not be located near the sprocket 64.

[0083] When viewed in a cross-section extending along both the front-to-back and left-to-right directions and located below the upper rear end 6c of the guide rod 6, the inner cover plate 70 may not contact or approach the surface of the guide rod 6 opposite to the main body housing 22. Alternatively, in the aforementioned cross-section view, the rear end 70a of the inner cover plate 70 may not be located behind the rear end 6b of the guide rod 6.

[0084] The inner cover plate 70 can also be integrated with the main body shell 22.

[0085] When viewed in the upper cross section extending in both the front-rear and left-right directions and including the upper rear end 6c of the guide rod 6, the outer cover plate 72 can also approach the surface of the guide rod 6 opposite to the sprocket cover 20.

[0086] The chainsaw 2 may also be without the outer cover plate 72. In this case, when viewed in an upper cross section extending in both the front-rear and left-right directions and including the upper rear end 6c of the guide rod 6, the abutment rib 20f of the sprocket cover 20 may be in contact with or close to the surface of the guide rod 6 opposite to the sprocket cover 20, and the rear end of the abutment rib 20f may be located further back than the rear end 6b of the guide rod 6.

[0087] The rear end 72a of the outer cover plate 72 may not be located near the sprocket 64.

[0088] When viewed in a cross-section extending along both the front-to-back and left-to-right directions and positioned below the upper rear end 6c of the guide rod 6, the outer cover 72 may not contact or approach the surface of the guide rod 6 opposite the sprocket cover 20. Alternatively, in the aforementioned cross-section, the rear end 72a of the outer cover 72 may not be located behind the rear end 6b of the guide rod 6.

[0089] The components forming space SP1 can be arbitrarily changed as long as they include brake drum 68, main body shell 22 and guide rod 6.

[0090] At least one component may be configured within space SP1. In this case, the component may be positioned between the main housing 22 and the guide rod 6, and when viewed in an upper cross-section extending in both the front-rear and left-right directions and including the upper rear end 6c of the guide rod 6, it may be in contact with or close to the surface of the guide rod 6 opposite to the main housing 22, and at least have its rear end positioned behind the rear end 6b of the guide rod 6.

[0091] The components that form space SP2 can be changed arbitrarily as long as they include sprocket cover 20, sprocket 64 and guide rod 6.

[0092] At least one component may be disposed within space SP2. In this case, it is preferable that the component is disposed between the sprocket cover 20 and the guide rod 6, and when viewed in an upper cross section extending in both the front-rear and left-right directions and including the upper rear end 6c of the guide rod 6, it is in contact with or close to the surface of the guide rod 6 opposite to the sprocket cover 20, and at least has its rear end positioned behind the rear end 6b of the guide rod 6.

[0093] Power can also be supplied to the motor 36 via a power cord. That is, the chainsaw 2 may not have a battery pack BT.

[0094] Motor 36 can also be an internal rotor type DC brushless motor. Alternatively, motor 36 can be a brushed motor or other types of electric motors.

[0095] The inner sprocket cover 21a and the outer sprocket cover 21b can also be formed as one piece.

[0096] As described above, in one or more embodiments, the chainsaw 2 includes: a saw chain 8; a guide rod 6 extending in a front-rear direction, on which the saw chain 8 is mounted; a sprocket 64 that causes the saw chain 8 to travel along the periphery of the guide rod 6; a motor 36 (an example of a prime mover) that causes the sprocket 64 to rotate about a rotation axis AX extending in a left-right direction; a brake drum 68 that rotates integrally with the sprocket 64; a main body housing 22 that houses the motor 36; a sprocket cover 20 that covers the sprocket 64; and an inner cover plate 70 (an example of a cover member) disposed between the main body housing 22 and the guide rod 6. When viewed in an upper cross-section extending in both the front-rear and left-right directions and including the upper rear end 6c of the guide rod 6, the inner cover plate 70 is in contact with or close to the surface of the guide rod 6 opposite to the main body housing 22, and the rear end 70a of the inner cover plate 70 is located further rearward than the rear end 6b (in this case, the upper rear end 6c) of the guide rod 6.

[0097] In the above structure, it is possible to prevent chips from entering the space SP1 formed by at least the brake drum 68, the main housing 22 and the guide rod 6.

[0098] In one or more embodiments, the rear end 70a of the inner cover plate 70 is located near the sprocket 64.

[0099] Typically, the sprocket 64 is positioned behind the guide rod 6 and behind the aforementioned space SP1. Therefore, in the above structure, it is possible to further suppress the entry of chips into the aforementioned space SP1.

[0100] In one or more embodiments, when viewed in cross-section extending in the front-back and left-right directions and located below the upper rear end 6c of the guide rod 6, the inner cover plate 70 is in contact with or close to the surface of the guide rod 6 opposite to the main body housing 22, and the rear end 70a of the inner cover plate 70 is located behind the rear end 6b of the guide rod 6.

[0101] In the above structure, compared to a structure in which the inner cover plate 70 is in contact or close to the surface of the guide rod 6 opposite to the main body housing 22 when viewed only from the upper side section, and the rear end 70a of the inner cover plate 70 is located in front of the rear end 6b of the guide rod 6, it is possible to suppress the entry of chips into the space SP1.

[0102] In one or more embodiments, the inner cover 70 is composed of components independent of the main housing 22.

[0103] According to the above structure, compared with the structure in which the inner cover plate 70 and the main body shell 22 are integrated, the chainsaw 2 can be easily assembled.

[0104] In one or more embodiments, an outer cover plate 72 (an example of a second cover member) is further provided between the sprocket cover 20 and the guide rod 6. When viewed in the upper cross section, the outer cover plate 72 is in contact with or close to the surface of the guide rod 6 opposite to the sprocket cover 20, and the rear end 72a of the outer cover plate 72 is located behind the rear end 6b of the guide rod 6 (here, the upper rear end 6c).

[0105] In the above structure, it is possible to prevent chips from entering the space SP2 formed by at least the sprocket cover 20, the sprocket 64 and the guide rod 6.

[0106] In one or more embodiments, the rear end 72a of the outer cover 72 is located near the sprocket 64.

[0107] Typically, the sprocket 64 is positioned behind the guide rod 6 and behind the aforementioned space. Therefore, in the above structure, it is possible to further suppress chips from entering the aforementioned space SP2.

[0108] In one or more embodiments, when viewed in cross-section extending in the front-back and left-right directions and located below the upper rear end 6c of the guide rod 6, the outer cover 72 is in contact with or close to the surface of the guide rod 6 opposite to the sprocket cover 20, and the rear end 72a of the outer cover 72 is located behind the rear end 6b of the guide rod 6.

[0109] In the above structure, compared to a structure in which the outer cover plate 72 is in contact or close to the surface opposite to the sprocket cover 20 of the guide rod 6 when viewed only from the upper side section, and the rear end 72a of the outer cover plate 72 is located in front of the rear end 6b of the guide rod 6, it is possible to suppress the entry of chips into the space SP2.

Claims

1. A chainsaw, wherein, This chainsaw features: Saw chain; A guide rod extending in the front-to-back direction, on which the saw chain is mounted; A sprocket that causes the saw chain to travel along the periphery of the guide bar; A prime mover that causes the sprocket to rotate about a rotation axis extending in the left-right direction; A brake drum that rotates integrally with the sprocket; The main housing, which houses the prime mover; A sprocket cover that covers the sprocket; as well as A cover component is disposed between the main housing and the guide rod. When viewed in an upper cross-section extending in both the front-to-back and left-to-right directions and including the upper rear end portion of the guide rod, the cover member is in contact with or close to the surface of the guide rod opposite to the main body housing, and the rear end of the cover member is located further back than the rear end of the guide rod.

2. The chainsaw according to claim 1, wherein, The rear end of the cover component is located near the sprocket.

3. The chainsaw according to claim 1 or 2, wherein, When viewed in cross-section extending in both the front-to-back and left-to-right directions and positioned below the upper rear end of the guide rod, the cover member is in contact with or close to the surface of the guide rod opposite to the main housing, and the rear end of the cover member is positioned further back than the rear end of the guide rod.

4. The chainsaw according to any one of claims 1 to 3, wherein, The cover component is composed of components that are independent of the main body shell.

5. The chainsaw according to any one of claims 1 to 4, wherein, The chainsaw also includes a second cover member disposed between the sprocket cover and the guide rod. When viewed from the upper cross section, the second cover member is in contact with or close to the surface of the guide rod opposite to the sprocket cover, and the rear end of the second cover member is located further back than the rear end of the guide rod.

6. The chainsaw according to claim 5, wherein, The rear end of the second cover component is located near the sprocket.

7. The chainsaw according to claim 5 or 6, wherein, When viewed in cross-section extending in both the front-to-back and left-to-right directions and positioned below the upper rear end of the guide rod, the second cover member is in contact with or close to the surface of the guide rod opposite the sprocket cover, and the rear end of the second cover member is positioned further rearward than the rear end of the guide rod.

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