Chainsaw

Abstract

This document discloses a technique for reducing the moment with the top handle as the pivot point. [Solution] The chainsaw comprises a saw chain, a guide bar extending in the front-rear direction to which the saw chain is attached, a sprocket that causes the saw chain to run along the periphery of the guide bar, a motor that rotates the sprocket around a rotation axis extending in the left-right direction, a battery pack that supplies power to the motor, a main body housing that houses the motor and holds the guide bar, and a top handle provided on the top of the main body housing and gripped by the user. When the chainsaw is viewed from the right, the lower end of the battery pack is located above the center line of the guide bar.

Description

Technical Field

[0001] The technology disclosed in the present specification relates to a chainsaw.

Background Art

[0002] Patent Document 1 discloses a chainsaw. The chainsaw includes a saw chain, a guide bar extending in the front-rear direction to which the saw chain is attached, a sprocket that causes the saw chain to travel along the peripheral edge of the guide bar, a motor that rotates the sprocket around a rotation axis extending in the left-right direction, a battery pack that supplies electric power to the motor, a main body housing that accommodates the motor, and a top handle provided on an upper portion of the main body housing and gripped by a user. When the chainsaw is viewed from the right side, the lower end of the battery pack is located below the center line of the guide bar.

Prior Art Literature

Patent Literature

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] Generally, since a battery pack has a certain weight, in the chainsaw as described above, the moment of inertia around the top handle is large. Therefore, there is a risk that the workability of an operation such as when the user grips the top handle and turns the chainsaw sideways may decrease. The present specification discloses a technique for reducing the moment of inertia around the top handle.

Means for Solving the Problem

[0005] This specification discloses a chainsaw. The chainsaw comprises a saw chain, a guide bar extending in the front-rear direction to which the saw chain is attached, a sprocket that causes the saw chain to travel along the periphery of the guide bar, a motor that rotates the sprocket around a rotation axis extending in the left-right direction, a battery pack that supplies power to the motor, a main body housing that houses the motor and holds the guide bar, and a top handle provided on the upper part of the main body housing and gripped by the user. When the chainsaw is viewed from the right, the lower end of the battery pack is located above the center line of the guide bar.

[0006] In the above configuration, the battery pack, which is a heavy object, is positioned relatively close to the center line of the top handle or its extension, resulting in a small moment of inertia around the top handle.

[0007] This specification also discloses other chainsaws. The chainsaw comprises a saw chain, a guide bar extending in the front-rear direction to which the saw chain is attached, a sprocket for driving the saw chain along the periphery of the guide bar, a motor for rotating the sprocket around a rotation axis extending in the left-right direction, a battery pack for supplying power to the motor, a main body housing for housing the motor and holding the guide bar, and a top handle provided on the upper part of the main body housing for gripping by the user. With the chainsaw placed on a mounting surface, the vertical height of the center of gravity of the battery pack from the aforementioned mounting surface is at least half the vertical height of the upper end of the top handle from the aforementioned mounting surface.

[0008] Even with the above configuration, the battery pack, which is a heavy component, is positioned relatively close to the center line of the top handle or its extension, resulting in a small moment of inertia around the top handle.

[0009] This specification also discloses further other chainsaws. The chainsaw comprises a saw chain, a guide bar extending in the front-rear direction to which the saw chain is attached, a sprocket for driving the saw chain along the periphery of the guide bar, a motor for rotating the sprocket around a rotation axis extending in the left-right direction, a battery pack for supplying power to the motor, a main body housing for housing the motor and holding the guide bar, and a top handle provided on the upper part of the main body housing and gripped by the user. A trigger switch operated by the user is provided on the underside of the front end of the top handle. When the chainsaw is viewed from the right, the distance from the reference line extended from the center line of the front end of the top handle to the lower end of the battery pack is 2.6 times or less the width of the front end of the top handle in the direction perpendicular to the center line.

[0010] Even with the above configuration, the battery pack, which is a heavy component, is positioned relatively close to the center line of the top handle or its extension, resulting in a small moment of inertia around the top handle. [Brief explanation of the drawing]

[0011] [Figure 1] This is a perspective view of chainsaw 2 in the embodiment. [Figure 2] This is a right side view of the chainsaw 2 in the embodiment. [Figure 3] This is a perspective view of the chainsaw 2 of the embodiment, with the battery pack BT removed from the battery pack mounting section 22c. [Figure 4] This is a left side view of the chainsaw 2 of the embodiment, with the side handle 14, handguard 16, and left side housing 10 removed. [Figure 5] This is a cross-sectional view of the chainsaw 2 of the embodiment, near the motor 36. [Figure 6] This is a longitudinal cross-sectional view of the chainsaw 2 of the embodiment, near the control device 42. [Figure 7]This is a right side view of the chainsaw 2 in the embodiment, with the sprocket cover 20 removed. [Figure 8] This is a right side view of the chainsaw 2 of the embodiment, with the sprocket cover 20 and outer cover plate 72 removed. [Figure 9] This is a right side view of the chainsaw 2 in the embodiment, with the sprocket cover 20, outer cover plate 72, guide bar 6, inner cover plate 70, brake cover 18, and brake drum cover 98 removed. [Figure 10] This is a cross-sectional view of the vicinity of the guide bar 6, when the chainsaw 2 of the embodiment is viewed from an upper cross-section including the upper rear end 6c of the guide bar 6. [Figure 11] This is a cross-sectional view of the vicinity of the guide bar 6, when the chainsaw 2 of the embodiment is viewed from a lower cross-section including the lower rear end 6d of the guide bar 6. [Figure 12] This is a perspective view of the chainsaw 2 in the embodiment, with the sprocket cover 20, outer cover plate 72, guide bar 6, inner cover plate 70, and brake cover 18 removed. [Figure 13] This is a perspective view showing the inner sprocket cover 21a of the chainsaw 2 of the embodiment. [Figure 14] This is a right side view of the chainsaw 2 of the embodiment, placed on the mounting surface P. [Modes for carrying out the invention]

[0012] Representative and non-limiting examples of the present invention are described in detail below with reference to the drawings. This detailed description is intended simply to show those skilled in the art details for carrying out preferred examples of the present invention and is not intended to limit the scope of the invention. Furthermore, the disclosed additional features and inventions may be used separately from or in conjunction with other features and inventions to provide a further improved chainsaw.

[0013] Further, combinations of features and steps disclosed in the following detailed description are not essential to the practice of the invention in the broadest sense, and are specifically described only for the purpose of illustrating representative embodiments of the invention. Furthermore, various features of the following representative embodiments, as well as various features of those recited in the claims, need not be combined in the order set forth or in the order listed herein in order to provide additional and useful embodiments of the invention.

[0014] All features described in the present specification and / or claims, apart from the configuration of features described in the embodiments and / or claims, are intended to be disclosed individually and independently of each other as limitations on the specific matters described in the original disclosure of the application and the claims. Furthermore, all descriptions of numerical ranges and groups or populations are provided with the intent to disclose intermediate configurations thereof as limitations on the specific matters described in the original disclosure of the application and the claims.

[0015] In one or more embodiments, the chainsaw may further comprise a control device that controls driving of the motor. In this case, when the chainsaw is viewed from the rear, the motor may at least partially overlap the control device.

[0016] With the above configuration, the vertical dimension of the chainsaw can be reduced.

[0017] In one or more embodiments, the chainsaw may further comprise a control device that controls driving of the motor. In this case, when the chainsaw is viewed from below, the battery pack may at least partially overlap the control device.

[0018] With the above configuration, the front-rear dimension of the chainsaw can be reduced.

[0019] In one or more embodiments, the battery pack may be configured to be detachable from the main housing by sliding in the left-right direction.

[0020] In the above configuration, the user can attach and detach the battery pack from the main housing by sliding it left or right.

[0021] (Examples) As shown in Figures 1 and 2, the chainsaw 2 of this embodiment comprises a main body 4, a guide bar 6, and a saw chain 8. The guide bar 6 is an elongated, plate-shaped member extending in the front-to-back direction, attached to the main body 4 so as to protrude forward from the main body 4. The saw chain 8 has multiple interconnected cutters and is attached along the periphery of the guide bar 6. A battery pack BT is attached to the main body 4. The battery pack BT contains multiple secondary battery cells (not shown) and is configured to be repeatedly rechargeable by external power. The chainsaw 2 drives a motor 36 (see Figure 5) with power supplied from the battery pack BT, thereby causing the saw chain 8 to run along the periphery of the guide bar 6, and cutting materials such as wood. In the following description, the longitudinal direction of the guide bar 6 is referred to as the front-to-back direction of the chainsaw 2, the direction perpendicular to the front-to-back direction is referred to as the up-and-down direction of the chainsaw 2, and the direction perpendicular to both the front-to-back and up-and-down directions is referred to as the left-to-right direction of the chainsaw 2. Please note that in some drawings, the saw chain 8 has been omitted for clarity.

[0022] The main body 4 comprises a left housing 10, a right housing 12, a side handle 14, a handguard 16, a brake cover 18, and a sprocket cover 20. The left housing 10 and the right housing 12 form the main body housing 22 and the top handle 24. The left housing 10 forms the outer shape of the left half of the main body housing 22 and the top handle 24, and the right housing 12 forms the outer shape of the right half of the main body housing 22 and the top handle 24. The sprocket cover 20 comprises an inner sprocket cover 21a and an outer sprocket cover 21b that is positioned in contact with the outer surface of the inner sprocket cover 21a.

[0023] The main body housing 22 comprises a lower main body housing 22a, which has a substantially rectangular parallelepiped shape with its longitudinal direction in the front-to-back direction of the main body 4, and an upper main body housing 22b that extends from the rear upper part of the lower main body housing 22a toward the rear upper part. As shown in Figure 3, a battery pack mounting portion 22c is formed on the rear surface of the upper main body housing 22b, which allows the battery pack BT to be attached and detached by sliding the battery pack BT in the left-to-right direction. The user can attach the battery pack BT to the battery pack mounting portion 22c by grasping the top handle 24 with their right hand and sliding the battery pack BT to the right with their left hand. The user can also remove the battery pack BT from the battery pack mounting portion 22c by grasping the top handle 24 with their right hand and sliding the battery pack BT to the left with their left hand.

[0024] As shown in Figure 1, the top handle 24 includes a roughly rectangular prism-shaped support portion 24a extending upward from the front upper surface of the lower main body housing 22a, and a gripping 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 cross-sectional shape of the gripping portion 24b is roughly circular. A recess 24c is formed on the upper surface of the support portion 24a. Inside the recess 24c are a power switch 26 for the user to switch the power of the chainsaw 2 on and off, and a power lamp 28 that indicates the power status of the chainsaw 2. A linearly extending front end gripping portion 24d is provided at the front end of the gripping portion 24b, and a trigger switch 30 for the user to operate the rotational drive of the saw chain 8 is located on the lower surface of the front end gripping portion 24d. A trigger lock lever 32 is positioned on the upper part of the gripping portion 24b, which switches between a state that allows the user to operate the trigger switch 30 and a state that prohibits it. A lock pin 34 is rotatably supported on the trigger lock lever 32, and a portion of the lock pin 34 is exposed from the upper surface of the trigger lock lever 32.

[0025] The side handle 14 has a roughly U-shaped outer shape that connects the upper rear left surface of the support portion 24a of the top handle 24 and the lower rear left surface of the lower main body housing 22a. The cross-sectional shape of the side handle 14 is roughly 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, the user rotates the lock pin 34 of the top handle 24 and pushes it into the trigger lock lever 32, while simultaneously pushing down the trigger lock lever 32 with the palm of their right hand, thereby allowing the user to operate the trigger switch 30. In this state, the user pushes up the trigger switch 30 with their right index finger, which drives the saw chain 8 to rotate.

[0026] As shown in Figure 4, the lower main body housing 22a houses the motor 36, oil tank 38, oil pump 40, and control device 42. The oil tank 38 is positioned in front of the motor 36 and oil pump 40. The control device 42 is positioned behind the motor 36 and oil pump 40.

[0027] When viewed from the rear of the chainsaw 2, the oil tank 38 partially overlaps with the motor 36, the control unit 42, and the battery pack BT. When viewed from the rear of the chainsaw 2, the motor 36 partially overlaps with the control unit 42 and the battery pack BT. When viewed from the rear of the chainsaw 2, the battery pack BT partially overlaps with the trigger switch 30.

[0028] When the chainsaw 2 is viewed from below, the oil tank 38 does not overlap with the motor 36, the control unit 42, or the battery pack BT. When the chainsaw 2 is viewed from below, the motor 36 does not overlap with the control unit 42 or the battery pack BT. When the chainsaw 2 is viewed from below, the control unit 42 partially overlaps with the battery pack BT.

[0029] As shown in Figure 5, the motor 36 is an outer rotor type DC brushless motor. The motor 36 rotates around a rotation axis AX that extends in the left-right direction. The motor 36 comprises a stator 46 around which a coil 44 is wound, a rotor 48 positioned radially outward from the stator 46, a cooling fan 50 fitted to the rotor 48, and an output shaft 52 positioned to pass through the center of the stator 46 and rotor 48 and fitted to the cooling fan 50. The coil 44, stator 46, rotor 48, and cooling fan 50 are housed in a motor case 37. The motor case 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 positioned along the left-right direction of the chainsaw 2 and is rotatably supported in the main body housing 22 via bearings 54, 56.

[0030] As shown in Figure 6, the control device 42 is fixed to the lower main body housing 22a. The control device 42 comprises a circuit board 58, a case 60, and a potting material 62. The circuit board 58 is housed in the case 60. The circuit board 58 comprises a plurality of switching elements (not shown) and a microcontroller (not shown). The switching elements are, for example, IGBTs or MOSFETs. The microcontroller controls the drive of the motor 36 by switching the switching elements between on and off states. The case 60 has a box shape with an opening on the top. The case 60 is equipped with a plurality of heat dissipation fins 60a arranged along the front-to-back and left-to-right directions of the case 60. Each of the plurality of heat dissipation fins 60a has a prism shape and protrudes downward from the bottom surface of the case 60 so as to be perpendicular to the bottom surface of the case 60. The potting material 62 is made of, for example, a resin material. The potting material 62 is poured into the case 60 in a molten state and solidifies, thereby being positioned inside the case 60. The potting material 62 contains the circuit board 58 inside.

[0031] Next, the airflow when the cooling fan 50 rotates will be explained. In Figures 5 and 6, the airflow is illustrated by arrows. As shown in Figure 6, when the cooling fan 50 rotates, air from outside the main housing 22 flows into the main housing 22 through the air intake port 22d. The air that flows into the main housing 22 flows to the front of the control device 42, passing through the gaps between the heat dissipation fins 60a. As the air passes between the heat dissipation fins 60a, the heat from the control device 42 is dissipated from the heat dissipation fins 60a into the air. In this embodiment, the main housing 22 is provided with a front rib 22e and a rear rib 22f that extend inward from the wall surface of the main housing 22. The front rib 22e and the rear rib 22f each have a substantially flat plate shape. With respect to the direction in which the heat dissipation fin 60a extends, the tip of the front rib 22e and the tip of the rear rib 22f are located between the tip and base portions of the heat dissipation fin 60a (i.e., the joint between the heat dissipation fin 60a and the lower surface of the case 60). As a result, air passes through the area near the base portion of the heat dissipation fin 60a. Since the base portion of the heat dissipation fin 60a is located near the circuit board 58, the heat from the control device 42 can be effectively cooled by dissipating heat from the base portion of the heat dissipation fin 60a into the air.

[0032] As shown in Figure 5, the air that has flowed to the front of the control device 42 flows into the motor case 37 through the air intake opening 37a. The air that has flowed into the motor case 37 flows through the gap between the stator 46 and the rotor 48, cooling the stator 46 and the rotor 48, and then reaches the cooling fan 50. The air that has reached the cooling fan 50 flows radially outward along the blades 50a, then flows circumferentially along the inner surface of the motor case 37, and flows out to the outside of the main housing 22 through the exhaust opening 37b of the motor case 37 and the exhaust port 22g of the main housing 22.

[0033] As shown in Figure 5, 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 onto the brake base 66. The brake drum 68 has a base 68a and a projection 68b that protrudes 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 that is located outside the cylindrical portion 68c and is tapered in diameter from the cylindrical portion 68c. The projection 68b has a cylindrical portion 68e having an outer diameter smaller than the outer diameter of the cylindrical portion 68c and a flange portion 68f that is located outside the cylindrical portion 68e and is tapered in diameter from the cylindrical portion 68e. The flange portion 68f of the projection 68b is in contact with the sprocket 64.

[0034] The sprocket 64 is exposed on the outside of the right-side housing 12. The saw chain 8 (see Figure 1) is stretched from the guide bar 6 across the sprocket 64. When the motor 36 is driven, the sprocket 64 rotates together with the output shaft 52 around the motor 36's rotation axis AX, causing the saw chain 8 (see Figure 1) to travel along the periphery of the sprocket 64 and the guide bar 6. In this embodiment, the rotation axis AX of the sprocket 64 coincides with the rotation axis AX of the motor 36.

[0035] As shown in Figure 7, the guide bar 6 is fixed to the right-side housing 12, sandwiched between an inner cover plate 70 and an outer cover plate 72. The inner cover plate 70 has a shape that curves 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 curves outward (i.e., to the right side of the chainsaw 2) near its upper and lower ends. As shown in Figure 8, the guide bar 6 has an elongated hole 6a formed along its longitudinal direction (i.e., the front-to-back direction of the chainsaw 2). The guide bar 6 is held in place by the main housing 22 via a support pin 74 and a support bolt 76 that pass through the elongated hole 6a. The support bolt 76 passes through the outer cover plate 72 (see Figure 7) and the sprocket cover 20 (see Figure 2), protruding to the outside of the sprocket cover 20. As shown in Figure 2, a nut 78 is attached to the support bolt 76, fastened from the outside of the sprocket cover 20. The user can adjust the tension of the saw chain 8 by loosening the nut 78 and sliding the guide bar 6 in the forward and backward directions, thereby changing the distance between the guide bar 6 and the sprocket 64.

[0036] As shown in Figure 8, the guide bar 6 has an engagement hole 82 that engages with an engagement claw 80. As shown in Figure 9, the engagement claw 80 is connected to an adjustment screw 86 via a rotary-to-linear motion conversion mechanism 84. The rotary-to-linear motion conversion mechanism 84 converts the rotational motion of the adjustment screw 86 into linear motion in the direction along the elongated hole 6a of the engagement claw 80 (i.e., the front-to-back direction). As shown in Figure 8, the adjustment screw 86 passes through the elongated hole 6a without touching its inner circumferential surface. When the user rotates the adjustment screw 86, the engagement claw 80 moves in the front-to-back direction, causing the guide bar 6 to slide in the front-to-back direction of the chainsaw 2. In this way, the front-to-back position of the guide bar 6 relative to the sprocket 64 can be adjusted.

[0037] As shown in Figure 2, the sprocket 64, inner cover plate 70, outer cover plate 72, and support pin 74 are covered by the sprocket cover 20. The sprocket cover 20 has a recess 20a. The recess 20a has a fastening opening 20b through which the support bolt 76 passes, and an adjustment opening 20c for external access to the adjustment screw 86. 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 with the sprocket cover 20 installed. The user can also adjust the tension of the saw chain 8 by rotating the adjustment screw 86 through the adjustment opening 20c with the sprocket cover 20 installed.

[0038] As shown in Figure 9, the handguard 16 is connected to the brake band 90 via a linkage mechanism 88. The linkage mechanism 88 and a portion of the brake band 90 are covered by a brake cover 18 (see Figure 2). The handguard 16 is pivotable around a pivot axis along the left-right direction of the chainsaw 2. The brake band 90 is positioned to surround the cylindrical portion 68c (see Figure 5) of the brake drum 68. The linkage mechanism 88 reduces the diameter of the brake band 90 when the handguard 16 is tilted forward, and expands the diameter of the brake band 90 when the handguard 16 is raised backward. When the brake band 90 is reduced in diameter, the inner surface of the brake band 90 and the outer surface of the cylindrical portion 68c of the brake drum 68 come into contact, and the frictional force between them brakes the rotation of the output shaft 52.

[0039] The oil tank 38 shown in Figure 1 stores lubricating oil for lubricating the saw chain 8. The oil tank 38 is provided with a removable cap 92 on a replenishment opening for replenishing the lubricating oil. The cap 92 of the oil tank 38 is exposed to the outside of the left housing 10 and is located on the left side of the front of the main housing 22.

[0040] As shown in Figure 4, the oil pump 40, in conjunction with the rotation of the motor 36, draws lubricating oil from inside the oil tank 38 via the inlet pipe 94 and supplies lubricating oil to the guide bar 6 and saw chain 8 (see Figure 1) via the outlet pipe 96. The amount of lubricating oil discharged from the oil tank 38 to the guide bar 6 and saw chain 8 (see Figure 1) by the oil pump 40 can be adjusted via the adjustment pin 97.

[0041] As shown in Figures 10 and 11, a space SP1 is formed by the main housing 22, the brake drum 68, the sprocket 64, and the guide bar 6. In front of space SP1 is a wall 22h extending in the left-right direction of the main housing 22, and to the left of space SP1 is a wall 22i extending in the front-rear direction of the main housing 22 and the flange portion 68d of the brake drum 68. Behind space SP1 are the cylindrical portion 68e of the brake drum 68 and the outer circumferential surface 64a of the sprocket 64, and to the right of space SP1 is the guide bar 6. With space SP1 formed in this way, when cutting work is performed using the chainsaw 2, chips may enter space SP1 as the saw chain 8 rotates, and the chips that enter may accumulate in space SP1.

[0042] In this embodiment, the inner cover plate 70 prevents chips from entering the space SP1. As shown in Figures 10 and 11, the inner cover plate 70 is provided between the main body housing 22 and the guide bar 6.

[0043] As shown in Figure 8, the rear end 6b of the guide bar 6 has an upper rear end 6c that protrudes rearward above the vertical center of the guide bar 6, a lower rear end 6d that protrudes rearward below the vertical center of the guide bar 6, and an intermediate rear end 6e that is recessed forward between the upper rear end 6c and the lower rear end 6d. In the guide bar 6 of this embodiment, the position of the upper rear end 6c in the front-rear direction is approximately the same as the position of the lower rear end 6d in the front-rear direction.

[0044] As shown in Figures 10 and 11, in this embodiment, the inner cover plate 70 extends in the front-rear and left-right directions, and when viewed in any cross-section including the rear end 6b of the guide bar 6 (i.e., the upper rear end 6c, the lower rear end 6d, or the intermediate rear end 6e), the inner cover plate 70 is in contact with the surface of the guide bar 6 facing the main housing 22 (i.e., the left side of the guide bar 6), and the rear end 70a of the inner cover plate 70 is located behind the rear end 6b of the guide bar 6. For example, as shown in Figure 10, the inner cover plate 70 extends in the front-rear and left-right directions, and when viewed in an upper cross-section including the upper rear end 6c of the guide bar 6, the inner cover plate 70 is in contact with the left side of the guide bar 6, and the rear end 70a of the inner cover plate 70 is located behind the rear end 6b of the guide bar 6 (in this case, the upper rear end 6c). Furthermore, as shown in Figure 11, the inner cover plate 70 extends in both the front-rear and left-right directions. When viewed from the lower cross section including the lower rear end 6d of the guide bar 6, the inner cover plate 70 is in contact with the left side of the guide bar 6, and the rear end 70a of the inner cover plate 70 is located behind the rear end 6b of the guide bar 6 (in this case, the lower rear end 6d). This configuration makes it possible to suppress chips from entering the space SP1.

[0045] As shown in Figure 8, the rear end 70a of the inner cover plate 70 is located behind the rear end 6b of the guide bar 6 and in the vicinity of the sprocket 64. In this specification, "in the vicinity of the sprocket 64" means, for example, that the distance from the sprocket 64 in the radial direction of the rotation axis AX of the sprocket 64 is within 1 mm, or for example, that the distance from the sprocket 64 in the radial direction of the rotation axis AX of the sprocket 64 is within 0.5 mm.

[0046] As shown in Figure 12, a brake drum cover 98 is fixed to the right side of the main housing 22. The brake drum cover 98 is positioned below the brake cover 18. The brake drum cover 98 has a circular portion 98a that surrounds the convex portion 68b (see Figure 5) of the brake drum 68, and a protruding portion 98b provided at the front end of the circular portion 98a and projecting outward from the circular portion 98a. As shown in Figures 10 and 11, the brake drum cover 98 is positioned inside the inner cover plate 70 (i.e., to the left of the inner cover plate 70). The protruding portion 98b is in contact with the left side of the inner cover plate 70. The position of the rear end 98c of the protruding portion 98b in the longitudinal direction is approximately the same as the position of the rear end 70a of the inner cover plate 70 in the longitudinal direction.

[0047] As shown in Figure 12, the intermediate lower end 18a of the brake cover 18 is positioned between the main housing 22 and the protruding portion 98b of the brake drum cover 98. As shown in Figure 10, the brake cover 18 is positioned inside the inner cover plate 70 (i.e., to the left of the inner cover plate 70). The intermediate lower end 18a is in contact with the left side of the inner cover plate 70.

[0048] As shown in Figures 10 and 11, the rear end portion 70b of the inner cover plate 70, a part of the circular portion 98a and the protruding portion 98b of the brake drum cover 98, and the intermediate lower end portion 18a of the brake cover 18 are arranged within the space SP1. Because the space SP1 is filled by the rear end portion 70b of the inner cover plate 70, a part of the circular portion 98a and the protruding portion 98b of the brake drum cover 98, and the intermediate lower end portion 18a of the brake cover 18, it is possible to prevent chips from entering the space SP1 and / or accumulating within the space SP1. In this embodiment, the distance in the front-rear direction between the rear end portion 70b of the inner cover plate 70 and the rear end portion 98c of the protruding portion 98b of the brake drum cover 98 and the outer circumferential surface 64a of the sprocket 64 is 6 mm or less, and the distance in the left-right direction between the protruding portion 98b of the inner cover plate 70 and the brake drum cover 98 and the left side of the guide bar 6 is 3 mm or less. This effectively prevents chips from entering the space SP1 and / or accumulating within the space SP1. 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 circumferential surface 64a of the sprocket 64 may be 6 mm or less. In addition to this, or 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 side of the guide bar 6 may be 3 mm or less. Even in such a configuration, it is possible to prevent chips from entering the space SP1 and / or accumulating within the space SP1.

[0049] The circular portion 98a of the brake drum cover 98 covers the base portion 68a (i.e., the cylindrical portion 68c and the flange portion 68d) and a part of the cylindrical portion 68e of the brake drum 68. This prevents chips from accumulating near the outer 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, the chips can be easily removed by removing the brake drum cover 98 from the main housing 22.

[0050] As shown in Figure 13, 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. As shown in Figures 10 and 11, the stepped portion 20d is positioned parallel to the guide bar 6.

[0051] As shown in Figures 10 and 11, a space SP2 is formed by the support pin 74 (see Figure 5), the sprocket cover 20, the sprocket 64, and the guide bar 6. The support pin 74 is located in front of the space SP2, and the guide bar 6 is located to the left of the space SP2. The outer circumferential surface 64a of the sprocket 64 is located behind the space SP2, and the stepped portion 20d of the sprocket cover 20 is located to the right of the space SP2. With such a space SP2 formed, when cutting work is performed using the chainsaw 2, chips may enter the space SP2 as the saw chain 8 rotates, and the chips that enter may accumulate in the space SP2.

[0052] In this embodiment, the outer cover plate 72 prevents chips from entering the space SP2. As shown in Figures 10 and 11, the outer cover plate 72 is provided between the sprocket cover 20 and the guide bar 6. The outer cover plate 72 is fixed to the sprocket cover 20.

[0053] In this embodiment, the outer cover plate 72 extends in the front-rear and left-right directions, and when viewed in any cross-section including the rear end 6b of the guide bar 6, the outer cover plate 72 is in contact with the surface of the guide bar 6 facing the sprocket cover 20 (i.e., the right side of the guide bar 6), and the rear end 72a of the outer cover plate 72 is located behind the rear end 6b of the guide bar 6. For example, as shown in Figure 10, the outer cover plate 72 extends in the front-rear and left-right directions, and when viewed in an upper cross-section including the upper rear end 6c of the guide bar 6, the outer cover plate 72 is in contact with the right side of the guide bar 6, and the rear end 72a of the outer cover plate 72 is located behind the rear end 6b of the guide bar 6 (in this case, the upper rear end 6c). Furthermore, as shown in Figure 11, the outer cover plate 72 extends in the front-rear and left-right directions. When viewed from the lower cross section including the lower rear end 6d of the guide bar 6, the outer cover plate 72 is in contact with the right side of the guide bar 6, and the rear end 72a of the outer cover plate 72 is located behind the rear end 6b of the guide bar 6 (in this case, the lower rear end 6d). This configuration makes it possible to suppress chips from entering the space SP2.

[0054] As shown in Figure 7, the rear end 72a of the outer cover plate 72 is located behind the rear end 6b of the guide bar 6 and in the vicinity of the sprocket 64.

[0055] As shown in Figure 13, the sprocket cover 20 is provided with a contact rib 20f that protrudes inward from the stepped portion 20d or wall 20e and has an outer shape substantially identical to that of the outer cover plate 72. The contact rib 20f is in contact with the entire outer surface of the outer cover plate 72.

[0056] As shown in Figures 10 and 11, the rear end portion 72b of the outer cover plate 72 and the contact rib 20f of the sprocket cover 20 are positioned within the space SP2. Because the space SP2 is filled by the rear end portion 72b of the outer cover plate 72 and the contact rib 20f of the sprocket cover 20, it is possible to prevent chips from entering the space SP2 and / or accumulating 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 bar 6 is 3 mm or less. This effectively prevents chips from entering the space SP2 and / or accumulating within the space SP2. In a modified example, in addition to or instead of the outer cover plate 72, the distance in the left-right direction between the stepped portion 20d of the sprocket cover 20 and the right surface of the guide bar 6 may be 3 mm or less. In this case, the stepped portion 20d of the sprocket cover 20 may be in contact with or close to the right surface of the guide bar 6. Even with this configuration, it is possible to prevent chips from entering space SP2 and / or accumulating within space SP2.

[0057] As shown in Figure 8, when the chainsaw 2 is viewed from the right, the lower end BU of the battery pack BT is located above the center line CL1 of the guide bar 6. Here, the center line CL1 refers to the line extending in the front-rear direction from the vertical center of the guide bar 6. As shown in Figure 9, when the chainsaw 2 is viewed from the right, the distance L from the reference line RL, which is an extension of the center line CL2 at the front grip portion 24d of the top handle 24, to the lower end BU of the battery pack BT is 2.6 times or less the width W in the direction perpendicular to the center line CL2 of the front grip portion 24d of the top handle 24. Here, the center line CL2 refers to the line passing through the center of the upper and lower surfaces (excluding the projection 31) of the front grip portion 24d of the top handle 24 at the position where the projection 31 is formed on the lower surface of the front grip portion 24d of the top handle 24. The projection 31 is located behind the trigger switch 30. Therefore, in a chainsaw 2 that does not have the projection 31, the center line CL2 described above may be a line passing through the center of the upper and lower surfaces of the front grip portion 24d of the top handle 24 at a position immediately behind the trigger switch 30 provided on the lower surface of the front grip portion 24d of the top handle 24 (for example, 1 mm behind the trigger switch 30).

[0058] As shown in Figure 14, with the chainsaw 2 mounted on the mounting surface P, the vertical height H1 of the center of gravity GR of the battery pack BT from the mounting surface P is more than half of the vertical height H2 of the upper end of the top handle 24 from the mounting surface P. The upper end of the top handle 24 here refers to the position of the support portion 24a and gripping portion 24b formed by the left housing 10 and the right housing 12 that has the greatest vertical height from the mounting surface P. In other words, the trigger lock lever 32 and lock pin 34 are not considered when determining the upper end of the top handle 24.

[0059] (modified version) When the chainsaw 2 is viewed from the rear, the motor 36 does not need to overlap with the control device 42.

[0060] When the chainsaw 2 is viewed from below, the battery pack BT does not need to overlap with the control device 42.

[0061] The battery pack BT may be configured to be detachable from the main unit housing by means other than sliding, such as inserting it into a battery pack case.

[0062] Motor 36 may be an inner rotor type DC brushless motor. Alternatively, motor 36 may be a brushed motor or another type of electric motor.

[0063] The inner sprocket cover 21a and the outer sprocket cover 21b may be formed integrally.

[0064] As described above, in one or more embodiments, the chainsaw 2 comprises a saw chain 8, a guide bar 6 extending in the front-rear direction to which the saw chain 8 is attached, a sprocket 64 that causes the saw chain 8 to travel along the periphery of the guide bar 6, a motor 36 that rotates the sprocket 64 around a rotation axis AX extending in the left-right direction, a battery pack BT that supplies power to the motor 36, a main body housing 22 that houses the motor 36 and holds the guide bar 6, and a top handle 24 provided on the upper part of the main body housing 22 and gripped by the user. When the chainsaw 2 is viewed from the right, the lower end BU of the battery pack BT is located above the center line CL1 of the guide bar 6.

[0065] In the above configuration, the heavy battery pack BT is positioned relatively close to the reference line RL, which is an extension of the center line CL2 of the top handle 24, resulting in a small moment of inertia around the top handle 24.

[0066] In one or more embodiments, the chainsaw 2 includes a saw chain 8, a guide bar 6 extending in the front-rear direction to which the saw chain 8 is attached, a sprocket 64 that causes the saw chain 8 to travel along the periphery of the guide bar 6, a motor 36 that rotates the sprocket 64 around a rotation axis AX extending in the left-right direction, a battery pack BT that supplies power to the motor 36, a main body housing 22 that houses the motor 36 and holds the guide bar 6, and a top handle 24 provided on the upper part of the main body housing 22 and gripped by the user. With the chainsaw 2 mounted on a mounting surface P, the vertical height H1 of the center of gravity GR of the battery pack BT from the mounting surface P is more than half the vertical height H2 of the upper end of the top handle 24 from the mounting surface P.

[0067] In the above configuration, the heavy battery pack BT is positioned relatively close to the reference line RL, which is an extension of the center line CL2 of the top handle 24, resulting in a small moment of inertia around the top handle 24.

[0068] In one or more embodiments, the chainsaw 2 includes a saw chain 8, a guide bar 6 extending in the front-rear direction to which the saw chain 8 is attached, a sprocket 64 that causes the saw chain 8 to travel along the periphery of the guide bar 6, a motor 36 that rotates the sprocket 64 around a rotation axis AX extending in the left-right direction, a battery pack BT that supplies power to the motor 36, a main body housing 22 that houses the motor 36 and holds the guide bar 6, and a top handle 24 provided on the upper part of the main body housing 22 and gripped by the user. A trigger switch 30, operated by the user, is provided on the lower surface of the front end gripping portion 24d (an example of the front end) of the top handle 24. When the chainsaw 2 is viewed from the right, the distance L from the reference line RL, which is an extension of the center line CL2 at the front end gripping portion 24d of the top handle 24, to the lower end BU of the battery pack BT is 2.6 times or less the width W in the direction perpendicular to the center line CL2 of the front end gripping portion 24d of the top handle 24.

[0069] In the above configuration, the heavy battery pack BT is positioned relatively close to the reference line RL, which is an extension of the center line CL2 of the top handle 24, resulting in a small moment of inertia around the top handle.

[0070] In one or more embodiments, the chainsaw 2 further includes a control device 42 that controls the drive of the motor 36. In this case, when the chainsaw 2 is viewed from the rear, the motor 36 overlaps with the control device 42 at least partially.

[0071] In the above configuration, the vertical dimensions of chainsaw 2 can be reduced.

[0072] In one or more embodiments, the chainsaw 2 further includes a control device 42 that controls the drive of the motor 36. In this case, when the chainsaw 2 is viewed from below, the battery pack BT overlaps with the control device 42 at least partially.

[0073] In the above configuration, the dimensions of the chainsaw 2 in the front-to-back direction can be reduced.

[0074] In one or more embodiments, the battery pack BT is configured to be detachable from the main body housing 22 by sliding in the left-right direction.

[0075] In the above configuration, the user can attach and detach the battery pack BT to and from the main unit housing 22 by sliding it left or right. [Explanation of Symbols]

[0076] 2: Chainsaw 4: Main unit 6: Guide bar 8: Saw chain 10: Left housing 12: Right side housing 14: Side handle 16: Handguard 18: Brake cover 20: Sprocket cover 22: Housing 22: Main housing 24: Top handle 26: Power switch 28: Power lamp 30: Trigger switch 31: Protrusion 32: Trigger lock lever 34: Lock pin 36: Motor 37: Motor case 38: Oil tank 40: Oil pump 42: Control device 44: Coil 46: Status 48: Rotor 50: Cooling fan 52: Output shaft 54: Bearings 56: Bearings 58: Circuit board 60: Case 62: Potting material 64: Sprocket 66: Brake base 68: Brake drum 70: Inner cover plate 72: Outer cover plate 74: Support pin 76: Support bolt 78: Nut 80: Engaging claw 82: Engagement hole 84: Rotary-to-linear motion conversion mechanism 86: Adjustment screw 88: Linkage mechanism 90: Brake band 92: Cap 94:Introduction tube 96: Outlet pipe 97: Adjustment pin 98: Brake drum cover BT: Battery Pack

Claims

1. It's a chainsaw, Saw chain and, It extends in the front-rear direction, and the guide bar to which the saw chain is attached, A sprocket that causes the saw chain to run along the periphery of the guide bar, A motor that rotates the sprocket around a rotation axis extending in the left-right direction, A battery pack that supplies power to the motor, A main body housing that houses the motor and holds the guide bar, A top handle is provided on the upper part of the main housing and is gripped by the user, It is equipped with, A chainsaw in which, when viewed from the right, the lower end of the battery pack is located above the center line of the guide bar.

2. It's a chainsaw, Saw chain and, It extends in the front-rear direction, and the guide bar to which the saw chain is attached, A sprocket that causes the saw chain to run along the periphery of the guide bar, A motor that rotates the sprocket around a rotation axis extending in the left-right direction, A battery pack that supplies power to the motor, A main body housing that houses the motor and holds the guide bar, A top handle is provided on the upper part of the main housing and is gripped by the user, It is equipped with, A chainsaw in which, when the chainsaw is placed on a mounting surface, the vertical height of the center of gravity of the battery pack from the aforementioned mounting surface is more than half the vertical height of the upper end of the top handle from the aforementioned mounting surface.

3. It's a chainsaw, Saw chain and, It extends in the front-rear direction, and the guide bar to which the saw chain is attached, A sprocket that causes the saw chain to run along the periphery of the guide bar, A motor that rotates the sprocket around a rotation axis extending in the left-right direction, A battery pack that supplies power to the motor, A main body housing that houses the motor and holds the guide bar, A top handle is provided on the upper part of the main housing and is gripped by the user, It is equipped with, A trigger switch, operated by the user, is provided on the underside of the front end of the top handle. A chainsaw in which, when viewed from the right, the distance from the reference line extended from the center line of the front end of the top handle to the lower end of the battery pack is 2.6 times or less the width of the front end of the top handle in the direction perpendicular to the center line.

4. The system further includes a control device for controlling the drive of the motor, The chainsaw according to any one of claims 1 to 3, wherein, when viewed from the rear, the motor at least partially overlaps with the control device.

5. The system further includes a control device for controlling the drive of the motor, The chainsaw according to any one of claims 1 to 4, wherein, when viewed from below, the battery pack at least partially overlaps with the control device.

6. The chainsaw according to any one of claims 1 to 5, wherein the battery pack is configured to be detachably attached to the main body housing by sliding in the left-right direction.

Images