Work machine

Abstract

To provide a technology which enables improvement of handling performance of a work machine.SOLUTION: A work machine disclosed by the specification includes: a working unit having a longitudinal direction set in a front-back direction; an electric motor configured to drive the working unit; a control unit configured to control the electric motor; a housing including a housing body which holds the working unit at a position located rearward of the working unit and houses the electric motor and the control unit, and a grip which extends from the housing body and is configured to be grasped by a user's hand; a battery pack attached to the housing and configured to supply electric power to the electric motor via the control unit; and a trigger lever which is provided at the grip and configured to operate the electric motor by being pulled toward the grip by a finger of the user. A front end of the control unit is disposed rearward of a rear end of the trigger lever.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The technology disclosed in this specification relates to a working machine.

Background Art

[0002] In Patent Document 1, there is disclosed a housing including a working part having a longitudinal direction in the front-rear direction, an electric motor for driving the working part, a control unit for controlling the electric motor, a housing body that holds the working part behind the working part and houses the electric motor and the control unit, a grip extending from the housing body and gripped by one hand of a user, a battery pack attached to the housing and capable of supplying power to the electric motor via the control unit, and a trigger lever provided on the grip and operating the electric motor when pulled toward the grip side by a finger of the user. The front end of the control unit is disposed in front of the front end of the trigger lever.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a working machine such as that of Patent Document 1, a user may try to change the posture of the working machine while gripping the grip. At this time, if it is difficult for the user to change the posture of the working machine, the user may not be able to work comfortably. In this specification, a technology capable of improving the handling performance of a working machine is provided. In this specification, "the ease of changing the posture of the working machine for the user" may be referred to as "the handling performance of the working machine".

Means for Solving the Problems

[0005] A work machine disclosed herein comprises a housing including a work section having a longitudinal direction in the front-rear direction, an electric motor for driving the work section, a control unit for controlling the electric motor, a housing body that holds the work section at the rear of the work section and houses the electric motor and the control unit, and a grip extending from the housing body and grasped by one hand of the user, a battery pack attached to the housing and capable of supplying power to the electric motor via the control unit, and a trigger lever provided on the grip that operates the electric motor when pulled toward the grip by the user's fingers. The front end of the control unit is positioned behind the rear end of the trigger lever.

[0006] The grip that the user holds is generally located away from the workpiece (for example, at the rear of the implement) for safety reasons. Furthermore, the weight of the workpiece is generally relatively large relative to the overall implement. Therefore, in implements, heavy components (such as the workpiece) tend to be concentrated in front of the front end of the trigger lever, resulting in a large moment when the front end of the trigger lever is the pivot point. Since the area near the front end of the trigger lever is where the user places their fingers, a large moment when the front end of the trigger lever is the pivot point reduces the implement's maneuverability. In contrast, with the above configuration, the front end of the control unit, which is relatively heavy among the implement's components, is positioned behind the rear end of the trigger lever. Therefore, the weight of the control unit reduces the moment when the front end of the trigger lever is the pivot point. Consequently, the implement's maneuverability can be improved. [Brief explanation of the drawing]

[0007] [Figure 1] This is a perspective view of the chainsaw T1 according to Example 1, taken from the front left and above. [Figure 2]This is a perspective view of the chainsaw T1 according to Example 1, with the battery pack B1 removed from the battery interface 160, as seen from the rear right upper side. [Figure 3] This is a bottom view of the chainsaw T1 according to Example 1, seen from below. [Figure 4] This is a perspective view of the chainsaw T1 according to Embodiment 1, with the sprocket cover 18 removed from the housing body 14, as seen from the rear left upper. [Figure 5] This is a cross-sectional view from the left of the internal structure near the base end of the grip 16 of the chainsaw T1 according to Example 1. [Figure 6] This is a cross-sectional view of the internal structure of the housing 4 of the chainsaw T1 according to Example 1, viewed from the right. [Figure 7] This is a view of the chainsaw T1 according to Embodiment 1, showing the electric motor 64, motor shaft 80, cooling fan 82, power transmission mechanism 70, oil pump 68, sprocket 26, and working section 10, as seen from the front right and above. [Figure 8] This is a view of the inside of the housing body 14 of the chainsaw T1 according to Embodiment 1, seen from the front along a direction perpendicular to the axis A1 of the motor shaft 80. [Figure 9] This is a perspective view of the chainsaw T2 according to Example 2, with the battery pack B2 removed from the battery interface 160, as seen from the rear right upper side. [Figure 10] This is a cross-sectional view of the internal structure of the housing 4 of the chainsaw T2 according to Example 2, viewed from the right. [Figure 11] This is a perspective view of the chainsaw T3 according to Example 3, with the battery pack B3 removed from the battery interface 360, as seen from the rear right upper side. [Figure 12] This is a cross-sectional view of the internal structure of the housing 4 of the chainsaw T3 according to Example 3, viewed from the right. [Figure 13] This is a perspective view of the chainsaw T4 according to Example 4, with the battery pack B4 removed from the battery interface 360, as seen from the rear right upper side. [Figure 14] This is a cross-sectional view of the internal structure of the housing 4 of the chainsaw T4 according to Embodiment 4, viewed from the right. [Figure 15] This is a perspective view of the modified chainsaw T1, with the battery pack B1 removed from the battery interface 160, taken from the rear right upper side. [Modes for carrying out the invention]

[0008] 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 work machine.

[0009] Furthermore, the combinations of features and processes disclosed in the following detailed description are not essential for carrying out the present invention in the broadest sense, and are described solely to illustrate representative examples of the present invention. Moreover, the various features of the following representative examples, as well as the various features described in the claims, do not necessarily have to be combined in the same way as the examples described herein, or in the order listed, to provide additional and useful embodiments of the present invention.

[0010] All features described herein and / or in the claims are intended to be disclosed individually and independently of each other, as limitations to the specific matters described in the original disclosure and in the claims, separate from the features described in the examples and / or in the claims. Furthermore, all descriptions of numerical ranges and groups or clusters are intended to disclose intermediate configurations as limitations to the specific matters described in the original disclosure and in the claims.

[0011] In one or more embodiments, the center of gravity position of the electric motor may be disposed behind the rear end of the trigger lever.

[0012] The electric motor is also a component with a relatively large weight among the components of the working machine. According to the above configuration, the center of gravity position of the electric motor is disposed behind the rear end of the trigger lever. Therefore, due to the weight of the electric motor, the moment when the front end of the trigger lever is used as a fulcrum can be reduced. Accordingly, the handling performance of the working machine can be further improved.

[0013] In one or more embodiments, the front end of the electric motor may be disposed behind the front end of the trigger lever.

[0014] According to the above configuration, due to the weight of the electric motor, the moment when the front end of the trigger lever is used as a fulcrum can be further reduced. Accordingly, the handling performance of the working machine can be further improved.

[0015] In one or more embodiments, the front end of the battery pack may be disposed behind the rear end of the trigger lever.

[0016] The battery pack is also a component with a relatively large weight among the components of the working machine. According to the above configuration, the front end of the battery pack is disposed behind the rear end of the trigger lever. Therefore, due to the weight of the battery pack, the moment when the front end of the trigger lever is used as a fulcrum can be reduced. Accordingly, the handling performance of the working machine can be further improved.

[0017] In one or more embodiments, the working machine may be housed in the housing body and further include a power transmission mechanism that transmits power from the electric motor to the working portion. The rear end of the power transmission mechanism may be disposed behind the front end of the trigger lever.

[0018] In some work implements, a power transmission mechanism (including a reduction gear, etc.) is installed between the electric motor and the work unit. The power transmission mechanism is also a relatively heavy component among the work implement's parts. With the above configuration, the rear end of the power transmission mechanism is positioned behind the front end of the trigger lever. Therefore, the weight near the rear end of the power transmission mechanism can reduce the moment when the front end of the trigger lever is used as the pivot point. Consequently, the maneuverability of the work implement can be further improved.

[0019] In one or more embodiments, the control unit may include a control board for controlling the electric motor and a controller case for housing the control board. The controller case may be made of a metal material.

[0020] In some work machines, metal materials are used for the controller case to improve the cooling efficiency of the control board. Since metal materials have a relatively high specific gravity, the weight of the control unit increases when metal is used for the controller case. In other words, the position of the control unit is more likely to affect the moment when the front end of the trigger lever is the pivot point. With the above configuration, metal material is used for the controller case. Therefore, the cooling efficiency of the control board can be improved. Furthermore, with the above configuration, the effect of reducing the moment due to the arrangement of the control unit is more pronounced. Consequently, the effect of improving the handling performance of the work machine according to this invention is more pronounced.

[0021] In one or more embodiments, the electric motor may be a brushless motor. The control unit may include a switching element for switching the current supplied to the electric motor.

[0022] Generally, when an electric motor is a brushless motor, the amount of heat generated in the control unit is relatively large due to the heat generated by multiple switching elements. In this case, there is a high need to use a metal material for the controller case in order to efficiently cool the control unit. Furthermore, when a metal material is used for the controller case, the improvement in the handling performance of the work machine according to this invention is more pronounced, as described above. With the above configuration, since the electric motor is a brushless motor, there is a high possibility that a metal material will be used for the controller case. Therefore, there is a high possibility that the improvement in the handling performance of the work machine according to this invention will be more pronounced.

[0023] In one or more embodiments, the working section may include a guide bar extending in the front-rear direction and a saw chain provided on the periphery of the guide bar and traveling along the periphery of the guide bar by the drive of the electric motor. The working machine may function as a chainsaw.

[0024] The above configuration can improve the handling performance of the chainsaw.

[0025] In one or more embodiments, the work machine may further include an oil tank attached to the housing body for storing lubricating oil for lubricating the saw chain. The oil tank may be located near the front end of the housing body.

[0026] In a chainsaw, lubricating oil stored in an oil tank must be supplied to the saw chain (or guide bar) to lubricate it. If the oil tank and the saw chain (or guide bar) are far apart, the supply path for the lubricating oil from the oil tank to the saw chain (or guide bar) becomes longer, which can lead to a larger size of the implement. In contrast, with the above configuration, the oil tank is located near the front end of the housing body, that is, near the saw chain (or guide bar). Therefore, the supply path for the lubricating oil can be shortened, and the implement can be made smaller.

[0027] In one or more embodiments, the electric motor may include a stator and a rotor. The work machine may further include a motor shaft fixed to the rotor. The axis of the motor shaft may be located on a plane extending in the front-rear, up-down, and rear directions. The control unit may be located on the axis of the motor shaft.

[0028] With the above configuration, the distance between the control unit and the electric motor can be reduced. Therefore, the distance of the electrical connections between the control unit and the electric motor can be reduced. Consequently, the work machine can be made smaller.

[0029] In one or more embodiments, the distance from the axis to the front end of the control unit may be smaller than the distance from the axis to the rear end of the control unit.

[0030] Generally, electric motors have a substantially axially symmetric shape along the axis of the motor shaft. With the above configuration, the center position of the control unit in the front-rear direction can be offset rearward along the radial direction of the axis. This allows the center position of the control unit to be offset rearward relative to the center position of the electric motor in the radial direction of the axis. With this configuration, it becomes easier to position the conductors that electrically connect the control unit and the electric motor behind the electric motor. The conductors positioned behind the electric motor are positioned behind the rear end of the trigger lever. In this case, the weight of the conductors can reduce the moment when the front end of the trigger lever is the pivot point. Therefore, the handling performance of the work machine can be further improved.

[0031] In one or more embodiments, when the inside of the housing body is viewed from the front along a direction perpendicular to the axis of the motor shaft, the control unit, the electric motor, and the oil tank may be arranged in substantially a straight line.

[0032] With the above configuration, the housing body can be made smaller in the radial direction of the axis. In other words, the work implement can be made smaller in the radial direction of the axis.

[0033] (Example 1) As shown in Figure 1, the implement used in this embodiment is a chainsaw T1. The chainsaw T1 is a so-called pruning chainsaw, mainly used for cutting wood and tree branches. The chainsaw T1 is relatively lightweight, weighing at most about 2000g. This makes it possible to carry the chainsaw T1 with one hand.

[0034] The chainsaw T1 comprises a housing 4, a guide bar 6, a saw chain 8, a handguard 20, and a battery pack B1. The guide bar 6 is an elongated, plate-shaped member attached to the housing 4 so as to protrude forward from the housing 4. The guide bar 6 is made of a metal material such as iron. The saw chain 8 has multiple interconnected cutters (not shown) and is attached along the periphery of the guide bar 6. A roughly rectangular battery pack B1 is attached to the housing 4. The chainsaw T1 uses power supplied from the battery pack B1 to move the saw chain 8 along the periphery of the guide bar 6.

[0035] Various guide bars 6 can be attached depending on the type of cutting work. The radius of curvature of the tip of the guide bar 6 is, for example, 15 mm. In this embodiment, the chainsaw T1 moves the saw chain 8 along the periphery of the guide bar 6 at a speed of, for example, 8 m / s. In this specification, the guide bar 6 and the saw chain 8 are sometimes collectively referred to as the "working section 10". In this embodiment, the weight of the working section 10 is, for example, about 180 g. The housing 4 is also provided with a working cover 12 that covers a part of the working section 10. Therefore, the user performs the cutting work by pressing the part of the working section 10 that is not covered by the working cover 12 against the object to be cut (for example, a tree branch). At this time, it is assumed that the load that the user applies to the chainsaw T1 is at most about 20 N.

[0036] In the following explanation, along the longitudinal direction of the guide bar 6, the direction from the housing 4 toward the guide bar 6 is defined as the forward direction, and the direction from the guide bar 6 toward the housing 4 is defined as the rearward direction. Furthermore, the direction perpendicular to the front-rear direction, from the work section 10 toward the work cover 12, is defined as the upward direction, and the direction toward the work cover 12 toward the work section 10 is defined as the downward direction. Finally, the direction perpendicular to both the front-rear and up-down directions is defined as the left-right direction. Note that in Figures 1 to 15, for the sake of simplicity, the saw chain 8 is shown as a ring-shaped member flush with the guide bar 6.

[0037] The housing 4 comprises a housing body 14, a grip 16, a first mounting portion 22, and a second mounting portion 24. The housing body 14 has a substantially rectangular parallelepiped shape, inclined from bottom to top as it moves from front to rear in the front-rear direction. The housing body 14 holds the work section 10 together with the sprocket cover 18 at the front. The grip 16 is connected to the front lower part of the housing body 14. The grip 16 has a substantially cylindrical shape, inclined from top to bottom as it moves from front to rear in the front-rear direction. The first mounting portion 22 is provided projecting downward from the housing 4 and is located near the base end of the grip 16. The second mounting portion 24 is provided projecting downward from the housing 4 and is located near the tip of the grip 16. The handguard 20 is attached to the first mounting portion 22 and the second mounting portion 24. The housing 4 (housing body 14, grip 16, first mounting portion 22, and second mounting portion 24) is made of a material with a Young's modulus greater than 100 MPa. In this embodiment, the housing 4 is made of a plastic material such as polyamide. The Young's modulus of polyamide may vary depending on the surrounding environment, but it can be said to be greater than at least 5000 MPa. The parts where the user's fingers are placed (the head 14a of the housing body 14 and the area around the grip 16) are coated with a rubber material such as nitrile butadiene rubber.

[0038] The battery pack B1 houses a rechargeable secondary battery, such as a lithium-ion battery. The output voltage of the battery pack B1 is, for example, 10V. The battery capacity of the battery pack B1 is, for example, 1.5Ah. The weight of the battery pack B1 is, for example, approximately 215g. As shown in Figure 3, a display unit 166 is provided on the bottom surface of the battery pack B1. The display unit 166 informs the user of the remaining battery level of the battery pack B1 by changing the display according to the remaining battery level of the battery pack B1.

[0039] As shown in Figure 2, the tip of the grip 16 is provided with a battery interface 160 for detachably receiving the battery pack B1. The battery pack B1 is attached to the battery interface 160 by sliding it from the rear upper to the front lower. The battery interface 160 also has a connection terminal 162 for connecting to the terminals (not shown) of the battery pack B1. The connection terminal 162 is electrically connected to the control unit 62 (see Figure 6) and the trigger switch 52 (see Figure 6), which will be described later. When the battery pack B1 is attached to the battery interface 160, the terminals of the battery pack B1 and the connection terminal 162 are electrically connected. This allows power to be supplied from the battery pack B1 to the control unit 62 and the trigger switch 52.

[0040] As shown in Figure 1, when the battery pack B1 is attached to the battery interface 160, the outer surfaces of the battery pack B1 and the grip 16 are smoothly connected. The battery pack B1 can be removed by pressing in the hook 164 provided on the battery pack B1 and sliding it from the front-down to the rear-up relative to the battery interface 160.

[0041] As shown in Figure 4, the sprocket cover 18 comprises a sprocket cover body 36 and a locking member 42. The sprocket cover body 36 includes a sleeve 38. The locking member 42 includes a locking member body 44, a nut 46, and a claw portion 48. Inside the sprocket cover 18, the sprocket 26 is exposed to the outside of the housing body 14. A saw chain 8 is stretched across the sprocket 26 from the guide bar 6. The guide bar 6 also has a notch 6a that extends along the front-rear direction. Pins 28, 30 and bolts 32, which are fixed protruding from the left side of the housing body 14, are inserted into the notch 6a from the right side.

[0042] From the state shown in Figure 4, the sprocket cover 18 can be attached to the housing body 14 by inserting a bolt 32 into the sleeve 38 of the sprocket cover body 36 and fastening a nut 46 of the locking member 42 to the bolt 32 that passes through the sleeve 38. With the nut 46 fastened to the bolt 32, the guide bar 6 is sandwiched and fixed between the housing body 14 and the sprocket cover 18. The user can adjust the tension of the saw chain 8 by changing the distance between the guide bar 6 and the sprocket 26 by sliding the guide bar 6 in the front-back direction relative to the housing body 14 with the bolt 32 and nut 46 loosened.

[0043] The user can tighten or loosen the bolt 32 and nut 46 by rotating the claw portion 48, which is positioned to the left of the locking member body 44, around the axis of the bolt 32. This allows the user to fasten the nut 46 to the bolt 32 with sufficient tightening torque without using any special tools. As shown in Figure 1, the claw portion 48 is normally held in a reclined position along the locking member body 44 by a torsion spring (not shown).

[0044] As shown in Figure 2, a trigger lever 50 for the user to drive the workpiece 10 is located on the lower surface near the base end of the grip 16. As shown in Figure 5, the trigger lever 50 is supported by the housing 4 so as to be rotatable around a pivot axis 50a that extends in the left-right direction. The user can pull up the trigger lever 50 toward the grip 16. In this specification, the front end of the portion of the trigger lever 50 that is exposed to the outside of the grip 16 is simply referred to as the "front end 50f". The rear end of the portion of the trigger lever 50 that is exposed to the outside of the grip 16 is simply referred to as the "rear end 50r".

[0045] Inside the housing 4 is a trigger switch 52 that detects the user's operation of pulling up the trigger lever 50. The trigger switch 52 is located directly above the trigger lever 50 and straddles the space between the grip 16 and the housing body 14. The trigger switch 52 is electrically connected to a control unit 62 (see Figure 6), which will be described later. The trigger switch 52 outputs a trigger-on signal to the control unit 62 while the trigger lever 50 is being pulled up. The housing 4 also contains a locking member 54 that switches between a state that allows and prohibits the user from operating the trigger lever 50. The locking member 54 is located directly above the trigger lever 50 and in front of the trigger switch 52. The locking member 54 is supported by the housing 4 so as to be rotatable around a pivot axis 54a that extends in the left-right direction.

[0046] When the locking member 54 is rotated upward, it mechanically interferes with the trigger lever 50, preventing the trigger lever 50 from rotating upward. When the locking member 54 is rotated downward, it no longer interferes with the trigger lever 50, allowing the trigger lever 50 to rotate upward.

[0047] As shown in Figure 1, the locking member 54 includes a left-side locking lever 58a that protrudes to the outside of the housing 4 through a through-hole 56a provided on the left side of the housing 4. As shown in Figure 2, the locking member 54 also includes a right-side locking lever 58b that protrudes to the outside of the housing 4 through a through-hole 56b provided on the right side of the housing 4. Hereinafter, the left-side locking lever 58a and the right-side locking lever 58b will be collectively referred to as "locking lever 58". The user can rotate the locking member 54 via the locking lever 58.

[0048] The trigger lever 50 and the locking member 54 are connected to each other by a torsion spring 60 (see Figure 5). The torsion spring 60 biases the trigger lever 50 to rotate downward and the locking member 54 to rotate upward. Therefore, when the user releases their hand from the trigger lever 50, the trigger lever 50 is rotated downward due to the biasing force of the torsion spring 60. Also, when the user releases their hand from the locking lever 58, the locking member 54 is rotated upward due to the biasing force of the torsion spring 60.

[0049] For example, when using the chainsaw T1, the user holds the chainsaw T1 by gripping the grip 16 with their right hand and resting their left hand on the head 14a. From this position, when the user pushes down the lock lever 58 with their right thumb, the user is allowed to operate the trigger lever 50. In this state, the user pulls up the trigger lever 50 with their right index finger, which drives the work unit 10.

[0050] (Handguard 20 configuration) The handguard 20 shown in Figure 1 is a protective device for protecting the user's hand when gripping the grip 16. If the saw chain 8 breaks while the user is performing a cutting operation (while the work unit 10 is running), the broken saw chain 8 may fly out from the guide bar 6 while maintaining its momentum. In such a case, the handguard 20 can prevent the saw chain 8 that has flown out from the guide bar 6 from coming into contact with the user's hand gripping the grip 16 (see Figure 1). For example, the handguard 20 is made of a material with a Young's modulus in the range of 1 MPa to 100 MPa. In this embodiment, the handguard 20 is made of a rubber material such as nitrile butadiene rubber. The Young's modulus of nitrile butadiene rubber may vary depending on the surrounding environment, but it can be said to be in the range of 1 MPa to 10 MPa.

[0051] The handguard 20 comprises a first end 202, a second end 204, and a guard body 206 that extends continuously between the first end 202 and the second end 204. The first end 202 is attached to a first mounting portion 22 so as to be rotatable around a pivot axis 22a extending in the left-right direction. By being attached to the first mounting portion 22, the first end 202 is positioned near the base end of the grip 16. The second end 204 is attached to a second mounting portion 24 so as to be rotatable around a pivot axis 24a (see Figure 2) extending in the left-right direction. By being attached to the second mounting portion 24, the second end 204 is positioned near the tip of the grip 16.

[0052] The guard body 206 comprises a plate portion 208 formed in a plate shape and a plurality of rib portions 210 (see Figure 3) protruding downward from the lower surface of the plate portion 208. The plate portion 208 is positioned so that its upper surface faces the grip 16. In this embodiment, the thickness of the plate portion 208 (thickness in the direction perpendicular to the upper and lower surfaces of the plate portion 208) is, for example, about 5 mm.

[0053] As shown in Figure 3, when the chainsaw T1 is viewed from below, the plate portion 208 has a roughly rectangular shape. The plate portion 208 has a width of approximately 29 mm to the left of the left side of the guide bar 6. The plate portion 208 has a width of approximately 30 mm to the right of the right side of the guide bar 6. The plate portion 208 also has a width of approximately 30 mm to the left of the left side of the grip 16 (see Figure 1). The plate portion 208 has a width of approximately 0.5 mm to the right of the right side of the grip 16.

[0054] The multiple rib sections 210 include a first rib section 212 extending in the front-rear direction along the lower surface of the plate section 208, a second rib section 214 extending in the left-right direction along the lower surface of the plate section 208, and a third rib section 216 extending along the peripheral edge of the lower surface of the plate section 208. There are four first rib sections 212 arranged in the left-right direction. When the chainsaw T1 is viewed from below, each of the first rib sections 212 extends in a substantially straight line between the first end 202 and the second end 204. There are also three second rib sections 214 arranged in the front-rear direction. The first rib sections 212 and the second rib sections 214 are connected at mutually perpendicular points. The second rib sections 214 are connected to the third rib section 216 at their left and right ends.

[0055] As shown in Figure 6, the plate portion 208 is composed of a first extension portion 220 that extends away from the grip 16 as it moves from the base end towards the tip end, a second extension portion 222 that extends away from the grip 16 as it moves from the tip end towards the base end, and a bent portion 224 that connects the first extension portion 220 and the second extension portion 222. The length of the first extension portion 220 in the extension direction is shorter than the length of the second extension portion 222 in the extension direction. The bending angle of the bent portion 224 is, for example, 100°. The radius of curvature of the bent portion 224 is, for example, 18 mm. As a result, in its natural state (when no external force is applied to the handguard 20), the handguard 20 has a shape that protrudes outward when viewed from the grip 16.

[0056] In the handguard 20 configured as described above, the handguard 20 is more elastically deformable than the housing 4. The handguard 20 is configured to begin to deform when a predetermined load of 5N or less is applied, for example, from a direction opposite to the lower surface of the plate portion 208. Here, "beginning to deform" means that the elastic strain of the handguard 20 exceeds 1%. Therefore, the user can deform the handguard 20 with a relatively small load.

[0057] (Internal structure of the T1 chainsaw) As shown in Figure 6, the housing body 14 contains a control unit 62, an electric motor 64, an oil tank 66, an oil pump 68, a reduction gear 72, and a cooling fan 82.

[0058] As shown in Figure 7, the electric motor 64 is an inner-rotor type DC brushless motor. The electric motor 64 comprises a stator 76 around which a coil 74 is wound, and a rotor 78 located inside the stator 76 and equipped with permanent magnets (not shown). In this embodiment, the weight of the electric motor 64 (coil 74, stator 76, and rotor 78) is, for example, approximately 180g. A motor shaft 80 is fixed to the rotor 78, positioned to pass through the center of both the stator 76 and the rotor 78. Therefore, the electric motor 64 is configured to rotate the motor shaft 80.

[0059] The cooling fan 82 is fixed to the motor shaft 80 below the rotor 78. The cooling fan 82 rotates in conjunction with the rotation of the motor shaft 80. When the cooling fan 82 rotates, an airflow is formed that moves from bottom to top along the axis A1 of the motor shaft 80 (see Figure 6). At this time, air is drawn in from the outside to the inside of the housing 4 through the left intake port 140 (see Figure 1) and the right intake port 142 (see Figure 2). Also, air is discharged from the inside to the outside of the housing 4 through the left exhaust port 144 (see Figure 1) and the right exhaust port 146 (see Figure 2). As a result, the cooling fan 82 can cool the electric motor 64 in conjunction with the driving of the electric motor 64.

[0060] The reduction gear 72 includes a first bevel gear 72a fixed to the motor shaft 80 below the cooling fan 82, and a second bevel gear 72b that meshes with the first bevel gear 72a. The second bevel gear 72b is fixed to the drive shaft 84. The drive shaft 84 is supported by the housing 4 (see Figure 1) so as to be rotatable around a rotation axis that extends in the left-right direction. A sprocket 26 is fixed to the drive shaft 84 to the left of the second bevel gear 72b. Therefore, when the electric motor 64 is driven, the rotational motion of the motor shaft 80 is transmitted to the saw chain 8 via the reduction gear 72, the drive shaft 84, and the sprocket 26. This causes the saw chain 8 to rotate around the sprocket 26 and the guide bar 6.

[0061] The oil tank 66 shown in Figure 6 is a tank for storing lubricating oil to lubricate the saw chain 8. The oil tank 66 can store a maximum of approximately 50cc of lubricating oil. The oil tank 66 is provided with an oil filler port (not shown) for replenishing the oil. A cap 660 is detachably attached to the oil filler port. The oil tank 66 is located near the front end of the housing body 14. As shown in Figure 2, the cap 660 and oil filler port of the oil tank 66 are exposed to the outside of the housing body 14. Therefore, the user can replenish the oil tank 66 by removing the cap 660 from the oil filler port without disassembling the housing body 14.

[0062] As shown in Figure 7, a worm gear 84a is fixed to the drive shaft 84 to the right of the second bevel gear 72b. The worm gear 84a meshes with the worm wheel 68a of the oil pump 68. Therefore, when the electric motor 64 is driven, the rotational motion of the motor shaft 80 is transmitted to the oil pump 68 via the reduction gear 72, drive shaft 84, worm gear 84a, and worm wheel 68a. This drives the oil pump 68. When the oil pump 68 is driven, lubricating oil is drawn into the oil supply passage 682 via the suction section 680 located inside the oil tank 66 (see Figure 6). Then, lubricating oil is supplied from the oil supply passage 682 to the guide bar 6 and saw chain 8 via the discharge section 684.

[0063] In this specification, the mechanism consisting of the reduction gear 72, the drive shaft 84, and the worm gear 84a may be referred to as the "power transmission mechanism 70". As shown in Figure 6, the power transmission mechanism 70 is located in the central part of the housing body 14. The power transmission mechanism 70 is located in front of and below the electric motor 64. The power transmission mechanism 70 is located behind the oil tank 66. In this embodiment, the weight of the power transmission mechanism 70 is, for example, approximately 110 g.

[0064] The control unit 62 is located directly below the top 14a of the housing body 14. The control unit 62 is located above and behind the electric motor 64. Below the control unit 62 and behind the electric motor 64, a wiring space S is formed. Although not shown, most of the conductors that electrically connect the various components such as the control unit 62 and the electric motor 64 are routed through the wiring space S.

[0065] The control unit 62 includes a control board (not shown) equipped with an inverter circuit having multiple switching elements and a control circuit that controls the operation of each switching element, and a roughly rectangular controller case 620 that houses the control board. The controller case 620 is made of a metal material such as aluminum. In this embodiment, the weight of the control unit 62 is, for example, about 60g.

[0066] The control unit 62 converts the DC power supplied from the battery pack B1 into three-phase AC power and supplies it to the electric motor 64 while the trigger switch 52 outputs a trigger-on signal. When the trigger switch 52 stops outputting a trigger-on signal, the control unit 62 cuts off the power supply from the battery pack B1 to the electric motor 64. The control unit 62 also controls the drive of the electric motor 64 so that the saw chain 8 travels in a predetermined direction. The predetermined direction of travel is such that the saw chain 8 travels forward when above the guide bar 6 and backward when below the guide bar 6.

[0067] (Positional relationship of main components with respect to axis A1) The axis A1 of the motor shaft 80 (see Figure 7) is located on a plane that extends in the front-rear and up-down directions. The axis A1 is inclined in the up-down direction, from rear to front as it moves from top to bottom. In this embodiment, the inclination angle of the axis A1 with respect to the up-down direction is 41°. The control unit 62 is located on axis A1. The control unit 62 (controller case 620) is located along a plane that is approximately perpendicular to axis A1. The distance from axis A1 to the front end 62f of the control unit 62 (coinciding with the front end of the controller case 620) is smaller than the distance from axis A1 to the rear end 62r of the control unit 62 (coinciding with the rear end of the controller case 620). In addition, the drive shaft 84 of the power transmission mechanism 70 is located approximately perpendicular to axis A1.

[0068] As shown in Figure 8, when viewing the inside of the housing body 14 (see Figure 1) from the front along a direction perpendicular to axis A1, the control unit 62, electric motor 64, cooling fan 82, power transmission mechanism 70 and sprocket 26, and oil tank 66 are arranged in approximately a straight line from top to bottom. When viewed from the front along a direction perpendicular to axis A1, the center of gravity 62G of the control unit 62, the center of gravity 64G of the electric motor 64, and the center of gravity 82G of the cooling fan 82 are all located on axis A1.

[0069] When viewed from the front along a direction perpendicular to axis A1, the control unit 62, the electric motor 64, and the cooling fan 82 each have a shape that is approximately symmetrical (approximately symmetrical with respect to axis A1). Although not shown, the grip 16 (see Figure 1) and the battery pack B1 (see Figure 1) also have a shape that is approximately symmetrical (approximately symmetrical with respect to axis A1). The sprocket 26 is positioned to the left of axis A1. The oil tank 66, oil pump 68, second bevel gear 72b, and worm gear 84a are positioned to the right of axis A1.

[0070] (Positional relationship of main components with respect to the trigger lever 50) Figure 6 illustrates a straight line A2 that passes through the front end 50f of the trigger lever 50 and extends vertically, and a straight line A3 that passes through the rear end 50r of the trigger lever 50 and extends vertically.

[0071] The front end 62f of the control unit 62 is located behind the rear end 50r of the trigger lever 50. The front end 64f of the electric motor 64 is located behind the front end 50f of the trigger lever 50 and in front of the rear end 50r of the trigger lever 50. The rear end 70r of the power transmission mechanism 70 (coinciding with the rear end of the first bevel gear 72a) is located behind the front end 50f of the trigger lever 50 and in front of the rear end 50r of the trigger lever 50. The front end B1f of the battery pack B1 is located behind the rear end 50r of the trigger lever 50. Also, the center of gravity position 62G of the control unit 62 is located behind the rear end 50r of the trigger lever 50. The center of gravity position 64G of the electric motor 64 is located behind the rear end 50r of the trigger lever 50. The center of gravity position 82G of the cooling fan 82 is located behind the front end 50f of the trigger lever 50 and in front of the rear end 50r of the trigger lever 50. The center of gravity BG1 of the battery pack B1 is located behind the rear end 50r of the trigger lever 50.

[0072] In the chainsaw T1 configured as described above, the center of gravity TG1 of the chainsaw T1 is located inside the housing 4, between straight lines A2 and A3. It can also be said that the center of gravity TG1 is located in a position that coincides with the locking member 54. Furthermore, the distance from straight line A2 to the center of gravity TG1 and the distance from straight line A3 to the center of gravity TG1 are approximately the same. In this embodiment, the center of gravity TG1 is determined with the oil tank 66 full of lubricating oil, the battery pack B1 attached to the battery interface 160, and all other components attached.

[0073] (Example 2) As shown in Figure 9, the implement in this embodiment is a chainsaw T2. The chainsaw T2 has a configuration that is substantially the same as the chainsaw T1 of Embodiment 1, except that it is equipped with a battery pack B2 instead of a battery pack B1. Below, only the differences between the chainsaw T2 and the chainsaw T1 will be described.

[0074] Battery pack B2 houses a rechargeable secondary battery, such as a lithium-ion battery. The output voltage of battery pack B2 is, for example, 10V. The battery capacity of battery pack B2 is, for example, 4.0Ah. The weight of battery pack B2 is, for example, approximately 375g. Battery pack B2 is detachably attached to the battery interface 160, similar to battery pack B1.

[0075] Compared to battery pack B1 (see Figure 2), battery pack B2 has a larger width in the direction in which the grip 16 extends. The width of battery pack B2 in the left-right direction is about the same as that of battery pack B1. The width of battery pack B2 in the direction perpendicular to the direction in which the grip 16 extends and the left-right direction is about the same as that of battery pack B1. As a result, the volume of battery pack B2 is larger than that of battery pack B1.

[0076] As shown in Figure 10, the front end B2f and center of gravity BG2 of the battery pack B2 are located behind the rear end 50r of the trigger lever 50. Furthermore, the center of gravity TG2 of the chainsaw T2 is located inside the housing 4, between straight lines A2 and A3. It can also be said that the center of gravity TG2 is located near the front end of the trigger switch 52. Additionally, the distance from straight line A2 to the center of gravity TG2 is greater than the distance from straight line A3 to the center of gravity TG2.

[0077] (Example 3) As shown in Figure 11, the implement in this embodiment is a chainsaw T3. The chainsaw T3 has a configuration that is substantially the same as the chainsaw T1 of Embodiment 1, except that it is equipped with a battery pack B3 instead of battery pack B1 and a battery interface 360 ​​instead of battery interface 160. Below, only the differences between the chainsaw T3 and the chainsaw T1 will be described.

[0078] Battery pack B3 houses a rechargeable secondary battery, such as a lithium-ion battery. The output voltage of battery pack B3 is, for example, 18V. The battery capacity of battery pack B3 is, for example, 2.0Ah. The weight of battery pack B3 is, for example, approximately 375g. The width of the grip 16 of battery pack B3 in the extending direction is about the same as that of battery pack B1 (see Figure 2). Compared to battery pack B1, battery pack B3 is wider in the left-right direction. Compared to battery pack B1, battery pack B3 is wider in the direction perpendicular to the extending direction and the left-right direction of the grip 16. As a result, the volume of battery pack B3 is larger than that of battery pack B1.

[0079] The battery pack B3 is mounted to the battery interface 360 ​​by sliding it from the rear upper to the front lower. The battery interface 360 ​​also has a connection terminal 362 for connecting to the terminals (not shown) of the battery pack B3. The connection terminal 362 is electrically connected to the control unit 62 (see Figure 12) and the trigger switch 52 (see Figure 12). When the battery pack B3 is mounted to the battery interface 360, the terminals of the battery pack B3 and the connection terminal 362 are electrically connected. This allows power to be supplied from the battery pack B3 to the control unit 62 and the trigger switch 52.

[0080] As shown in Figure 12, when the battery pack B3 is attached to the battery interface 360, the outer surface of the battery pack B3 and the grip 16 are smoothly connected. The battery pack B3 can be removed by pressing in the hook 364 (see Figure 11) provided on the battery pack B3 and sliding it from the front-down to the rear-up relative to the battery interface 360.

[0081] The front end B3f and center of gravity BG3 of the battery pack B3 are located behind the rear end 50r of the trigger lever 50. The center of gravity TG3 of the chainsaw T3 is located inside the housing 4, between straight lines A2 and A3. It can also be said that the center of gravity TG3 is located near the front end of the trigger switch 52. Furthermore, the distance from straight line A2 to the center of gravity TG3 is greater than the distance from straight line A3 to the center of gravity TG3. Note that the center of gravity TG3 of the chainsaw T3 is in approximately the same position as the center of gravity TG2 of the chainsaw T2 in Embodiment 2.

[0082] (Example 4) As shown in Figure 13, the implement in this embodiment is a chainsaw T4. The chainsaw T4 has a configuration that is substantially the same as the chainsaw T3 of Embodiment 3, except that it is equipped with a battery pack B4 instead of battery pack B3. Below, only the differences between the chainsaw T4 and the chainsaw T3 will be described.

[0083] Battery pack B4 houses a rechargeable secondary battery, such as a lithium-ion battery. The voltage of battery pack B4 is, for example, 18V. The battery capacity of battery pack B4 is, for example, 6.0Ah. The weight of battery pack B4 is, for example, approximately 670g. Battery pack B4 is detachably attached to the battery interface 360, similar to battery pack B3.

[0084] Compared to battery pack B3 (see Figure 11), battery pack B4 has a larger width in the direction in which the grip 16 extends. The width of battery pack B4 in the left-right direction is about the same as that of battery pack B3. The width of battery pack B4 in the direction perpendicular to the direction in which the grip 16 extends and the left-right direction is about the same as that of battery pack B3. As a result, the volume of battery pack B4 is larger than that of battery pack B3.

[0085] As shown in Figure 14, the front end B4f and center of gravity BG4 of the battery pack B4 are located behind the rear end 50r of the trigger lever 50. Furthermore, the center of gravity TG4 of the chainsaw T4 is located inside the housing 4, and behind the straight line A3. The center of gravity TG3 can also be said to be located near the rear end of the trigger switch 52.

[0086] In the following, the Chainsaw T1, Chainsaw T2, Chainsaw T3, and Chainsaw T4 will sometimes be collectively referred to as "Chainsaw T".

[0087] (modified version) In the above embodiment, the working machine was described as a chainsaw T having a guide bar 6 and a saw chain 8 as the working section 10. In another embodiment, the working machine may be a reciprocating saw having a saw blade as the working section 10. In the case where the working machine is a reciprocating saw, the working machine does not need to have an oil tank 66 and an oil pump 68.

[0088] In the above embodiment, a configuration in which the electric motor 64 is an inner rotor type DC brushless motor was described. In another embodiment, the electric motor 64 may be an outer rotor type DC brushless motor. Alternatively, the electric motor 64 may be a brushed motor or another type of electric motor.

[0089] In the above embodiment, a configuration was described in which a plastic material such as polyamide is used for the housing 4. In another embodiment, a plastic material other than polyamide (e.g., polycarbonate) may be used for the housing 4, as long as the material has a Young's modulus greater than 100 MPa. In yet another embodiment, a material other than a plastic material (e.g., a metallic material such as aluminum) may be used for the housing 4, as long as the material has a Young's modulus greater than 100 MPa.

[0090] In the above embodiment, a configuration was described in which a rubber material such as nitrile butadiene rubber was used for the handguard 20. In another embodiment, a rubber material other than nitrile butadiene rubber (for example, ethylene propylene rubber) may be used for the handguard 20, as long as the Young's modulus is in the range of 1 MPa to 100 MPa.

[0091] In the above embodiment, at least one of the first end 202 and the second end 204 of the handguard 20 may be non-rotatably attached to at least one of the corresponding first mounting portion 22 and second mounting portion 24.

[0092] In the above embodiment, the multiple rib portions 210 of the handguard 20 do not necessarily have to include at least one of the first rib portion 212, the second rib portion 214, and the third rib portion 216.

[0093] In the above embodiment, a configuration was described in which the handguard 20 is formed from a material with a relatively low Young's modulus (rubber material), making it more elastically deformable than the housing 4. In another embodiment, the handguard 20 may be configured to swing relative to the housing 4, like a so-called swing door. In this case, when the handguard 20 is in contact with an obstacle and a load is applied to it, the handguard 20 deforms from a closed state to an open state. In yet another embodiment, the handguard 20 may be configured to be translationally movable between a first position and a second position relative to the housing 4. In this case, when the handguard 20 is in contact with an obstacle and a load is applied to it, the handguard 20 translates between the first and second positions, changing the position of the handguard 20 relative to the housing 4. When the handguard 20 is deformed by a method other than elastic deformation, a material other than rubber (for example, a plastic material such as polyamide) may be used for the handguard 20, or a material with a Young's modulus greater than 100 MPa may be used.

[0094] In the above embodiment, the chainsaw T (example of work implement) does not necessarily have a power transmission mechanism 70. In this case, for example, the sprocket 26 may have multiple teeth formed on it, and the multiple teeth of the sprocket 26 may mesh with the first bevel gear 72a fixed to the motor shaft 80. Also, the worm wheel 68a of the oil pump 68 may mesh with the first bevel gear 72a fixed to the motor shaft 80.

[0095] In the above embodiment, a configuration was described in which a metal material such as aluminum is used for the controller case 620. In another embodiment, a metal material other than aluminum (for example, iron) may be used for the controller case 620. In yet another embodiment, a material other than a metal material (for example, a plastic material such as polyamide) may be used for the controller case 620.

[0096] As shown in Figure 15, the chainsaw T1 (an example of a workpiece) may be equipped with an exhaust port 544 instead of the exhaust ports 144 and 146 in the above embodiment. The exhaust port 544 is provided on the top 14a of the housing body 14. In this case, when the cooling fan 82 rotates, air is discharged from the inside of the housing 4 to the outside through the exhaust port 544 instead of the exhaust ports 144 and 146. In this case as well, the cooling fan 82 can cool the electric motor 64 in conjunction with the driving of the electric motor 64. Note that the above configuration may also be applied to chainsaws T2, T3, and T4.

[0097] (Correspondence) As described above, in one or more embodiments, the chainsaw T (an example of a workpiece) comprises a housing 4 including a workpiece 10 having a longitudinal direction in the front-rear direction, an electric motor 64 for driving the workpiece 10, a control unit 62 for controlling the electric motor 64, a housing body 14 that holds the workpiece 10 at the rear of the workpiece 10 and houses the electric motor 64 and the control unit 62, and a grip 16 extending from the housing body 14 and grasped by one hand of the user, a battery pack B1 (or battery packs B2, B3, B4) attached to the housing 4 and capable of supplying power to the electric motor 64 via the control unit 62, and a trigger lever 50 provided on the grip 16 that operates the electric motor 64 when pulled toward the grip 16 by the user's fingers. The front end 62f of the control unit 62 is positioned behind the rear end 50r of the trigger lever 50.

[0098] The grip 16 held by the user is generally positioned away from the work section 10 (for example, at the rear of the chainsaw T) for user safety reasons. Furthermore, the weight of the work section 10 is generally relatively large relative to the overall weight of the chainsaw T. Therefore, in the chainsaw T, heavy objects (such as the work section 10) tend to be concentrated in front of the front end 50f of the trigger lever 50, resulting in a large moment when the front end 50f of the trigger lever 50 is the pivot point. Since the area near the front end 50f of the trigger lever 50 is the part held by the user, a large moment when the front end 50f of the trigger lever 50 is the pivot point reduces the maneuverability of the chainsaw T. In contrast, with the above configuration, the front end 62f of the control unit 62, which is relatively heavy among the components of the chainsaw T, is positioned behind the rear end 50r of the trigger lever 50. Therefore, the weight of the control unit 62 reduces the moment when the front end 50f of the trigger lever 50 is the pivot point. Therefore, the handling performance of the chainsaw T can be improved.

[0099] In one or more embodiments, the center of gravity position 64G of the electric motor 64 is located behind the rear end 50r of the trigger lever 50.

[0100] The electric motor 64 is also a relatively heavy component among the chainsaw T's parts. According to the above configuration, the center of gravity 64G of the electric motor 64 is positioned behind the rear end 50r of the trigger lever 50. Therefore, the weight of the electric motor 64 reduces the moment when the front end 50f of the trigger lever 50 is used as the pivot point. Consequently, the handling performance of the chainsaw T can be further improved.

[0101] In one or more embodiments, the front end 64f of the electric motor 64 is positioned behind the front end 50f of the trigger lever 50.

[0102] With the above configuration, the weight of the electric motor 64 can further reduce the moment when the front end 50f of the trigger lever 50 is used as the pivot point. Therefore, the handling performance of the chainsaw T can be further improved.

[0103] In one or more embodiments, the front end B1f of battery pack B1 (or the front end B2f of battery pack B2, the front end B3f of battery pack B3, and the front end B4f of battery pack B4) is positioned behind the rear end 50r of the trigger lever 50.

[0104] The battery pack B1 (or battery packs B2, B3, B4) is also a relatively heavy component among the chainsaw T's parts. With the above configuration, the front end B1f of battery pack B1 (or the front end B2f of battery pack B2, the front end B3f of battery pack B3, and the front end B4f of battery pack B4) is positioned behind the rear end 50r of the trigger lever 50. Therefore, the weight of battery pack B1 (or battery packs B2, B3, B4) can reduce the moment when the front end 50f of the trigger lever 50 is used as the pivot point. Thus, the handling performance of the chainsaw T can be further improved.

[0105] In one or more embodiments, the chainsaw T further comprises a power transmission mechanism 70 housed in a housing body 14, which transmits power from an electric motor 64 to the work section 10. The rear end 70r of the power transmission mechanism 70 is positioned behind the front end 50f of the trigger lever 50.

[0106] In the chainsaw T, a power transmission mechanism 70 (including a reduction gear 72, etc.) is sometimes provided between the electric motor 64 and the workpiece 10. The power transmission mechanism 70 is also a relatively heavy component among the components of the chainsaw T. With the above configuration, the rear end 70r of the power transmission mechanism 70 is positioned behind the front end 50f of the trigger lever 50. Therefore, the weight near the rear end 70r of the power transmission mechanism 70 can reduce the moment when the front end 50f of the trigger lever 50 is used as the pivot point. Thus, the handling performance of the chainsaw T can be further improved.

[0107] In one or more embodiments, the control unit 62 includes a control board for controlling the electric motor 64 and a controller case 620 for housing the control board. The controller case 620 is made of a metallic material.

[0108] In the chainsaw T, metal material is sometimes used for the controller case 620 to improve the cooling efficiency of the control board. Since metal material has a relatively high specific gravity, the weight of the control unit 62 increases when metal material is used for the controller case 620. In other words, the position of the control unit 62 is more likely to affect the moment when the front end 50f of the trigger lever 50 is the pivot point. With the above configuration, metal material is used for the controller case 620. Therefore, the cooling efficiency of the control board can be improved. Furthermore, with the above configuration, the effect of reducing the moment due to the arrangement of the control unit 62 is more pronounced. Therefore, the effect of improving the handling performance of the chainsaw T according to the present invention is more pronounced.

[0109] In one or more embodiments, the electric motor 64 is a brushless motor. The control unit 62 includes a switching element for switching the current supplied to the electric motor 64.

[0110] Generally, when the electric motor 64 is a brushless motor, the amount of heat generated in the control unit 62 is relatively large due to the heat generated by the multiple switching elements. In this case, there is a high need to use a metal material for the controller case 620 in order to efficiently cool the control unit 62. Furthermore, when a metal material is used for the controller case 620, as described above, the effect of improving the handling performance of the chainsaw T according to this invention will be more pronounced. With the above configuration, since the electric motor 64 is a brushless motor, there is a high possibility that a metal material will be used for the controller case 620. Therefore, there is a high possibility that the effect of improving the handling performance of the chainsaw T according to this invention will be more pronounced.

[0111] In one or more embodiments, the working section 10 includes a guide bar 6 extending in the front-rear direction and a saw chain 8 provided on the periphery of the guide bar 6 and driven by an electric motor 64 to travel along the periphery of the guide bar 6. The working machine functions as a chainsaw T.

[0112] The above configuration improves the handling performance of the chainsaw T.

[0113] In one or more embodiments, the chainsaw T further comprises an oil tank 66 attached to the housing body 14 for storing lubricating oil for lubricating the saw chain 8. The oil tank 66 is located near the front end of the housing body 14.

[0114] In a chainsaw T, lubricating oil stored in an oil tank 66 must be supplied to the saw chain 8 (or guide bar 6) in order to lubricate the saw chain 8. If the distance between the oil tank 66 and the saw chain 8 (or guide bar 6) is large, the oil supply passage 682 (an example of a lubricating oil supply passage from the oil tank to the saw chain or guide bar) becomes long, which may lead to a larger chainsaw T. In contrast, with the above configuration, the oil tank 66 is located near the front end of the housing body 14, that is, near the saw chain 8 (or guide bar 6). Therefore, the oil supply passage 682 can be shortened, and the chainsaw T can be made smaller.

[0115] In one or more embodiments, the electric motor 64 comprises a stator 76 and a rotor 78. The chainsaw T further comprises a motor shaft 80 fixed to the rotor 78. The axis A1 of the motor shaft 80 is located on a plane extending in the front-rear, up-down, and rear directions. The control unit 62 is located on the axis A1 of the motor shaft 80.

[0116] According to the above configuration, the distance between the control unit 62 and the electric motor 64 can be reduced. Therefore, the distance of the electrical wires connecting the control unit 62 and the electric motor 64 can be reduced. Consequently, the chainsaw T can be made smaller.

[0117] In one or more embodiments, the distance from axis A1 to the front end 62f of the control unit 62 is smaller than the distance from axis A1 to the rear end 62r of the control unit 62.

[0118] Generally, the electric motor 64 has a substantially axially symmetric shape along the axis A1 of the motor shaft 80. With the above configuration, the center position of the control unit 62 in the front-rear direction can be offset rearward along the radial direction of axis A1. This allows the center position of the control unit 62 to be offset rearward relative to the center position of the electric motor 64 in the radial direction of axis A1. With this configuration, it becomes easier to position the conductor that electrically connects the control unit 62 and the electric motor 64 behind the electric motor 64. In other words, it becomes easier to position the conductor further rearward relative to the trigger lever 50. The conductor positioned behind the electric motor 64 is positioned behind the rear end 50r of the trigger lever 50. In this case, the weight of the conductor can reduce the moment when the front end 50f of the trigger lever 50 is the pivot point. Therefore, the handling performance of the chainsaw T can be further improved.

[0119] In one or more embodiments, when the inside of the housing body 14 is viewed from the front along a direction perpendicular to the axis A1 of the motor shaft 80, the control unit 62, the electric motor 64, and the oil tank 66 are arranged in a substantially straight line.

[0120] With the above configuration, the housing body 14 can be made smaller in the radial direction of axis A1. In other words, the chainsaw T can be made smaller in the radial direction of axis A1. [Explanation of symbols]

[0121] 4: Housing 6: Guide bar 6a: Notch 8: Saw chain 10: Work Department 12: Work cover 14: Housing body 14a:Head 16: Grip 18: Sprocket cover 20: Handguard 22: First mounting section 22a: Rotary shaft 24: Second mounting section 24a: Rotary shaft 26: Sprocket 28, 30: Pin 32: Bolt 36: Sprocket cover body 38: Sleeves 42:Locking member 44: Locking member body 46: Nut 48: Nail area 50: Trigger lever 50a: Rotary shaft 50f: Front end of the trigger lever 50r: Rear end of trigger lever 52: Trigger switch 54: Locking component 54a: Rotary shaft 56a: Through hole 56b: Through hole 58a: Left side lock lever 58b: Right-side lock lever 60: Torsion spring 62: Control Unit 62G: Center of gravity of the control unit 62f: Front end of the control unit 62r: Rear end of the control unit 64: Electric motor 64G: Center of gravity of the electric motor 64f: Front end of electric motor 66: Oil tank 68: Oil pump 68a: Worm wheel 70: Power transmission mechanism 70r: Rear end of power transmission mechanism 72:Reducer 72a: First bevel gear 72b: Second bevel gear 74: Coil 76: Status 78: Rotor 80: Motor shaft 82: Cooling fan 82G: Center of gravity of the cooling fan 84: Drive shaft 84a: Worm gear 140: Left side air intake 142: Right-side air intake 144: Left side exhaust port 146: Right-side exhaust port 160: Battery Interface 162: Connection terminal 164: Hook 166:Display section 202: First end 204 :Second end 206: Guard body 208: Plate section 210: Rib section 212: First rib section 214: Second rib section 216: Third rib section 220: 1st extension part 222: 2nd extension part 224: Bending section 360: Battery Interface 362: Connection terminal 364: Hook 544: Exhaust vent 620: Controller Case 660: Cap 680: Suction part 682: Oil supply route 684:Discharge part B1, B2, B3, B4: Battery pack B1f, B2f, B3f, B4f: Front end of the battery pack BG1, BG2, BG3, BG4: Center of gravity of the battery pack S: Wiring space T1, T2, T3, T4: Chainsaw TG1, TG2, TG3, TG4: Center of gravity of the chainsaw

Claims

1. A working section having a longitudinal direction in a front-rear direction; an electric motor that drives the working unit; A control unit for controlling the electric motor; a housing including a housing main body that holds the working unit behind the working unit and houses the electric motor and the control unit, and a grip that extends from the housing main body and is held by one hand of a user; a battery pack attached to the housing and capable of supplying power to the electric motor via the control unit; a trigger lever that is provided on the grip and that operates the electric motor when pulled toward the grip by a user's finger, A work machine, wherein a front end of the control unit is disposed rearward of a rear end of the trigger lever.

2. The work machine according to claim 1 , wherein a center of gravity of the electric motor is located rearward of the rear end of the trigger lever.

3. The work machine according to claim 1 , wherein a front end of the electric motor is disposed rearward of a front end of the trigger lever.

4. The work machine according to claim 1 , wherein a front end of the battery pack is disposed rearward of the rear end of the trigger lever.

5. the electric motor further includes a power transmission mechanism that is accommodated in the housing body and transmits power from the electric motor to the working unit, The work machine according to claim 1 , wherein a rear end of the power transmission mechanism is disposed rearward of a front end of the trigger lever.

6. the control unit includes a control board that controls the electric motor, and a controller case that houses the control board; 2. The work machine according to claim 1, wherein the controller case is made of a metal material.

7. the electric motor is a brushless motor, The work machine according to claim 1 , wherein the control unit includes a switching element for switching a current supplied to the electric motor.

8. The working unit includes a guide bar extending in the front-rear direction, and a saw chain provided on a periphery of the guide bar and running along the periphery of the guide bar by being driven by the electric motor, 2. The work implement of claim 1, which functions as a chain saw.

9. The saw chain further includes an oil tank attached to the housing body and configured to store lubricating oil for lubricating the saw chain. The work machine according to claim 8 , wherein the oil tank is disposed near a front end of the housing body.

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