JP7728208B2 - Work equipment - Google Patents

Description

The technology disclosed in this specification relates to work machines.

Patent Document 1 discloses a work machine comprising a main body having a motor housing and a working unit attached to the main body. The main body comprises a fan housed in the motor housing and a motor housed in the motor housing for driving the working unit and the fan. The motor housing is located on a first side of the motor in the axial direction of the motor, and comprises a wall defining the motor housing and an intake opening provided in the wall.

Japanese Patent Application Laid-Open No. 2002-210705

In the work machine described in Patent Document 1, when the fan is driven, water adhering to the wall of the motor housing flows into the interior of the motor housing through the intake opening. If water enters the motor housing, it may adhere to the motor.

This specification provides technology that can prevent water from entering the motor housing of a work machine.

The working machine disclosed in this specification comprises a main body having a motor housing and a working unit attached to the main body. The main body comprises a fan housed in the motor housing and a motor housed in the motor housing for driving the working unit and the fan. The motor housing is located on a first side of the motor in an axial direction of the motor and comprises a wall defining the motor housing and a first air intake opening provided in the wall. The wall may comprise a reduced diameter section on a second side in the axial direction that reduces in diameter from the second side opposite the first side in the axial direction to the first side, a bellmouth section provided at an end of the reduced diameter section on the first side and defining the first air intake opening, and a waterproof groove recessed from the outer peripheral surface of the wall section, either between the first end of the reduced diameter section and the bellmouth in the axial direction or in the bellmouth.

With the above configuration, when water flows along the narrowed portion of the wall of the motor housing, it enters the waterproof groove before reaching the first air intake opening. Water that enters the waterproof groove flows downward without reaching the first air intake opening. This reduces the amount of water that reaches the air intake opening. This further reduces water intrusion into the motor housing.

1 is a perspective view of a chainsaw 2 of a first embodiment as viewed from above, rear, and left. FIG. FIG. 2 is a left side view of the chainsaw 2 of the first embodiment as viewed from the left. 1 is a perspective view of a chainsaw 2 of a first embodiment as viewed from above and rear right. FIG. 1 is a perspective view of the chainsaw 2 in the first embodiment, seen from above and behind the left, with the battery cover 50 and the battery pack 200 removed. FIG. 1 is a perspective view of the chainsaw 2 in the first embodiment, seen from above and to the front right, with the battery cover 50 and the battery pack 200 removed. FIG. FIG. 2 is a left cross-sectional view of the chainsaw 2 according to the first embodiment, as viewed from the left. 1 is a front cross-sectional view of a chainsaw 2 according to a first embodiment, as viewed from the front. 1 is a front cross-sectional view of a chainsaw 2 according to a first embodiment, as viewed from the front. FIG. 2 is a perspective view of the fan 110 of the first embodiment as viewed from above, front left. FIG. 2 is a perspective view of the fan 110 in the first embodiment with the cover removed, as viewed from above and on the front left. FIG. 2 is a front cross-sectional view of a fan 110 according to the first embodiment, as viewed from the front. FIG. 10 is a perspective view of an inner housing 86, a fan 110, a duct 130, and a mounting unit 66 in the first embodiment, as viewed from above, rear, left. 1 is a front cross-sectional view of a chainsaw 2 according to a first embodiment, as viewed from the front. FIG. 10 is a perspective view of an inner housing 86, a motor unit 82, a duct 130, and a mounting unit 66 in the first embodiment, as viewed from the upper rear right. FIG. 2 is a perspective view of the battery pack 200 according to the first embodiment, as viewed from the front right below. FIG. 10 is a front cross-sectional view of a chainsaw 302 according to a second embodiment, as viewed from the front. FIG. 10 is a front cross-sectional view of a chainsaw 402 according to a third embodiment, as viewed from the front. FIG. 11 is a top cross-sectional view of a chainsaw 402 according to a third embodiment, as viewed from the front.

Representative, non-limiting examples of the present invention will now be described in detail with reference to the drawings. This detailed description is intended simply to provide those skilled in the art with details for implementing preferred examples of the present invention, and is not intended to limit the scope of the present invention. Furthermore, the additional features and inventions disclosed below can be used separately or in conjunction with other features and inventions to provide further improved work machines, manufacturing methods, and methods of using the same.

Furthermore, the combinations of features and steps disclosed in the following detailed description are not essential to practicing the invention in its broadest sense, but are described solely to specifically illustrate representative embodiments of the present invention. Furthermore, the various features of the representative embodiments described above and below, as well as the various features of those described in the independent and dependent claims, do not necessarily have to be combined in the exact embodiments described herein, or in the exact order listed, to provide additional and useful embodiments of the present invention.

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

In one or more embodiments, the work machine comprises a main body having a motor housing and a working unit attached to the main body, the main body comprising a fan housed in the motor housing and a motor housed in the motor housing and driving the working unit and the fan, the motor housing being located on a first side of the motor in the axial direction of the motor, and comprising a wall defining the motor housing and a first air intake opening provided in the wall, the wall being in a front The motor housing may include a reduced diameter portion on a second side in the axial direction, the reduced diameter portion decreasing in diameter from the second side opposite the first side in the axial direction toward the first side, and the first intake opening being defined by an end portion of the first side of the reduced diameter portion; a bellmouth portion extending radially outward from the first side end of the reduced diameter portion; and a waterproof groove portion recessed from the outer circumferential surface of the wall portion toward the inside of the motor housing portion, the waterproof groove portion being provided between the first side end of the reduced diameter portion and the bellmouth portion in the axial direction.

In one or more embodiments, the depth of the waterproof groove may vary circumferentially.

When molding a wall portion that includes a reduced diameter portion, a bellmouth portion, and a waterproof groove, one possible manufacturing method is to use two molds to mold the wall portion. When using two molds, if the depth of the waterproof groove is constant around the entire circumference, demolding becomes difficult. The above configuration makes demolding easier. Therefore, it is possible to further prevent water from entering the motor housing, and it is also possible to easily form a wall portion that includes a reduced diameter portion, a bellmouth portion, and a waterproof groove.

In one or more embodiments, when the work machine is in an operating state, the waterproof grooves at the upper and lower parts may be at their maximum depth, and the waterproof grooves at the left and right parts may be at their minimum depth.

A relatively large amount of water that flows down the wall reaches the top of the waterproof groove. With the above configuration, the top of the waterproof groove is the deepest. This prevents water that accumulates at the top of the waterproof groove from overflowing the bellmouth. This further prevents water from entering the motor housing.

In one or more embodiments, the main body may include a main body housing that houses the motor housing. One or more second air intake openings may be provided on the outer peripheral surface of the main body housing. When the work machine is in an operating state, at least one of the one or more second air intake openings may be located higher than the first air intake opening, and the one or more second air intake openings may be located on the second axial side of the first air intake opening.

With the above configuration, water adhering to the outer surface of the main body flows into the second air intake opening. The water that flows into the second air intake opening adheres to the wall of the motor housing. The water that adheres to the wall of the motor housing flows from the second side to the first side in the axial direction. As it flows from the second side to the first side, some of the water flows downward. Furthermore, some of the water flowing along the wall of the motor housing from the second side to the first side is blocked by the waterproof groove. Therefore, water flowing in from the second air intake opening can be prevented from entering the motor housing.

In one or more embodiments, the implement may be a chainsaw.

Chainsaws are sometimes used in environments where there is a possibility of water getting on the main body, such as in places where it is raining. For this reason, even if water gets on the main body, it is necessary to prevent the water from entering the motor housing space. The above configuration is useful because it can prevent water from getting into the motor housing space.

(First Example)
As shown in FIG. 1 , the chainsaw 2 includes a main body 4, a guide bar 6, and a saw chain 8. The guide bar 6 is a long, thin, plate-like member attached to the main body 4 so as to protrude forward from the main body 4. The guide bar 6 is made of a metal material such as iron. The saw chain 8 includes a plurality of interconnected cutters and is attached along the periphery of the guide bar 6. In the following description, when the chainsaw 2 is placed on a horizontal mounting surface S such as the ground as shown in FIG. 2 , the direction perpendicular to the mounting surface S is referred to as the up-down direction of the chainsaw 2, the direction obtained by projecting the longitudinal direction of the guide bar 6 onto the mounting surface S is referred to as the front-rear direction of the chainsaw 2, and the direction perpendicular to the up-down direction and the front-rear direction of the chainsaw 2 is referred to as the left-right direction of the chainsaw 2.

As shown in Figure 1, the main body 4 includes a main body housing 10, a front hand guard 12, a front handle 14, a sprocket cover 16 (see Figure 3), a battery storage compartment 18, a rear handle 20, and a rear hand guard 22. The main body housing 10 is composed of a left housing 24 and a right housing 26. The main body housing 10 has a roughly rectangular parallelepiped shape with its longitudinal direction extending in the front-to-rear direction of the main body 4.

A front air intake section 30 protruding to the left is provided on the left surface of the left housing 24. The front air intake section 30 has a truncated cone section 32 and a flat plate section 34. The flat plate section 34 is provided at the left end of the truncated cone section 32. The truncated cone section 32 increases in diameter from left to right. The truncated cone section 32 has multiple outer air intake openings 32a. The multiple outer air intake openings 32a are arranged in a row in the circumferential direction of the truncated cone section 32. Each of the multiple outer air intake openings 32a has an elongated hole shape, with its longitudinal direction aligned with the generatrix of the truncated cone section 32.

The front handle 14 includes a left-side fixing portion 14a extending leftward from the lower front portion of the left housing 24 (more specifically, the front intake portion 30), a left-side grip portion 14b extending upward from the left end of the left-side fixing portion 14a, an upper grip portion 14c extending rightward from the upper end of the left-side grip portion 14b, a right-side grip portion 14d extending rearward and downward from the right end of the upper grip portion 14c, and a right-side fixing portion 14e extending downward from the lower end of the right-side grip portion 14d (see Figure 3). The left-side fixing portion 14a is screwed to the lower front portion of the left housing 24. As shown in Figure 3, the right-side fixing portion 14e is screwed to the right housing 26, located rearward of the sprocket cover 16. The front hand guard 12 is rotatably supported on the upper front portion of the main housing 10. The front hand guard 12 is located forward of the front handle 14. The front hand guard 12 protects the user's hands when gripping the upper grip portion 14c of the front handle 14.

The rear handle 20 extends rearward and downward from the upper rear surface of the main body housing 10 and is bent downward. The rear hand guard 22 extends rearward from the lower rear surface of the main body housing 10 and is connected to the lower end of the rear handle 20. The rear hand guard 22 comprises a first guard portion 22a located directly below the rear handle 20 and a second guard portion 22b extending to the right from the first guard portion 22a. The rear hand guard 22 protects the user's hands when gripping the rear handle 20.

A power button 40 is located on the top surface of the rear handle 20 near the front end, allowing the user to switch the chainsaw 2 on and off. A trigger lever 42 is located on the underside of the rear handle 20 near the front end, allowing the user to operate the rotational drive of the saw chain 8. A lock lever 44 is located on the top surface of the rear handle 20, switching between a state where the user is permitted to operate the trigger lever 42 and a state where the user is prohibited from operating the trigger lever 42. When using the chainsaw 2, the user holds the chainsaw 2 by grasping the rear handle 20 with their right hand and the front handle 14 with their left hand. From this state, when the user presses down on the lock lever 44 on the rear handle 20 with the palm of their right hand, the user is permitted to operate the trigger lever 42. In this state, the user can pull up the trigger lever 42 with the index finger of their right hand, causing the saw chain 8 to rotate.

The battery compartment 18 is located between the front handle 14 and the rear handle 20. The battery compartment 18 includes an openable battery cover 50 and a battery interface (hereinafter, sometimes referred to as "IF") section 52 (see FIG. 4). As shown in FIG. 4, the battery IF section 52 includes an IF front surface 54, an IF right surface 56, an IF rear surface 58 (see FIG. 5), an IF left surface 60 (see FIG. 5), and an IF bottom surface 62. The IF front surface 54 extends in the left-right and up-down directions and faces rearward. The IF right surface 56 extends in the front-rear and up-down directions and faces leftward. The IF bottom surface 62 extends in the front-rear and left-right directions and faces upward. As shown in FIG. 5, the IF rear surface 58 extends in the left-right and up-down directions and faces forward. The IF left surface 60 extends in the front-rear and up-down directions and faces rightward.

As shown in FIG. 4, an IF-side intake opening 54a is provided on the IF front face 54. As shown in FIG. 6, an intake pipe 64 is connected to the IF-side intake opening 54a. The intake pipe 64 is formed, for example, from a rubber material. In a modified example, the intake pipe 64 may be formed from a resin or other material. The intake pipe 64 includes a first air passage 64a extending forward from the IF-side intake opening 54a and a second air passage 64b bending from the front end of the first flow path and extending downward. The opening of the end 64c of the second air passage 64b faces vertically downward. In this embodiment, the intake pipe 64 is attached to the IF front face 54 so that the opening of the end 64c faces vertically downward when the chainsaw 2 is in the position shown in FIG. 2. In a modified example, the intake pipe 64 may be rotatably attached to the IF-side intake opening 54a so that the opening of the end 64c faces vertically downward regardless of the state of the chainsaw 2.

As shown in FIG. 7, a right-side opening 56a is formed on the IF right surface 56. A mounting unit 66 is provided in the right-side opening 56a. As shown in FIG. 4, a first front rail 66a extending vertically is provided at the front end of the mounting unit 66, and a first rear rail 66b extending vertically is provided at the rear end. Five device-side terminals 68 are held by the mounting unit 66. The five device-side terminals 68 are provided between the first front rail 66a and the first rear rail 66b and are aligned in the front-to-rear direction. An inner exhaust hole 66c is provided at the bottom of the mounting unit 66. As shown in FIG. 7, an outer exhaust hole 66d is formed at the bottom of the rear surface of the mounting unit 66. A battery storage space BS is defined by the battery cover 50 and the battery IF section 52. As shown in FIG. 6, a seal member 53 is provided at the location where the battery cover 50 and the battery IF section 52 abut when the battery cover 50 is closed. Therefore, when the battery cover 50 is closed, the battery storage compartment 18 is sealed.

As shown in Figure 6, a rear air intake opening 70 is provided on the lower rear surface of the main body housing 10. The rear air intake opening 70 has an elongated hole shape with its longitudinal direction aligned with the left-right direction. A sponge 72 is attached to the rear air intake opening 70. The sponge 72 allows air to enter the interior of the main body housing 10 while preventing water and dust from entering the interior of the main body housing 10.

The control unit 80, motor unit 82, oil tank 84, and inner housing 86 are located at the front of the interior of the main housing 10. The control unit 80, motor unit 82, and oil tank 84 are located forward of the battery storage section 18. The control unit 80 is located above the motor unit 82. The oil tank 84 stores lubricating oil for lubricating the saw chain 8. The motor storage section 88, which houses the motor unit 82, is located at the front of the interior of the main housing 10. The motor storage section 88 is defined by the left housing 24 (see Figure 8), right housing 26, control unit 80, oil tank 84, and inner housing 86. A front exhaust opening 88a is formed in the front of the motor storage section 88. The motor unit 82 is fixed to the left housing 24 with screws.

The motor unit 82 includes a motor cover 90 and a motor 92. The motor cover 90 has a waterproof structure. As shown in FIG. 8, the motor cover 90 includes a cover main body portion 94 and a lid portion 96. The cover main body portion 94 includes a main body side disc portion 94a, a first cylindrical portion 94b having a cylindrical shape, and a second cylindrical portion 94c having a cylindrical shape. A main body side opening 94e is provided in the center of the main body side disc portion 94a. The first cylindrical portion 94b extends leftward from the radially outer end of the main body side disc portion 94a. The second cylindrical portion 94c extends rightward from the outer peripheral end of the main body side opening 94e of the main body side disc portion 94a. The first cylindrical portion 94b is provided with multiple fins 94d extending radially outward. The lid portion 96 includes a lid side disc portion 96a. A lid-side circular opening 96b is provided in the center of the lid-side disc portion 96a. The lid-side disc portion 96a covers the opening at the left end of the first cylindrical portion 94b.

The motor 92 is waterproofed by the motor cover 90. The motor 92 is an inner rotor type DC brushless motor. The motor 92 includes a stator 100, a rotor 102 arranged inside the stator 100, and an output shaft 104 arranged to pass through the center of the stator 100 and the rotor 102 and engaged with the rotor 102. The output shaft 104 extends along the axial direction A. The axial direction A is parallel to the left-right direction. The left end of the output shaft 104 is located to the left of the left end of the motor cover 90, and the right end of the output shaft 104 is located to the right of the right end of the motor cover 90. In other words, the output shaft 104 passes through the motor cover 90 in the left-right direction. Multiple waterproof members 90a are provided in the motor cover 90 at the locations where the output shaft 104 passes through.

A worm gear 105 and a sprocket 106 are fixed to the right end of the output shaft 104. The left end of the sprocket 106 is engaged with the worm gear 105, and a brake drum 107 is attached to its right end. The saw chain 8 (see Figure 1) is stretched over the sprocket 106 from the guide bar 6. When the motor 92 is driven, the sprocket 106 rotates along with the output shaft 104, causing the saw chain 8 to rotate around the sprocket 106 and guide bar 6. When the motor 92 is driven and the user pushes the front hand guard 12 (see Figure 1) forward, the rotation of the output shaft 104 is braked via the brake drum 107.

A fan 110 is attached to the left end of the output shaft 104 via a bushing 108. As shown in Figure 9, the fan 110 is a so-called closed fan. The fan 110 comprises a fan disk 112, multiple blades 114, and a cover 116. A central opening 112a is provided in the center of the fan disk 112. The fan disk 112 has a cylindrical rib 112b extending forward from the outer periphery of the central opening 112a. As shown in Figure 10, the fan disk 112 and the multiple blades 114 are integrally molded. The multiple blades 114 extend leftward from the fan disk 112. When viewed from the left, the multiple blades 114 are shaped so that their radially inner ends are located clockwise relative to their radially outer ends. As shown in FIG. 9, the cover portion 116 is welded to the left end of the blade portion 114. A cover-side intake opening 116a is provided in the center of the cover portion 116. The diameter of the cover-side intake opening 116a is larger than the diameter of the central opening 112a. As shown in FIG. 11, multiple ventilation passages 110a are defined by the left surface of the fan disk portion 112, the right surface of the cover portion 116, and two circumferentially adjacent blade portions 114. As shown in FIG. 9, multiple fan exhaust openings 110b are defined on the outer circumferential surface of the fan 110.

The inner housing 86 in Figure 12 is fixed to the right housing 26 (see Figure 1) with screws. As shown in Figure 8, the left wall portion 86a of the inner housing 86 is provided with an inner air intake opening 120 and a waterproof portion 122. The waterproof portion 122 has a reduced diameter portion 122a and a bellmouth portion 122b. The outer and inner diameters of the reduced diameter portion 122a decrease from right to left. The bellmouth portion 122b is provided at the left end of the reduced diameter portion 122a. The bellmouth portion 122b has a shape that does not obstruct the flow of air that flows from right to left along the outer peripheral surface of the left wall portion 86a and is drawn into the motor housing portion 88 via the inner air intake opening 120. The bellmouth portion 122b defines the inner air intake opening 120. A waterproof groove portion 124 recessed from the outer peripheral surface of the left wall portion 86a is formed in the bellmouth portion 122b. Specifically, the waterproof groove 124 is recessed radially inward from the outer peripheral surface of the left wall portion 86a. The depth D1 of the waterproof groove 124 is constant around the entire circumference.

As shown in FIG. 13, the inner air intake opening 120 is located a distance L1 to the left of the outer air intake opening 32a. The inner air intake opening 120 has a circular shape. The inner air intake opening 120 is located more inward than the outer air intake opening 32a. Here, "the inner air intake opening 120 is located more inward than the outer air intake opening 32a" means that air flowing from the outside of the chainsaw 2 to the inside passes through the outer air intake opening 32a and then the inner air intake opening 120. As shown in FIG. 8, the inner air intake opening 120 is located farther from the motor 92 in the left-right direction than the outer air intake opening 32a. As shown in FIG. 13, the vertical distance L2 between the bottom end of the uppermost outer air intake opening 32a and the top end of the waterproof groove portion 124 is within 10 cm.

As shown in FIG. 6, a duct 130 is housed inside the main housing 10. As shown in FIG. 12, the duct 130 includes a fan-side end 132, a mounting unit-side end 134 (see FIG. 14), and a flow path 136 connecting the fan-side end 132 and the mounting unit-side end 134. As shown in FIG. 8, the fan-side end 132 is located between the left surface of the left housing 24 and the left wall 86a of the inner housing 86. A fan-side opening 132a is formed in the fan-side end 132 of the duct 130. The fan-side opening 132a faces the inner air intake opening 120 of the inner housing 86. The opening area of the fan-side opening 132a is between one-third and one-half the opening area of the inner air intake opening 120. As shown in FIG. 14, the mounting unit-side end 134 of the duct 130 is attached to the lower part of the right surface of the mounting unit 66. As shown in Figure 7, an attachment unit side opening 134a is formed in the attachment unit side end 134.

As shown in FIG. 15, the battery pack 200 includes a battery housing 202. The battery housing 202 houses multiple battery cells C (see FIG. 7). The battery housing 202 includes a hook 204, a second front rail 206 provided at the front end of the battery housing 202, and a second rear rail 208 provided at the rear end of the battery housing 202. The second front rail 206 and the second rear rail 208 have shapes corresponding to the first front rail 66a and the first rear rail 66b (see FIG. 4) of the chainsaw 2, respectively. The hook 204 includes an engagement portion 204a and a hook operating portion 204b. The hook 204 is biased toward the outside of the battery housing 202 by a spring (not shown). When the battery pack 200 is attached to the battery IF section 52 (see Figure 4) of the chainsaw 2, the engaging section 204a of the hook 204 fits into the engaged section 66e (see Figure 7) of the mounting unit 66 of the chainsaw 2, securing the battery pack 200 to the battery IF section 52. When the hook operating section 204b is pressed in from this state, the engaging section 204a comes out of the engaged section 66e. In this state, the battery pack 200 can be slid relative to the battery IF section 52, and the battery pack 200 can be removed from the battery IF section 52 (i.e., the chainsaw 2).

A first battery vent 202a is formed in the lower right surface of the battery housing 202. As shown in FIG. 7, when the battery pack 200 is attached to the chainsaw 2, the first battery vent 202a faces the inner exhaust hole 66c of the mounting unit 66. As shown in FIG. 15, a second battery vent 202b is formed in the left portion of the front surface of the battery housing 202. When the battery pack 200 is attached to the chainsaw 2, the second battery vent 202b faces the IF-side intake opening 54a (see FIG. 4) on the IF front surface 54 of the battery IF section 52.

Next, we will explain the airflow when the motor 92 of the chainsaw 2 is running. When the motor 92 in Figure 8 is driven, the sprocket 106 and fan 110 rotate. In this embodiment, the fan disk 112, blades 114, and cover 116 of the fan 110 rotate integrally. When the fan 110 is driven, air outside the main housing 10 passes through the outer air intake opening 32a of the left housing 24 and the inner air intake opening 120 of the inner housing 86 and is drawn into the motor housing 88. As shown in Figure 6, the air that enters the motor housing 88 passes around the motor cover 90, thereby cooling the motor 92 inside the motor cover 90. The air flowing through the motor housing 88 also cools the control unit 80 that defines the motor housing 88. The air inside the motor housing 88 is then exhausted to the outside through the front exhaust opening 88a on the front surface of the motor housing 88.

Furthermore, when the fan 110 is driven, air within the battery housing 18 is drawn into the motor housing 88 via the duct 130. Specifically, as shown in FIG. 7, air within the battery housing 18 passes through the second battery vent 202b (see FIG. 15) of the battery pack 200, the first battery vent 202a of the battery pack 200, the inner exhaust hole 66c of the mounting unit 66, the outer exhaust hole 66d of the mounting unit 66, and the mounting unit side opening 134a of the duct 130, before being drawn into the duct 130. The air flowing through the battery pack 200 cools the multiple battery cells C within the battery pack 200. As shown in FIG. 8, the air that flows into the duct 130 passes through the fan-side opening 132a and the inner intake opening 120 of the inner housing 86, before being drawn into the motor housing 88. The air flow thereafter is the same as the air flow that flows in through the outer intake opening 32a of the left housing 24.

As described above, when the battery cover 50 is closed, the battery compartment 18 is sealed. Therefore, if the motor 92 continues to be driven, a negative pressure state will be created inside the battery compartment 18. In this case, as shown in FIG. 6, air inside the main housing 10 will be sucked into the battery compartment 18. Specifically, the air inside the main housing 10 passes through the intake pipe 64 and the IF-side intake opening 54a on the IF front surface 54, and is sucked into the battery compartment 18.

Furthermore, as the motor 92 continues to be driven, a negative pressure state also develops inside the main housing 10. In this case, air outside the main housing 10 is drawn into the main housing 10 through the rear intake opening 70 located at the bottom rear surface of the main housing 10. The air that passes through the rear intake opening 70 and enters the main housing 10 flows forward, passes through the intake pipe 64 and the IF-side intake opening 54a on the IF front surface 54, and enters the battery storage section 18. In this way, while the motor 92 is being driven, the motor 92, control unit 80, and multiple battery cells C in the battery pack 200 are cooled.

1, 8, and 13, a chainsaw 2 (an example of a "working machine") includes a main body 4 having a motor housing 88, and a saw chain 8 (an example of a "working unit") attached to the main body 4. The main body 4 includes a fan 110 housed in the motor housing 88, and a motor 92 housed in the motor housing 88 and driving the saw chain 8 and the fan 110. The motor housing 88 is located to the left of the motor 92 in the axial direction A of the motor 92 (an example of a "first side"), and includes a left wall 86a (an example of a "wall") that defines the motor housing 88, and an inner air intake opening 120 (an example of a "first air intake opening") provided in the left wall 86a. The left wall portion 86a includes a reduced diameter portion 122a whose diameter decreases from the right side (an example of the "second side") to the left side in the axial direction A, a bellmouth portion 122b provided at the left end of the reduced diameter portion 122a and defining the inner air intake opening 120, and a waterproof groove portion 124 provided in the bellmouth portion 122b and recessed from the outer peripheral surface of the left wall portion 86a. With the above configuration, when water flows down the reduced diameter portion 122a of the left wall portion 86a of the motor housing 88, it enters the waterproof groove portion 124 before reaching the inner air intake opening 120. Water that enters the waterproof groove portion 124 flows downward without reaching the inner air intake opening 120. This reduces the amount of water that reaches the inner air intake opening 120. This further reduces water intrusion into the motor housing 88. The chainsaw 2 may be used in environments where there is a possibility of water adhering to the main body 4, such as in places where it is raining. For this reason, even if water does adhere to the main body 4, it is necessary to prevent the water from entering the motor housing 88. The above configuration is useful in that it can prevent water from entering the motor housing 88.

In one or more embodiments, as shown in FIG. 8 , the main body 4 includes a main body housing 10 that houses the motor housing 88. An outer air intake opening 32a (an example of a "second air intake opening") is provided on the outer peripheral surface of the main body housing 10. When the chainsaw 2 is in the operating position (as shown in FIG. 2 ), the outer air intake opening 32a is located above the inner air intake opening 120, and is located to the right of the inner air intake opening 120 in the axial direction A. With the above configuration, water adhering to the outer peripheral surface of the main body 4 flows into the outer air intake opening 32a. The water that flows into the outer air intake opening 32a adheres to the left wall 86a of the motor housing 88. The water that adheres to the left wall 86a of the motor housing 88 flows from the right to the left in the axial direction A. As the water flows from the right to the left, some of the water flows downward. Additionally, some of the water flowing from the second side to the first side along the left wall 86a of the motor housing 88 is blocked by the waterproof groove 124. This prevents water from flowing in through the outer air intake opening 32a and entering the motor housing 88.

(Second Example)
A chainsaw 302 of the second embodiment will be described with reference to Figure 16. The chainsaw 2 of the second embodiment has a left housing 324 with a structure different from the left housing 24 (see Figure 8) of the first embodiment. In the following, components common to the embodiments will be assigned the same reference numerals and will not be described again.

The left housing 324 has multiple outer air intake openings 332a, multiple left air intake openings 332b located to the right of the outer air intake openings 332a, and a rightward extension 334 that defines an air passage connecting the outer air intake openings 332a and the left air intake openings 332b. In this embodiment, the multiple outer air intake openings 332a and the multiple left air intake openings 332b are arranged side by side in the front-to-rear direction. The multiple outer air intake openings 332a and the multiple left air intake openings 332b are located above the inner air intake opening 120.

(Third Example)
A chainsaw 402 of the third embodiment will be described with reference to Figures 17 and 18. In the chainsaw 402 of the third embodiment, the structure of a left wall portion 486a of an inner housing 486 differs from the structure of the left wall portion 86a of the inner housing 86 of the first embodiment (see Figures 8 and 13).

As shown in FIG. 17 , the left wall portion 486a of the inner housing 486 is provided with an inner air intake opening 420 and a waterproof portion 422. The waterproof portion 422 has a reduced diameter portion 422a and a bellmouth portion 422b extending radially outward from the left end of the reduced diameter portion 422a. The outer and inner diameters of the reduced diameter portion 422a decrease from right to left. The bellmouth portion 422b is provided at the left end of the reduced diameter portion 422a. The bellmouth portion 422b defines the inner air intake opening 420. The bellmouth portion 422b has a waterproof groove portion 424 recessed from the outer peripheral surface of the left wall portion 486a. Specifically, the waterproof groove portion 424 is recessed radially inward from the outer peripheral surface of the left wall portion 486a. The depth of the waterproof groove 424 is maximum at D2 at the top and bottom of the waterproof groove 424. As shown in FIG. 18, the depth of the waterproof groove 424 is minimum at D3 at the left and right sides of the waterproof groove 424. Depth D3 is smaller than depth D2. In this embodiment, the depth of the waterproof groove 424 varies along the circumferential direction. That is, the depth of the waterproof groove 424 is not constant around the entire circumference.

In one or more embodiments, as shown in Figures 17 and 18, the depth of the waterproof groove 424 varies circumferentially. When molding the left wall 486a, which includes the reduced diameter portion 422a, the bellmouth portion 422b, and the waterproof groove 424, a manufacturing method using two molds to mold the left wall 486a is conceivable. When using two molds, if the depth of the waterproof groove 424 is constant around the entire circumference, demolding becomes difficult. The above configuration facilitates demolding. Therefore, water intrusion into the motor housing 88 can be further suppressed, and the wall portion including the reduced diameter portion 422a, the bellmouth portion 422b, and the waterproof groove 424 can be easily formed.

In one or more embodiments, as shown in Figures 17 and 18, when the chainsaw 402 is in an operating state, the maximum depth of the waterproof groove portions 424 at the upper and lower portions is D2, and the minimum depth of the waterproof groove portions 424 at the left and right portions is D3. Of the water that flows down the left wall portion 486a, a relatively large amount reaches the upper portion of the waterproof groove portion 424. With the above configuration, the upper portion of the waterproof groove portion 424 is the deepest. This prevents water that accumulates at the upper portion of the waterproof groove portion 424 from overflowing the bellmouth portion 422b. This further prevents water from entering the motor housing portion 88.

(First variant) The "working machine" is not limited to the chainsaw 2, but may also be a pole saw, blower, brush cutter, hedge trimmer, high-pressure washer, sprayer, lawn mower, scarifier, cultivator, etc.

(Second Modification) The chainsaw 2 may have a waterproof groove portion to the right of the waterproof portion 122. The waterproof groove portion may be located between the right end of the outer air intake opening 32a and the bellmouth portion 122b in the axial direction A.

(Third variant) The waterproof groove portion 424 in Figure 8 may have its greatest depth in a portion different from the upper and lower portions of the waterproof portion 122.

(Fourth Modification) The main body housing 10 may be provided with an inner air intake opening 120. In this modification, the left wall portion of the main body housing 10 is an example of a "wall portion."

(Fifth variant) The motor 92 may be a brushed DC motor or another type of motor such as an AC motor.

DESCRIPTION OF REFERENCE NUMERALS 2: Chainsaw 4: Main body 6: Guide bar 8: Saw chain 10: Main body housing 12: Front hand guard 14: Front handle 14a: Left fixing portion 14b: Left grip portion 14c: Upper grip portion 14d: Right grip portion 14e: Right fixing portion 16: Sprocket cover 18: Battery storage portion 20: Rear handle 22: Rear hand guard 22a: First guard portion 22b: Second guard portion 24: Left housing 26: Right housing 30: Front air intake portion 32: Truncated cone portion 32a: Outer air intake opening 34: Flat portion 40: Power button 42: Trigger lever 44: Lock lever 50: Battery cover 52: Battery IF portion 53: Seal member 54: IF front surface 54a: IF side air intake opening 56: IF right surface 56a : right side opening 58 : IF rear surface 60 : IF left surface 62 : IF bottom surface 64 : intake pipe 64a : first air passage 64b : second air passage 64c : end portion 66 : mounting unit 66a : first front rail 66b : first rear rail 66c : inner exhaust hole 66d : outer exhaust hole 66e : engaged portion 68 : device side terminal 70 : rear intake opening 72 : sponge 80 : control unit 82 : motor unit 84 : oil tank 86 : inner housing 86a : left wall portion 88 : motor accommodating portion 88a : front exhaust opening 90 : motor cover 90a : waterproof member 92 : motor 94 : cover main body portion 94a : main body side disc portion 94b : first cylindrical portion 94c : second cylindrical portion 94d : fins 94e : main body side opening 96 : lid portion 96a : lid side disc portion 96b : lid side circular opening 100 : stator 102 : rotor 104 : output shaft 105 : worm gear 106 : sprocket 107 : brake drum 108 : bushing 110 : fan 110a : ventilation passage 110b : fan exhaust opening 112 : fan disc portion 112a : central opening 112b : rib portion 114 : blade portion 116 : cover portion 116a : cover side intake opening 120 : inner intake opening 122 : waterproof portion 122a : reduced diameter portion 122b : bell mouth portion 124 : waterproof groove portion 130 : duct 132 : fan side end portion 132a : fan side opening 134 : mounting unit side end portion 134a : mounting unit side opening 136 : Flow path portion 200 : Battery pack 202 : Battery housing 202a : First battery vent 202b : Second battery vent 204 : Hook 204a : Engagement portion 204b : Hook operating portion 206 : Second front rail 208 : Second rear rail 302 : Chainsaw 324 : Left side housing 332a : Outer air intake opening 332b : Left side air intake opening 334 : Right extension portion 402 : Chainsaw 420 : Inner air intake opening 422 : Waterproof portion 422a : Reduced diameter portion 422b : Bell mouth portion 424 : Waterproof groove portion 486 : Inner housing 486a : Left wall portion A : Axial direction BS : Battery accommodating space C : Battery cell S : Mounting surface

Claims (5)

A work machine,
a main body having a motor housing;
a working unit attached to the main body,
The main body portion is
a fan accommodated in the motor accommodating section;
a motor housed in the motor housing section and driving the working section and the fan,
The motor accommodating portion is
a wall portion that is located on a first side of the motor in an axial direction of the motor and that defines the motor accommodating portion;
a first intake opening provided in the wall portion,
The wall portion is
a tapered portion on a second side in the axial direction, the tapered portion having a diameter tapered from the second side opposite to the first side in the axial direction toward the first side;
a bellmouth portion provided at a first end of the reduced diameter portion, the bellmouth portion defining the first intake opening;
a waterproof groove portion recessed from the outer peripheral surface of the wall portion, the waterproof groove portion being provided between the first side end of the reduced diameter portion and the bellmouth portion in the axial direction, or on the bellmouth portion. The work machine described in claim 1, wherein the depth of the waterproof groove varies along the circumferential direction. The work machine described in claim 2, wherein, when the work machine is in operation, the waterproof groove portions at the upper and lower parts are at their maximum depth, and the waterproof groove portions at the left and right parts are at their minimum depth. The main body portion is
a main body housing that accommodates the motor accommodating portion,
One or more second intake openings are provided on the outer circumferential surface of the main body housing,
When the work machine is in a working state, at least one second air intake opening of the one or more second air intake openings is located above the first air intake opening,
The work machine according to claim 1 , wherein the one or more second intake openings are provided on the second side in the axial direction relative to the first intake opening. The work machine according to claim 1 , wherein the work machine is a chainsaw.