Work machine

Abstract

To prevent liquid from being little supplied to a discharge pipe even when an amount of liquid stored in a liquid tank decreases.SOLUTION: A work machine discharges liquid. The work machine comprises a discharge pipe for discharging liquid, and a liquid tank. The liquid tank includes a tank body for storing liquid, a supply port for supplying the liquid to the tank body, a communication hole, a protrusion to be disposed on a top of the tank body when the work machine is placed on a placement surface, a cap to be engaged with the protrusion to close the supply port, and a unidirectional valve attached to the protrusion. When the cap is engaged with the protrusion to close the supply port, the communication hole communicates the inside of the liquid tank with the outside of the work machine. The unidirectional valve is configured to prohibit a flow of fluid heading from the inside of the liquid tank toward the outside of the work machine through the communication hole and to allow a flow of the fluid heading from the outside of the work machine toward the inside of the liquid tank through the communication hole.SELECTED DRAWING: Figure 15

Description

[Technical field]

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

[0002] Patent Document 1 discloses a working machine that discharges liquid. The working machine includes a discharge pipe that discharges the liquid and a liquid tank. The liquid tank has a tank body that stores the liquid and a supply port for supplying the liquid to the tank body, and includes a protrusion that connects to the top of the tank body when the working machine is placed on a mounting surface, and a cap that engages with the protrusion to close the supply port. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-91023 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned working machine, as the working machine operates, the amount of liquid stored in the liquid tank decreases, and the volume of the void in the liquid tank increases. Because the supply port is blocked by a cap and air is unlikely to flow into the liquid tank, when the amount of liquid stored in the liquid tank decreases, the pressure in the void in the liquid tank decreases. This makes it difficult for the liquid to be supplied toward the discharge pipe. This specification provides a technology that can suppress the difficulty in supplying the liquid toward the discharge pipe even when the amount of liquid stored in the liquid tank decreases. [Means for solving the problem]

[0005] This specification discloses a working machine that discharges liquid. The working machine includes a discharge pipe that discharges liquid and a liquid tank. The liquid tank has a tank body that stores liquid, a supply port for supplying liquid to the tank body, and a communication hole, and includes a protrusion that is disposed on an upper portion of the tank body when the working machine is placed on a placement surface, a cap that engages with the protrusion to close the supply port, and a one-way valve attached to the protrusion. When the cap engages with the protrusion to close the supply port, the communication hole communicates between the inside of the liquid tank and the outside of the working machine. The one-way valve is configured to prohibit a flow of fluid from the inside of the liquid tank toward the outside of the working machine through the communication hole, and to allow a flow of fluid from the outside of the working machine toward the inside of the liquid tank through the communication hole.

[0006] According to the above configuration, even when the cap engages with the protruding portion and blocks the supply port, when the one-way valve opens, the inside of the liquid tank communicates with the outside of the work machine via the communication hole. Even if the amount of liquid stored in the liquid tank decreases, it is possible to prevent a decrease in pressure in the void within the liquid tank due to fluid, for example air, flowing into the liquid tank via the communication hole. This makes it possible to prevent the liquid from becoming difficult to supply toward the discharge pipe. [Brief description of the drawings]

[0007] [Figure 1] FIG. 2 is a perspective view of a working machine 2 according to an embodiment. [Diagram 2] 2 is a right side view of the working machine 2 according to the embodiment when the discharge pipe 10 is removed from the main unit 4. FIG. [Diagram 3] FIG. 2 is an exploded perspective view of the working machine 2 of the embodiment. [Figure 4] 2 is a perspective view of the working machine 2 according to the embodiment when a cover portion 34 is open. FIG. [Diagram 5] FIG. 2 is a top view of the working machine 2 of the embodiment. [Figure 6] 2 is a rear view of the working machine 2 according to the embodiment with the rear body housing 28 removed. FIG. [Figure 7]FIG. 2 is an exploded perspective view of the fan unit 18 and the control unit 20 of the embodiment. [Figure 8] FIG. 2 is a perspective view of the emission pipe 10 of the embodiment. [Figure 9] FIG. 2 is an exploded perspective view of the liquid tank 24 of the embodiment. [Figure 10] FIG. 2 is a horizontal sectional view of the working machine 2 of the embodiment. [Figure 11] FIG. 2 is a perspective view of the liquid tank 24, the discharge tube 91, and the supply line 113 of the embodiment. [Figure 12] 2 is a horizontal cross-sectional view of the vicinity of a protruding portion 92 of the liquid tank 24 of the embodiment. FIG. [Figure 13] FIG. 2 is a vertical sectional view of a working machine 2 according to an embodiment of the present invention. [Figure 14] 1 is an enlarged cross-sectional view of the liquid tank 24 of the embodiment when the one-way valve 144 is closed. [Figure 15] 1 is an enlarged cross-sectional view of the liquid tank 24 of the embodiment when a one-way valve 144 is open. [Figure 16] FIG. 2 is a perspective view of a frame unit 6 according to the embodiment. [Figure 17] 2 is a perspective view of the working machine 2 of the embodiment when a frame unit 6 and a harness unit 8 are removed from a main body housing 16. FIG. [Figure 18] 2 is an exploded perspective view of the working machine 2 of the embodiment when the discharge pipe 10 is detached from the main unit 4. FIG. [Figure 19] FIG. 2 is a rear view of the working machine 2 according to the embodiment. [Figure 20] 2 is a vertical cross-sectional view of the vicinity of a lower opposing surface 200 of the working machine 2 of the embodiment. [Figure 21] FIG. 2 is a front view of the working machine 2 of the embodiment. [Figure 22] 2 is a cross-sectional perspective view of the discharge pipe 10, the cylindrical member 250, and the liquid nozzle 252 of the embodiment. [Diagram 23] FIG. 2 is a perspective view of a liquid nozzle 252 according to an embodiment. [Figure 24] 2 is a cross-sectional view of a second supply pipe 240 and a liquid nozzle 252 according to the embodiment. [Diagram 25]13 is an enlarged cross-sectional view of the vicinity of the tip of a liquid nozzle 252 in the embodiment. [Figure 26] 2 is an enlarged cross-sectional view of the vicinity of a corner 290 of a liquid nozzle 252 in the embodiment. [Figure 27] FIG. 13 is a front view of a modified liquid nozzle 252 as viewed from the front side. [Figure 28] 13 is an enlarged cross-sectional view of the vicinity of the tip of a liquid nozzle 252 of a modified example. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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 provide those skilled in the art with details for implementing the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Additionally, the additional features and inventions disclosed can be used separately or together with other features and inventions to provide further improved working machines.

[0009] In addition, the combinations of features and steps disclosed in the following detailed description are not essential for implementing the present invention in the broadest sense, but are specifically described only to illustrate representative embodiments of the present invention. Furthermore, the various features of the following representative embodiments and the various features described in the claims do not have to be combined in the exact manner of the embodiments described herein or in the order listed in order to provide additional and useful embodiments of the present invention.

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

[0011] In one or more embodiments, the protrusion may include a sidewall defining the feed opening. The access hole may be disposed in the sidewall.

[0012] According to the above configuration, it is possible to prevent the configuration of the protruding portion from becoming complicated, and to prevent the liquid from becoming difficult to be supplied toward the discharge pipe.

[0013] In one or more embodiments, the cap may include a spirally extending engagement rail. The sidewall may include a first side portion including an engaged rail extending circumferentially along the outer surface of the sidewall, the engaged rail engaging with the engagement rail, and a second side portion not including an engaged rail formed in the circumferential direction of the outer surface of the sidewall. The communication hole may be disposed in the second side portion.

[0014] According to the above-mentioned configuration, the side wall is divided into an area where the engaged rail is disposed and an area where the communication hole is disposed. The engagement between the engaged rail and the engaging rail can prevent the inside of the liquid tank from being difficult to communicate with the outside of the work machine via the communication hole.

[0015] In one or more embodiments, the second side may be recessed radially inwardly from the first side.

[0016] According to the above configuration, even when the cap engages with the protruding portion, the outer surface of the second side portion does not come into contact with the cap, which makes it possible to prevent the inside of the liquid tank from becoming difficult to communicate with the outside of the working machine via the communication hole.

[0017] In one or more embodiments, the one-way valve may be disposed inside the liquid tank and include a valve portion capable of blocking the communication hole.

[0018] According to the above-mentioned configuration, it is possible to prevent foreign matter, such as sand, from being attached to the valve portion outside the liquid tank, thereby preventing the one-way valve from becoming difficult to open and close due to sand or the like.

[0019] In one or more embodiments, the liquid tank may include a filter unit that is attachable to the supply port of the protrusion and that captures foreign matter contained in the liquid when the liquid is supplied to the tank body. The valve unit may be disposed between the filter unit and the side wall.

[0020] According to the above configuration, it is possible to prevent foreign matter contained in the liquid, such as sand, from adhering to the valve portion, thereby preventing the one-way valve from becoming difficult to open and close due to sand or the like.

[0021] In one or more embodiments, when the cap engages with the protrusion to close the supply port, the communication hole may be covered by the cap.

[0022] According to the above configuration, it is possible to prevent sand or the like outside the liquid tank from clogging the communication hole.

[0023] In one or more embodiments, when the cap engages with the protrusion to close the supply port, a communication space may be defined between the cap and the protrusion. The communication hole may communicate the communication space with the interior of the liquid tank. The communication space may communicate with the outside of the work machine at a lower end.

[0024] According to the above-mentioned configuration, sand or the like outside the liquid tank is unlikely to enter the communication space, which can further prevent the communication hole from being clogged with sand or the like.

[0025] In one or more embodiments, the one-way valve may be an umbrella valve.

[0026] According to the above configuration, the one-way valve can be opened with a relatively weak force.

[0027] (Example) As shown in FIG. 1, the working machine 2 is a backpack-type working machine. The working machine 2 is configured to discharge (spray) a liquid. The working machine 2 is, for example, a mist blower. The liquid is, for example, a chemical solution or water. The liquid is stored in a liquid tank 24 described later. The working machine 2 includes a main body unit 4, a frame unit 6, a harness unit 8, a discharge pipe 10, and a handle unit 12. The frame unit 6 is attached to the main body unit 4. The harness unit 8 is attached directly and / or indirectly to the main body unit 4. The discharge pipe 10 is attached to the lower right side of the main body unit 4. The handle unit 12 is attached to the discharge pipe 10. A user wears the harness unit 8 and carries the working machine 2 on his / her back, and grips the handle unit 12 and moves the discharge pipe 10 to spray the liquid from the discharge pipe 10. 2, the main unit 4 has a facing surface 4a that faces the user's back when the work machine 2 is carried by the user. In the following, when the work machine 2 is placed on a placement surface P such as the ground, the direction perpendicular to the facing surface 4a is referred to as the front-rear direction, the direction perpendicular to the placement surface P is referred to as the up-down direction, and the direction perpendicular to the front-rear direction and the up-down direction is referred to as the left-right direction.

[0028] As shown in Fig. 3, the main body unit 4 includes a main body housing 16, a fan unit 18, a control unit 20, a battery unit 22, and a liquid tank 24. The main body housing 16 supports the fan unit 18, the battery unit 22, and the liquid tank 24. The main body housing 16 includes a front main body housing 26 and a rear main body housing 28. As shown in Fig. 2, the front main body housing 26 includes a facing surface 30 that faces the back of the user when the work machine 2 is carried on the user's back. The facing surface 30 forms a part of the facing surface 4a of the main body unit 4.

[0029] As shown in Fig. 4, the rear main body housing 28 includes a main body portion 32 and a cover portion 34. The main body portion 32 is fixed to the front main body housing 26 with screws (not shown). The cover portion 34 is rotatably attached to the front main body housing 26. The cover portion 34 rotates around a rotation axis extending in the left-right direction. The rotation axis of the cover portion 34 is disposed above the battery unit 22. The cover portion 34 is disposed rearward of the battery unit 22.

[0030] As shown in FIG. 3 and FIG. 4, a first internal space 36 and a second internal space 38 are defined between the front body housing 26 and the rear body housing 28. The fan unit 18 and the control unit 20 are arranged in the first internal space 36. A cover 40 is attached near the lower part of the left side surface of the body housing 16, and the first internal space 36 communicates with the outside of the working machine 2 through an intake port 40a of the cover 40. The second internal space 38 is arranged on the upper side of the first internal space 36. The second internal space 38 is separated from the first internal space 36. The battery unit 22 is arranged in the second internal space 38. Therefore, a battery pack BP, which will be described later, is arranged in the second internal space 38. By opening the cover portion 34 upward, the second internal space 38 communicates with the outside of the working machine 2.

[0031] The fan unit 18, the battery unit 22, and the liquid tank 24 are arranged in a vertical line. The battery unit 22 is arranged above the fan unit 18, and the liquid tank 24 is arranged above the battery unit 22. As shown in FIG. 5, when the working machine 2 is placed on the placement surface P (see FIG. 2) and viewed from above, at least 50% or more of the liquid tank 24 overlaps with each of the fan unit 18 and the battery unit 22. In FIG. 5, the outline of the fan unit 18 is illustrated by a broken line, and the outline of the battery unit 22 is illustrated by a dashed line. In addition, at least 50% or more of the area of ​​the fan unit 18 overlaps with each of the battery unit 22 and the liquid tank 24. In addition, at least 50% or more of the area of ​​the battery unit 22 overlaps with each of the fan unit 18 and the liquid tank 24.

[0032] Next, the center of gravity will be described with reference to Figures 2 and 6. The center of gravity of the fan unit 18 is located at center of gravity G1. When two battery packs BP are disposed in the second internal space 38, the center of gravity of the battery unit 22 is located at center of gravity G2, and when two battery packs BP are not disposed in the second internal space 38, the center of gravity of the battery unit 22 is located at center of gravity G3. When the liquid tank 24 is filled with liquid to its maximum amount, the center of gravity of the liquid tank 24 is located at center of gravity G4, and when no liquid is stored in the liquid tank 24, the center of gravity of the liquid tank 24 is located at center of gravity G5. In addition, when two battery packs BP are arranged in the second internal space 38 and the liquid tank 24 is filled with liquid to its maximum amount, the center of gravity of the main unit 4 is at center of gravity position G6, and when two battery packs BP are arranged in the second internal space 38 and no liquid is stored in the liquid tank 24, the center of gravity of the main unit 4 is at center of gravity position G7.

[0033] 2, the positions of the centers of gravity G2 and G3 of the battery unit 22 are substantially the same in the front-rear direction and the up-down direction. The position of the center of gravity G4 of the liquid tank 24 is substantially the same as the position of the center of gravity G5 in the front-rear direction and is disposed slightly below the position of the center of gravity G5 in the up-down direction. The position of the center of gravity G6 of the main body unit 4 is disposed slightly behind the position of the center of gravity G7 in the front-rear direction and is disposed above the position of the center of gravity G7 in the up-down direction.

[0034] In the front-rear direction, the center of gravity G1 of the fan unit 18, the center of gravity G2 and G3 of the battery unit 22, the center of gravity G4 and G5 of the liquid tank 24, and the center of gravity G6 and G7 of the main unit 4 are located in an area that is 1 / 3 of the width of the main unit 4 in the front-rear direction (in this embodiment, an area that is 1 / 6 of the width of the main unit 4 in the front-rear direction). In FIG. 2, the area that is 1 / 3 of the width of the main unit 4 in the front-rear direction is illustrated by a dashed line. The center of gravity G1 is located near the center position CP1 of the main unit 4 in the front-rear direction. The center positions G2, G3, G4, G5, G6, and G7 are located closer to the opposing surface 4a (front side) than the center position CP1. The center position CP1 is located in the center between the front end and the rear end of the main unit 4. In FIG. 2, the center position CP1 is illustrated by a dashed line.

[0035] 6, the positions of the centers of gravity G2 and G3 of the battery unit 22 are substantially the same in the left-right direction. The positions of the centers of gravity G4 and G5 of the liquid tank 24 are substantially the same in the left-right direction. The position of the center of gravity G6 of the main body unit 4 is disposed farther from the discharge pipe 10 (to the left) than the position of the center of gravity G7 in the left-right direction.

[0036] In the left-right direction, the center of gravity G1 of the fan unit 18, the center of gravity G2, G3 of the battery unit 22, the center of gravity G4, G5 of the liquid tank 24, and the center of gravity G6, G7 of the main unit 4 are located in an area that is 1 / 3 of the left-right width of the main unit 4 (in this embodiment, an area that is 1 / 6 of the left-right width of the main unit 4). In FIG. 6, the area that is 1 / 3 of the left-right width of the main unit 4 is illustrated by a dashed line. The center of gravity G1, G6, and G7 are located on the discharge pipe 10 side (right side) of the center position CP2 of the main unit 4 in the left-right direction. The center of gravity G2, G3, G4, and G5 are located near the center position CP2 of the main unit 4 in the left-right direction. The center position CP2 is located in the center between the right end and the left end of the main unit 4. In FIG. 6, the center position CP2 is illustrated by a dashed line.

[0037] As shown in FIG. 7, the fan unit 18 includes a fan 44, an electric motor 46, a motor housing 48, a cover member 50, a cone 52, and a tubular member 54. The fan 44 is, for example, an axial fan. A shaft 46a of the electric motor 46 is connected to the fan 44. The electric motor 46 rotates the fan 44. The electric motor 46 is, for example, a brushless motor. The motor housing 48 accommodates the electric motor 46. A plurality of rectifying fins 55 are formed on the outer surface of the motor housing 48. The cover member 50 closes the left end opening of the motor housing 48. The cone 52 is connected to the right end of the motor housing 48. The tubular member 54 has a substantially cylindrical shape. The tubular member 54 accommodates the fan 44, the electric motor 46, the motor housing 48, and the cover member 50 inside. The inner surface of the tubular member 54 is connected to the plurality of rectifying fins 55. The cylindrical member 54 is supported by the main housing 16 (see FIG. 3).

[0038] The control unit 20 is attached to the upper part of the cylindrical member 54. The control unit 20 includes a control board 56 having a plurality of switching elements (not shown) and a microcomputer. The control board 56 controls the rotation of the electric motor 46. The control board 56 is housed in a case 57. An opening 54a is formed in the upper part of the cylindrical member 54, and at least a portion of the lower surface of the case 57 covers the opening 54a of the cylindrical member 54. The case 57 is made of, for example, a metal material. The control unit 20 is covered by a cover member 58. The case 57 and the cover member 58 are attached to the cylindrical member 54.

[0039] The discharge pipe 10 shown in Fig. 1 is attached to the tubular member 54. The discharge pipe 10 is disposed on the right side of the main unit 4. The discharge pipe 10 includes a curved pipe 60 attached to the tubular member 54 (see Fig. 3), a bellows tube 62 attached to the curved pipe 60, an intermediate tube 64 attached to the bellows tube 62, and a tip tube 66 attached to the intermediate tube 64. The bellows tube 62 is configured so that the orientations of the intermediate tube 64 and the tip tube 66 can be adjusted. As shown in Fig. 8, a dome-shaped diffusion cover 70 is attached to the tip of the tip tube 66.

[0040] A handle unit 12 is attached to the intermediate tube 64. The handle unit 12 includes a grip portion 72 that is gripped by a user, a trigger 74 attached to the grip portion 72, and a head portion 76 connected to the grip portion 72. The user can adjust the orientation of the intermediate tube 64 and the tip tube 66 by gripping the grip portion 72 and moving the handle unit 12. The user can also press the trigger 74 with the fingers of the hand holding the grip portion 72. When the trigger 74 is pressed, a signal is sent to the control board 56 (see FIG. 7).

[0041] As shown in FIG. 1, the head unit 76 includes a main power button 78 and an adjustment button 80. The main power button 78 is disposed on the rear surface of the head unit 76. The main power button 78 accepts a user's operation to switch the working machine 2 between an on state and an off state. The user operates the main power button 78 with the fingers of the hand holding the grip unit 72. When the main power button 78 is operated, a signal is sent to the control board 56 (see FIG. 7). The adjustment button 80 is disposed on the upper surface of the head unit 76. The adjustment button 80 accepts a user's operation to adjust the rotation speed of the electric motor 46 (see FIG. 7). The user can operate the adjustment button 80 with the fingers of the hand opposite to the hand holding the grip unit 72. When the adjustment button 80 is operated, a signal is sent to the control board 56.

[0042] When the user presses the trigger 74 while the working machine 2 is in the on state, as shown in FIG. 7, the control board 56 rotates the shaft 46a of the electric motor 46, and the fan 44 rotates. As a result, as shown in FIG. 3, air flows from the outside of the working machine 2 into the first internal space 36 through the multiple air intakes 40a (see FIG. 4). The air that has flowed in flows into the inside of the tubular member 54. As shown in FIG. 7, the air that has flowed in is sent out by the fan 44, rectified by the multiple rectifying fins 55, and then flows along the cone 52. Since at least a part of the lower surface of the case 57 blocks the opening 54a of the tubular member 54, the air sent out by the fan 44 flows along the lower surface of the case 57. As a result, the case 57 is cooled, and as a result, the control unit 20 (control board 56) is cooled. Thereafter, the air flows inside the discharge pipe 10 shown in FIG. 8, passes through the diffusion cover 70, and is discharged to the outside of the working machine 2. The air is guided radially outward of the tip tube 66 by the diffusion fins 70a of the diffusion cover 70 and released over a wide area.

[0043] As shown in Figs. 3 and 4, the battery unit 22 is disposed above the fan unit 18 and the control unit 20. The battery unit 22 includes a right battery mounting portion 84, a left battery mounting portion 86, and a plurality of battery packs BP (two in this embodiment). The right battery mounting portion 84 and the left battery mounting portion 86 are aligned in the left-right direction. A central wall 88 is disposed in the second internal space 38, the right battery mounting portion 84 is disposed on the right surface of the central wall 88, and the left battery mounting portion 86 is disposed on the left surface of the central wall 88. The central wall 88 is disposed at the center of the second internal space 38 in the left-right direction. The central wall 88 is disposed on a plane along the up-down direction and the front-rear direction.

[0044] The battery pack BP can be attached to and detached from the right battery mounting portion 84 and the left battery mounting portion 86 when the cover portion 34 is open. The battery pack BP can be attached to and detached from the right battery mounting portion 84 and the left battery mounting portion 86 by sliding the battery pack BP in the forward and backward directions. The battery pack BP includes, for example, a lithium-ion battery. The power of the battery pack BP can be supplied to the electric motor 46 (see FIG. 7). When the battery pack BP is attached to both the right battery mounting portion 84 and the left battery mounting portion 86, the power is first supplied to the electric motor 46 from one of the battery packs BP, in this embodiment, the right battery pack BP arranged on the discharge pipe 10 side. When the remaining power of the right battery pack BP becomes zero, the power is supplied to the electric motor 46 from the left battery pack BP. In this state, when the right battery pack BP with zero remaining power is removed from the right battery attachment part 84, the center of gravity positions G6, G7 (see FIG. 6) of the main unit 4 move in a direction (left side) away from the discharge pipe 10. When the work machine 2 is carried on the user's back, the work machine 2 is prevented from tilting toward the discharge pipe 10.

[0045] The liquid tank 24 is disposed above the battery unit 22. As shown in FIG. 9, the liquid tank 24 includes a tank body 90, a protrusion 92, a filter unit 94, and a tank cap 96. The tank body 90 stores liquid to be discharged (sprayed). The capacity of the tank body 90 is, for example, 10 L or more, and in this embodiment, 15 L. The tank body 90 includes a facing surface 90a that faces the back of the user when the work machine 2 is carried on the user's back. The facing surface 90a constitutes a part of the facing surface 4a (see FIG. 2) of the main unit 4.

[0046] A first engagement groove 98 and a second engagement groove 100 are formed near the lower part of the right end of the tank body 90. The first engagement groove 98 and the second engagement groove 100 are recessed toward the inside of the tank body 90. As shown in FIG. 10, a third engagement groove 102 and a fourth engagement groove 104 are formed near the lower part of the left end of the tank body 90. The third engagement groove 102 and the fourth engagement groove 104 are recessed toward the inside of the tank body 90. A first engagement wall 106, a second engagement wall 108, a third engagement wall 110, and a fourth engagement wall 112 are formed in the body housing 16. When the tank body 90 is sandwiched between the front body housing 26 and the rear body housing 28, the first engagement wall 106 engages with the first engagement groove 98, the second engagement wall 108 engages with the second engagement groove 100, the third engagement wall 110 engages with the third engagement groove 102, and the fourth engagement wall 112 engages with the fourth engagement groove 104. As a result, the lower part of the tank body 90 is fixed to the main body housing 16 inside the main body housing 16. As shown in FIG. 1, when the tank body 90 is fixed to the main body housing 16, the upper part of the tank body 90 is disposed on the upper side of the main body housing 16.

[0047] As shown in FIG. 11, a discharge part 90b and a supply part 90c are formed at the lower end of the tank body 90. A discharge tube 91 is connected to the discharge part 90b. The discharge tube 91 is made of, for example, a resin material. Normally, a discharge cock 91a on the discharge tube 91 is closed. By opening the discharge cock 91a, the user can discharge the liquid stored in the tank body 90 to the outside of the liquid tank 24 via the discharge part 90b and the discharge tube 91. A supply line 113 is connected to the supply part 90c. The supply line 113 will be described in detail later.

[0048] As shown in FIG. 9, the protruding portion 92 is connected to the upper surface (upper portion) of the tank body 90. When the work machine 2 is placed on the placement surface P (see FIG. 2), the protruding portion 92 is disposed above the upper surface of the tank body 90. The protruding portion 92 has a side wall 114 having a substantially cylindrical shape. The side wall 114 defines a supply port 116. The supply port 116 is defined by the inner surface of the side wall 114. In other words, the supply port 116 is formed by the protruding portion 92, and the protruding portion 92 is configured by the side wall 114. The supply port 116 is an opening for supplying liquid to the inside of the tank body 90. A plurality of ribs 118 are formed on the inner surface of the side wall 114. The plurality of ribs 118 extend radially inward of the side wall 114.

[0049] The side wall 114 includes a first side portion 120 and a second side portion 122. The first side portion 120 has a generally cylindrical shape. The first side portion 120 includes an engaged rail 124 disposed on an outer surface of the first side portion 120. The engaged rail 124 extends spirally along the circumferential direction of the outer surface of the first side portion 120. The engaged rail 124 is partially interrupted in the circumferential direction of the outer surface of the first side portion 120.

[0050] The second side portion 122 is connected to the first side portion 120. The outer surface of the second side portion 122 has a planar shape. In a modified example, the outer surface of the second side portion 122 may have a curved shape. The engaged rail 124 is not formed on the outer surface of the second side portion 122 in the circumferential direction of the side wall 114. As shown in FIG. 12, the outer surface of the second side portion 122 is recessed radially inward of the side wall 114 compared to the outer surface of the first side portion 120. The outer surface of the second side portion 122 and the outer surface of the first side portion 120 are separated from the inner surface of the tank cap 96. The distance between the outer surface of the second side portion 122 and the inner surface of the tank cap 96 is greater than the distance between the outer surface of the first side portion 120 and the inner surface of the tank cap 96.

[0051] 9, a plurality of (six in this embodiment) communication holes 126 are formed in the second side portion 122. The plurality of communication holes 126 penetrate the second side portion 122 in the thickness direction.

[0052] The filter unit 94 includes a base member 128, a filter 130, fins 132, and a handle 133. The base member 128 includes a first tube portion 134 having a substantially cylindrical shape, and a second tube portion 136 having a substantially cylindrical shape with a larger diameter than the first tube portion 134. The first tube portion 134 supports the filter 130. The filter 130 is disposed at the lower end opening of the first tube portion 134. When the liquid is supplied to the inside of the tank body 90, the filter 130 captures foreign matter, such as sand, contained in the liquid. The second tube portion 136 is connected to the upper end of the first tube portion 134. As shown in FIG. 13, when the filter unit 94 is attached to the protruding portion 92, the lower end of the second tube portion 136 is placed on the multiple ribs 118.

[0053] 9, the fins 132 are connected to the lower end of the first cylindrical portion 134. The handle 133 is connected to the first cylindrical portion 134. When a user grips the handle 133 and rotates the filter unit 94, the fins 132 rotate to agitate the liquid inside the tank body 90.

[0054] The tank cap 96 is capable of blocking the supply port 116 of the side wall 114 from above. The tank cap 96 has a generally cylindrical shape with a bottom wall at the upper end. As shown in FIG. 13, the tank cap 96 is provided with an engaging rail 140 disposed on the inner surface of the tank cap 96. The engaging rail 140 extends spirally along the circumferential direction of the inner surface of the tank cap 96. When the tank cap 96 blocks the supply port 116 of the side wall 114, the engaging rail 140 engages with the engaged rail 124.

[0055] As shown in FIG. 14, when the engaging rail 140 engages with the engaged rail 124 and the tank cap 96 closes the supply port 116, the tank cap 96 covers the multiple communication holes 126. Even in this state, the multiple communication holes 126 communicate between the inside of the liquid tank 24 and the outside of the working machine 2. A communication space 142 is defined between the tank cap 96 and the side wall 114. The width of the communication space 142, i.e., the distance between the inner surface of the tank cap 96 and the outer surface of the side wall 114, is maximum between the outer surface of the second side portion 122 and the inner surface of the tank cap 96 in the circumferential direction of the side wall 114. The communication space 142 is directly communicated with the multiple communication holes 126. The communication space 142 is directly communicated with the outside of the working machine 2 at the lower end.

[0056] The liquid tank 24 further includes a one-way valve 144. The one-way valve 144 is attached to the second side portion 122. The one-way valve 144 is, for example, an umbrella valve. The one-way valve 144 is made of, for example, an elastic material, in this embodiment, a rubber material. The one-way valve 144 includes a fixed portion 146 and a valve portion 148. The fixed portion 146 is inserted into and fixed to the second side portion 122. The valve portion 148 is connected to one end of the fixed portion 146. The valve portion 148 has, for example, a disk shape. The valve portion 148 is elastically deformable. The valve portion 148 is disposed inside the liquid tank 24 between the second side portion 122 and the base member 128. The valve portion 148 is abuttable against the inner surface of the second side portion 122. The valve portion 148, by abutting against the inner surface of the second side portion 122, prohibits fluid (e.g., air and / or liquid) from flowing from inside the liquid tank 24 to the outside of the work machine 2 through the multiple communication holes 126. Moreover, the valve portion 148, by moving away from the inner surface of the second side portion 122, allows fluid to flow from the outside of the work machine 2 to inside the liquid tank 24 through the multiple communication holes 126.

[0057] The valve portion 148 is in contact with the inner surface of the second side portion 122 under normal conditions, for example, when the working machine 2 is not working. As a result, the multiple communication holes 126 are blocked, and the inside of the liquid tank 24 is not in communication with the outside of the working machine 2 through the multiple communication holes 126. When the working machine 2 is used to work, for example, when the working machine 2 is used to spray liquid from the discharge pipe 10 (see FIG. 1) or when the liquid in the liquid tank 24 is discharged to the outside of the liquid tank 24 through the discharge portion 90b and the discharge tube 91, the amount of liquid in the tank body 90 decreases. As a result, the volume of the void in the liquid tank 24 increases. Since the inside of the liquid tank 24 is not in communication with the outside of the working machine 2, the pressure of the void in the liquid tank 24 decreases. As shown in FIG. 15, when the pressure of the void in the liquid tank 24 becomes lower than the pressure (atmospheric pressure) outside the working machine 2, the valve portion 148 is elastically deformed to separate from the inner surface of the second side portion 122. As a result, air outside the work machine 2 flows into the communication space 142 from the underside of the tank cap 96, as shown in Fig. 15 as air flow AF, and passes through the communication space 142 and the multiple communication holes 126, and then flows into the inside of the liquid tank 24. This increases the pressure in the voids within the liquid tank 24. This makes it possible to prevent a situation in which it becomes difficult for the liquid in the liquid tank 24 to be supplied toward the discharge pipe 10, or a situation in which it becomes difficult for the liquid in the liquid tank 24 to be discharged to the outside of the liquid tank 24 via the discharge portion 90b and the discharge tube 91, due to a decrease in pressure in the voids within the liquid tank 24.

[0058] The frame unit 6 shown in FIG. 16 is fixed to the main body unit 4 (see FIG. 1). The frame unit 6 includes a pair of side frames 170, 172, a rear frame 174, a top frame 176, a lower frame 178, a first fixed frame 180, and a second fixed frame 182. Hereinafter, the pair of side frames 170, 172 may be referred to as the right side frame 170 and the left side frame 172. Each of the frames 170, 172, 174, 176, 178, 180, 182 is made of a metal material, for example, aluminum. Each of the frames 170, 172, 174, 176, 178, 180, 182 is elastically deformable by an external force acting thereon.

[0059] The right side frame 170 includes a first right side frame 170a extending in the front-rear direction, a second right side frame 170b extending downward from the front end of the first right side frame 170a, and a third right side frame 170c extending rearward from the lower end of the second right side frame 170b. A first contact member 184 is attached to the connection portion between the second right side frame 170b and the third right side frame 170c. The first contact member 184 is made of a resin material, for example, polycarbonate.

[0060] The left side frame 172 is disposed to the left of the right side frame 170. The left side frame 172 includes a first left side frame 172a extending in the front-rear direction, a second left side frame 172b extending downward from the front end of the first left side frame 172a, and a third left side frame 172c extending rearward from the lower end of the second left side frame 172b. A second contact member 186 is attached to the connection between the second left side frame 172b and the third left side frame 172c. The second contact member 186 is made of a resin material, for example, polycarbonate. The second contact member 186 has a shape similar to that of the first contact member 184.

[0061] The rear frame 174 is connected to the rear end of the third right side frame 170c and the rear end of the third left side frame 172c. The rear frame 174 is integrally formed with the pair of side frames 170, 172. The rear frame 174 extends in the left-right direction. A third contact member 188 is attached to the connection portion between the rear frame 174 and the third right side frame 170c. In addition, a fourth contact member 190 is attached to the connection portion between the rear frame 174 and the third left side frame 172c. The third contact member 188 and the fourth contact member 190 are made of a resin material, for example, polypropylene. As shown in FIG. 2, when the working machine 2 is placed on the placement surface P, only the first contact member 184, the second contact member 186, the third contact member 188, and the fourth contact member 190 contact the placement surface P.

[0062] 16, the top frame 176 is connected to the first right-side frame 170a and the first left-side frame 172a with screws. The top frame 176 extends rearward from the rear end of the first right-side frame 170a, then bends and extends to the left, and then bends and extends forward to the rear end of the first left-side frame 172a.

[0063] The lower frame 178 is connected to the third right side frame 170c and the third left side frame 172c. The lower frame 178 is disposed between the third right side frame 170c and the third left side frame 172c. The lower frame 178 is disposed forward of the rear frame 174. The lower frame 178 extends in the left-right direction.

[0064] The first fixed frame 180 is connected to the second right side frame 170b and the second left side frame 172b. The first fixed frame 180 extends in the left-right direction. The second fixed frame 182 is connected to the second right side frame 170b and the second left side frame 172b below the first fixed frame 180. The second fixed frame 182 extends in the left-right direction.

[0065] As shown in FIG. 17, a first fixing groove 192 and a second fixing groove 194 are formed in the opposing surface 30 of the main body housing 16. The first fixing groove 192 and the second fixing groove 194 are recessed rearward from the opposing surface 30. The first fixing groove 192 extends in the left-right direction near the upper end of the opposing surface 30. The second fixing groove 194 extends in the left-right direction near the lower end of the opposing surface 30. As shown in FIG. 18, the first fixing frame 180 is received in the first fixing groove 192 and fixed to the main body housing 16 by a screw. The upper surface of the first fixing frame 180 abuts against the upper surface of the first fixing groove 192 of the main body housing 16. When the first fixing frame 180 is received in the first fixing groove 192, the entire first fixing frame 180 is disposed rearward of the opposing surface 30 in the front-rear direction. The second fixed frame 182 is received in the second fixing groove 194 and fixed to the main body housing 16 by screws. The upper surface of the second fixed frame 182 abuts against the upper surface of the second fixing groove 194 of the main body housing 16. Furthermore, when the second fixed frame 182 is received in the second fixing groove 194, the entire second fixed frame 182 is disposed rearward of the opposing surface 30 in the front-to-rear direction. This makes it possible to prevent the first fixed frame 180 and the second fixed frame 182 from coming into contact with the user's back when the user carries the work machine 2 on his / her back.

[0066] 11, 13, and 18, a receiving groove 196 is formed in the lower part of the tank body 90. The receiving groove 196 extends from the front right end of the tank body 90 toward the rear, then bends and extends leftward from the right end to the left end of the tank body 90, and then bends and extends forward to the front left end of the tank body 90. The first right-side frame 170a, the first left-side frame 172a, and the top frame 176 are received in the receiving groove 196 and support the upper part of the tank body 90 from below.

[0067] The positional relationship between the main body unit 4 and the frame unit 6 when the frame unit 6 is fixed to the main body unit 4 will be described. As shown in FIG. 19, the second right side frame 170b is disposed on the right side (outside) of the main body housing 16 in the left-right direction. The second left side frame 172b is disposed on the left side (outside) of the main body housing 16. That is, the main body housing 16 is disposed between the second right side frame 170b and the second left side frame 172b. Therefore, the battery unit 22 (see FIG. 3) and the fan unit 18 (see FIG. 3), for example, the battery pack BP (see FIG. 3) and the electric motor 46 (see FIG. 7) are disposed between the second right side frame 170b and the second left side frame 172b.

[0068] In terms of the up-down direction, the top frame 176 is disposed above (outside) the main body housing 16. The rear frame 174 is disposed below (outside) the main body housing 16. In other words, the main body housing 16 is disposed between the top frame 176 and the rear frame 174. Therefore, the battery unit 22 and the fan unit 18, for example, the battery pack BP and the electric motor 46, are also disposed between the top frame 176 and the rear frame 174.

[0069] 5, in the front-rear direction, the rear frame 174 is disposed rearward (outward) from the main body housing 16. Therefore, the rear frame 174 is disposed rearward from the battery unit 22 and the fan unit 18, for example, from the battery pack BP and the electric motor 46.

[0070] As shown in Fig. 20, the lower frame 178 is disposed below (outside) the main body housing 16. The lower frame 178 faces a lower opposing surface 200 of the main body housing 16. The lower opposing surface 200 forms the lower surface of the main body housing 16. The lower opposing surface 200 has a curved shape that is convex downward toward the lower frame 178. In the left-right direction, the center of the lower opposing surface 200 is disposed closest to the lower frame 178, and both end portions of the lower opposing surface 200 are disposed furthest from the lower frame 178.

[0071] When the work machine 2 falls and collides with the placement surface P from the lower end side, at least one of the contact members 184, 186, 188, 190 collides with the placement surface P first. As a result, before the main body housing 16 collides with the placement surface P, the third right-side frame 170c (see FIG. 16) and / or the third left-side frame 172c (see FIG. 16) and / or the rear frame 174 (see FIG. 16) are elastically deformed. Thereafter, the lower frame 178 comes into contact with the lower opposing surface 200, and the lower frame 178 is elastically deformed to match the shape of the lower opposing surface 200. As a result, the impact caused by the fall is absorbed by the lower frame 178, and damage to the main body housing 16 is suppressed.

[0072] As shown in FIG. 18, the harness unit 8 is attached to the main unit 4. The harness unit 8 includes a pad 204, a waist belt 206, and a shoulder harness unit 208. The pad 204 is fixed to the opposing surface 30 of the main body housing 16. The pad 204 is disposed at a position facing the first fixing groove 192 of the main body housing 16. The pad 204 comes into contact with the user's back when the user carries the working machine 2 on his / her back. The waist belt 206 is disposed below the pad 204. The waist belt 206 is disposed at a position facing the second fixing groove 194 of the main body housing 16. The waist belt 206 is attached to the user's waist when the user carries the working machine 2 on his / her back.

[0073] The shoulder harness unit 208 includes a right shoulder harness 210 that is attached to the right shoulder of the user, and a left shoulder harness 212 that is attached to the left shoulder of the user. A first upper mounting portion 214 is formed on the opposing surface 90a of the tank body 90, and the right shoulder harness 210 is attached to the first upper mounting portion 214. The right shoulder harness 210 is directly attached to the tank body 90. A first lower mounting portion 216 is formed on the right end of the second fixing frame 182, and the right shoulder harness 210 is also attached to the first lower mounting portion 216. The first lower mounting portion 216 is disposed below the first upper mounting portion 214. The right shoulder harness 210 is attached to the main body housing 16 via the second fixing frame 182.

[0074] A second upper mounting portion 218 is formed on the opposing surface 90a of the tank body 90, and the left shoulder harness 212 is attached to the second upper mounting portion 218. The left shoulder harness 212 is directly attached to the tank body 90. A second lower mounting portion 220 is formed on the left end of the second fixing frame 182, and the left shoulder harness 212 is also attached to the second lower mounting portion 220. The second lower mounting portion 220 is disposed below the second upper mounting portion 218. The left shoulder harness 212 is attached to the main body housing 16 via the second fixing frame 182.

[0075] As shown in FIG. 21, in the left-right direction, the center position CP3 between the first upper mounting part 214 and the second upper mounting part 218 is disposed closer to the discharge pipe 10 (to the right) than the center position CP2 of the main body unit 4. The center position CP3 is located at the center between the geometric center of the first upper mounting part 214 and the geometric center of the second upper mounting part 218. That is, the left-right distance from the center position CP3 to the left end of the first upper mounting part 214 is substantially equal to the left-right distance from the center position CP3 to the right end of the second upper mounting part 218. In FIG. 21, the center position CP2 is illustrated by a dashed line, and the center position CP3 is illustrated by a dashed line. In the left-right direction, the center position CP2 is disposed between the first upper mounting part 214 and the second upper mounting part 218. When two battery packs BP (see FIG. 3) are disposed in the second internal space 38 (see FIG. 3) and the liquid tank 24 is filled with liquid to the maximum extent, the center of gravity of the main unit 4 is at the center of gravity G6, and the center of gravity of the working machine 2 is at the first overall center of gravity G8. When two battery packs BP are disposed in the second internal space 38 and no liquid is stored in the liquid tank 24, the center of gravity of the main unit 4 is at the center of gravity G7, and the center of gravity of the working machine 2 is at the second overall center of gravity G9. In the left-right direction, the center of gravity positions G6, G7, the first overall center of gravity position G8, and the second overall center of gravity position G9 are disposed between the first upper mounting portion 214 and the second upper mounting portion 218. The center of gravity positions G6, G7, the first overall center of gravity position G8, and the second overall center of gravity position G9 are disposed on the discharge pipe 10 side (right side) of the center position CP2. The center of gravity position G6 and the first overall center of gravity position G8 are located on the opposite side (left side) of the discharge pipe 10 from the center position CP3. The first overall center of gravity position G8 is located closer to the center position CP3 than the center of gravity position G6. The center of gravity position G7 and the second overall center of gravity position G9 are located closer to the discharge pipe 10 (right side) than the center position CP3. The second overall center of gravity position G9 is located farther away from the center of gravity position G7 than the center position CP3. In the left-right direction, the center position CP3 is located approximately in the center between the first overall center of gravity position G8 and the second overall center of gravity position G9.That is, the distance in the left-right direction from the center position CP3 to the first overall center-of-gravity position G8 is approximately equal to the distance in the left-right direction from the center position CP3 to the second overall center-of-gravity position G9.

[0076] Next, the supply line 113 will be described. As shown in FIG. 8 and FIG. 11, the supply line 113 includes a first supply pipe 230, a first supply cock 232, an electromagnetic valve 234, a supply tube 236, a second supply cock 238, a second supply pipe 240, and a third supply cock 242. When the work machine 2 is working, the first supply cock 232, the second supply cock 238, and the third supply cock 242 are open. As shown in FIG. 11, the first supply pipe 230 is connected to the supply section 90c of the tank body 90. The first supply pipe 230 is made of a metal material. The first supply cock 232 and the electromagnetic valve 234 are arranged on the first supply pipe 230. The first supply cock 232 is operated by the user's hand. The first supply cock 232 opens and closes the first supply pipe 230. Although not shown, the solenoid valve 234 is disposed inside the main body housing 16 (see FIG. 3). The solenoid valve 234 is electrically connected to the control board 56 (see FIG. 7). The solenoid valve 234 opens and closes under the control of the control board 56.

[0077] The supply tube 236 is connected to the first supply pipe 230. The supply tube 236 is made of, for example, a resin material. As shown in FIG. 8, the supply tube 236 extends along the discharge pipe 10. The second supply cock 238 is disposed on the supply tube 236. The supply tube 236 is fixed to the discharge pipe 10 at a position where the second supply cock 238 is disposed. The second supply cock 238 is operated by a user's hand. The second supply cock 238 opens and closes the supply tube 236.

[0078] As shown in FIG. 22, the second supply pipe 240 is connected to the supply tube 236. The second supply pipe 240 is made of, for example, a resin material. The tip tube 66 includes a first tip tube 67 and a second tip tube 68 attached to the front end of the first tip tube 67, and the second supply pipe 240 is formed integrally with the first tip tube 67. The second supply pipe 240 includes an outer portion 244, a first inner portion 246, and a second inner portion 248. The outer portion 244 is disposed outside the tip tube 66. The third supply cock 242 is disposed in the outer portion 244. The third supply cock 242 is operated by the user's hand. The third supply cock 242 opens and closes the outer portion 244. The first inner portion 246 and the second inner portion 248 are disposed inside the tip tube 66. The first inner portion 246 extends downward from the lower end of the outer portion 244. The second inner portion 248 extends from the lower end of the first inner portion 246 toward the discharge opening 68a of the second end tube 68. When the first supply cock 232 (see FIG. 11), the solenoid valve 234 (see FIG. 11), the second supply cock 238 (see FIG. 8), and the third supply cock 242 are open, the liquid in the liquid tank 24 (see FIG. 8) can flow through the first supply pipe 230 (see FIG. 8), the supply tube 236, and the second supply pipe 240.

[0079] In the following, an example will be described in which the longitudinal direction of the tip tube 66 is aligned with the front-rear direction. The working machine 2 further includes a tubular member 250 and a liquid nozzle 252. The tubular member 250 is disposed inside the second tip tube 68. The tubular member 250 has a generally cylindrical shape with a longitudinal direction. The tubular member 250 includes a front-side tubular portion 250a and a rear-side tubular portion 250b. The front-side tubular portion 250a is connected to the second tip tube 68 via a plurality of fins 254. The front-side tubular portion 250a, the plurality of fins 254, and the second tip tube 68 are integrally formed. The rear-side tubular portion 250b is disposed on the rear side of the front-side tubular portion 250a. The rear-side tubular portion 250b is connected to the fins 254 and the second tip tube 68 by a screw. The diameter of the inner surface of the tubular member 250 becomes smaller from the rear end toward the front end, and then becomes larger. A portion of the air flowing inside the tip tube 66 flows inside the tubular member 250 as indicated by arrow F1 in FIG. 22, and the remainder of the air flowing inside the tip tube 66 flows outside the tubular member 250 as indicated by arrow F2 in FIG. 22.

[0080] The liquid nozzle 252 is, for example, a nozzle of a high concentration small volume spray (Ultra Low Volume) type. The liquid nozzle 252 is disposed inside the second end tube 68. The front end of the liquid nozzle 252 is disposed at a position closest to the discharge opening 68a of the second end tube 68 (the frontmost side), and the rear end of the liquid nozzle 252 is disposed at a position farthest from the discharge opening 68a of the second end tube 68 (the rearmost side). The front end of the liquid nozzle 252 corresponds to the tip of the liquid nozzle 252, and the rear end of the liquid nozzle 252 corresponds to the base end of the liquid nozzle 252. The liquid nozzle 252 has a longitudinal direction in the front-rear direction. The liquid nozzle 252 is made of a metal material, for example, brass. In a modified example, the liquid nozzle 252 may be made of a resin material. As shown in FIG. 23, the liquid nozzle 252 includes an insertion portion 256 and a nozzle portion 258. The insertion portion 256 has a substantially cylindrical shape. As shown in FIG. 24, an elastic member 262 is attached to the outer surface of the insert portion 256. The elastic member 262 is, for example, an O-ring. A male screw portion 264 is formed on the outer surface of the insert portion 256. A female screw portion 248a is formed on the inner surface of the second inner portion 248. The insert portion 256 is connected to the second inner portion 248 by inserting the insert portion 256 into the inner surface of the second inner portion 248 and screwing the male screw portion 264 of the insert portion 256 into the female screw portion 248a of the second inner portion 248. When the insert portion 256 is connected to the second inner portion 248, the elastic member 262 is sandwiched between the outer surface of the insert portion 256 and the inner surface of the second inner portion 248. This seals the gap between the outer surface of the insert portion 256 and the inner surface of the second inner portion 248.

[0081] The nozzle portion 258 is connected to the front end of the insertion portion 256. The nozzle portion 258 has a side surface 266. The side surface 266 forms at least a part of the outer shape of the nozzle portion 258. A part of the air flowing inside the tip tube 66 (see FIG. 22) flows toward the front end (tip) of the liquid nozzle 252 along the side surface 266 as shown by the arrow F1. The side surface 266 has a first side surface 268 and a second side surface 270. The diameter of the rear end of the first side surface 268 is approximately equal to the diameter of the outer surface of the second inner portion 248. The diameter of the first side surface 268 becomes smaller from the rear end to the front end of the nozzle portion 258. The first side surface 268 has a smooth curved shape. The second side surface 270 is disposed on the front side of the first side surface 268. The diameter of the second side surface 270 is equal to the diameter of the front end of the first side surface 268 and is constant in the front-rear direction. As shown in FIG. 22, at least a portion of the first side surface 268 and the second side surface 270 are surrounded by the rear tube portion 250b.

[0082] As shown in FIG. 24, the liquid nozzle 252 further includes a liquid passage 274. The liquid passage 274 is disposed inside the insertion portion 256 and the nozzle portion 258. The liquid passage 274 extends from the rear end (base end) to the front end (tip end) of the liquid nozzle 252. The liquid passage 274 is disposed on the central axis CX of the liquid nozzle 252. In FIG. 24 and FIG. 25, the central axis CX is illustrated by a broken line. The central axis CX extends in the front-rear direction (the longitudinal direction of the liquid nozzle 252). The liquid passage 274 includes a main passage 276, a transition passage 278, and a throttle passage 280. The diameter of the main passage 276 is, for example, 5 mm. The main passage 276 extends from the rear end of the insertion portion 256 toward the front side. The main passage 276 is disposed across the insertion portion 256 and the nozzle portion 258. 25, the transition passage 278 is connected to the main passage 276. The diameter of the transition passage 278 gradually decreases toward the front side. The diameter of the throttle passage 280 is smaller than the diameter of the main passage 276. The diameter of the throttle passage 280 is, for example, 0.5 mm. The throttle passage 280 extends from the front end of the transition passage 278 to a tip surface 282 of the nozzle portion 258.

[0083] The tip surface 282 of the nozzle portion 258 corresponds to the tip surface of the liquid nozzle 252. The tip surface 282 includes an inclined surface 284 and a non-inclined surface 286. The inclined surface 284 is provided with an outlet 280a of the throttle passage 280. The outlet 280a is provided at the center of the inclined surface 284. The center of the inclined surface 284 is provided on the central axis CX. When a plane perpendicular to the central axis CX is defined as a virtual plane VP1, the inclined surface 284 is inclined with respect to the virtual plane VP1. In FIG. 25, the virtual plane VP1 is illustrated by a dashed line. The inclination angle of the inclined surface 284 with respect to the virtual plane VP1 is, for example, 5 degrees or more, and in this embodiment, is 20 degrees. The front end of the inclined surface 284 is provided forward of the rear end of the inclined surface 284 (the tip side of the liquid nozzle 252). The front end of the inclined surface 284 is farther from the central axis CX than the rear end of the inclined surface 284. That is, the inclined surface 284 becomes more distant from the central axis CX as it approaches the front side (the tip side of the liquid nozzle 252).

[0084] The non-inclined surface 286 is disposed around the entire periphery of the inclined surface 284. The non-inclined surface 286 is disposed forward of the inclined surface 284. The non-inclined surface 286 is farther from the central axis CX than the inclined surface 284. The non-inclined surface 286 is approximately parallel to the imaginary plane VP1. The non-inclined surface 286 is inclined with respect to the inclined surface 284. In addition, the non-inclined surface 286 is approximately perpendicular to the second side surface 270.

[0085] The liquid nozzle 252 further includes a corner portion 290. The corner portion 290 is farther from the central axis CX than the non-inclined surface 286. As shown in FIG. 26, the corner portion 290 connects the second side surface 270 and the non-inclined surface 286. FIG. 26 is an enlarged cross-sectional view of the corner portion 290 of the liquid nozzle 252, and the corner portion 290 is exaggerated. The corner portion 290 is disposed around the entire circumference of the non-inclined surface 286. The corner portion 290 constitutes a corner of the front end (tip) of the liquid nozzle 252. The radius of curvature of the corner portion 290 is, for example, 0.3 mm or less. The corner portion 290 is a sharp corner (pin angle). The corner portion 290 may be sharp at an acute angle or may be sharp at an obtuse angle. The corner portion 290 has a curved shape. In a modified example, the corner portion 290 may have a planar shape. The corner portion 290 is connected to the second side surface 270 at a side surface connection point 292, and is connected to the non-inclined surface 286 at a tip connection point 294. In the vicinity of the corner portion 290, a virtual side surface 296 extending from the second side surface 270 and a virtual tip surface 298 extending from the non-inclined surface 286 intersect at a first point 300 at a substantially right angle. The distance L1 between the first point 300 and the side surface connection point 292 is, for example, 0.3 mm or less. The distance L2 between the first point 300 and the tip connection point 294 is, for example, 0.3 mm or less. The distance L2 is substantially equal to the distance L1. In a modified example, the distance L2 may be different from the distance L1.

[0086] Next, a method for manufacturing the liquid nozzle 252 will be described. The manufacturing method includes an insertion portion cutting step, a tip surface cutting step, a side surface cutting step, and a liquid flow path forming step. As shown in FIG. 24, in the insertion portion cutting step, a cutting blade is moved from the rear end (base end) of the liquid nozzle 252 toward the front end (tip end) to form the insertion portion 256 in the liquid nozzle 252. Also, the cutting blade is moved spirally in the circumferential direction of the outer surface of the insertion portion 256 to form a male screw portion 264 in the insertion portion 256. Next, as shown in FIG. 26, in the tip surface cutting step, the cutting blade is moved in a direction away from the central axis CX (in the first direction D1 in FIG. 26) starting from the central axis CX at the front end (tip end) of the liquid nozzle 252 to form a tip surface 282 in the liquid nozzle 252. Next, in the side cutting process, the cutting blade is moved from the insertion portion 256 toward the tip surface 282 (in the second direction D2 in FIG. 26) on the side of the liquid nozzle 252 to form the side surface 266 on the liquid nozzle 252. As a result, a sharp corner portion 290 is formed at the front end (tip) of the liquid nozzle 252. At this time, a minute protrusion (burr) (not shown) is formed on the corner portion 290, and this protrusion is disposed on the central axis CX side from the second side surface 270 and extends toward the front side. In other words, the protrusion does not protrude in a direction away from the central axis CX from the second side surface 270. Finally, as shown in FIG. 24, in the liquid flow path forming process, a hole puncher is inserted into the liquid nozzle 252 to form a liquid passage 274 in the liquid nozzle 252.

[0087] Next, the behavior of the liquid discharged from the liquid nozzle 252 being atomized will be described. First, as shown in FIG. 22, when the electric motor 46 (see FIG. 7) rotates to rotate the fan 44 (see FIG. 7), air flows into the discharge pipe 10. After flowing through the discharge pipe 10 to the tip pipe 66, the air flows into the inside of the tubular member 250 as indicated by the arrow F1 in FIG. 22, and flows along the side surface 266 of the liquid nozzle 252 toward the front end (tip) of the liquid nozzle 252. In addition, since the first side surface 268 of the liquid nozzle 252 is surrounded by the tubular member 250 and the diameter of the first side surface 268 becomes smaller from the rear end to the front end of the nozzle portion 258, the air flows more easily into the inside of the tubular member 250, and the space through which the air flows (the space around the first side surface 268) becomes narrower, thereby increasing the flow rate of the air. The air flowing along the side surface 266 passes through the liquid nozzle 252 and flows inside the tubular member 250 from the rear end to the front end of the tubular member 250. As shown in FIG. 25, this air flow generates a pressure difference between the area near the side surface 266 and the front area of ​​the tip surface 282 of the liquid nozzle 252, and as a result, an air flow (vortex flow) SW1 shown in FIG. 25 is generated in the front area of ​​the tip surface 282 of the liquid nozzle 252. The air flow SW1 first flows toward the tip surface 282 of the liquid nozzle 252 along the central axis CX. Next, the air flow SW1 bends in a direction away from the central axis CX and flows on the tip surface 282 toward the corner 290, in the order of the inclined surface 284 and the non-inclined surface 286. Finally, the air flow SW1 merges with the air flow flowing along the side surface 266 near the corner 290.

[0088] As air flow SW1 flows over tip surface 282 toward corner 290, the liquid discharged from discharge port 280a of throttle passage 280 to the outside of liquid nozzle 252 flows over tip surface 282, in this order, inclined surface 284 and non-inclined surface 286, toward corner 290. The generation of this air flow SW1 causes the liquid to be discharged from discharge port 280a to the outside of liquid nozzle 252 without using a driving source such as a pump.

[0089] The liquid that has flowed up to the corner 290 moves towards the side surface 266. Because the corner 290 is a sharp corner, the liquid is less likely to form a puddle on the corner 290, and moves smoothly from the corner 290 towards the side surface 266. As a result, when the liquid collides with the air flowing along the side surface 266, the liquid is atomized. The liquid is atomized to have a diameter of, for example, 50 micrometers or less. Due to the configuration of the liquid nozzle 252 of this embodiment, the electric motor 46-driven (electric) working machine 2 of this embodiment can atomize the liquid even though the air volume of the fan 44 is lower than that of an engine-driven working machine.

[0090] 22, the atomized liquid flows inside the tip tube 66 together with the air flowing inside the tubular member 250 as indicated by the arrow F1. Thereafter, the liquid and air flowing inside the tubular member 250 merge with the air flowing outside the tubular member 250 as indicated by the arrow F2, and are discharged (sprayed) from the diffusion cover 70 to the outside of the second tip tube 68.

[0091] (effect) The working machine 2 of this embodiment discharges liquid. The working machine 2 includes a discharge pipe 10 that discharges liquid, and a liquid tank 24. The liquid tank 24 includes a tank body 90 that stores liquid, a supply port 116 for supplying liquid to the tank body 90, and a communication hole 126. The liquid tank 24 includes a protrusion 92 that is disposed on the upper part of the tank body 90 when the working machine 2 is placed on the placement surface P, a tank cap 96 (an example of a cap) that engages with the protrusion 92 and closes the supply port 116, and a one-way valve 144 attached to the protrusion 92. When the tank cap 96 engages with the protrusion 92 and closes the supply port 116, the communication hole 126 communicates between the inside of the liquid tank 24 and the outside of the working machine 2. The one-way valve 144 is configured to prohibit the flow of fluid from the inside of the liquid tank 24 to the outside of the work machine 2 through the communication hole 126, and to allow the flow of fluid from the outside of the work machine 2 to the inside of the liquid tank 24 through the communication hole 126.

[0092] According to the above configuration, even when the tank cap 96 is engaged with the protruding portion 92 and blocking the supply port 116, when the one-way valve 144 is opened, the inside of the liquid tank 24 and the outside of the work machine 2 communicate with each other via the communication hole 126. Even if the amount of liquid stored in the liquid tank 24 decreases, a decrease in pressure in the void within the liquid tank 24 can be suppressed by fluid, for example air, flowing into the inside of the liquid tank 24 via the communication hole 126. This makes it possible to suppress the liquid from becoming difficult to be supplied toward the discharge pipe 10.

[0093] The protrusion 92 also includes a side wall 114 that defines a supply port 116. The communication hole 126 is disposed in the side wall 114.

[0094] According to the above configuration, it is possible to prevent the configuration of the protruding portion 92 from becoming complicated, and to prevent the liquid from becoming difficult to be supplied toward the discharge pipe 10.

[0095] The tank cap 96 also includes an engaging rail 140 that extends spirally. The side wall 114 includes a first side portion 120 that includes an engaged rail 124 that extends circumferentially around the outer surface of the side wall 114 and engages with the engaging rail 140, and a second side portion 122 that does not include an engaged rail 124 in the circumferential direction of the outer surface of the side wall 114. The communication hole 126 is disposed in the second side portion 122.

[0096] According to the above configuration, an area in which the engaged rail 124 is disposed and an area in which the communication hole 126 is disposed are distinguished on the side wall 114. The engagement between the engaged rail 124 and the engaging rail 140 can prevent the inside of the liquid tank 24 and the outside of the work machine 2 from becoming difficult to communicate with each other via the communication hole 126.

[0097] Additionally, the second side portion 122 is recessed radially inwardly relative to the first side portion 120 .

[0098] According to the above configuration, even when the tank cap 96 engages with the protruding portion 92, the outer surface of the second side portion 122 does not come into contact with the tank cap 96. This makes it possible to prevent the inside of the liquid tank 24 and the outside of the work machine 2 from becoming difficult to communicate with each other via the communication hole 126.

[0099] Moreover, the one-way valve 144 is disposed inside the liquid tank 24 and includes a valve portion 148 that is capable of closing the communication hole 126 .

[0100] According to the above-mentioned configuration, it is possible to prevent foreign matter, such as sand, outside the liquid tank 24 from adhering to the valve portion 148. This makes it possible to prevent the one-way valve 144 from becoming difficult to open and close due to sand or the like.

[0101] The liquid tank 24 also includes a filter unit 94 that can be attached to the supply port 116 of the protruding portion 92 and captures foreign matter contained in the liquid when the liquid is supplied to the tank body 90. The valve portion 148 is disposed between the filter unit 94 and the side wall 114.

[0102] The above configuration can prevent foreign matter contained in the liquid, such as sand, from adhering to the valve portion 148. This can prevent the one-way valve 144 from becoming difficult to open and close due to sand or the like.

[0103] Furthermore, when the tank cap 96 engages with the protruding portion 92 to close the supply port 116 , the communication hole 126 is covered by the tank cap 96 .

[0104] According to the above-described configuration, it is possible to prevent sand or the like outside the liquid tank 24 from clogging the communication hole 126.

[0105] Furthermore, when the tank cap 96 engages with the protruding portion 92 to close the supply port 116, a communication space 142 is defined between the tank cap 96 and the protruding portion 92. The communication hole 126 communicates the interior of the liquid tank 24 with the communication space 142. The communication space 142 communicates with the outside of the work machine 2 at its lower end.

[0106] According to the above-mentioned configuration, sand or the like outside the liquid tank 24 is unlikely to enter the communication space 142. This makes it possible to further prevent the communication hole 126 from being blocked by sand or the like.

[0107] Additionally, the one-way valve 144 is an umbrella valve.

[0108] According to the above configuration, the one-way valve 144 can be opened with a relatively weak force.

[0109] (Modification) The work machine 2 according to one embodiment may be an engine-powered work machine.

[0110] The work machine 2 according to one embodiment is not limited to a mist blower, and may be, for example, a sprayer or a high-pressure cleaner.

[0111] The work machine 2 according to one embodiment may be a work machine equipped with a built-in battery. In this case, the built-in battery is charged by connecting a power cord to an external power source.

[0112] The battery unit 22 according to one embodiment may include only one battery pack BP.

[0113] The working machine 2 according to one embodiment is not limited to a backpack-type working machine, and may be, for example, a stationary working machine or a handheld working machine.

[0114] The one-way valve 144 according to one embodiment is not limited to an umbrella valve, but may be, for example, a duckbill valve.

[0115] The liquid tank 24 according to one embodiment does not necessarily have to include the filter unit 94 .

[0116] In the liquid tank 24 according to one embodiment, the side wall 114 may not include the second side portion 122. In this case, the multiple communication holes 126 may be arranged in the first side portion 120 at a location where the engaged rail 124 is partially discontinued.

[0117] The shoulder harness unit 208 according to one embodiment does not have to be attached to the liquid tank 24. In this case, the shoulder harness unit 208 is attached only to the main body housing 16.

[0118] In the work machine 2 according to one embodiment, the vertical arrangement of the fan unit 18, the battery unit 22, and the liquid tank 24 is not limited to the configuration of this embodiment. For example, the fan unit 18 may be arranged above the battery unit 22, and the liquid tank 24 may be arranged above the fan unit 18.

[0119] 27, in a liquid nozzle 252 according to one embodiment, a plurality of discharge ports 280a may be formed in a tip surface 282. The plurality of discharge ports 280a may be arranged, for example, around a central axis CX.

[0120] 28, in the liquid nozzle 252 according to one embodiment, the tip surface 282 may further include a central non-inclined surface 310. The central non-inclined surface 310 is approximately parallel to the imaginary plane VP1. The discharge port 280a of the throttle passage 280 is arranged in the central non-inclined surface 310. The inclined surface 284 is connected to the periphery of the central non-inclined surface 310.

[0121] In one embodiment of the fluid nozzle 252, the tip surface 282 does not need to include the non-inclined surface 286. In this case, the inclined surface 284 is connected to the corner portion 290.

[0122] In one embodiment of the liquid nozzle 252, the corner portion 290 may be disposed on only a portion of the circumferential edge of the tip surface 282 in the circumferential direction. [Explanation of symbols]

[0123] 2: Work equipment 4: Main unit 4a, 30, 90a: opposing surfaces 6: Frame unit 10: Release tube 16: Main housing 18: Fan unit 20: Control unit 22: Battery unit 24: Liquid tank 44: Fan 46: Electric motor 66: Tip tube 84: Right battery mounting area 86: Left battery mounting area 90: Tank body 92:Protrusion 94: Filter unit 96: Tank cap 114: Side wall 116: Supply port 120: First side 122: Second side 124: Engaged rail 126:Communication hole 140: Engagement rail 142:Communication space 144: One-way valve 148: Valve section 170: Right side frame 172: Left side frame 174: Rear frame 178: Lower Frame 196: Receiving groove 200: Lower facing surface 208: Shoulder harness unit 210: Right shoulder harness 212: Left shoulder harness 214: First upper mounting part 218: Second upper mounting part 250: Cylinder parts 252: Liquid nozzle 258: Nozzle section 266: Side 268 :1st side 270:Second side 274:Liquid passage 280a: Outlet 282:Tip surface 284: Inclined surface 290: Corner 296: Virtual side 298: Virtual tip surface BP: Battery pack CP1, CP2, CP3: Center position CX: Central axis G1, G2, G3, G4, G5, G6, G7, G8, G9: Center of gravity position P: Placement surface SW1: Air flow VP1: Virtual surface

Claims

1. A work machine that discharges liquid, A discharge pipe for discharging the liquid; A liquid tank; and The liquid tank includes: A tank body that stores the liquid; a protrusion having a supply port for supplying the liquid to the tank body and a communication hole, the protrusion being disposed on an upper portion of the tank body when the working machine is placed on a placement surface; a cap that engages with the protrusion to close the supply port; a one-way valve attached to the protrusion, when the cap is engaged with the protruding portion to close the supply port, the communication hole communicates between the inside of the liquid tank and the outside of the working machine, The one-way valve is configured to prohibit a flow of fluid from the inside of the liquid tank to the outside of the work machine through the communication hole, and to allow the flow of fluid from the outside of the work machine to the inside of the liquid tank through the communication hole.

2. the protrusion has a sidewall defining the supply opening; The work machine according to claim 1 , wherein the communication hole is disposed in the side wall.

3. The cap includes a spirally extending engagement rail; The side wall is a first side portion including an engaged rail extending circumferentially along an outer surface of the side wall, the engaged rail engaging with the engaging rail; a second side portion on which the engaged rail is not formed in the circumferential direction of the outer surface of the side wall, The work machine according to claim 2 , wherein the communication hole is disposed in the second side portion.

4. The work machine according to claim 3 , wherein the second side portion is recessed radially inwardly from the first side portion.

5. The work machine according to claim 2 , wherein the one-way valve is disposed inside the liquid tank and includes a valve portion capable of closing the communication hole.

6. the liquid tank includes a filter unit that can be attached to the supply port of the protruding portion and that captures foreign matter contained in the liquid when the liquid is supplied to the tank body; The work machine according to claim 5 , wherein the valve portion is disposed between the filter unit and the side wall.

7. The work machine according to claim 1 , wherein when the cap is engaged with the protruding portion to close the supply port, the communication hole is covered by the cap.

8. When the cap is engaged with the protrusion to close the supply port, a communication space is defined between the cap and the protrusion, the communication hole communicates the interior of the liquid tank with the communication space, The work machine according to claim 7 , wherein the communication space communicates at a lower end with the outside of the work machine.

9. The work machine according to claim 1 , wherein the one-way valve is an umbrella valve.

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