Work machine and nozzle

Abstract

To provide a work machine and a nozzle that can satisfy the needs for increasing a gas discharge amount and discharging gas over a wide range, and has improved convenience.SOLUTION: A nozzle 40 comprises: an inflow part 41 into which air exhausted from an exhaust part flows; a discharge part 42 whose flow path area along a plane perpendicular to an air circulation direction is larger than that of the inflow part 41, and which discharges air downstream of the inlet section 41; and a pipe part 43 which is provided between the inflow part 41 and the discharge part 42 and through which air flows from the inflow part 41 toward the discharge part 42. The pipe part 43 is provided with a vent port 44 which communicates the inside and outside of the pipe part 43. This makes it possible to realize an air duster which can increase an air discharge amount and discharge air over a wide range. Therefore, it is possible to improve convenience of the air duster.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a work machine including a fan that rotates by the driving force of a motor and a nozzle that discharges gas by the rotation of the fan, and to a nozzle that is detachably provided in an exhaust section of the work machine body. [Background technology]

[0002] For example, Patent Document 1 describes a blower device having a main body and an exhaust pipe. The main body has a fan rotated by the driving force of an engine, and the exhaust pipe has a nozzle that discharges gas by the rotation of the fan. A protuberance (convex portion) is provided in the center of the nozzle opening to discharge a large amount of gas and to allow the gas flowing out from the center to reach a long distance. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-264298 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the technology described in the above-mentioned Patent Document 1, it is difficult to further increase the amount of gas (air volume) discharged from the nozzle or to discharge the gas over a wider range.

[0005] An object of the present invention is to provide a working machine and a nozzle that can meet the needs for increasing the amount of gas discharged and for enabling the gas to be discharged over a wide range, and that have improved convenience. [Means for solving the problem]

[0006] One form of a work machine comprises a motor, a fan that rotates by the driving force of the motor, a housing that houses the fan and has an intake section arranged upstream of the fan and an exhaust section arranged downstream of the fan, and a nozzle that is detachably provided to the exhaust section, the nozzle comprising an inlet section into which gas exhausted from the exhaust section flows, a discharge section having a flow path area along a perpendicular plane perpendicular to the flow direction of the gas larger than that of the inlet section and discharging the gas downstream of the inlet section, and a pipe section provided between the inlet section and the discharge section through which the gas flows from the inlet section to the discharge section, and the pipe section is provided with an air vent that connects the inside and outside of the pipe section.

[0007] In one embodiment of the nozzle, the nozzle is removably attached to an exhaust section of a work machine body, and comprises an inlet section into which gas exhausted from the exhaust section flows, a discharge section having a flow path area along a perpendicular plane perpendicular to the flow direction of the gas larger than that of the inlet section and discharging the gas downstream of the inlet section, and a pipe section provided between the inlet section and the discharge section through which the gas flows from the inlet section to the discharge section, and the pipe section is provided with an air vent connecting the inside and outside of the pipe section. Effect of the Invention

[0008] According to the present invention, it is possible to meet the needs for increasing the amount of gas discharged and for enabling the gas to be discharged over a wide range, and it is possible to realize a work machine and a nozzle with improved convenience. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a perspective view of the blower as viewed from the nozzle side. [Diagram 2] FIG. 2 is a view taken along the arrow A in FIG. [Diagram 3] FIG. 3 is a cross-sectional view taken along line BB in FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line CC in FIG. [Diagram 5] FIG. 5 is a view taken along the arrow D in FIG. 4. [Figure 6]FIG. 5 is a view taken along the arrow E in FIG. 4. [Figure 7] FIG. 2 is a view of the nozzle alone as seen from the direction of arrow A in FIG. [Figure 8] 8 is a cross-sectional view taken along lines FF, GG, HH and JJ in FIG. 7. [Figure 9] FIG. 4 is a view corresponding to FIG. 3 and illustrating the flow of gas inside the housing. [Figure 10] FIG. 5 is a diagram corresponding to FIG. 4 and illustrating the flow of gas inside the nozzle. [Figure 11] FIG. 4 is a diagram showing an analysis result of the first embodiment. [Figure 12] FIG. 13 is a diagram showing an analysis result of a comparative example. [Figure 13] FIG. 11 is a top view of the nozzle of the second embodiment. [Figure 14] FIG. 11 is a view of the nozzle of the second embodiment as viewed from below. [Figure 15] FIG. 7 is a view of a nozzle according to a second embodiment, which corresponds to FIG. 6. [Figure 16] FIG. 5 is a view of a nozzle according to a second embodiment, which corresponds to FIG. [Figure 17] FIG. 11 is a diagram showing an analysis result of the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] <Embodiment 1> Hereinafter, the first embodiment of the present invention will be described in detail with reference to the drawings.

[0011] Figure 1 is an oblique view of the blower from the nozzle side, Figure 2 is a view taken from the direction of arrow A in Figure 1, Figure 3 is a cross-sectional view taken along line BB in Figure 2, Figure 4 is a cross-sectional view taken along line CC in Figure 3, Figure 5 is a view taken from the direction of arrow D in Figure 4, Figure 6 is a view taken from the direction of arrow E in Figure 4, Figure 7 is a view of the nozzle alone taken from the direction of arrow A in Figure 1, and Figure 8 is cross-sectional views taken along lines FF, GG, HH and JJ in Figure 7.

[0012] <Air Duster Overview> 1 to 3, the air duster 10 corresponds to the working machine of the present invention, and is a blower that can be held by a worker in one hand. The air duster 10 includes an air duster main body 20 and a nozzle 40 that is detachably attached to the air duster main body 20. Here, the air duster 10 is used, for example, to blow away dust and the like that has adhered to an air conditioner filter, or to inflate an air mat, a floating ring, or the like.

[0013] <Air duster body> The air duster body 20 corresponds to the work machine body in the present invention, and includes a resin housing 21. The housing 21 is formed by butting a first housing half 21a and a second housing half 21b together, and is hollow inside.

[0014] 1, the housing 21 includes a motor accommodating section 22 and a battery mounting section 23. In addition, a handle section 24 that is held by an operator is provided between the motor accommodating section 22 and the battery mounting section 23 in the vertical direction of FIG.

[0015] 1 and 3, the direction in which the motor housing section 22, the handle section 24, and the battery mounting section 23 are arranged is defined as the up-down direction. The direction in which the motor housing section 22 and the nozzle 40 are arranged, i.e., the direction in which the air Air (see Figs. 9 and 10) flows, is defined as the front-rear direction. Furthermore, the direction in which the first and second housing halves 21a, 21b butt together, i.e., the direction in which the first and second housing halves 21a, 21b face each other, is defined as the left-right direction.

[0016] <Motor housing> As shown in Fig. 3, a motor unit 50 is housed inside the motor accommodating section 22. When the motor unit 50 is driven, a flow of air (Air) is generated inside the motor accommodating section 22, and the air (Air) circulates inside the motor accommodating section 22. Specifically, when the motor unit 50 is driven, a fan 54 forming the motor unit 50 is rotated, and air (Air) (see Fig. 9) flows from the rear to the front of the motor accommodating section 22.

[0017] An intake section 22a serving as an air inlet is provided behind the motor accommodating section 22, and an exhaust section 22b serving as an air outlet is provided in front of the motor accommodating section 22. That is, a fan 54 is accommodated in the motor accommodating section 22 of the housing 21, and the intake section 22a is disposed upstream of the fan 54, and the exhaust section 22b is disposed downstream of the fan 54. In other words, a motor unit 50 having a fan 54 is provided between the intake section 22a and the exhaust section 22b.

[0018] Here, the upstream side of the fan 54 is the side from which the air flows toward the fan 54, and the downstream side of the fan 54 is the side from which the air flows away from the fan 54.

[0019] Further, a nozzle fixing portion 22c is integrally provided with the exhaust portion 22b of the motor housing portion 22. A cylindrical portion 43b (see FIG. 4) forming the nozzle 40 is detachably attached to the nozzle fixing portion 22c. That is, the nozzle 40 is detachably provided on the exhaust portion 22b.

[0020] Furthermore, an LED light LT is provided on the nozzle 40 side (front side) of the motor housing 22 so as to be aligned vertically with the exhaust part 22b. The LED light LT turns on when the air duster 10 is in operation, and illuminates the front of the air duster 10. In other words, the LED light LT illuminates the direction in which the air Air is discharged. This ensures that workability is not impaired even at night or in the dark.

[0021] <Motor unit> 3, the motor unit 50 includes a drive unit 51. The drive unit 51 includes a brushless motor 53 having a rotating shaft 52, a fan 54 rotated by the rotating shaft 52, and a control board 55 that controls the brushless motor 53. The brushless motor 53 corresponds to the motor in the present invention.

[0022] Fan 54 is a turbo centrifugal fan disposed on one axial side (rear side) of brushless motor 53. That is, fan 54 is rotated by the driving force of brushless motor 53, draws in air from the center of fan 54, and discharges the drawn air radially outward of fan 54.

[0023] Further, drive system electronic components (not shown) such as FETs that switch at high speed are mounted on the control board 55. Furthermore, a power supply line (not shown) that supplies a drive current to the brushless motor 53 and a signal line (not shown) that supplies an on signal and an off signal from the trigger switch SW to the control board 55 are electrically connected to the control board 55.

[0024] <Fan case> The motor unit 50 includes a resin fan case 56. The fan case 56 is formed in a substantially cylindrical shape, and covers one axial side (rear side) of the drive unit 51. The fan case 56 is accommodated inside the housing 21 (motor accommodating section 22), and the brushless motor 53 and the fan 54 that form the drive unit 51 are accommodated inside the fan case 56.

[0025] The fan case 56 includes a bottom wall 56a and a side wall 56b, and the fan 54 is disposed near the bottom wall 56a. An intake opening 56c is provided in the center of the bottom wall 56a so as to face the center of the fan 54 in the axial direction of the rotating shaft 52. As a result, as the fan 54 rotates, air is sucked into the center of the fan 54 through the intake opening 56c.

[0026] Here, the intake section 22a and exhaust section 22b of the motor housing section 22 and the motor unit 50 arranged between the intake section 22a and the exhaust section 22b in the front-rear direction of the air duster 10 are all arranged on the axis CT. Here, the axis CT is a line segment passing through the rotation center of the fan 54, and the axis of the rotating shaft 52 is also arranged on the axis CT. As a result, the air sucked in from the intake section 22a flows approximately straight toward the exhaust section 22b.

[0027] In this way, the air flow inside the motor housing 22 is made substantially straight, thereby improving the intake efficiency and exhaust efficiency of the air duster 10. The intake opening 56c provided in the fan case 56 corresponds to the fan case intake port in the present invention.

[0028] Here, a substantially cylindrical air flow path AP (see FIGS. 3 and 9) is formed between side wall portion 56b of fan case 56 and drive portion 51. Fan 54 is disposed on one axial side (rear side) of air flow path AP, and air discharged radially outward from fan 54 flows inside air flow path AP from one axial side to the other axial side.

[0029] An air exhaust port 56d formed in a substantially annular shape is provided on the other axial side (front side) of the air flow path AP, and the air flowing through the air flow path AP is exhausted from the air exhaust port 56d toward the other axial side (see FIG. 9).

[0030] <Battery mounting section> 1, a battery pack BT consisting of a secondary battery such as a lithium ion battery is removably provided in the battery mounting section 23. Specifically, a rail portion (not shown) is provided in the battery mounting section 23 so as to extend in the front-rear direction, and the battery pack BT is movable along the rail portion.

[0031] A motor side terminal unit TU (see Figure 3) is provided on one longitudinal side (rear side) of the rail portion, and a battery side terminal unit (not shown) provided on one longitudinal side (rear side) of the battery pack BT is electrically connected to the motor side terminal unit TU when the battery pack BT is fixed to the battery mounting portion 23.

[0032] When removing the battery pack BT from the battery attachment portion 23, the battery pack BT may be moved to the other longitudinal side (front side) relative to the rail portion while pressing the lock-free switch LS provided on the battery pack BT.

[0033] <Handle section> 1 and 3, the handle portion 24 is disposed between the motor housing portion 22 and the battery mounting portion 23, and extends in the vertical direction. The handle portion 24 is formed in a substantially cylindrical shape so that it can be easily gripped by an operator, and is smaller than the motor housing portion 22 and the battery mounting portion 23.

[0034] In this way, the handle portion 24 is provided between the relatively heavy drive portion 51 and the battery pack BT, which allows the operator to hold the handle portion 24 in a well-balanced manner. In other words, the load on the operator's wrist (load that twists the wrist) can be reduced. This also improves the operability of the air duster 10.

[0035] 3, a trigger switch SW to be operated by an operator is accommodated inside the handle portion 24. The trigger switch SW is disposed on the motor accommodating portion 22 side (upper side) of the handle portion 24, so that when the operator grips the handle portion 24, he or she can easily press and operate the trigger switch SW with the index finger or the like.

[0036] The trigger switch SW is disposed between the control board 55 and the LED light LT and the battery pack BT so that a drive current can be supplied to the control board 55 (brushless motor 53) and the LED light LT. Thus, by turning on the trigger switch SW (pulling it in with an index finger or the like), a drive current is supplied to the brushless motor 53 and the LED light LT. On the other hand, by turning off the trigger switch SW (releasing the index finger or the like), the supply of drive current to the brushless motor 53 and the LED light LT is stopped.

[0037] <Nozzle> 3 and 4, the nozzle 40 is formed into a tubular shape by injection molding or the like of a resin material such as plastic, and air (see Figs. 9 and 10) can flow through the inside of the nozzle 40. The air corresponds to the gas in the present invention.

[0038] An inlet section 41 is provided on the motor housing section 22 side (rear side) of the nozzle 40. The inlet section 41 is a portion into which the air (Air) exhausted from the exhaust section 22b (see FIG. 3) of the motor housing section 22 flows, and the air (Air) that has flowed into the inlet section 41 flows from the upstream side (rear side) to the downstream side (front side) inside the nozzle 40. Here, the flow path area of ​​the inlet section 41 along a plane perpendicular to the flow direction (front-rear direction) of the air (Air) is S1 as shown in the shaded portion in FIG. 5.

[0039] The inlet section 41 also has an inlet 41a which is an inlet for the air (Air). As shown in Fig. 5, the inlet 41a has a circular shape along a plane perpendicular to the flow direction of the air (Air), and the inlet 41a has a diameter D1. The diameter D1 of the inlet 41a is approximately equal to the inner diameter of the exhaust section 22b. Therefore, the air (Air) flows smoothly from the exhaust section 22b toward the inlet 41a.

[0040] Here, the flow passage area S1 of the inflow portion 41 is equal to the opening area of ​​the inlet 41a, and the opening area of ​​the inlet 41a is S1. In this embodiment, S1 is 359.1 mm 2" is set.

[0041] As shown in Fig. 4, the nozzle 40 has a discharge section 42 on the opposite side (front side) from the motor housing section 22 side. The discharge section 42 is a section that discharges air (Air) on the downstream side (front side) of the inlet section 41, and is a section that is directed toward, for example, dust or the like to which the air (Air) is discharged. Here, the flow path area of ​​the discharge section 42 along a plane perpendicular to the flow direction of the air (Air) is S2, as shown in the shaded area in Fig. 6.

[0042] Specifically, the flow path area S2 of the discharge portion 42 is larger than the flow path area S1 of the inlet portion 41 (flow path area S2>flow path area S1).

[0043] The discharge section 42 also has a discharge port 42a which serves as an outlet for the air Air. As shown in Fig. 6, the discharge port 42a has a flat shape along a plane perpendicular to the flow direction of the air Air. More specifically, the discharge port 42a has a shape that is flattened in the vertical direction and opens in an elongated shape in the horizontal direction.

[0044] Here, the flow path area S2 of the discharge portion 42 is equal to the opening area of ​​the discharge port 42a, and the opening area of ​​the discharge port 42a is S2. In other words, the opening area S2 of the discharge port 42a is larger than the opening area S1 of the inlet 41a (opening area S2>opening area S1). In this embodiment, S2 is 545.7 mm 2 " is set.

[0045] In this way, by opening the outlet side of the nozzle 40 larger than the inlet side, it is not necessary to narrow the flow of the air that has flowed into the nozzle 40 downstream. This allows the air to flow smoothly inside the nozzle 40.

[0046] Note that the opening area S1 of the inlet 41a is larger than the opening area S3 of the suction opening 56c of the fan case 56 arranged on the upstream side thereof (see the shaded part in FIG. 3). That is, the opening area S3 of the suction opening 56c is smaller than the opening area S1 of the inlet 41a (S3 < S1). In the present embodiment, S3 is set to "220.4 mm 2 ".

[0047] Also by this, the flow of the air Air flowing into the fan case 56 due to the drive of the motor unit 50 does not need to be constricted on the downstream side. Therefore, the air Air can smoothly flow through the inside of the motor housing portion 22.

[0048] As shown in FIG. 4, a pipe portion 43 forming the main body portion of the nozzle 40 is provided between the inlet portion 41 and the discharge portion 42 of the nozzle 40. Air Air flows through the pipe portion 43 from the inlet portion 41 toward the discharge portion 42.

[0049] As shown in FIGS. 2 and 4, a plurality of ventilation holes 44 are provided in the pipe portion 43. These ventilation holes 44 are holes that communicate the inside and the outside of the pipe portion 43, and air Air can flow through them (see FIG. 9). Specifically, due to the negative pressure generated by the air Air flowing into the pipe portion 43 from the inlet portion 41, the air Air flows through the ventilation holes 44 from the outside to the inside of the pipe portion 43. That is, the plurality of ventilation holes 44 function as a so-called "ejector". Thereby, it is possible to increase the air volume of the air Air discharged from the discharge port 42a.

[0050] Here, the pipe portion 43 includes a flow path area expansion portion 43a in which the flow path area along the orthogonal plane orthogonal to the air Air flow direction gradually increases from the upstream side to the downstream side in the air Air flow direction. And a plurality of ventilation holes 44 are provided in this flow path area expansion portion 43a. Thereby, it is possible to gradually increase the air volume of the air Air as the air Air flows from the upstream side to the downstream side of the flow path area expansion portion 43a.

[0051] 4 and 6, the pipe section 43 includes a cylindrical section 43b having a flow passage whose cross section along a plane perpendicular to the flow direction of the air Air is circular, and a flat section 43c having a flow passage whose cross section along a plane perpendicular to the flow direction of the air Air is flat. Specifically, the flat section 43c has a long length L1 in a first orthogonal direction (left-right direction) and a short length L2 in a second orthogonal direction (up-down direction) perpendicular to the first orthogonal direction (L1>L2).

[0052] Here, the cylindrical portion 43b is disposed on the inlet portion 41 side, and the flat portion 43c is disposed on the outlet portion 42 side. The flat portion 43c forms substantially the same portion as the flow path area expansion portion 43a. That is, the flat portion 43c is provided with a plurality of ventilation holes 44. Furthermore, in the flow direction of the air Air, the length L3 of the flat portion 43c is about 13 times the length L4 of the cylindrical portion 43b (L3 ≈ 13 × L4).

[0053] 4, 5 and 7, a pair of protrusions T are integrally provided on the outer periphery of the cylindrical portion 43b. These protrusions T are provided at intervals of 180 degrees in the circumferential direction of the cylindrical portion 43b. In other words, the pair of protrusions T are disposed opposite each other with the cylindrical portion 43b at the center.

[0054] As a result, the nozzle 40 can be attached to and detached from the nozzle fixing part 22c (see FIG. 3) of the motor housing part 22 by rotating it 180 degrees around the axis CT. Specifically, referring to FIG. 3, the nozzle 40 can be attached to the nozzle fixing part 22c even if it is turned upside down. Therefore, the nozzle 40 can be easily attached to the nozzle fixing part 22c, improving the convenience of the air duster 10.

[0055] The specific shape of the flattened portion 43c will be described. When the nozzle 40 is viewed from above and below, the flattened portion 43c has a generally trumpet shape that gradually widens from the upstream side to the downstream side. Moreover, as shown in Figures 3 and 6, when the nozzle 40 is viewed from the front-rear and left-right directions, the flattened portion 43c has a generally uniform thickness in the front-rear and left-right directions.

[0056] Also, as shown in FIGS. 5, 6, and 7, the flat portion 43c has a symmetrical shape (mirror symmetry) about the axis CT in the first orthogonal direction. Thereby, the discharge destination of the air Air discharged from the discharge port 42a can be easily controlled. Therefore, the operability of the air duster 10 is improved. Also, the appearance (design) of the nozzle 40 is improved.

[0057] And, the length L1 of the downstream-side flow path of the flat portion 43c in the first orthogonal direction is larger than the diameter D1 of the flow path of the cylindrical portion 43b (L1 > D1). Also, the length L2 of the downstream-side flow path of the flat portion 43c in the second orthogonal direction is smaller than the diameter D1 of the flow path of the cylindrical portion 43b (L2 < D1). More specifically, the length L2 of the downstream-side flow path of the flat portion 43c in the second orthogonal direction is equal to or less than half of the diameter D1 of the flow path of the cylindrical portion 43b (L2 < D1 / 2).

[0058] Thereby, the nozzle 40 can discharge the air Air linearly extending in the left-right direction. Therefore, the nozzle 40 can discharge the air Air even into a narrow space.

[0059] Also, as shown in FIGS. 3 and 6, the length of the flat portion 43c in the second orthogonal direction of the flow path gradually increases from the upstream side to the downstream side in the air Air flow direction. Specifically, the length L2 of the downstream-side flow path of the flat portion 43c in the second orthogonal direction is larger than the length L5 of the upstream-side flow path of the flat portion 43c in the second orthogonal direction (L2 > L5).

[0060] Thereby, it is easy to release the mold (not shown) for molding the nozzle 40, and the nozzle 40 can be easily manufactured. That is, the shape of the nozzle 40 (flat portion 43c) is a shape considering the draft of the mold, thereby improving the manufacturability.

[0061] 6, the length L2 of the flow path of the flat portion 43c in the second orthogonal direction is the largest near the axis line CT, and the length of the flow path of the flat portion 43c in the second orthogonal direction is the largest near the axis line CT, and the length of the flow path of the flat portion 43c in the second orthogonal direction is the largest near the axis line CT.

[0062] This allows a sufficient amount of air (Air) to flow through the center (the part of the axis CT) in the left-right direction of the nozzle 40. Therefore, it is easy to control the air (Air) discharged from the nozzle 40 toward dust or the like (discharge destination), improving the operability of the air duster 10.

[0063] 4, a conical portion 45 is provided on the upstream side of the flat portion 43c, i.e., on the cylindrical portion 43b side. The conical portion 45 is tapered from the cylindrical portion 43b side toward the flat portion 43c side. Specifically, the conical portion 45 has a function of gradually decreasing the flow path area along a plane perpendicular to the flow direction of the air Air from the cylindrical portion 43b side toward the flat portion 43c side.

[0064] This allows the air (Air) flowing from the cylindrical portion 43b toward the upstream side of the flat portion 43c to flow smoothly. If the flow path area were to change suddenly, the pressure fluctuation of the air (Air) would increase, preventing the smooth flow of the air (Air), increasing the load on the brushless motor 53 (see FIG. 3) and reducing the efficiency of the air duster 10.

[0065] Specifically, as shown in [FF cross section] of Fig. 8, the flow area S1 (575.25) in the cylindrical portion 43b gradually decreases to a flow area S4 (478.05) in the upstream portion of the conical portion 45 as shown in [GG cross section] of Fig. 8 (S1>S4). Also, as shown in [HH cross section] of Fig. 8, the flow area S5 (352.45) in the downstream portion of the conical portion 45 changes to a smaller flow area (S4>S5), and then as shown in [JJ cross section] of Fig. 8, the flow area S6 (362.66) gradually increases to a larger flow area (S5). <S6)。

[0066] As a result, the air (Air) flowing from the cylindrical portion 43b to the upstream side of the flat portion 43c via the conical portion 45 flows smoothly without large pressure fluctuations. Note that the numerical values ​​of S1, S4, S5, and S6 shown in Fig. 8 (575.25, 478.05, 352.45, and 362.66) are simply numerical values ​​given for reference to compare the flow path areas and have no unit.

[0067] 2, 4, and 7, the plurality of ventilation holes 44 are disposed in a dispersed manner on the upper and lower sides of the flat portion 43c. Specifically, the flat portion 43c has an upper wall 43d and a lower wall 43e that face each other in the second orthogonal direction (the up-down direction), and the plurality of ventilation holes 44 are provided in each of the upper wall 43d and the lower wall 43e.

[0068] Here, the upper wall 43d is provided with a total of 20 ventilation holes 44, and the lower wall 43e is provided with a total of 18 ventilation holes 44. The upper wall 43d corresponds to one side wall portion in the present invention, and the lower wall 43e corresponds to the other side wall portion in the present invention.

[0069] 7, the multiple ventilation holes 44 provided in the upper wall 43d are provided on the left and right sides, ten of them at each side, at positions away from the axis line CT, centered on the axis line CT. Specifically, when the nozzle 40 is viewed from above and below, each ventilation hole 44 is formed in a substantially rectangular shape, and is arranged orderly at predetermined intervals in the flow direction (front-back direction) of the air Air.

[0070] In contrast, the multiple ventilation holes 44 provided in the lower wall 43e are provided on the left and right sides, nine of them at positions close to the axis line CT, with the axis line CT as the center. The ventilation holes 44 provided in the lower wall 43e are also formed in a substantially rectangular shape and are arranged orderly at predetermined intervals in the flow direction (front-rear direction) of the air Air.

[0071] In this way, the multiple ventilation holes 44 provided in the flat portion 43c are arranged symmetrically (mirror symmetrically) about the axis line CT in the first orthogonal direction. This makes it possible to easily adjust the discharge width of the air Air in the first orthogonal direction by arranging the ventilation holes 44 on both sides of the axis line CT. In addition, the appearance (design) of the nozzle 40 is improved.

[0072] 7, the ventilation holes 44 (solid lines) provided in the upper wall 43d and the ventilation holes 44 (dashed lines) provided in the lower wall 43e do not overlap each other when viewed from the second orthogonal direction (up-down direction). This allows the air Air that flows into the flat portion 43c to be spread evenly in the left-right direction of the flat portion 43c (see FIG. 10).

[0073] If the ventilation holes 44 provided in the upper wall 43d and the ventilation holes 44 provided in the lower wall 43e were to overlap each other in the second orthogonal direction, there is a risk of impeding the smooth flow of air (Air) flowing inside the flat portion 43c. That is, the air (Air) flows from the outside of the flat portion 43c to the inside through the ventilation holes 44, but at that time, the air (Air) flowing in through the ventilation holes 44 in the upper wall 43d and the air (Air) flowing in through the ventilation holes 44 in the lower wall 43e collide with each other in the vertical direction, and as a result, the amount of air (Air) introduced into the inside of the flat portion 43c is reduced. This means that the amount of air (Air) discharged from the discharge port 42a of the nozzle 40 is reduced.

[0074] The length of the ventilation holes 44 in the front-rear direction is set to "3.8 to 3.9 mm", and the ventilation holes 44 are set to this size, arranged at a predetermined interval, and distributed on the upper wall 43d and the lower wall 43e, thereby ensuring sufficient strength of the nozzle 40. Also, in this embodiment, the total opening area of ​​the ventilation holes 44 is "917.4 mm 2 " is set.

[0075] As shown in the shaded area in Fig. 7, the four most upstream vents 44 out of the multiple vents 44 are located near the boundary BD between the cone-shaped part 45 and the flat part 43c when viewed from the second orthogonal direction. This makes it possible to efficiently introduce external air Air into the flat part 43c from the part where the negative pressure is the largest when the air Air flows (the flat part 43c side of the boundary BD). This reduces the load on the brushless motor 53 (see Fig. 3) while improving the efficiency of the air duster 10.

[0076] In this embodiment, the ventilation holes 44 shown in the shaded area are arranged to follow the shape of the boundary part BD. In other words, the ventilation holes 44 shown in the shaded area are arranged in an arc shape to follow the arc shape of the boundary part BD. This makes it possible to further improve the efficiency of the air duster 10. Here, the total of four ventilation holes 44 shown in the shaded area correspond to the upstream ventilation holes in the present invention.

[0077] Also, as shown in FIG. 7, when the flat portion 43c is divided into three equal parts into a first region AR1, a second region AR2 and a third region AR3 along the flow direction of air Air (front-to-back direction), ventilation holes 44 are provided throughout the first region AR1, the second region AR2 and the third region AR3.

[0078] However, unlike the present embodiment, it is not necessary to provide the ventilation holes 44 throughout the first area AR1, the second area AR2, and the third area AR3, and it is sufficient to provide the ventilation holes 44 at least in the first area AR1 on the upstream side depending on the specifications of the nozzle 40. In other words, it is also possible to deal with the problem by providing a minimum number of ventilation holes 44 only in the portion where the negative pressure is the largest when the air Air flows.

[0079] <Air flow> Next, the operation of the air duster 10 formed as above, in particular the flow of air, will be described in detail with reference to the drawings.

[0080] Figure 9 is a diagram corresponding to Figure 3 showing the gas flow inside the housing, Figure 10 is a diagram corresponding to Figure 4 showing the gas flow inside the nozzle, Figure 11 is a diagram showing the analysis results of embodiment 1, and Figure 12 is a diagram showing the analysis results of the comparative example.

[0081] When the operator presses the trigger switch SW, the brushless motor 53 is driven. Then, the rotary shaft 52 rotates in a predetermined direction at a predetermined speed, and the fan 54 also rotates accordingly. This causes air (Air) to flow through the inside of the motor housing 22 and the inside of the nozzle 40.

[0082] Specifically, the air Air flows into the motor housing 22 from the intake portion 22a at the rear of the motor housing 22, and then flows into the intake opening 56c of the fan case 56, as shown by the arrow W1 in FIG.

[0083] Next, as shown by arrow W2 in FIG. 9, the air Air flows from the radial outside of fan 54 into air flow path AP between side wall portion 56b of fan case 56 and driver 51, and is discharged to the front of fan case 56.

[0084] 9, the air Air flows inside the motor housing portion 22 and reaches the exhaust portion 22b in front of the motor housing portion 22. Next, the air Air flows into the cylindrical portion 43b through the inlet 41a of the nozzle 40 (see FIG. 4).

[0085] The air Air that has flowed into the cylindrical portion 43b passes through the conical portion 45 and then flows into the inside of the flat portion 43c, as shown by the arrow W4 in Fig. 9. As a result, the air Air flows inside the flat portion 43c from the upstream side to the downstream side, and is discharged from the discharge port 42a (see Fig. 4) to the front of the air duster 10.

[0086] At that time, inside the flat portion 43c, as shown by the arrow W5 in Fig. 9, air (Air) flows from the outside to the inside of the nozzle 40 (flat portion 43c) through the multiple ventilation holes 44 and merges with the flow (main flow) of the arrow W4. This increases the amount of air (Air) inside the flat portion 43c. Therefore, a large amount of air (Air) is discharged from the discharge port 42a.

[0087] The air Air flowing inside the flat portion 43c flows so as to avoid the multiple ventilation holes 44. Specifically, as shown by arrow W5 in Fig. 9, the air Air that has flowed into the ventilation hole 44 collides with the mainstream air Air shown by arrow W4 in Fig. 9. This causes the air Air to flow so as to avoid the multiple ventilation holes 44.

[0088] As a result, in combination with the arrangement of the multiple ventilation holes 44 shown in Fig. 7, the air Air flowing through the flat portion 43c from its upstream side to its downstream side spreads in the first orthogonal direction (left-right direction) as shown by the arrow W6 in Fig. 10. This allows a large amount of air Air to be discharged from the discharge port 42a, and the air Air can be discharged over a wide range in the first orthogonal direction.

[0089] Here, when the state of the air flowing through the nozzle 40 in this embodiment was analyzed by a computer, the analysis results shown in Fig. 11 were obtained. Note that the shading in the upper part of Fig. 11 indicates the flow velocity of the air. Moreover, the shading in the lower part of Fig. 11 indicates the pressure of the air.

[0090] Specifically, as shown in the lower part of Fig. 11, as air (Air) flows into the nozzle 40 from the multiple ventilation holes 44 (see Fig. 7) provided in the nozzle 40, the pressure in the negative pressure region generated upstream of the nozzle 40 becomes relatively small, as indicated by the arrow "NP Low". This means that the amount of air (Air) flowing through the nozzle 40 is increasing.

[0091] Also, as shown in the upper part of FIG. 11, it was found that most of the air Air discharged from the discharge port 42a was discharged almost evenly with a wide discharge width DW1 in the first orthogonal direction (the vertical direction in FIG. 11).

[0092] In contrast, Fig. 12 shows the analysis results of a comparative example (a nozzle NZ having the same shape as the nozzle 40 without an air vent), and as shown in the lower part of Fig. 12, since the nozzle NZ is not provided with an air vent, it can be seen that the pressure in the negative pressure area generated on the upstream side of the nozzle NZ becomes very large, as indicated by the arrow "NP High". Therefore, the amount of air Air flowing inside the nozzle NZ does not increase, and in addition, flow resistance occurs to the air Air flowing inside the nozzle NZ.

[0093] Also, as shown in the upper part of FIG. 12, it was found that the air Air discharged from the discharge port OP of the nozzle NZ is discharged with a narrow discharge width DW2 (DW2 < DW1) instead of being discharged widely in the first orthogonal direction (the vertical direction in FIG. 12). Note that the shading in the upper part of FIG. 12 also indicates the velocity of the air Air. Also, the shading in the lower part of FIG. 12 indicates the pressure of the air Air.

[0094] As described in detail above, according to the air duster 10 of the first embodiment, the nozzle 40 includes an inflow portion 41 into which the air Air exhausted from the exhaust portion 22b flows, a flow path area along an orthogonal plane orthogonal to the flow direction of the air Air is larger than that of the inflow portion 41, and a discharge portion 42 that discharges the air Air on the downstream side of the inflow portion 41, and a pipe portion 43 provided between the inflow portion 41 and the discharge portion 42 through which the air Air flowing from the inflow portion 41 to the discharge portion 42 flows. The pipe portion 43 is provided with a vent hole 44 that communicates the inside and the outside of the pipe portion 43.

[0095] Thereby, it is possible to realize the air duster 10 that enables an increase in the discharge amount of the air Air and the discharge of the air Air over a wide range. Therefore, it is possible to improve the convenience of the air duster 10.

[0096] Also, according to the air duster 10 of the first embodiment, the inflow portion 41 includes an inflow port 41a that serves as an inlet for the air Air, the discharge portion 42 includes a discharge port 42a that serves as an outlet for the air Air, and the opening area S2 of the discharge port 42a is larger than the opening area S1 of the inflow port 41a.

[0097] Thereby, the flow of the air Air flowing into the nozzle 40 does not need to be restricted on the downstream side thereof. Therefore, the air Air can be smoothly circulated inside the nozzle 40, and thus the load on the brushless motor 53 can be reduced, and the efficiency of the air duster 10 can be improved.

[0098] Furthermore, according to the air duster 10 of embodiment 1, it is provided with a fan case 56 that houses a brushless motor 53 and a fan 54 and is housed in the motor housing section 22, and the opening area S3 of the intake opening 56c provided in the fan case 56 is smaller than the opening area S1 of the inlet 41a.

[0099] This eliminates the need to throttle the flow of air (Air) that has flowed into fan case 56 by driving motor unit 50 on the downstream side. Therefore, air (Air) can circulate smoothly inside motor housing portion 22.

[0100] Furthermore, according to the air duster 10 of embodiment 1, the pipe portion 43 is provided with a flow path area expansion portion 43a in which the flow path area along a perpendicular plane perpendicular to the flow direction of the air Air gradually increases from the upstream side to the downstream side in the flow direction of the air Air, and an air vent 44 is provided in the flow path area expansion portion 43a.

[0101] This allows the flow rate of the air Air to be gradually increased as the air Air flows from the upstream side to the downstream side of the flow path area expansion portion 43a.

[0102] Furthermore, according to the air duster 10 of embodiment 1, the pipe portion 43 includes a cylindrical portion 43b having a flow path with a circular cross-sectional shape along an orthogonal plane perpendicular to the flow direction of the air Air, and a flat portion 43c having a flow path with a flat cross-sectional shape along an orthogonal plane perpendicular to the flow direction of the air Air, and the flat portion 43c has a long length in a first orthogonal direction along the orthogonal plane perpendicular to the flow direction of the air Air and a short length in a second orthogonal direction perpendicular to the first orthogonal direction, an air vent 44 is provided in the flat portion 43c, and the length L1 of the flow path downstream of the flat portion 43c in the first orthogonal direction is greater than the diameter D1 of the flow path of the cylindrical portion 43b.

[0103] Furthermore, according to the air duster 10 of the first embodiment, the length L2 of the flow passage on the downstream side of the flattened portion 43c in the second orthogonal direction is smaller than the diameter D1 of the flow passage of the cylindrical portion.

[0104] This allows the nozzle 40 to discharge the air (Air) so as to extend linearly in the left-right direction. Therefore, the nozzle 40 can discharge the air (Air) even into a narrow space.

[0105] Furthermore, according to the air duster 10 of embodiment 1, a conical section 45 is provided on the upstream side of the flat section 43c, which tapers toward the downstream side and gradually changes the flow path area along the perpendicular plane perpendicular to the flow direction of the air Air from the cylindrical section 43b side to the flat section 43c side.

[0106] This allows the air (Air) to flow smoothly by suppressing pressure fluctuations that occur from the cylindrical portion 43b toward the upstream side of the flat portion 43c. Since the pressure fluctuations of the air (Air) are suppressed, the load on the brushless motor 53 can be reduced, and the efficiency of the air duster 10 can be improved.

[0107] According to the air duster 10 of the first embodiment, the ventilation opening 44 includes an upstream ventilation opening arranged near the boundary portion BD between the conical portion 45 and the flat portion 43c when viewed from the second orthogonal direction. According to the air duster 10 of the first embodiment, the multiple upstream ventilation openings (ventilation openings 44) are arranged in line following the shape of the boundary portion BD.

[0108] This allows the efficiency of the air duster 10 to be further improved.

[0109] Furthermore, according to the air duster 10 of the first embodiment, the length L2 of the flow passage on the downstream side of the flat portion 43c in the second orthogonal direction is equal to or less than half the diameter D1 of the flow passage of the cylindrical portion 43b.

[0110] This also allows the nozzle 40 to discharge the air (Air) so as to extend linearly in the left-right direction. Therefore, the nozzle 40 can discharge the air (Air) even into a narrow space.

[0111] Furthermore, according to the air duster 10 of the first embodiment, the length of the flow path of the flattened portion 43c in the second orthogonal direction gradually increases from the upstream side to the downstream side in the flow direction of the air Air.

[0112] This makes it possible to easily release the die used to mold the nozzle 40, and thus to easily manufacture the nozzle 40. Thus, the manufacturability of the nozzle 40 can be improved.

[0113] Furthermore, according to the air duster 10 of the first embodiment, the flat portion 43c has a symmetrical shape with respect to the axis line CT in the first orthogonal direction.

[0114] This makes it easy to control the destination of the air Air discharged from the outlet 42a. This improves the operability of the air duster 10. Also, the appearance (design) of the nozzle 40 can be improved.

[0115] Furthermore, according to the air duster 10 of the first embodiment, the length of the flow passage of the flat portion 43c in the second orthogonal direction is greater in the vicinity of the axis CT than in other portions.

[0116] This allows a sufficient amount of air Air to flow through the center (the part of the axis CT) in the left-right direction of the nozzle 40. Therefore, it is easy to control the air Air discharged from the nozzle 40 toward dust or the like (discharge destination), improving the operability of the air duster 10.

[0117] Furthermore, according to the air duster 10 of the first embodiment, the nozzle 40 can be attached to and detached from the exhaust part 22b of the motor housing part 22 by rotating 180 degrees around the axis line CT.

[0118] This allows the nozzle 40 to be easily attached to the nozzle fixing part 22c without considering the directionality, thereby improving the convenience of the air duster 10.

[0119] Furthermore, according to the air duster 10 of the first embodiment, a plurality of ventilation holes 44 are provided in each of the upper wall 43d and the lower wall 43e which face each other in the second orthogonal direction and form the flat portion 43c.

[0120] This ensures that the nozzle 40 has sufficient strength.

[0121] Furthermore, according to the air duster 10 of the first embodiment, the ventilation hole 44 provided in the upper wall 43d and the ventilation hole 44 provided in the lower wall 43e do not overlap with each other when viewed from the second orthogonal direction.

[0122] This allows the air Air that has flowed into the flat portion 43c to be spread evenly in the first orthogonal direction (left-right direction) of the flat portion 43c (expanded discharge width).

[0123] Moreover, according to the air duster 10 of the first embodiment, a plurality of ventilation holes 44 are provided lined up in the flow direction of the air Air.

[0124] This makes it possible to improve the appearance (design) of the nozzle 40.

[0125] <Embodiment 2> Next, a second embodiment of the present invention will be described in detail with reference to the drawings. Note that parts having the same functions as those in the first embodiment are given the same reference numerals and detailed descriptions thereof will be omitted.

[0126] Figure 13 shows a view of the nozzle of embodiment 2 from above, Figure 14 shows a view of the nozzle of embodiment 2 from below, Figure 15 shows a view corresponding to Figure 6 of the nozzle of embodiment 2, Figure 16 shows a view corresponding to Figure 4 of the nozzle of embodiment 2, and Figure 17 shows the analysis results of embodiment 2.

[0127] As shown in Figs. 13 to 17, in the second embodiment, only the shape of the nozzle 60 is different from that in the first embodiment. Specifically, in the nozzle 60 of the second embodiment, a bulging portion 62 that bulges out in a step-like manner in the first orthogonal direction (left-right direction) is provided on the downstream side of the flat portion 61. In the nozzle 60 of the second embodiment, a first vent hole (vent hole) 63 consisting of a plurality of round holes and a second vent hole (vent hole) 64 consisting of a plurality of long holes are provided on each of the upper wall 43d and the lower wall 43e. Furthermore, in the nozzle 60 of the second embodiment, a total of four long protrusions 65 extending from the upstream side to the downstream side are provided on the inside of the flat portion 61.

[0128] 13, the upper wall 43d is provided with a plurality of first ventilation holes 63 arranged in a substantially V-shape with the upper side of the V facing the upstream side on the upstream side (rear side) of the flattened portion 61. The upper wall 43d is provided with a plurality of second ventilation holes 64 arranged in a substantially V-shape with the upper side of the V facing the downstream side on the downstream side (front side) of the flattened portion 61.

[0129] 14, the lower wall 43e is provided with a plurality of second ventilation holes 64 arranged in a substantially M-shape with the upper side of the M facing the upstream side on the upstream side (rear side) of the flattened portion 61. The lower wall 43e is provided with a plurality of first ventilation holes 63 arranged in a substantially V-shape with the upper side of the V facing the downstream side on the downstream side (front side) of the flattened portion 61.

[0130] Furthermore, first ventilation holes 63 (three on each side) are provided in a portion of the lower wall 43e corresponding to the bulging portion 62 on both sides in the first orthogonal direction, and are arranged in a line in the front-rear direction. The first ventilation holes 63, three on each side of the bulging portion 62 in a line, have the function of preventing the discharge width DW3 (see FIG. 17) of the air Air from spreading too much in the first orthogonal direction.

[0131] 15 and 16, a total of four long protrusions 65 are provided on the upper wall 43d and the lower wall 43e, respectively, facing the inside of the flat portion 61 and facing each other. As shown in FIG. 16, each long protrusion 65 is thinner on the downstream side than on the upstream side in the first orthogonal direction. This is to ensure the draft angle of the mold.

[0132] The second embodiment thus constructed can also achieve the same effects as the first embodiment, as shown in Fig. 17. That is, a wide discharge width DW3 (DW3 ≒ DW1) can be obtained. The shading in the upper part of Fig. 17 also indicates the velocity of the air (Air). The shading in the lower part of Fig. 17 also indicates the pressure of the air (Air).

[0133] In addition, in the second embodiment, a total of four long protrusions 65 are provided, which increases the strength of the nozzle 60. That is, the long protrusions 65 function as reinforcing ribs. This allows more first and second ventilation holes 63, 64 to be provided, and further allows the first and second ventilation holes 63, 64 to be arranged in a more complex manner on each of the upper wall 43d and the lower wall 43e (improved design).

[0134] The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications are possible without departing from the gist of the present invention. For example, the above-mentioned air duster 10 is shown to have a motor unit 50 that is driven by the supply of drive current from the battery pack BT, but the present invention is not limited to this, and can also be applied to one in which drive current is supplied to the motor unit from a commercial power source (AC power source) via a power cord.

[0135] Also, instead of the air duster 10, the nozzle 40 may be attached to a known blower, such as that described in JP 2022-123186 A. In the air duster 10, the axis CT, which is the center of rotation of the rotating shaft 52 of the brushless motor 53 and the center of rotation of the fan 54, extends in the front-rear direction, which is the flow direction of the air Air inside the nozzle 40, but the blower described in JP 2022-123186 A has the axis of the rotation center of the motor's rotating shaft and the axis of the rotation center of the fan extending in the left-right direction. In this way, the blower may be configured so that the axis of the rotation center of the motor's rotating shaft or the rotation center of the fan extends in a direction different from the front-rear direction.

[0136] In addition, the material, shape, size, number, installation location, etc. of each component in each of the above-mentioned embodiments are arbitrary as long as the present invention can be achieved, and are not limited to the above-mentioned embodiments. [Explanation of symbols]

[0137] 10... air duster (work machine), 20... air duster body (work machine body), 21... housing, 21a... first housing half, 21b... second housing half, 22... motor housing section, 22a... intake section, 22b... exhaust section, 22c... nozzle fixing section, 23... battery mounting section, 24... handle section, 40... nozzle, 41... inlet section, 41a... inlet port, 42... outlet section, 42a... outlet port, 43... pipe section, 43a... flow path area expansion section, 43b... cylindrical section, 43c... flat section, 43d... upper side wall (one side wall section), 43e... lower side wall (other side wall section), 44... vent, 45... cone-shaped section, 50... motor unit, 51... drive section, 52... rotating shaft, 53... brushless motor motor, 54...fan, 55...control board, 56...fan case, 56a...bottom wall, 56b...side wall, 56c...intake opening (fan case intake), 56d...air exhaust, 60...nozzle, 61...flat section, 62...bulge, 63...first vent (vent), 64...second vent (vent), 65...long protruding section, AP...air flow path, AR1...first area, AR2...second area, AR3...third area, Air...air (gas), BD...boundary, BT...battery pack, CT...axis, LS: lock-free switch, LT...LED light, NZ...nozzle, OP...discharge port, SW...trigger switch, T...projection, TU...motor side terminal unit

Claims

1. A motor; a fan that rotates by the driving force of the motor; a housing that houses the fan and has an intake section disposed upstream of the fan and an exhaust section disposed downstream of the fan; A nozzle detachably provided in the exhaust section; Equipped with The nozzle is an inlet portion into which gas exhausted from the exhaust portion flows; a discharge portion having a flow path area along a plane perpendicular to a flow direction of the gas that is larger than that of the inlet portion and that discharges the gas downstream of the inlet portion; a pipe portion provided between the inlet portion and the outlet portion and through which the gas flows from the inlet portion to the outlet portion; Equipped with The pipe portion is provided with a vent hole that communicates the inside and the outside of the pipe portion. Work machine.

2. The inflow section includes an inlet that serves as an inlet for the gas, The discharge unit includes a discharge port that serves as an outlet for the gas, The opening area of ​​the discharge port is larger than the opening area of ​​the inlet. The work machine according to claim 1.

3. a fan case that houses the motor and the fan and is housed in the housing; an opening area of ​​a fan case inlet provided in the fan case is smaller than an opening area of ​​the inlet; The work machine according to claim 2.

4. the pipe portion includes a flow path area expansion portion in which a flow path area along the perpendicular plane gradually increases from an upstream side to a downstream side in a flow direction of the gas, The vent is provided in the flow path area expansion section. The work machine according to claim 1.

5. The pipe portion is A cylindrical portion having a flow path whose cross-sectional shape along the orthogonal plane is circular; A flat portion having a flow path whose cross-sectional shape along the orthogonal plane is flat; Equipped with The flat portion has a long length in a first orthogonal direction along the orthogonal surface and a short length in a second orthogonal direction perpendicular to the first orthogonal direction, The vent hole is provided in the flat portion, and a length of a flow path downstream of the flat portion in the first orthogonal direction is greater than a diameter of the flow path in the cylindrical portion. The work machine according to claim 2.

6. A length of the flow passage downstream of the flat portion in the second orthogonal direction is smaller than a diameter of the flow passage of the cylindrical portion. A work machine according to claim 5.

7. A conical portion is provided on the upstream side of the flat portion, the conical portion being tapered toward the downstream side and gradually changing the flow path area along the perpendicular plane from the cylindrical portion side toward the flat portion side. A work machine according to claim 6.

8. The vent includes an upstream vent disposed near a boundary between the conical portion and the flat portion when viewed from the second orthogonal direction. A work machine according to claim 7.

9. The upstream vents are arranged in a line following the shape of the boundary portion. A work machine according to claim 8.

10. The length of the flow passage downstream of the flat portion in the second orthogonal direction is equal to or less than half the diameter of the flow passage of the cylindrical portion. A work machine according to claim 6.

11. a length of the flow path of the flat portion in the second orthogonal direction gradually increases from the upstream side to the downstream side in the gas flow direction; A work machine according to claim 5.

12. The flat portion has a symmetric shape with respect to a line segment passing through a rotation center of the fan in the first orthogonal direction. A work machine according to claim 5.

13. The plurality of ventilation openings are arranged symmetrically about a line segment passing through a rotation center of the fan in the first orthogonal direction. A work machine according to claim 12.

14. a length of the flow passage of the flat portion in the second orthogonal direction is greater in a vicinity of a line segment passing through a rotation center of the fan than in other portions; A work machine according to claim 6.

15. When the flat portion is divided into three equal parts, a first region, a second region and a third region, along the gas flow direction, the ventilation hole is provided in at least the first region. A work machine according to claim 5.

16. The nozzle is detachable from the exhaust portion of the housing by being rotated 180 degrees around a line segment passing through a rotation center of the fan. The work machine according to claim 1.

17. A plurality of the ventilation holes are provided in each of one side wall portion and another side wall portion that face each other in the second orthogonal direction and form the flat portion. A work machine according to claim 5.

18. The ventilation hole provided in the one side wall portion and the ventilation hole provided in the other side wall portion do not overlap with each other when viewed from the second orthogonal direction.

18. A work machine according to claim 17.

19. The ventilation holes are provided in a plurality of positions aligned in the gas flow direction. The work machine according to claim 1.

20. A nozzle detachably provided on an exhaust section of a working machine body, an inlet portion into which gas exhausted from the exhaust portion flows; a discharge portion having a flow path area along a plane perpendicular to a flow direction of the gas that is larger than that of the inlet portion and that discharges the gas downstream of the inlet portion; a pipe portion provided between the inlet portion and the outlet portion and through which the gas flows from the inlet portion to the outlet portion; Equipped with The pipe portion is provided with a vent hole that communicates the inside and the outside of the pipe portion. nozzle.

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