Work equipment

Abstract

The present invention improves cooling performance. In a hammer drill body 10, a dust collection port 22A, a first air intake port 22B, and a second air intake port 22C are formed in a lower housing section 22, and an exhaust port 23A is formed in an upper housing section 23 that houses a transmission mechanism 50. A fan 62 having a cooling fan 63 and a dust collection fan 65 is provided in the lower housing section 22. Cooling air W1 is generated by rotation of the cooling fan 63, and dust collection air W2 is generated by rotation of the dust collection fan 65. Here, a fan guide 70 is provided in the lower housing section 22, and the fan guide 70 has rectification elements 76-1 to 76-5. The rectification elements 76-1 to 76-5 rectify the cooling air W1 blown from the cooling fan 63 and the dust collection air W2 blown from the dust collection fan 65, and cause the cooling air W1 and the dust collection air W2 to flow to the exhaust port 23A. This allows for cooling of the transmission mechanism 50 disposed in the upper housing section 23.

Description

[Technical Field]

[0001] The present invention relates to a work machine. [Background technology]

[0002] In the drilling tool (working machine) described in Patent Document 1 below, a dust collection fan and a cooling fan are mounted on the output shaft of a motor so as to be rotatable together. When the dust collection fan rotates, a dust collection airflow is generated that flows from the suction port of the drilling tool into the drilling tool. This generates a dust collection airflow inside a dust collector connected to the suction port of the drilling tool, allowing dust to be collected by the dust collector. Furthermore, when the cooling fan rotates, a cooling airflow is generated that flows into the drilling tool, and the cooling air cools the motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-201526 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-described drilling tool has room for improvement in the following respects. Specifically, a work machine such as a drilling tool has heat-generating parts other than a motor. A transmission mechanism for transmitting the driving force of a motor to a drill bit, which is one example of a heat-generating part, is operated by the driving force of the motor, and therefore the temperature of the transmission mechanism rises due to frictional heat during operation. Therefore, by improving the cooling performance of the transmission mechanism, it is possible to improve the performance of the drilling tool, such as durability. Meanwhile, in the above-described drilling tool, although the transmission mechanism is cooled by flowing a portion of the dust-collecting air toward the transmission mechanism, the cooling air is immediately exhausted from the radially outer side of the cooling fan to the outside of the drilling tool. In other words, the transmission mechanism is cooled only by a portion of the dust-collecting air. Therefore, the above-described drilling tool has room for improvement in terms of efficiently cooling the transmission mechanism.

[0005] SUMMARY OF THE INVENTION In consideration of the above, an object of the present invention is to provide a work machine with improved cooling performance. [Means for solving the problem]

[0006] One or more embodiments of the present invention include a motor, an output shaft that rotates when driven by the motor, a transmission mechanism that transmits the rotational force of the output shaft to the tool bit; and a centrifugal fan. a first fan fixed to the output shaft and rotating integrally with the output shaft; It is a centrifugal fan, a second fan located on one side of the first fan in the axial direction of the output shaft, fixed to the output shaft and rotating integrally with the output shaft; and a straightening member that houses the first fan and the second fan and merges a first airflow blown out from the first fan and a second airflow blown out from the second fan when the output shaft rotates to one side in the rotation direction, and causes the merged airflow to flow toward one side in the axial direction, wherein the straightening member the second fan is disposed radially outward of the output shaft with respect to at least the second fan, and changes the direction of the second airflow to one side in the axial direction; a rectifying section that rectifies the second air flow so that it flows to one side in the axial direction and prevents the second air flow from flowing to the other side in the axial direction; The rectifying portion is formed in a rib shape extending in a direction inclined toward one side in the axial direction as it approaches one side in the rotation direction, as viewed from the radial direction of the output shaft. , a work machine.

[0010] One or more embodiments of the present invention are a work machine in which a straightening extension portion is provided at one axial end of the straightening portion, extending to one side in the axial direction, and the straightening extension portion has an extension surface connected to the other side of the straightening portion in the rotational direction and arranged along a plane perpendicular to the rotational direction.

[0011] One or more embodiments of the present invention are directed to a work machine in which the straightening member has a guide wall, the guide wall is positioned radially outward of the output shaft relative to the first fan and the second fan and extends in the rotational direction, and the straightening portion extends from the guide wall radially inward of the output shaft.

[0012] One or more embodiments of the present invention are a work machine having a housing including a first housing portion that houses the motor and the rectifying member and has an air intake port and a dust collection port formed therein, and a second housing portion that has an exhaust port formed therein, wherein the rectifying member has a partition wall that separates a part of the space on one side in the axial direction relative to the second fan as a second air flow passage portion, the second air flow passage portion communicates with the dust collection port, and the rectifying member and the second air flow passage portion are arranged in a position that does not overlap when viewed from the axial direction.

[0013] One or more embodiments of the present invention are directed to a work machine in which a sub-straightening unit is provided radially outward of the first fan, and the sub-straightening unit is arranged on the other side of the rotational direction relative to the straightening unit, and is formed in the shape of a rib extending along a direction that inclines toward one side of the axial direction as it approaches one side of the rotational direction when viewed radially from the output shaft.

[0014] One or more embodiments of the present invention are a work machine in which, when viewed from the radial direction of the output shaft, the inclination angle of one end of the straightening unit relative to the rotational direction in the direction of rotation is set to be larger than the inclination angle of one end of the sub-straightening unit relative to the rotational direction in the direction of rotation.

[0015] One or more embodiments of the present invention are directed to a work machine in which the length of the airflow straightening portion in the axial direction is set to be longer than the length of the sub-airflow straightening portion in the axial direction.

[0016] One or more embodiments of the present invention are directed to a work machine in which the volume of the first airflow blown out from the first fan is greater than the volume of the second airflow blown out from the second fan.

[0017] In one or more embodiments of the present invention, the housing is provided with a dust collector, ,collectionThe working machine is configured to include a suction section that uses a dust wind to suck in air around the tool tip and cause it to flow into the dust collecting device, and a discharge section that is connected to the dust collection port and causes the collected dust wind in the dust collecting device to flow out into the first housing section.

[0018] One or more embodiments of the present invention may include the biography mechanism teeth, A work machine is housed in the second housing portion. One or more embodiments of the present invention include a motor, an output shaft that rotates when driven by the motor, a transmission mechanism that transmits the rotational force of the output shaft to a tool bit, a centrifugal fan that is a first fan fixed to the output shaft and rotates integrally with the output shaft, a centrifugal fan that is located on one side of the first fan in the axial direction of the output shaft and is fixed to the output shaft and rotates integrally with the output shaft, and a fan that houses the first fan and the second fan and rotates integrally with the first fan when the output shaft rotates to one side in the rotational direction. a straightening member that joins a first air flow blown out from the output shaft and a second air flow blown out from the second fan and directs the air toward one side in the axial direction, the straightening member being arranged radially outward of the output shaft relative to the first fan and the second fan and having a guide wall that extends in the rotational direction, and a straightening section that straightens the second air flow so that it flows toward one side in the axial direction and prevents it from flowing toward the other side in the axial direction, the straightening section extending from the guide wall radially inward of the output shaft. [Effects of the Invention]

[0019] According to one or more embodiments of the present invention, the cooling performance of a work machine can be improved. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a side view of a hammer drill according to an embodiment of the present invention, viewed from the right side. [Figure 2] 2 is a cross-sectional view showing the inside of the hammer drill shown in FIG. 1 as viewed from the right side. [Figure 3] 2 is a two-view diagram showing the periphery of a lower housing part of the hammer drill body shown in FIG. 1, as viewed from the right side and from below. [Figure 4] 3 is an enlarged cross-sectional view showing the periphery of the blower mechanism shown in FIG. 2. FIG. [Figure 5] 5A and 5B are three views of the fan shown in FIG. 4, seen from above, from the right, and from below. [Figure 6] 5 is a perspective view of the blower mechanism shown in FIG. 4, seen obliquely from the front right. [Figure 7] FIG. 7 is a plan view of the blower mechanism shown in FIG. 6 as seen from above. [Figure 8] FIG. 8 is a plan view of a fan guide in the blower mechanism shown in FIG. 7. [Figure 9] 9 is a cross-sectional view showing a modification of the fan guide shown in FIG. 8, as viewed from the front side. DETAILED DESCRIPTION OF THE INVENTION

[0021] A hammer drill 1 as a work machine according to this embodiment will be described below with reference to the drawings. As shown in FIG. 1 , the hammer drill 1 includes a hammer drill body 10 and a dust collector 80. The dust collector 80 is detachably attached to the hammer drill body 10. The dust collector 80 sucks air around the tool bit T attached to the hammer drill body 10. The arrows UP, FR, and RH shown in the drawings indicate the upper side, front side, and right side of the hammer drill 1. In the following description, when the up / down, front / rear, and left / right directions are used, they refer to the up / down, front / rear, and left / right directions of the hammer drill 1 unless otherwise specified. The hammer drill body 10 will be described first, followed by the dust collector 80.

[0022] (Regarding the hammer drill body 10) As shown in Figures 1 and 2, the hammer drill body 10 is configured as a power tool for performing processes such as drilling holes in a workpiece. The hammer drill body 10 includes a housing 20, a motor 40, and a transmission mechanism 50 that transmits the driving force of the motor 40 to the bit tip T. The hammer drill body 10 also has an air blowing mechanism 60 that generates cooling air W1 as a first air flow and dust-collecting air W2 as a second air flow. The configuration of the hammer drill body 10 will be described below, but the configuration of the air blowing mechanism 60 will be described after the dust collector 80 has been described.

[0023] (Regarding the Housing 20) As shown in FIGS. 1 to 4, the housing 20 forms the outer shell of the hammer drill body 10. The housing 20 includes a main body housing 21 that forms the front portion of the housing 20, and a handle housing 24 that forms the rear portion of the housing 20. The main body housing 21 is formed in a generally inverted L shape when viewed from the right side. Specifically, the main body housing 21 includes a lower housing portion 22 that serves as a first housing portion and forms the lower portion of the main body housing 21, and an upper housing portion 23 that serves as a second housing portion and forms the upper portion of the main body housing 21. The rear end of the upper housing portion 23 is connected to the upper end of the lower housing portion 22, and the upper housing portion 23 protrudes forward beyond the lower housing portion 22.

[0024] The handle housing 24 extends in the vertical direction, and the upper and lower ends of the handle housing 24 are bent forward and connected to the rear end of the main housing 21. The lower end of the lower housing portion 22 protrudes downward beyond the handle housing 24.

[0025] A dust collection port 22A is formed penetrating the front wall at the upper end of the lower housing portion 22 in the front-rear direction. A plurality of first air intake ports 22B (see FIG. 3 ) serving as air intake ports are formed penetrating each of the left and right side walls at the lower end of the lower housing portion 22. The first air intake ports 22B are formed as approximately elongated holes with the front-rear direction as the longitudinal direction and are arranged in a row in the front-rear direction. A plurality of second air intake ports 22C (see FIG. 3 ) serving as air intake ports are formed penetrating the bottom wall of the lower housing portion 22. The second air intake ports 22C are formed as approximately elongated holes with the left-right direction as the longitudinal direction. Two rows of second air intake ports 22C are arranged in a row in the left-right direction, with five second air intake ports 22C arranged in a row in the front-rear direction. A plurality of exhaust ports 23A (five in this embodiment) are formed penetrating each of the left and right side walls at the rear end of the upper housing portion 23. The exhaust ports 23A are formed in a generally elongated hole shape with the longitudinal direction extending in the front-rear direction, and are arranged side by side in the vertical direction.

[0026] A trigger 30 is provided at the upper end of the handle housing 24. The trigger 30 protrudes forward from the handle housing 24 and can be pulled rearward. A switch mechanism 31 is provided on the handle housing 24 behind the trigger 30. The switch mechanism 31 has a switch (not shown) that is operated by the trigger 30. The switch is electrically connected to a controller 32 provided at the lower end of the lower housing portion 22 and outputs an output signal to the controller 32 according to the operation state of the trigger 30. The controller 32 is disposed between the left and right first air intake ports 22B and above the second air intake port 22C. A battery pack 33 is attached to the lower end of the handle housing 24, and power is supplied from the battery pack 33 to a motor 40 and the controller 32, which will be described later.

[0027] (Regarding the Motor 40) As shown in FIGS. 2 and 4, the motor 40 is configured as a three-phase brushless motor and is accommodated in the lower housing portion 22 of the main body housing 21. Specifically, the motor 40 is disposed above the controller 32 and is electrically connected to the controller 32. The motor 40 has an output shaft 41 whose axial direction is the vertical direction. The lower end of the output shaft 41 is rotatably supported by a motor bearing 35 fixed to the lower housing portion 22, and the upper end portion of the output shaft 41 is rotatably supported by a motor bearing 36 held in a bearing holder 51A of an inner housing 51 (described later). A substantially cylindrical rotor 42 is provided radially outward from the lower portion of the output shaft 41, and a stator 43 is provided radially outward from the rotor 42. A pinion gear 41A is formed on the upper end of the output shaft 41.

[0028] (Regarding the Transmission Mechanism 50) As shown in Fig. 2, the transmission mechanism 50 is configured as a mechanical part that transmits the rotational force of the motor 40 to the tool bit T to drive the tool bit T. The transmission mechanism 50 includes an inner housing 51, an intermediate shaft 52, and a transmission part 57, and is housed in the upper housing part 23 of the main body housing 21 and is disposed in front of the exhaust port 23A.

[0029] The inner housing 51 is formed in a generally bottomed elliptical cylinder shape that is open to the front. The inner housing 51 is disposed above the motor 40 so as to separate the rear end of the upper housing portion 23 in the front-rear direction. Specifically, the inner housing 51 is disposed in close proximity to the front side of the exhaust port 23A. A bearing holder 51A is formed at the lower end of the inner housing 51, and the bearing holder 51A is formed in a generally stepped cylinder shape that is open to the bottom. The upper end of the output shaft 41 of the motor 40 is inserted into the bearing holder 51A, and the motor bearing 36 is held by the bearing holder 51A.

[0030] The intermediate shaft 52 is formed in a generally cylindrical shape with its axial direction extending in the front-rear direction, and its front and rear ends are rotatably supported by bearings 53 and 54 fixed to the main body housing 21. A bevel gear 55 is provided at the rear end of the intermediate shaft 52 so as to rotate integrally therewith, and the bevel gear 55 is meshed with a pinion gear 41A of the output shaft 41. As a result, when the motor 40 is driven and the output shaft 41 rotates, the intermediate shaft 52 rotates about its own axis. A motion conversion member 56 is provided on the intermediate shaft 52, and the motion conversion member 56 is configured to convert the rotational motion of the intermediate shaft 52 into reciprocating motion in the front-rear direction and transmit the motion to a transmission unit 57 (described later).

[0031] The transmission part 57 extends in the front-rear direction above the intermediate shaft 52. The tool bit T is attached to the front end part of the transmission part 57. The tool bit T is formed in a substantially cylindrical shape with its axial direction extending in the front-rear direction, and the rear end part of the tool bit T is attached to the transmission part 57. The transmission part 57 is also connected to the intermediate shaft 52. As a result, the rotational force of the motor 40 is transmitted to the tool bit T, causing the tool bit T to rotate about its own axis and perform drilling on the workpiece.

[0032] The transmission mechanism 50 generates heat due to friction when transmitting the rotational force of the motor 40 to the tool bit T to drive the tool bit T. The transmission mechanism 50 is an example of a heat-generating part.

[0033] 1 and 2, the dust collecting device 80 is formed in a generally rectangular box shape as a whole. The dust collecting device 80 is disposed in front of the lower housing portion 22 of the hammer drill body 10 and is assembled to the main body housing 21. The dust collecting device 80 includes a cover 82, a suction portion 84, and a dust collecting portion 86.

[0034] (Regarding the Cover 82) The cover 82 forms the outer periphery of the upper and rear end portions of the dust collecting device 80. The cover 82 is composed of two cover members divided in the left-right direction, and the cover 82 is formed by assembling the divided cover members together. A rear end portion 82A of the cover 82 protrudes rearward beyond a dust collecting portion 86 (described later) and is positioned to cover the lower end portion of the lower housing portion 22 of the hammer drill body 10 from both the left-right direction and the bottom side. A first opening portion 82B for taking in air from a first intake port 22B of the hammer drill body 10 is formed through the rear end portion 82A of the cover 82, and the first opening portion 82B is positioned outside the first intake port 22B in the left-right direction. A second opening portion 82C for taking in air from a second intake port 22C of the hammer drill body 10 is formed through the rear end portion 82A of the cover 82, and the second opening portion 82C is positioned below the first opening portion 82B.

[0035] (Regarding the suction unit 84) The suction unit 84 constitutes the upper part of the dust collector 80. The suction unit 84 is formed in a generally cylindrical shape extending in the front-rear direction and is attached to the cover 82. The front end of the suction unit 84 is bent upward, and a suction nozzle 84A is provided at the tip of the suction unit 84. The suction nozzle 84A is formed in a generally cylindrical shape with its axial direction extending in the front-rear direction. The suction nozzle 84A is arranged coaxially with the tool tip T, and the tip of the tool tip T is inserted through the suction nozzle 84A. The suction nozzle 84A and the suction unit 84 are in communication with each other. The dust collection air W2 generated by the dust collection fan 65, which will be described later, sucks air around the tip of the tool tip T into the suction unit 84.

[0036] (Regarding the dust collecting section 86) The dust collecting section 86 is formed in a substantially rectangular box shape, and is disposed below the suction section 84 and attached to the cover 82. The dust collecting section 86 has a cyclone chamber 86A and a filter chamber 86B.

[0037] The cyclone chamber 86A communicates with the rear end of the suction section 84, and the dust-collecting airflow W2 sucked into the suction section 84 flows into the cyclone chamber 86A. A cyclone section 87 is provided inside the cyclone chamber 86A. The cyclone section 87 is formed in a substantially cylindrical shape with its axial direction extending in the front-to-rear direction, and the cyclone section 87 swirls the dust-collecting airflow W2 that has flowed into the cyclone chamber 86A, separating the air and dust in the dust-collecting air W2.

[0038] The filter chamber 86B is located behind the cyclone unit 87, and the dust-collected air W2, from which dust has been separated by the cyclone unit 87, flows into the filter chamber 86B. A filter (not shown) is provided in the filter chamber 86B, and the dust-collected air W2 that flows into the filter chamber 86B passes through the filter and flows upward. A discharge section 88 is provided above the filter chamber 86B. The discharge section 88 is formed in a generally cylindrical shape extending in the front-to-rear direction, and the front end of the discharge section 88 bends downward and opens toward the cyclone chamber 86A. This allows the discharge section 88 to communicate with the cyclone chamber 86A. The rear end of the discharge section 88 is inserted from the front into the dust collection port 22A of the hammer drill body 10. This allows the dust-collected air W2 that has passed through the filter chamber 86B to flow into the housing 20 through the dust collection port 22A.

[0039] (Regarding the Air Blowing Mechanism 60) Next, a description will be given of the air blowing mechanism 60 of the hammer drill body 10. As shown in Figures 2 and 4 to 8, the air blowing mechanism 60 includes a fan 62 and a fan guide 70 serving as a rectifying member.

[0040] (Regarding the fan 62) The fan 62 is fixed to the upper part of the output shaft 41 of the motor 40 so as to be rotatable together with the motor 40, and is disposed above the rotor 42 and stator 43 of the motor 40. The fan 62 is formed in a disk shape with its thickness extending vertically. The fan 62 includes a cooling fan 63 serving as a first fan that constitutes the lower part of the fan 62, and a dust-collecting fan 65 serving as a second fan that constitutes the upper part of the fan 62, and the cooling fan 63 and the dust-collecting fan 65 are configured as centrifugal fans.

[0041] The cooling fan 63 includes a base plate 64 and a plurality of cooling air vanes 63A. The base plate 64 is generally circular and has a thickness extending in the vertical direction. A fan fixing portion 64A is formed in the center of the base plate 64. The fan fixing portion 64A is generally cylindrical and has an axial direction extending in the vertical direction, protruding from the base plate 64 on both sides in the vertical direction. The output shaft 41 is fitted into the fan fixing portion 64A, and the fan fixing portion 64A is fixed to the output shaft 41 so as to be rotatable integrally therewith.

[0042] The cooling air blades 63A are formed on the lower surface of the base plate 64 and extend in a generally arc-like shape along the radial direction of the base plate 64 when viewed from below. The cooling air blades 63A are arranged at predetermined angular intervals around the circumferential direction of the base plate 64. When the fan 62 rotates together with the output shaft 41 in one direction (the direction of arrow A in FIGS. 5 to 7), cooling air W1 is generated from the tips of the cooling air blades 63A and blown outward in the radial direction of the fan 62 (see FIGS. 4 and 7). Specifically, cooling air W1 is generated and flows into the main body housing 21 from the first air intake port 22B and the second air intake port 22C of the main body housing 21. The cooling air W1 passes upward beside the controller 32, passes upward between the rotor 42 and the stator 43 of the motor 40, and flows into the cooling fan 63 from below (see FIG. 2).

[0043] The dust collection fan 65 includes a base plate 64, a plurality of dust collection air blades 65A, and a fan cover 66. That is, the base plate 64 serves as a common part for the cooling fan 63 and the dust collection fan 65. The dust collection air blades 65A are formed on the upper surface of the base plate 64 and extend in a generally arc shape along the radial direction of the base plate 64 when viewed from above. The plurality of dust collection air blades 65A are arranged at predetermined angular intervals around the circumferential direction of the base plate 64. The vertical height of the dust collection air blades 65A is set higher than the vertical height of the cooling air blades 63A.

[0044] The fan cover 66 is formed in a generally annular plate shape with its thickness extending vertically, and is connected to the upper end of the dust-collecting airflow impeller 65A. The fan cover 66 is slightly inclined upward as it extends radially inward in a side view. A central opening of the fan cover 66 defines a fan-side suction port 66A, through which the output shaft 41 passes. Furthermore, the dust collection port 22A of the housing 20 (the rear end of the discharge portion 88 of the dust collector 80) is located diagonally above and in front of the dust-collecting fan 65.

[0045] When the fan 62 rotates together with the output shaft 41 in one rotational direction, the dust collection air impeller 65A generates dust collection air W2 that is blown outward in the radial direction of the fan 62 (see FIGS. 4 and 7). Specifically, the dust collection air W2 is generated and flows into the main body housing 21 through the dust collection port 22A of the main body housing 21, and the dust collection air W2 flows into the dust collection fan 65 through the fan-side suction port 66A of the dust collection fan 65. In addition, the fan 62 is designed so that the air volume of the cooling air W1 blown out from the cooling fan 63 is greater than the air volume of the dust collection air W2 blown out from the dust collection fan 65.

[0046] (Regarding the fan guide 70) The fan guide 70 is formed in a generally cylindrical shape with a bottom that is open downward. The fan guide 70 is attached to the main housing 21 of the housing 20, and the fan 62 is housed inside the fan guide 70. The fan guide 70 includes a guide base 71, a partition wall 72, and a rectifying mechanism 73.

[0047] (Regarding the guide base 71) The guide base 71 is formed in a generally annular plate shape with its thickness direction extending vertically, and is slightly inclined upward as it extends radially inward in a side view. A central opening of the fan guide 70 is configured as a guide-side suction port 71A, and the inner diameter of the guide-side suction port 71A is generally the same as the inner diameter of the fan-side suction port 66A of the fan 62. The guide base 71 is disposed above the fan 62 and coaxially with the fan 62, and the output shaft 41 passes through the guide-side suction port 71A. The outer diameter of the guide base 71 is set larger than the outer diameter of the fan 62, and the guide base 71 covers the fan 62 from above.

[0048] (Regarding the partition wall 72) The partition wall 72 is formed in a generally U-shaped plate shape that is open to the front in a plan view and protrudes upward from the upper surface of the guide base 71. Specifically, the rear end of the partition wall 72 protrudes upward from the edge of the guide-side suction port 71A. As a result, the space above the guide base 71 (fan 62) is partitioned by the partition wall 72, and the space surrounded by the partition wall 72 and open to the front constitutes a dust-collecting airflow passage 72A, which serves as a second airflow passage. In addition, the rear end of the discharge section 88 of the dust collector 80 protrudes rearward from the dust collection port 22A and is located at the front end of the dust-collecting airflow passage 72A. In other words, the dust-collecting airflow passage 72A is in communication with the dust collection port 22A. As a result, the dust collection air W2 that flows into the dust collection air passage section 72A from the discharge section 88 passes through the dust collection air passage section 72A and flows into the dust collection fan 65 through the guide side suction port 71A and the fan side suction port 66A.

[0049] (Regarding the Flow Straightening Mechanism 73) The flow straightening mechanism 73 includes a pair of front and rear guide walls 74, 75, and a plurality of (five in this embodiment) flow straightening pieces 76-1, 76-2, 76-3, 76-4, 76-5 serving as flow straightening sections.

[0050] The guide walls 74, 75 are formed in a generally elongated plate shape with their thickness direction aligned with the radial direction of the fan 62 and extending in the circumferential direction of the fan 62. That is, the guide walls 74, 75 are curved in a generally arc shape in plan view. The guide walls 74, 75 are disposed radially outward of the fan 62 and connected to the guide base 71. Specifically, the front guide wall 74 extends downward from the front end of the guide base 71. The rear guide wall 75 is disposed at a position offset rearward from the guide base 71 in plan view, and upper ends of both longitudinal ends of the guide wall 75 extend forward and are connected to the outer periphery of the guide base 71. The lower ends of the guide walls 74, 75 are disposed below the lower end of the fan 62.

[0051] Of the flow straightening pieces 76-1 to 76-5, the three flow straightening pieces 76-1 to 76-3 are configured similarly, and the two flow straightening pieces 76-4 and 76-5 are configured similarly to the flow straightening pieces 76-1 to 76-3 except for the following points. Below, the flow straightening pieces 76-1 to 76-3 will be described first, and then the flow straightening pieces 76-4 and 76-5 will be described.

[0052] The flow straightening pieces 76-1 to 76-3 are formed integrally with the rear guide wall 75, extend radially inward of the fan 62 from the inner circumferential surface of the guide wall 75, and are arranged at predetermined intervals around the fan 62. When viewed from the radially inner side of the fan 62 (output shaft 41), the flow straightening pieces 76-1 to 76-3 are formed like ribs extending in a direction that slopes upward toward one side in the rotation direction of the fan 62. Specifically, the flow straightening pieces 76-1 to 76-3 are curved in a substantially arc shape so that intermediate portions in the longitudinal direction of the flow straightening pieces 76-1 to 76-3 are convex downward and toward one side in the rotation direction of the fan 62. The sides of the flow straightening pieces 76-1 to 76-3 facing the other side in the rotation direction of the fan 62 are configured as flow straightening surfaces 76A. When viewed from the radial direction of the fan 62, the flow straightening pieces 76-1 to 76-3 overlap with the cooling airflow blade portions 63A of the cooling fan 63 and the dust collection airflow blade portions 65A of the dust collection fan 65. Specifically, the overlap distance d1 in the vertical direction between the flow straightening pieces 76-1 to 76-3 and the dust collection airflow blade portions 65A is set to be larger than the overlap distance d2 in the vertical direction between the flow straightening pieces 76-1 to 76-3 and the cooling airflow blade portions 63A (see FIG. 7).

[0053] Flow straightening extension portions 77 are integrally formed at the upper ends of the flow straightening pieces 76-1 to 76-3. The flow straightening extension portions 77 are formed in a generally rectangular plate shape with the rotation direction of the fan 62 as the plate thickness direction, and extend upward from the upper ends of the flow straightening pieces 76-1 to 76-3. The flow straightening extension portions 77 also protrude upward beyond the guide base 71, and the radially inner end of the flow straightening extension portion 77 in the fan 62 extends upward from the guide base 71. The three flow straightening extension portions 77 are connected by connecting walls 78 provided on the guide base 71, and the connecting walls 78 extend along the circumferential direction of the guide base 71 in a plan view. The side of the flow straightening extension portion 77 facing the other rotation direction of the fan 62 is configured as an extended surface 77A. The extension surface 77A is disposed along a plane perpendicular to the rotation direction of the fan 62, and the lower end of the extension surface 77A is connected to the upper end of the flow rectifying surfaces 76A of the flow rectifying pieces 76-1 to 76-3.

[0054] The flow straightening piece 76-4 is formed integrally with the rear guide wall 75, extends from the inner circumferential surface of the guide wall 75 radially inward of the fan 62, and is disposed on one side of the flow straightening piece 76-3 in the rotation direction of the fan 62. The flow straightening piece 76-5 is disposed on one side of the flow straightening piece 76-4 in the rotation direction of the fan 62, and is disposed adjacent to the front guide wall 74 on the other side of the rotation direction of the fan 62, and is connected to the guide wall 74. The flow straightening pieces 76-4 and 76-5 do not have the flow straightening extension portions 77 of the flow straightening pieces 76-1 to 76-3. Furthermore, the lower ends of the flow straightening pieces 76-4 and 76-5 are disposed lower than the lower ends of the flow straightening pieces 76-1 to 76-3.

[0055] The exhaust port 23A of the housing 20 is disposed substantially directly above the flow straightening pieces 76-1 to 76-4 in a side view. The cooling air W1 and the dust-collecting air W2 blown outward in the radial direction from the fan 62 are straightened by the flow straightening surfaces 76A of the flow straightening pieces 76-1 to 76-5, flow upward through the fan guide 70, and are exhausted to the outside of the housing 20 through the exhaust port 23A (see FIG. 4). The dust-collecting air passage 72A partitioned by the partition wall 72 is disposed in a position that does not overlap with the flow straightening pieces 76-1 to 76-5 in a plan view.

[0056] (Operation and Effect) When drilling a hole with the hammer drill 1 configured as described above, an operator pulls the trigger 30 of the hammer drill body 10 to drive the motor 40 and rotate the tool bit T around its own axis, thereby drilling a hole in the workpiece.

[0057] Furthermore, when the motor 40 is driven, the fan 62 rotates together with the output shaft 41 of the motor 40. As a result, the cooling fan 63 of the fan 62 generates cooling air W1, and the dust collection fan 65 of the fan 62 generates dust collection air W2.

[0058] Specifically, air below the cooling fan 63 is drawn into the cooling fan 63 and blown outward in the radial direction of the cooling fan 63. This generates cooling air W1 that flows into the main body housing 21 from the first air intake port 22B and the second air intake port 22C of the housing 20. The cooling air W1 that flows into the main body housing 21 passes upward past the side of the controller 32 and also passes upward between the rotor 42 and the stator 43 of the motor 40 (see FIG. 2). This allows the controller 32 and the motor 40 to be cooled by the cooling air W1.

[0059] The cooling air W1 that has cooled the motor 40 then flows into the cooling fan 63 and is blown out from the cooling air blade portion 63A radially outward of the fan 62 and toward one side in the direction of rotation. The cooling air W1 blown out from the cooling air blade portion 63A strikes the guide wall 75 of the fan guide 70 and flows along the inner circumferential surface of the guide wall 75 toward one side in the direction of rotation of the fan 62. At this time, the cooling air W1 strikes the flow rectifying surface 76A at the lower end of the flow rectifying pieces 76-1 to 76-4 and flows along the flow rectifying surface 76A toward one side in the direction of rotation of the fan 62. Similarly, the cooling air W1 blown out from the cooling air blade portion 63A strikes the flow rectifying surface 76A at the lower end of the flow rectifying piece 76-5 and flows along the flow rectifying surface 76A toward one side in the direction of rotation of the fan 62. As a result, the direction of the cooling air W1 is changed upward (to one axial side of the output shaft 41) by the airflow straightening surface 76A, and the cooling air W1 is blown upward from the airflow straightening pieces 76-1 to 76-5. Furthermore, in the airflow straightening pieces 76-1 to 76-3, the airflow straightening extension portions 77 extend above the airflow straightening pieces 76-1 to 76-3, so the cooling air W1 flows upward along the airflow straightening extension portions 77 and is blown upward from the airflow straightening extension portions 77 (see FIGS. 4 and 7).

[0060] Meanwhile, as the dust-collecting fan 65 rotates, air in the dust-collecting airflow passage 72A flows into the dust-collecting fan 65 through the guide-side inlet 71A of the fan guide 70 and the fan-side inlet 66A of the dust-collecting fan 65 and is then blown outward in the radial direction of the dust-collecting fan 65. As a result, in the dust collector 80, which is connected to the dust-collecting airflow passage 72A, dust-collected air W2 is generated, flowing from the suction nozzle 84A to the discharge portion 88. Specifically, the dust-collected air W2 flows from the suction nozzle 84A into the suction portion 84, and the dust-collected air W2 that has flowed into the suction portion 84 passes through the cyclone chamber 86A and the filter chamber 86B of the dust collector 86. As a result, dust contained in the dust-collected air W2 is collected in the cyclone chamber 86A, and the dust-separated dust-collected air W2 is exhausted from the discharge portion 88 of the dust collector 80 toward the hammer drill body 10 (see FIG. 2).

[0061] The dust-collected air W2 discharged from the discharge portion 88 of the dust collector 80 to the hammer drill body 10 passes through the dust-collected air passage portion 72A of the fan guide 70 and flows into the dust-collecting fan 65 from the guide-side suction port 71A of the fan guide 70 and the fan-side suction port 66A of the fan 62. The dust-collected air W2 is then blown outward in the radial direction of the fan 62 and toward one side in the rotational direction from the dust-collecting air blade portion 65A of the dust-collecting fan 65.

[0062] The dust-collected air W2 blown out from the dust-collecting fan 65 strikes the guide wall 75 of the fan guide 70 and flows along the inner circumferential surface of the guide wall 75 toward one side in the rotation direction of the fan 62. At this time, the dust-collected air W2 is drawn into the cooling air W1 and merges with it. That is, the dust-collected air W2 strikes the rectifying surfaces 76A at the lower ends of the rectifying pieces 76-1 to 76-5 and flows along the rectifying surfaces 76A toward one side in the rotation direction of the fan 62. As a result, the rectifying surfaces 76A change the direction of the dust-collected air W2 upward (to one axial side of the output shaft 41) and the dust-collected air W2 is blown out upward from the rectifying pieces 76-1 to 76-5. In other words, the rectifying surfaces 76A of the rectifying pieces 76-1 to 76-5 prevent the dust-collected air W2 from flowing downward (to the other axial side of the output shaft 41). In addition, in the airflow straightening pieces 76-1 to 76-3, the dust collection airflow W2 flows upward along the airflow straightening extension portion 77 together with the cooling airflow W1, and is blown out upward from the airflow straightening extension portion 77 (see FIGS. 4 and 7).

[0063] The cooling air W1 and dust-collecting air W2 blown upward from the rectifying extension 77 and the rectifying pieces 76-4, 76-5 flow upward through the space between the inner housing 51 of the transmission mechanism 50 and the rear wall of the main housing 21, and are exhausted from the exhaust port 23A to the outside of the housing 20. As a result, the transmission mechanism 50 is cooled by the cooling air W1 and dust-collecting air W2 flowing out from the fan guide 70.

[0064] As described above, in the hammer drill body 10, the dust collection port 22A, the first air intake port 22B, and the second air intake port 22C are formed in the lower housing portion 22 that houses the motor 40, and the exhaust port 23A is formed in the upper housing portion 23 that houses the transmission mechanism 50. The fan 62 having the cooling fan 63 and the dust collection fan 65 is provided within the lower housing portion 22. When the cooling fan 63 rotates, cooling air W1 is generated that flows from the first air intake port 22B and the second air intake port 22C toward the cooling fan 63, and when the dust collection fan 65 rotates, dust collection air W2 is generated that flows from the dust collection port 22A toward the dust collection fan 65. Here, the fan guide 70 is provided within the lower housing portion 22, and the fan guide 70 has air straightening pieces 76-1 to 76-5. The rectifying pieces 76-1 to 76-5 rectify the cooling air W1 blown out from the cooling fan 63 and the dust-collected air W2 blown out from the dust-collecting fan 65 and direct them to the exhaust port 23A. Thus, the cooling air W1 and the dust-collected air W2 after reaching the fan 62 are not immediately exhausted to the outside of the housing 20, but are rectified by the rectifying pieces 76-1 to 76-5 and directed toward the upper housing portion 23. As a result, the transmission mechanism 50 disposed in the upper housing portion 23 can be cooled by utilizing the dust-collected air W2 for collecting dust around the tip of the tool bit T and the cooling air W1 for cooling the controller 32 and the motor 40. In other words, the transmission mechanism 50 can be cooled by utilizing the cooling air W1 and the dust-collected air W2 after reaching the fan 62. Therefore, the transmission mechanism 50 can be efficiently cooled, and the cooling performance of the hammer drill 1 can be improved.

[0065] The cooling fan 63 and the dust collection fan 65 are centrifugal fans that are fixed to the output shaft 41 of the motor 40 and are arranged side by side in the axial direction of the output shaft 41. This allows the cooling fan 63 and the dust collection fan 65 to generate cooling air W1 and dust collection air W2 by drawing air into the fan 62 from spaces on both sides of the output shaft 41 in the axial direction. The cooling air W1 and the dust collection air W2 blown outward in the radial direction from the fan 62 are joined together, and the joined cooling air W1 and dust collection air W2 are rectified by the rectifying pieces 76-1 to 76-5 and can be discharged toward the transmission mechanism 50.

[0066] Moreover, the exhaust port 23A is disposed above the fan 62. Furthermore, the flow straightening pieces 76-1 to 76-5 are disposed radially outward of the dust-collecting fan 65 and change the direction of the cooling air W1 and the dust-collecting air W2 blown out from the fan 62 radially outward and toward one side in the rotation direction to an upward direction. Specifically, the flow straightening pieces 76-1 to 76-5 have flow straightening surfaces 76A, which, when viewed from the radial direction of the output shaft 41, are inclined upward toward one side in the rotation direction of the fan 62. This allows the cooling air W1 and the dust-collecting air W2 blown out from the fan 62 radially outward and toward one side in the rotation direction to be guided along the flow straightening surfaces 76A, thereby efficiently changing the direction of the cooling air W1 and the dust-collecting air W2 upward (toward the exhaust port 23A).

[0067] Additionally, stratum extension portions 77 extending upward are provided at the upper ends of the stratum pieces 76-1 to 76-3. The stratum extension portions 77 have extension surfaces 77A connected to the stratum surface 76A, and the extension surfaces 77A are arranged along a plane perpendicular to the rotation direction of the fan 62. This increases the length for stratuming the cooling air W1 and the dust-collecting air W2. Therefore, the cooling air W1 and the dust-collecting air W2 blown upward from the stratum pieces 76-1 to 76-3 can be effectively directed upward along the extension surfaces 77A.

[0068] The fan guide 70 also has a guide wall 75, which is disposed radially outward (rearward) of the fan 62. The guide wall 75 extends circumferentially of the fan 62, with the radial direction of the fan 62 being its plate thickness direction, and the flow straightening pieces 76-1 to 76-4 extend radially inward from the inner circumferential surface of the guide wall 75. This allows the cooling air W1 and the dust-collected air W2 blown radially outward from the fan 62 to flow toward one side in the rotation direction along the inner circumferential surface of the guide wall 75. That is, the cooling air W1 and the dust-collected air W2 can be guided to the flow straightening surfaces 76A of the flow straightening pieces 76-1 to 76-4 while preventing the cooling air W1 and the dust-collected air W2 from flowing radially outward of the fan 62 beyond the flow straightening pieces 76-1 to 76-4. Therefore, it is possible to suppress a decrease in the volume of the cooling air W1 and the dust collection air W2 rectified by the airflow rectifying pieces 76-1 to 76-5.

[0069] The amount of cooling air W1 blown out radially outward from cooling fan 63 is set to be greater than the amount of dust collection air W2 blown out radially outward from dust collection fan 65. Furthermore, the overlap distance d1 in the vertical direction between flow rectification pieces 76-1 to 76-5 and dust collection fan 65 (dust collection air blade portion 65A) is set to be longer than the overlap distance d2 in the vertical direction between flow rectification pieces 76-1 to 76-5 and cooling fan 63 (cooling air blade portion 63A). This makes it possible to suppress the generation of turbulence caused by the large volume of cooling air W1 hitting the flow rectification pieces 76-1 to 76-5, and to change the direction of cooling air W1 by flow rectification pieces 76-1 to 76-5.

[0070] The fan guide 70 also has a partition wall 72 that separates the space above the fan 62 into a dust-collected airflow passage 72A. The dust-collected airflow passage 72A is connected to the dust collection port 22A of the housing 20 and is positioned so that the airflow straightening pieces 76-1 to 76-5 and the dust-collected airflow passage 72A do not overlap in a plan view. This allows the partition wall 72 to prevent interference between the dust-collected airflow W2 flowing into the housing 20 from the dust collection port 22A and the cooling airflow W1 and the dust-collected airflow W2 discharged upward from the airflow straightening pieces 76-1 to 76-5 above the fan 62. That is, the partition wall 72 separates the space above the fan 62 into an area for supplying the dust-collected airflow W2 to the fan 62 and an area for exhausting the cooling air W1 and the dust-collected air W2. Therefore, the cooling air W1 and the dust collecting air W2 blown upward by the airflow straightening pieces 76-1 to 76-5 can be effectively directed toward the exhaust port 23A.

[0071] (Modification of fan guide 70) Next, a modification of the fan guide 70 will be described with reference to Fig. 9. This modification has the same configuration as the fan guide 70 of the present embodiment, except for the following points. In Fig. 9, the same reference numerals are used to designate parts that are configured in the same way as the present embodiment.

[0072] That is, in the fan guide 70 of this modified example, sub-flow rectifying pieces 90-1 to 90-3 are integrally formed at three locations on the inner circumferential surface of the rear guide wall 75 as sub-flow rectifying portions. The sub-flow rectifying pieces 90-1 to 90-3 are arranged corresponding to the flow rectifying pieces 76-1 to 76-3, respectively. Specifically, the sub-flow rectifying pieces 90-1 to 90-3 are arranged on the other side in the rotation direction of the fan 62 and below the flow rectifying pieces 76-1 to 76-3. That is, the sub-flow rectifying pieces 90-1 to 90-3 are arranged radially outward from the cooling fan 63.

[0073] The sub-flow rectifying pieces 90-1 to 90-3 extend in a direction that slopes upward toward one side in the rotation direction of the fan 62, as viewed from the radial direction of the fan 62, and the extension length of the sub-flow rectifying pieces 90-1 to 90-3 is set to be shorter than the flow rectifying length of the flow rectifying pieces 76-1 to 76-3. Also, as viewed from the radial direction of the fan 62, the inclination angle AN1 of the upper end portions of the flow rectifying pieces 76-1 to 76-5 with respect to the rotation direction of the fan 62 is set to be larger than the inclination angle AN2 of the upper end portions of the sub-flow rectifying pieces 90-1 to 90-3 with respect to the rotation direction of the fan 62.

[0074] In the modified fan guide 70, the cooling air W1 blown outward in the radial direction from the cooling fan 63 is rectified by the sub-flow rectifying pieces 90-1 to 90-3 and guided to the flow rectifying pieces 76-1 to 76-3. The cooling air W1 and the dust-collecting air W2 are then joined together, rectified by the flow rectifying pieces 76-1 to 76-5, and blown upward from the flow rectifying pieces 76-1 to 76-5. As in the present embodiment, the dust-collecting air W2 for collecting dust around the tip of the tool bit T and the cooling air W1 for cooling the motor 40 and the controller 32 can be utilized to cool the transmission mechanism 50 disposed in the upper housing portion 23. This allows the transmission mechanism 50 to be efficiently cooled.

[0075] Furthermore, in the modified fan guide 70, when viewed from the radial direction of the fan 62, the inclination angle AN1 of the upper ends of the airflow rectifying pieces 76-1 to 76-5 relative to the rotation direction of the fan 62 is set to be larger than the inclination angle AN2 of the upper ends of the sub-airflow rectifying pieces 90-1 to 90-3 relative to the rotation direction of the fan 62. This makes it possible to guide the cooling air W1 to the airflow rectifying pieces 76-1 to 76-5 while suppressing a decrease in the wind speed of the cooling air W1 blown outward in the radial direction from the cooling fan 63 to one side in the rotation direction.

[0076] In addition to the transmission mechanism 50, the heat-generating parts may include circuit parts such as the controller 32 that generate heat when the motor 40 is driven. In this embodiment, the controller 32 is disposed in the first housing part (lower housing part 22). However, if the controller 32 is configured to be disposed in the second housing part (upper housing part 23), the circuit parts such as the controller 32 can also be cooled efficiently. The second housing part is not limited to being disposed above the first housing part, but may be disposed in the front, rear, right, left, or bottom. For example, the handle housing 24 disposed behind the lower housing part 22 may be configured to correspond to the second housing part, and the exhaust port 23A and the controller 32 may be disposed in the handle housing 24.

[0077] For example, the present invention may be configured to include a housing having a motor, a heat-generating portion that generates heat when the motor is driven, a first housing portion that houses the motor and has an air intake port and a dust collection port formed therein, and a second housing portion that houses the heat-generating portion and has an exhaust port formed therein; a cooling fan that is provided in the first housing portion and rotates to one side in the direction of rotation to generate cooling air that flows into the first housing portion from the air intake port; a dust collection fan that is provided in the first housing portion and rotates to one side in the direction of rotation to generate dust-collected air that flows into the first housing portion from the dust collection port; and a rectifying member that is provided in the first housing portion and has a rectifying portion that rectifies the cooling air blown out from the cooling fan and the dust-collected air blown out from the dust collection fan and flows them to the exhaust port. The cooling fan and the dust collection fan may be centrifugal fans fixed to the output shaft of the motor so as to be rotatable together with the motor, and arranged side by side in the axial direction of the output shaft.

[0078] The second housing part is arranged on one axial side of the first housing part, the dust collecting fan is arranged on one axial side of the cooling fan, and the straightening part is arranged radially outward of the output shaft at least with respect to the dust collecting fan, and the direction of the cooling air blown radially outward from the cooling fan and the dust collecting air blown radially outward from the dust collecting fan may be changed to one axial side. The flow straightening portion may be formed in the shape of a rib extending in a direction inclined toward one side in the axial direction as it extends toward one side in the rotation direction, as viewed in the radial direction of the output shaft.

[0079] A straightening extension portion extending to one side in the axial direction is provided at one axial end of the straightening portion, and the straightening extension portion may have an extension surface connected to the other side of the straightening portion in the rotational direction and arranged along a plane perpendicular to the rotational direction.

[0080] The straightening member has a guide wall, which is arranged radially outward of the output shaft relative to the cooling fan and the dust collecting fan and extends in the rotational direction, and the straightening portion may extend from the guide wall radially inward of the output shaft.

[0081] The straightening member has a partition wall that separates a part of the space on one axial side of the dust collection fan as a dust collection air passage section, and the dust collection air passage section communicates with the dust collection port, and may be positioned so that the straightening section and the dust collection air passage section do not overlap when viewed from the axial direction.

[0082] A sub-straightening section is provided radially outward of the cooling fan, and the sub-straightening section is arranged on the other side of the rotational direction relative to the straightening section, and may be formed in the shape of a rib extending along a direction that inclines toward one side of the axial direction as it approaches one side of the rotational direction when viewed radially from the output shaft.

[0083] When viewed from the radial direction of the output shaft, the inclination angle of one end of the straightening section relative to the rotational direction may be set to be larger than the inclination angle of one end of the sub-straightening section relative to the rotational direction.

[0084] The length of the flow straightening portion in the axial direction may be set to be longer than the length of the sub-flow straightening portion in the axial direction.

[0085] The volume of the cooling air blown out from the cooling fan may be larger than the volume of the dust-collecting air blown out from the dust-collecting fan.

[0086] A dust collecting device is attached to the housing, and the dust collecting device may include a suction section that uses dust collecting wind to suck in air around the tool bit and cause it to flow into the dust collecting device, and a discharge section that is connected to the dust collection port and causes the dust collecting wind in the dust collecting device to flow out into the first housing section.

[0087] The heat generating portion may be a transmission mechanism that transmits the driving force of the motor to the tool bit. [Explanation of symbols]

[0088] 1... hammer drill (working machine), 20... housing, 22... lower housing portion (first housing portion), 22A... dust collection port, 22B... first air intake port (air intake port), 22C... second air intake port (air intake port), 23... upper housing portion (second housing portion), 23A... exhaust port, 40... motor, 41... output shaft, 50... transmission mechanism (heat generating portion), 63... cooling fan (first fan), 65... dust collection fan (second fan), 70... fan guide (rectifying member), 72... Cut wall, 72A...dust collection air passage section (second air flow passage section), 74...guide wall, 75...guide wall, 76-1...flow straightening piece (flow straightening section), 76-2...flow straightening piece (flow straightening section), 76-3...flow straightening piece (flow straightening section), 76-4...flow straightening piece (flow straightening section), 76-5...flow straightening piece (flow straightening section), 77...flow straightening extension section, 77A...extension surface, 84...suction section, 88...discharge section, 90-1...sub-flow straightening piece (sub-flow straightening section), 90-2...sub-flow straightening piece (sub-flow straightening section), 90-3...sub-flow straightening piece (sub-flow straightening section)

Claims

1. A motor; an output shaft that rotates when driven by the motor; a transmission mechanism that transmits a rotational force of the output shaft to the tool bit; a first fan that is a centrifugal fan fixed to the output shaft and rotates integrally with the output shaft; a second fan, which is a centrifugal fan, located on one side of the first fan in the axial direction of the output shaft, fixed to the output shaft, and rotating integrally with the output shaft; a straightening member that houses the first fan and the second fan therein, and that merges a first airflow blown out from the first fan and a second airflow blown out from the second fan when the output shaft rotates toward one side in the rotation direction, and causes the merged airflow to flow toward one side in the axial direction, the rectifying member is disposed radially outward of the output shaft with respect to at least the second fan, and has a rectifying portion that changes the direction of the second airflow to one side in the axial direction and rectifies the second airflow so that it flows to one side in the axial direction and suppresses it from flowing to the other side in the axial direction, A work machine, wherein the straightening portion is formed in the shape of a rib extending along a direction inclined toward one side of the axial direction as it approaches one side of the rotation direction when viewed from the radial direction of the output shaft.

2. A straightening extension portion extending to one side in the axial direction is provided at one end of the straightening portion in the axial direction, The work machine according to claim 1 , wherein the flow straightening extension portion has an extension surface connected to the other side surface of the flow straightening portion in the rotational direction and disposed along a plane perpendicular to the rotational direction.

3. The flow straightening member has a guide wall, the guide wall is disposed radially outward of the output shaft with respect to the first fan and the second fan and extends in the rotation direction, The work machine according to claim 1 , wherein the flow straightening portion extends from the guide wall radially inward of the output shaft.

4. A housing having a first housing portion that accommodates the motor and the rectifying member and has an air intake port and a dust collection port formed therein, and a second housing portion that has an exhaust port formed therein, the rectifying member has a partition wall, and the partition wall separates a part of a space on one side in the axial direction from the second fan as a second air flow passage portion; The work machine according to claim 1, wherein the second air flow passage portion is in communication with the dust collection port and is arranged in a position where the straightening portion and the second air flow passage portion do not overlap when viewed from the axial direction.

5. A sub-rectifier section is provided radially outward of the first fan, The work machine described in claim 4, wherein the sub-straightening portion is arranged on the other side of the rotational direction relative to the straightening portion, and is formed in the shape of a rib extending along a direction that inclines toward one side of the axial direction as it approaches one side of the rotational direction when viewed radially of the output shaft.

6. A work machine as described in Claim 5, wherein, when viewed from the radial direction of the output shaft, the inclination angle of one end of the straightening section relative to the rotation direction in the direction of rotation is set to be larger than the inclination angle of one end of the sub-straightening section relative to the rotation direction in the direction of rotation.

7. A work machine as described in Claim 5, wherein the length of the straightening portion in the axial direction is set longer than the length of the sub-straightening portion in the axial direction.

8. A work machine as described in claim 1, wherein the air volume of the first air flow blown out from the first fan is greater than the air volume of the second air flow blown out from the second fan.

9. A dust collector is attached to the housing, The dust collecting device is a suction section that sucks air around the tool bit by dust collection airflow and causes the air to flow into the dust collector; an exhaust portion connected to the dust collection port and configured to allow the dust-collected airflow in the dust collector to flow into the first housing portion; The work machine according to any one of claims 4 to 7, comprising:

10. A work machine as described in Claim 4, wherein the transmission mechanism is housed in the second housing portion.

11. A motor, an output shaft that rotates when driven by the motor; a transmission mechanism that transmits a rotational force of the output shaft to the tool bit; a first fan that is a centrifugal fan fixed to the output shaft and rotates integrally with the output shaft; a second fan, which is a centrifugal fan, located on one side of the first fan in the axial direction of the output shaft, fixed to the output shaft, and rotating integrally with the output shaft; a straightening member that houses the first fan and the second fan therein, and that merges a first airflow blown out from the first fan and a second airflow blown out from the second fan when the output shaft rotates toward one side in the rotation direction, and causes the merged airflow to flow toward one side in the axial direction, The flow rectifying member is a guide wall disposed radially outward of the output shaft relative to the first fan and the second fan and extending in the rotation direction; a rectifying portion that rectifies the second air flow so that the second air flow flows toward one side in the axial direction and suppresses the second air flow from flowing toward the other side in the axial direction, The work machine, wherein the flow straightening portion extends from the guide wall radially inward of the output shaft.

Images