Power tool

Abstract

To improve a dust collecting function in a power tool having a cyclonic separator.SOLUTION: A power tool includes a housing, a motor, a fan, and a cyclonic separator. The fan is rotated by the motor to generate an airflow that flows in from a plurality of first air inlets of the housing and flows inside the housing. The cyclonic separator has a plurality of second air inlets arranged in a circumferential direction of the cyclonic separator. The plurality of first inlets and the plurality of second inlets are apart from each other in an axial direction of the cyclonic separator. A first dust collecting chamber configured to collect dust by an inertial force is defined (i) between the plurality of first air inlets and the plurality of second air inlets in the axial direction of the cyclonic separator, and (ii) between an internal surface of the housing and the cyclonic separator. A second dust collecting chamber configured to collect dust by centrifugal force is defined in the cyclonic separator.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present disclosure relates to a power tool with a cyclone separator. [Background technology]

[0002] Generally, when using a power tool to process concrete, wood, metal, etc., a large amount of dust is generated. Dust that gets into the housing of the power tool can cause malfunctions within the housing. Therefore, for example, the power tool disclosed in Patent Document 1 is equipped with a cyclone separator for collecting dust. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 1,137,467 Summary of the Invention [Problem to be solved by the invention]

[0004] The power tool disclosed in Patent Document 1 has a housing with multiple air intake grilles arranged corresponding to the multiple air intake ports of the cyclone separator. The air outside the housing is filtered out of large particles by these air intake grilles before entering the cyclone separator through the air intake ports. This power tool has room for further improvement in terms of more effective dust collection.

[0005] The present disclosure aims to provide improved dust collection in power tools equipped with cyclone separators. [Means for solving the problem]

[0006] One non-limiting aspect of the present disclosure provides a power tool configured to drive a removably attached accessory tool, the power tool including a housing, a motor, a fan, and a cyclone separator.

[0007] The housing has a plurality of first air inlets. The motor is accommodated in the housing. The fan is accommodated in the housing. The fan is configured to be rotated by the motor and generate an airflow that flows through the plurality of first air inlets and flows inside the housing. The cyclone separator is accommodated in the housing. The cyclone separator has a plurality of second air inlets arranged in a circumferential direction of the cyclone separator. The plurality of first air inlets of the housing and the plurality of second air inlets of the cyclone separator are spaced apart from each other in an axial direction of the cyclone separator. A first dust collecting chamber configured to collect dust by inertial force is defined (i) between the plurality of first air inlets and the plurality of second air inlets in the axial direction of the cyclone separator, and (ii) between the inner surface of the housing and the cyclone separator. A second dust collecting chamber configured to collect dust by centrifugal force is defined in the cyclone separator.

[0008] The power tool according to this embodiment includes two dust collection chambers (a first dust collection chamber and a second dust collection chamber defined in a cyclone separator downstream of the first dust collection chamber) arranged in a flow path of air generated by a fan and flowing inside the housing. The first dust collection chamber uses inertial force to capture dust particles with relatively large particle sizes. Meanwhile, the second dust collection chamber uses centrifugal force to capture dust particles with smaller particle sizes that are not captured in the first dust collection chamber. Thus, the power tool according to this embodiment can perform effective dust collection in two stages. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a top view of a grinder according to a first embodiment. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] FIG. 2 is a cross-sectional view taken along line VI-VI in FIG. [Figure 7] FIG. 2 is a cross-sectional view of a cyclone separator. [Figure 8] FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7. [Figure 9] FIG. 2 is a perspective view of a cyclone separator. [Figure 10] FIG. 2 is an exploded perspective view of the cyclone separator. [Figure 11] FIG. 7 is an enlarged partial view of FIG. 6 showing the cover in the closed position and the locking member in the locked position. [Figure 12] FIG. 6 is a cross-sectional view taken along line XII-XII in FIG. 5. [Figure 13] 12 is a partial cross-sectional view corresponding to FIG. 11, showing the cover in the open position and the locking member in the locked position; [Figure 14] 12 is a partial cross-sectional view corresponding to FIG. 11, showing the cover in the closed position and the locking member in the unlocked position. [Figure 15] FIG. 10 is a perspective view of a grinder according to a second embodiment, showing a state in which the cover is in a closed position. [Figure 16] 1 is a perspective view of the grinder with the cover in the open position. FIG. [Figure 17] 1 is a partial cross-sectional view of the grinder showing the cover in a closed position. [Figure 18] 1 is a partial cross-sectional view of the grinder showing the cover in an open position. DETAILED DESCRIPTION OF THE INVENTION

[0010] In one non-limiting embodiment of the present disclosure, the housing may have at least one first exhaust port. The at least one first exhaust port may be disposed between the plurality of first inlets and the plurality of second inlets in the axial direction of the cyclone separator and may communicate between the inside and outside of the first dust collection chamber. According to this embodiment, dust contained (accumulated) in the first dust collection chamber defined in the housing can be discharged through the at least one first exhaust port.

[0011] In addition to or instead of the above embodiment, the at least one first outlet may be arranged so as not to overlap with the plurality of second inlets, which can prevent air from outside the housing from flowing directly into the inlet of the cyclone separator without passing through the first dust collecting chamber.

[0012] In addition to or instead of the above embodiment, the power tool may have a normal posture during use defined with respect to the direction of gravity. At least one first exhaust port may be configured to open in the direction of gravity when the power tool is in the normal posture. According to this embodiment, when the power tool is in the normal posture, dust can be discharged through the first exhaust port by utilizing the weight of the dust itself.

[0013] In addition to or instead of the above embodiment, the power tool may be a grinder. The grinder may include a spindle configured to be rotatably driven by a motor about a drive axis that defines the up-down direction of the power tool. The spindle may have a lower end configured to removably hold a tool accessory. The housing may extend in a front-to-rear direction perpendicular to the up-down direction. The housing may be configured so that auxiliary handles can be removably attached to the right and left sides in a left-to-right direction perpendicular to the up-down direction and the front-to-rear direction. The at least one first discharge port may include at least one of (i) a lower discharge port opening downward from the housing, (ii) a left discharge port opening leftward from the housing, and (iii) a right discharge port opening rightward from the housing.

[0014] According to this embodiment, when the grinder is in a position where the lower end of the spindle faces the direction of gravity, the weight of the dust can be used to discharge the dust through the lower discharge port. Also, when the grinder is in a position where the auxiliary handle is attached to the right side of the housing and the left side faces the direction of gravity, the weight of the dust can be used to discharge the dust through the left discharge port. Furthermore, when the grinder is in a position where the auxiliary handle is attached to the left side of the housing and the right side faces the direction of gravity, the weight of the dust can be used to discharge the dust through the right discharge port.

[0015] In addition to or instead of the above embodiment, the power tool may be a grinder. The grinder may include a spindle configured to be rotatably driven by a motor about a drive axis that defines the up-down direction of the power tool. The spindle may have a lower end configured to removably hold a tool accessory. The housing may extend in a front-to-rear direction perpendicular to the up-down direction. The multiple first air intake ports may be formed on the right and left sides of the housing in a left-to-right direction perpendicular to the up-down direction and the front-to-rear direction.

[0016] When not in use, grinders are often placed on the ground, floor, or workbench with the upper end of the spindle facing the direction of gravity, or with the lower end of the spindle facing the direction of gravity. According to this embodiment, when the grinder is placed in the above-mentioned position, it is possible to reduce the possibility that dust floating around the grinder will fall from above and enter the housing through the first air intake port.

[0017] In addition to or instead of the above embodiment, the power tool may further include a seal. The seal may be configured to close a gap between the housing and the cyclone separator on an axial side of the cyclone separator opposite the first air inlets and the second air inlets. According to this embodiment, it is possible to prevent dust-containing air from flowing forward from the first dust collecting chamber into the housing without passing through the cyclone separator.

[0018] In addition to or instead of the above embodiment, the axial direction of the cyclone separator may define the front-rear direction of the power tool. The multiple first air intake ports may be located rearward of the multiple second air intake ports. The cyclone separator may include (i) an outer cylinder, (ii) an intermediate cylinder arranged radially inside the outer cylinder and having a rear end located forward of the rear end of the outer cylinder, and (iii) an inner cylinder arranged radially inside the intermediate cylinder and having a rear end located forward of the rear end of the intermediate cylinder. The first dust collection chamber may be defined between the housing and the outer cylinder. A dust separation chamber may be defined between the intermediate cylinder and the inner cylinder, and the dust collection chamber communicates with the first dust collection chamber via the multiple second air intake ports. An exhaust passage may be defined within the inner cylinder, communicating the dust separation chamber with the outside of the cyclone separator. The second dust collection chamber may be defined between the outer cylinder and the intermediate cylinder and communicate with the dust separation chamber. According to this embodiment, a cyclone separator capable of effective dust collection is realized.

[0019] In addition to or instead of the above embodiment, the cyclone separator may be configured so that a first swirling flow is generated in the dust separating chamber and a second swirling flow is generated in the second dust collecting chamber. According to this embodiment, dust can be effectively separated from air by centrifugal force in both the dust separating chamber and the second dust collecting chamber.

[0020] In addition to or instead of the above embodiment, the second dust collection chamber may include (i) a rear dust collection chamber defined within the outer cylinder behind the intermediate cylinder and communicating with the dust separating chamber, and (ii) a front dust collection chamber defined between the outer cylinder and the intermediate cylinder forward of the rear dust collection chamber and communicating with the rear dust collection chamber. According to this embodiment, dust-laden air flowing rearward from the intermediate cylinder is swirled forward in the front dust collection chamber around the intermediate cylinder, allowing the front dust collection chamber to efficiently capture dust.

[0021] In addition to or instead of the above embodiment, the front dust collection chamber may be configured so that the cross-sectional area thereof at least partially decreases toward the front. According to this embodiment, the flow rate of the air in the front dust collection chamber can be increased, and dust can be separated more efficiently by centrifugal force.

[0022] Additionally or alternatively, the outer cylinder, intermediate cylinder, and inner cylinder may be separate components that are connected together to form a single separator assembly, which allows for easy assembly of the cyclone separator into the housing.

[0023] Additionally or alternatively, the cyclone separator may be disposed within the housing so as to be removable from the housing, allowing a user to remove the cyclone separator from the housing and dispose of dust at a desired location or clean the interior of the cyclone separator and / or the housing.

[0024] In addition to or instead of the above embodiment, the airflow generated by the fan may be cooling airflow for the motor. The motor may be disposed downstream of the cyclone separator in the flow direction of the airflow. This embodiment can reduce the possibility of the motor malfunctioning due to dust contained in the cooling airflow for the motor.

[0025] In addition to or instead of the above embodiment, the power tool may be a grinder. The grinder may further include a spindle configured to be rotatably driven by a motor about a drive axis that defines the up-down direction of the power tool. The spindle may have a lower end configured to removably hold an accessory tool. The rotation axis of the motor may extend in a front-to-rear direction perpendicular to the drive axis. The motor may be disposed rearward of the spindle. The cyclone separator may be disposed rearward of the motor. According to this embodiment, an optimal arrangement of the cyclone separator in the grinder is realized.

[0026] First Embodiment An electric disc grinder 1A (hereinafter simply referred to as grinder 1A) according to a first embodiment will be described below with reference to FIGS. 1 to 14. The grinder 1A is an example of a power tool. More specifically, the grinder 1A is an example of a rotary tool configured to perform processing work (e.g., grinding, polishing, cutting) by rotating a disc-shaped tip tool 91 (e.g., a grinding stone, a rubber pad, a brush, a blade). The grinder 1A is also called an angle grinder.

[0027] First, the general configuration of the grinder 1A will be described.

[0028] 1 to 6, the outer shell of the grinder 1A is formed by an elongated housing 10A. The housing 10A is also referred to as a main body housing.

[0029] As shown in FIG. 6, the housing 10A accommodates a motor 21 and a spindle 25. The motor 21 is disposed such that the rotation axis RX of its output shaft 215 extends along the longitudinal axis of the housing 10A. The spindle 25 is accommodated at one end of the housing 10A in the longitudinal direction. The spindle 25 is operably coupled to the output shaft 215 of the motor 21 and is configured to be rotated about the drive axis DX by the rotational power of the motor 21. A power cord 19 connectable to an external AC power source is connected to the other end of the housing 10A in the longitudinal direction. However, the grinder 1A may be provided with a battery attachment portion for removably receiving a rechargeable battery instead of the power cord 19.

[0030] One axial end of the spindle 25 protrudes from the housing 10A to the outside. This end is configured to removably hold the tool bit 91 and is referred to as a tool mounting portion 251. The spindle 25 rotates the tool bit 91 mounted on the tool mounting portion 251 in response to the driving of the motor 21.

[0031] The drive axis DX of the spindle 25 extends in a direction intersecting the rotation axis RX of the output shaft 215 (more specifically, in a direction perpendicular to the rotation axis RX). In the following description, for convenience, the extension direction of the rotation axis RX of the output shaft 215 (which is also the longitudinal direction of the housing 10A) is defined as the front-rear direction of the grinder 1A. In the front-rear direction, the side on which the spindle 25 is located is defined as the front side of the grinder 1A, and the opposite side (the side on which the power cord 19 is located) is defined as the rear side of the grinder 1A. In addition, the extension direction of the drive axis DX is defined as the up-down direction of the grinder 1A. In the up-down direction, the side on which the tool mounting portion 251 is located is defined as the lower side of the grinder 1A, and the opposite side is defined as the upper side of the grinder 1A. The direction perpendicular to the front-rear direction and the up-down direction is defined as the left-right direction of the grinder 1A.

[0032] The detailed configuration of the grinder 1A will be described below.

[0033] First, the housing 10A will be described. As shown in Figures 1 to 6, the housing 10A includes a gear housing 11, a motor housing 13A, and a handle housing 15.

[0034] The gear housing 11 constitutes the front end of the housing 10A. A plurality of exhaust ports 103 are provided in the upper part of the gear housing 11 for discharging air from the inside of the housing 10A to the outside. Note that the exhaust ports 103 in this embodiment are configured to penetrate the gear housing 11 in the front-rear direction.

[0035] The gear housing 11 is also configured to allow attachment of a side handle (also referred to as an auxiliary handle) 95. More specifically, the gear housing 11 is provided with a handle attachment portion 111 configured as a female thread portion. The side handle 95 includes a long grip portion 951 configured to be gripped by a user, and a male thread portion (not shown) protruding from one end of the grip portion 951. The side handle 95 is attached to the gear housing 11 by fastening the male thread portion into the handle attachment portion 111 (female thread portion). However, the side handle 95 may be attached to the gear housing 11 by any other method.

[0036] In this embodiment, the handle attachment portions 111 are provided on the left, right, and upper sides of the gear housing 11. The user can attach the side handle 95 to any of the three handle attachment portions 111 depending on their dominant hand or work environment and use it as an auxiliary handle. When the side handle 95 is attached to the gear housing 11 (housing 10A), the grip portion 951 protrudes to the left, right, or upper side from the housing 10A.

[0037] The motor housing 13A is formed in a cylindrical shape. In this embodiment, the motor housing 13A is a single (seamless) cylindrical member. The motor housing 13A is fixed to the rear end of the gear housing 11 and extends rearward from the gear housing 11.

[0038] The handle housing 15 is cylindrical, fixed to the rear end 133 of the motor housing 13A, and extends rearward of the motor housing 13A. The front half of the handle housing 15 is configured as an accommodating section for a part of the cyclone separator 5A (described later) and the controller 20. The rear half of the handle housing 15 is configured as a gripping section 155 configured to be gripped by the user. The handle housing 15 of this embodiment is formed by a left shell 15L and a right shell 15R that are connected and fixed to each other in the left-right direction (see FIG. 1).

[0039] The front end 151 of the handle housing 15 is cylindrical and has roughly the same diameter as the motor housing 13A. An intermediate section 152 extending rearward from the front end 151 of the handle housing 15 is cup-shaped with a diameter that decreases toward the rear. The front end 151 and intermediate section 152 form the front half of the handle housing 15. The intermediate section 152 is provided with a plurality of air intake ports 101 for allowing air to flow from the outside of the housing 10A into the inside. More specifically, a plurality of air intake ports 101 are formed on each of the right and left sides of the handle housing 15, connecting the inside and outside of the housing 10A.

[0040] The grip portion 155 (the rear half of the handle housing 15) is cylindrical and has a smaller diameter than the front half of the handle housing 15. The grip portion 155 is the part that the user holds when performing processing work using the grinder 1A, and may also be referred to as a main grip (main handle).

[0041] The elements disposed within the housing 10A will now be described.

[0042] As shown in FIG. 6, the motor 21, the fan 23, the spindle 25, the controller 20, the main switch 158, and the cyclone separator 5A are arranged in the housing 10A.

[0043] The motor 21 is disposed in the motor housing 13A (approximately in the center of the housing 10A). The motor 21 includes a main body 210 including a stator 211 and a rotor 212, and an output shaft 215 that rotates integrally with the rotor 212. Note that, although a commutator motor is employed as the motor 21 in this embodiment, the type of the motor 21 is not particularly limited, and may be, for example, a brushless DC motor.

[0044] The fan 23 is fixed to the output shaft 215 in front of the main body 210 of the motor 21. The fan 23 rotates integrally with the output shaft 215 to generate an airflow (motor cooling air) for cooling the motor 21. Specifically, the airflow generated by the fan 23 flows into the housing 10A through the intake port 101, passes through the cyclone separator 5A and the motor 21, and flows out to the outside through the exhaust port 103.

[0045] The spindle 25 is supported rotatably around the drive axis DX within the gear housing 11 (front end of the housing 10A). A large bevel gear is fixed to the upper end of the spindle. The front end of the output shaft 215 of the motor 21 protrudes into the gear housing 11. A small bevel gear is fixed to the front end of the output shaft 215. The small bevel gear meshes with the large bevel gear of the spindle 25. As described above, the tool mounting portion 251, which is the lower end of the spindle 25, protrudes downward from the housing 10A.

[0046] The controller 20 is housed in the middle portion 152 of the handle housing 15. The controller 20 is configured to control the operation of the grinder 1A (for example, the driving of the motor 21). When viewed from the left or right, the controller 20 is located so as to at least partially overlap with the air intake 101 of the housing 10A. This allows the air flowing into the housing 10A from the air intake 101 to effectively cool the controller 20.

[0047] The main switch 158 is a switch for starting the motor 21 and is housed in the grip portion 155. A trigger (also called a switch lever) 157 is provided on the underside of the grip portion 155. The trigger 157 is a manually operated member that can be pressed by a user while holding the grip portion 155. The main switch 158 is normally off, and is configured to be turned on while the trigger 157 is pressed. The main switch 158 is connected to the controller 20. The controller 20 is configured to drive the motor 21 while the main switch 158 is on.

[0048] The cyclone separator 5A is a device that swirls dust-containing air (hereinafter also simply referred to as air) and separates the dust from the air by utilizing centrifugal force. As described above, in this embodiment, the airflow (cooling air for the motor 21) generated by the fan 23 flows in through the air intake 101, cools the motor 21 while flowing through the housing 10A, and flows out through the air exhaust 103. The cyclone separator 5A is disposed between the air intake 101 and the motor 21 on the flow path within the housing 10A. That is, in this embodiment, the cyclone separator 5A is disposed in a position where it can separate dust from the cooling air for the motor 21 before the cooling air reaches the motor 21.

[0049] More specifically, the cyclone separator 5A is disposed within the housing 10A between the intake port 101 and the motor 21 in the front-rear direction. More specifically, the front end of the cyclone separator 5A is rearward of the main body 210 of the motor 21, and the rear end of the cyclone separator 5A is forward of the intake port 101. Note that the controller 20 is located at approximately the same position as the intake port 101 in the front-rear direction, and therefore the rear end of the cyclone separator 5A is forward of the controller 20. Furthermore, as will be described in detail later, the cyclone separator 5A has an intake port 51 at its front end, and is disposed so that the axis SX of the cyclone separator 5A extends in the front-rear direction (the longitudinal direction of the housing 10A).

[0050] In this embodiment, the cyclone separator 5A is disposed across the rear end 133 of the motor housing 13A and the front end 151 of the handle housing 15. Most of the cyclone separator 5A is located within the rear end 133 of the motor housing 13A. Hereinafter, the portion of the housing 10A that accommodates the cyclone separator 5A will also be referred to as the separator accommodating portion 16.

[0051] The detailed configuration of the cyclone separator 5A will be described below.

[0052] As shown in Figures 7 and 8, the cyclone separator 5A has (i) a plurality of air intake ports 51 that connect the inside and outside of the cyclone separator 5A, (ii) a dust separation chamber 52 that connects with the air intake ports 51, (iii) an exhaust path 53 that connects the dust separation chamber 52 with the internal space of the motor housing 13A, (iv) a dust collection chamber 54 that connects with the dust separation chamber 52, and (v) a dust discharge port 55 that connects the dust collection chamber 54 with the outside of the cyclone separator 5A.

[0053] The air intake port 51 is an opening for allowing air to flow from the outside to the inside of the cyclone separator 5A. In this embodiment, the multiple air intake ports 51 are arranged at equal intervals in the circumferential direction around the axis SX of the cyclone separator 5A at the front end of the cyclone separator 5A. As will be described in detail later, air flows into the air intake port 51 from the air intake port 101 of the housing 10A and passes through the housing 10A.

[0054] Dust separating chamber 52 is a space (chamber) defined within cyclone separator 5A, and is formed in a conical cylindrical shape whose diameter decreases toward the rear from intake port 51. In dust separating chamber 52, a first swirling flow toward the rear is generated, and dust is separated from the air by centrifugal force.

[0055] The exhaust passage 53 is an air flow path defined radially inside (on the inner circumferential side) of the dust separation chamber 52, and the rear end (inlet) of the exhaust passage 53 is inside the dust separation chamber 52. The air from which a certain amount of dust has been removed in the dust separation chamber 52 flows from the rear end of the exhaust passage 53 into the exhaust passage 53, flows forward, and flows from the front end (outlet) of the exhaust passage 53 into the motor housing 13A.

[0056] The dust collection chamber 54 is a space (chamber) defined behind the dust separation chamber 52 and radially outward (on the outer circumferential side) of the dust separation chamber 52 within the cyclone separator 5A. A second swirling flow is generated within the dust collection chamber 54, and dust is separated from the air by centrifugal force. The dust separated from the air is contained (accumulated) in the dust collection chamber 54.

[0057] The dust outlet 55 is an opening for discharging the dust collected in the dust collection chamber 54 to the outside of the cyclone separator 5A. In this embodiment, the dust outlet 55 is provided at the lower end of the cyclone separator 5A.

[0058] Hereinafter, there will be described components of the cyclone separator 5A that define the above-mentioned air intake 51, dust separation chamber 52, exhaust path 53, dust collection chamber 54, and dust discharge port 55. As shown in Figures 7 to 10, the cyclone separator 5A of this embodiment is formed by a first member 61, a second member 62, and a third member 63 that are connected to each other.

[0059] The first member 61 includes an inner cylindrical portion 611, a base portion 613, multiple guide vanes 615, and a connecting portion 617. The inner cylindrical portion 611 has an axis extending in the front-rear direction and is a cylindrical portion with both axial ends open. The front end of the inner cylindrical portion 611 increases in diameter as it extends forward. The base portion 613 is a disk-shaped (annular) portion that protrudes radially outward from the front end of the inner cylindrical portion 611. The multiple guide vanes 615 are arranged at substantially equal intervals around the circumferential direction of the base portion 613. Each of the guide vanes 615 protrudes rearward from the rear surface of the base portion 613 and extends in a tangential direction of a circle centered on the axis of the inner cylindrical portion 611. The inner cylindrical portion 611 extends rearward beyond the rear ends of the guide vanes 615. The connecting portion 617 is a long cylindrical portion, and a thread is formed on the inner circumferential surface of the connecting portion 617. The connecting portion 617 is supported by a plurality of ribs that protrude radially inward from the inner surface of the inner cylindrical portion 611 , and extends rearward beyond the inner cylindrical portion 611 along the axis of the inner cylindrical portion 611 .

[0060] The second member 62 includes an intermediate cylindrical portion 621 and a flange portion 623. The intermediate cylindrical portion 621 has an axis extending in the front-rear direction and is a conical cylindrical portion with both axial ends open. The intermediate cylindrical portion 621 is disposed around (radially outward from) the inner cylindrical portion 611 of the first member 61. The inner diameter of the intermediate cylindrical portion 621 is larger than the outer diameter of the inner cylindrical portion 611 and gradually decreases toward the rear. The flange portion 623 protrudes radially outward from the front end of the intermediate cylindrical portion 621. The second member 62 is disposed such that the front surface of the flange portion 623 abuts against the receiving surface of the rear end of the guide vane 615 of the first member 61. The rear end of the inner cylindrical portion 611 of the first member 61 is disposed inside the intermediate cylindrical portion 621, and the rear end of the inner cylindrical portion 611 is located forward of the rear end of the intermediate cylindrical portion 621. The connecting portion 617 of the first member 61 extends rearward beyond the intermediate cylindrical portion 621.

[0061] The third member 63 includes an outer tube portion 631. The outer tube portion 631 has an axis extending in the front-rear direction, and is a tube portion with one axial end open and the other axial end closed. More specifically, the outer tube portion 631 includes a cylindrical peripheral wall portion 632 and a circular bottom wall portion 635 that closes the rear end of the peripheral wall portion 632.

[0062] The peripheral wall portion 632 of the outer cylinder portion 631 is disposed around (radially outward from) the intermediate cylinder portion 621 of the second member 62. The inner diameter of the peripheral wall portion 632 is larger than the outer diameter of the intermediate cylinder portion 621 and smaller than the outer diameter of the flange portion 623. The third member 63 is disposed so that the front end of the peripheral wall portion 632 abuts against the rear surface of the flange portion 623 of the second member 62. The intermediate cylinder portion 621 of the second member 62 is disposed inside the outer cylinder portion 631, and the rear end of the intermediate cylinder portion 621 is located forward of the rear end of the outer cylinder portion 631. In addition, the outer diameter of the peripheral wall portion 632 is smaller than the inner diameter of the separator accommodating portion 16 (the rear end portion 133 of the motor housing 13A and the front end portion 151 of the handle housing 15) (see FIG. 11).

[0063] Furthermore, a portion of the peripheral wall portion 632 protrudes radially outward more than the other portions. Hereinafter, this portion will be referred to as the protruding portion 633. More specifically, the protruding portion 633 is formed as a portion that protrudes downward from the lower front end portion of the peripheral wall portion 632. The portion of the peripheral wall portion 632 other than the protruding portion 633 has substantially uniform inner and outer diameters. The rear end of the protruding portion 633 is located forward of the rear end of the intermediate cylindrical portion 621. The protruding portion 633 has an opening that penetrates the protruding portion 633 in the vertical direction (i.e., an opening that connects the inside and outside of the peripheral wall portion 632). This opening is the dust discharge port 55 for discharging dust from the cyclone separator 5A to the outside.

[0064] Note that a cover 71 that closes the dust discharge port 55 and a locking mechanism 75 for the cover 71 are attached to the cyclone separator 5A of the present embodiment (more specifically, the outer cylinder portion 631 of the third member 63). The cover 71 and the locking mechanism 75 will be described in detail later.

[0065] A through-hole for the screw 65 is formed in the center of the bottom wall 635 of the outer cylinder 631. A cylindrical receiving portion 636 is provided around the through-hole on the front surface of the bottom wall 635. The rear end of the connecting portion 617 of the first member 61 is fitted into the receiving portion 636. In this state, the screw 65 is fastened from the rear of the bottom wall 635 through the through-hole into the threaded hole of the connecting portion 617, thereby coaxially connecting and fixing the first member 61, the second member 62, and the third member 63 to one another. In this manner, in this embodiment, the first member 61, the second member 62, and the third member 63 (including the cover 71 and the locking mechanism 75) are coaxially connected and fixed to one another and integrated to constitute a single separator assembly 50 having an axis SX.

[0066] In this embodiment, a seal 59 is attached to the separator assembly 50 and is integrated with the separator assembly 50. More specifically, the seal 59 is fitted into and held at the front end of the separator assembly 50 (the base portion 613 of the first member 61) from the front. The seal 59 is made of an elastic material (e.g., rubber or synthetic resin foam). The seal 59 covers the outer periphery of the base portion 613. The seal 59 also protrudes forward from the front end of the base portion 613.

[0067] The arrangement of the cyclone separator 5A will be described below. As shown in Fig. 11, the cyclone separator 5A is held in the housing 10A with the dust outlet 55 positioned so that it faces the underside of the grinder 1A. In this embodiment, in the front-rear direction, most of the front end side of the cyclone separator 5A is housed in the rear end 133 of the motor housing 13A, and the rear end of the cyclone separator 5A is housed in the front end 151 of the handle housing 15. The cyclone separator 5A is disposed coaxially with the motor 21.

[0068] When the cyclone separator 5A is assembled to the housing 10A, the separator assembly 50, to which the seal 59 is attached, is first positioned circumferentially so that the dust discharge port 55 faces downward, and then fitted into the cylindrical motor housing 13A from the rear. The cyclone separator 5A is positioned in the front-rear direction at a position where the seal 59 abuts on a protrusion 141 provided inside the motor housing 13A. The seal 59 seals the gap between the front end of the cyclone separator 5A and the inner surface of the housing 10A (motor housing 13A).

[0069] 5 and 12, the left and right shells 15L, 15R of the handle housing 15 are arranged to sandwich the rear end of the cyclone separator 5A, and are each fixed to the rear end 133 of the motor housing 13A with screws 140. Furthermore, the left and right shells 15L, 15R are connected to each other in the left-right direction with screws (not shown). In this way, the cyclone separator 5A configured as the separator assembly 50 can be easily assembled to the handle housing 15.

[0070] In this embodiment, the cyclone separator 5A is positioned and held in the circumferential direction by engagement between a plurality of protrusions 145 provided inside the housing 10A (motor housing 13A and handle housing 15) and recesses 501 provided on the outer periphery of the cyclone separator 5A and the seal 59. The protrusions 145 of the housing 10A utilize a structure provided for connecting the motor housing 13A and the handle housing 15 with the screws 140. The cyclone separator 5A is positioned and held in the front-rear direction by being sandwiched in the front-rear direction between the protrusions 141 of the motor housing 13A and the protrusions 145 provided inside the handle housing 15.

[0071] With the configuration described above, as shown in FIG. 7, in the front-to-rear direction, the gap between the guide vanes 615 arranged between the rear surface of the base portion 613 of the first member 61 and the front surface of the flange portion 623 of the second member 62 forms the air intake 51 for allowing air to flow into the cyclone separator 5A.

[0072] The dust separation chamber 52 is defined inside the conical cylindrical intermediate cylinder portion 621 of the second member 62 (between the intermediate cylinder portion 621 and the inner cylinder portion 611). As described above, the guide vanes 615 are arranged at equal intervals in the circumferential direction and extend in the tangential direction of a circle centered on the axis AX (see FIG. 8). Therefore, the air flowing in from the intake port 51 gathers in the dust separation chamber 52 while swirling around the inner cylinder portion 611, efficiently generating a first swirling flow that flows rearward. The first swirling flow flows rearward along the inner surface of the conical intermediate cylinder portion 621. During this time, some of the dust contained in the first swirling flow collides with the inner surface of the intermediate cylinder portion 621 due to centrifugal force, is captured, and separated from the air.

[0073] The exhaust passage 53 is defined inside the inner cylindrical portion 611 of the first member 61. As described above, dust is separated from the air that flows into the exhaust passage 53 from its inlet (the opening at the rear end of the inner cylindrical portion 611). The air that flows out from the outlet (the opening at the front end of the inner cylindrical portion 611) of the exhaust passage 53 flows into the motor housing 13A. This air cools the motor 21 as it passes around the motor 21 and between the stator 211 and the rotor 212, and then flows out to the outside from the exhaust port 103 of the gear housing 11. Note that the above-mentioned seal 59 closes the gap between the front end of the cyclone separator 5A and the inner surface of the housing 10A, so the interior of the cyclone separator 5A and the internal space of the motor housing 13A are substantially in communication only via the exhaust passage 53.

[0074] The dust collection chamber 54 is defined inside the outer cylinder portion 631 of the third member 63 (between the outer cylinder portion 631 and the intermediate cylinder portion 621). The dust collection chamber 54 includes an area (hereinafter referred to as a rear dust collection chamber 541) behind the intermediate cylinder portion 621 (dust separation chamber 52) and an area (hereinafter referred to as a front dust collection chamber 543) in front of the rear dust collection chamber 541 and radially outward (on the outer periphery) of the intermediate cylinder portion 621. The air that flows from the dust separation chamber 52 into the rear dust collection chamber 541 while swirling generates a second swirling flow. The second swirling flow moves forward while swirling around the intermediate cylinder portion 621 in the front dust collection chamber 543, and swirls at the front end of the front dust collection chamber 543. The dust contained in the second swirling flow collides with the inner surface of outer cylinder portion 631 (circumferential wall portion 632) due to centrifugal force and is collected.

[0075] Due to the configuration of the intermediate cylinder portion 621 and the outer cylinder portion 631 described above, the cross-sectional area of ​​the front dust collection chamber 543 decreases toward the front. This increases the flow rate of the air in the front dust collection chamber 543, enabling dust to be separated more efficiently by centrifugal force. Furthermore, because the front end of the front dust collection chamber 543 is closed by the flange portion 623 of the second member 62, dust mainly accumulates in the front end portion of the front dust collection chamber 543.

[0076] As described above, since protrusion 633 is provided at the lower front end of outer cylinder 631, the front end of front dust collection chamber 543 includes an area that protrudes downward further than rear dust collection chamber 541. Dust that enters this area is then likely to remain there without being caught in the second swirling flow. Hereinafter, this area will be referred to as storage chamber 545.

[0077] As described above, the dust discharge port 55 is an opening formed in the protruding portion 633 of the outer cylinder portion 631, and connects the dust collection chamber 54 (storage chamber 545 of the front dust collection chamber 543) to the outside of the cyclone separator 5A.

[0078] 2 and 11, an opening 105 that passes through the housing 10A in the vertical direction is provided at the lower end of the housing 10A. The opening 105 is located directly below the dust discharge port 55 and communicates with the dust discharge port 55. As a result, the dust discharge port 55 and the opening 105 communicate between the inside of the cyclone separator 5A and the outside of the housing 10A.

[0079] In this embodiment, opening 105 is formed across rear end 133 of motor housing 13A and front end 151 of handle housing 15. More specifically, opening 105 is formed by combining a recess (cutout) recessed forward from the rear end of motor housing 13A with a recess (cutout) recessed rearward from the front end of front end 151 of handle housing 15. This makes it possible to maintain the rigidity of motor housing 13A and handle housing 15 better than when opening 105 is formed as a single through-hole in motor housing 13A or handle housing 15.

[0080] The detailed configurations of the cover 71 and the locking mechanism 75 will be described below.

[0081] As shown in FIGS. 7 and 11, the cover 71 is displaceable between a closed position where the dust discharge port 55 is closed and an open position where the dust discharge port 55 is open, as shown in FIG. 13. More specifically, the cover 71 of this embodiment is supported by the outer cylinder portion 631 so as to be rotatable about a rotation axis PX between the closed position and the open position. The rotation axis PX extends in the left-right direction behind the dust discharge port 55. The opening 105 of the housing 10A is configured so as not to interfere with the opening and closing operation of the cover 71. In this embodiment, the opening 105 is configured so that the entire cover 71 fits within the range of the opening 105 in both the closed position and the open position, as viewed from below the grinder 1A (see FIGS. 2, 11, and 13).

[0082] As shown in Figures 7 to 10, the cover 71 includes a main body 711 configured to completely cover the dust discharge outlet 55 from below when the cover 71 is in the closed position, a connecting portion 713 provided at the rear end of the main body 711, and a retaining plate 72 attached to the underside of the main body 711.

[0083] In this embodiment, the dust outlet 55 is substantially rectangular, and the main body 711 has a corresponding rectangular shape. The connecting portion 713 includes two cylindrical portions extending in the left-right direction along the rotation axis PX. Meanwhile, two cylindrical support portions 715 are provided on the protruding portion 633 of the outer cylinder portion 631. The support portions 715 are arranged rearward of the dust outlet 55, respectively, on the left and right sides of the connecting portion 713 of the cover 71. A rod 717 is inserted through the support portions 715 and the connecting portion 713 along the rotation axis PX. The cover 71 is rotatably supported by the support portions 715 via the rod 717. The holding plate 72 covers most of the main body 711 from below. The holding plate 72 has an elongated hole 721 extending in the front-rear direction.

[0084] The cover 71 is biased toward the open position by a biasing spring 73. The biasing spring 73 in this embodiment is a torsion coil spring (more specifically, a double torsion spring) and is disposed around the rod 717. The biasing spring 73 is engaged with the outer cylinder portion 631 and the cover 71, and is configured to bias the cover 71 in a direction that rotates counterclockwise (downward) relative to the outer cylinder portion 631 when viewed from the left side.

[0085] Furthermore, a seal 77 is attached to the lower end of the protruding portion 633 of the outer cylinder portion 631 so as to surround the dust discharge port 55. The seal 77 is made of an elastic material (for example, rubber or synthetic resin foam). When the cover 71 is in the closed position, the seal 77 closes the gap between the cover 71 (main body 711) and the dust discharge port 55, thereby preventing dust from leaking out from the gap between the cover 71 and the dust discharge port 55.

[0086] The locking mechanism 75 is configured to be switchable, in response to manual operation by the user, between a locked state in which the cover 71 is locked in the closed position and an unlocked state in which the cover 71 cannot be locked. More specifically, as shown in Figures 7 to 10, the locking mechanism 75 of this embodiment includes a locking member 751, a receiving portion 757 with which the locking member 751 can engage, and a biasing spring 759 that biases the locking member 751.

[0087] The locking member 751 is supported by the cover 71 so as to be movable between a locked position and an unlocked position in response to manual operation by the user. The locked position is a position where the locking member 751 can engage with the receiving portion 757 when the cover 71 is in the closed position, as shown in FIGS. 7 to 9. The unlocked position is a position where the locking member 751 cannot engage with the receiving portion 757 when the cover 71 is in the closed position, as shown in FIG.

[0088] More specifically, the locking member 751 is supported between the main body 711 of the cover 71 and the holding plate 72 so as to be slidable in the front-rear direction. The locking member 751 is an elongated member extending in the front-rear direction, and the front end of the locking member 751 is configured as an engaging portion 752 that can engage with a receiving portion 757. The locking member 751 also has a tab 753 that protrudes downward from the lower end of the center portion in the front-rear direction. The tab 753 is an operating portion for manual operation by the user. The tab 753 protrudes below the holding plate 72 through an elongated hole 721 of the holding plate 72 and is slidable in the front-rear direction within the elongated hole 721. The user can move the locking member 751 in the front-rear direction relative to the cover 71 by holding the tab 753.

[0089] In this embodiment, tab 753 passes through opening 105 of housing 10A and protrudes downward from the lower end of housing 10A (see FIG. 11). Therefore, the user can easily operate tab 753 even when tab 753 is difficult to see.

[0090] The receiving portion 757 protrudes downward from the protruding portion 633 of the outer cylinder portion 631 in front of the dust discharge port 55, and has an engaging hole 758. The engaging hole 758 is provided at a position facing the locking member 751 from the front when the cover 71 is in the closed position, and is configured to receive the engaging portion 752 of the locking member 751.

[0091] The biasing spring 759 biases the locking member 751 forward relative to the cover 71 (away from the rotation axis PX). More specifically, a recess 754 is formed in the upper part of the locking member 751, extending forward from the rear end of the locking member 751 and having a closed front end. The biasing spring 759 is disposed within the recess 754. Furthermore, a protrusion 712 that protrudes downward is provided on the lower surface of the main body 711 of the cover 71. The protrusion 712 abuts against the rear end of the biasing spring 759 within the recess 754.

[0092] With this configuration, as shown in FIG. 7, when the cover 71 is in the closed position, the locking member 751 is urged forward by the biasing spring 759, and at the locked position, the engaging portion 752 engages with the engaging hole 758 of the receiving portion 757. In other words, the locking mechanism 75 is in a locked state. On the other hand, as shown in FIG. 14, when the user presses the tab 753 rearward and moves the locking member 751 rearward to the unlocked position against the biasing force of the biasing spring 759, the engaging portion 752 disengages from the engaging hole 758. In other words, the locking mechanism 75 is switched to an unlocked state. When the user releases the tab 753 in this state, the cover 71 is urged to rotate by the biasing spring 73 and rotates to the open position, as shown in FIG. 13. The locking member 751 is also urged forward by the biasing spring 759 and is placed in the locked position.

[0093] When performing processing using the grinder 1A, the user attaches the side handle 95 to one of the three handle attachment portions 111 (see FIG. 1), grips the grip portion 155 of the handle housing 15 with one hand, and grips the side handle 95 with the other. The grinder 1A can be used in various positions, but it is relatively often used in a position in which the drive shaft DX of the spindle 25 extends vertically and the lower end of the spindle 25 faces the direction of gravity (vertically downward). Therefore, the position of the grinder 1A at this time is specified as the normal position of the grinder 1A.

[0094] 11 , dust discharge port 55 of cyclone separator 5A and opening 105 of housing 10A communicating with dust discharge port 55 are configured to open in the direction of gravity when grinder 1A is in the normal position. Therefore, when grinder 1A is in the normal position, a user can operate locking member 751 to open cover 71, and easily discharge dust accumulated in dust collection chamber 54 to the outside of housing 10A using the dust's own weight. In particular, in this embodiment, cover 71 automatically rotates to the open position due to the biasing force of biasing spring 759, so a user can open cover 71 simply by unlocking locking member 751.

[0095] When returning cover 71 to the closed position, the user presses tab 753 rearward, moves locking member 751 rearward to the unlocked position against the biasing force of biasing spring 759, and further rotates cover 71 to the closed position against the biasing force of biasing spring 73. When the user releases the rearward pressure on tab 753 while cover 71 is in the closed position, locking member 751 is biased forward by biasing spring 759 to the locked position, and engaging portion 752 is inserted into engaging hole 758 of receiving portion 757. In other words, locking mechanism 75 is switched to the locked state.

[0096] Furthermore, in addition to the cyclone separator 5A, the grinder 1A of this embodiment includes a structure upstream of the cyclone separator 5A in the airflow direction for separating dust from the air by using inertial force. In other words, the grinder 1A is configured to separate dust from the cooling air of the motor 21 in two stages. More specifically, as shown in Fig. 11, a dust collection chamber 18 capable of separating dust with a relatively large particle size by using inertial force is defined within the housing 10A of this embodiment.

[0097] The dust collection chamber 18 will now be described. The dust collection chamber 18 is a space (chamber) defined between the inner surface of the housing 10A and the outer surface of the cyclone separator 5A in the front-to-rear direction within the internal space of the housing 10A, between the air intake 101 of the housing 10A and the air intake 51 of the cyclone separator 5A. As described above, the air intake 101 is located behind the rear end of the cyclone separator 5A. Therefore, the dust collection chamber 18 includes an area behind the cyclone separator 5A and an area radially outward (on the outer periphery) of the cyclone separator 5A.

[0098] As described above, the gap between the front end of cyclone separator 5A and housing 10A in front of intake port 51 of cyclone separator 5A is closed by seal 59. Therefore, dust collection chamber 18 is isolated from the internal space of motor housing 13A. This prevents air that flows into dust collection chamber 18 from intake port 101 from flowing directly from dust collection chamber 18 into motor housing 13A without passing through cyclone separator 5A.

[0099] The air that flows into the dust collection chamber 18 from the air intake 101 collides with obstacles such as the rear end surface of the cyclone separator 5A (bottom wall portion 635 of the outer cylinder portion 631) and protrusions on the inner surface of the housing 10A as it flows forward toward the air intake 51 of the cyclone separator 5A, and is captured.

[0100] As shown in FIGS. 1 to 3 and 11 , the housing 10A is provided with a dust outlet 180 for discharging dust collected in the dust collection chamber 18 to the outside of the housing 10A. The dust outlet 180 is an opening that connects the dust collection chamber 18 to the outside of the housing 10A. In this embodiment, the housing 10A is provided with three dust outlets 180. One of the dust outlets 180 is provided at the bottom end of the housing 10A. Hereinafter, this dust outlet 180 will also be referred to as a lower outlet 181. The remaining two of the dust outlets 180 are provided on the left and right sides of the housing 10A. Hereinafter, these dust outlets 180 will also be referred to as a left outlet 182 and a right outlet 183, respectively.

[0101] More specifically, the lower discharge port 181 (see FIGS. 2 and 11) is a portion of the opening 105 of the housing 10A formed between the protrusion 633 of the cyclone separator 5A and the housing 10A, behind the protrusion 633 (the gap between the protrusion 633 and the handle housing 15). The lower discharge port 181 is configured to open in the direction of gravity when the grinder 1A is in the normal position. Therefore, when the grinder 1A is in the normal position, the lower discharge port 181 can easily discharge dust in the dust collection chamber 18 to the outside of the housing 10A by utilizing the dust's own weight.

[0102] The left discharge port 182 (see FIGS. 1 and 2) is an elongated hole formed on the left side of the rear end 133 of the motor housing 13A and extending in the circumferential direction of the motor housing 13A. The right discharge port 183 (see FIGS. 1 and 3) is an elongated hole formed on the right side of the rear end 133 of the motor housing 13A and extending in the circumferential direction of the motor housing 13A. The left discharge port 182 and the right discharge port 183 are located rearward of the intake port 51 of the cyclone separator 5A.

[0103] Generally, when machining a floor surface that extends in a generally horizontal direction, a user attaches the side handle 95 to the handle attachment portion 111 on the left or right side of the gear housing 11 and uses the grinder 1A with the side handle 95 extending away from the floor (generally upward in the direction of gravity). When the side handle 95 attached to the left side is in a position extending away from the floor, the right-side discharge port 183 opens in the direction of gravity, allowing dust in the dust collection chamber 18 to be easily discharged to the outside of the housing 10A using the dust's own weight. Similarly, when the side handle 95 attached to the right side is in a position extending away from the floor, the left-side discharge port 182 opens in the direction of gravity, allowing dust in the dust collection chamber 18 to be easily discharged to the outside of the housing 10A using the dust's own weight.

[0104] All of the dust discharge ports 180 of the housing 10A are arranged so as not to overlap with the air intake ports 51 of the cyclone separator 5A. In other words, a straight line that is perpendicular to the axis SX of the cyclone separator 5A and passes through the dust discharge ports 180 does not intersect with the air intake ports 101. This makes it possible to prevent air outside the housing 10A from flowing directly into the air intake ports 51 of the cyclone separator 5A without passing through the dust collection chamber 18 inside the housing 10A.

[0105] As described above, the grinder 1A of this embodiment includes the dust collection chamber 18 and the dust collection chamber 54 in the flow path of the air generated by the fan 23 and flowing through the housing 10A. The dust collection chamber 18, defined within the housing 10A upstream of the cyclone separator 5A, uses inertial force to capture relatively large particles of dust. Meanwhile, the dust collection chamber 54 within the cyclone separator 5A uses centrifugal force to capture smaller particles of dust not captured by the dust collection chamber 18. In particular, by capturing a certain amount of dust in the dust collection chamber 18 and reducing the amount of dust flowing into the cyclone separator 5A, the dust separation rate within the cyclone separator 5A can be improved. In this way, the grinder 1A can effectively collect dust in two stages, thereby reducing the possibility of malfunction of the motor 21 due to dust contained in the air flowing into the motor housing 13A.

[0106] When not in use, grinder 1A is often placed on the ground, floor, or workbench with the upper end of spindle 25 facing the direction of gravity, or with the upper end of spindle 25 facing the direction of gravity. In this embodiment, since air intake 101 is provided on the side of housing 10A, when grinder 1A is placed in the above-mentioned position, it is possible to reduce the possibility that dust floating around grinder 1A will fall from above and enter housing 10A through air intake 101.

[0107] The grinder 1A of this embodiment also includes a cover 71 that can open and close the dust discharge port 55 of the cyclone separator 5A, and a locking mechanism 75 that is configured to lock the cover 71 in the closed position. The locking mechanism 75 will not be unlocked unless the user manually operates the tab 753 of the locking member 751. This reduces the possibility that dust will be discharged through the dust discharge port 55 at an unintended time and in an unintended place.

[0108] Furthermore, when the dust discharge outlet 55 is opened and closed using a sliding cover, dust may accumulate in the portion that holds the cover in a slidable manner, which may cause problems when opening and closing the cover. In contrast, the cover 71 of this embodiment is pivotable, which makes it less likely to cause problems when opening and closing the cover 71 than a sliding cover. Also, compared to a sliding cover, the space required for opening and closing the cover 71 in the axial direction of the cyclone separator 5A can be reduced. Furthermore, as described above, the pivot axis PX of the cover 71 is located behind the dust discharge outlet 55. Therefore, when the cover 71 is opened and dust is discharged, less dust can be scattered toward the user than when the pivot axis is located in front of the dust discharge outlet 55.

[0109] Second Embodiment An electric disc grinder 1B (hereinafter simply referred to as grinder 1B) according to a second embodiment will be described below with reference to Figures 15 to 18. The grinder 1B differs from the grinder 1A of the first embodiment only in that the cyclone separator 5B is removable from the housing 10B. Therefore, in the following, components that are substantially the same as those in the first embodiment are given the same reference numerals as those in the first embodiment, and descriptions thereof will be omitted or simplified as appropriate, and components that are different from those in the first embodiment will mainly be described.

[0110] The outer shell of the grinder 1B is formed by a long housing 10B. The housing 10B includes a gear housing 11, a motor housing 13B, and a handle housing 15. Although detailed illustration is omitted, similar to the first embodiment, a motor 21, a fan 23, a spindle 25, a controller 20, a main switch 158, and a cyclone separator 5B are arranged inside the housing 10B (see FIG. 6). The handle housing 15 has an intake port 101, and the gear housing 11 has an exhaust port 103. The relative positions of these elements in the housing 10B are substantially the same as those in the first embodiment.

[0111] Meanwhile, in this embodiment, unlike the first embodiment, the housing 10B includes an opening 161 and a cover 165 configured to close the opening 161. The opening 161 is formed in the upper half of the rear end portion of the motor housing 13B. A cyclone separator 5B is accommodated in the portion of the motor housing 13B corresponding to the opening 161.

[0112] The cyclone separator 5B of this embodiment has a shorter axial (front-rear) length than the cyclone separator 5A of the first embodiment, but other configurations are substantially identical to the cyclone separator 5A (see FIG. 11). Most of the cyclone separator 5B is located within the rear end of the motor housing 13B, and only the rear end of the cyclone separator 5B is located within the handle housing 15. The cyclone separator 5B is held in a position where the cover 71 and locking mechanism 75 are disposed within the opening 105 of the housing 10B, the seal 59 fitted at the front end abuts against a protrusion 141 in the motor housing 13A, and the protrusion 146 in the handle housing 15 abuts against the rear end of the outer cylinder portion 631.

[0113] The cover 165 is formed with an arc-shaped cross section corresponding to the upper half of the motor housing 13B. The cover 165 is displaceable between a closed position (see FIGS. 15 and 17) in which the opening 161 is closed and an open position (see FIGS. 16 and 18) in which the opening 161 is open. More specifically, the cover 165 is supported on the left side of the motor housing 13B so as to be rotatable about a rotation axis extending in the front-to-rear direction. A locking piece 166 is provided on the free end (right end) of the cover 165. The locking piece 166 is flexible and has a pawl 167 at its tip. Although not shown in detail, a groove is formed in the right side of the motor housing 13B, into which the pawl 167 of the locking piece 166 can engage. The cover 165 is locked in the closed position when the pawl 167 engages with this groove. When the cover 165 is in the closed position, similar to the first embodiment, a dust collection chamber 18 is defined within the housing 10B between the inner surface of the housing 10B (including the cover 165) and the outer surface of the cyclone separator 5B (see FIG. 17).

[0114] The opening 161 and the cover 165 need only enable the cyclone separator 5B to be removed and attached, and define the dust collection chamber 18 within the housing 10B when the cover 165 is closed, and the size, shape, and opening / closing manner thereof may be changed as desired.

[0115] In this embodiment, a user can remove or install the cyclone separator 5B to or from the housing 10B with the cover 165 in the open position (see FIGS. 16 and 18) and the opening 161 open. For example, when removing the cyclone separator 5B, the user moves the cyclone separator 5B upward until the cover 71 and locking mechanism 75 are released from the opening 105, and then pushes the cyclone separator 5B forward to compress the seal 59 and remove it from the housing 10B through the opening 161. When installing the cyclone separator 5B, the procedure is reversed.

[0116] As described above, in the grinder 1B of this embodiment, the cyclone separator 5B is detachable from the housing 10B. This allows the user to detach the cyclone separator 5B from the housing 10B and carry only the cyclone separator 5B to a desired location to dispose of dust or clean up, thereby improving convenience.

[0117] In this embodiment, the dust discharge port 180 that connects the dust collection chamber 18 to the outside is only the lower discharge port 181. However, a user can remove the cyclone separator 5B and easily discharge the dust accumulated in the dust collection chamber 18 from the opening 105 or opening 161 of the housing 10B. However, similar to the first embodiment, dust discharge ports 180 may also be provided on the left and right sides of the housing 10A and / or the cover 165.

[0118] The correspondence between each component (feature) of the above embodiment and each component (feature) of the present disclosure or invention is shown below. However, each component of the embodiment is merely an example and does not limit each component of the present disclosure or invention.

[0119] Each of the grinders 1A and 1B is an example of a "power tool" and a "grinder." Each of the housings 10A and 10B is an example of a "housing." The air intake 101 is an example of a "first air intake." The motor 21 and the fan 23 are examples of a "motor" and a "fan," respectively. Each of the cyclone separators 5A and 5B is an example of a "cyclone separator." The air intake 51 is an example of a "second air intake." The dust collection chamber 18 of the housings 10A and 10B is an example of a "first dust collection chamber." The dust collection chamber 54 of the cyclone separators 5A and 5B is an example of a "second dust collection chamber."

[0120] The dust discharge port 180 of the housings 10A and 10B is an example of a "first discharge port." The lower discharge port 181, the left discharge port 182, and the right discharge port 183 are examples of a "lower discharge port," a "left discharge port," and a "right discharge port," respectively. The spindle 25 is an example of a "spindle." The side handle 95 is an example of an "auxiliary handle." The seal 59 is an example of a "seal." The outer cylinder portion 631 is an example of an "outer cylinder." The middle cylinder portion 621 is an example of an "middle cylinder." The inner cylinder portion 611 is an example of an "inner cylinder." The dust separation chamber 52 is an example of a "dust separation chamber." The exhaust path 53 is an example of an "exhaust path." The rear dust collection chamber 541 and the front dust collection chamber 543 are examples of a "rear dust collection chamber" and a "front dust collection chamber," respectively. The separator assembly 50 is an example of a "separator assembly."

[0121] It should be noted that the above-described embodiments are merely examples, and the power tools according to the present disclosure are not limited to the illustrated grinders 1A and 1B. For example, the following modifications can be made. Furthermore, at least one of these modifications can be adopted in combination with the grinders 1A and 1B illustrated in the embodiments and at least one of the features described in each claim.

[0122] The power tool according to the present disclosure may be embodied as a power tool used for processing work that generates dust, such as grinders 1A and 1B. Non-limiting examples of such power tools include a concrete planer, a hammer drill, and a circular saw for cutting metal.

[0123] The housing of the power tool according to the present disclosure only needs to have a plurality of first air intakes and define a first dust collection chamber, and the components constituting the housing, the shape, number, and position of the first air intakes, and / or the shape and position of the first dust collection chamber may be modified as appropriate. For example, the motor housing 13A (13B) and the handle housing 15 in the above-described embodiment may be integrally formed by a left shell and a right shell that are connected to each other.

[0124] The cyclone separator according to the present disclosure does not need to be an integrated assembly formed by connecting multiple components to each other, as described above. For example, a portion of the cyclone separator may be integrally formed with the housing. Furthermore, the configuration of the cyclone separator may be modified as appropriate as long as it can separate and collect dust from air flowing in through an air intake port in a dust collection chamber using centrifugal force. For example, the cyclone separators 5A and 5B of the above-described embodiments include three cylindrical portions: an inner cylindrical portion 611, an intermediate cylindrical portion 621, and an outer cylindrical portion 631. However, the cyclone separator according to the present disclosure may include at least (i) an outer cylindrical portion that communicates with an air intake port and defines a dust collection chamber capable of separating and collecting dust, and (ii) an inner cylindrical portion that is disposed radially inside the outer cylindrical portion and defines an exhaust path for discharging the air from which dust has been separated in the dust collection chamber to the outside.

[0125] In the above embodiment, the cover 71 and the locking mechanism 75 are provided on the cyclone separators 5A and 5B and constitute part of the separator assembly 50. However, the cover 71 and at least a part of the mechanism for locking the cover 71 in the closed position may be provided on the housing 10A. For example, the cover 71 may be supported on the housing 10A so as to be rotatable or slidable. The biasing spring 73 that biases the cover 71 toward the open position may be a type of spring other than a torsion coil spring (e.g., a leaf spring or a compression coil spring), or the cover 71 may not be biased toward the open position. Alternatively, the cover 71 may be provided with an engaging portion (e.g., a hole, a recess, or a protrusion), and the locking member 751 may be configured to be engageable with the engaging portion of the cover 71 and supported on the housing 10A so as to be movable between a locked position and an unlocked position. The locking member 751 may be rotatable instead of sliding, and may not be biased toward the locked position. Alternatively, the cover 71 and the locking mechanism 75 may be omitted.

[0126] In view of the spirit of the present invention and the above-described embodiments, the following aspects are constructed, and at least one of the following aspects may be adopted in combination with the features of the embodiments and their variants, or at least one of the features described in each claim. [Aspect 1] The intermediate cylinder has a conical shape whose diameter decreases toward the rear, At least a portion of the outer cylinder is cylindrical and has a substantially uniform diameter. [Aspect 2] a circumferential portion of a front end portion of the outer cylinder forms a protruding portion that protrudes radially outward; The dust outlet is provided in the protrusion. The protrusion 633 in the above embodiment is an example of the "protrusion" of this aspect. [Aspect 3] The outer cylinder, the intermediate cylinder, and the inner cylinder are coaxially fixed by one screw. The screw 65 in the above embodiment is an example of the "screw" of this aspect. [Aspect 4] An engagement portion is provided inside the housing and configured to engage with the cyclone separator and restrict movement of the cyclone separator in at least one of the axial direction and the circumferential direction. Each of the protrusions 141, 145, and 146 in the above embodiment is an example of the "engagement portion" of this aspect. [Aspect 5] The power tool further includes a controller configured to control the operation of the motor. The controller is disposed within the housing adjacent to the plurality of first air intakes. The controller 20 in the above embodiment is an example of the "controller" of this aspect. [Aspect 6] The power tool comprises: a cover that is displaceable between a closed position that closes the dust discharge port and an open position that opens the dust discharge port; a spring that biases the cover toward the open position; and a locking mechanism configured to lock the cover in the closed position. The cover 71, the biasing spring 73, and the locking mechanism 75 in the above embodiment are examples of the "cover," "biasing spring," and "locking mechanism" of this aspect, respectively. [Aspect 7] The locking mechanism includes an operating unit configured to be manually operated by a user, and is configured to switch between a locked state in which the cover is locked in the closed position and an unlocked state in which the cover cannot be locked in response to the operating unit being manually operated. The locking member 751 (tab 753) in the above embodiment is an example of the "operation portion" of this aspect. [Aspect 8] The cover, the spring, and the locking mechanism are connected to and integrated with the cyclone separator to form a single separator assembly. [Explanation of symbols]

[0127] 1A, 1B: disc grinder (grinder), 10A, 10B: housing, 101: intake port, 103: exhaust port, 105: opening, 11: gear housing, 111: handle mounting portion, 13A, 13B: motor housing, 133: rear end portion, 140: screw, 141: convex portion, 145: convex portion, 146: convex portion, 15: handle housing, 15L: left side shell, 15R: right side shell, 151: front end portion, 152: middle portion, 155: grip portion, 157 : Trigger, 158: Main switch, 16: Separator housing, 161: Opening, 165: Cover, 166: Locking piece, 167: Claw, 18: Dust collection chamber, 180: Dust outlet, 181: Lower outlet, 182: Left outlet, 183: Right outlet, 19: Power cord, 20: Controller, 21: Motor, 210: Main body, 211: Stator, 212: Rotor, 215: Output shaft, 251: Tool mounting part, 23: Fan, 25: Spindle, 5A, 5B: Sub Ichron separator, 50: separator assembly, 501: recess, 51: intake port, 52: dust separation chamber, 53: exhaust path, 54: dust collection chamber, 541: rear dust collection chamber, 543: front dust collection chamber, 545: storage chamber, 55: dust discharge port, 59: seal, 61: first member, 611: inner cylinder portion, 613: base portion, 615: guide vane, 617: connecting portion, 62: second member, 621: intermediate cylinder portion, 623: flange portion, 63: third member, 631: outer cylinder portion, 632: peripheral wall portion, 6 33: protrusion, 635: bottom wall, 636: receiving portion, 65: screw, 71: cover, 711: main body, 712: protrusion, 713: connecting portion, 715: support portion, 717: rod, 72: holding plate, 721: elongated hole, 73: biasing spring, 75: locking mechanism, 751: locking member, 752: engaging portion, 753: tab, 754: recess, 757: receiving portion, 758: engaging hole, 759: biasing spring, 77: seal, 91: tip tool, 95: side handle, 951: gripping portion

Claims

1. 1. A power tool configured to drive a removably attached tool accessory, comprising: a housing having a plurality of first air intake ports; a motor housed in the housing; a fan accommodated in the housing, the fan being rotated by the motor and configured to generate an airflow that enters through the plurality of first air intakes and flows inside the housing; a cyclone separator accommodated in the housing, the cyclone separator having a plurality of second air inlets arranged in a circumferential direction of the cyclone separator; the first intake ports and the second intake ports are spaced apart from each other in an axial direction of the cyclone separator; (i) a first dust collection chamber configured to collect dust by inertial force is defined between the plurality of first air intakes and the plurality of second air intakes in the axial direction of the cyclone separator, and (ii) between an inner surface of the housing and the cyclone separator; The power tool, wherein the cyclone separator includes a second dust collection chamber configured to collect dust by centrifugal force.

2. The power tool according to claim 1, The housing is disposed between the plurality of first air intake ports and the plurality of second air intake ports in the axial direction of the cyclone separator, and has at least one first exhaust port that connects the inside and outside of the first dust collecting chamber.

3. The power tool according to claim 2, The power tool, wherein the at least one first exhaust port is arranged so as not to overlap with the plurality of second intake ports.

4. The power tool according to claim 2 or 3, The electric power tool has a normal posture during use defined with respect to the direction of gravity, The power tool, wherein the at least one first outlet is configured to open in the direction of gravity when the power tool is in the normal position.

5. The power tool according to claim 2 or 3, The power tool is a grinder, a spindle configured to be rotated by the motor about a drive axis that defines a vertical direction of the power tool, the spindle having a lower end configured to removably hold the tool bit; The housing extends in a front-rear direction perpendicular to the up-down direction, The housing is configured so that auxiliary handles can be removably attached to the right and left sides in a left-right direction perpendicular to the up-down direction and the front-rear direction, The at least one first exhaust outlet includes at least one of (i) a lower exhaust outlet that opens downward from the housing, (ii) a left exhaust outlet that opens to the left of the housing, and (iii) a right exhaust outlet that opens to the right of the housing.

6. The power tool according to any one of claims 1 to 5, The power tool is a grinder, a spindle configured to be rotated by the motor about a drive axis that defines a vertical direction of the power tool, the spindle having a lower end configured to removably hold the tool bit; The housing extends in a front-rear direction perpendicular to the up-down direction, The power tool is characterized in that the plurality of first air intake ports are formed on the right and left sides of the housing in a left-right direction perpendicular to the up-down direction and the front-rear direction.

7. The power tool according to any one of claims 1 to 6, The power tool further comprises a seal configured to close a gap between the housing and the cyclone separator on the opposite side of the cyclone separator from the plurality of first air inlets relative to the plurality of second air inlets in the axial direction of the cyclone separator.

8. The power tool according to any one of claims 1 to 7, the axial direction of the cyclone separator defines a front-to-rear direction of the power tool; the first air intake ports are disposed rearward of the second air intake ports, The cyclone separator includes: (i) an outer cylinder; (ii) an intermediate cylinder disposed radially inside the outer cylinder and having a rear end positioned forward of a rear end of the outer cylinder; and (iii) an inner cylinder disposed radially inside the intermediate cylinder and having a rear end positioned forward of the rear end of the intermediate cylinder, the first dust collecting chamber is defined between the housing and the outer cylinder, a dust separation chamber communicating with the first dust collection chamber via the plurality of second air intake ports is defined between the intermediate cylinder and the inner cylinder; an exhaust passage that communicates the dust separation chamber with the outside of the cyclone separator is defined within the inner cylinder; The power tool, characterized in that the second dust collection chamber is defined between the outer cylinder and the intermediate cylinder and communicates with the dust separation chamber.

9. The power tool according to claim 8, The cyclone separator is configured to generate a first swirling flow in the dust separation chamber and a second swirling flow in the second dust collection chamber.

10. The power tool according to claim 8 or 9, The second dust collection chamber includes: (i) a rear dust collection chamber defined within the outer cylinder and rearward of the intermediate cylinder, the rear dust collection chamber communicating with the dust separation chamber; and (ii) a front dust collection chamber defined between the outer cylinder and the intermediate cylinder and forward of the rear dust collection chamber, the front dust collection chamber communicating with the rear dust collection chamber.

11. The power tool according to claim 10, The power tool is characterized in that the front dust collecting chamber is configured so that a cross-sectional area thereof at least partially decreases toward the front.

12. A power tool according to any one of claims 1 to 5, The power tool, wherein the outer cylinder, the intermediate cylinder, and the inner cylinder are separate members that are connected together to form a single separator assembly.

13. The power tool according to any one of claims 1 to 12, The power tool, wherein the cyclone separator is disposed within the housing and is removable from the housing.

14. The power tool according to any one of claims 1 to 13, The airflow generated by the fan is cooling air for the motor, The power tool, wherein the motor is disposed downstream of the cyclone separator in the flow direction of the air flow.

15. The power tool according to claim 14, The power tool is a grinder, a spindle configured to be rotated by the motor about a drive axis that defines a vertical direction of the power tool, the spindle having a lower end configured to removably hold the tool bit; The rotation shaft of the motor extends in a front-rear direction perpendicular to the drive shaft, The motor is disposed behind the spindle; The power tool is characterized in that the cyclone separator is disposed behind the motor.

Images