Die grinder

Abstract

To provide a die grinder which can improve visibility of a processing object below the die grinder.SOLUTION: A die grinder comprises: a motor; a spindle which is rotationally driven around a drive shaft regulating the die grinder in a cross direction; a motor housing which accommodates the motor; a handle housing which is connected with a rear side of the motor housing and includes a gripping part a user grips; a housing with a tool housing where the spindle and a circuit board are arranged; and two or more light emission parts which are assembled at a front face of the circuit board. When a direction orthogonal to the drive shaft from a cross-sectional center of the gripping part to the drive shaft is defined as a lower direction and when the front face thereof is divided into four quadrants defined by a vertical direction passing through the drive shaft and a right and left direction passing through the drive shaft orthogonal to the vertical direction, among four quadrants the two or more light emission parts include at least a first light emission part arranged at a right upper quadrant relative to the drive shaft and a second light emission part arranged at a left upper quadrant relative to the drive shaft.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to a die grinder. [Background technology]

[0002] A die grinder is known that uses a motor as a drive source, rotates a spindle using the rotational force generated by the motor, and rotates a tool such as a grinding wheel attached to the tip of the spindle around a drive shaft to perform grinding and other operations (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-045953 Summary of the Invention [Problem to be solved by the invention]

[0004] A technique for improving the visibility of a workpiece when performing work such as grinding using a die grinder is desired. When performing work using a die grinder, the workpiece may be positioned in a direction intersecting the drive shaft relative to the tool bit. Therefore, a technique for improving the visibility of a workpiece positioned in a direction intersecting the drive shaft is desired. [Means for solving the problem]

[0005] The present disclosure can be realized in the following forms.

[0006] According to a first aspect of the present disclosure, there is provided a die grinder comprising: a motor driven by electricity; a spindle driven by the power of the motor to rotate about a drive axis that defines a front-to-rear direction of the die grinder; a housing including a motor housing that accommodates the motor; a handle housing connected to the rear of the motor housing and including a grip portion configured to be held by a user; a tool housing in which the spindle and a circuit board are disposed; and two or more light-emitting units mounted on a front surface of the circuit board. When the direction perpendicular to the drive shaft is defined as a downward direction, a direction from the center of a cross section of the grip portion toward the drive shaft, and the front surface is divided into four quadrants by a vertical direction passing through the drive shaft and a horizontal direction passing through the drive shaft and perpendicular to the vertical direction, the two or more light-emitting units include at least a first light-emitting unit disposed in the upper right quadrant with respect to the drive shaft and a second light-emitting unit disposed in the upper left quadrant with respect to the drive shaft.

[0007] According to the die grinder of the above aspect, it is possible to improve the visibility of the workpiece below the die grinder.

[0008] According to a second aspect of the present disclosure, there is provided a die grinder comprising: a motor driven by power supplied from a battery; a spindle driven by the power of the motor to rotate about a drive axis that defines a front-to-rear direction of the die grinder; a motor housing that accommodates the motor; a handle housing connected to the rear of the motor housing and including a grip portion configured to be held by a user; a tool housing in which the spindle and a circuit board are disposed; two or more light-emitting units assembled to the front surface of the circuit board; and a battery mounting portion into which the battery can be attached and detached along an attachment / detachment direction that intersects with the drive axis. The handle housing includes a handle recess in which the outer surface of the handle housing is recessed relative to the outer surface of the motor housing. When the direction from the drive shaft toward the handle recess along the attachment / detachment direction is defined as the downward direction, and the front surface is divided into four quadrants based on the vertical direction passing through the drive shaft and the horizontal direction passing through the drive shaft and perpendicular to the vertical direction, the two or more light-emitting units include, of the four quadrants, at least a first light-emitting unit that is arranged in the upper right quadrant relative to the drive shaft, and a second light-emitting unit that is arranged in the upper left quadrant relative to the drive shaft.

[0009] According to the die grinder of the above aspect, it is possible to improve the visibility of the workpiece below the die grinder.

[0010] According to a third aspect of the present disclosure, there is provided a die grinder comprising: a motor driven by electricity; a spindle driven by the power of the motor to rotate about a drive shaft that defines a front-to-rear direction of the die grinder; a motor housing that accommodates the motor; a handle housing connected to the rear of the motor housing and including a grip portion configured to be held by a user; a tool housing in which the spindle and a circuit board are disposed; and two or more light-emitting units attached to a front surface of the circuit board. When the position where the curvature of the cross-sectional shape of the grip portion is greatest is defined as a tip portion, and the direction from the center of the cross section of the grip portion or the drive shaft toward the tip portion is defined as a downward direction, and the front surface is divided into four quadrants by a vertical direction passing through the drive shaft and a horizontal direction passing through the drive shaft and perpendicular to the vertical direction, the two or more light-emitting units include at least a first light-emitting unit disposed in the upper right quadrant with respect to the drive shaft and a second light-emitting unit disposed in the upper left quadrant with respect to the drive shaft.

[0011] According to the die grinder of the above aspect, it is possible to improve the visibility of the workpiece below the die grinder.

[0012] According to a fourth aspect of the present disclosure, there is provided a die grinder including: a motor driven by electricity; a spindle driven by power from the motor to rotate about a drive axis that defines a front-to-rear direction of the die grinder; a housing including a motor housing that houses the motor; a handle housing connected to the rear of the motor housing and including a grip portion configured to be held by a user; a tool housing in which the spindle and a circuit board are disposed; two or more light-emitting units assembled to the front surface of the circuit board; and an operating unit provided on the housing that switches the motor on and off. Among the directions perpendicular to the drive shaft, the direction from the center of the cross section of the grip portion or the drive shaft toward the operating portion is defined as the upward direction, and when the front surface is divided into four quadrants by the vertical direction passing through the drive shaft and the horizontal direction passing through the drive shaft and perpendicular to the vertical direction, the two or more light-emitting units include, of the four quadrants, at least a first light-emitting unit that is arranged in the upper right quadrant with respect to the drive shaft, and a second light-emitting unit that is arranged in the upper left quadrant with respect to the drive shaft.

[0013] According to the die grinder of the above aspect, it is possible to improve the visibility of the workpiece below the die grinder.

[0014] According to a fifth aspect of the present disclosure, there is provided a die grinder including: a motor driven by electricity; a spindle driven by power from the motor to rotate about a drive axis that defines a front-to-rear direction of the die grinder; a housing including a motor housing that accommodates the motor; a handle housing connected to the rear of the motor housing and including a grip portion configured to be held by a user; a tool housing in which the spindle and a circuit board are disposed; two or more light-emitting units assembled to the front surface of the circuit board; and an operating unit provided on the housing that switches the motor on and off. Among the directions perpendicular to the drive shaft, the direction from the center of the cross section of the grip portion or the drive shaft toward the operating portion is defined as the rightward or leftward direction, and when the front surface is divided into four quadrants by the up-down direction that is perpendicular to the left-right direction and passes through the drive shaft, and the left-right direction that passes through the drive shaft, the two or more light-emitting units include, of the four quadrants, at least a first light-emitting unit that is arranged in the upper right quadrant with respect to the drive shaft, and a second light-emitting unit that is arranged in the upper left quadrant with respect to the drive shaft.

[0015] According to the die grinder of the above aspect, it is possible to improve the visibility of the workpiece below the die grinder.

[0016] According to a sixth aspect of the present disclosure, there is provided a die grinder comprising: a motor driven by electricity; a spindle driven by the power of the motor to rotate about a drive shaft that defines a front-to-rear direction of the die grinder; a housing including a motor housing that accommodates the motor; a handle housing connected to the rear of the motor housing and including a grip portion configured to be held by a user; a tool housing in which the spindle and a circuit board are disposed; two or more light-emitting units mounted on a front surface of the circuit board; and a paddle switch provided on the grip portion for switching the motor on and off. When the direction from the center of the cross section of the grip portion toward the paddle switch is defined as a downward direction, and the front surface is divided into four quadrants by a vertical direction passing through the drive shaft and a horizontal direction passing through the drive shaft and perpendicular to the vertical direction, the two or more light-emitting units include at least a first light-emitting unit disposed in the upper right quadrant of the four quadrants with respect to the drive shaft and a second light-emitting unit disposed in the upper left quadrant with respect to the drive shaft.

[0017] According to the die grinder of the above aspect, it is possible to improve the visibility of the workpiece below the die grinder. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a perspective view showing the external configuration of a die grinder according to a first embodiment. [Figure 2] FIG. 1 is a side view of a die grinder according to a first embodiment. [Figure 3] FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 2. [Figure 4] FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. [Figure 5] FIG. 4 is an explanatory diagram showing the internal configuration of a tool housing. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] FIG. 8 is a cross-sectional view taken along the line VIII-VIII in FIG. 7 . [Figure 9]9 is a cross-sectional view taken along the line IX-IX in FIG. 7. [Figure 10] FIG. 10 is a front view showing the arrangement of light-emitting units as a comparative example. [Figure 11] 11 is a cross-sectional view taken along the line XI-XI in FIG. [Figure 12] Cross-sectional view taken along the line XII-XII in Figure 10. [Figure 13] FIG. 10 is an explanatory diagram showing a simulation result of the downward illumination range by the lighting device. [Figure 14] FIG. 10 is an explanatory diagram showing a simulation result of the appearance of light emitted by the irradiation device. [Figure 15] FIG. 10 is an explanatory diagram showing a simulation result of a downward illumination range by a lighting device of a comparative example. [Figure 16] FIG. 10 is an explanatory diagram showing a simulation result of the appearance of light emitted by an irradiation device of a comparative example. [Figure 17] FIG. 10 is a front view showing the arrangement of light-emitting units as a second comparative example. [Figure 18] 18 is a cross-sectional view taken along the line XVIII-XVIII in FIG. 17. [Figure 19] 19 is a cross-sectional view taken along the line XIX-XIX in FIG. 17. [Figure 20] FIG. 10 is an explanatory diagram showing a simulation result of the downward illumination range by the lighting device of the second comparative example. [Figure 21] FIG. 10 is an explanatory diagram showing the results of a simulation of the appearance of light emitted by the irradiation device of the second comparative example. [Figure 22] FIG. 4 is an explanatory diagram showing the configuration of the lower part of the barrel. [Figure 23] FIG. 4 is an explanatory diagram showing the configuration of the inner circumferential surface of a tool housing. [Figure 24] FIG. 4 is an explanatory diagram showing the internal configuration of a lower portion of the motor housing. [Figure 25] FIG. 10 is a second explanatory diagram showing the internal configuration of the lower part of the motor housing. [Figure 26] FIG. 10 is a first explanatory diagram showing a method for defining a direction according to another embodiment. [Figure 27] FIG. 10 is a second explanatory diagram showing a method for defining a direction according to another embodiment. [Figure 28]FIG. 10 is a third explanatory diagram showing a method for defining a direction according to another embodiment. [Figure 29] FIG. 4 is a fourth explanatory diagram showing a method for defining a direction according to another embodiment. [Figure 30] FIG. 5 is a fifth explanatory diagram showing a method for defining a direction according to another embodiment. [Figure 31] FIG. 6 is a sixth explanatory diagram showing a method for defining a direction according to another embodiment. [Figure 32] FIG. 10 is an explanatory diagram showing the arrangement position of a light-emitting unit according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0019] Representative, non-limiting embodiments of the present invention will now be described in detail with reference to the accompanying drawings. This detailed description is intended simply to provide those skilled in the art with details for implementing preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Additionally, additional features and inventions disclosed below may be used separately or in conjunction with other features and inventions to provide further improved devices, methods of making and using the same.

[0020] Furthermore, the combinations of features and steps disclosed in the following detailed description are not essential to practicing the invention in its broadest sense, but are described solely to illustrate specific exemplary embodiments of the invention. Furthermore, the various features of the exemplary embodiments described above and below, and those described in the independent and dependent claims, do not necessarily have to be combined in the exact embodiments described herein, or in the exact order listed, to provide additional and useful embodiments of the invention.

[0021] All features described in this specification and / or claims are intended to be disclosed individually and independently of one another as limitations on the original disclosure and claimed particulars, apart from any configuration of the features described in the embodiments and / or claims. Furthermore, all numerical ranges and group or aggregation descriptions are intended to disclose intermediate configurations thereof as limitations on the original disclosure and claimed particulars.

[0022] In one or more embodiments, the two or more light emitting portions may further include a third light emitting portion disposed on the front surface below the drive shaft. According to this type of die grinder, by arranging the light emitting unit below the drive shaft, it is possible to suppress the upward irradiation of light from the light emitting unit while improving the illuminance of the workpiece below.

[0023] In one or more embodiments, the front surface may have an annular shape, and when a circle connecting a midpoint between an inner peripheral edge portion closer to the drive shaft and an outer peripheral edge portion of the front surface is defined as an intermediate circle, the two or more light-emitting units may be disposed on the front surface in a region more inward than the intermediate circle. According to the die grinder of this configuration, the range of light irradiated onto the workpiece can be made wider compared to when the light emitting unit is disposed in a region outside the middle circle.

[0024] In one or more embodiments, the die grinder may further include a protective member disposed in front of the light-emitting unit and transmitting light from the light-emitting unit. The protective member may include a main body that covers the light-emitting unit, a base that extends rearward from the main body, and a claw that is disposed at a tip of the base and configured to fit into a recess that is provided in a member disposed rearward of the circuit board. According to this type of die grinder, the lighting device can be easily attached and detached by using a snap fit, and the lighting device can be easily repaired.

[0025] In one or more embodiments, the die grinder may further include a spindle bearing that rotatably supports the spindle, a barrel that houses the spindle bearing, and a bearing retainer that is disposed forward of the spindle bearing and fixed to a front end of the barrel. The recess may be provided on an outer surface of the bearing retainer. The circuit board and the two or more light-emitting units may be held between the bearing retainer and the protective member with the claws and the recesses engaged. According to the die grinder of this configuration, the protective member can be prevented from becoming large in the radial direction, compared to when the protective member engages with the outer peripheral surface of a barrel or the like.

[0026] In one or more embodiments, the die grinder may include a barrel that houses at least a portion of the spindle. The barrel may include a first wall and a second wall that protrude from an outer surface of the barrel. Electrical wires connected to the circuit board may be disposed in a barrel electrical wireway defined by the first wall and the second wall. According to the die grinder of this aspect, the barrel can be reinforced by the first wall portion and the second wall portion, and a wiring path for the electric wires can be formed around the barrel.

[0027] In one or more embodiments, a first protrusion protruding toward the second wall portion may be provided on a surface of the first wall portion facing the second wall portion, and a second protrusion protruding toward the first wall portion may be provided on a surface of the second wall portion facing the first wall portion. According to the die grinder of this type, it is possible to suppress or prevent the electric wire from falling off from the barrel electric wireway.

[0028] In one or more embodiments, the interior surface of the tool housing may include a recess capable of receiving the first wall portion and the second wall portion. According to the die grinder of this configuration, it is possible to provide a die grinder in which the tool housing is easy to grip and which is highly maneuverable.

[0029] In one or more embodiments, the motor housing may include an outer wall portion and a support wall portion that supports the motor inside the motor housing. A motor wireway may be provided in the motor housing between the support wall portion and the outer wall portion for passing the electric wires. According to the die grinder of this configuration, contact between the electric wire and each part inside the motor housing can be suppressed.

[0030] In one or more embodiments, the die grinder may further include a fan for cooling the motor, a motor bearing provided in the housing between the motor and the spindle and rotatably supporting a motor shaft of the motor, and a motor bearing retainer supporting the motor bearing. The motor bearing retainer may include an opening through which airflow delivered from the fan can pass. The barrel electrical line, the opening, and the motor electrical line may be configured to communicate with each other. With this type of die grinder, by using the opening as a wiring path for the electric wires, it is possible to suppress or prevent the motor housing from becoming larger in the radial direction compared to when a wiring path is formed that bypasses the motor bearing retainer.

[0031] In one or more embodiments, the die grinder may further include a controller configured to control operation of the die grinder, and the controller may be located at a location through which the drive shaft passes. According to the die grinder of this configuration, the radial size of the die grinder can be reduced.

[0032] In one or more embodiments, the motor may include a motor shaft that is driven to rotate about a motor axis, and the motor axis and the drive shaft may be configured to be coaxial. According to the die grinder of this configuration, the radial size of the die grinder can be reduced.

[0033] In one or more embodiments, the die grinder may further include a battery for supplying power to the motor, and a battery mounting portion to which the battery can be attached or detached.

[0034] A. First embodiment: A1. Die Grinder 100 external configuration: As shown in FIG. 1, the die grinder 100 is an example of a power tool having a total length of approximately 400 mm in the front-to-rear direction. The die grinder 100 rotates a spindle 90 around a drive axis TX by a rotational force generated by driving a motor 20 (described later). A tool tip TT is attached to the tip of the spindle 90 and rotates with the rotation of the spindle 90. In the example of FIG. 1, the tool tip TT is a substantially cylindrical mounted grindstone or the like, whose side surface TS functions as a grinding surface. A user operates the die grinder 100 to rotate the tool tip TT and press the side surface TS against a workpiece to perform grinding or other work.

[0035] The tip tool TT is not limited to a cylindrical shape, and may be switched to various shapes depending on the object to be processed, such as a cone shape including a circular cone. Furthermore, the tip tool TT may be a tool other than a grinding wheel, such as a flap wheel with sanding paper attached. The die grinder 100 is also sometimes called a "hand grinder" or a "straight grinder."

[0036] For ease of explanation, the direction in which the drive shaft TX extends is defined herein as the "front-rear direction of the die grinder 100." In the front-rear direction, the end side of the housing HS where the spindle 90 is disposed is defined as the "front side of the die grinder 100," and the opposite side is defined as the "rear side of the die grinder 100." The definitions of the up-down direction and the left-right and rear directions will be described later.

[0037] The die grinder 100 includes a generally cylindrical housing HS that extends in the front-to-rear direction. The housing HS includes a motor housing 30, a handle housing 40, and a tool housing 50. The motor housing 30 accommodates a motor 20.

[0038] The handle housing 40 is connected to the rear of the motor housing 30. The handle housing 40 includes a grip portion 42, a handle recess 44, and a battery mounting portion 46 (see FIG. 4) for mounting the battery BT.

[0039] The grip portion 42 is configured to be gripped by a user. The cross-sectional width of the grip portion 42 is smaller than the cross-sectional width of the motor housing 30, and is configured to have a width and cross-sectional shape that makes it easy for a user to grip. In this embodiment, the grip portion 42 is covered with an insulating material such as an elastomer.

[0040] 2 and 3 show the cross-sectional center HX of the gripping portion 42. The "cross-sectional center HX of the gripping portion 42" refers to the centroid of the cross-sectional shape of the gripping portion 42 in the outer shape HF, as shown in FIG. 3. The cross-sectional center HX of the gripping portion 42 may be defined using the center of gravity of the cross section of the gripping portion 42. In the die grinder 100 of this embodiment, among directions perpendicular to the drive axis TX, the direction DD1 from the cross-sectional center HX of the gripping portion 42 toward the drive axis TX is defined as the downward direction, and the opposite direction is defined as the upward direction. Furthermore, the direction perpendicular to the front-rear direction and the up-down direction is defined as the left-right direction. The downward direction can be a convenient direction for moving the die grinder 100 toward the workpiece when machining the workpiece using the die grinder 100.

[0041] The straight line HL shown in FIG. 2 indicates the position of the cross-sectional center HX in the front-rear direction of the gripping portion 42. The straight line HL is, for example, a regression line calculated by the least squares method using multiple cross-sectional centers HX in the front-rear direction. As shown in FIG. 2, in the die grinder 100 of this embodiment, the straight line HL is above the drive axis TX over the entire length of the gripping portion 42 in the front-rear direction, and the cross-sectional center HX is located above the drive axis TX at any position in the front-rear direction of the gripping portion 42. If the straight line HL intersects with the drive axis TX at any position in the front-rear direction of the gripping portion 42, the up-down direction may be defined by a method shown in another embodiment described below.

[0042] 1 and 2, the upper end of the grip portion 42 is configured to be approximately flush with the upper end of the motor housing 30. Therefore, the lower outer surface of the handle housing 40 has an appearance that is concave upward relative to the lower outer surface of the motor housing 30 and the lower outer surface at the rear end of the handle housing 40. The concave portion on the lower side of the handle housing 40 is also referred to as the "handle recess 44."

[0043] As shown in FIG. 1 , the tool housing 50 is connected to the front of the motor housing 30. The tool housing 50 houses the spindle 90, the lighting device DL, and other components. The cross-sectional width of the tool housing 50 is smaller than that of the motor housing 30, and is configured to have a cross-sectional width and cross-sectional shape that are convenient for a user to grip. In this embodiment, the tool housing 50 is covered with an insulating material such as an elastomer. A user can use the die grinder 100, for example, by holding the grip portion 42 of the handle housing 40 with one hand and the tool housing 50 with the other hand.

[0044] The lighting device DL is configured to be able to irradiate light toward the work area including the workpiece or its surroundings. By providing the lighting device DL, the visibility of the workpiece can be improved. In this embodiment, the lighting device DL is disposed at the front end of the tool housing 50.

[0045] A2. Internal structure of Die Grinder 100: As shown on the left side of Fig. 4, the handle housing 40 accommodates the controller 10, the switch 14, etc. The controller 10 is configured as a computer having a CPU as a central processing unit and memories such as RAM and ROM. The controller 10 controls various operations of the die grinder 100, such as driving control of the motor 20.

[0046] The controller 10 is disposed at a position where the drive shaft TX passes. This configuration allows the radial size of the housing HS to be reduced. The controller 10 has a generally flat plate shape and is disposed at the rear end of the handle housing 40 so that its surface intersects with the drive shaft TX. By accommodating the controller 10 at the rear end of the handle housing 40, which is easier to form an internal space than the motor housing 30 or the tool housing 50, the components inside the housing HS can be disposed efficiently.

[0047] In this embodiment, a battery attachment section 46 configured to allow a battery BT to be attached and detached is provided at the rear end of the handle housing 40. The battery attachment section 46 is provided at a position at the rear end of the handle housing 40 where the drive shaft TX passes. The battery BT is a well-known secondary battery such as a lithium-ion battery including multiple cells.

[0048] In the example of FIG. 4 , the attachment / detachment direction DB of the battery BT is a direction perpendicular to the drive shaft TX and coincides with the up-and-down direction in this embodiment. A user can remove the battery BT from the battery attachment section 46 by pulling the battery BT upward in the attachment / detachment direction DB. A user can attach the battery BT to the battery attachment section 46 by pushing the battery BT downward in the attachment / detachment direction DB. The battery BT attached to the battery attachment section 46 can supply power to the motor 20, the lighting device DL, the controller 10, and the like. The battery BT is electrically connected to the circuit board 70 via an electric wire 12 wired inside the housing HS, and supplies power to the lighting device DL.

[0049] As shown in the center of FIG. 4, the motor housing 30 accommodates the motor 20 and other components. The motor 20 is a brushless DC motor that is driven under the control of the controller 10. The motor 20 includes a motor body 21 including a stator and a rotor, a motor shaft 22, and a fan 26 attached to the motor shaft 22. The fan 26 rotates together with the motor shaft 22. The fan 26 generates an airflow for cooling the motor 20.

[0050] The motor shaft 22 is rotatably supported relative to the motor housing 30 by a front motor bearing 201 and a rear motor bearing 202 provided within the motor housing 30. The motor shaft 22 rotates together with the rotor around the motor rotation axis MX. In this embodiment, the motor shaft 22 is connected to the spindle 90 via a coupling 204, and the motor rotation axis MX and the drive shaft TX are configured to be coaxial. However, the motor rotation axis MX and the drive shaft TX do not have to be coaxial. For example, the motor rotation axis MX and the drive shaft TX may be configured to be parallel to each other while being close enough to each other that the drive shaft TX passes through the motor main body 21. By arranging the motor rotation axis MX and the drive shaft TX of the motor 20 close to each other, the radial size of the die grinder 100 can be reduced.

[0051] The front motor bearing 201 is supported in the motor housing 30 with its movement restricted by a motor bearing retainer 32. The motor bearing retainer 32 has an opening 322 formed therein that functions as a ventilation port for allowing airflow from the fan 26 to pass through.

[0052] As shown in FIG. 5 , the tool housing 50 accommodates a barrel 60 and a lighting device DL. The barrel 60 accommodates a spindle 90 and other components. The spindle 90 is rotatably supported relative to the barrel 60 by a front spindle bearing 601 and a rear spindle bearing 602 held within the barrel 60. The front spindle bearing 601 is fixed by a bearing retainer 66, restricting movement in the front-to-rear direction. A collet cone 92 and a collet nut 94 for fixing the tool bit TT are provided at the front end of the spindle 90. The tool bit TT inserted into the collet cone 92 is non-rotatably attached to the spindle 90 by tightening the collet nut 94.

[0053] As shown in FIG. 4, in this embodiment, an operation unit SW1 for switching the motor 20 on and off is provided above the motor housing 30. In the example of FIG. 4, a slide switch is used as the operation unit SW1. Operating the slide switch switches the switch 14 on and off, thereby switching the motor 20 on and off. The operation unit SW1 is not limited to a slide switch, and various switches such as a touch sensor may be used. When the motor 20 is turned on by operating the operation unit SW1, the motor shaft 22 is driven, and the spindle 90 and the tool bit TT rotate integrally with the motor shaft 22 via the coupling 204.

[0054] 4, the illumination device DL is disposed at the front end of the housing HS. Specifically, it is disposed within the tool housing 50, between the front end of the barrel 60 and the front end of the tool housing 50. In this embodiment, the illumination device DL is configured to be able to suitably irradiate the workpiece WS disposed below the die grinder 100 with light LT.

[0055] As shown in FIG. 5, the lighting device DL includes a light-emitting unit 80, a protective member 86, and a circuit board 70. The light-emitting unit 80 is an LED light powered by a battery BT. The light-emitting unit 80 is covered with a protective member 86 made of transparent resin. The protective member 86 transmits light emitted from the light-emitting unit 80. In cases where the protective member 86 does not include a claw portion 864 (described later), the protective member 86 can also be made of glass.

[0056] The circuit board 70 is a so-called LED board, and light-emitting units 80 are mounted on a front surface 72 thereof. An electric wire 12 for supplying power from a battery BT is connected to the circuit board 70. The front surface 72 of the circuit board 70 has an opening formed in the center through which the spindle 90 can be inserted, and has a circular ring shape surrounding the drive shaft TX. In this embodiment, the number of light-emitting units 80 mounted on the circuit board 70 is three. The arrangement of the light-emitting units 80 will be described later.

[0057] In this embodiment, the on / off operation of the operation unit SW1 is linked to the on / off operation of the light-emitting unit 80. Light LT emitted from the illumination device DL is irradiated onto the workpiece WS from an opening 56 formed at the front end of the tool housing 50.

[0058] A3. How to assemble the DL lighting device: A method for assembling the lighting device DL and the like to the barrel 60 and the like will be described with reference to Fig. 6. Note that in Fig. 6, some components such as the spindle 90 are not shown to facilitate understanding of the technology. First, the spindle 90 with the front spindle bearing 601 attached is inserted into the barrel 60 from the front end of the barrel 60.

[0059] Next, the bearing retainer 66 is attached to the front end of the barrel 60, thereby fixing the front spindle bearing 601 to the barrel 60. A male thread (not shown) is formed on the outer peripheral surface of the bearing retainer 66. The male thread of the bearing retainer 66 screws into a female thread (not shown) formed on the inner peripheral surface of the front end of the barrel 60. When the bearing retainer 66 is screwed into the front end of the barrel 60, the bearing retainer 66 is fixed to the front end of the barrel 60 so as to restrict movement of the front spindle bearing 601 in the front-to-rear direction. In addition to the female thread, a recess 662 shaped to correspond to the claw 864 is formed on the outer peripheral surface of the bearing retainer 66.

[0060] Next, the protective member 86 is fixed to the bearing retainer 66. In this embodiment, a so-called snap fit is used to fix the protective member 86 to the bearing retainer 66. By using a snap fit, the protective member 86 can be easily attached and detached, and repair of the lighting device DL can be easily performed.

[0061] The circuit board 70, on which the light emitting unit 80 is mounted, is fixed to the protective member 86 with an adhesive or the like. The protective member 86 includes a substantially annular main body 860 that covers the front surface 72 of the circuit board 70, a base 862 that protrudes rearward from the outer edge of the main body 860, and claws 864 formed at the tip of the base 862. The claws 864 protrude radially inward from the outer edge of the main body 860.

[0062] The protective member 86 is made of a transparent resin having elasticity. Therefore, when the protective member 86 is moved rearward toward the bearing retainer 66, the claws 864 come into contact with the outer peripheral surface of the bearing retainer 66 and are subjected to a reaction force from the outer peripheral surface, causing them to bend back in a direction away from the bearing retainer 66. By further moving the protective member 86 toward the bearing retainer 66, the claws 864 are released from the reaction force from the outer peripheral surface and engage with the recesses 662 of the bearing retainer 66.

[0063] In the present embodiment, the protective member 86 is configured to be fixed to the bearing retainer 66. Therefore, compared to a case where the protective member 86 engages with the outer peripheral surface of the barrel 60, an increase in the radial size of the protective member 86 can be suppressed, and an increase in the radial size of the tool housing 50 can be suppressed or prevented.

[0064] When the protective member 86 is fixed to the bearing retainer 66, the protective member 86 and the circuit board 70 are held between the bearing retainer 66 and the protective member 86 with the tabs 864 engaged with the recesses 662. As a result, the lighting device DL is fixed to the bearing retainer 66 and the barrel 60.

[0065] Once the spindle 90, bearing retainer 66, protective member 86, etc. are fixed to the barrel 60, the tool housing 50 is attached to the outer periphery of the barrel 60. As shown in Fig. 5, the protective member 86 is exposed to the outside from the opening 56 at the front end of the tool housing 50 and is fixed so that its movement in the front-to-rear direction is restricted by the inner circumferential surface of the protrusion 54. The protrusion 54 is a portion that protrudes radially inward at the front end of the tool housing 50 and defines the opening 56.

[0066] The lighting device DL is fixed forward of the front end of the barrel 60. Therefore, compared to a configuration in which the lighting device DL is housed inside the barrel 60 or a configuration in which the protective member 86 is engaged with the inner circumferential surface of the barrel 60, attachment and detachment of the protective member 86 is easier, and repair of the lighting device DL can be performed more easily. However, the die grinder 100 is not limited to these configurations. For example, the recess 662 may be formed in a member other than the bearing retainer 66, such as the inner circumferential surface of the barrel 60 or the outer circumferential surface of the barrel 60. Note that when the recess 662 is formed in the inner circumferential surface of the barrel 60, the claw portion 864 is configured to protrude radially outward from the base portion 862.

[0067] A4. Arrangement of the light emitting unit 80 on the circuit board 70: The position of the light-emitting unit 80 on the circuit board 70 will be described with reference to FIGS. 7 to 21. As shown in FIG. 7, the front surface 72 of the circuit board 70 is divided into four quadrants by a vertical direction D1 passing through the drive axis TX and a horizontal direction D2 passing through the drive axis TX and perpendicular to the vertical direction D1. Specifically, the upper right with respect to the drive axis TX is defined as the first quadrant Q1, the upper left as the second quadrant Q2, the lower left as the third quadrant Q3, and the lower right as the fourth quadrant Q4. The light-emitting unit 80 includes at least a first light-emitting unit 81 disposed in the first quadrant Q1 and a second light-emitting unit 82 disposed in the second quadrant Q2. The first light-emitting unit 81 and the second light-emitting unit 82 are disposed at positions at an elevation angle of 30 degrees with respect to the horizontal direction D2.

[0068] FIG. 8 schematically shows the results of a simulation of the range of light emitted by the first light-emitting unit 81. The results of a simulation of the range of light emitted by the second light-emitting unit 82 are similar to those of the first light-emitting unit 81, and therefore will not be described here. As shown in FIG. 8, the light emitted from the first light-emitting unit 81 is emitted to the outside of the die grinder 100 through the opening 56 at the front end of the tool housing 50. Therefore, the range of light emitted by the first light-emitting unit 81 can be determined by the protrusion 54 at the front end of the tool housing 50. In this embodiment, the angle θ1 between the horizontal plane HZ1 passing through the first light-emitting unit 81 and the light LT1 emitted most downward from the first light-emitting unit 81 is 75.1 degrees.

[0069] 7, in the die grinder 100 of this embodiment, the light-emitting unit 80 further includes a third light-emitting unit 83 disposed on the front surface 72 directly below the drive shaft TX. By disposing the light-emitting unit 80 directly below the drive shaft TX, it is possible to improve the illuminance downward while suppressing the upward irradiation of light from the light-emitting unit 80. Therefore, the light-emitting unit 80 can be suitably disposed so as to improve the visibility of the workpiece WS while suppressing discomfort to the user.

[0070] Fig. 9 schematically shows the results of a simulation of the range of light emitted by the third light-emitting unit 83. As shown in Fig. 9, the angle θ3 between the horizontal plane HZ3 passing through the third light-emitting unit 83 and the light LT3 emitted most downward from the third light-emitting unit 83 is 42.8 degrees.

[0071] 10 to 12, the illumination range of the illumination device DL of a die grinder 100R, which is configured differently from the die grinder 100 of the present embodiment, will be described as a comparative example. As shown in Fig. 10, the circuit board 70R of the comparative example includes three light-emitting units 80. Specifically, the light-emitting unit 80 includes a first light-emitting unit 81R arranged in the fourth quadrant Q4, a second light-emitting unit 82R arranged in the third quadrant Q3, and a third light-emitting unit 83R arranged directly above the drive shaft TX.

[0072] Fig. 11 schematically shows the results of a simulation of the illumination range of light emitted by the first light-emitting unit 81R. As shown in Fig. 11, in the illumination range of light emitted from the first light-emitting unit 81R, the angle θR1 between the horizontal plane HR1 passing through the first light-emitting unit 81R and the light LR1 emitted most downward from the first light-emitting unit 81R is 47.3 degrees.

[0073] From the perspective of comparing the range of light illumination by the light-emitting unit 80 arranged laterally of the drive shaft TX, the first light-emitting unit 81 of the die grinder 100 of this embodiment is compared with the first light-emitting unit 81R of the die grinder 100R of the comparative example. The angle θ1 formed by the die grinder 100 of this embodiment shown in FIG. 8 is wider than the angle θR1 formed by the die grinder 100R of the comparative example shown in FIG. 11. In other words, according to the die grinder 100 of this embodiment, the range of light illumination downward by the first light-emitting unit 81 and the second light-emitting unit 82 arranged laterally of the drive shaft TX is wider than that of the comparative example.

[0074] Fig. 12 shows a schematic diagram of a simulation result of the range of light emitted by the third light emitter 83R. As shown in Fig. 12, components such as the spindle 90, collet nut 94, and tool bit TT are disposed directly below the third light emitter 83R. Therefore, the light LR3 emitted downward from the third light emitter 83R may be blocked by these components.

[0075] 13 and 14, in the die grinder 100 of this embodiment, the downward illumination range of the first light emitter 81 and the second light emitter 82 is wider than in the comparative example, and light can be irradiated closer to the tool tip TT than in the comparative example. In contrast, in the die grinder 100R of the comparative example, the illuminance near the tool tip TT is lower, as shown in FIGS.

[0076] As shown in Figures 15 and 16, in the die grinder 100R of the comparative example, light is diffused non-uniformly in the left-right direction in front of the tool tip TT. In contrast, as shown in Figures 13 and 14, in the die grinder 100 of this embodiment, light is diffused uniformly in the left-right direction in front of the tool tip TT, and the area of ​​high illuminance in front of the tool tip TT is wider than in the comparative example.

[0077] 16, in the die grinder 100R of the comparative example, a shadow SD of the tool tip TT and the like is formed by the light LR3 emitted downward from the third light emitter 83R. In contrast, in the die grinder 100 of the present embodiment, a shadow SD of the tool tip TT and the like is not formed, and the die grinder 100 of the present embodiment provides a better appearance of the illuminated area than the comparative example. As described above, the die grinder 100 of the present embodiment can improve the visibility of the workpiece WS below the tool tip TT.

[0078] 7, in the die grinder 100 of this embodiment, the light emitting unit 80 is arranged in a state where it is located in a radially inner region close to the drive shaft TX on the front surface 72 of the circuit board 70. This will be described in detail below.

[0079] 7 schematically illustrates an intermediate circle 72CL between two peripheral portions of the front surface 72. Specifically, the intermediate circle 72CL is a circle formed by connecting the intermediate positions between the radially inner peripheral portion 72R2, which is closer to the drive shaft TX, and the radially outer peripheral portion 72R1. In the die grinder 100 of this embodiment, the first light-emitting portion 81, the second light-emitting portion 82, and the third light-emitting portion 83 are arranged in a region of the front surface 72 that is closer to the drive shaft TX than the intermediate circle 72CL in the radial direction.

[0080] 17 to 21, the illumination range of the light-emitting unit 80 disposed in a radially outer region away from the drive axis TX will be described as a second comparative example. As shown in FIG. 17, the circuit board 70R2 of the die grinder 100R2 of the second comparative example is similar to the circuit board 70 of the die grinder 100 of the present embodiment in that the light-emitting units 80 are disposed in three locations: the first quadrant Q1, the second quadrant Q2, and directly below the drive axis TX. However, the die grinder 100R2 differs from the present embodiment in that the first light-emitting unit 81R2, the second light-emitting unit 82R2, and the third light-emitting unit 83R2 are disposed radially outward, away from the drive axis TX, relative to the intermediate circle 72CL. The first light-emitting unit 81R2 and the second light-emitting unit 82R2 are disposed at an elevation angle of 30 degrees relative to the left-right direction D2. The simulation results of the illumination range of the light emitted by the second light-emitting unit 82R2 are similar to those of the first light-emitting unit 81R2, and therefore will not be described here.

[0081] FIG. 18 schematically illustrates the results of a simulation of the range of light emitted by the first light-emitting unit 81R2. As shown in FIG. 18, the angle θRR1 between the horizontal plane HRR1 passing through the first light-emitting unit 81R2 and the light LRR1 emitted most downward from the first light-emitting unit 81R2 is 75.0 degrees. Therefore, the range of light emitted forward by the first light-emitting unit 81 of the die grinder 100 according to this embodiment is slightly wider than that of the second comparative example. However, the range of light emitted by the first light-emitting unit 81R2 of the second comparative example is wider than that of the first light-emitting unit 81R of the comparative die grinder 100R.

[0082] FIG. 19 schematically illustrates the results of a simulation of the light irradiation range of the third light-emitting unit 83R2. As shown in FIG. 19, the angle θRR3 between the horizontal plane HRR3 passing through the third light-emitting unit 83R2 and the light LRR3 emitted most downward from the third light-emitting unit 83R2 is 33.3 degrees. Therefore, according to the die grinder 100 of this embodiment, the light irradiation range of the third light-emitting unit 83R2 is wider than the light irradiation range of the third light-emitting unit 83R2 of the second comparative example. However, according to the die grinder 100R2 of the second comparative example, the light irradiation range of the third light-emitting unit 83R2 is wider than the third light-emitting unit 83R of the comparative die grinder 100R.

[0083] As described above, the range of light emitted by the first light-emitting unit 81 and the second light-emitting unit 82 is wider when the first light-emitting unit 81 and the second light-emitting unit 82 are arranged in the first quadrant Q1 and the second quadrant Q2 than when they are arranged in the third quadrant Q3 and the fourth quadrant Q4, and is even wider when they are arranged radially inward relative to the intermediate circle 72CL than when they are arranged radially outward.

[0084] 20 and 21, the downward illumination range of the die grinder 100R2 of the second comparative example is wider in the area of ​​high illumination in front of the tool bit TT, and the light is diffused more uniformly in the left-right direction, resulting in a better appearance, compared to the die grinder 100R of the comparative example shown in FIGS. 15 and 16. The illumination range of the die grinder 100 of this embodiment is wider than the illumination range of the die grinder 100R2 of the second comparative example. That is, the die grinder 100 of this embodiment can further widen the area of ​​high illumination in front of the tool bit TT compared to the second comparative example.

[0085] A5. Arrangement of the wire 12 inside the die grinder 100: Fig. 22 shows the configuration of the underside of the die grinder 100 with the tool housing 50 removed. As shown in Fig. 22, the electric wire 12 connected to the lighting device DL is connected to the electric wire 12 on the controller 10 side via a connector 16. This will be explained in detail below.

[0086] The electric wires 12 connected to the lighting device DL are led rearward along the outer surface of the barrel 60 below the barrel 60. The electric wires 12 led rearward of the barrel 60 pass through a through-hole 68 formed in the barrel 60 and are led into the housing HS.

[0087] 22, a plurality of ribs 60R are formed on the outer surface of the barrel 60 in order to reduce the weight and reinforce the barrel 60. In the die grinder 100 according to this embodiment, the ribs 60R on the lower side of the barrel 60 are utilized to efficiently form a wiring path for the electric wire 12.

[0088] 22, a first wall portion 61 and a second wall portion 62 are formed on the lower side of the barrel 60, protruding from the outer surface of the barrel 60. The first wall portion 61 and the second wall portion 62 also function as ribs 60R. The first wall portion 61 and the second wall portion 62 extend rearward along the barrel 60 and are arranged close to each other.

[0089] The electric wires 12 led from the lighting device DL are arranged in a barrel electric wire path 63 defined between a first wall portion 61 and a second wall portion 62. The first wall portion 61 and the second wall portion 62, which also function as the ribs 60R, make it possible to efficiently form a wiring path for the electric wires 12 around the barrel 60. Furthermore, compared to a case where a new wiring path different from the ribs 60R is formed in the tool housing 50 or the barrel 60, it is possible to prevent the barrel 60 or the tool housing 50 from becoming larger in the radial direction.

[0090] 22 , in the die grinder 100 of this embodiment, a protrusion 54 is further formed between the first wall portion 61 and the second wall portion 62 to prevent the electric wire 12 from falling off from the barrel electric wireway 63. Specifically, a first protrusion 611 protruding toward the second wall portion 62 is provided on a surface of the first wall portion 61 facing the second wall portion 62. A second protrusion 622 protruding toward the first wall portion 61 is provided on a surface of the second wall portion 62 facing the first wall portion 61.

[0091] The number of first protrusions 611 and second protrusions 622 may be set arbitrarily. In this embodiment, two first protrusions 611 and one second protrusion 622 are formed at an angle θ. The first protrusions 611 and the second protrusions 622 are arranged alternately in the front-rear direction. With this configuration, the electric wire 12 can be arranged in the barrel electric wireway 63 while being curved in the left-right direction. Therefore, it is possible to more reliably suppress or prevent the electric wire 12 from falling off the barrel electric wireway 63.

[0092] As shown in FIG. 23 , a recess 52 is formed on the inner peripheral surface of the tool housing 50. The recess 52 is configured with a shape and position that allows it to accommodate the first wall portion 61 and the second wall portion 62 of the barrel 60. With this configuration, the first wall portion 61 and the second wall portion 62 absorb the uneven shape of the outer surface of the barrel 60, allowing the tool housing 50 to be configured with a smooth cylindrical shape. Furthermore, since the recess 52 accommodates the first wall portion 61 and the second wall portion 62, it is possible to restrict rotation of the tool housing 50 relative to the barrel 60. Therefore, it is possible to provide a die grinder 100 in which the tool housing 50 is easy to grip and has high operability.

[0093] 24, in the die grinder 100 of this embodiment, a motor electric wire path 306 is provided inside the motor housing 30 for guiding the electric wire 12, which is led from the through hole 68 of the barrel 60 into the housing HS, to the handle housing 40. This will be described in detail below.

[0094] As shown in FIG. 24 , a support wall 304 is formed below the motor housing 30 to support the motor main body 21 below the motor main body 21. A motor electric cable path 306 is a space defined between the support wall 304 and an outer wall 302 of the motor housing 30. Providing the motor electric cable path 306 allows the electric wires 12 from the tool housing 50 to pass through to the handle housing 40 at the rear of the housing HS while preventing contact with various parts inside the motor housing 30. In addition, it is possible to prevent or prevent the motor housing 30 from becoming large in the left-right direction.

[0095] In the die grinder 100 of this embodiment, a portion of the opening 322 provided in the motor bearing retainer 32 and functioning as a ventilation hole also serves as a wiring path for the electric wire 12. Specifically, as shown in FIG. 25 , the front end 304E of the support wall portion 304 extends to an opening 322B, which is disposed below the drive shaft TX, among the multiple openings 322 provided in the motor bearing retainer 32. Also, as shown in FIG. 24 , the through hole 68 formed in the motor housing 30 is disposed so as to face the front end of the motor electric wire 306 via the opening 322B. As described above, the barrel electric wire 63, the opening 322, and the motor electric wire 306 are configured to communicate with each other.

[0096] According to the die grinder 100 of this embodiment, by utilizing part of the ventilation holes of the motor bearing retainer 32 as a wiring path for the electric wires 12, it is possible to suppress or prevent the motor housing 30 from becoming larger in the radial direction, compared to forming a wiring path that bypasses the motor bearing retainer 32. For example, it is possible to suppress the outer shape of the motor housing 30 from protruding downward. Furthermore, by utilizing the openings 322 provided in the motor bearing retainer 32 as ventilation holes, it is possible to form a wiring path for the electric wires 12 that connects the tool housing 50 and the motor housing 30 without changing the design of the motor bearing retainer 32.

[0097] As described above, according to the die grinder 100 of this embodiment, the light-emitting unit 80 includes at least a first light-emitting unit 81 disposed in the upper right quadrant with respect to the drive axis TX and a second light-emitting unit 82 disposed in the upper left quadrant with respect to the drive axis TX. According to the die grinder 100 of this embodiment, the light directed forward from the tool bit TT can be uniformly diffused in the left-right direction on the workpiece WS below, and the area of ​​high illuminance can be widened. Therefore, the visibility of the workpiece WS below the tool bit TT can be improved.

[0098] In the die grinder 100 of this embodiment, the light-emitting unit 80 further includes a third light-emitting unit 83 disposed directly below the drive shaft TX. By disposing the light-emitting unit 80 directly below the drive shaft TX, it is possible to improve the illuminance on the workpiece WS below while suppressing the upward irradiation of light LT by the light-emitting unit 80. Therefore, the light-emitting unit 80 can be suitably disposed so as to improve the visibility of the workpiece WS while suppressing discomfort to the user.

[0099] According to the die grinder 100 of this embodiment, the light-emitting unit 80 is disposed in a region radially inward of the intermediate circle 72CL on the front surface 72. According to the die grinder 100 of this embodiment, the range of light irradiation on the workpiece WS can be made wider than when the light-emitting unit 80 is disposed in a region radially outward of the intermediate circle 72CL.

[0100] The die grinder 100 of this embodiment is provided with a protective member 86 in front of the light-emitting unit 80 that transmits light LT from the light-emitting unit 80. The protective member 86 is provided with a base portion 862 that extends rearward from the main body portion 860, and a claw portion 864 that is provided at the tip of the base portion 862 and configured to fit into a recessed portion 662 that is provided in a member that is disposed rearward of the circuit board 70. By using a snap fit to attach and detach the lighting device DL, the lighting device DL can be easily attached and detached, and repair of the lighting device DL can be easily performed.

[0101] According to the die grinder 100 of this embodiment, the recess 662 is provided on the outer surface of the bearing retainer 66. The circuit board 70 and the two or more light emitting units 80 are held between the bearing retainer 66 and the protective member 86, with the claws 864 engaged with the recesses 662. Compared to a case where the protective member 86 engages with the outer peripheral surface of the barrel 60, the radial increase in size of the protective member 86 can be suppressed, and the radial increase in size of the tool housing 50 can be suppressed or prevented.

[0102] According to the die grinder 100 of this embodiment, the barrel 60 includes a first wall portion 61 and a second wall portion 62 that protrude from the outer surface of the barrel 60. The electric wires 12 connected to the circuit board 70 are arranged in a barrel electric wire path 63 defined by the first wall portion 61 and the second wall portion 62. The first wall portion 61 and the second wall portion 62 reinforce the barrel 60, and the electric wires 12 can be arranged around the barrel 60 efficiently.

[0103] According to the die grinder 100 of this embodiment, a first protrusion 611 protruding toward the second wall portion 62 is provided on a surface of the first wall portion 61 facing the second wall portion 62, and a second protrusion 622 protruding toward the first wall portion 61 is provided on a surface of the second wall portion 62 facing the first wall portion 61. The electric wire 12 can be arranged in the barrel electric wireway 63 in a state where it is curved in the left-right direction. Therefore, it is possible to more reliably suppress or prevent the electric wire 12 from falling off the barrel electric wireway 63.

[0104] According to the die grinder 100 of this embodiment, the inner surface of the tool housing 50 is provided with a recess 662 capable of accommodating the first wall portion 61 and the second wall portion 62. The first wall portion 61 and the second wall portion 62 absorb the uneven shape of the outer surface of the barrel 60, allowing the tool housing 50 to be configured with a smooth cylindrical shape. Furthermore, accommodating the first wall portion 61 and the second wall portion 62 in the recess 52 makes it possible to restrict rotation of the tool housing 50 relative to the barrel 60. Therefore, it is possible to provide a die grinder 100 in which the tool housing 50 is easy to grip and has high operability.

[0105] According to the die grinder 100 of this embodiment, a motor electric wire path 306 for passing the electric wire 12 is provided in the motor housing 30 between the support wall portion 304 and the outer wall 302. The electric wire 12 from the tool housing 50 can be passed through to the handle housing 40 at the rear of the housing HS while preventing contact with each part inside the motor housing 30.

[0106] According to the die grinder 100 of this embodiment, the barrel electric wire passage 63, the opening 322, and the motor electric wire passage 306 are configured to communicate with one another. Compared to forming a wiring path that bypasses the motor bearing retainer 32, this can suppress or prevent the motor housing 30 from becoming larger in the radial direction. For example, it can suppress the outer shape of the motor housing 30 from protruding downward. Furthermore, by utilizing the opening 322 provided in the motor bearing retainer 32 as a ventilation hole, it is possible to form a wiring path for the electric wire 12 connecting the tool housing 50 and the motor housing 30 without changing the design of the motor bearing retainer 32.

[0107] According to the die grinder 100 of this embodiment, the controller 10 is disposed at a position where the drive shaft TX passes, which allows the radial size of the housing HS to be reduced.

[0108] According to the die grinder 100 of this embodiment, the motor rotation shaft MX and the drive shaft TX are configured to be coaxial, which allows the radial size of the housing HS to be reduced.

[0109] B. Other Embodiments: (B1) In the die grinder 100 of the first embodiment described above, an example was given in which the downward direction was defined as the direction perpendicular to the drive axis TX, that is, the direction from the cross-sectional center HX of the gripping portion 42 toward the drive axis TX. In contrast, the upward direction or the downward direction may be defined by the methods described in (B1.1) to (B1.5) below.

[0110] (B1.1) As shown in Figure 26, the attachment / detachment direction DB of the battery BT in the battery mounting portion 46 may be defined as the up-down direction. In this case, the direction DD2 from the cross-sectional center HX of the grip portion 42 or the drive shaft TX toward the handle recess 44 along the attachment / detachment direction DB is defined as the down-down direction.

[0111] (B1.2) Figure 27 shows the position of the tip TP where the curvature is greatest in the outer shape HF of the cross-sectional shape of the grip portion 42. The direction DD3 from the drive axis TX toward the tip TP may be defined as the downward direction. Alternatively, the direction from the center HX of the cross section of the grip portion 42 toward the tip TP instead of the drive axis TX may be defined as the downward direction. Note that Figure 27 shows a cross section at the same position as Figure 3. By positioning the tip TP, where the curvature is greatest, downward, the grip portion 42 can be shaped to be easy for the user to grip.

[0112] (B1.3) As shown in Figure 28, among directions perpendicular to the drive axis TX, the direction DU1 from the drive axis TX toward the operating unit SW1 may be defined as the upward direction. Alternatively, instead of the drive axis TX, the direction from the cross-sectional center HX of the grip 42 toward the operating unit SW1 may be defined as the upward direction. By positioning the operating unit SW1 at the top, the user can easily operate it while still gripping the grip 42.

[0113] 29 and 30, instead of or in addition to the operation unit SW1 shown in the first embodiment, operation units SW2 and SW3 for switching the motor 20 on and off may be provided on the side of the housing HS. By locating the operation units SW2 and SW3 on the side, the user can easily operate them while still gripping the handle 42.

[0114] In this case, the directions DS1 and DS2 from the cross-sectional center HX of the gripping part 42 toward the operating parts SW2 and SW3 may be defined as the rightward or leftward direction. Alternatively, the directions from the drive shaft TX toward the operating parts SW2 and SW3 instead of the cross-sectional center HX of the gripping part 42 may be defined as the rightward or leftward direction.

[0115] (B1.5) As shown in Figure 31, a paddle switch SW4 may be provided on the housing HS instead of or in addition to the operating unit SW1 shown in the first embodiment. The paddle switch SW4 is a switch that turns on the motor 20 by sliding or pushing it, and turns off the motor 20 when the operation of the paddle switch SW4 is released. In this case, the direction DD4 from the drive shaft TX toward the paddle switch SW4 may be defined as the downward direction. Instead of the drive shaft TX, the direction from the cross-sectional center HX of the grip portion 42 toward the paddle switch SW4 may be defined as the downward direction.

[0116] (B2) In the die grinder 100 of the first embodiment described above, an example was shown in which the light-emitting unit 80 included the first light-emitting unit 81 arranged in the first quadrant Q1, the second light-emitting unit 82 arranged in the second quadrant Q2, and the third light-emitting unit 83 arranged directly below the drive axis TX. In contrast, the die grinder 100 may not include the third light-emitting unit 83, and may include only the first light-emitting unit 81 arranged in the first quadrant Q1 and the second light-emitting unit 82 arranged in the second quadrant Q2. Even in this case, the forward illumination range of the light emitted by the first light-emitting unit 81 and the second light-emitting unit 82 arranged to the sides of the drive axis TX can be widened, thereby improving the visibility of the workpiece WS.

[0117] Furthermore, four or more light-emitting units 80 may be provided, provided that the first light-emitting unit 81 is disposed in the first quadrant Q1 and the second light-emitting unit 82 is disposed in the second quadrant Q2. Increasing the number of light-emitting units 80 can further improve the illuminance of the workpiece WS. In the example shown in FIG. 32, six light-emitting units 80 are provided. Specifically, in addition to the first light-emitting unit 81, the second light-emitting unit 82, and the third light-emitting unit 83, a fourth light-emitting unit 84, a fifth light-emitting unit 85, and a sixth light-emitting unit 87 are also provided. In this case, it is preferable that each light-emitting unit 80, including the fourth light-emitting unit 84, the fifth light-emitting unit 85, and the protective member 86, be positioned inside the intermediate circle 72CL. This configuration can improve the illumination range of each light-emitting unit 80.

[0118] (B3) In each of the above embodiments, the die grinder 100 is provided with a battery attachment section 46 configured to allow the battery BT to be attached and detached to the rear end of the handle housing 40. However, instead of the battery attachment section 46, a power cord connectable to an AC power source, such as an external commercial power source, may be provided. In this case, power supplied from the commercial power source is supplied to the motor 20 via electric wires and a connector wired inside the housing HS. The motor 20 is driven by this AC power. In this case, an AC motor may be used as the motor 20 instead of a DC motor.

[0119] The present disclosure is not limited to the above-described embodiments and can be realized in various configurations without departing from the spirit thereof. For example, the technical features in the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention section can be appropriately replaced or combined to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted. [Explanation of symbols]

[0120] 10...controller, 12...electric wire, 14...switch, 16...connector, 20...motor, 21...motor body, 22...motor shaft, 26...fan, 30...motor housing, 32...motor bearing retainer, 40...handle housing, 42...gripping portion, 44...handle recess, 46...battery mounting portion, 50...tool housing, 52...recess, 54...protrusion, 56...opening, 60...barrel, 60R...rib, 61...first Wall portion, 62...second wall portion, 63...barrel electric wireway, 66...bearing retainer, 68...through hole, 70, 70R, 70R2...circuit board, 72...front surface, 72CL...middle circle, 72R1, 72R2...periphery, 80...light-emitting portion, 81, 81R, 81R2...first light-emitting portion, 82, 82R, 82R2...second light-emitting portion, 83, 83R, 83R2...third light-emitting portion, 84...fourth light-emitting portion, 85...fifth light-emitting portion, 86...protective member, 87...sixth light-emitting portion, 90... Spindle, 92...collet cone, 94...collet nut, 100, 100R, 100R2...die grinder, 201...front motor bearing, 202...rear motor bearing, 204...coupling, 302...outer wall, 304...support wall portion, 304E...front end, 306...motor electrical wiring, 322, 322B...opening, 601...front spindle bearing, 602...rear spindle bearing, 611...first protrusion, 62 2...second protrusion, 662...recess, 860...main body, 862...base, 864...claw, BT...battery, DL...lighting device, HS...housing, HR1, HRR1, HRR3, HZ1, HZ3...horizontal surface, LR1, LR3, LRR1, LRR3...light, MX...motor rotating shaft, SD...shadow, SW1, SW2, SW3...operation part, SW4...paddle switch, TP...tip, TS...side, TT...tip tool, TX...drive shaft, WS...machined object

Claims

1. A die grinder, a motor that is rotated by electricity and has a motor shaft that extends in the front-to-rear direction of the die grinder; a spindle that is driven to rotate about a drive shaft by rotation of the motor shaft; a circuit board that is passed through by the spindle; a housing that houses the motor, the spindle and the circuit board being disposed on a front side of the motor; an operation unit for switching the motor on and off; two or more light emitting units attached to the front surface of the circuit board; Among directions perpendicular to the drive shaft, a direction from the center of a cross section of the housing or the drive shaft toward the operation unit is defined as an upward direction, When the front surface is divided into four quadrants by a vertical direction passing through the drive shaft and a horizontal direction passing through the drive shaft and perpendicular to the vertical direction, the two or more light-emitting units include a first light-emitting unit disposed in at least the upper right quadrant with respect to the drive shaft among the four quadrants, and a second light-emitting unit disposed in the upper left quadrant with respect to the drive shaft; Die grinder.

2. A die grinder, a motor driven by electricity; a spindle that is driven to rotate around a drive shaft that defines a front-rear direction of the die grinder by the power of the motor; a housing including: a motor housing that houses the motor; a handle housing that is connected to a rear side of the motor housing and includes a grip portion configured to be gripped by a user; and a tool housing in which the spindle and a circuit board are disposed; two or more light emitting units attached to the front surface of the circuit board; Among directions perpendicular to the drive shaft, a direction from the center of a cross section of the grip portion toward the drive shaft is defined as a downward direction, When the front surface is divided into four quadrants by a vertical direction passing through the drive shaft and a horizontal direction passing through the drive shaft and perpendicular to the vertical direction, the two or more light-emitting units include a first light-emitting unit disposed in at least the upper right quadrant with respect to the drive shaft among the four quadrants, and a second light-emitting unit disposed in the upper left quadrant with respect to the drive shaft; Die grinder.

3. A die grinder, a motor driven by power supplied from a battery; a spindle that is driven to rotate around a drive shaft that defines a front-rear direction of the die grinder by the power of the motor; a housing including: a motor housing that houses the motor; a handle housing that is connected to a rear side of the motor housing and includes a grip portion configured to be gripped by a user; and a tool housing in which the spindle and a circuit board are disposed; two or more light emitting units attached to the front surface of the circuit board; a battery mounting portion into which the battery can be attached and detached along an attachment and detachment direction that intersects with the drive shaft, the handle housing includes a handle recess in which an outer surface of the handle housing is recessed relative to an outer surface of the motor housing; a downward direction is defined as a direction from the drive shaft toward the handle recess along the attachment / detachment direction, When the front surface is divided into four quadrants by a vertical direction passing through the drive shaft and a horizontal direction passing through the drive shaft and perpendicular to the vertical direction, the two or more light-emitting units include a first light-emitting unit disposed in at least the upper right quadrant with respect to the drive shaft among the four quadrants, and a second light-emitting unit disposed in the upper left quadrant with respect to the drive shaft; Die grinder.

4. A die grinder, a motor driven by electricity; a spindle that is driven to rotate around a drive shaft that defines a front-rear direction of the die grinder by the power of the motor; a housing including: a motor housing that houses the motor; a handle housing that is connected to a rear side of the motor housing and includes a grip portion configured to be gripped by a user; and a tool housing in which the spindle and a circuit board are disposed; two or more light emitting units attached to the front surface of the circuit board; a position where the curvature of the cross-sectional shape of the gripping portion is maximum is defined as a tip end portion, and a direction from the center of the cross-section of the gripping portion or the drive shaft toward the tip end portion is defined as a downward direction; When the front surface is divided into four quadrants by a vertical direction passing through the drive shaft and a horizontal direction passing through the drive shaft and perpendicular to the vertical direction, the two or more light-emitting units include a first light-emitting unit disposed in at least the upper right quadrant with respect to the drive shaft among the four quadrants, and a second light-emitting unit disposed in the upper left quadrant with respect to the drive shaft; Die grinder.

5. A die grinder, a motor driven by electricity; a spindle that is driven to rotate around a drive shaft that defines a front-rear direction of the die grinder by the power of the motor; a housing including: a motor housing that houses the motor; a handle housing that is connected to a rear side of the motor housing and includes a grip portion configured to be gripped by a user; and a tool housing in which the spindle and a circuit board are disposed; two or more light emitting units attached to the front surface of the circuit board; an operation unit provided in the housing for switching the motor on and off, Among directions perpendicular to the drive shaft, a direction from the center of a cross section of the grip portion or the drive shaft toward the operation portion is defined as an upward direction; When the front surface is divided into four quadrants by a vertical direction passing through the drive shaft and a horizontal direction passing through the drive shaft and perpendicular to the vertical direction, the two or more light-emitting units include a first light-emitting unit disposed in at least the upper right quadrant with respect to the drive shaft among the four quadrants, and a second light-emitting unit disposed in the upper left quadrant with respect to the drive shaft; Die grinder.

6. A die grinder, a motor driven by electricity; a spindle that is driven to rotate around a drive shaft that defines a front-rear direction of the die grinder by the power of the motor; a housing including: a motor housing that houses the motor; a handle housing that is connected to a rear side of the motor housing and includes a grip portion configured to be gripped by a user; and a tool housing in which the spindle and a circuit board are disposed; two or more light emitting units attached to the front surface of the circuit board; an operation unit provided in the housing for switching the motor on and off, Among directions perpendicular to the drive shaft, a direction from the center of a cross section of the grip portion or the drive shaft toward the operation portion is defined as a rightward direction or a leftward direction, When the front surface is divided into four quadrants by a vertical direction that is perpendicular to the left-right direction and passes through the drive shaft, and a left-right direction that passes through the drive shaft, the two or more light-emitting units include a first light-emitting unit disposed in at least the upper right quadrant with respect to the drive shaft among the four quadrants, and a second light-emitting unit disposed in the upper left quadrant with respect to the drive shaft; Die grinder.

7. A die grinder, a motor driven by electricity; a spindle that is driven to rotate around a drive shaft that defines a front-rear direction of the die grinder by the power of the motor; a housing including: a motor housing that houses the motor; a handle housing that is connected to a rear side of the motor housing and includes a grip portion configured to be gripped by a user; and a tool housing in which the spindle and a circuit board are disposed; two or more light emitting units attached to the front surface of the circuit board; a paddle switch provided on the grip portion for switching the motor on and off; a direction from the center of a cross section of the grip portion toward the paddle switch is defined as a downward direction; When the front surface is divided into four quadrants by a vertical direction passing through the drive shaft and a horizontal direction passing through the drive shaft and perpendicular to the vertical direction, the two or more light-emitting units include a first light-emitting unit disposed in at least the upper right quadrant with respect to the drive shaft among the four quadrants, and a second light-emitting unit disposed in the upper left quadrant with respect to the drive shaft; Die grinder.

8. A die grinder according to any one of claims 1 to 7, The two or more light-emitting units further include a third light-emitting unit disposed on the front surface below the drive shaft. Die grinder.

9. A die grinder according to any one of claims 1 to 7, the front surface has a circular ring shape; When a circle connecting an intermediate position between an inner peripheral edge portion closer to the drive shaft and an outer peripheral edge portion of the two peripheral edge portions of the front surface is defined as an intermediate circle, the two or more light-emitting units are arranged on the front surface in an area inside the middle circle; Die grinder.

10. A die grinder according to any one of claims 1 to 7, Further, a protective member is provided in front of the light emitting unit and transmits light from the light emitting unit, The protective member is a main body that covers the light emitting unit; a base that extends rearward from the main body; and a claw that is provided at a tip of the base and configured to fit into a recess that is provided in a member that is located rearward of the circuit board. Die grinder.

11. 11. The die grinder according to claim 10, a spindle bearing that rotatably supports the spindle; a barrel that houses the spindle bearing; a bearing retainer disposed in front of the spindle bearing and fixed to the front end of the barrel; the recess is provided on an outer surface of the bearing retainer, the circuit board and the two or more light emitting units are held between the bearing retainer and the protective member with the claws and the recesses engaged with each other; Die grinder.

12. A die grinder according to any one of claims 1 to 7, a barrel that accommodates at least a portion of the spindle; the barrel includes a first wall portion and a second wall portion protruding from an outer surface of the barrel; an electric wire connected to the circuit board is disposed in a barrel electric wireway defined by the first wall portion and the second wall portion; Die grinder.

13. 13. The die grinder of claim 12, a first protrusion protruding toward the second wall portion is provided on a surface of the first wall portion facing the second wall portion; a second protrusion protruding toward the first wall portion is provided on a surface of the second wall portion facing the first wall portion; Die grinder.

14. 13. The die grinder of claim 12, the housing includes a tool housing in which the spindle and a circuit board are disposed; a recess capable of accommodating the first wall portion and the second wall portion is provided on an inner surface of the tool housing; Die grinder.

15. 13. The die grinder of claim 12, the housing includes a motor housing that houses the motor; the motor housing includes an outer wall portion and a support wall portion that supports the motor inside the motor housing, In the motor housing, a motor electric line path for passing the electric wires is provided between the support wall portion and the outer wall portion. Die grinder.

16. 16. The die grinder of claim 15, Furthermore, a fan for cooling the motor; a motor bearing provided in the housing between the motor and the spindle, the motor bearing rotatably supporting a motor shaft of the motor; a motor bearing retainer that supports the motor bearing, the motor bearing retainer has an opening through which the airflow delivered from the fan can pass; the barrel lineway, the opening, and the motor lineway are configured to communicate with each other. Die grinder.

17. A die grinder according to any one of claims 1 to 7, further comprising a controller configured to control operation of the die grinder; The controller is disposed at a position where the drive shaft passes. Die grinder.

18. A die grinder according to any one of claims 1 to 7, the motor includes a motor shaft that is driven to rotate about a motor rotation axis; The motor rotation shaft and the drive shaft are configured to be coaxial. Die grinder.

19. A die grinder according to any one of claims 1, 2, or 4 to 7, a battery for supplying power to the motor; a battery mounting section to which the battery can be attached and detached, Die grinder.

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