power tools

Abstract

To provide a power tool capable of appropriately detecting detection results related to a sub-handle that can be attached to the power tool. [Solution] The power tool comprises a motor, a housing, a handle, and a controller. The housing has a plurality of handle mounting sections. The handle extends in one direction and is detachably mounted on the plurality of handle mounting sections. The controller is configured to control the drive of the motor. The handle includes a body section and a shaft section. The body section includes a gripping section configured to be gripped by a user. The shaft section is configured to be positioned in a protruding position that extends from the body section toward the plurality of handle mounting sections. The housing includes a detection mechanism that includes a plurality of detection sections which are pressed by the shaft section positioned in the protruding position when the handle is mounted on the plurality of handle mounting sections. The detection mechanism outputs a signal to the controller as a result of the plurality of detection sections being pressed by the shaft section.

Description

Technical Field

[0001] The present disclosure relates to a power tool.

Background Art

[0002] Power tools to which a sub-handle can be attached to improve the operability of the power tool are known. For example, Patent Document 1 discloses a power tool to which a sub-handle including a capacitance detection unit can be attached. In this power tool, the capacitance detection unit detects a change in capacitance caused by a user gripping the sub-handle, so as to detect whether the sub-handle is gripped. The detection result of the capacitance detection unit is output as an electric signal from the capacitance detection unit of the sub-handle to the tool main body.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conventional art, in order to attach the sub-handle to the main body of the power tool, a connection terminal for electrically connecting the detection unit provided on the sub-handle and the tool main body may be provided at the connecting portion between the sub-handle and the tool main body. Therefore, in the conventional art, if a poor connection between the terminals occurs when connecting the sub-handle and the tool main body, it may not be possible to obtain an appropriate detection result.

[0005] One non-limiting object of the present disclosure is to provide a power tool capable of appropriately detecting a detection result related to a sub-handle that can be attached to the power tool.

Means for Solving the Problems

[0006] According to one non-limiting aspect of the present disclosure, a power tool is provided. The power tool comprises a motor, a housing, a handle, and a controller. The motor includes an output shaft that rotates about a motor rotation axis. The housing houses the motor and has a plurality of handle mounting sections. The handle extends in one direction and is detachably mounted on the plurality of handle mounting sections. The controller is configured to control the driving of the motor. The handle includes a body section and a shaft section. The body section includes a grip section configured to be gripped by a user. The shaft section is configured to be positioned to project outward from the body section toward the plurality of handle mounting sections. The housing includes a detection mechanism comprising a plurality of detection sections corresponding to the plurality of handle mounting sections, which are pressed by the shaft section positioned in the projecting position when the handle is mounted on the plurality of handle mounting sections. The detection mechanism outputs a signal to the controller as a result of the plurality of detection sections being pressed by the shaft section.

[0007] According to this embodiment of the power tool, no electrical connection terminals are provided in the handle mounting portion that connects the handle and the housing. Therefore, it is possible to suppress or prevent electrical connection failures when connecting the handle and the housing, and to appropriately detect information about the handle.

[0008] According to another non-limiting aspect of the present disclosure, a power tool is provided. The power tool comprises a housing and a handle. The housing has a plurality of handle mounting sections. The handle extends in one direction and is detachably mounted on the plurality of handle mounting sections. The handle includes a body and a locking mechanism. The body includes a gripping section configured to be gripped by a user. The locking mechanism is configured to be switchable between a locked state in which the handle is fixed as it is mounted on the plurality of handle mounting sections and an unlocked state in which the locked handle is detachable from the plurality of handle mounting sections. The locking mechanism comprises (i) an operating section configured to be switchable between a first position and a second position closer to the body than the first position, and (ii) a locking section. The locking section is configured to be positioned (i) in a mounting position in which the handle can be mounted on the plurality of handle mounting sections when the operating section is positioned in the second position, and (ii) in a locking position in which the handle mounted on the plurality of handle mounting sections is locked when the operating section is positioned in the first position.

[0009] According to this embodiment, the handle can be attached to and detached from the handle mounting part by a simple method of operating the control unit. Therefore, it is possible to provide a power tool in which the handle can be easily attached and detached. [Brief explanation of the drawing]

[0010] [Figure 1] A perspective view showing the outer casing of a grinder according to the first embodiment. [Figure 2] A front view showing the configuration of the front end of the grinder. [Figure 3] A cross-sectional view showing the III-III position as shown in Figure 2. [Figure 4] A perspective view showing the outline of the sub-handle. [Figure 5] An explanatory diagram showing the fixing mechanism provided on the sub-handle. [Figure 6] A cross-sectional view showing the VI-VI position as shown in Figure 5. [Figure 7] A perspective view showing the configuration of the handle mounting section. [Figure 8] A cross-sectional view showing the internal configuration of the sub-handle in a state where the operation unit is being operated. [Figure 9] A cross-sectional view showing the IX-IX position indicated in Figure 2. [Figure 10] A cross-sectional view showing the operation of the shaft portion when the grip lever is pressed. [Figure 11] A cross-sectional view showing the XI-XI position indicated in Figure 3. [Figure 12] A perspective view showing the external configuration of the detection unit. [Figure 13] An explanatory view showing the internal configuration of the detection unit. [Figure 14] An explanatory view showing the rear surface configuration of the detection unit. [Figure 15] A cross-sectional view showing the XV-XV position indicated in Figure 2. [Figure 16] An explanatory view showing the configuration of the electrode unit. [Figure 17] An explanatory view showing the configuration of the outer electrode. [Figure 18] An explanatory view showing the configuration of the inner electrode. [Figure 19] An explanatory view showing a state where the detection unit detects gripping of the sub-handle. [Figure 20] A cross-sectional view showing the configuration of a detection unit included in a grinder according to another embodiment. [Mode for Carrying Out the Invention]

[0011] In the following, representative and non-limiting specific examples of the present invention will be described in detail with reference to the drawings. This detailed description is merely intended to provide a person skilled in the art with details for implementing preferred examples of the present invention, and is not intended to limit the scope of the present invention. Furthermore, the additional features and inventions disclosed below may be used separately or in combination with other features and inventions to provide further improved apparatuses, methods of manufacturing the same, and methods of using the same.

[0012] Furthermore, the combinations of features and steps disclosed in the following detailed description are not essential for practicing the present invention in its broadest sense, and are described solely for the purpose of illustrating representative specific examples of the present invention. Further, various features of the representative specific examples described above and below, as well as various features of those recited in the independent and dependent claims, are not required to be combined exactly as the specific examples described herein or in the order listed, in order to provide additional and useful embodiments of the present invention.

[0013] All features described in the present specification and / or claims are intended to be disclosed individually and independently of each other, as limitations to the original disclosure of the application and the claimed specific matters, apart from the configuration of the features described in the embodiments and / or claims. Further, all recitations of numerical ranges and groups or collections are made with the intention of disclosing intermediate configurations thereof as limitations to the original disclosure of the application and the claimed specific matters.

[0014] In one non-limiting embodiment of the present disclosure, the handle may further comprise (i) a pressure detection unit provided on the grip portion, which is pressed when a user grips the grip portion, and (ii) a conversion mechanism that converts the motion of the pressed pressure detection unit into linear movement of the shaft portion. The shaft portion may be configured such that (i) when a user does not grip the grip portion, the shaft portion is disposed at a storage position where it is stored in the main body portion, and (ii) when a user grips the grip portion, the shaft portion is disposed at the projecting position by the pressure detection unit and the conversion mechanism. According to this embodiment, gripping of the handle can be detected without electrically connecting the handle and the housing. Accordingly, it is possible to prevent occurrence of poor electrical connection when the handle and the housing are coupled, and to properly detect gripping of the handle.

[0015] In addition to or in lieu of the above embodiments, the detection mechanism may further include (i) an inner electrode arranged to surround the motor rotation shaft, and (ii) an outer electrode arranged radially outward from the inner electrode and surrounding the inner electrode. The detection mechanism may output the signal to the controller due to at least a portion of the outer electrode, which is pressed by the shaft, being electrically connected to the inner electrode. According to this embodiment, the detection mechanism can be realized with a simple configuration using an inner electrode and an outer electrode.

[0016] In addition to or in lieu of the above embodiments, the outer electrode may include (i) a conductive outer body portion extending in the circumferential direction about the motor rotation axis, and (ii) an outer first elastic portion and an outer second elastic portion connected to the outer body portion, which are conductive and elastic. The outer first elastic portion and the outer second elastic portion may function as the plurality of detection portions and be pressed by the shaft portion and electrically connected to the inner electrode. According to this embodiment, by using a conductive elastic member in the detection section of the detection mechanism, the electrical connection and disconnection between the outer electrode and the inner electrode can be suitably switched, thereby improving the detection accuracy of the detection mechanism.

[0017] In addition to or in lieu of the above embodiments, the outer first elastic portion may be a long plate including (i) one end connected to the outer main body and (ii) the other end configured as a free end and pressed by the shaft portion. The width of the other end may be configured to be narrower than the width of the one end. The other end may be pressed by the shaft portion and electrically connected to the inner electrode. According to this embodiment, compared to the case where the width of the outer first elastic portion is uniform from one end to the other, it is possible to displace the outer first elastic portion significantly while suppressing or preventing damage to one end of the outer first elastic portion. Furthermore, the portion of the outer first elastic portion that is pressed can be brought into contact with the inner electrode with a small pressing force. Therefore, it becomes easier to obtain detection results related to the handle, and the detection accuracy of the detection mechanism can be improved.

[0018] In addition to or in lieu of the above embodiments, the inner electrode may include (i) a conductive inner body portion extending in the circumferential direction about the motor rotation axis, and (ii) a conductive and elastic inner first elastic portion and an inner second elastic portion connected to the inner body portion. The inner first elastic portion and the inner second elastic portion may be positioned corresponding to the outer first elastic portion and the outer second elastic portion, and may be electrically connected to the outer first elastic portion and the outer second elastic portion which are pressed by the shaft portion. According to this embodiment, by using an elastic member in the area where the outer first elastic part and the outer second elastic part come into contact, the outer first elastic part and the outer second elastic part are less likely to separate from each other when pressed and come into contact with the inner first elastic part and the inner second elastic part. Therefore, chattering at the contact point between the outer first elastic part and the outer second elastic part and the inner first elastic part and the inner second elastic part can be suppressed or prevented.

[0019] In addition to or in lieu of the above embodiments, the inner first elastic portion may be a long plate including (i) one end connected to the inner main body and (ii) the other end configured as a free end and electrically connected to the outer first elastic portion which is pressed by the shaft. The width of the other end may be configured to be narrower than the width of the one end. The other end may be electrically connected to the outer electrode which is pressed by the shaft. According to this embodiment, compared to the case where the width of the inner first elastic portion is uniform from one end to the other, it is possible to displace the inner first elastic portion significantly while suppressing or preventing damage to one end of the inner first elastic portion. Furthermore, by making the elastic modulus of the other end of the inner first elastic portion lower than that of the one end, the inner first elastic portion can be bent with a relatively small pressing force. Therefore, the inner first elastic portion, when pressed by the outer first elastic portion, is less likely to separate from the outer first elastic portion, and chattering at the contact point between the outer first elastic portion and the inner first elastic portion can be suppressed or prevented.

[0020] In addition to the above embodiments, or in place of the above embodiments, a restricting portion may be provided between the outer electrode and the inner electrode to restrict contact between the outer electrode and the inner electrode. According to this embodiment, it is possible to suppress or prevent the malfunction of an electrical short circuit between the outer electrode and the inner electrode.

[0021] In addition to or in lieu of the above embodiments, the handle may further include a fixing mechanism capable of switching between a fixed state in which the handle attached to the plurality of handle mounting parts is fixed, and an unfixed state in which the fixed handle can be removed from the plurality of handle mounting parts. The fixing mechanism may include (i) an operating unit configured to be switchable between a first position and a second position closer to the main body than the first position, and (ii) a fixing unit. The fixing unit may be configured to be positioned such that (i) when the operating unit is positioned in the second position, it can be positioned in a mounting position in which the handle can be attached to the plurality of handle mounting parts, and (ii) when the operating unit is positioned in the first position, it can be positioned in a fixing position in which the handle attached to the plurality of handle mounting parts is fixed. According to this embodiment, the handle can be attached to and detached from the handle mounting part by a simple method of operating the control unit. Therefore, it is possible to provide a power tool in which the handle can be easily attached and detached.

[0022] In addition to or in lieu of the above embodiments, the fixing mechanism may further include a biasing member that biases the operating section from the second position toward the first position. According to this embodiment, the first and second positions of the operating section can be easily switched by utilizing the biasing force of the biasing member. Therefore, it is possible to provide a power tool with an easily detachable handle.

[0023] In addition to or in lieu of the above embodiments, the fixing mechanism may further include (i) an outer cylinder connected to the operating portion and configured to move parallel to the extending direction of the shaft portion, and (ii) an inner cylinder housed in the outer cylinder, having a holding portion that movably holds the fixing portion. The inner cylinder may be configured to accept the plurality of handle mounting portions inside the inner cylinder. The fixing portion may be configured such that (i) in the fixing position, its movement radially outward is restricted by the outer cylinder, and it protrudes into the inner cylinder and engages with the plurality of handle mounting portions received inside the inner cylinder, and (ii) in the mounting position, it retracts radially outward from the inner surface of the inner cylinder and does not engage with the plurality of handle mounting portions received inside the inner cylinder. According to this embodiment, the arrangement of the fixing part can be switched using a simple configuration with an inner cylinder and an outer cylinder.

[0024] In addition to or instead of the above embodiments, the shaft portion may be positioned radially inward from the outer cylinder and the inner cylinder, and configured to be movable relative to the outer cylinder and the inner cylinder. According to this embodiment, it is possible to provide a power tool with a rational structure in which the handle can be easily attached and detached and the shaft portion is efficiently arranged.

[0025] A. First Embodiment: A1. Configuration of power tools: With reference to the drawings, representative and non-limiting embodiments of this disclosure will be described in detail. In the following embodiments, a handheld electric disc grinder 100 (hereinafter also simply referred to as "grinder 100") is given as an example of the "power tool" according to this disclosure. Grinder 100 is an example of a rotary tool configured to perform processing operations such as grinding, polishing, and cutting on a workpiece by rotating a tip tool attached to a spindle. Note that the power tool is not limited to grinder 100, but may be various power tools equipped with a sub-handle 60, such as a hammer drill, driver drill, belt sander, or chainsaw.

[0026] As shown in Figures 1 and 2, the grinder 100 comprises a housing 10 including a gripping section 18 and a sub-handle 60 configured to be gripped by the user. The sub-handle 60 is detachably connected to a plurality of handle mounting sections 16 formed on the outer surface of the housing 10.

[0027] The housing 10 is a long, hollow body that forms the outer casing of the grinder 100. As shown in Figure 3, the housing 10 houses the motor 20, a spindle 30 operably connected to the output shaft 21 of the motor 20, and a detection unit 70.

[0028] As shown in Figure 3, the motor 20 is positioned such that the rotation axis RX of the output shaft 21 extends substantially parallel to the long axis of the housing 10 and the gripping portion 18. In this embodiment, the motor 20 is configured to operate on power supplied from a rechargeable battery 93 that is removablely mounted in the housing 10. However, the motor 20 may be configured to operate on power supplied from an external AC power source via a power cord extending from one end of the housing 10 in the long axis direction.

[0029] The spindle 30 is located within the other end of the housing 10 in the direction of its long axis. The spindle 30 is supported within the housing 10 so as to be rotatable around the drive axis TX. The drive axis TX intersects the rotation axis RX of the output shaft 21. In this embodiment, the drive axis TX is perpendicular to the rotation axis RX. For this reason, the grinder is sometimes also called an angle grinder.

[0030] One axial end of the spindle 30 is exposed to the outside from the housing 10. A cutting tool 91 is detachably attached to one end of the spindle 30. Examples of cutting tools 91 that can be attached to the grinder 100 include grinding wheels, cutting wheels, blades, brushes, etc. The user selects the appropriate cutting tool 91 according to the desired work and attaches it to the grinder 100. The spindle 30 rotates around the drive axis TX by receiving power from the motor 20. As the cutting tool 91 rotates in accordance with the rotation of the spindle 30, the grinder 100 becomes capable of machining work on the workpiece. Depending on the type of cutting tool 91, the grinder 100 can perform machining work such as grinding, polishing, and cutting on the workpiece. The cutting tool 91 is partially covered by a wheel cover 92 attached to the housing 10.

[0031] For the sake of explanation, the direction in which the drive axis TX extends is defined as the vertical direction of the grinder 100. In the vertical direction, one end of the spindle 30 to which the tip tool 91 is attached is defined as the lower side of the grinder 100, and the opposite end is defined as the upper side of the grinder 100. The direction in which the rotation axis RX of the output shaft 21 extends is defined as the front-rear direction of the grinder 100. In the front-rear direction, the side where the spindle 30 is located is defined as the front side of the grinder 100, and the opposite side is defined as the rear side of the grinder 100. The direction perpendicular to the vertical and front-rear directions is defined as the left-right direction of the grinder 100.

[0032] As shown in Figure 1, the housing 10 includes a motor housing 11, a gear housing 15 connected to the front end of the motor housing 11, a gripping portion 18 connected to the rear end of the motor housing 11, and a controller housing 13 connected to the rear end of the gripping portion 18.

[0033] As shown in Figure 3, the controller housing 13 is formed in a cylindrical shape that widens towards the rear from the rear end of the gripping portion 18. In other words, the controller housing 13 is formed such that the outer shape of the cross-section perpendicular to the rotation axis RX increases towards the rear from the gripping portion 18. The upper part of the dial 95 is held at the upper end of the controller housing 13 with the upper portion exposed to the outside. The dial 95 is configured as an operating device for setting the rotation speed of the motor 20 steplessly by receiving rotational operation by the user.

[0034] The controller housing 13 houses the controller 94. The controller 94 includes a CPU as a processor that controls the drive of the motor 20, a memory device such as RAM and ROM, and a circuit board equipped with switching elements that operate based on control signals from the CPU. The controller 94 performs each function realized by the grinder 100 according to this embodiment by reading and executing a program stored in memory from the CPU.

[0035] In this embodiment, the rear side of the controller housing 13 is provided with a battery mounting portion 132 into which the battery 93 can be slidably engaged. The battery mounting portion 132 is provided with a power receiving terminal that can be electrically connected to the power supply terminal of the battery 93.

[0036] The motor housing 11 is a housing having a long cylindrical portion extending in the front-rear direction. As shown in Figure 3, the motor housing 11 houses the motor 20. The output shaft 21 of the motor 20 extends in the front-rear direction. The front and rear ends of the output shaft 21 are supported by bearings, respectively. The front end of the output shaft 21 of the motor 20 protrudes into the gear housing 15, and a drive bevel gear 22 is fixed to this portion.

[0037] As shown in Figure 3, the gear housing 15 houses the spindle 30. The spindle 30 is a long, roughly cylindrical shaft. The spindle 30 is positioned within the gear housing 15 so as to extend vertically and is supported by multiple bearings so as to be rotatable around the drive axis TX. A driven bevel gear 32, which meshes with the drive bevel gear 22 of the output shaft 21, is fixed to the upper part of the spindle 30.

[0038] The gripping portion 18 is formed in a cylindrical shape with a generally uniform diameter and extends linearly in the front-rear direction. The gripping portion 18 is configured to be gripped by the user and functions as a so-called main handle. The gripping portion 18 is formed to be thinner than the motor housing 11 and controller housing 13 to make it easier for the user to grip. As shown in Figure 3, a switch 19 is provided inside the gripping portion 18, and a paddle switch 14, which can be manually operated by the user, is provided at the lower end of the gripping portion 18.

[0039] Switch 19 is a so-called mechanical switch. Switch 19 is located behind the motor 20 within the housing 10. Switch 19 is switched on and off by the operation of the paddle switch 14. The motor 20 is driven while the gripping part 18 and the sub-handle 60 are gripping, and while switch 19 is turned on. Note that switch 19 may be composed of a microswitch.

[0040] The paddle switch 14 switches the on and off of the switch 19 located inside the gripping portion 18. Alternatively, the paddle switch 14 may be replaced with a switch knob that can be slid in the forward and backward directions, a trigger switch, or a snap switch.

[0041] The paddle switch 14 includes a pressing portion 142, a lock-off lever 144, and a coil spring 146. The paddle switch 14 is biased outward from the gripping portion 18 by the coil spring 146 and is normally positioned in a stop position where the motor 20 is stopped.

[0042] When the user presses the paddle switch 14 into the gripping part 18 against the biasing force of the coil spring 146, the paddle switch 14 is displaced to the starting position for starting the motor 20. In the starting position, the pressing part 142 pushes the plunger 192 of the switch 19, thereby switching the switch 19 to the ON position.

[0043] The lock-off lever 144 normally restricts the displacement of the paddle switch 14 to the activated position. The lock-off lever 144 is configured to be rotatable, and when rotated by the user's manual operation, displacement of the paddle switch 14 to the activated position is permitted.

[0044] The user attaches the tip tool 91 corresponding to the desired machining operation, grips the gripping part 18 and the sub-handle 60, and switches the paddle switch 14 to the ON position. This turns on the switch 19. The controller 94 starts driving the motor 20 in response to the switch 19 being turned on. In this embodiment of the grinder 100, as will be described later, the controller 94 allows the motor 20 to drive when it detects that the grip lever 624 of the sub-handle 60 is pressed and that the switch 19 is turned on.

[0045] When the motor 20 is driven, the rotation of the output shaft 21 is transmitted to the spindle 30, causing the spindle 30 to rotate. As a result, the tip tool 91 fixed to the spindle 30 is rotated in a predetermined direction. In this embodiment, the rotation direction of the spindle 30 is clockwise when viewed from above. The user can perform machining work with the grinder 100 by pressing the tip tool 91 against the workpiece. The controller 94 can also set the rotation speed of the motor 20 based on a resistance value set via the dial 95.

[0046] A2. Configuration of sub-handle 60: As shown in Figure 4, the sub-handle 60 extends in one direction and is configured to be grasped by the user. As shown in Figures 4 and 5, the sub-handle 60 comprises a main body 62, a shaft portion 64, and a fixing mechanism 50.

[0047] The main body 62 has a long, roughly cylindrical shape that extends in one direction. In this embodiment, the long axis of the main body 62 coincides with the central axis HX of the main body 62. "Central axis HX of the main body 62" means a straight line based on the center of the cross-sectional shape of the main body 62. "Cross-sectional shape of the main body 62" means the outer shape of the main body 62 in a cross section perpendicular to the direction of extension of the main body 62. "Center of the cross-sectional shape" includes the centroid or the center of gravity of the cross-sectional shape. In this embodiment, the center of gravity of the cross section of the main body 62 is defined as the center of the cross-sectional shape of the main body 62. For convenience, in the following description, the direction corresponding to the central axis HX is defined as the "axial direction DX" of the sub-handle 60. In the axial direction DX, the side to which the handle mounting portion 16 is attached is defined as the "inner axial direction X1," and the opposite side is defined as the "outer axial direction X2."

[0048] As shown in Figure 4, the main body 62 comprises a gripping portion 622, a grip lever 624, and a flange portion 626. The gripping portion 622 is the part that can be gripped by the user. The gripping portion 622 is configured to have a thickness (outer diameter), length, and shape that is easy for the user to grip. The grip lever 624 detects the state in which the user is gripping the gripping portion 622, as will be described later. The flange portion 626 is a part that is larger in diameter than the gripping portion 622. The flange portion 626 protects the user's hand when gripping the gripping portion 622.

[0049] As shown in Figure 6, the shaft portion 64 is a rod-shaped member extending in the axial direction DX. A pin 642 provided at the tip of the shaft portion 64 on the axially inner side X1 is configured to be able to contact a part of the detection unit 70 inside the housing 10. The detection unit 70 detects information about the sub-handle 60 by contacting the shaft portion 64. "Information about the sub-handle 60" means, for example, information such as (i) whether the sub-handle 60 is being held by a user, (ii) whether the sub-handle 60 is being attached to one of the multiple handle mounting portions 16, or (iii) which of the multiple handle mounting portions 16 the sub-handle 60 is being attached to. In this embodiment, the detection unit 70 acquires information on whether the sub-handle 60 is being held by a user. Hereinafter, this function of the detection unit 70 may also be called the "gripping detection function".

[0050] In this embodiment, the shaft portion 64 is operated by the grip lever 624, and the position of the shaft portion 64 is switched. Specifically, the arrangement of the shaft portion 64 is switched between a housing position in which it is housed in the main body 62 and a protruding position in which it protrudes from the main body 62 toward the handle mounting portion 16. The shaft portion 64 in the protruding position comes into contact with the detection unit 70 inside the housing 10. The detection unit 70 detects the gripping of the gripping portion 622 due to contact with the shaft portion 64.

[0051] As shown in Figure 4, the fixing mechanism 50 is connected to the sub-handle 60, and by attaching the fixing mechanism 50 to the handle mounting portion 16, the sub-handle 60 can be attached to the handle mounting portion 16. The fixing mechanism 50 also operates in response to user operation and can fix the sub-handle 60 attached to the handle mounting portion 16. The fixing mechanism 50 includes an operating portion 52, an outer cylinder 54, an inner cylinder 56, a fixing portion 58, and a recess 546. The recess 546 is formed at the tip of the fixing mechanism 50 on the axially inward X1 (more specifically, at the tip of the small diameter portion 544 of the outer cylinder 54 and the tip of the inner cylinder 56).

[0052] The operating section 52 and the outer cylinder 54 form the outer casing of the fixing mechanism 50. The operating section 52 is connected to the outer cylinder 54 and is a so-called flange with a larger diameter than the outer cylinder 54. The operating section 52 is configured to be switchable by manual operation by the user between a first position X1 axially inward and a second position X2 axially outward from the first position. Figures 4 to 6 show the sub-handle 60 with the operating section 52 in the first position.

[0053] When the operating unit 52 is positioned in the first position, the fixing mechanism 50 is switched to a fixed state in which the sub-handle 60 attached to the handle mounting part 16 can be fixed to the handle mounting part 16. When the operating unit 52 is positioned in the second position, the fixing mechanism 50 is switched to an unfixed state in which the sub-handle 60 fixed to the handle mounting part 16 can be removed from the handle mounting part 16 as the outer cylinder 54 moves outward in the axial direction X2. In this embodiment of the grinder 100, the fixing mechanism 50 is configured so that the sub-handle 60 cannot be attached to the handle mounting part 16 when the fixing mechanism 50 is in the fixed state.

[0054] The outer cylinder 54 has a large diameter portion 542, a small diameter portion 544 with a smaller outer diameter than the large diameter portion 542, and a first contact surface 540 connecting the large diameter portion 542 and the small diameter portion 544. The small diameter portion 544 has a substantially cylindrical shape and is positioned at the tip of the axially inward X1 of the sub-handle 60. As will be described later, the small diameter portion 544 functions as a first fitting portion that fits with a second fitting portion 162 formed on the handle mounting portion 16. As shown in Figure 6, a recess 545 is formed on the inner surface of the small diameter portion 544 at the tip of the axially inward X1 of the small diameter portion 544. The recess 545 is configured to accept a part of the fixing portion 58. The large diameter portion 542 is connected to the axially outward X2 of the small diameter portion 544 and has a substantially cylindrical shape with a larger diameter than the small diameter portion 544.

[0055] As shown in Figures 4 and 6, the inner cylinder 56 has a substantially cylindrical shape that extends in the axial direction DX. The inner cylinder 56 holds a fixing portion 58. When the operating portion 52 is positioned in the second position, the fixing portion 58 is positioned in a mounting position where a handle can be attached to the handle mounting portion 16, and when the operating portion 52 is positioned in the first position, it is positioned in a fixing position where handles attached to the multiple handle mounting portions 16 are fixed. At the tip of the innermost axial direction X1 of the inner cylinder 56, a third fitting portion 561 is defined on the inside of the inner cylinder 56 that can receive the fourth fitting portion 167, which will be described later.

[0056] In this embodiment, the fixing part 58 is a metal sphere (ball). As shown in Figure 6, the fixing part 58 is held by the holding part 560. The holding part 560 is a through hole that penetrates the inner cylinder 56 radially (thickness direction). The diameter of the opening formed on the inner surface 56W of the inner cylinder 56 by the holding part 560 is smaller than the diameter of the holding part 560. Also, the diameter of the fixing part 58 is configured to be larger than the thickness of the inner cylinder 56. With this configuration, the inner cylinder 56 can hold the fixing part 58 in the holding part 560 with the fixing part 58 protruding from the inner surface 56W toward the central axis HX.

[0057] As shown in Figure 6, a pin 55 is fixed to the large-diameter portion 542 on the axially outward side X2 from the operating portion 52. The pin 55 is a rod-shaped member positioned perpendicular to the central axis HX. The pin 55 is inserted through a through hole 564 formed in the inner cylinder 56. The through hole 564 restricts the movement direction of the pin 55 to a predetermined range in the axial direction DX. As a result, the outer cylinder 54 and the operating portion 52 can move relative to the inner cylinder 56 within a range of movement corresponding to the movement range of the pin 55.

[0058] The pin 55 is inserted through the biasing cylinder 57, and connects the outer cylinder 54 and the biasing cylinder 57 so that they can move integrally. The pin 55 is inserted through a through hole 644 formed in the shaft portion 64. Therefore, the operating portion 52, the outer cylinder 54, the pin 55, and the biasing cylinder 57 are configured to be movable relative to the inner cylinder 56 within the through hole 564 and relative to the shaft portion 64 within the through hole 644.

[0059] A3. Configuration of the handle mounting section 16: As shown in Figure 7, the housing 10 has a handle mounting portion 16 to which a sub-handle 60 can be attached. In this embodiment, the handle mounting portion 16 is formed on the outer surface of the housing 10 near the boundary between the motor housing 11 and the gear housing 15. The grinder 100 in this embodiment has three handle mounting portions 16 on the right, left, and top sides of the housing 10 (see Figure 11). As shown in Figure 1, a resin cap 160 is attached to the handle mounting portion 16 to which the sub-handle 60 is not attached. By attaching the cap 160, foreign matter such as dust cut by the grinder 100 can be prevented from entering the handle mounting portion 16.

[0060] In power tools such as the grinder 100, the orientation and position of the housing 10 when using the power tool may be switched depending on the type of tip tool 91, such as when the lower side of the housing 10 is positioned vertically downwards, or when the left side of the housing 10 is positioned vertically downwards. In cases where the orientation of the power tool can be switched by the user, it is preferable that the mounting position of the sub-handle 60 on the housing 10 can be changed from the viewpoint of improving user convenience. In the grinder 100 of this embodiment, the housing 10 is provided with multiple handle mounting parts 16, so that the mounting position of the sub-handle 60 can be easily changed.

[0061] In this embodiment, the three handle mounting sections 16 are provided on the right, left, and upper sides of the housing 10, respectively. In this embodiment, an example in which the sub-handle 60 is connected to the handle mounting section 16 provided on the left side of the housing 10 will be described. Note that the number of handle mounting sections 16 is not limited to three; it may be one or any number greater than or equal to three.

[0062] As shown in Figure 7, the handle mounting portion 16 includes a second contact surface 161, a second fitting portion 162, and a fourth fitting portion 167.

[0063] The second contact surface 161 is part of the outer surface of the housing 10. The second contact surface 161 contacts the first contact surface 540 of the sub-handle 60 when the sub-handle 60 is attached to the handle mounting portion 16.

[0064] The second fitting portion 162 is a recess formed in the second contact surface 161. As described above, the second fitting portion 162 is configured to fit with the small diameter portion 544, which is the first fitting portion.

[0065] The fourth fitting portion 167 is a projection formed approximately in the center of the bottom surface 162B of the second fitting portion 162. The fourth fitting portion 167 protrudes from the bottom surface 162B toward the sub-handle 60. The fourth fitting portion 167 is configured to be able to fit with the third fitting portion 561 of the fixing mechanism 50. The sub-handle 60 is mounted on the handle mounting portion 16 by fitting the second fitting portion 162 with the small diameter portion 544, and by fitting the fourth fitting portion 167 with the third fitting portion 561.

[0066] An insertion hole 168 is formed at the tip of the fourth fitting portion 167, which can receive the pin 642 of the sub-handle 60. In addition, a groove 164 extending in the circumferential direction is formed on the outer surface of the fourth fitting portion 167 around its central axis HX. The groove 164 is configured to receive the fixing portion 58 provided at the tip of the sub-handle 60, as will be described later. The inner cylinder 56 is locked to the fourth fitting portion 167 by the fitting of the groove 164 and the fixing portion 58. As a result, the sub-handle 60 mounted on the handle mounting portion 16 is fixed to the handle mounting portion 16.

[0067] In this embodiment, two protrusions 166 are formed on the bottom surface 162B of the second fitting portion 162. In this embodiment, the two protrusions 166 are the heads of bolts inserted through the bottom surface 162B. The two protrusions 166 are located radially outward of the fourth fitting portion 167. The two protrusions 166 are fitted into two recesses 546 formed at the axially inward X1 tip of the fixing mechanism 50, i.e., at the tip of the sub-handle 60. Therefore, the two recesses 546 and the two protrusions 166 are fitted around the fourth fitting portion 167, thereby restricting the rotation of the sub-handle 60 mounted on the handle mounting portion 16 around the fourth fitting portion 167.

[0068] A4. Installation and fixing method for sub-handle 60: Referring to Figures 8 and 9 along with Figure 6, a method for attaching the sub-handle 60 to the handle mounting section 16 and a method for fixing the sub-handle 60 to the handle mounting section 16 will be described. The fixing mechanism 50 switches the arrangement of the fixing section 58 by switching the operating section 52 between a first position and a second position. The sub-handle 60 is switched between a state in which it can be attached to and detached from the handle mounting section 16 and a state in which it can be fixed, by utilizing the arrangement of the fixing section 58.

[0069] The inner cylinder 56 is fixed inside the flange portion 626 by a locking portion 568. In other words, the inner cylinder 56 is immovable relative to the main body 62. Inside the inner cylinder 56, a biasing cylinder 57 is arranged so as to be movable relative to the inner cylinder 56.

[0070] As shown in Figure 6, when the operating part 52 is positioned in the first position, the tip of the outer cylinder 54 becomes substantially flush with the tip of the inner cylinder 56. At this time, the outer surface of the inner cylinder 56 is covered by the inner surface of the outer cylinder 54. Therefore, the fixing part 58 positioned in the holding part 560 is restricted from moving radially outward from the outer surface of the inner cylinder 56 by the inner surface of the outer cylinder 54. As a result, the fixing part 58 is held in a state where it protrudes radially inward from the inner surface 56W of the inner cylinder 56. At this time, in the fixed state of the fixing mechanism 50, the tip of the fourth fitting part 167 contacts the fixing part 58, thus restricting the entry of the fourth fitting part 167 into the third fitting part 561. Therefore, when the operating part 52 is positioned in the first position, the attachment of the sub-handle 60 to the handle mounting part 16 is restricted.

[0071] As shown in Figure 8, when the operating part 52 is moved axially outward X2, the operating part 52 is positioned in the second position. At this time, a recess 545 formed at the tip of the small diameter portion 544 of the outer cylinder 54 is positioned radially outward of the fixing part 58. Therefore, the fixing part 58 positioned in the holding part 560 can be retracted radially outward from the outer surface of the inner cylinder 56. At this time, the fourth fitting part 167 can be fitted into the third fitting part 561, and the fixing mechanism 50 is in a state where the sub-handle 60 can be attached to the handle mounting part 16, and the sub-handle 60 fixed to the handle mounting part 16 can be removed from the handle mounting part 16.

[0072] As shown in Figure 9, when the fourth fitting portion 167 is fitted into the third fitting portion 561, the groove 164 of the fourth fitting portion 167 is positioned radially inward of the fixing portion 58. In this state, when the operating portion 52 is moved axially inward X1, the operating portion 52 is returned to the first position. The fixing portion 58 is restricted from moving radially outward beyond the outer surface of the inner cylinder 56 by the inner surface of the outer cylinder 54, and is held in a state that protrudes radially inward beyond the inner surface 56W of the inner cylinder 56. At this time, the fixing portion 58 fits into the groove 164 of the fourth fitting portion 167, and the fixing mechanism 50 is locked to the handle mounting portion 16. In this way, when the sub-handle 60 is mounted on the handle mounting portion 16 and the operating portion 52 is positioned in the first position, the sub-handle 60 mounted on the handle mounting portion 16 becomes fixed in a state where it can be fixed to the handle mounting portion 16.

[0073] As shown in Figure 6, a support portion 574 is provided inside the main body 62 of the sub-handle 60. The support portion 574 is a so-called spring holder, and a spring 59 that can expand and contract along the axial direction DX is positioned there. The spring 59 biases the biasing cylinder 57 in the axial direction X1.

[0074] The biasing cylinder 57 is equipped with a flange 572 that protrudes radially outward from the rest of the biasing cylinder 57. The spring 59 biases the flange 572 away from the support portion 574. Therefore, as shown in Figure 6, the biasing cylinder 57 is positioned away from the support portion 574 by the biasing of the spring 59. Consequently, the operating portion 52 and the outer cylinder 54 are positioned at the first position, which is the furthest from the flange portion 626. That is, the operating portion 52 is normally positioned at the first position by the biasing of the spring 59. With this configuration, it is possible to easily switch between the first and second positions of the operating portion 52, and to switch between the fixed and unfixed states of the fixing mechanism 50.

[0075] A5. Configuration of the grip detection mechanism: The grinder 100 of this embodiment is configured to detect whether the sub-handle 60 attached to the handle mounting portion 16 is being gripped. Specifically, a detection unit 70 provided in the housing 10 detects when the grip portion 622 is gripped by the user and the grip lever 624 provided on the grip portion 622 is pressed. The detection unit 70 is pressed by the shaft portion 64 protruding from the sub-handle 60, and outputs a signal to the controller 94 due to the pressing of the grip lever 624. The controller 94 detects that the sub-handle 60 is being gripped based on the input signal.

[0076] As shown in Figures 4 and 6, the main body 62 of the sub-handle 60 includes two grip levers 624 and a conversion mechanism 68. The two grip levers 624 are provided on the gripping portion 622 of the sub-handle 60. The two grip levers 624 are connected to the shaft portion 64 via the conversion mechanism 68. In this embodiment, the grinder 100 has two conversion mechanisms 68 on the sub-handle 60, each corresponding to one of the two grip levers 624. Since the functions of the two conversion mechanisms 68 are the same, the following explanation will use only one of the conversion mechanisms 68.

[0077] As shown in Figures 6 and 10, the conversion mechanism 68 converts the operation of the grip lever 624 into linear movement of the shaft portion 64. In this embodiment, when at least one of the two grip levers 624 is pushed down toward the central axis HX, the conversion mechanism 68 moves the shaft portion 42 toward the axial inward X1, and the pin 642 protrudes from the tip of the fixing mechanism 50.

[0078] As shown in Figure 6, a lever shaft 620 is provided at the axially outer end 624E2 of the grip lever 624, and the axially inner end 624E1 is rotatable about the lever shaft 620. The grip lever 624 is biased radially outward by a spring 625 provided inside the main body 62. Therefore, under normal circumstances, the end 624E1 of the grip lever 624 protrudes radially outward from the outer surface of the gripping portion 622.

[0079] The axially inner end 624E1 of the grip lever 624 is connected to a conversion mechanism 68. In this embodiment, the conversion mechanism 68 employs a link mechanism, which is a type of power assist mechanism, so that the shaft portion 64 can be operated by pushing down the grip lever 624 with a relatively small force. The conversion mechanism 68 includes a first link 686, a second link 688, a first shaft 681, a second shaft 682, a third shaft 683, and a fourth shaft 684. The conversion mechanism 68 is connected to the shaft portion 64 via the fourth shaft 684. The second shaft 682 and the third shaft 683 are rotating shafts fixed inside the gripping portion 622.

[0080] The first shaft 681 is located at the axially inward end 624E1 of the grip lever 624 and moves together with the end 624E1. The end 624E1 is connected to the first link 686 via the first shaft 681. The first link 686 is an elongated member in the axial direction DX and is configured to rotate around the second shaft 682. The rotation of the first link 686 is transmitted to the second link 688.

[0081] The second link 688 is an elongated member that intersects the extending direction of the first link 686. The second link 688 is configured to rotate around the third shaft 683. A fourth shaft 684 is provided at the tip of the second link 688. The fourth shaft 684 is a pivot axis formed on the shaft portion 64 and moves in conjunction with the movement of the shaft portion 64.

[0082] When the user grasps the gripping portion 622 and pushes down the grip lever 624, the grip lever 624 rotates around the lever shaft 620. As shown by arrow A1 in Figure 6, when the end portion 624E1 of the grip lever 624 is pushed down toward the central axis HX, the first link 686 rotates around the second axis 682.

[0083] As shown by arrow A2 in Figure 6, when the first link 686 rotates around the second axis 682, the tip of the first link 686 comes into contact with the second link 688. Due to the contact with the first link 686, the second link 688 rotates around the third axis 683.

[0084] As shown by arrow A3 in Figure 6, when the second link 688 rotates about the third shaft 683, the fourth shaft 684 connected to the tip of the second link 688 moves axially inward X1 along the central axis HX. As a result, as shown in Figure 10, the pin 642 at the tip of the shaft portion 64 is positioned to protrude from the main body 62 toward the housing 10 (hereinafter also referred to as the "protruding position"). In this embodiment, the above operation can be achieved by operating either one of the two grip levers 624, or by operating both grip levers 624.

[0085] A6. Configuration of detection unit 70: As shown in Figure 11, the detection unit 70 is located radially inward of the three handle mounting portions 16. The detection unit 70 is positioned in a protruding position and is configured to detect the pin 642 of the shaft portion 64 that protrudes from the sub-handle 60. Note that the sub-handle 60 is not shown in Figure 11 for ease of understanding.

[0086] As shown in Figure 12, the detection unit 70 comprises a main body 72, a cover 74, a plurality of pressing parts 76, and a guide 78. A through hole 720 is formed approximately in the center of the main body 72, through which an output shaft 21 or the like can be inserted.

[0087] As shown in Figure 13, the main body 72 is made of an insulating material. Inside the main body 72, there is a space for housing the electrode unit 80. Specifically, inside the main body 72, there are two interconnected spaces: an electrode housing section 724 and a lead wire housing section 726.

[0088] The electrode housing section 724 extends circumferentially so as to surround the rotation axis RX. The outer electrode 82 and inner electrode 84 of the electrode unit 80 are housed in the electrode housing section 724.

[0089] The lead wire housing section 726 is defined below the electrode housing section 724. The electrode housing section 724 and the lead wire housing section 726 are in communication with each other. The first terminal 826 and the second terminal 846 of the electrode unit 80 are located in the lead wire housing section 726.

[0090] As shown in Figure 12, a cover 74 is provided on the front surface 72F of the main body 72. The electrode housing section 724 and the lead wire housing section 726 are sealed by the cover 74, preventing foreign matter from entering from the gear housing 15. Figure 13 shows the detection unit 70 with the cover 74 removed.

[0091] As shown in Figures 12 and 13, the multiple pressing portions 76 are resin plungers. The multiple pressing portions 76 are provided adjacent to the radially inward side of the multiple handle mounting portions 16. The multiple pressing portions 76 prevent foreign matter from entering the electrode housing portion 724 and lead wire housing portion 726 from outside the detection unit 70, such as the insertion hole 168.

[0092] Multiple pressing portions 76 are pressed by pins 642 positioned in a protruding position. In the grinder 100 of this embodiment, multiple pressing portions 76 are indirectly pressed by intermediate members 760 which are pressed by pins 642 positioned in a protruding position. Multiple pressing portions 76 may also be pressed directly by pins 642. The pressing portions 76 pressed by pins 642 press at least a portion of the outer electrode 82 of the electrode unit 80.

[0093] As shown in Figures 12 and 14, the guide 78 is provided on the back surface 72R of the main body 62. As shown in Figure 14, the guide 78 is formed in a cylindrical shape and guides the lead wire 83, which is located inside the main body 72, into the inside of the housing 10.

[0094] As shown in Figure 14, a resin cover 780 is provided on the back surface 72R of the main body 62, specifically in the portion connecting the guide 78 and the lead wire housing 726. The cover 780 prevents foreign objects from entering the lead wire housing 726 from the motor housing 11.

[0095] As shown in Figures 13 and 14, the cover 780 has a first through-hole 781 and a second through-hole 782. The first through-hole 781 is through which a first lead wire 831 is inserted to electrically connect the first terminal 826 to the controller 94. The second lead wire 832 is inserted through which the second terminal 846 is inserted to electrically connect the controller 94 to the second through-hole 782. The first lead wire 831 and the second lead wire 832 are led from the lead wire housing 726 to the outside of the detection unit 70 via the first through-hole 781 and the second through-hole 782, and then led to the motor housing 11 via the guide 78. In the following description, when the first lead wire 831 and the second lead wire 832 are not distinguished, they will simply be referred to as "lead wire 83".

[0096] As shown by lead wire 83A in Figure 15, lead wire 83, which is routed from inside the detection unit 70 through the cover 780 to the rear side of the detection unit 70, is placed in a through hole 112 formed at the lower end of the motor housing 11. As shown by lead wire 83B in Figure 15, lead wire 83, which is placed in the through hole 112, is routed around the motor 20 to a through hole 114 near the upper end of the motor housing 11. In this embodiment, the motor housing 11 is provided with a guide member that has a wiring path formed therein that bypasses the motor 20. By arranging the lead wire 83 in the wiring path, it is possible to prevent the lead wire 83, which is routed around the motor 20, from coming into contact with the motor 20.

[0097] The through-hole 114 extends from the inside of the motor housing 11 to the inside of the gripping portion 18. As shown by the lead wire 83C in Figure 15, the lead wire 83, which is led to the through-hole 114, is guided through the through-hole 114 into the inside of the gripping portion 18 and electrically connected to the controller 94 of the controller housing 13.

[0098] A7. Configuration of electrode unit 80: As shown in Figure 16, the electrode unit 80 detects that multiple pressing portions 76 are pressed by the pin 642 by utilizing the current flow between the electrodes. The electrode unit 80 includes an outer electrode 82 and an inner electrode 84.

[0099] As shown in Figure 16, the outer electrode 82 includes an outer body 820 and a first terminal 826. The outer body 820 is a metal plate extending in the circumferential direction. The first terminal 826 is connected to one end 82E of the outer body 820. The other end 82F is fixed to the electrode housing 724 to restrict the rotation of the outer electrode 82 relative to the body 72. In this embodiment, the outer body 820 has an outer first elastic portion 821, an outer second elastic portion 822, and an outer third elastic portion 823 formed thereon.

[0100] The inner electrode 84 is positioned radially inward of the outer electrode 82. The inner electrode 84 includes an inner body 840 and a second terminal 846. The inner body 840 is a metal plate extending in the circumferential direction. The front-to-back width of the inner body 840 is approximately the same as the front-to-back width of the outer body 820. The second terminal 846 is connected to one end 84E of the inner body 840. The other end 84F is fixed to the electrode housing 724 to restrict the rotation of the inner electrode 84 relative to the body 72. In this embodiment, the inner body 840 has an inner first elastic portion 841, an inner second elastic portion 842, and an inner third elastic portion 843 formed thereon.

[0101] As shown in Figure 13, the outer electrode 82 and the inner electrode 84 are fixed to the electrode housing portion 724 of the detection unit 70 in a state where they are separated from each other so as not to conduct electricity under normal circumstances. As shown in Figure 13, the electrode housing portion 724 has a first restricting portion 721 and a second restricting portion 722 formed thereon. The first restricting portion 721 and the second restricting portion 722 are formed between the outer electrode 82 and the inner electrode 84 in the electrode housing portion 724. The first restricting portion 721 and the second restricting portion 722 have the function of so-called spacers that restrict contact between the outer electrode 82 and the inner electrode 84. In addition, the first restricting portion 721 restricts the radially outward displacement of the inner first elastic portion 841, the inner second elastic portion 842, and the inner third elastic portion 843. By configuring it in this way, the inner first elastic portion 841, the inner second elastic portion 842, and the inner third elastic portion 843 come into contact with the outer electrode 82, thereby suppressing or preventing the malfunction of a short circuit between the outer electrode 82 and the inner electrode 84. Note that the first restricting portion 721 and the second restricting portion 722 have different widths (heights) in the front-rear direction. The second restricting portion 722 is configured to be lower than the first restricting portion 721 in order to avoid interference with the outer first elastic portion 821, the outer second elastic portion 822, and the outer third elastic portion 823.

[0102] As shown in Figure 13, when a part of the outer electrode 82 contacts a part of the inner electrode 84 via a pin 642 protruding from the sub-handle 60, the outer electrode 82 and the inner electrode 84 become electrically connected. In this embodiment, the outer first elastic portion 821 contacts the inner first elastic portion 841, thereby making the outer electrode 82 and the inner electrode 84 electrically connected.

[0103] As shown in Figures 16 and 17, the outer first elastic portion 821 is a long plate extending in the circumferential direction. More specifically, when the electrode unit 80 is viewed from the front, the outer first elastic portion 821 extends counterclockwise from one end 821E in the opening 828. The outer second elastic portion 822 and the outer third elastic portion 823 are configured similarly to the outer first elastic portion 821. Therefore, in the following explanation, the outer first elastic portion 821 will be used as an example, and the explanations of the outer second elastic portion 822 and the outer third elastic portion 823 will be omitted.

[0104] As shown in Figure 17, the outer first elastic portion 821 is provided in a circumferentially elongated opening 828 formed in the outer body 820. In this embodiment, the outer first elastic portion 821 is formed by cutting out a part of the outer body 820 and is formed integrally with the outer body 820. The outer first elastic portion 821 has a lower modulus of elasticity than the outer body 820 and is configured to be more flexible than the outer body 820. One end 821E of the outer first elastic portion 821 is connected to the outer body 820 and is electrically connected to the outer body 820. The other end 821F is a free end. Note that the outer first elastic portion 821 may be formed separately from the outer body 820, assuming that it is electrically connected to the outer body 820.

[0105] As shown in Figure 17, a projection 82P is formed at the other end 821F of the outer first elastic portion 821, projecting toward the inner electrode 84. The projection 82P is formed by bending a part of the other end 821F. The projection 82P functions as a contact that electrically connects the outer first elastic portion 821 to the inner first elastic portion 841 of the inner electrode 84.

[0106] As shown in Figures 16 and 18, the inner first elastic portion 841 is a long plate extending in the circumferential direction. More specifically, when the electrode unit 80 is viewed from the front, the inner first elastic portion 841 extends clockwise from one end 841E in the opening 848. The inner second elastic portion 842 and the inner third elastic portion 843 have the same function as the inner first elastic portion 841. Therefore, in the following explanation, the inner first elastic portion 841 will be used as an example, and the explanations of the inner second elastic portion 842 and the inner third elastic portion 843 will be omitted.

[0107] As shown in Figure 18, the inner first elastic portion 841 is provided in a circumferentially elongated opening 848 formed in the inner body 840. In this embodiment, the inner first elastic portion 841 is formed by cutting out a part of the inner body 840 and is formed integrally with the inner body 840. The inner first elastic portion 841 has a lower modulus of elasticity than the inner body 840 and is configured to be more flexible than the inner body 840. One end 841E of the inner first elastic portion 841 is connected to the inner body 840 and is electrically connected to the inner body 840. The other end 841F is a free end. Note that the inner first elastic portion 841 may be formed separately from the inner body 840, assuming that it is electrically connected to the inner body 840.

[0108] As shown in Figure 13, the outer first elastic portion 821 is positioned to correspond to the leftmost of the multiple pressing portions 76. Also, as shown in Figure 16, the outer first elastic portion 821 is positioned to correspond to the inner first elastic portion 841 of the inner electrode 84. In other words, the left pressing portion 76, the outer first elastic portion 821, and the inner first elastic portion 841 are arranged in this order radially inward.

[0109] The outer first elastic portion 821 is normally configured to be substantially flush with the outer body 820. When the left pressing portion 76 is pressed by the pin 642 of the sub-handle 60, the pressing portion 76 presses against the outer first elastic portion 821. The protruding portion 82P of the pressed outer first elastic portion 821 moves toward the inner electrode 84 and makes contact with the inner first elastic portion 841. As a result, the outer electrode 82 and the inner electrode 84 are electrically connected.

[0110] As shown in Figure 17, in the outer first elastic portion 821, the width OW1 of the other end 821F in the front-rear direction is configured to be narrower than the width OW2 of the one end 821E in the front-rear direction. In other words, the width of the outer first elastic portion 821 is configured to gradually decrease towards the tip.

[0111] Here, for example, if the width OW1 of the other end 821F and the width OW2 of the one end 821E are the same, that is, if the width of the outer first elastic portion 821 is uniform from one end 821E to the other end 821F, the displacement of the outer first elastic portion 821 at one end 821E tends to be greater than the displacement of the outer first elastic portion 821 near the other end 821F that is being pressed. As a result, stress tends to concentrate at one end 821E of the outer first elastic portion 821, which may make the one end 821E more prone to damage. In contrast, in this embodiment, the width of the outer first elastic portion 821 is gradually reduced towards the tip. In other words, when the other end 821F is pressed, the displacement of the outer first elastic portion 821 at the other end 821F and the displacement of the outer first elastic portion 821 at one end 821E are configured to be approximately the same. As a result, the outer first elastic portion 821 can be displaced approximately uniformly overall. Therefore, according to this embodiment, the outer first elastic portion 821 can be displaced more significantly while suppressing or preventing damage to one end 821E of the outer first elastic portion 821, compared to the case where the width of the outer first elastic portion 821 is uniformly configured from one end 821E to the other end 821F.

[0112] Furthermore, by configuring the elastic modulus of the other end 821F to be lower than that of the one end 821E, the outer first elastic portion 821 can be bent with a relatively small pressing force. As a result, the outer first elastic portion 821 can be brought into contact with the inner first elastic portion 841 with a relatively small pressing force. Consequently, the detection unit 70 can more easily detect that the pin 642 is in a protruding position, thereby improving the detection accuracy of the detection unit 70.

[0113] As shown in Figure 18, in the inner first elastic portion 841, the width IW1 of the other end 841F in the front-rear direction is configured to be narrower than the width IW2 of the one end 841E in the front-rear direction. In other words, the width of the inner first elastic portion 841 is configured to gradually decrease towards the tip. In other words, the displacement of the inner first elastic portion 841 at the other end 841F and the displacement of the inner first elastic portion 841 at the one end 841E are configured to be approximately the same. Therefore, the inner first elastic portion 841 can be displaced approximately uniformly overall. Accordingly, according to this embodiment, the inner first elastic portion 841 can be displaced more significantly while suppressing or preventing damage to the one end 841E of the inner first elastic portion 841, compared to the case where the width of the inner first elastic portion 841 is configured to be uniform from one end 841E to the other end 841F.

[0114] Furthermore, by configuring the elastic modulus of the other end 841F to be lower than that of the one end 841E, the inner first elastic portion 841 can be bent with a relatively small pressing force. Therefore, when the outer first elastic portion 821 is pressed and comes into contact with the inner first elastic portion 841, the outer first elastic portion 821 and the inner first elastic portion 841 are less likely to separate. Consequently, chattering at the contact point between the outer first elastic portion 821 and the inner first elastic portion 841 can be suppressed or prevented.

[0115] In the grinder 100 of this embodiment, the extending direction of the outer first elastic portion 821 and the extending direction of the inner first elastic portion 841 are configured to be opposite to each other. That is, the vicinity of one end 841E of the inner first elastic portion 841 and the outer first elastic portion 821 are arranged so as not to overlap with each other in the radial direction. A first restricting portion 721 is arranged near one end 841E of the inner first elastic portion 841. With this configuration, the radial inward displacement of the outer first elastic portion 821 is not restricted by the first restricting portion 721, and only the radial outward displacement of the inner first elastic portion 841 can be restricted by the first restricting portion 721.

[0116] As shown in Figure 10, when the gripping portion 622 of the sub-handle 60 fixed to the handle mounting portion 16 is gripped by the user, the grip lever 624 is pressed. The pressure on the grip lever 624 is converted into movement of the shaft portion 64 by the conversion mechanism 68. The shaft portion 64 is positioned in a protruding position, and the pin 642 protrudes from the sub-handle 60.

[0117] As shown in Figure 19, the protruding pin 642 is inserted into an insertion hole 168 formed in the fourth fitting portion 167 of the handle mounting portion 16. The inserted pin 642 presses against the intermediate member 760 located inside the handle mounting portion 16. The pressed intermediate member 760 presses against the pressing portion 76, which in turn presses against the other end 821F of the outer first elastic portion 821. Due to the pressing by the outer first elastic portion 821, the protruding portion 82P comes into contact with the other end 841F of the inner first elastic portion 841. As a result, the outer electrode 82 and the inner electrode 84 are electrically connected, and current flows between the outer electrode 82 and the inner electrode 84. The current flow between the outer electrode 82 and the inner electrode 84 is output as a signal to the controller 94 via the lead wire 83. The controller 94 detects the energization between the outer electrode 82 and the inner electrode 84 as a signal and detects that the pin 642 is in a protruding position, that is, that the gripping portion 622 of the sub-handle 60 is being gripped.

[0118] As described above, the grinder 100 of this embodiment has a sub-handle 60 with a shaft portion 64 that protrudes toward the handle mounting portion 16, and a detection unit 70 for detecting the protrusion of the shaft portion 64 is provided in the housing 10. Since the detection unit 70 is provided in the housing 10, there are no electrical connection terminals provided in the handle mounting portion 16 that connects the sub-handle 60 and the housing 10. Therefore, it is possible to suppress or prevent electrical connection failures when connecting the sub-handle 60 and the housing 10, and to appropriately detect information regarding the sub-handle 60.

[0119] According to this embodiment, the sub-handle 60 further includes a grip lever 624 that is pressed when the user grips the gripping portion 622, and a conversion mechanism 68 that converts the movement of the pressed grip lever 624 into linear movement of the shaft portion 64. When the user does not grip the gripping portion 622, the shaft portion 64 is positioned in a housing position where it is housed in the main body 62. When the user grips the gripping portion 622, the shaft portion 64 is configured to be positioned in a protruding position by the pressure detection unit and the conversion mechanism 68. The grinder 100 of this embodiment has a structure that mechanically moves the pin 642 of the sub-handle 60. Therefore, the gripping of the sub-handle 60 can be detected without electrically connecting the sub-handle 60 and the housing 10. Thus, it is possible to prevent electrical connection failures from occurring when connecting the sub-handle 60 and the housing 10, and the gripping of the sub-handle 60 can be appropriately detected.

[0120] According to this embodiment, the detection unit 70 includes an electrode unit 80 which comprises an inner electrode 84 and an outer electrode 82 that is positioned radially outward from the inner electrode 84 and surrounds the inner electrode 84. The detection unit 70 outputs a signal to the controller 94 because the outer first elastic portion 821 of the outer electrode 82, which is pressed by the pin 642, is electrically connected to the inner electrode 84. The detection unit 70 can be realized with a simple configuration using the inner electrode 84 and the outer electrode 82.

[0121] According to this embodiment, the outer electrode 82 includes a metal outer body 820 and a metal, elastic outer first elastic portion 821 and outer second elastic portion 822 connected to the outer body 820. The outer first elastic portion 821 and outer second elastic portion 822 are pressed by the shaft portion 64 and electrically connected to the inner electrode 84. By using a conductive elastic member in the detection portion of the detection unit 70, the electrical connection and disconnection between the outer electrode 82 and the inner electrode 84 can be suitably switched, thereby improving the detection accuracy of the detection unit 70.

[0122] According to this embodiment, the outer first elastic portion 821 is a long plate including one end 821E connected to the outer body 820 and the other end 821F pressed by the shaft portion 64. The width OW1 of the other end 821F of the outer first elastic portion 821 is configured to be narrower than the width OW2 of the one end 821E. Therefore, when the other end 821F is pressed, the outer first elastic portion 821 can be displaced substantially uniformly overall. Thus, compared to the case where the width of the outer first elastic portion 821 is configured to be uniform from one end 821E to the other end 821F, it is possible to displace the outer first elastic portion 821 more significantly while suppressing or preventing damage to the one end 821E of the outer first elastic portion 821. Furthermore, by configuring the elastic modulus of the pressed portion of the outer first elastic portion 821 to be lower than the elastic modulus of the other portions, the pressed portion of the outer first elastic portion 821 can be brought into contact with the inner electrode 84 with a small pressing force. Therefore, it becomes easier to obtain detection results regarding the sub-handle 60, and the detection accuracy of the detection unit 70 can be improved.

[0123] According to this embodiment, the inner electrode 84 includes a metal inner body 840 and a metal, elastic inner first elastic portion 841 and inner second elastic portion 842 connected to the inner body 840. The inner first elastic portion 841 and inner second elastic portion 842 are positioned corresponding to the outer first elastic portion 821 and outer second elastic portion 822, and are electrically connected to the outer first elastic portion 821 and outer second elastic portion 822 which are pressed by the shaft portion 64. By using an elastic member in the portion where the outer first elastic portion 821 and outer second elastic portion 822 make contact, the outer first elastic portion 821 and outer second elastic portion 822 are less likely to separate from each other when pressed and come into contact with the inner first elastic portion 841 and inner second elastic portion 842. Therefore, chattering can be suppressed or prevented at the contact points between the outer first elastic portion 821 and the outer second elastic portion 822 and the inner first elastic portion 841 and the inner second elastic portion 842.

[0124] According to this embodiment, the inner first elastic portion 841 is a long plate including one end 841E connected to the inner body 840 and the other end 841F electrically connected to the outer first elastic portion 821. The width IW1 of the other end 841F of the inner first elastic portion 841 is configured to be narrower than the width IW2 of the one end 841E. Therefore, when the other end 841F of the inner first elastic portion 841 is pressed, it can be displaced substantially uniformly overall. Thus, compared to the case where the width of the inner first elastic portion 841 is configured to be uniform from one end 841E to the other end 841F, it is possible to displace the inner first elastic portion 841 more significantly while suppressing or preventing damage to the one end 841E of the inner first elastic portion 841. Furthermore, by configuring the elastic modulus of the other end 841F to be lower than the elastic modulus of the one end 841E, the inner first elastic portion 841 can be bent with a relatively small pressing force. Therefore, the inner first elastic portion 841, which is pressed by the outer first elastic portion 821, is less likely to separate from the outer first elastic portion 821, and chattering at the contact point between the outer first elastic portion 821 and the inner first elastic portion 841 can be suppressed or prevented.

[0125] According to this embodiment, a first restricting portion 721 and a second restricting portion 722 are arranged between the outer electrode 82 and the inner electrode 84 to restrict contact between the outer electrode 82 and the inner electrode 84. By arranging a so-called spacer between the outer electrode 82 and the inner electrode 84, it is possible to suppress or prevent the malfunction of an electrical short circuit between the outer electrode 82 and the inner electrode 84.

[0126] According to this embodiment, the sub-handle 60 further includes a fixing mechanism 50 that can switch between a fixed state in which the sub-handle 60 mounted on the plurality of handle mounting parts 16 is fixed, and an unfixed state in which the sub-handle 60 mounted on the plurality of handle mounting parts 16 can be detached from the plurality of handle mounting parts 16. The fixing mechanism 50 includes an operating part 52 configured to be switchable between a first position and a second position closer to the main body than the first position, and a fixing part 58. When the operating part 52 is positioned in the second position, the fixing part 58 is positioned in a mounting position in which the sub-handle 60 can be mounted on the plurality of handle mounting parts 16, and when the operating part 52 is positioned in the first position, the fixing part 58 is positioned in a fixing position in which the handles mounted on the plurality of handle mounting parts 16 are fixed. The sub-handle 60 can be attached to and detached from the handle mounting parts 16 by the simple method of operating the operating part 52. Therefore, a grinder 100 in which the sub-handle 60 can be easily attached to and detached can be provided.

[0127] According to this embodiment, the fixing mechanism 50 further includes a spring 59 that biases the operating section 52 from the second position toward the first position. By utilizing the biasing force of the spring 59, the operating section 52 can be easily switched between the first and second positions. Therefore, a grinder 100 can be provided in which the sub-handle 60 is easier to attach and detach.

[0128] According to this embodiment, the fixing mechanism 50 further includes an outer cylinder 54 configured to move parallel to the extending direction of the shaft portion 64, and an inner cylinder 56 housed in the outer cylinder 54. The inner cylinder 56 has a holding portion 560 that movably holds the fixing portion 58. The inner cylinder 56 is configured to be able to receive a plurality of handle mounting portions 16 inside the inner cylinder 56. In the fixed position, the fixing portion 58 is restricted from moving radially outward by the outer cylinder 54, protruding into the inner cylinder 56 and engaging with the plurality of handle mounting portions 16 received inside the inner cylinder 56. In the mounting position, the fixing portion 58 is configured to retract radially outward from the inner surface 56W of the inner cylinder 56 and not engage with the plurality of handle mounting portions 16 received inside the inner cylinder 56. The arrangement of the fixing portion 58 can be switched by a simple configuration using the inner cylinder 56 and the outer cylinder 54.

[0129] According to this embodiment, the shaft portion 64 is positioned radially inward from the outer cylinder 54 and the inner cylinder 56, and is configured to be movable relative to the outer cylinder 54 and the inner cylinder 56. Therefore, it is possible to provide a grinder 100 with a rational structure in which the sub-handle 60 can be easily attached and detached, and the shaft portion 64 is efficiently positioned.

[0130] The correspondence between each component (feature) of the above embodiments and each component (feature) of the present disclosure or invention is shown below. However, each component of the embodiments is merely an example and does not limit each component of the present disclosure or invention.

[0131] Grinder 100 is an example of a "power tool". Rotation axis RX is an example of a "motor rotation axis". Output shaft 21 and motor 20 are examples of an "output shaft" and a "motor". Multiple handle mounting parts 16 are an example of "multiple handle mounting parts". Housing 10 is an example of a "housing". Sub-handle 60 is an example of a "handle". Controller 94 is an example of a "controller". Gripping part 622 and main body 62 are examples of a "gripping part" and a "main body". Shaft part 64 and pin 642 are examples of a "shaft". Outer first elastic part 821, outer second elastic part 822, and outer third elastic part 823 are examples of "multiple detection parts". Detection unit 70 is an example of a "detection mechanism". Grip lever 624 is an example of a "pressure detection part", and conversion mechanism 68 is an example of a "conversion mechanism". Inner electrode 84 and outer electrode 82 are examples of an "inner electrode" and an "outer electrode". The outer body 820 is an example of an "outer body section," and the outer first elastic section 821 and outer second elastic section 822 are examples of an "outer first elastic section" and an "outer second elastic section." One end 821E and the other end 821F are examples of an "end section" and an "other end section." Widths OW1 and OW2 are examples of the "width of the other end section" and the "width of one end section." The inner body 840 is an example of an "inner body section," and the inner first elastic section 841 and inner second elastic section 842 are examples of an "inner first elastic section" and an "inner second elastic section." One end 841E and the other end 841F are examples of an "end section" and an "other end section." Widths IW1 and IW2 are examples of the "width of the other end section" and the "width of one end section." The first restricting section 721 and the second restricting section 722 are examples of "restricting sections." The fixing mechanism 50 is an example of a "fixing mechanism." The operating part 52 is an example of an "operating part," and the fixing part 58 is an example of a "fixing part." The spring 59 is an example of a "biasing member." The outer cylinder 54 and inner cylinder 56 are examples of an "outer cylinder" and an "inner cylinder." The holding part 560 is an example of a "holding part."

[0132] B. Other embodiments: The power tools relating to this disclosure are not limited to the grinder 100 of the embodiment described above. For example, modifications are possible, as are not limited to those described below. At least one of these modifications may be adopted in combination with the grinder 100 of the embodiment and at least one of the features described in the claims.

[0133] (B1) In the first embodiment described above, an example was shown in which the grinder 100 is equipped with a grip detection mechanism including a grip lever 624, a conversion mechanism 68, and a shaft portion 64. In contrast, the grinder 100 may be equipped with a detection mechanism other than the grip detection mechanism, such as a detection mechanism that detects whether or not the sub-handle 60 is attached to one of the multiple handle mounting portions 16, or a detection mechanism that detects which of the multiple handle mounting portions 16 the sub-handle 60 is attached to. In this case, the sub-handle 60 does not need to be equipped with a conversion mechanism 68, and the pin 642 of the shaft portion 64 may always be positioned in a protruding position.

[0134] (B2) In the first embodiment described above, the detection unit 70 is provided with an electrode unit 80 including an outer electrode 82 and an inner electrode 84, and an example is shown in which an outer first elastic part 821, an outer second elastic part 822, and an outer third elastic part 823 are provided at positions corresponding to the plurality of handle mounting parts 16. In contrast, as shown in the detection unit 70b of Figure 20, a plurality of switch units 75 including a tactile switch 73 may be provided. In the first embodiment described above, whether or not the sub-handle 60 is grasped by the user is detected when the pressing part 76 is pressed by the pin 642, a part of the outer electrode 82 of the electrode unit 80 contacts a part of the inner electrode 84, and current flows between the outer electrode 82 and the inner electrode 84. In contrast, in the example of Figure 20, the grasping of the sub-handle 60 is detected when the tactile switch 73 is turned on by the pin 642. Note that Figure 20 shows a cross-sectional view from the rear of the housing 10 at the position where the handle mounting part 16 is provided in the front-rear direction.

[0135] As shown in Figure 20, the detection unit 70b comprises a circuit board 71 and a plurality of switch units 75 mounted on the circuit board 71. The circuit board 71 is electrically connected to the controller 94 via lead wires (not shown). The circuit board 71 extends in a direction perpendicular to the rotation axis RX (in the example of Figure 20, the vertical and horizontal directions) and is arranged throughout the entire space within the housing 10. By arranging the circuit board 71 over a wide area within the housing 10, the number of lead wires electrically connecting the plurality of switch units 75, the controller 94, and various loads such as the lighting unit can be reduced, simplifying the configuration within the housing 10.

[0136] Each of the multiple switch units 75 includes a tactile switch 73, a plate portion 77, and a shaft portion 79. The tactile switch 73 has a plunger 732. The plate portion 77 is positioned between the plunger 732 and the insertion hole 168 of the fourth mating portion 167 and is configured to rotate about the shaft portion 79. More specifically, as indicated by the arrows in Figure 20, the plate portion 77 reciprocates between a position that pushes down the plunger 732 and a position that contacts the inner surface of the housing 10. Normally, the plate portion 77 is separated from the plunger 732, and the tactile switch 73 is normally off.

[0137] When the user grips the sub-handle 60, the pin 642 enters the housing 10 through the insertion hole 168 of the fourth mating portion 167. The pin 642 presses against the plate portion 77, and the pressed plate portion 77 pushes down the plunger 732. When the plunger 732 is pushed down, the tactile switch 73 turns ON and supplies power to the controller 94 via the circuit board 71 and lead wires (not shown). The powered controller 94 allows the motor 20 to be driven.

[0138] Thus, even when detection unit 70b is provided instead of detection unit 70, the same effects as in the first embodiment can be achieved. Detection unit 70b is an example of a "detection mechanism". The multiple switch units 75 are an example of "multiple detection units". Note that, as shown in the example in Figure 20, the intermediate member 760 in the insertion hole 168 may be omitted. In this case, the number of parts in the housing 10 can be reduced.

[0139] Furthermore, the detection unit 70b may be equipped with various push-button switches, not limited to the tactile switch 73. Push-button switches include, in addition to the tactile switch 73, push momentary switches, rocker switches (sometimes called seesaw switches), membrane switches, etc. The push-button switch is switched on or off by being pressed by the pin 642 of the shaft portion 64, and the on / off switching is output to the controller 94 via the circuit board 71. Note that multiple push-button switches may be connected in parallel by multiple lead wires instead of the circuit board 71.

[0140] (B3) In the first embodiment described above, an example was shown in which the housing 10 has three handle mounting portions 16 on the right, left, and upper sides. However, the number of handle mounting portions 16 is not limited to three. The housing 10 may have two handle mounting portions 16, such as the right and left sides of the housing 10, or any number of two or more handle mounting portions 16. In this case, it is preferable that the number of members such as the pressing portion 76, the outer first elastic portion 821, and the inner first elastic portion 841 is the same as the number of handle mounting portions 16.

[0141] (B4) In the first embodiment described above, an example was shown in which an intermediate member 760 and a pressing portion 76 pressed by the intermediate member 760 are provided, and the pin 642 indirectly presses the outer first elastic portion 821 via the intermediate member 760 and the pressing portion 76. In contrast, at least one of the intermediate member 760 and the pressing portion 76 may be omitted. If neither the intermediate member 760 nor the pressing portion 76 is provided, the pin 642 may directly press the outer first elastic portion 821.

[0142] (B5) In the first embodiment described above, the sub-handle 60 is shown as being connected to the handle mounting portion 16 in a direction in which the axial direction DX is perpendicular to the rotation axis RX. In contrast, the sub-handle 60 may be connected to the handle mounting portion 16 in a direction in which the axial direction DX is inclined at a predetermined angle with respect to the rotation axis RX.

[0143] (B6) In the first embodiment described above, an example was shown in which the sub-handle 60 has two grip levers 624. In contrast, the sub-handle 60 may have one grip lever 624, or any number of grip levers 624, three or more.

[0144] (B7) In the first embodiment described above, an example was shown in which the operating unit 52 is configured to be switchable by the user between a first position X1 axially inward and a second position X2 axially outward from the first position. In contrast, when the sub-handle 60 is attached to the handle mounting unit 16, at least a part of the handle mounting unit 16 may be configured to displace the operating unit 52 from the first position to the second position. With the grinder 100 configured in this way, the user can fix the sub-handle 60 to the handle mounting unit 16 by pressing the sub-handle 60 against the handle mounting unit 16 without manually operating the operating unit 52. In this case, the user can remove the sub-handle 60 fixed to the handle mounting unit 16 by manually displacing the operating unit 52 from the first position to the second position.

[0145] This disclosure is not limited to the embodiments described above, and can be implemented in various configurations without departing from its spirit. For example, the technical features in the embodiments corresponding to the technical features in each form described in the summary of the invention can be replaced or combined as appropriate in order to solve some or all of the above-described problems, or to 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 deleted as appropriate. [Explanation of Symbols]

[0146] 10…Housing, 11…Motor housing, 13…Controller housing, 14…Paddle switch, 15…Gear housing, 16…Handle mounting section, 18…Gripping section, 19…Switch, 20…Motor, 21…Output shaft, 22…Drive bevel gear, 30…Spindle, 32…Driven bevel gear, 42…Shaft section, 50…Fixing mechanism, 52…Operating section, 54…Outer cylinder, 55…Pin, 56…Inner cylinder, 56W…Inner surface, 57…Biting cylinder 58...Fixing part, 59...Spring, 60...Sub-handle, 62...Main body, 64...Shaft part, 68...Conversion mechanism, 70, 70b...Detection unit, 71...Circuit board, 72...Main body, 72F...Front, 72R...Back, 74...Cover, 75...Switch unit, 76...Pressing part, 77...Plate part, 78...Guide, 79...Shaft part, 80...Electrode unit, 82...Outer electrode, 82E...One end, 82F...Other end, 82P...Protruding part, 83, 83A, 83B,83C...Lead wire, 84...Inner electrode, 84E...One end, 84F...Other end, 91...Tip tool, 92...Wheel cover, 93...Battery, 94...Controller, 95...Dial, 100...Electric disc grinder, 112...Through hole, 114...Through hole, 132...Battery mounting part, 142...Pressing part, 144...Lock-off lever, 146...Coil spring, 160...Cap, 161...Second contact surface, 162...Second fitting part, 162B...Bottom surface 164…groove, 166…protrusion, 167…fourth fitting part, 168…insertion hole, 192…plunger, 540…first contact surface, 542…large diameter part, 544…small diameter part, 545…recess, 546…recess, 560…holding part, 561…third fitting part, 564…through hole, 568…locking part, 572…flange, 574…support part, 620…lever shaft, 622…gripping part, 624…grip lever, 625…spring, 626…flange part, 642…pin, 644… Through hole, 681...First axis, 682...Second axis, 683...Third axis, 684...Fourth axis, 686...First link, 688...Second link, 720...Through hole, 721...First restricting part, 722...Second restricting part, 724...Electrode housing part, 726...Lead wire housing part, 732...Plunger, 760...Intermediate member, 780...Cover, 781...First through hole, 782...Second through hole, 820...Outer body, 821...Outer first elastic part, 821E...One end, 821F...Others End, 822...Outer second elastic part, 823...Outer third elastic part, 826...First terminal, 828...Opening, 831...First lead wire, 832...Second lead wire, 840...Inner body, 841...Inner first elastic part, 841E...One end, 841F...Other end, 842...Inner second elastic part, 843...Inner third elastic part, 846...Second terminal, 848...Opening, 624E1...End, 624E2...End, DX...Axial axis, TX...Drive axis, HX...Center axis, RX...Rotation axis

Claims

1. It is a power tool, A motor including an output shaft that rotates around the motor's rotation axis, A housing that houses the motor and has multiple handle mounting portions, A handle extending in one direction and detachably attached to the plurality of handle mounting parts, The system includes a controller capable of controlling the drive of the motor, The aforementioned handle is A main body including a gripping portion configured to be grasped by the user, It includes a shaft portion that can be positioned at a protruding position that protrudes from the main body toward the plurality of handle mounting portions, The housing comprises a detection mechanism including a plurality of detection units corresponding to the plurality of handle mounting portions, which are pressed by the shaft portion positioned at the protruding position when the handle is mounted on the plurality of handle mounting portions. The detection mechanism outputs a signal to the controller when the plurality of detection units are pressed by the shaft. Power tools.

2. The power tool according to claim 1, The handle further comprises (i) a pressure detection unit provided on the gripping portion which is pressed when the user grips the gripping portion, and (ii) a conversion mechanism which converts the movement of the pressed pressure detection unit into linear movement of the shaft portion. The shaft portion is configured such that (i) when the user does not grasp the gripping portion, it is positioned in a housing position within the main body, and (ii) when the user grasps the gripping portion, it is positioned in the protruding position by the pressure detection unit and the conversion mechanism. Power tools.

3. A power tool according to claim 1 or claim 2, The aforementioned detection mechanism is Furthermore, the device comprises (i) an inner electrode arranged to surround the motor rotation axis, and (ii) an outer electrode arranged radially outward from the inner electrode and surrounding the inner electrode. The signal is output to the controller as a result of at least a portion of the outer electrode, which is pressed by the shaft, being electrically connected to the inner electrode. Power tools.

4. The power tool according to claim 3, The outer electrode includes (i) a conductive outer body portion extending in the circumferential direction about the motor rotation axis, and (ii) an outer first elastic portion and an outer second elastic portion connected to the outer body portion, which are conductive and elastic. The outer first elastic portion and the outer second elastic portion function as the plurality of detection portions and are pressed by the shaft portion and electrically connected to the inner electrode. Power tools.

5. The power tool according to claim 4, The outer first elastic portion is a long plate including (i) one end connected to the outer main body and (ii) the other end which is configured as a free end and is pressed by the shaft portion. The width of the other end is configured to be narrower than the width of the one end. The other end is pressed by the shaft and electrically connected to the inner electrode. Power tools.

6. A power tool according to claim 4 or claim 5, The inner electrode includes (i) a conductive inner body portion extending in the circumferential direction about the motor rotation axis, and (ii) a conductive and elastic inner first elastic portion and an inner second elastic portion connected to the inner body portion. The inner first elastic portion and the inner second elastic portion are positioned corresponding to the outer first elastic portion and the outer second elastic portion, and are electrically connected to the outer first elastic portion and the outer second elastic portion which are pressed by the shaft portion. Power tools.

7. The power tool according to claim 6, The inner first elastic portion is a long plate including (i) one end connected to the inner main body and (ii) the other end which is configured as a free end and is electrically connected to the outer first elastic portion which is pressed by the shaft portion. The width of the other end is configured to be narrower than the width of the one end. The other end is electrically connected to the outer electrode which is pressed by the shaft portion. Power tools.

8. A power tool according to any one of claims 3 to 6, Furthermore, a restricting portion is provided between the outer electrode and the inner electrode to restrict contact between the outer electrode and the inner electrode. Power tools.

9. A power tool according to any one of claims 1 to 8, The handle further includes a fixing mechanism that can switch between a fixed state in which the handle is fixed to the plurality of handle mounting parts and an unfixed state in which the fixed handle can be removed from the plurality of handle mounting parts. The fixing mechanism comprises (i) an operating unit configured to be switchable between a first position and a second position closer to the main body than the first position, and (ii) a fixing unit. The fixing portion is configured such that (i) when the operating portion is positioned in the second position, it can be positioned in a mounting position on which the handle can be attached to the plurality of handle mounting portions, and (ii) when the operating portion is positioned in the first position, it can be positioned in a fixing position on which the handle attached to the plurality of handle mounting portions is fixed. Power tools.

10. The power tool according to claim 9, The fixing mechanism further includes a biasing member that biases the operating section from the second position toward the first position. Power tools.

11. A power tool according to claim 9 or claim 10, The fixing mechanism further comprises (i) an outer cylinder connected to the operating portion and configured to move parallel to the extending direction of the shaft portion, and (ii) an inner cylinder housed in the outer cylinder, having a holding portion that movably holds the fixing portion. The inner cylinder is configured to be able to receive the plurality of handle mounting parts inside the inner cylinder, The fixing portion is configured such that (i) in the fixing position, its radial outward movement is restricted by the outer cylinder, it protrudes into the inner cylinder and engages with the plurality of handle mounting portions received inside the inner cylinder, and (ii) in the mounting position, it retracts radially outward from the inner surface of the inner cylinder and does not engage with the plurality of handle mounting portions received inside the inner cylinder. Power tools.

12. The power tool according to claim 11, The shaft portion is positioned radially inward from the outer cylinder and the inner cylinder, and is configured to be movable relative to the outer cylinder and the inner cylinder. Power tools.

13. It is a power tool, A housing having multiple handle mounting sections, A handle extending in one direction and detachably attached to the plurality of handle mounting parts, The aforementioned handle is A main body including a gripping portion configured to be grasped by the user, The device includes a fixing mechanism that can switch between a fixed state in which the handles attached to the plurality of handle mounting parts are fixed, and an unfixed state in which the fixed handles can be removed from the plurality of handle mounting parts, The fixing mechanism comprises (i) an operating unit configured to be switchable between a first position and a second position closer to the main body than the first position, and (ii) a fixing unit. The fixing portion is configured such that (i) when the operating portion is positioned in the second position, it can be positioned in a mounting position on which the handle can be attached to the plurality of handle mounting portions, and (ii) when the operating portion is positioned in the first position, it can be positioned in a fixing position on which the handle attached to the plurality of handle mounting portions is fixed. Power tools.

14. The power tool according to claim 13, The fixing mechanism further includes a biasing member that biases the operating section from the second position toward the first position. Power tools.

15. A power tool according to claim 13 or claim 14, The fixing mechanism further comprises (i) an outer cylinder connected to the operating section and configured to move parallel to the extending direction of the handle, and (ii) an inner cylinder movably housed in the outer cylinder and having a holding section that movably holds the fixing section. The inner cylinder is configured to be able to receive the plurality of handle mounting parts inside the inner cylinder, The fixing portion is configured such that (i) in the fixing position, its radial outward movement is restricted by the outer cylinder, it protrudes into the inner cylinder and engages with the plurality of handle mounting portions received inside the inner cylinder, and (ii) in the mounting position, it retracts radially outward from the inner surface of the inner cylinder and does not engage with the plurality of handle mounting portions received inside the inner cylinder. Power tools.

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