Tool

Abstract

The tool has: a first attachment; at least two first mounting parts for selectively mounting the first attachment in a detachable manner; a single first intermediate member configured to be provided in a manner common to the at least two first mounting parts and having at least one pressed part, wherein when the first attachment is mounted on one first mounting part arbitrarily selected from the at least two first mounting parts, the at least one pressed part is directly or indirectly pressed by the first attachment, and when the at least one pressed part is pressed, the first intermediate member is displaced; and a single first sensor configured to detect the displacement of the first intermediate member.

Description

Technical Field

[0001] The present invention relates to a tool configured to be able to detachably mount an attachment. Background Art

[0002] Sometimes, various attachments are detachably mounted on a tool. For example, in a grinding machine having a tip tool configured to be rotationally driven, a side handle is prepared as a detachable attachment. The side handle is mounted so that a user can hold it with the other hand when holding the handle of the grinding machine with one hand.

[0003] In such a grinding machine, it is desired to prevent the use of the grinding machine in a state where no attachment is mounted. For example, Patent Document 1 below discloses a grinding machine having a sensor for detecting whether a side handle is mounted.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: U.S. Patent Application Publication No. 2018 / 272494 Summary of the Invention

[0007] However, a grinding machine is generally configured to be able to selectively mount a side handle at a plurality of positions. When separate sensors are provided for each mounting position of the side handle, the number of components and the cost increase. In particular, in a large grinding machine having three mounting positions, this problem becomes apparent. Not limited to grinding machines, any tool configured to selectively mount an attachment at any of a plurality of positions has this problem. Therefore, in a tool configured to be able to selectively mount an attachment at a plurality of positions, it is desired to reduce the number of sensors for detecting whether the attachment is mounted.

[0008] This specification discloses a tool. The tool may have: a first attachment; at least two first mounting portions for selectively and detachably mounting the first attachment; a single first intermediate member configured to be provided in a manner common to the at least two first mounting portions and having at least one pressed portion, wherein when the first attachment is mounted on any one of the at least two first mounting portions, the at least one pressed portion is directly or indirectly pressed by the first attachment, and when the at least one pressed portion is pressed, the first intermediate member is displaced; and a single first sensor configured to detect the displacement of the first intermediate member.

[0009] According to this tool, regardless of which of the at least two first mounting parts the first attachment is installed on, a single first intermediate part arranged in a way that the at least two first mounting parts share will be displaced. Therefore, the displacement of this first intermediate part can be detected by a single first sensor. That is, there is no need to separately provide sensors for detecting whether an attachment is installed on each of the at least two first mounting parts, so the number of sensors can be reduced. Brief Description of the Drawings

[0010] Figure 1 It is a perspective view of the grinder according to the first embodiment of the present invention, showing the state where the side handle is removed.

[0011] Figure 2 It is a perspective view of the grinder, showing the state where the side handle is removed.

[0012] Figure 3 It is a perspective view of the grinder, showing the state where the side handle is installed.

[0013] Figure 4 It is a longitudinal sectional view of the grinder, showing the state where the side handle is removed.

[0014] Figure 5 It is a perspective view of the first intermediate part.

[0015] Figure 6 It is a view showing the internal structure of the grinder, showing the state where the side handle is removed.

[0016] Figure 7 It is a perspective view showing the internal structure of the grinder, showing the state where the side handle is removed.

[0017] Figure 8 It is a view showing the internal structure of the grinder, showing the state where the side handle is installed.

[0018] Figure 9 It is a perspective view showing the internal structure of the grinder, showing the state where the side handle is installed.

[0019] Figure 10 It is a view showing the internal structure of the grinder according to the second embodiment of the present invention, showing the state where the side handle is removed.

[0020] Figure 11 It is a view showing the internal structure of the grinder according to the second embodiment, showing the state where the side handle is installed.

[0021] Figure 12 It is a perspective view of the first intermediate part according to the second embodiment.

[0022] Figure 13It is a partial longitudinal sectional view of the grinding machine according to the third embodiment of the present invention, showing the state where the side handle is removed.

[0023] Figure 14 It is a partial longitudinal sectional view of the grinding machine according to the third embodiment, showing the state where the side handle is installed.

[0024] Figure 15 It is a perspective view showing the internal structure of the grinding machine according to the third embodiment, showing the state where the side handle is removed.

[0025] Figure 16 It is a perspective view showing the internal structure of the grinding machine according to the third embodiment, showing the state where the side handle is installed.

[0026] Figure 17 It is a perspective view of the first intermediate member according to the third embodiment.

[0027] Figure 18 It is a perspective view of the sensor housing.

[0028] Figure 19 It is a perspective view of the anti - detachment member.

[0029] Figure 20 It is a perspective view showing the arrangement of the first intermediate member, the sensor housing, and the anti - detachment member. Detailed embodiments

[0030] In one or more embodiments, the tool may have: a first attachment; at least two first mounting portions for selectively and detachably mounting the first attachment; a single first intermediate member configured to be provided in a manner common to at least two first mounting portions and having at least one pressed portion, when the first attachment is mounted on any one of the at least two first mounting portions, at least one pressed portion is directly or indirectly pressed by the first attachment, and when the at least one pressed portion is pressed, the first intermediate member is displaced; and a single first sensor configured to detect the displacement of the first intermediate member.

[0031] According to this tool, regardless of which of the at least two first mounting portions the first attachment is mounted on, the single first intermediate member provided in a manner common to the at least two first mounting portions is displaced. Therefore, the displacement of the first intermediate member can be detected by the single first sensor. That is, there is no need to separately provide sensors for detecting whether an attachment is installed for each of the at least two first mounting portions, so the number of sensors can be reduced.

[0032] In one or more embodiments, it may be that the tool has a biasing member that biases the first intermediate member to a position where it is not directly or indirectly pressed by the first attachment. According to this structure, when the first attachment is removed, the first intermediate member can automatically return to the position before displacement by the biasing force of the biasing member (loading member).

[0033] In one or more embodiments, it may be that at least one pressed portion has a pressed surface that forms an angle with respect to the pressing direction in which the first attachment directly or indirectly presses the at least one pressed portion, so that the first intermediate member is displaced in a direction different from the pressing direction. According to this structure, the first intermediate member can be easily displaced in a desired direction.

[0034] In one or more embodiments, it may be that the first intermediate member has a first intermediate member body having a shape of a ring or a part of a ring. It may be that at least two first mounting portions are respectively arranged at positions separated from each other in the circumferential direction of the ring or the part of the ring. According to this structure, the first intermediate member has a shape corresponding to the arrangement of the at least two first mounting portions, and thus, at least two first mounting portions can share a single first intermediate member with a simple structure.

[0035] In one or more embodiments, it may be that at least one pressed portion is respectively provided at at least two positions corresponding to the positions of the at least two first mounting portions. According to this structure, at least one pressed portion is only arranged at the required parts, and thus, compared with the case where at least one pressed portion is formed as a continuous single part, the at least one pressed portion can be made more compact.

[0036] In one or more embodiments, it may be that at least one pressed portion projects radially outward from the first intermediate member body. According to this structure, it is easy to form a shape that is directly or indirectly pressed by the first attachment. In addition, the diameter of the first intermediate member body can be made smaller.

[0037] In one or more embodiments, it may be that the first intermediate member is configured to rotate circumferentially when at least one pressed portion is pressed. According to this structure, it is easy to displace the first intermediate member. In addition, there is no need to ensure a displacement space for the first intermediate member in the direction in which the rotation axis of the first intermediate member extends, and thus, the size of the tool in this direction can be made more compact.

[0038] In one or more embodiments, it may be that the first intermediate member body has a notch portion that is partially lacking in the circumferential direction. It may be that the biasing member is housed in the notch portion. According to this structure, the size of the tool will not become larger due to the provision of the biasing member.

[0039] In one or more embodiments, it is possible that the first intermediate member has a tilting axis. It is possible that the first intermediate member is configured to tilt about the tilting axis when at least one pressed portion is pressed.

[0040] In one or more embodiments, it is possible that the first intermediate member has a first magnet and a magnet holding portion that holds the first magnet. It is possible that the first sensor is a magnetic sensor that detects the displacement of the first magnet.

[0041] In one or more embodiments, it is possible that the magnet holding portion projects radially outward from the first intermediate member main body. With this structure, when the first intermediate member is configured to rotate, the distance from the rotation axis of the first intermediate member to the first magnet can be increased. Therefore, the displacement amount of the first magnet becomes larger for the same rotation angle of the first intermediate member. As a result, it is easy to ensure the detection accuracy of the magnetic sensor.

[0042] In one or more embodiments, it is possible that the magnet holding portion is provided at a position in the circumferential direction different from at least one pressed portion. With this structure, the magnet holding portion can be formed at an arbitrary position in the circumferential direction other than the position of at least one pressed portion. Therefore, the degree of freedom in arranging the magnetic sensor is increased. In other words, the arrangement of the magnetic sensor can be determined without increasing the tool size.

[0043] In one or more embodiments, it is possible that the tilting axis is located at a position radially outside the first intermediate member main body. It is possible that the first magnet is arranged at a position radially outside the first intermediate member main body and is substantially opposite to the tilting axis with the first intermediate member main body interposed therebetween. With this structure, the distance from the tilting axis of the first intermediate member to the first magnet can be increased. That is, the displacement amount of the first magnet can be increased for the same tilting angle of the first intermediate member. Therefore, it is easy to ensure the detection accuracy of the magnetic sensor.

[0044] In one or more embodiments, it is possible that the magnetic sensor and the first magnet are arranged such that the magnetic sensor and the first magnet face each other in the direction in which the tilting axis extends. With this structure, a magnetic sensor of the alternating magnetic field operation type can be used to detect the displacement of the first magnet with high accuracy.

[0045] In one or more embodiments, it is possible that the first sensor is a microswitch. It is possible that the first intermediate member has a contact portion that comes into contact with the microswitch when the first intermediate member is displaced to turn the microswitch on.

[0046] In one or more embodiments, it is possible that the contact portion is provided at a position in the circumferential direction different from at least one pressed portion. According to this structure, the contact portion can be formed at an arbitrary position in the circumferential direction other than the position of at least one pressed portion. Therefore, the degree of freedom in arranging the microswitch is increased. In other words, the arrangement of the microswitch can be determined in such a way that the size of the tool does not increase.

[0047] In one or more embodiments, it is possible that the tool includes: a second attachment; a second mounting portion for detachably mounting the second attachment; a second intermediate member configured to pivot when the second attachment is mounted on the second mounting portion and is directly or indirectly pressed by the second attachment; and a second sensor for detecting that the second intermediate member has pivoted. According to this structure, it is also possible to detect whether the second attachment is mounted or not.

[0048] In one or more embodiments, it is possible that the second intermediate member has a second magnet. It is possible that the second sensor is a magnetic sensor configured to detect the displacement of the second magnet.

[0049] In one or more embodiments, it is possible that the tool includes: an electric motor; and a controller configured to control the drive of the electric motor. It is possible that the controller performs the following control: allowing the drive of the electric motor when both a first condition and a second condition are satisfied, where the first condition means that it is detected by the first sensor that the first attachment is mounted on either one of at least two first mounting portions, and the second condition means that it is detected by the second sensor that the second attachment is mounted on the second mounting portion, and prohibiting the drive of the electric motor when at least one of the first condition and the second condition is not satisfied.

[0050] In one or more embodiments, it is possible that the tool includes: a bearing for rotatably supporting the motor shaft of the electric motor; and a housing having a cylindrical portion for housing and supporting the bearing. It is possible that the first intermediate member is arranged such that the first intermediate member body surrounds the outer circumference of the cylindrical portion. According to this structure, no special component for supporting the first intermediate member is required, so that the size of the tool can be made compact.

[0051] In one or more embodiments, it is possible that the tool is a grinder having a tip tool configured to rotate by an electric motor. It is possible that the first attachment is a side handle. It is possible that the second attachment is a cover that partially covers the tip tool.

[0052] Next, embodiments of the present invention will be described in more detail with reference to the drawings.

[0053] A. First Embodiment:

[0054] Next, with reference toFigures 1 - 9 A description will be given of the first embodiment of the present invention. In the following embodiments, a handheld electric disk grinder (hereinafter also simply referred to as a grinder) 10 is exemplified as a tool.

[0055] First, reference is made to Figures 1 - 4 to describe the outline of the grinder 10. As Figure 4 shown, the grinder 10 is configured to rotate a substantially disk-shaped tip tool 28 mounted on a main shaft 25. The main shaft 25 rotates by the rotational driving force provided by an electric motor 31. As the tip tool 28 that can be mounted on the grinder 10, a grinding wheel, a rubber pad, a brush, a blade, etc. are prepared. The user selects a suitable tip tool 28 according to the desired machining operation and mounts it on the grinder 10. According to the grinder 10, machining operations such as grinding, polishing, and cutting can be performed on the workpiece according to the type of the tip tool 28.

[0056] In the following description, the direction in which the rotation axis AX1 of the electric motor 31 (in other words, the motor shaft 32) extends is defined as the front-rear direction of the grinder 10. The side where the tip tool 28 is located in the front-rear direction is defined as the front side, and the opposite side is defined as the rear side. In addition, the direction in which the rotation axis AX2 of the main shaft 25 (in other words, the rotation axis of the tip tool 28) extends is defined as the up-down direction of the grinder 10. The side where the tip tool 28 is located in the up-down direction is defined as the lower side, and the opposite side is defined as the upper side. In addition, the direction orthogonal to the up-down direction and the front-rear direction is defined as the left-right direction of the grinder 10. The right side when observing the front side from the rear side in the left-right direction is defined as the right side of the grinder 10, and the opposite side is defined as the left side of the grinder 10.

[0057] As Figures 1 - 4 shown, the grinder 10 has a gear housing 20, a motor housing 30, and a handle housing 40. As Figure 4 shown, the electric motor 31 is housed in the motor housing 30 located between the gear housing 20 and the handle housing 40 in the front-rear direction, that is, the longitudinal direction of the grinder 10. The electric motor 31 is rotatably supported by a bearing 34 housed in the gear housing 20 and a bearing 35 housed in the motor housing 30 near the rear end of the motor housing 30. The electric motor 31 is driven by electric power supplied from the outside (alternating current power in this embodiment, but it can also be direct current power).

[0058] As Figure 4As shown, inside the motor housing 30, a controller 33 is also housed near the rear end and lower end of the motor housing 30. The controller 33 controls the driving of the electric motor 31 by controlling the power supplied to the electric motor 31. The controller 33 is adjacent to the electric motor 31 in the front-rear direction and is arranged on the rear side of the electric motor 31.

[0059] Inside the gear housing 20, a mechanism for transmitting the rotational driving force of the electric motor 31 to the tip tool 28 is housed. Specifically, a small bevel gear 23, a large bevel gear 24, and a main shaft 25 are housed inside the gear housing 20. The small bevel gear 23 is fixed around the motor shaft 32 at the front end of the motor shaft 32 of the electric motor 31. The main shaft 25 is supported by bearings separated in the up-down direction so as to be rotatable about the rotation axis AX2. The rotation axis AX2 intersects (more specifically, is orthogonal to) the rotation axis AX1 of the electric motor 31. The large bevel gear 24 is fixed around the main shaft 25 on the upper side of the main shaft 25 and meshes with the small bevel gear 23. The gear housing 20 has a second mounting portion 22 at its lower end for detachably mounting the cover 400. The second mounting portion 22 has a cylindrical shape extending in the up-down direction. The main shaft 25 extends in the up-down direction inside the gear housing 20 and extends out from the gear housing 20 (more specifically, the second mounting portion 22) at the lower side.

[0060] At the lower end of the main shaft 25 extending out from the gear housing 20, an inner flange 26 is mounted around the main shaft 25. An external thread portion is formed at a position below the inner flange 26 in the main shaft 25, and a lock nut 27 is mounted on the external thread portion. The tip tool 28 is clamped between the inner flange 26 and the lock nut 27, and the position of the tip tool 28 relative to the main shaft 25 is fixed by tightening the lock nut 27.

[0061] The gear housing 20 has a cylindrical portion 21 extending in the front-rear direction at its rear end. The above-mentioned bearing 34 is housed in the cylindrical portion 21 and is supported by the cylindrical portion 21.

[0062] The handle housing 40 is a part that a user holds with one hand when using the grinding machine 10. The handle housing 40 has a cylindrical shape extending substantially in the front-rear direction. A switch 41 for driving the electric motor 31 is housed inside the handle housing 40. An operation member 50 is provided on the lower side of the handle housing 40, and the operation member 50 is configured to be displaceable between a disconnect position where the switch 41 is in the off state and a connect position where the switch 41 is in the on state. A lock switch 57 is provided near the front end of the operation member 50 in the front-rear direction, and the lock switch 57 is used to lock the operation member 50 in the disconnect position and prevent its displacement to the connect position.

[0063] When the user operates the operating member 50 from the off position to the on position, the switch 41 detects this operation and sends a detection signal to the controller 33. When receiving this detection signal, the controller 33 supplies power to the electric motor 31 to drive the electric motor 31. When the electric motor 31 is driven, the rotation of the motor shaft 32 is transmitted to the main shaft 25 while being decelerated by the small bevel gear 23 and the large bevel gear 24. At this time, the direction of the rotational movement is also changed from the direction around the motor shaft 32 to the direction around the rotation axis AX2 of the main shaft 25. According to this mechanism, along with the rotation of the motor shaft 32, the main shaft 25 rotates around the rotation axis AX2. As a result, the tip tool 28 fixed by the inner flange 26 and the lock nut 27 rotates together with the main shaft 25.

[0064] As Figure 1 shown, the grinding machine 10 further has a side handle 300 and a cover 400 as its accessories. The side handle 300 is prepared for the user to hold with the other hand than the hand holding the handle housing 40. By using the side handle 300, the user can hold the grinding machine 10 more stably. The side handle 300 has a handle portion 310 for the user to hold and a mounting portion 320 for mounting on the gear housing 20. The mounting portion 320 has a cylindrical shape extending in the longitudinal direction of the side handle 300 and extends from one end of the handle portion 310 in the longitudinal direction of the side handle 300. An external thread is formed on the outer peripheral surface of the mounting portion 320.

[0065] As Figure 1 shown in FIG. 2, the gear housing 20 has three first mounting portions 29a to 29c for detachably mounting the side handle 300. The first mounting portions 29a to 29c are arranged at positions separated from each other in the circumferential direction around the rotation axis AX1. More specifically, the first mounting portion 29a is formed on the left side surface of the gear housing 20, the first mounting portion 29b is formed on the upper surface of the gear housing 20, and the first mounting portion 29c is formed on the right side surface of the gear housing 20. The three first mounting portions 29a to 29c are respectively provided at positions rotationally symmetric with respect to the rotation axis AX1. The first mounting portions 29a to 29c are respectively in the form of through holes communicating the inside and the outside of the gear housing 20. An internal thread that engages with the external thread of the mounting portion 320 is formed on the inner surface forming the through hole.

[0066] By screwing the mounting portion 320 of the side handle 300 into one of the first mounting portions 29a to 29c selected from the three first mounting portions, the side handle 300 can be mounted on the gear housing 20. The user can arbitrarily select the mounting position of the side handle 300 from the first mounting portions 29a to 29c according to the type of operation performed with the grinding machine 10 or according to whether the user is right-handed or left-handed. In the present embodiment, three first mounting portions 29a to 29c are provided, but the number of the first mounting portions is not particularly limited, and may be two or four or more. For example, only two first mounting portions 29a and 29c may be provided.

[0067] As Figure 1 shown, the cover 400 has a cover body 410 that covers a part of the tip tool 28 and a mounting portion 420 for mounting on the second mounting portion 22. The cover body 410 covers approximately the rear half of the tip tool 28. In the present embodiment, the cover body 410 covers the upper surface and the circumferential surface of the tip tool 28, but depending on the type of the tip tool 28 used, it may cover the upper surface, the lower surface, and the circumferential surface between the upper surface and the lower surface. The mounting portion 420 has an open substantially annular shape and extends upward from the upper surface of the cover body 410. As Figure 2 shown, the mounting portion 420 has two flanges 421 and 422 facing each other at two top portions in the circumferential direction. In a state where the mounting portion 420 is arranged so as to surround the second mounting portion 22 of the gear housing 20, a bolt 423 is inserted into the threaded holes formed in the flanges 421 and 422 and tightened, whereby the radius of the annular shape of the mounting portion 420 becomes smaller and the mounting portion 420 is fixed to the second mounting portion 22.

[0068] The above-described grinding machine 10 can drive the electric motor 31 only in a state where the side handle 300 is mounted on any one of the first mounting portions 29a to 29c of the gear housing 20. In a state where the side handle 300 is not mounted, even if the user operates the operation member 50 to the ON position and a detection signal is sent from the switch 41 to the controller 33, the controller 33 prohibits the driving of the electric motor 31. The presence or absence of the mounting of the side handle 300 is detected by a single sensor 70 described later. Hereinafter, the structure for performing this detection will be described in detail with reference to the drawings.

[0069] As Figure 4 shown, the grinding machine 10 has a first intermediate member 60 and a sensor 70. The first intermediate member 60 has a substantially annular shape and is arranged so as to surround the outer circumference of the cylindrical portion 21 of the gear housing 20 (see Figure 4 , Figure 6 , Figure 7 ). The first intermediate member 60 is supported by the cylindrical portion 21 in a state where it is prevented from falling off by a circlip 69 (seeFigure 6 , Figure 7 ). According to this configuration, there is no special component for supporting the first intermediate member 60, so the size of the grinding machine 10 can be made compact.

[0070] The first intermediate member 60 is configured to be mounted on any one of the first mounting portions 29a to 29c by the side handle 300 and is pressed by the mounting portion 320 of the side handle 300, thereby undergoing displacement. In the present embodiment, as such a displacement operation, the first intermediate member 60 rotates by a predetermined angle about the rotation axis AX1. The position of the first intermediate member 60 when the side handle 300 is not mounted on any one of the first mounting portions 29a to 29c of the gear housing 20 is also referred to as the non-mounted position (see Figure 6 , Figure 7 ). The position of the first intermediate member 60 when the side handle 300 is mounted on any one of the first mounting portions 29a to 29c is also referred to as the mounted position (see Figure 8 , Figure 9 ).

[0071] As Figure 5 shown, the first intermediate member 60 is a single component and is provided in a manner common to the first mounting portions 29a to 29c. The first intermediate member 60 has a first intermediate member main body 61. In the present embodiment, the first intermediate member main body 61 has a ring shape centered on the rotation axis AX1 of the electric motor 31. However, the first intermediate member 60 may also have a shape that is a part of a ring (in other words, a non-closed ring shape). A through hole for inserting the cylindrical portion 21 is formed in the central portion of the first intermediate member main body 61.

[0072] The first intermediate member 60 also has three pressed portions 62a to 62c. The three pressed portions 62a to 62c are arranged separately from each other in the circumferential direction. The pressed portion 62a is the portion that is pressed by the side handle 300 (more specifically, the tip of the mounting portion 320) when the side handle 300 is mounted on the first mounting portion 29a of the gear housing 20. Similarly, the pressed portion 62b is the portion that is pressed by the side handle 300 when the side handle 300 is mounted on the first mounting portion 29b, and the pressed portion 62c is the portion that is pressed by the side handle 300 when the side handle 300 is mounted on the first mounting portion 29c. Therefore, the pressed portions 62a to 62c are respectively arranged at angular positions corresponding to the angular positions of the first mounting portions 29a to 29c (see Figure 6 , Figure 7 ).

[0073] The pressed portions 62a to 62c respectively protrude radially outward from the first intermediate member main body 61. Therefore, it is easy to form a shape that is pressed by the side handle 300. In addition, the diameter of the first intermediate member main body 61 can be made smaller.

[0074] As Figure 6 and Figure 7 shown, the pressed portion 62a has a pressed surface 63a, and the pressed surface 63a forms an angle with respect to the direction in which the through hole constituting the first mounting portion 29a extends (in other words, the mounting direction of the side handle 300, or the direction in which the side handle 300 presses the pressed portion 62a when the side handle 300 is mounted on the first mounting portion 29a). Similarly, the pressed portion 62b has a pressed surface 63b, and the pressed surface 63b forms an angle with respect to the direction in which the through hole constituting the first mounting portion 29b extends. Similarly, the pressed portion 62c has a pressed surface 63c, and the pressed surface 63c forms an angle with respect to the direction in which the through hole constituting the first mounting portion 29c extends. In the present embodiment, the pressed surfaces 63a to 63c form an angle of approximately 45 degrees with respect to the direction in which the side handle 300 presses the pressed portions 62a to 62c (see Figure 6 ). This angle can be set at any angle so that the first intermediate member 60 is displaced in a direction different from the direction in which the side handle 300 presses the pressed portions 62a to 62c. In an alternative embodiment, this angle may also be set within the range of 30 degrees or more and 60 degrees or less. According to the pressed surfaces 63a to 63c formed at such an angle, the first intermediate member 60 can be easily rotated. Further, the pressed surfaces 63a to 63c extend to a position protruding forward from the first intermediate member main body 61. Therefore, the contact area between the pressed surfaces 63a to 63c and the mounting portion 320 of the side handle 300 is increased, and the pressed surfaces 63a to 63c can be reliably pressed by the side handle 300.

[0075] By comparing Figure 6 , Figure 7 and Figure 8 , Figure 9 , it can be seen that by mounting the side handle 300 on the first mounting portion 29a, the pressed surface 63a of the pressed portion 62a is pressed by the mounting portion 320 of the side handle 300, and the first intermediate member 60 rotates counterclockwise from the position shown in Figure 6 , Figure 7 to the position shown in Figure 8 , Figure 9 .

[0076] As Figure 5 shown, the first intermediate member 60 further has a magnet 67 and a magnet holding portion 66 for holding the magnet 67. The magnet 67 is provided for detecting the displacement (i.e., rotational movement) of the first intermediate member 60 described above by the sensor 70. Therefore, in the present embodiment, the sensor 70 is a magnetic sensor.

[0077] As Figure 4 , Figure 6As shown, the sensor 70 is fixed to the gear housing 20 near the lower end of the gear housing 20 in the vertical direction. Further, the sensor 70 is fixed near the rear end of the gear housing 20 at a position substantially the same as that of the first intermediate member 60 in the front-rear direction. The sensor 70 is connected to the controller 33 through a signal line disposed at the bottom of the motor housing 30 in the front-rear direction. The detection result of the sensor 70 is output to the controller 33. By arranging the controller 33 and the sensor 70 such that the controller 33 and the sensor 70 are located near the lowermost part of the grinding machine 10 and the electric motor 31 is located between the controller 33 and the sensor 70 as in the present embodiment, an increase in the size of the grinding machine 10 can be suppressed, and the wiring can be made efficient.

[0078] Corresponding to the position of the sensor 70, a magnet holding portion 66 is provided near the lowermost part of the first intermediate member main body 61 (see Figure 6 ). As Figure 5 shown, the magnet holding portion 66 has a substantially rectangular parallelepiped shape and protrudes radially outward from the first intermediate member main body 61 toward the rotation axis AX1. The magnet holding portion 66 holds the magnet 67 such that the magnet 67 and the sensor 70 face each other in the vertical direction.

[0079] According to this structure, the sensor 70 can detect a difference in the position of the magnet 67 caused by the presence or absence of the mounting side handle 300. In other words, the sensor 70 can detect whether the first intermediate member 60 is in the non-mounting position shown in Figure 6 , Figure 7 or in the mounting position shown in Figure 8 , Figure 9 . The sensor 70 and the magnet 67 may be configured such that the sensor 70 detects a magnetic field only when the first intermediate member 60 is in the non-mounting position. Alternatively, the sensor 70 and the magnet 67 may be configured such that the sensor 70 detects a magnetic field only when the first intermediate member 60 is in the mounting position. Alternatively, the sensor 70 and the magnet 67 may be configured such that the sensor 70 detects a magnetic field when the magnet 67 crosses the sensor 70 as the first intermediate member 60 moves between the mounting position and the non-mounting position.

[0080] As described above, the magnet holding portion 66 protrudes radially outward from the first intermediate member main body 61, whereby the distance from the rotation axis of the first intermediate member main body 61 (in other words, the rotation axis AX1) to the magnet 67 can be increased. Therefore, the displacement amount of the magnet 67 becomes larger for the same rotation angle of the first intermediate member main body 61. As a result, it is easy to ensure the detection accuracy of the sensor 70. Further, since the magnet 67 is provided at a position circumferentially different from the pressed portions 62a to 62c, the degree of freedom in arranging the sensor 70 is increased. As a result, the sensor 70 can be arranged as described above, and an increase in the size of the grinder 10 can be suppressed. However, the arrangements of the magnet 67 and the sensor 70 can be set arbitrarily. For example, the magnet 67 may be held by the first intermediate member main body 61, or may be held by any one of the pressed portions 62a to 62c.

[0081] As Figure 5 shown, the first intermediate member 60 further has two notch portions 64. The notch portion 64 is a portion that is partially lacking in the circumferential direction. The two notch portions 64 are provided at positions that are rotationally symmetric by 180 degrees with respect to the rotation axis AX1. In the present embodiment, the notch portion 64 is located on the inner circumferential side of the first intermediate member main body 61, but may be located on the outer circumferential side of the first intermediate member main body 61.

[0082] In each of the two notch portions 64, a protrusion 65 extends substantially in the circumferential direction from the circumferential side surface of the first intermediate member main body 61 forming the notch portion 64 in the direction from the non-mounted position toward the mounted position. As Figures 6 - 9 shown, the protrusion 65 is provided to hold the spring 68 as a biasing member within the notch portion 64. The spring 68 is in the form of a helical spring and is arranged so as to surround the protrusion 65. One end of the spring 68 is seated on the circumferential side surface of the first intermediate member main body 61 forming the notch portion 64 (the side surface on the base end side of the protrusion 65). The other end of the spring 68 is seated on the spring seat 20a of the gear housing 20. The spring seat 20a extends from the front side of the gear housing 20 to the rear side into the notch portion 64 (in Figures 6 - 9 only the spring seat 20a corresponding to the upper notch portion 64 can be observed).

[0083] The spring 68 biases the first intermediate member 60 in the direction from the mounted position toward the non-mounted position. Therefore, when the side handle 300 is installed, the first intermediate member 60 rotates counterclockwise from the non-mounted position to the mounted position against the biasing force of the spring 68, and when the side handle 300 is removed, the first intermediate member 60 automatically returns from the mounted position to the non-mounted position by the biasing force of the spring 68. By arranging the spring 68 within the notch portion 64, an increase in the size of the grinder 10 due to ensuring the installation space for the biasing member can be prevented.

[0084] According to the above-mentioned grinder 10, regardless of which of the first mounting portions 29a to 29c the side handle 300 is mounted on, the single first intermediate member 60 provided in a manner common to the first mounting portions 29a to 29c is displaced (rotated). And the single sensor 70 can detect the displacement of the first intermediate member 60. Therefore, there is no need to provide sensors for detecting the presence or absence of the side handle 300 for each of the first mounting portions 29a to 29c, so the number of sensors can be reduced.

[0085] B. Second Embodiment:

[0086] Refer to Figures 10 - 12 The second embodiment of the present invention will be described. The grinder 100 according to the second embodiment is different from the first embodiment only in that it has a first intermediate member 160 and a sensor 170 instead of the first intermediate member 60 and the sensor 70 of the first embodiment. Hereinafter, only the differences between the second embodiment and the first embodiment will be described. In Figure 10 , Figure 11 , the same structural elements as those in the first embodiment are denoted by the same reference numerals as in the first embodiment, and the description thereof is omitted.

[0087] As Figure 10 and Figure 11 shown, the sensor 170 is fixed to the gear housing 20 near the lower end of the gear housing 20 in the vertical direction. In addition, the sensor 170 is fixed near the rear end of the gear housing 20 at a position substantially the same as that of the first intermediate member 160 in the front-rear direction (the illustration is omitted). The sensor 170 is in the form of a microswitch and has an actuating portion 171.

[0088] As Figure 12 shown, the first intermediate member 160 has a contact portion 166. The contact portion 166 is a portion for contacting the actuating portion 171 of the sensor 170. Therefore, the contact portion 166 is provided near the lowermost part of the first intermediate member main body 61 according to the position of the sensor 170. The contact portion 166 is provided at a position in the circumferential direction different from that of the pressed portions 62a to 62c. Therefore, similarly to the first embodiment, the degree of freedom in the arrangement of the sensor 170 is increased. However, the arrangements of the contact portion 166 and the sensor 170 can be set arbitrarily.

[0089] In this grinder 100, in a state where the side handle 300 is not mounted, the first intermediate member 160 is located at the non-mounted position ( Figure 10 ), and the contact portion 166 does not contact the actuating portion 171. Therefore, the sensor 170 is in an off state. In contrast, when the side handle 300 is mounted, the first intermediate member 160 rotates to the mounted position ( Figure 11)When it is in this state, the contact portion 166 comes into contact with the actuating portion 171, and the sensor 170 changes to the on state. In this way, it is possible to detect whether or not the mounting side handle 300 is installed by means of a single sensor 170.

[0090] C. Third Embodiment:

[0091] Refer to Figures 13 - 20 The third embodiment of the present invention will be described. The grinding machine 200 according to the third embodiment is different from the first embodiment mainly in that it has a first intermediate member 260 and a first sensor 270 instead of the first intermediate member 60 and the sensor 70 of the first embodiment, and also in that it detects whether or not the cover 400 is installed. Hereinafter, only the differences between the third embodiment and the first embodiment will be described. In Figures 13 - 20 those, the same structural elements as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof is omitted.

[0092] As Figure 13 and Figure 14 shown, the first intermediate member 260 is arranged in the same manner as in the first embodiment, with the first intermediate member main body 261 surrounding the outer periphery of the cylindrical portion 21. Further, as Figure 17 and Figure 20 shown, the first intermediate member 260 is the same as in the first embodiment, and has an annular first intermediate member main body 261 and pressed portions 262a to 262c that are dispersedly arranged at circumferential positions corresponding to the first mounting portions 29a to 29c. Pressed surfaces 263a to 263c that face forward and radially outward are formed on the pressed portions 262a to 262c. The first intermediate member 260 further has a protruding portion 264 that protrudes radially outward from the lowermost portion of the first intermediate member main body 261. Tilting shafts 265 extend in the left and right directions from the right and left surfaces of the protruding portion 264, respectively. The tilting shafts 265 have a tilting axis AX3 that extends in the left and right directions. Since the protruding portion 264 is located at a position radially outside the first intermediate member main body 261, the tilting axis AX3 is also located at a position radially outside the first intermediate member main body 261.

[0093] The tilting shafts 265 are mounted on the gear housing 20 by means of anti - detachment members 280 in such a manner that the first intermediate member 260 can tilt (in other words, pivot) about the tilting shafts 265. As Figure 19As shown, the anti - detachment member 280 has a main body 281 and protrusions 282, 283. The main body 281 has the shape of a rectangular flat plate orthogonal to the front - rear direction. The protrusions 282, 283 protrude forward from the front surface of the main body 281 and are arranged separately in the left - right direction. Semi - circular grooves 282a, 283a extending in the left - right direction are respectively formed in the protrusions 282, 283. The main body 281 has through - holes 284, 285 at both ends in its left - right direction. As Figure 15 , Figure 16 shown, by inserting and fastening the bolt 286 through the through - holes 284, 285 into the threaded holes formed in the gear housing 20, the anti - detachment member 280 is fixed to the gear housing 20.

[0094] Before installing the anti - detachment member 280, the tilting shaft 265 of the first intermediate member 260 is inserted into a semi - circular groove (not shown) formed in the gear housing 20 from the rear side. In this state, when the anti - detachment member 280 is installed on the gear housing 20 from the rear side, a circular hole is formed by the semi - circular groove of the gear housing 20 and the grooves 282a, 283a of the anti - detachment member 280. The tilting shaft 265 is pivotally held in this hole.

[0095] As Figure 13 , Figure 14 shown, the first intermediate member 260 also has a protrusion 268 that extends backward from the first intermediate member main body 61. The protrusion 268 is located near the pressed portion 262b. Around the protrusion 268, a spring 266 in the form of a helical spring is arranged in such a way that the protrusion 268 is inserted into the inside of the spring 266. One end of the spring 266 rests on the rear surface of the first intermediate member main body 261, and the other end rests on the front surface of the anti - detachment portion 272 of a sensor housing 271 described later. The spring 266 biases the first intermediate member 260 forward.

[0096] In a state where the side handle 300 is not installed, as Figure 13 and Figure 15 shown, the first intermediate member 260 is arranged at an angle substantially orthogonal to the rotation axis AX1 in the longitudinal section. In contrast, when the side handle 300 is installed on any one of the first mounting portions 29a - 29c, any one of the pressed surfaces 263a - 263c corresponding to the installation position of the side handle 300 is pressed. As described above, the pressed surfaces 263a - 263c all face forward and radially outward. Therefore, when the side handle 300 is installed from the radially outer side toward the rotation axis AX1, the pressed surfaces 263a - 263c receive a backward force. Accordingly, as Figure 14 and Figure 16As shown, the first intermediate member 260 tilts backward about the tilt axis 265 against the loading force of the spring 266. On the other hand, when the side handle 300 is removed, the first intermediate member 260 returns to the position shown by the loading force of the spring 266. Figure 13 and Figure 15 the position shown.

[0097] As Figure 17 shown, the first magnet 267 is held on the right side surface of the pressed portion 262b. When the first intermediate member 260 tilts by installing the side handle 300, the first magnet 267 held on the first intermediate member 260 also moves together. This movement is detected by the first sensor 270 in the form of a magnetic sensor. In this way, it is possible to detect whether the side handle 300 is installed or not by a single first sensor 270. The first magnet 267 is located at a position radially outside the first intermediate member main body 261 and is substantially facing the tilt axis AX3 with the first intermediate member main body 261 in between. Therefore, the distance from the tilt axis AX3 to the first magnet 267 can be increased. That is, for the same tilt angle of the first intermediate member 260, the displacement amount of the first magnet 267 can be increased. Therefore, it is easy to ensure the detection accuracy of the first sensor 270.

[0098] As Figure 20 shown, the first sensor 270 is provided in a state of being housed in the sensor housing 271. As Figure 18 shown, the sensor housing 271 has a detachment prevention portion 272, a sensor housing portion 273, and mounting portions 274, 275. The detachment prevention portion 272 has the shape of a rectangular flat plate orthogonal to the front-rear direction. As Figure 13 , Figure 14 , Figure 20 shown, the detachment prevention portion 272 supports the rear end of the spring 266. In addition, as Figure 15 and Figure 16 shown, the detachment prevention portion 272 is arranged so as to extend to a position below the upper end of the first intermediate member main body 261, and thus also functions as a detachment prevention member for the first intermediate member 260.

[0099] The sensor housing portion 273 is located above and to the right of the detachment prevention portion 272 and has a box-shaped shape extending forward from the detachment prevention portion 272. The first sensor 270 is housed inside the sensor housing portion 273. The mounting portions 274, 275 extend to the right or left from the left and right ends of the detachment prevention portion 272, respectively. The mounting portions 274, 275 have through holes 276, 277 extending in the front-rear direction, respectively. As Figure 15 , Figure 16As shown, the bolt 278 is inserted through the through holes 276 and 277 and fastened to the threaded hole formed in the gear housing 20, whereby the sensor housing 271 is fixed to the gear housing 20.

[0100] According to this sensor housing 271, as Figure 20 shown, the first sensor 270 is held in such a manner that the first sensor 270 and the first magnet 267 face each other in the left-right direction (in other words, the direction in which the tilt axis AX3 extends). Therefore, a magnetic sensor of the alternating magnetic field operation type can be used as the first sensor 270 to detect the displacement of the first magnet 267 in the front-back direction with high precision. However, the arrangement of the first sensor 270 and the first magnet 267, and the form of the first sensor 270 are not particularly limited. For example, in an alternative embodiment, the first sensor 270 and the first magnet 267 may be arranged to face each other in the front-back direction, and a magnetic sensor of the unidirectional operation type may be used as the first sensor 270.

[0101] As Figure 13 and Figure 14 shown, in order to detect the presence or absence of the mounting cover 400, the grinding machine 200 further includes a second intermediate member 290, a second magnet 294, and a second sensor 296. The second intermediate member 290 has: a magnet holding portion 291 for holding the second magnet 294; and a pressed portion 292 that is pressed by the mounting portion 420 of the cover 400 when the cover 400 is mounted. The magnet holding portion 291 and the pressed portion 292 form a substantially L-shaped configuration when viewed from the left-right direction. A through hole 293 extending in the left-right direction is formed at the connecting portion between the magnet holding portion 291 and the pressed portion 292. The magnet holding portion 291 holds the second magnet 294 at its tip (the end portion opposite to the above-mentioned connecting portion).

[0102] The grinding machine 200 further includes an integral housing 297 that holds the second intermediate member 290 and the second sensor 296. The housing 297 has a box-shaped configuration with a partially open top, and the second sensor 296 is fixed to the inner surface on the upper side thereof so as to face the second magnet 294. Moreover, the housing 297 has a right surface and a left surface (not shown in the figure). The right surface and the left surface each have a through hole extending in the left-right direction. By inserting a pin through these through holes and the through hole 293, the second intermediate member 290 is held by the housing 297 so as to be pivotable about the pin. In this way, by mounting the second sensor 296 and the second intermediate member 290 on the common integral housing 297, the relative positions of the second sensor 296 and the second intermediate member 290 (more specifically, the second magnet 294) are defined. Therefore, it is not necessary to adjust the relative positions of the two when assembling the grinding machine 200.

[0103] A spring 295 is disposed between the pressed portion 292 and the inner surface of the upper side of the housing 297. The spring 295 biases the pressed portion 292 downward. Therefore, in a state where the cover 400 is not installed, the pressed portion 292 extends in a direction substantially parallel to the front-rear direction in a side cross-section (illustration omitted). In contrast, when the cover 400 is installed on the second mounting portion 22 of the gear housing 20, as Figure 13 , Figure 14 shown, the top end of the pressed portion 292 is pressed upward by the mounting portion 420, and the second intermediate member 290 pivots clockwise against the biasing force of the spring 295. Accordingly, the second magnet 294 also displaces in the front-rear direction. By detecting this displacement by the first sensor 270, it is possible to detect whether the cover 400 is installed or not.

[0104] The detection results of the first sensor 270 and the second sensor 296 are respectively output to the controller 33. In the present embodiment, the controller 33 is configured to allow the driving of the electric motor 31 only when the signal input from the first sensor 270 indicates that the side handle 300 is installed and the input signal indicates that the cover 400 is installed. In a state where at least one of the side handle 300 and the cover 400 is not installed, even if the user operates the operation member 50 to the ON position and a detection signal is sent from the switch 41 to the controller 33, the controller 33 prohibits the driving of the electric motor 31.

[0105] The embodiments of the present invention have been described above. The above-described embodiments are merely for facilitating the understanding of the present invention and do not limit the present invention. The present invention can be changed and improved without departing from its gist, and equivalents thereof are also included in the present invention. In addition, within the scope of being able to solve at least a part of the above technical problems or being able to exhibit at least a part of the effects thereof, the technical solutions and the respective elements described in the specification can be arbitrarily combined or omitted.

[0106] For example, the shapes and forms of the structural components of the above-described grinder 10 are merely exemplary and can be arbitrarily changed as long as the functions of the structural components are ensured. For example, instead of protruding radially outward, the pressed portions 62a to 62c of the first intermediate member 60 may also protrude only forward or backward. Or, in the third embodiment, the pressed portion may also be a single portion that continuously extends from the position of the pressed portion 262a to the position of the pressed portion 262c along the outer circumference of the first intermediate member main body 261.

[0107] Alternatively, when the side handle 300 is installed, the first intermediate members 60, 160, 260 may be indirectly pressed by the side handle 300. That is, an additional member that is pressed by the side handle 300 and displaced may be provided, and the first intermediate members 60, 160, 260 may be displaced by this additional member. Similarly, when the cover 400 is installed, the second intermediate member 290 may be indirectly pressed by the cover 400.

[0108] Moreover, the structure including the second intermediate member 290, the second magnet 294, and the second sensor 296 exemplified as the third embodiment may be applied to the first or second embodiment.

[0109] Not limited to magnetic sensors or microswitches, the sensors 70, 170, 270 may also be any type of sensor capable of detecting the displacement of the first intermediate members 60, 160, 260. For example, the sensors may also be photoelectric sensors, ultrasonic distance sensors, etc.

[0110] Furthermore, instead of or in addition to the structure that permits or prohibits the driving of the electric motor 31 according to the installation state of the side handle 300 (or the side handle 300 and the cover 400), the grinders 10, 100, 200 may have a notification unit for notifying the user that the side handle 300 (or the side handle 300 and the cover 400) is not installed. The form of notification may be light emission, sound emission, text display, or a combination of these methods. For example, the notification unit may also have at least one of a light-emitting element such as an LED, a GUI screen, and a speaker.

[0111] Moreover, the above-described embodiments are not limited to the grinder 10, and can also be applied to any tool configured to be able to selectively install accessories at multiple locations.

[0112] Description of Reference Numerals

[0113] 10, 100, 200: Grinding machines; 20: Gear housing; 20a: Spring seat; 21: Cylindrical portion; 22: Second mounting portion; 23: Pinion gear; 24: Bull gear; 25: Spindle; 26: Inner flange; 27: Lock nut; 28: Tip tool; 29a - 29c: First mounting portion; 30: Motor housing; 31: Electric motor; 32: Motor shaft; 33: Controller; 34, 35: Bearings; 40: Handle housing; 41: Switch; 50: Operating member; 57: Locking switch; 60, 160, 260: First intermediate member; 61, 261: First intermediate member body; 62a - 62c, 262a - 262c: Pressed portion; 63a - 63c, 263a - 263c: Pressed surface; 64: Notch portion; 65: Protrusion; 66: Magnet holding portion; 67: Magnet; 68: Spring; 69: Snap ring; 70, 170: Sensors; 166: Contact portion; 171: Actuating portion; 264: Protruding portion; 265: Tilting shaft; 266: Spring; 267: First magnet; 268: Protrusion; 270: First sensor; 271: Sensor housing; 272: Anti - detachment portion; 273: Sensor receiving portion; 274, 265: Mounting portion; 276, 267: Through - hole; 278: Bolt; 280: Anti - detachment member; 281: Main body; 282, 283: Protruding portion; 282a, 283a: Groove; 284, 285: Through - hole; 286: Bolt; 290: Second intermediate member; 291: Magnet holding portion; 292: Pressed portion; 293: Through - hole; 294: Second magnet; 295: Spring; 296: Second sensor; 297: Housing; 300: Side handle; 310: Handle portion; 320: Mounting portion; 400: Cover; 410: Cover body; 420: Mounting portion; 421, 422: Flange; 423: Bolt; AX1, AX2: Rotation axes; AX3: Tilting axis.

Claims

1. A tool, characterized in that, comprises: a first accessory; at least two first mounting parts for selectively mounting the first accessory in a detachable manner; a single first intermediate member configured to be provided in a manner common to the at least two first mounting parts and having at least one pressed portion, wherein when the first accessory is mounted on any one of the at least two first mounting parts selected, the at least one pressed portion is directly or indirectly pressed by the first accessory, and when the at least one pressed portion is pressed, the first intermediate member is displaced; and a single first sensor configured to detect that the first intermediate member has been displaced.

2. The tool according to claim 1, characterized in that it has a biasing member that biases the first intermediate member to a position where it is not directly or indirectly pressed by the first accessory.

3. The tool according to claim 1 or 2, characterized in that the at least one pressed portion has a pressed surface that forms an angle with respect to the pressing direction in which the first accessory directly or indirectly presses the at least one pressed portion, so that the first intermediate member is displaced in a direction different from the pressing direction.

4. The tool according to claim 1 or 2, characterized in that the first intermediate member has a first intermediate member body having a shape of a ring or a part of a ring, the at least two first mounting parts are respectively arranged at positions separated from each other in the circumferential direction of the ring or the part of the ring.

5. The tool according to claim 4, characterized in that the at least one pressed portion is provided at a position corresponding to the positions of the at least two first mounting parts.

6. The tool according to claim 4, characterized in that the at least one pressed portion protrudes radially outward from the first intermediate member body.

7. The tool according to claim 4, characterized in that the first intermediate member is configured to rotate along the circumferential direction when the at least one pressed portion is pressed.

8. The tool according to claim 2, characterized in that the first intermediate member has a first intermediate member body having a shape of a ring or a part of a ring, the at least two first mounting parts are respectively arranged at positions separated from each other in the circumferential direction of the ring or the part of the ring, the first intermediate member is configured to rotate along the circumferential direction when the at least one pressed portion is pressed, the first intermediate member body has a notch portion that is partially lacking along the circumferential direction, the biasing member is housed in the notch portion.

9. The tool according to claim 4, characterized in that the first intermediate member has a tilting axis, the first intermediate member is configured to tilt about the tilting axis when the at least one pressed portion is pressed.

10. The tool according to claim 1 or 2, characterized in that the first intermediate member has a first magnet and a magnet holding portion that holds the first magnet, the first sensor is a magnetic sensor that detects the displacement of the first magnet.

11. The tool according to claim 10, wherein the first intermediate member has a first intermediate member main body having a shape of a ring or a part of a ring, the first intermediate member is configured to rotate in the circumferential direction of the ring or the part of the ring when the at least one pressed portion is pressed, the magnet holding portion projects radially outward from the first intermediate member main body.

12. The tool according to claim 11, wherein the magnet holding portion is provided at a position in the circumferential direction different from the at least one pressed portion.

13. The tool according to claim 10, wherein the first intermediate member has a first intermediate member main body having a shape of a ring or a part of a ring, the first intermediate member has a tilting axis, the first intermediate member is configured to tilt about the tilting axis when the at least one pressed portion is pressed, the tilting axis is located at a position radially outside the first intermediate member main body, the first magnet is disposed at a position radially outside the first intermediate member main body and substantially facing the tilting axis with the first intermediate member main body interposed therebetween.

14. The tool according to claim 13, wherein the magnetic sensor and the first magnet are arranged such that the magnetic sensor and the first magnet face each other in the direction in which the tilting axis extends.

15. The tool according to claim 1 or 2, wherein the first sensor is a microswitch, the first intermediate member has a contact portion for contacting the microswitch when the first intermediate member is displaced to turn on the microswitch.

16. The tool according to claim 15, wherein the first intermediate member has a first intermediate member main body having a shape of a ring or a part of a ring, the at least one pressed portion is provided at a position corresponding to the position of the at least two first mounting portions, the contact portion is provided at a position in the circumferential direction of the ring or the part of the ring different from the at least one pressed portion.

17. The tool according to claim 1 or 2, characterized in that, comprising: a second accessory; a second mounting portion for detachably mounting the second accessory; a second intermediate member configured to pivot when the second accessory is mounted on the second mounting portion and is directly or indirectly pressed by the second accessory; and a second sensor for detecting that the second intermediate member has pivoted.

18. The tool according to claim 17, wherein the second intermediate member has a second magnet, the second sensor is a magnetic sensor configured to detect the displacement of the second magnet.

19. The tool according to claim 17, characterized in that, comprising: an electric motor; and a controller configured to control the driving of the electric motor, the controller performs the following control: The driving of the electric motor is permitted when both the first condition and the second condition are satisfied. The first condition means that the first accessory is mounted on either one of the at least two first mounting portions detected by the first sensor. The second condition means that the second accessory is detected by the second sensor to be mounted on the second mounting portion. When at least one of the first condition and the second condition is not satisfied, the driving of the electric motor is prohibited.

20. The tool according to claim 19, characterized in that, It has: a bearing that rotatably supports the motor shaft of the electric motor; and a housing having a cylindrical portion that houses and supports the bearing. The first intermediate member has a first intermediate member main body having a shape of a ring or a part of a ring. The first intermediate member is arranged such that the first intermediate member main body surrounds the outer periphery of the cylindrical portion.

21. The tool according to claim 20, wherein the tool is a grinding machine having a tip tool configured to rotate by the electric motor. The first accessory is a side handle. The second accessory is a cover that partially covers the tip tool.

22. A grinding machine, characterized in that, It has: an electric motor; a tip tool configured to rotate by the electric motor; a side handle; at least two first mounting portions for selectively and detachably mounting the side handle; a single first intermediate member configured to be provided in a manner common to the at least two first mounting portions and having a first intermediate member main body and at least two pressed portions. The first intermediate member main body has a shape of a ring or a part of a ring. The at least two pressed portions are arranged at at least two positions corresponding to the positions of the at least two first mounting portions respectively. When the side handle is mounted on one of the at least two first mounting portions arbitrarily selected, the pressed portion is directly or indirectly pressed by the side handle. When any one of the at least two pressed portions is pressed, the first intermediate member rotates in the circumferential direction of the ring or the part of the ring. a biasing member that biases the first intermediate member to a position when it is not directly or indirectly pressed by the side handle; and a single first sensor configured to detect the rotation of the first intermediate member. The at least two first mounting portions are respectively arranged at positions separated from each other in the circumferential direction. The at least two pressed portions respectively have pressed surfaces that form an angle with respect to the pressing direction in which the side handle directly or indirectly presses the pressed portion, so that the first intermediate member rotates in a direction different from the pressing direction. The at least two pressed portions respectively project radially outward from the first intermediate member main body.

Images