Power tool

Abstract

A tool is provided. A power tool has a motor that provides driving force to a tip tool, a brake mechanism that is arranged on a driving force transmission path from the motor to the tip tool and brakes the driving of the tip tool, at least one attachment portion that removably mounts an accessory, and a restriction member that is displaced by the accessory directly or indirectly when the accessory is mounted on any one of the at least one attachment portion. In a state where the accessory is not mounted on any one of the at least one attachment portion, the restriction member is located at a blocking position that is a position where the brake state of the brake mechanism is blocked by inter-member contact. In a state where the accessory is mounted on any one of the at least one attachment portion, the restriction member is located at an allowing position that is a position where the brake state is allowed to be released because inter-member contact does not occur. Accordingly, the power tool that removably mounts the accessory is improved.

Description

Technical Field

[0001] This invention relates to a power tool. Background Technology

[0002] Sometimes, various accessories are detachably mounted on power tools. For example, in a grinder having a top tool configured as a rotary drive, a cover (also called a wheel cover, disc cover, blade housing, etc.) and a side handle are provided as detachable accessories, wherein the cover is used to cover a portion of the top tool; and the side handle is used to hold the grinder with the other hand while the user holds the handle of the grinder with one hand.

[0003] In such grinding machines, it is required to prevent use of the grinding machine without the accessories installed. For example, Patent Document 1 discloses a grinding machine with a sensor and a controller, the sensor being used to detect whether a cover is installed; the controller prohibits rotation of the top tool when the cover is not installed. Patent Document 2 discloses a grinding machine with a sensor for detecting whether a cover is installed and a sensor for detecting whether a side handle is installed. Patent Document 3 discloses a grinding machine with a blocking member that moves depending on whether an accessory is installed. In this grinding machine, when no accessory is installed, a mechanical element that engages with an operating member for turning a switch on comes into contact with the blocking member, thereby preventing the operating member from moving to the on position.

[0004] [Existing Technical Documents]

[0005] [Patent Literature]

[0006] Patent Document 1: International Publication No. 2017 / 051893

[0007] Patent Document 2: U.S. Patent Application Publication No. 2018 / 272494

[0008] Patent Document 3: U.S. Patent Application Publication No. 2018 / 0326554 Summary of the Invention

[0009] [The technical problem the invention aims to solve]

[0010] However, the aforementioned technologies have room for improvement. For example, in the technologies described in Patent Documents 1 and 2, in the event of sensor malfunction or decreased sensor sensitivity due to dust adhesion, the installation of the cover or side handle may fail to be detected. Furthermore, in the technology described in Patent Document 3, since the displacement of the operating parts is restricted only when no accessories are installed, there is room for improvement in reliably restricting the drive of the tip tool. These points are not limited to grinders and are common to power tools with detachable accessories.

[0011] [Technical solutions used to solve technical problems]

[0012] This specification discloses a power tool. The power tool may include: a motor, a braking mechanism, at least one mounting portion, and a limiting member, wherein the motor is configured to provide driving force to a tip tool; the braking mechanism is disposed on the driving force transmission path from the motor to the tip tool and is configured to brake the drive of the tip tool; the at least one mounting portion is configured to detachably mount an accessory; the limiting member is configured to be displaced by direct or indirect pressure from the accessory when the accessory is mounted on any of the at least one mounting portion. Specifically, when the accessory is not mounted on any of the at least one mounting portion, the limiting member is in a blocking position, which means a position that prevents the release of the braking state of the operating braking mechanism by inter-component abutment; when the accessory is mounted on any of the at least one mounting portion, the limiting member is in an allowable position, which means a position that allows the release of the operating braking state due to the absence of inter-component abutment.

[0013] According to this power tool, a structure can be implemented that allows the tip tool to be driven only when an accessory is installed, without the use of sensors and solely through mechanical means. Furthermore, when no accessory is installed, a limiting component prevents the release of the braking mechanism from the braking state. That is, the power tool is held in a braking state. In other words, the tip tool is in a forced stopped state, regardless of the on / off state of the switch used to drive the tip tool. Therefore, the driving of the tip tool can be more reliably limited when no accessory is installed. Attached Figure Description

[0014] Figure 1 yes Figure 2 A longitudinal sectional view of the grinding machine according to the first embodiment of the present invention, AA, with no side handle installed, the top tool in a braked state, and the operating components in the disengaged position.

[0015] Figure 2 yes Figure 1 A cross-sectional view of BB's grinding machine.

[0016] Figure 3 yes Figure 1 A partial cross-sectional view of the CC grinder.

[0017] Figure 4 yes Figure 1 A partial cross-sectional view of the DD grinding machine.

[0018] Figure 5 yes Figure 1 Longitudinal sectional view of the EE grinding machine.

[0019] Figure 6 yes Figure 1 A longitudinal sectional view of the FF grinder.

[0020] Figure 7 yes Figure 1 A partially enlarged view of the grinding machine shown.

[0021] Figure 8 It is a 3D view of the limiting component.

[0022] Figure 9 It is a 3D view of the intermediate component.

[0023] Figure 10 Is with Figure 1 The corresponding longitudinal section view of the grinder shows that it is equipped with a side handle, the top tool is in the brake-off state, and the operating parts are in the on position.

[0024] Figure 11 Is with Figure 5 The corresponding longitudinal sectional view of the grinder shows the state with the side handle installed.

[0025] Figure 12 Is with Figure 6 The corresponding longitudinal sectional view of the grinder shows the state with the side handle installed.

[0026] Figure 13 Is with Figure 7 The corresponding enlarged view of the grinder shows the state with the side handle installed.

[0027] Figure 14 This is a longitudinal sectional view of the grinding machine according to the second embodiment of the present invention, without a side handle, with the top tool in a braked state and the operating component in a locked state in the disconnected position.

[0028] Figure 15 Is with Figure 14 The corresponding longitudinal section view of the grinder shows that it is equipped with a side handle, the top tool is in the brake-released state, and the operating parts are in the disconnected position in the lock-released state.

[0029] Figure 16 Is with Figure 14 The corresponding longitudinal section view of the grinder shows that it is equipped with a side handle, the top tool is in the brake-released state, and the operating part is in the energized position in the lock-released state.

[0030] Figure 17 yes Figure 14 A partially enlarged view of the grinding machine shown.

[0031] Figure 18 yes Figure 15 A partially enlarged view of the grinding machine shown.

[0032] Figure 19 yes Figure 14 A partial cross-sectional view of GG's grinding machine.

[0033] Figure 20 yes Figure 15 A partial cross-sectional view of GG's grinding machine.

[0034] [Explanation of reference numerals in the attached figures]

[0035] 10, 140: Grinding machine; 20: Gear housing; 20a: Hole; 20b: Stop; 22: Mounting part; 23: Small bevel gear; 24: Large bevel gear; 25: Main shaft; 26: Inner flange; 27: Locking nut; 28: Top tool; 29a: Mounting part; 29a: First mounting part; 29b: Mounting part; 29b: Second mounting part; 30, 430: Motor housing; 31: Electric motor; 32: Motor shaft; 33: Bearing; 34: Bearing support; 35: Protrusion; 36: Through hole; 37: Abutment part; 38: Abutment surface; 39: Baffle plate; 40, 440: Handle housing; 41: Switch; 42: Input component; 43: Hole; 44: Support part; 45: Linkage component; 46: Arm; 46: First arm; 47: Second arm; 48: Third arm; 49: Through hole; 50, 450: Operating component; 51: Front end; 52: Rear end; 53: Protrusion; 54: Locking component; 55: Abutting end; 56: Operating end; 57: Pin; 58: Hole; 60, 460: Braking mechanism; 61: Brake retainer; 62: Brake plate; 62a: Cylindrical part; 62b: Braked part; 63, 463: Braking component; 63a, 463a: Disc; 63b: Inner protrusion; 63c: Outer protrusion; 64: Brake shoe; 65: Force-applying component; 66, 466: Brake release component; 70: Restricting component; 71: Main body; 72: Through hole; 73: Pressed part; 74: Groove; 75: Restricting part; 76: Screw; 77: Force-applying part; 80: Intermediate part; 81: Pressing part; 82: Pressed part; 83: Groove; 84: Through hole; 85: Press-in pin; 86: Leaf spring; 200: Side handle; 210: Mounting part; 220: Pressing part; 300: Cover; 310: Cover body; 320: Mounting part; 431: Through hole; 443: Locking part; 444: Base; 445: Engaging part; 446: Support part; 451: Actual end; 452: Engaging part; 453, 454: Protrusion; 455: Pivoting component; 456: First arm; 457: Second arm; 458: Pin; 463d: Notch; 465: Helical spring; 467: Flange part; 468: Pushing part; 469: Top end part; AX1, AX2: Rotation axis. Detailed Implementation

[0036] In one or more embodiments, at least one mounting portion may have multiple mounting portions. Based on this structure, the above embodiments can be applied to power tools capable of selectively mounting accessories at multiple mounting locations.

[0037] In one or more embodiments, the limiting component may be a single component shared by the plurality of mounting portions. According to this structure, since the plurality of mounting portions share a single limiting component, the number of parts can be reduced, and the device structure can be simplified.

[0038] In one or more embodiments, the plurality of mounting portions may include a first mounting portion and a second mounting portion. Permissible positions may include a first permissible position and a second permissible position. The limiting member may be configured such that, when the accessory is mounted on the first mounting portion, the limiting member displaces from a blocking position in a first direction to a first permissible position, and when the accessory is mounted on the second mounting portion, the limiting member displaces from a blocking position in a second direction opposite to the first direction to a second permissible position. According to this structure, a reasonable structure is provided for multiple mounting portions to share a single limiting member. In other words, a structure can be implemented with a simple device structure such that, when the accessory is mounted on any of the plurality of mounting portions, the limiting member is pressed by the accessory to allow the release operation of the braking state.

[0039] In one or more embodiments, the power tool may further include an intermediate component configured to be displaced by the accessory when the accessory is mounted on any of the at least one mounting portion. The limiting component may also be configured to be displaced by the intermediate component when the accessory is mounted on any of the at least one mounting portion. According to this structure, a reasonable configuration is provided for displacement of the limiting component in a manner that allows release of the operating brake state when the accessory is mounted on any of the at least one mounting portion. In other words, compared to the case where the limiting component is directly pushed by the accessory when the accessory is mounted on any of the at least one mounting portion, the limiting component can be miniaturized, and therefore, its layout within the device is less constrained by space limitations.

[0040] In one or more embodiments, the motor may have a motor shaft. The power tool may also have a final output shaft configured to transmit driving force from the motor shaft and to mount a tip tool. A braking mechanism may be disposed around the motor shaft. According to this configuration, since the braking mechanism is not disposed around the final output shaft, the area around the final output shaft can be miniaturized and lightened. In such power tools, the user typically holds parts other than the area around the final output shaft during use; therefore, according to this configuration, the operability of the power tool is improved by miniaturizing and lightening the area around the final output shaft.

[0041] In one or more embodiments, the braking mechanism may further include a braked component, a braking component, a force-applying component, and a brake release component. The braked component is fixed to the motor shaft and configured to circumferentially surround the motor shaft. The braking component is configured to achieve a braking state by being pressed against the braked component and is displaceably positioned between a braking position abutting the braked component and a non-braking position separated from the braked component. The force-applying component applies force to the braking component towards the braking position. The brake release component is configured to push the braking component from the braking position to the non-braking position against the force of the force-applying component, thereby displacing it. According to this structure, the large size of power tools can be suppressed while providing braking functionality.

[0042] In one or more embodiments, the power tool may further include a switch and an operating component, wherein the switch drives a motor; and the operating component is configured to displace between an open position (disconnecting the switch) and an on position (connecting the switch). A brake release component may be configured to be linked with the displacement of the operating component between the open and on positions. According to this structure, timing adjustments for the brake release operation and the switch connection operation (i.e., the operation of displacing the operating component from the open to the on position) become easier. Specifically, a structure can be easily implemented that reliably releases the brake state before the switch becomes on.

[0043] In one or more embodiments, the power tool may further include a linkage component configured to move in conjunction with the displacement of the operating component between an open position and an on position. The linkage component may be configured to push the switch in such a way that it moves from the open position to the on position, thereby turning the switch on, and simultaneously push the brake release component to release the braking state. According to this structure, a reliable release of the braking state before the switch becomes on can be easily achieved.

[0044] In one or more embodiments, the power tool may further include a switch, an operating member, and a locking part, wherein the switch is used to drive a motor; the operating member is configured to be displaceable between an open position (turning the switch off) and an on position (turning the switch on); and the locking part is configured to switch the state of the operating member between a locking state (preventing the operating member from moving from the open position to the on position) and a locking release state (allowing the operating member to move from the open position to the on position) by changing the engagement state with the operating member. The brake release member may be configured to be linked with an operation for switching between the locking and locking release states. According to this structure, if the state of the operating member is switched from the locking state to the locking release state (at which point the switch is in the open state), the braking state is released by the brake release member. Therefore, a structure that reliably releases the braking state before the switch becomes on can be easily implemented.

[0045] Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. Furthermore, in the following embodiments, a portable electric disc grinder (hereinafter simply referred to as a grinder) is illustrated as a power tool.

[0046] First, the first embodiment of the present invention will be described. For example... Figure 1 As shown, the grinding machine 10 according to the first embodiment is configured to drive a generally disc-shaped tip tool 28 mounted on a main shaft 25, which serves as the final output shaft, to rotate. The main shaft 25 is rotated by a rotational driving force provided by an electric motor 31, which serves as a prime mover. Grinding wheels, grinding pads, brushes, saw blades, etc., are prepared as the tip tool 28 that can be mounted on the grinding machine 10. The user selects an appropriate tip tool 28 according to the desired processing operation and mounts it on the grinding machine 10. Using the grinding machine 10, grinding, polishing, cutting, and other processing operations can be performed on the workpiece depending on the type of tip tool 28.

[0047] 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-back direction of the grinder 10. The side containing the tip tool 28 in the front-back direction is defined as the front side, and the opposite side is defined as the rear side. Furthermore, the direction in which the rotation axis AX2 of the spindle 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 containing the tip tool 28 in the up-down direction is defined as the lower side, and the opposite side is defined as the upper side. Additionally, the direction orthogonal to the up-down and front-back directions is defined as the left-right direction of the grinder 10. The right side when viewed from the rear 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.

[0048] like Figure 1 and Figure 2 As shown, the grinder 10 has a gear housing 20, a motor housing 30, and a handle housing 40. An electric motor 31 is housed within the motor housing 30, located between the gear housing 20 and the handle housing 40 in the longitudinal direction, i.e., the length direction of the grinder 10. The electric motor 31 is configured to be driven by externally supplied electricity (alternating current in this embodiment, but direct current is also possible).

[0049] The gear housing 20 houses a mechanism for transmitting the rotational driving force of the electric motor 31 to the tip tool 28. Specifically, the gear housing 20 houses a small bevel gear 23, a large bevel gear 24, and a spindle 25. The small bevel gear 23 is fixed around the front end of the motor shaft 32 of the electric motor 31. The spindle 25 is supported by bearings arranged separately in the vertical direction, allowing it to rotate around a rotation axis AX2. The rotation axis AX2 intersects (more specifically, is orthogonal) the rotation axis AX1 of the electric motor 31. The large bevel gear 24 is fixed around the upper side of the spindle 25 and meshes with the small bevel gear 23. The gear housing 20 has a mounting portion 22 for detachably mounting a cover 300 at its lower end. The mounting portion 22 has a cylindrical shape extending in the vertical direction. The main shaft 25 extends vertically within the gear housing 20 and extends from the gear housing 20 (more specifically, the mounting portion 22) on the lower side.

[0050] At the lower end of the main shaft 25 extending from the gear housing 20, an inner flange 26 is mounted around the main shaft 25. An external thread is formed in the main shaft 25 below the inner flange 26, and a locking nut 27 is mounted on the external thread. A tip tool 28 is held between the inner flange 26 and the locking nut 27, and the position of the tip tool 28 relative to the main shaft 25 is fixed by tightening the locking nut 27.

[0051] The handle housing 40 is the part used by the user to hold the grinder 10 with one hand when using it. The handle housing 40 has a generally cylindrical shape extending in the front-to-back direction. Inside the handle housing 40 is a switch 41 for driving the electric motor 31. An operating member 50 is provided on the lower side of the handle housing 40, which is configured to be in an off position (see reference) where the switch 41 is in the off state. Figure 1 ) and the ON position that makes switch 41 ON (refer to Figure 10 Displacement between ).

[0052] When the user operates the operating component 50 from the off position to the on position, thereby driving the electric motor 31, the rotation of the motor shaft 32 is slowed down by the small bevel gear 23 and the large bevel gear 24, and simultaneously transmitted to the main shaft 25. At this time, the direction of rotational motion also changes 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, and as a result, the tip tool 28, which is fixed by the inner flange 26 and the locking nut 27, rotates together with the main shaft 25. As can be seen from the above description, the motor shaft 32, the small bevel gear 23, the large bevel gear 24, and the main shaft 25 form the driving force transmission path from the electric motor 31 to the tip tool 28.

[0053] like Figure 1 , Figure 2 and Figure 7 As shown, the grinding machine 10 also includes a braking mechanism 60, which is configured to brake the drive of the tip tool 28. In this embodiment, the braking mechanism 60 is disposed around the motor shaft 32 in the drive force transmission path from the electric motor 31 to the tip tool 28. Specifically, the braking mechanism 60 is disposed within a brake holder 61, which is disposed in the longitudinal direction between the gear housing 20 and the motor housing 30. The braking mechanism 60 includes a brake plate 62, a braking component 63, a brake shoe 64, a force application component 65, and a brake release component 66.

[0054] like Figure 7 As shown, the brake plate 62 has a cylindrical portion 62a and a braked portion 62b. The cylindrical portion 62a extends coaxially with the rotation axis AX1 in the front-rear direction, surrounding the motor shaft 32 circumferentially. The cylindrical portion 62a is fixed to the motor shaft 32 by pressing. The braked portion 62b is a flange-shaped portion extending radially outward from the rear end of the cylindrical portion 62a along the rotation axis AX1. The front end face of the braked portion 62b is formed as a plane orthogonal to the rotation axis AX1.

[0055] like Figure 7 As shown, the braking component 63 is an annular component arranged to surround the motor shaft 32. The braking component 63 has a radially extending disk 63a, an inner protrusion 63b, and an outer protrusion 63c. The inner protrusion 63b protrudes forward from the disk 63a along the inner edge of the disk 63a. The outer protrusion 63c is the portion extending forward from the disk 63a and is formed only at the bottom of the outer periphery of the disk 63a. The outer protrusion 63c extends to a position further forward than the inner protrusion 63b.

[0056] like Figure 7As shown, brake pad 64 is fixed to the rear end of disc 63a of brake component 63. Brake pad 64 is a disc-shaped component that surrounds cylindrical portion 62a circumferentially and is positioned to overlap with braked portion 62b when viewed from the front-rear direction. Disc 63a of brake component 63 extends to a position radially outward beyond brake pad 64.

[0057] like Figure 7 As shown, the force-applying component 65 in this embodiment is in the form of a helical spring. In a compressed state, the force-applying component 65 is positioned between the bearing support 34 of the supporting bearing 33 and the braking component 63, wherein the bearing 33 supports the motor shaft 32 on the front side. The force-applying component 65 is configured such that the cylindrical portion 62a of the brake plate 62 passes through its interior. The front end of the force-applying component 65 is embedded in the protrusion 35 of the bearing support 34 (i.e., protruding cylindrically from the bearing support 34 circumferentially to the rear), and the rear end of the force-applying component 65 is embedded radially outward of the inner protrusion 63b of the braking component 63. Therefore, the position of the force-applying component 65 in the direction orthogonal to the rotation axis AX1 is fixed, and the braking component 63 and brake shoe 64 are also held in appropriate positions in the direction orthogonal to the rotation axis AX1. With this structure, the braking component 63 and brake shoe 64 are configured to be displaceable in the front-rear direction according to the amount of compression of the force-applying component 65.

[0058] The force-applying component 65 always applies force to the braking component 63 and the brake pad 64 rearward (the braking position described later). Therefore, when no force is applied to the braking component 63 from the outside, the brake pad 64 abuts against the front end face of the braked portion 62b of the brake plate 62 and pushes the braked portion 62b rearward. This enables the braking function of the braking mechanism 60. In the state where the brake pad 64 pushes against the braked portion 62b (hereinafter referred to as the braking state), even if current is supplied to the electric motor 31, the rotation of the tip tool 28 stops. The position of the braking component 63 and the brake pad 64 in the braking state is also referred to as the braking position (in...). Figure 1 and Figure 7 (as shown in the image).

[0059] In this braking mechanism 60, the brake can be released by displacing the brake member 63 and the brake pads 64 forward. This released state is also referred to as the brake-released state. Specifically, a brake-release member 66, capable of displacement in the front-rear direction, is disposed on the rear side of the brake member 63. When this brake-release member 66 displaces forward, it abuts against the lower part of the disc 63a of the brake member 63, thereby pushing the brake member 63 forward. Thus, as... Figure 13As shown, the braking component 63 and brake pad 64 resist the force of the force-applying component 65 and displace forward. As a result, the brake pad 64 separates from the braked portion 62b of the brake plate 62, and the brake is released. The position of the braking component 63 and brake pad 64 in the brake-released state is also referred to as the non-braking position (in...). Figure 10 and Figure 13 (As shown in the diagram). The mechanism for displacing the brake release component 66 in the front-rear direction will be described later. According to the above-described braking mechanism 60, since its structural components are compactly arranged around the motor shaft 32, it is possible to suppress the enlargement of the grinding machine 10 while providing braking function.

[0060] The grinder 10 also has a side handle 200 (see reference). Figures 10-12 ) and cover 300 (refer to) Figure 1 As an accessory, the side handle 200 is prepared for the user to hold with the hand opposite to that holding the handle housing 40. By using the side handle 200, the user can hold the grinder 10 more stably. The side handle 200 has a handle portion (not shown) for the user to hold, a mounting portion 210 for mounting on the gear housing 20, and a pressing portion 220. The mounting portion 210 has a cylindrical shape extending along the length direction of the side handle 200 and extends from one end of the handle portion along the length direction of the side handle 200. External threads are formed on the outer peripheral surface of the mounting portion 210. The pressing portion 220 (see reference) Figure 11 The part extending cylindrically from the top of the mounting part 210 has an outer diameter smaller than that of the mounting part 210. The function of the pressing part 220 will be described later.

[0061] like Figure 2 As shown, the gear housing 20 has multiple (two in this embodiment) mounting portions 29a and 29b for detachably mounting the side handle 200. The mounting portions 29a and 29b are positioned at the same location in the front-rear direction and are separated from each other in the circumferential direction about the rotation axis AX1. More specifically, the first mounting portion 29a is formed on the left side of the gear housing 20, and the second mounting portion 29b is formed on the right side of the gear housing 20. The first mounting portion 29a and the second mounting portion 29b are both through-holes that communicate between the interior and exterior of the gear housing 20. An internal thread is formed on the inner surface of the through-hole to engage with the external thread of the mounting portion 210.

[0062] The side handle 200 can be mounted onto the gear housing 20 by screwing the mounting portion 210 of the side handle 200 onto one of the two mounting portions 29a and 29b. The user can arbitrarily select the mounting position of the side handle 200 from the mounting portions 29a and 29b depending on the type of work performed using the grinder 10, or whether they are right-handed or left-handed. In this embodiment, although two mounting portions 29a and 29b are provided, the number of mounting portions for mounting the side handle 200 is not particularly limited, and can be any number of more than one.

[0063] like Figure 1 As shown, the cover 300 has a cover body 310 and a mounting portion 320, wherein the cover body 310 covers a portion of the tip tool 28; the mounting portion 320 is used for mounting to the mounting portion 22. The cover body 310 covers approximately half of the rear side of the tip tool 28. In this embodiment, the cover body 310 covers the upper surface, lower surface, and circumferential surface between the upper and lower surfaces of the tip tool 28, but it may also cover only the upper surface and the circumferential surface depending on the type of tip tool 28 used. The mounting portion 320 has an open, generally annular shape and extends upward from the upper surface of the cover body 310. Since the structure of the mounting portion 320 is known, it is not shown in the figure, but the mounting portion 320 has two opposing flanges at two apex positions in the circumferential direction. When the mounting portion 320 is configured to surround the mounting portion 22 of the gear housing 20, the mounting portion 320 is fixed to the mounting portion 22 by inserting and tightening bolts in the threaded holes formed in the flanges, thereby reducing the radius of the annular shape of the mounting portion 320.

[0064] The aforementioned grinding machine 10 has a mechanical structure such that the braking mechanism 60 can only be released when the side handle 200 is installed in either of the mounting portions 29a or 29b of the gear housing 20. This mechanical structure will now be described in detail with reference to the accompanying drawings.

[0065] like Figure 1 As shown, an operating member 50 is provided on the lower side of the motor housing 30 and the handle housing 40. The operating member 50 is an elongated member extending in the front-to-back direction. The operating member 50 has a front end portion 51, a rear end portion 52, and two protrusions 53. The front end portion 51 and the rear end portion 52 are thinner than the other parts of the operating member 50 and protrude forward and backward, respectively.

[0066] like Figure 7 As shown, the front end portion 51 is inserted into a through hole 36 extending in the front-rear direction formed at the bottom of the motor housing 30, and engages with the motor housing 30 through its concave-convex shape. Figure 1As shown, the rear end portion 52 is supported by the bottom of the handle housing 40. Specifically, a hole 43 communicating with the interior of the handle housing 40 is formed in the bottom of the handle housing 40. A support portion 44 for defining the rear end of the hole 43 is formed on the rear side of the hole 43. The diameter of the support portion 44 is larger than the diameter of the portion of the support portion 44 further rearward in the handle housing 40, and its radially outer end protrudes forward. As a result, a stepped portion is formed on the radially inner side of the support portion 44. The rear end portion 52 of the operating member 50 is mounted on the stepped portion of the support portion 44. With this structure, the operating member 50 is mounted on the motor housing 30 and the handle housing 40 in an anti-disengagement state. Thus, the operating member 50 is configured such that it can be fulcrumped by the engagement portion of the front end portion 51 with the motor housing 30. Figure 1 The disconnection position shown is pivoted counterclockwise to Figure 10 The connection position is shown.

[0067] like Figure 1 As shown, two protrusions 53 extend upward from the upper part of the operating member 50 and are separated in the left-right direction (in Figure 1 In the middle, only the protrusion 53 on the left side can be seen. The protrusion 53 is located in the front-back direction at the position corresponding to the hole 43.

[0068] like Figure 1 As shown, a locking member 54 is mounted on the operating member 50. The locking member 54 is positioned approximately at the center of the operating member 50 in the front-rear direction. The locking member 54 is configured to be in a locked state (see reference 50) by changing its engagement state with the operating member 50. Figure 1 ) and lockout / unlock status (refer to Figure 10 The state of the operating component 50 is switched between the open and closed positions, wherein the locked state is a state that prevents the operating component 50 from moving from the closed position to the closed position; and the locked-out state is a state that allows the operating component 50 to move from the closed position to the closed position.

[0069] Specifically, the locking member 54 is supported by the operating member 50 via a pin 57, which is supported within a boss located inside the operating member 50. The locking member 54 can be centered on the pin 57. Figure 1 The locking position shown and Figure 10 The locking component 54 pivots between the shown lock-out positions. The locking component 54 is always engaged by a torsion spring (not shown). Figure 1 Apply force to the locking position shown.

[0070] The locking member 54 has an abutting end 55 and an operating end 56. When the locking member 54 is in the locked position, it protrudes downward through a hole 58. Additionally, the abutting end 55 abuts against abutting portion 37 at the rear end and bottom of the motor housing 30, which is configured to protrude downward from the motor housing 30. Therefore, even if the user moves the operating member 50 from the disengaged position (see reference...), the locking member 54 can still operate. Figure 1 To the connected position (refer to) Figure 10 When the user pushes the operating member 50 upward (hereinafter also referred to as the activation operation), the pivoting of the operating member 50 is also prevented. Thus, the locked state of the operating member 50 is maintained. On the other hand, when the user pulls the operating end 56 backward with their finger, the locking member 54 pivots counterclockwise against the force of the torsion spring. As a result, as... Figure 10 As shown, the locking member 54 is housed within the hole 58 of the operating member 50. That is, the locking member 54 is retracted to a position where it does not abut against the contact portion 37. As a result, the user can pivot the operating member 50 to... Figure 10 The connection position is shown.

[0071] like Figure 1 As shown, a connecting rod member 45 is positioned above the operating member 50. The connecting rod member 45 has a through hole 49 extending in the left-right direction. A pin (not shown) is inserted into this through hole 49, and the pin is supported by a boss formed inside the motor housing 30. Thus, the connecting rod member 45 is configured to pivot about the pin. The connecting rod member 45 is subjected to a counterclockwise force by a torsion spring (not shown).

[0072] The linkage assembly 45 has three arms 46, 47, and 48 extending radially outward along its pivot axis. The first arm 46 is located at the uppermost side, the third arm 48 at the lowermost side, and the second arm 47 is located between the first arm 46 and the third arm 48. When a force is applied counterclockwise to the first arm 46 of the linkage assembly 45, it abuts against the contact surface 38 of the motor housing 30, thereby defining the initial pivot position of the linkage assembly 45. When the first arm 46 resists the force of the torsion spring from... Figure 1 When the initial position shown is pivoted clockwise, as Figure 10 As shown, the input component 42 of the switch 41 is pushed backward, thereby positioning the switch 41 in a position that can be switched from the off state to the on state.

[0073] The second arm 47, when viewed from above, is positioned to overlap with the two protrusions 53 of the operating member 50. Furthermore, the tip of the second arm 47 is directly above the protrusions 53. When the user pushes the operating member 50 upwards, the operating member 50... Figure 1 The disconnection position shown is shifted to Figure 10 When the connection position is shown, such as Figure 10 As shown, the second arm 47 is lifted upward by the protrusion 53. Consequently, the linkage 45 pivots clockwise against the force of the torsion spring, and as described above, the switch 41 is switched to the on state via the first arm 46. Conversely, when the user releases the force pushing the operating member 50 upward, the linkage 45 returns to its original position under the force of the torsion spring. Figure 1 The operating unit 50 also returns to the initial position shown. Figure 1 The switch 41 returns to the off position as shown. Thus, the linkage 45 is configured to move in conjunction with the operating member 50 between the off and on positions.

[0074] like Figure 1 As shown, the third arm 48 has a generally L-shaped bend from its top side to the front side. The rear end of a brake release member 66 is mounted at the top of the third arm 48. The brake release member 66 is an elongated member extending along the bottom of the motor housing 30 in the front-rear direction. The brake release member 66 passes through the third arm 48 through a deflector 39 (see reference 39) disposed on the front side of the electric motor 31. Figure 7 ), and extends to the rear of the braking component 63.

[0075] When operated by the user, the operating component 50 is... Figure 1 The disconnection position shown is shifted to Figure 10 When in the engaged position as shown, the linkage component 45 pivots clockwise as described above. At this time, the third arm 48 pushes the brake release component 66 forward. Thus, as... Figure 10 As shown in Figure 13, the brake release member 66 moves forward, pushing the disc 63a of the brake member 63 forward. As a result, as described above, the brake of the brake mechanism 60 is released. The linkage member 45 and the brake release member 66 are configured such that the brake release via the third arm 48 and the brake release member 66 occurs before the first arm 46 switches the switch 41 to the ON state. If the operating member 50 is linked with the brake release member 66 as in this embodiment, a structure that reliably releases the brake state before the switch 41 is turned ON can be easily achieved. In particular, in this embodiment, the operating member 50 and the brake release member 66 are linked via the linkage member 45, so the circumferential positions of the arms 46, 47, and 48 on the linkage member 45 can be appropriately set, thereby easily achieving a structure that reliably releases the brake state before the switch 41 is turned ON. When the user releases the force pushing the operating component 50 upwards, the brake release component 66 returns to its initial position (without pushing the brake component 63 forward) through the force applied by the force application component 65. Figure 1 and Figure 7 ).

[0076] With the side handles 200 not installed on the mounting sections 29a and 29b, the grinder 10 has the function of preventing the aforementioned forward displacement of the brake release member 66 (the forward displacement used to release the brake of the brake mechanism 60). This function is achieved by a single limiting member 70 (see reference 70). Figure 8 ) and two intermediate components 80 (refer to) Figure 9 (Give full play to its potential) Figure 8 and Figure 9 The orientation shown in the diagram indicates the orientation of the limiting component 70 and the intermediate component 80 when they are assembled in the grinding machine 10. Furthermore, as described later, the two intermediate components 80 are configured to be symmetrical about the rotation axis AX1. Figure 9 The orientation of the middle component 80 on the right side is shown in the figure.

[0077] First, the intermediate component 80 will be explained. For example... Figure 9 As shown, the intermediate component 80 has a pushing portion 81 and a pushed portion 82 extending in a direction orthogonal to the vertical direction. A groove 83 is formed on the upper surface of the pushing portion 81. The groove 83 is formed on the upper side and the side away from the rotation axis AX1 (e.g., Figure 9 As shown, in the middle component 80, which is positioned on the right side relative to the rotation axis AX1 (open on the right side), the pushed portion 82 extends downward from approximately the center of the pushed portion 81 in the left-right direction. A through hole 84 is formed on the side of the pushed portion 81 that is away from the rotation axis AX1 relative to the pushed portion 82. The through hole 84 extends in the front-back direction.

[0078] like Figure 3 As shown, each intermediate component 80 is mounted to the gear housing 20 via a press-fit pin 85, which passes through a through-hole 84 from the rear and extends into the interior of the gear housing 20. A small gap is maintained between the intermediate component 80 and the head of the press-fit pin 85 in the front-rear direction to allow the intermediate component 80 to pivot about the press-fit pin 85.

[0079] like Figure 5 As shown, each intermediate component 80 is stressed by a leaf spring 86, which serves as a force-applying component. Specifically, the leaf spring 86 has a generally L-shaped bend, with one bent side housed within a hole 20a formed in the gear housing 20. The other bent side is housed within a groove 83 of the intermediate component 80. Thus, the intermediate component 80 is always positioned at its initial position, where it abuts against the push-down portion 82 and the stop member 20b (see reference). Figure 5 Apply force. For example... Figure 2 and Figure 5 As shown, the stop member 20b is the portion that protrudes inward from the inner surface of the gear housing 20, and it is also the portion that forms the mounting portions 29a and 29b. Additionally, as... Figure 2As shown, the two intermediate components 80 are configured such that their pushed-out portions 82 respectively block the inner ends of the mounting portions 29a and 29b of the gear housing 20.

[0080] Such an intermediate component 80 is pivoted by the pushing part 220 of the side handle 200 when the side handle 200 is installed in either of the mounting parts 29a or 29b. For example, as Figure 11 As shown, when the side handle 200 is installed in the second mounting portion 29b of the mounting portions 29a and 29b, the right-side middle member 80 pivots against the force of the leaf spring 86 in the direction where the pushed portion 82 moves away from the stop member 20b. Although the figure is omitted, when the side handle 200 is installed in the mounting portion 29a, the left-side middle member 80 pivots in the direction of the force of the leaf spring 86.

[0081] Next, the limiting component 70 will be described. For example... Figure 8 As shown, the limiting member 70 has a main body 71, two pressing portions 73, and a limiting portion 75. The main body 71 has an annular shape that opens at the top. The pressing portions 73 are portions that protrude forward from both ends (top ends) of the main body 71. A groove 74 is formed on the upper surface of the pressing portion 73. The upper and front sides of the groove 74 are open. The limiting portion 75 is a portion that protrudes rearward from the main body 71 at the bottom (center of the open annular shape). Two through holes 72 are formed approximately at the center of the main body 71 in the vertical direction, and these two through holes 72 penetrate the main body 71 in the front-rear direction. The through holes 72 are elongated holes with the vertical direction as their length direction.

[0082] like Figure 6 As shown, the limiting member 70 is configured to circumferentially surround the motor shaft 32. Figure 3 and Figure 6 As shown, the limiting member 70 is mounted to the bearing support 34 by two screws 76, which pass through two through holes 72 and engage with the threaded holes of the bearing support 34. A small gap is formed between the head of the screw 76 and the bearing support 34 in the front-to-back direction, and the through holes 72 are elongated. Therefore, the limiting member 70 is supported by the bearing support 34 by the screws 76 in a manner that allows it to be displaced along the through holes 72.

[0083] like Figure 5 As shown, the pressed portion 73 of the limiting member 70 is above the intermediate member 80 and close to the pressing portion 81 of the intermediate member 80. Figure 5 As shown, in the state where the side handle 200 is not installed, the pressed part 73 and the pressing part 81 are slightly separated in the vertical direction. Additionally, as... Figure 4 As shown, when viewed from above and below, the front part of the pressed part 73 overlaps with the rear part of the pressed part 81.

[0084] And, as Figure 4 and Figure 6 As shown, the force-applying component 77 is disposed between the pushed portion 73 and the gear housing 20 in a compressed state. In this embodiment, the force-applying component 77 is in the form of a helical spring. Figure 4 As shown, the force-applying member 77 is located within the groove 74. The outer edge of the pressed portion 73 forming the groove 74 restricts the movement of the force-applying member 77. The force-applying member 77 applies a downward force to the pressed portion 73. The forces exerted by the two force-applying members 77 are equal, such as... Figure 6 As shown, when the side handle 200 is not installed, the two pushed parts 73 are located in the same vertical direction.

[0085] And, as Figure 1 and Figure 7 As shown, in the state where the side handle 200 is not installed, the limiting portion 75 of the limiting member 70 is close to the outer protrusion 63c on the front side of the brake member 63 (more specifically, the outer protrusion 63c) of the brake mechanism 60. In other words, the limiting portion 75 is located at the brake member 63 from... Figure 7 The braking position displacement shown is to Figure 13 The outer protrusion 63c is on the displacement path of the non-braking position shown. Therefore, even if the brake release member 66 pushes the outer protrusion 63c forward as a result of the user performing the activation operation of the operating member 50 as described above, the outer protrusion 63c will come into contact with the limiting member 75, thereby limiting further displacement of the outer protrusion 63c. As a result, the braking state of the brake release mechanism 60 is prevented. In other words, the limiting member 75 prevents the braking state of the operating brake mechanism 60 from being released by the contact between the components (here, the contact between the limiting member 75 and the outer protrusion 63). The position of the limiting member 70 at this time is also called the blocking position.

[0086] On the other hand, when the side handle 200 is mounted on either of the mounting portions 29a or 29b, the braking state of the operating brake mechanism 60 is released. Specifically, when the side handle 200 is mounted on either of the mounting portions 29a or 29b, the limiting member 70 is indirectly (in other words, via the intermediate member 80) pushed by the pushing portion 220 of the side handle 200, thereby displacing it in a tilting manner in the left-right direction. For example, when the side handle 200 is mounted on the second mounting portion 29b of the mounting portions 29a or 29b, as... Figure 11 As shown, the middle component 80 on the right pivots as described above, resisting the force of the force-applying component 77 on the right and pushing up the pushed portion 73c on the right. Thus, as... Figure 11 and Figure 12 As shown, the limiting member 70 is tilted so that the right-side pressed portion 73 is positioned above the left-side pressed portion 73.

[0087] At this time, as Figure 12 As shown, the limiting part 75 also shifts to the upper right. Therefore, the limiting part 75 is moved from the braking member 63... Figure 7 The braking position displacement shown is to Figure 13 The outer protrusion 63c disengages along its displacement path in the non-braking position shown. As a result, as... Figure 13 As shown, when the user performs the operation of the operating component 50 as described above, the brake release component 66 pushes the outer protrusion 63c forward, causing the outer protrusion 63c to displace forward without contacting the restricting component 75 (i.e., without the aforementioned contact between components). Therefore, the braking state of the braking mechanism 60 is released. The position of the restricting component 70 at this time is also referred to as the permitted position.

[0088] Although the illustration is omitted, when the side handle 200 is mounted on the mounting portion 29a, the left-side intermediate member 80 pivots as described above, pushing up the left-side pressed portion 73c against the force exerted by the left-side force-applying member 77. As a result, the limiting member 70 tilts and displaces such that the left-side pressed portion 73 is positioned higher than the right-side pressed portion 73. That is, when the side handle 200 is mounted on the mounting portion 29a, the limiting member 70 displaces in the opposite direction to the displacement direction when the side handle 200 is mounted on the mounting portion 29b. In this case, the limiting portion 75 also moves away from the braking member 63. Figure 7 The braking position displacement shown is to Figure 13 The outer protrusion 63c disengages along its displacement path in the non-braking position shown. Therefore, the braking state of the braking mechanism 60 is released.

[0089] When the side handle 200 is removed from the mounting portion 29a or mounting portion 29b, the limiting portion 75 returns to its original position due to the force of the force-applying member 77. Figure 6 and Figure 7 The blocking location is shown.

[0090] According to the aforementioned grinding machine 10, when the side handle 200 is not installed on either of the mounting portions 29a or 29b, the limiting member 70 is in a blocking position, which is a position where the limiting member 75 prevents the release of the braking state of the operating brake mechanism 60 by abutting between the components. On the other hand, when the side handle 200 is installed on either of the mounting portions 29a or 29b, the limiting member 75 is displaced to an allowable position, which is a position where the limiting member 75 allows the release of the braking state of the operating brake mechanism 60. Therefore, a structure that allows the tip tool 28 to be driven only when the side handle 200 is installed can be achieved using only mechanical structures without the use of sensors. Moreover, when the side handle 200 is not installed, the tip tool 28 is in a forced stop state of the braking mechanism 60 (a state in which the driving of the tip tool 28 is stopped regardless of the on / off state of the switch 41). Therefore, compared with a structure that only prevents the on operation of the operating member 50, the driving of the tip tool 28 when the side handle 200 is not installed can be more reliably limited.

[0091] Furthermore, according to the grinding machine 10, since a single limiting part 70 is shared by the two mounting parts 29a and 29b, the number of parts can be reduced, and the device structure can be simplified. Because the limiting part 70 has an annular shape corresponding to the arrangement of the mounting parts 29a and 29b, which are separated circumferentially along the rotation axis AX1, a single limiting part 70 can be shared by the mounting parts 29a and 29b with a simple structure. Moreover, since the limiting part 70 is indirectly pressed by the side handle 200 via the intermediate part 80, it can be miniaturized compared to a structure where it is directly pressed by the side handle 200 (in other words, a structure where the limiting part 70 is sized to reach the position directly pressed by the side handle 200). Therefore, when designing the layout within the device, space constraints are less likely to occur.

[0092] Furthermore, according to the grinder 10, the braking mechanism 60 is not arranged around the main shaft 25, but around the motor shaft 32. Therefore, the area around the main shaft 25 (i.e., the gear housing 20 and its internal structure) can be miniaturized and lightened. That is, the gear housing 20, located relatively far from the handle housing 40 for the user to hold, can be miniaturized and lightened. Therefore, the operability of the grinder 10 can be improved. Moreover, since the distance between the braking mechanism 60 and the operating member 50 that links the braking release member 66 to the braking mechanism 60 is shorter, the mechanical structure for linking the braking release member 66 to the operating member 50 can be simplified.

[0093] Furthermore, according to the grinding machine 10, the displacement direction of the limiting member 70 is opposite when the side handle 200 is installed in the mounting part 29a and when the side handle 200 is installed in the mounting part 29b. Therefore, a structure can be achieved with a simple device structure in which, when the side handle 200 is installed in either the mounting part 29a or 29b, the limiting member 70 is pushed by the side handle 200 to allow the braking state of the operating brake mechanism 60 to be released.

[0094] Below, refer to Figures 14-20 The second embodiment of the present invention will be described below. Hereinafter, only the differences between the second embodiment and the first embodiment will be described. Furthermore, structural elements that are the same as or similar to those in the first embodiment will be labeled with the same reference numerals as those in the first embodiment, and their descriptions will be omitted. Figure 14 As shown, the grinding machine 410 according to the second embodiment has an operating member 450 instead of an operating member 50, a locking part 443 instead of a locking member 54, a pivoting member 455 instead of a connecting rod member 45, and a braking mechanism 460 instead of a braking mechanism 60.

[0095] like Figure 14 As shown, the operating member 450 is an elongated member extending in the front-rear direction and is disposed on the underside of the motor housing 430 and the handle housing 440. The operating member 450 has an actuating end 451, a engaging portion 452, a protrusion 453, and a protrusion 454. The actuating end 451 is the front end portion of the operating member 450 and has a smaller thickness (width in the vertical direction) than other portions. The actuating end 451 passes through a through hole 431 formed in the motor housing 430 (see reference). Figure 17 The motor housing 430 is then reached. The engaging portion 452 is for engaging with the locking member 433 (described later). In this embodiment, it is a protrusion protruding rearward from the rear end of the operating member 450. The protrusion 453 protrudes upward from the upper part of the operating member 450. The protrusion 453 is positioned on the rear side of the operating member 450 in the front-rear direction. The protrusion 454 protrudes downward from the lower part of the operating member 450. The protrusion 454 is positioned approximately at the center of the operating member 450 in the front-rear direction.

[0096] The operating component 450 can pivot vertically about the portion of the actuating end 451 located within the through hole 431. When the operating component 450 moves from its initial position... Figure 14 The disconnection position shown is shifted upwards to... Figure 16 When in the indicated ON position, switch 41 switches from OFF to ON via pivot component 455.

[0097] Specifically, the pivot member 455 is positioned above the protrusion 453 of the operating member 450. The pivot member 455 is configured to pivot about a pin 458 supported on a boss in the handle housing 440, and has a first arm 456 and a second arm 457 extending radially outward from its pivot axis. The first arm 456 is positioned directly above the protrusion 453, and the second arm 457 is positioned above the first arm 456. Although not shown in the figures, the pivot member 455 is subjected to a counterclockwise force by a force-applying member (e.g., a torsion spring) such that the first arm 456 abuts against the protrusion 453 of the operating member 450.

[0098] In the unlocked state described later, when the user pushes the operating member 450 upward, the operating member 450 is pivoted upward. As a result, the protrusion 453 causes the first arm 456 of the pivoting member 455 to displace upward against the force of the applying member, and the pivoting member 455 pivots clockwise. Consequently, the second arm 457 also pivots clockwise along with it. Furthermore, when the operating member 450 pivots to... Figure 16 When in the ON position, the input component 42 of switch 41 is pushed by the second arm 457 and pressed into the interior of switch 41. Thus, switch 41 switches from the OFF state to the ON state. When the user releases the upward pushing operation on the operating component 450, the operating component 450 pivots downwards due to the force exerted by the force-applying component on the pivoting component 455, thereby returning to the ON position. Figure 14 The disconnected position is shown. At this time, the pivoting component 455 also returns to the position by the force applied by the force-applying component 455. Figure 14 At the position shown, input component 42 is also disengaged from switch 41. Thus, switch 41 returns from the ON state to the OFF state.

[0099] The locking portion 443 has the same function as the locking member 54 in the first embodiment. Compared with the self-displaceable locking member 54 in the first embodiment, the locking portion 443 is a fixed (i.e., non-displaceable) engagement structure. In this embodiment, the locking portion 433 is formed as part of the handle housing 440 (more specifically, the rear and lower part) at a position rearward of the operating member 450.

[0100] like Figure 14 As shown, the locking portion 443 has a base 444, an engaging portion 445, and a support portion 446. The base 444 is a portion that protrudes downward from the lower part of the handle housing 440. The engaging portion 445 and the support portion 446 protrude forward from the base 444. The engaging portion 445 is located above the support portion 446, and a recess with a front opening is formed between the engaging portion 445 and the support portion 446. The support portion 446 extends to a position further forward than the engaging portion 445.

[0101] like Figure 14 As shown, the operating member 450 is inserted into the through hole 431 through the actuating end 451, and the engaging part 452 is mounted on the support part 446. The operating member 450 is held in an anti-dislodgement state and is movable in the front-back and vertical directions. The movement of the operating member 450 in the front-back and vertical directions is achieved by manual operation by the user. The user can easily move the operating member 450 in the front-back direction by placing their finger on the protrusion 454.

[0102] like Figure 17 and Figure 19 As shown, the braking mechanism 460 has a braking component 463 replacing the braking component 63 and a brake release component 466 replacing the brake release component 66. The braking component 463 has a radially extending disk 463a and an inner protrusion 63b, but no outer protrusion 63c. A notch 463d with an open lower side is formed at the lower end of the disk 463a.

[0103] like Figure 14 , Figure 17 and Figure 19 As shown, the brake release member 466 is disposed between the limiting portion 75 of the limiting member 70 and the operating member 450 in a manner that allows displacement in the longitudinal direction. Figure 17 and Figure 19 As shown, in this embodiment, the brake release member 466 is a plate-shaped member extending in the front-rear direction. A flange portion 467 is formed at the rear end of the brake release member 466, and the vertical width and horizontal width of this flange portion 467 are larger than the other portions. Furthermore, as... Figure 19 As shown, a pushing portion 468 is formed on the front side of the brake release member 466, and the width of the pushing portion 468 is larger than that of the other portions. The portion of the brake release member 466 that is forward of the pushing portion 468 is formed into an elongated tip portion 469. (As shown...) Figure 17 and Figure 19 As shown, the top portion 469 extends through the notch 463d of the braking member 463 and into the vicinity of the limiting portion 75 of the limiting member 70.

[0104] like Figure 17As shown, a helical spring 465, serving as a force-applying component, is provided around the brake release component 466. The helical spring 465 is held in a compressed state between the baffle 39 and the flange 467, the baffle 39 being embedded inside the motor housing 430. Through the helical spring 465, the brake release component 466 is always subjected to a rearward force, i.e., towards the operating component 450. Therefore, regardless of the front-rear position of the brake release component 466, the flange 467 always abuts against the actuating end 451 of the operating component 450 in the front-rear direction. When the user moves the operating component 450 forward, the brake release component 466 resists the force of the helical spring 465 and is pushed forward by the operating component 450, moving forward together with the operating component 450. On the other hand, when the user releases the force that moved the operating component 450 forward, the operating component 450 and the brake release component 466 return to their original positions due to the force of the helical spring 465. Thus, the brake release component 466 is configured to move in conjunction with the operating component 450 in the longitudinal direction.

[0105] The function of this grinding machine 410 will be explained below. First, as... Figure 14 As shown, when the operating member 450 is in the locked state in the disengaged position, the engaging portion 452 of the operating member 450 is received in the recess between the engaging portion 445 of the locking portion 443 and the support portion 446. This position of the operating member 450 is also referred to as the locked position. When the operating member 450 is in the locked position, since the engaging portion 445 is directly above the engaging portion 452, even if the user intends to push the operating member 450 upwards, the engaging portion 452 will abut against the engaging portion 445, thereby restricting the upward displacement of the operating member 450. Therefore, the operating member 450 is prevented from moving from the disengaged position (see reference...) Figure 14 To the connected position (refer to) Figure 16 Displacement.

[0106] When the operating component 450 is in the locked state in the disengaged position, the brake release component 466 is not pushed forward by the operating component 450, but is located in the... Figure 14 , Figure 17 and Figure 19 The position shown. At this time, as... Figure 19 As shown, the pushing part 468 of the brake release member 466 separates from the disk 463a of the brake member 463 in the front-rear direction. Furthermore, as... Figure 14 , Figure 17 As shown in Figure 19, the braking component 463 and the brake shoe 64 are located in the braking position that pushes the brake plate 62.

[0107] To release the locked operating component 450, the user needs to move the operating component 450 forward. However, as... Figure 17 and Figure 19 As shown, without the side handle installed, the limiting part 75 of the limiting member 70 is located in front of the top end 469 of the brake release member 46. Therefore, if the user wants to move the operating member 450 forward, the forward movement of the brake release member 466 (and the operating member 450) is limited because the top end 469 of the brake release member 466, which is linked to the operating member 450, abuts against the limiting part 75. In this way, the limiting part 75 prevents the state of the operating member 450 from being switched from the locked state to the unlocked state by the abutment between the components (here, the abutment between the limiting part 75 and the top end 469 of the brake release member 466). In other words, the limiting part 75 blocks the displacement path for moving the brake release member 466 forward.

[0108] On the other hand, when the side handle 200 is mounted on either of the mounting portions 29a or 29b (refer to the first embodiment), the limiting member 70 is displaced in the same manner as in the first embodiment, such as... Figure 18 and Figure 20 As shown, the limiting member 70 is positioned so as not to obstruct the displacement path for moving the brake release member 466 forward. That is, the aforementioned contact between the components does not occur, allowing the operating member 450 and the brake release member 466 to move forward. Therefore, the user can move the operating member 450 and the brake release member 466 forward against the force of the coil spring 465. Figure 18 and Figure 20 The location shown.

[0109] At this time, as Figure 15 As shown, the engaging portion 452 of the operating member 450 is supported on the support portion 446 of the locking portion 443, but there is no engaging portion 445 directly above the engaging portion 452. Therefore, the operating member 450 is in a state where it can be displaced upward (i.e., the lock-out state). The position of the operating member 50 at this time is also called the lock-out position.

[0110] As the operating component 50 moves from the locked position to the unlocked position, the brake release component 466 moves forward, such as Figure 20 As shown, the pushing part 468 of the brake release component 466 abuts against the disc 463a of the brake component 463 and pushes it forward. Thus, as... Figure 18 As shown, the braking component 463 and the brake shoe 64 are moved forward to a position where the brake shoe 64 is separated from the braked portion 62b of the brake plate 62 in the longitudinal direction (i.e., the brake release position). In this way, the braking state of the braking mechanism 460 is released.

[0111] In this way, when the operating component 450 is in the disengaged position and the lock is released, if the user moves the operating component 450 upward, such as... Figure 16 As shown, in the above manner, switch 41 is in the ON state via pivot member 455. On the other hand, when the grinding machine 410 is stopped, when the user releases the upward displacement operation of operating member 450, as described above, operating member 450 moves from the ON position (refer to...) Figure 16 Return to the disconnected position (see reference) Figure 14 At this time, the operating component 450, through the force of the coil spring 465, moves from the locked-out position (refer to...). Figure 15 Return to the locked position (see reference) Figure 14 And the brake release component 466 from Figure 18 and Figure 20 Return to the location shown Figure 17 and Figure 19 The position is shown. Simultaneously, the braking component 463 and brake pads 64 also return from the non-braking position to the braking position. As can be seen from the above description, in this embodiment, through the linkage of the operating component 450 and the brake release component 466, the following structure is provided: the locking release operation of the operating component 450 also serves as the release operation of the braking state of the braking mechanism 460.

[0112] According to the above-described grinding machine 410, similar to the first embodiment, a structure can be implemented using only mechanical structures without the use of sensors, allowing the tip tool 28 to be driven only when the side handle 200 is installed. Furthermore, similar to the first embodiment, when the side handle 200 is not installed, the tip tool 28 is in a forced-stop state caused by the braking mechanism 60. Therefore, compared to a structure that only prevents the operation of the operating member 50 from being engaged, the driving of the tip tool 28 when the side handle 200 is not installed can be more reliably restricted.

[0113] Furthermore, since it is easy for users to recognize the displacement of the operating component 450 that accompanies the release operation, the user can easily realize that if the electric motor 31 cannot be driven even though the operating component 450 is moved from the off position to the on position, the reason is not that the switch 41 is malfunctioning, but that the operation lock cannot be released because the side handle 200 is not installed.

[0114] Furthermore, according to the grinding machine 410, if the user moves the operating member 450 forward, switching the state of the operating member 450 from the locked state to the unlocked state, the braking state can be released by the braking release member 466 even if the operating member 450 remains in the off position. Therefore, a structure that reliably releases the braking state before the switch 41 becomes the on state can be easily realized.

[0115] The embodiments of the present invention have been described above. These embodiments are merely for the purpose of facilitating understanding of the present invention and are not intended to limit the invention. The present invention can be modified and improved without departing from its spirit, and the present invention includes its equivalents. Furthermore, within the scope of solving at least some of the above-described technical problems or achieving at least some of the effects, the structural elements described in the claims and specification can be arbitrarily combined or omitted.

[0116] For example, the shape and form of the structural components of the grinding machine 10 described above are merely illustrative. As long as the functions of the structural components can be ensured, any changes can be made. For example, when the side handle 200 is installed on either of the mounting portions 29a or 29b, the limiting member 70 can be displaced by being pushed directly by the side handle 200 without passing through the intermediate member 80.

[0117] Furthermore, the limiting member 70 can be shaped such that, when directly or indirectly pressed by the side handle 200, it rotates around a rotation axis parallel to the rotation axis AX1 instead of displacing at an angle. In this case, the through hole 72 of the limiting member 70 can be formed in an arc shape to guide the rotational displacement of the limiting member 70. The rotation direction of the limiting member 70 can be the same or different when the side handle 200 is mounted on the mounting portion 29a and when the side handle 200 is mounted on the mounting portion 29b.

[0118] Furthermore, the braking mechanism 60 or braking mechanism 460 can be configured such that it is arranged around the main shaft 25 to brake the rotation of the main shaft 25. In this case, a conversion mechanism can be added to convert the displacement direction of the brake release member 66 or brake release member 466 into the displacement direction of the braking member 63 or the braking member 463 and brake shoe 64.

[0119] Furthermore, in the second embodiment, instead of the locking part 443, which is a fixed engaging structure, a locking member configured in a displaceable manner can be provided as the locking part. In this case, the brake release member is configured to perform a brake release operation in conjunction with the displacement of the locking member from the locking position to the locking release position.

[0120] Furthermore, the grinder 10 or grinder 410 can be configured to prevent the displacement of the brake release member 66 or brake release member 466 for brake release when the cover 300 is not installed, instead of the side handle 200. In this case, a limiting member that is directly or indirectly pressed by the cover 30 can be provided. Alternatively, the grinder 10 or grinder 410 can be configured to prevent the displacement of the brake release member 66 or brake release member 466 for brake release when at least one of the side handle 200 and the cover 300 is not installed. In this case, an additional limiting member that allows displacement depending on whether the cover 300 is installed can be provided. In this case, the additional limiting member can be configured to be arranged in the front-rear direction with the limiting member 70, and when at least one of the side handle 200 and the cover 300 is not installed, it blocks the displacement path of the brake release member 66 or brake release member 466 for brake release side by side with the limiting member 70.

[0121] Furthermore, the above embodiments are not limited to grinding machines, but can be applied to any power tool with accessories that can be installed in a detachable manner.

[0122] The following shows the correspondence between the structural elements of the above-described embodiments and the structural elements of the present invention. However, the structural elements of the embodiments are merely examples and do not limit the structural elements of the present invention. Grinding machines 10 and 410 are examples of "power tools". Top tool 28 is an example of a "top tool". Electric motor 31 is an example of a "motor". Braking mechanisms 60 and 460 are examples of "braking mechanisms". Side handle 200 is an example of an "accessory". Mounting parts 29a and 29b are examples of "mounting parts". Restricting member 70 is an example of a "restricting member". Intermediate member 80 is an example of an "intermediate member". Motor shaft 32 is an example of a "motor shaft". Main shaft 25 is an example of a "final output shaft". Brake plate 62 is an example of a "braked member". Braking members 63 and 463 and brake shoes 64 are examples of "braking members". Force-applying member 65 is an example of a "force-applying member". Brake release components 66 and 466 are examples of "brake release components". Operating components 50 and 450 are examples of "operating components". Linkage component 45 is an example of "linkage component". Locking part 433 is an example of "locking part".

Claims

1. A power tool, characterized in that, It has a motor, a braking mechanism, multiple mounting parts, and limiting components, among which, The motor is configured to provide driving force to the top tool; The braking mechanism is configured on the driving force transmission path from the motor to the tip tool and is configured to brake the drive of the tip tool. The plurality of mounting parts are configured to install the accessories in a detachable manner; The limiting component is configured such that it is directly or indirectly pushed and displaced by the accessory when the accessory is installed in any of the plurality of mounting portions. When the accessory is not installed on any of the plurality of mounting portions, the limiting member is in a blocking position, which means that the braking state of the braking mechanism is prevented from being released by the abutment between the components. With the accessory installed on any of the plurality of mounting portions, the limiting member is in a permissible position, which means a position that allows the release operation of the braking state without causing contact between the components. The limiting component is a single component shared by the multiple mounting parts.

2. A power tool, characterized in that, It includes a motor, a braking mechanism, at least one mounting part, a limiting component, and an intermediate component, wherein, The motor is configured to provide driving force to the top tool; The braking mechanism is configured on the driving force transmission path from the motor to the tip tool and is configured to brake the drive of the tip tool. The at least one mounting part is configured to install the accessory in a detachable manner; The limiting member is configured to be displaced by direct or indirect pressure from the accessory when the accessory is installed in any of the at least one mounting portion. The intermediate component is configured such that it is pushed and displaced by the accessory when the accessory is installed in any of the at least one mounting portion. When the accessory is not installed on any of the at least one mounting portion, the limiting member is in a blocking position, which means that the braking state of the braking mechanism is prevented from being released by the abutment between the components. With the accessory installed on any one of the at least one mounting portion, the limiting member is in a permissible position, which means a position that allows the release operation of the braking state without causing contact between the components. The limiting member is further configured to be displaced by the intermediate member when the accessory is installed in any of the at least one mounting portion.

3. The power tool according to claim 2, characterized in that, The at least one mounting part has multiple mounting parts.

4. The power tool according to claim 3, characterized in that, The limiting component is a single component shared by the multiple mounting parts.

5. The power tool according to claim 1 or 4, characterized in that, The plurality of mounting parts includes a first mounting part and a second mounting part. The permitted positions include a first permitted position and a second permitted position. The limiting component is configured as follows: When the accessory is installed in the first mounting part, the limiting member moves from the blocking position in the first direction to the first allowable position. When the accessory is installed in the second mounting part, the limiting member is displaced from the blocking position to the second allowable position in a second direction opposite to the first direction.

6. The power tool according to claim 1, characterized in that, It also includes an intermediate component configured to be displaced by the accessory when the accessory is installed in any of the plurality of mounting portions. The limiting component is configured such that it is pushed and displaced by the intermediate component when the accessory is installed in any of the plurality of mounting portions.

7. The power tool according to any one of claims 1 to 4 and 6, characterized in that, The motor has a motor shaft. The power tool also has a final output shaft configured to transmit the driving force from the motor shaft and to mount the top tool. The braking mechanism is arranged around the motor shaft.

8. The power tool according to claim 7, characterized in that, The braking mechanism includes a braked component, a braking component, a force-applying component, and a brake release component, wherein... The braked component is fixed to the motor shaft and configured to surround the motor shaft circumferentially; The braking component is configured to achieve the braking state by being pressed against the braked component, and is disposed in a displaceable manner between a braking position abutting the braked component and a non-braking position separated from the braked component; The force-applying component applies force to the braking component toward the braking position; The brake release component is configured to push the brake component from the brake position to the non-brake position in a manner that resists the force exerted by the force-applying component, thereby displacing the brake component.

9. The power tool according to claim 8, characterized in that, It also has switches and operating components, among which, The switch is used to drive the motor; The operating component is configured to be movable between an open position (where the switch is in an open state) and an on position (where the switch is in an on state). The brake release component is configured to move in conjunction with the displacement of the operating component between the disconnected position and the connected position.

10. The power tool according to claim 9, characterized in that, It also includes a linkage component configured to move in conjunction with the displacement of the operating component between the disconnected position and the connected position. The linkage component is configured to push the switch in such a way that it is displaced from the disconnected position to the connected position when the operating component is displaced, thereby putting the switch into the connected state, and to push the brake release component in such a way that it releases the brake state.

11. The power tool according to claim 8, characterized in that, It also has a switch, an operating component, and a locking mechanism, among which, The switch is used to drive the motor; The operating component is configured to be movable between an off position that puts the switch in an off state and an on position that puts the switch in an on state. The locking part is configured such that by changing the engagement state with the operating component, the state of the operating component can be switched between a locked state and a locked-out state. The locked state refers to a state that prevents the operating component from moving from the disconnected position to the connected position; the locked-out state refers to a state that allows the operating component to move from the disconnected position to the connected position. The brake release component is configured to be linked with an operation for switching between the locked state and the unlocked state.

Images