tool

Abstract

A tool is disclosed. The tool can have a prime mover, a transmission mechanism, a housing, a tip tool holding portion, an accessory, a link member, and a detection sensor, wherein the transmission mechanism is connected to the prime mover; the housing is configured to house the prime mover and the transmission mechanism; the tip tool holding portion is connected to the transmission mechanism and configured to hold a tip tool; the accessory is detachably mounted to the housing; the link member is configured to act in response to detachment of the accessory; and the detection sensor is housed inside the housing and has a non-contact sensor element. The detection sensor can use the sensor element to detect the action of the link member.

Description

[0001] This application is a divisional application of the invention patent application filed on March 12, 2021 under National Application No. 201980060062.2 (International Application No. PCT / JP2019 / 035259) with the title of "Tool". TECHNICAL FIELD

[0002] The technology disclosed in this specification relates to a tool. BACKGROUND

[0003] A tool is disclosed in International Publication No. 2017 / 051893, which has a prime mover, a transmission mechanism (power transmission mechanism), a housing, a tip tool holding portion, an accessory, and a detection sensor, wherein the transmission mechanism is connected to the prime mover; the housing houses the prime mover and the transmission mechanism; the tip tool holding portion is connected to the transmission mechanism and holds a tip tool; the accessory is detachably attached to the housing; and the detection sensor is provided outside the housing. In this tool, it is possible to detect whether the accessory is attached to the housing or not by the detection sensor. SUMMARY

[0004] [PROBLEMS TO BE SOLVED BY THE INVENTION]

[0005] The tool described above is sometimes used in an environment where a large amount of dust is contained in the air. In such a case, when the detection sensor is provided outside the housing, the detection sensor can be erroneously detected due to the influence of dust. A technology is desired in which it is possible to accurately detect whether the accessory is attached to the housing or not even when the tool is used in an environment where a large amount of dust is contained.

[0006] [MEANS FOR SOLVING THE PROBLEMS]

[0007] A tool is disclosed in this specification. The tool can have a prime mover, a transmission mechanism, a housing, a tip tool holding portion, an accessory, a link member, and a detection sensor, wherein the transmission mechanism is connected to the prime mover; the housing houses the prime mover and the transmission mechanism; the tip tool holding portion is connected to the transmission mechanism and holds a tip tool; the accessory is detachably attached to the housing; the link member operates in response to the attachment and detachment of the accessory; and the detection sensor is housed inside the housing and has a non-contact sensor element. The detection sensor can detect the operation of the link member using the sensor element.

[0008] According to the above structure, since the detection sensor is housed inside the housing, the detection sensor is not easily affected by dust. Therefore, even if the tool is used in an environment where dust is abundant, it is possible to accurately detect whether or not the accessory is attached to the housing. In addition, according to the above structure, the detection sensor uses a non-contact sensor element to detect the operation of the link member. Thereby, even when vibration or impact is applied to the link member, it is possible to prevent the impact or vibration from being applied to the sensor element through the link member. It is possible to prevent false detection by the sensor element due to the impact or vibration, and it is possible to improve the durability of the sensor element.

[0009] The present specification also discloses another tool. The tool can have a prime mover, a transmission mechanism, a housing, a tip tool holding portion, an accessory, a link member, and a detection sensor, wherein the transmission mechanism is connected to the prime mover; the housing houses the prime mover and the transmission mechanism; the tip tool holding portion is connected to the transmission mechanism and is used to hold a tip tool; the accessory is detachably attached to the housing; the link member operates in response to the attachment and detachment of the accessory; and the detection sensor is housed inside the housing. The link member can rotate relative to the housing in response to the attachment and detachment of the accessory. The detection sensor can detect the rotational operation of the link member.

[0010] According to the above structure, since the detection sensor is housed inside the housing, the detection sensor is not easily affected by dust. Therefore, even if the tool is used in an environment where dust is abundant, it is possible to accurately detect whether or not the accessory is attached to the housing. In addition, according to the above structure, even when the detection sensor is arranged at a position away from the attachment position of the accessory, it is possible to effectively utilize the idle space inside the housing to arrange the link member extending from the attachment position of the accessory to the position of the detection sensor, without making the link member a large and complex mechanism. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 is a longitudinal sectional view of the grinder 2 of Embodiment 1.

[0012] Figure 2 is a perspective view showing the internal structure of the grinder 2 of Embodiment 1.

[0013] Figure 3 is a perspective view of the cover detection mechanism 54 in a state where the cover 6 is not attached in the grinder 2 of Embodiment 1.

[0014] Figure 4 is a perspective view showing the internal structure of the detection sensor 58 of the grinder 2 of Embodiment 1.

[0015] Figure 5is a perspective view of the light interrupter 72 of the grinder 2 of Example 1.

[0016] Figure 6 is a perspective view of the sensor rod 68 of the grinder 2 of Example 1.

[0017] Figure 7 is a longitudinal sectional view of the detection sensor 58 in a state where the cover 6 is not attached in the grinder 2 of Example 1.

[0018] Figure 8 is a perspective view of the cover detection mechanism 54 in a state where the cover 6 is attached in the grinder 2 of Example 1.

[0019] Figure 9 is a longitudinal sectional view of the detection sensor 58 in a state where the cover 6 is attached in the grinder 2 of Example 1.

[0020] Figure 10 is a diagram schematically showing the circuit structure of the grinder 2 of Example 1.

[0021] Figure 11 is a flowchart showing the processing executed by the microcomputer 82 of the grinder 2 of Example 1.

[0022] Figure 12 is a flowchart showing the cover determination processing executed by the microcomputer 82 of the grinder 2 of Example 1.

[0023] Figure 13 is a diagram showing examples of the signal pattern 90 of the emission signal and the signal patterns 92, 94, 96, 98 of the light reception signal in the grinder 2 of Example 1.

[0024] Figure 14 is a perspective view of the grinder 102 of Example 2.

[0025] Figure 15 is a longitudinal sectional view of the vicinity of the cover attachment portion 52 in a state where the cover 6 is not attached in the grinder 102 of Example 2.

[0026] Figure 16 is a transverse sectional view of the vicinity of the handle attachment portions 110, 112 in a state where the sub handle 108 is not attached in the grinder 102 of Example 2.

[0027] Figure 17 is a perspective view of the detection unit 118 of the grinder 102 of Example 2.

[0028] Figure 18 is a perspective view of the link member 122 and the light interrupter 128 in a state where the link member 122 is positioned at a shielding position (an occlusion position) in the grinder 102 of Example 2.

[0029] Figure 19 FIG. 6 is a perspective view of the link member 122 and the light interrupter 128 in a state where the link member 122 is located at the open position in the grinder 102 of Embodiment 2.

[0030] Figure 20 FIG. 7 is a longitudinal sectional view of the vicinity of the cover mounting portion 52 in a state where the cover 6 is mounted in the grinder 102 of Embodiment 2.

[0031] Figure 21 FIG. 8 is a transverse sectional view of the vicinity of the handle mounting portions 110, 112 in a state where the sub handle 108 is mounted in the grinder 102 of Embodiment 2. DETAILED DESCRIPTION

[0032] Hereinafter, representative and non-limiting embodiments of the present application will be described in detail with reference to the accompanying drawings. This detailed description is merely supposed to indicate details of preferred examples for carrying out the present application to those skilled in the art, and is not supposed to limit the scope of the present application. In addition, the following disclosed additional features and technical solutions can be used separately from or together with other features and technical solutions in order to provide further improved tools, methods of manufacturing and using the same.

[0033] In addition, as for the combination of features and processes disclosed in the following detailed description, it is not necessary to carry out the present application in the broadest sense, but only the contents described are recorded in order to particularly describe representative examples of the present application. Also, as for various features of the above and below representative examples, and various features recorded in technical solutions and additional technical features, it is not necessary to combine them as in the examples described herein or in the order listed in order to provide additional and useful embodiments of the present application.

[0034] Separately from the structure of features described in the embodiments and / or technical solutions, all features described in the specification and / or claims are intended to be disclosed individually and independently of each other as a limitation on the disclosure of the original application and the specific matters claimed. Also, as for the description related to all numerical ranges and compositions or groups, it is intended to disclose the intermediate structures thereof as a limitation on the disclosure of the original application and the specific matters claimed.

[0035] In one or more embodiments, the tool can include a prime mover, a transmission mechanism, a housing, a tip tool holding portion, an attachment, a link member, and a detection sensor, wherein the transmission mechanism is connected to the prime mover; the housing houses the prime mover and the transmission mechanism; the tip tool holding portion is connected to the transmission mechanism and holds a tip tool; the attachment is detachably attached to the housing; the link member operates in response to the attachment being attached to or detached from the housing; and the detection sensor is housed inside the housing and includes a non-contact sensor element. The detection sensor can detect the operation of the link member using the sensor element.

[0036] According to the above structure, since the detection sensor is housed inside the housing, the detection sensor is less likely to be affected by dust. Therefore, even if the tool is used in an environment where dust is present, it is possible to accurately detect whether the attachment is attached to the housing. In addition, according to the above structure, the detection sensor detects the operation of the link member using a non-contact sensor element. Accordingly, even when vibration or impact is applied to the link member, it is possible to prevent the impact or vibration from being applied to the sensor element through the link member. It is possible to prevent false detection by the sensor element due to the impact or vibration, and it is possible to improve the durability of the sensor element.

[0037] In one or more embodiments, the tool can further include a control unit that controls the operation of the prime mover. The control unit can permit the driving of the prime mover based on a detection signal from the detection sensor.

[0038] According to the above structure, it is possible to permit the driving of the prime mover only when the attachment is attached to the housing.

[0039] In one or more embodiments, the link member can extend from the inside of the housing to the outside.

[0040] According to the above structure, it is possible to detect whether the attachment is attached to the housing, the attachment not entering the inside of the housing when attached to the housing.

[0041] In one or more embodiments, the detection sensor can further include a sensor housing that houses the sensor element, and a sensor rod that extends from the inside of the sensor housing to the outside and operates in response to the operation of the link member. The sensor element can detect the operation of the sensor rod.

[0042] According to the above structure, since the sensor element of the detection sensor is housed inside the sensor housing, it is assumed that even in the case where dust flows into the inside of the housing, the sensor element can be inhibited from being affected by the dust.

[0043] In one or more embodiments, the sensor element can have a light emitting element and a light receiving element that receives light from the light emitting element. The sensor rod can be movable between a first position and a second position, the first position being a position where the light emitting element and the light receiving element are not shielded (not blocked) from each other, and the second position being a position where the light emitting element and the light receiving element are shielded (blocked) from each other. When the fitting is not attached to the housing, the sensor rod can be positioned in one of the first position and the second position. When the fitting is attached to the housing, the sensor rod can be positioned in the other of the first position and the second position.

[0044] As described above, for a sensor element having a light emitting element and a light receiving element, it is less likely to be affected by an external environment such as metal dust, compared to a sensor element having a magnet and a Hall element, for example. According to the above structure, since the position of the sensor rod is switched between the first position and the second position in response to attachment and detachment of the fitting, it is possible to determine whether the fitting is attached to the housing or not, depending on whether or not light is transmitted from the light emitting element to the light receiving element.

[0045] In one or more embodiments, the light emitting element can emit light in accordance with a light emitting signal having a prescribed signal pattern.

[0046] In a structure in which the position of the sensor rod is switched between the first position and the second position in response to attachment and detachment of the fitting, when it is desired to determine whether the fitting is attached to the housing or not, only depending on whether or not light is transmitted from the light emitting element to the light receiving element, in the case where the light receiving element has a turn-on failure or a turn-off failure, it is possible that the determination as to whether the fitting is attached to the housing or not is made erroneously. According to the above structure, in the case where the sensor rod is positioned at the first position and light is normally transmitted from the light emitting element to the light receiving element, the light receiving signal received by the light receiving element has the same signal pattern as the light emitting signal emitted by the light emitting element. Therefore, by comparing the signal pattern of the light receiving signal received by the light receiving element and the signal pattern of the light emitting signal emitted by the light emitting element, it is possible to determine whether the fitting is attached to the housing or not, and accordingly, it is possible to prevent erroneous determination due to a failure of the detection sensor.

[0047] In one or more embodiments, the sensor rod can be formed in a shape that is slidable on a side surface inside the sensor housing. The sensor rod can have a substantially flat base and an abutting portion, where the base has a length direction in a vertical direction and a width direction in a horizontal direction, and the abutting portion protrudes from the sensor housing and abuts against the link member. The base can be formed with a cutout portion having a shape that does not shield between the light emitting element and the light receiving element, and a shielding portion having a shape that shields between the light emitting element and the light receiving element.

[0048] According to the above structure, a sensor rod that extends from the inside of the sensor housing to the outside and operates in response to the operation of the link member can be achieved with a simple structure.

[0049] In one or more embodiments, the accessory can have a cover that at least partially covers the tip tool. The housing can have a cover mounting portion for mounting the cover. The link member can have a round shaft, a front lever fixed to a front end of the shaft, and a rear lever fixed to a rear end of the shaft. The front end of the shaft can protrude outside the housing through a through hole formed in the housing. The front lever can be disposed outside the housing and near the cover mounting portion. The rear lever can be disposed inside the housing and below the detection sensor.

[0050] According to the above structure, a link member that causes a sensor rod to operate in response to the attachment and detachment of a cover as an accessory can be achieved with a simple structure.

[0051] In one or more embodiments, in the tool, when the cover is mounted to the cover mounting portion, the front lever is pressed by the cover and turned upward, the rear lever is also turned upward, the abutting portion is pressed by the rear lever and the sensor rod moves upward, and accordingly, the cutout portion is disposed between the light emitting element and the light receiving element, so that light from the light emitting element reaches the light receiving element without being shielded.

[0052] According to the above structure, the attachment and detachment of the cover with respect to the housing can be detected by the detection sensor with a simple structure.

[0053] In one or more embodiments, the link member can be rotatably supported by the housing. The link member can be configured to rotate relative to the housing in response to attachment and detachment of the accessory.

[0054] According to the above-described configuration, even when the detection sensor is disposed at a position away from the mounting position of the accessory, the idle space inside the housing can be effectively utilized to dispose the link member extending from the mounting position of the accessory to the position of the detection sensor without making the link member a large and complex mechanism.

[0055] In one or more embodiments, the prime mover can be an electric motor. The length direction of the link member can be disposed along a first direction substantially parallel to an output shaft of the electric motor housed inside the housing. The rotation axis of the link member can be disposed along the first direction. The sensor rod can be held by the sensor housing in a manner movable along a second direction substantially orthogonal to the first direction. The detection sensor can further include an elastic member housed inside the sensor housing and applying a force to the sensor rod from the first position to the second position.

[0056] According to the above-described configuration, the structure of the link member and the detection sensor can be simplified.

[0057] In one or more embodiments, the tool can further include a control unit that controls electric power supplied to the electric motor. The detection sensor can be disposed between the electric motor and the control unit.

[0058] According to the above-described configuration, the idle space inside the housing between the electric motor and the control unit can be effectively utilized to dispose the detection sensor.

[0059] In one or more embodiments, the tool can further include a battery detachably mounted to the housing and supplying electric power to the electric motor. The detection sensor can be disposed between the electric motor and the battery.

[0060] According to the above-described configuration, the idle space inside the housing between the electric motor and the battery can be effectively utilized to dispose the detection sensor.

[0061] In one or more embodiments, the accessory can be a cover at least partially covering the tip tool.

[0062] According to the above-described configuration, whether the cover at least partially covering the tip tool is mounted to the housing can be detected by the detection sensor.

[0063] In one or more embodiments, the detection sensor can further include a sensor housing that houses the sensor element. The link member can extend from an inside of the sensor housing to an outside of the sensor housing. The sensor element can detect an operation of the link member.

[0064] According to the above structure, since the sensor element directly detects the operation of the link member without a member such as a sensor rod, the structure of the detection sensor can be simplified, and the number of components can be reduced.

[0065] In one or more embodiments, the sensor element can include a light emitting element and a light receiving element that receives light from the light emitting element. The link member can be movable between a first position in which the light emitting element and the light receiving element are not shielded and a second position in which the light emitting element and the light receiving element are shielded. When the accessory is not attached to the housing, the link member can be positioned in one of the first position and the second position. When the accessory is attached to the housing, the link member can be positioned in the other of the first position and the second position.

[0066] According to the above structure, compared to a case in which a sensor element having a magnet and a Hall element is used, for example, the detection sensor can be less affected by an external environment such as metal dust.

[0067] In one or more embodiments, the light emitting element can emit light in accordance with a light emitting signal having a predetermined signal pattern.

[0068] According to the above structure, erroneous determination due to a defect of the detection sensor can be prevented.

[0069] In one or more embodiments, the link member can include a swing shaft that is held in the sensor housing in a swingable manner, an abutting arm that protrudes to an outside of the sensor housing, and a detection arm that is housed in an inside of the sensor housing. The abutting arm can include a flange and a protruding portion that protrudes from the flange. The detection arm can include a shielding portion that has a shape that shields between the light emitting element and the light receiving element.

[0070] According to the above structure, by a simple structure, the link member that operates in response to attachment and detachment of the accessory and the detection sensor that detects the operation of the link member can be implemented.

[0071] In one or more embodiments, the accessory can have a cover that at least partially covers the tip tool. The housing can have a cover mounting portion for mounting the cover. The sensor housing can be disposed inside the housing and near a center portion in the left-right direction of the housing. The sensor housing can be held by the housing with the swing axis disposed in the left-right direction and the protruding portion facing downward. The abutting arm can protrude outside the housing via a through-hole of the housing. The flange and the protruding portion can be disposed outside the housing and near the cover mounting portion.

[0072] According to the above structure, the cover can be detected with respect to the housing by a detection sensor with a simple structure.

[0073] In one or more embodiments, the accessory can have a handle that can be held by a user. The housing can have a handle mounting hole for mounting the handle. The sensor housing can be disposed inside the housing. The sensor housing can be held by the housing with the swing axis disposed in the up-down direction and the protruding portion facing the handle mounting hole. When the handle is not mounted on the handle mounting hole, the flange can abut against an inner surface of the housing and the protruding portion can enter the handle mounting hole.

[0074] According to the above structure, the handle can be detected with respect to the housing by a detection sensor with a simple structure.

[0075] In one or more embodiments, the link member can be rotatably supported by the sensor housing. The link member can rotate with respect to the sensor housing in response to the attachment and detachment of the accessory.

[0076] In a structure in which the link member and the detection sensor are separately mounted on the housing, when errors occur in the respective mounting positions, the relative positional relationship of the link member and the sensor element can differ from the intended one, and the detection sensor can make a false determination. According to the above structure, since the link member is mounted to the sensor housing, the relative positional relationship of the link member and the sensor element can be managed with high precision.

[0077] In one or more embodiments, the prime mover can be an electric motor. The rotation axis of the link member and the sensor element can be arranged in a direction substantially orthogonal to an output shaft of the electric motor housed inside the housing.

[0078] According to the above structure, the idle space around the output shaft of the electric motor in the inside of the housing can be effectively used to arrange the link member and the detection sensor.

[0079] In one or more embodiments, the rotation axis of the link member can be arranged in a second direction that is substantially orthogonal to a first direction, the first direction being substantially parallel to the output shaft of the electric motor. The tool can further include an elastic member that applies a force to the link member from the first position to the second position.

[0080] According to the above structure, the structure of the link member and the detection sensor can be simplified.

[0081] In one or more embodiments, the detection sensor can be arranged between the tip tool holding portion and the electric motor in a direction in which the output shaft of the electric motor extends.

[0082] According to the above structure, the idle space between the tip tool holding portion and the electric motor in the inside of the housing can be effectively used to arrange the detection sensor.

[0083] In one or more embodiments, the tool can include a plurality of the detection sensors and a plurality of the link members, the plurality of the link members corresponding to the plurality of the detection sensors.

[0084] According to the above structure, in a case where a plurality of attachment positions exist, it can be detected whether an attachment is attached to each of the attachment positions.

[0085] In one or more embodiments, the attachment can include a cover that at least partially covers the tip tool and / or a handle that can be held by a user.

[0086] According to the above structure, it can be detected by the detection sensor whether the cover that at least partially covers the tip tool and the handle that can be held by a user are attached to the housing.

[0087] In one or more embodiments, the tool can include a prime mover, a transmission mechanism, a housing, a tip tool holding portion, an accessory, a link member, and a detection sensor, wherein the transmission mechanism is connected to the prime mover; the housing houses the prime mover and the transmission mechanism; the tip tool holding portion is connected to the transmission mechanism and holds a tip tool; the accessory is detachably attached to the housing; the link member operates in response to the attachment and detachment of the accessory; and the detection sensor is housed inside the housing. The link member can rotate with respect to the housing in response to the attachment and detachment of the accessory. The detection sensor can detect the rotation of the link member.

[0088] According to the above structure, since the detection sensor is housed inside the housing, the detection sensor is less likely to be affected by dust. Therefore, even when the tool is used in an environment where dust is abundant, it is possible to accurately detect whether the accessory is attached to the housing. In addition, according to the above structure, even when the detection sensor is disposed at a position away from the attachment position of the accessory, it is possible to effectively use the idle space inside the housing to dispose the link member extending from the attachment position of the accessory to the position of the detection sensor without making the link member a large and complex mechanism.

[0089] In one or more embodiments, the tool can further include a control unit that controls the operation of the prime mover. The control unit can allow the driving of the prime mover based on a detection signal from the detection sensor.

[0090] According to the above structure, the driving of the prime mover is allowed only when the accessory is attached to the housing.

[0091] In one or more embodiments, the link member can be rotatably supported by the housing. The link member can extend from the inside of the housing to the outside of the housing.

[0092] According to the above structure, it is possible to effectively use the idle space inside the housing to dispose the link member extending from the attachment position of the accessory outside the housing to the position of the detection sensor inside the housing.

[0093] (Embodiment 1)

[0094] As Figure 1As shown, the grinder 2 of the present embodiment is a tool used in a state where a grinding wheel 4 as a top tool and a cover 6 as an accessory are attached. The grinder 2 is capable of performing grinding and deburring of a welded portion of a metal or the like by rotation of the grinding wheel 4. In addition, by replacing the grinding wheel 4 in correspondence with the material of a workpiece and the contents of work, and replacing the cover 6 in correspondence with the replaced grinding wheel 4, cutting of a workpiece such as concrete, a block, a brick, a stone, and the like can be performed. Further, in the following description, the longitudinal direction of the grinder 2 will be referred to as the front-rear direction, the direction of the rotational axis of the grinding wheel 4 will be referred to as the up-down direction, and the direction orthogonal to the front-rear direction and the up-down direction will be referred to as the left-right direction.

[0095] The grinder 2 has a main housing 8, a gear housing cover 9, a gear housing 10, and a bearing case 12.

[0096] An electric motor 14 as a prime mover is housed in the front inner portion of the main housing 8. The electric motor 14 is, for example, a brushless DC motor of an inner rotor type. The electric motor 14 has an output shaft 16 extending in the front-rear direction. The output shaft 16 is rotatably supported to the gear housing cover 9 by a bearing 18, and is rotatably supported to the main housing 8 by a bearing 20. A battery 22 is attached to the rear end of the main housing 8. The battery 22 is, for example, a rechargeable secondary battery such as a lithium ion battery. The battery 22 is a slide-in battery which is detachable by sliding it in the up-down direction with respect to the main housing 8. A control substrate 24 is housed in the rear inner portion of the main housing 8. Electric power supplied from the battery 22 is supplied to the electric motor 14 through the control substrate 24. A slide switch 26 which is slidable in the front-rear direction is provided on the front upper surface of the main housing 8. The slide switch 26 is switchable between an on position and an off position by the user's operation. The position of the slide switch 26 is detectable by a main switch 28 housed in the inner portion of the main housing 8. The main switch 28 is connected to the control substrate 24. In the case where the slide switch 26 is in the on position, electric power from the battery 22 is supplied to the electric motor 14 through the control substrate 24, so that the electric motor 14 rotates the output shaft 16. In the case where the slide switch 26 is in the off position, the electric power supplied from the battery 22 to the electric motor 14 is interrupted, so that the electric motor 14 stops the output shaft 16. A display portion 30 is provided on the rear upper surface of the main housing 8. The display portion 30 changes the display in accordance with the operation state of the grinder 2 and the battery remaining amount of the battery 22, so that the user is informed of the operation state of the grinder 2 and the battery remaining amount of the battery 22.

[0097] The gear housing 10 is mounted on the front of the main housing 8 via the gear housing cover 9. Inside the gear housing 10 are housed a first bevel gear 32 and a second bevel gear 34, which are meshed with each other. The first bevel gear 32 is fixed to the front end of the output shaft 16. The second bevel gear 34 is fixed to the upper end of the main shaft 36, which extends vertically. In the following description, the first bevel gear 32 and the second bevel gear 34 will be simply referred to collectively as bevel gear 38. The bevel gear 38 is a reduction mechanism for slowing down the rotation of the electric motor 14 and transmitting it to the main shaft 36; it can be referred to as a transmission mechanism. The gear housing 10 rotatably supports the upper end of the main shaft 36 via bearings 40. Figure 2 As shown, a shaft locking member 42 is provided on the upper surface of the gear housing 10. When the user presses the shaft locking member 42 downward, the rotation of the second bevel gear 34 is prohibited, thereby prohibiting the rotation of the main shaft 36.

[0098] like Figure 1 As shown, the bearing housing 12 is mounted below the gear housing 10. The bearing housing 12 rotatably supports the spindle 36 via bearings 44. The spindle 36 can rotate relative to the bearing housing 12 about a rotation axis extending vertically. At the lower end of the spindle 36, a grinding wheel 4 can be mounted via an inner flange 46 and an outer flange 48. The inner flange 46 engages with the spindle 36. The grinding wheel 4 is mounted on the spindle 36 from below the inner flange 46 and engages with the inner flange 46. The outer flange 48 is screwed onto the spindle 36 from the lower end of the spindle 36 and clamps the grinding wheel 4 between it and the inner flange 46. In the grinding machine 2, when the electric motor 14 rotates, the grinding wheel 4 and the spindle 36 rotate together about the rotation axis, thereby grinding the workpiece. The spindle 36 can also be referred to as a top tool holder for holding the grinding wheel 4 as a top tool. Furthermore, in the following description, the main body housing 8, gear housing cover 9, gear housing 10 and bearing housing 12 may be simply referred to as housing 50.

[0099] The cover 6 is mounted on a generally cylindrical cover mounting portion 52 formed on the bearing housing 12. When mounted on the grinding machine 2, the cover 6 is shaped to at least partially cover the grinding wheel 4. When mounted on the grinding machine 2, the cover 6 may also have a shape that at least partially covers the spindle 36. When the workpiece is ground by the grinding wheel 4, the cover 6 prevents cutting powder from flying towards the user side.

[0100] like Figure 2 As shown, the grinding machine 2 has a cover detection mechanism 54. The cover detection mechanism 54 has a connecting rod member 56 and a detection sensor 58. The detection sensor 58 is housed inside the main body housing 8. The detection sensor 58 is disposed between the electric motor 14 and the control board 24. The detection sensor 58 is positioned rearward of the electric motor 14 and forward of the battery 22 and the control board 24.

[0101] like Figure 3 As shown, the linkage assembly 56 has a circular shaft 60, a front control lever 62, and a rear control lever 64, wherein the front control lever 62 is fixed to the front end of the shaft 60; and the rear control lever 64 is fixed to the rear end of the shaft 60. Figure 2 As shown, shaft 60 is positioned at the lower front right of the interior of the main housing 8, along the longitudinal direction of the grinding machine 2. Shaft 60 is rotatably supported on the main housing 8. The front end of shaft 60 protrudes outward from the housing 50 through a through hole 10a formed in the gear housing 10, and a front control lever 62 is positioned outside the housing 50. The front control lever 62 is positioned near the cover mounting portion 52 of the bearing housing 12. The rear control lever 64 is positioned inside the main housing 8, below the detection sensor 58. When the cover 6 is mounted on the cover mounting portion 52, the front control lever 62 rotates upward. When the front control lever 62 rotates, shaft 60 and rear control lever 64 also rotate integrally.

[0102] like Figure 3 , Figure 4 As shown, the detection sensor 58 includes a sensor housing 66, a sensor rod 68, a compression spring 70, and an optical interruptor 72. The sensor housing 66 has a generally rectangular parallelepiped shape and an opening on its lower surface. The sensor rod 68 protrudes downwards from the opening on the lower surface of the sensor housing 66. The compression spring 70 is housed within the sensor housing 66. The optical interruptor 72 is also housed within the sensor housing 66. Furthermore, although not shown, a rubber seal is provided in the opening on the lower surface of the sensor housing 66. This seal abuts against the periphery of the sensor rod 68 and allows the sensor rod 68 to slide. This prevents dust from entering the interior of the sensor housing 66.

[0103] like Figure 5 As shown, the optical interruptor 72 includes a sensor substrate 74 and a light-emitting portion 76 and a light-receiving portion 78 mounted on the sensor substrate 74. The sensor substrate 74 is fixed to the rear surface inside the sensor housing 66. The sensor substrate 74 is connected to the control substrate 24 via wiring (not shown). The light-emitting portion 76 and the light-receiving portion 78 are disposed on the front surface of the sensor substrate 74. The light-emitting portion 76 and the light-receiving portion 78 are arranged facing each other in the left-right direction. A light-emitting element 76a (see reference) is disposed inside the light-emitting portion 76. Figure 10 The light-receiving part 78 is equipped with a light-receiving element 78a (see reference). Figure 10 ).

[0104] like Figure 6As shown, the sensor rod 68 has a generally flat base 68a, an upper guide portion 68b, and a lower guide portion 68c. The base 68a has its length in the vertical direction and its width in the rear-rear direction. The upper guide portion 68b is located at the upper end of the base 68a. The lower guide portion 68c is located below the center of the base 68a in the vertical direction. The upper guide portion 68b and the lower guide portion 68c are shaped to slide relative to the inner side surface of the sensor housing 66. A rounded-corner abutment portion 68d is formed at the lower end of the base 68a. A spring-bearing portion 68e is formed on the upper surface of the upper guide portion 68b. A notch portion 68f is formed behind the base 68a at a position above the center in the vertical direction. The base 68a above the notch portion 68f forms a shielding portion 68g.

[0105] like Figure 4 As shown, the compression spring 70 is located inside the sensor housing 66, positioned above the sensor rod 68. Figure 7 As shown, the upper end of the compression spring 70 abuts against the spring receiving portion 66a formed on the top surface inside the sensor housing 66, and the lower end of the compression spring 70 abuts against the spring receiving portion 68e of the sensor rod 68. The compression spring 70 applies a downward force to the sensor rod 68 relative to the sensor housing 66. The sensor rod 68 can move downward to the lower limit position where the lower surface of the upper guide portion 68b abuts against the upper surfaces of the light-emitting portion 76 and the light-receiving portion 78 of the optical interruptor 72. When the sensor rod 68 is in the lower limit position, the shielding portion 68g of the base 68a is disposed between the light-emitting portion 76 and the light-receiving portion 78. In this state, the light from the light-emitting portion 76 is shielded by the shielding portion 68g and does not reach the light-receiving portion 78.

[0106] like Figure 3 As shown, the rear control lever 64 of the linkage assembly 56 is located below the abutment portion 68d of the detection sensor 58. When the cover 6 is not installed on the grinder 2 and no external force is applied to the front control lever 62, the sensor lever 68 is maintained at the lower limit position because no upward force is applied to the abutment portion 68d from the rear control lever 64.

[0107] When the cover 6 is installed on the grinder 2, the front control lever 62 is pushed upward by the cover 6, as... Figure 8 As shown, the front control lever 62 rotates upward. Accordingly, the rear control lever 64 also rotates upward, and the abutment portion 68d of the sensor lever 68 is pushed upward by the rear control lever 64. Figure 9 As shown, with the sensor rod 68 pushed upwards, the notch 68f of the base 68a is positioned between the light-emitting part 76 and the light-receiving part 78. In this state, light from the light-emitting part 76 reaches the light-receiving part 78 without being blocked. The position of the sensor rod 68 in this state is also referred to as the upper limit position.

[0108] Furthermore, when the cover 6 is removed from the grinder 2, the sensor rod 68 is pressed down by the force of the compression spring 70, such as... Figure 3 As shown, the rear control lever 64 rotates downwards, and the front control lever 62 also rotates downwards.

[0109] In the grinding machine 2 of this embodiment, when the grinding wheel 4 is facing downwards, gravity acts on the sensor rod 68 in the direction that moves it from the upper limit position to the lower limit position, and gravity acts on the front control lever 62 and the rear control lever 64 in the direction that rotates them downwards. Therefore, even if the compression spring 70 does not exert its force on the sensor rod 68 due to damage or aging, when the cover 6 is removed from the grinding machine 2 and the grinding wheel 4 is facing downwards, the sensor rod 68 will still move to the lower limit position by its own weight, and the front control lever 62 and the rear control lever 64 will also rotate downwards by their own weight.

[0110] Figure 10 The circuit structure of the grinder 2 is shown. An regulator 80, a microcomputer 82, a motor driver 84, and an indicator lamp 86 are mounted on the control board 24. The regulator 80 adjusts the electrical power supplied from the battery 22 to a predetermined voltage. The motor driver 84 has multiple switching elements (not shown) controlled by the microcomputer 82 for controlling the electrical power supplied to the electric motor 14. The indicator lamp 86 has multiple light-emitting elements (not shown) for switching the content displayed on the display unit 30. The microcomputer 82 receives signals indicating the on / off state from the main switch 28. Additionally, the microcomputer 82 sends light-emitting signals to the light-emitting element 76a of the optical interrupter 72 and receives light-receiving signals from the light-receiving element 78a of the optical interrupter 72.

[0111] Figure 11 This is a flowchart illustrating the processing performed by the microcomputer 82.

[0112] In step S2, the microcomputer 82 enters standby mode until the main switch 28 is turned on. When the main switch 28 is turned on, the process proceeds to step S4.

[0113] In step S4, the microcomputer 82 performs... Figure 12 The mask determination process is shown below.

[0114] for Figure 12 Regarding the mask determination process shown, in step S32, the microcomputer 82 sends a light-emitting signal to the light-emitting element 76a of the optical interruptor 72. In this embodiment, the microcomputer 82 sends a signal pattern 90 as the light-emitting signal (see reference). Figure 13The signal mode 90 has a pulse train that switches between H potential and L potential according to a predetermined period.

[0115] In step S34, the microcomputer 82 receives the light signal from the light-receiving element 78a of the optical interrupter 72.

[0116] In step S36, the microcomputer 82 determines whether the periods of the light emission signal sent in step S32 and the light reception signal received in step S34 are consistent.

[0117] like Figure 13 As shown, when the cover 6 is mounted on the cover mounting portion 52, thus the light-emitting portion 76 and the light-receiving portion 78 are not obstructed, signal mode 92, which receives a pulse train with the same period as the light-emitting signal signal mode 90, is used as the light-receiving signal. Conversely, when the cover 6 is not mounted on the cover mounting portion 52, thus the light-emitting portion 76 and the light-receiving portion 78 are obstructed, signal mode 94, which receives a constant L potential, is used as the light-receiving signal. Furthermore, when signal mode 96, which receives a constant H potential, is used as the light-receiving signal, and signal mode 98, which receives a pulse train with a different period than the light-emitting signal, is used as the light-receiving signal, it is considered that the optical interruptor 72 has malfunctioned.

[0118] exist Figure 12 In step S36, if the periods of the light-emitting signal and the light-receiving signal are consistent ("yes"), the microcomputer 82 determines that the cover 6 is installed on the cover mounting part 52, and proceeds to step S38. In step S38, the microcomputer 82 allows the electric motor 14 to be driven. After step S38, the process ends. Figure 12 The mask determination process is shown below.

[0119] exist Figure 12 In step S36, if the periods of the emitted light signal and the received light signal are inconsistent ("No"), the microcomputer 82 determines that the cover 6 is not installed on the cover mounting part 52, or determines that the optical interruptor 72 is malfunctioning, and proceeds to step S40. In step S40, the microcomputer 82 disables the drive of the electric motor 14. After step S40, the process ends. Figure 12 The mask determination process is shown below.

[0120] Return to Figure 11 In the next step, S6, after step S4, the microcomputer 82 determines whether driving the electric motor 14 is permitted. If driving the electric motor 14 is prohibited ("No"), the process proceeds to step S8.

[0121] In step S8, the microcomputer 82 controls the indicator light 86, and the display unit 30 displays a warning.

[0122] In step S10, the microcomputer 82 stands by until the main switch 28 is turned off. When the main switch 28 is turned off ("Yes"), the processing proceeds to step S12.

[0123] In step S12, the microcomputer 82 controls the display lamp 86 to cancel the warning display in the display portion 30. After step S12, the processing returns to step S2.

[0124] In step S6, in the case where the driving of the electric motor 14 is allowed ("Yes"), the processing proceeds to step S14. In step S14, the microcomputer 82 controls the motor driver 84 to start the driving of the electric motor 14. Thereby, the grinding wheel 4 is rotated, so that the grinding of the workpiece can be performed using the grinder 2.

[0125] In step S16, the microcomputer 82 again performs the cover determination processing shown in FIG. 8. As a result of this cover determination processing, when the cover 6 is kept mounted on the cover mounting portion 52, the driving of the electric motor 14 is allowed (step S38 of FIG. 8), and when the cover 6 is detached from the cover mounting portion 52, the driving of the electric motor 14 is prohibited (step S40 of FIG. 8). Figure 12 Figure 12 Figure 12

[0126] In step S18, the microcomputer 82 determines whether the driving of the electric motor 14 is allowed. In the case where the driving of the electric motor 14 is prohibited ("No"), the processing proceeds to step S20.

[0127] In step S20, the microcomputer 82 controls the motor driver 84 to stop the driving of the electric motor 14.

[0128] In step S22, the microcomputer 82 controls the display lamp 86 to perform the warning display by the display portion 30.

[0129] In step S24, the microcomputer 82 stands by until the main switch 28 is turned off. When the main switch 28 is turned off ("Yes"), the processing proceeds to step S12.

[0130] In step S12, the microcomputer 82 controls the display lamp 86 to cancel the warning display in the display portion 30. After step S12, the processing returns to step S2.

[0131] In step S18, in the case where the driving of the electric motor 14 is allowed ("Yes"), the processing proceeds to step S26. In step S26, the microcomputer 82 determines whether the main switch 28 is turned off. In the case where the main switch 28 is not turned off ("No"), the processing returns to step S16.

[0132] ​​​In step S26, when the main switch 28 is off ("Yes"), the process proceeds to step S28. In step S28, the microcomputer 82 controls the motor driver 84 to stop the drive of the electric motor 14. After step S28, the process returns to step S2.

[0133] Since the microcomputer 82 performs the above-described process, the grinder 2 drives the electric motor 14 only in the case where the slide switch 26 is in the on position and the cover 6 is attached. Accordingly, it is possible to prevent the electric motor 14 from being driven in the state where the cover 6 is not attached.

[0134] Further, for the above-described process, it is also possible to configure so as to perform the cover determination process of step S16 every time a prescribed time (for example, 1 minute) elapses, instead of always performing the process. Or, it is also possible to configure so as to not perform the cover determination process of step S16. By reducing the number of times of execution of the cover determination process, it is possible to suppress the power consumption of the battery 22. Figure 11 Figure 11 By reducing the number of times of execution of the cover determination process, it is possible to suppress the power consumption of the battery 22.

[0135] As described above, in one or more embodiments, the grinder 2 (example of a tool) has an electric motor 14 (example of a prime mover), a bevel gear 38 (example of a transmission mechanism) connected to the electric motor 14, a housing 50 that houses the electric motor 14 and the bevel gear 38, a spindle 36 (example of a tip tool holding portion) connected to the bevel gear 38 and holding a grinding wheel 4 (example of a tip tool), a cover 6 (example of an accessory) that is detachably attached to the housing 50, a link member 56 that operates in response to the attachment and detachment of the cover 6, and a detection sensor 58 that is housed inside the housing 50 and has a light interrupter 72 (example of a non-contact sensor element). The detection sensor 58 detects the operation of the link member 56 using the light interrupter 72.

[0136] According to the above-described structure, since the detection sensor 58 is housed inside the housing 50, the detection sensor 58 is less likely to be affected by dust. Thus, even when the grinder 2 is used in an environment with a large amount of dust, it is possible to accurately detect whether the cover 6 is attached to the housing 50. Further, according to the above-described structure, the detection sensor 58 detects the operation of the link member 56 using the light interrupter 72 as a non-contact sensor element. Accordingly, even when vibration or impact is applied to the link member 56, it is possible to prevent the impact or vibration from being applied to the light interrupter 72 through the link member 56. It is possible to prevent false detection by the light interrupter 72 due to the impact or vibration, and it is possible to improve the durability of the light interrupter 72.

[0137] ​In one or more embodiments, the grinder 2 also has a control substrate 24 (an example of a control unit) that controls the operation of the electric motor 14. The control substrate 24 permits the driving of the electric motor 14 in accordance with a detection signal from the detection sensor 58.

[0138] According to the above-described structure, the driving of the electric motor 14 is permitted only when the cover 6 is attached to the housing 50.

[0139] In one or more embodiments, the link member 56 extends from the inside of the housing 50 to the outside.

[0140] According to the above-described structure, it is possible to detect whether the cover 6 that does not enter the inside of the housing 50 when attached to the housing 50 is attached to the housing 50.

[0141] In one or more embodiments, the detection sensor 58 also has a sensor housing 66 that houses the optical interrupter 72, and a sensor lever 68 that extends from the inside of the sensor housing 66 to the outside and that operates in response to the operation of the link member 56. The optical interrupter 72 detects the operation of the sensor lever 68.

[0142] According to the above-described structure, since the optical interrupter 72 of the detection sensor 58 is housed in the inside of the sensor housing 66, even when dust flows into the inside of the housing 50, the optical interrupter 72 can be inhibited from being affected by the dust.

[0143] In one or more embodiments, the optical interrupter 72 has a light emitting element 76a and a light receiving element 78a that receives light from the light emitting element 76a. The sensor lever 68 is movable between an upper limit position (an example of a first position) at which the light emitting element 76a and the light receiving element 78a are not shielded from each other, and a lower limit position (an example of a second position) at which the light emitting element 76a and the light receiving element 78a are shielded from each other. When the cover 6 is not attached to the housing 50, the sensor lever 68 is positioned at the lower limit position. When the cover 6 is attached to the housing 50, the sensor lever 68 is positioned at the upper limit position.

[0144] As described above, for the optical interrupter 72 having the light emitting element 76a and the light receiving element 78a, it is less likely to be affected by the external environment such as metal dust, compared to a sensor element having a magnet and a Hall element, for example. According to the above-described structure, since the position of the sensor lever 68 is switched between the upper limit position and the lower limit position in response to the attachment and detachment of the cover 6, it is possible to determine whether the cover 6 is attached to the housing 50 or not, based on whether the light is transmitted from the light emitting element 76a to the light receiving element 78a or not.

[0145] In one or more embodiments, the light emitting element 76a emits light in accordance with a light emitting signal having a prescribed signal pattern 100.

[0146] In a configuration in which the position of the sensor rod 68 is switched between the upper limit position and the lower limit position in response to the attachment and detachment of the cover 6, when it is desired to determine whether the cover 6 is attached to the housing 50 only on the basis of whether or not light is transmitted from the light emitting element 76a to the light receiving element 78a, in the case where the light receiving element 78a has a turn-on failure or a turn-off failure, it is possible that a false determination is made as to whether the cover 6 is attached to the housing 50. According to the above-described configuration, in the case where the sensor rod 68 is positioned at the upper limit position and light is normally transmitted from the light emitting element 76a to the light receiving element 78a, the light receiving signal received by the light receiving element 78a has the same signal pattern 92 as the light emitting signal emitted by the light emitting element 76a. Therefore, by comparing the signal pattern 92, 94, 96, 98 of the light receiving signal received by the light receiving element 78a with the signal pattern 90 of the light emitting signal emitted by the light emitting element 76a, it is possible to determine whether the cover 6 is attached to the housing 50, and accordingly, it is possible to prevent a false determination due to a failure of the detection sensor 58.

[0147] In one or more embodiments, the sensor rod 68 is formed in a shape that is slidable on the side surface inside the sensor housing 66. The sensor rod 68 has a base portion 68a and an abutting portion 68d, wherein the base portion 68a is a substantially flat plate shape and has a length direction in the up-down direction and a width direction in the front-rear direction, and the abutting portion 68d protrudes from the sensor housing 66 and abuts against the link member 56. The base portion 68a is formed with a cutout portion 68f having a shape that does not shield between the light emitting element 76a and the light receiving element 78a, and a shielding portion 68g having a shape that shields between the light emitting element 76a and the light receiving element 78a.

[0148] According to the above-described configuration, by a simple configuration, it is possible to realize the sensor rod 68 that extends from the inside of the sensor housing 66 to the outside and that operates in response to the operation of the link member 56.

[0149] In one or more embodiments, the housing 50 has a cover mounting portion 52 for mounting the cover 6. The link member 56 has a round rod shaft 60, a front lever 62 fixed to a front end of the shaft 60, and a rear lever 64 fixed to a rear end of the shaft 60. The front end of the shaft 60 protrudes to the outside of the housing 50 through a through-hole 10a formed in the housing 50. The front lever 62 is disposed outside the housing 50 in the vicinity of the cover mounting portion 52. The rear lever 64 is disposed inside the housing 50 below the detection sensor 58.

[0150] According to the above-described structure, the link member 56 that operates in response to the attachment and detachment of the cover 6 as an accessory can be realized by a simple structure.

[0151] In one or more embodiments, in the grinder 2, when the cover 6 is mounted to the cover mounting portion 52, the front lever 62 is pressed by the cover 6 to rotate upward, the rear lever 64 also rotates upward, the abutting portion 68d is pressed by the rear lever 64 to move the sensor rod 68 upward, and accordingly, the notch portion 68f is disposed between the light emitting element 76a and the light receiving element 78a, so that the light from the light emitting element 76a reaches the light receiving element 78a without being shielded.

[0152] According to the above-described structure, the attachment and detachment of the cover 6 with respect to the housing 50 can be detected by the detection sensor 58 with a simple structure.

[0153] In one or more embodiments, the link member 56 is rotatably supported to the housing 50. The link member 56 rotates with respect to the housing 50 in response to the attachment and detachment of the cover 6.

[0154] According to the above-described structure, even when the detection sensor 58 is disposed at a position away from the mounting position of the cover 6, the inside of the housing 50 can be effectively used to dispose the link member 56 extending from the mounting position of the cover 6 to the position of the detection sensor 58 without making the link member 56 a large and complex mechanism.

[0155] In one or more embodiments, the length direction of the link member 56 is disposed in a front-rear direction (an example of a first direction) parallel to the output shaft 16 of the electric motor 14 housed inside the housing 50. The rotation axis of the link member 56 is disposed in the front-rear direction. The sensor rod 68 is held to the sensor housing 66 in a manner movable in an up-down direction (an example of a second direction) orthogonal to the front-rear direction. The detection sensor 58 also has a compression spring 70 (an example of an elastic member) housed inside the sensor housing 66 that applies a force to the sensor rod 68 from an upper limit position to a lower limit position.

[0156] According to the above structure, the structure of the link member 56, the detection sensor 58 can be simplified.

[0157] In one or more embodiments, the grinder 2 further has a control substrate 24 (an example of a control unit) that controls electric power supplied to the electric motor 14. The detection sensor 58 is disposed between the electric motor 14 and the control substrate 24.

[0158] According to the above structure, the detection sensor 58 can be disposed effectively using a space that is unused between the electric motor 14 and the control substrate 24 inside the housing 50.

[0159] In one or more embodiments, the grinder 2 further has a battery 22 that is detachably mounted to the housing 50 and supplies electric power to the electric motor 14. The detection sensor 58 is disposed between the electric motor 14 and the battery 22.

[0160] According to the above structure, the detection sensor 58 can be disposed effectively using a space that is unused between the electric motor 14 and the battery 22 inside the housing 50.

[0161] In one or more embodiments, the cover 6 (an example of an accessory) at least partially covers the grinding wheel 4.

[0162] According to the above structure, it can be detected by the detection sensor 58 whether the cover 6 that at least partially covers the grinding wheel 4 is mounted to the housing 50.

[0163] In one or more embodiments, the grinder 2 (an example of a tool) has an electric motor 14 (an example of a prime mover), a bevel gear 38 (an example of a transmission mechanism), a housing 50, a spindle 36 (an example of a tip tool holding portion), a cover 6 (an example of an accessory), a link member 56, and a detection sensor 58, wherein the bevel gear 38 is connected to the electric motor 14; the housing 50 houses the electric motor 14 and the bevel gear 38; the spindle 36 is connected to the bevel gear 38 and holds a grinding wheel 4 (an example of a tip tool); the cover 6 is detachably mounted to the housing 50; the link member 56 operates in response to detachment and attachment of the cover 6; and the detection sensor 58 is housed inside the housing 50. The link member 56 rotates with respect to the housing 50 in response to detachment and attachment of the cover 6. The detection sensor 58 detects the rotational operation of the link member 56.

[0164] According to the above structure, since the detection sensor 58 is housed inside the housing 50, the detection sensor 58 is not easily affected by dust. Therefore, even when the grinder 2 is used in an environment with a large amount of dust, it is possible to accurately detect whether the cover 6 is installed on the housing 50. In addition, according to the above structure, even when the detection sensor 58 is disposed at a position away from the installation position of the cover 6, it is possible to effectively use the idle space inside the housing 50 to dispose the link member 56 extending from the installation position of the cover 6 to the position of the detection sensor 58 without making the link member 56 a large and complex mechanism.

[0165] In one or more embodiments, the grinder 2 further has a control substrate 24 (an example of a control unit) that controls the operation of the electric motor 14. The control substrate 24 permits the driving of the electric motor 14 in accordance with the detection signal from the detection sensor 58.

[0166] According to the above structure, the driving of the electric motor 14 is permitted only in the case where the cover 6 is installed on the housing 50.

[0167] In one or more embodiments, the link member 56 is rotatably supported to the housing 50. The link member 56 extends from the inside of the housing 50 to the outside.

[0168] According to the above structure, it is possible to effectively use the idle space inside the housing 50 to dispose the link member 56 extending from the installation position of the cover 6 on the outside of the housing 50 to the position of the detection sensor 58 inside the housing 50.

[0169] In the above-described embodiment, a structure is described in which, when the sensor lever 68 is positioned at the upper limit position, the cutout portion 68f is disposed between the light emitting portion 76 and the light receiving portion 78 so that the light emitting element 76a and the light receiving element 78a are not shielded, and, when the sensor lever 68 is positioned at the lower limit position, the shield portion 68g is disposed between the light emitting portion 76 and the light receiving portion 78 so that the light emitting element 76a and the light receiving element 78a are shielded. Unlike this, for example, the sensor lever 68 can be shaped so that the positions of the cutout portion 68f and the shield portion 68g are interchanged. In this case, when the sensor lever 68 is positioned at the upper limit position, the shield portion 68g is disposed between the light emitting portion 76 and the light receiving portion 78 so that the light emitting element 76a and the light receiving element 78a are shielded, and, when the sensor lever 68 is positioned at the lower limit position, the cutout portion 68f is disposed between the light emitting portion 76 and the light receiving portion 78 so that the light emitting element 76a and the light receiving element 78a are not shielded.

[0170] (Embodiment 2)

[0171] As Figure 14As shown, the grinder 102 of the present embodiment has substantially the same structure as the grinder 2 of Embodiment 1. In the following, points different from the grinder 2 of Embodiment 1 will be explained for the grinder 102 of the present embodiment.

[0172] In the grinder 102 of the present embodiment, the housing 50 has a partition housing 104 in addition to the main body housing 8, the gear housing cover 9, the gear housing 10, and the bearing box 12. The partition housing 104 is provided between the gear housing cover 9 and the gear housing 10.

[0173] The grinder 102 of the present embodiment does not have the cover detection mechanism 54. Instead, as shown, the grinder 102 has a cover detection unit 106. The cover detection unit 106 is provided to the partition housing 104. The cover detection unit 106 detects whether the cover 6 is installed on the cover mounting portion 52. Figure 15

[0174] As shown, the grinder 102 has a sub handle 108 as an accessory in addition to the cover 6. The sub handle 108 is detachably installed to the gear housing 10. When a user uses the grinder 102, the user holds the main body housing 8 with one hand and holds the sub handle 108 with the other hand, whereby the user can stably hold the grinder 102. Figure 14

[0175] As shown, handle mounting portions 110, 112 are provided to the gear housing 10. The handle mounting portion 110 is disposed to a right side surface of the gear housing 10, and the handle mounting portion 112 is disposed to a left side surface of the gear housing 10. The handle mounting portions 110, 112 have handle mounting holes 110a, 112a that penetrate the gear housing 10 from the outside to the inside, and inner threads are formed on inner peripheral surfaces thereof that correspond to outer threads of a threaded portion 108a (see FIG. 8) of the sub handle 108. The sub handle 108 can be installed to the handle mounting portion 110 with the threaded portion 108a screwed to the handle mounting hole 110a, and can be installed to the handle mounting portion 112 with the threaded portion 108a screwed to the handle mounting hole 112a. Figure 16 Figure 21

[0176] The handle detection unit 114 is disposed corresponding to the handle mounting portion 110. The handle detection unit 114 detects whether the sub handle 108 is installed to the handle mounting portion 110. The handle detection unit 116 is disposed corresponding to the handle mounting portion 112. The handle detection unit 116 detects whether the sub handle 108 is installed to the handle mounting portion 112.

[0177] Figure 15 The cover detection unit 106 and​​​​Figure 16 The handle detection units 114 and 116 each have the same structure. In the following description, the cover detection unit 106, the handle detection units 114 and 116 can also be simply collectively referred to as detection units 118. In the following description, the structure of the detection units 118 will be described with reference to Figures 17-19 .

[0178] As shown in Figure 17 , the detection unit 118 has a detection sensor 120, a link member 122 and a compression spring 124. The detection sensor 120 has a sensor housing 126 and an optical interrupter 128. As shown in Figure 18 , Figure 19 , the optical interrupter 128 has a sensor substrate 128c and a light emitting element 128a and a light receiving element 128b mounted on the sensor substrate 128c. The light emitting element 128a and the light receiving element 128b are arranged facing each other. The sensor substrate 128c is held in the sensor housing 126 in such a manner that the light emitting element 128a and the light receiving element 128b are housed in the sensor housing 126. The sensor substrate 128c is connected to the control substrate 24 by a wiring not shown. The microcomputer 82 of the control substrate 24 sends a light emitting signal to the light emitting element 128a of the optical interrupter 128 and receives a light receiving signal from the light receiving element 128b of the optical interrupter 128 by the same process as in Embodiment 1.

[0179] The link member 122 has a swing shaft 122a, an abutting arm 122b and a detection arm 122c. The swing shaft 122a is held in the sensor housing 126 in a swingable manner. The link member 122 is held in the sensor housing 126 in such a manner that the abutting arm 122b protrudes outside the sensor housing 126 and the detection arm 122c is housed inside the sensor housing 126. The abutting arm 122b has a flange 122d and a protruding portion 122e protruding from the flange 122d. The detection arm 122c has a shielding portion 122f having a shape that shields between the light emitting element 128a and the light receiving element 128b. The link member 122 can swing between a shielding position (refer to Figure 18 ) in which the shielding portion 122f is arranged to shield between the light emitting element 128a and the light receiving element 128b and an open position (refer to Figure 19 ) in which the shielding portion 122f is arranged not to shield between the light emitting element 128a and the light receiving element 128b. Further, a sealing member (not shown) can also be provided on an opening portion of the sensor housing 126 through which the link member 122 penetrates. By providing the sealing member on the opening portion of the sensor housing 126, accordingly, it is possible to suppress the influence on the operation of the optical interrupter 128 due to the intrusion of dust from the outside of the sensor housing 126 into the inside.

[0180] As shown in FIG. 12, the compression spring 124 is installed to a protrusion 126a formed on the outside of the sensor housing 126. The compression spring 124 applies a force to the link member 122 toward the sensor housing 126 in a manner that the link member 122 swings from the open position (refer to FIG. 11) to the shielding position (refer to FIG. 12). Figure 17 Figure 19 As shown in FIG. 12, the compression spring 124 is installed to a protrusion 126a formed on the outside of the sensor housing 126. The compression spring 124 applies a force to the link member 122 toward the sensor housing 126 in a manner that the link member 122 swings from the open position (refer to FIG. 11) to the shielding position (refer to FIG. 12). Figure 18

[0181] As shown in FIG. 12, the compression spring 124 is installed to a protrusion 126a formed on the outside of the sensor housing 126. The compression spring 124 applies a force to the link member 122 toward the sensor housing 126 in a manner that the link member 122 swings from the open position (refer to FIG. 11) to the shielding position (refer to FIG. 12). Figure 15 As shown in FIG. 12, the compression spring 124 is installed to a protrusion 126a formed on the outside of the sensor housing 126. The compression spring 124 applies a force to the link member 122 toward the sensor housing 126 in a manner that the link member 122 swings from the open position (refer to FIG. 11) to the shielding position (refer to FIG. 12).

[0182] Figure 15 As shown in FIG. 12, the compression spring 124 is installed to a protrusion 126a formed on the outside of the sensor housing 126. The compression spring 124 applies a force to the link member 122 toward the sensor housing 126 in a manner that the link member 122 swings from the open position (refer to FIG. 11) to the shielding position (refer to FIG. 12).

[0183] As shown in FIG. 12, the compression spring 124 is installed to a protrusion 126a formed on the outside of the sensor housing 126. The compression spring 124 applies a force to the link member 122 toward the sensor housing 126 in a manner that the link member 122 swings from the open position (refer to FIG. 11) to the shielding position (refer to FIG. 12). Figure 20 Figure 15 As shown in FIG. 12, the compression spring 124 is installed to a protrusion 126a formed on the outside of the sensor housing 126. The compression spring 124 applies a force to the link member 122 toward the sensor housing 126 in a manner that the link member 122 swings from the open position (refer to FIG. 11) to the shielding position (refer to FIG. 12).

[0184] As shown in FIG. 12, the compression spring 124 is installed to a protrusion 126a formed on the outside of the sensor housing 126. The compression spring 124 applies a force to the link member 122 toward the sensor housing 126 in a manner that the link member 122 swings from the open position (refer to FIG. 11) to the shielding position (refer to FIG. 12). Figure 16 ​​​​As shown, the handle detection unit 114 is disposed on the right side of the partition housing 104. The handle detection unit 114 is held in the partition housing 104 with the swing axis 122a of the linkage member 122 arranged vertically and the protrusion 122e facing to the right. In the handle detection unit 114, the detection sensor 120 is housed inside the partition housing 104, and the flange 122d and protrusion 122e of the linkage member 122 are disposed inside the gear housing 10. In the handle detection unit 114, the protrusion 122e enters the handle mounting hole 110a, and the flange 122d abuts against the inner surface of the gear housing 10.

[0185] The handle detection unit 116 is disposed on the left side of the partition housing 104. The handle detection unit 116 is held in the partition housing 104 with the pivot axis 122a of the linkage member 122 arranged vertically and the protrusion 122e facing to the left. In the handle detection unit 116, the detection sensor 120 is housed inside the partition housing 104, and the flange 122d and protrusion 122e of the linkage member 122 are disposed inside the gear housing 10. In the handle detection unit 116, the protrusion 122e enters the handle mounting hole 112a, and the flange 122d abuts against the inner surface of the gear housing 10.

[0186] like Figure 16 As shown, when the secondary handle 108 is not installed on either of the handle mounting portions 110 or 112, for each handle detection unit 114 or 116, the connecting rod member 122 is in a shielded position, and the shielding portion 122f is configured to shield between the light-emitting element 128a and the light-receiving element 128b. In this case, the control board 24 determines that the secondary handle 108 is not installed on either of the handle mounting portions 110 or 112.

[0187] like Figure 21 As shown, when the secondary handle 108 is installed on one of the handle mounting portions 110 and 112, such as handle mounting portion 112, the protrusion 122e of the linkage member 122 of the handle detection unit 116 abuts against and presses against the threaded portion 108a of the secondary handle 108. Accordingly, in the handle detection unit 116, the linkage member 122 swings from the shielded position to the open position, and the shielded portion 122f is configured not to shield between the light-emitting element 128a and the light-receiving element 128b. In this case, the control board 24 determines that the secondary handle 108 is installed on the handle mounting portion 112. Furthermore, when the secondary handle 108 is removed from the handle mounting portion 112 from this state, in the handle detection unit 116, the linkage member 122 swings from the open position to the shielded position by the force of the compression spring 124, thereby returning to the open position. Figure 16 The state shown.

[0188] As described above, in one or more embodiments, the grinder 102 (example of a tool) has an electric motor 14 (example of a prime mover), a bevel gear 38 (example of a transmission mechanism) connected to the electric motor 14, a housing 50 that houses the electric motor 14 and the bevel gear 38, a spindle 36 (example of a tip tool holding portion) connected to the bevel gear 38 and holding a grinding wheel 4 (example of a tip tool), a cover 6 or sub handle 108 (example of an accessory) removably attached to the housing 50, a link member 122 that operates in response to the cover 6 or sub handle 108 being attached to or detached from the housing 50, and a detection sensor 120 housed inside the housing 50 and having an optical interrupter 128 (example of a non-contact sensor element). The detection sensor 120 detects the operation of the link member 122 using the optical interrupter 128.

[0189] According to the above-described structure, since the detection sensor 120 is housed inside the housing 50, the detection sensor 120 is not easily affected by dust. Therefore, even when the grinder 102 is used in an environment with a large amount of dust, it is possible to accurately detect whether the cover 6 or the sub handle 108 is attached to the housing 50. In addition, according to the above-described structure, the detection sensor 120 detects the operation of the link member 122 using the optical interrupter 128 as a non-contact sensor element. Accordingly, even when vibration or impact is applied to the link member 122, it is possible to prevent the impact or vibration from being applied to the optical interrupter 128 through the link member 122. It is possible to prevent false detection by the optical interrupter 128 due to the impact or vibration, and it is possible to improve the durability of the optical interrupter 128.

[0190] In one or more embodiments, the grinder 102 further has a control substrate 24 (example of a control unit) that controls the operation of the electric motor 14. The control substrate 24 permits the driving of the electric motor 14 in accordance with a detection signal from the detection sensor 120.

[0191] According to the above-described structure, the driving of the electric motor 14 is permitted only when the cover 6 or the sub handle 108 is attached to the housing 50.

[0192] In one or more embodiments, the link member 122 of the cover detection unit 106 extends from the inside of the housing 50 to the outside.

[0193] According to the above-described structure, it is possible to detect whether the cover 6 that does not enter the inside of the housing 50 when attached to the housing 50 is attached to the housing 50.

[0194] In one or more embodiments, the detection sensor 120 also has a sensor housing 126 that houses a light interrupter 128. The link member 122 extends from the inside of the sensor housing 126 to the outside. The light interrupter 128 detects the movement of the link member 122.

[0195] According to the above structure, since the light interrupter 128 directly detects the movement of the link member 122 without passing through the sensor rod 68 or the like of Embodiment 1, the structure of the detection sensor 120 can be simplified, and the number of parts can be reduced.

[0196] In one or more embodiments, the light interrupter 128 has a light emitting element 128a and a light receiving element 128b that receives light from the light emitting element 128a. The link member 122 is movable between an open position (an example of the first position) in which the light emitting element 128a and the light receiving element 128b are not shielded from each other and a shielded position (an example of the second position) in which the light emitting element 128a and the light receiving element 128b are shielded from each other. When the cover 6 and the sub handle 108 are not attached to the housing 50, the link member 122 is in the shielded position. When the cover 6 and the sub handle 108 are attached to the housing 50, the link member 122 is in the open position.

[0197] According to the above structure, compared to a case in which a sensor element using a magnet and a Hall element is used, for example, the detection sensor 120 is less likely to be affected by the external environment such as metal dust.

[0198] In one or more embodiments, the light emitting element 128a emits light in accordance with a light emitting signal having a predetermined signal pattern.

[0199] According to the above structure, erroneous determination due to a failure of the detection sensor 120 can be prevented.

[0200] In one or more embodiments, the link member 122 has a swing shaft 122a that is held in the sensor housing 126 in a swingable manner, an abutting arm 122b that protrudes to the outside of the sensor housing 126, and a detection arm 122c that is housed in the inside of the sensor housing 126. The abutting arm 122b has a flange 122d and a protruding portion 122e that protrudes from the flange 122d. The detection arm 122c has a shield portion 122f that has a shape that shields the light emitting element 128a and the light receiving element 128b from each other.

[0201] According to the above structure, the link member 122 that operates in response to the attachment and detachment of the cover 6 and the sub handle 108 and the detection sensor 120 that detects the operation of the link member 122 can be realized with a simple structure.

[0202] In one or more embodiments, the housing 50 has a cover mounting portion 52 for mounting the cover 6. For the cover detection unit 106, the sensor housing 126 is disposed inside the housing 50, and is located near the central portion in the left-right direction of the housing 50. The sensor housing 126 is held to the housing 50 in a manner in which the swing shaft 122a is disposed in the left-right direction and the protruding portion 122e faces downward. The abutting arm 122b protrudes to the outside of the housing 50 through the through hole 10b of the housing 50. The flange 122d and the protruding portion 122e are disposed outside the housing 50, and are located near the cover mounting portion 52.

[0203] According to the above structure, the attachment and detachment of the cover 6 with respect to the housing 50 can be detected by the detection sensor 120 with a simple structure.

[0204] In one or more embodiments, the housing 50 has handle mounting holes 110a, 112a for mounting the sub handle 108. For the handle detection units 114, 116, the sensor housing 126 is disposed inside the housing 50. The sensor housing 126 is held to the housing 50 in a manner in which the swing shaft 122a is disposed in the up-down direction and the protruding portion 122e faces the handle mounting holes 110a, 112a. When the sub handle 108 is not mounted on the handle mounting holes 110a, 112a, the flange 122d abuts against the inner surface of the housing 50, and the protruding portion 122e enters the handle mounting holes 110a, 112a.

[0205] According to the above structure, the attachment and detachment of the sub handle 108 with respect to the housing 50 can be detected by the detection sensor 120 with a simple structure.

[0206] In one or more embodiments, the link member 122 is rotatably supported to the sensor housing 126. The link member 122 rotates with respect to the sensor housing 126 in response to the attachment and detachment of the cover 6 and the sub handle 108.

[0207] In a structure in which the link member 122 and the detection sensor 120 are separately mounted on the housing 50, when errors occur in the respective mounting positions, the relative positional relationship of the link member 122 and the light interrupter 128 differs from that expected, and the detection sensor 120 can make a false determination. According to the above structure, since the link member 122 is mounted to the sensor housing 126, the relative positional relationship of the link member 122 and the light interrupter 128 can be managed with high precision.

[0208] In one or more embodiments, in the cover detection unit 106, the rotation axis of the link member 122 and the light interrupter 128 are arranged in the up-down direction (an example of a direction that is substantially orthogonal to the output shaft 16 of the electric motor 14 housed inside the housing 50). In the handle detection units 114, 116, the rotation axis of the link member 122 and the light interrupter 128 are arranged in the left-right direction (an example of a direction that is substantially orthogonal to the output shaft 16 of the electric motor 14).

[0209] According to the above-described structure, the idle space around the output shaft 16 of the electric motor 14 inside the housing 50 can be effectively utilized to arrange the link member 122 and the detection sensor 120.

[0210] In one or more embodiments, in the cover detection unit 106, the rotation axis of the link member 122 is arranged in the left-right direction (an example of a second direction) that is orthogonal to the front-rear direction (an example of a first direction), which is parallel to the output shaft 16 of the electric motor 14. The cover detection unit 106 of the grinder 102 has a compression spring 124 (an example of an elastic member) that applies a force to the link member 122 from the open position to the shield position. In the handle detection units 114, 116, the rotation axis of the link member 122 is arranged in the up-down direction (an example of a second direction) that is orthogonal to the front-rear direction (an example of a first direction), which is parallel to the output shaft 16 of the electric motor 14. The handle detection units 114, 116 of the grinder 102 have a compression spring 124 (an example of an elastic member) that applies a force to the link member 122 from the open position to the shield position.

[0211] According to the above-described structure, the structure of the link member 122 and the detection sensor 120 can be further simplified.

[0212] In one or more embodiments, the detection sensor 120 is arranged between the spindle 36 and the electric motor 14 in the front-rear direction (an example of a direction in which the output shaft 16 of the electric motor 14 extends).

[0213] According to the above-described structure, the idle space between the spindle 36 and the electric motor 14 inside the housing 50 can be effectively utilized to arrange the detection sensor 120.

[0214] In one or more embodiments, the grinder 102 has a plurality of detection sensors 120 and a plurality of link members 122 corresponding to the cover detection unit 106 and the handle detection units 114, 116, wherein the plurality of link members 122 correspond to the plurality of detection sensors 120. In one or more embodiments, the grinder 102 has a plurality of detection sensors 120 and a plurality of link members 122 corresponding to the cover detection unit 106 and the handle detection units 114, 116, wherein the plurality of link members 122 correspond to the plurality of detection sensors 120.

[0215] According to the above structure, it is possible to detect whether the cover 6 and the sub-handle 108 are attached to the cover attachment portion 52 and the handle attachment portions 110, 112, respectively.

[0216] In one or more embodiments, the cover 6 as the accessory at least partially covers the grinding wheel 4, and the sub-handle 108 as the accessory is a handle that can be held by a user.

[0217] According to the above structure, it is possible to detect, by the detection sensor 120, whether the cover 6 that at least partially covers the grinding wheel 4 and the sub-handle 108 that can be held by a user are attached to the housing 50.

[0218] In one or more embodiments, the grinder 102 (an example of a tool) has an electric motor 14 (an example of a prime mover), a bevel gear 38 (an example of a transmission mechanism), a housing 50, a spindle 36 (an example of a tip tool holding portion), a cover 6 or a sub-handle 108 (an example of an accessory), a link member 122, and a detection sensor 120, wherein the bevel gear 38 is connected to the electric motor 14; the housing 50 houses the electric motor 14 and the bevel gear 38; the spindle 36 is connected to the bevel gear 38 and holds a grinding wheel 4 (an example of a tip tool); the cover 6 or the sub-handle 108 is attached to the housing 50 in a detachable manner; the link member 122 operates in response to attachment and detachment of the cover 6 or the sub-handle 108; and the detection sensor 120 is housed inside the housing 50. The link member 122 rotates with respect to the housing 50 in response to attachment and detachment of the cover 6 or the sub-handle 108. The detection sensor 120 detects the rotational operation of the link member 122.

[0219] According to the above structure, since the detection sensor 120 is housed inside the housing 50, the detection sensor 120 is less likely to be affected by dust. Therefore, even when the grinder 102 is used in an environment with a large amount of dust, it is possible to accurately detect whether the cover 6 and the sub-handle 108 are attached to the housing 50. In addition, according to the above structure, even when the detection sensor 120 is disposed at a position away from the attachment position of the cover 6 or the sub-handle 108, it is possible to effectively use the idle space inside the housing 50 to dispose the link member 122 extending from the attachment position of the cover 6 or the sub-handle 108 to the position of the detection sensor 120, without making the link member 122 a large and complex mechanism.

[0220] In one or more embodiments, the grinder 102 further has a control substrate 24 (an example of a control unit) that controls the operation of the electric motor 14. The control substrate 24 permits driving of the electric motor 14 in accordance with a detection signal from the detection sensor 120.

[0221] According to the above structure, the electric motor 14 can be driven only when the cover 6 and the auxiliary handle 108 are mounted on the housing 50.

[0222] (Modified Example)

[0223] In the above embodiments, a structure using light interruptors 72 and 128 having light-emitting elements 76a and 128a and light-receiving elements 78a and 128b as non-contact sensor elements is described. In contrast, a Hall element (not shown) that detects magnetic field from a magnet (not shown) fixed to the sensor rod 68 and the connecting rod member 122 can also be used as a non-contact sensor element.

[0224] In the above embodiments, the structure of the electric motor 14 is described as an internal rotor type brushless DC motor, but the electric motor 14 can also be, for example, an external rotor type brushless DC motor. Alternatively, the electric motor 14 can also be a brushed DC motor. Alternatively, the electric motor 14 can also be other types of motors such as an AC motor.

[0225] In the above embodiments, the structure of the grinder 2 operating by supplying direct current from the battery 22 is described, but the grinder 2 can also be configured to operate by supplying alternating current from a power line (not shown).

[0226] In the above embodiments, the example described is a grinding machine 2 as the tool, an electric motor 14 as the prime mover, a grinding wheel 4 as the top tool, a spindle 36 as the top tool holder, and a cover 6 or a secondary handle 108 as the accessory. However, the tool can also be other types of tools, the prime mover can also be other types of prime movers, the top tool can also be other types of top tools, the top tool holder can also be other types of top tool holders, and the accessory can also be other types of accessories.

Claims

1. A tool, characterized in that, It comprises a prime mover, a transmission mechanism, a housing, a top tool holder, accessories, and a connecting rod assembly, among which, The transmission mechanism is connected to the prime mover; The housing is used to house the prime mover and the transmission mechanism; The tip tool holding part is connected to the transmission mechanism to hold the tip tool; The accessory is detachably installed on the housing; The linkage component moves in response to the disassembly and assembly of the accessory. The linkage assembly has a front control lever that rotates relative to the housing in response to the removal or installation of the accessory. When the front control lever is turned in one direction, the driving of the prime mover is prohibited; when the front control lever is turned in another direction different from the first direction, the driving of the prime mover is permitted.

2. The tool according to claim 1, characterized in that, The connecting rod assembly also has a shaft. When the direction along the output shaft of the prime mover is taken as the front-rear direction, the front end of the shaft is positioned forward of the front end of the prime mover, and the rear end of the shaft is positioned rearward of the rear end of the prime mover.

3. The tool according to claim 2, characterized in that, It also includes a control unit that controls the operation of the prime mover. When the direction along the output shaft of the prime mover is taken as the front-rear direction, the control unit is positioned further back than the rear end of the shaft.

4. The tool according to claim 1, characterized in that, The prime mover is an electric motor.

5. The tool according to claim 4, characterized in that, It also has a battery, which is detachably installed in the housing, for supplying electrical power to the electric motor.

6. A tool, characterized in that, It comprises a prime mover, a transmission mechanism, a housing, a top tool holder, accessories, and a connecting rod assembly, among which, The transmission mechanism is connected to the prime mover; The housing is used to house the prime mover and the transmission mechanism; The tip tool holding part is connected to the transmission mechanism to hold the tip tool; The accessory is detachably installed on the housing; The linkage component moves in response to the disassembly and assembly of the accessory. The connecting rod component has a shaft. With the direction along the output shaft of the prime mover taken as the front-rear direction, the front end of the shaft is positioned forward of the front end of the prime mover, and the rear end of the shaft is positioned rearward of the rear end of the prime mover. When the axis rotates in one direction, the driving of the prime mover is prohibited; when the axis rotates in another direction different from the first direction, the driving of the prime mover is permitted.

7. The tool according to claim 6, characterized in that, It also includes a control unit that controls the operation of the prime mover. When the direction along the output shaft of the prime mover is taken as the front-rear direction, the control unit is positioned further back than the rear end of the shaft.

8. The tool according to claim 6, characterized in that, The prime mover is an electric motor.

9. The tool according to claim 8, characterized in that, It also has a battery, which is detachably installed in the housing, for supplying electrical power to the electric motor.

10. The tool according to any one of claims 1 to 9, characterized in that, The accessory has a cover that at least partially covers the top tool and / or a handle that can be gripped by the user.

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