阅读说明：本技术 工具 (Tool with a locking mechanism ) 是由 松原孝 山路峻平 水谷彰良 大谷亮介 金子博贵 于 2019-09-06 设计创作，主要内容包括：本说明书公开一种工具。可以为,所述工具具有原动机、传动机构、壳体、顶端工具保持部、配件、连杆部件和检测传感器,其中,所述传动机构与所述原动机连接；所述壳体用于收容所述原动机和所述传动机构；所述顶端工具保持部与所述传动机构连接,用于保持顶端工具；所述配件以可拆装的方式被安装于所述壳体；所述连杆部件响应于所述配件的拆装而动作；所述检测传感器被收容于所述壳体的内部,且具有非接触式传感器元件。可以为,所述检测传感器使用所述传感器元件来检测所述连杆部件的动作。(The present specification discloses a tool. The tool may have a prime mover, a transmission mechanism, a housing, a tip tool holding portion, a fitting, a link member, and a detection sensor, wherein the transmission mechanism is connected to the prime mover; the housing is used for accommodating the prime mover and the transmission mechanism; the top end tool holding part is connected with the transmission mechanism and used for holding a top end tool; the accessory is detachably mounted to the housing; the link member operates in response to attachment and detachment of the accessory; the detection sensor is housed inside the housing and has a noncontact sensor element. The detection sensor may detect the motion of the link member using the sensor element.)

1. A tool, characterized in that it comprises a tool body,

has a prime mover, a transmission mechanism, a housing, a tip tool holding portion, a fitting, a link member, and a detection sensor,

the transmission mechanism is connected with the prime mover;

the housing is used for accommodating the prime mover and the transmission mechanism;

the top end tool holding part is connected with the transmission mechanism and used for holding a top end tool;

the accessory is detachably mounted to the housing;

the link member operates in response to attachment and detachment of the accessory;

the detection sensor is housed inside the housing and has a noncontact sensor element,

the detection sensor detects the motion of the link member using the sensor element.

2. The tool of claim 1,

further comprises a control means for controlling the operation of the prime mover,

the control unit allows driving of the prime mover in accordance with a detection signal from the detection sensor.

3. The tool according to claim 1 or 2,

the link member extends from the inside to the outside of the housing.

4. The tool of claim 3,

the detection sensor further has a sensor housing and a sensor rod, wherein,

the sensor housing houses the sensor element;

the sensor lever extends from the inside to the outside of the sensor housing and acts in response to the action of the link member,

the sensor element detects an action of the sensor lever.

5. The tool of claim 4,

the sensor element has a light emitting element and a light receiving element that receives light from the light emitting element,

the sensor rod can move between a 1 st position and a 2 nd position, wherein the 1 st position is a position which does not shield the light-emitting element and the light-receiving element; the 2 nd position is a position for shielding the light emitting element and the light receiving element,

the sensor lever is located in one of the 1 st position and the 2 nd position when the accessory is not mounted on the housing,

when the fitting is mounted on the housing, the sensor lever is located at the other of the 1 st position and the 2 nd position.

6. The tool of claim 5,

the light emitting element emits light in accordance with a light emission signal having a predetermined signal pattern.

7. The tool according to claim 5 or 6,

the sensor rod is formed in a shape slidable on a side surface of an inner side of the sensor housing,

the sensor rod has a base portion and an abutting portion of a substantially flat plate shape, wherein,

the base portion of a substantially flat plate shape has a longitudinal direction in a vertical direction and a width direction in a front-rear direction;

the abutting portion protrudes from the sensor housing and abuts against the link member,

a notch portion and a shielding portion formed in the base portion, wherein the notch portion has a shape that does not shield a space between the light emitting element and the light receiving element; the shielding portion has a shape for shielding a gap between the light emitting element and the light receiving element.

8. The tool of claim 7,

the fitting having a cover at least partially covering the tip tool,

the housing has a cover mounting portion for mounting the cover,

the link member has a circular bar axis, a front joystick and a rear joystick, wherein,

the front operating lever is fixed to a front end of the shaft;

the rear operating lever is fixed to the rear end of the shaft,

the front end of the shaft protrudes to the outside of the housing through a through hole formed in the housing,

the front joystick is disposed in the vicinity of the hood mounting portion outside the housing,

the rear joystick is disposed below the detection sensor inside the housing.

9. The tool of claim 8,

when the cover is attached to the cover attachment portion, the front lever is pressed by the cover to rotate upward, the rear lever also rotates upward, and the contact portion is pressed by the rear lever to move the sensor rod upward, whereby the cutout portion is disposed between the light emitting element and the light receiving element, and light from the light emitting element reaches the light receiving element without being shielded.

10. The tool according to any one of claims 1 to 6,

the link member is rotatably supported by the housing,

the link member rotates relative to the housing in response to attachment and detachment of the fitting.

11. The tool of claim 10,

the prime mover is an electric motor,

the link member is disposed in a longitudinal direction along a 1 st direction substantially parallel to an output shaft of the electric motor housed in the housing,

the rotation axis of the link member is arranged along the 1 st direction,

the sensor lever is held to the sensor housing in a manner movable in a 2 nd direction substantially orthogonal to the 1 st direction,

the detection sensor further includes an elastic member which is accommodated in the sensor housing and biases the sensor lever from the 1 st position to the 2 nd position.

12. The tool of claim 11,

further comprising a control unit for controlling the electric power supplied to the electric motor,

the detection sensor is disposed between the electric motor and the control unit.

13. The tool according to claim 11 or 12,

and a battery removably mounted to the housing for supplying electric power to the electric motor,

the detection sensor is disposed between the electric motor and the battery.

14. The tool according to any one of claims 1 to 13,

the fitment has a cap that at least partially covers the tip tool.

15. The tool according to claim 1 or 2,

the detection sensor also has a sensor housing that houses the sensor element,

the link member extends from the inside to the outside of the sensor housing,

the sensor element detects an action of the link member.

16. The tool of claim 15,

the sensor element has a light emitting element and a light receiving element, wherein the light receiving element receives light from the light emitting element,

the connecting rod part can move between a 1 st position and a 2 nd position, wherein the 1 st position is a position which does not shield the light-emitting element and the light-receiving element; the 2 nd position is a position for shielding the light emitting element and the light receiving element,

when the attachment is not mounted on the housing, the link member is located at one of the 1 st position and the 2 nd position,

when the attachment is attached to the housing, the link member is located at the other of the 1 st position and the 2 nd position.

17. The tool of claim 16,

the light emitting element emits light in accordance with a light emission signal having a predetermined signal pattern.

18. The tool of claim 16 or 17,

the link member has a swing shaft, an abutting arm, and a detecting arm, wherein,

the swing shaft is swingably held to the sensor housing;

the abutment arm protrudes outside the sensor housing;

the detection arm is housed inside the sensor housing,

the abutment arm having a flange and a protrusion, wherein the protrusion protrudes from the flange,

the detection arm has a shielding portion having a shape that shields a gap between the light emitting element and the light receiving element.

19. The tool of claim 18,

the fitting having a cover at least partially covering the tip tool,

the housing has a cover mounting portion for mounting the cover,

the sensor case is disposed in the housing in the vicinity of a central portion in the left-right direction of the housing,

the sensor case is held by the case such that the swing shaft is arranged in the left-right direction and the protruding portion faces downward,

the abutting arm protrudes to the outside of the housing through the through hole of the housing,

the flange and the protruding portion are disposed in the vicinity of the cover mounting portion outside the housing.

20. The tool of claim 18,

the accessory has a handle that can be held by a user,

the housing having a handle mounting hole for mounting the handle,

the sensor housing is disposed inside the housing,

the sensor housing is held by the case such that the swing shaft is arranged in the vertical direction and the protruding portion faces the handle attachment hole,

when the handle is not mounted in the handle mounting hole, the flange abuts against the inner surface of the housing, and the protruding portion enters the handle mounting hole.

21. The tool of any one of claims 15 to 17,

the link member is rotatably supported by the sensor housing,

the link member rotates relative to the sensor housing in response to attachment and detachment of the fitting.

22. The tool of claim 21,

the prime mover is an electric motor,

the rotating shaft of the link member and the sensor element are arranged in a direction substantially orthogonal to the output shaft of the electric motor housed in the housing.

23. The tool of claim 22,

the rotation shaft of the link member is arranged in a 2 nd direction substantially orthogonal to a 1 st direction, wherein the 1 st direction is substantially parallel to the output shaft of the electric motor,

the tool further includes an elastic member that urges the link member from the 1 st position to the 2 nd position.

24. The tool of claim 22 or 23,

the detection sensor is disposed between the tip tool holding portion and the electric motor in a direction in which an output shaft of the electric motor extends.

25. The tool according to any one of claims 15 to 24,

having a plurality of said detection sensors and a plurality of said link members, wherein,

the plurality of link members correspond to the plurality of detection sensors.

26. The tool according to any one of claims 15 to 25,

the accessory has a cover at least partially covering the tip tool and/or a handle that can be held by a user.

27. A tool, characterized in that it comprises a tool body,

has a prime mover, a transmission mechanism, a housing, a tip tool holding portion, a fitting, a link member, and a detection sensor,

the transmission mechanism is connected with the prime mover;

the housing houses the prime mover and the transmission mechanism;

the top end tool holding part is connected with the transmission mechanism and used for holding a top end tool;

the accessory is detachably mounted to the housing;

the link member operates in response to attachment and detachment of the accessory;

the detection sensor is accommodated in the interior of the housing,

the link member rotates relative to the housing in response to attachment and detachment of the fitting,

the detection sensor detects a rotational motion of the link member.

28. The tool of claim 27,

further comprises a control means for controlling the operation of the prime mover,

the control unit allows driving of the prime mover in accordance with a detection signal from the detection sensor.

29. The tool of claim 27 or 28,

the link member is rotatably supported by the housing,

the link member extends from the inside to the outside of the housing.

Technical Field

The technology disclosed in this specification relates to a tool.

Background

International publication No. 2017/051893 discloses a tool having a prime mover, a transmission mechanism (power transmission mechanism) connected to the prime mover, a housing, a tip tool holding portion, an attachment, and a detection sensor; the housing houses the prime mover and the transmission mechanism; the top end tool holding part is connected with the transmission mechanism and holds a top end tool; the accessory is detachably mounted to the housing; the detection sensor is provided outside the housing. In this tool, whether or not the accessory is attached to the housing can be detected by the detection sensor.

Disclosure of Invention

[ problem to be solved by the invention ]

Such a tool is sometimes used in an environment where a large amount of dust is contained in the air. In such a case, if the detection sensor is provided outside the housing, the detection sensor may erroneously detect the dust. A technique is desired that can accurately detect whether or not a component is attached to a housing even when a tool is used in an environment with a large amount of dust.

[ solution for solving problems ]

The present specification discloses a tool. The tool may have a prime mover, a transmission mechanism, a housing, a tip tool holding portion, a fitting, a link member, and a detection sensor, wherein the transmission mechanism is connected to the prime mover; the housing is used for accommodating the prime mover and the transmission mechanism; the top end tool holding part is connected with the transmission mechanism and used for holding a top end tool; the accessory is detachably mounted to the housing; the link member operates in response to attachment and detachment of the accessory; the detection sensor is housed inside the housing and has a noncontact sensor element. The detection sensor may detect the motion of the link member using the sensor element.

According to the above configuration, since the detection sensor is housed inside the case, the detection sensor is less likely to be affected by dust. Therefore, even when the tool is used in an environment with a large amount of dust, whether or not the accessory is attached to the housing can be accurately detected. In addition, according to the above configuration, the detection sensor detects the motion of the link member using the non-contact sensor element. Accordingly, even when vibration or impact acts on the link member, the impact or vibration is prevented from acting on the sensor element through the link member. Erroneous detection by the sensor element due to shock or vibration can be prevented, and the durability of the sensor element can be improved.

Another tool is also disclosed. The tool may have a prime mover, a transmission mechanism, a housing, a tip tool holding portion, a fitting, 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 top end tool holding part is connected with the transmission mechanism and used for holding a top end tool; the accessory is detachably mounted to the housing; the link member operates in response to attachment and detachment of the accessory; the detection sensor is housed inside the case. The link member may rotate relative to the housing in response to attachment and detachment of the fitting. The detection sensor may detect a rotational motion of the link member.

According to the above configuration, since the detection sensor is housed inside the case, the detection sensor is less likely to be affected by dust. Therefore, even if the tool is used in an environment with a large amount of dust, it is possible to accurately detect whether or not the accessory is attached to the housing. Further, according to the above configuration, even when the detection sensor is disposed at a position distant from the attachment position of the attachment, the link member extending from the attachment position of the attachment to the position of the detection sensor can be disposed by effectively utilizing the free space inside the housing, without requiring a large and complicated mechanism for the link member.

Drawings

Fig. 1 is a longitudinal sectional view of a grinding mill 2 of example 1.

Fig. 2 is a perspective view showing the internal structure of the grinder 2 of example 1.

Fig. 3 is a perspective view of the cover detection mechanism 54 in a state where the cover 6 is not attached to the grinder 2 of example 1.

Fig. 4 is a perspective view showing an internal structure of a detection sensor 58 of the grinder 2 according to embodiment 1.

Fig. 5 is a perspective view of a photointerrupter 72 of the grinding machine 2 of example 1.

Fig. 6 is a perspective view of a sensor rod 68 of the grinder 2 of embodiment 1.

Fig. 7 is a vertical cross-sectional view of the detection sensor 58 in the state where the cover 6 is not attached to the grinding machine 2 of example 1.

Fig. 8 is a perspective view of the cover detection mechanism 54 in a state where the cover 6 is attached to the grinder 2 of example 1.

Fig. 9 is a vertical sectional view of the detection sensor 58 in the state where the cover 6 is attached to the grinding machine 2 of example 1.

Fig. 10 is a diagram schematically showing the circuit configuration of the grinder 2 of embodiment 1.

Fig. 11 is a flowchart illustrating a process performed by the microcomputer 82 of the grinder 2 of embodiment 1.

Fig. 12 is a flowchart for explaining a cover determination process executed by the microcomputer 82 of the grinder 2 of example 1.

Fig. 13 is a diagram showing an example of a signal pattern 90 of a light emission signal and signal patterns 92, 94, 96, and 98 of light reception signals in the grinder 2 according to example 1.

Fig. 14 is a perspective view of the grinder 102 of embodiment 2.

Fig. 15 is a vertical cross-sectional view of the vicinity of the cover attachment portion 52 in the state where the cover 6 is not attached to the grinding machine 102 of example 2.

Fig. 16 is a cross-sectional view of the vicinity of the handle attachment portions 110 and 112 in the state where the sub-handle 108 is not attached to the grinder 102 of example 2.

Fig. 17 is a perspective view of the detection unit 118 of the grinder 102 of embodiment 2.

Fig. 18 is a perspective view of the link member 122 and the photointerrupter 128 in a state where the link member 122 is located at the shielding position (shielding position) in the grinder 102 according to example 2.

Fig. 19 is a perspective view of the link member 122 and the photointerrupter 128 in a state where the link member 122 is located at the open position in the grinder 102 of example 2.

Fig. 20 is a vertical cross-sectional view of the vicinity of the cover attachment portion 52 in the state where the cover 6 is attached to the grinding machine 102 according to example 2.

Fig. 21 is a cross-sectional view of the vicinity of the handle attachment portions 110 and 112 in a state where the sub-handle 108 is attached to the grinder 102 according to example 2.

Detailed Description

Representative, non-limiting examples of the present invention are described in detail below with reference to the accompanying drawings. This detailed description is merely intended to show those skilled in the art the details of preferred embodiments for practicing the invention, and is not intended to limit the scope of the invention. In addition, additional features and aspects disclosed below may be employed separately or in combination with other features and aspects in order to provide further improved tools, methods of making and methods of using the same.

In addition, combinations of features and steps disclosed in the following detailed description are not essential to practice of the present invention in the broadest sense, and are described only for the purpose of specifically describing representative specific examples of the present invention. Furthermore, various features of the above-described and below-described representative examples, as well as various features described in claims and additional technical features, need not be combined in the order of the examples described herein in order to provide additional and useful embodiments of the present invention.

All features described in the present specification and/or claims are intended to be disclosed separately and independently of each other as limitations on the disclosure of the original application and as specified in the claims, apart from the structure of the features described in the examples and/or the claims. Further, all the descriptions relating to the numerical ranges, compositions and groups have the meaning of disclosing the intermediate structures thereof as limitations to the disclosure of the original application and the specific matters claimed.

In the 1 or more embodiments, the tool may have a prime mover, a transmission mechanism connected to the prime mover, a housing, a tip tool holding portion, a fitting, a link member, and a detection sensor; the housing houses the prime mover and the transmission mechanism; the top end tool holding part is connected with the transmission mechanism and holds a top end tool; the accessory is detachably mounted to the housing; the link member operates in response to attachment and detachment of the accessory; the detection sensor is housed inside the housing and has a noncontact sensor element. The detection sensor may detect the motion of the link member using the sensor element.

According to the above configuration, since the detection sensor is housed inside the case, the detection sensor is less likely to be affected by dust. Therefore, even if the tool is used in an environment with a large amount of dust, it is possible to accurately detect whether or not the accessory is attached to the housing. In addition, according to the above configuration, the detection sensor detects the motion of the link member using the non-contact sensor element. Accordingly, even when vibration or impact acts on the link member, the impact or vibration is prevented from acting on the sensor element through the link member. Erroneous detection by the sensor element due to shock or vibration can be prevented, and the durability of the sensor element can be improved.

In the 1 or more embodiments, the tool may further include a control unit that controls an operation of the prime mover. The control unit may allow the drive of the prime mover in accordance with a detection signal from the detection sensor.

According to the above configuration, the drive of the prime mover can be permitted only when the attachment is attached to the housing.

In the 1 or more embodiments, the link member may extend from the inside to the outside of the housing.

According to the above configuration, it is possible to detect whether or not the accessory is attached to the housing, and the accessory does not enter the housing when the accessory is attached to the housing.

In the 1 or more embodiments, the detection sensor may further include a sensor housing and a sensor rod, wherein the sensor housing houses the sensor element; the sensor lever extends from the inside to the outside of the sensor housing, and acts in response to the action of the link member. The sensor element may detect an operation of the sensor lever.

According to the above configuration, since the sensor element of the detection sensor is housed inside the sensor case, even if dust flows into the inside of the case, the influence of the dust on the sensor element can be suppressed.

In the 1 or more embodiments, the sensor element may include a light emitting element and a light receiving element, and the light receiving element may receive light from the light emitting element. The sensor lever may be movable between a 1 st position and a 2 nd position, wherein the 1 st position is a position where a space between the light emitting element and the light receiving element is not shielded (not shielded); the 2 nd position is a position for shielding (shielding) the light emitting element and the light receiving element. It may be that the sensor lever is located at one of the 1 st position and the 2 nd position when the accessory is not mounted on the housing. It may be that, when the accessory is mounted on the housing, the sensor lever is located at the other of the 1 st position and the 2 nd position.

As described above, a sensor element including a light emitting element and a light receiving element is less susceptible to an external environment such as metal dust than a sensor element including a magnet and a hall element, for example. According to the above configuration, since the position of the sensor lever is switched between the 1 st position and the 2 nd position in response to attachment and detachment of the attachment, it is possible to determine whether or not the attachment is attached to the housing based on the presence or absence of transmission of light from the light emitting element to the light receiving element.

In the 1 or more embodiments, the light emitting element may emit light in accordance with a light emission signal having a predetermined signal pattern.

In a configuration in which the position of the sensor lever is switched between the 1 st position and the 2 nd position in response to attachment and detachment of the attachment, when it is desired to determine whether or not the attachment is made to the housing based only on the presence or absence of transmission of light from the light emitting element to the light receiving element, there is a possibility that an erroneous determination may be made as to whether or not the attachment is made to the housing in the case where an on failure or an off failure occurs in the light receiving element. According to the above configuration, when the sensor lever is located at the 1 st 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 with the signal pattern of the light emitting signal emitted by the light emitting element, it is determined whether or not the accessory is attached to the housing, and thus it is possible to prevent erroneous determination due to a failure of the detection sensor.

In the 1 or more embodiments, the sensor rod may be formed in a shape slidable on a side surface of the inside of the sensor housing. The sensor lever may have a substantially flat plate-shaped base portion and an abutting portion, wherein the base portion may have a longitudinal direction (longitudinal direction) and a transverse direction (transverse direction); the abutting portion protrudes from the sensor housing and abuts against the link member. The base portion may be formed with a notch portion having a shape that does not shield a space between the light emitting element and the light receiving element, and a shielding portion (shielding portion); the shielding portion has a shape for shielding a gap between the light emitting element and the light receiving element.

According to the above configuration, the sensor lever that extends from the inside to the outside of the sensor housing and operates in response to the operation of the link member can be realized with a simple configuration.

In 1 or more embodiments, the fitting may have a cap that at least partially covers the tip tool. The housing may have a cover mounting portion for mounting the cover. The link member may have a round bar shaft, a front joystick and a rear joystick, wherein the front joystick is fixed to a front end of the shaft; the rear operating lever is fixed to a rear end of the shaft. The front end of the shaft may protrude to the outside of the housing through a through hole formed in the housing. The front joystick may be disposed outside the housing and near the hood attachment portion. The rear joystick may be disposed inside the housing and below the detection sensor.

According to the above configuration, the link member that operates the sensor lever in response to attachment and detachment of the cover as the attachment can be realized with a simple configuration.

In the 1 or more embodiments, in the tool, when the cover is attached to the cover attachment portion, the front lever is pressed by the cover to rotate upward, the rear lever also rotates upward, and the contact portion is pressed by the rear lever to move the sensor lever upward, whereby the cutout portion is disposed between the light emitting element and the light receiving element, and light from the light emitting element reaches the light receiving element without being shielded.

According to the above configuration, the attachment/detachment of the cover to/from the housing can be detected by the detection sensor with a simple configuration.

In the 1 or more embodiments, the link member may be rotatably supported by the housing. The link member may rotate relative to the housing in response to attachment and detachment of the fitting.

According to the above configuration, even when the detection sensor is disposed at a position distant from the attachment position of the attachment, the link member extending from the attachment position of the attachment to the position of the detection sensor can be disposed by effectively utilizing the free space inside the housing, without requiring a large and complicated mechanism for the link member.

In the 1 or more embodiments, the prime mover may be an electric motor. The link member may be disposed in a longitudinal direction along a 1 st direction substantially parallel to an output shaft of the electric motor housed in the housing. The rotation axis of the link member may be arranged along the 1 st direction. The sensor lever may be held by the sensor housing so as to be movable in a 2 nd direction substantially orthogonal to the 1 st direction. The detection sensor may further include an elastic member that is housed inside the sensor case and biases the sensor lever from the 1 st position to the 2 nd position.

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

In the 1 or more embodiments, the tool may further include a control unit that controls electric power supplied to the electric motor. The detection sensor may be disposed between the electric motor and the control unit.

According to the above configuration, the detection sensor can be disposed by effectively utilizing the vacant space between the electric motor and the control unit inside the housing.

In the 1 or more embodiments, the tool may further include a battery that is detachably attached to the housing and supplies electric power to the electric motor, and the detection sensor may be disposed between the electric motor and the battery.

According to the above configuration, the detection sensor can be disposed by effectively utilizing the empty space between the electric motor and the battery inside the case.

In 1 or more embodiments, the fitting may be a cap that at least partially covers the tip tool.

According to the above configuration, whether or not the cover at least partially covering the tool bit is attached to the housing can be detected by the detection sensor.

In the 1 or more embodiments, the detection sensor may further include a sensor housing that houses the sensor element. The link member may extend from the inside to the outside of the sensor housing. The sensor element may detect an operation of the link member.

According to the above configuration, since the sensor element directly detects the operation of the link member without using a member such as a sensor lever, the configuration of the detection sensor can be simplified, and the number of components can be reduced.

In the 1 or more embodiments, the sensor element may include a light emitting element and a light receiving element, and the light receiving element may receive light from the light emitting element. The link member may be movable between a 1 st position and a 2 nd position, wherein the 1 st position is a position where the light emitting element and the light receiving element are not shielded from each other; the 2 nd position is a position where the light emitting element and the light receiving element are shielded from each other. The link member may be located at one of the 1 st position and the 2 nd position when the accessory is not mounted on the housing. The link member may be located at the other of the 1 st position and the 2 nd position when the accessory is mounted on the housing.

According to the above configuration, for example, the sensor element having the magnet and the hall element can be less susceptible to the external environment such as metal dust.

In the 1 or more embodiments, the light emitting element may emit light in accordance with a light emission signal having a predetermined signal pattern.

According to the above configuration, erroneous determination due to a failure of the detection sensor can be prevented.

In the 1 or more embodiments, the link member may have a swing shaft, a contact arm, and a detection arm, wherein the swing shaft is swingably held to the sensor housing; the abutment arm protrudes outside the sensor housing; the detection arm is housed inside the sensor housing. The abutment arm may have a flange and a projection, wherein the projection projects from the flange. The detection arm may have a shielding portion having a shape that shields a gap between the light emitting element and the light receiving element.

According to the above configuration, the link member that operates in response to attachment and detachment of the attachment and the detection sensor that detects the operation of the link member can be realized with a simple configuration.

In 1 or more embodiments, the fitting may have a cap that at least partially covers the tip tool. The housing may have a cover mounting portion for mounting the cover. The sensor case may be disposed inside the case and located near a central portion of the case in the left-right direction. The sensor case may be held by the case such that the swing shaft is arranged in the left-right direction and the protruding portion faces downward. The abutment arm may protrude to the outside of the housing through a through hole of the housing. The flange and the protruding portion may be disposed outside the case and in the vicinity of the cover mounting portion.

According to the above configuration, the attachment/detachment of the cover to/from the housing can be detected by the detection sensor with a simple configuration.

In one or more embodiments, the accessory may have a handle that can be held by a user. The housing may have a handle mounting hole for mounting the handle. The sensor housing may be disposed inside the housing. The sensor case may be held by the case such that the swing shaft is disposed in the vertical direction and the protruding portion faces the handle attachment hole. When the handle is not mounted on the handle mounting hole, the flange may abut against an inner surface of the housing, and the protruding portion may enter the handle mounting hole.

According to the above configuration, the attachment/detachment of the handle to/from the housing can be detected by the detection sensor with a simple configuration.

In the 1 or more embodiments, the link member may be rotatably supported by the sensor housing. The link member may rotate relative to the sensor housing in response to attachment and detachment of the fitting.

In a configuration in which the link member and the detection sensor are mounted independently on the housing, if an error occurs in the mounting position of each of the link member and the detection sensor, the relative positional relationship between the link member and the sensor element may be different from an expected relationship, and the detection sensor may make an erroneous determination. According to the above configuration, since the link member is attached to the sensor housing, the relative positional relationship between the link member and the sensor element can be managed with high accuracy.

In the 1 or more embodiments, the prime mover may be an electric motor. The rotation shaft of the link member and the sensor element may be arranged in a direction substantially orthogonal to the output shaft of the electric motor housed in the housing.

According to the above configuration, the link member and the detection sensor can be disposed by effectively utilizing the vacant space around the output shaft of the electric motor in the interior of the housing.

In the 1 or more embodiments, the rotation shaft of the link member may be disposed in a 2 nd direction substantially orthogonal to a 1 st direction, wherein the 1 st direction is substantially parallel to the output shaft of the electric motor. The tool may further include an elastic member that biases the link member from the 1 st position to the 2 nd position.

According to the above configuration, the link member and the detection sensor can be more simplified in configuration.

In the 1 or more embodiments, the detection sensor may be disposed between the tip tool holding portion and the electric motor in a direction in which an output shaft of the electric motor extends.

According to the above configuration, the detection sensor can be disposed by effectively utilizing the vacant space between the distal end tool holding portion and the electric motor in the interior of the housing.

In the 1 or more embodiments, the tool may have a plurality of the detection sensors and a plurality of the link members corresponding to the plurality of the detection sensors.

According to the above configuration, when there are a plurality of attachment positions for the accessories, it is possible to detect whether or not the accessories are attached to each of the attachment positions.

In one or more embodiments, the accessory may have a cover at least partially covering the tip tool and/or a handle for a user to hold.

According to the above configuration, it is possible to detect whether or not the cover at least partially covering the tool bit and the handle which can be held by the user are attached to the housing by the detection sensor.

In the 1 or more embodiments, the tool may have a prime mover, a transmission mechanism connected to the prime mover, a housing, a tip tool holding portion, a fitting, a link member, and a detection sensor; the housing houses the prime mover and the transmission mechanism; the top end tool holding part is connected with the transmission mechanism and holds a top end tool; the accessory is detachably mounted to the housing; the link member operates in response to attachment and detachment of the accessory; the detection sensor is housed inside the case. The link member may rotate relative to the housing in response to attachment and detachment of the fitting. The detection sensor may detect a rotational motion of the link member.

According to the above configuration, since the detection sensor is housed inside the case, the detection sensor is less likely to be affected by dust. Therefore, even when the tool is used in an environment with a large amount of dust, whether or not the accessory is attached to the housing can be accurately detected. Further, according to the above configuration, even when the detection sensor is disposed at a position distant from the attachment position of the attachment, the link member extending from the attachment position of the attachment to the position of the detection sensor can be disposed by effectively utilizing the free space inside the housing, without requiring a large and complicated mechanism for the link member.

In the 1 or more embodiments, the tool may further include a control unit that controls an operation of the prime mover. The control unit may allow the drive of the prime mover in accordance with a detection signal from the detection sensor.

According to the above configuration, the drive of the prime mover can be permitted only when the attachment is attached to the housing.

In the 1 or more embodiments, the link member may be rotatably supported by the housing. The link member may extend from the inside to the outside of the housing.

According to the above configuration, the link member extending from the attachment position of the accessory outside the housing to the position of the detection sensor inside the housing can be disposed by effectively utilizing the free space inside the housing.

(example 1)

As shown in fig. 1, a grinder (grinder)2 of the present embodiment is a tool used in a state where a grinding wheel (grinding wheel)4 as a tip tool and a cover (cover)6 as an attachment are attached. The grinding machine 2 can grind and deburr a welded portion of metal by rotation of the grinding wheel 4. Further, by replacing the grinding wheel 4 according to the material and work content of the workpiece and replacing the cover 6 according to the replaced grinding wheel 4, it is possible to cut a workpiece such as concrete, a block (block), a brick, or stone. In the following description, the longitudinal direction of the grinding machine 2 is referred to as the front-rear direction, the rotational axis direction of the grinding wheel 4 is referred to as the vertical direction, and the direction perpendicular to the front-rear direction and the vertical direction is referred to as the lateral direction.

The grinding mill 2 has a main body housing 8, a gear housing cover 9, a gear housing 10 and a bearing housing 12.

An electric motor 14 as a prime mover is housed in the front interior of the main body case 8. The electric motor 14 is, for example, an inner rotor type brushless dc motor. The electric motor 14 has an output shaft 16 extending in the front-rear direction. The output shaft 16 is rotatably supported by the gear housing cover 9 via a bearing 18, and is rotatably supported by the main body housing 8 via a bearing 20. A battery 22 is mounted to the rear end of the main body case 8. The battery 22 is a rechargeable secondary battery such as a lithium ion battery. The battery 22 is a slide type battery that is detachable by being slid in the vertical direction with respect to the main body case 8. A control board 24 is housed in the rear interior of the main body case 8. The electric power supplied from the battery 22 is supplied to the electric motor 14 through the control substrate 24. A slide switch 26 slidable in the front-rear direction is provided on the upper surface of the front of the main body case 8. The slide switch 26 is switchable between an on position and an off position by a user's operation. The position of the slide switch 26 can be detected by a main switch 28 housed inside the main body case 8. The main switch 28 is connected to the control board 24. When 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 board 24, and the electric motor 14 rotates the output shaft 16. When the slide switch 26 is in the off position, the electric power supplied from the battery 22 to the electric motor 14 is interrupted, and the electric motor 14 stops the output shaft 16. A display unit 30 is provided on the upper surface of the rear of the main body case 8. The display unit 30 changes the display according to the operating state of the grinder 2 and the remaining battery level of the battery 22, and notifies the user of the operating state of the grinder 2 and the remaining battery level of the battery 22.

The gear housing 10 is attached to the front of the main body housing 8 by a gear housing cover 9. A 1 st bevel gear 32 and a 2 nd bevel gear 34 disposed to mesh with each other are housed inside the gear housing 10. The 1 st bevel gear 32 is fixed to the front end portion of the output shaft 16. The 2 nd bevel gear 34 is fixed to an upper end portion of a main shaft 36 extending in the up-down direction. In the following description, the 1 st bevel gear 32 and the 2 nd bevel gear 34 will also be referred to simply as bevel gears 38. The bevel gear 38 is a speed reduction mechanism that reduces the speed of rotation of the electric motor 14 and transmits the rotation to the main shaft 36, and may be referred to as a transmission mechanism. The gear housing 10 rotatably supports an upper end portion of the main shaft 36 via a bearing 40. As shown in fig. 2, a shaft lock 42 is provided on the upper surface of the gear housing 10. When the user pushes the shaft locking member 42 downward, the rotation of the 2 nd bevel gear 34 is prohibited, and the rotation of the main shaft 36 is prohibited.

As shown in fig. 1, the bearing housing 12 is mounted below the gear housing 10. The bearing housing 12 rotatably supports the main shaft 36 via a bearing 44. The main shaft 36 is rotatable relative to the bearing housing 12 about a rotation axis extending in the up-down direction. 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 is fitted to the main shaft 36. The grinding wheel 4 is attached to the spindle 36 from below the inner flange 46 and fitted into the inner flange 46. The outer flange 48 is screwed to the spindle 36 from the lower end portion of the spindle 36, and holds the grinding wheel 4 between the inner flange 46. In the grinder 2, when the electric motor 14 rotates, the grinding wheel 4 rotates around the rotation axis together with the spindle 36, whereby the workpiece can be ground. The spindle 36 may also be referred to as a tip tool holding portion for holding the grinding wheel 4 as a tip tool. In the following description, the main body housing 8, the gear housing cover 9, the gear housing 10, and the bearing housing 12 may be collectively referred to simply as a housing 50.

The cover 6 is attached to a substantially cylindrical cover attachment portion 52 formed in the bearing housing 12. When mounted on the grinding machine 2, the cover 6 is formed in a shape to cover at least partially the grinding wheel 4. The hood 6 may also have a shape that at least partially covers the spindle 36 when mounted to the grinding machine 2. The cover 6 prevents the cutting powder from scattering toward the user side when the workpiece is ground by the grinding wheel 4.

As shown in fig. 2, the grinder 2 has a hood detection mechanism 54. The cover detection mechanism 54 has a link member 56 and a detection sensor 58. The detection sensor 58 is housed inside the main body case 8. The detection sensor 58 is disposed between the electric motor 14 and the control board 24. The detection sensor 58 is disposed behind the electric motor 14 and in front of the battery 22 and the control board 24.

As shown in fig. 3, the link member 56 has a round bar shaft 60, a front operating lever 62 and a rear operating lever 64, wherein the front operating lever 62 is fixed to the front end of the shaft 60; the rear operating lever 64 is fixed to the rear end of the shaft 60. As shown in fig. 2, the shaft 60 is disposed at the lower front right side in the main body case 8 so that the longitudinal direction thereof is along the front-rear direction of the grinding machine 2. The shaft 60 is rotatably supported by the main body case 8. The tip of the shaft 60 protrudes outside the housing 50 through a through hole 10a formed in the gear housing 10, and the front lever 62 is disposed outside the housing 50. The front joystick 62 is disposed near the cover mounting portion 52 of the bearing housing 12. The rear joystick 64 is disposed below the detection sensor 58 inside the main body case 8. When the cover 6 is attached to the cover attachment portion 52, the front operating lever 62 is rotated upward. When the front operating lever 62 rotates, the shaft 60 and the rear operating lever 64 also rotate integrally.

As shown in fig. 3, 4, the detection sensor 58 has a sensor housing 66, a sensor rod 68, a compression spring 70, and a photo-interrupter 72, wherein the sensor housing 66 has a substantially rectangular parallelepiped shape and has an opening at a lower surface; the sensor rod 68 protrudes partially downward from an opening in the lower surface of the sensor housing 66; the compression spring 70 is housed within the sensor housing 66; the photointerrupter 72 is housed within the sensor housing 66. Although not shown, a rubber seal is provided in an opening in the lower surface of the sensor housing 66, and the seal abuts against the periphery of the sensor rod 68 and allows the sensor rod 68 to slide. Accordingly, dust can be prevented from flowing into the sensor housing 66.

As shown in fig. 5, the photo-interrupter 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 of the inside of the sensor housing 66. The sensor board 74 is connected to the control board 24 by a 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 section 76 and the light receiving section 78 are arranged to face each other in the left-right direction. A light emitting element 76a (see fig. 10) is disposed inside the light emitting section 76, and a light receiving element 78a (see fig. 10) is disposed inside the light receiving section 78.

As shown in fig. 6, the sensor lever 68 has a substantially flat plate-shaped base portion 68a, an upper guide portion 68b, and a lower guide portion 68c, wherein the base portion 68a has a longitudinal direction in the vertical direction and a width direction in the front-rear direction; the upper guide portion 68b is provided at an upper end of the base portion 68 a; the lower guide portion 68c is provided below the center of the base portion 68a in the vertical direction. The upper guide portion 68b and the lower guide portion 68c are formed in a shape slidable with respect to the inner side surface of the sensor housing 66. An abutting portion 68d having a rounded shape is formed at the lower end of the base portion 68 a. A spring receiving portion 68e is formed on the upper surface of the upper guide portion 68 b. A notch 68f is formed rearward of the upper position of the base portion 68a with respect to the center in the vertical direction. The upper base portion 68a of the notch portion 68f constitutes a shielding portion 68 g.

As shown in fig. 4, the compression spring 70 is disposed above the sensor rod 68 in the interior of the sensor housing 66. As shown in fig. 7, the upper end of the compression spring 70 abuts against a spring receiving portion 66a formed on the top surface of the inside of the sensor case 66, and the lower end of the compression spring 70 abuts against a spring receiving portion 68e of the sensor lever 68. The compression spring 70 biases the sensor rod 68 downward with respect to the sensor housing 66. The sensor rod 68 is movable downward to a lower limit position where the lower surface of the upper guide 68b abuts against the upper surfaces of the light emitting portion 76 and the light receiving portion 78 of the photointerrupter 72. When the sensor lever 68 is at the lower limit position, the shielding portion 68g of the base portion 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.

As shown in fig. 3, the rear operating lever 64 of the link member 56 is located below the contact portion 68d of the detection sensor 58. In a state where the cover 6 is not attached to the grinder 2 and no external force acts on the front operating lever 62, an upward force does not act on the contact portion 68d from the rear operating lever 64, and therefore the sensor lever 68 is maintained at the lower limit position.

When the cover 6 is attached to the grinder 2, the front operating lever 62 is pushed up by the cover 6, and the front operating lever 62 is rotated upward as shown in fig. 8. Accordingly, the rear operating lever 64 also rotates upward, and the contact portion 68d of the sensor lever 68 is pushed up by the rear operating lever 64. As shown in fig. 9, in a state where the sensor lever 68 is pushed up, the notch portion 68f of the base portion 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 reaches the light receiving portion 78 without being shielded. The position of the sensor lever 68 in this state is also referred to as an upper limit position.

When the cover 6 is removed from the grinder 2, the sensor lever 68 is pressed down by the urging force of the compression spring 70, and as shown in fig. 3, the rear operating lever 64 is rotated downward, and the front operating lever 62 is also rotated downward.

In the grinding machine 2 of the present embodiment, when the grinding wheel 4 is oriented downward, the gravity in the direction in which the sensor rod 68 is moved from the upper limit position to the lower limit position acts on the sensor rod 68, and the gravity in the direction in which the front operating lever 62 and the rear operating lever 64 are rotated downward acts on the front operating lever 62 and the rear operating lever 64. Therefore, even if the urging force of the compression spring 70 is not applied to the sensor lever 68 due to the breakage or deterioration of the compression spring 70, in a state where the cover 6 is detached from the grinding machine 2, the grinding wheel 4 is in a downward state, and at this time, the sensor lever 68 moves to the lower limit position by its own weight, and the front operating lever 62 and the rear operating lever 64 rotate downward by its own weight.

Fig. 10 shows a circuit configuration of the grinder 2. A regulator 80, a microcomputer 82, a motor driver 84, and a display lamp 86 are mounted on the control substrate 24. The regulator 80 adjusts the electric power supplied from the battery 22 to a predetermined voltage. The motor driver 84 has a plurality of switching elements (not shown) controlled by the microcomputer 82 for controlling the electric power supplied to the electric motor 14. The display lamp 86 includes a plurality of light emitting elements (not shown) for switching the content displayed on the display unit 30. The microcomputer 82 receives a signal indicating the on/off state from the main switch 28. The microcomputer 82 transmits a light emission signal to the light emitting element 76a of the photointerrupter 72, and receives a light receiving signal from the light receiving element 78a of the photointerrupter 72.

Fig. 11 is a flowchart showing the processing performed by the microcomputer 82.

In step S2, the microcomputer 82 stands by until the main switch 28 is turned on. When the main switch 28 is turned on, the process advances to step S4.

In step S4, the microcomputer 82 performs the cover determination process shown in fig. 12.

In the cover determination process shown in fig. 12, in step S32, the microcomputer 82 transmits a light emission signal to the light emitting element 76a of the photointerrupter 72. In the present embodiment, the microcomputer 82 transmits a signal pattern 90 (see fig. 13) as a light emission signal, and the signal pattern 90 has a pulse train in which the H potential and the L potential are switched at a predetermined cycle.

In step S34, the microcomputer 82 receives the light receiving signal from the light receiving element 78a of the photointerrupter 72.

In step S36, the microcomputer 82 determines whether or not the periods of the light emission signal transmitted in step S32 and the light reception signal received in step S34 coincide.

As shown in fig. 13, when the cover 6 is attached to the cover attachment portion 52 and thus the light emitting portion 76 and the light receiving portion 78 are not shielded from each other, a signal pattern 92 of a pulse train having the same cycle as the signal pattern 90 of the light emitting signal is received as the light receiving signal. In contrast, when the cover 6 is not mounted on the cover mounting portion 52 and thus the space between the light emitting portion 76 and the light receiving portion 78 is shielded, the signal pattern 94 of which the L potential is constant is received as the light receiving signal. When the signal pattern 96 receiving the H potential and being constant is used as the light receiving signal and the signal pattern 98 receiving the pulse train having the period different from that of the light emitting signal is used as the light receiving signal, it is considered that some abnormality occurs in the photo-interrupter 72.

In step S36 of fig. 12, when the periods of the light emission signal and the light reception signal match (yes), the microcomputer 82 determines that the cover 6 is attached to the cover attachment portion 52, and the process proceeds to step S38. In step S38, the microcomputer 82 permits driving of the electric motor 14. After step S38, the cover determination process shown in fig. 12 is ended.

In step S36 of fig. 12, if the periods of the light emission signal and the light reception signal do not match (in the case of no), the microcomputer 82 determines that the cover 6 is not attached to the cover attachment portion 52 or that an abnormality has occurred in the photointerrupter 72, and the process proceeds to step S40. In step S40, the microcomputer 82 prohibits the driving of the electric motor 14. After step S40, the cover determination process shown in fig. 12 is ended.

Returning to fig. 11, in the next step S6 of step S4, the microcomputer 82 determines whether or not to permit the driving of the electric motor 14. In the case where the driving of the electric motor 14 is prohibited (in the case of no), the process proceeds to step S8.

In step S8, the microcomputer 82 controls the indicator lamp 86 to display a warning on the display unit 30.

In step S10, the microcomputer 82 stands by until the main switch 28 is turned off. When the main switch 28 is turned off (when yes), the process proceeds to step S12.

In step S12, the microcomputer 82 controls the indicator lamp 86 to cancel the warning display on the display unit 30. After step S12, the process returns to step S2.

In step S6, when the driving of the electric motor 14 is permitted (in the case of "yes"), the process proceeds to step S14. In step S14, the microcomputer 82 controls the motor driver 84 to start driving the electric motor 14. Accordingly, the grinding wheel 4 rotates, and the workpiece can be ground by the grinder 2.

In step S16, the microcomputer 82 performs the cover determination process shown in fig. 12 again. As a result of this cover determination process, when the cover 6 is kept attached to the cover attachment portion 52, the drive of the electric motor 14 is permitted (step S38 in fig. 12), and when the cover 6 is detached from the cover attachment portion 52, the drive of the electric motor 14 is prohibited (step S40 in fig. 12).

In step S18, the microcomputer 82 determines whether or not to permit the driving of the electric motor 14. In the case where the driving of the electric motor 14 is prohibited (in the case of no), the process proceeds to step S20.

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

In step S22, the microcomputer 82 controls the indicator lamp 86 to display a warning on the display unit 30.

In step S24, the microcomputer 82 stands by until the main switch 28 is turned off. When the main switch 28 is turned off (when yes), the process proceeds to step S12.

In step S12, the microcomputer 82 controls the indicator lamp 86 to cancel the warning display on the display unit 30. After step S12, the process returns to step S2.

In step S18, when the driving of the electric motor 14 is permitted (in the case of "yes"), the process proceeds to step S26. In step S26, the microcomputer 82 determines whether the main switch 28 is off. In the case where the main switch 28 is not turned off (in the case of no), the process returns to step S16.

In step S26, when the main switch 28 is turned off (when yes), the process advances to step S28. In step S28, the microcomputer 82 controls the motor driver 84 to stop driving the electric motor 14. After step S28, the process returns to step S2.

Since the microcomputer 82 performs the above-described processing, the grinder 2 drives the electric motor 14 only when the slide switch 26 is in the on position or when the cover 6 is attached. This prevents the electric motor 14 from being driven without the cover 6 attached.

Note that, in the above-described processing, the cover determination processing in step S16 in fig. 11 may be performed every time a predetermined time (for example, 1 minute) has elapsed, and this processing is not always performed. Alternatively, the cover determination process of step S16 in fig. 11 may not be performed. By reducing the number of times the cover determination process is executed, power consumption of the battery 22 can be suppressed.

As described above, in the 1 or more embodiments, the grinding machine 2 (an example of a tool) has the electric motor 14 (an example of a prime mover), the bevel gear 38 (an example of a transmission mechanism), the housing 50, the spindle 36 (an example of a tip tool holding portion), the cover 6 (an example of an attachment), the link member 56, and the 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 with a bevel gear 38 and holds a grinding wheel 4 (an example of a tip tool); the cover 6 is detachably attached to the housing 50; the link member 56 operates in response to attachment and detachment of the cover 6; the detection sensor 58 is housed inside the housing 50, and has a photo-interrupter 72 (an example of a non-contact sensor element). The detection sensor 58 detects the movement of the link member 56 using the photo-interrupter 72.

According to the above configuration, 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 grinding mill 2 is used in an environment with a large amount of dust, it can be accurately detected whether the cover 6 is mounted on the housing 50. Further, according to the above configuration, the detection sensor 58 detects the operation of the link member 56 using the photo-interrupter 72 as a non-contact sensor element. Accordingly, even when vibration or shock acts on the link member 56, the shock or vibration is prevented from acting on the photo-interrupter 72 through the link member 56. Erroneous detection by the photo-interrupter 72 due to shock or vibration can be prevented, and the durability of the photo-interrupter 72 can be improved.

In the embodiment 1 or more, the grinder 2 further includes a control board 24 (an example of a control unit), and the control board 24 controls the operation of the electric motor 14. The control board 24 allows driving of the electric motor 14 based on the detection signal from the detection sensor 58.

According to the above configuration, the driving of the electric motor 14 can be permitted only when the cover 6 is attached to the housing 50.

In 1 or more embodiments, the link member 56 extends from the inside to the outside of the housing 50.

With the above configuration, it is possible to detect whether or not the cover 6 is attached to the housing 50 so as not to enter the housing 50 when the cover is attached to the housing 50.

In 1 or more embodiments, the detection sensor 58 further has a sensor housing 66 and a sensor rod 68, wherein the sensor housing 66 houses a photointerrupter 72; the sensor rod 68 extends from the interior to the exterior of the sensor housing 66 and acts in response to the action of the link member 56. The photo-interrupter 72 detects the operation of the sensor lever 68.

According to the above configuration, since the photo-interrupter 72 of the detection sensor 58 is housed inside the sensor case 66, even when dust flows into the inside of the case 50, the photo-interrupter 72 can be suppressed from being affected by the dust.

In the 1 or more embodiments, the photointerrupter 72 includes a light emitting element 76a and a light receiving element 78a, and the light receiving element 78a receives light from the light emitting element 76 a. The sensor lever 68 is movable between an upper limit position (an example of a 1 st position) in which a space between the light emitting element 76a and the light receiving element 78a is not shielded, and a lower limit position (an example of a 2 nd position); in the lower limit position, a space between the light emitting element 76a and the light receiving element 78a is shielded. When the cover 6 is not mounted on the housing 50, the sensor lever 68 is located at the lower limit position. When the cover 6 is mounted on the housing 50, the sensor lever 68 is located at the upper limit position.

As described above, the photointerrupter 72 including the light emitting element 76a and the light receiving element 78a is less susceptible to external environments such as metal powder than a sensor element including a magnet and a hall element, for example. According to the above configuration, since the position of the sensor lever 68 is switched between the upper limit position and the lower limit position in response to attachment and detachment of the cover 6, it is possible to determine whether or not the cover 6 is attached to the housing 50 based on the presence or absence of transmission of light from the light emitting element 76a to the light receiving element 78 a.

In the 1 or more embodiments, the light emitting element 76a emits light in accordance with a light emission signal having the predetermined signal pattern 100.

In the configuration in which the position of the sensor lever 68 is switched between the upper limit position and the lower limit position in response to attachment and detachment of the cover 6, if it is desired to determine whether or not the cover 6 is attached to the housing 50 only based on the presence or absence of transmission of light from the light emitting element 76a to the light receiving element 78a, when an on failure or an off failure occurs in the light receiving element 78a, there is a possibility that an erroneous determination may be made as to whether or not the cover 6 is attached to the housing 50. According to the above configuration, when the sensor lever 68 is 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 76 a. Therefore, by comparing the signal patterns 92, 94, 96, 98 of the light reception signal received by the light receiving element 78a with the signal pattern 90 of the light emission signal emitted by the light emitting element 76a to determine whether or not the cover 6 is attached to the housing 50, erroneous determination due to a failure of the detection sensor 58 can be prevented.

In the 1 or more embodiments, the sensor rod 68 is formed in a shape slidable on the side surface of the inside of the sensor housing 66. The sensor lever 68 has a base portion 68a and an abutting portion 68d, wherein the base portion 68a has a substantially flat plate shape, and has a longitudinal direction in a vertical direction and a width direction in a front-rear direction; 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 notched portion 68f and a shielding portion 68g, wherein the notched portion 68f has a shape that does not shield a space between the light emitting element 76a and the light receiving element 78 a; the shielding portion 68g has a shape for shielding a gap between the light emitting element 76a and the light receiving element 78 a.

According to the above configuration, the sensor lever 68 that extends from the inside to the outside of the sensor housing 66 and operates in response to the operation of the link member 56 can be realized by a simple configuration.

In the 1 or more embodiments, the case 50 has a cover mounting portion 52, and the cover mounting portion 52 is used for mounting the cover 6. The link member 56 has a round bar shaft 60, a front operating lever 62 and a rear operating lever 64, wherein the front operating lever 62 is fixed to the front end of the shaft 60; the rear operating lever 64 is fixed to the rear end of the shaft 60. The tip of the shaft 60 protrudes outside the housing 50 through a through hole 10a formed in the housing 50. The front joystick 62 is disposed outside the housing 50 and near the hood attachment portion 52. The rear joystick 64 is disposed inside the housing 50 and below the detection sensor 58.

According to the above configuration, the link member 56 that operates the sensor lever 68 in response to attachment and detachment of the cover 6 as an accessory can be realized with a simple configuration.

In the embodiment of 1 or more, in the grinder 2, when the cover 6 is attached to the cover attachment portion 52, the front lever 62 is pressed by the cover 6 to rotate upward, the rear lever 64 also rotates upward, the contact portion 68d is pressed by the rear lever 64 to move the sensor rod 68 upward, and the cutout 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.

With the above configuration, the attachment/detachment of the cover 6 to/from the housing 50 can be detected by the detection sensor 58 with a simple configuration.

In the 1 or more embodiments, the link member 56 is rotatably supported by the housing 50. The link member 56 rotates relative to the housing 50 in response to attachment and detachment of the cover 6.

According to the above configuration, even when the detection sensor 58 is disposed at a position distant from the mounting position of the cover 6, the link member 56 extending from the mounting position of the cover 6 to the position of the detection sensor 58 can be disposed by effectively utilizing the free space inside the housing 50, without requiring a large and complicated mechanism for the link member 56.

In the embodiment 1 or more, the link member 56 is disposed in the longitudinal direction along the front-rear direction (example of the 1 st direction) parallel to the output shaft 16 of the electric motor 14 housed in the case 50. The rotation shaft of the link member 56 is arranged in the front-rear direction. The sensor lever 68 is held by the sensor housing 66 so as to be movable in the vertical direction (example of the 2 nd direction) orthogonal to the front-rear direction. The detection sensor 58 further includes a compression spring 70 (an example of an elastic member), and the compression spring 70 is housed inside the sensor housing 66 and biases the sensor lever 68 from the upper limit position to the lower limit position.

With the above configuration, the link member 56 and the detection sensor 58 can be simplified in configuration.

In the 1 or more embodiments, the grinder 2 further has a control substrate 24 (an example of a control unit), and the control substrate 24 controls the electric power supplied to the electric motor 14. The detection sensor 58 is disposed between the electric motor 14 and the control board 24.

According to the above configuration, the detection sensor 58 can be disposed by effectively utilizing the empty space between the electric motor 14 and the control board 24 inside the housing 50.

In the embodiment 1 or more, the grinder 2 further includes a battery 22, and the battery 22 is detachably attached 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.

According to the above configuration, the detection sensor 58 can be disposed by effectively utilizing the empty space between the electric motor 14 and the battery 22 inside the case 50.

In the 1 or more than 1 embodiment, the cover 6 as an accessory covers the grinding wheel 4 at least partially.

According to the above configuration, it can be detected by the detection sensor 58 whether or not the cover 6 at least partially covering the grinding wheel 4 is attached to the housing 50.

In the 1 or more embodiments, the grinding machine 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 attachment), 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 with a bevel gear 38 and holds a grinding wheel 4 (an example of a tip tool); the cover 6 is detachably attached to the housing 50; the link member 56 operates in response to attachment and detachment of the cover 6; the detection sensor 58 is housed inside the housing 50. The link member 56 rotates relative to the housing 50 in response to attachment and detachment of the cover 6. The detection sensor 58 detects the rotational movement of the link member 56.

According to the above configuration, since the detection sensor 58 is housed inside the housing 50, the detection sensor 58 is less susceptible to dust. Therefore, even when the grinding mill 2 is used in an environment with a large amount of dust, it can be accurately detected whether the cover 6 is mounted on the housing 50. Further, according to the above configuration, even when the detection sensor 58 is disposed at a position distant from the mounting position of the cover 6, the link member 56 extending from the mounting position of the cover 6 to the position of the detection sensor 58 can be disposed by effectively utilizing the vacant space inside the housing 50, without requiring a large and complicated mechanism for the link member 56.

In the embodiment 1 or more, the grinder 2 further includes a control board 24 (an example of a control unit), and the control board 24 controls the operation of the electric motor 14. The control board 24 allows driving of the electric motor 14 based on the detection signal from the detection sensor 58.

According to the above configuration, the driving of the electric motor 14 can be permitted only when the cover 6 is attached to the housing 50.

In the 1 or more embodiments, the link member 56 is rotatably supported by the housing 50. The link member 56 extends from the inside to the outside of the housing 50.

According to the above configuration, the link member 56 extending from the mounting position of the cover 6 outside the housing 50 to the position of the detection sensor 58 inside the housing 50 can be disposed by effectively utilizing the vacant space inside the housing 50.

In the above-described embodiment, the configuration has been described in which when the sensor lever 68 is 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 from each other, and when the sensor lever 68 is at the lower limit position, the shielding 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 from each other. In contrast, for example, the sensor lever 68 may have a shape in which the positions of the cutout portion 68f and the shielding portion 68g are interchanged. In this case, when the sensor lever 68 is at the upper limit position, the shielding portion 68g is disposed between the light emitting portion 76 and the light receiving portion 78, and the light emitting element 76a and the light receiving element 78a are shielded from each other, and when the sensor lever 68 is at the lower limit position, the cutout portion 68f is disposed between the light emitting portion 76 and the light receiving portion 78, and the light emitting element 76a and the light receiving element 78a are not shielded from each other.

(example 2)

As shown in fig. 14, 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 example 1 will be described with respect to the grinder 102 of this example.

In the grinding mill 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 housing 12. The partition case 104 is provided between the gear case cover 9 and the gear case 10.

The grinder 102 of the present embodiment does not have the hood detection mechanism 54. Instead, as shown in fig. 15, the grinder 102 has a cover detection unit 106. The cover detection unit 106 is provided to the partition case 104. The cover detection unit 106 detects whether or not the cover 6 is attached to the cover attachment portion 52.

As shown in fig. 14, the grinder 102 has a sub-handle 108 as an accessory in addition to the cover 6. The sub-handle 108 is detachably attached to the gear housing 10. When the user uses the grinder 102, the main body case 8 is held with one hand, and the sub-handle 108 is held with the other hand, whereby the user can stably hold the grinder 102.

As shown in fig. 16, the gear housing 10 is provided with handle attachment portions 110 and 112. The handle mounting portion 110 is disposed on the right side surface of the gear housing 10, and the handle mounting portion 112 is disposed on the left side surface of the gear housing 10. The handle attachment portions 110 and 112 have handle attachment holes 110a and 112a, the handle attachment holes 110a and 112a penetrate the gear housing 10 from the outside to the inside, and have internal threads formed on the inner peripheral surface thereof corresponding to the external threads of the threaded portion 108a (see fig. 21) of the sub-handle 108. The sub-handle 108 may be attached to the handle attachment portion 110 by screwing the screw portion 108a thereof into the handle attachment hole 110a, or may be attached to the handle attachment portion 112 by screwing the screw portion 108a thereof into the handle attachment hole 112 a.

The partition case 104 is provided with handle detection units 114 and 116. The handle detection unit 114 is disposed corresponding to the handle attachment portion 110. The handle detection unit 114 detects whether or not the sub-handle 108 is attached to the handle attachment portion 110. The handle detection unit 116 is disposed corresponding to the handle attachment portion 112. The handle detection unit 116 detects whether or not the sub-handle 108 is attached to the handle attachment portion 112.

The cover detection unit 106 shown in fig. 15 and the handle detection units 114 and 116 shown in fig. 16 have the same structure. In the following description, the cover detection unit 106 and the handle detection units 114 and 116 may also be collectively referred to simply as a detection unit 118. In the following description, the structure of the detection unit 118 will be described with reference to fig. 17 to 19.

As shown in fig. 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 a photointerrupter 128. As shown in fig. 18 and 19, the photointerrupter 128 includes a sensor substrate 128c, and a light emitting element 128a and a light receiving element 128b mounted on the sensor substrate 128 c. The light emitting element 128a and the light receiving element 128b are disposed to face each other. The sensor substrate 128c is held in the sensor case 126 such that the light emitting element 128a and the light receiving element 128b are housed in the sensor case 126. The sensor substrate 128c is connected to the control substrate 24 by a wiring not shown. The microcomputer 82 of the control board 24 transmits a light emission signal to the light emitting element 128a of the photointerrupter 128 and receives a light reception signal from the light receiving element 128b of the photointerrupter 128 by the same processing as in embodiment 1.

The link member 122 has a swing shaft 122a, a contact arm 122b, and a detection arm 122 c. The swing shaft 122a is swingably held to the sensor housing 126. The link member 122 is held by the sensor housing 126 such that the contact arm 122b projects outward of the sensor housing 126 and the detection arm 122c is housed inside the sensor housing 126. The abutment arm 122b has a flange 122d and a projection 122e, wherein the projection 122e projects from the flange 122 d. The detection arm 122c has a shielding portion 122f having a shape for shielding a gap between the light emitting element 128a and the light receiving element 128 b. The link member 122 is swingable between a shielding position (see fig. 18) configured to shield the shielding portion 122f between the light emitting element 128a and the light receiving element 128b and an open position (see fig. 19); the open position is configured such that the shielding portion 122f does not shield between the light emitting element 128a and the light receiving element 128 b. Further, a seal member (not shown) may be provided in an opening portion of the sensor housing 126 through which the link member 122 penetrates. By providing the sealing member in the opening of the sensor case 126, it is possible to suppress the influence of dust entering the sensor case 126 from the outside to the inside on the operation of the photo-interrupter 128.

As shown in fig. 17, the compression spring 124 is mounted to a protrusion 126a formed on the outside of the sensor housing 126. The compression spring 124 biases the link member 122 toward the sensor housing 126 so that the link member 122 swings from the open position (see fig. 19) to the shielding position (see fig. 18).

As shown in fig. 15, the cover detection unit 106 is disposed near the center portion of the partition case 104 in the left-right direction, and is disposed at the lower portion of the partition case 104. The cover detection unit 106 is held by the partition case 104 such that the swing shaft 122a of the link member 122 is disposed in the left-right direction and the protrusion 122e faces downward. In the cover detection unit 106, the detection sensor 120 is housed inside the partition case 104, the contact arm 122b of the link member 122 protrudes outside the case 50 through the through hole 10b of the gear case 10, and the flange 122d and the protruding portion 122e are disposed outside the case 50. In the cover detection unit 106, the flange 122d of the link member 122 is notched at the front so as not to interfere with the gear housing 10.

As shown in fig. 15, in a state where the cover 6 is not attached to the cover attachment portion 52, the link member 122 is located at the shielding position, and the shielding portion 122f is arranged to shield a gap between the light emitting element 128a and the light receiving element 128 b. In this case, the control board 24 determines that the cover 6 is not mounted on the cover mounting portion 52.

As shown in fig. 20, when the hood 6 is mounted to the hood mounting portion 52, the protruding portion 122e of the link member 122 abuts against and presses the upper end of the hood 6. Accordingly, the link member 122 swings from the shielding position to the open position, and the shielding portion 122f is arranged not to shield the light emitting element 128a and the light receiving element 128 b. In this case, the control board 24 determines that the cover 6 is mounted on the cover mounting portion 52. When the cover 6 is detached from the cover attaching portion 52 from this state, the link member 122 is swung from the open position to the shielding position by the urging force of the compression spring 124, and the state shown in fig. 15 is returned.

As shown in fig. 16, the handle detection unit 114 is disposed at the right portion of the partition case 104. The handle detection unit 114 is held by the partition case 104 such that the swing shaft 122a of the link member 122 is disposed in the vertical direction and the protrusion 122e faces the right side. In the handle detection unit 114, the detection sensor 120 is housed inside the partition case 104, and the flange 122d and the protruding portion 122e of the link member 122 are disposed inside the gear case 10. In the handle detection unit 114, the protrusion 122e enters the handle attachment hole 110a, and the flange 122d abuts against the inner surface of the gear housing 10.

The handle detection unit 116 is disposed at the left portion of the partition case 104. The handle detection unit 116 is held by the partition case 104 such that the swing shaft 122a of the link member 122 is disposed in the vertical direction and the protruding portion 122e faces the left side. In the handle detection unit 116, the detection sensor 120 is housed inside the partition case 104, and the flange 122d and the protruding portion 122e of the link member 122 are disposed inside the gear case 10. In the handle detection unit 116, the protrusion 122e enters the handle attachment hole 112a, and the flange 122d abuts against the inner surface of the gear housing 10.

As shown in fig. 16, in a state where the sub-handle 108 is not attached to any of the handle attachment portions 110 and 112, the link member 122 is located at the shielding position and the shielding portion 122f is disposed to shield a space between the light emitting element 128a and the light receiving element 128b with respect to the handle detection units 114 and 116. In this case, the control board 24 determines that the sub-handle 108 is not attached to either of the handle attachment portions 110 and 112.

As shown in fig. 21, when the sub-handle 108 is attached to one of the handle attachment portions 110 and 112, for example, the handle attachment portion 112, the protruding portion 122e of the link member 122 of the handle detection unit 116 abuts against and is pressed against the threaded portion 108a of the sub-handle 108. Accordingly, in the handle detection unit 116, the link member 122 swings from the shielding position to the opening position, and the shielding portion 122f is arranged not to shield between the light emitting element 128a and the light receiving element 128 b. In this case, the control board 24 determines that the sub-handle 108 is attached to the handle attachment portion 112. When the sub-handle 108 is detached from the handle attachment portion 112 from this state, the link member 122 is swung from the open position to the shielding position by the urging force of the compression spring 124 in the handle detection unit 116, and the state shown in fig. 16 is returned.

As described above, in the 1 or more embodiments, the grinding machine 102 (an example of a tool) has the electric motor 14 (an example of a prime mover), the bevel gear 38 (an example of a transmission mechanism), the housing 50, the spindle 36 (an example of a tip tool holding portion), the cover 6 or the sub-handle 108 (an example of an attachment), the link member 122, and the 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 with a bevel gear 38 and holds a grinding wheel 4 (an example of a tip tool); the cover 6 or the sub-handle 108 is detachably attached to the housing 50; the link member 122 operates in response to attachment and detachment of the cover 6 or the sub-handle 108; the detection sensor 120 is housed inside the housing 50, and has a photo-interrupter 128 (an example of a non-contact sensor element). The detection sensor 120 detects the motion of the link member 122 using the photo-interrupter 128.

According to the above configuration, since the detection sensor 120 is housed inside the housing 50, the detection sensor 120 is less susceptible to 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. Further, according to the above configuration, the detection sensor 120 detects the operation of the link member 122 using the photo-interrupter 128 as a non-contact sensor element. Accordingly, even when vibration or shock acts on the link member 122, the shock or vibration is prevented from acting on the photo-interrupter 128 through the link member 122. Erroneous detection by the photointerrupter 128 due to shock or vibration can be prevented, and the durability of the photointerrupter 128 can be improved.

In the 1 or more embodiments, the grinder 102 further includes a control board 24 (an example of a control unit), and the control board 24 controls the operation of the electric motor 14. The control board 24 allows driving of the electric motor 14 based on the detection signal from the detection sensor 120.

According to the above configuration, the driving of the electric motor 14 can be permitted only when the cover 6 and the sub handle 108 are attached to the housing 50.

In the 1 or more embodiments, the link member 122 of the cap detection unit 106 extends from the inside to the outside of the housing 50.

With the above configuration, it is possible to detect whether or not the cover 6 is attached to the housing 50 so as not to enter the housing 50 when the cover is attached to the housing 50.

In 1 or more embodiments, the detection sensor 120 further has a sensor housing 126, the sensor housing 126 housing a photointerrupter 128. The link member 122 extends from the inside to the outside of the sensor housing 126. The photointerrupter 128 detects the motion of the link member 122.

According to the above configuration, the photo-interrupter 128 directly detects the operation of the link member 122 without using the sensor lever 68 and the like of embodiment 1, so that the configuration of the detection sensor 120 can be simplified and the number of parts can be reduced.

In the 1 or more embodiments, the photointerrupter 128 includes a light emitting element 128a and a light receiving element 128b, and the light receiving element 128b receives light from the light emitting element 128 a. The link member 122 is movable between an open position (an example of the 1 st position) in which a space between the light emitting element 128a and the light receiving element 128b is not shielded, and a shielded position (an example of the 2 nd position); in the shielding position, a space between the light emitting element 128a and the light receiving element 128b is shielded. When the cover 6 and the sub-handle 108 are not attached to the housing 50, the link member 122 is located at the shielding position. When the cover 6 and the sub-handle 108 are attached to the housing 50, the link member 122 is located at the open position.

According to the above configuration, the sensor element using the magnet and the hall element, for example, can be less susceptible to the external environment such as metal dust.

In the 1 or more embodiments, the light emitting element 128a emits light in accordance with a light emission signal having a predetermined signal pattern.

With the above configuration, erroneous determination due to a failure of the detection sensor 120 can be prevented.

In the 1 or more embodiments, the link member 122 has a swing shaft 122a, a contact arm 122b, and a detection arm 122c, wherein the swing shaft 122a is held in a swingable manner to the sensor housing 126; the abutting arm 122b protrudes to the outside of the sensor housing 126; the detection arm 122c is housed inside the sensor housing 126. The abutment arm 122b has a flange 122d and a projection 122e, wherein the projection 122e projects from the flange 122 d. The detection arm 122c has a shielding portion 122f having a shape for shielding a gap between the light emitting element 128a and the light receiving element 128 b.

With the above configuration, the link member 122 that operates in response to 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 configuration.

In the 1 or more embodiments, the case 50 has a cover mounting portion 52, and the cover mounting portion 52 is used for mounting the cover 6. The cover detection unit 106 has a sensor case 126 disposed inside the case 50 and located near the center of the case 50 in the lateral direction. The sensor case 126 is held by the case 50 such that the swing shaft 122a is arranged in the left-right direction and the protrusion 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 case 50 and in the vicinity of the cover attachment portion 52.

With the above configuration, the attachment/detachment of the cover 6 to/from the housing 50 can be detected by the detection sensor 120 with a simple configuration.

In the 1 or more embodiments, the housing 50 has handle mounting holes 110a, 112a, and the handle mounting holes 110a, 112a are used for mounting the sub-handle 108. The sensor housing 126 is disposed inside the housing 50 for the handle detection units 114 and 116. The sensor case 126 is held by the case 50 such that the swing shaft 122a is disposed in the vertical direction and the protruding portion 122e faces the handle attachment holes 110a and 112 a. When the sub-handle 108 is not attached to the handle attachment holes 110a and 112a, the flange 122d abuts against the inner surface of the housing 50, and the protrusion 122e enters the handle attachment holes 110a and 112 a.

With the above configuration, the attachment/detachment of the sub-handle 108 to/from the housing 50 can be detected by the detection sensor 120 with a simple configuration.

In the 1 or more embodiments, the link member 122 is rotatably supported by the sensor housing 126. The link member 122 rotates relative to the sensor housing 126 in response to attachment and detachment of the cover 6 and the sub-handle 108.

In the configuration in which the link member 122 and the detection sensor 120 are independently attached to the housing 50, if an error occurs in the attachment position of each, the relative positional relationship between the link member 122 and the photointerrupter 128 may be different from expected, and the detection sensor 120 may make an erroneous determination. According to the above configuration, since the link member 122 is attached to the sensor housing 126, the relative positional relationship between the link member 122 and the photo-interrupter 128 can be managed with high accuracy.

In the embodiment of 1, or 1 or more, in the cover detection unit 106, the rotation shaft of the link member 122 and the photointerrupter 128 are arranged in the vertical direction (an example of a direction substantially orthogonal to the output shaft 16 of the electric motor 14 housed in the case 50). In the handle detection units 114 and 116, the rotation shaft of the link member 122 and the photointerrupter 128 are arranged in a lateral direction (an example of a direction substantially perpendicular to the output shaft 16 of the electric motor 14).

According to the above configuration, the link member 122 and the detection sensor 120 can be disposed by effectively utilizing the vacant space around the output shaft 16 of the electric motor 14 inside the housing 50.

In the embodiment 1 or more, in the cover detection unit 106, the rotation axis of the link member 122 is arranged in the left-right direction (example of the 2 nd direction) orthogonal to the front-back direction (example of the 1 st direction) 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), and the compression spring 124 biases the link member 122 from the open position to the shielding position. In the handle detection units 114 and 116, the rotation shaft of the link member 122 is disposed in the vertical direction (example of the 2 nd direction) orthogonal to the front-rear direction (example of the 1 st direction) parallel to the output shaft 16 of the electric motor 14. The handle detection units 114 and 116 of the grinder 102 have compression springs 124 (examples of elastic members), and the compression springs 124 urge the link members 122 from the open position to the shielding position.

With the above configuration, the link member 122 and the detection sensor 120 can be more simplified in configuration.

In the embodiment of 1 or more, the detection sensor 120 is disposed between the main shaft 36 and the electric motor 14 in the front-rear direction (an example of the direction in which the output shaft 16 of the electric motor 14 extends).

According to the above configuration, the detection sensor 120 can be disposed by effectively utilizing the empty space between the main shaft 36 and the electric motor 14 inside the housing 50.

In the 1 or more embodiments, the grinder 102 has a plurality of detection sensors 120 and a plurality of link members 122 corresponding to the hood detection unit 106 and the handle detection units 114 and 116, wherein the plurality of link members 122 correspond to the plurality of detection sensors 120.

With the above configuration, it is possible to detect whether or not the cover 6 and the sub-handle 108 are attached to the cover attachment portion 52 and the handle attachment portions 110 and 112, respectively.

In the 1 or more embodiments, the cover 6 as an accessory covers at least a part of the grinding wheel 4, and the sub-handle 108 as an accessory is a handle that can be held by a user.

According to the above configuration, it is possible to detect whether or not the cover 6 at least partially covering the grinding wheel 4 is attached to the housing 50 and the sub-handle 108 which can be gripped by the user by the detection sensor 120.

In the 1 or more embodiments, the grinding machine 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 attachment), 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 with a bevel gear 38 and holds a grinding wheel 4 (an example of a tip tool); the cover 6 or the sub-handle 108 is detachably attached to the housing 50; the link member 122 operates in response to attachment and detachment of the cover 6 and the sub-handle 108; the detection sensor 120 is housed inside the housing 50. The link member 122 rotates relative to the housing 50 in response to attachment and detachment of the cover 6 and the sub-handle 108. The detection sensor 120 detects the rotational movement of the link member 122.

According to the above configuration, since the detection sensor 120 is housed inside the housing 50, the detection sensor 120 is less susceptible to 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. Further, according to the above configuration, even when the detection sensor 120 is disposed at a position distant from the mounting position of the cover 6 or the sub handle 108, the link member 122 extending from the mounting position of the cover 6 or the sub handle 108 to the position of the detection sensor 120 can be disposed by effectively utilizing the free space inside the housing 50, and there is no need to make the link member 122a large and complicated mechanism.

In the 1 or more embodiments, the grinder 102 further includes a control board 24 (an example of a control unit), and the control board 24 controls the operation of the electric motor 14. The control board 24 allows driving of the electric motor 14 based on the detection signal from the detection sensor 120.

According to the above configuration, the driving of the electric motor 14 can be permitted only when the cover 6 and the sub handle 108 are attached to the housing 50.

(modification example)

In the above-described embodiment, the configuration in which the photointerrupters 72 and 128 each having the light emitting elements 76a and 128a and the light receiving elements 78a and 128b are used as the proximity sensor elements has been described. In contrast, for example, a hall element (not shown) that detects magnetism from a magnet (not shown) fixed to the sensor lever 68 or the link member 122 may be used as the proximity sensor element.

In the above-described embodiment, the electric motor 14 is configured as an inner rotor type brushless dc motor, but the electric motor 14 may be an outer rotor type brushless dc motor, for example. Alternatively, the electric motor 14 may be a brushed dc motor. Alternatively, the electric motor 14 may be another type of motor such as an ac motor.

In the above-described embodiment, the configuration in which the grinder 2 operates by supplying dc power from the battery 22 has been described, but the grinder 2 may be configured to operate by supplying ac power from a power supply line (not shown).

In the above-described embodiment, the case where the tool is the grinder 2, the prime mover is the electric motor 14, the tip tool is the grinding wheel 4, the tip tool holding portion is the main shaft 36, and the attachment is the cover 6 or the sub-handle 108 has been described as an example, but the tool may be another type of tool, the prime mover may be another type of prime mover, the tip tool may be another type of tip tool, the tip tool holding portion may be another type of tip tool holding portion, and the attachment may be another type of attachment.