JP7532819B2 - Work tools - Google Patents

Description

The present invention relates to power tools, such as electric screwdrivers, grinders, jigsaws, and chainsaws, that perform various tasks by driving the tip tool with electricity or air.

2. Description of the Related Art Power tools are widely used in work sites and factories, in which a tool tip such as a drill or a driver is rotationally driven by a motor to perform a desired task (see, for example, Patent Document 1).
Among such power tools, there are some which have an auxiliary handle attached to the main body so that a user can use the power tool in a stable position.
For example, Patent Document 1 discloses an electric power tool that detects whether the user is gripping the auxiliary handle and limits the output torque in order to prevent accidents such as injury caused by the user not holding the auxiliary handle firmly.

Patent No. 5899471 Patent No. 5914809

However, the above-mentioned conventional power tools (power tools) have the following problems.
That is, the electric power tool disclosed in the above publication can prevent injury to the user by detecting the grip of the auxiliary handle and limiting the output torque, but the gripping strength of the auxiliary handle varies from user to user, and the control of the above electric power tool may limit the output torque against the user's will depending on the skill level of each user (skilled or unskilled).

The objective of the present invention is to provide a power tool that ensures the safety of the user and allows appropriate control taking into account the skill level of the user.

The power tool according to the first invention is a power tool that performs a predetermined task by driving an attached tool tip, and includes an auxiliary handle that is held by a user during work, a main body, and a behavior detection unit. The auxiliary handle has a detection unit that detects the gripping force with which the user grips the auxiliary handle, and a transmission unit that transmits the detection result from the detection unit. The main body has a drive unit that drives the tool tip, a receiving unit that receives the detection result from the transmission unit, and a control unit that controls the operation of the drive unit. The behavior detection unit detects the behavior of the auxiliary handle or the main body. The control unit decides whether or not to permit the operation of the drive unit based on the gripping force detection result from the detection unit and the behavior detection result from the behavior detection unit.

Here, in a work tool that includes an auxiliary handle attached to the main body so that the work tool can be held with both hands in a stable position to perform various tasks, a decision is made as to whether or not to allow the drive unit to operate based on the detection results of the gripping force holding the auxiliary handle and the behavior (vibration) of the work tool.
Here, the power tools include, for example, power tools such as electric screwdrivers, grinders, jigsaws, and chainsaws, which perform various operations by driving a tool tip with electricity or air.

The behavior detector that detects the behavior (vibration) of the power tool during work is, for example, an acceleration sensor or a gyro sensor, and is provided on the main body side or auxiliary handle side included in the power tool.
This makes it possible, for example, to allow operation of the drive unit only when the detected gripping force of the holding handle and the vibration of the work tool that occurs when working while gripping the auxiliary handle with that gripping force are within an acceptable range.

Therefore, when the gripping force is smaller than a predetermined value or when the vibration of the power tool during work is equal to or greater than a predetermined amount, the operation of the drive unit is prohibited, thereby improving the safety of the user.
As a result, the safety of the user can be ensured, and appropriate control can be performed taking into account the skill levels of users.

The power tool of the second invention is the power tool of the first invention, wherein when the detection result in the behavior detection unit is that operation of the drive unit cannot be permitted, the control unit adjusts the grip force grip threshold value set for determining whether or not to permit operation of the drive unit to be increased.
Here, when the result (amount of shaking) detected by the behavior detection unit is outside the acceptable range and operation of the drive unit is not permitted, the gripping threshold value of the gripping force set as a condition for permitting operation of the drive unit is increased.

As a result, when the amount of shaking detected by the behavior detection unit is large, the grip threshold value of the grip force of the auxiliary handle set to allow the drive unit to operate can be changed to a larger value, thereby making it possible to create a state in which the drive unit will not operate unless the grip force becomes large.
Therefore, the user needs to grip the auxiliary handle more firmly in order to operate the drive unit, and as a result, the amount of shaking of the power tool can be reduced.

The power tool of the third invention is the power tool of the first or second invention, wherein the control unit has a first threshold value that stops operation of the drive unit if the detection result in the behavior detection unit is exceeded even once, and a second threshold value that is smaller than the first threshold value and stops operation of the drive unit if the second threshold value is exceeded a predetermined number of times or more within a predetermined time.
Here, in the control that stops the operation of the drive unit depending on the detection result in the behavior detection unit, two threshold values are set: a first threshold value that stops the operation if it is detected once, and a second threshold value that stops the operation if it is detected a predetermined number of times or more.

As a result, by using a combination of a first threshold value that immediately stops the operation of the drive unit and a second threshold value that stops the operation of the drive unit when the detection result (amount of shaking of the work tool) detected in the behavior detection unit is detected a predetermined number of times or more, the operation of the drive unit is immediately stopped when the amount of shaking is greater than the first threshold value, and can be stopped when an amount of shaking that is greater than the second threshold value is detected a predetermined number of times or more when the amount of shaking is smaller than the first threshold value and greater than the second threshold value.
As a result, it is possible to implement step-by-step control in which the power tool is stopped immediately or when a predetermined condition is satisfied, depending on the amount of vibration of the power tool.

The power tool according to the fourth invention is the power tool according to any one of the first to third inventions, and the control unit has a high-speed, low-torque mode in which the drive unit is controlled to output low torque at a high rotation speed, and a low-speed, high-torque mode in which the drive unit is controlled to output high torque at a rotation speed lower than that in the high-speed, low-torque mode.

Here, the control unit controls the drive unit in a high-speed, low-torque mode or a low-speed, high-torque mode that is selected according to the type of work, etc.
Here, the high-speed, low-torque mode is selected, for example, for screw tightening work using an electric screwdriver, and the low-speed, high-torque mode is selected, for example, for grinding work using a disc grinder.
This allows an appropriate mode to be selected depending on the type of work being performed using the power tool, making it possible to perform the work at an optimum rotation speed and output torque for that work.

The power tool according to the fifth aspect of the present invention is the power tool according to the fourth aspect of the present invention, and in the low-speed, high-torque mode, the control unit sets a threshold value for the detection result detected by the behavior detection unit that is smaller than the threshold value set in the high-speed, low-torque mode that stops the operation of the drive unit.

Here, the threshold value for stopping the operation of the drive unit is set to be smaller in the low-speed, high-torque mode than in the high-speed, low-torque mode.
As a result, the threshold value for the amount of shaking in the low-speed, high-torque mode, in which there is a high risk of an accident, such as a user getting injured if they do not hold the auxiliary handle firmly, is set to a smaller value than in the high-speed, low-torque mode, making it possible to perform safer control, such as stopping the operation of the drive unit early if shaking occurs.

The power tool of the sixth invention is the power tool of the fourth or fifth invention, wherein in at least one of the high-speed, low-torque mode and the low-speed, high-torque mode, the gripping force threshold value set for the detection result in the detection unit is set in multiple stages.
Here, in at least one of the high-speed, low-torque mode and the low-speed, high-torque mode, a threshold value related to the force for gripping the auxiliary handle is set in stages.
This allows the user to set an appropriate mode and stage according to the type of work, etc., and perform the work appropriately using the power tool while ensuring the safety of the user.

A power tool according to a seventh aspect of the present invention is the power tool according to any one of the first to sixth aspects of the present invention, wherein the behavior detection unit is provided on the auxiliary handle.
Here, a behavior detection unit such as an acceleration sensor is provided on the auxiliary handle side.
This makes it possible to detect shaking on the auxiliary handle side and determine whether or not to stop the operation of the drive unit depending on the amount of shaking.

The power tool according to an eighth aspect of the present invention is the power tool according to the seventh aspect of the present invention, wherein the behavior detection unit is provided near an end of the auxiliary handle opposite to the connection portion with the main body.
Here, a behavior detection unit such as an acceleration sensor is disposed at the end of the auxiliary handle.
As a result, by arranging the behavior detection unit at the end (opposite the connection side) where the amount of displacement is greatest when the auxiliary handle shakes, the amount of shake of the auxiliary handle can be detected with high accuracy.

A power tool according to a ninth aspect of the present invention is the power tool according to any one of the first to eighth aspects of the present invention, wherein the behavior detection unit is an acceleration sensor.
Here, an acceleration sensor is used as the behavior detection unit.
This makes it possible to detect wobble occurring in the power tool using an inexpensive configuration.

The power tool according to the tenth invention is the power tool according to any one of the first to ninth inventions, in which the main body has a non-contact power supply unit that supplies power to the auxiliary handle. The auxiliary handle has a non-contact power receiving unit that receives power from the non-contact power supply unit of the main body.

Here, the auxiliary handle attached to the main body receives power from the main body side using a non-contact power supply method.
As a result, compared to a contact-type configuration in which power is supplied to the auxiliary handle, the contact parts are not exposed, thereby preventing the occurrence of short circuits, rust, etc. at the exposed contact parts when the auxiliary handle is not attached.
As a result, in a configuration equipped with an auxiliary handle, the device can be used without being restricted by the usage environment.

The power tool according to an eleventh aspect of the present invention is the power tool according to any one of the first to tenth aspects of the present invention, wherein the detection unit is a pressure sensor.
Here, a pressure sensor is used as a detector that detects the user's gripping of the auxiliary handle and transmits a grip signal.
This allows the strength (pressure) with which the user holds the auxiliary handle to be detected and transmitted to the main body, thereby making it possible, for example, to control the output torque of the drive unit according to the holding strength detected in the detection unit.

The power tool according to the twelfth invention is the power tool according to any one of the first to eleventh inventions, in which the drive unit is a motor that rotates the tool tip.

Here, a motor driven by electricity is used as the drive unit.
This makes it possible to electrically control the output torque of the drive unit, for example, in accordance with the grip signal detected by the detection unit and the detection result detected by the behavior detection unit.

The power tool of the present invention ensures the safety of the user and provides appropriate control taking into account the skill level of the user.

1 is an overall perspective view showing a configuration of a power tool according to an embodiment of the present invention; 2 is a perspective view showing the power tool of FIG. 1 with an auxiliary handle detached from a main body. FIG. 2 is a control block diagram of the power tool of FIG. 1 . 2A and 2B are perspective views showing the arrangement of pressure sensors provided in the auxiliary handle of FIG. 1; 5A and 5B are cross-sectional views showing a connection structure between the auxiliary handle and the main body portion in FIG. 4A. 3A and 3B are cross-sectional views showing the configuration of a lock mechanism that maintains the connection between the auxiliary handle and the main body in FIG. 2 . 3A and 3B are cross-sectional views showing the configuration of a lock release mechanism that releases the connection between the auxiliary handle and the main body in FIG. 2 . 5 is a flowchart showing a process flow when gripping of an auxiliary handle of the power tool of FIG. 1 is detected and an operation is performed. 9 is a flowchart showing a process flow when the grip detection signal in the flowchart of FIG. 8 is processed according to a detection level. 10A to 10D are diagrams showing processed signals obtained by processing the grip detection signal detected in the processing in the flowchart of FIG. 9 . 5 is a flowchart showing a process flow of operation permission control based on a grip value when an auxiliary handle is gripped in the electric power tool of FIG. 1 . 5 is a flowchart showing a process flow of update control of the operation permission threshold based on a behavior detection signal detected by an acceleration sensor in the power tool of FIG. 1 . 13A to 13C are graphs illustrating the update control of the operation permission threshold in FIG. 12 . 13 is a diagram showing the work modes set in the power tool of FIG. 1 , and the corresponding operation permission thresholds, operation permission grip value ranges, first behavior detection thresholds, and second behavior detection thresholds of FIG. 12 . FIG. 13 is an overall perspective view showing the configuration of an electric power tool provided with another locking mechanism according to another embodiment of the present invention. 16 is a perspective view showing the power tool of FIG. 15 with the auxiliary handle detached from the main body. 17A and 17B are cross-sectional views showing the configuration of a locking mechanism that maintains the connection between the auxiliary handle and the main body in FIG. 16. 17A and 17B are cross-sectional views showing the configuration of a lock release mechanism that releases the connection between the auxiliary handle and the main body in FIG. 16 .

A power tool (power tool) 10 according to one embodiment of the present invention will be described below with reference to FIGS. 1 to 14. FIG.
Note that the content described below is merely one embodiment of the present invention, and it is not intended that the present invention be limited to the configuration described in this embodiment.
(1) Configuration of power tool 10 As shown in FIG. 1, the power tool 10 according to this embodiment is used for various tasks such as tightening and loosening screws, drilling holes, etc. by rotating and driving a tip tool 30, such as a screwdriver or drill, attached to the tip of the power tool 10 by a brushless motor (drive unit 17) supplied with power from a battery (not shown).
As shown in FIGS. 1 and 2 , the power tool 10 includes a main body 11 and an auxiliary handle 20 that is detachably attached to the main body 11 .

(2) Configuration of main body 11 The main body 11 is equipped with a drive unit 17 that is powered by a built-in battery (not shown), and performs various tasks by replacing various tip tools 30 that are detachably attached to the tip portion.

As shown in Fig. 1, the main body 11 includes a rotating section 12 having a tip tool 30 attached to its tip and rotated by a driving section 17 (see Fig. 3), a main handle 13 that is held by the user's right hand during operation, an operating section (trigger switch) 14 that drives the driving section 17 (see Fig. 3) depending on the amount of operation, and a connected section 15 to which an auxiliary handle 20 is attached. In addition, as shown in Fig. 3, the main body 11 includes a control section 16, a driving section 17, a non-contact power supply section 18, and a signal receiving section (receiving section) 19 inside.

1, the rotating unit 12 is provided at the tip of the main body 11 where the tip tool 30 is attached. The rotating unit 12 is rotated by a drive unit 17 (see FIG. 3) to perform various operations according to the attached tip tool 30.
As shown in FIG. 1, the main handle 13 is a gripping portion for a user that extends downward from the bottom surface of the main body 11, and in the power tool 10 shown in FIG. 1, is held by the user's right hand during operation.

The operating unit (trigger switch) 14 is provided near the base of the main handle 13 as shown in FIG. 1, and is operated by the index finger of the user's right hand while holding the main handle 13 during work. The operating unit 14 then transmits an operation signal corresponding to the amount of operation to the control unit 16 as shown in FIG. 3. In response, the control unit 16 drives the drive unit 17 so that the number of rotations corresponds to the amount of operation of the operating unit 14.

2, the connected portion 15 is a substantially cylindrical portion provided on the left side surface of the main body 11, and the auxiliary handle 20 is attached to the connected portion 15. The connected portion 15 has a cylindrical portion 15a, an attachment/detachment button 15b, and an insertion hole 15c.
2, the cylindrical portion 15a is disposed substantially perpendicular to the left side surface of the main body 11, and the auxiliary handle 20 is inserted and attached to the inner peripheral surface of the cylindrical portion. Also, a first recess (alignment portion) 15aa and a second recess (alignment portion) 15ab are formed on the inner peripheral surface of the cylindrical portion 15a, the first recess (alignment portion) 15aa being recessed radially outward.

As shown in FIG. 2, the first recess 15aa is formed on the inner circumferential surface of the cylindrical portion 15a, and a first protrusion 23aa formed on the outer circumferential surface of the cylindrical portion 23 on the auxiliary handle 20 side is inserted into the first recess 15aa.
As shown in Figure 2, the second recess 15ab is formed at a position opposite to the first recess 15aa on the inner surface of the cylindrical portion 15a, and the second convex portion 23ab formed on the outer peripheral surface of the cylindrical portion 23 on the auxiliary handle 20 side is inserted into it.

Here, the first recess 15aa is formed so as to have a groove width (a dimension in a direction intersecting the insertion direction) smaller than that of the second recess 15ab.
As shown in FIG. 2, the attachment/detachment button 15b is disposed on the outer circumferential surface of the cylindrical portion 15a, and when pressed, causes the auxiliary handle 20 to transition from a held state to a detachable state.

As shown in FIG. 2, the insertion hole 15c is a hole formed substantially in the center of the cylindrical portion 15a, and the insertion shaft 22a of the auxiliary handle 20 is inserted into the insertion hole 15c.
3, the control unit 16 is connected to the operation unit 14 and the signal receiving unit 19. The control unit 16 controls the number of rotations of the drive unit 17 based on the operation amount signal received from the operation unit 14. The control unit 16 also determines whether or not to permit the operation of the drive unit 17 based on the detection result (amount of shake) of the acceleration sensor 28 received via the signal receiving unit 19 and a grip detection signal (grip force) indicating that the user has gripped the grip unit 21 of the auxiliary handle 20.

As shown in FIG. 3, the drive unit 17 is a motor driven by electricity, and applies a rotational drive force to the tool tip 30 (the rotating unit 12).
As shown in FIG. 3, the non-contact power supply unit 18 receives power from a battery (not shown), and also supplies power from the main body 11 to the non-contact power receiving unit 24 of the auxiliary handle 20 in a non-contact manner without passing through electrical wiring or the like.
As shown in FIG. 3, the signal receiving section (receiving section) 19 receives the detection results of the pressure sensor 25 and the acceleration sensor 28 provided on the auxiliary handle 20 side via a signal transmitting section 26 on the auxiliary handle 20 side.

(3) Configuration of the auxiliary handle 20 The auxiliary handle 20 is held by the left hand of the user so that the user can perform the work in a stable state, for example, when performing an operation in which the drive unit 17 outputs a high-torque rotational drive force. The auxiliary handle 20 is detachably attached to the connection part 15 provided on the left side surface of the main body 11, as shown in FIG.

The auxiliary handle 20 may be attached to the right side of the main body 11, or to another location such as the upper or lower part, instead of the left side of the main body 11 as shown in FIG.
As shown in Fig. 1, the auxiliary handle 20 includes a grip portion 21, a connection portion 22, and a cylindrical portion 23. Furthermore, as shown in Fig. 3, the auxiliary handle 20 includes therein a non-contact power receiving portion 24, a pressure sensor 25, a signal transmitting portion (transmitting portion) 26, a grip detection signal processing portion 27, and an acceleration sensor (behavior detecting portion) 28.

As shown in FIG. 1 , the grip portion 21 is a portion of the auxiliary handle 20 that is gripped by the user's left hand, and is disposed so as to extend in a direction substantially perpendicular to the left side surface of the main body portion 11 .
As shown in FIG. 2 , the connecting portion 22 is a portion that is connected to the cylindrical portion 15 a of the connected portion 15 of the main body portion 11 , and has an insertion shaft 22 a that protrudes toward the main body portion 11 .

The insertion shaft 22 a is inserted into an insertion hole 15 c provided at the center of the cylindrical portion 15 a of the main body 11 .
1, the cylindrical portion 23 is inserted into the inner peripheral surface of the cylindrical portion 15a constituting the connected portion 15 of the main body portion 11. As a result, the auxiliary handle 20 is aligned with the left side surface of the main body portion 11. The outer peripheral surface of the cylindrical portion 23 is formed with a first convex portion (alignment portion) 23aa and a second convex portion (alignment portion) 23ab that protrude radially inward.

As shown in FIG. 2, the first convex portion 23aa is formed on the outer peripheral surface of the cylindrical portion 23, and is inserted along the first concave portion 15aa formed on the inner peripheral surface of the cylindrical portion 15a on the main body portion 11 side.
As shown in Figure 2, the second convex portion 23ab is formed on the opposite side of the first convex portion 23aa on the outer peripheral surface of the cylindrical portion 23, and is inserted along the second recess 15ab formed on the inner peripheral surface of the cylindrical portion 15a on the main body portion 11 side.

Here, the first convex portion 23aa is formed so as to have a smaller width (dimension in a direction intersecting the insertion direction) than the second convex portion 23ab.
As a result, the first convex portion 23aa and the second convex portion 23ab on the auxiliary handle 20 side are inserted along the first concave portion 15aa and the second concave portion 15ab on the main body portion 11 side, respectively. As a result, the auxiliary handle 20 can be positioned in the rotational direction around the insertion axis 22a.

Furthermore, since the widths of the first convex portion 23aa and the second convex portion 23ab (the first recess 15aa and the second recess 15ab) are different, the auxiliary handle 20 cannot be attached even if it is rotated 180 degrees.
Therefore, the auxiliary handle 20 can be reliably positioned in the rotational direction around the insertion axis 22a.

As shown in FIG. 3, the non-contact power receiving unit 24 receives power from the non-contact power supply unit 18 of the main body 11 and supplies power to other components (pressure sensor 25, signal transmission unit 26, grip detection signal processing unit 27, acceleration sensor 28). As a result, the auxiliary handle 20 receives power from the main body 11, and can have a simple configuration without an internal power source such as a battery.

As shown in Figure 3, the pressure sensor 25 is provided inside the gripping portion 21 of the auxiliary handle 20 that is gripped by the user, and detects whether or not the user is gripping the gripping portion 21, or the degree of gripping force with which the user is gripping the gripping portion 21, and transmits the result to the grip detection signal processing unit 27.
4(a), the pressure sensor 25 is a pressure sensor 25a disposed so as to extend along the longitudinal direction deep in the grip portion 21 of the auxiliary handle 20. As a result, when the grip portion 21 is gripped by the user, the pressure sensor 25 detects the grip and transmits a signal according to the gripping force to the grip detection signal processing unit.

The pressure sensor 25 may be a pressure sensor 25b disposed at the base of the auxiliary handle 20 as shown in FIG. 4(b).
As shown in Figure 3, the signal transmitting unit (transmitting unit) 26 transmits a grip detection signal detected by the pressure sensor 25 and a behavior detection signal indicating the behavior (amount of shake) of the auxiliary handle 20 detected by the acceleration sensor 28 to the signal receiving unit 19 of the main body 11.

As shown in FIG. 3, the grip detection signal processing unit 27 performs a process of converting the grip detection signal detected by the pressure sensor 25 into different pulse signals depending on the grip force (see FIG. 10(a) to FIG. 10(d)).
The acceleration sensor (behavior detection unit) 28 is provided to detect the behavior of the auxiliary handle 20 (the amount of shaking that occurs during work) and transmits the detected amount of shaking to the signal transmission unit 26, as shown in Fig. 3. The acceleration sensor 28 is also disposed at the end of the auxiliary handle 20, as shown in Fig. 4(a) and Fig. 4(b).
This makes it possible to more effectively detect the behavior (amount of vibration) of the auxiliary handle 20 that occurs during work, compared to a configuration in which the acceleration sensor 28 is disposed near the center of the power tool 10 (near the connection portion).

<Connection structure between main body 11 and auxiliary handle 20>
The connection structure of the auxiliary handle 20 to the main body 11 in the power tool 10 of this embodiment will be described below with reference to Figs. 5(a) and 5(b).

In addition, in the configuration shown in Figures 5 (a) and 5 (b), for the sake of convenience of explanation, only the connected portion 15 is shown as the configuration on the main body portion 11 side, and the configuration other than the connected portion 15 is omitted from the illustration.
That is, in this embodiment, as shown in Figure 5 (a), the auxiliary handle 20 is inserted in a state in which the insertion shaft 22a on the auxiliary handle 20 side is inserted into the insertion hole 15c on the main body portion 11 side, and the outer peripheral surface of the cylindrical portion 23 is inserted into the inner peripheral surface of the cylindrical portion 15a of the connected portion 15 of the main body portion 11.

At this time, due to the alignment effect of the above-mentioned alignment portions (first and second recesses 15aa, 15ab and first and second convex portions 23aa, 23ab), the non-contact power supply portion 18 provided on the main body portion 11 side and the non-contact power receiving portion 24 on the auxiliary handle 20 side are positioned close to each other in opposing positions, as shown in Figure 5 (b).
This makes it possible to improve the efficiency of power supply from the non-contact power supply unit 18 to the non-contact power receiving unit 24 .

In addition, due to the alignment effect of the above-mentioned alignment portions (first and second recesses 15aa, 15ab and first and second convex portions 23aa, 23ab), the signal receiving portion 19 provided on the main body portion 11 side and the signal transmitting portion 26 on the auxiliary handle 20 side are arranged in close proximity to each other in opposing positions, as shown in Figure 5 (b).
This makes it possible to improve the efficiency of signal transmission from the signal transmitting unit 26 to the signal receiving unit 19 .

<Locking mechanism for holding the main body 11 and the auxiliary handle 20>
In the power tool 10 of this embodiment, as shown in Figures 6(a) and 6(b), a locking portion (locking mechanism) 62b is provided at the tip of the insertion shaft 62a on the auxiliary handle 20 side, and a locked portion (locking mechanism) 56c is provided on the main body 11 side.
FIG. 6A shows the power tool 10 in a state immediately before the connecting portion 22 (cylindrical portion 23) on the auxiliary handle 20 side is connected to the connected portion 15 on the main body 11 side.

An unlock button 56, which will be described later, is constantly biased by an elastic member 56b such as a spring toward the outside in the radial direction about the central axis of the cylindrical portion 15a, and is provided on the main body portion 11 in a state in which it can move along the radial direction. An insertion hole 56a into which an insertion shaft 62a is inserted is provided at the bottom of the unlock button 56.
When the connection portion 22 of the auxiliary handle 20 is brought closer to the connected portion 15 of the main body portion 11 from the state shown in Figure 6 (a), the locking portion 62b provided at the tip of the insertion shaft 62a is inserted along the insertion hole 56a of the unlock button 56 provided at the center of the cylindrical portion 15a of the main body portion 11.

At this time, the insertion shaft 62a has a locking portion 62b at its tip that protrudes radially inward. The locking portion 62b has a tapered surface at its tip that is arranged at an angle to the insertion direction. Therefore, the insertion shaft 62a advances inside the insertion hole 56a while pressing the insertion hole 56a (unlock button 56) radially inward (downward in the figure), and is held in the position shown in FIG. 6(b).

In the state shown in Figure 6 (b), the rear end face of the portion of the locking portion 62b that protrudes in a direction intersecting the insertion direction is caught on the edge portion (locked portion 56c) of the insertion hole 56a formed at the bottom of the unlock button 56 provided on the main body portion 11, and is held in place.
This allows the auxiliary handle 20 to be held to the main body 11 and unable to come off, allowing the user to use the power tool 10 with the auxiliary handle 20 in a stable state.

On the other hand, when removing the auxiliary handle 20 attached to the main body portion 11, as shown in Figure 7 (a), the unlock button 56 protruding radially outward from the outer circumferential surface of the cylindrical portion 15a of the main body portion 11 is pushed radially inward.
At this time, the unlock button 56 is pushed radially inward, so that the insertion hole 56a, which is a part of the unlock button 56, also moves radially inward.

As a result, the interlocking portion 56c provided on the edge portion of the insertion hole 56a also moves radially inward, thereby releasing the interlocking relationship between the interlocking portion 56c and the interlocking portion 62b provided at the tip of the insertion shaft 62a on the auxiliary handle 20 side.
As a result, as shown in FIG. 7( b ), the insertion shaft 62 a of the auxiliary handle 20 can be pulled out of the insertion hole 56 a of the main body 11 , and the auxiliary handle 20 can be removed from the main body 11 .

<Operation control of the drive unit 17 in the power tool 10>
The power tool 10 of this embodiment has the above-described configuration, and when performing work with the auxiliary handle 20 attached, controls are performed by detecting whether the auxiliary handle 20 is being gripped. The flow of such operation control processing will be described below with reference to the flowcharts shown in Figures 8 and 9.

That is, in the power tool 10 of this embodiment, as shown in FIG. 8, first, in step S11, the pressure sensor 25 on the auxiliary handle 20 waits until it detects a grip detection signal indicating that the grip portion 21 is being gripped by the user.
Then, when a grip detection signal is detected in step S11, in step S12, the grip detection signal processing unit 27 on the auxiliary handle 20 converts the grip detection signal from a voltage value to a pulse-shaped level signal, and outputs the converted processed signal to the signal transmission unit 26.

Next, in step S13, the signal transmitting unit 26 on the auxiliary handle 20 side transmits a processed signal to the signal receiving unit 19 on the main body 11 side.
Next, in step S<b>14 , the signal receiving section 19 on the main body 11 side receives the processed signal from the signal transmitting section 26 on the auxiliary handle 20 side, and outputs it to the control section 16 .
Next, in step S15, the control unit 16 on the main body 11 side waits until a signal indicating the amount of operation detected when the user operates the operation unit 14 is input.

Then, in step S15, when the input of the amount of operation by which the operation unit 14 is operated is detected, it is found that the user has operated the operation unit 14 while gripping the auxiliary handle 20.
Therefore, upon detecting such a state indicating gripping of the auxiliary handle 20 and operation of the operation unit 14, in step S16, the control unit 16 permits operation of the drive unit 17. This allows the user to perform work using the power tool 10 with the auxiliary handle 20 in a stable state.

The grip detection signal detected in step S11 may be output as a signal of a different level depending on the strength with which the user grips the grip portion 21 of the auxiliary handle 20.
In this case, processing is performed according to the flowchart shown in Fig. 9. The flowchart shown in Fig. 9 differs from that of Fig. 8 only in that step S12 is changed to steps S12a and S12b, and the processing in the other steps S is the same as that of Fig. 8.

That is, when a grip detection signal is detected in step S11, which is detected when the user grips the grip portion 21 of the auxiliary handle 20, the detection level (voltage value) of the grip detection signal is determined in step S12a.
Here, the detection level (voltage value) of the grip detection signal is determined in four stages: strong, medium, weak, and none.

Next, in step S12b, the grip detection signal processing unit 27 converts the grip detection signal into four types of processing signals depending on the detection level of the grip detection signal determined in step S12a.
Specifically, the grip detection signal processing unit 27 converts the grip detection signal detected by the pressure sensor 25 into four types of processing signals shown in FIG. 10( a ) to FIG. 10 ( d ).

When the detection level of the grip detection signal is "strong", as shown in FIG. 10(a), the grip detection signal processing unit 27 converts it into a pulse-shaped processed signal having the largest pulse width.
When the detection level of the grip detection signal is "medium", the grip detection signal processing unit 27 converts it into a pulse-shaped processed signal having a smaller pulse width than that of "strong", as shown in FIG. 10(b).

When the detection level of the grip detection signal is "weak", the grip detection signal processing unit 27 converts it into a pulse-shaped processed signal having a narrower pulse width than that of "medium", as shown in FIG. 10(c).
When the detection level of the grip detection signal is "absent," the grip detection signal processing unit 27 converts it into a pulse-shaped processed signal having the smallest pulse width, as shown in FIG. 10(d).
As a result, the signal transmitting unit 26 on the auxiliary handle 20 side transmits a processed signal that classifies the grip detection signal detected by the pressure sensor 25 into four levels depending on the magnitude of the grip force, thereby allowing the control unit 16 on the main body unit 11 side to recognize how strongly the user is gripping the auxiliary handle 20.

<Operation permission control of the drive unit 17 by the power tool 10>
In the power tool 10 of this embodiment, operation permission control of the drive unit 17 is performed to perform work in a safer state with the auxiliary handle 20 attached. The operation permission control of the drive unit 17 will be described below with reference to the flowcharts shown in Figures 11 and 12.

That is, in the power tool 10 of this embodiment, as shown in FIG. 11, first, in step S21, the control unit 16 on the main body 11 side determines whether the preset mode is the "low speed, high torque mode."
If the "low speed, high torque mode" has been set, the process proceeds to step S22, and if not, the process proceeds to step S26.

The "low speed, high torque mode" determined here is one of the modes set in advance in the control unit 16.
As shown in FIG. 14, the control unit 16 is set to a "high speed, low torque mode" in which the drive unit is controlled to output low torque at a high rotation speed, and a "low speed, high torque mode" in which the drive unit is controlled to output high torque at a lower rotation speed than in the high speed, low torque mode.

14, in the control unit 16, the "high speed, low torque mode" is subdivided into five stages, control numbers H1 to H5, depending on the range of grip values that allow the operation of the drive unit 17. Similarly, the "low speed, high torque mode" is subdivided into three stages, control numbers L1 to L3, depending on the range of grip values that allow the operation of the drive unit 17.
The "low speed, high torque mode" determined in step S21 is a mode in which the rotation speed provided by the drive unit 17 is relatively low but a high torque is provided, and is selected when work requires torque rather than rotation speed. Since the "low speed, high torque mode" outputs a high torque compared to other modes, the user needs to hold the power tool 10 firmly while working. Therefore, in step S21, it is first determined whether the mode is the "low speed, high torque mode."

Next, in step S22, since it is determined in step S21 that the mode is the "low speed, high torque mode", the control unit 16 calls up a pre-registered low speed, high torque control number from a storage unit such as a memory (not shown).
Next, in step S23, it is determined whether or not the auxiliary handle 20 is attached to the main body 11. If the auxiliary handle 20 is attached to the main body 11, the process proceeds to step S24. On the other hand, if the auxiliary handle 20 is not attached, it is determined that the conditions for performing work in the "low speed, high torque mode" are not met, and the process proceeds to step S28, where the operation of the drive unit 17 is prohibited and the process ends.

This allows work in the "low speed, high torque mode" to be performed with the auxiliary handle 20 reliably attached to the main body 11, thereby improving safety.
Here, the presence or absence of the auxiliary handle 20 may be detected by determining whether or not communication is performed between the signal receiving unit 19 on the main body 11 and the signal transmitting unit 26 on the auxiliary handle 20. Alternatively, the presence or absence of the auxiliary handle 20 may be determined using a sensor or the like that detects the attachment of the auxiliary handle 20.

Next, in step S24, it is determined whether the value of the grip detection signal (grip value) detected by the pressure sensor 25 on the auxiliary handle 20 side is within the range of operational permitting grip values corresponding to the control number called in step S22.
Here, if the grip value is within the range of the permissible operation grip value, it is determined that the conditions for performing work in the "low speed, high torque mode" are met, and the process proceeds to step S25, where operation of the drive unit 17 is permitted and the process is terminated.

On the other hand, if the grip value is smaller than the range of permissible grip values, it is determined that the conditions for performing the operation in the "low speed, high torque mode" are not met, and the process proceeds to step S26.
Next, in step S26, since it was determined in step S21 that the mode is not "low speed, high torque mode", or since it was determined in step S24 that the grip value is smaller than the range of permissible grip values, the control number for the "high speed, low torque mode", which has more lenient usage conditions than the "low speed, high torque mode", is called.

Next, in step S27, it is determined whether or not the grip value is within the range of operation allowable grip values corresponding to the control number of the "high speed, low torque mode" called in step S26.
Here, if the grip value is within the range of the permissible operation grip value, it is determined that the conditions for performing work in the "high speed, low torque mode" are met, and the process proceeds to step S25, where operation of the drive unit 17 is permitted and the process is terminated.

On the other hand, if the grip value is smaller than the range of permissible grip values, it is determined that the conditions for performing work in the "high speed, low torque mode" are not met, and the process proceeds to step S28, where operation of the drive unit 17 is prohibited and processing is terminated.
As described above, in the power tool 10 of this embodiment, when working in a "low speed, high torque mode" or the like that requires safe work using the auxiliary handle 20, the grip of the auxiliary handle 20 is detected, and it is determined whether the magnitude of the grip force (grip value) is within the range corresponding to the set mode, and operation of the drive unit 17 is permitted only if it is within the range, thereby enabling safer work to be performed using the power tool 10 with the auxiliary handle 20.

Furthermore, in the power tool 10 of this embodiment, the operation permission control of the drive unit 17 is performed according to the gripping force with which the auxiliary handle 20 described above is gripped, and as shown in Figure 12, the behavior (amount of shaking) of the power tool 10 is detected, and if the amount of shaking exceeds a predetermined range, control is performed to stop the operation of the drive unit 17.
Specifically, as shown in FIG. 12, first, in step S31, the control unit 16 on the main body 11 side acquires, via the signal transmitting unit 26 and the signal receiving unit 19, a behavior detection signal detected by the acceleration sensor 28 provided at the end of the grip portion 21 on the auxiliary handle 20 side.

This enables the control unit 16 to recognize that the power tool 10 is shaking.
Next, in step S32, as shown in FIG. 13(a), it is determined whether the behavior detection signal received from the acceleration sensor 28 exceeds the first behavior detection threshold of two preset thresholds (first and second behavior detection thresholds) within a predetermined time during work (e.g., 60 seconds).

If the behavior detection signal exceeds the first preset behavior detection threshold as shown in Fig. 13(a), the process proceeds to step S33. On the other hand, if the behavior detection signal does not exceed the first preset behavior detection threshold as shown in Fig. 13(b), the process proceeds to step S27.
As shown in Fig. 14, the first behavior detection threshold is set for each control number of a preset mode. For example, in the case of control numbers H1 to H5 of the high-speed, low-torque mode, the first behavior detection threshold is set to 20 m/ ^s2 . In the case of control numbers L1 to L3 of the low-speed, high-torque mode, the first behavior detection threshold is set to 18 m/ ^s2 , which is smaller than the value of the high-speed, low-torque mode.

Next, in step S33, since it is determined in step S32 that the first behavior detection threshold has been exceeded, the control unit 16 determines that the amount of shaking of the power tool 10 is large, and stops the operation of the drive unit 17 to discontinue the work.
Next, in step S34, the control unit 16 acquires from the pressure sensor 25 the magnitude of the gripping force (grip value) of the auxiliary handle 20 when the first behavior detection threshold was exceeded (when the amount of shaking was large).

Next, in step S35, the control unit 16 compares the grip value acquired from the pressure sensor 25 with the range of operational allowable grip values in the control table for each control No. of the set work mode shown in FIG.
FIG. 14 shows a control table including the range of gripping values permitted for operation in the control table for each control number of the set work mode.

For example, for control numbers H1 to H5 in the high-speed, low-torque mode, the permitted grip value ranges are set to 26 kg or more, 21 to 25 kg, 16 to 20 kg, 11 to 15 kg, and 0 to 10 kg. And for control numbers L1 to L3 in the low-speed, high-torque mode, the permitted grip value ranges are set to 26 kg or more, 21 to 25 kg, and 0 to 20 kg.

Next, in step S36, the range of the gripping operation permission value is updated to a larger range in the table based on the result of the comparison in step S35, and the process returns to step S31.
As a result, if, depending on the user's skill, the amount of shaking becomes large even within the range of the permissible grip value corresponding to the control number of each work mode, the user's skill is determined to be low, and the range of grip values for which operation of the drive unit 17 is permitted can be changed to a larger value range, as shown in Figure 13 (c).

Therefore, by optimizing the range of the allowable grip value according to the skill of the user, the safety of the user can be ensured and appropriate control can be performed taking into account the skill differences of users.
Furthermore, in step S37, since it is determined in step S32 that the acquired behavior detection signal does not exceed the first behavior detection threshold, the amount of shaking is considered to be relatively small. Therefore, in step S37, as shown in Fig. 13B, a second behavior detection threshold smaller than the first behavior detection threshold is set within a predetermined time (e.g., 60 seconds), and it is determined whether the acquired behavior detection signal exceeds the second behavior detection threshold.

As shown in Fig. 14, the second behavior detection threshold is set for each control number of a preset mode. For example, in the case of control numbers H1 to H5 of the high-speed, low-torque mode, the second behavior detection threshold is set to 15 m/ ^s2 , which is smaller than the first behavior detection threshold (20 m/ ^s2 ). In the case of control numbers L1 to L3 of the low-speed, high-torque mode, the second behavior detection threshold is set to 12 m/ ^s2 , which is smaller than the value of the high-speed, low-torque mode and smaller than the first behavior detection threshold (18 m/ ^s2 ).

If the behavior detection signal exceeds the second behavior detection threshold, the process proceeds to step S38. On the other hand, if the behavior detection signal does not exceed the second behavior detection threshold, the process determines that the amount of shaking of the power tool 10 is small and that the power tool 10 is in a good working condition, and returns to step S31 without stopping the operation of the drive unit 17.
Next, in step S38, since it is determined in step S37 that the second behavior detection threshold has been exceeded, the control unit 16 sets the processing flag to ON.

Next, in step S39, it is determined whether the number of times that the value of the detected behavior detection signal exceeds the second behavior detection threshold within a predetermined time (for example, 60 seconds) exceeds a predetermined number of times (for example, 5 times).
If the detected value of the behavior detection signal exceeds the second behavior detection threshold a predetermined number of times (e.g., 5 times), the process proceeds to step S40. On the other hand, if the detected value of the behavior detection signal does not exceed the second behavior detection threshold a predetermined number of times (e.g., 5 times), the process proceeds to step S43.

Next, in step S40, since it was determined in step S39 that the value of the detected behavior detection signal exceeded the second behavior detection threshold a predetermined number of times (e.g., five times), the control unit 16 acquires from the pressure sensor 25 the maximum value of the magnitude of the grip force (grip value) of the auxiliary handle 20 during the period in which the second behavior detection threshold was exceeded, taking into consideration that although there was no shaking amount large enough to exceed the first behavior detection threshold, shaking exceeding the second behavior detection threshold occurred many times within the predetermined time.

Next, in step S41, the control unit 16 compares the maximum grip value acquired from the pressure sensor 25 with the range of operational allowable grip values in the control table for each control No. of the set work mode shown in Figure 14.
Next, in step S42, based on the result of the comparison in step S41, the table is updated to include a larger range of the operation permission grip value, as shown in FIG. 13(c), and the process returns to step S31.

As a result, depending on the user's skill, if shaking exceeding the second behavior detection threshold occurs more than a predetermined number of times even within the range of the operation allowable grip value corresponding to the control No. of each work mode, the user's skill is determined to be low, and the range of grip values for which operation of the drive unit 17 is allowed can be changed to a larger value range.
Therefore, by optimizing the range of the allowable grip value according to the skill of the user, the safety of the user can be ensured and appropriate control can be performed taking into account the skill differences of users.

Next, in step S43, since it is determined in step S39 that the value of the detected behavior detection signal has not exceeded a predetermined number of times (e.g., five times) that the second behavior detection threshold has been exceeded, it is determined that the number of vibrations of the power tool 10 is small and the working condition is good, and the process proceeds to step S44 without stopping the operation of the drive unit 17.
Next, in step S44, the processing flag that was set to ON in step S38 is set to OFF, and the process returns to step S31.

As described above, in the power tool 10 of this embodiment, when an amount of shaking that exceeds the first behavior detection threshold occurs during work using the power tool 10 with the auxiliary handle 20, the operation of the drive unit 17 is immediately stopped, and the magnitude of the force for gripping the grip portion 21 of the auxiliary handle 20 (operation permission grip value), which is set to permit operation, is changed to a larger value as shown in FIG. 13(c).

As a result, if an amount of shaking exceeds the first behavior detection threshold, the driving of the drive unit 17 is stopped to ensure safety, and the table can be rewritten so that operation of the drive unit 17 is not permitted unless the object is gripped with a greater force.
Furthermore, if an amount of shaking occurs that does not exceed the first behavior detection threshold but exceeds the second behavior detection threshold, and occurs a predetermined number of times within a predetermined time, the driving of the drive unit 17 is stopped to ensure safety, and the table can be rewritten so that operation of the drive unit 17 is not permitted unless the object is gripped with a greater force.

On the other hand, if the detected behavior detection signal does not exceed the first behavior detection threshold, or if the amount of shaking does not exceed the first behavior detection threshold but exceeds the second behavior detection threshold and the number of shaking occurrences within a specified time does not exceed a specified number, it is determined that the number of shakings of the power tool 10 is small and the working condition is good, and work can be continued without stopping the operation of the drive unit 17.

[Other embodiments]
Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the gist of the invention.
(A)
In the above embodiment, the auxiliary handle 20 is held relative to the main body 11 of the power tool 10 using the locking mechanism (the locked portion 56c and the locking portion 62b) shown in Fig. 6. However, the present invention is not limited to this.

For example, as shown in FIGS. 15 and 16, the power tool 110 may include an auxiliary handle 120 that is detachably attached to a main body 111.
In addition, in the power tool 110 shown in Figures 15 to 18, different symbols are used for components having configurations different from those of the power tool 10 described in the above embodiment, and the same symbols are used for components having the same configurations as the power tool 10, and descriptions of those components are omitted.

That is, as shown in Figures 15 and 16, the power tool 110 employs a locking mechanism (groove portion 115c and engaging portion 123a) at the connection portion between the main body 111 and the auxiliary handle 120 that is different from the locking mechanism shown in Figure 6.
Specifically, as shown in Figure 16, three engagement portions (alignment portions, locking mechanisms) 123a formed to protrude radially outward from the outer peripheral surface of the cylindrical portion 123 on the auxiliary handle 120 side are inserted into three recesses (alignment portions) 115b formed along the circumferential direction of the cylindrical portion 115a of the connected portion 115 on the main body portion 111 side.

Here, it is preferable that the three recesses 115b and the three locking portions 123a have different dimensions in the circumferential direction, so that when the auxiliary handle 120 is attached to the main body 111, it is possible to perform alignment in the rotational direction (the rotational direction around the axis of the cylindrical portion 23).
In addition, in the power tool 110, as shown in FIG. 17(a), the three locking portions 123a on the auxiliary handle 120 side are inserted into the three recesses 115b on the main body 111 side, and then the auxiliary handle 120 is rotated clockwise so that the three locking portions 123a engage with the groove portions (locking portions) 115c communicating with the three recesses 115b.

As a result, the three locking portions 123a are fitted into the grooves 115c. Furthermore, as shown in FIG. 17(b), a spring (unlocking mechanism) 132 arranged to be wound around the outer periphery of the cylindrical portion 115d provided near the central axis of the cylindrical portion 115a on the main body portion 111 side applies a biasing force to the auxiliary handle 120 in the removal direction, thereby holding the auxiliary handle 120 on the main body portion 111 side.

On the other hand, when removing the auxiliary handle 120 from the main body 111, as shown in Figure 18 (a), the unlocking portion 131, which is arranged so that a portion of it protrudes from the outer circumferential surface of the cylindrical portion 115a, is operated to move toward the main body 11, causing the spring 132, which is arranged so that it is sandwiched between the wall surface of the main body 111, to move in the direction of contraction.
In this state, by rotating the auxiliary handle 120 counterclockwise, the three locking portions 123a can be removed from the three recesses 115b.
This allows the auxiliary handle 120 to be detached from the main body portion 111 side.

(B)
In the above embodiment, an example has been described in which the operation permission threshold value and the operation permission grip value range are set for each control number of each work mode (high speed low torque, low speed high torque) as shown in Fig. 14. However, the present invention is not limited to this.

For example, the operation permission threshold value and the range of operation permission grip value set for each control number of each work mode (high speed, low torque, low speed, high torque) are not limited to the values shown in Figure 14, and may be appropriately set to larger or smaller values depending on the type of work tool, work content, etc.
Similarly, the first and second behavior detection thresholds set for each control number of each work mode (high speed, low torque, low speed, high torque) are not limited to the values shown in FIG. 14 but may be appropriately set to larger or smaller values depending on the type of work tool, work content, etc.

(C)
In the above embodiment, an example has been described in which the acceleration sensor 28 for detecting the behavior of the power tool 10 during operation is provided on the auxiliary handle 20. However, the present invention is not limited to this.
For example, a behavior detection unit such as an acceleration sensor may be provided on the main body side.

Even in this case, the behavior detection unit provided on the main body side detects the behavior (amount of shaking) of the power tool (work tool) during work, thereby achieving the same effect as above.
Furthermore, the behavior detection unit such as an acceleration sensor may be provided on both the main body side and the auxiliary handle side.
In addition, even if the behavior detection unit such as an acceleration sensor is provided on the main body side, it is preferable to place it as close to the end as possible, which makes it easier to detect the amount of shaking that occurs in the main body, compared to a configuration in which the behavior detection unit is provided near the center of the main body.

(D)
In the above embodiment, an example has been described in which signals are transmitted and received by non-contact communication between the main body 11 and the auxiliary handle 20. However, the present invention is not limited to this.
For example, the communication between the main body and the auxiliary handle may be in a contact state in which signals are transmitted and received.

(E)
In the above embodiment, an example has been described in which the acceleration sensor 28 is used as the behavior detection unit that detects the behavior of the power tool 10 during operation. However, the present invention is not limited to this.
For example, instead of the acceleration sensor, another sensor such as a gyro sensor may be used.

(F)
In the above embodiment, the power tool 10 in which the drive unit 17 is driven by power supplied from a replaceable battery (not shown) has been described as an example. However, the present invention is not limited to this.
For example, the power tool may be an electric tool in which power is supplied to a drive unit via a power cable to drive the drive unit.

(G)
In the above embodiment, the power tool 10 is described as an example in which the user holds the main handle 13 with his/her right hand and the auxiliary handle 20 with his/her left hand. However, the present invention is not limited to this.
For example, the power tool may be equipped with an auxiliary handle so that the main handle is held in the user's left hand and the auxiliary handle is held in the user's right hand.

(H)
In the above embodiment, an example has been described in which a trigger switch that adjusts the output torque of the drive unit (motor) 17 in accordance with the pulling amount (operation amount) is used as the operation unit for driving the drive unit (motor) 17 of the power tool 10. However, the present invention is not limited to this.
For example, instead of the trigger switch, another switch such as an ON/OFF switch may be used.

(I)
In the above embodiment, the power tool 10 equipped with a motor driven by electricity has been described as an example, but the present invention is not limited to this.
For example, the present invention may be applied to a power tool in which a drive unit is operated by air instead of electricity.

(J)
In the above embodiment, the present invention has been described as being applied to the power tool 10 such as an electric screwdriver as an example of the power tool according to the present invention. However, the present invention is not limited to this.
For example, the present invention may be applied to power tools for performing various tasks, such as grinders, jigsaws, chainsaws, etc., other than electric screwdrivers.

(K)
In the above embodiment, an example has been described in which the present invention is applied to the power tool 10 including the auxiliary handle 20 that is detachably attached to the main body 11. However, the present invention is not limited to this.
For example, the present invention may be applied to an electric power tool (power tool) that includes an auxiliary handle that is undetachably fixed to a main body.

The power tool of the present invention, when equipped with an auxiliary handle, has the advantage that it can be used without being restricted by the usage environment, and is therefore widely applicable to various types of power tools.

10 Power tools (work tools)
11: Main body portion 12: Rotating portion 13: Main handle 14: Operation portion 15: Connected portion 15a: Cylindrical portion 15aa: First recess (alignment portion)
15ab Second recess (alignment portion)
15b Attachment/detachment button 15c Insertion hole 16 Control unit 17 Driving unit 18 Non-contact power supply unit 19 Signal receiving unit (receiving unit)
20 Auxiliary handle 21 Grip portion 22 Connection portion 22a Insertion shaft 23 Cylindrical portion 23aa First protrusion (alignment portion)
23ab second protrusion (alignment portion)
24 Non-contact power receiving unit 25 Pressure sensor (grip detection unit)
25a, 25b Pressure sensor (grip detection unit)
26 Signal transmission unit (transmission unit)
27 Grasping detection signal processing unit 28 Acceleration sensor (behavior detection unit)
30 Tip tool 56 Unlock button (unlock mechanism)
56a Insertion hole 56b Elastic member 56c Locked part (lock mechanism)
62a: Insertion shaft 62b: Locking portion (locking mechanism)
110 Power tools (work tools)
111: Main body portion 115: Connected portion 115a: Cylindrical portion 115b: Recessed portion (alignment portion)
115c Groove (locking mechanism)
115d Cylindrical portion 120 Auxiliary handle 123 Cylindrical portion 123a Locking portion (alignment portion, locking mechanism)
131 Unlocking part 132 Spring (unlocking mechanism)

Claims (11)

A power tool that drives an attached tool tip to perform a predetermined task,
An auxiliary handle that is held by a user during work, the auxiliary handle having a detection unit that detects a gripping force with which the user holds the auxiliary handle, and a transmission unit that transmits a detection result from the detection unit;
A main body having a drive unit that drives the tool bit, a receiving unit that receives the detection result from the transmitting unit, and a control unit that controls the operation of the drive unit;
A behavior detection unit that detects a behavior of the auxiliary handle or the main body;
Equipped with
The control unit determines to permit operation of the drive unit when the detected grip force of the auxiliary handle and a vibration of the work tool caused when working while gripping the auxiliary handle with that grip force are within an allowable range based on the detection result of the grip force by the detection unit and the detection result of the behavior by the behavior detection unit, and adjusts to a larger grip force grip threshold value set for determining whether or not to permit operation of the drive unit when the detection result by the behavior detection unit indicates that the operation of the drive unit cannot be permitted.
Work tools. A power tool that drives an attached tool tip to perform a predetermined task,
An auxiliary handle that is held by a user during work, the auxiliary handle having a detection unit that detects a gripping force with which the user holds the auxiliary handle, and a transmission unit that transmits a detection result from the detection unit;
A main body having a drive unit that drives the tool bit, a receiving unit that receives the detection result from the transmitting unit, and a control unit that controls the operation of the drive unit;
A behavior detection unit that detects a behavior of the auxiliary handle or the main body;
Equipped with
The control unit determines to permit operation of the drive unit when the detected grip force of the auxiliary handle and a vibration of the work tool caused when working while gripping the auxiliary handle with that grip force are within an allowable range based on the detection result of the grip force by the detection unit and the detection result of the behavior by the behavior detection unit, and has a first threshold value for stopping operation of the drive unit if the detection result by the behavior detection unit is exceeded even once, and a second threshold value for stopping operation of the drive unit if the detection result is smaller than the first threshold value and exceeds a predetermined number of times or more within a predetermined time.
Work tools. The control unit has a high-speed, low-torque mode in which the drive unit is controlled to output a low torque at a high rotation speed, and a low-speed, high-torque mode in which the drive unit is controlled to output a high torque at a lower rotation speed than in the high-speed, low-torque mode.
The power tool according to claim 1 or 2. The control unit, in the low-speed, high-torque mode, sets a threshold value for the detection result detected by the behavior detection unit that is smaller than a threshold value that is set in the high-speed, low-torque mode and that stops the operation of the drive unit.
The power tool according to claim 3. In at least one of the high-speed low-torque mode and the low-speed high-torque mode, the gripping force threshold value set for the detection result in the detection unit is set in a plurality of stages.
The power tool according to claim 3 or 4. The behavior detection unit is provided on the auxiliary handle.
The power tool according to any one of claims 1 to 5. The behavior detection unit is provided near an end of the auxiliary handle on an opposite side to a connection portion with the main body.
The power tool according to claim 6. The behavior detection unit is an acceleration sensor.
The power tool according to any one of claims 1 to 7. The main body portion has a non-contact power supply portion that supplies power to the auxiliary handle,
The auxiliary handle has a non-contact power receiving unit to which power is supplied from the non-contact power supply unit of the main body.
The power tool according to any one of claims 1 to 8. The detection unit is a pressure sensor.
The power tool according to any one of claims 1 to 9. The drive unit is a motor that rotates the tool tip.
The power tool according to any one of claims 1 to 10.

Images