JP7505212B2 - Work tools - Google Patents

Description

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

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 have the following problems.
That is, the power tool disclosed in the above publication does not take into consideration the individual skill level of the user (someone who is good at operating the power tool and some who is not.) Therefore, when users have different gripping strengths on the auxiliary handle, there is a risk that the output torque will be contrary to the operator's intention depending on the individual skill level.

The objective of the present invention is to provide a power tool that can provide safe and appropriate control according to the user's skill level.

The power tool according to the first invention is a power tool that drives an attached tool tip to perform a specified task, and includes a main body, a power supply, a motor, a motor information detection unit, and a control unit. The power supply is provided in the main body and supplies power. The motor is provided in the main body and receives power from the power supply to drive the tool tip. The motor information detection unit is provided in the main body and detects information about the motor during work. The control unit is provided in the main body and controls the operation of the motor according to the skill level of the user estimated based on the motor information detected by the motor information detection unit.

Here, the skill level of the user is estimated based on information about the motor during operation (power consumption, etc.) detected by the motor information detection unit, and the operation of the motor is controlled according to the estimation result.
Here, the information about the motor during operation detected by the motor information detection unit includes, for example, the power consumption of the motor, the voltage of the motor, and the like.

In addition, the estimation of the user's skill level based on the detected motor information is based on the empirical rule that, for example, when a user with a high skill level works, stable use of the power tool is expected, so power consumption is likely to be low, and when a user with a low skill level works, power consumption is likely to be high, so power consumption is likely to be high, because use of the power tool is unstable.
This allows the operation of the motor to be controlled according to the skill level estimated based on the results of detecting information about the motor during operation, so that, for example, the threshold value set for stopping the motor operation can be increased for users with a high skill level, and the threshold value set for stopping the motor operation can be lowered for users with a low skill level, with safety in mind.
As a result, appropriate control with a high degree of safety can be performed according to the skill level of each user.

The power tool according to the second invention is the power tool according to the first invention, wherein the control unit selects a threshold value set for stopping the operation of the motor in accordance with a skill level of a user estimated based on information about the motor.
Here, a threshold value set for stopping the operation of the motor is selected according to the skill level of the user estimated based on the information about the motor.

This allows for control such as increasing the threshold value set to stop the motor from operating for users with a high level of skill, and decreasing the threshold value set to stop the motor from operating for users with a low level of skill, taking safety into consideration.

The power tool according to the third invention is the power tool according to the second invention, wherein the control unit has a plurality of work modes including a threshold value set for stopping operation of the motor, and determines whether or not to change from the currently set first work mode to the second work mode depending on the skill level of the user estimated based on information about the motor.
Here, depending on the skill level of the user estimated based on the motor information, it is determined whether or not to change the current work mode (first work mode), which includes a threshold value set to stop the operation of the motor, to another work mode (second work mode) in which a different threshold value is set.
This makes it possible to select a work mode in which a high threshold is set for stopping motor operation when the estimated skill level is high, and to select a work mode in which a low threshold is set for stopping motor operation when the estimated skill level is low, taking safety into consideration.

A power tool according to a fourth invention is a power tool according to any one of the first to third inventions, wherein the control unit changes the work mode in accordance with an estimated skill level of the user when motor information exceeds a predetermined threshold by a first time threshold.
Here, for example, if motor information such as power consumption exceeds a predetermined threshold by the first time threshold, it is determined that the power consumption is higher than necessary and the estimated skill level is low, and an operation mode corresponding to the low skill level is selected.
This allows the work mode to be changed in accordance with the estimated skill level of the user, thereby ensuring safety during work for users with low skill levels.

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 the control unit maintains the work mode if the motor information exceeds the predetermined threshold by a second time threshold that is longer than the first time threshold.

Here, for example, if motor information such as power consumption does not exceed a predetermined threshold by the first time threshold, but exceeds the predetermined threshold by a second time threshold that is longer than the first time threshold, the skill level is determined to be normal and the current work mode is maintained.
This allows the work mode to be maintained in accordance with the estimated skill level of the user, thereby allowing a user with a normal skill level to carry out work in a work mode suitable for the user.

The power tool according to a sixth aspect of the present invention is the power tool according to the fourth aspect of the present invention, wherein the control unit changes the work mode in accordance with an estimated skill level of the user if the motor information does not exceed a predetermined threshold by the second time threshold within a predetermined time longer than the first time threshold.
Here, for example, if motor information such as power consumption does not exceed a predetermined threshold by a second time threshold that is longer than the first time threshold, the skill level is determined to be high, and a work mode corresponding to a higher skill level is selected from the current work mode.
This allows the work mode to be changed in accordance with the estimated skill level of the user, thereby providing users with a high skill level with comfort during work.

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 motor information includes power consumption or voltage of the motor during work.
Here, the information about the motor detected by the motor information detection unit includes the power consumption or voltage of the motor during operation.
This makes it possible to easily estimate the skill level of a user by detecting the power consumption or voltage of the motor during work.

The power tool according to the eighth invention is the power tool according to any one of the first to seventh inventions, further comprising an auxiliary handle that is attached to the main body and is held by the user during work, the auxiliary handle having a grip detection unit that detects the gripping force with which the user grips the auxiliary handle, and a transmission unit that transmits the detection result of the grip detection unit to the main body.

Here, in a work tool that includes an auxiliary handle that is attached to the main body so that the work tool can be held with both hands in a stable position to perform various tasks, the gripping force that holds the auxiliary handle is detected and transmitted to the main body.
Here, the auxiliary handle attached to the main body may be configured to be integrated with the main body, or may be configured to be detachable from the main body.
This makes it possible to implement control such as determining whether or not to stop the operation of the motor depending on the magnitude of the force with which the grip portion is gripped.

The power tool according to the ninth aspect of the present invention is the power tool according to the eighth aspect of the present invention, further comprising a receiver provided in the main body for receiving the detection result of the grip detection unit transmitted from the transmitter. The control unit determines whether or not to stop the operation of the motor according to the detection result of the grip detection unit.

Here, in a power tool equipped with an auxiliary handle, whether or not to stop the operation of the motor is determined according to the strength of the force with which the user grips the grip portion.
This makes it possible, for example, to permit operation of the motor only when the detected gripping force of the holding handle is within an acceptable range.
Therefore, when the gripping force is smaller than a predetermined value, the operation of the motor 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 according to the tenth invention is the power tool according to the eighth or ninth invention, and further includes a non-contact power supply unit that is provided on the main body and supplies power to the auxiliary handle in a non-contact state. The auxiliary handle has a non-contact power receiving unit that receives power supplied from the non-contact power supply unit.

Here, the auxiliary handle attached to the main body receives power from the main body side using a non-contact power supply system.
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, further comprising a behavior detection unit that detects the behavior of the main body portion.
Here, a behavior detection unit such as an acceleration sensor, a gyro sensor, or the like is provided to detect the behavior (vibration) of the power tool that occurs during work.
This makes it possible to implement control such as stopping the operation of the motor based on the detection results of the behavior (vibration) of the power tool that occurs during work.

The power tool according to the twelfth aspect of the present invention is the power tool according to the eleventh aspect of the present invention, in which the control unit determines whether or not to permit the motor to operate based on the behavior detection result in the behavior detection unit.

Here, the behavior (vibration) of the power tool that occurs during work is detected, and based on the detection result, it is determined whether or not to permit operation of the motor.
This makes it possible to permit operation of the motor only when the behavior (vibration) of the power tool occurring during work is within an acceptable range.
Therefore, when the vibration of the power tool during work is equal to or greater than a predetermined amount, the operation of the motor is prohibited, thereby improving the safety of the user.

The power tool of the thirteenth invention is the power tool of the eleventh or twelfth invention, wherein the control unit has a first threshold value that stops operation of the motor 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 motor if the detection result in the behavior detection unit is exceeded a predetermined number of times or more within a predetermined time.
Here, in the control that stops the motor operation depending on the detection result in the behavior detection unit, two thresholds are set: a first threshold that stops the motor operation if it is detected once, and a second threshold that stops the motor 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 motor for the detection result (amount of shaking of the work tool) detected in the behavior detection unit and a second threshold value that stops the operation of the motor when it is detected a predetermined number of times or more, the motor operation 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 it 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 14th invention is a power tool according to any one of the 11th to 13th inventions, and the control unit has a high-speed, low-torque mode in which the motor is controlled to output low torque at a high rotation speed, and a low-speed, high-torque mode in which the motor is controlled to output high torque at a lower rotation speed than in the high-speed, low-torque mode.

Here, the control unit controls the motor 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 fifteenth aspect of the present invention is the power tool according to the fourteenth 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 and that stops the operation of the motor.

Here, the threshold value for stopping the operation of the motor 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 motor operation early if shaking occurs.

The power tool of the 16th invention is the power tool of the 14th or 15th invention, wherein in at least one of the high-speed, low-torque mode and the low-speed, high-torque mode, the grip force threshold value set for the detection result in the grip 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 seventeenth aspect of the present invention is the power tool according to any one of the eleventh to sixteenth 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, and indirectly detects behavior (shake) that occurs in the main body during work.

This allows the behavior (shake) of the main body to be indirectly detected by detecting the behavior (shake) of the auxiliary handle, and a decision can be made as to whether or not to stop the motor operation depending on the amount of shake.

The power tool according to an eighteenth aspect of the present invention is the power tool according to the seventeenth aspect of the present invention, wherein the behavior detection unit is provided near the end of the auxiliary handle opposite 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 nineteenth aspect of the present invention is the power tool according to any one of the eleventh to eighteenth 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 present invention allows for safe and appropriate control according to 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 of operation permission control based on a grip value when an auxiliary handle is gripped in the power tool of FIG. 1 . 5 is a flowchart showing a process flow of control for setting an operation mode according to the amount of power consumption of a motor during operation in the power tool of FIG. 1 . 10 is a graph showing the relationship between the amount of power consumption and the passage of time described in the process of the work mode setting control in FIG. 9 . 2 is a diagram showing work modes set in the power tool of FIG. 1 , corresponding operation permission thresholds, operation permission grip value ranges, a first behavior detection threshold, and a second behavior detection threshold; 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 .

A power tool (power tool) 10 according to one embodiment of the present invention will be described below with reference to Figs. 1 to 13(c).
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 a tip tool 30, such as a screwdriver or drill, attached to the tip of the power tool 10 using a brushless motor (motor 17) powered by 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 motor 17 that is driven by power supplied from 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 motor 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 motor 17 (see Fig. 3) depending on the amount of operation, and a connected section 15 to which an auxiliary handle 20 is attached. As shown in Fig. 3, the main body 11 also includes a control section 16, a motor 17, a non-contact power supply section 18a, a power supply section 18b, 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 motor 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 operation 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 operation unit 14 then transmits an operation signal according to the amount of operation to the control unit 16 as shown in FIG. 3. In response, the control unit 16 drives the motor 17 to rotate at a speed according to the amount of operation of the operation 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.
As shown in Fig. 3, the control unit 16 is connected to the operation unit 14, the power supply unit 18b, and the signal receiving unit 19. The control unit 16 controls the number of rotations of the motor 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 motor 17 based on the detection result (shake amount) 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. Furthermore, as shown in Fig. 3, the control unit 16 has a voltage detection unit (motor information detection unit) 16a, a current detection unit (motor information detection unit) 16b, and a calculation unit 16c.

The voltage detection unit 16 a is connected to the motor 17 , and detects the voltage of the motor 17 as information about the motor 17 .
The current detection unit 16 b is connected to the motor 17 , and detects the current flowing through the motor 17 as information about the motor 17 .
The calculation unit 16c calculates the power consumption of the motor 17 using the voltage of the motor 17 detected by the voltage detection unit 16a and the current value of the motor 17 detected by the current detection unit 16b.

The control unit 16 uses the power consumption of the motor 17 during work calculated by the calculation unit 16c to control the drive of the motor 17 in accordance with an estimate of the skill level of the user, which will be described later.
As shown in FIG. 3, the motor 17 is driven by electricity and applies a rotational driving force to the tool tip 30 (the rotating portion 12).
The non-contact power supply unit 18a is supplied with power from the power supply unit 18b, and supplies power in a non-contact state from the main body 11 to the non-contact power receiving unit 24 of the auxiliary handle 20 without passing through electrical wiring, as shown in Fig. 3. Although the non-contact power supply unit 18a and the power supply unit 18b are omitted in Fig. 3, they are actually electrically connected.

As shown in FIG. 3, the signal receiving unit (receiving unit) 19 receives the detection results of the pressure sensor 25 and acceleration sensor 28 provided on the auxiliary handle 20 side via the signal transmitting unit 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 work in which the motor 17 outputs a high-torque rotational driving 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. This allows the auxiliary handle 20 to be 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 18a of the main body 11 and supplies power to other components (pressure sensor 25, signal transmitting 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 processing to convert the grip detection signal detected by the pressure sensor 25 into a pulse signal.
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 shaking) of the auxiliary handle 20 that occurs during work, compared to a configuration in which the acceleration sensor 28 is positioned near the center of the power tool 10 (near the connection part).

<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 18a 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 non-contact power supply unit 18a to 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 permission control of motor 17 according to gripping force of auxiliary handle 20>
In the power tool 10 of this embodiment, operation permission control of the motor 17 is performed to enable work to be performed in a safer state with the auxiliary handle 20 attached. The operation permission control of the motor 17 will be described below with reference to the flowchart shown in FIG.

That is, in the power tool 10 of this embodiment, as shown in FIG. 8, first, in step S11, 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 S12, and if not, the process proceeds to step S16.

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. 11, the control unit 16 is set to a "high speed, low torque mode" in which the motor is controlled to output low torque at a high rotational speed, and a "low speed, high torque mode" in which the motor is controlled to output high torque at a rotational speed lower than that in the high speed, low torque mode.

11, 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 the grip value that allows the operation of the motor 17. Similarly, the "low speed, high torque mode" is subdivided into three stages, control numbers L1 to L3, depending on the range of the grip value that allows the operation of the motor 17.
The "low speed, high torque mode" determined in step S11 is a mode in which the rotation speed provided by the motor 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 S11, it is first determined whether the mode is the "low speed, high torque mode."

Next, in step S12, since it is determined in step S11 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 S13, 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 S14. 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 S18, where the operation of the motor 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 S14, 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 grip values corresponding to the control number called in step S12.
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 S15, where operation of the motor 17 is permitted and the process ends.

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 S16.
Next, in step S16, because it was determined in step S11 that the mode is not "low speed, high torque mode," or because it was determined in step S14 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 S17, 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 S16.
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 S15, where operation of the motor 17 is permitted and the process ends.

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 S18, where operation of the motor 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 motor 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.

<Setting and Control of Operation Permission Threshold According to Activity Level Estimated According to Power Consumption>
In the power tool 10 of this embodiment, following the process shown in Fig. 8, the power consumption of the motor 17 during operation is calculated, and an operation permission threshold is set according to the calculated power consumption. The operation permission control of the motor 17 will be described below with reference to the flowchart shown in Fig. 9.

That is, in step S21, the voltage detection section 16a and the current detection section 16b of the control section 16 on the main body section 11 side detect the voltage value V and the current value I of the motor 17 during work.
Next, in step S22, the power consumption W (=V×I) is calculated using the voltage value V and current value I of the motor 17 detected in step S21.
Next, in step S23, the control unit 16 acquires the currently set work mode (control No. H3).

As described above, the control unit 16 has two operation modes, namely, a high-speed, low-torque mode and a low-speed, high-torque mode, as shown in FIG. 11, and an appropriate operation mode is set by the user or automatically in accordance with the power consumption during operation, etc.
11, the "high speed, low torque mode" is divided into five stages, control numbers H1 to H5, depending on the range of grip values that allow the operation of the motor 17. Similarly, the "low speed, high torque mode" is divided into three stages, control numbers L1 to L3, depending on the range of grip values that allow the operation of the motor 17.

The acquisition of the current control number in step S23 may be performed prior to steps S21 and S22.
Next, in step S24, it is determined whether or not the power consumption of the motor 17 calculated in step S22 exceeds a preset power consumption threshold within a predetermined time (for example, 5 minutes).

If the power consumption of the motor 17 exceeds the power consumption threshold within five minutes, the process proceeds to step S25, and if the power consumption does not exceed the power consumption threshold, the process proceeds to step S26.
Next, in step S25, since it is determined in step S24 that the power consumption of motor 17 calculated in step S22 exceeded the power consumption threshold within 5 minutes (see the solid line in FIG. 10), control unit 16 estimates that the skill level of the user is low based on the comparison result between the power consumption of motor 17 and the power consumption threshold , and changes and sets task No. H2 corresponding to a user with a low skill level.

In the work No. H2 set here, the grip value allowable operation range (21 to 25 kg) is set to a larger range of values as shown in FIG. 11, compared to the grip value allowable operation range (16 to 20 kg) of the work No. H3 before the change.
As a result, in step S25, the mode is changed to one intended for users with a low skill level who are not allowed to operate unless they grip the auxiliary handle 20 more firmly, so that the work can be performed in an appropriate work mode according to the user's skill level.

On the other hand, in step S26, since it was determined in step S24 that the power consumption of motor 17 calculated in step S22 did not exceed the power consumption threshold within 5 minutes, it is determined whether the power consumption threshold was exceeded between 5 and 10 minutes.
If the power consumption of the motor 17 exceeds the power consumption threshold value between 5 and 10 minutes, the process proceeds to step S27, and if the power consumption threshold value is not exceeded, the process proceeds to step S28.

In step S27, since it is determined in step S26 that the power consumption of motor 17 calculated in step S22 exceeded the power consumption threshold value between 5 and 10 minutes (see the dashed line in FIG. 10), control unit 16 estimates that the skill level of the user is normal, and maintains task No. H3, which corresponds to a user with a normal skill level, without any change.
As a result, in step S27, it is determined that the skill level of the user estimated from the power consumption matches the currently set work mode (control No.), and the work mode is maintained without being changed, so that the user can carry out work in an appropriate work mode according to his or her skill level.

In step S28, since it is determined in step S26 that the power consumption of motor 17 calculated in step S22 does not exceed the power consumption threshold value between 5 and 10 minutes (see the dashed line in FIG. 10), control unit 16 estimates that the skill level of the user is higher than normal based on the comparison result between the power consumption of motor 17 and the power consumption threshold value , and changes task No. H4, which corresponds to a user with a high skill level, and maintains it.

In the work No. H4 set here, the grip value allowable operation range (111 to 15 kg) is set to a smaller range of values as shown in FIG. 11, compared to the grip value allowable operation range (16 to 20 kg) of the work No. H3 before the change.
As a result, in step S75, the mode is changed to one suitable for users with a high skill level who can grip the auxiliary handle 20 with a weaker gripping force without any problems, so that the work can be carried out in an appropriate work mode according to the user's skill level.

<Operation permission control of the motor 17 according to the shaking amount of the power tool 10>
In the power tool 10 of this embodiment, the operation permission control of the motor 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 motor 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. 11, 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 ).

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 motor 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. 11 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 motor 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. 13(b), 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. 11, 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 the power tool 10 is in a good working condition, and returns to step S31 without stopping the operation of the motor 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 amount of shaking that exceeds the first behavior detection threshold has not occurred, but taking into consideration that shaking that exceeds the second behavior detection threshold has occurred many times within a predetermined time, the control unit 16 obtains 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.

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 FIG.
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 permitting 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 motor 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 motor 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 motor 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 motor 17 is stopped to ensure safety, and the table can be rewritten so that operation of the motor 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 drive of motor 17 is stopped to ensure safety, and the table can be rewritten so that operation of motor 17 is not permitted unless the object is gripped with 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 motor 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, an example has been described in which the present invention is applied to the power tool 10 in which the auxiliary handle 20 is 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 has only a main body without an auxiliary handle.

(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. 11. 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 11, 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. 11 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 between the main body 11 and the auxiliary handle 20 by non-contact communication. However, the present invention is not limited to this.
For example, the communication between the main body and the auxiliary handle may be a system in which signals are transmitted and received while in contact with each other.

(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 motor 17 is driven by the power supplied from the power supply unit 18b provided in the main body 11 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 motor via a power cable to drive the motor.

(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 motor 17 in accordance with the pulling amount (operation amount) is used as the operation unit for driving the 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 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.

(J)
In the above embodiment, an example has been described in which the power consumption calculated by the voltage detection unit 16a, which detects the voltage value of the motor 17, and the current detection unit 16b, which detects the current value of the motor 17, respectively, is used as the information of the motor 17. However, the present invention is not limited to this.
For example, other information effective for estimating the skill level of the user (for example, only the voltage value of the motor 17) may be detected as motor information, and the motor may be controlled.

(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 a power tool (power tool) that includes an auxiliary handle that is fixed in an undetachable manner to the main body.

The power tool of the present invention has the advantage of being able to provide safe and appropriate control according to the skill level of the user, and is therefore widely applicable to various power tools driven by a motor.

10. Power tools (power tools)
11: Main body 12: Rotating section 13: Main handle 14: Operation section 15: Connected section 15a: Cylindrical section 15aa: First recess 15ab: Second recess 15b: Attachment/detachment button 15c: Insertion hole 16: Control section 16a: Voltage detection section (motor information detection section)
16b Current detection unit (motor information detection unit)
16c Calculation unit 17 Motor 18a Non-contact power supply unit 18b Power supply unit 19 Signal receiving unit 20 Auxiliary handle 21 Grip unit 22 Connection unit 22a Insertion shaft 23 Cylindrical portion 23aa First convex portion 23ab Second convex portion 24 Non-contact power receiving unit 25 Pressure sensor (Grip detection unit)
25a, 25b Pressure sensor (grip detection unit)
26 Signal 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: Locking portion (locking mechanism)
62a: Insertion shaft 62b: Locking portion (locking mechanism)

Claims (18)

A power tool that drives an attached tool tip to perform a predetermined task,
A main body portion,
A power supply unit provided in the main body unit and supplying power;
a motor provided in the main body and receiving power from the power supply unit to drive the tool bit;
a motor information detection unit provided in the main body unit and detecting a power consumption or a voltage of the motor during operation;
a control unit provided in the main body unit, which estimates a skill level of a user based on the power consumption or voltage of the motor detected by the motor information detection unit , and controls an operation of the motor in accordance with the estimated skill level ;
A work tool equipped with: The control unit selects a threshold value set to stop the operation of the motor according to a skill level of the user.
The power tool according to claim 1. the control unit has a plurality of work modes including the threshold value set for stopping the operation of the motor, and determines whether or not to change from a currently set first work mode to a second work mode according to a skill level of the user .
The power tool according to claim 2. The control unit changes the work mode according to the skill level when the power consumption or voltage of the motor exceeds a predetermined threshold by a first time threshold.
The power tool according to claim 3. The control unit maintains the working mode when the power consumption or voltage of the motor exceeds a predetermined threshold by a second time threshold that is longer than the first time threshold.
The power tool according to claim 4. The control unit changes the work mode according to the skill level when the power consumption or voltage of the motor does not exceed a predetermined threshold by a second time threshold within a predetermined time longer than the first time threshold.
The power tool according to claim 4. The device further includes an auxiliary handle that is attached to the main body and is held by the user during work, the auxiliary handle having a grip detection unit that detects the gripping force of the user holding the auxiliary handle, and a transmission unit that transmits the detection result of the grip detection unit to the main body.
The power tool according to any one of claims 1 to 6 . A receiving unit is provided in the main body and receives the detection result of the grip detection unit transmitted from the transmitting unit,
The control unit determines whether or not to stop the operation of the motor depending on a detection result of the grip detection unit.
The power tool according to claim 7 . The device further includes a non-contact power supply unit provided in the main body and configured to supply power to the auxiliary handle in a non-contact state,
The auxiliary handle has a non-contact power receiving unit that receives power supplied from the non-contact power supply unit.
The power tool according to claim 7 or 8 . The device further includes a behavior detection unit that detects the behavior of the main body unit.
The power tool according to any one of claims 1 to 9 . The control unit determines whether or not to permit operation of the motor based on a result of the detection of the behavior by the behavior detection unit.
The power tool according to claim 10 . The control unit has a first threshold value that stops the operation of the motor when 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 the operation of the motor when the detection result in the behavior detection unit is exceeded a predetermined number of times or more within a predetermined time.
The power tool according to claim 10 or 11 . The control unit has a high-speed, low-torque mode in which the motor is controlled to output a low torque at a high rotation speed, and a low-speed, high-torque mode in which the motor 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 any one of claims 10 to 12 . 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 motor.
The power tool according to claim 13 . The handle further includes an auxiliary handle having a gripping detection unit that detects a gripping force applied by the user,
In at least one of the high-speed low-torque mode and the low-speed high-torque mode, the grip force threshold value set for the detection result in the grip detection unit is set in a plurality of stages.
The power tool according to claim 13 or 14 . The behavior detection unit is provided on the auxiliary handle.
The power tool according to claim 15 . The behavior detection unit is provided near an end of the auxiliary handle on an opposite side to a connection portion between the auxiliary handle and the main body.
The power tool according to claim 16 . The behavior detection unit is an acceleration sensor.
A power tool according to any one of claims 10 to 17 .

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