JP2010194663A - Power tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power tool with improved calculation accuracy of a vibration value applied to a user. <P>SOLUTION: This power tool 1 includes: an output part 11 for outputting rotational drive from a motor 2 to the outside while generating impact vibration; a gripping part 12 which the user grips; a power source part 13 for supplying electric power to the motor 2; a control part 9 for stopping the motor 2 when fastening torque from the output part 11 reaches a prescribed value; a vibration detecting part 7 for detecting the impact vibration; and a calculation part for calculating the vibration value applied to the user from the detection result of the vibration detecting part 7. The calculation part calculates the vibration value from the impact vibration immediately before stopping of the motor 2 by the control part 9. The calculation accuracy of the vibration value can thereby be improved. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a power tool with vibration generation such as an impact wrench, and more particularly to a power tool that is hand-held and that receives the vibrations of a user's hand.

  Some rotary tools equipped with an impact mechanism generate vibrations when driving, such as screw tightening, and the vibrations generated by the use of the above tools are applied to the user's arm. there were.

  In the case where the vibration is applied to the worker, the exposure amount of vibration, which is the effective value of the vibration applied to the worker, in particular, the hand and arm, is less than the exposure limit value, preferably from the point of danger to the health and safety of the worker. It is required to be below the exposure control value.

  For example, as shown in Patent Document 1, an acceleration sensor is provided on the tool side, vibration generated during work is detected by the acceleration sensor, and an acceleration load value generated within a work time T of one work day from the output of the acceleration sensor or Calculate the vibration load value.

  Then, when the obtained acceleration load value or vibration load value exceeds a preset maximum acceleration load value or maximum vibration load value, there is one that notifies the operator to that effect. The acceleration load value or the vibration load value is the vibration exposure amount in Patent Document 1.

JP 2004-230548 A

  However, in Patent Document 1, since the vibration from when the operator operates the tool to when the work is stopped is measured, it is easily affected by disturbance vibration, and the accuracy of the operator's vibration exposure amount is low. was there.

  Accordingly, the present invention has been invented in view of the above problems, and provides an electric tool capable of calculating a vibration exposure amount with improved accuracy by reducing the influence of disturbance vibration on a vibration measurement value. It was an issue.

  In order to solve the above problems, an electric power tool 1 according to the present invention includes an output unit 11 that outputs rotational driving from a motor 2 to the outside while generating impact vibration, a gripping unit 12 that a user grips, and the motor 2, a power supply unit 13 that supplies power, a control unit 9 that stops the motor 2 when a tightening torque by the output unit 11 reaches a predetermined value, and a vibration detection unit 7 that detects a striking vibration generated in the drive unit 4. And a calculation unit that calculates a vibration value applied to the user from the detection result of the vibration detection unit 7. And the said calculation part calculates the said vibration value from the impact vibration just before the motor 2 stop by the said control part 9, It is characterized by the above-mentioned.

  By adopting such a configuration, the vibration value is calculated by the impact vibration immediately before the stop of the motor 2 where the change in the work load is small. Can be removed from.

  The invention according to claim 2 is characterized in that the vibration value is calculated from vibration between a plurality of hits immediately before the motor 2 stops.

  The invention according to claim 3 is characterized in that the vibration value is calculated from vibrations for a predetermined time immediately before the motor 2 is stopped.

  Further, the invention according to claim 4 is characterized in that a notification unit 8 that notifies the calculation result of the calculation unit to the outside is provided in a portion located opposite to the output side of the output unit 11.

  The invention according to claim 5 is characterized in that the power supply unit 13 is provided with a notification unit 8 that notifies the calculation result of the calculation unit to the outside at a position opposite to the output side of the output unit 11. .

  As described above, the power tool of the present invention calculates the vibration value from the impact vibration immediately before the motor stops, thereby reducing the influence of disturbance vibration and calculating the vibration value with improved accuracy. Yes.

  Further, it is preferable that the vibration value is calculated from vibration between a plurality of hits immediately before the motor stops or vibration for a predetermined time, so that a decrease in calculation accuracy due to disturbance vibration can be suppressed.

  Further, it is preferable that the notification unit is provided on the opposite side to the output side of the output unit, so that the notification unit is arranged on the user side, and the user can easily recognize the notification unit.

It is explanatory drawing of the electric tool of this invention. It is explanatory drawing of the detection information of a vibration detection part same as the above. It is explanatory drawing of the installation position of an alerting | reporting part same as the above. It is explanatory drawing of the other example of the arrangement position of an alerting | reporting part same as the above. It is explanatory drawing regarding control of a control part same as the above.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the electric power tool 1 of the present invention includes an output unit 11 that outputs rotational drive, a grip unit 12 that a user grips, and a power source unit 13 that supplies power to the output unit 11. It is.

  The output unit 11 includes a motor 2 that receives power supply from the power supply unit 13, a deceleration unit 3 that decelerates the rotational drive from the motor 2, and a drive that outputs the rotational drive decelerated while generating impact vibration to the outside. Part 4.

  The drive unit 4 is, for example, an impact mechanism in which a hammer of an impact rotary tool that performs a screw tightening operation or the like hits an anvil, and generates an impact pulse when outputting rotational drive.

  In addition, the gripping part 12 is located on the outer periphery of the motor 2 and protrudes from the output part 11, and detects the striking vibration generated by the switch 4 for turning on / off the output part 11 and the driving part 4. And a vibration detection unit 7 that performs the above-described operation.

  The vibration detection unit 7 is disposed at a root portion that is continuous with the output unit 11 of the gripping unit 12, and detects a striking vibration generated in the drive unit 4 through the housing of the electric power tool 1.

  For example, the vibration detection unit 7 is an acceleration sensor that detects vibration from acceleration, and the vibration signal to be detected has a peak Amax for each hit of the drive unit 4 as shown in FIG.

  The vibration detection unit 7 counts the number of peaks Amax as the number of hits, and outputs the detection result and the counted number of hits to the control unit 9 as shown in FIG.

  Further, the control unit 9 calculates a vibration value and the like from the input detection result and the number of hits, and when the input hit number reaches a predetermined number, the rotation drive of the motor 2 is cut off and the output unit 11 is automatically activated. Control to stop is performed.

  Then, the control unit 9 sets the time when the impact vibration detected as the detection result is used as the work use time of the electric power tool 1, and the vibration value for several seconds immediately before the automatic stop or for several seconds immediately before the automatic stop. calculate.

  Further, the control unit 9 calculates an effective value due to the impact of the impact vibration accumulated in the work time for the user holding the grip unit 12 from the calculated vibration value and the work use time. The calculation result by the control unit 9 is the vibration exposure amount in the work applied to the user's arm holding the grip unit 12. The vibration exposure amount is not limited to each work, and a total amount such as every work day or every month may be calculated.

  Further, the control unit 9 outputs an output signal based on the calculated vibration value and the calculated vibration exposure amount to the notification unit 8, and externally displays information based on the calculation result and the calculation result on the display of the notification unit 8. It is to inform to.

  As shown in FIG. 3, the notification unit 8 is provided at an end portion on the motor 2 side opposite to the output side of the output unit 11, and according to the output signal, the current vibration value / vibration exposure amount. In addition, the amount of work that can be performed before reaching the preset exposure amount input in advance is notified.

  The power supply unit 13 is disposed at the tip of the gripping part 12 protruding from the output unit 11. Reference numeral 6 of the power supply unit 13 is a battery pack mounting part that allows the battery pack to be attached and detached.

  And as shown in FIG. 4, you may provide the alerting | reporting part 8 in the site | part located on the opposite side to the output side of the output part 11 of the power supply part 13, without providing in the output part 11. FIG.

  Of course, the notification unit 8 is provided in both the output unit 11 and the power supply unit 13, and one notifies the current vibration value and vibration exposure amount, and the other notifies the remaining work amount that can be performed. The information may be different.

  The control of the motor 2 stop by the control unit 9 not only calculates the tightening torque from the number of hits, but also calculates the tightening torque from the rotation angle or energy at the time of hitting the output shaft (not shown) of the output unit 11. May be. In other words, as long as the control unit 9 can control the stop of the motor 2 so that the tightening operation can be performed with a specified tightening torque, a detection unit that detects the rotation angle and the like is not limited to the number of hits. The design can be changed.

  In this way, by calculating the vibration value from the impact vibration immediately before the automatic stop, the impact vibration is excluded by excluding the impact vibration in the initial and middle periods where the change in work load is severe and disturbance vibration is likely to occur from the calculation of the vibration value. Thus, the vibration value calculation accuracy can be improved.

  Further, since the vibration value with improved accuracy can be calculated, the calculation accuracy of the vibration exposure amount, which is the total amount of vibration values when the user who grips the grip portion 12 is using the work, is also improved.

  In addition, since the impact vibration to be detected is stable vibration immediately before the automatic stop, the amount of impact vibration to be detected is reduced and correction such as removal of disturbance vibration is not required, improving the accuracy and efficiency of detecting the impact vibration. It has become.

  And since the amount of detection information used for calculation can be reduced, the calculation time of the vibration value can be shortened, and the capacity of a storage unit (not shown) for storing the detection information can be suppressed, thereby suppressing an increase in production cost. It has become a thing.

  In addition, by providing the notification unit 8 positioned opposite to the output side of the output unit 11, the notification unit 8 is arranged facing the user side, and the user receives notification information such as display by the notification unit 8. It is easy to recognize.

  And since the user can easily recognize the notification information by the notification unit 8, the use of the electric tool 1 exceeding the appropriate amount of the vibration exposure amount can be prevented, and the health hazard is caused to the user due to the accumulation of the impact vibration. Can be prevented, and safety is improved.

  Furthermore, since the notification unit 8 is disposed in a portion other than the gripping unit 12, the notification unit 8 does not get in the way when the user grips the gripping unit 12, and is covered by the user's hand gripped by the notification unit 12. It has nothing to do with usability.

  In addition, since the control unit 9 can change the predetermined number for automatic stop and the set exposure amount, the vibration value calculation condition and the vibration exposure amount calculation condition can be changed according to the tightening torque of the work content. Highly accurate calculation / calculation results can be obtained.

DESCRIPTION OF SYMBOLS 1 Electric tool 11 Output part 12 Grip part 13 Power supply part 2 Motor 3 Deceleration part 4 Drive part 5 Switch 6 Battery pack mounting part 7 Vibration detection part 8 Notification part 9 Control part

Claims (5)

  The output unit that outputs the rotational drive from the motor to the outside while generating impact vibration, the grip unit that the user grips, the power supply unit that supplies power to the motor, and the tightening torque by the output unit reach a predetermined value Then, a control unit that stops the motor, a vibration detection unit that detects a striking vibration generated in the drive unit, and a calculation unit that calculates a vibration value applied to the user from the detection result of the vibration detection unit. An electric power tool characterized in that the calculation unit calculates the vibration value from an impact vibration immediately before the motor is stopped by the control unit.   The power tool according to claim 1, wherein the vibration value is calculated from vibration between a plurality of hits immediately before the motor stops.   The power tool according to claim 1, wherein the vibration value is calculated from vibration for a predetermined time immediately before the motor stops.   The reporting unit for reporting the calculation result of the calculation unit to the outside is provided in a portion located opposite to the output side of the output unit. Power tools.   The reporting unit for reporting the calculation result of the calculation unit to the outside is provided in the power supply unit at a position opposite to the output side of the output unit. The electric tool as described in.

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