KR20180075765A - Electric tool automatically stopped by over-oscillation - Google Patents

Abstract

The present invention relates to an electric tool performing electric motion work by axial rotation of a motor installed therein and, more specifically, provides an electric tool automatically stopped by over-oscillation, which comprises: an oscillation detection unit installed in the electric tool to detect oscillation for a measurement oscillation value to be provided; an over-oscillation detection unit providing an accumulated time value by accumulating excessive time when the measurement oscillation value exceeds a predetermined reference oscillation value; and an emergency stop unit blocking operation of the electric motor when the accumulated time value exceeds a predetermined reference accumulated time value.

Description

ELECTRIC TOOL AUTOMATICALLY STOPPED BY OVER-OSCILLATION "

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a power tool that performs power transmission using shaft rotation of an embedded electric motor or the like.

Generally, a power tool having a hammer drill function is relatively large in magnitude of vibrations generated during operation and has a large vibration amount compared to other functions due to a drilling operation using a blow or the like. This is because the risk of damage to the body such as the wrist of a worker is high, and if the vibration of a certain size or more occurs over a certain period of time during the work, the worker is prohibited from carrying out the electric operation any more.

However, the conventional power tool has a problem that it is difficult to comply with such regulations because a function or means for measuring the vibration value is not provided. Further, even when the vibration value of the power tool itself is measured, there is no way to count the occurrence time of the vibration exceeding a predetermined size, accumulate the vibration time, and notify the operator of the occurrence time. As a result, the manager who manages the worker also has a problem that it is difficult to secure the worker's work stability or observe the above-mentioned laws and regulations.

Korean Patent Publication No. 10-2015-0045366 (Published Oct. 11, 2016) Korean Registered Patent No. 20-0477687 (registered on July 02, 2015)

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a power tool capable of providing work stability to an operator by preventing occurrence of physical damage or the like caused by over vibration applied to an operator . In addition, we want to measure the power applied to the actual worker more accurately. Further, it is possible to easily recognize the information about the vibration to the worker who is working. Also, it is intended to protect the workers who perform the electric operation by measuring the cumulative time that the vibration of the size exceeding a certain reference value is applied to the worker in total.

In order to solve the above-described problems, an embodiment of the present invention provides a power tool for performing an electric operation by rotation of a shaft of a built-in motor, the power tool comprising: chapter; An over-vibration detecting unit for accumulating time exceeding a predetermined reference vibration value to provide an accumulated time value; And an emergency stop unit for stopping the driving of the power tool when the cumulative time value exceeds a preset reference cumulative time value.

Preferably, the vibration sensing unit is an acceleration sensor that measures acceleration for at least one of three axes that are orthogonal to each other.

Preferably, the acceleration sensor is disposed in a grip portion where the palm of the operator abuts.

An alarm sound generator for generating a first alarm sound at predetermined intervals when the measured vibration value exceeds the reference vibration value; And a display unit for displaying the occurrence of overvibration as an external.

When the cumulative time value exceeds the reference cumulative time value, the alarm sound generator generates a second alarm sound distinguished from the first alarm sound, and the display unit displays an out-of-period occurrence as an external.

It is preferable that the accumulated time value is automatically initialized at intervals of one day or forcedly artificially initialized according to a change of an operator.

As described above, according to the present invention, various effects including the following can be expected. However, the present invention does not necessarily achieve the following effects.

The power tool according to one embodiment can prevent the occurrence of physical damage due to excessive vibration applied to an operator, thereby providing work stability. Further, the position of the vibration sensing part is limited to the grip part, so that the vibration actually transmitted to the operator can be more accurately measured. The operator can easily confirm the magnitude and duration of the vibration generated in the power tool through visual or auditory sense when the vibration exceeds the preset reference value. Further, the power tool can automatically cut off the operation of the power tool through the emergency stop portion, thereby further improving safety for the operator.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram of a power tool according to an embodiment of the present invention; FIG.
FIG. 2 is a perspective view illustrating the installation of a vibration sensing unit according to an embodiment; FIG.
Figure 3 is an operational flow diagram of Figure 1;

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

FIG. 1 is a configuration diagram of an electric power tool according to an embodiment of the present invention, and FIG. 2 is a perspective view illustrating a vibration sensing unit according to an embodiment of the present invention. Referring to FIGS. 1 and 2, an electric power tool that is automatically stopped when excessive vibration is detected includes a vibration sensing part 20, a vibration detection part 30, an emergency stop part 40, an alarm sound generating part 50, (60) and the like.

The electric power tool carries out various kinds of electric power operations such as drilling and hammering by using the shaft rotation of the motor 10 and the like installed therein. Particularly, a power tool having a hammer drill function is prone to generate a larger vibration than other power tools because the workpiece is partially crushed through the impact.

The vibration sensing portion 20 is fixedly installed in the electric power tool and senses the vibration to provide a measured vibration value. For example, the vibration sensing portion 20 is preferably an acceleration sensor that measures acceleration for at least one of three axes that are orthogonal to each other in space. That is, the vibration detection section 20 measures the acceleration of the power tool in at least one axis including the X axis, the Y axis, and the Z axis by the vibration generated during the operation.

The acceleration sensor measures the dynamic force such as vibration or impact of the power tool having the acceleration sensor by using each measured voltage value on the X axis, Y axis and Z axis as an output signal. Such an acceleration sensor can sense the movement of the power tool through a change in speed. Specifically, the acceleration sensor measures the moving amount of the moving part having an appropriate mass by the electromotive force of the magnet and the coil to extract the acceleration. The acceleration sensor can convert angular accelerations of three axes into angular vibration values of three axes by a predetermined algorithm set in advance. At this time, the measured vibration value is calculated by summing all of the vibration values for each axis.

Referring to FIG. 2, the acceleration sensor is preferably disposed on the grip portion 70 where the palm of the operator abuts. The acceleration sensor is installed to be electrically connected to the printed circuit board 80 in the grip portion 70 of the main body housing of the power tool for the purpose of exchanging electric signals with the printed circuit board 80 disposed in the power tool. As a result, the magnitude of the vibration actually applied to the operator can be more accurately measured.

And the vibration detecting unit 30 accumulate the time exceeded when the measured vibration value exceeds a predetermined reference vibration value to provide an accumulated time value. The reference vibration value is a constant. However, the value of the power tool can be changed by changing the setting of the power tool. As a result, the overvoltage detecting unit 30 compares the measured vibration value measured with 100 ms, for example, and the reference vibration value, and if the measured vibration value exceeds the reference vibration value, .

Alternatively, the cumulative time value may be calculated by a method of accumulating the exceeding time only when the time at which the measured vibration value exceeds the reference vibration value is equal to or greater than a predetermined counting allowable time value. For example, if the allowable counting time value is 500 ms, and the time exceeding 300 ms is not accumulated, the accumulated time can be accumulated to 700 ms.

The power tool may further include an alarm sound generator 50 for generating a first alarm sound at predetermined intervals when the measured vibration value exceeds the reference vibration value. At this time, the frequency of occurrence of the event in which the first alarm sound is generated may be intermittent or continuous. At this time, the alarm sound generating unit 50 generates a second alarm sound distinguished from the first alarm sound when the accumulated time value exceeds a predetermined reference accumulation time value. The first alarm sound is a warning sound for notifying a danger, while the second alarm sound is an effect sound for notifying that the driving of the power tool is stopped and stopped.

The emergency stop section 40 cuts off the driving of the power tool when the accumulated time value exceeds a preset reference cumulative time value. That is, when the amount of vibration applied to the operator exceeds an allowable amount, the power tool is forcibly stopped and locked. The locking can be implemented by a method of shutting off the power supplied to the motor 10 or the like. That is, the power tool is automatically switched to the locked state to protect the operator. However, such a lock can be released by resetting the power tool according to the worker's shift or by forcibly unlocking according to an arbitrary judgment of the manager.

The cumulative time value can be automatically initialized at intervals of one day or artificially force initialized according to operator changes. That is, the power tool can adjust the accumulated time value to a zero value in a 24-hour period. Or when the power tool is used for shift work, that is, when the worker is used more than the daily work time per worker, the cumulative time value according to the work of the previous worker is preferably forcedly initialized by artificially. This can be implemented by a method of electronically resetting the cumulative time value as described above.

The display unit 60 includes a function of externally displaying the occurrence of over vibration. Specifically, the display unit 60 visually informs the operator of the risk of overvoltage at the same time as the first alarm sound is generated. This can be in the form of light as well as text. Also, the display unit 60 can display the out-of-sight occurrence as an external. Concretely, the display unit 60 visually informs the operator of the risk that the excessive vibration is accumulated during the transient time, simultaneously with the generation of the second alarm sound. In addition, the display unit 60 notifies the operator of the automatic stop of the over-vibration when the driving of the power tool is interrupted by the emergency stop unit 40. [

3 is an operational flow chart of Fig. Referring to FIG. 3, a schematic flow of the automatic stop of the power tool according to the occurrence of overvoltage is as follows. The worker performs work such as hammer drilling while gripping the grip portion 70 of the power tool. In the process, vibration occurs in the power tool. The power tool measures the measured vibration value using a preset sampling time using the vibration detector 20 such as an acceleration sensor. Here, if the magnitude of the measured vibration value exceeds the preset magnitude of the reference vibration value, the power tool generates the first alarm sound through the alarm sound generating unit 50 and generates the first alarm sound through the display unit 60 Mark danger.

On the other hand, if the cumulative time value provided through the overvoltage detecting unit 30 exceeds a preset reference cumulative time value, the power tool generates a second alarm sound through the alarm sound generating unit 50, To indicate the out-of-hours status as external. At the same time, the power tool cuts off the driving of the power tool through the emergency stop part (40). At this time, the power tool can display outside that the operation of the power tool is stopped due to overexcitation of vibration through the display unit 60.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention.

10: motor 20:
30: Overvoltage detection unit 40: Emergency stop unit
50: alarm sound generator 60:
70: grip portion 80: printed circuit board

Claims (6)

1. An electric power tool for performing an electric operation by rotation of an axis of a built-in motor,
A vibration sensor installed in the power tool to detect a vibration and provide a measured vibration value;
An over-vibration detecting unit for accumulating time exceeding a predetermined reference vibration value to provide an accumulated time value; And
And an emergency stop part for stopping the driving of the power tool when the cumulative time value exceeds a preset reference cumulative time value.
The method according to claim 1,
Wherein the vibration sensing unit is automatically stopped when an overspeed is detected, which is an acceleration sensor that measures acceleration for at least one of three axes that are orthogonal to each other.
3. The method of claim 2,
Wherein the acceleration sensor is automatically stopped when overvibration is detected in a grip portion where a palm of a worker touches.
The method according to claim 1,
An alarm sound generator for generating a first alarm sound at predetermined intervals when the measured vibration value exceeds the reference vibration value; And a display unit for displaying the occurrence of overvibration as an externally.
5. The method of claim 4,
When the cumulative time value exceeds the reference cumulative time value, the alarm sound generating unit generates a second alarm sound distinguished from the first alarm sound, and the display unit displays the alarm signal Power tool that stops automatically.
The method according to claim 1,
Wherein the cumulative time value is automatically initialized at intervals of one day or automatically stopped when artificial forced oscillation is detected according to a change of an operator.

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