KR20170075309A - Portable electric sawing devices - Google Patents

Portable electric sawing devices Download PDF

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Publication number
KR20170075309A
KR20170075309A KR1020150184792A KR20150184792A KR20170075309A KR 20170075309 A KR20170075309 A KR 20170075309A KR 1020150184792 A KR1020150184792 A KR 1020150184792A KR 20150184792 A KR20150184792 A KR 20150184792A KR 20170075309 A KR20170075309 A KR 20170075309A
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KR
South Korea
Prior art keywords
acceleration
axis
cutter chain
monitoring unit
reference value
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KR1020150184792A
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Korean (ko)
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KR101825351B1 (en
Inventor
성금길
곽기석
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영남이공대학교 산학협력단
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Priority to KR1020150184792A priority Critical patent/KR101825351B1/en
Publication of KR20170075309A publication Critical patent/KR20170075309A/en
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Publication of KR101825351B1 publication Critical patent/KR101825351B1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27G—ACCESSORY MACHINES OR APPARATUS FOR WORKING WOOD OR SIMILAR MATERIALS; TOOLS FOR WORKING WOOD OR SIMILAR MATERIALS; SAFETY DEVICES FOR WOOD WORKING MACHINES OR TOOLS
    • B27G19/00—Safety guards or devices specially adapted for wood saws; Auxiliary devices facilitating proper operation of wood saws
    • B27G19/003—Safety guards or devices specially adapted for wood saws; Auxiliary devices facilitating proper operation of wood saws for chain saws
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27B—SAWS FOR WOOD OR SIMILAR MATERIAL; COMPONENTS OR ACCESSORIES THEREFOR
    • B27B9/00—Portable power-driven circular saws for manual operation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16P—SAFETY DEVICES IN GENERAL; SAFETY DEVICES FOR PRESSES
    • F16P1/00—Safety devices independent of the control and operation of any machine
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B5/00—Measuring arrangements characterised by the use of mechanical techniques
    • G01B5/30—Measuring arrangements characterised by the use of mechanical techniques for measuring the deformation in a solid, e.g. mechanical strain gauge
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L3/00—Measuring torque, work, mechanical power, or mechanical efficiency, in general
    • G01L3/16—Rotary-absorption dynamometers, e.g. of brake type
    • G01L3/18—Rotary-absorption dynamometers, e.g. of brake type mechanically actuated
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
    • G01P15/00—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/0092—Arrangements for measuring currents or voltages or for indicating presence or sign thereof measuring current only
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
    • G01R19/16566—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533
    • G01R19/1659—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533 to indicate that the value is within or outside a predetermined range of values (window)

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Wood Science & Technology (AREA)
  • Forests & Forestry (AREA)
  • General Engineering & Computer Science (AREA)
  • Sawing (AREA)

Abstract

A portable electric saw machine is disclosed. According to an aspect of the present invention, there is provided a cutter chain comprising: a housing having a handle on one side; a guide bar extending from the other side of the housing and having a guide groove formed along an edge surface; A brake for stopping the rotation of the cutter chain, a monitoring unit for determining in real time whether or not a cut operation is performed by the cutter chain, an acceleration sensor for sensing the acceleration of the housing, And a controller for controlling the brake based on data transmitted from the sensor. Wherein the acceleration sensor includes at least one of a first axis set on the basis of the guide bar, a second axis perpendicular to the first axis, a third axis perpendicular to the first axis and a third axis perpendicular to the first axis, The acceleration is measured in one direction or the rotation acceleration based on the at least one axis selected from the first axis, the second axis, the third axis, and a combination thereof is measured.

Description

[0001] PORTABLE ELECTRIC SAWING DEVICES [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a portable electric saw device, and more particularly, to a portable electric saw device capable of stopping operation of a saw top by sensing a kickback or an unexpected behavior of a user.

Portable electric chainsaws can be used when working on wood in wood processing or forestry.

A portable electric saw is not fixed to a frame but is carried by a worker. When a cutter blade rotates at a high speed, it touches a cutting object, or a kickback phenomenon which is instantaneously thrown out to a worker during a cutting operation may occur have. The kickback phenomenon may cause injury to the operator, and means for preventing safety accidents due to the kickback phenomenon should be provided.

In addition, even in the idle state before and after the cutting operation, an unexpected situation in which the electric saw is worn due to the lack of attention of the operator may occur. Such an unexpected situation may cause injuries to nearby people, and it is necessary to take measures to prevent safety accidents caused by such unexpected situations. However, chainsaws can exhibit different behavioral characteristics in kickback and unexpected situations, and both need to be distinguished. That is, in order to prevent a safety accident by the electric saw, it is necessary to judge whether a kickback phenomenon or an unexpected situation occurs. In order to accurately determine whether a kickback phenomenon or an unexpected situation occurs, It is necessary to distinguish whether it is necessary to judge whether a kickback phenomenon occurs or whether an occurrence of an unexpected situation should be judged.

Prior art related to a portable power saw is disclosed in Korean Patent Publication No. 10-1142263 entitled " Portable electric power saw capable of speed control ".

The embodiments of the present invention can provide a portable electric saw device in which a kickback phenomenon and an unexpected situation can be accurately discriminated according to whether or not a cutting operation is performed by a cutter chain.

According to an aspect of the present invention, there is provided a cutter chain comprising: a housing having a handle on one side; a guide bar extending from the other side of the housing and having a guide groove formed along an edge surface; A brake for stopping the rotation of the cutter chain, a monitoring unit for determining in real time whether or not a cut operation is performed by the cutter chain, an acceleration sensor for sensing the acceleration of the housing, And a controller for controlling the brake based on data transmitted from the sensor. Wherein the acceleration sensor includes at least one of a first axis set on the basis of the guide bar, a second axis perpendicular to the first axis, a third axis perpendicular to the first axis and a third axis perpendicular to the first axis, The acceleration is measured in one direction or the rotation acceleration based on the at least one axis selected from the first axis, the second axis, the third axis, and a combination thereof is measured.

When the acceleration or the rotation acceleration measured by the acceleration sensor exceeds a predetermined first reference value during the cutting operation by the cutter chain, the controller determines that a kickback has occurred and stops the cutter chain.

Wherein the monitoring unit includes a current sensor that senses a current magnitude of electricity supplied to the motor in real time, and the monitoring unit monitors the current magnitude of the electric current supplied to the motor by the cutter chain when the amount of change in the magnitude of the current sensed by the current sensor exceeds a predetermined fourth reference value It can be determined that it is in the cutting operation and can be notified to the control unit. The control unit may stop the chain of cutters when the acceleration or the rotation acceleration measured by the acceleration sensor exceeds the first reference value after the notification of the monitoring unit.

Wherein the monitoring unit includes a pressure sensor that detects a pressure of the cutter chain pressing the guide bar in real time, and the monitoring unit monitors the pressure of the guide bar during a cutting operation by the cutter chain when the pressure sensed by the pressure sensor exceeds a predetermined fifth reference value It is possible to notify the control unit thereof. The control unit may stop the chain of cutters when the acceleration or the rotation acceleration measured by the acceleration sensor exceeds the first reference value after the notification of the monitoring unit.

Wherein the monitoring unit includes a strain gauge that detects a strain of the guide bar in real time and the monitoring unit monitors the strain of the guide bar during a cutting operation by the cutter chain when the strain detected by the strain gauge exceeds a predetermined sixth reference value It is possible to notify the control unit thereof. The control unit may stop the chain of cutters when the acceleration or the rotation acceleration measured by the acceleration sensor exceeds the first reference value after the notification of the monitoring unit.

The controller may determine that an unexpected condition has occurred and stop the chain if the acceleration or the rotation acceleration measured by the acceleration sensor exceeds a predetermined second reference value before or after the cutting operation by the cutter chain . The first reference value may be set to be larger than the second reference value.

The control unit may stop the cutter chain when the human body approaches the cutter chain based on data transmitted from the infrared sensor.

Further comprising a timer for measuring an idling time of the cutter chain based on data transmitted from the monitoring unit, wherein the control unit controls the idling time of the cutter chain based on data transmitted from the timer to a predetermined third reference value The cutter chain can be stopped.

According to the embodiments of the present invention, it is possible to determine in real time whether or not the cutting operation by the cutter chain is performed in real time, and it is possible to accurately discriminate the kickback phenomenon and the unexpected situation according to whether or not the cutting operation is performed by the cutter chain , Thereby stopping the cutter chain, thereby preventing a kickback phenomenon and a safety accident caused by an unexpected situation.

1 is a view illustrating a portable electric saw apparatus according to an embodiment of the present invention.
2 is a view showing the inside of the housing.
3 is a view showing the inside of the housing in a state where the cutter chain is mounted.
4 is a view showing the interior of the housing with the cutter chain removed.
5 is a view showing a control unit.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated in the drawings and described in detail in the detailed description. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter, a preferred embodiment of a portable electric saw apparatus according to the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals designate corresponding or corresponding components, A duplicate description will be omitted.

FIG. 1 is a view showing a portable electric saw apparatus according to an embodiment of the present invention, FIG. 2 is an interior view of the housing, FIG. 3 is a view showing a state in which a cutter chain is mounted inside the housing, FIG. 5 is a view showing the control unit. FIG.

1 to 5, a portable electric saw apparatus according to an embodiment of the present invention includes a housing 100, a handle 110, a guide bar 120, a cutter chain 130, an electric motor 140, A monitoring unit 200, an acceleration sensor 300, a timer 400, an infrared ray sensor 500, and a controller 600. [

Inside the housing 100, a receiving space for mounting various electromechanical devices may be formed.

On / off switch 160 and stop button 170 may be provided on the outside of housing 100. The operator can input an on-off signal for allowing or blocking the electric power supply to the electric motor 140 via the on-off switch 160 and stop the rotational movement of the cutter chain 130 via the stop button 170 You can enter a stop signal that can be received. Electric supply to the electric motor 140 may be performed by a battery mounted on the housing 100 or an external power source.

The handle 110 may be formed on one side of the housing 100. The operator can hold the handle 110 and carry the portable electric saw device or perform the cutting operation.

The guide bar 120 may be coupled to the housing 100. Specifically, the guide bar 120 may be coupled to the housing 100 to extend from the other side of the housing 100 to the outside of the housing 100.

The guide bar 120 may have a plate shape and a guide groove 121 may be formed along the edge surface of the guide bar 120.

The cutter chain 130 can be inserted into the guide groove 121 and rotated. Specifically, the sprocket 180 may be rotatably coupled to the housing 100, and the cutter chain 130 may be engaged with the sprocket 180 while being inserted into the guide groove 121, The rotation can be performed. The cutter chain 130 may be formed in an annular shape.

The cutter chain 130 may include a plurality of cutter blades 131. The plurality of cutter blades 131 may be formed on the outer circumferential surface of the cutter chain 130 and may be spaced apart from each other in the longitudinal direction of the cutter chain 130.

The electric motor 140 is coupled to the housing 100 to rotate the cutter chain 130. For example, the first bevel gear 141 formed on the rotating shaft of the electric motor 140 is engaged with the second bevel gear 143 formed on the rotating shaft of the sprocket 180, so that the rotational force generated by the electric motor 140 And may be transmitted to the sprocket 180 through the first bevel gear 141 and the second bevel gear 143.

The brake 150 may be coupled to the housing 100 to stop rotational movement of the cutter chain 130. The brake 150 applies a frictional force to the rotary shaft of the electric motor 140 or the rotary shaft of the sprocket 180 or engages with the first bevel gear 141, the second bevel gear 143 or the cutter chain 130, 130 can be stopped.

The monitoring unit 200 can determine whether or not the cutting operation by the cutter chain 130 is performed in real time, that is, at a constant cycle.

The monitoring unit 200 may include a current sensor 210 as an example. The current sensor 210 may be coupled to the housing 100 and sense the current magnitude of electricity supplied to the motor 140 in real time. When the cutter chain 130 comes into contact with the object to be cut in the idle state to start the cutting operation, the load applied to the electric motor 140 increases due to the frictional force generated between the cutter chain 130 and the object to be cut, 130 needs to be increased in magnitude of the current applied to the motor 140 in order to rotate at a predetermined number of revolutions. Accordingly, the magnitude of the current sensed by the current sensor 140 changes. Therefore, when the difference between the current magnitude of the current magnitude sensed by the current sensor 210, that is, the current magnitude in the idling state, and the current magnitude exceeds the preset fourth reference value, the monitoring unit 200 monitors the cutter chain 130, It can be judged that the workpiece is in the cutting operation. Here, the fourth reference value may be set as a change amount of the current size when a force capable of cutting the cutting object is applied in a state in which the cutter chain 130 is in contact with the cutting object.

The monitoring unit 200 may include a pressure sensor 220 as another example. The pressure sensor 220 can be coupled to the guide bar 120 and specifically to the bottom surface of the guide groove 121 so that the cutter chain 130 can sense the pressure of the guide bar 120 in real time. When the cutter chain 130 comes into contact with the object to be cut in the idle state to start the cutting operation, the pressure applied to the pressure sensor 220 by the force of the object to be cut by the cutter chain 130 is increased. Therefore, when the difference between the pressure or pressure change detected by the pressure sensor 220, that is, the difference between the pressure in the idle state and the current pressure, exceeds the predetermined fifth reference value, the monitoring unit 200 It can be judged that it is in the cutting operation. Here, the fifth reference value may be set as a change amount of the pressure when a force capable of cutting the cutting object is applied while the cutter chain 130 is in contact with the cutting object.

The monitoring unit 200 may include a strain gauge 230 as another example. The strain gauge 230 can be coupled to the guide bar 120, specifically, to one side of the guide bar 120, and can sense the strain of the guide bar 120 in real time. When the cutter chain 130 is brought into contact with the object to be cut in the idle state to start the cutting operation, the force of pressing the cutter chain 130 causes the deformation of the guide bar 120. Therefore, the monitoring unit 200 may determine the strain of the guide bar 120 sensed by the strain gauge 230, for example, between the width of the guide bar 120 in the idle state and the width of the current guide bar 120 If the strain exceeds the sixth reference value, it can be determined that the cutting operation is performed by the cutter chain 130. Here, the sixth reference value can be set to the strain rate of the guide bar 120 when a force capable of cutting the cutting object is applied in a state where the cutter chain 130 is in contact with the cutting object.

The monitoring unit 200 may include at least one of a current sensor 210, a pressure sensor 220, and a strain gauge 230. For example, the monitoring unit 200 may include two or more of the current sensor 210, the pressure sensor 220, and the strain gauge 230.

The acceleration sensor 300 may be coupled to the housing 100 and sense the acceleration of the housing 100 in real time. The acceleration sensor 300 includes a first axis set with respect to the guide bar 120, a second axis perpendicular to the first axis, a third axis perpendicular to the first axis and the second axis, And a rotation acceleration based on at least one of the axes selected from the first axis, the second axis, the third axis, and a combination of the first axis, the second axis, and the third axis can be measured . In the drawing, x-axis and z-axis perpendicular to the y-axis with the direction of the guide bar 120 as a y-axis are shown as an example. The acceleration sensor 300 may sense acceleration or rotational acceleration in the x-axis, y-axis, and z-axis directions, as illustrated by way of example in FIG. For example, when the kickback occurs, the acceleration sensor 300 can detect acceleration based on at least one of rotation acceleration based on the x-axis or x-axis, y-axis, z-axis, and combinations thereof . As another example, when the user wields the electric saw apparatus in an operating state, the acceleration sensor 300 may calculate the rotation acceleration based on at least one axis selected from the x-axis, the y-axis, the z-axis, Axis, a z-axis, and a combination thereof.

The timer 400 may be coupled to the housing 100 and may measure the idle time of the cutter chain 130 based on data transmitted from the monitoring unit 200. Specifically, the timer 400 can measure the elapsed time from the input of the on signal through the on / off switch 160, that is, the idling time, It is determined that the cutting operation by the cutter chain 130 is completed in the monitoring unit 200, and the idling time can be measured again.

The infrared sensor 500 may be coupled to the housing 100 or the guide bar 120 to sense whether the human body is approaching the cutter chain 130.

The control unit 600 may control the brake 150 based on data transmitted from the monitoring unit 200 and the acceleration sensor 300. Specifically, the controller 600 can calculate the time rate of change of the velocity or the angular velocity of the housing 100 sensed by the acceleration sensor 300, that is, the acceleration or the rotational acceleration, It is determined that a kickback phenomenon has occurred and the brake 150 is controlled so as to stop the cutter chain 130. When the acceleration or the rotation acceleration of the housing 100 exceeds the predetermined first reference value, . Alternatively, if it is determined by the monitoring unit 200 that the cutter chain 130 is rotating before and after the cutting operation by the cutter chain 130, When the acceleration or the rotation acceleration of the housing 100 exceeds the predetermined second reference value, it is determined that an unexpected situation occurs in which the operator wields the portable electric saw apparatus, so that the operator can stop the cutter chain 130 by controlling the brake 150 have. Here, the first reference value may be set as the acceleration or the rotational acceleration of the housing 100 when the kickback phenomenon occurs, and the second reference value may be determined by analyzing the general behavior of the general operator, Acceleration or rotational acceleration. In this case, although the first reference value may be larger than the second reference value in a specific direction, the movement patterns of the electric saw apparatus according to the kickback and the movement patterns of the electric saw apparatus according to the unexpected state are generally different. The top apparatus may have a database (not shown) storing the first reference value and the second reference value for changes in acceleration or rotational acceleration depending on the kickback and the unexpected situation, respectively. In this case, the control unit 600 can accurately determine the kickback phenomenon and the unexpected situation by comparing the acceleration or the rotation acceleration measured by the acceleration sensor 300 with the first reference value and the second reference value stored in the database have.

And a control unit 600. If the idle time of the cutter chain 130 exceeds a preset third reference value, the controller 600 determines that the operator has left the portable electric power tool, The cutter chain 130 can be stopped. Here, the third reference value may be set in consideration of a rest period that a general worker has between a series of operations. If it is detected that the human body is approaching the cutter chain 130 based on the data transmitted from the infrared sensor 500, the control unit 600 determines that the unauthorized person is approaching the infant or the like and controls the brake 150 The cutter chain 130 can be stopped.

Meanwhile, in order to more accurately measure the kickback phenomenon and the unexpected situation, the present invention may utilize at least one of the current sensor 210, the pressure sensor 220, the strain gauge 230, and a combination thereof.

Even if the control unit 600 determines that a kickback occurs because the acceleration or the rotation acceleration measured by the acceleration sensor 300 exceeds the first reference value by utilizing the information provided by the acceleration sensor 300 and the current sensor 210, If the amount of change in the magnitude of the current sensed by the sensor 210 does not exceed the fourth reference value, it can be determined that the kickback is not performed. In this case, however, the portable electric saw apparatus may be in operation (idle, for example), so that when the on-off switch 160 is determined to be on, the control unit 600 determines whether the acceleration measured by the acceleration sensor 300 If the rotation acceleration exceeds the second reference value, it can be determined that an unexpected situation has occurred.

The control unit 600 determines that a kickback occurs because the acceleration or rotation acceleration measured by the acceleration sensor 300 exceeds the first reference value by using the information provided by the acceleration sensor 300 and the pressure sensor 220 It can be determined that the pressure is not a kickback if the pressure sensed by the pressure sensor 220 does not exceed the fifth reference value. In this case, however, the portable electric saw apparatus may be in operation (idle, for example), so that when the on-off switch 160 is determined to be on, the control unit 600 determines whether the acceleration measured by the acceleration sensor 300 If the rotation acceleration exceeds the second reference value, it can be determined that an unexpected situation has occurred.

The control unit 600 determines that a kickback occurs because the acceleration or the rotation acceleration measured by the acceleration sensor 300 exceeds the first reference value by using information provided from the acceleration sensor 300 and the strain gage 230 It can be determined that the strain is not a kickback if the strain detected by the strain gage 230 does not exceed the sixth reference value. In this case, however, the portable electric saw apparatus may be in operation (idle, for example), so that when the on-off switch 160 is determined to be on, the control unit 600 determines whether the acceleration measured by the acceleration sensor 300 If the rotation acceleration exceeds the second reference value, it can be determined that an unexpected situation has occurred.

As described above, in the portable electric saw apparatus of the present invention, it is possible to determine in real time whether or not the cutting operation by the cutter chain is carried out, and it is possible to detect the acceleration sensor 300, the current sensor 210, the pressure sensor 220, It is possible to accurately discriminate the kickback phenomenon and the unexpected situation according to whether or not the cutting operation by the cutter chain is performed through the strain gauge 230 or the like. By thus stopping the cutter chain, a kickback phenomenon and a safety accident Can be prevented.

It will be apparent to those skilled in the art that various modifications and additions to, or additions to, the components may be made without departing from the scope of the present invention as set forth in the appended claims. The present invention can be variously modified and changed by those skilled in the art, and it is also within the scope of the present invention.

100: Housing
110: Handle
120: Guide bar
121: Guide groove
130: Cutter chain
131: Cutter blade
140: Electric motor
141: 1st bevel gear
143: 2nd bevel gear
150: Brake
160: On-off switch
170: Stop button
180: sprocket
200: Monitoring section
210: Current sensor
220: Pressure sensor
230: Strain gauge
300: acceleration sensor
400: timer
500: Infrared sensor
600:

Claims (6)

A housing having a handle on one side;
A guide bar extending from the other side of the housing and having guide grooves formed along edge surfaces thereof;
A cutter chain inserted into the guide groove and rotated;
An electric motor for rotating the cutter chain;
A brake for stopping rotational movement of the cutter chain;
A monitoring unit for determining in real time whether or not the cutting operation by the cutter chain is performed;
An acceleration sensor for sensing an acceleration of the housing; And
And a controller for controlling the brake based on data transmitted from the monitoring unit and the acceleration sensor,
Wherein the acceleration sensor includes at least one selected from a first axis set with reference to the guide bar, a second axis perpendicular to the first axis, a third axis perpendicular to the first axis and a second axis perpendicular to the first axis, Measuring acceleration in one direction or measuring rotation acceleration based on the at least one axis selected from the first axis, the second axis, the third axis, and a combination thereof. The method according to claim 1,
Wherein the control unit determines that a kickback has occurred when the acceleration or the rotation acceleration measured by the acceleration sensor exceeds a predetermined first reference value during a cutting operation by the cutter chain, . The method according to claim 1,
Wherein the monitoring unit includes a current sensor for sensing a current magnitude of electricity supplied to the motor in real time,
Wherein the monitoring unit determines that the amount of change in the current magnitude sensed by the current sensor exceeds a predetermined fourth reference value and is notified to the control unit during cutting operation by the cutter chain,
Wherein the control unit stops the chain of cutters when the acceleration or the rotation acceleration measured by the acceleration sensor exceeds the first reference value after the notification of the monitoring unit. The method according to claim 1,
Wherein the monitoring unit includes a pressure sensor for sensing in real time the pressure at which the cutter chain presses the guide bar,
Wherein the monitoring unit determines that the pressure detected by the pressure sensor exceeds a predetermined fifth reference value and is notified to the control unit during cutting operation by the cutter chain,
Wherein the control unit stops the chain of cutters when the acceleration or the rotation acceleration measured by the acceleration sensor exceeds the first reference value after the notification of the monitoring unit. The method according to claim 1,
Wherein the monitoring unit includes a strain gauge that detects a strain of the guide bar in real time,
The monitoring unit determines that the strain detected by the strain gage exceeds a preset reference value of 6 and is in the process of cutting by the cutter chain,
Wherein the control unit stops the chain of cutters when the acceleration or the rotation acceleration measured by the acceleration sensor exceeds the first reference value after the notification of the monitoring unit. 6. The method according to any one of claims 2 to 5,
Wherein the control unit determines that an unexpected situation has occurred when the acceleration or the rotation acceleration measured by the acceleration sensor exceeds a predetermined second reference value before and after the cutting operation by the cutter chain, Top device.
KR1020150184792A 2015-12-23 2015-12-23 Portable electric sawing devices KR101825351B1 (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108943205A (en) * 2018-04-25 2018-12-07 江山显进机电科技服务有限公司 Double-deck double upper overturning timber panel point pressure type pressing detection aligning gears
CN111093921A (en) * 2017-07-24 2020-05-01 费斯托工具有限责任公司 Power tool and method for identifying a kickback event of a power tool
WO2023156612A1 (en) * 2022-02-18 2023-08-24 Festool Gmbh Handheld power tools with kickback detection and methods of detecting a kickback condition of a handheld power tool

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2536536A1 (en) * 2010-02-17 2012-12-26 GARDENA Manufacturing GmbH Power tools

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111093921A (en) * 2017-07-24 2020-05-01 费斯托工具有限责任公司 Power tool and method for identifying a kickback event of a power tool
CN108943205A (en) * 2018-04-25 2018-12-07 江山显进机电科技服务有限公司 Double-deck double upper overturning timber panel point pressure type pressing detection aligning gears
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