JP5605751B2 - Portable cutting machine - Google Patents

Description

  The present invention relates to a portable cutting machine, and more particularly to a portable cutting machine that automatically soft-starts the portable cutting machine depending on the application.

  A conventional portable cutting machine includes a motor, a saw blade that is driven by the motor to cut a workpiece, a saw cover that covers almost half of the outer peripheral portion of the saw blade, a saw cover that rotatably supports the workpiece. And a base abutting on the member. The base is formed with an opening for projecting the saw blade downward when the saw cover is on the upper side. In addition, there is a portable cutting machine with a soft start control that soft-starts the rotation of the motor in order to reduce the reaction from the workpiece in the initial stage of the saw blade rotation.

  In a portable cutting machine with soft start control, the rotation of the motor is soft-started at the initial stage of the saw blade rotation. When the machining accuracy is required, for example, when the workpiece is cut by aligning the blade edge of the saw blade with the black line of the workpiece, the soft start control is performed when the cutting edge of the saw blade is caused by reaction from the workpiece. Prevents deviation from the black line, and its function is fully demonstrated.

  However, with such a cutting machine, even if it is necessary to finish the cutting operation in a short time without requiring processing accuracy, the rotation of the motor is soft-started, so the cutting operation cannot be completed in a short time. , Which led to a decrease in work efficiency. There are also portable cutting machines equipped with a switch that switches the presence or absence of soft start control, but the user must set the presence or absence of soft start according to the application every time cutting work is performed, leading to a reduction in work efficiency. It was.

  In view of such a situation, the present invention provides a portable cutting machine in which a soft start is automatically activated in accordance with an application.

The portable cutting machine according to claim 1, wherein a motor, switch means for controlling on / off of power supply to the motor, a saw blade that is driven by the motor to cut a workpiece, and the saw blade A saw cover for covering, a base on which the saw cover is rotatably supported and an opening for projecting the saw blade is formed; soft start means for soft-starting rotation of the motor; and before the motor starts rotating, Detecting means for detecting that the workpiece is approaching a predetermined distance or less with respect to the saw blade, and the detection means is predetermined with respect to the saw blade before the motor starts rotating. When it is detected that the distance is below the distance, the soft start means is started and the motor starts to rotate .

For example, when cutting a workpiece along a black line drawn on the surface, when the user needs to start the motor softly, for example, when a soft start of the motor is required, the user must move the tip of the saw blade before the saw blade rotates. Next, the saw blade is rotated by the switch means in accordance with the black line, and cutting of the workpiece is started. When the user takes the operation, when starting the rotation of the saw blade, rotation of the motors is soft start. Therefore, since the rotation of the saw blade is also soft-started, the reaction from the member to be processed at the initial stage of the rotation of the motor can be suppressed, and for example, the deviation of the blade edge of the saw blade from the black line of the member to be processed can be prevented. On the other hand, if the motor does not require soft start as the user's initial operation, the saw blade starts rotating according to the amount of current flowing through the motor, so that the workpiece can be cut in a short time. it can.

  When the detecting means detects that the workpiece is within a predetermined distance with respect to the saw blade before the rotation of the motor is started, the rotation of the motor is soft-started by the soft start means when the saw blade starts to rotate. Accordingly, since the rotation of the saw blade is also soft-started, the reaction from the workpiece in the cutting operation at the initial stage of the rotation of the motor is suppressed, and for example, the deviation of the blade edge of the saw blade from the black line of the workpiece can be prevented. it can. On the other hand, if the detection means does not detect that the workpiece is within a predetermined distance with respect to the saw blade before the motor starts rotating, if the rotation of the saw blade is started, the motor is not controlled by the soft start means. Start rotating. Therefore, when cutting the workpiece, the cutting operation can be completed in a short time.

The portable cutting machine according to claim 2 is the portable cutting machine according to claim 1 , wherein the detecting means detects that the workpiece is below a predetermined distance with respect to the saw blade. When the switch means is turned on, the soft start means is started and the switch means is turned on before the detection means detects that the workpiece is below a predetermined distance with respect to the saw blade. And the soft start means does not start and the motor starts rotating.

  With the above configuration, when the power supply to the motor is started, whether or not the soft start means is started is automatically set based on whether or not the detection means detects that the workpiece is within a predetermined distance from the saw blade. be able to.

Portable cutting machine according to claim 3 wherein, there is provided a claim 1 or 2 portable cutting machine, wherein said detection means, that is positioned further forward than the saw blade with respect to the cutting direction of the saw blade Features. With the above configuration, the detection unit can easily detect whether the workpiece is within a predetermined distance with respect to the saw blade.

A portable cutting machine according to a fourth aspect is the portable cutting machine according to the first aspect, wherein the detecting means is attached to the base. With the above configuration, the detection unit can accurately detect whether the workpiece is within a predetermined distance with respect to the saw blade.

The portable cutting machine according to claim 5 , wherein a motor, switch means for controlling on / off of power supply to the motor, a saw blade driven by the motor to cut a workpiece, and the saw blade A saw cover for covering, a base on which the saw cover is rotatably supported and an opening for projecting the saw blade is formed, and a soft start means for soft-starting the rotation of the motor, the switch means, The power supply to the motor is controlled, and the motor is started to rotate when operated more than a predetermined pulling amount, and the operation speed of the switch means is controlled within the predetermined pulling amount region. Detecting means for detecting, and when the operating speed is equal to or lower than a predetermined speed, the soft start means is started and the motor starts rotating, and the operating speed is If greater than the constant speed, the motor is characterized in that starts rotating without starting up said soft start means.

  When the operation speed detected by the detection means is equal to or lower than a predetermined speed, the rotation of the motor is soft-started by the soft start means. Accordingly, since the rotation of the saw blade is also soft-started, the reaction from the workpiece in the cutting operation at the initial stage of the rotation of the motor is suppressed, and for example, the deviation of the blade edge of the saw blade from the black line of the workpiece can be prevented. it can. On the other hand, when the operation speed detected by the detection means exceeds a predetermined speed, the motor starts rotating without being controlled by the soft start means. Therefore, when cutting the workpiece, the cutting operation can be completed in a short time.

The portable cutting machine according to claim 6 , wherein a motor, switch means for controlling on / off of power feeding to the motor, a saw blade driven by the motor to cut a workpiece, and the saw blade A saw cover for covering, a base on which the saw cover is rotatably supported and an opening for projecting the saw blade is formed, and a soft start means for soft-starting the rotation of the motor, the switch means, The power supply to the motor is controlled, and when the motor is operated over a predetermined pulling amount, rotation of the motor is started, and the operating time of the switch means is reduced within the predetermined pulling region. and a detecting means for detecting for, when the operation time is equal to or less than a predetermined time, the motor starts to rotate without starting up said soft start means, the operation time is before When exceeding the predetermined time, the motor and startup of the soft-start means is characterized by starting the rotation.

When the operation time detected by the detection means is less than or equal to the predetermined time, the motor starts rotating without being controlled by the soft start means. Therefore, when cutting the workpiece, the cutting operation can be completed in a short time. On the other hand, when the operation time detected by the detection means exceeds a predetermined time, the rotation of the motor is soft-started by the soft start means. Accordingly, since the rotation of the saw blade is also soft-started, the reaction from the workpiece in the cutting operation at the initial stage of the rotation of the motor is suppressed, and for example, deviation of the blade edge of the saw blade from the black line of the workpiece can be prevented. it can.

  According to the portable cutting machine of the present invention, when the workpiece is cut, the motor is automatically soft-started according to the user's initial movement operation that requires the motor to be soft-started. It is possible to achieve an excellent effect that the reaction from the workpiece can be suppressed.

The top view of the portable cutting machine by embodiment of this invention. The side view of a portable cutting machine. The power supply circuit diagram of a portable cutting machine. The flowchart of the process which cut | disconnects a workpiece by a portable cutting machine. The side view of the portable cutting machine during cutting work. The side view of the portable cutting machine during cutting work. The side view of embodiment at the time of using a microswitch as a detection means. The figure explaining the relationship between the pulling amount of a trigger switch, and the rotation speed of a saw blade.

  Hereinafter, a first embodiment of a portable cutting machine according to the present invention will be described with reference to FIGS. 1 and 2 show the overall configuration of the portable cutting machine 1, in which the right side is the front in the cutting direction and the left side is the rear in the cutting direction. The portable cutting machine 1 mainly includes a base 2 that is placed in contact with a workpiece during cutting operation, and is positioned on the opposite side of the workpiece 2 with respect to the base 2 and rotates relative to the base 2. The circular saw body 3 is provided so as to be movable.

  One side of the base 2 is in contact with and slides on the workpiece W, and an opening (not shown) for projecting the saw blade 6 toward the workpiece W is formed. Further, a rotation support portion 11 for rotating the circular saw body 3 with respect to the base 2 is provided in the vicinity of the front end portion in the cutting direction of the base 2, and the rotation support portion 11 includes a rotation pin. 12 extends parallel to the circular saw shaft 6A.

  The circular saw body 3 forms an outer shell with a housing 4 and a saw cover 5. The housing 4 is located on one side of the saw blade 6, and a motor 7 for rotationally driving the saw blade 6 and a power transmission mechanism (not shown) for transmitting the rotation of the motor 7 to the saw blade 6 are provided in the housing 4. Is built-in. A handle 8 and a trigger switch 14 that is operated by a user to control the rotation of the motor 7 are provided on the top of the housing 4. The trigger switch 14 corresponds to switch means. The saw cover 5 covers the upper half of the saw blade 6 and is integrally provided at one end of the housing 4. The end of the saw cover 5 on the front side in the cutting direction is rotatably connected to the rotation pin 12 so that the protruding amount of the saw blade 6 from the base 2 can be changed. Further, between the base 2 and the circular saw body 3, there is provided a fixing release mechanism 13 for fixing and releasing the rotational position of the circular saw body 3.

  A safety cover 9 is provided on the outer periphery of the saw blade 6 so as to be rotatable about a circular saw shaft 6A so as to cover the lower half of the saw blade 6 when not in use. When the workpiece W is cut forward from its rear end face, the safety cover 9 rotates to expose the lower half of the saw blade 6.

  Further, a sensor 15 for detecting the workpiece W is provided as a soft start means in the vicinity of the rotation support portion 11 of the base 2 and at a portion closer to the saw blade 6 than the tip portion in the cutting direction of the base 2. The sensor 15 is composed of an ultrasonic sensor, a laser sensor, a microswitch, or the like. The detection surface of the base 2 is attached downward at a distance D from the blade edge 6a of the saw blade 6 in the cutting direction A of the saw blade 6. ing. When the workpiece W is disposed at a close distance so as to face the detection surface, the sensor 15 has the edge W1 of the workpiece W positioned at a distance D or less with respect to the cutting edge 6a of the saw blade 6. As a result, a high level signal is output. On the other hand, the sensor 15 outputs a low level signal when there is no workpiece W facing the detection surface at a close distance.

  Further, a power supply circuit 20 that rotates the motor 7 is provided in the housing 4. As shown in FIG. 3, the power supply circuit 20 has a trigger switch 14, a soft start switch 22, and a motor 7 connected in series to a power supply 21. Further, the power supply circuit 20 has a controller 23. The controller 23 is connected to the sensor 15 and monitors on / off of the trigger switch 14 and controls on / off of the soft start switch 22. The soft start switch 22 has a function of soft-starting the rotation of the motor 7 when the trigger switch 14 is turned on when power is supplied to the motor 7 when turned on by a high level signal from the controller 23. . On the other hand, when the soft start switch 22 is turned off by a low level signal from the controller 23, when the trigger switch 14 is turned on, the motor 7 rotates without receiving any action of the soft start switch 22. Start. In the present invention, “soft start” is control for increasing the rotational speed of the motor 7 at a predetermined increase rate smaller than usual over a predetermined period from the start of power supply to the motor 7.

  Next, cutting of the workpiece W using the portable cutting machine 1 will be described with reference to the flowchart of FIG.

  When the portable cutting machine 1 is connected to the power source 21 to cut the workpiece W, the controller 23 and the sensor 15 are activated (S1). For example, as shown in FIG. 1, when the workpiece W is cut along the black line L, the cutting accuracy is required. Therefore, before starting the rotation of the saw blade 6, as shown in FIG. 5, the user arranges the saw blade 6a so that the blade edge 6a is as close as possible to the edge W1 of the workpiece W, as shown in FIG. The 6 cutting edges 6a are aligned with the black line L. This operation corresponds to a user's initial operation that requires a soft start of the motor. At this time, the edge W1 of the workpiece W is located closer to the saw blade 6 than the sensor 15, so that the detection surface of the sensor 15 faces the workpiece W at a close distance. That is, since the sensor 15 detects the workpiece W, it outputs a high level signal to the controller 23. Therefore, the controller 23 determines that the workpiece W is located within the predetermined distance D from the cutting edge 6a (S2: YES), and turns on the soft start switch 22 (S3).

  Next, when the trigger switch 14 is turned on (S4: YES), the rotation of the motor 7 is soft-started by the action of the soft-start switch 22 (S5). Therefore, the user can cut the workpiece W along the black line L without deviating from the black line L of the cutting edge 6a because the reaction from the workpiece W that occurs in the initial rotation of the motor 7 is suppressed.

  Next, when the cutting of the workpiece W is completed and the trigger switch 14 is turned off (S6: YES), the power supply to the motor 7 is interrupted and the saw blade 6 stops rotating (S7).

  On the other hand, when cutting the workpiece W without requiring processing accuracy, for example, when the cutting portion of the workpiece W by the saw blade 6 may be slightly displaced from the black line L, first, FIG. As shown in FIG. 5, only the vicinity of the tip 2A in the cutting direction of the base 2 is placed on the workpiece W. This operation does not correspond to the user's initial operation that requires a soft start of the motor. At this time, the edge W1 of the workpiece W is spaced from the cutting edge 6a and is located at a distance from the cutting edge 6a by a distance D. That is, the sensor 15 does not detect the workpiece W and outputs a low level signal to the controller 23. Accordingly, the controller 23 determines that the workpiece W is not within the predetermined distance D from the cutting edge 6a (S2: NO), and turns off the soft start switch 22 (S8).

  Next, when the trigger switch 14 is turned on (S9: YES), the rotation of the motor 7 starts without soft start (S10). That is, the rotation of the motor 7 reaches the specified rotational speed within a short time (S10), and the cutting of the workpiece W can be started.

  Next, when the cutting of the workpiece W is completed and the trigger switch 14 is turned off (S6: YES), the power supply to the motor 7 is interrupted and the saw blade 6 stops rotating (S7).

  As described above, when the cutting edge 6a of the saw blade 6 is brought close to the workpiece W and the cutting edge 6a and the black line L are aligned to cut the workpiece W with high accuracy, the sensor 15 outputs a high level signal. The soft start switch 22 is turned on. Accordingly, since the rotation of the motor 7 is soft-started when the trigger switch 14 is turned on, the reaction from the workpiece W that is likely to occur at the early stage of the saw blade 6 is suppressed, and the cutting edge 6a is prevented from being displaced from the black line L. It is possible to process the workpiece W with high accuracy.

  Further, when it is desired to cut the workpiece W in a short time, for example, when the cutting blade 6 is rotated and then the cutting work is performed close to the workpiece W, the workpiece W is separated from the cutting edge 6a by more than the distance D. Therefore, the soft start switch 22 is turned off. In this state, when starting the rotation of the saw blade, the motor 7 starts rotating without soft start, so that the specified rotational speed is reached in a short time, and the cutting operation can be completed efficiently.

  Further, in the above embodiment, the microswitch 30 shown in FIG. 7 may be used instead of the sensor 15. The microswitch 30 is turned on and outputs a high level signal when the workpiece W is disposed at a close distance so as to face the detection surface. On the other hand, when there is no workpiece W facing the detection surface at a close distance, the micro switch 30 remains off and outputs a low level signal.

  Further, the sensor 15 that detects the workpiece W can be attached to an arbitrary position of the portable cutting machine 1. Furthermore, the sensor 15 does not necessarily have to be directly attached to the portable cutting machine 1.

  Next, a second embodiment of the portable cutting machine according to the present invention will be described with reference to the drawings. In the second embodiment, detection is performed to detect soft start driving within a moving range while the switch means is not operated by the operator, that is, until the motor 7 starts to be driven from the OFF state. Means are provided to switch the soft start mechanism ON / OFF.

  The switch means is a trigger switch 14 having an operation unit. In the vicinity of the trigger switch 14, the operation time or the operation speed of the operation unit at a predetermined pulling amount (play) when power supply to the motor 7 is started. It has a detecting means for detecting. The trigger switch 14 is a position where the motor 7 is not driven, that is, a position where the trigger switch 14 is OFF (position 1), a position where the operator pulls the trigger switch 14 and the cutting blade is driven at a normal rotation speed, ie, the trigger switch 14. Is at the maximum position (position 2), and the operator slightly pulls the trigger switch 14 and the motor 7 starts to drive (position 3). From position 1 to position 3 is a range of play of the so-called trigger switch 14.

  First, an example in which a sensor that detects the operation speed of the operation unit is used as detection means will be described. As shown in FIG. 8A, the detecting means detects the pulling speed of the trigger switch 14 from the position 1 to the position 3, and when the pulling speed exceeds a predetermined speed, the cutting blade is driven at a normal rotational speed. Set in the control unit (not shown). Conversely, as shown in FIG. 8B, when the pulling speed is equal to or lower than a predetermined speed, the control unit (not shown) is set so that the soft start mechanism operates. That is, when the predetermined pulling speed at which the soft start mechanism operates is (pulling speed)> (predetermined pulling speed), the control unit (not shown) is set to drive the cutting blade at the normal rotation speed. To do. Conversely, when (pulling speed) ≦ (predetermined pulling speed), a control unit (not shown) is set so that the soft start mechanism works.

  Next, an example in which a sensor that detects the operation time of the operation unit is used as the detection unit will be described. As shown in FIG. 8B, the detection means detects the pulling time of the trigger switch 14 from position 1 to position 3, and when the pulling time exceeds a predetermined time, the control unit ( Set to (not shown). On the other hand, as shown in FIG. 8A, when the pulling time does not exceed the predetermined time, the control unit (not shown) is set to drive the cutting blade at the normal rotation speed. That is, the control unit (not shown) is set so that the soft start mechanism works when the predetermined pulling time for operating the soft start mechanism is (pulling time) ≧ (predetermined pulling time). Conversely, when (pulling time) <(predetermined pulling time), the control unit (not shown) is set so that the cutting blade is driven at a normal rotational speed.

  Although the sensor that detects the trigger switch 14 from the position 1 to the position 3 with the time and speed is used, the trigger switch 14 is temporarily pressed at the position 3 and the soft start mechanism is operated with the predetermined temporary pressing time. You may comprise so that a switch may turn ON. Note that a motion sensor, an acceleration sensor, or the like is appropriately used as the sensor.

  In the above description, the sensor is used as the detection means to control the soft start drive. However, without using the sensor, the operator pulls the trigger switch 14 over a predetermined pulling amount (play) and pulls the trigger switch 14 completely. A latch or a temporary fixing portion may be provided near the intermediate position below the above state so that the trigger switch 14 can be pulled in two stages, and the soft start mechanism may be operated at that position. Furthermore, it is good also as a structure which can provide the trigger switch 14 with a button, a lever, etc. separately, and can lock the pulling amount of the trigger switch 14 near an intermediate position by operating and switching a button, a lever, etc. That is, any member can be used as long as it can be locked in the vicinity of the intermediate position even when the trigger switch 14 is pulled to the maximum extent.

  A commercial power source or a battery pack can be used as the power source 21. When an AC power source is used as the power source 21, an AC motor can be used. When a DC power source is used as the power source 21, a DC motor can be used. Further, when the power source 21 is an AC power source and the motor 7 is for DC, the power circuit 20 includes a rectifier circuit, and when the power source 21 is a DC power source and the motor 7 is for AC, the power circuit 20 is Including an inverter circuit.

  The present invention can be applied not only to a portable cutting machine but also to a tabletop cutting machine of the same type as a cutting machine.

  The portable cutting machine of the present invention can be used for an appropriate portable cutting machine that requires a soft start of rotation of a motor depending on the application.

2 Base 5 Saw cover 6 Saw blade 7 Motor 14 Switch means 22 Soft start means

Claims (6)

A motor,
Switch means for controlling on / off of power supply to the motor;
A saw blade that is driven by the motor to cut the workpiece;
A saw cover covering the saw blade;
A base on which the saw cover is rotatably supported and an opening for projecting the saw blade is formed;
Soft start means for soft starting rotation of the motor;
Detecting means for detecting that the workpiece has approached a predetermined distance or less with respect to the saw blade before the start of rotation of the motor;
With
When the detection means detects that the workpiece is below a predetermined distance with respect to the saw blade before the rotation of the motor starts, the soft start means starts when the switch means is operated The portable cutting machine characterized in that the motor starts to rotate. After the detecting means detects that the workpiece is below a predetermined distance with respect to the saw blade, the soft start means is started when the switch means is turned on,
If the switch means is turned on before the detection means detects that the workpiece is below a predetermined distance with respect to the saw blade, the soft start means will not start and the motor will start rotating. The portable cutting machine according to claim 1, wherein:   The portable cutting machine according to claim 1 or 2, wherein the detecting means is located in front of the saw blade with respect to a cutting direction of the saw blade.   The portable cutting machine according to any one of claims 1 to 3, wherein the detection means is attached to the base. A motor,
Switch means for controlling on / off of power supply to the motor;
A saw blade that is driven by the motor to cut the workpiece;
A saw cover covering the saw blade;
A base on which the saw cover is rotatably supported and an opening for projecting the saw blade is formed;
Soft start means for soft starting rotation of the motor;
With
The switch means is configured to control power supply to the motor and to start rotation of the motor when a predetermined pulling amount is reached from the start of operation of the switch means .
Detecting means for detecting an operation speed of the switch means from the start of operation of the switch means to the predetermined pull amount within the predetermined pull amount region;
When the operation speed is less than or equal to a predetermined speed, the soft start means starts and the motor starts to rotate, and when the operation speed exceeds the predetermined speed, the soft start means does not start and the motor A portable cutting machine characterized by starting rotation. A motor,
Switch means for controlling on / off of power supply to the motor;
A saw blade that is driven by the motor to cut the workpiece;
A saw cover covering the saw blade;
A base on which the saw cover is rotatably supported and an opening for projecting the saw blade is formed;
Soft start means for soft starting rotation of the motor;
With
The switch means is configured to control power supply to the motor and to start rotation of the motor when a predetermined pulling amount is reached from the start of operation of the switch means .
Detecting means for detecting an operation time of the switch means required from the start of operation of the switch means to the predetermined pulling amount ;
When the operation time is less than or equal to a predetermined time, the soft start means does not start and the motor starts rotating, and when the operation time exceeds the predetermined time, the soft start means starts and the motor A portable cutting machine characterized by starting rotation.

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