JP4192460B2 - Electric tool with linear motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric tool with a linear motor that performs cutting or cutting work by attaching a blade such as a jigsaw or saver saw to a shaft end of a linear motor and reciprocating the blade with a linear motor.
[0002]
[Prior art]
When a conventional reciprocating tool such as a jigsaw or saver saw is cut or cut by a reciprocating motion, a predetermined reciprocating amount is secured by a mechanism that converts the rotational motion of the motor rotor into a linear motion. However, there is a problem that not only the mechanism is complicated, but also vibration and noise are large.
[0003]
[Problems to be solved by the invention]
To solve this problem, Japanese Patent Application No. 2001-205735 has a linear motor-equipped power tool that performs cutting or cutting work by attaching a blade such as a jigsaw or saver saw to the shaft end of a linear motor and reciprocating the blade with a linear motor. Proposed by issue. However, when the power switch is turned on, the movement start position is not fixed because the position where the mover starts moving is determined by the timing when the power switch is turned off. For this reason, when the reciprocating operation is performed from the position of the mover when the power switch is turned on, the mover hits the housing of the electric tool on the forward side or the reverse side, resulting in inconvenience in work. In addition, since the conventional electric tool which converts motor rotation into reciprocating motion mechanically reciprocates within a predetermined range, there is no inconvenience.
[0004]
The object of the present invention is to eliminate the disadvantages of the prior art described above.
[0005]
[Means for Solving the Problems]
The above-described object is achieved by providing a movable position information area on the movable element and providing a movable element operation area detecting means for detecting the movable position information area.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the electric tool with a linear motor of the present invention will be described with reference to the drawings showing an embodiment. FIG. 1 is a conceptual diagram showing a basic configuration of an electric tool with a linear motor of the present invention. 1 is a linear motor, 1a is a mover of the linear motor 1, 2 is a switching means for changing the frequency and direction of voltage applied to the linear motor 1, and the reciprocating speed of the linear motor 1 is controlled by changing the frequency. By changing the application direction, the forward movement (forward movement) and the backward movement (backward movement) of the linear motor 1 are switched. 3a is a trigger lever disposed at the base of the grip portion of the electric power tool T, 3b is a power switch that operates in conjunction with the trigger lever 3a, the contact is closed when the trigger lever 3a is pulled, and the contact is opened when the trigger lever 3a is returned. 4a is a control means for controlling the switching means 2. 4b is a reciprocating movement amount setting means for setting the reciprocating movement amount, and 4c is a reciprocating movement speed setting means for setting the reciprocating movement speed, both of which are variable resistors or digital output values whose resistance value changes by rotation or linear motion. Consists of a digital switch and the like. Reference numeral 5 denotes a DC power source, 6 denotes a tip tool such as the blade attached to the shaft end of the linear motor 1, and 9 denotes a mover operation region detecting means.
[0007]
FIG. 2 is a basic detection configuration diagram for reciprocating the mover 1a within a predetermined region. A notch 1b is provided at the end opposite to the shaft end where the tip tool 6 is attached to the mover 1a to form a moveable position information area, and a mover operation area detecting means 9 for detecting the moveable position information area is provided. ing. The mover operation area detection means 9 is composed of a forward movement restriction detection means 9a and a backward movement restriction detection means 9b. Specifically, 9a and 9b are composed of a reflection type photo sensor and an inductance type sensor. Although two detection means 9a and 9b are provided, the same effect can be obtained with only one detection means.
[0008]
When the trigger lever 3 a is pulled, the power switch 3 b is closed, and a voltage is supplied from the DC power source 5 to the linear motor 1 via the switching means 2. The control means 4a for controlling the switching means 2 controls the driving frequency and the driving voltage application direction by the reciprocating movement amount setting means 4b and the reciprocating movement speed setting means 4c, so that the reciprocating movement amount and the reciprocating movement speed of the linear motor 1 are controlled. Control. The above operation can be limited to a reciprocating movement region determined by the mover operation region detecting means 9.
[0009]
FIG. 3 is a circuit diagram showing a specific circuit configuration of FIG. Reference numerals 1b and 1c denote first-phase and second-phase motor coils when the linear motor 1 is a two-phase stepping motor. Reference numeral 2 denotes switching means that forms a bridge circuit with resistors and transistors. Reference numeral 4a denotes arithmetic means 4a1, ROM 4a2, and RAM 4a3. , A control means comprising a single chip microcomputer (hereinafter referred to as a microcomputer) comprising a timer 4a4, an output port 4a5, an A / D converter 4a6, and a reset input terminal 4a7. 4b is a reciprocating movement amount setting means comprising a variable resistor, 4c is a reciprocating movement speed setting means comprising a variable resistor, 5 is a DC power source comprising a battery, 7 is a three-terminal regulator serving as a power source for the microcomputer 4a, etc. Is a reset IC for generating a reset signal to the microcomputer 4a.
[0010]
4 and 5 are a main operation flow and a timer interrupt operation flow based on FIG. When the power switch 3b is closed by operating the trigger lever 3a, the microcomputer 4a starts operation (step 101), resets the initial position setting end flag, and performs initial setting (step 102). Subsequently, the set value is read from the reciprocating movement amount setting means 4b (step 103), and the reciprocating movement amount K is calculated and set by the calculating means 4a1 (step 104). Next, the set value is read from the reciprocating speed setting means 4c (step 105), the actual reciprocating speed is calculated by the calculating means 4a1, the drive frequency, that is, the timer interruption time is determined (step 106), and the timer is started (step). 107). If the reciprocating speed is set to be increased, the microcomputer 4a shortens the timer interruption time so as to increase the driving frequency.
[0011]
When the timer interrupt operation is performed (step 201), it is first determined whether the initial position setting end flag is set (step 202), and when the initial position setting end flag is reset, reverse control is performed (step 203). ). Subsequently, it is determined from the signal from the backward movement restriction detection means 9b whether or not the movable piece 1a is in the backward movement restriction position by using the notch 1b which is the movable position information area of the movable body 1a (step 204). When the mover 1a has not reached the retreat limit position, a return is made (step 221). When the mover 1a reaches the backward limit position, an initial position setting end flag is set (step 205), and a forward flag is set (step 206).
[0012]
When the initial position setting end flag is set, it is determined whether the forward flag is set (step 210). When the forward flag is set, forward control is performed (step 211). This controls the switching means 2 from the output port 4a5 of the microcomputer 4a. Next, the actual movement step number n is counted up (step 212), and it is determined whether the movement amount K has been reached (step 213). If the movement amount K is not reached, a return is made (step 221). When the movement amount K is reached, the forward flag is reset (step 214), the actual movement step number n is reset to 0 count (step 215), and a return is made (step 221). When the forward flag is reset, reverse control is performed (step 216). Next, the actual movement step number n is counted up (step 217), and it is determined whether the movement amount K has been reached (step 218). If the movement amount K is not reached, a return is made (step 221). When the movement amount K is reached, a forward flag is set (step 219), the actual movement step number n is reset to 0 count (step 220), and a return is made.
[0013]
In the above embodiment, the initial position is set by the backward movement, but the same effect can be obtained even by the forward movement.
[0014]
【The invention's effect】
As described above, according to the present invention, by installing the movable position information area on the movable element and by installing the movable element operation area detecting means for detecting the movable position information area, the movable element of the linear motor can be set in a predetermined manner. It is possible to reciprocate within the range.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing a basic configuration of an embodiment of an electric tool with a linear motor according to the present invention.
FIG. 2 is a basic detection configuration diagram for reciprocating a mover within a predetermined region.
3 is a circuit diagram showing an example of a specific circuit configuration of FIG. 1. FIG.
FIG. 4 is a flowchart showing a main operation based on FIG. 3;
FIG. 5 is a flowchart showing a timer interrupt operation based on FIG. 3;
[Explanation of symbols]
1 is a linear motor, 2 is a switching means, 3a is a trigger lever, 3b is a power switch, 4a is a control means (microcomputer), 4b is a reciprocating movement amount setting means, 4c is a reciprocating movement speed setting means, 5 is a DC power supply, 6 Is a tip tool, and 9 is a mover operation area detecting means.

Claims (1)

An electric tool with a linear motor that attaches a tip tool to the shaft end of a linear motor and performs cutting or cutting work by reciprocating the tip tool,
A position information area formed on the mover of the linear motor and indicating a movement position of the mover;
An operation area detecting means for detecting the position information area in a non-contact manner;
Drive signal output means for switching the forward movement operation and the backward movement operation of the mover by outputting a drive signal to the linear motor;
An electric tool with a linear motor, comprising control means for controlling the drive signal output means based on a detection signal from the operation area detection means .

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