JPS61214982A - Electric nailer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an electric nailer that drives nails in a magazine from a nailing opening into a workpiece such as a construction board by attracting a plunger by excitation of an electromagnetic solenoid. This relates to nail driving control.

(Prior art) Conventionally, in the case of an electric nailer that drives a nail into a board or the like by suction driving a plunger by exciting an electromagnetic solenoid with a direct current from an AC power source, the nailer is driven once for each nail driven. An electromagnetic solenoid is repeatedly energized a specified number of times at predetermined time intervals, but with this method, for example, the nail head may remain due to changes in the hardness of the board depending on the nail driving position, or In addition, each time the length or thickness of the nail changes, it is necessary to test drive the nail and adjust the number of times the nail is driven, that is, the number of times the power is supplied to excite the 'R magnetic solenoid. The disadvantage was that the change in hardness did not change the fact that the head of the nail remained or the nail was driven in too far.

(Problems to be Solved by the Invention) The present invention allows nail driving to be performed in an optimal state even if the hardness of the board changes, or the length or thickness of the nail changes, without making any troublesome adjustments. Our goal is to provide an electric nailer that can be used at a constant rate.

(Means for Solving the Problem) The present invention provides an electric nailer in which nails in a magazine are driven out of a nailing opening into a workpiece by suction of a plunger by excitation of an electromagnetic solenoid, and the plunger corresponds to the amount of driven nails. a full stroke detection sensor that generates an output signal corresponding to the full stroke movement when the plunger moves the full stroke; and after the electromagnetic solenoid is energized by switch operation, the full stroke detection sensor corresponds to the full stroke movement of the plunger. The electric nailer is provided with a driving control circuit that excites the electromagnetic solenoid at arbitrary time intervals until an output signal is generated.

(Function) When a nail is driven by the excitation of the electromagnetic solenoid when the switch is turned on, if the hardness of the board is relatively soft, the electromagnetic solenoid moves the entire stroke with one excitation and completes the driving of the nail. At the same time, when this driving is completed, an output signal corresponding to the full stroke movement of the plunger is generated from the full stroke detection sensor, and the nail driving operation is automatically stopped. Because the plunger does not move the full stroke when energized, the electromagnetic solenoid continues to be energized at arbitrary time intervals, and when the nail is driven, the full stroke detection sensor generates an output signal corresponding to the full stroke of the plunger. Then, the nail driving operation is automatically stopped, and the nail can be stably driven into an optimal state without being over-driven or under-driven.

(Example) Next, the configuration of an example of the present invention will be described with reference to the drawings.

Due to the suction of the plunger 3 against the urging force of the spring 2 due to the excitation of the electromagnetic solenoid 1, the hammer 4 protruding from the tip of the plunger 3 drives out the nails 6 stored in the magazine 5 one by one from the lower part. At the same time as driving, the regulation plate 8 moves upward against the biasing force of a spring (not shown) while the nail driving lower is in contact with a workpiece such as a board, and the nail 6 in the magazine 5 moves in the direction of the nail driving lower. A main switch SW1, which is operated by an automatic return lever 11, is attached to the handle 10 of the electric nailer 9, and a main switch SW1, which is operated by an automatic return lever 11, is attached to the upper part of the main body 12 of the electric nailer 9. Light emitting element 13 and light receiving element 14 of photoelectric switch PS1 as a detection sensor
is installed.

Next, FIG. 2 is an electrical control circuit diagram of this embodiment, in which the electromagnetic solenoid 1 of the electric nailer 9 is connected to the AC power supply AC via the silicon AC control element TRCl, and the silicon AC control element TRC1 is connected to the AC power source AC. A trigger circuit 16 consisting of the light receiving element 15 of the cover PC1 and resistors R1 to R4, a series circuit of a protective resistor R5, and a capacitor C1 are connected to form a drive circuit 17 for the electromagnetic solenoid 1.

The full-wave rectifier RE1 connected to the AC power supply AC via the transformer PTI includes a resistor R6 and a Zener diode ZD1.
An inverter ITI is connected which inputs the trapezoidal wave formed by the AC waveform and outputs a pulse at the zero cross of the AC waveform.
Full wave rectifier R via diode D1 and capacitor C2
The stabilized power supply circuit element Q1 connected to EI includes a main switch SW1, resistors R7 to R9, and a transistor TR1.
A one-shot circuit 19, in this case, resistors RIO to R1, is connected to the one-shot circuit 19 via a zero-cross circuit 18 that synchronizes the output from the main switch SW1 at the zero-cross of the AC waveform.
2, capacitors C3, C4, inverters lT2, IT3
, a NOR circuit N0R1, and an AND circuit AND1 are connected, and the light emitting element 13 and the light receiving element 14 are connected to the power supply VC through resistors R13 and R14, respectively.
The output from the photoelectric switch PS1 and the output from the main switch SW1 connected to
JK flip-flop circuit J input via IT4
The output from the AND circuit AND2 which inputs the output from K-FF1 and the output from the one-shot circuit 19 is connected to the resistor R.
15 to the transistor T'R2 to control the trigger circuit 16 of the silicon AC control element TRC1.

Next, the operation of this embodiment will be explained.

In response to the driving of the nail 6 , the nail driving lower of the electric nailer 9 comes into contact with a workpiece such as a board, and in this state, the regulating plate 8 moves upward against the biasing force of a spring (not shown) and closes the magazine 5 .
In addition to regulating the movement of the inner nail 6 in the lower nail driving direction, when the main switch SWI is turned on in this state, the one-shot circuit 19 is activated in synchronization with the zero cross of the AC waveform.
The silicon AC control element TRCl is connected via the photocoupler PC1 and the trigger circuit 16 at regular intervals determined by the time constant of
is triggered and turned on, and this turn-on operation is performed as many times as the photoelectric switch PSI is in the OFF state in which the plunger 3 does not move the entire stroke by suction, but even in one turn-on operation, the plunger 3 moves the entire stroke by suction. At times, the photoelectric switch PS1 is turned on and the JK flip-flop circuit JK-FF is turned on.
The output of I is reversed and the nail driving operation is completed, and when the nail driving operation of the electric nailer 9 is released from the workpiece such as a board in response to the next nail driving in this completed state, the regulating plate 8 is activated by a spring (not shown). The electric nailer 9 is moved downward by the biasing force to release the restriction on movement of the nail 6 in the magazine 5 in the lower nail driving direction.
When the main switch SW1 is turned to O6 while the nail driving lower is brought into contact with a workpiece such as a board for the next nail driving, the above operation is repeated again.

The photoelectric switch PSI as a full stroke detection sensor that is turned on when the plunger 3 has suctioned a full stroke is a piezoelectric element or a piezoelectric element that comes into contact with the plunger 3 and generates an output when the plunger 3 has suctioned a full stroke. Any full stroke detection sensor can be used, such as one that detects the peak of the magnetic flux density of a magnetic open circuit using a coil.

(Effects of the Invention) The present invention provides an electric nailer with a full stroke detection sensor that generates an output signal corresponding to the full stroke movement when the plunger moves the full stroke corresponding to the amount of nail driven. For example, a driving control circuit as shown in FIG. 2 is provided which excites the electromagnetic solenoid at arbitrary time intervals until the full stroke detection sensor generates an output signal corresponding to the full stroke movement of the plunger after the electromagnetic solenoid is energized. As a result, even if the hardness of the board changes, or the length or thickness of the nail changes, the driving of the nail can be maintained at the optimum level without making any troublesome adjustments. be.

[Brief explanation of drawings]

FIG. 1 is a cutaway front view of one embodiment of the present invention, FIG. 2 is its electric circuit diagram, and FIG. 3 is its operating diagram. 1... Electromagnetic solenoid 3... Plunger 4...
Hammer 6... Nail 9... Electric nailer 16... Trigger circuit 17.
...Drive circuit 18...Zero cross circuit 19...
・One-shot circuit PSL...Photoelectric switch RCI...Silicon AC control element Applicant Makita Electric Co., Ltd. Representative Patent attorney Oka 1) Hidehiko (and 2 others)! Figure 2: No drawings Figure 3

Claims (3)

[Claims] (1) An electric nailer drives the nails in the magazine out of the nailing opening and into the workpiece by suction of the plunger due to the excitation of an electromagnetic solenoid. a full stroke detection sensor that generates an output signal corresponding to the movement of the plunger; and a full stroke detection sensor that activates the electromagnetic solenoid until the full stroke detection sensor generates an output signal that corresponds to the full stroke movement of the plunger after the electromagnetic solenoid is energized by a switch operation. An electric nailer characterized in that it is provided with a driving control circuit that excites at arbitrary time intervals. (2) The electric nailer according to claim 1, wherein a photoelectric element is used as the full stroke detection sensor. (3) The electric nailer according to claim 1, wherein a piezoelectric element is used as the full stroke detection sensor.