JPH0557634A - Driving tool - Google Patents

Abstract

PURPOSE:To eliminate malfunction due to chattering and deterioration of reliability due to variation with the lapse of time. CONSTITUTION:In a driving tool provided with a reciprocated striker 3 for driving continuously supplied nails or staples into a board and the like by means of the striker 3, a switching element S1 provided between the driving source for the striker and an electric power supply, a pulse generating means to generate pulse for ON/OFF of the switching element S1, and a switch to start the pulse generating means are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a striking tool for striking nails or staples continuously supplied with a reciprocating striker onto a board or the like by the striker, and more particularly to adjusting the striking force.

[0002]

2. Description of the Related Art In a device in which a striker is reciprocally driven by a drive source such as a motor or a solenoid, conventionally, a switch has been constituted and a mechanical stop system has been adopted as shown in FIG. That is, the switches SW1 and SW2 are turned on and off at the same time. In the initial state, the switches SW1 and SW2 are turned off and the switch SW3 is turned on. When the switches SW1 and SW2 are turned on, a circuit is formed on the normally open side of the switches SW1 and SW3, the motor 2 is started, and when the driving is completed, the switch SW1 and SW2 are turned on.
3 is turned off, a circuit is constituted by the normally open side of the switch SW2 and the normally closed side of the switch SW3, and the motor 2 stops. When the switches SW1 and SW2 are turned off, a circuit is constituted by the normally closed side of the switch SW2 and the normally closed side of the switch SW3, and the motor 2 moves to a position where the switch SW3 is turned on again, and when the switch SW3 is turned on. Switch SW1, 2
Is turned off, the switch SW3 is turned on, and the motor 2 is stopped.

[0003]

In this case, since three switches SW1, SW2, and SW3 having mechanical contacts are used, chattering of the contacts in these switches may cause a malfunction such as double strike. In addition, there is a problem that reliability deteriorates due to a change with time of the switch contact.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a driving tool which is free from malfunction due to chattering and deterioration in reliability due to aging.

[0005]

SUMMARY OF THE INVENTION The present invention, however, provides a drive source and a power source for a striker in a driving tool for driving a nail or staple, which is provided with a reciprocating striker and continuously supplied, into a board or the like by the striker. It is characterized in that it is provided with a switching element provided between and, a pulse generating means for generating a pulse for turning on / off the switching element, and a switch for starting the pulse generating means.

According to the present invention, since a switching element that electrically turns on and off and a pulse generating means that controls the switching element are used instead of a mechanical switch, the problem caused by the mechanical switch can be eliminated. it can.

[0007]

The present invention will be described below in detail with reference to the illustrated embodiments. The mechanical structure will be described first. In the tool body of this driving tool, a motor 2 and a striker 3 are housed in a tool body 1 as shown in FIGS. 8 to 11, and a magazine 4 is attached to the lower portion of the tool body 1. ing. The magazine 4 includes a guide rod 40, a pressing spring 41, and a pressing frame 42, and continuously supplies the staple 5 to a position below the striker 3. In the figure, 10 is a battery pack, and 11 is a main switch. A deceleration portion 21 that decelerates the rotation of the motor 2 is attached, a rotary plate 23 is attached to the output shaft of the deceleration portion 21, and an eccentric pin 24 is provided on the surface of the rotary plate 23. On the other hand, the striker 3 is held by the upper and lower guide blocks 15 and 16 so as to be slidable up and down, and as shown in FIG. 9, an engaging plate 30 having a horizontally elongated hole 31 with which the eccentric pin 24 is engaged is attached. By the eccentric rotation of the eccentric pin 24, the eccentric pin 24 is reciprocally driven up and down.

As shown in FIG. 1, a pulse generating circuit P is connected to the main switch 11, and the drive switching element S1 for driving the motor 2 and the both ends of the motor 2 are short-circuited to forcibly stop the motor 2. The braking switching element S2 is connected. Now, when the signal from the main switch 11 is input to the pulse generating circuit P, the pulse generating circuit P turns off the braking switching element S2 which has been on until then and drives it as shown in FIG. The switching element S1 is turned on only for the time t ₁ to rotate the motor 2 and cause the striker 3 to move up and down. During this time, the staple 5 is ejected. Then, after the lapse of time t ₁ , the driving switching element S1 is turned off and the braking switching element S2 is turned on to forcibly stop the motor 2.

In this case, however, the switching element S
Since the power supply may be short-circuited at the moment when 1 and S2 are switched, in reality, as shown in FIG. 3, from when the main switch 11 is turned on until the driving switching element S1 is turned on, the driving switching element S1 is turned on. Motor 2 from turning off to turning on the braking switching element S2
Between the start and stop of each t ₂ . It is preferable to prevent the short circuit of the power supply after the time of t ₄ .

When the main switch 11 causes chattering, the driving switching element S1 is turned on because the measurement of the time t ₁ is started from the second turn-on due to the chattering of the main switch 11, as shown in FIG. Is longer than set, and striker 3
The stop position is shifted, but as shown in FIGS. 5 and 6, the latch circuit L is provided in place of the pulse generation circuit P, and the main switch 11 and the striker 3 come to predetermined positions. This can be prevented by providing the reset switch 12 that sometimes generates one pulse and setting the OFF timing of the driving switching element S1 to the ON time of the reset switch 12.

Further, in this structure, when the signal of the reset switch 12 is input, the main switch 11 is erroneously input.
When is turned on, the operation of the latch circuit L becomes indefinite and malfunctions. However, as shown in FIG. 7, while the driving switching element S1 is on, the signal of the main switch 11 is the latch circuit. This can be prevented by providing a gate circuit G that prevents the input to L.

The pulse generated by the pulse generating means formed by the pulse generating circuit P and the latch circuit L is as follows.
Of course, it may be a triangular wave as well as a square wave.

[0013]

As described above, in the present invention, since the electric switching element is used for the switch of the motor, malfunction due to chattering or the like can be electrically prevented, and a large current flows. Since the switch contact is not necessary, it is possible to minimize deterioration of reliability of the switch contact due to aging.

[Brief description of drawings]

FIG. 1 is a block circuit diagram of an embodiment.

FIG. 2 is a time chart of the above.

FIG. 3 is another time chart.

FIG. 4 is a time chart of still another example.

FIG. 5 is a block circuit diagram of another example.

FIG. 6 is a time chart of the above.

FIG. 7 is a block circuit diagram of still another example.

FIG. 8 is a sectional view of an example.

FIG. 9 is a sectional view of an engaging portion between an eccentric pin and a striker.

FIG. 10 is a sectional view of a magazine.

FIG. 11 is a cross-sectional view at the time of ejecting staples.

FIG. 12 is a circuit diagram of a conventional example.

[Explanation of symbols]

 3 Striker P Pulse generator S1 Driving switching element S2 Braking switching element 11 Main switch

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mikihiro Yamashita 1048, Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Works Co., Ltd.

Claims (1)

[Claims] 1. A driving tool for driving nails or staples continuously supplied with a striker driven reciprocally to a board or the like by the striker, and a switching element provided between a drive source for the striker and a power supply, A driving tool comprising pulse generating means for generating a pulse for turning on and off the switching element and a switch for starting the pulse generating means.