JP3022243B2 - Nailer safety equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device for a nailing machine, and more particularly to a safety device for preventing a malfunction when a nail is dropped.

[0002]

2. Description of the Related Art Conventionally, a trigger device of a portable nailing machine has
It is composed of a trigger lever and a contact arm arranged in the nose part, and when the trigger lever is pulled and the tip of the contact arm is brought into contact with the nail driving target and pushed in, the other end of the contact arm is The tip of the arm pivotally attached to the trigger lever is pushed up, and the arm pushed up entirely by the trigger lever and the contact arm arm pushes the valve stem of the switching valve for starting operation, and the nail is fired. Therefore, a mechanical safety mechanism is provided in which the nail is not fired even when the trigger lever is operated in the off position where the contact arm is not pressed against the object to be driven.

[0003]

When a conventional portable nailing machine is erroneously dropped and the nailing machine collides with a floor or the like with its nose part facing upward, a trigger lever and a contact arm are used. May be slid or rotated by inertia to be in a fired operation state, and the nail may be fired upward.

[0004] Therefore, there arises a technical problem to be solved in order to eliminate the possibility that the nail is shot in an unexpected direction at the time of falling and to improve safety, and the present invention solves the above-mentioned problem. The purpose is to:

[0005]

SUMMARY OF THE INVENTION The present invention is proposed to achieve the above-mentioned object, and comprises a driving mechanism comprising a piston / cylinder mechanism and a main mechanism for introducing compressed air into the cylinder or discharging compressed air from the cylinder. A pneumatic nailer, comprising: a switching valve; a starting valve for operating the main switching valve; and a trigger lever and a contact arm for supplying a starting signal to the starting valve. An arm or a start / stop device for mechanically or electrically locking the start operation valve at the off position is provided, and a pressure switch or a pressure detector such as a piezoelectric element is provided on a rear end surface of the drive mechanism housing of the nailing machine, A safety device for a nailing machine provided with a control circuit for switching to a start / stop state via the start / stop means in response to an ON signal of the pressure detector A.

[0006]

When the nailing machine of the present invention falls on the floor or the like with the nose part facing upward and the rear end face of the drive mechanism housing collides with the floor or the like, the pressure is detected by a pressure switch or the like provided on the rear end face. The container turns on. When the trigger lever and the contact arm move to the ON position due to the impact at the time of the collision, the mechanical or electrical start / stop means stops the drive current output to the start operation solenoid valve by the ON signal of the pressure detector. Since the trigger lever or the contact arm is locked at the off position to prevent the activation of the air cylinder, the nail is not fired into the air.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an air-driven nail driver 1. A casing 2 is formed integrally with a drive mechanism housing 3 and a grip 4 as an air chamber, and the drive mechanism housing 3 incorporates an air cylinder. . A trigger lever 5 is slidably mounted on the lower surface of the drive mechanism housing 3, and a contact arm 7 is mounted on the outer periphery of the nose 6.

The trigger housing 8 in front of the trigger lever 5 contains a trigger switch, a contact switch, a start control circuit, and a start operation solenoid valve, which will be described later. The slider portion of the trigger lever 5 and the contact arm 7 are extended into the trigger housing portion 8, and the trigger switch is turned on by operating the trigger lever 5, and the contact switch is turned on by pressing the contact arm 7 against the target to be driven.

A pressure switch 10 is mounted on an end cap 9 fitted to the rear end surface of the drive mechanism housing 3, and a sensor plate 11 is mounted on the pressure switch 10. An air coupling 12 is attached to an end of the grip portion 4, and connects the air coupling 12 and an air compressor via an air hose. Further, a nail magazine 13 is provided between the nose part 6 and the grip part 4,
The connected nail loaded in the nail magazine 13 is driven by a nail feed mechanism 14.
To supply the nose part 6 sequentially.

FIG. 2 shows a circuit of a nail driving mechanism of the nail driving machine 1. A driver rod 17 connected to a piston 16 in an air cylinder 15 descends in the nose 6 to remove a nail in the nose 6. Fire. The upper end of the air cylinder 15 is open, and the connection between the air cylinder 15 and the air chamber 19 is turned on and off when the main switching valve 18 provided at the upper end opening of the air cylinder 15 moves up and down. The pressure in the air chamber 19 acts on the upper surface (lower in the figure) of the main switching valve 18 via a starting operation solenoid valve 20 (hereinafter simply referred to as a solenoid valve) and a pilot passage 21. Since the pressure receiving area on the upper surface is larger than the pressure receiving area on the outer peripheral portion of the lower surface, the main switching valve 18 is pressed against the upper end opening of the air cylinder 15 due to the pressure difference between the upper and lower sides, so that the air cylinder 15 and the air chamber 19 are shut off. , The air cylinder 15 communicates with the atmosphere.

The trigger switch 22 and the contact switch 23 are input to a first AND gate 24, and the output is input to a second AND gate 25 for controlling the solenoid valve 20. The output signal of the pressure switch 10 is input to the one-shot multivibrator 26, and the inverted output of the one-shot multivibrator 26 is input to the second AND gate 25.

When an ON signal is output from the second AND gate 25 to the solenoid valve drive current amplifier 27, the solenoid valve 20 is driven, the pilot passage 21 is opened, and the main switching valve 18 is opened.
Is switched, and the air chamber 19 and the air cylinder 15 communicate with each other. Then, the piston 16 is driven downward by the high-pressure air in the air chamber 19, and the nail in the nose portion 6 is fired.

Normally, the off signal of the pressure switch 10 is inverted via the one-shot multivibrator 26 and input to the second AND gate 25. Therefore, when the trigger lever 5 and the contact arm 7 are turned on, the on signal is output from the first AND gate 24 to the second
Is input to the AND gate 25, the electromagnetic valve 20 is driven and the air cylinder 15 is activated.

On the other hand, when the nailing machine 1 is erroneously dropped and the sensor plate 11 collides with the floor or the like, the pressure switch 1
0 is turned on, and the inverted output of the one-shot multivibrator 26 is turned off for a certain time. Accordingly, even if the trigger lever 5 and the contact arm 7 move to the on position due to inertia when the nose portion 6 collides with a floor or the like with the nose part 6 facing upward, an on signal is output from the second AND gate 25. No nails are fired into the air. Then, after the impact at the time of collision converges and the pressure switch 10 is turned off and the trigger lever 5 and the contact arm 7 return to the standby position, the inverted output of the one-shot multivibrator 26 changes to on, and the nailing machine 1 The start / stop state is released. Note that various circuits can be applied to the control circuit instead of those described above, and a microcomputer may be used.

FIG. 3 shows another embodiment, which is basically the same as the structure of the mechanical trigger device of the conventional nailing machine. A contact arm is provided on the lower surface of the distal end of a free arm 32 pivotally attached to a trigger lever 31. The upper end of 33 is opposed, and the trigger arm 31 is pulled and the contact arm 33 is pressed against a plate or the like, whereby the entire free arm 32 is pushed upward and the manually operated start operation valve 34 is switched.

A lock pin 35 of a solenoid drive type is provided on the back side of the trigger lever 31, and a lock pin drive solenoid 36 is connected to a control device 37. The lock pin drive solenoid 36 is controlled by the control device 37 according to the state of the pressure switch 10. When the pressure switch 10 is turned on due to a drop or the like, a drive current is output to the lock pin drive solenoid 36, and the lock pin 35 projects. The trigger lever 31 is locked in the off position, and prevents the nail from being erroneously fired as in the safety device of FIG.

The present invention is not limited to the above-described embodiment. For example, the contact arm 33 may be locked at the off position by a solenoid-driven lock pin 35.

[0018]

According to the present invention, as described in detail in the above-described embodiment, when the air cylinder built-in portion of the nailing machine collides with a floor or the like, the impact is detected and the start / stop processing of the air cylinder is performed. Accordingly, when the nailing machine is dropped, it is possible to prevent the starting mechanism from malfunctioning due to an impact, to eliminate the possibility that the nail is fired in an unexpected direction, and to further improve safety.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention and is a side view of an air-driven nailing machine.

FIG. 2 is a block diagram of the safety device according to claim 2;

FIG. 3 is a block diagram of the safety device according to claim 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pneumatic driven nail driver 2 Casing 3 Drive mechanism housing 5,31 Trigger lever 6 Nose part 7,33 Contact arm 9 End cap 10 Pressure switch 11 Sensor plate 20 Solenoid valve 22 Trigger switch 23 Contact switch 24,25 AND gate 26 One-shot multivibrator 35 Lock pin 36 Lock pin drive solenoid 37 Control device

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akifumi Hamano 6-6 Nihonbashi Hakozakicho, Chuo-ku, Tokyo Max. Co., Ltd. (72) Inventor Yoichi Kimura 6-6 Nihonbashi Hakozakicho, Chuo-ku, Tokyo Max Inside (72) Inventor Hiroshi Hanagasaki 6-6, Hakozakicho, Nihonbashi, Chuo-ku, Tokyo Inside Max Corporation (56) References JP-A-1-115579 (JP, A) JP-A-63-283876 (JP, A) JP-A 5-88880 (JP, U) JP-A 55-2542 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B25C 7/00 B25C 1 / 04

Claims (3)

(57) [Claims] 1. A drive mechanism comprising a piston / cylinder mechanism, a main switching valve for introducing compressed air into the cylinder or discharging the compressed air from the cylinder, a starting operation valve for operating the main switching valve, and the starting operation valve A trigger lever (5) or a contact arm (7) or a start operation valve is mechanically or electrically turned to an off position. And a pressure switch (10) or a pressure detector such as a piezoelectric element is provided on a rear end face of the drive mechanism housing (3) of the nailing machine.
A safety device for a nailing machine, comprising a control circuit for switching to a start / stop state via the start / stop means in response to an ON signal of the pressure detector. 2. A safety device for a nailing machine according to claim 1, wherein said starting and stopping means is a control circuit for controlling a driving current to an electromagnetically driven starting operation valve (20) of the nailing machine. 3. The method according to claim 2, wherein the start / stop means includes a trigger lever (3
A safety device for a nailing machine according to claim 1, comprising a lock pin (35) for mechanically locking the contact arm (33) in the off position or a lock pin drive solenoid (36).