JPH09314480A - Pneumatic nail driver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the reaction in starting and the impact in driving a pneumatic nail driver. SOLUTION: In a pneumatic cylinder unit 3 inserted in a cylinder holder in a housing 2a of a mechanism part, a head valve 8 is assembled with a pneumatic cylinder 17. A control port and a trigger valve 9 of the head valve 8 are connected to each other by a flexible hose 10, and the pneumatic cylinder unit 3 is urged in the driving direction of a nail by a spring 21. When a piston is started, the repulsion is absorbed by the upward movement of the pneumatic cylinder 17 in the opposite direction to that of a piston 13. When the piston 13 collides with a bumper 22 at a bottom part of the cylinder, the kinematic energy of collision is absorbed by the mass of the pneumatic cylinder 17, and the repulsion during the starting and the impact during the driving are not transmitted to a housing 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air nailing machine for hand-held work, and more particularly to an air nailing machine which reduces recoil at the time of starting and impact at the time of driving.

[0002]

2. Description of the Related Art In a conventional general pneumatic nailing machine, an air cylinder is fixed in a housing with a grip, and a space around the air cylinder and a space in the grip portion are under pressure. It is an air chamber. When the nose is pressed against a plate material and the trigger lever is operated, the head valve at the top of the air cylinder opens and the pressure air in the pressure air chamber flows into the air cylinder, which activates the piston and drives the nose block. The driver rod ejects the nail that is being supplied to the passage.

In the above pneumatic nailing machine, since the air cylinder is fixed to the housing, at the moment when the head valve is opened and the piston is activated, the pressure of the pressurized air causes the housing to recoil in the direction opposite to the moving direction of the piston. Occurs. Also, when the nail is driven and the piston collides with the shock absorbing bumper arranged at the bottom of the air cylinder, kinetic energy in the same direction as the direction of injection of the nail is applied to the housing, causing a reaction to the operator's hand. The impact is transmitted, which causes discomfort to the operator and causes fatigue.

Further, the applicant of the present application mounts an air cylinder and a cylinder housing on a grip and a nose block which are integrally connected so as to be slidable in the direction of injection of a nail, and when the nail is hammered, the air cylinder and the cylinder housing are moved according to the internal pressure of the cylinder. By moving the cylinder and the cylinder housing, a recoil at the time of starting the piston is absorbed, and a pneumatic nailing machine is proposed in which the fluctuation of the nail driving depth due to the recoil is prevented (Japanese Patent Publication No.
23915). However, even in the above-described pneumatic nailing machine, there is a problem that the impact of the collision is transmitted to the nose block and the grip when the piston ejects the nail and collides with the bumper provided on the nose block side.

Therefore, there is a technical problem to be solved in order to suppress the recoil and impact at the time of nailing to reduce the degree of fatigue and improve workability, and the present invention solves the above problems. The purpose is to

[0006]

DISCLOSURE OF THE INVENTION The present invention is proposed in order to achieve the above-mentioned object, and an air cylinder is housed in a housing, and the compressed air supplied into the housing is used as a power source for the air. In an air nailer that drives a piston in a cylinder and injects a nail supplied into the nose block of the housing by a driver rod connected to the piston, an upper end is closed and a shock absorbing member for the piston is attached to a lower end. A built-in air cylinder unit is mounted in the housing so as to be slidable within a certain range in the axial direction of the cylinder, and a suspension is provided in the housing for urging the air cylinder unit in the nail ejection direction. The reaction force and the collision energy between the piston and the shock absorbing member at the end of the stroke are Is converted into a reciprocating motion energy of the gas-cylinder unit is intended to provide an air nailing machine, characterized by damping the housing.

Further, an air nailing machine provided with shock absorbing means on both sides in the sliding direction of the air cylinder unit, an air nailing machine in which the shock absorbing means is an air damper, and the shock absorbing means is a vibration absorbing rubber or silicone. An air nailing machine which is an elastic material damper such as gel is provided.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an air nailer 1, in which a die-cast housing 2 is formed by integrally forming a mechanism housing 2a and a grip 2b. The air cylinder unit 3 is inserted in the mechanism housing 2a whose both ends are open, the nose block 4 is coupled to the tip of the mechanism housing 2a, and the end cap 5 is attached to the rear end opening. .

By connecting the air hose connector 6 connected to the end of the grip 2b and the air compressor with a hose, pressurized air is supplied to the periphery of the air cylinder unit 3 and the pressurized air chamber 7 in the grip 2b.

Head valve 8 of air cylinder unit 3
Control port and trigger valve 9 are flexible hose 1
When the contact arm 11 mounted on the nose block 4 is pushed in and the trigger lever 12 is turned on, the trigger valve 9 opens and the pressure air acting on the back surface of the head valve 8 is discharged. ,
The head valve 8 retracts due to the pressure difference between the back surface and the outer peripheral surface of the head valve, and the air chamber of the air cylinder unit 3 and the pressurized air chamber 7 communicate with each other. As a result, the pressure air in the pressure air chamber 7 flows into the air chamber, and the piston 1
3 is driven forward from the standby position, and the driver rod 14 connected to the piston 13 ejects the nail in the nose block 4.

A nail feed mechanism 1 is provided on the side surface of the nose block 4.
5 is arranged, a spring offset type air cylinder (not shown) of the nail feeding mechanism 15 moves backward and forward in conjunction with the nail striking operation, and sequentially nose blocks the connected nails stored in the nail magazine 16. Supply into 4

As shown in FIG. 2, in the air cylinder unit 3, the head cover 18 is mounted on the top of the air cylinder 17, the head valve 8 is inserted into the head cover 18, and when the head valve 8 is lowered, the pressure is reduced. The air chamber 7 and the air chamber of the air cylinder 17 are shut off,
When rising, the pressure air chamber 7 and the air cylinder 17 communicate with each other as described above.

The air cylinder unit 3 is inserted into cylindrical cylinder holders 19 and 20 which are fixed vertically in the mechanism housing 2a and is slidable in the axial direction of the air cylinder 17, so that the mechanism housing 2a. A compression coil spring 21 inserted between the end cap 5 at the upper end of the air cylinder unit 3 and the head cover 18 of the air cylinder unit 3 stabilizes the air cylinder unit 3 at the lower end position in the sliding range.

Further, similarly to the conventional pneumatic nailing machine, a bumper 22 made of oil resistant rubber is provided on the inner bottom of the air cylinder unit 3.
Vents 24, 25 communicating with the surrounding blowback chamber 23 are provided near the lower end of the air cylinder unit 3 and above the air cylinder unit 3, and a check valve 26 is attached to the upper vent 24. ing.

FIG. 3 shows an air nailer 31 according to a third aspect of the present invention. The air cylinder unit 32 has an O-ring 34 mounted on the outer peripheral surface of an upper flange 33a formed at the upper and lower intermediate portions of the outer peripheral surface of the air cylinder 33. Then, the mechanism unit housing 2a
It is inserted in the cylinder holder 19 inside.

The upper and lower ends of the upper cylinder holder 19 into which the flange 33a is inserted are closed to form an air chamber 35, and the air chamber 35 is connected to the atmosphere by a vent 36. Therefore, the air cylinder unit 32 receives sliding resistance due to the viscosity of the air in the air chamber 35, but the flange 33a does not collide with the upper and lower surfaces of the air chamber 35 during nailing, and the sliding resistance is maximized. The size of the vent hole 36 is set to be small.

Although not shown in the drawing, instead of the vent hole 36 communicating with the atmosphere, a vent hole penetrating vertically in the flange 33a is provided, or an air passage connecting the upper and lower chambers of the flange 33a is provided. The air cylinder unit 32 may be slidable by communicating air on both upper and lower sides of 33a. Further, in the case of an air nailing machine using a high-power type air cylinder unit, the ventilation hole 36 of the air chamber in FIG. 3 may be closed to increase the damping force.

Next, the operation of the pneumatic nailing machine of the present invention will be described with reference to FIG.
The air nailer 31 will be described as an example. First, when the trigger operation is performed from the initial state shown in FIG. 3, the head valve 8 opens as shown in FIG.
3 and the piston 13 is driven in the protruding direction,
The air cylinder 33 floats in the direction opposite to the piston 13 to absorb the repulsive force at the time of startup.

Then, as shown in FIG. 5, the driver rod 14 drives the nail into the object to be driven and, at the same time, the piston 13 is driven.
Collides with the bumper 22 at the bottom of the cylinder, but the floating air cylinder 33 descends to absorb the kinetic energy of the collision, and the recoil at the time of starting and the impact at the time of driving are not transmitted to the housing 2.

Then, the piston 13 rises by the pressure of the compressed air accumulated in the blowback chamber 23 when the piston descends, and the air cylinder 33 returns to the initial position of FIG. 3 by the bias of the compression coil spring 21.

FIG. 6 shows the pneumatic nailing machine 41 of the invention as claimed in claim 4, wherein an elastic damper ring is provided on the flange 43a of the air cylinder 43 of the air cylinder unit 42 to cover the upper and lower surfaces of the flange 43a and the outer peripheral surface. 44 is attached. As the material of the damper ring 44, a vibration-proof rubber such as silicone rubber or urethane rubber, or a vibration-damping material having self-shape retention and restoration such as silicone gel is used.
In this pneumatic nailing machine 41, due to the action of the damper ring 44, the sliding resistance of the air cylinder 43 is increased as compared with the pneumatic nailing machine of FIGS. 2 and 3, but the pneumatic nailing machine having a high working air pressure is used. If the vibration damping force of the air damper is insufficient in the machine, it is effective to use the damper ring 44.

The present invention is not limited to the above embodiment, and although not shown, the air cylinder units 3, 32, 42 and the head valve 8 are separated and the head valve is incorporated in the housing 2 side. The outlet port of the head valve and the air chamber of the air cylinder may be connected by a flexible hose. Further, a flexible hose is not used to connect the head valve 8 on the housing side to the air cylinder, and a slide valve structure is provided in which air ports are provided on the sliding surfaces of the air cylinder and the cylinder holder. Various modifications can be made within the technical scope of the present invention, such as supplying pressurized air to the air cylinder through the peripheral surface port, and it goes without saying that the present invention extends to those modifications.

[0023]

As described above, in the pneumatic nailing machine of the present invention, the air cylinder unit is slidably assembled with respect to the housing, and there is a reaction at the time of starting the piston and a piston at the time of nailing. The air cylinder unit slides and absorbs the impact caused by the bumper collision. Therefore,
The recoil and impact are not transmitted to the housing grip, which is effective in reducing fatigue and improving workability.

Further, since the impact of the piston is not transmitted to the nose block and the housing, the required degree of connection strength between the nose block and the housing is lowered, so that the weight of the nose block can be reduced and the weight of the pneumatic nailing machine can be reduced. Can contribute to.

[Brief description of drawings]

FIG. 1 is a side sectional view of an air nailing machine showing an embodiment of the present invention.

FIG. 2 is a sectional view of a main part of the pneumatic nailing machine according to claim 1.

FIG. 3 is a sectional view of an essential part of the pneumatic nailing machine according to claim 3;

FIG. 4 is a cross-sectional view of essential parts showing an operating state of the pneumatic nailing machine of FIG.

5 is a cross-sectional view of essential parts showing an operating state of the pneumatic nailing machine of FIG.

FIG. 6 is a sectional view of an essential part of the pneumatic nailing machine according to claim 4;

[Explanation of symbols] 1 air nailer 2 housing 3 air cylinder unit 4 nose block 7 pressure air chamber 8 head valve 10 flexible hose 13 piston 14 driver rod 17 air cylinder 18 head cover 19, 20 cylinder holder 21 compression coil spring 22 bumper 31 Air nailer 32 Air cylinder unit 33 Air cylinder 33a Flange 35 Air chamber 36 Vent 41 Air nailer 42 Air cylinder unit 43 Air cylinder 43a Flange 44 Damper ring

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takao Tsukada 6-6, Hakozakicho, Nihonbashi, Chuo-ku, Tokyo Max Co., Ltd.

Claims (4)

[Claims] 1. An air cylinder is housed in a housing,
In an air nailing machine for driving a piston in the air cylinder by using pressurized air supplied into the housing as a power source and injecting a nail supplied into the nose block of the housing by a driver rod connected to the piston. , An air cylinder unit with the upper end closed and a shock absorbing member for the piston built in at the lower end is slidably mounted within the housing in a certain range in the axial direction of the cylinder, and the air cylinder unit is ejected with a nail in the housing. A suspension that urges in the direction is provided, and the reaction force at the time of starting the piston and the collision energy between the piston and the shock absorbing member at the end of the stroke are converted into reciprocating kinetic energy of the air cylinder unit to suppress the housing. An air nailer that is characterized. 2. The pneumatic nailing machine according to claim 1, wherein buffer means is provided on both sides of the air cylinder unit in the sliding direction. 3. The pneumatic nailing machine according to claim 2, wherein the buffer means is an air damper. 4. The pneumatic nailing machine according to claim 2, wherein the cushioning means is a vibration damper or an elastic material damper such as silicone gel.