JP2001162557A - Driving machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving machine embodied in a small-sized and lightweight construction in which a driver blade is made lighter for decreasing the reaction and also made thinner so that the height of the machine body is lessened and it is made practicable that a surplus energy of the driver blade is absorbed without enlarging a piston bumper. SOLUTION: A driver blade 4 is composed of a blade part 4b and a piston part 4a made of the same material, and the piston part 4a is provided with a thin walled portion 4d, and the surplus energy is absorbed by deflecting the piston part 4a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving machine for driving a fastener such as a nail, for example, a pneumatic nailing machine, and has an improved piston and driver blade.

[0002]

2. Description of the Related Art A pneumatic driving machine is provided with a driver blade made of a high-strength metal material for driving a fastener into a material to be driven such as wood, and a piston made of a light metal which receives the pressure of compressed air. I have.

[0003] The piston 4a and the driver blade 4b are
As shown in FIG. 6, they are integrally connected via a screw 4g, and an adhesive is applied to the screw fitting portion, or the piston 4a described in Registered Utility Model No. 2559438 is plastically flowed, so that the screw fitting is performed. The joint is not loosened.

A pneumatic driving machine will be described with reference to FIGS. An air passage 13 provided with a check valve 12 and a lower portion of a piston 4 a in the cylinder 3 are provided in the cylinder 3 so that compressed air flowing from the pressure accumulating chamber 2, which will be described later, into the cylinder 3 flows only in the direction of the return air chamber 11. An air passage 8 is provided in communication with the side to return the driver blade 4 to the top dead center. A piston bumper 7 made of a flexible material such as rubber is provided near the bottom dead center of the driver blade 4 to absorb excess energy after driving the nail 5 of the driver blade 4.

The driver blade 4b integrally connected to the piston 4a is pressed above the piston 4a in the cylinder 3 by the compressed air in the pressure accumulating chamber 2, and moves rapidly in the cylinder 3 toward the bottom dead center. The nail 5 is driven, and the air below the piston 4 a in the cylinder 3 flows into the return air chamber 11 through the air passage 8, and after the piston 4 a passes through the air passage 13 provided in the cylinder 3, the cylinder 3 The compressed air above the inner piston 4 a also flows into the return air chamber 11. Excess energy of the driver blade 4b after driving the nail 5 is converted into heat and sound by the piston 4a bending the piston bumper 7. When the compressed air above the piston 4a in the cylinder 3 is exhausted, the driver blade 4b presses the lower side of the piston 4a in the cylinder 3 by the compressed air accumulated in the return air chamber 11, and returns to the top dead center. .

The driving machine body 1 moves upward as a reaction to the driver blade 4b, which is integrally connected to the piston 4a, moves rapidly in the direction of the bottom dead center in the cylinder 3. In order to reduce this recoil, the piston 4a
In order to reduce the weight, a light metal having a small specific gravity is used, or the driver blade 4b is hollow.

As shown in FIG. 7, in order to prevent the piston bumper 7 from being caught in the air passage 8 and being damaged when the piston bumper 7 is bent, the outer periphery of the piston bumper 7 is reduced in thickness in consideration of the deformation allowance, and a large gap 15 is provided. ing.

As shown in FIG. 8, the distance between the lower surface 4e of the piston 4a in contact with the piston bumper 7 and the seal member 6 is increased, and the air passage 8 is disposed above the piston bumper 7, so that the piston bumper 7 The device is designed so that the piston bumper 7 does not get caught in the air passage 8 even if it bends.

[0009]

In the above-mentioned driving machine, the piston 4a is made of a light metal having a low specific gravity, or the driver blade 4b is hollowed to reduce the reaction. Although the device is devised, the driver blade 4b and the piston 4a are inevitably heavy and thick in order to secure the strength of the connecting portion with the screw while securing the strength. Further, if the distance between the lower surface 4e of the piston 4a and the lower surface 4e of the piston 4a, which is in contact with the piston bumper 7, is increased so that the piston 4 does not break due to the air passage 8 when the piston 4 is bent, the piston 4 becomes thicker. , It will be heavy. In addition, the connection between the piston 4a and the driver blade 4b requires a large number of work steps, and a heavy load is applied.

When the outer circumference of the piston bumper 7 is reduced in anticipation of a deformation allowance so that the piston bumper 7 does not get caught in the air passage 8 when the piston bumper 7 is bent, the volume of the piston bumper 7 is reduced and excess energy is absorbed. In some cases, the strength of the piston bumper 7 was insufficient.

SUMMARY OF THE INVENTION An object of the present invention is to provide a small and lightweight driving machine which eliminates the above-mentioned disadvantages of the prior art, has a small recoil, and can absorb excess energy.

[0012]

The above object is achieved by integrally forming a piston and a driver blade and providing a thin portion on the piston so that the piston bends in the thrust direction when the piston comes into contact with the piston bumper. Is done.

[0013]

1 to 4 show one embodiment of the present invention. First, the overall structure will be described. Compressed air from a compressor (not shown) is accumulated in the accumulator chamber 2 of the driving machine body 1 via an air hose (not shown). A cylindrical cylinder 3 is provided in the driving machine main body 1, and a driver blade 4 is provided in the cylinder 3 so as to be able to reciprocate up and down. The driver blade 4 includes a piston 4 a and a blade 4 b having a conventional structure. The nails 5 are driven into one piece by the tip 4c and made of the same material. A thin-walled portion 4d having a reduced thickness is provided inside the piston portion 4a, and absorbs a part of surplus energy after driving the nail 5 and contributes to weight reduction. Further, since the driver blade 4 is made of a high-strength material, the thickness between the piston lower surface 4e and the piston upper surface 4f can be reduced, and the screw portion 4g for coupling is not provided.
The length of the driver blade 4 and thus the height of the driving machine main body 1 can be reduced, and the recoil can be reduced by reducing the weight. A partition wall 4h is provided on the outer periphery of the piston lower surface 4e. When the piston bumper 7 contacts the piston lower surface 4e at the bottom dead center, the piston bumper 7 and the air passage 8 are cut off. However, the piston bumper 7 is prevented from being damaged by being caught in the air passage 8. A seal member 6 such as an O-ring for sealing between the piston portion 4a and the cylinder 3 is provided on the outer periphery of the piston portion 4a.

A sleeve valve 9 is provided on the outer periphery of the upper side of the cylinder 3. The lower end of the sleeve valve 9 opens the upper end of the cylinder 3 and closes the exhaust valve 10, so that the pressure accumulating chamber 2 communicates with the upper side of the piston portion 4a in the cylinder 3. When the sleeve valve 9 rises, the upper end of the cylinder 3 is closed and the exhaust valve 10 is opened, so that the upper side of the piston 4a in the cylinder 3 communicates with the atmosphere. A return air chamber 11 for storing compressed air for returning the driver blade 4 to the top dead center is provided on the outer periphery of the lower end of the cylinder 3, and the return air chamber 1 is returned from the cylinder 3 during the reciprocation of the driver blade 4.
An air passage 13 having a check valve 12 communicating only in one direction is provided, and an air passage 8 communicating the cylinder 3 and the return air chamber 11 is provided on the outer periphery of the lower end of the cylinder 3. A piston bumper 7 for absorbing excess energy of the driver blade 4 after driving the nail 5 is provided at the lower end of the cylinder 3. The piston bumper 7 is made of a flexible material such as rubber, and converts surplus energy into heat and sound by being deformed.

Next, the driving operation of the driving machine 1 having the above-described configuration will be described.

FIG. 1 shows a state in which compressed air is stored in the pressure accumulating chamber 2.
Shown in The sleeve valve 9 shuts off the space between the pressure accumulating chamber 2 and the cylinder 3, and the upper side of the piston portion 4a of the cylinder 3 communicates with the atmosphere. The driver blade 4 is located at the top dead center.

FIG. 3 shows a state in which the driver blade 4 has moved to the bottom dead center and is in impact contact with the piston bumper 7. Open the sleeve valve 9 and store the pressure accumulating chamber 2 and cylinder 3
When the upper side of the piston portion 4a of the cylinder 3 communicates with the upper side of the piston portion 4a of the cylinder 3 to shut off the atmosphere, the compressed air in the accumulator 2 flows into the upper side of the piston portion 4a of the cylinder 3, and the driver blade 4 rapidly moves toward the bottom dead center. Descends.

The driver blade 4 descends while driving a nail 5 (not shown) in the tail cover 14 into the wood,
When the sealing member 6 passes through the air passage 13, the cylinder 3
A portion of the compressed air above the piston portion 4a of the
Through the return air chamber 11. Air below the piston portion 4 a of the cylinder 3 flows into the return air chamber 11 via the air passage 8. Excess energy after driving the nail 5 is converted into heat or sound by bending the piston bumper 7. The space 15 around the outer periphery of the piston bumper 7 is filled,
The gap 16 inside the piston bumper 7 is reduced.

Due to the inertial force of the driver blade 4, the thin portion 4d bends and absorbs a part of the surplus energy after the nail 5 is driven.

Even if the piston bumper 7 bends to the outer periphery, the piston bumper 7 and the air passage 8 are blocked by the partition wall 4h, so that the piston bumper 7 does not get caught in the air passage 8.

FIG. 4 shows a state in which the driver blade 4 statically presses the piston bumper 7 by the pressure of the pressure accumulating chamber 2 after the piston bumper 7 absorbs the excess energy after the nail 5 is driven. The driver blade 4 and the piston bumper 7 have no impact deflection and have returned to the top dead center side from the state of FIG.

When the sleeve valve 9 is closed in this state,
The compressed air above the piston portion 4a of the cylinder 3 is exhausted to the atmosphere, and the compressed air stored in the return air chamber 11 causes the driver blade 4 to return to the top dead center and return to the state shown in FIG.

In the driver blade 4 shown in FIG. 2, the thickness of the thin portion 4d is insufficient, and
Was found to be damaged. FIG. 5 shows a configuration of the driver blade 40 for preventing this breakage, in which the thickness of the thin portion 40d is increased. Since the center shape of the thinned portion is simply a drill hole, machining can be simplified, and the secondary effect of facilitating the manufacture of the driver blade 40 can be obtained.

[0024]

According to the present invention, since the piston and the driver blade are made of an integral material, the piston and the driver blade can be made lighter and thinner than a conventional driver blade, so that the recoil of the driving machine body can be reduced and the driving machine can be driven. The height of the main body can be reduced, and as a result, the size and weight can be reduced. Since a thin portion is provided in the piston portion so that the thin portion bends when the piston portion comes into contact with the piston bumper, excess energy can be absorbed without reducing the volume of the piston bumper. Furthermore, a partition is provided around the lower surface of the piston that contacts the piston bumper to block the piston bumper and the air passage, so that the distance between the lower surface of the piston that contacts the piston bumper and the seal member is not increased, and when the piston bumper is bent. It is possible to obtain an operational effect such that the piston bumper can be prevented from being caught in the air passage and damaged.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a driving machine according to the present invention.

FIG. 2 is a sectional view showing one embodiment of a driver blade constituting the driving machine of the present invention.

FIG. 3 is a cross-sectional view showing a state where the driver blade receives an impact force.

FIG. 4 is a sectional view showing a state after the impact force of the driver blade has been absorbed.

FIG. 5 is a sectional view showing another embodiment of the driver blade.

FIG. 6 is a sectional view showing a conventional screw connection type driver blade.

FIG. 7 is a cross-sectional view showing a piston bumper reduced in thickness in anticipation of a deformation allowance.

FIG. 8 is a cross-sectional view showing a conventional driver blade in which a distance between a lower surface of a piston and a seal member is large.

[Explanation of symbols]

1 is a driving machine body, 4 is a driver blade, 4a is a piston portion, 4b is a blade portion, 4d is a thin portion, 4e is a piston lower surface, 4f is a piston upper surface, 4g is a screw portion, 4h is a partition, and 7 is a piston bumper. , 8 are air passages.

Claims (2)

[Claims] 1. A reciprocating movement is provided in a cylinder,
A driving machine including a piston fixedly driven by compressed air, a driver blade integrally connected to a piston and hitting a stopper, and a piston bumper for absorbing excess energy of the driver blade, wherein the piston and the driver blade are provided. And a thin portion provided on the piston so that the piston bends in the thrust direction when the piston comes into contact with the piston bumper. 2. The driving machine according to claim 1, wherein a partition wall is provided on an outer periphery of a lower surface of the piston in contact with a piston bumper of the piston.