JPS5843233B2 - Nailer bumper device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a screwdriver, which is a nailing member that is slidably and tightly fitted into a main cylinder built into a tool body and is integrally connected, as a nailing part that protrudes from the main body. This relates to a bumper device for a nail gun, which is arranged to receive the main piston at the bottom dead center position of the main piston to operate the main piston vigorously within the driver guide hole formed through the nose of the nail gun. be.

As shown in Fig. 1, this type of nailing machine operates by applying fluid pressure such as compressed air pressure to the main piston A to cause the main piston A to rapidly lower in the main cylinder B. The head E' of the nail E, which is pre-loaded into the driver guide hole ' of the nose D, is hit with the tip C' of the driver C integrally arranged in the axial direction of the nose D, and the nail E is pushed from the nose tip D''. There is a known structure in which nailing work can be easily performed by driving out the nails one by one.

That is, when driving a single nail, fluid pressure is introduced into the piston upper chamber B1 of the main cylinder B, and residual air in the piston lower chamber B2 is released to the atmosphere to drive the main piston A. It is rapidly moved forward from the top dead center toward the bottom dead center, and after completing the nail driving, return fluid pressure (spring pressure, etc. may be used in some cases) is applied to the main piston lower chamber B2 at the bottom dead center position, and The upper chamber B1 of the main piston is opened to the atmosphere, and the main piston is moved back from the bottom dead center position toward the top dead center.

Then, the main piston A is at the bottom dead center position,
The receiver is designed to be stopped by a bumper member F made of a hard rubber material, etc., but this bumper member F is designed to be strong enough to withstand the extremely large impact force of the main piston A directly. Therefore, it is formed as an integral piece in the shape of a thick block.

Therefore, when this bumper member F is formed from a rubber material or the like, variations in the molding structure are likely to occur between the inner wall center area and the outer periphery area, making it difficult to create a bumper with uniform properties as a whole. Met.

In addition, since this type of nailing machine is used to drive a large number of nails continuously and quickly, the collision between the main piston A and the bumper member F occurs repeatedly, and the work is extremely high. Since the process is carried out at high speed, there is a risk that the bumper member F will be rapidly heated and seize up.

Particularly in the case of a bumper with a large mass, it is difficult for heat to be released from the central part due to the characteristics of the rubber.

In addition, as mentioned above, if there is variation in properties between the center of the wall thickness and the outer surface, the bumper member F will be subject to severe wear and tear, making it impossible to use it continuously for a long time, and requiring frequent maintenance and inspection. .

The present invention has been proposed in view of such conventional circumstances, and aims to provide a highly reliable bumper for stopping the main piston of a nailer at the bottom dead center. .

Furthermore, it is an object of the present invention to form a bumper with less variation in properties as a whole.

Furthermore, another object of the present invention is to sufficiently prevent the bumper from rising during nail driving operations.

Furthermore, another object of the present invention is to provide a bumper device in which the bumper can be easily and accurately assembled near the lower end of the main cylinder, and the assembled state is stable.

Furthermore, the present invention aims to provide a bumper that is easy to manufacture and process and has excellent mass productivity.

A further object of the present invention is to provide a bumper that can release the back pressure during nail driving, that is, when the main piston moves forward, that is, can smoothly exhaust the lower chamber of the main piston.

The bumper device of the present invention is a bumper that is disposed at the lower end of a main cylinder built into a nailing machine body, and that receives a main piston that is slidably and tightly fitted into the main cylinder at the bottom dead center position. , this bumper has an outer ring block that has an engaging part on the outer circumferential wall that engages with the lower end of the main cylinder and has a through hole inside, and an inner ring block that has a driver insertion hole inside and an upper half part and a lower half part. A ring block is provided between the outer ring block and the inner ring block, and relative engagement means capable of preventing at least the inner ring block from being pulled out or dropped toward the main piston side, and the outer ring block The present invention is characterized in that voids through which air can flow are maintained between the butt and the inner ring block and between the upper half and lower half of the inner ring block.

Hereinafter, the present invention will be described with reference to embodiments shown in FIG. 2 and subsequent figures.

In Fig. 2, 1 is a bumper, and in this example, it is divided into two independent annular blocks: an outer ring block 11 which is an outer bumper portion divided in the radial direction, and an inner ring block 12 which is an inner bumper portion. It is designed to be assembled and used as an integral part.

Further, the inner ring block 12 is further divided into two in the axial direction, and two independent annular blocks, an upper half part 120 and a lower half part 121, are integrally assembled.

Reference numeral 2 denotes a nailing machine main body, which has a main cylinder 3 built therein and a nose 4 disposed at its lower end.

That is, the diameter of the vicinity of the lower end 2a of the main body 2 is reduced, and the lower end 31 of the main cylinder 3 is tightly fitted and held therein, and furthermore, the lower end is provided with a connecting portion provided at the base end of the nose 4 (upper end side in the figure). 41 are integrally connected.

As a result, the nose 4 has a driver guide hole 100 formed through the nose 4 in its axial direction and protrudes coaxially with the lower ends of the main body 2 and the main cylinder 3.

The inner wall of the connecting part 41 of the nose 4 has a flat part 41b inside the annular inclined surface 41a on the outer circumferential side, and further has a stepped part 42 in which the driver guide 5 is fitted and held.
is formed, and the portion 42 has a driver insertion hole 51 in the center.
A driver guide 5 having a diameter is loosely fitted therein.

A flange portion 52 is formed at the upper end of the driver guide 5 in the figure, and its surface 52a becomes the seating portion 12b of the inner block 12, and the flange portion periphery 52
A gap 8 is maintained between the step part peripheral wall 42a and the step part peripheral wall 42a.

The connecting portion 41 also includes a corner portion 4 of the stepped portion 42.
An opening 43 is provided that communicates 2b with the outside.

6 is a main piston, and an O-ring 6 is installed in the main cylinder 3 so that it can move freely in the vertical direction in the figure.
1 and are tightly fitted.

A female threaded hole 62 for connecting the driver is cut in the direction of the solid axis of the piston 6, and a female threaded portion 71 formed at the base end of the driver 7 is screwed into the hole 62, and the driver 7 is screwed into the hole 62.
are combined into one.

Note that a large diameter portion 3c constituting a bumper holding portion is formed on the inner peripheral wall of the lower end portion 31 of the main cylinder 3 and has a slightly larger diameter than the cylinder main diameter portion 3a from the stepped portion 3b. There is.

As shown in FIGS. 3A to 3C, the outer ring block 11 of the bumper 1 has a piston contact surface 11a annularly in contact with the lower surface 6a of the piston 6 on the upper end surface in the axial direction, Further, a seating portion 11b for the inclined surface 41a and flat portion 41b of the nose connecting portion 41 is formed on the lower end surface in the axial direction and the outer periphery on the lower end side, and furthermore, the outer peripheral wall bulges outward most at the midway point in the height direction. This forms an outwardly bulging portion 11c, and furthermore, an upper tapered portion 11d and a lower tapered portion 11e are continuously formed which gradually decrease in diameter from the core portion 11C toward both upper and lower ends in the axial direction.

Note that the vicinity of the outwardly bulging portion 11c is fitted into the large diameter portion 3c of the main cylinder 3, and is locked by the step portion 3b.

In addition, the inner through-hole peripheral wall 11' is provided with an inward bulge 11f so as to have a minimum diameter at a slightly upper position in the middle, and from this bulge 11f to each of the upper and lower end surfaces in the axial direction. An upwardly tapered portion 11h is continuously formed in the opposite direction and gradually increases in diameter.

Further, the inner ring block 12 has a driver insertion hole 13A formed in the center thereof so as to pass through it in the vertical direction, and an annular main piston contact surface 12a formed in the upper end surface in the axial direction. A seating portion 1.2b on the driver guide 5 is formed on the end face.

The diameter of the driver insertion hole 13A is the diameter of the driver insertion hole 13A.
Although the diameter is slightly larger than that of the shaft, the difference in diameter is slight.

Furthermore, the outer circumferential wall 12' of the inner ring block 12 has an outwardly bulging portion 12 which has its maximum diameter at a position slightly lower than the midway point in the axial direction.
e, and an upper tapered portion 12f and a lower tapered portion 12g are formed continuously from the core portion 12e, the diameter of which gradually decreases toward both upper and lower ends.

The inner diameter of the inward bulging portion 11f, which is the smallest diameter portion of the inner through hole 13B of the outer ring block 11, is greater than the outer diameter of the outer bulging portion 12e of the outer peripheral wall 12' of the inner ring block 12. Short and through hole 13 of outer ring block 11
What is the inner peripheral wall surface of the downwardly tapered hole portion 11i extending from the inwardly bulging portion 11f of the B inner peripheral wall 11′ toward the lower end, and the outer peripheral wall surface of the upper tapering portion 12f extending from the outwardly bulging portion 12e of the inner block 12 toward the upper end? The angles of inclination are such that they are parallel to each other, and sometimes the inner peripheral wall surface 11' and the outer peripheral wall surface 12' are assembled.
A small gap is maintained between them.

Further, the heights of the outer ring block 11 and the inner ring block 12 are the same, so that each piston contact surface 11
a and 12a are flush with each other.

Furthermore, the upper and lower sides of the bumper 1 in the axial direction, that is, the upper and lower sides in FIG. The inner ring block 12 is in communication in the vertical direction through the driver insertion hole 13A of the inner ring block 12.

Furthermore, in the present invention, the inner ring block 12 is formed separately into three independent upper and lower parts in the axial direction of the upper half part 120 and the lower half part 121, and is used by integrally assembling them. .

That is, in the illustrated example, the upper half portion 120 is
As shown in Figure A, it has a driver insertion hole 13A' that penetrates in the axial direction at the center, the piston contact surface 12a is formed at the upper end in the axial direction, and a comb tooth shape is formed at the lower end in the axial direction. A lower half assembly fitting portion 123 having an uneven shape is formed.

Furthermore, as shown in FIG. 4B, the lower half portion 121 has a concave groove 121a that communicates the inside and outside in the axial lower end surface where the seating portion 12b is formed, and a comb in the axial upper end surface. An upper half assembly fitting portion 124 having a tooth-like unevenness is formed.

Then, the concave portions X in each of the matching portions 123 and 124 are
The same number of convex portions Y are formed, and the concave portions X or convex portions Y in one fitting portion 123 or 124 and the convex portions Y or concave portions X in the other fitting portion 124 or 123 are mutually different. They are arranged to face each other.

The concave portion X of one of the compatible parts and the convex part Y of the other compatible part are formed such that the width of the concave part X is wider than the width of the convex part Y, and the concave part The depth of the portion X and the height of the convex portion Y are formed to have the same dimensions.

Therefore, when the matching concave portion X and convex portion Y are assembled as shown in FIG. It will be in a retained state.

Furthermore, as shown in the fourth diagram, if a radial concave groove YX is formed on the tip surface of the convex portion Y, this groove Y
A similar gap can be maintained and formed through X.

In the above configuration, the bumper 1 is located at the stepped portion 3 of the main cylinder 3 at the outwardly bulging portion 11c on the outer periphery of the outer ring block 11.
b, and furthermore, the inner ring block 12 has an upper tapered part 12f upward from the outer bulge 12e formed in the upper half part 120 of the inner ring block 12.
1f and relatively engages with the downward tapered portion 11h, preventing the main cylinder 3 from falling upward in FIG. .

This means that a stable installation condition can be obtained even when the nailer is used for ceiling driving, that is, when the nose 7 is directed upward and the nail is driven from below onto the surface to be nailed (not shown). become.

Further, the bumper 1 is arranged between the outer ring block 11 and the inner ring block 12, and further between the upper half portion 12 of the inner ring block 12.
0 and the lower half part 121 have a gap that can penetrate up and down in the axial direction and a gap that communicates with the inside and outside, so that air on the lower chamber side of the main piston flows into the outer ring block 1 during nail driving.
1 outer periphery and driver insertion hole 13A of inner ring block 12
In other words, the outer ring block 1
By exhausting the bumper 1 to the outside through the opening 43 after the entire outer circumferential surface of the bumper 1 and the entire outer circumferential surface of the inner ring block 12 are fully brought into contact with air, temperature rise due to compression heat of the bumper 1 can be extremely effectively suppressed. .

In addition, the bumper 1 includes an outer ring block 11 and an inner ring block 12.
Upper half part 120 and lower half part 121 that constitute
Since the blocks 11 and 12 can be separately formed and assembled together for use, the mass of each block 11 and 12 can be reduced compared to the case where the entire bumper 1 is integrally molded. The heat of compression can be dissipated extremely effectively.

Further, as in the above embodiment, the lower end seating portion 11b of the outer ring block 11 and the lower end seating portion 12 of the inner ring block 12 are provided.
Since it is extremely easy to design the space between the outer periphery 51b of the flange portion of the driver guide 5 and the peripheral wall 42a of the stepped portion 42 as shown in FIG. Damage caused by biting of the bumper 1 in the above-mentioned space due to the rattling of the driver guide 5 can be easily avoided.

In addition, when assembling the bumper 1, before assembling the nose 4, first fit the outer ring block 11 from the lower end side of the open main cylinder 3 in FIG. The upper half 120 of the inner ring block 12 is fitted into the inner hole of the inner ring block 12, and the lower half part 12
1 is fitted in a suitable manner, and then the nose 4 can be assembled together with the driver guide 5 so as to close the lid.

In this case, if the bumper 1 is integrally formed as a whole, it is extremely difficult for an operator to bend it by hand, so there is a drawback that fitting the bumper 1 into the lower end of the main cylinder 3 becomes complicated.

However, in the present invention, the outer ring block 11 is formed into an inner ring shape independent of the inner ring block 12, and a large through hole is formed in the central portion, making it easy to bend and therefore extremely easy to assemble. The attached person can perform the work.

Also, when removing the bumper 1 for repairs or the like, it is easy to remove the driver guide 5 together with the nose 4, first remove the inner ring block 12 from the outer ring block 11, and then remove the outer ring block 11. Can be removed.

Particularly when the bumper 1 is slightly deformed after being used for a long period of time, the bending of each block 11° and 12 is very effective.

As is clear from the embodiments described above, the intended purpose of the present invention can be fully achieved.

Note that the present invention is not limited to the structure shown in each of the above embodiments, but includes an outer ring block having an engaging portion on the outer circumferential wall for engaging the lower end of the main cylinder and having a through hole inwardly;
It consists of an inner ring block which has a driver insertion hole inward and is made up of an upper half part and a lower half part, and between the outer ring block and the inner ring block there is at least a hole on the main piston side of the inner ring block. Relative engagement means capable of preventing removal and falling are provided, and gaps through which air can flow between the outer ring block and the inner ring block and between the upper half part and the lower half part of the inner ring block. Further, various modifications are included as long as they include a configuration characterized by holding the following.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view schematically showing the structure of a conventional nailing machine equipped with a bumper. FIGS. 2 to 4 are diagrams showing an embodiment of the present invention,
FIG. 2 is an enlarged longitudinal cross-sectional view of the main part of the bumper in an assembled state, and FIG. 3 shows the bumper, with A being a plan view, B being a bottom view, and C being an external perspective view. FIG. 4 shows the inner ring block of the bumper, A is a side view of the upper half, B is a side view of the lower half, C is a perspective view of the assembled state, and D is an enlarged side view of the main part. 1... Bumper, 2... Nailer body, 3
...Main cylinder, 4...Nose,
S...Main piston, 7...Driver, 10...Protrusion, 11...Outer ring block, 12...Inner ring Block, 120...
...Upper half part, 121...Lower half part, 13A...Driver insertion hole, 13B...
...Through hole in outer ring block, 14...Gap between each block, X...Concave portion, Y...Convex portion.

Claims (1)

[Claims] 1. A bumper that is disposed at the lower end of the main cylinder built into the nailer body and that receives and stops the main piston, which is slidably and tightly fitted into the main cylinder, at the bottom dead center position, and this bumper is installed on the outer peripheral wall. It consists of an outer ring block which has an engaging part to the lower end of the main cylinder and has a through hole inwardly, and an inner ring block which has a driver insertion hole inwardly and consists of an upper half part and a lower half part,
Relative engagement means capable of preventing at least the inner ring block from being pulled out or dropped toward the main piston side is disposed between the outer ring block and the inner ring block, and the outer ring block and the inner ring block A bumper device for a nailing machine, characterized in that a gap is maintained between the inner annular block and between the upper and lower flap portions and the lower half portion to allow air to flow therethrough.