JPH0679644A - Driver holding structure of nailing machine - Google Patents

Abstract

PURPOSE:To provide a driver holding structure which can absorb the misalignment and inclination of a cylinder relative to a driver guide in a simple configuration, with the cost suppressed, and without impairing the durability. CONSTITUTION:A flange is formed at the top of a driver 5 extending in the axial direction of a cylinder 2, and a holder and cap screw are installed on a piston 4 and held in such a way as enwrapping the flange, and gaps are furnished in the radial direction and axial direction along the contour of the flange, and the misalignment and inclination of the cylinder 2 relative to the driver guide 8 are absorbed through relative displacement of the piston and the driver 5 within the extent of the gaps.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driver holding structure in a nail driver.

[0002]

2. Description of the Related Art In a conventional nail driving machine, a driver is held by a piston that reciprocally slides in a cylinder by air pressure, and the driver moves up and down while being guided by a driver guide to strike the nail head. Generally, the nail is driven by doing so. The driver holding structure of this piston is a structure (prior art example) in which the piston and the driver are screwed as shown in FIG. 3 of Japanese Utility Model Laid-Open No. 54-53779, Japanese Utility Model Laid-Open No. 56-72673. FIG. 2 shows a structure in which a piston and a driver are pin-coupled (conventional example), and further, the piston and the driver as shown in FIG. 1 of the same publication are connected via an elastic material. A known structure (conventional example) is known.

[0003]

However, in the above-mentioned conventional example, it is difficult to absorb the misalignment and inclination between the air cylinder and the driver guide, which are caused by reasons such as manufacturing cost, and it is difficult to absorb the misalignment between the driver and the driver guide. The increase in sliding resistance due to the twist between the piston and the air cylinder becomes great. Therefore, a large amount of air is required at the time of striking and returning the piston, and since the contact between the piston and the bumper at the driving-in lowest point is not ensured, the air tends to leak, and the driving force at low pressure is increased. There is a shortage. Further, in the above-mentioned conventional example, stress concentration due to the up-and-down movement of the driver occurs at the contact portion between the pin and the insertion hole, and particularly, the maximum stress acts on this contact portion at the time of idle driving, so that there is a problem in durability of the driver. There is a problem. Further, although the conventional example uses an elastic material such as urethane, there is a problem that the durability of the driver is not sufficient.

Therefore, the present invention solves the problem of providing a driver holding structure having a simple structure which does not increase the manufacturing cost and which can absorb the misalignment and inclination between the cylinder and the driver guide without impairing the durability. This is a technical issue that should be addressed.

[0005]

For this purpose, the following driver holding structure for a nail driver was created. That is, a nailing machine equipped with a piston that reciprocally slides in a cylinder, a driver that is held by the piston and extends in the axial direction of the cylinder, and a driver guide that guides the lower end of the driver in the axial direction of the cylinder. In the above, while a flange is formed on the upper end of the driver, a holding portion is formed on the piston so as to be able to contact the upper and lower end surfaces of the flange, and the outer shape of the collar is formed between the holding portion and the flange. A gap is provided along the gap, and the piston and the driver are displaced relative to each other within the range of the gap so that misalignment and inclination between the cylinder and the driver guide can be absorbed.

[0006]

In the driver holding structure having the above structure, the flange formed at the upper end of the driver is held in the holding portion of the piston with a predetermined gap, and the piston and the driver are freely displaced relative to each other. It is configured to get. Therefore, the misalignment and inclination between the cylinder and the driver guide are absorbed by this gap, and the piston and the driver guide are not twisted, so that the sliding resistance between them can be reduced and the contact between the piston and the bumper etc. The contact is secure and the air does not leak easily. Further, it is not necessary to form a hole in the mounting portion of the driver to which the maximum stress is applied, and the collar of the driver can ensure a sufficient cross-sectional area, and in particular, the durability of the driver at the time of idle driving is improved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the nailing machine 1 is roughly classified into a substantially cylindrical main body housing 3 having a cylinder 2 and a piston 4 which reciprocally slides in the cylinder 2 by an air pressure supplied from the outside. A driver 5 that can reciprocate by a piston 4 to drive a nail, a handle portion 6 that is provided orthogonal to the main body housing 3, and a driver 5 that is attached to the lower end portion of the main body housing 3 and reciprocates. A driver guide 8 having a nail guide path 7 formed therein, which is piercably inserted and accommodates a nail to be driven, and a bracket having one end attached to the driver guide 8 and the other end protruding from the handle portion 6. 9 is attached to the nail guideway 7
It is composed of a nail magazine 10 into which nails can be sequentially fed.

The cylinder 2 is attached to the upper end of the bracket 9.
A joint 11 for connecting an air hose for supplying air to the cylinder is provided in a protruding manner, and the joint 11 is communicated with the cylinder 2 via an air chamber (not shown) provided in the handle portion 6. . And
A trigger valve 13 that controls the supply of air from the air chamber into the cylinder 2 via the head valve 12 is provided at the base portion of the main body housing 3 and the handle portion 6, and the trigger valve 13 is opened and closed. A trigger 14 for operating is rotatably supported by a bracket 15 integrally formed with the body housing 3. On the other hand, the cylinder 2 has a piston 4 (which will be described later in detail) having an O-ring 16 mounted therein, and when a predetermined amount of air is supplied into the cylinder 2, the piston 4 slides inside the cylinder 2. It is configured to move up and down. A cushion 17 is attached to the piston 4 so that the cushion 17 can come into contact with the lower end of the head valve 12 when the piston 4 moves up to the uppermost point, and the piston 4 is attached to the lower end of the main body housing 3 at the lowest point. A cushion 18 is attached so that it can come into contact when lowered. A front seal 19 for loosely maintaining the airtightness of the cylinder 2 is loosely fitted to the lower end of the main body housing 3 with the driver 5 (described later in detail) inserted therethrough. The driver guide 8 mounted on the lower end of the main body housing 3 for guiding the driver 5 in the axial direction of the cylinder 2 is assembled so that the center axis of the nail guide path 7 and the axis of the cylinder 2 substantially coincide with each other. Has been. In addition, a nail magazine 10 whose one end is attached to the driver guide 8
Has a nail accommodating path (not shown) for accommodating a nail group to be driven, one of which is communicated with the nail guide path 7 of the driver guide 8 and which is continuously connected in a row.
The group of nails can be sequentially fed into the nail guide path 7 of the driver guide 8. Further, the main body housing 3 is provided with an exhaust passage 20 whose one end is communicated with the cylinder 2 through the head valve 12 and the other end is opened to the atmosphere. It is configured to be able to exhaust air.

Next, the driver 5 will be described.
As shown in FIGS. 2 and 3, the flat shaft portion 5a of the steel driver 5 is formed in a substantially rectangular cross section corresponding to the nail guide path 7 of the driver guide 8, and the upper end thereof has a smooth circular cross section. The lower part 5b of the neck is formed by the transition.
A disk-shaped brim 5c is formed at the tip of the. Further, the lower end of the flat shaft portion 5a is formed with a protrusion 5d capable of contacting the head of the nail to be driven. Tsuba 5c of this driver 5
Next, the piston 4 that holds will be described in detail.

As shown in FIGS. 2 and 3, the piston 4 includes a piston body 22, a holder 21 into which the driver 5 is inserted, and a cap screw 23 screwed into the piston body 22. The holder 21 and the cap screw 23 constitute a holding portion in the present invention. The holder 21 is formed in a cylindrical shape and has a predetermined size larger than the outer diameter of the through hole 21a through which the lower neck 5b of the driver 5 can be inserted and the flange 5c of the driver 5 and a predetermined size deeper than the thickness of the flange 5c. The counterbore 21b is formed concentrically. The holder 21 is made of steel having high strength so as to withstand contact with the outer peripheral surface and the lower end surface of the collar 5c. Further, the piston body 22 is made of aluminum or the like in a lightweight manner, and an O-ring groove 22a for mounting the O-ring 16 and a taper groove 22b for mounting the cushion 17 are formed on the outer peripheral portion thereof. ing. Further, a through hole 22c through which the lower neck portion 5b of the driver 5 is inserted is formed in the inner peripheral portion thereof.
And a fitting hole portion 22d corresponding to the holder 21 and a screw hole 22e that can be screwed into the cap screw 23 are formed at concentric positions. Further, the cap screw 23 made of steel is provided in the screw hole 22e of the piston body 22.
A male screw 23a that can be screwed into the
b is formed in a flat shape capable of contacting the upper end surface of the collar 5c of the driver 5. A groove 23c for rotation is provided at the upper end of the cap screw 23.

The assembled state of the piston 4 and the driver 5 is shown in FIG. 3, and there is a piston 4 between them.
A predetermined gap C in the radial direction (diameter 28 mm in this embodiment)
₁ (diameter gap 0.4 mm in this embodiment) is provided, and a predetermined gap C ₂ (gap 0.1 m in this embodiment) is provided in the axial direction.
m) is provided. As shown in FIG. 1, the piston 4 and the driver 5 assembled in this manner are assembled in the cylinder 2 with a certain amount of “rattle”, and the flat shaft portion 5 a of the driver 5 is installed in the cylinder 2. The protrusion 5d of the driver 5 faces the nail (not shown) which penetrates the lower front seal 19 and is inserted into the nail guide path 7 of the driver guide 8 and is fed into the nail guide path 7. ing.

Next, the operation of the present embodiment constructed as described above will be described. Now, when the trigger 14 of the nailing machine 1 which has been prepared for operation is pulled and tilted, a predetermined amount of air is supplied into the cylinder 2, the piston 4 slides in the cylinder 2, and the flat shaft portion 5a of the driver 5 is moved. Moves down in the nail guide path 7 of the driver guide 8. By the way, although misalignment and inclination due to machining tolerances are inevitable between the cylinder 2 and the nail guide path 7 of the driver guide 8,
Since the piston 4 and the driver 5 are relatively displaced within the range of the clearances C ₁ and C ₂ to absorb the above error,
The driver 5 can move up and down while maintaining a substantially straight state, and since the piston 4 is not twisted, sliding resistance is reduced. Further, unlike the conventional example, it is not necessary to form a hole in the mounting portion of the driver to which the maximum stress is applied, and the collar 5c of the driver 5 can ensure a sufficient cross-sectional area. The property is improved. That is, the driver holding structure of this embodiment has high reliability.

Next, another embodiment will be described with reference to FIG. The driver holding structure of this embodiment is the screw holder 2 into which the driver 5 described in the above embodiment is inserted.
6 is screwed into the piston 25 to hold the driver 5. The other configurations are the same as those in the above-described embodiment, and therefore their explanations are omitted. This screw holder 26 is the holder 2 in the above-mentioned embodiment.
The driver 5 is constructed in the same manner as 1 and is capable of supporting the driver 5, and an external thread 26a is provided on the outer peripheral portion. Further, the lower surface of the piston body 27 is provided with a screw hole 27a into which the male screw 26a of the screw holder 26 can be screwed, and the bottom surface 27b of the screw hole 27a has the screw hole 27a.
It is formed so as to be able to contact the upper end surface of the collar 5c. That is, this embodiment is similar to the piston main body 22 of the above-described embodiment.
The cap holder 23 and the cap screw 23 are integrated with each other.
There is no difference from the above-mentioned embodiment except that a screwing method is used. There is a predetermined radial gap C ₁ between the piston 25 and the collar 5c of the driver 5, and a predetermined axial gap. It has C ₂ . Therefore, it is possible to obtain the same effects as those of the above-described embodiment.

[0014]

In the driver holding structure according to the present invention, the brim formed at the upper end of the driver is held in the holding portion of the piston with a predetermined gap, and the piston and the driver are freely opposed to each other. Since the structure allows displacement, misalignment and inclination between the cylinder and the driver guide are absorbed by this gap. Therefore, since the piston and the driver guide are not twisted, the sliding resistance can be reduced, and the piston and the bumper are surely brought into contact with each other, so that the air hardly leaks. Further, it is not necessary to interpose an elastic member between the driver and the piston,
Moreover, since the contact area between the two is wide, the durability is improved.

[Brief description of drawings]

FIG. 1 is a view in which a main part of a nailing machine according to an embodiment is cut away.

FIG. 2 is an exploded perspective view showing a piston and a driver of the embodiment.

FIG. 3 is a cross-sectional view showing an assembled state of the piston and the driver of the embodiment.

FIG. 4 is a sectional view showing an assembled state of a piston and a driver of another embodiment.

[Explanation of symbols]

1 nail driver 2 cylinder 4 piston 5 driver 5c collar 7 nail guide path 8 driver guide 21 holder 23 cap screw C ₁ , C ₂ gap

Claims (1)

[Claims] 1. A piston that reciprocally slides in a cylinder,
In a nailing machine provided with a driver which is held by the piston and extends in the axial direction of the cylinder, and a driver guide which guides the lower end portion of the driver in the axial direction of the cylinder, a collar is formed at the upper end portion of the driver. On the other hand, the piston is formed with a holding portion that can come into contact with the upper and lower end surfaces of the flange, and a gap is provided between the holding portion and the flange along the outer shape of the flange, and within the range of this gap. A driver holding structure in a nail driving machine, wherein the piston and the driver are relatively displaced to absorb misalignment and inclination between the cylinder and the driver guide.