WO2014119168A1

WO2014119168A1 - Nail gun

Info

Publication number: WO2014119168A1
Application number: PCT/JP2013/083955
Authority: WO
Inventors: 駒崎　義一
Original assignee: 日立工機株式会社
Priority date: 2013-01-31
Filing date: 2013-12-18
Publication date: 2014-08-07
Also published as: JPWO2014119168A1; JP6123808B2

Abstract

Provided is a nail gun that stabilizes the drive depth of nails. When a nail (5) is driven, and the nail head comes into contact with wood (4), an excessive reaction force is generated at a driver blade (56). The driver blade (56) is impelled by a piston (11) via a spring (55). However, the driver blade (56) slides in opposition to the elastic force of the spring (55) due to the reaction force of the nail (5). A piston upper chamber (11a) and a piston lower chamber (11b), which are partitioned by the piston (11) in a cylinder inner chamber (10a), are linked via a slit (58), and compressed air in the piston upper chamber (11a) leaks into the piston lower chamber (11b). As a result, the speed of the piston decreases, and the nail (5) is not excessively driven into the wood (4).

Description

Driving machine

The present invention relates to a driving machine that drives a driver blade to drive a stopper into a material to be driven by striking the stopper.

FIG. 7 shows a cross-sectional view of a conventional driving machine 200 that hits a stopper such as a nail using compressed air as a power source. *

The schematic structure and operation process of nailing with the driving machine 200 will be described below. Compressed air from a compressor (not shown) is accumulated in the pressure accumulation chamber 245 via an air hose (not shown). The main valve 219 is movable in the vertical direction, and controls the flow path between the pressure accumulation chamber 245 that stores pressure and the inner chamber 210a of the cylinder 210. When the operator presses the push lever 202 against the wood 204 and operates the trigger 236, the main valve 219 moves downward to leave the exhaust cover 234, and the pressure accumulation chamber 245 communicates with the cylinder inner chamber 210a. At the same time, the lower part of the main valve 219 comes into contact with the cylinder plate 241 to block the cylinder inner chamber 210a and the expansion chamber 246 from each other. The compressed air accumulated in the pressure accumulating chamber 245 flows into the upper chamber of the piston 211 in the cylinder 210, pushes down the driver blade 256 integrated with the piston 211, and drives the nail into the wood 204. *

As the piston 211 descends, the air compressed in the lower chamber of the piston 211 passes through the check valve 212 installed in the middle of the cylinder 210 and the return passage 208 installed under the cylinder 210 to return the air chamber 244. Filled. When the piston 211 further descends and passes through the check valve 212, high-pressure air in the upper chamber of the piston 211 that pushes down the piston 211 is filled from the check valve 212 into the return air chamber 244. *

When the driving machine body 201 rises due to the reaction of driving, the push lever 202 is configured to turn off the trigger valve unit 254, or when the operator releases the trigger 236 and turns off the trigger valve unit 254, the main valve 219 moves upward and returns to the initial position. *

The main valve 219 is in contact with the exhaust cover 234 to block the pressure accumulating chamber 245 and the cylinder inner chamber 210a, and the lower portion of the main valve 219 is separated from the cylinder plate 241 so that the cylinder inner chamber 210a and the expansion chamber 246 communicate with each other. . *

As a result, the compressed air in the upper chamber of the piston 211 passes through the expansion chamber 246 and is discharged out of the driving machine main body 201. The piston 211 is moved upward by the compressed air in the return air chamber 244 and returned to the initial position. *

In such a driving machine, it is required to drive a stopper such as a nail into a member to be driven such as wood, and various techniques have been proposed. For example, there is a driving machine that changes the cross section of the injection hole of the stopper and forms an injection hole that matches the size of the stopper to be driven (see Patent Document 1).
JP 2009-83091 A

By the way, the best construction state using the conventional type driving machine as described above is a state in which the nail head is indented into the wood so that it is flush with or minutely from the wood. For this purpose, there are techniques for adjusting the supply pressure and techniques for adjusting the movable range of the push lever at the tip of the driving machine. *

However, since the hardness of wood partially varies depending on the density of nodes and annual rings, there is a problem that the nail cannot be driven completely by a certain adjustment, or that the nail is driven too much. *

For such a problem, for example, it can be assumed that the reaction of the main body is detected by a sensor and the supply pressure of the compressed air is controlled through an arithmetic process, but the entire nail contacts the wood after the nail tip contacts the wood. The time until it is driven is only about 1 ms, and even if the supply pressure is controlled within this time, there is a possibility that the air cannot be followed because it is a compressible fluid. Furthermore, it is expensive because of sensors and arithmetic devices, and a drive power supply for that purpose must be newly prepared. Therefore, there is a part that is not practical for putting a technology for detecting recoil with a sensor into the market, and another technology has been demanded. *

This invention is made | formed in view of the above situations, Comprising: It aims at providing the technique which solves the said subject.

The present invention includes a housing, a piston provided inside the housing so as to be capable of reciprocating, a driver blade connected to the piston for striking a fastening material, and provided inside the housing for driving the piston. A driving mechanism, wherein the driver blade and the piston are relatively movable in accordance with an operation of driving the fastening material. Further, an elastic material may be provided between the piston and the driver blade. The drive mechanism includes a pressure accumulating chamber for storing compressed air provided in the housing, and a cylinder for slidably guiding the piston. The piston and the cylinder are a piston upper chamber and a piston lower chamber. A seal member that blocks compressed air between the driver blade and the piston, and the piston upper chamber and the piston lower chamber when the driver blade and the piston move relative to each other. You may provide the communicating path which connects. The spring constant of the elastic material may be set to a strength at which the communication path is released when a predetermined load or more is applied from the fastening material. The present invention includes a housing having a pressure accumulating chamber therein, a cylinder provided in the housing, a piston provided in the cylinder so as to be able to reciprocate, and a driver blade connected to the piston. And a driving machine that drives the piston by the pressure of compressed air stored in the pressure accumulating chamber and strikes the fastening material by the driver blade. The driver blade that drives the fastening material and the driver blade are fixed A piston that drives the driver blade by the action of compressed air, and when the force acting on the driver blade from the fastening material becomes larger than a predetermined value, the driver blade is interposed via the piston. A mechanism for releasing the force acting on the is provided. The present invention includes a housing, a piston provided inside the housing so as to be capable of reciprocating, a driver blade connected to the piston for striking a fastening material, and provided inside the housing for driving the piston. A driving mechanism, wherein the piston and the driver blade are capable of relative movement, and when the head of the fastening material collides with the upper surface of the fastening material, the magnitude of the collision force Relative movement according to.

According to the present invention, it is possible to realize a driving machine that satisfactorily drives a fastening material (stopper) such as a nail into a driven member such as wood.

It is sectional drawing which shows the driving device of a standby state based on embodiment of this invention. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1 according to the embodiment of the present invention. It is sectional drawing which showed the driving machine of the state immediately after the start of the nailing operation | work based on embodiment of this invention. It is sectional drawing which showed the driving machine in the middle of the piston falling and driving the nail into the timber based on embodiment of this invention. It is sectional drawing which showed the driving machine of the state which the head of the nail contacted the timber based on embodiment of this invention. It is a relationship diagram of reaction force which acts on a driver blade, and penetration amount of a nail to wood. It is sectional drawing of the driving machine based on background art.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 6. FIG. 1 is a sectional view of a driving machine 100 showing an example of the present embodiment, and shows a state in which an external compressor (not shown) is connected. FIG. 2 is a cross-sectional view taken along the line AA in FIG. *

As shown in FIG. 1, the driving machine 100 includes a driving machine main body 1, a handle 38 extending in a direction substantially orthogonal to the injection direction, and a nose portion 3 positioned at the lower end of the driving machine main body 1. It is provided as a unit. In order to accumulate compressed air from a compressor (not shown), a pressure accumulating chamber 45 is formed inside the handle 38 and the driving machine main body 1. The pressure accumulating chamber 45 is connected to the compressor via an air hose (not shown). The pressure accumulating chamber 45 constitutes a drive mechanism together with a cylinder 10 and a main valve 19 which will be described later. The drive mechanism is not limited to the compressed air method, and for example, an electric method or a gas combustion method may be adopted. *

The driving machine main body 1 includes a housing 40 and an exhaust cover 34 that covers the upper portion of the housing 40, and further includes a cylindrical cylinder 10 inside and a piston 11 that can slide up and down (reciprocate) inside the cylinder inside the cylinder 10. And a driver blade 56 formed integrally with the piston 11. *

The cylinder 10 has a cylindrical shape and slidably supports the piston 11 on the inner surface. A return air chamber 44 for storing compressed air for returning the driver blade 56 to the top dead center is formed on the outer periphery of the lower end of the cylinder 10. *

A check valve 12 is provided at the axially central portion of the cylinder 10, and an air passage that allows inflow of compressed air from the inside of the cylinder 10 to the return air chamber 44 outside the cylinder 10 is formed. . *

A return passage 8 that is always open to the return air chamber 44 is formed below the cylinder 10. Furthermore, the lower end of the cylinder 10 is provided with a bumper 7 for absorbing surplus energy of the piston 11 after driving a nail. *

A connection portion of the handle 38 to the driving machine main body 1 is provided with a trigger 36 operated by an operator and a trigger valve portion 54 that is a switching valve for sending and exhausting compressed air. *

When the operator presses the push lever 2 against the wood 4 and operates the trigger 36, the main valve 19 moves downward and is separated from the exhaust cover 34. As a result, the pressure accumulation chamber 45 and the inner chamber of the cylinder 10 (cylinder inner chamber 10a) communicate with each other. *

The outer periphery of the piston 11 is substantially the same shape as the inner surface of the cylinder 10, and has a disk shape with a small gap that can slide on the inner surface of the cylinder 10. A concave groove 111 is provided on the outer peripheral surface of the piston 11 over the circumference, and an O-ring 112 is disposed in the concave groove 111. A gap between the inner surface of the cylinder 10 and the outer periphery of the piston 10 is sealed by the O-ring 112. A hole penetrating the piston 11 is formed in the central portion of the piston 11, and a driver blade 56 is disposed on the inner diameter of the piston 11, and can slide integrally with the piston 11 inside the cylinder 10. Yes. In addition, a trumpet 57 is fitted to the upper end of the driver blade 56. With these structures, the driver blade 56 is prevented from falling off the piston 11. *

A spring 55 is disposed below the piston 11, and the lower end of the spring 55 is engaged with a flange portion 56 a formed on the driver blade 56. As a result, the driver blade 56 is urged downward with respect to the piston 11. As will be described later, the biasing force of the spring 55 is set so that the piston 11 and the driver blade 56 move relative to each other only when a strong repulsive force is applied to the driver blade 56 from below. The blade 56 is at a position moved downward relative to the piston 11. *

An O-ring 59 is fitted directly under the tomewa 57 and is compressed between the piston 11 and the tomewa 57 by a spring 55. The air flow between the piston 11 and the tomewa 57 is blocked by the O-ring 59. *

As shown in FIG. 2, eight slits 58 extending in the axial direction (vertical direction in FIG. 1) are formed on the circumference of the piston 11 in the engaging portion between the piston 11 and the driver blade 56. The lower end of the slit 58 extends to the vicinity of the flange portion 56 a below the lower end of the piston 11. Therefore, when the seal by the O-ring 59 is released, the upper and lower sides of the piston 11 (piston upper chamber 11a and piston lower chamber 11b) communicate with each other through the piston 11 and the tome 57. The slit 58 corresponds to the communication path in the present invention. *

Next, operation | movement of the driving machine of this embodiment is demonstrated. FIG.
It is sectional drawing which showed the driving machine 100 of the state immediately after the start of a nailing operation | work. When the operator presses the push lever 2 against the wood 4 and operates the trigger 36, the main valve 19 moves downward and leaves the exhaust cover 34. As a result, the pressure accumulation chamber 45 and the cylinder inner chamber 10a communicate with each other.

At the same time, the lower part of the main valve 19 comes into contact with the cylinder plate 41, and the communication between the cylinder inner chamber 10a and the expansion chamber 46 is blocked. *

FIG. 4 is a cross-sectional view showing the driving machine 100 in the middle of the piston 11 being lowered and driving the nail 5 into the wood 4. The compressed air accumulated in the pressure accumulating chamber 45 flows into the piston upper chamber 11a, which is a space above the piston 11 in the cylinder inner chamber 10a. As a result, the compressed air pushes down the piston 11. The driver blade 56 connected to the piston 11 moves downward together with the piston 11 and is driven into the wood 4 by hitting the nail 5. *

At this time, the reaction force of the nail 5 acts upward on the driver blade 56. With the reaction force generated in the state shown in FIG. 3, the spring constant of the spring 55, that is, the operating load is set so that the driver blade 56 does not slide. Detailed setting of the operating load will be described later with reference to FIG. The spring 55 may be replaced by an elastic member such as a rubber member as long as it has a structure having elastic characteristics. *

FIG. 5 is a cross-sectional view showing the driving machine 100 in a state where the head of the nail 5 is in contact with the wood. When the head of the nail 5 contacts the wood 4, the reaction force acting on the driver blade 56 increases rapidly. *

Since force due to compressed air acts on the upper surface of the piston 11, the driver blade 56 slides upward against the elastic force of the spring 55. Since the driver blade 56 moves upward with respect to the piston 11, the amount of protrusion of the driver blade 56 from the nose portion 2 decreases. This can prevent the head of the nail 5 from being driven deeper than necessary. As a result of the relative movement of the piston 11 and the driver blade 56, the seal against the slit 58 by the O-ring 59 is released. Then, as indicated by arrows in the figure, the compressed air in the piston upper chamber 11a is released through the slit 58 to the piston lower chamber 11b, which is the space below the piston 11 in the cylinder inner chamber 10a. *

As a result, the pressure in the piston upper chamber 11a decreases and the pressure in the piston lower chamber 11b increases. Therefore, the piston 11 and the driver blade 56 are rapidly decelerated. *

FIG. 6 shows a relationship diagram between the reaction force acting on the driver blade 56 and the amount of penetration of the nail 5 into the wood 4. The solid line in FIG. 6 shows the case where the nail 5 is driven into the wood 4 having high hardness, and the broken line shows the case where the nail 5 is driven into the wood 4 having low hardness. The reaction force acting on the driver blade 56 from the nail 5 (fastening material) is generated when the tip of the nail 5 reaches the wood 4, and the nail head (head) of the nail 5 collides with the wood 4. It rises greatly when you do. The spring constant of the spring 55 (elastic material) is preferably set to a strength at which the communication path is released when a predetermined load or more is applied from the nail 5 (fastening material). That is, the operating load of the spring 55 is equal to or less than the reaction force FSmax when the nail head collides with the wood 4 using the low hardness wood 4 and the shaft portion of the nail 5 is driven using the high hardness wood 4. What is necessary is just to set between reaction force FHmin or more when there is. The dimensions and the number of the slits 58 can be arbitrarily selected and can be adjusted according to the required amount of deceleration of the piston 11 and the driver blade 56. *

As described above, according to the present embodiment, when the head of the nail 5 comes into contact with the wood 4, the piston 11 and the driver blade 56 are rapidly decelerated, and excessive driving of the nail 5 into the wood 4 can be prevented. *

That is, when the nail 5 is driven and the nail head comes into contact with the wood 4, an excessive reaction force is generated in the driver blade 56. The driver blade 56 is urged against the piston 11 by a spring 55, but the driver blade 56 slides against the elastic force of the spring 55 due to the reaction force of the nail 5. Then, the piston upper chamber 11a and the piston lower chamber 11b separated by the piston 11 in the cylinder inner chamber 10a communicate with each other through the slit 58, and the compressed air in the piston upper chamber 11a leaks to the piston lower chamber 11b. Therefore, the piston speed is reduced, and the nail 5 can be prevented from being driven excessively into the wood 4. *

The present invention has been described based on the embodiments. This embodiment is an exemplification, and it is understood by those skilled in the art that various modifications can be made to combinations of the respective components and the like, and such modifications are within the scope of the present invention. For example, the piston 11 and the driver blade 56 may be relatively movable without providing the slit 58 (communication path). In this case, the piston 11 and the driver blade 56 are configured to move relative to each other when the nail head collides with the upper surface of the wood, thereby further enhancing the effect of preventing the nail head of the nail 5 from being driven excessively after reaching the wood. It is done. In the driving machine 100 described above, the driver blade 56 moves relative to the cylinder 10 when the force from the nail 5 acting on the driver blade 56 is equal to or greater than a predetermined value. However, a certain effect can be obtained even if the relative movement is not performed and the force of the compressed air acting on the cylinder 10 is not further applied. That is, only the structure which turns on / off the communication state of the slit 58 without providing the spring 55 may be used. Further, a function of releasing the fixed state between the driver blade 56 and the cylinder 10 and releasing the force, for example, a function of freely rotating the driver blade 56 may be provided.

DESCRIPTION OF SYMBOLS 1 Driving machine main body 2 Push lever 3 Nose part 7 Bumper 8 Return passage 10 Cylinder 10a Cylinder inner chamber 11 Piston 11a Piston upper chamber 11b Piston lower chamber 12 Check valve 19 Main valve 34 Exhaust cover 36 Trigger 38 Handle 40 Housing 41 Cylinder Plate 44 Return air chamber 45 Accumulation chamber 46 Expansion chamber 54 Trigger valve section 55 Spring 56 Driver blade 57 Tomewa 58 Slit 59 O-ring 100 Driving machine 111 Concave groove 112 O-ring

Claims

A housing, a piston provided so as to be capable of reciprocating inside the housing, a driver blade connected to the piston for striking a fastening material, a drive mechanism provided inside the housing for driving the piston, The driver blade and the piston are capable of moving relatively with the operation of driving the fastening material.
The driving machine according to claim 1, further comprising an elastic material between the piston and the driver blade.
The drive mechanism includes a pressure accumulation chamber for storing compressed air provided in the housing, and a cylinder for slidably guiding the piston. The piston and the cylinder have a piston upper chamber and a piston lower chamber. And a seal member that blocks compressed air between the driver blade and the piston, and the piston upper chamber and the piston lower chamber when the driver blade and the piston move relative to each other. The driving machine according to claim 2, further comprising a communication path that allows communication.
The driving force according to claim 1 or 2, wherein a spring constant of the elastic material is set to a strength at which the communication path is released when a predetermined load or more is applied from the fastening material. Machine.
A housing having a pressure accumulating chamber therein; a cylinder provided in the housing; a piston provided in the cylinder so as to be capable of reciprocating; and a driver blade connected to the piston; A driving machine that drives the piston by the pressure of compressed air stored in a chamber and strikes a fastening material by the driver blade, the driver blade driving the fastening material, and the driver blade is fixed and compressed air acts And a piston that drives the driver blade, and acts on the driver blade via the piston when a force acting on the driver blade from the fastening material becomes larger than a predetermined value. A driving machine characterized by having a mechanism for releasing the force to perform.
A housing, a piston provided so as to be capable of reciprocating inside the housing, a driver blade connected to the piston for striking a fastening material, a drive mechanism provided inside the housing for driving the piston, The piston and the driver blade can be moved relative to each other, and when the head of the fastening material collides with the upper surface of the fastening material, the relative movement according to the magnitude of the collision force A driving machine characterized by moving.