JP2009178811A - Nail driving machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent an end of a nail driving portion from separating from a driven material even if a reaction is received during nail driving. <P>SOLUTION: A nail driving machine includes a contact member for forming a combustion chamber sealed by moving a movable sleeve 8 upward after movement to an upper portion of a body having a hammering mechanism by being pressed against the driven material and a movable cover 38 disposed so as to cover an outside of the contact member and slidable in a nail driving direction. The contact member is always spring-forced in a driving direction independently of the movable sleeve 8. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a nail driver for holding a member for guiding a nail so as not to be separated from a material to be driven when the nail is lifted by a reaction.

  In general, the gas combustion type nailing machine is provided with a striking piston slidable in a vertical direction on a striking cylinder disposed in a body, and a movable sleeve provided on the top of the striking cylinder is moved up and down to move the striking piston. The combustion chamber can be opened and closed by making contact with and separating from the cylinder and the cylinder head above it, and the cylinder is mixed with the mixed gas obtained by stirring and mixing the combustible gas and air with a fan in the sealed combustion chamber. A spark plug disposed in the head is ignited and explosively burned, and this high-pressure combustion gas is caused to act on the striking piston so as to be shocked and driven by a driver coupled to the lower surface side of the striking piston. It is comprised so that a nail may be driven out from a part (refer patent document 1).

  By the way, a contact member is slidably provided on the outside of the nose portion, a lower end thereof is spring-biased so as to protrude from the nose portion, and an upper end is connected to a member called a cage connected below the movable sleeve. It is arrange | positioned so that engagement is possible. The cage is always biased downward by a spring.

  As a contact member, in addition to a contact arm arranged outside the nose portion as shown in Patent Document 1, a nail driving direction (vertical direction) is provided below the nose portion with the same injection port as the nose portion. There is known a member (so-called contact nose) that is slidably provided (see Patent Document 2). The upper part of the contact nose is also arranged at the lower part of the cage.

In the above configuration, when the nail is driven, when the lower end of the contact member is pressed against the material to be driven, the contact member moves up relative to the body. Is moved upward to form a sealed combustion chamber. Along with that, combustible gas is ejected into the combustion chamber, triggering the mixed gas obtained by mixing with air by the fan and igniting the spark plug, burning the internal mixed gas, and this combustion pressure makes the nail Is to be typed in.
JP-A-2005-22069 JP2007-30091

  However, when the nail is driven, the striking piston is suddenly driven downward, so that the nail driver itself is lifted by the reaction, and the nose portion and the contact member are instantaneously separated from the material to be driven. Since these members are used to guide the nail to be driven and to be driven correctly, for example, if the nose portion is separated from the driven material, the nail posture is not maintained and buckling is likely to occur. Problems such as scattering of the connecting band around, damage to the nail, and scattering of the broken nail.

  The reason is that the contact member is spring-biased together with the movable sleeve, but when the nail driver is lifted by reaction during nail driving, the contact member also separates from the driven material. The reason is that a coil spring is usually arranged at the top of the cage to urge the movable sleeve and the contact nose downward, but when the contact member is pressed against the material to be driven, the cage resists the coil spring. The movable sleeve is moved to the top dead center by bending the spring, and the movable sleeve is configured to be held at the top dead center until the trigger is released and then the contact member under the cage. The spring force of the above-mentioned spring does not reach. Therefore, when the nail is driven, the striking piston is suddenly driven downward, so that when the nail driver itself is lifted by the reaction and momentarily separated from the material to be driven, the contact member which is in a free state is moved downward. This is because the load to be pushed down is only gravity, which is insufficient and cannot cope with the separation operation. In particular, when nails are driven toward a wall or a ceiling, gravity does not work on the contact member or gravity works in the opposite direction, so that it is not possible to cope with the separation operation.

  The present invention solves the above problems and prevents buckling by preventing the end of the driven portion from separating from the driven material even when the nail guide member receives a reaction during driving the nail. It is an object of the present invention to provide a gas combustion type nailing machine capable of satisfactorily preventing the scattering of the connection band of the connection nail and the broken nail.

  In order to solve the above-mentioned problem, the invention according to claim 1 is provided such that a striking piston is slidable in a vertical direction on a striking cylinder disposed in a body, and a movable sleeve provided on an upper portion of the striking cylinder is vertically moved. The combustion chamber can be opened and closed by moving it into contact with and separating from the striking cylinder and the cylinder head thereabove, and the gas mixture in the sealed combustion chamber is opened by an ignition plug disposed in the combustion chamber. Ignition and explosive combustion, this high-pressure combustion gas is applied to the striking piston to drive it shockingly, and for nail injection provided below the body by a driver coupled to the lower surface side of the striking piston In a gas combustion type nailing machine for driving out a nail from a nose portion, the movable sleeve is moved by being moved above the body by being pressed against a material to be driven. A contact member that is moved upward to form a sealed combustion chamber; and a movable cover that is disposed so as to cover the outside of the contact member and is slidable in the nail driving direction. It is characterized in that the spring is always biased in the nail driving direction independently of the sleeve.

  The invention according to claim 2 is a nailing machine comprising a body having a striking mechanism for driving out a nail using air pressure as a power source, and a nose portion that is provided below the body and injects the nail, and presses against a material to be driven. A contact member that allows the nail to be driven out is provided so as to be slidable along the nose portion, and the outside of the contact member is covered with a movable cover that is slidable in the nail driving direction. It is characterized in that the spring is always biased in the nail driving direction.

  The invention according to claim 3 is the contact nose according to claim 1 or 2, wherein the contact member is slidably disposed below the nose portion and has a nail injection port.

  According to a fourth aspect of the present invention, in the first or second aspect, the contact member is a contact arm slidably provided along the nose portion.

  According to a fifth aspect of the present invention, in the first or second aspect, the movable cover is constantly biased in the nail driving direction instead of spring biasing the contact member.

  The invention according to claim 1 covers a contact member that forms a closed combustion chamber by moving the movable sleeve upward by pressing it against the workpiece and moving the movable sleeve upward to cover the outside of the contact member. And a movable cover that is slidable in the nail driving direction and is always urged by a spring in the nail driving direction independently of the movable sleeve. When the piston is suddenly driven downward and the nailing machine itself is lifted by its reaction and moves away from the driven material instantaneously, the contact member is moved by a spring bias acting independently of the movable sleeve. Because it protrudes in the driving direction, the lower end of the contact member remains in contact with the workpiece without leaving the driven material. It is equity. Therefore, the position of the nail is maintained, and problems such as buckling, scattering of the connection band, damage to the nail, and scattering of the nail that has been broken do not occur.

  According to a second aspect of the present invention, in the nailing machine driven by air pressure, a contact nose that allows the nail to be driven by being pressed against the material to be driven is provided slidably along the nose portion, The outside is covered with a movable cover that can slide in the nail driving direction, and the movable cover is always spring-biased in the nail driving direction, so that the nail driver itself is lifted by the reaction during nail driving. Even if it moves away from the material to be driven instantaneously, the movable cover protrudes in the driving direction by the spring force of the coil spring, so the lower end of the movable cover remains in contact with the material without being separated from the material to be driven. Retained. Therefore, even if the contact nose is separated, the nail posture does not tilt greatly, it is difficult to buckle, the connection band is scattered around, the nail is damaged, the damaged nail is scattered, etc. The problem never occurs.

  In the invention according to claim 3, since the contact member is a contact nose that is slidably disposed below the nose portion and has a nail injection port, the nail can be directly guided.

  In the invention according to claim 4, since the contact member is a contact arm slidably provided along the nose portion, it is possible to effectively prevent the connection band and the nail from being scattered outside the nose. Can do.

  The invention according to claim 5 is a structure in which the movable cover is always spring-biased in the nail driving direction, so that the nail driver itself is lifted by the reaction at the time of nail driving so as to be instantaneously separated from the driven material. Even if the movable cover moves, the movable cover protrudes in the driving direction due to the spring bias, so that the lower end of the movable cover is held in a contacted state without separating from the driven material. Therefore, even if the contact nose is separated, the nail posture does not tilt greatly, it is difficult to buckle, the connection band is scattered around, the nail is damaged, the damaged nail is scattered, etc. The problem never occurs.

  In addition, since the movable cover is always urged by a spring in the nail driving direction, the movable cover is free of rattling, the operation feeling is good, and the contact member is always covered, so that air launch can be made more difficult.

  Further, when the nail driver is lifted by reaction when nailing, especially when the combustion chamber is held at the top dead center position and the spring force pushing the combustion chamber does not act on the contact member, the movable cover is moved by the spring bias. Since the nail guide is pushed in the nail driving direction, the contact member also produces the same effect.

  1 and 2, reference numeral 1 denotes a body of a combustion nailing machine. A striking mechanism is provided inside the body 1, and an injection nose for striking a nail is provided below. A gas can (not shown) filled with a fuel gas liquefied from a combustible gas is attached to the rear of the striking mechanism. A grip 2 and a magazine 3 are connected to the body 1 and the magazine 3 is configured to open to the nose portion 4 and supply nails.

  The striking mechanism is a combustion in which a striking piston 6 is slidably provided in a striking cylinder 5 disposed in the body 1 and hermetically formed as shown in FIG. 3 by a movable sleeve 8 provided on the top of the striking cylinder 5. In the chamber 10, the combustible mixed gas is ignited and explosively burned, and the striking piston 6 is driven by the high-pressure combustion gas to strike the nail in the nose portion 4. 9 is a trigger for starting operation.

  That is, the striking piston 6 is slidably accommodated in the striking cylinder 5, and the striking piston 7 is integrally coupled below the striking piston 6. Further, the upper wall portion 11 of the nose portion 4 is formed in a dish shape, and an injection port 12 for guiding the sliding of the striking piston 7 is formed at the center thereof. The rear side of the injection port 12 opens at the tip of the magazine 3.

  The combustion chamber 10 is formed by an annular movable sleeve 8 disposed between the upper end surface of the impact piston 6 and a cylinder head 13 formed inside the impact cylinder 5 and the upper portion of the body 1. A sealed combustion chamber 10 is formed by moving the sleeve 8 upward to seal the cylinder head 13 as shown in FIG. 3, and an upper portion of the combustion chamber 10 by moving downward as shown in FIG. Is open and communicates with the atmosphere.

  The lower end of the movable sleeve 8 is connected to the upper end of the contact member 14. The contact member 14 is provided so as to be slidable in the nail driving direction along the nose portion 4 and moves upward relative to the nose portion 4 by pressing the lower end against the driven material P. ing. The contact member 14 will be described in detail later.

  Incidentally, as shown in FIGS. 3 and 4, the movable sleeve 8 is operatively linked to the contact member 14 via a member called a cage 17. The cage 17 is formed by connecting the lower ends of the link-like portions 17a on both sides with the bottom portion 17b. Although the link-like portions on both sides are omitted in the drawing, the upper end is coupled to the lower end of the movable sleeve 8, and the bottom portion 17b is the nose. It is arranged between the part 4 and the striking cylinder 5. A main coil spring 18 is disposed between the lower surface of the striking cylinder 5 and the bottom portion 17b of the cage 17, whereby the movable sleeve 8 is constantly urged downward. A contact member 14 is engaged with the lower portion of the cage 17.

  Although not described because it is a known technique, the operation of the trigger 9 is effective only when the contact member 14 moves to the top dead center together with the movable sleeve 8. Further, when the movable sleeve 8 moves to the top dead center, the lock bar 20 is held at that position.

  The cylinder head 13 is injected into the combustion chamber 10 by the injection nozzle 21 communicating with the gas container, an ignition plug (not shown) for igniting and burning the mixed gas, and the injection nozzle 21. A rotating fan 22 is provided for agitating the combustible gas with the air in the combustion chamber 10 to generate a mixed gas having a predetermined air-fuel ratio in the combustion chamber 10. Reference numeral 23 denotes a gas can storage chamber.

  When starting the nailing machine, first, as shown in FIG. 3, the lower end of the contact member 14 is strongly pressed against the driven material P, and the contact member 14 is moved to the top dead center. As a result, the movable sleeve 8 is also moved upward together with the cage 17 to come into contact with the cylinder head 13 to form a sealed combustion chamber 10. When the combustion chamber 10 is sealed, the combustible gas is injected from the injection nozzle 21 into the combustion chamber 10, the motor is operated, the rotary fan 22 rotates, and the combustible gas and air are agitated and mixed.

  Since the operation of the trigger 9 becomes effective when the contact member 14 moves to the top dead center, when the trigger 9 is pulled, the circuit connected to the spark plug is turned on, so that the mixed gas is ignited and burned. And expands explosively. The pressure of the combustion gas acts on the upper surface of the striking piston 6 to drive downwardly, and the striking piston 7 strikes a leading nail (not shown) in the magazine 3 supplied in the nose portion 4. Then, it is driven into the workpiece P.

  When the driving is completed, the temperature in the combustion chamber 10 suddenly decreases, so that the space above the striking piston 6 that has expanded to the striking cylinder 5 becomes negative pressure, and the striking piston 6 is top dead due to the differential pressure from the atmospheric pressure from below. Move return to point. Then, by pulling up the nail driver to separate the nose portion 4 from the driven material P, the urging force of the main coil spring 18 causes the movable sleeve 8 and the contact member 14 to move downward to open the combustion chamber 10, and FIG. Thus, the next driving operation is prepared by returning to the initial state.

  Incidentally, as shown in FIG. 4, the contact member 14 includes an upper arm member 15 and a lower contact nose 16. The arm member 15 is an arm-like member whose upper and lower ends are bent, and the upper portion penetrates the upper wall portion 11 of the nose portion 4, and the upper end bent portion 15 a is disposed so as to be engageable with the bottom portion 17 b of the cage 17, The movable sleeve 8 is linked via the cage 17. An injection port 12 is formed below the contact nose 16 so as to be continuous with the injection port of the nose portion 4. A bulging portion 24 that extends outward is formed at the upper end of the injection port 12, and an upper cylindrical portion 25 of the bulging portion 24 is formed in a large-diameter cylindrical shape so as to surround the nose portion 4. ing.

  The lower end of the arm member 15 and the upper end of the contact nose 16 are connected through an adjustment mechanism a. The adjustment mechanism a adjusts the contact nose 16 to move in the nail driving direction. As shown in FIGS. 5 and 10, the adjustment mechanism a moves laterally from the upper wall portion 11 of the nose portion 4 and the midway portion of the nose portion 4. A hollow screw 27 provided between the projecting support arm 26 and a first screw shaft 28 which is inserted into the hollow screw 27 so as to be movable up and down and rotates integrally with the hollow screw 27. The adjustment screw 30, the arm member 15 held at the same position of the screw shaft 28, and the contact nose 16 screwed into the first adjustment screw 30 are configured.

  A bent portion 31 is formed at the lower end of the arm member 15, and the bent portion 31 is held so as to be rotatable with respect to the screw shaft 28 and not vertically movable. On the other hand, a connecting piece 33 is formed so as to protrude from one side of the upper cylindrical portion 25 of the contact nose 16, and a female screw portion 34 formed on the connecting piece 33 is screwed to the first adjusting screw 30. .

  According to the adjustment mechanism a, when the adjustment dial 35 fixed to the upper end of the hollow screw 27 is rotated, the first adjustment screw 30 is rotated together with the screw shaft 28 as shown in FIG. When the first adjustment screw 30 rotates, the lower end bent portion 31 of the arm member 15 is held at the same position, but the first adjustment screw 30 and the connecting piece 33 at the upper end of the contact nose 16 are screwed together. Therefore, the contact nose 16 slides in the nail driving direction. As a result, the entire length of the contact member 14 changes and the top dead center position does not change, but the lower end position of the contact nose 16 at the bottom dead center changes, so that the nail driving depth can be adjusted.

  Incidentally, when the nail is driven so as to be in the most depressed state (hereinafter referred to as the most depressed state), the adjustment may be performed as shown in FIG. In this case, since the lower end of the contact nose 16 approaches the bottom dead center of the striking piston 7, when the contact nose 16 is pressed against the workpiece and the nail is driven out, the nail is driven deeply by the striking piston 7. The part sinks into the surface of the workpiece. On the other hand, when the nail is driven so as to be in the most floating state (hereinafter referred to as the most floating state) with respect to the driven material, adjustment may be performed as shown in FIG. In this case, since the tip of the contact nose 16 is far from the bottom dead center of the striking piston 7, when the contact nose 16 is pressed against the workpiece and the nail is driven out, the nail is driven shallowly by the striking piston 7. The part floats from the surface of the workpiece. Therefore, optimum driving can be realized according to the material of the material P to be driven.

  The top dead center position of the contact member 14 is a position when the lower end bent portion 31 of the arm member 15 contacts the lower surface of the support arm 26 of the nose portion 4. At this time, the above-described movable sleeve 8 moves upward. A closed combustion chamber 10 is formed. Moreover, the bottom dead center position is a position when the upper end bending part 15a contacts the upper protrusion 36 (refer FIG. 4) of the upper wall part 11 of the nose part 4 in principle. The top dead center and the bottom dead center of the contact nose 16 are moved by adjustment by the adjustment mechanism a.

  Next, the nose portion 4 and the contact member 14 are covered with a cover. As shown in FIG. 4, the cover includes a fixed cover 37 and a movable cover 38. As shown in FIG. 1, the fixed cover 37 covers the front part of the nose part 4, the adjustment mechanism a, and the lower part of the arm member 15. The cover and the movable cover 38 are formed so as to cover the outer periphery of the contact nose 16.

  The distal end side (lower portion) of the movable cover 38 is formed in a straight cylindrical shape, and the mortar-shaped portion 41 at the upper portion of the cylindrical portion 40 is formed so as to spread gradually in a mortar shape and become thicker. Similarly, the upper portion of the contact nose 16 is also formed in a large-diameter cylindrical shape via the bulging portion 24, and the lower surface of the bulging portion 24 has a shape that matches the upper surface of the mortar-shaped portion 41. Therefore, the bulging portion 24 of the contact nose 16 can be in contact with the mortar-shaped portion of the movable cover 38, and the contact member 14 is restricted to a position in contact with the movable cover 38 and cannot move further downward.

  Next, as shown in FIG. 7, the spring receiver 16 a at the upper end of the contact nose 16 is formed with a spring receiver 42, and between the spring receiver 42 and the upper wall 4 a of the nose 4. A coil spring 43 is arranged. The contact nose 16 is constantly urged by the spring force of the coil spring 43 so as to protrude in the nail driving direction.

  According to the above configuration, the movable sleeve 8 and the contact nose 16 are urged downward by the main coil spring 18 and the coil spring 43 disposed on the bottom portion 17 b of the cage 17. When the nail is driven, when the contact nose portion 16 is pressed against the driven material P as shown in FIG. 8, the cage 17 deflects the spring against the main coil spring 18 as described above, and the movable sleeve 8 is set to the top dead center. Since the movable sleeve 8 is held at the top dead center until it is moved and released after the trigger 9 is operated, the spring force of the main coil spring 18 does not reach the contact nose 16 below the cage 17. However, the coil spring 43 urges the contact nose 16 to move downward. Therefore, when the nail driving piston 6 is suddenly driven downward when the nail is driven, the nail driver itself is lifted by the reaction and moved so as to be instantaneously separated from the driven material, as shown in FIG. Since the nose 16 protrudes in the driving direction due to the spring force of the coil spring 43, the lower end of the contact nose 16 is held in a contacted state without separating from the driven material P. Therefore, the position of the nail is maintained, and problems such as buckling, scattering of the connecting band, damage to the nail, and scattering of the nail that has been broken do not occur.

  The spring force of the coil spring 43 may be small as long as it is sufficient to urge the contact nose 16 to move downward.

  Further, the main coil spring 18 that biases the cage 17 upward does not need to be disposed in the nose portion 4. The structure arrange | positioned at the upper part of the movable sleeve 8 or the side part of the striking cylinder 5 may be sufficient.

  7 and 8, the contact nose 16 is cut at the side wall, so that it does not appear in the hollow, but of course the main part is formed in the hollow.

  By the way, prevention of separation from the driven material of the nailing machine is not limited to the configuration in which the contact member is spring-biased. As shown in FIGS. 9 to 11, the cover material may be spring-biased.

  That is, as shown in FIG. 9, the periphery of the nose portion 4 is covered with the fixed cover 37, and the periphery of the contact nose 16 is covered with the movable cover 38, and the contact nose 16 is directly pushed up by hand to be in the air. Cannot fire. The movable cover 38 is slidable along the contact nose 16 in the nail driving direction. The bottom dead center of the movable cover 38 is movable at a position where the lower end of the movable cover 38 is substantially the same as the lower end of the contact nose 16 so that the adjustment mechanism a is aligned with the bottom dead center when the contact nose 16 is in the most depressed state. This is a position where the engaging portion 45 formed at the upper end of the arm portion 44 protruding above the cover 38 is in contact with the protrusion 46 provided on the nose portion 4.

  Further, as shown in FIG. 4, the position where the engaging piece 52 on the upper portion of the movable cover 38 abuts on the rising portion 54 (locking portion) on the upper portion of the contact nose 16 may be set as the bottom dead center position.

  Further, the top dead center position of the movable cover 38 is a position where it abuts on an adjustment nut 48 that moves up and down in conjunction with the contact nose 16 when the adjustment mechanism a is operated. That is, a second adjustment screw 47 is formed on the outer periphery of the hollow screw 27, and an adjustment nut 48 is screwed to the second adjustment screw 47. The adjustment nut 48 is engaged with the nose portion 4 so as not to rotate, and an L-shaped engagement piece 50 is integrally formed on a side portion of the adjustment nut 48, and the lower end of the engagement piece 50 is formed on the movable cover. 38 is formed so as to face the arm portion 44 protruding upward from the upper end of 38, and the engagement piece 50 and the arm portion 44 come into contact with each other.

  According to the above configuration, when the adjustment dial 35 of the adjustment mechanism a is rotated, the second adjustment screw 47 is rotated and the adjustment nut 48 is moved in parallel with the nail driving direction. However, when the second adjustment screw 47 rotates, the first adjustment screw also rotates as described above, so that the contact nose 16 also moves in the same direction. Accordingly, by rotating the adjustment dial 52, the adjustment nut 48 and the contact nose 16 are interlocked, and the support arm 53 of the contact nose 16 and the adjustment nut 48 always maintain the same positional relationship. As described above, the top dead center of the movable cover 38 also changes in the nail driving direction in accordance with the position of the adjustment nut 48 interlocked with the contact nose 16, but no matter where the adjustment nut 48 is located, the top dead center The protruding amount of the contact nose 16 protruding from the lower end of the movable cover 38 is always substantially the same, and the protruding amount is small.

  Therefore, if the movable cover 38 is pushed up to the top dead center and the contact nose 16 is pushed up to the top dead center, the nail driver can theoretically be activated in the air, but the protruding amount of the contact nose 16 is small. Even if you use a tool, it is very difficult to push it to top dead center, and it is practically impossible to fire a nail in the air.

  As shown in FIGS. 10 and 11, a spring receiving portion 42 is formed at the upper end of the movable cover 38, and a coil spring 53 is provided between the spring receiving portion 42 and the upper wall portion 4 a of the nose portion 4. Is arranged. The movable cover 38 is always urged by the spring force of the coil spring 53 so as to protrude in the nail driving direction.

  Therefore, even with the above configuration, even if the striking piston 6 is suddenly driven downward at the time of nail driving and the nail driver itself is lifted by the reaction and moves so as to be momentarily separated from the material to be driven, the movable cover Since 38 protrudes in the driving direction by the spring force of the coil spring 53, the lower end of the movable cover 38 is held in a contacted state without separating from the driven material. Therefore, even if the contact nose 16 is separated, the nail posture does not tilt greatly, buckling is unlikely to occur, the connection band is scattered around, the nail is damaged, or the damaged nail is scattered. Such a problem does not occur.

  Further, since the movable cover 38 is always urged by a spring in the nail driving direction, there is no backlash, the operation feeling is good, and the contact nose 16 is always covered, so that air launch can be made more difficult.

  Note that a configuration in which both the contact nose 16 and the movable cover 38 are not spring-biased but only one of them is spring-biased may be employed. For example, if only the movable cover 38 is spring-biased, the main coil spring 18 that pushes the movable sleeve 8 while the combustion chamber is held at the top dead center position, particularly when the nail driver is lifted by reaction during nail driving. Although the spring force does not act on the contact nose 16, not only the movable cover 38 but also the rising portion 54 at the top of the contact nose 16 is engaged by the engaging piece 52 of the movable cover 38 as shown in FIG. Since the contact nose 16 is also pushed in the nail driving direction through the movable cover 38 by using the combined structure, the contact nose 16 can also produce the same nail guide effect.

  Next, a structure for preventing separation from a material to be driven in a pneumatic nailing machine in which a nail is driven using compressed air as a driving source will be described with reference to FIGS.

  The nail driver shown in FIG. 12 includes a body 1 ′ having a striking mechanism for driving out a nail using air pressure as a driving source, and a nose portion 4 ′ provided below the body 1 ′ and ejecting the nail. A contact nose 16 ′ having a nail injection port below 4 ′ is slidably provided. Also in this example, the contact nose 16 ′ is integrally coupled with the upper arm member 15 ′, and the contact nose The spring is biased so that the lower end of 16 'protrudes toward the lower end. The upper end of the arm member 15 'is disposed so as to be engageable with the contact lever 55 of the trigger 9'.

  When driving a nail by the nailing machine, the contact nose 16 'is pressed against the material to be driven and pressed into the body 1', thereby pushing up the arm member 15 'against the spring bias and contacting the trigger 9'. The lever 55 is rotated. By pulling up the trigger 9 'in this state, the valve stem 57 of the start valve 56 is pushed in and the nail driver is started. Even if the trigger 9 ′ is pulled without pressing the contact nose 16 ′, the contact lever 55 cannot press the valve stem 57, so it does not start.

  The contact nose 16 'is covered with a movable cover 38'. The movable cover 38 'has a cylindrical shape, and an engagement piece 58 is bent at a part of the upper end. The engagement piece 58 can engage with the upper end of the contact nose 16' and the lower surface 61 of the nose portion 4 '. Yes. A coil spring 53 'is provided between the bent portion 59 at the upper end of the movable cover 38' and the protruding portion 60 of the nose portion 4 '. The movable cover 38' is always urged downward by the coil spring 53 '. . Therefore, the engagement piece 58 of the movable cover 38 'is always engaged with the upper end of the contact nose 16'. As shown in FIG. 13, when the contact nose 16 ′ is pressed against the workpiece P and moves to the top dead center, the movable cover 38 ′ also moves upward and engages the lower surface of the nose portion 4 ′.

  Therefore, even with the above configuration, even if the striking piston 6 is suddenly driven downward at the time of nail driving and the nail driver itself is lifted by the reaction and moves so as to be momentarily separated from the material to be driven, the movable cover Since 38 'protrudes in the driving direction by the spring force of the coil spring 53', the lower end of the movable cover 38 'is held in a contacted state without separating from the driven material. Therefore, even if the contact nose 16 'is separated, the movable cover 38' does not tilt the nail so that buckling is unlikely to occur, and the connection band is scattered around, the nail is damaged, Problems such as spatter of damaged nails do not occur.

  According to the above configuration, when the movable cover 38 ′ moves in the nail driving direction by the spring force of the coil spring 53 ′, the engagement piece 58 of the movable cover 38 ′ is always engaged with the upper end of the contact nose 16 ′. Therefore, the contact nose 16 ′ also moves in the nail driving direction, so that the above-described effects can be exhibited.

  Further, since the movable cover 38 'is always urged by the spring in the nail driving direction, there is no backlash, the operation feeling is good, and the contact nose 16' is always covered to make it difficult to launch in the air.

  As shown in FIG. 14, even if the movable cover 38 ′ is lifted up to the top dead center by hand and the tip of the exposed contact nose 16 ′ is pushed in the air to drive out the nail, the movable cover 38 ′ is a coil spring Since it is biased downward by 53 ′, it is difficult to hold at the top dead center, and the exposure amount of the contact nose 16 ′ is very small. Because it is difficult, it is practically impossible to fire a nailer in the air.

  Furthermore, although the above-mentioned embodiment is an example which provided the movable cover in the contact nose, the structure which provides a movable cover in the arm member of the nail driver using compressed air, and urges the movable cover or the contact arm downward. The same effect can be obtained also.

The perspective view of the gas combustion type nailing machine according to the present invention Longitudinal sectional view of the main part of the nailing machine in the normal state Longitudinal cross-sectional view of the main part of the nailing machine when nailing Longitudinal sectional view of the nose part of the nailing machine Longitudinal sectional view of the nose of the nailing machine cut along another surface Longitudinal sectional view when the contact nose of the nose part is adjusted to the most floating state Sectional view cut along a plane different from that of FIG. Sectional view of the main part showing the state pressed against the workpiece Vertical section showing the top and bottom dead center of the movable cover Sectional drawing of the principal part which shows the state which biased the movable cover The perspective view of the principal part which shows the state which spring-biased the movable cover Longitudinal cross-sectional view of the main part showing the state that the movable cover of the pneumatic nailer is urged Longitudinal sectional view showing the state pressed against the workpiece Longitudinal sectional view showing a condition that is difficult to launch in the air

Explanation of symbols

1, 1 'body 4, 4' nose part 8 movable sleeve 16, 16 'contact nose 43, 53, 53' coil spring 38, 38 'movable cover

Claims (5)

A striking piston disposed in the body is slidable in the vertical direction, and a movable sleeve provided at the top of the striking cylinder is moved up and down to contact the striking cylinder and the cylinder head above it. The combustion chamber can be opened and closed by contact and separation, and the gas mixture in the sealed combustion chamber is ignited by an ignition plug disposed in the combustion chamber and explosively combusted. In the gas combustion type nailing machine in which a nail is driven from a nail injection nose portion provided below the body by a driver coupled to the lower surface side of the striking piston by acting on the striking piston.
A contact member that moves upward above the body by being pressed against the material to be driven to move the movable sleeve upward to form a sealed combustion chamber, and a nail that is disposed so as to cover the outside of the contact member And a movable cover slidable in the direction, and the contact member is always spring-biased in the nail driving direction independently of the movable sleeve. In a nailing machine including a body having a striking mechanism for driving out a nail using air pressure as a power source, and a nose portion provided below the body and ejecting the nail,
A contact member that allows the nail to be driven by being pressed against the material to be driven is slidable along the nose portion, and the outside of the contact member is covered with a movable cover that can slide in the nail driving direction. A nailing machine characterized in that the movable cover is always spring-biased in the nail driving direction.   The nail driver according to claim 1 or 2, wherein the contact member is a contact nose having a nail injection port that is slidably disposed below the nose portion.   The nailing machine according to claim 1 or 2, wherein the contact member is a contact arm slidably provided along the nose portion.   3. The nail driver according to claim 1, wherein the movable cover is constantly biased in the nail driving direction instead of spring-biasing the contact member.

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