JP4877462B2 - Guide mechanism for driving tool trigger - Google Patents

Description

  The present invention relates to a trigger guide mechanism for a driving tool that smoothly guides the trigger in a driving tool in which a guide is provided at the base of a grip of a tool body and an activation trigger is slidably guided on the guide. It is.

  For example, as an example of a driving tool, there is a gas combustion type nailing machine, which is a mixture gas of flammable gas and air injected into a combustion chamber sealed in the tool body. The high pressure combustion gas is generated in the combustion chamber by burning the mixed gas thus stirred in the combustion chamber, and this high pressure combustion gas is applied to the striking piston accommodated in the striking cylinder. Is driven in an impact cylinder, and a nail supplied to a nose part below the body is driven into a steel plate or concrete by a driver coupled to the lower surface side of the impact piston.

  By the way, the mixed gas filled in the combustion chamber is provided with a switch for generating sparks and igniting, and a guide part is formed in the synthetic resin tool body, and a trigger for turning on the switch is provided in the guide part. It is slidably stored. Then, by pulling the trigger and operating it linearly, the switch is pushed in and turned on. After the driving operation, the combustion chamber is opened.

By the way, the trigger is a synthetic resin part, and on one side thereof, a J-shaped arm that operates together with sealing and opening of the combustion chamber is integrally formed. The arm is housed in the tool body, and the other body parts are exposed to the outside. Thus, the trigger does not have a symmetrical shape in the front-rear direction across the main body part where the finger is hung. There is a slight clearance between the guide portion and the trigger. Therefore, when the trigger is pulled with a finger, the arm side remains and the opposite side is pulled, that is, a moment is generated so that the trigger rotates in the front-rear direction. For this reason, friction is generated between the inner surface of the guide portion and the outer surface of the trigger during the pulling operation. Since both the guide part and the trigger are made of synthetic resin, they are not excellent in wear resistance, so the friction surface gradually wears as the switch is operated repeatedly. And the clearance between a guide part and a trigger becomes large, and also the rotation tendency of a trigger becomes strong and wear advances further. For this reason, particles such as sand existing in the working environment enter the tool body from the widened clearance. In particular, when driving with a glove, it is easy to enter because the glove itself has many fine particles such as sand attached to it. These particles further promote wear between the guide portion and the trigger. If the wear becomes severe, the trigger is inclined with respect to the sliding direction, so that it may not be possible to slide to the stroke end, or it may enter into the switch and the contact cannot be pushed.
JP-A-8-290370

  For this reason, it is also conceivable that the guide portion and the switch are made of metal such as iron. However, although metal is excellent in abrasion resistance, since it is heavy, the whole weight increases and it becomes difficult to handle.

  It is also conceivable to increase the clearance between the guide portion and the trigger so that the sand that has entered can be easily discharged to the outside by the opposite idea. However, even if it is effective for discharging sand, if the clearance is large, there is a drawback that the playability is not good because the play when the trigger is pulled is large.

  It is an object of the present invention to provide a guide mechanism for a trigger of a driving tool that eliminates the above-described drawbacks, prevents wear of the guide portion and the trigger, can prevent sand from entering well, and does not impair the operability of the trigger. Let that be the issue.

In order to solve the above-mentioned problems, the invention according to claim 1 is directed to a trigger guide for a driving tool in which a guide portion is provided at a base portion of a grip of a tool body, and an activation trigger is slidably received and guided in this guide portion. in mechanism, it is made to protrude from the metal protrusions on the sides of the trigger on the inner surface of the guide portion, formed by attaching a metal guide member engaged with the projection continuously during sliding of the trigger The protrusion is guided so as to slide along the outer surface of the guide member when the trigger slides .

  The invention according to claim 2 is characterized in that the guide member is detachably attached to the guide portion.

  According to the first aspect of the invention, when the trigger slides, the guide fitting protruding from the side surface of the trigger is guided by the guide member of the guide portion, so that friction is generated between the guide fitting and the guide member. However, since both are made of metal, wear is very small. Therefore, since the gap between the guide fitting and the guide member can be kept small, it is possible to satisfactorily prevent the entry of fine particles such as sand existing in the work environment, and the trigger should always be operated smoothly and reliably. Can do.

  According to the invention which concerns on Claim 2, when wear of a guide member becomes large, it can replace | exchange easily.

  In FIG. 1, reference numeral 1 denotes a tool body of a gas combustion type driving tool (nailing machine). The tool body 1 is made of synthetic resin, and a grip 2 and a magazine 3 are connected to each other, and a striking piston / cylinder mechanism 4 and a combustion chamber 5 are provided.

  The striking piston / cylinder mechanism 4 is configured such that a striking piston 7 is slidably accommodated in a striking cylinder 6 and a driver 8 is integrally coupled below the striking piston 7.

  The combustion chamber 5 is formed by an annular movable sleeve 11 disposed between the upper end surface of the striking piston 7, the striking cylinder 6, and an upper wall (cylinder head) 10 formed inside the upper housing 9. The closed combustion chamber 5 is formed by moving the movable sleeve 11 until it hits the upper wall 10 as indicated by the arrow, and the upper portion of the combustion chamber 5 is communicated with the atmosphere by moving downward. It is configured.

  The movable sleeve 11 is linked to the contact arm 13 via the link member 12. By pressing the nose portion 15 against the workpiece P, the contact arm 13 moves relatively upward, and the link member 12 is pushed up against the spring 14 to move the movable sleeve 11. As a result, the combustion chamber 5 is shut off from the atmosphere, and a sealed combustion chamber 5 is formed.

  When the trigger 16 is pulled after the combustion chamber is sealed, the spark plug 17 ignites the mixed gas, and the mixed gas burns and expands explosively. Since the pressure of the combustion gas acts on the upper surface of the striking piston 7 and drives downward, the driver 8 strikes the leading nail N1 supplied into the nose portion 6 and drives it into the material P to be driven. Thereafter, the movable sleeve 11 moves down and the combustion chamber 5 is opened again.

  Next, an ignition switch 18 and a trigger 16 for operating the spark plug 17 are provided at the base of the grip 2 and are urged downward by a spring 19. That is, the trigger 16 includes a rectangular parallelepiped trigger body 16a and a J-shaped arm 16b each made of a synthetic resin, as shown in FIGS. The trigger main body 16a and the arm 16b are coupled to each other by a pin 20 and a long hole 21, and are relatively movable in the vertical direction, and are urged to move away from each other by a spring 22. Also, a guide protrusion 28 is formed on one side of the trigger body 16a. A protrusion 23 is formed on the upper end of the arm 16b, a guide protrusion 24 is formed on the outer surface, and an engagement shaft 25 is formed on the lower end. The engagement shaft 25 is engaged with an engagement groove 27 of a lock plate 26 that is rotatably provided on the tool body 1 (see FIG. 2).

  Further, a metal shaft pin 31a penetrates in the left-right direction through the upper side wall 30 on the opposite side of the arm 16b of the trigger body 16a, whereby the protrusion 31 protrudes from the side surface of the trigger body 16a. A rubber washer 32 disposed inside the side wall 30 is engaged with the two grooves 29 closer to the center of the shaft pin 31a, and the shaft pin 31a is held so as not to protrude left and right.

  Next, as shown in FIG. 6, the tool body 1 and the grip 2 are divided into left and right members 1 a, 2 a and members 1 b, 2 b, and a trigger guide portion 33 is formed at the base of the grip 2. . The guide portion 33 is formed in a box shape having an opening on the lower side and the tool body side, and three protrusions 34, 35, and 36 are formed on the inner surfaces on both the left and right sides. The two front protrusions 34 and 35 close to the tool main body are formed at positions close to each other, and the other one protrusion 36 is formed near the rear end. An ignition limit switch 18 is provided on the upper bottom portion of the guide portion 33.

  As shown in FIGS. 5 and 6, a space is formed between the protrusions 35 and 36 on both sides of the guide portion 33, and a guide member 37 made of metal such as iron is provided in this space. Has been placed. The guide member 37 is a U-shaped sheet metal member, and when the width of the guide member 37 is accommodated in the space, the protrusion of the trigger 16 is interposed between the leg piece 38 on one side and the protrusion 36 on the rear side of the guide part 33. It is formed to the extent that 31 can slide. Further, the height of the leg pieces 38 on both sides is formed substantially the same as the height of the ridges 35 and 36. The guide member 37 is preferably heat-treated in order to improve wear resistance.

  The trigger 16 is inserted from below the guide portion 33, and is slidably accommodated in the space between the left and right protrusions 34, 35, 36. Special fixing means are not required. As a result, the protrusion 31 of the trigger 16 engages with the outer surface of one leg piece 38 of the guide member 37 as shown in the figure. The guide protrusion 28 on one side of the trigger 16 is disposed between the two protrusions 34 and 35 on one side of the front portion of the guide portion 33. The guide protrusion 24 on the side surface of the arm 16 b is arranged to engage with the two protrusions 34 and 35 on the other side of the guide part 33.

  In the above-described configuration, when the trigger 16 is pulled and slid upward when driven, the projection 23 at the upper end pushes the contact of the limit switch 18 at the upper bottom portion of the guide portion 33 to turn on the switch as shown in FIG.

  By the way, when the trigger 16 slides as described above, the guide protrusion 24 of the trigger main body 16a and the guide protrusion 28 of the arm 16b are connected to the guide portion 33 as shown in FIGS. Guided by the front protrusions 34 and 35, and the protrusion 31 of the trigger 16 is continuously guided along the outer surface of the leg piece 38 of the guide member 37 of the guide 33.

  Further, when the trigger body 16a is pulled up with a finger, the arm 16b is connected to the front side, and therefore, the rear side tends to be lifted first, and the arm 16b is rotated via the pin 20. This is even more so because it is possible. For this reason, the frictional force between the rear protrusion 31 and the rear leg piece 38 of the guide member 37 becomes the largest. However, since both the protrusion 31 and the guide member 37 are made of metal, the sliding resistance is small and the sliding portion is not easily worn. Therefore, since the trigger 16 always slides smoothly, wear between the trigger 16 and the guide portion 33 is reduced, and the gap between the two can be kept small. For this reason, the entry of sand can be prevented well, and the trigger 16 can always be operated smoothly and reliably. Further, when wear of the guide member 37 increases, it can be easily replaced.

  By the way, when the trigger 16 is pulled as shown in FIG. 2, the arm 16b also moves up with a slight delay, and the engagement shaft 25 rotates the lock plate 26, so that the lock plate 26 and the movable sleeve 11 are driven together. It enters below the bent portion 39 of the link member 12 that has moved upward. For this reason, the trigger 16 is locked and cannot be returned downward until the lock plate 26 is pushed out and the lock is released when the lower moving sleeve 11 moves downward after driving.

  The guide member is not limited to a U-shape. For example, it is formed in a thick plate shape, a square bar shape, or a square tube shape, and a fixed wall for fixing the guide member to the guide portion is formed, and the guide member is fixed to the fixed wall by locking, bonding, screwing, or the like. It may be configured.

  Similarly, the protrusion 31 is not limited to the circular protrusion by the shaft pin. It may be square or plate-shaped. Also, a spring pin having a C-shaped cross section may be used.

  In this connection, as shown in FIG. 7, the shaft pin 31a is formed with an engagement groove 29 on one side of the shaft pin 31a of the enlarged diameter head, and when one side wall of the shaft pin 31a passes through the trigger body 16a. The rubber washer 32 may be engaged with the engagement groove 29 on the opposite side of the enlarged diameter head.

  Further, contrary to the above-described embodiment, a metal protrusion protrudes from the inner surface of the guide portion, and a metal surface that engages the protrusion continuously when sliding on the side surface of the trigger body. It is good also as a structure which attached the guide member.

  The guide mechanism for the trigger of the driving tool described above can be applied not only to a gas combustion type driving tool but also to a power tool.

It is a longitudinal cross-sectional view which shows the principal part at the time of non-operation of a gas combustion type nailer. It is a partial expanded sectional view at the time of the action | operation of the said gas combustion type nailer. (A) and (b) are a trigger and its exploded perspective view, respectively. It is a principal part enlarged view of FIG. It is sectional drawing on the AA line of FIG. It is a disassembled perspective view of a tool main body and a trigger part. It is a disassembled perspective view of other embodiment of an axial pin.

2 Grip 16 Trigger 31 Projection 33 Guide part 37 Guide member

Claims (2)

In the guide mechanism of the trigger for the driving tool, a guide portion is provided at the base of the grip of the tool body, and the trigger for starting is slidably stored in this guide portion and guided.
Are made to protrude from the metal protrusions on the sides of the trigger on the inner surface of the guide portion, continuously during sliding of the trigger be those fitted with metal guide member engaged with the protrusion A guide mechanism for a trigger of a driving tool, wherein the protrusion is guided so as to slide along an outer surface of the guide member when the trigger slides .   2. The trigger guide mechanism for a driving tool according to claim 1, wherein the guide member is detachably attached to the guide portion.

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