JP2010023168A - Pneumatic tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain the shortening of an assembly period and cost reduction. <P>SOLUTION: A pneumatic tool is provided with a driving force switching dial 27 of a driving force adjustment mechanism rotatably attached onto a cylinder cap; a dial guide 31 for guiding rotation of the switching dial 27 mounted around the switching dial 27; and a fitting protrusion portion 37 formed on an external surface of the dial guide 31. In addition, a resin cylinder cap protector 36 covering the cylinder cap 14 is formed with an opening 40 fittable to the fitting protrusion portion 37 on a portion adapted to the fitting protrusion portion 37. When the cylinder cap protector 36 is placed from above the cylinder cap 14, the fitting protrusion portion 37 and the opening 40 are fitted to each other to fix the cylinder cap protector 36. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a pneumatic tool in which a cylinder cap of a pneumatic tool such as a nailing machine, a screw driving machine, and a screwing machine using compressed air as a drive source is covered with a cylinder cap protector.

  In general, a cylinder cap is disposed at the upper end of the impact cylinder of these pneumatic tools, and the cylinder cap is covered with a cylinder cap protector made of synthetic resin.

By the way, the cylinder cap protector needs to be attached so as not to fall off from the cylinder cap. Conventionally, as shown in Patent Document 1, openings are formed on both sides of a cylinder cap protector, and rubber engaging members that can be fitted into the openings are bonded and fixed to outer surfaces on both sides of the cylinder cap. . When the cylinder cap is covered with the cylinder cap protector, the opening of the cylinder cap protector is engaged with the engaging member and attached.
JP2007-326203A

  However, in the above-described mounting method, work steps such as degreasing and adhesion are required to fix the engaging member to the cylinder cap, which requires time for assembly and increases costs. Also, when discarding, the rubber engaging member has to be peeled off from the metal cylinder cap and separated, which is troublesome.

  An object of the present invention is to provide a pneumatic tool that can solve the above-mentioned problems, reduce assembly time, reduce costs, and can be easily discarded.

  In order to solve the above-mentioned problem, the invention according to claim 1 is configured such that the cylinder cap provided on the upper part of the impact cylinder of the tool body is covered with a cylinder cap protector and the amount of compressed air supplied to the impact cylinder is adjusted. In a pneumatic tool having a driving force adjusting mechanism for adjusting driving force, a driving force switching dial of the driving force adjusting mechanism is rotatably provided on the cylinder cap, and the switching dial is rotated around the switching dial. A dial guide for guiding is provided, and a fitting projection is formed on the outer surface of the dial guide, and the cylinder cap protector made of resin covering the cylinder cap is fitted with a portion corresponding to the fitting projection. An opening that can be fitted with the protrusion is formed, and the cylinder cap protection The by the said fitting projection and the opening is fitted when covered from above the cylinder cap, characterized in that fixed to the cylinder cap protector.

  According to a second aspect of the present invention, in the first aspect, the lower end portion of the fitting protrusion and the lower edge portion of the opening are formed obliquely so that the inner side is higher and the outer side is lower. Features.

  According to the first aspect of the present invention, the driving force switching dial is rotatably provided on the cylinder cap, the dial guide for guiding the rotation of the switching dial is provided around the switching dial, and the outer surface of the dial guide. The resin cylinder cap protector that covers the cylinder cap is formed with an opening that can be fitted with the fitting protrusion at a portion corresponding to the fitting protrusion. Since the cylinder cap protector is fixed by fitting the fitting protrusion and the opening when the cylinder cap protector is covered from above the cylinder cap, the cylinder cap protector is assembled. In addition, work such as degreasing and bonding is not required as before, and the cylinder cap protector is assembled. Since the fitting projection may be formed integrally with the dial guide necessary, it requires only a number of parts reduced. Therefore, the assembly time can be shortened, and the cost can be reduced. In addition, when parts are bonded, there is a possibility that the adhesion may be peeled off, in which case the cylinder cap protector may fall off, but the cylinder cap protector is assembled to the dial guide, so there is no risk of dropping off. . Furthermore, at the time of disposal, it is not necessary to peel off the adhesion of the rubber engagement member to the metal cylinder cap as in the prior art, and the disposal work is simple because the metal part and the resin part are simply separated. .

  According to the second aspect of the present invention, since the lower edge portion of the opening portion enters the inside of the lower end portion of the fitting protrusion, the cylinder cap protector is stably held on the cylinder cap without coming off.

  In the following, an embodiment of a pneumatic tool according to the present invention will be described with reference to the drawings with a screw driving machine. The pneumatic tool is not limited to a screw driving machine. What is necessary is just to drive using compressed air, for example, a general nailing machine etc. may be sufficient.

  As shown in FIG. 1, the screw driving machine operates the trigger valve 3 by pulling the trigger 2 provided on the tool body 1, and the main valve 4 moves up in conjunction with the trigger valve 3. The chamber 5 is opened with respect to the striking cylinder 6, and the compressed air in the main air chamber 5 is supplied to the top of the striking cylinder 6, and the striking piston 7 is driven by this air pressure, and is integrally coupled with the striking piston 7. The driver bit 8 is struck downward so that a driving screw (not shown) supplied from the magazine 10 into the nose portion 11 is driven into the object to a certain depth. The driver bit 8 is rotated by a rotary gear 13 driven by an air motor 12 and is configured to further rotate a driven driving screw and screw it into an object.

  By the way, in the screw driving machine, a driving force adjusting mechanism capable of adjusting the driving force by adjusting the amount of compressed air supplied from the main air chamber 5 to the driving cylinder 6 is provided on the upper portion of the cylinder cap 14. ing.

  That is, as shown in detail in FIGS. 2 and 3, a piston stop 15 that holds the striking piston 7 at the top dead center is disposed between the striking cylinder 6 and the cylinder cap 14 thereon. The piston stop 15 is formed in a cylindrical shape, an engagement claw 16 that engages and holds the bulging portion at the upper end of the striking piston 7 is formed at a constant interval, and a valve housing 17 is provided in the middle portion. A fitting hole 18 is formed in the upper portion of the valve housing 17 and the center of the cylinder cap 14.

  A switching valve 20 is accommodated in the valve housing 17 so as to be movable up and down. An operating rod 21 protrudes upward from the center of the switching valve 20. The operating rod 21 passes through the fitting hole 18. An O-ring 22 is attached to the outer periphery of the switching valve 20. When the switching valve 20 is moved to the bottom dead center, the O-ring 22 comes into contact with the lower edge 23 of a slightly smaller diameter at the lower part of the valve housing 17 to be in a sealed state, but the switching valve 20 is located above that. In some cases, a small clearance is formed between the O-ring 22 of the switching valve 20 and the inner wall of the valve housing 17.

  On the other hand, a first air supply port 24 is formed in the lower portion of the side wall of the valve housing 17. A second air supply port 25 is formed through the center of the switching valve 20 and the operating rod 21. The first air supply port 24 has a larger cross-sectional area than the second air supply port 25.

  Next, a guide pin 26 is provided so as to intersect with the upper portion of the operating rod 21 that protrudes upward through the cylinder cap 14.

  A switching dial 27 made of synthetic resin is provided on the upper portion of the cylinder cap 14 so as to be rotatable around the operating rod 21 in the horizontal direction. The switching dial 27 has an annular shape, and an operation lever 28 projects from one side of the side wall portion. A Z-shaped switching guide groove 30 having an inclined middle portion is formed on the opposite side of the side wall portion. . The guide pin 26 is slidably engaged in the guide groove 30.

  Further, a dial guide 31 made of synthetic resin is provided on the outer periphery of the switching dial 27. The inner peripheral surface of the dial guide 31 is formed to be slidable on the outer peripheral surface of the switching dial 27, and the switching dial 27 is configured to be guided along the dial guide 31 and rotate.

  A fixed cover 32 is disposed above the dial guide 31, and a screw 33 passing through the dial guide 31 from the fixed cover 32 is screwed to the mounting leg 34 of the cylinder cap 14, thereby fixing the dial guide 31. A switching dial 27 is rotatably guided inside the dial guide 31.

  The dial guide 31 is formed with an engaging groove 35 that engages with the guide pin 26. The engagement groove 35 constitutes a detent of the operating rod 21 by engaging with the guide pin 26.

  Next, as shown in FIGS. 3 and 4, a cylinder cap protector 36 made of synthetic resin is put on the outside of the dial guide 31. An opening 39 is formed on one side of the cylinder cap protector 36, the operation lever 28 of the switching dial 27 is disposed inside the opening 39, and its end is exposed to the outside. For this reason, the operation lever 28 can be rotated in the left-right direction from the outside of the cylinder cap protector 36.

  According to the above configuration, when the switching dial 27 is rotated in the left-right direction together with the operation lever 28, the Z-shaped guide groove 30 moves left and right in the guide pin 26 portion. It slides along the other end from one end of the intermediate part, and moves in the vertical direction accordingly. When the guide pin 26 moves up and down, the operating rod 21 also moves up and down.

  When the operating rod 21 moves upward together with the guide pin 26, the strong mode is set, and the switching valve 20 moves upward from the first air supply port 24 as shown in FIG. Compressed air is supplied to the striking cylinder 6 through the first air supply port 24. In addition, since there is a clearance between the O-ring 22 of the switching valve 20 and the inner peripheral surface of the valve housing 17, a part of the compressed air passes through this clearance, and the impact cylinder 6 also passes through the second air supply port 25. Supplied in. In this case, a large amount of compressed air is supplied, and a large driving force is obtained.

  On the other hand, when the actuating rod 21 moves downward together with the guide pin 26, the mode is changed to the weak mode, and the switching valve 20 moves downward from the first air supply port 24 as shown in FIG. The O-ring 22 on the outer periphery of the switching valve 20 is in contact with the lower edge 23 of the valve housing 17 and sealed. Therefore, the compressed air from the main air chamber 5 is supplied into the striking cylinder 6 through the second air supply port 25 only. In this case, since only a small amount of compressed air is supplied compared to the case where the operating rod 21 moves up, the driving force is small.

  Thus, the magnitude of the driving force can be selected by adjusting the supply amount of the compressed air by operating the operation lever 28.

  Next, the cylinder cap protector 36 is fixed to the cylinder cap 14 as follows. That is, as shown in FIGS. 3 to 5, substantially rectangular fitting projections 37 are formed on the outer surfaces of the left and right sides of the dial guide 31. The lower end of the fitting protrusion 37 is formed obliquely so that the inside is high and the outside is low, and the lower end outside 37a is formed so as to float from the outer surface of the cylinder cap 14 (see FIG. 2A). ). On the other hand, the cylinder cap protector 36 that covers the cylinder cap 14 is formed so as to cover the entire outer surface of the cylinder cap 14, and a fixing bolt 38 that fixes the cylinder cap 14 to the housing of the tool body 1 is covered below the cylinder cap protector 36. A cover 41 is formed. Moreover, the opening part 40 which can be fitted with this fitting protrusion 37 is formed in the site | part corresponding to the said fitting protrusion 37 in the both sides of right and left. The lower edge portion 40a of the opening 40 is formed obliquely so as to expand outward (see FIG. 2A).

  In the above configuration, when the cylinder cap protector 36 is put on the cylinder cap 14 from above, the opening 40 is slightly extended and fitted into the fitting protrusion 37 so that the cylinder cap protector 36 is connected to the cylinder cap. It is fixed on the cap 14. At this time, the lower edge portion 40 a of the opening 40 of the cylinder cap protector 36 is engaged with the inside of the lower end portion outer side 37 a of the fitting projection 37. In this way, the lower edge portion 40a of the opening portion 40 enters the inside of the lower end portion of the fitting projection 37, so that the cylinder cap protector 36 is stably held on the cylinder cap 14 without coming off.

  According to the above configuration, the assembly of the cylinder cap protector 36 does not require work such as degreasing or adhesion as in the prior art, and the fitting protrusion 37 necessary for the assembly of the cylinder cap protector 36 is provided with the dial guide 31. Therefore, the number of parts can be reduced. Therefore, the assembly time can be shortened, and the cost can be reduced. Further, when the parts are bonded, the bonding may be peeled off. In this case, the cylinder cap protector may drop off. However, since the cylinder cap protector 36 is structured to be assembled to the dial guide 31, it may drop off. There is no. Further, at the time of disposal, it is not necessary to peel off the rubber engagement member from the metal cylinder cap 14 as in the prior art, and the metal parts and the resin parts are simply separated, so the disposal work is easy. is there.

  The fitting protrusion 37 and the opening 40 are not limited to a rectangular shape. For example, it may be circular.

Longitudinal sectional view of a screw driving machine according to the present invention (A) and (b) are explanatory drawings of the operation mode of the driving force adjusting mechanism. Disassembled perspective view of the periphery of the cylinder cap Cylinder cap protector mounting mode illustration The perspective view which shows the attachment state of a cylinder cap protector

Explanation of symbols

1 Tool Body 14 Cylinder Cap 15 Dial Guide 27 Switching Dial 31 Dial Guide 36 Cylinder Cap Protector 37 Fitting Projection 40 Opening

Claims (2)

In a pneumatic tool having a driving force adjusting mechanism for adjusting a driving force by covering a cylinder cap provided on an upper portion of a hitting cylinder of a tool body with a cylinder cap protector and adjusting an amount of compressed air supplied to the hitting cylinder. ,
A driving force switching dial of the driving force adjusting mechanism is rotatably provided on the cylinder cap, a dial guide for guiding the rotation of the switching dial is provided around the switching dial, and a fitting protrusion is provided on an outer surface of the dial guide. The cylinder cap protector made of resin that covers the cylinder cap is formed with an opening that can be fitted with the fitting protrusion at a portion corresponding to the fitting protrusion,
A pneumatic tool, wherein the cylinder cap protector is fixed by fitting the fitting protrusion and the opening when the cylinder cap protector is placed from above the cylinder cap.   2. The pneumatic tool according to claim 1, wherein a lower end portion of the fitting protrusion and a lower edge portion of the opening are formed obliquely such that the inner side is higher and the outer side is lower.

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