JP2010201520A - Driving machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure coupling strength between a piston and a driver blade in a driving machine, and to reduce a manufacturing cost. <P>SOLUTION: The driving machine is equipped with: a cylindrical cylinder; the piston reciprocating in the cylinder; and the driver blade coupled with the piston. The driver blade is formed like a plate. The piston has a groove formed for inserting the driver blade. The piston and the driver blade are coupled through tightening with a nut. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a driving machine for driving a stopper such as a nail or a staple by a driver blade that reciprocates with a piston.

  2. Description of the Related Art A driving machine for driving a stopper such as a nail or a staple into a workpiece is known that uses air or gas as a power source. In a driving machine using compressed air of 10 atm or less as a power source, in order to obtain a sufficient driving force, the diameter of the piston must be increased. In the case of a piston having a large diameter, if the piston is formed by forging, the piston becomes too thin. Therefore, in a driving machine using compressed air of 10 atm or less as a power source, a piston and a driver blade are manufactured as separate parts and then combined. Generally, the material of the piston is a light metal such as aluminum or magnesium. The material of the driver blade is hardened high strength tool steel.

  A method of connecting a piston and a driver blade in a conventional driving machine will be described with reference to FIGS.

  As shown in FIG. 6, a method of coupling the driver blade 4 by forming a screw portion 5 is known.

  Further, as shown in FIG. 7, a screw connection is known in which a piston is sandwiched and connected by a nut and a driver blade.

  As shown in FIG. 8, pin coupling is known in which a groove is provided in a piston and the driver blades are coupled with each other by press-fitting the pins so that a gap is not generated by giving a tightening allowance to each other. The pin connection has an advantage that material costs and processing costs can be reduced because all driver blades can be molded into a plate shape.

  In the driving machine using compressed air of 20 atm or more as a power source, a sufficient driving force can be obtained even if the diameter of the piston is small. In a driving machine having a small piston diameter, a structure in which a piston and a driver blade are integrated as shown in Patent Document 1 is known.

Japanese Patent No. 3915961

  Since the screw connection is performed by a screw portion formed on the piston and the driver blade, there is no problem like the pin connection. However, since the screw part is formed on the upper part of the driver blade, the upper part of the driver blade has a cylindrical shape. In this case, since the entire driver blade is first cut out as a cylinder from the material, the plate-like portion is cut out from the cylinder shape and processed. Chips generated when the plate-shaped part is cut off are discarded. Therefore, the screw connection requires higher material costs and processing costs than the pin connection.

  In the above-described pin connection, a hole is provided in the driver blade and the boss in order to press-fit the pin. Therefore, the impact at the time of driving is concentrated around the hole, resulting in poor durability.

  The present invention is intended to reduce the material cost and processing cost of a driver blade and increase the coupling strength between the driver blade and the piston.

  In order to solve the above-mentioned problems, the present invention provides a driving machine including a cylindrical cylinder, a piston that reciprocates in the cylinder, and a driver blade connected to the piston. A groove for inserting the driver blade was provided in the piston, and the piston and the driver blade were joined by tightening with a nut.

  According to the first aspect of the present invention, since the groove for inserting the driver blade is provided in the piston, the entire driver blade can be formed into a plate shape. Therefore, when manufacturing the driver blade, it is not necessary to cut out the entire driver blade as a cylinder, and wasteful chips can be suppressed. Furthermore, since the piston and the driver blade are coupled by being tightened with a nut, the coupling strength is higher than that of the pin coupling. As a result, the material cost and processing cost of the driver blade can be reduced, and the coupling strength between the piston and the driver blade can be increased.

  According to the second aspect of the present invention, it is easy to align the center axes of the piston, the driver blade, and the nut in the vertical direction by providing an inclination at the portion where the driver blade and the nut contact each other.

Side surface sectional drawing which shows one Embodiment of this invention nailing machine. Sectional drawing which shows one Embodiment of the piston kumi of this invention nailing machine. The perspective view which shows one Embodiment of the piston of this invention nailer. The perspective view which shows one Embodiment of the driver blade of this invention nailing machine. The perspective view which shows one Embodiment of the nut of this invention nailer. Sectional drawing which shows one Embodiment of the coupling | bonding of the piston and driver blade of a conventional nailing machine. Sectional drawing which shows one Embodiment of the screw coupling | bonding of the conventional nailer. The perspective view which shows one Embodiment of the pin connection of the conventional nailer.

  The driving machine 1 shown in FIG. 1 will be described. For convenience of explanation, the upper direction in the drawing is defined as the upper direction and the lower direction in the drawing is defined as the lower direction. However, this definition does not limit the present invention.

  As shown in FIG. 1, in the driving machine, compressed air from an air compressor (not shown) is accumulated in a pressure accumulating chamber 11 in the driving machine 1 via an air hose (not shown). The driving machine is provided with a cylindrical cylinder 17 in which a piston 3 that reciprocates so as to slide up and down is disposed. A rubber bumper 25 is disposed below the cylinder 7. An injection part 35 for driving a stopper is formed below the bumper 25.

  The pressure accumulating chamber 11 is connected to an air compressor (not shown) via an air hose and an air plug, and accumulates compressed air serving as power for the driving machine.

  The cylinder 17 accommodates the piston 3 so as to be slidable up and down. The piston 3 has substantially the same outer peripheral surface as the inner periphery of the cylinder 17, and has a seal member such as an O-ring on the outer periphery of the piston 3. Therefore, the cylinder 17 is separated by the piston 3 into an upper chamber of the cylinder 17 and a lower chamber of the cylinder 17. The cylinder upper chamber can selectively communicate with the pressure accumulation chamber 11 and the atmosphere. A head valve 16 is provided on the upper portion of the cylinder 17 and is urged downward by a spring.

  The bumper 25 is located at the lower end in the cylinder 17, and the upper surface thereof abuts when the piston 3 reaches the bottom dead center. Since the bumper 25 is an elastic body such as rubber, it is deformed and absorbs surplus energy of the piston 3.

  The injection unit 35 is located at the lower end of the bumper 25 and forms an injection port 34 therein. A stopper housed in the magazine 10 is urged toward the injection port 34 by a spring in the injection unit 35.

  Next, a connection structure between the driver blade 4 and the piston 3 according to the gist of the present invention will be described with reference to FIGS.

  The piston kumi 2 includes a piston 3, a driver blade 4, and a nut 8. A boss portion 28 protrudes from below the cylindrical piston 3. The boss portion 28 has a cylindrical shape with a diameter smaller than that of the piston 3, and the length in the vertical direction is larger than that of the piston 3. A screw portion 5 is formed on the outer periphery of the boss portion 28. The cylindrical boss portion 28 is provided with a groove 6 in the longitudinal direction of the boss portion 28. The thickness of the groove 6 provided in the boss portion 28 is substantially equal to the thickness of the plate-like driver blade 4. The groove 6 is formed from the lower end of the boss portion 28 to the piston abutting surface 30. Further, the upper portion of the driver blade 4 can be fitted into the groove 6.

  The driver blade 4 is plate-shaped and has a driver blade abutting surface (A) 31 and a driver blade abutting surface (B) 33. A vertical region where the driver blade abutting surface (A) 31 and the driver blade abutting surface (B) 33 are formed is defined as an upper portion of the driver blade 4. The area below the upper part of the driver blade 4 is defined as the lower part of the driver blade 4. The driver blade abutting surface (A) 31 is a surface formed on the upper end surface of the driver blade 4. The width of the upper part of the driver blade 4 and the lower part of the driver blade 4 are different, and the width of the upper part of the driver blade 4 is larger than the width of the lower part of the driver blade 4. The driver blade abutment surface (B) 33 formed on the upper portion of the driver blade 4 is provided with an inclination for changing the width of the driver blade 4. Due to this inclination, the width of the driver blade 4 changes from the width at the top of the driver blade 4 to the width at the bottom of the driver blade 4. Further, the outer diameter of the boss portion 28 is smaller than the width of the upper portion of the driver blade 4 and larger than the width of the lower portion of the driver blade 4.

  The nut 8 has a two-sided width 29 on the outer periphery. The upper end surface of the nut 8 is a nut abutting surface 32. The upper end on the outer peripheral side of the nut 8 is higher in the vertical direction than the upper end on the inner peripheral side. Therefore, the nut abutting surface 32 has an inclination. The nut abutting surface 32 and the driver blade abutting surface (B) 33 can contact each other. Therefore, the inclination of the nut abutting surface 32 and the driver blade abutting surface (B) 33 is set equal.

  When connecting the driver blade 4 to the piston 3, the upper portion of the driver blade 4 is fitted into the groove 6 formed in the boss portion 28 of the piston 3. At this time, the driver blade abutting surface (A) 31 that is the upper end surface of the driver blade 4 is in contact with the piston abutting surface 30. Since the width of the upper portion of the driver blade 4 is larger than the outer diameter of the boss portion 28, the driver blade abutting surface (A) 31 and the driver blade abutting surface (B) 33 protrude from the outer diameter of the boss portion 28.

  Next, the nut 8 is fastened to the screw portion 5 of the piston 3. The nut 8 has a nut abutting surface 32 on the upper end surface. Further, since the driver blade abutting surface (B) 33 protrudes from the boss diameter 28 of the piston 3, the nut abutting surface 32 and the driver blade abutting surface ( B) 33 contacts. Even after the nut abutting surface 32 and the driver blade abutting surface (B) 33 contact each other, when the nut 8 is further tightened, the nut abutting surface 32 is pressed against the driver blade abutting surface (B) 33. The nut abutting surface 32 is provided with an inclination caused by a difference in position between the upper end on the outer peripheral side and the upper end on the inner peripheral side of the nut 8 in the vertical direction. The driver blade abutting surface (B) 33 is provided with an inclination for changing the width of the driver blade 4 from the width at the top of the driver blade 4 to the width at the bottom of the driver blade 4. Further, the inclinations of the nut abutting surface 32 and the driver blade abutting surface (B) 33 are in a substantially parallel relationship. Therefore, the piston 3, the driver blade 4 and the nut 8 are positioned by pressing the nut abutting surface 32 against the driver blade abutting surface (B) 33.

  Further, since the nut 8 has a two-sided width 29, a wrench or the like can be used when the nut 8 is fastened to the threaded portion 5 of the piston 3. Thereby, it becomes easy to give a rotational torque to the nut 8 at the time of an assembly, and an assembly property improves. Finally, the nut 8 and the piston 3 are fixed with an adhesive to prevent the nut 8 from loosening.

    Next, the operation of the driving machine 1 will be described. When an air hose (not shown) is connected, a part of the compressed air accumulated in the pressure accumulating chamber 1 flows into the control valve 13 through the air passage 12 and further into the head valve chamber 15 through the air passage 4. Flow into. The compressed air sent to the head valve chamber 15 further brings the head valve 16 and the cylinder 17 into close contact with each other and prevents the inflow of compressed air.

  When the trigger 18 is pulled, the plunger 32 in the control valve 3 is pushed up, and the compressed air in the head valve chamber 15 is discharged to the atmosphere via the air passage 14. When the compressed air in the head valve chamber 15 is exhausted, the head valve 16 is pushed up by the pressure of the compressed air in the pressure accumulating chamber 11, and the upper chamber of the cylinder 17 and the pressure accumulating chamber 11 communicate with each other. At the same time, the upper chamber of the cylinder 17 and the atmosphere are shut off, and the compressed air in the pressure accumulating chamber 11 flows into the upper chamber of the cylinder 17. The compressed air that has flowed into the upper chamber of the cylinder 17 suddenly moves the piston 3 to the bottom dead center and drives a stopper. At this time, the air in the lower chamber of the cylinder 17 flows into the return air chamber 13 through the air passage 21. An air passage 24 provided with a check valve 23 that allows compressed air to flow only in the direction of the return air chamber 22 is provided on the side surface of the cylinder 17. Therefore, when the piston 3 is positioned below the air passage 24 provided in the cylinder 17, a part of the compressed air that has flowed into the upper chamber of the cylinder 7 flows into the return air chamber 22 through the air passage 24. The piston 3 lowered by the compressed air flowing in from the pressure accumulating chamber 11 comes into contact with the bumper 25 at the bottom dead center. The bumper 25 absorbs excess energy of the piston 3 and deforms.

  The impact when the stopper is driven is first transmitted by the driver blade 4 to the piston 3 from the driver blade abutting surface (A) 31 via the piston abutting surface 30 when the driver blade 4 drives the stopper. After the piston 3 collides with the bumper 25, the inertia energy of the driver blade 4 is transmitted to the nut 8 through the screw 5, and the inertia energy of the driver blade 4 and the inertia energy of the nut 8 are transmitted to the piston 3 through the screw 5. Communicated.

  When the trigger 18 is returned, the plunger 32 returns and compressed air flows into the control valve 13. Then, the compressed air flows into the head valve chamber 5 through the air passage 2 and the air passage 4. When the compressed air flows into the head valve chamber 5, the sleeve valve 6 is pushed down, and the pressure accumulating chamber 1 and the upper chamber of the cylinder 7 are shut off. The exhaust valve unit 17 communicates the upper chamber of the cylinder 17 with the atmosphere. The piston 3 is pressed from the lower side by the compressed air accumulated in the return chamber air 22 and moves to the top dead center side. The air in the upper chamber side of the cylinder 17 is released to the atmosphere and returns to the initial state. When this process is repeated, the connected stoppers are sequentially driven.

  Since the configuration of the present invention does not provide the boss portion 28 hole of the piston 3, the strength can be ensured. Further, in the present invention, since the driver blades 4 can all be made into plate-like members in the same manner as the pin connection, no extra chips are generated even when the material is cut out, and the processing costs and material costs can be reduced. . Further, the nut abutting surface 32 and the driver blade abutting surface (B) 33 come into contact with each other by tightening the nut 8 to the threaded portion 5 of the piston 3. Even after the nut abutting surface 32 and the driver blade abutting surface (B) 33 are in contact with each other, the nuts 8 are further tightened so that the central axes of the piston 3, the nut 8, and the driver blade 4 can be aligned.

  As mentioned above, although this invention was demonstrated taking the example of the pneumatic type driving machine, the same effect can be acquired also about a combustion type driving machine. In the present invention, the driver blade and the piston are coupled by tightening the nut to the boss portion of the piston. However, the method for coupling the driver blade and the piston is not limited to the configuration of the present invention. For example, the same effect can be obtained even when the driver blade and the piston are coupled by press-fitting an annular member into the boss portion of the piston.

1: Driving machine 2: Piston kumi 3: Piston 4: Driver blade 5: Screw part 6: Groove 7: Pin 8: Nut 28: Boss part 29: Width across flats 30: Piston abutting face 31: Driver blade abutting face (A 32: Nut abutting surface 33: Driver blade abutting surface (B)

Claims (3)

  In a driving machine comprising a cylindrical cylinder, a piston that reciprocates in the cylinder, and a driver blade connected to the piston, the driver blade is plate-shaped and the driver blade is inserted into the piston A driving machine characterized in that a groove is provided and the piston and the driver blade are coupled by tightening with a nut.   2. The driving machine according to claim 1, wherein an inclination is provided at a contact portion between the driver blade and the nut.   In a driving machine comprising a cylindrical cylinder, a piston that reciprocates in the cylinder, and a driver blade connected to the piston, the driver blade is plate-shaped and the driver blade is inserted into the piston A driving machine characterized in that a groove is provided and the piston and the driver blade are joined by press-fitting an annular member.

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