JP2013193168A - Driving machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving machine that reduces impact transmission to an operator while securing operability.SOLUTION: There is provided a driving machine that includes a housing 2 having a driver blade 32A and a piston 32 for striking a nail by moving to a bottom dead center, and a handle 2A extended from the housing 2 in which the handle 2A is applied with an elastic force from the inside to the outside of the handle 2A, and the handle 2A is provided with an elasticity switching mechanism 6 which decreases the elastic force according to actions of the driver blade 32A and the piston 32.

Description

  The present invention relates to a driving machine, and more particularly, to a driving machine with reduced impact at the time of hitting.

  In a driving machine for driving a material to be driven such as a nail, for example, in a pneumatic driving machine using compressed air as disclosed in Patent Document 1, a piston and a blade integrated with the piston are dead by the pressure of the compressed air. It moves rapidly from the point toward the bottom dead center, and hits the nail at the lower end of the blade near the bottom dead center.

  In the driving machine, a reaction occurs when the piston or the like moves suddenly, and further a reaction occurs when the blade hits the nail. Since this reaction is transmitted to the worker holding the handle, the worker absorbs this reaction with his / her arm. In order to suppress this reaction, in Patent Document 1, a hook-shaped grip guide is provided on the handle to cope with the reaction by improving the gripping property. In Patent Document 2, recoil absorption is performed by providing a cushioning material on the handle.

JP 2009-66709 A JP 2011-36927 A

  In the configuration shown in Patent Document 2, since the handle is configured to have an elastic body, the elastic force always works, and when the handle does not need elasticity, for example, when the driving machine is pressed against the mating member, the elastic force Sometimes worked. When pressing the driving machine against the mating member, it is necessary to specify an accurate driving position, and therefore it is preferable that no elastic force acts on the handle. Therefore, an object of this invention is to provide the driving machine which reduced the reaction transmission to an operator, ensuring workability | operativity.

  In order to solve the above-mentioned problems, the present invention comprises a housing having a striking mechanism that moves to one dead center side and strikes a material to be driven, and a handle that extends from the housing. Is characterized in that an elastic force is applied from the inside to the outside of the handle, and the handle is provided with an elastic switching mechanism that switches the elastic force according to the operation of the striking mechanism. Provide a driving machine.

  According to such a configuration, for example, until the striking mechanism moves to one dead point, the elasticity of the handle can be increased, that is, the handle can be in a state of high elasticity. If the handle has a high modulus of elasticity, that is, it is in a hard state, when the operator grips the handle, the driving machine will not be shaken. And workability can be improved.

  In the driving machine configured as described above, the elastic switching mechanism is preferably configured to reduce the elastic force when the striking mechanism is operated.

  According to such a configuration, the elasticity of the handle can be reduced when the hitting mechanism is operated, that is, the handle can be in a soft state with a low elastic modulus, so that the reaction and impact generated by the operation of the hitting mechanism are absorbed by the handle. It is possible to reduce the reaction and the like transmitted to the worker.

  The handle further includes a base portion extending from the housing and a surface portion that is disposed on the base portion and defines a handle surface, and the elastic switching mechanism is configured to move the surface portion from the base portion to the surface portion. A first elastic body that can be biased with a first biasing force toward the head, and a biasing force reduction mechanism that reduces the biasing force of the first elastic body when the striking mechanism starts to move. Is preferred.

  According to such a configuration, the elasticity of the handle can be easily switched.

  The elastic switching mechanism preferably includes a second elastic body capable of urging the surface portion from the base portion toward the surface portion with a second urging force.

  According to such a configuration, even when the urging force of the first elastic body is reduced to 0, the urging force of the second elastic body is 0 or more, so the surface portion is urged by the second elastic body. Therefore, the recoil can be surely reduced.

  Moreover, it is preferable that this 1st elastic body is compressed air, and this urging | biasing force reduction mechanism is a pressure reduction mechanism which reduces the pressure of this compressed air.

  According to such a configuration, the urging force can be changed only by changing the pressure of the compressed air, and the change of the urging force can be facilitated.

  Moreover, it is preferable that this striking mechanism is a pneumatic striking mechanism driven by the pressure of compressed air.

  According to such a structure, since each motive power of an elastic switching mechanism and a striking mechanism can be made common, the structure of a driving machine can be simplified.

  Further, it is preferable that the urging force lowering mechanism lowers the pressure of the compressed air when the pneumatic striking mechanism is operated.

  The pneumatic striking mechanism preferably has a main valve portion that controls the striking operation, and it is preferable that the control of the main valve portion and the control of the biasing force reduction mechanism are interlocked.

  According to such a configuration, the elastic switching mechanism can be operated at the same time that the striking mechanism starts moving to one dead center.

  An air chamber capable of storing the compressed air is formed between the base portion and the surface portion, and the biasing force reduction mechanism controls communication / blocking of a passage between the air chamber and the atmosphere. A valve portion is preferred.

  According to such a configuration, the pressure in the air chamber can be easily switched, and the operability can be improved.

  In addition, a recess is formed in the base, and the passage is opened in the bottom surface of the recess. The surface portion is movably disposed in the recess, and the air chamber is formed in the recess. It is preferable that it is formed so as to have airtightness between the inner bottom surface and the surface portion.

  The base is formed with a recess that opens toward the surface portion, and the passage opens at the bottom of the recess, and a plunger is disposed in the recess so as to protrude out of the recess. The air chamber may be formed so as to have airtightness between the inner bottom surface of the recess and the plunger in the recess.

  According to these structures, an air chamber can be defined reliably.

  The handle or the housing further has a pressure accumulating chamber for storing the compressed air, and the air chamber and the valve chamber are communicated with the air chamber and the valve chamber in the passage. Blocking the air chamber and the atmosphere and the pressure accumulating chamber, communicating the air chamber and the atmosphere, blocking the air chamber and the pressure accumulating chamber and the valve unit, and communicating the air chamber and the pressure accumulating chamber. It is preferable that a switching valve for maintaining any one state of the air chamber and the valve unit and the atmosphere is interposed.

  According to such a configuration, it is possible to selectively select three states: a state in which the handle is always soft, a state in which the handle is always hard, and a state in which the handle is soft and does not strike only when hit.

  According to the driving machine of the present invention, reaction transmission to an operator can be reduced while ensuring workability.

Side surface sectional drawing of the driving machine concerning embodiment of this invention. The side surface fragmentary sectional view which shows the handle | steering-wheel periphery of the driving machine concerning embodiment of this invention. Sectional drawing along the III-III line in FIG. The side surface fragmentary sectional view which shows the valve part periphery of the driving device concerning embodiment of this invention (the state where the 2nd through-hole is connected with the 2nd opening part). The side surface fragmentary sectional view which shows the valve part periphery of the driving device concerning embodiment of this invention (the state where the 2nd through-hole is connected with the pressure accumulation chamber opening part). The side surface fragmentary sectional view which shows the valve part periphery of the driving device concerning embodiment of this invention (a state where the 2nd through-hole is connected with an atmospheric opening part). The side surface fragmentary sectional view which shows the handle | steering-wheel periphery which concerns on the modification of the driving device concerning embodiment of this invention.

  Hereinafter, a driving machine according to an embodiment of the present invention will be described with reference to FIGS. 1 to 7. A nailing machine 1 as a driving machine shown in FIG. 1 is a tool for driving a nail 1A into a wood W which is a workpiece, and mainly switches between a housing 2, a nose part 4, a trigger valve part 5 and elastic switching. And mechanism 6.

  The housing 2 includes a cylindrical cylinder built-in portion 21 and a handle 2A extending from the cylinder built-in portion 21 in a direction crossing an injection direction described later. In order to accumulate compressed air from a compressor (not shown), a pressure accumulating chamber 2a is formed in the handle 2A of the nailing machine 1 and in the cylinder built-in portion 21. The pressure accumulating chamber 2a is connected to the compressor by an air hose (not shown) via a mounting portion 2C described later of the handle 2A.

  The cylinder built-in part 21 which forms a cylinder is connected to the above-described nose part 4 at the cylindrical lower end. A cylinder 31 having a cylindrical shape is provided inside the cylinder built-in portion 21. A piston 32 having a driver blade 32A for hitting the nail 1A is built in the cylinder 31. The direction in which the driver blade 32A moves together with the piston 32 to strike the nail 1A and the axial direction of the cylinder 31 are defined as the injection direction, and the nose portion 4 side with respect to the cylinder built-in portion 21 is defined as the lower side (the opposite is the upper side). . In addition, the direction perpendicular to the vertical direction is defined with the direction in which the handle 2A extends as the rear, and the front-rear direction is defined, and the direction perpendicular to the front-rear direction and the vertical walking (the direction perpendicular to the magazine surface in FIG. 1) is Defined as direction.

  A return chamber forming portion 21 </ b> A formed so as to surround the outer periphery of the cylinder 31 is provided in the cylinder built-in portion 21 and outside the cylinder 31 at a substantially intermediate position in the vertical direction of the cylinder 31. The return chamber forming portion 21A is engaged with each of the outer peripheral surface of the cylinder 31 and the inner peripheral surface of the cylinder built-in portion 21 via a plurality of resin O-rings.

  In the cylinder built-in portion 21, an annular shape surrounding the outer periphery of the cylinder 31 is formed above the lower end of the cylinder 31, and the lower end portion of the cylinder 31 is accommodated in the ring, and the inner peripheral surface in the ring A cylinder support portion 21 </ b> B that is in close contact with the outer peripheral surface of the cylinder 31 is provided. By maintaining the airtightness between the outer peripheral surface of the cylinder 31 and the inner peripheral surface of the cylinder built-in portion 21 with the cylinder support portion 21B and the return chamber forming portion 21A, the cylinder support portion 21B and the return chamber forming portion 21A are provided below the return chamber forming portion 21A. A return chamber 21 b is formed between the outer peripheral surface and the inner peripheral surface of the cylinder built-in portion 21.

  A through hole 31a is formed in the lower portion of the cylinder 31 to communicate the inner space of the cylinder 31 and the return chamber 21b. The through hole 31 a is formed in the vicinity of the lower end of the cylinder 31 and below the bottom dead center of the piston 32. A plurality of check valves 31B are arranged around the circumference between the return chamber forming portion 21A and the through hole 31a in the vertical direction of the cylinder 31 so as to allow inflow from the cylinder 31 to the return chamber 21b and reject the reverse. Is provided.

  The piston 32 abuts on the inner surface of the cylinder 31 via an O-ring and is disposed in the cylinder 31 so as to slide. In the cylinder 31, airtightness is provided between a space above the piston 32 and a space below the piston 32. Configured to keep.

  The driver blade 32A is configured to extend downward from the center position on the lower surface of the piston 32, and the tip (lower end) is configured to protrude toward the nose portion 4 side from a through hole 41a described later. Yes. The striking mechanism is mainly defined by the piston 32 and the driver blade 32A.

  A piston bumper 33 made of a resin such as rubber, which absorbs surplus energy of the piston 32 after driving the nail 1A, is provided in the lowermost end of the cylinder built-in portion 21 and in the cylinder 31.

  A main valve portion 22 that holds the main valve 22A is provided above the cylinder 31 and above the cylinder 31. The main valve 22A is configured to have a protruding portion that protrudes upward from the center of the disk portion together with a disk portion that forms a disk shape whose axial direction is the vertical direction and is substantially the same as the outer diameter of the cylinder 31. A through hole 22a is formed from the protruding portion to the disc portion, and the lower surface of the disc portion is in contact with the upper end of the cylinder 31 so that the inside of the cylinder 31 and the pressure accumulating chamber 2a can be shut off.

  The main valve portion 22 is formed with a main valve chamber 22b which opens downward (cylinder 31 side) and can accommodate the main valve 22A so as to be movable up and down, and an exhaust passage 22c opened to the atmosphere. On the inner surface of the main valve chamber 22b, a passage in the main valve passage portion 22C communicating with the trigger valve portion 5 described later is opened at a position always above the main valve 22A. The exhaust passage 22c is also opened at the upper end of the through hole 22a, and the main valve 22A communicates with the through hole 22a in a state where the main valve 22A moves downward (on the cylinder 31 side), and the main valve 22A moves upward. It is comprised so that it may interrupt | block from the through-hole 22a. The main valve passage portion 22C connects the main valve portion 22 and the trigger valve portion 5 and feeds compressed air from the trigger valve portion 5 into the main valve chamber 22b through a passage formed therein, or the main valve The compressed air in the chamber 22b is released into the atmosphere.

  In the housing 2, a trigger lever 24 operated by an operator is provided at a lower position of the base end portion of the handle 2 </ b> A. The trigger lever 24 is pivotally supported by a rotation shaft portion 24A fixed to the housing 2 with the direction perpendicular to the vertical direction and the front-rear direction as an axial direction, and extends rearward from the rotation shaft portion 24A and rotates. The shaft portion 24A is configured to be rotatable about the fulcrum. Further, since the roller portion 25 is biased by the spring 24D, the turntable 22 can be reliably rotated even when the contact surface 25C is worn.

  The trigger lever 24 is provided with a shaft portion 24B extending in parallel with the rotation shaft portion 24A on the rear side of the rotation shaft portion 24A. The shaft portion 24B is provided with a contact portion 24C that extends toward the rotation shaft portion 24A (front side) and is rotatable with respect to the shaft portion 24B. Further, the rotation shaft portion 24A is provided with a spring (not shown) that urges the trigger lever 24 clockwise on the paper surface of FIG. 1 with the rotation shaft portion 24A as a fulcrum.

  As shown in FIG. 2, the handle 2 </ b> A has a base portion 25 extending from the housing 2, the above-described elastic switching mechanism 6 is disposed on the base portion 25, and the surface of the elastic switching mechanism 6 is resin-coated 2 </ b> B. Is installed. The aforementioned pressure accumulating chamber 2a is also formed in the space in the base 25. Further, in the base portion 25, recesses 25 a and 25 a that open upward and downward and have the longitudinal direction as the longitudinal direction are formed on the upper side and the lower side, respectively. The base portion 25 is provided with a base inner passage portion 25A in which passages are formed at the bottom surface in the recesses 25a and 25a and positions near the bottom surface, respectively. The passage of the base inner passage portion 25A is the main valve passage portion 22C. It communicates with the passage. A switching valve 26 is provided in the base inner passage portion 25A. In the base inner passage portion 25A, the recess 25a side from the switching valve 26 is defined as a first passage portion 25B, and the main valve passage portion 22C side from the switching valve 26 is defined as a second passage portion 25C.

  The switching valve 26 includes a frame part 27 and a valve part 28. The frame portion 27 is configured integrally with the housing 2, has a through hole 27 a penetrating in the left-right direction, has a cylindrical shape, and is disposed in the pressure accumulating chamber 2 a. The through hole 27 a opens to the outside of the housing 2. The frame portion 27 includes a first opening portion 27b that opens toward the inside of the through hole 27a on the side opposite to the concave portion 25a of the first passage portion 25B, and a side opposite to the main valve passage portion 22C of the second passage portion 25C. A second opening 27c is formed that opens toward the inside of the through hole 27a. The first opening 27b and the second opening 27c are arranged side by side in the diameter direction passing through the central axis of the through hole 27a.

  Further, a pressure accumulation chamber opening 27d communicating with the pressure accumulation chamber 2a is formed in the frame portion 27 in the vicinity of the second opening 27c and on the lower side which is one side in the circumferential direction of the second opening 27c, and in the vicinity of the second opening 27c. In addition, an atmospheric opening 27e that communicates with the atmosphere via the atmospheric communication passage 27A is formed on the upper side that is the other circumferential side of the second opening 27c. The second opening portion 27c, the pressure accumulating chamber opening portion 27d, and the atmospheric opening portion 27e are formed so that the width in the circumferential direction of the frame portion 27 is equal.

  The valve portion 28 is formed in a cylindrical shape having substantially the same diameter as the through hole 27a and closed at both ends in the left-right direction, and is rotatably mounted in the through hole 27a. An end portion of the valve portion 28 protrudes from the housing 2, and has an operation portion 28 </ b> A that is operated by an operator at the protruding portion.

  A first through hole 28 a and a second through hole 28 b that penetrate the inside and outside of the valve portion 28 are formed on the outer peripheral surface of the valve portion 28. The first through hole 28a and the second through hole 28b are arranged side by side in the diameter direction passing through the central axis of the valve portion 28, and the second through hole 28b is formed to have substantially the same width as the second opening 27c. ing. The first through hole 28a communicates with the first opening 27b in any case where the second through hole 28b communicates with any one of the second opening 27c, the pressure accumulation chamber opening 27d, and the atmospheric opening 27e. The width is expanded in the circumferential direction.

  As shown in FIG. 1, the handle 2 </ b> A is provided with a mounting portion 2 </ b> C to which an air hose (not shown) is connected at the rear end. By attaching an air hose (not shown) to the mounting part 2C, compressed air is supplied from the compressor (not shown) to the pressure accumulating chamber 2a.

  As shown in FIGS. 2 and 3, the elastic switching mechanism 6 is mainly composed of a pair of plates 61 and 61 and a spring 62 which are surface portions. The pair of plates 61, 61 has a substantially moving shape, and is inserted into the recesses 25 a, 25 a located above and below the base 25, respectively. In the following description, the upper plate 61 will be described unless otherwise specified. The plate 61 is configured to match the inner shape of the recess 25a, and is configured to have an O-ring 61A between the inner surface of the plate 61 and airtightness between the inner surface of the plate 61. Therefore, an air chamber 61a is formed between the plate 61 and the bottom surface of the recess 25a in the recess 25a.

  The retaining portions 61B and 61B are fixed to the base 25 by pins 61C and 61C on the surface of the base 25 and on the front and rear sides of the plate 61, respectively. A part of the retaining portion 61B is located above the plate 61, and the plate 61 is prevented from falling off from the recess 25a. The above-described resin coating 2B covers the surface of the plate 61 and the surface of the retaining portion 61B.

  Three springs 62 are arranged in the air chamber 61a between the base 25 and the plate 61 in the front-rear direction, and urge the plate 61 toward the opening side of the recess 25a. A force by which the spring 62 biases the plate 61 against the base 25 is defined as a second biasing force. The spring 62 corresponds to the second elastic body of the present invention.

  As shown in FIG. 1, the nose portion 4 includes a plate 41 that is positioned at the lower end of the cylinder built-in portion 21 and connected to the cylinder built-in portion 21, and a push lever 42 that is provided so as to be movable up and down with respect to the plate 41. It is configured to include.

  The plate 41 includes a base portion 41A configured in a flange shape and connected to the cylinder built-in portion 21, and a guide portion 41B extending downward from the base portion 41A and extending in the vertical direction. The base portion 41A closes the lower end of the cylinder built-in portion 21 and carries the piston bumper 33. A through hole 41a is formed at the center of the base portion 41A, and the driver blade 32A is inserted through the cylinder 31. The guide portion 41B is formed with an injection passage 41b that is perforated in the vertical direction and communicates with the through hole 41a and opens downward at the lower end of the guide portion 41B. The above-mentioned push lever 42 is mounted on the guide portion 41B so as to be movable up and down. The driver blade 32A is inserted into the injection passage 41b.

  Since the cross-sectional shape of the injection passage 41b is configured to substantially match the cross-sectional shape of the driver blade 32A, when the driver blade 32A is inserted into the injection passage 41b, the injection passage 41b of the guide portion 41B is passed through the injection passage 41b. A gap is hardly formed between the wall surface to be defined and the driver blade 32A, and a lubricant is interposed in the slight gap, so that the space below the piston 32 in the cylinder 31 is formed in the through hole 41a and the injection. Communication with the atmosphere via the passage 41b is suppressed.

  The push lever 42 is mainly formed by bending a plate material such as a metal plate, and mainly includes a contact portion 42A and an action portion 42B. The abutting portion 42A is mounted on the guide portion 41B so as to be movable up and down, and is configured to protrude downward so that its lower end is positioned below the lower end of the guide portion 41B.

  The action part 42B is configured integrally with the contact part 42A, is configured in a shaft shape extending in the vertical direction, and has an upper end extending near the base of the handle 2A and a position below the tip of the contact part 24C. Yes. A spring 4A is interposed between the action part 42B and the housing 2 in the vicinity of the action part 42B, and the push lever 42 is urged downward with respect to the housing 2 via the action part 42B. The position at which the push lever 42 is moved to the lowermost side with respect to the housing 2 by being biased by the spring 4A is defined as a bottom dead center which is one of the dead centers, and the push lever 42 is against the spring 4A. Is defined as the top dead center which is the other dead center.

  The above-mentioned action part 42B is in contact with the contact part 24C when the push lever 42 is located at the top dead center and the contact part 24C is lifted upward and the push lever 42 is located at the bottom dead center. It is configured to be.

  Further, the guide unit 41B is connected to a magazine device 43 that supplies a nail 1A into the injection passage 41b and incorporates a bundle in which a plurality of nails 1A are bundled and connected. The magazine device 43 is mainly composed of a magazine 43A and a feeder 43B. The magazine 43A extends from the plate 41 in substantially the same direction as the handle 2A extending direction, and is connected to the end of the handle 2A at an intermediate portion in the extending direction, and incorporates a bundle of nails 1A therein. The feeder 43B is built in the magazine 43A, has a spring (not shown), and urges the nail 1A toward the injection passage 41b by the elastic force of the spring (not shown).

  The trigger valve portion 5 is disposed in the housing 2 at a position near the trigger lever 24 and the base end portion of the handle 2A. As shown in FIG. 2, the trigger valve portion 5 mainly includes an outer frame 51, an inner frame 52, and a plunger 53. The outer frame 51 is configured in a cylindrical shape with the vertical direction as the axial direction, and is mounted on the housing 2 so that the opening of the main valve passage portion 22 </ b> C faces the outer periphery of the outer frame 51. O-rings are mounted on the outer periphery of the outer frame 51 and above and below the main valve passage portion 22 </ b> C, so that airtightness is maintained between the housing 2 and the outer periphery of the outer frame 51. The outer frame 51 is formed with an outer wall through hole 51a that communicates the inside and outside of the cylinder.

  The inner frame 52 is formed in a cylindrical shape having an up-down direction as an axial direction, and has a through-hole 52a penetrating in the up-down direction, and the outer wall through-hole 51a opening faces the outer periphery of the inner frame 52. 51 is mounted. The upper end of the inner frame 52 is exposed in the pressure accumulation chamber 2 a, and the lower end protrudes downward from the outer frame 51. O-rings are mounted on the outer periphery of the inner frame 52 and above and below the outer wall through-hole 51a to maintain airtightness between the outer frame 51 and the outer periphery of the inner frame 52. The inner frame 52 is formed with an inner wall through hole 52b that communicates the inside and outside of the cylinder.

  An O-ring 52A is mounted near the upper end of the inner peripheral surface of the through hole 52a. A cap 52B is attached to the lower end of the outer periphery of the inner frame 52. The cap 52B is attached to the outer periphery of the inner frame 52 through an O-ring to cover the lower end of the inner frame 52, and a cap through hole 52c coaxial with the through hole of the inner frame 52 is formed at the center.

The plunger 53 is formed in a round bar shape extending in the vertical direction, and is formed in the cap through hole 52c and the through hole 52a. The upper end side of the plunger 53 is configured to have substantially the same diameter as the inner diameter in the vicinity of the upper end of the through-hole 52a. The plunger 53 moves upward to fit the O-ring 52A and the O-ring 52A of the through-hole 52a. The communication between the lower space and the pressure accumulation chamber 2a can be blocked. That is, in the state where the plunger 53 is positioned below, the pressure accumulating chamber 2a and the main valve passage 22C communicate with each other via the outer wall through hole 51a, the inner wall through hole 52b, and the through hole 52a, as will be described later. Since the atmosphere and the main valve passage portion 22C are blocked, the main valve passage portion 22C and the space communicating with the main valve passage portion 22C are filled with compressed air.
To do.

  The lower end side of the plunger 53 is configured to have a smaller diameter than the cap through hole 52c. A flange 53A and an O-ring 53B are attached to the lower end side of the plunger 53. The flange portion 53A is located above the cap 52B and regulates the position of the plunger 53 below. The O-ring 53B is positioned below the flange portion 53A. When the plunger 53 is moved upward, the O-ring 53B is separated from the cap through-hole 52c. When the plunger 53 is moved downward, the O-ring 53B is positioned in the cap through-hole 52c. The gap between the cap through-hole 52c and the outer periphery of the plunger 53 can be closed, and communication between the space above the O-ring 53B of the cap through-hole 52c and the atmosphere can be blocked. That is, when the plunger 53 is positioned above, the atmosphere and the main valve passage 22C communicate with each other through the outer wall through hole 51a, the inner wall through hole 52b, and the cap through hole 52c, and accumulate pressure as described above. Since the chamber 2a and the main valve passage portion 22C are blocked, the main valve passage portion 22C and the space communicating with the main valve passage portion 22C become atmospheric pressure.

  The lower end of the plunger 53 is configured to be able to come into contact with a position between the portion where the action portion 42B comes into contact with the shaft portion 24B in the contact portion 24C. When the trigger lever 24 is pulled, the contact portion 24C is also moved upward to contact the plunger 53, and the plunger 53 can be moved upward. A spring 54 is mounted on the plunger 53 above the flange 53A. The spring 54 is disposed in the inner wall through hole 52b, takes a reaction force on the inner frame 52, and biases the plunger 53 downward via the flange portion 53A.

  When the nailing machine 1 configured as described above performs a driving operation, first, an air hose (not shown) is mounted on the mounting portion 2C to fill the pressure accumulating chamber 2a with compressed air. When the trigger lever 24 or the like is not operated, the plunger 53 is in the lower position, so that the pressure accumulation chamber 2a communicates with the main valve passage portion 22C, and the main valve chamber 22b is filled with compressed air. In this state, a pressure difference is generated between the upper end (portion facing the main valve chamber 22b) and the lower end (portion facing the inner space of the cylinder 31) of the main valve 22A. The internal space of the cylinder 31 and the pressure accumulating chamber 2a are shut off.

  Further, by operating the operation portion 28A, the valve portion 28 is disposed at a position where the second through hole 28b and the second opening portion 27c communicate with each other as shown in FIG. As a result, the compressed air in the main valve passage portion 22C flows into the air chamber 61a through the base portion passage portion 25A, and the air chamber 61a is filled with the compressed air.

  When the air chamber 61a is filled with compressed air, the air chamber 61a functions as a so-called air spring, and the plate 61 is urged in a direction toward the opening of the recess 25a, that is, in a direction toward the plate 61 from the base 25. A force that urges the plate 61 against the base 25 by the air spring is defined as a first urging force. Since compressed air is much higher pressure than atmospheric pressure, there is a force relationship of “first urging force >> second urging force” between the air spring 61 and the spring 62 by the air chamber 61a. Occur.

  When the plate 61 is biased by the air spring, the plate 61 is in a state of being stretched, and the elasticity of the handle 2A is large and the elastic modulus becomes high. Therefore, even if the operator grasps the handle 2A, the plate 61 does not move toward the base 25 against the biasing force of the air spring and the surface of the handle 2A is not deformed with a normal gripping force. Thus, the operator can stably hold the handle 2A. Therefore, the tip of the nose portion 4 can be accurately guided to the place where the nail 1A of the wood W is driven.

  Next, at the place where the nail 1A is driven, the nailing machine 1 is pressed against the wood W, and the trigger lever 24 is pulled. By pushing the nailing machine 1 against the wood W, the push lever 42 moves upward with respect to the housing 2, and the action part 42B pushes the front end of the contact part 24C upward. When the trigger lever 24 is pulled in this state, the shaft portion 24B moves upward together with the trigger lever 24, so that the rear end of the contact portion 24C connected to the shaft portion 24B also moves upward. In this movement, the contact portion 24C rotates upward with the point supported by the action portion 42B as a fulcrum, and contacts the plunger 53 to push the plunger 53 upward. When the plunger 53 moves upward, the communication between the pressure accumulating chamber 2a and the main valve passage portion 22C is cut off, the main valve passage portion 22C and the atmosphere communicate, and the inside of the main valve chamber 22b is brought to atmospheric pressure. Become.

  When the main valve chamber 22b becomes atmospheric pressure, the urging force on the lower surface of the main valve 22A becomes larger than the urging force on the upper surface, the main valve 22A moves upward, and the exhaust passage 22c and the internal space of the cylinder 31 And the communication between the space in the cylinder 31 and the pressure accumulating chamber 2a. The compressed air that has flowed in causes a pressure difference in the upper 31 direction between the space above the piston 32 and the space below the piston 32 in the cylinder 31, and the piston 32 moves downward rapidly. As the piston 32 moves, the driver blade 32A also suddenly moves downward in the injection passage 41b, hits the nail 1A disposed in the injection passage 41b, and hits the nail 1A on the wood W.

  As the piston 32 descends, the space below the piston 32 shrinks, and the air in the space below the piston 32 flows into the return chamber 21b through the through hole 31a. In addition, after the piston 32 descends backward from the check valve 31B, the compressed air in the space above the piston 32 flows into the return chamber 21b via the check valve 31B. Further, the piston 32 moves downward and finally comes into contact with the piston bumper 33 to stop the downward movement of the piston 32.

  Further, since the main valve passage 22C and the atmosphere communicate with each other, the air chamber 61a also becomes atmospheric pressure, and therefore the air spring by the air in the air chamber 61a hardly acts on the plate 61. The urging force applied to the plate 61 by the air chamber 61a at this time is defined as a third urging force. Since the third urging force is almost zero, the plate 61 receives only the second urging force by the spring 62, and the plate 61 can easily move to the base 25 side. That is, the handle 2A has a low elastic modulus and becomes soft, and can easily absorb an impact.

  At the time of striking, the piston 32 and the driver blade 32A are suddenly moved downward by the compressed air, so that an impact based on these reaction forces is generated. Even when the driver blade 32A hits the nail 1A, an impact based on the hitting is generated. Further, when the piston 32 moves to the bottom dead center, it comes into contact with the piston bumper 33, but an impact is also generated at this time. On the other hand, since the handle 2A absorbs the impact at the time of hitting as described above, the transmission of these impacts to the operator holding the handle 2A is suppressed.

  After the nail 1A is driven into the wood W, the nail driver 1 (push lever 42) is moved away from the wood W, or the pulling operation of the trigger lever 24 is released, thereby making contact. Since the upward biasing of the plunger 53 by the portion 24B is released, the plunger 53 moves downward, the pressure accumulating chamber 2a and the main valve passage portion 22C communicate again, and the compressed air flows into the air chamber 61a. Thus, the handle 2A returns to its original state of great elasticity.

  Since compressed air also flows into the main valve chamber 22b, the main valve 22A again moves downward, shuts off the pressure accumulating chamber 2a and the inner space of the cylinder 31, and also separates the space above the piston 32 in the cylinder 31. The atmosphere is communicated via the exhaust passage 22c. The space below the piston 32 and the return chamber 21b communicate with each other through a through hole 31a, and the space below the return chamber 21b and the piston 32 is in a high pressure state. On the other hand, since the space above the piston 32 is at atmospheric pressure because it communicates with the atmosphere through the exhaust passage 22c, the pressure in the cylinder 31 between the space above the piston 32 and the space below the piston 32 becomes an upper << lower pressure. A difference arises, and the piston 32 moves upward rapidly and returns to the state shown in FIG. Thereafter, when the above-described operation of driving the nail 1A is performed, the handle 2A becomes soft again, and after the nail driver 1 (push lever 42) is separated from the wood W after the driving is finished, the pulling operation of the trigger lever 24 is released. If any of the operations is performed, the handle 2A becomes hard again.

  In the nailing machine 1 in the present embodiment, the compressed air is used as the first elastic body, and the trigger valve portion 5 is used as the valve portion, thereby switching from the first urging force to the third urging force to the plate 61. Can be performed easily and instantaneously. Therefore, the handle 2A can be instantaneously changed from a hard state to a soft state in accordance with the occurrence of an impact accompanying the hitting operation, and the elastic change of the handle 2A can be easily followed by the hitting operation.

  In addition, since the second urging force is applied by the spring 62, the plate 61 can be urged by the spring 62 even if the third urging force is substantially zero as in the present embodiment. Elasticity is not lost from the handle 2A, and an impact can be absorbed suitably and reliably. In the present embodiment, the third urging force is set to almost zero. However, the present invention is not limited to this, and the third urging force is absorbed when an impact is generated while the operator holds the handle 2A. If the urging force is such that the elasticity that can be applied to the handle 2A is sufficient, it is not necessarily required to be zero.

  Further, when the operation portion 28A is operated and the valve portion 28 is arranged at a position where the second through hole 28b and the pressure accumulation chamber opening portion 27d communicate with each other as shown in FIG. Regardless of the operation, it is always filled with compressed air. In this state, the handle 2A can always be kept in a hard state.

  Further, by operating the operation portion 28A and arranging the valve portion 28 at a position where the second through hole 28b and the atmospheric opening portion 25e communicate with each other as shown in FIG. Become normal pressure. In this state, the handle 2A can always be kept in a soft state biased only by the spring 62. That is, by switching the operation unit 28A, three states can be selectively selected: the handle 2A is always soft, is always hard, and is soft when not being hit only and hard.

  The driving machine of the present invention is not limited to the above-described embodiment, and various improvements and modifications can be made within the scope described in the claims. For example, as a modification, as shown in FIG. 7, a plunger accommodating space 125 a that opens to the plate 61 side is formed on the bottom surface in the recess 25 a without using the entire space between the plate 61 and the base portion 25 as an air chamber. A structure may be provided in which a plunger accommodating portion 125 is defined, the plunger 125A is built in the plunger accommodating space 125a, and the base inner passage portion 25A is opened in the plunger accommodating space 125a.

  In this configuration, an O-ring 125B is interposed between the plunger housing space 125a and the plunger 125A to maintain the airtightness between the plunger housing space 125a and the plunger 125A. Therefore, an air chamber 61a is defined between the bottom surface of the plunger accommodating space 125a and the plunger 125A.

  According to such a configuration, in the air chamber 61a, the plunger 125A that is a sliding member can be made smaller than the plate 61 that is a sliding member in the above-described embodiment. By reducing the sliding member, the sealing distance (periphery length of the O-ring) between the base portion 25 and the sliding member can be shortened, and the air tightness of the air chamber 61a can be further improved. . Therefore, in the structure which concerns on a modification, it can endure higher pressure compressed air than the compressed air used with the nailing machine 1 concerning the above-mentioned embodiment.

  In the present embodiment and the modification, the tool for driving the piston using compressed air as power has been described, but the power for driving the piston is not limited to compressed air. Further, the first urging force and the third urging force for urging the plate have been described as compressed air. However, the present invention is not limited to this, and other mechanical configurations, for example, the base portion of the plate in a state in which the first urging force is applied. A member that abuts on the side and restricts the movement of the plate to the base side, and is separated from the base side of the plate in a state in which a third urging force is applied, and is allowed to move to the base side of the plate. Also good.

  The driving machine of the present invention is not limited to the nailing machine 1 described above, and can be widely applied as long as it is a tool that requires a driving operation, that is, an operation that generates an impact in terms of characteristics.

1: Nailer 1A: Nail 1B: Socket 2: Housing 2A: Handle 2B: Resin coating 2C: Mounting part 2a: Pressure accumulating chamber 4: Nose part 4A: Spring 5: Trigger valve part 6: Elastic switching mechanism 21: Built-in cylinder Part 21A: Chamber forming part 21B: Cylinder support part 21b: Return chamber 22: Main valve part
22A: Main valve 22C: Main valve passage 22a: Through hole 22b: Main valve chamber 22c: Exhaust passage 24: Trigger lever 24: Trigger
24A: Rotating shaft portion 24B: Shaft portion 24C: Abutting portion 25: Base portion 25A: Passage 25B: First passage portion 25C: Passage portion 25A in the second base portion: Recess 26: Switching valve 27: Frame portion 27A: Air connection Passage 27a: Through hole 27b: First opening 27c: Second opening 27d: Pressure accumulator opening 27e: Atmospheric opening 28: Valve 28A: Operation part 28a: First through hole 28b: Second through hole 31: Cylinder 31B: Check valve 31a: Through hole 32: Piston 32A: Driver blade 33: Piston bumper 41: Plate 41A: Base portion 41B: Guide portion 41a: Through hole 41b: Injection passage 42: Push lever 42A: Contact portion 42B : Action part 43: Magazine device 43A: Magazine 43B: Feeder 51: Outer frame 51a: Outer wall through hole 52: Inner frame 52A: O-ring 52B: Cage 52a: through hole 52b: cap through hole 53: plunger 53A: collar 53B: O-ring 61: plate 61A: O-ring 61B: retaining part 61C: pin 61a: air chamber 62: spring

Claims (12)

A housing having a striking mechanism for moving to one dead point side and striking a material to be driven;
A handle extending from the housing,
An elastic force is applied to the handle from the inside to the outside of the handle,
The driving machine, wherein the handle is provided with an elastic switching mechanism that switches the elastic force in accordance with the operation of the striking mechanism.   2. The driving machine according to claim 1, wherein the elastic switching mechanism is configured to reduce the elastic force when the striking mechanism is operated. The handle has a base extending from the housing and a surface portion disposed on the base to define a handle surface;
The elastic switching mechanism includes a first elastic body capable of urging the surface portion from the base portion to the surface portion with a first urging force, and the first elastic body when the striking mechanism starts moving. The driving machine according to claim 1, further comprising: an urging force lowering mechanism that lowers the urging force.   The driving mechanism according to claim 3, wherein the elastic switching mechanism includes a second elastic body capable of urging the surface portion from the base portion toward the surface portion with a second urging force. Machine. The first elastic body is compressed air,
5. The driving machine according to claim 3, wherein the biasing force reduction mechanism is a pressure reduction mechanism that reduces the pressure of the compressed air.   6. The driving machine according to claim 5, wherein the hitting mechanism is a pneumatic hitting mechanism driven by a pressure of compressed air.   7. The driving machine according to claim 6, wherein the biasing force reducing mechanism reduces the pressure of the compressed air when the pneumatic striking mechanism is operated. The pneumatic striking mechanism has a main valve portion that controls the striking motion,
8. The driving machine according to claim 6, wherein the control of the main valve unit and the control of the urging force reduction mechanism are interlocked. An air chamber capable of storing the compressed air is formed between the base portion and the surface portion,
9. The driving force according to claim 5, wherein the urging force reduction mechanism is a valve unit that controls communication / blocking of a passage between the air chamber and the atmosphere. Machine. A recess is formed in the base and the passage opens on the bottom surface of the recess.
The surface portion is movably disposed in the recess,
10. The driving machine according to claim 9, wherein the air chamber is formed so as to have airtightness between the inner bottom surface of the recess and the surface portion in the recess. The base is formed with a recess that opens toward the surface, and the passage opens on the bottom surface of the recess.
A plunger is disposed in the recess so as to be able to protrude outside the recess,
10. The driving machine according to claim 9, wherein the air chamber is formed in the recess so as to have airtightness between the bottom surface of the recess and the plunger. The handle or the housing further has a pressure accumulation chamber for storing the compressed air,
In the passage, between the valve portion and the air chamber, the air chamber and the valve portion are communicated, the air chamber and the atmosphere and the pressure accumulating chamber are blocked, and the air chamber and the atmosphere are communicated. A switching valve that keeps the air chamber, the accumulator chamber, and the valve portion, and the air chamber, the accumulator chamber, and the air chamber, the valve portion, and the atmosphere. The driving machine according to any one of claims 9 to 11, characterized in that an intervening wire is interposed.

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