The present invention relates to a driver for driving fasteners such as nails or staples into a driving object material.
A driver for driving fasteners such as nails into a driving object material has a driver blade, which drives the fasteners through an injection port of the driver. The driver blade is attached to an actuating piston, which is reciprocatably incorporated in a driver body. When the actuating piston is actuated in a driving direction, the fastener is driven through the injection port by the driver blade.
In a driver described in Patent Literature 1, an actuating piston is actuated by the compressed air supplied from outside into a pressure accumulation chamber in the driver. When a trigger is operated to drive a fastener into a driving object material, the compressed air in the pressure accumulation chamber is supplied into a cylinder, and the actuating piston is actuated in the driving direction.
PTL 1: Japanese Patent Application Laid-Open Publication No. 2008-149404
In a type of driver, a gas pressure accumulation member is incorporated in a driver body, and compressed gas is filled in a pressure accumulation chamber in a gas pressure accumulation member. In this type of driver, when a trigger is operated, the gas pressure accumulation member is shrunk in an axial direction by an electric motor, and the gas pressure accumulation member is then expanded in the axial direction by the compressed gas in the shrunk pressure accumulation chamber. Thus, a driver blade is actuated by the gas pressure accumulation member.
In this type of driver, the driver blade enters the interior of the gas pressure accumulation member. Therefore, when the driver blade is worn and is to be replaced, the gas pressure accumulation member has also been required to be disassembled. Therefore, the conventional driver has a problem that maintenance thereof is cumbersome.
An object of the present invention is to make it possible to easily carry out the replacement of a driver blade in a driver having a gas pressure accumulation member.
A driver of the present invention includes: a gas pressure accumulation member;
actuation mechanism which compresses the gas pressure accumulation member and then releases the compression; and a driver blade which is attached to the gas pressure accumulation member so as to be attachable/detachable from outside and strikes a fastener in conjunction with the release of the compression of the gas pressure accumulation member.
According to the present invention, the driver blade is attached to the gas pressure accumulation member so as to be attachable and detachable from outside. Therefore, the replacement of the driver blade or the actuating piston can be easily carried out.
Hereinafter, a driver according to an embodiment of the present invention will be described with reference to
The actuating piston 5 has a cylindrical part 5a and an end wall part 5b which is integrated with a lower end part thereof, and is housed in the main body 2a so as to be reciprocatable in the vertical direction in
Air is exemplified as the gas which is filled and contained in the inside of the gas pressure accumulation member 4. However, the gas is not limited to air. For example, nitrogen gas or carbon dioxide gas can also be used.
The housing 2 is made of resin such as nylon or polycarbonate. The cam 12 and the gas pressure accumulation member 4 are mainly incorporated in the main body 2a of the housing 2. A sub body 23 is mounted on the grip 2c of the housing 2, and the motor 10 and the deceleration mechanism 11 are mainly incorporated in the sub body 23.
A flat-plate-like blade guide 26 which guides a driver blade 6 is provided at a lowermost end part of the main body 2a. A driver guide 7 is disposed to be opposed to a front surface of the blade guide 26, and the driver guide 7 projects to the lower side of the main body 2a. An injection port 21a is formed between the driver guide 7 and the blade guide 26. This injection port 21a penetrates through the main body 2a and communicates with the bottom wall of the actuating piston 5. On the upper side of the blade guide 26, a cover plate (not shown) which is positioned at a front surface of the later-described driver blade 6 is disposed. In a lower part of the main body 2a, a receiving part 21b which receives the press-down force of the actuating piston 5 is provided.
As shown in
A detachable battery 16 is mounted at a rear end of the grip 2c. A power-supply control unit 82 is provided in the grip 2c. The power-supply control unit 82 controls the electric power which is supplied from the battery 16 to the motor 10 based on detection results from the starting switch 13a, and others.
A push lever 14 is mounted in the housing 2 so as to be vertically movable with respect to the main body 2a. The push lever 14 has a distal end part, in other words, a lower end part 14a projecting from a lower end part of the injection port 21a and an upper end part 14c positioned in the vicinity of the trigger 13, and the part between the lower end part 14a and the upper end part 14c serves as a bent arm part 14b. A nose 24 is attached to a front surface of the driver 7 so as to be opposed to the lower end part 14a of the push lever 14. The part between the nose 24 and the lower end part 14a serves as a part of the injection port 21a. As shown in
As shown in
As shown in
When the trigger 13 is pulled in the state in which the push lever 14 and the free end part 100a are engaged, the switch plunger 96 presses the starting switch 13a, which is provided in the grip 2c, via the switch lever 15 and sets it to an ON state, and as a result of this ON state, the motor 10 connected to the battery 16 is activated. In this manner, when the switch plunger 96 is at a downward limit position, the driver maintains an OFF state. On the other hand, when the switch plunger 96 is moved upward against a drag of the spring 101, the switch lever 15 is turned to set the starting switch 13a to an ON state, so that the motor 10 is activated and the driving operation by the driver is started.
The deceleration mechanism 11 which is positioned in the rear of the gas pressure accumulation member 4 and is made up of a planetary gear mechanism 71, a final gear 72 which is actuated by the deceleration mechanism 11, and a gear holder 73 which retains the final gear 72 are disposed in the main body 2a. The gear holder 73 is provided with a supporting shaft 25a which rotatably supports the final gear 72. The supporting shaft 25a projects from the gear holder 73 to the front side. In the gear holder 73, a through hole 25b is formed to be positioned on the lower side of the supporting shaft 25a. The output shaft of the deceleration mechanism 11 penetrates through the through hole 25b, and the output shaft is provided with an output gear 71a which is meshed with the final gear 72.
On the lower side of the sub body 23, the magazine 9 is disposed so as to extend in the front-rear direction. In the magazine 9, a supply port is formed so as to communicate from a distal end thereof to the injection port 21a of the driver guide 7 via the blade guide 26. The fasteners 102 in the magazine 9 are supplied to the supply port. In the magazine 9, a pusher (not shown) which pushes the fasteners 102 toward the supply port is provided. The magazine 9 is disposed on the lower side of the sub body 23 so that the direction in which the pusher pushes the fasteners 102 is parallel to the front-rear direction. In the magazine 9, the plurality of fasteners 102 mutually coupled in an aligned manner are retained, and a front-side end part of the magazine 9 is opposed to the rear side of the blade guide 26 in the injection port 21a. Thus, the fasteners 102 are supplied to a position on the rear side of the blade guide 26 in the injection port 21a. The pusher is slidably mounted in the magazine 9, is biased by a spring (not shown) toward the blade guide 26 side in the front, and is disposed in the rear of the fasteners 102. Accordingly, the top of the fasteners 102 is sequentially supplied into the injection port 21a by the pusher.
As shown in
The push lever 14 is always pressed toward the top dead center by the spring 95 provided between the push lever 14 and the blade guide 26. The spring force of the spring 95 is set to be smaller than the spring force of the plunger spring 101 which presses the switch plunger 96 toward the lower side.
The feed passage 26a on the front surface of the blade guide 26 shown in
The driver guide 7 is provided on a front surface of the feed passage 26a. Since the pressing force from the spring (not shown) applied to the pusher via the fasteners 102 is applied to the driver guide 7, this pressing force does not act on the push lever 14. Therefore, the pressing force of the spring 95 which pushes up the push lever 14 can be set to be small regardless of the pressing force of the pusher.
The distal end part 14a of the push lever 14 has a guide surface for the vertical movement of the driver blade 6. More specifically, the distal end part 14a of the push lever 14 is fixed by a screw so as to form the injection port 21a together with the approximately flat-plate-like nose 24 which covers a part of the distal end part 14a. The nose 24 and the push lever 14 are integrated with each other so as to be slidable in the vertical direction. Also, as shown in
The deceleration mechanism 11 has the planetary gear mechanism 71, which is coupled to the rotating shaft 10a of the motor 10, and the final gear 72. The planetary gear mechanism 71 is a publicly known gear mechanism having a sun gear attached to the rotating shaft 10a, a planetary gear meshed therewith, a carrier which supports the planetary gear, and others. As shown in
The final gear 72 which is a rotor constitutes the cam 12, and a first latching part 12a and a second latching part 12b which are provided to project toward the actuating piston 5 are provided on a front surface of the final gear 72. As shown in
As shown in
The first pin 91 has an approximately-cylindrical first base part 91a which projects from the front surface of the final gear 72 and a flange part 91b which is disposed at a front end part of the first base part 91a and has a larger diameter than that of the first base part 91a. For the reasons in terms of processing that it is not easy to process the boundary part between the first base part 91a and the first flange part 91b into an orthogonal shape, an annular groove is formed in the circumferential direction of the first base part 91a. In a first roller 93, a first through hole 93a which is rotatably mated with the first flange part 91b and a second through hole 93b which has a smaller diameter than that of the first through hole 93a are coaxially formed. Since the outer diameter of the first flange part 91b is larger than the diameter of the through hole 93b, the first roller 93 is prevented from falling from the first pin 91. In the first roller 93, the depth of the through hole 93a in the axial direction is designed to be approximately the same as the length of the first flange part 91b in the front-rear direction. Therefore, the front ends of the first flange part 91b and the first roller 93 are disposed on the same plane.
Like the first pin 91, the second pin 92 also has a second base part 92a and a second flange part 92b. Also in the second roller 94, a first through hole 94a and a second through hole 94b which has a smaller diameter than that of the first through hole 94a are coaxially formed like the first roller 93. Since the second latching part 12b projects more than the first latching part 12a, the second flange part 92b has a larger distance in the front-rear direction compared with the first flange part 91b. In accordance with this, the first through hole 94a of the second roller 94 is formed to have a larger axial-direction depth than that of the first through hole 93a of the first roller 93. As a result, the contact area between the second roller 94 and the second flange part 92b is larger than the contact area between the first roller 93 and the first flange part 91b.
In the housing 2, a tubular guide part 3 is provided, and the gas pressure accumulation member 4 provided in the tubular guide part 3 is made up of an accordion-like bellows 41. Compressed air is contained in the bellows 41. The bellows 41 is formed of a flexible material such as fiber-reinforced rubber and is configured to have air tightness by, for example, a metal thin film. The upper and lower ends of the bellows 41 are sealed with a sealing member 41a and a sealing member 41b whose end surfaces are flat surfaces. The bellows 41 forms a hollow tubular shape and is expansible/shrinkable straight in the vertical direction. Intermediate rings 42 are provided at several locations at small-diameter parts of the bellows 41, several bulges are provided like a Japanese lantern between the intermediate rings 42 and the bellows 41, and the sealing member 41a and the sealing member 41b are provided at both ends of the bellows 41 so as to seal it to maintain air tightness. The intermediate rings 42 between the swellings are mated in order to receive the tensile force caused by the internal pressure and maintain the outer diameters of the small-diameter parts. The thickness of the rubber film of the bellows 41 is normally about 2 to 4 mm. The bellows 41 has an inner-surface rubber layer for maintaining air tightness, a cord-reinforced layer for supporting the tensile force caused by the internal pressure, and an outer-surface rubber layer for protecting the main body from the influence of the external environment. Normally, ring-like steel-made bead wires are embedded in the attachment parts to the sealing member 41a and the sealing member 41b at the both ends of the bellows 41.
The actuating piston 5 is detachably attached to the lower end surface of the gas pressure accumulation member 4, and the upper end thereof is received by a receiving part 2d in the housing 2. The gas pressure accumulation member 4 has a gas filling port 61 at an upper end part thereof, and gas can be refilled therein.
The actuating piston 5 has a bottomed tubular shape with an approximately U-shape cross section, and as shown in
The latched part 52a projects from an upper-side position of the actuating piston 5 toward the rear side so as to have a projecting distance with which it can be engaged with the latching part 12a. The latched part 52b projects from a lower end position of the actuating piston 5 toward the rear side so as to have a projecting distance with which it cannot be engaged with the latching part 12a but can be engaged with the latching part 12b. The driver blade 6 is detachably mounted on the attachment part 51.
As shown in
A piston bumper 8 serving as a buffer for reducing shock in the downward movement of the actuating piston 5 is housed in a lower end part in the housing 2. The piston bumper 8 is made of soft rubber or resin such as urethane, is disposed below the actuating piston 5, and is configured to be able to abut on the lower end surface of the actuating piston 5. The magazine 9 is attached to a right lateral surface of the driver guide 7.
Next, the operation of the driver 1 will be described.
In the state shown in
As a result, as shown in
When the cam 12, that is, the final gear 72 is rotated by the motor 10, the latching part 12a is engaged with the lower surface of the latched part 52a before the latching part 12b reaches the top dead center. In this state, by the continued rotation of the final gear 72, the actuating piston 5 is moved toward the upper side. When the latching part 12b has passed the top dead center and is detached from the latched part 52b, the actuating piston 5 is further moved up in conjunction with the upward displacement of the latching part 12a. When the latching part 12a reaches the top dead center, as shown in
The upward movement of the actuating piston 5 by the rotation of the cam 12 is carried out against the gas pressure of the compressed gas in the gas pressure accumulation member 4, and the air in the gas pressure accumulation member 4 is compressed and energy is accumulated in conjunction with the upward movement of the actuating piston 5. Therefore, when the latching part 12a is detached from the latched part 52a, as shown in
When the fastener 102 is driven into the driving object material by the driver blade 6, the driver 1 is moved in the direction opposite to the driving object material 36 by the reactive force of the driving. The plunger spring 101 is always pressing the switch plunger 96 downward with respect to the free end part 100a of the trigger arm 100. Since the load thereof is set to be larger than the load of the spring 95 which is pushing up the push lever 14 to the top dead center, the contact point of the switch plunger 96 with the trigger arm 100 serves as the point of effort. Also, the pin 99 serves as the point of fulcrum, and the free end part 100a of the trigger arm 100 pushes down the upper end part 14c of the push lever 14. As a result, the driver 1 is moved in a direction away from the surface of the driving object material 36, but the distal end part 14a of the push lever 14 is moved toward the relatively lower side with respect to the driver 1 so as to keep abutting on the surface of the driving object material 36. In this manner, until the fastener 102 is completely driven into the driving object material 36, a head part of the fastener 102 is reliably guided by the injection port formed by the distal end part 14a of the push lever 14 and the nose 24.
The timing at which the latching part 12a is detached from the latched part 52a and the timing at which the latching part 12b is engaged with the latched part 52b are adjusted by the power-supply control unit 82 so that the actuating piston 5 is returned after the actuating piston 5 has collided with the piston bumper 8 and stopped. In this adjustment, the rotation state of the final gear 72 is set by a detection signal from a microswitch 83 shown in
According to the present embodiment, the actuating piston 5 is fixed to the gas pressure accumulation member 4 so as to be attachable/detachable from the outside, and the driver blade 6 is fixed to the actuating piston 5. Therefore, the driver blade 6 can be replaced by replacing the actuating piston 5 without disassembling the gas pressure accumulation member 4. Accordingly, the replacement of the driver blade 6 can be easily carried out. Moreover, according to the present embodiment, when the latched part 52b is moved upward by the latching part 12b and the latched part 52a is moved upward by the latching part 12a in conjunction with approximately one rotation of the cam 12, the actuating piston 5 is moved upward. Therefore, the stroke of the actuating piston 5 can be enlarged even with the cam 12 having a comparatively small diameter.
Also, since the gas pressure accumulation member 4 is separately provided from the actuating piston 5 and the driver blade 6, compression of the gas pressure accumulation member 4 can be achieved with the comparatively simple cam structure, and the driver can be manufactured at low cost. Since there is no piston sliding part in the gas pressure accumulation member 4, wear of a sealing part of the sliding part does not occur. Further, since gas leakage from the sliding part in the compression of the gas pressure accumulation member 4 is less likely to occur, the reduction in the pressure due to the gas leakage of the gas pressure accumulation member 4 caused by repeated operation can be prevented, and thus, energy drop can be prevented. Moreover, since the expanding/shrinking accordion part whose strength is comparatively low is not directly compressed by the actuating piston 5, durability of the gas pressure accumulation member 4 can be improved.
The embodiment adopts the structure in which the gas pressure accumulation member 4 is compressed by moving the actuating piston 5, but it is also possible to adopt the structure in which the gas pressure accumulation member is compressed by actuating the driver blade to move the actuating piston 5 itself instead of just moving the actuating piston 5.
Next, the second embodiment of the present invention will be described.
In the driver 1 of the first embodiment, the power of the motor 10 is transmitted to the actuating piston 5 by using the deceleration mechanism 11 and the cam 12. However, in a driver 1a of the present embodiment shown in
As shown in
When the rotating shaft 29 is rotated in the direction of an arrow from a state in which the movable body 31 and the rotor 33 are at a bottom dead center as shown in
As shown in
An inner piston 35 is made up of a sleeve 35a which is fixed to an upper end part in the housing 2 and a cylindrical sliding part 35b which is housed in the sleeve 35a so as to be vertically slidable. The inner piston 35 penetrates through the interior of the gas pressure accumulation member 4 in the vertical direction, and a distal end of the sliding part 35b is detachably fixed to the actuating piston 5. In other words, the actuating piston 5 is attached to the gas pressure accumulation member 4 so as to be attachable/detachable from the outside. A distal end part of the wire 37 is fixed to the inner side of the sliding part 35b by a fixing member 37a. The fixing member 37a is attached to a coupling sleeve 51b provided at the actuating piston 5.
Next, the operation of the driver 1a will be described.
When the trigger 13 of the housing 2 and the push lever 14 are operated in the state shown in
Also in the present embodiment, since the actuating piston 5 is attached to the gas pressure accumulation member 4 so as to be attachable/detachable from the outside, and the driver blade 6 is attached to the actuating piston 5, the replacement of the driver blade 6 can be easily carried out. Also, since the comparatively simple hoisting structure using the wire 37 is used, the driver can be manufactured at low cost, and since the accordion part is not compressed, the durability of the gas pressure accumulation member 4 can be improved. Moreover, since there is no piston sliding part, wear of the sealing part and occurrence of gas leakage can be prevented. Moreover, since the wind-up mechanism 28 is adopted, the gas pressure accumulation member 4 can be compressed with a comparatively long stroke with respect to the structure of the cam or the like.
The wind-up mechanism 28 has a structure in which the wire is wound up by penetrating through the center of the gas pressure accumulation member 4, but similar effects can be obtained also when the wire is wound up by providing latching parts at the piston like the first embodiment. Specifically, as shown in
Next, the third embodiment of the present invention will be described.
In the drivers 1 and 1a of the first and second embodiments, the gas pressure accumulation member 4 is configured to contain the compressed gas in the bellows 41. However, as shown in
Since the structure in which the power of the motor 10 is transmitted to the actuating piston 5 by using the deceleration mechanism 11 and the cam 12 is similar to that of the driver 1 of the first embodiment, descriptions thereof will be omitted.
The gas pressure accumulation member 4a has the pressure accumulation cylinder 43 and the pressure accumulation piston 44 which forms a gas pressure accumulation chamber 55 together with the pressure accumulation cylinder 43. The gas pressure accumulation chamber 55 is filled with compressed gas which biases the pressure accumulation piston 44 in a forward direction such as compressed nitrogen gas having a pressure of 0.5 to 10 MPa.
The pressure accumulation cylinder 43 is made up of a tubular body part 43a and a closing wall 60 provided at one end part thereof. The one end part of the tubular body part 43a is closed by the closing wall 60, and a rod through hole 48 is provided at the other end part of the tubular body part 43a. A gas filling port 61 which communicates the gas pressure accumulation chamber 55 of the pressure accumulation cylinder 43 to the outside is provided at a center part of the closing wall 60, and a gas filling valve 62 is attached to the gas filling port 61. As shown in
An annular engaging groove 43c is formed on a lower part of the outer peripheral surface of the pressure accumulation cylinder 43, and an annular engaging groove 43d is formed in an upper part thereof. When the gas pressure accumulation member 4a is to be attached to the inside of the housing 2 of the driver 1, a fixing ring part 2e of the housing 2 is engaged with the annular engaging groove 43d, and a fixing ring part 2f is engaged with the annular engaging groove 43c, thereby fixing the gas pressure accumulation member 4a to the housing 2. As another structure, the gas pressure accumulation member may be fixed between a lower end part of the outer periphery of the pressure accumulation cylinder 43 and a ring-like engaging part (illustration omitted) provided on the housing 2.
As shown in
As shown in
In the gas pressure accumulation chamber 55, the internal space of the pressure accumulation cylinder 43, the inner pressure accumulation chamber 44c of the pressure accumulation piston 44, and the gas pressure accumulation chamber 55b outside the rod part 44a at the time of the upward movement of the pressure accumulation piston 44 are mutually communicated. By virtue of this, when the pressure accumulation piston 44 is moved up to compress the gas pressure accumulation chamber 55, the inner pressure accumulation chamber 44c and the gas pressure accumulation chamber 55b can be effectively utilized as a part of the gas pressure accumulation chamber 55. Therefore, a large volume of the gas pressure accumulation chamber 55 can be ensured although it is compact. Compressed gas such as compressed nitrogen gas is filled in the gas pressure accumulation chamber 55 from a gas supply source such as a nitrogen gas cylinder (not shown) via a gas hose and the gas filling valve 62. The biasing force caused by the compressed gas acts on the pressure accumulation piston 44, and this functions as energy to rapidly move the pressure accumulation piston 44 to the lower side.
Next, the metal-made sleeve 49 which closes the part between the pressure accumulation cylinder 43 and the pressure accumulation piston 44 and forms the rod through hole 48 will be described. As shown in
On the outer peripheral surface of the sleeve 49, an annular engaging part 49e with which the stopper ring 56 is to be engaged is formed in order to fix the sleeve 49 to the pressure accumulation cylinder 43. The stopper ring 56 is attached to the annular engaging groove 43b provided at the distal end part of the pressure accumulation cylinder 43, and the annular engaging part 49e on the sleeve 49 side is engaged with the stopper ring 56 from the upper side, thereby fixing the sleeve 49 to the pressure accumulation cylinder 43 by the stopper ring 56. Furthermore, a seal-member attaching groove 49f is formed in an outer-peripheral upper level part of the sleeve 49, and a seal member 50 made up of, for example, an O ring is attached to the seal-member attaching groove 49f. By virtue of this, the part between the outer surface of the sleeve 49 and the inner surface of the pressure accumulation cylinder 43 is gas-tightly sealed. The flange part 44b of the pressure accumulation piston 44 can be brought into contact with the upper surface 49g of the sleeve 49 via the damper 46.
The flange part 44b abuts on the damper 46 in a case in which the actuating piston 5 is moved downward, the pressure accumulation piston 44 and the actuating piston 5 strongly abut on the piston bumper 8 and are stopped, and the piston bumper 8 is deflected to some degree. On the other hand, usage of the damper 46 becomes unnecessary if a gap is made to be provided between the flange part 44b and the upper surface 49g of the sleeve 49 in the case in which the actuating piston 5 is moved downward, the pressure accumulation piston 44 and the actuating piston 5 strongly abut on the piston bumper 8 and are stopped, and the piston bumper 8 is deflected to some degree.
The dust seal 53 attached to the dust-seal attaching groove 49a is made of a hard material such as urethane resin or NBR. This dust seal 53 removes dust and others adhered onto the outer peripheral surface of the rod part 44a of the pressure accumulation piston 44 and prevents dust and others from entering from a sliding gap between the rod part 44a and the rod through hole 48.
The U packing 45 is made of a rubber material which is more flexible than the guide ring 59 made of synthetic resin, is attached to the U-packing attaching groove 49d, and gas-tightly seals the part between the sleeve 49 and the outer peripheral surface of the rod part 44a of the pressure accumulation piston 44. Lip-like parts 45a are provided at the parts of the upper end surface of the U packing 45 on which the gas pressure act, and when the gas pressure of the compressed gas acts thereon, the lip-like parts 45a are expanded and gas-tightly seal the part between the rod part 44a and the sleeve 49.
The backup ring 54 is made of a synthetic resin material harder than the U packing 45 and forms a ring-like washer shape. The backup ring 54 has a thickness approximately equal to the radial-direction thickness of the U packing 45 and abuts on the surface of the U packing 45 that is on the opposite side of the surface on which the gas pressure acts. In order to prevent the U packing 45 from being displaced to the lower side due to a high pressure, the backup ring 54 receives the U packing 45, which receives the gas pressure, on the back side. In order to improve the slidability of the pressure accumulation cylinder 43 and the pressure accumulation piston 44, the sleeve-like guide ring 59, which is made of synthetic resin, attached to the rod through hole 48 and guides the rod part 44a of the pressure accumulation piston 44, is attached to the guide-ring attaching groove 49b of the sleeve 49. The guide ring 59 has a shape of an integral ring or partially-cut ring, and a gap capable of accepting a volume increase caused by thermal expansion of a thick-plate part of the guide ring 59 made of synthetic resin is provided between the guide ring 59 and the guide-ring attaching groove 49b and the rod part 44a.
Both of the upper and lower ring latching walls 49c for forming the guide-ring attaching groove 49b are formed so as not to contact the outer peripheral surface of the rod part 44a of the pressure accumulation piston 44. The diameter of the inner peripheral surface of the ring latching walls 49c is set to be larger than the outer diameter of the rod part 44a of the pressure accumulation piston 44 by a predetermined length (for example, about 0.2 to 0.5 mm).
In a modification example shown in
The actuating piston 5 is made up of a bottomed tubular body having an approximately U-shape cross section, and the driver blade 6 for driving nails is attached to the attachment part 51 provided to project toward the lower side. Since the driver blade 6 is guided by the injection port 21a made up of the driver guide 7, the blade guide 26, and the nose 24, the vertical movement of the actuating piston 5 is guided by the driver blade 6. The actuating piston 5 is always biased downward by the gas pressure accumulation member 4. The end wall part 5b is detachably fixed to the gas pressure accumulation member 4 so as to cover the lower end part of the gas pressure accumulation member 4. In other words, the actuating piston 5 is attached to the gas pressure accumulation member 4 so as to be attachable/detachable from outside. On the lateral surface of the actuating piston 5, the latched parts 52a and 52b are provided to be arranged in the vertical direction. The attachment part 51 is provided on the lower end surface of the actuating piston 5 so as to project therefrom. Also, the cylindrical part 5a extending toward the upper side like a tube is in slidable contact with the tubular guide part 3 of the housing 2 and prevents the actuating piston 5 from being tilted with respect to the housing 2 when sliding vertically. Although not shown in the drawings, it is also possible to improve slidability and wear resistance by providing a tubular thin steel plate between the tubular guide part 3 and the cylindrical part 5a. In the embodiments, the actuating piston 5 is coupled to the driver blade 6 for driving nails, but similar effects can be achieved also when the attachment part 51 is directly provided at the lower part of the pressure accumulation piston 44, the driver blade 6 is attached to the pressure accumulation piston 44, and the driver blade 6 is replaced by detaching it from the pressure accumulation piston 44.
Next, the operation of the driver 1b will be described.
When the trigger 13 of the housing 2 and the push lever 14 are operated in the state shown in
In the gas pressure accumulation member 4a, the backup ring 54 has the width equal to the radial-direction thickness of the U packing 45 and abuts on the opposite-side surface that is on the opposite side of the gas-pressure acting surface of the U packing 45 to back up it. Therefore, even when the gas pressure of the compressed gas acts on the gas-pressure acting surface of the U packing 45, the opposite-side surface of the U packing 45 is received and backed up by the backup ring 54. Thus, the U packing 45 is prevented from entering the gap between the guide ring 59 and the sleeve 49 and being damaged. Even if a part of the U packing 45 enters the gap between the backup ring 54 and the rod part 44a, adverse effects on the U packing 45 are scarcely generated because the thickness of the backup ring 54 in the shaft center direction is small and the entered length is small. Since the guide ring 59 is integrally formed without having a cut part, the U packing 45 is prevented from entering the guide ring 59 and being damaged.
Moreover, the ring latching walls 49c are formed so as not to be brought into metal-contact with the surface of the rod part 44a of the pressure accumulation piston 44. The guide-ring attaching groove 49b of the guide ring 59 is extended to the opposite side of the U packing 45 with respect to the backup ring 54. Moreover, the guide ring 59 is mated with the outer side of the rod part 44a. Therefore, the rod part 44a of the pressure accumulation piston 44 is guided by the guide ring 59 made of synthetic resin.
In this manner, when the pressure accumulation piston 44 is vertically moved while being guided by the rod through hole 48, the U packing 45 made of synthetic resin, the guide ring 59, the dust seal 53 and others are only brought into contact with the outer peripheral surface of the rod part 44a. Therefore, plating coating of the surface of the rod part 44a is not damaged. Accordingly, the durability of the U packing 45 is improved, and the durability of the guide ring 59 is improved. Moreover, since the backup ring 54 and the U packing 45 are integrally formed to omit a conventional backup ring, the number of parts assembled with the sleeve 49 can be reduced, downsizing at least in the shaft-center direction is achieved, and the manufacturing cost can be reduced.
Then, when the upward movement of the actuating piston 5 by the cam 12 is released, as shown in
Also in the present embodiment, since the actuating piston 5 is fixed to the gas pressure accumulation member 4a so as to be attachable/detachable from outside and the driver blade 6 is fixed to the actuating piston 5, the replacement of the driver blade 6 can be easily carried out.
The shapes of the actuating piston 5 and the gas pressure accumulation members 4 and 4a are arbitrary and are not limited to those shown in the above-described embodiments. For example, the gas pressure accumulation member 4 is not required to be formed into an accordion-like shape. Also, an intermediate ring coil spring is not required to be wound around the small-diameter part of the accordion-like shape of the gas pressure accumulation member 4. Moreover, the configuration of actuation mechanism is also arbitrary and is not limited to those in the above-described embodiments. Further, the method of fixing the driver blade 6 to the actuating piston 5 is arbitrary and is not limited to those in the above-described embodiments. The embodiment adopts the structure in which the gas pressure accumulation member is compressed by moving the actuating piston, but it is also possible to adopt the structure in which the gas pressure accumulation member is compressed by actuating the driver blade 6 itself by the cam 12 to move the actuating piston 5 instead of just moving the actuating piston.
Moreover, the structure in which the flange part 44b of the pressure accumulation piston 44 is received by the damper 46 is adopted, but effects similar to those described above can be achieved also when the stopper of the pressure accumulation piston 44 in the driving directly receives the rod part 44a by a damper (not shown) and a gap is provided between the pressure accumulation piston 44 and the damper 46.
Next, modification examples in which the above-described embodiments are partially changed will be described. The illustrated sizes, shapes, strokes, and others of the driver body and the pistons of the driver in the first to third embodiments are only examples and can be arbitrarily changed. Other than those, the person skilled in the art can implement the modes in which various modifications are made in the above-described embodiments without departing from the gist of the present invention.
This driver is applied for driving fasteners such as nails or staples into a driving object material such as a timber.
Number | Date | Country | Kind |
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2012-218310 | Sep 2012 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2013/005610 | 9/24/2013 | WO | 00 |