WO2015037299A1

WO2015037299A1 - Driving tool

Info

Publication number: WO2015037299A1
Application number: PCT/JP2014/066286
Authority: WO
Inventors: 荒田　憲; 直治石川
Original assignee: 株式会社マキタ
Priority date: 2013-09-10
Filing date: 2014-06-19
Publication date: 2015-03-19
Also published as: JP6367053B2; JP2015077676A; JP2018144229A; JP6554590B2

Abstract

An air tank for replenishing compressed air inside conventional hammering piston upper chambers was built into air spring-type driving tools that return a hammering piston to top dead center, using an electric motor as the drive source therefor, move the hammering piston downwards, by using the compressed air in the hammering piston upper chamber generated as a result, and drive the driving tool. As a result, air tank replacement and other maintenance was difficult. In order to improve the maintenance characteristics of driving tools, the present invention has a configuration comprising a pump unit (50) that generates compressed air by the reciprocal motion of a pump piston (52) and replenishes the hammering piston upper chamber (25), separately from the compressed air for the hammering piston upper chamber (25). Conventional air tanks can be eliminated as a result of having said built-in pump unit (50).

Description

Driving tool

This invention relates to a driving tool for driving a driving tool such as a nail or a staple into wood.

This type of driving tool includes not only a compressed air driven nail driver using a compressed air supplied by a compressed gas supply device such as an external compressor as a driving source, but also an electric tacker for driving staples using an electric motor as a driving source. A so-called driving tool is provided. A technique relating to a conventional electric tacker is disclosed in a patent document (Japanese Patent Laid-Open No. 9-94769).

This electric tacker increases the air pressure in the upper chamber of the piston by moving the piston up to the top dead center by the power of the electric motor, then releases the power of the electric motor and lowers the piston by the air pressure in the upper chamber of the piston. The driving tool is hit by a driver and driven.

Also, in order to supply or replenish the compressed air to the piston upper chamber, it is equipped with a cassette type air tank (air cylinder) that is filled with compressed air in advance and can be easily replaced. By replenishing compressed air from the air tank to the piston upper chamber, an appropriate driving force is ensured over a long period of time. For this reason, the air tank whose remaining amount is reduced is appropriately replaced.

As described above, in the conventional driving tool, it is necessary to replace the air tank for replenishing the compressed air. In this respect, it is necessary to further improve the maintainability or usability of the driving tool. An object of this invention is to improve the maintainability of a driving tool.

The above problems are solved by the following inventions. According to a first aspect of the present invention, a striking piston provided with a driving tool striking driver is moved upward from an initial position to a top dead center by a piston driving section using an electric motor as a driving source, and compression of the striking piston upper chamber generated thereby is performed. A driving tool for driving a driving tool by lowering a driving piston with gas and generating a compressed gas by reciprocating a pump piston separately from the compressed gas in the upper piston chamber and replenishing the upper piston chamber It is a driving tool provided with a section.

According to the first invention, since the compressed gas is newly generated in the pump portion and this is replenished to the striking piston upper chamber, there is no need to replace it as in the conventional replenishing air tank. The pump gas is permanently replenished with compressed gas. Thus, since there is no need to replace the conventional air tank, the maintenance performance can be improved and the running cost can be reduced.

Also, since the conventional air tank can be omitted, the driving tool can be made compact or downsized. In addition to normal air (air), nitrogen gas or the like is used as the compressed gas.

The second invention is a driving tool according to the first invention, wherein the pump unit is configured to operate in conjunction with the driving operation. According to the second invention, the compressed gas is automatically generated in conjunction with the driving operation and is replenished to the upper piston chamber, so that the pressure drop in the upper piston chamber is prevented in advance and always suitable. A striking force can be obtained. Since the compressed gas for replenishment is newly generated in the pump section in this way, the conventional air tank is not required at all, and maintenance work such as replacement thereof is not required almost permanently, so that the driving tool is maintainable. Can be increased.

The third invention is a driving tool according to the second invention, wherein the pump part is configured to operate by a downward movement in the driving direction of the driving piston. According to the third aspect of the invention, each time the striking piston moves down, the pump portion automatically operates to replenish the striking piston upper chamber with the compressed gas. It is possible to obtain an appropriate striking force at all times. Since the compressed gas for replenishment is newly generated in the pump section in this way, the conventional air tank is not required at all, and maintenance work such as replacement thereof is not required almost permanently, so that the driving tool is maintainable. Can be increased.

The fourth invention is a driving tool according to the second invention, wherein the pump unit is configured to operate in conjunction with the operation of the piston drive unit. According to the fourth aspect of the invention, since the pump unit automatically operates each time the piston drive unit operates and the compressed gas is replenished to the striking piston upper chamber, the pressure drop in the striking piston upper chamber is prevented beforehand. Therefore, it is possible to obtain an appropriate hitting force at all times. Since the compressed gas for replenishment is newly generated in the pump section in this way, the conventional air tank is not required at all, and maintenance work such as replacement thereof is not required almost permanently, so that the driving tool is maintainable. Can be increased.

The fifth invention is a driving tool according to the fourth invention, wherein the pump unit is configured to convert the pump piston into a reciprocating motion through a crank mechanism using the motor power of the piston driving unit as a driving source. According to the fifth aspect of the present invention, when the piston drive unit is activated, the pump unit is activated in conjunction with this. In the pump unit, the pump piston reciprocates through the crank mechanism, whereby compressed gas is generated and replenished to the upper piston chamber.

The sixth invention is a driving tool according to the first invention, wherein the pump unit is configured to operate using a pump motor different from the electric motor of the piston drive unit as a drive source. According to the sixth aspect of the invention, the compressed gas can be replenished to the upper chamber of the striking piston by operating the pump irrespective of the operation of the striking piston. Durability can be increased. The pump motor operation (air replenishment) can be configured to operate based on the fluctuation of the gas pressure in the upper chamber of the striking piston detected by the pressure sensor. Can be configured to operate separately.

According to a seventh aspect of the present invention, a striking piston provided with a driver for striking a driving tool is moved upward from an initial position to a top dead center by a piston driving section using an electric motor as a driving source, and compression of the striking piston upper chamber generated thereby A driving tool for driving a driving tool by lowering a driving piston with gas, and a connecting tool for connecting an external compressed gas supply device for replenishing compressed gas to the upper chamber of the driving piston. . According to the seventh invention, when the striking force is reduced due to the gas pressure drop in the striking piston upper chamber, an external compressed gas supply device is connected to the connection port to replenish the striking piston upper chamber with the compressed gas. it can. In the first to sixth inventions, in contrast to the configuration in which the pump portion for replenishing the compressed gas in the upper chamber of the striking piston is built in, the seventh invention does not have such a pump portion, and an external compressed gas prepared separately. The supply device is connected to replenish the impact piston upper chamber with compressed gas. In the seventh invention, as a result of not incorporating the pump portion, the configuration of the driving tool can be simplified and reduced in weight.

The eighth invention is the driving tool according to the seventh invention, wherein the connection port is housed inside. According to the eighth invention, since the connection port for connecting the external compressed gas supply device is housed in, for example, the tool body instead of being protruded to the outside, damage to the connection port can be prevented, The handleability of the driving tool can be improved.

According to a ninth invention, in any one of the first to eighth inventions, there is provided a relief valve for releasing the compressed gas in the upper striking piston chamber to the atmosphere and maintaining the gas pressure in the striking piston upper chamber at a constant pressure. It is a driving tool. According to the ninth aspect of the present invention, excessive increase in the gas pressure in the upper chamber of the striking piston can be regulated and kept at an appropriate gas pressure at all times. It is possible to improve the durability of the driving tool by preventing damage to each part.

A tenth aspect of the invention is a driving tool according to the ninth aspect, wherein the relief valve is built in a handle portion that is gripped by a user. According to the tenth aspect of the invention, since the relief valve is housed in the handle portion, not in a state of protruding to the outside, damage to the relief valve can be prevented and handling of the driving tool can be improved. .

The eleventh invention is a driving tool comprising a pressure sensor for detecting the gas pressure in the upper chamber of the striking piston in any one of the first to tenth inventions. According to the eleventh invention, the pressure sensor detects a decrease in the gas pressure in the upper chamber of the striking piston due to air leakage or the like, and based on this, the compressed gas is replenished in the upper chamber of the striking piston. An appropriate striking force can always be obtained by preventing a pressure drop. In this way, new compressed gas for replenishment is generated in the pump section, or compressed gas is replenished from the external compressed gas supply device, so that the conventional air tank is not required at all and maintenance work such as replacement is almost permanent. Therefore, the maintainability of the driving tool can be improved.

It is a longitudinal cross-sectional view of the driving tool of 1st Embodiment. This figure has shown the state which a striking piston is located in the middle of an upward movement. It is a longitudinal cross-sectional view of the driving tool of 1st Embodiment. This figure shows a state where the striking piston is located at the top dead center. It is a longitudinal cross-sectional view of the driving tool of 1st Embodiment. This figure shows a state where the striking piston is located at the bottom dead center. FIG. 4 is a cross-sectional view taken along line (IV)-(IV) in FIG. 1 and is a cross-sectional view in the middle of upward movement of the piston drive unit. FIG. 3 is a view as viewed in the direction of arrow (V) in FIG. FIG. 4 is a view in the direction of an arrow (VI) in FIG. It is a figure which shows the operating state of a piston drive part. This figure shows a state corresponding to the mid-up position. It is a figure which shows the operating state of a piston drive part. This figure shows a state corresponding to the top dead center. It is a figure which shows the operating state of a piston drive part. This figure shows a state corresponding to the bottom dead center. It is a longitudinal cross-sectional view of the driving tool of 2nd Embodiment. This figure shows a state where the striking piston is located at the top dead center. FIG. 11 is a cross-sectional view taken along line (XI)-(XI) in FIG. 10 and is a cross-sectional view in a top dead center state of a piston drive unit. It is a longitudinal cross-sectional view of the driving tool of 2nd Embodiment. This figure shows a state where the striking piston is located at the bottom dead center. FIG. 13 is a cross-sectional view taken along line (XIII)-(XIII) in FIG. 12 and is a cross-sectional view in the bottom dead center state of the piston drive unit. It is a longitudinal cross-sectional view of the driving tool of 3rd Embodiment. This figure shows a state where the striking piston is located at the top dead center. FIG. 15 is a cross-sectional view taken along line (XV)-(XV) in FIG. 14 and is a cross-sectional view in the top dead center state of the piston drive unit. It is a longitudinal cross-sectional view of the driving tool of 3rd Embodiment. This figure shows a state where the striking piston is located at the bottom dead center. FIG. 17 is a cross-sectional view taken along line (XVII)-(XVII) in FIG. 16 and is a cross-sectional view in the bottom dead center state of the piston drive unit. It is a longitudinal cross-sectional view of the driving tool of 4th Embodiment. This figure shows a state where the striking piston is located at the top dead center. FIG. 19 is a cross-sectional view taken along the line (XIX)-(XIX) in FIG. 18 and is a cross-sectional view in the top dead center state of the piston drive unit.

Next, an embodiment of the present invention will be described with reference to FIGS. 1 to 4 show a driving tool 10 according to the first embodiment. The driving tool 10 includes a tool main body 11, a handle 12 that a user grips, and a magazine 13 in which a number of driving tools can be loaded.

The main body housing 14 of the tool main body 11 is provided with a cylinder 15, and the striking piston 16 is provided in the cylinder 15 so as to reciprocate up and down. A driver 17 for hitting the driving tool n is attached to the center of the lower surface of the hitting piston 16. The tip of the driver 17 enters a driving path 18 a of a nose 18 provided at the lower part of the tool body 11. The tip of the magazine 13 is coupled to the nose portion 18. In conjunction with the driving operation, driving tools n are supplied from the magazine 13 one by one into the driving passage 18a.

The handle portion 12 is provided in a state of protruding from the side portion of the tool main body portion 11 to the side. A trigger-type switch lever 19 is provided on the lower side of the base portion of the handle portion 12. When the user pulls the switch lever 19 upward with the fingertip of the hand holding the handle portion 12, the switch body 20 is turned on. When the switch body 20 is turned on, a piston drive unit 30 described later is activated. The pulling operation of the switch lever 19 is effective only when the contact lever 21 provided along the nose portion 18 is moved upward. As shown in FIG. 1, the contact lever 21 is spring-biased in a direction in which its tip end protrudes slightly from the tip end of the nose portion 18, and the contact lever 21 is relatively lifted by pressing the nose portion 18 against the driving material W. Move.

A battery mounting portion 23 is provided on the distal end side of the handle portion 12. A battery pack 22 as a power source is attached to the battery attachment portion 23. The battery pack 22 can be repeatedly used by removing it from the battery mounting portion 23 and charging it with a separately prepared charger.

A relief valve 24 is provided at the base of the handle portion 12. When the gas pressure in the striking piston upper chamber 25 of the tool body 11 becomes equal to or higher than a certain pressure, the relief valve 24 is opened and air is released (released to the atmosphere). The relief valve 24 keeps the gas pressure in the striking piston upper chamber 25 at an appropriate pressure, thereby preventing damage to each part of the seal.

The striking piston 16 is moved down by the gas pressure in the striking piston upper chamber 25. As the striking piston 16 moves downward, the driver 17 moves down in the driving passage 18a. When the head of one driving tool n supplied from the magazine 13 into the driving path 18a is hit by the driver 17, the driving tool n is driven from the tip of the nose portion 18 and driven into the driving material W. .

The driving tool n is driven in the process in which the striking piston 16 moves downward to reach the bottom dead center. When the striking piston 16 reaches bottom dead center, the pump unit 50 is activated. The present invention has a great feature in that the pump unit 50 is provided. The pump unit 50 will be described later.

The striking piston 16 moves up to the top dead center when the piston wire 26 is wound up by the operation of the piston drive unit 30. The piston wire 26 passes through a partition wall 29 that hermetically partitions the main body housing 14 and the drive unit housing 31, and reaches the drive unit housing 31 from within the striking piston upper chamber 25.

The piston drive unit 30 is housed in a drive unit housing 31 provided on the upper part of the tool body 11. As shown in FIG. 4, the piston drive unit 30 includes an electric motor 32 as a drive source, an operation wheel 33, a winding wheel 34, and the piston wire 26. The drive gear 35 attached to the output shaft 32 a of the electric motor 32 is meshed with the intermediate gear 36. The intermediate gear 36 is rotatably supported by the drive unit housing 31 via a support shaft 36a. The intermediate gear 36 is meshed with the operating gear 37. The operating gear 37 is supported by an operating shaft 38 that is rotatably supported by the drive unit housing 31 via

bearings

38a and 38b. The operation shaft 38 is provided with a two-sided width portion 38c. The operating gear 37 is supported by the two-surface width portion 38c. For this reason, the operating shaft 38 rotates integrally with the rotation of the operating gear 37. An operation gear 37 and the operation wheel 33 are supported on the two-surface width portion 38 c of the operation shaft 38. For this reason, the operation wheel 33 rotates integrally with the operation gear 37 via the two-surface width portion 38 c of the operation shaft 38. Further, the operation wheel 33 is supported through the two-surface width portion 38c so as to be movable in the axial direction. A compression spring 39 is interposed between the operation wheel 33 and the operation gear 37. The operation wheel 33 is urged toward the winding wheel 34 by the compression spring 39.

The hoisting wheel 34 is supported by the operating shaft 38 in a state of being rotatable relative to the operating shaft 38 via a bearing 34a. The operation gear 37, the operation wheel 33, and the winding wheel 34 are supported coaxially. The hoisting wheel 34 is supported by the operating shaft 38 in a state in which it cannot be displaced in the axial direction.

When the electric motor 32 is started, the operating shaft 38 rotates through the engagement of the drive gear 35 and the intermediate gear 36 and the engagement of the intermediate gear 36 and the operating gear 37. The operation wheel 33 rotates integrally with the rotation of the operation shaft 38. The winding wheel 34 rotates in the winding direction of the piston wire 26 (clockwise direction in FIG. 1) by the rotation of the working hole 33, and then the engagement state with the working wheel 33 is released to reverse the winding direction ( The piston wire 26 can be rotated in the feeding direction). When the winding wheel 34 becomes rotatable in the feeding direction of the piston wire 26 (counterclockwise direction in FIG. 1), the striking piston 16 is moved downward by the gas pressure in the striking piston upper chamber 25.

The operation wheel 33 has a function (winding mechanism) that rotates the winding wheel 34 in the winding direction by rotation in one direction and then allows rotation in the feeding direction. Details of the winding mechanism of the working wheel 33 are shown in FIGS.

The working convex part 33a and the engaging convex part 33b are provided in the opposing surface (side facing the winding wheel 34) of the working wheel 33. As shown in FIG. The operating convex portion 33a is provided on the outer peripheral side with respect to the engaging convex portion 33b. An operation block 40 is provided in the drive housing 31 corresponding to the operation convex portion 33a on the outer peripheral side. The winding wheel 34 is provided with a winding projection 34b corresponding to the engagement projection 33b on the inner peripheral side.

1 and 4 and FIGS. 7 to 9, the operation convex portion 33 a is not engaged with the operation block 40, so that the operation wheel 33 is close to the hoisting wheel 34. . In this position, when the electric motor 32 is started by pulling the switch lever 19, the operation protrusion 33a is engaged with the operation block 40 during one rotation of the operation wheel 33 as shown in FIG. The operation wheel 33 gradually moves backward in a direction away from the winding wheel 34 (upward in FIG. 5). During this time, as shown in FIG. 8, the engaging convex portion 33b engages with the winding convex portion 34b and the winding wheel 34 rotates in the winding direction indicated by the arrow in FIG. 8, whereby the piston wire 26 is wound up and the striking piston 16 moves to top dead center as shown in FIG. Movement to the top dead center of the striking piston 16 is made against the gas pressure in the striking piston upper chamber 25.

After the striking piston 16 moves to the top dead center, the operation wheel 33 further rotates, and when the operation convex portion 33a rides on the top of the operation block 40 as shown in FIGS. The retreat distance of 33 is the maximum. In the previous stage, the engagement state of the engaging convex portion 33b with respect to the winding convex portion 34b is released, and the rotation of the winding wheel 34 in the feeding direction is allowed.

At the moment when the rotation of the hoisting wheel 34 in the feeding direction is allowed, the piston 16 is moved down and driven by the gas pressure in the striking piston upper chamber 25 as shown in FIG. After driving, the operation wheel 33 further rotates, so that the operation protrusion 33a is detached from the operation block 40, and the operation wheel 33 is returned to the winding wheel 34 side by the urging force of the compression spring 39. Thereafter, when the operating wheel 33 further rotates, the engaging convex portion 33b engages with the winding convex portion 34b, and in this engaged state, the operating wheel 33 continues to rotate integrally with the winding wheel 34, thereby causing the piston wire 26 to rotate. It is wound up and the striking piston 16 is moved up to the position shown in FIG.

In the first embodiment, in the series of driving operations described above, the pump unit 50 is activated when the striking piston 16 reaches the bottom dead center. As shown in FIGS. 1 to 3, a cushion holder 51 is housed in the lower part of the cylinder 15. A bottom dead center damper 27 for absorbing an impact at the bottom dead center of the striking piston 16 is mounted on the inner peripheral side of the cushion holder 51. A cylindrical pump piston 52 is interposed between the cushion holder 51 and the cylinder 15. The space between the inner peripheral surface of the pump piston 52 and the outer peripheral surface of the cushion holder 51 is hermetically sealed by a seal rubber 52a, and the space between the outer peripheral surface of the pump piston 52 and the inner peripheral surface of the cylinder 15 is hermetically sealed by a seal rubber 52b. ing. The pump piston 52 is urged in a direction in which it is displaced upward by a compression spring 53.

An annular airtight replenishing air chamber 56 is formed around the cushion holder 51 and between the cylinder 15, the pump piston 52, and the cushion holder 51. The replenishing air chamber 56 includes an exhaust check valve 54 provided at the lower portion of the cylinder 15 and an intake check valve 55 provided at the lower portion of the cushion holder 51. Through the check valve 54, the replenishing air chamber 56 communicates with the striking piston upper chamber 25 on the outer peripheral side only in the exhaust direction. Through the check valve 55, the replenishing air chamber 56 is the striking piston lower chamber 28 in the intake direction only and communicates with the atmosphere side.

As shown in FIG. 3, when the striking piston 16 moves downward to reach the bottom dead center, a driving operation is performed and the pump piston 52 is pushed downward by the striking piston 16. The pump piston 52 is pushed downward against the urging force of the compression spring 53. When the pump piston 52 moves downward, the compressed gas in the replenishing air chamber 56 is returned to the striking piston upper chamber 25 through the check valve 54. When the striking piston 16 moves upward from the bottom dead center, the pump piston 52 is returned upward by the urging force of the compression spring 53. As a result of the pump piston 52 being returned upward and the replenishment air chamber 56 having a negative pressure, the check valve 55 is opened, and the impact piston lower chamber 28 and then the air is sucked into the replenishment air chamber 56. The gas sucked into the replenishing air chamber 56 is replenished into the striking piston upper chamber 25 via the check valve 54 when the pump piston 52 moves down due to the striking piston 16 reaching the bottom dead center. Is done.

According to the driving tool 10 of the first embodiment configured as described above, every time the driving piston 16 reaches the bottom dead center and the driving operation is performed, the pump unit 50 is activated and compressed into the driving piston upper chamber 25. The gas is automatically refilled. As described above, the relief piston 24 is provided in the striking piston upper chamber 25. By this relief valve 24, excessive air replenishment to the striking piston upper chamber 25 is released to the inside of the handle portion 12 and to the atmosphere, so that the striking piston upper chamber 25 is always maintained at an appropriate gas pressure, so that the striking piston 16 An appropriate driving force is ensured.

In addition, the pump unit 50 is operated in conjunction with the downward movement of the striking piston 16 in the driving direction and the striking piston upper chamber 25 is automatically refilled with compressed air. There is no need to do. For this reason, according to the first embodiment, since there is no need to replace the air tank as in the prior art, its maintainability is improved and its running cost can be reduced.

In addition, since it is not necessary to interior a conventional air tank, the driving tool 10 can be downsized or made compact.

Various modifications can be made to the embodiment described above. For example, in the first embodiment, the pump unit 50 that operates in conjunction with the downward movement operation of the striking piston 16 is exemplified as the supplementary air generating means. Instead, for example, the second embodiment shown in FIGS. 10 to 13 is used. The pump part 60 can be provided. The second embodiment is characterized by the pump unit 60, and the same basic components as those of the first embodiment, such as other basic configurations, will be described using the same reference numerals and description thereof will be omitted.

The pump unit 60 of the second embodiment uses the electric motor 32 of the piston drive unit 30 as a common drive source. As shown in FIGS. 11 and 13, the drive gear 35 of the electric motor 32 is engaged with another intermediate gear 61 in addition to the intermediate gear 36 described above. The intermediate gear 61 is rotatably supported by the drive unit housing 31 via a bearing 61a. An operating gear 62 is engaged with the intermediate gear 61. The operation gear 62 is supported by an operation shaft 63 that is rotatably supported by the drive housing 31 via

bearings

62a and 62b. An operation disc 68 is attached to one end side of the operation shaft 63. One end side of the operating rod 64 is rotatably coupled to the operating disc 68 through the support shaft 64a. The support shaft 64 a is eccentric by a certain dimension with respect to the operation shaft 63 that is the rotation center of the operation disk 68.

The pump piston 65 is coupled to the other end side of the operating rod 64 via a support shaft 64b in a relatively rotatable state. The pump piston 65 is housed in a pump cylinder portion 29 a provided on the partition wall 29 so as to be reciprocable and airtight. The pump piston 65 is provided with an air passage 65a communicating between the pump piston upper chamber (inside the drive unit housing 31) on the upper surface side and the pump piston lower chamber on the lower surface side. The air passage 65 a is hermetically sealed by a check valve 66. The check valve 66 allows the flow of compressed gas from the pump piston upper chamber to the pump piston lower chamber, and seals the flow of compressed gas in the opposite direction.

The check cylinder 67 is also provided in the pump cylinder part 29a. The check valve 67 allows the flow of compressed gas from the lower chamber of the pump piston into the upper chamber 25 of the striking piston, and seals the flow of compressed gas in the opposite direction.

As described above, when the electric motor 32 is activated, the piston drive unit 30 is activated, the striking piston 16 is moved to the top dead center, and the pump unit 60 is activated. When the electric motor 32 is activated, the operating shaft 63 rotates about the axis via the intermediate gear 61 and the operating gear 62, and thus the operating disk 68 rotates. When the working disc 68 rotates around the axis of the working shaft 63, the working rod 64 cranks up and down. The pump piston 65 reciprocates up and down in the pump cylinder portion 29a by the crank movement of the operating rod 64. In the second embodiment, the number of teeth of the intermediate gear 61 and the operating gear 62 is set so that the pump piston 65 reciprocates a plurality of times during one reciprocating operation of the striking piston 16 (during one driving operation). ing.

At the stage where the pump piston 65 moves up in the pump cylinder portion 29a, the pump piston lower chamber side becomes negative pressure, so that the compressed gas passes from the inside of the drive unit housing 31 to the pump piston lower chamber via the air passage 65a and the check valve 66. Is inhaled. When the pump piston 65 moves down in the pump cylinder portion 29 a, the compressed gas in the pump piston lower chamber is exhausted (supplemented) into the striking piston upper chamber 25 through the check valve 67.

As described above, according to the driving tool 10 according to the second embodiment, the pump unit 60 operates in conjunction with the operation of the piston driving unit 30 and the compressed gas is automatically refilled into the striking piston upper chamber 25. . For this reason, also in 2nd Embodiment, since it is not necessary to incorporate the conventional air tank for replenishment, while the maintainability of the said driving tool 10 is improved, the running cost can be reduced.

Further changes can be made to the driving tool 10 of the second embodiment. For example, in the second embodiment, the configuration in which the pump unit 60 is operated using the electric motor 32 of the piston drive unit 30 as a common drive source is exemplified, but a configuration using a drive source unique to the pump unit may be used. A driving tool 10 including a pump unit 70 according to the third embodiment is shown in FIGS. As shown in the drawing, the drive system of the pump unit 70 according to the third embodiment is separated from the drive system of the piston drive unit 30. About the member and structure similar to 1st or 2nd embodiment, the description is abbreviate | omitted using a same code | symbol.

The pump unit 70 of the third embodiment is also provided in the drive unit housing 31. The pump unit 70 of the third embodiment includes a unique electric motor 71 as its drive source. A drive gear 71 b attached to the output shaft 71 a of the electric motor 71 is engaged with the operating gear 72. One end side of the operating rod 64 is coupled to the operating gear 72. One end side of the operating rod 64 is rotatably coupled to the operating gear 72 via a support shaft 64a. The rotation center (support shaft 64 a) on one end side of the operating rod 64 is eccentric by a certain dimension with respect to the rotation center of the operating gear 72. A pump piston 65 similar to that in the second embodiment is rotatably attached to the other end side of the operating rod 64 via a support shaft 64b. As in the second embodiment, the pump piston 65 is reciprocally moved up and down in the pump cylinder portion 29a provided on the partition wall 29 and is housed in an airtight manner.

A pressure sensor 73 is attached to the partition wall 29. The pressure sensor 73 detects the gas pressure in the striking piston upper chamber 25. When the gas pressure in the striking piston upper chamber 25 detected by the pressure sensor 73 becomes lower than a certain pressure, the electric motor 71 of the pump unit 70 is activated. When the electric motor 71 is activated, the pump piston 65 reciprocates in the pump cylinder 29a, so that the compressed gas is replenished to the striking piston upper chamber 25. When the gas pressure in the striking piston upper chamber 25 reaches a constant pressure due to the replenishment of the compressed gas, this is detected by the pressure sensor 73, whereby the electric motor 71 is stopped and the air replenishment operation of the pump unit 70 is stopped.

According to the driving tool 10 of the third embodiment described above, the gas pressure in the striking piston upper chamber 25 is detected by the pressure sensor 73, and based on this, the pump unit 70 is operated and the striking piston upper chamber 25 is inside. Compressed gas is replenished. For this reason, it is possible to ensure an appropriate striking force of the striking piston 16 while omitting the conventional air tank, thereby ensuring the maintainability of the driving tool 10 and reducing the running cost.

18 and 19 show the driving tool 10 of the fourth embodiment. Also in the fourth embodiment, the basic configuration of the piston driving unit 30 and other driving tools 10 is the same as that of each of the above embodiments. The same members and structures as those in the first to third embodiments are denoted by the same reference numerals, and the description thereof is omitted.

The driving tool 10 of the fourth embodiment is connected to an external compressed gas supply device 80 such as an external compressor or an air injection device instead of the

pump parts

50, 60, 70 of the driving tool 10 of the first to third embodiments. A connecting port 81 is provided, and the means for replenishing the striking piston upper chamber 25 with compressed gas is different.

The connection port 81 is provided on the partition wall 29. The drive unit housing 31 is provided with a lid 82. In FIG. 18, a state where the lid 82 is opened is indicated by a two-dot chain line. By opening the lid 82, the external compressed gas supply device 80 can be connected to the connection port 81 via the air hose 83. With the air hose 83 of the external compressed gas supply device 80 connected to the connection port 81, the compressed gas can be replenished to the striking piston upper chamber 25 by operating the external compressed gas supply device 80. When the gas pressure in the striking piston upper chamber 25 reaches a constant pressure, excess compressed gas is discharged to the outside through the relief valve 24. For this reason, even if there is an excessive replenishment of compressed gas by the external compressed gas supply device 80, the excess amount is released from the relief valve 24, so that the gas pressure in the striking piston upper chamber 25 is always maintained at an appropriate gas pressure, Thereby, damage of each seal part etc. can be prevented beforehand and durability of the driving tool 10 can be enhanced.

According to the driving tool 10 of the fourth embodiment configured as described above, when the gas pressure in the striking piston upper chamber 25 decreases and a sufficient striking force of the striking piston 16 cannot be obtained, the lid portion 82. Is opened and the external compressed gas supply device 80 is connected to the connection port 81 via the air hose 83, so that the compressed gas can be replenished into the striking piston upper chamber 25. For this reason, the conventional cassette type air tank can be omitted, the maintainability of the driving tool 10 can be improved, and the running cost can be reduced.

The connection port 81 may be arranged not in the drive unit housing 31 but in the main body housing 14. By adopting a configuration in which the connection port 81 of the external compressed gas supply device 80 is built in the drive unit housing 31 or the main body housing 14, damage or contamination of the connection port 81 can be avoided, and the handling of the driving tool 10 can be avoided. Can increase the sex.

Claims

A striking piston provided with a driver for striking tool striking is moved upward from an initial position to a top dead center by a piston driving section using an electric motor as a driving source, and the striking piston is moved by the compressed gas in the striking piston upper chamber generated thereby. A driving tool for driving the driving tool down and
A driving tool comprising a pump unit that generates compressed gas by reciprocating movement of a pump piston separately from the compressed gas in the upper chamber of the striking piston and replenishes the striking piston upper chamber.
2. The driving tool according to claim 1, wherein the pump unit is configured to operate in conjunction with a driving operation.
3. The driving tool according to claim 2, wherein the pump unit is configured to operate by a downward movement operation in a driving direction of the driving piston.
The driving tool according to claim 2, wherein the pump unit is configured to operate in conjunction with the operation of the piston driving unit.
5. The driving tool according to claim 4, wherein the pump unit is configured to convert the pump piston into a reciprocating motion of a pump piston through a crank mechanism using a motor power of the piston driving unit as a driving source.
2. The driving tool according to claim 1, wherein the pump unit is configured to operate using a pump motor different from the electric motor of the piston driving unit as a driving source.
A striking piston provided with a driver for striking tool striking is moved upward from an initial position to a top dead center by a piston driving section using an electric motor as a driving source, and the striking piston is moved by the compressed gas in the striking piston upper chamber generated thereby. A driving tool for driving the driving tool down and
A driving tool comprising a connection port for connecting an external compressed gas supply device for replenishing compressed gas to the upper chamber of the striking piston.
8. The driving tool according to claim 7, wherein the connection port is provided inside the driving tool.
9. The driving tool according to any one of claims 1 to 8, wherein the compressed gas in the upper chamber of the striking piston is opened to the atmosphere to keep the gas pressure in the upper chamber of the striking piston at a constant pressure. Driving tool equipped with.
10. The driving tool according to claim 9, wherein the relief valve is built in a handle portion that is gripped by a user.
The driving tool according to any one of claims 1 to 10, further comprising a pressure sensor for detecting a gas pressure in the upper chamber of the striking piston.