JP7780102B2 - Work equipment - Google Patents

Description

The present invention relates to a work machine.

In the driving tool (work machine) described in Patent Document 1 below, a piston is housed inside a cylinder so that it can move up and down, and a driver blade is attached to the piston, extending downward. The driving tool also has a wheel with a pin configured to engage with the rack of the driver blade. As the wheel rotates, the driver blade and piston rise to top dead center. At top dead center of the driver blade and piston, the driver blade and pin are disengaged, and the piston descends from top dead center. This causes the driver blade to strike the fastener, ejecting it downward. As the piston descends to bottom dead center, it collides with a bumper (shock absorbing part), and the impact force of the piston is absorbed by the bumper.

The driving tool also has a lubricating oil supply mechanism that supplies lubricating oil to the driver blade and pin. This reduces wear on the rack and pin of the driver blade and improves the maintainability of the driving tool.

International Publication No. 2018/180082

However, the above-mentioned driving machine leaves room for improvement in the following respects. Specifically, while the above-mentioned driving machine can supply lubricating oil to the driver blade and pin, it does not have a means for supplying lubricating oil between the piston and cylinder. As a result, over long-term use of the driving machine, frictional resistance between the piston and cylinder increases, which may result in a decrease in the striking force (driving force) of the driver blade against the fastener. In this case, the durability of the driving machine decreases, so the above-mentioned driving machine leaves room for improvement in terms of improving its durability. Furthermore, the above-mentioned driving machine leaves room for improvement in the following respects. Specifically, while the above-mentioned driving machine leaves room for lubricating oil to the driver blade and pin, it does not have a means for supplying lubricating oil between the piston and bumper. Furthermore, as mentioned above, when the piston descends to bottom dead center, the piston collides with the bumper, which may reduce the wear resistance of the bumper and reduce the durability of the driving machine. As a result, the above-mentioned driving machine leaves room for improvement in terms of improving its durability.

Taking the above into consideration, the present invention aims to provide a work machine that can improve durability.

One or more embodiments of the present invention are a work machine comprising: a support portion, a piston, and a striking portion including a driver blade extending from the piston, the striking portion being movably supported on the support portion and performing a striking action to apply a striking force to a struck member by moving to one side in a first direction from a non-striking position which is the top dead center toward a striking position which is the bottom dead center ; and a lubricating oil supply portion that supplies lubricating oil to the striking portion in association with the striking action of the striking portion, wherein the support portion is a pressure accumulator container having a pressure chamber filled with gas therein, the pressure accumulator container having a cylindrical cylinder that supports the piston so that it can move in the first direction , the striking portion is provided inside the pressure accumulator container so as to be movably in the first direction, and performs the striking action by moving to one side in the first direction due to the pressure of the gas in the pressure chamber, and the lubricating oil supply portion is provided inside the pressure accumulator container on the other side in the first direction of the piston which is positioned at the top dead center , and supplies lubricating oil between the piston and the cylinder in association with the striking action of the striking portion.

Durability can be improved according to one or more embodiments of the present invention.

1 is a side view of a driving tool according to a first embodiment, as viewed from the left side. FIG. 2 is a side view of the inside of the housing of the driving tool shown in FIG. 1 as seen from the left side. 3 is a cross-sectional view showing the nose of the driving tool shown in FIG. 2 and the inside of the pressure accumulator vessel as viewed from the left side. FIG. FIG. 4 is an enlarged cross-sectional view of the upper end portion of the pressure accumulator vessel shown in FIG. 3 . 5 is an exploded cross-sectional perspective view of the upper end of the pressure accumulator vessel shown in FIG. 4 with a head cover removed. FIG. 5 is a cross-sectional view showing an example in which the inner diameter of the flange portion of the head nut and the inner diameter of the filter shown in FIG. 4 are changed. FIG. FIG. 11 is an enlarged cross-sectional view showing an upper end portion of a pressure accumulator container in a driving machine according to a second embodiment. FIG. 8 is a cross-sectional view showing a modified example of the lubricating oil supply mechanism of the driving machine shown in FIG. 7 . FIG. 10 is a cross-sectional view showing another modified example of the lubricating oil supply mechanism of the driving tool shown in FIG. 7 . FIG. 11 is a side view of the driving tool according to the third embodiment, as seen from the left side. 11 is a side view of the inside of the housing of the driving tool shown in FIG. 10 as seen from the left side. 12 is a cross-sectional view of the nose of the driving tool shown in FIG. 11 and the inside of the pressure accumulator vessel, as seen from the left side. FIG. FIG. 13 is a partially cutaway perspective view showing the top of the nose, bumper, and filter shown in FIG. 12. 13 is a cross-sectional view seen from the left side of the state in which the striking part shown in FIG. 12 has descended to the bottom dead center. 15 is a cross-sectional view of the bumper shown in FIG. 14 in a state where the bumper is compressed and deformed and the impact part is in an inverted position, as viewed from the left side. 14A is a cross-sectional view from above (cross-sectional view taken along line 7A-7A in FIG. 14 ) showing the state in which the blade mounting portion of the piston shown in FIG. 14 is inserted into the upper part of the bumper, and FIG. 14B is a cross-sectional view from above (cross-sectional view taken along line 7B-7B in FIG. 14 ) showing the state in which the bumper shown in FIG. 14 is housed in the nose. 13 is a partially cutaway side view seen from the left side showing an example in which the lubricant supply mechanism shown in FIG. 12 is applied to another driving machine. FIG.

(First embodiment) Below, using Figures 1 to 5, we will explain the driving machine 10 as a work machine according to the first embodiment. Note that the arrows UP, FR, and LH shown as appropriate in the drawings indicate the upper side, front side, and left side of the driving machine 10, respectively. In the following explanation, when the up/down, front/rear, and left/right directions are used, they refer to the up/down, front/rear, and left/right directions of the driving machine 10 unless otherwise specified. The up/down direction corresponds to the first direction of the present invention, the lower side corresponds to one side of the first direction of the present invention, and the upper side corresponds to the other side of the first direction of the present invention.

As shown in Figures 1 to 3, the driving machine 10 has a driving machine main body 12, to which a magazine 80 is attached. The driving machine 10 is configured as an electric tool that drives nails N, which serve as fasteners, loaded in the magazine 80 into a workpiece W. The driving machine main body 12 includes a housing 14, a nose 30, a pressure accumulator container 40, and a drive mechanism 70. The driving machine main body 12 also has a lubricating oil supply mechanism 90. Each component of the driving machine 10 will be described below.

(Regarding the housing 14) As shown in Figures 1 and 2, the housing 14 is formed into a hollow, approximately inverted P-shape in side view from the left side. Specifically, the housing 14 has a main body housing portion 14A extending in the vertical direction, a handle portion 14B extending diagonally upward and rearward from the vertical middle portion of the main body housing portion 14A, a motor housing portion 14C extending rearward from the lower end of the main body housing portion 14A, and a battery attachment portion 14D extending downward from the rear end of the handle portion 14B and connected to the rear end of the motor housing portion 14C.

A control unit 20 is provided within the battery mounting section 14D of the motor housing section 14C, which controls the motor 72 (described later) and thereby controls the driving of the striking section 50 (described later). A battery 22 is removably mounted in the battery mounting section 14D. The battery 22 is electrically connected to the control unit 20, and supplies power from the battery 22 to the control unit 20.

A trigger 24 is provided within the front end of the handle portion 14B. The trigger 24 protrudes downward from the handle portion 14B and is configured to be able to be pulled upward. In addition, a trigger switch (not shown) is provided within the front end of the handle portion 14B. When the trigger 24 is pulled, the trigger 24 presses the trigger switch, and a detection signal is output from the trigger switch to the control unit 20.

(Regarding the nose 30) As shown in Figures 2 and 3, the nose 30 is made of metal and is disposed within the lower end of the main housing portion 14A. The nose 30 has a nose mounting tube portion 30A that forms the upper portion of the nose 30, and an injection portion main body 30B that extends downward from the nose mounting tube portion 30A. The nose mounting tube portion 30A is formed in a generally bottomed cylindrical shape that is open upward. An injection hole 30C is formed through the center of the bottom wall of the nose mounting tube portion 30A. A generally cylindrical bumper 34 is housed inside the nose mounting tube portion 30A. When the striking portion 50, described below, descends from top dead center to bottom dead center, the striking portion 50 collides with the bumper 34, and the kinetic energy of the striking portion 50 is absorbed by the bumper 34.

The injection unit main body 30B extends downward from the nose mounting tube portion 30A behind the injection hole 30C. A blade guide 32 is provided on the front side of the injection unit main body 30B, below the injection hole 30C. The blade guide 32 is formed in a generally elongated shape extending in the vertical direction and is fixed to the injection unit main body 30B. The blade guide 32 is composed of a main guide member 32A and a sub-guide member 32B, which are assembled to each other. An injection path 32C is formed inside the blade guide 32, and the injection path 32C is disposed in the injection hole 30C of the nose 30. A driver blade 54 (described later) is inserted into the injection path 32C so as to be movable relative to the injection hole 30C in the vertical direction. A guide slit 32D is formed in the lower part of the blade guide 32, and the guide slit 32D opens the injection path 32C to the rear. Furthermore, a driving depth adjustment mechanism 36 extending in the vertical direction is provided on the left side of the blade guide 32. The upper end of the driving depth adjustment mechanism 36 is connected to the nose 30, and the lower end of the driving depth adjustment mechanism 36 protrudes downward beyond the blade guide 32.

(Regarding the pressure accumulator vessel 40) The pressure accumulator vessel 40 is formed as a generally cylindrical vessel with a bottom that is open to the bottom. The pressure accumulator vessel 40 includes a head portion 44 that forms the upper end of the pressure accumulator vessel 40, and a cylinder 42 that extends downward from the head portion 44.

(Regarding the cylinder 42) The cylinder 42 is formed in a roughly cylindrical shape with its axial direction extending in the vertical direction, and is arranged above the nose 30 and within the main housing portion 14A. A male thread 42A is formed on the outer periphery of the upper end of the cylinder 42, and a male thread 42B is formed on the outer periphery of the lower end of the cylinder 42. The male thread 42B at the lower end of the cylinder 42 is threaded into a female thread 30D formed on the inner periphery of the nose mounting tube portion 30A, thereby fastening the cylinder 42 to the nose mounting tube portion 30A.

(Regarding the head portion 44) As shown in Figures 2 to 4, the head portion 44 is formed as a generally cylindrical shape with a bottom that is open downward. The head portion 44 includes a head base 46 that forms the lower portion of the head portion 44 and a head cover 48 that forms the upper portion of the head portion 44. As also shown in Figure 5, the head base 46 is formed as a generally cylindrical shape with its axial direction extending vertically. An engagement recess 46A for attaching a head nut 94 (described later) is formed in the upper portion of the inner surface of the head base 46. The engagement recess 46A is formed in a stepped shape that widens radially outward and is open upward. The head base 46 is positioned radially outward from the upper end of the cylinder 42 and is fixed to the cylinder 42 via the head nut 94 (described later). The upper end of the head base 46 is also positioned above the cylinder 42.

The rear end of the head base 46 protrudes rearward, and a head communication hole 46B is formed through the rear end of the head base 46 to connect the inside and outside of the head unit 44. A valve (not shown) is provided in the head communication hole 46B, and the operator can use the valve to fill the head unit 44 with gas. The gas filled in the head unit 44 may be air, an inert gas, etc., and in this embodiment, air is filled in the head unit 44.

As shown in Figures 2 to 4, the head cover 48 is formed in a concave shape that is open downward, and the outer periphery of the head cover 48 is curved in a generally arc shape that convex radially outward from the head portion 44 in a vertical cross-sectional view. The upper end of the head base 46 is fitted into the lower end of the head cover 48, and the head cover 48 is fixed to the head base 46. As a result, the upper end of the cylinder 42 is covered by the head portion 44. The interior of the head portion 44 is configured as a pressure chamber 44A, and the pressure chamber 44A is connected to the interior of the cylinder 42.

(Regarding the striking section 50)
3 to 5, the striking portion 50 is formed in an elongated shape extending in the vertical direction and is housed in the cylinder 42 so as to be movable in the vertical direction. Specifically, the striking portion 50 is configured to be movable between the top dead center (the position indicated by the solid line in FIG. 3) and the bottom dead center (the position indicated by the two-dot chain line in FIG . 3 ), which is located below the top dead center. The striking portion 50 includes a piston 52 that forms the upper end of the striking portion 50 and a driver blade 54 that extends downward from the piston 52.

The piston 52 is formed in a generally cylindrical shape with its axis extending vertically. The outer diameter of the piston 52 is slightly smaller than the inner diameter D1 of the cylinder 42. A pair of upper and lower first grooves 52A, which open radially outward, are formed at both vertical ends of the outer periphery of the piston 52. The first grooves 52A are formed around the entire circumferential circumference of the piston 52. The first grooves 52A are formed as stepped grooves, and the width dimension (vertical dimension) of the outer periphery of the first grooves 52A is set larger than the width dimension of the inner periphery of the first grooves 52A. A sliding ring 56 made of resin is provided within the groove on the outer periphery of the first grooves 52A. The sliding ring 56 is formed in a ring shape with a generally rectangular cross section and is fitted into the groove on the outer periphery of the first grooves 52A. The outer periphery of the sliding ring 56 is curved in a generally arc shape that convexly extends radially outward from the piston 52 in a vertical cross-sectional view. When the piston 52 moves up and down, the outer peripheral surface of the sliding ring 56 slides on the inner peripheral surface of the cylinder 42 .

A second groove portion 52B that is open radially outward is formed between a pair of upper and lower first groove portions 52A on the outer periphery of the piston 52, and the second groove portion 52B is formed around the entire circumferential circumference of the piston 52. An X-ring 58 made of an elastic material such as rubber is provided in the second groove portion 52B. The X-ring 58 is formed in a ring shape with a roughly X-shaped cross section and is fitted into the second groove portion 52B. The X-ring 58 seals the gap between the cylinder 42 and the piston 52, and the X-ring 58 ensures an airtight state within the pressure chamber 44A.

A blade mounting portion 52C is formed in the center of the piston 52 for mounting the driver blade 54 described below. The blade mounting portion 52C is formed in an approximately cylindrical shape with its axial direction extending vertically, and extends downward from the piston 52.

The driver blade 54 is formed in a generally elongated shape extending in the vertical direction. The upper end of the driver blade 54 is fitted into the blade mounting portion 52C, and the driver blade 54 extends downward from the piston 52. The blade mounting portion 52C is provided with a pin 60 whose axial direction is the front-to-rear direction, through which the upper end of the driver blade 54 is inserted. As a result, the driver blade 54 is fixed to the piston 52 with the vertical movement of the driver blade 54 restricted by the pin 60. The lower end of the driver blade 54 is movably inserted within the injection path 32C of the blade guide 32, and the nail N in the injection path 32C is struck from above by the driver blade 54 as the striking portion 50 moves from top dead center to bottom dead center.

(Regarding the drive mechanism 70) As shown in FIG. 2, the drive mechanism 70 has a motor 72, a reduction mechanism 74, and a conversion unit 76. The motor 72 is configured as a brushless motor, is housed within the rear end side of the motor housing portion 14C, and is electrically connected to the control unit 20. The motor 72 has a drive shaft 72A whose axial direction is the front-to-rear direction, and the front end of the drive shaft 72A is connected to a reduction mechanism 74 located in front of the motor 72. The reduction mechanism 74 is also connected to a conversion unit 76 located in front of the reduction mechanism 74, so that the rotational force of the motor 72 is transmitted to the conversion unit 76 via the reduction mechanism 74.

The conversion unit 76 is located to the right of the blade guide 32 and is housed within the lower part of the nose 30. The conversion unit 76 is configured as a mechanism that transmits the rotational force of the motor 72 to the driver blade 54, moving the driver blade 54 upward. Specifically, the conversion unit 76 engages with the driver blade 54 at bottom dead center, and operation of the conversion unit 76 causes the driver blade 54 to rise from bottom dead center to top dead center. On the other hand, when the driver blade 54 reaches top dead center, the engagement between the driver blade 54 and the conversion unit 76 is released. This causes the impact unit 50 to descend due to the pressure in the pressure chamber 44A.

(Regarding the magazine 80) As shown in Figures 1 and 3, the magazine 80 is composed of a magazine case 82 and a feeder 84. The magazine case 82 is formed in a generally long, flat shape with the longitudinal direction being the front-to-rear direction and the thickness direction being the left-to-right direction. The magazine case 82 is disposed adjacent to the rear side of the blade guide 32, and the front end of the magazine case 82 is fixed to the blade guide 32. In addition, the front part of the magazine case 82 is connected to the ejection path 32C of the blade guide 32.

The feeder 84 is arranged within the magazine case 82 so that it can move relatively forward and backward. The feeder 84 is also biased forward by a biasing spring (not shown), biasing the nails N toward the ejection path 32C. This allows the nails N to be supplied by the feeder 84 into the ejection path 32C of the ejection unit main body 30B.

(Regarding the lubricating oil supply mechanism 90) As shown in Figures 4 and 5, the lubricating oil supply mechanism 90 is provided inside the pressure accumulator vessel 40 and is configured as a mechanical part that supplies lubricating oil between the cylinder 42 and the piston 52. The lubricating oil supply mechanism 90 is configured to include a filter 92 and a head nut 94 as an assembly member for holding the filter 92.

The head nut 94 has a nut portion 94A, which is formed in a generally cylindrical shape with its axial direction extending vertically. The nut portion 94A is fitted into the mating recess 46A of the head base 46 of the head portion 44 described above, thereby integrating the head base 46 and the head nut 94. In other words, the head nut 94 and the head portion 44 are unitized, and the head nut 94 constitutes part of the head portion 44. A female thread 94B is formed on the inner periphery of the nut portion 94A. The female thread 94B of the head nut 94 is threaded onto the male thread 42A of the cylinder 42, thereby fastening the head nut 94 to the upper end of the cylinder 42. In other words, the head portion 44 is fixed to the cylinder 42 by threading the head nut 94, which is unitized with the head portion 44, into the cylinder 42.

The upper end of the nut portion 94A is positioned above the upper end of the cylinder 42. A flange portion 94C protruding radially inward is formed at the upper end of the nut portion 94A. The flange portion 94C is formed around the entire circumferential circumference of the head nut 94 and is positioned above and spaced apart from the upper end surface of the cylinder 42. The inner diameter D2 of the flange portion 94C is set smaller than the inner diameter D1 of the cylinder 42. Furthermore, the female thread 94B is positioned below and spaced apart from the flange portion 94C, and the portion of the head nut 94 between the female thread 94B and the flange portion 94C is configured as a filter accommodating portion 94D that accommodates the filter 92, which will be described later.

Multiple (four in this embodiment) exposed portions 94E are formed at the upper end of the nut portion 94A. The exposed portions 94E are formed in a concave shape that is open upward and radially outward from the nut portion 94A. Furthermore, the radially inner end of the nut portion 94A at the exposed portions 94E is positioned radially inward from the inner surface of the nut portion 94A and penetrates in the vertical direction. This allows the pressure chamber 44A to communicate with the inside of the cylinder 42 (inside the upper end of the nut portion 94A) via the exposed portions 94E. Furthermore, the exposed portions 94E are positioned at equal intervals (every 90 degrees) around the circumferential direction of the head nut 94.

The filter 92 is made of nonwoven fabric. It is formed in a generally annular plate shape with its thickness extending vertically. The filter 92 is housed within the filter housing portion 94D of the head nut 94. The outer diameter of the filter 92 is approximately the same as the inner diameter of the head nut 94. Because the female thread 94B protrudes inward from the inner wall of the head nut 94, when the filter 92 is housed within the filter housing portion 94D, the filter 92 is temporarily held in place by being caught above the female thread 94B. By fastening the head nut 94 with the filter 92 temporarily held in place to the cylinder 42, the filter 92 is sandwiched vertically between the cylinder 42 and the flange portion 94C of the head nut 94 and positioned coaxially with the cylinder 42. When the filter 92 is assembled, a portion of the filter 92 is exposed to the pressure chamber 44A via the exposed portion 94E.

Furthermore, the inner diameter D3 of the filter 92 is set to be larger than the inner diameter D2 of the flange portion 94C and smaller than the inner diameter D1 of the cylinder 42. Furthermore, the filter 92 is impregnated with lubricating oil. As will be described in detail later, when the driving tool 10 is in operation, lubricating oil is dispersed from the filter 92 and supplied between the cylinder 42 and the piston 52.

(Function and effect) Next, we will explain the operation of the driving machine 10 and the function and effect of this embodiment.

When the driving tool 10 is in an inoperative state, the striking unit 50 is positioned in a standby position. The standby position is between the bottom dead center and top dead center of the striking unit 50, slightly toward the bottom dead center. When the control unit 20 detects operation of the trigger 24 based on the output signal from the trigger switch, the control unit 20 drives the motor 72. When the motor 72 is driven, the driving force of the motor 72 activates the conversion unit 76, causing the striking unit 50 to rise from the standby position to the top dead center. When the striking unit 50 reaches the top dead center, the driver blade 54 of the striking unit 50 and the conversion unit 76 are disengaged. In this state, the nail N is supplied into the injection path 32C. The striking unit 50 then descends to the bottom dead center due to the pressure in the pressure chamber 44A, striking the nail N downward. As a result, the nail N is ejected downward from the injection path 32C and driven into the workpiece W. The conversion unit 76, which continues to operate due to the driving force of the motor 72, re-engages with the driver blade 54, and the striking unit 50 rises from the bottom dead center. When the striking unit 50 reaches the standby position, the motor 72 stops driving, and the conversion unit 76 stops operating, so that the striking unit 50 stops with the conversion unit 76 and driver blade 54 still engaged.

In this way, during one cycle of the driving operation of the driving tool 10, the striking part 50 moves back and forth in the vertical direction, and the piston 52 of the striking part 50 slides on the inner surface of the cylinder 42. Specifically, the sliding ring 56 attached to the piston 52 slides on the inner surface of the cylinder 42. Therefore, if the cylinder 42 or the sliding ring 56 wears out due to repeated driving operations of the driving tool 10, the sliding resistance of the sliding ring 56 will increase, and the driving force of the striking part 50 into the nail N may decrease. This may reduce the durability of the driving tool 10.

Here, in the driving tool 10, a lubricating oil supply mechanism 90 is provided in the pressure accumulator vessel 40, and the lubricating oil supply mechanism 90 supplies lubricating oil between the piston 52 of the striking unit 50 and the cylinder 42 in accordance with the striking operation of the striking unit 50. Specifically, a filter 92 of the lubricating oil supply mechanism 90 is provided in the pressure chamber 44A, and the filter 92 is impregnated with lubricating oil. When the striking unit 50 rises from the bottom dead center to the top dead center, the gas in the pressure chamber 44A is pressurized, and when the striking unit 50 descends from the top dead center to the bottom dead center, the gas in the pressure chamber 44A is depressurized. In other words, during the driving operation of the driving tool 10, the gas in the pressure chamber 44A alternates between pressurized and depressurized states. As a result, the pressure fluctuations of the gas in the pressure chamber 44A cause the lubricating oil in the filter 92 to scatter. More specifically, when the striking part 50 descends from the top dead center to the bottom dead center, an airflow is generated from the pressure chamber 44A toward the cylinder 42, causing the lubricating oil in the filter 92 to splash into the cylinder 42. This supplies lubricating oil between the piston 52 of the striking part 50 and the cylinder 42. As a result, wear on the piston 52 (sliding ring 56) and the cylinder 42 is suppressed. This improves the durability of the driving tool 10. While applying lubricating oil to the inside of the cylinder 42 in advance during the manufacturing of the driving tool 10 can prevent short-term wear on the piston 52 and the cylinder 42, repeated use of the driving tool 10 can cause uneven distribution of the lubricating oil or gradual leakage of the lubricating oil, potentially resulting in wear on the piston 52 and the cylinder 42. According to this embodiment, the lubricating oil impregnated in the filter 92 is supplied little by little between the piston 52 and the cylinder 42 with each repeated use, ensuring long-term lubrication.

Furthermore, the filter 92 is disposed above the cylinder 42, and when viewed from the top-bottom direction, a portion of the filter 92 is disposed inside the cylinder 42. Specifically, the filter 92 is formed in a roughly annular plate shape with the plate thickness direction extending in the top-bottom direction, and is disposed above the cylinder 42 coaxially with the cylinder 42. The inner diameter D3 of the filter 92 is set smaller than the inner diameter D1 of the cylinder 42. This allows the lubricating oil impregnated in the filter 92 to be efficiently dispersed within the cylinder 42.

Furthermore, as described above, the filter 92 is formed in a roughly annular plate shape with the thickness direction in the vertical direction, and is arranged coaxially with the cylinder 42. Therefore, the lubricating oil impregnated in the filter 92 can be supplied to the entire circumferential direction of the inner surface of the cylinder 42.

Furthermore, the head nut 94 of the lubricating oil supply mechanism 90 is fastened to the upper end of the cylinder 42, and the filter 92 is sandwiched vertically between the head nut 94 and the cylinder 42 and held between them. This allows the filter 92 to be held in place with a simple structure, while being positioned adjacent to the upper side of the upper opening of the cylinder 42.

Furthermore, the head nut 94 has a filter accommodating portion 94D, which is configured to be able to accommodate the filter 92 in a temporarily held state. As a result, by assembling the filter 92 in a temporarily held state to the head nut 94 and assembling the head nut 94 in this state to the cylinder 42, the filter 92 can be sandwiched and held in the vertical direction by the head nut 94 and the cylinder 42. This improves the ease of assembling the lubricating oil supply mechanism 90 to the cylinder 42.

Furthermore, the pressure accumulator container 40 has a head portion 44 whose interior is configured as a pressure chamber 44A, and the head portion 44 is fixed to a head nut 94. This allows the lubricating oil supply mechanism 90 and head portion 44 to be united, and the head nut 94 to be screwed (assembled) into the cylinder 42 in the lubricating oil supply mechanism 90 and head portion 44 in the united state, thereby allowing the head portion 44 to be assembled to the cylinder 42. Therefore, the ease of assembly of the pressure accumulator container 40 can be improved.

Furthermore, the head nut 94 is formed with four exposed portions 94E that connect the pressure chamber 44A to the inside of the cylinder 42, and the filter 92 is exposed to the pressure chamber 44A by the exposed portions 94E. This allows the air flow generated when the striking part 50 descends from top dead center to bottom dead center to pass from the pressure chamber 44A into the exposed portions 94E and into the cylinder 42. In other words, the air flow that passes through the exposed portions 94E can pass through the filter 92 and flow into the cylinder 42. This allows the lubricating oil in the filter 92 to be more effectively dispersed into the cylinder 42 by the air flow.

In the first embodiment, the inner diameter D2 of the flange portion 94C of the head nut 94 is set to be smaller than the inner diameter D3 of the filter 92. Alternatively, as shown in FIG. 6, the inner diameter D2 of the flange portion 94C may be set to be larger than the inner diameter D3 of the filter 92 and smaller than the inner diameter D1 of the cylinder 42. In this case, when viewed from the top-to-bottom direction, the inner peripheral portion of the filter 92 is positioned radially inward of the flange portion 94C and the inner peripheral surface of the cylinder 42. As a result, when the striking portion 50 descends from top dead center to bottom dead center, the air flow flowing from the pressure chamber 44A into the interior of the cylinder 42 can efficiently splash the lubricating oil impregnated in the filter 92 toward the cylinder 42.

(Second embodiment) Below, using Figure 7, we will explain the driving machine 100 as a work machine of the second embodiment. The driving machine 100 of the second embodiment is configured in the same way as the driving machine 10 of the first embodiment, except for the points described below. In Figure 7, components that are configured in the same way as the driving machine 10 of the first embodiment are given the same symbols.

As shown in Figure 7, in the second embodiment, a lubricating oil supply mechanism 110 is provided on the piston 52 instead of the lubricating oil supply mechanism 90 of the first embodiment. In addition, the head nut 94 used in the lubricating oil supply mechanism 90 forms part of the head portion 44 and is fastened and fixed to the cylinder 42. In other words, in the second embodiment, only the head nut 94 is united with the head portion 44.

A storage section 52D is formed in the center of the piston 52 to accommodate the lubricating oil supply mechanism 110, which will be described later. The storage section 52D is formed in a concave shape that opens upward, and the bottom of the storage section 52D is located radially inward of the lower first groove section 52A. The storage section 52D is formed in a circular shape in a plan view and is located coaxially with the piston 52. A step section 52E is formed on the upper surface of the piston 52, stepping down one step. The step section 52E is formed in a circular shape with a larger diameter than the storage section 52D in a plan view. The piston 52 has multiple (four in this embodiment) communication passages 52F formed radially inward of the lower first groove section 52A. The communication passages 52F extend radially of the piston 52 and connect the first groove section 52A and the storage section 52D. As a result, the first groove portion 52A and the communication passage 52F form a supply passage 52G that connects the accommodation portion 52D with the outside of the piston 52, and the supply passage 52G is configured to supply lubricating oil from the lubricating oil supply mechanism 110 to between the piston 52 and the cylinder 42. The communication passages 52F are arranged at equal intervals (every 90 degrees) around the circumference of the piston 52.

(Regarding the lubricating oil supply mechanism 110) The lubricating oil supply mechanism 110 is composed of a cap 112, a filter 114, and a weight 116. The cap 112 is formed in a generally circular plate shape with the thickness direction in the vertical direction. A cap flange 112A that protrudes radially outward is formed at the upper end of the outer periphery of the cap 112, and the cap flange 112A is formed around the entire circumferential circumference of the cap 112. With the cap flange 112A positioned in the step portion 52E of the piston 52, the cap 112 is fitted into the upper end of the accommodating portion 52D of the piston 52, closing the opening of the accommodating portion 52D.

The filter 114 is made of nonwoven fabric, similar to the filter 92 of the first embodiment. The filter 114 is formed in a roughly cylindrical shape with its axial direction in the vertical direction, and is housed within the lower part of the housing portion 52D of the piston 52. That is, the lower end of the filter 114 is located radially inside the supply path 52G. On the other hand, the upper end of the filter 114 is located below the cap 112 at a distance, and is also located radially inside the second groove portion 52B of the piston 52. The filter 114 is impregnated with lubricating oil.

The weight 116 is formed in a generally circular plate shape with the thickness direction extending in the vertical direction. The weight 116 is housed in the housing portion 52D of the piston 52 and is positioned between the cap 112 and the filter 114. The diameter of the weight 116 is set smaller than the diameter of the housing portion 52D, and the weight 116 is housed within the housing portion 52D so that it can move relatively in the vertical direction. As described above, in the second embodiment, the lubricating oil supply mechanism 110 is unitized with the striking portion 50.

In the second embodiment, during the driving operation of the driving tool 100, the lubricating oil supply mechanism 110 is activated, and lubricating oil is supplied between the piston 52 and the cylinder 42. Specifically, when the striking part 50 descends from top dead center to bottom dead center, the weight 116 is displaced downward due to inertial force. As a result, the weight 116 presses the filter 114 downward, and the lubricating oil impregnated in the filter 114 is scattered inside the communicating passage 52F of the piston 52. The lubricating oil scattered inside the communicating passage 52F seeps out from between the first groove portion 52A of the piston 52 and the sliding ring 56 to the outside of the piston 52 and is supplied between the piston 52 and the cylinder 42. As a result, wear on the piston 52 (sliding ring 56) and the cylinder 42 can be suppressed. Therefore, even in the second embodiment, the durability of the driving tool 100 can be improved.

Furthermore, in the second embodiment, as described above, lubricating oil scattered into the communicating passage 52F seeps out from between the first groove portion 52A and the sliding ring 56 to the outside of the piston 52 and is supplied between the piston 52 and the cylinder 42. This allows lubricating oil to be efficiently supplied to the sliding ring 56 sliding on the inner surface of the cylinder 42.

In the second embodiment, the communicating passage 52F of the supply path 52G is located radially inward of the lower first groove portion 52A. However, as shown in FIG. 8, the communicating passage 52F may also be located radially inward of the upper first groove portion 52A. In this case, the filter 114 and the weight 116 in the lubricating oil supply mechanism 110 are configured upside down. As a result, in the example shown in FIG. 8, when the striking portion 50 rises from bottom dead center to top dead center, the inertial force generated in the weight 116 displaces the weight 116 upward. Therefore, the weight 116 presses the filter 114 upward, and the lubricating oil impregnated in the filter 114 splashes into the communicating passage 52F. Therefore, even in this case, the lubricating oil splashed into the communicating passage 52F seeps out from between the first groove portion 52A and the sliding ring 56 to the outside of the piston 52 and is supplied between the piston 52 and the cylinder 42. Therefore, wear on the piston 52 (sliding ring 56) and the cylinder 42 can be suppressed, and the durability of the driving tool 100 can be improved.

Furthermore, as shown in FIG. 9, a communication passage 52F may be provided radially inward of each of the pair of upper and lower first groove portions 52A. In this case, in the lubricating oil supply mechanism 110, a filter 114 is disposed radially inward of each of the pair of upper and lower communication passages 52F, and a weight 116 is disposed between the upper and lower filters 114. As a result, in this case, lubricating oil can be supplied between the piston 52 and the cylinder 42 both when the striking portion 50 is rising and when it is falling. Although not shown, a groove portion that opens radially outward can be provided on the outer periphery of the piston 52 above the upper first groove portion 52A or below the lower first groove portion 52A, and an X-ring 58 can be provided in the groove portion to prevent air from leaking from the pressure chamber 44A via the communication passage 52F and the accommodation portion 52D.

(Third embodiment) Below, using the drawings, we will explain the driving machine 210 as a work machine according to the third embodiment. Note that the arrows UP, FR, and LH shown as appropriate in the drawings indicate the upper side, front side, and left side of the driving machine 210, respectively. In the following explanation, when the up/down, front/rear, and left/right directions are used, they will refer to the up/down, front/rear, and left/right directions of the driving machine 210 unless otherwise specified. The up/down direction corresponds to the movement direction of the present invention, the lower side corresponds to one side of the movement direction of the present invention, and the upper side corresponds to the other side of the movement direction of the present invention.

As shown in Figures 10 to 12, the driving machine 210 has a driving machine main body 212, to which a magazine 280 is attached. The driving machine 210 is configured as an electric tool that drives nails N, which serve as striking members loaded in the magazine 280, into a workpiece W. The driving machine main body 212 is configured to include a housing 214, a nose 230, a pressure accumulator container 240, and a drive mechanism 270. The driving machine main body 212 also has a lubricant supply mechanism 290. Each component of the driving machine 210 will be described below.

(Regarding the housing 214) As shown in Figures 10 and 11, the housing 214 is formed in a hollow, approximately inverted P-shape when viewed from the left side. Specifically, the housing 214 has a main body housing portion 214A extending in the vertical direction, a handle portion 214B extending diagonally upward and rearward from the vertical middle portion of the main body housing portion 214A, a motor housing portion 214C extending rearward from the lower end portion of the main body housing portion 214A, and a battery attachment portion 214D extending downward from the rear end portion of the handle portion 214B and connected to the rear end portion of the motor housing portion 214C.

A control unit 220 is provided within the rear end of the motor housing section 214C, which controls the motor 272 (described later) and thereby controls the driving of the striking section 250 (described later). A battery 222 is removably attached to the upper end of the battery attachment section 214D. The battery 222 is electrically connected to the control unit 220, and supplies power from the battery 222 to the control unit 220.

A trigger 224 is provided within the front end of the handle portion 214B. The trigger 224 protrudes downward from the handle portion 214B and is configured to be able to be pulled upward. In addition, a trigger switch (not shown) is provided within the front end of the handle portion 214B. When the trigger 224 is pulled, the trigger 224 presses the trigger switch, and a detection signal is output from the trigger switch to the control unit 220.

(Regarding nose 230) As shown in Figures 11 to 13, nose 230 is made of metal and is disposed within the lower end of main body housing portion 214A. Nose 230 has a nose-side housing portion 231 as a housing portion constituting the upper portion of nose 230, and an injection portion main body 232 extending downward from nose-side housing portion 231. Nose-side housing portion 231 is formed in a generally bottomed cylindrical shape that is open upward. The upper part of the inner periphery of nose-side housing portion 231 is configured as fixing portion 231A for fastening and fixing cylinder 242, which will be described later. Fixing portion 231A is formed in a stepped shape that is wider radially outward than inner periphery surface 231B of nose-side housing portion 231, and is open upward. A female thread is formed on the inner periphery of fixing portion 231A. Additionally, a pair of front and rear positioning portions 231C are formed on the outer periphery of the bottom surface of the nose side accommodating portion 231. The positioning portions 231C are configured with a pair of left and right positioning protrusions 231D, which protrude upward from the bottom surface of the nose side accommodating portion 231 and protrude radially inward from the inner periphery 231B of the nose side accommodating portion 231. An injection hole 231E serving as an insertion hole is formed through approximately the center of the bottom wall of the nose side accommodating portion 231. The injection hole 231E is formed in a generally rectangular shape with the left-right direction as the longitudinal direction.

A bumper 292 that constitutes the lubricant supply mechanism 290, which will be described later, is housed inside the nose-side housing 231. During the driving operation of the driving tool 210, the piston 252 of the striking section 250, which will be described later, collides with the bumper 292 from above, and the impact force of the striking section 250 is absorbed by the bumper 292. The bumper 292 will be described later.

The injection unit main body 232 extends downward from both the front and rear sides of the injection hole 231E in the bottom wall of the nose side accommodating section 231. A blade guide 234 is provided in the injection unit main body 232 below the injection hole 231E. The blade guide 234 is formed in a generally elongated shape extending in the vertical direction and is fixed to the injection unit main body 232. The blade guide 234 is composed of a main guide member 234A and a sub-guide member 234B, which are assembled to each other. An injection path 234C is formed inside the blade guide 234, and the injection path 234C is positioned below the injection hole 231E of the nose 230. A driver blade 254 (described later) is inserted into the injection path 234C so as to be movable relative to the injection hole 231E in the vertical direction. The lower part of the ejection passage 234C is open to the rear and communicates with a magazine case 282, which will be described later, so that nails N are supplied from the magazine case 282 to the lower part of the ejection passage 234C.

(Regarding the pressure accumulator vessel 240) As shown in Figures 11 and 12, the pressure accumulator vessel 240 is formed as a generally cylindrical shape with a bottom that is open to the bottom as a whole. The pressure accumulator vessel 240 is configured to include a head portion 244 that forms the upper end of the pressure accumulator vessel 240, and a cylinder 242 that extends downward from the head portion 244. The nose 230 and pressure accumulator vessel 240 described above correspond to the support portion of the present invention.

(Regarding cylinder 242) Cylinder 242 is formed in a roughly stepped cylindrical shape with its axial direction extending in the vertical direction, and is disposed above nose 230 and within main body housing portion 214A. Specifically, a step portion 242A that is bent in a roughly crank shape in cross section is formed at the lower end portion of cylinder 242, and the diameter of the portion of cylinder 242 above step portion 242A is set to be shorter than the diameter of the lower end of cylinder 242. The portion of cylinder 242 above step portion 242A is configured as cylinder main body portion 242B, and a male thread 242C is formed on the outer periphery of the upper end of cylinder main body portion 242B.

14 , the lower end of the cylinder 242 (the portion of the cylinder 242 below the stepped portion 242A) is configured as a cylinder-side accommodating portion 242D. A male thread 242E is formed on the outer periphery of the lower end of the cylinder-side accommodating portion 242D. The cylinder-side accommodating portion 242D is disposed within the fixing portion 231A of the nose-side accommodating portion 231, and the male thread 242E of the cylinder-side accommodating portion 242D is threadedly engaged with the fixing portion 231A, thereby fastening the cylinder 242 to the nose-side accommodating portion 231. As a result, the cylinder-side accommodating portion 242D is closed by the nose-side accommodating portion 231. The nose-side accommodating portion 231 and the cylinder-side accommodating portion 242D are configured to accommodate a bumper 292 and a filter 294, which will be described later. Furthermore, an inclined surface 242G is formed on the lower end portion of the inner circumferential surface 242F of the cylinder side accommodating portion 242D, and the inclined surface 242G is slightly inclined radially outward as it extends downward. Furthermore, a lower opening surface 242H on the inner circumferential surface of the cylinder side accommodating portion 242D is disposed substantially flush with the inner circumferential surface 231B of the nose side accommodating portion 231. As a result, the inner circumferential surface 242F of the cylinder side accommodating portion 242D is disposed radially inward of the inner circumferential surface 231B of the nose side accommodating portion 231.

An inner tube 242J is formed at the upper end of the cylinder side accommodating section 242D. The inner tube 242J is formed in an approximately cylindrical shape with its axial direction in the vertical direction and extends downward from the radially inner end of the stepped section 242A. Specifically, the inner circumferential surface of the inner tube 242J is arranged flush with the inner circumferential surface of the cylinder main body section 242B. As a result, a filter accommodating section 242K is formed at the upper end of the cylinder side accommodating section 242D, surrounded by the inner tube 242J, the stepped section 242A, and the side wall of the cylinder side accommodating section 242D. The filter accommodating section 242K is open downward and formed in a groove shape that follows the circumferential direction of the cylinder 242, and is configured as an accommodating section that accommodates the filter 294, which will be described later.

(Regarding the head portion 244) As shown in Figure 12, the head portion 244 is formed as a whole in a roughly bottomed cylindrical shape that is open to the bottom. The head portion 244 is composed of a head base 245 that forms the lower part of the head portion 244, and a head cover 246 that forms the upper part of the head portion 244. The head base 245 is formed in a roughly cylindrical shape with the axial direction being the up-down direction. A head nut 247 is fixed to the upper part of the inner surface of the head base 245. The head base 245 is positioned radially outside the upper end of the cylinder 242, and the head nut 247 is threaded into the male thread 242C of the cylinder main body portion 242B, thereby fastening the head base 245 (head portion 244) to the cylinder 242.

The rear end of the head base 245 projects rearward, and a head communication hole 245A is formed through the rear end of the head base 245 to communicate the inside and outside of the head unit 244. A valve (not shown) is provided in the head communication hole 245A, and an operator uses the valve to fill the head unit 244 with gas. The gas filled in the head unit 244 may be air, an inert gas, or the like, and in this embodiment, the head unit 244 is filled with air.

The head cover 246 is formed in a concave shape that is open to the bottom, and the outer periphery of the head cover 246 is curved in a roughly arc shape that convex radially outward from the head portion 244 in a vertical cross-sectional view. The upper end of the head base 245 is fitted into the lower end of the head cover 246, and the head cover 246 is fixed to the head base 245. As a result, the upper end of the cylinder 242 is covered by the head portion 244. The interior of the head portion 244 is configured as a pressure chamber 244A, and the pressure chamber 244A is connected to the interior of the cylinder 242.

(Regarding the striking portion 250) As shown in Figures 12 and 14, the striking portion 250 is formed in an elongated shape extending in the vertical direction and is housed within the cylinder 242 so as to be movable in the vertical direction. Specifically, the striking portion 250 is configured to be movable between top dead center (the position shown in Figure 12) as a non-striking position and bottom dead center (the position shown in Figure 14) as a striking position moved downward from top dead center. As will be described in detail later, when the striking portion 250 descends from top dead center to bottom dead center, it collides with a bumper 292 (described below), which undergoes vertical compressive deformation, thereby absorbing the impact force of the striking portion 250. Therefore, when the striking portion 250 descends, it temporarily descends to an inversion position (the position shown in Figure 15) below bottom dead center, and the bumper 292 returns to its initial state, thereby positioning the striking portion 250 at bottom dead center. The striking portion 250 includes a piston 252 that forms the upper end of the striking portion 250 , and a driver blade 254 that extends downward from the piston 252 .

The piston 252 is formed in a generally bottomed cylindrical shape that is open upward, and the outer diameter of the piston 252 is set slightly smaller than the inner diameter of the cylinder main body 242B. A pair of upper and lower first grooves 252A extending circumferentially around the piston 252 is formed on the outer periphery of the piston 252. The first grooves 252A are formed around the entire circumferential circumference of the piston 252. A resin sliding ring 256 is provided within the first groove 252A, and the sliding ring 256 is formed in a ring shape with a generally rectangular cross section. The outer periphery of the sliding ring 256 protrudes radially outward beyond the outer periphery of the piston 252, and the outer periphery of the sliding ring 256 slides on the inner periphery of the cylinder 242 when the piston 252 moves up and down.

A second groove portion 252B extending circumferentially around the piston 252 is formed on the outer periphery of the piston 252 between a pair of upper and lower first groove portions 252A, and the second groove portion 252B is formed around the entire circumferential circumference of the piston 252. An X-ring 258 made of an elastic material such as rubber is provided in the second groove portion 252B, and the X-ring 258 is formed in a ring shape with a roughly X-shaped cross section. The X-ring 258 seals between the cylinder 242 and the piston 252, and ensures an airtight state inside the pressure chamber 244A.

A blade mounting portion 252C for mounting a driver blade 254 (described later) is formed in the center of the underside of the piston 252. The blade mounting portion 252C is formed in an approximately cylindrical shape with its axial direction in the vertical direction and extends downward from the piston 252. A piston-side engagement portion 252D is formed on the outer periphery of the underside of the piston 252. The piston-side engagement portion 252D is formed in a ring shape (annular) when viewed from below and protrudes downward from the underside of the piston 252. The inner circumferential surface of the piston-side engagement portion 252D is configured as a piston-side engagement surface 252E, which, when viewed circumferentially of the piston 252, inclines radially outward as it approaches the bottom. In addition, the outer periphery of the piston-side engaging portion 252D protrudes slightly radially outward from the outer periphery of the piston 252, and when the piston 252 moves up and down, the outer periphery of the piston-side engaging portion 252D slides on the inner periphery of the cylinder 242.

The driver blade 254 is formed in the shape of a roughly elongated plate with its thickness in the front-to-rear direction and extending in the up-down direction. A roughly cylindrical fixing device 259 is provided at the upper end of the driver blade 254, and the fixing device 259 is fixed to the blade mounting portion 252C of the piston 252. As a result, the driver blade 254 is fixed to the piston 252 in a state where it extends downward from the piston 252. The lower end of the driver blade 254 is movably inserted within the injection path 234C of the blade guide 234, and the striking portion 250 is configured to move from top dead center to bottom dead center, causing the driver blade 254 to strike the nail N in the injection path 234C from above.

(Regarding the drive mechanism 270) As shown in FIG. 11, the drive mechanism 270 has a motor 272, a reduction mechanism 274, and a conversion unit 276. The motor 272 is configured as a brushless motor, is housed within the rear end side of the motor housing unit 214C, and is electrically connected to the control unit 220. The motor 272 has a drive shaft 272A whose axial direction is the front-to-rear direction, and the front end of the drive shaft 272A is connected to a reduction mechanism 274 located in front of the motor 272. The reduction mechanism 274 is also connected to a conversion unit 276 located in front of the reduction mechanism 274, and the rotational force of the motor 272 is transmitted to the conversion unit 276 via the reduction mechanism 274.

The conversion unit 276 is located to the right of the blade guide 234 and is housed within the lower part of the nose 230. The conversion unit 276 is configured as a mechanism that transmits the rotational force of the motor 272 to the driver blade 254, moving the driver blade 254 upward. Specifically, the conversion unit 276 engages with the driver blade 254 at bottom dead center, and activation of the conversion unit 276 causes the driver blade 254 to rise from bottom dead center to top dead center. On the other hand, when the driver blade 254 reaches top dead center, the engagement between the driver blade 254 and the conversion unit 276 is released. This causes the striking unit 250 to descend due to the pressure in the pressure chamber 244A.

(Regarding Magazine 280)
10 , the magazine 280 includes a magazine case 282 and a feeder 284. The magazine case 282 is formed in a generally long, flat shape with its thickness in the left-right direction and extends in a direction that slopes upward toward the rear. The magazine case 282 is disposed adjacent to the rear side of the blade guide 234, and the interior of the magazine case 282 communicates with the ejection path 234C of the blade guide 234.

The feeder 284 is mounted on the magazine case 282 so as to be movable relative to the magazine case 282 in the longitudinal direction. The feeder 284 is also biased forward by a biasing spring (not shown), biasing the nails N loaded in the magazine case 282 toward the ejection path 234C. This allows the nails N to be supplied by the feeder 284 into the ejection path 234C of the blade guide 234.

(Regarding the lubricant supply mechanism 290) As shown in Figures 12 to 16, the lubricant supply mechanism 290 is composed of a bumper 292 as an impact absorbing part and a filter 294 as a lubricant holding part for supplying lubricant to the bumper 292 and the piston 252.

The bumper 292 is made of an elastic material such as rubber. The bumper 292 is configured to receive the piston 252 of the striking portion 250 as it descends to bottom dead center, absorbing the impact force generated when the striking portion 250 descends. The bumper 292 is formed in a generally cylindrical shape with its axial direction extending vertically. It is accommodated within the cylinder-side accommodating portion 242D of the cylinder 242 and is placed on the bottom surface of the nose-side accommodating portion 231 of the nose 230. The outer diameter of the bumper 292 is set slightly smaller than the inner diameter of the inner peripheral surface 242F of the cylinder-side accommodating portion 242D, and the bumper 292 is disposed adjacent to the radially inner side of the cylinder-side accommodating portion 242D (see Figures 14 and 16(A)). An outer inclined surface 292A is formed at the lower part of the outer periphery of the bumper 292, and the outer inclined surface 292A slopes radially inward as it extends downward. The outer inclined surface 292A is disposed radially opposite the lower end (inclined surface 242G and lower opening surface 242H) of the cylinder-side accommodating portion 242D of the cylinder 242 and the inner circumferential surface 231B of the nose-side accommodating portion 231 of the bumper 292. Therefore, when the bumper 292 is accommodated, a gap G is formed between the lower portion of the bumper 292 and the cylinder 242 and the nose-side accommodating portion 231 (see FIGS. 14 , 15 , and 16B ). A pair of front and rear positioning ribs 292B are formed on the outer inclined surface 292A. The positioning ribs 292B are shaped like ribs extending in the vertical direction, and the amount of protrusion of the positioning ribs 292B from the outer inclined surface 292A is set so that the positioning ribs 292B are flush with the outer circumferential surface of the upper portion of the bumper 292 when viewed in the vertical direction. The lower end of the positioning rib 292B is positioned between a pair of positioning protrusions 231D in the positioning portion 231C of the nose side accommodating portion 231 (see Figure 16 (B)), and the position of the bumper 292 in the circumferential direction relative to the nose 230 and the cylinder 242 is determined.

An inner inclined surface 292C is formed on the lower part of the inner peripheral surface of the bumper 292. The inner inclined surface 292C slopes radially outward as it extends downward. This causes the radial thickness dimension of the lower part of the bumper 292 to be smaller than the thickness dimension of the upper part of the bumper 292. Specifically, the thickness dimension of the lower part of the bumper 292 is set to decrease as it extends downward. The inner diameter of the upper part of the bumper 292 is set to be slightly larger than the diameter of the blade mounting portion 252C of the piston 252, so that the blade mounting portion 252C is inserted into the upper part of the bumper 292 at the bottom dead center of the striking portion 250. A pair of left and right notched grooves 292D are formed on the inner peripheral surface of the upper part of the bumper 292. The notched grooves 292D open radially inward of the bumper 292 and extend vertically. The lower end of the notched groove 292D is located in the vertical middle of the inner inclined surface 292C, and both vertical ends of the notched groove 292D are open outward in the vertical direction.

A bumper-side engaging portion 292E serving as an abutment is provided at the radially inner end of the upper surface of the bumper 292. The bumper-side engaging portion 292E is formed in a ring shape (annular shape) when viewed from above, and protrudes upward from the radially inner end of the upper surface of the bumper 292. The outer peripheral surface of the bumper-side engaging portion 292E is configured as a bumper-side engaging surface 292F, which , when viewed in the circumferential direction of the bumper 292, is inclined radially outward as it extends downward. At the bottom dead center of the piston 252, the piston-side engaging portion 252D of the piston 252 is disposed adjacent to and radially outward from the bumper-side engaging portion 292E, and the piston-side engaging surface 252E of the piston-side engaging portion 252D abuts against the bumper-side engaging surface 292F of the bumper-side engaging portion 292E from above, thereby engaging the piston-side engaging portion 252D with the bumper-side engaging portion 292E (see FIG. 14). As a result, when the piston 252 descends to the bottom dead center and collides with the bumper 292, the bumper 292 is compressed and deformed while the piston 252 and the bumper 292 are engaged radially, and the piston 252 (striking portion 250) moves to the reversal position (see FIG. 15).

A pressing portion 292G is provided at the radially outer end of the upper surface of the bumper 292. The pressing portion 292G is formed in a ring shape (annular shape) when viewed from above and protrudes upward from the radially outer end of the upper surface of the bumper 292. As a result, a lubricant storage groove portion 292H is formed at the upper end of the bumper 292 between the bumper side engagement portion 292E and the pressing portion 292G as a lubricant storage portion that is open to the upper side. The inner surface of the pressing portion 292G is configured as a pressing inclined surface 292G1, which, when viewed from the circumferential direction of the bumper 292, inclines radially inward as it extends downward. The upper part of the pressing portion 292G is located within the radially outer portion of the opening of the filter accommodating portion 242K. The bottom surface of the lubricant reservoir groove portion 292H is disposed below and spaced apart from the inner tube 242J of the cylinder 242.

The filter 294 is made of a porous material such as nonwoven fabric or soft foam. The filter 294 is formed in a roughly cylindrical shape with its axis extending vertically and is housed in the filter housing portion 242K of the cylinder 242. This positions the bumper 292 and the filter 294 facing each other in the vertical direction. The lower surface of the filter 294 is flush with the lower end surface of the inner cylinder 242J. That is, the filter 294 is housed in the filter housing portion 242K so as to fill the entire filter housing portion 242K. The hardness of the filter 294 is set lower than that of the bumper 292, and the filter 294 is impregnated with lubricating oil as a lubricant. Furthermore, as described above, the pressing portion 292G of the bumper 292 is located radially outward from the opening of the filter housing portion 242K. As a result, the pressing portion 292G presses the outer periphery of the lower end of the filter 294, and the filter 294 is housed in the filter accommodating portion 242K in a compressively deformed state (see FIG. 14 ). Therefore, lubricating oil seeps out of the filter 294 and flows into the lubricant reservoir groove 292H of the bumper 292. Meanwhile, when the piston 252 descends to bottom dead center and collides with the bumper 292, causing the bumper 292 to compress and deform, the pressing portion 292G is displaced downward and moves away from the filter 294. In other words, the pressing portion 292G is released from pressing the filter 294. A communication hole connecting the filter accommodating portion 242K to the outside of the housing 214 may be provided in the filter accommodating portion 242K, allowing lubricating oil to be replenished into the filter accommodating portion 242K from the outside of the housing 214 via the communication hole.

Furthermore, an upwardly protruding surrounding wall 231F is formed in the center of the bottom surface of the nose side accommodating portion 231 of the nose 230 described above. The surrounding wall 231F is formed in a roughly cylindrical shape with its axial direction in the up-down direction, and protrudes upward from the bottom wall of the nose side accommodating portion 231. The aforementioned injection hole 231E is located radially inside the surrounding wall 231F, and the surrounding wall 231F surrounds the injection hole 231E. Furthermore, the lower end of the bumper 292 is located radially outside the surrounding wall 231F.

(Function and effect) Next, we will explain the operation of the driving machine 210 and the function and effect of this embodiment.

When the driving tool 210 is in an inoperative state, the striking unit 250 is positioned in a standby position. The standby position is located between the bottom dead center and top dead center of the striking unit 250, slightly below the top dead center. When the control unit 220 detects operation of the trigger 224 based on the output signal from the trigger switch, the control unit 220 drives the motor 272. When the motor 272 is driven, the driving force of the motor 272 activates the conversion unit 276, causing the striking unit 250 to rise from the standby position to the top dead center. When the striking unit 250 reaches the top dead center, the driver blade 254 of the striking unit 250 and the conversion unit 276 are disengaged. In this state, the nail N is supplied into the injection path 234C. The striking unit 250 then descends to the bottom dead center due to the pressure in the pressure chamber 244A, striking the nail N downward. This causes the nail N to be ejected downward from the ejection path 234C and driven into the workpiece W. The conversion unit 276, which continues to operate due to the driving force of the motor 272, re-engages with the driver blade 254, and the striking unit 250 rises from the bottom dead center. When the striking unit 250 reaches the standby position, the motor 272 stops driving and the conversion unit 276 stops operating, so that the striking unit 250 stops while the engagement between the conversion unit 276 and the driver blade 254 is maintained.

Furthermore, when the striking portion 250 descends to the bottom dead center, the piston 252 collides with the bumper 292. At this time, the impact force input from the piston 252 to the bumper 292 causes the bumper 292 to compress and deform in the vertical direction, and the striking portion 250 moves to a reversal position below the bottom dead center. This allows the bumper 292 to absorb the impact force from the striking portion 250. Furthermore, when the striking portion 250 descends from the bottom dead center to the reversal position, the piston-side engaging portion 252D of the piston 252 abuts against the bumper-side engaging portion 292E of the bumper 292, and the piston-side engaging portion 252D and the bumper-side engaging portion 292E engage with each other, causing the piston 252 to descend. Then, the bumper 292 returns to its initial state, causing the piston 252 to return from the reversal position to the bottom dead center.

In this way, during the driving operation of the driving tool 210, the bumper 292 receives the impact portion 250 (piston 252) as it descends to the bottom dead center, absorbing the impact force from the impact portion 250. For this reason, the bumper-side engagement portion 292E of the bumper 292 may wear out due to repeated driving operations of the driving tool 210. If the bumper 292 were to wear out, the impact absorption performance of the bumper 292 would decrease, and the durability of the driving tool 210 may also decrease.

In the driving tool 210, a filter 294 impregnated with lubricating oil is housed in the filter housing portion 242K of the cylinder 242. The filter 294 is configured to be able to contact the bumper 292. Specifically, the filter 294 is positioned above the bumper 292, and the pressing portion 292G of the bumper 292 presses the outer periphery of the lower end of the filter 294 from below. This causes the lubricating oil to seep out of the filter 294 and be supplied to the upper surface of the bumper 292. The lubricating oil supplied to the upper surface of the bumper 292 flows through the lubricant storage groove portion 292H and into the bumper-side engagement portion 292E. This allows the lubricating oil to be supplied to the bumper-side engagement portion 292E, which is the contact point of the bumper 292 with the piston 252. As a result, wear on the bumper-side engagement portion 292E of the bumper 292 can be suppressed. Therefore, the impact absorption performance of the bumper 292 can be maintained well, and the durability of the driving tool 210 can be improved.

Furthermore, when viewed from above, the filter 294 is formed in an annular shape, and the piston 252 is positioned inside the filter 294. This allows lubricating oil to be supplied to the bumper side engagement portion 292E over the entire circumferential direction of the bumper 292. Therefore, lubricating oil can be effectively supplied to the bumper side engagement portion 292E.

Furthermore, the filter 294 is positioned above the bumper 292. In other words, the filter 294 and the piston 252 are positioned on the same upper side of the bumper 292. This allows lubricating oil to be efficiently supplied to the bumper side engagement portion 292E, which is the receiving surface of the piston 252 on the bumper 292.

Furthermore, in the vertical direction, the filter 294 is positioned so that it overlaps with the piston 252 at bottom dead center. This allows the filter 294 to be positioned adjacent to the upper side of the bumper 292, which receives the piston 252 at bottom dead center. This allows lubricating oil to be efficiently supplied from the filter 294 to the upper part of the bumper 292.

In addition, a pressing portion 292G is formed on the outer periphery at the upper end of bumper 292. When viewed from above, pressing portion 292G is formed in a circular ring shape and protrudes upward from bumper 292. Pressing portion 292G presses the outer periphery of the lower end of filter 294 from below. This allows pressing portion 292G to compress and deform filter 294, allowing the lubricating oil impregnated in filter 294 to be supplied to the upper surface of bumper 292.

Furthermore, an annular bumper-side engagement portion 292E is formed on the inner periphery at the upper end of the bumper 292, and the piston 252, which has descended to bottom dead center, abuts against the bumper-side engagement portion 292E. In other words, the bumper-side engagement portion 292E, which is the contact point of the bumper 292 with the piston 252, is positioned radially inward of the pressing portion 292G that presses the filter 294. This allows the lubricating oil seeping out from the filter 294 to be efficiently supplied to the bumper-side engagement portion 292E.

Furthermore, a circular piston-side engagement portion 252D that protrudes downward is formed on the underside of the piston 252. When the piston 252 is at bottom dead center, the piston-side engagement portion 252D is positioned radially outward of the bumper-side engagement portion 292E, and the piston-side engagement portion 252D and the bumper-side engagement portion 292E engage radially. This allows the bumper 292 and the piston 252 to maintain a good contact state when the piston 252 descends to bottom dead center. This allows the bumper 292 to effectively absorb the impact force of the piston 252.

In addition, a lubricant storage groove portion 292H is formed at the upper end of the bumper 292 between the pressing portion 292G and the bumper side engagement portion 292E. This allows the lubricant oil that seeps out from the filter 294 to be temporarily stored in the lubricant storage groove portion 292H, and the lubricant oil in the lubricant storage groove portion 292H to be supplied to the bumper side engagement portion 292E.

Furthermore, the bumper 292 is made of an elastic material such as rubber. Therefore, when the bumper 292 receives the piston 252 that has descended to the bottom dead center, the bumper 292 undergoes compressive deformation in the vertical direction, and then the bumper 292 returns to its initial state. This allows the pressing portion 292G of the bumper 292 to efficiently exude the lubricating oil from the filter 294 and supply it to the bumper 292. That is, when the bumper 292 receives the piston 252 at the bottom dead center, the bumper 292 undergoes compressive deformation in the vertical direction, causing the pressing portion 292G of the bumper 292 to be displaced downward, and the pressing state of the pressing portion 292G against the filter 294 is released. Then, as the bumper 292 returns to its initial state, the pressing portion 292G displaces upward and presses the filter 294 again. That is, with each driving operation of the driving tool 210, the pressing portion 292G alternates between pressing and not pressing the filter 294. This causes the lubricant to circulate inside the filter 294. Therefore, by pressing the filter 294 with the pressing portion 292G with each driving operation of the driving tool 210, the lubricant inside the filter 294 can be efficiently exuded and supplied to the bumper 292.

Furthermore, an outer inclined surface 292A is formed on the outer peripheral surface of the lower portion of bumper 292, and an inner inclined surface 292C is formed on the inner peripheral surface of the lower portion of bumper 292, so that the radial thickness of the lower portion of bumper 292 is thinner than the thickness of the upper portion. Furthermore, the upper portion of bumper 292 is positioned adjacent to the radially inner side of cylinder-side accommodating portion 242D of cylinder 242. This allows the lower portion of bumper 292 to be effectively compressed and deformed, displacing the upper portion of bumper 292 downward along the inner peripheral surface of cylinder-side accommodating portion 242D, when a downward impact force is input from piston 252 to bumper 292. In other words, pressing portion 292G can be displaced vertically along the inner peripheral surface of cylinder-side accommodating portion 242D. Therefore, pressing portion 292G can be effectively switched between a pressing state and a non-pressing state against filter 294.

Furthermore, when the bumper 292 is accommodated in the nose side accommodation portion 231 and the cylinder side accommodation portion 242D, a gap G is formed between the lower part of the bumper 292 and the inner surface 231B of the nose side accommodation portion 231. Therefore, when a downward impact force is input from the piston 252 to the bumper 292, the deformation of the lower part of the bumper 292 that expands in the radial direction can be absorbed by the gap G. This allows the bumper 292 to be compressed and deformed more effectively.

In addition, a cylindrical surrounding wall 231F is provided on the bottom surface of the nose side accommodating portion 231, and the injection hole 231E of the nose 230 is surrounded by the surrounding wall 231F. Therefore, even if lubricating oil seeps out of the filter 294 and flows along the inner surface 242F of the cylinder side accommodating portion 242D to the bottom surface of the nose side accommodating portion 231, the surrounding wall 231F can prevent the lubricating oil from flowing toward the injection hole 231E. Therefore, it is possible to prevent the lubricating oil from leaking from the injection hole 231E.

In this embodiment, an example has been shown in which the lubricant supply mechanism 290 is applied to the driving tool 210, which is powered by power supplied from the battery 222, but the lubricant supply mechanism 290 may also be applied to various types of driving tools. For example, as shown in Figure 17, the lubricant supply mechanism 290 may be applied to a driving tool 2100, which is a well-known work machine driven by compressed air supplied from an air compressor (not shown). Below, a brief description of the driving tool 2100 will be given using Figure 17. In Figure 17, components configured in the same way as in this embodiment are given the same reference numerals.

In the driving tool 2100, the interior of the handle portion 214B of the housing 214 is configured as a pressure accumulator chamber, and an air supply plug 2102 is provided at the rear end of the handle portion 214B. An air hose (not shown) is connected to the air supply plug 2102, and compressed air is supplied from an air compressor (not shown) to the pressure accumulator chamber via the air hose. In addition, a trigger 224 is provided at the front end of the handle portion 214B. A push lever 2104 is provided at the lower end of the nose 230, and is configured to be able to move back and forth in the vertical direction.

The bumper 292 of the lubricant supply mechanism 290 is housed in the cylinder-side housing portion 242D of the cylinder 242, and the filter 294 is housed in the filter housing portion 242K of the cylinder 242. When the trigger 224 is operated with the push lever 2104 pressed from above into the workpiece W, compressed air in the accumulator chamber flows into the upper side of the piston 252 in the cylinder 242 through a specified flow path, causing the striking portion 250 to descend from top dead center to bottom dead center. Therefore, when the bumper 292 receives the piston 252 that has descended to bottom dead center, the bumper 292 is compressed and deformed in the vertical direction, and then the bumper 292 returns to its initial state. This allows the pressing portion 292G of the bumper 292 to efficiently seep out the lubricant in the filter 294 and supply it to the bumper 292. Therefore, the impact absorption performance of the bumper 292 can be maintained well, and the durability of the driving tool 2100 can be improved.

In addition, the upper surface of the bumper 292 may be flat, without the pressing portion 292G protruding upward from the upper surface of the bumper 292. In this case, if the filter 294 is shaped to protrude downward from the filter accommodating portion 242K, the upper surface of the bumper 292 can press the filter 294. Also, the filter 294 may be positioned radially outward of the bumper 292, and the bumper 292, which is compressed vertically when the striking portion 250 descends, may expand radially outward to press the filter 294.

10...driving machine (work machine), 40...pressure accumulator vessel, 42...cylinder, 44...head portion, 50...impact portion, 52D...accommodation portion, 52G...supply path, 56...sliding ring (sliding member), 90...lubricating oil supply mechanism, 92...filter, 94...head nut (assembly member), 94D...filter accommodation portion, 94E...exposed portion, 100...driving machine, 110...lubricating oil supply mechanism, 114...filter, 116...weight, N...nail (fastener), 210...driving machine (work machine), 230... nose (support portion), 231... nose side accommodation portion (accommodation portion), 231E... injection hole (insertion hole), 231F... surrounding wall, 240... pressure accumulator vessel (support portion), 242D... cylinder side accommodation portion (accommodation portion), 250... striking portion, 292... bumper (shock absorbing portion), 292E... bumper side engaging portion (abutment portion), 292G... pressing portion, 292H... lubricant storage groove portion (lubricant storage portion), 294... filter (lubricant holding portion), 2100... driving machine

Claims (7)

A support part;
a striking section including a piston and a driver blade extending from the piston, movably supported on the support section, and configured to perform a striking action of applying a striking force to a member to be struck by moving in one direction from a non-striking position , which is the top dead center, to a striking position, which is the bottom dead center ;
a lubricant supply unit that supplies lubricant to the striking unit in response to a striking operation of the striking unit,
the support portion is a pressure accumulator container having a pressure chamber therein filled with gas, the pressure accumulator container having a cylindrical cylinder that supports the piston so as to be movable in the first direction,
the impact portion is provided inside the pressure accumulator container so as to be movable in the first direction, and performs the impact action by moving to one side in the first direction due to the pressure of the gas in the pressure chamber;
The lubricating oil supply unit is located inside the pressure accumulator container on the other side of the first direction of the piston located at the top dead center , and supplies lubricating oil between the piston and the cylinder in response to the impact motion of the impact unit. the lubricating oil supply unit has a filter impregnated with the lubricating oil,
The work machine according to claim 1, wherein the lubricating oil is splashed from the filter by an air flow generated in the pressure chamber when the striking part makes a striking operation, and is supplied between the striking part and the pressure accumulator container. a portion inside the pressure accumulator container on the other side of the cylinder in the first direction is configured as the pressure chamber,
The work machine according to claim 2, wherein the lubricating oil supply unit is disposed in the pressure chamber. The work machine described in claim 3, wherein the filter is disposed on the other side of the cylinder in the first direction, and a portion of the filter is disposed inside the cylinder when viewed in the first direction. the lubricating oil supply unit has an assembly member assembled to the other end of the cylinder in the first direction,
The work machine according to claim 3 , wherein the filter is sandwiched between the assembly member and the cylinder in the first direction. The work machine described in claim 5, wherein the mounting member has a filter housing portion, and the filter housing portion is configured to be able to house the filter in a temporarily held state. the pressure accumulator vessel has a head portion covering the other end of the cylinder in the first direction and having the pressure chamber therein,
7. The work machine according to claim 5, wherein the head portion is fixed to the cylinder by the assembly member.