Work machine

Abstract

The present invention enables the driving force of a work machine to be maintained over a long period. A driving machine 1 comprises: a tubular cylinder 10; a pressure accumulation container 14 that seals the upper end of the cylinder 10 in the vertical direction Z1; a piston 11 that, together with the cylinder 10 and the pressure accumulation container 14, demarcates a pressure chamber 13, and that imparts a striking force to a fastener; and a nut 26 that partitions the internal space of the cylinder 10 and the internal space of the pressure accumulation container 14. Grease 27 is applied to the inside wall 10a of the cylinder 10, and the nut 26 has a through-hole 26c that connects to the internal space of the cylinder 10 and the internal space of the pressure accumulation container 14 and guides air-flow passing therethrough to the inside wall 10a of the cylinder 10.

Description

Work equipment

[0001] The present invention relates to a work machine such as a driving machine.

[0002] 2. Description of the Related Art As an example of a working machine, a driving machine having a cylindrical cylinder and a piston that reciprocates within the cylinder is known.

[0003] As an example of the above-mentioned driving machine, Patent Document 1 discloses a driving machine equipped with a cylindrical cylinder, a piston that reciprocates within the cylinder, and a pressure accumulator chamber that is provided above the cylinder and communicates with the cylinder.

[0004] JP 2018-1336 A

[0005] In the driving machine described in the above-mentioned Patent Document 1, grease (lubricant) is applied to the inner wall of the cylinder so that the piston moves smoothly between the piston and the cylinder.

[0006] However, the reciprocating motion of the piston sometimes scrapes the grease out of the piston's range of motion and accumulates on the top of the piston. When grease accumulates on the top of the piston, the piston's smooth operation is impaired and the sliding resistance during reciprocating motion increases. As a result, there is a risk of the driving force of the driving tool decreasing.

[0007] An object of the present invention is to provide a work machine that can maintain a driving force for a long period of time.

[0008] The work machine of the present invention comprises a cylindrical cylinder extending in a first direction, a pressure accumulator container that closes one end of the cylinder in the first direction and whose interior is connected to the interior of the cylinder, a piston portion that is arranged to be movable within the cylinder in the first direction, that cooperates with the cylinder and the pressure accumulator container to define a pressure chamber, and that applies an impact force to a stopper by moving to the other side in the first direction due to the pressure of gas within the pressure chamber, and a partition portion that separates the internal space of the cylinder from the internal space of the pressure accumulator container, wherein a lubricant is applied to the inner wall of the cylinder, and the partition portion has a through hole that communicates with the internal space of the cylinder and the internal space of the pressure accumulator container and directs the air flow passing through it toward the inner wall of the cylinder.

[0009] According to the present invention, it is possible to maintain the driving force in the work machine for a long period of time.

[0010] 1 is a side cross-sectional view showing the internal structure of a working machine according to an embodiment of the present invention. FIG. 1 is a cross-sectional view showing the positions of the piston at the top dead center and the bottom dead center of the working machine of FIG. 2. FIG. 2 is a plan view showing the structure of the working machine of FIG. 2 with the pressure accumulator container removed and viewed from above. FIG. 3 is a view showing the structure of a partition (nut) assembled to the working machine of FIG. 2, where (a) is a plan view and (b) is a side view. FIG. 4 is a view showing the structure of the partition of FIG. 4, where (a) is a bottom view and (b) is a cross-sectional view taken along line A-A in FIG. 4(a). FIG. 3 is a cross-sectional view showing the flow of air passing through the through-hole of the partition when the piston is pressurized in the working machine of FIG. 2. FIG. 4 is a cross-sectional view showing the structure of a working machine according to a first modified example of the present invention when the piston is pressurized. FIG. 7 is a plan view showing the structure of the working machine of FIG. 7 with the pressure accumulator container removed and viewed from above. FIG. 9 is a cross-sectional view showing the structure of a working machine according to a second modified example of the present invention when the piston is pressurized. FIG. 10 is a plan view showing the structure of the working machine of FIG. 9 with the pressure accumulator container removed and viewed from above. FIG. 11 is a cross-sectional view showing the structure of a working machine according to a third modified example of the present invention when the piston is pressurized. Fig. 12 is a plan view showing the structure of the working machine of Fig. 11 when the pressure accumulator container is removed and viewed from above. Fig. 13 is a cross-sectional view showing the structure of the working machine of a fourth modified example of the present invention when the piston is pressurized. Fig. 14 is a plan view showing the structure of the working machine of Fig. 13 when the pressure accumulator container is removed and viewed from above.

[0011] Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

[0012] In this embodiment, a driving tool will be described as an example of a work machine. As shown in Figure 1, the driving tool 1 has a housing 2. The housing 2 includes a cylinder case 3, a motor case 4, and a handle 5. The cylinder case 3 houses a cylinder 10, and the motor case 4 houses an electric motor 20.

[0013] The motor case 4 and the handle 5 extend substantially parallel to each other from the cylinder case 3, and the end of the motor case 4 and the end of the handle 5 are connected to each other by a connecting portion 7. The housing 2 has two housing halves molded from a synthetic resin such as nylon or polycarbonate, and the housing 2 is assembled by butting together these two housing halves.

[0014] The cylinder 10 has a cylindrical shape extending in the vertical direction (first direction) Z1, and a piston portion 11 is accommodated in the cylinder 10 so as to be able to reciprocate. The piston portion 11 reciprocates between top dead center and bottom dead center along the axial direction of the cylinder 10 (vertical direction Z1) inside the cylinder 10. A piston chamber 12 whose volume increases and decreases as the piston portion 11 reciprocates is defined within the cylinder 10 by an inner wall 10a (inner peripheral surface) of the cylinder 10 and an upper surface 11c of the piston portion 11.

[0015] Meanwhile, a driver blade 16 is connected to the underside 11e of the piston portion 11. The driver blade 16 is integral with the piston portion 11 and reciprocates together with the piston portion 11. That is, a striking portion 6 made up of the piston portion 11 and the driver blade 16 reciprocates within the cylinder 10. Specifically, an injection portion 8 is provided at the end of the cylinder case 3, and an injection passage 9 is provided inside the injection portion 8. The driver blade 16 reciprocates in the injection passage 9 in conjunction with the reciprocating movement of the piston portion 11. In the following description, the reciprocating direction of the piston portion 11 and the driver blade 16 in FIG. 1 is defined as the up-down direction (first direction) Z1.

[0016] A magazine 19 that stores a large number of fasteners (for example, nails) 18 is attached to the housing 2. The fasteners 18 stored in the magazine 19 are supplied one by one to the injection passage 9 by a supply mechanism provided in the magazine 19. The driver blade 16 strikes the heads of the fasteners 18 that are sequentially supplied to the injection passage 9. The fasteners 18 whose heads have been struck by the striking unit 6 pass through the injection passage 9 of the injection unit 8, are driven out from the injection port that is the exit of the injection passage 9, and are driven into a mating material 24 such as wood or gypsum board.

[0017] An electric motor 20 is housed in the motor case 4, and an output shaft 21 of the electric motor 20 is connected to a wheel driven by the electric motor 20 via a planetary gear reduction mechanism. The electric motor 20 operates using power supplied from a battery 22 attached to a connecting portion 7 of the housing 2. A controller 23 serving as a control unit is also housed inside the connecting portion 7. The controller 23 is a microcomputer composed of a CPU, ROM, RAM, etc., and controls the electric motor 20. Specifically, the electric motor 20 is a brushless motor, and the controller 23 changes the duty ratio of the motor current supplied to the electric motor 20 depending on the control mode. In other words, the controller 23 controls the electric motor 20 using pulse width modulation (PWM).

[0018] A rubber or urethane damper 15 is provided at the bottom of the cylinder 10. The damper 15 receives the piston 11 when it reaches bottom dead center, preventing it from colliding with the cylinder 10. A driver blade 16 extends downward from the piston 11, penetrates the damper 15, and protrudes from the cylinder 10 through a through-hole provided at the bottom of the cylinder 10.

[0019] A pressure accumulator vessel 14 that forms a pressure chamber 13 is provided above the cylinder 10, and the pressure chamber 13 is in communication with the piston chamber 12. The piston chamber 12 and the pressure chamber 13 are pre-filled with high-pressure gas (compressed air in this embodiment). When the piston 11, which is at the bottom dead center, is to be moved to the top dead center, the electric motor 20 is operated under the control of the controller 23.

[0020] The injection unit 8 is also provided with a push lever 25. The push lever 25 is held so as to be movable in the vertical direction Z1, while being constantly biased downward by a coil spring 25a (see FIG. 2, described later). When the push lever 25 is pressed against the mating material 24 and moves upward against the bias of the spring 25a, a signal is output. The handle 5 is also provided with a trigger 17 that is operated by the operator, and when the trigger 17 is operated, a trigger switch 17a built into the handle 5 is activated, and a signal for the driving operation is output.

[0021] When the controller 23 receives both a signal from the operation of the push lever 25 and a signal from the operation of the trigger portion 17, it supplies a motor current to the electric motor 20, causing the electric motor 20 to operate. This rotates the wheel, pushing up the driver blade 16 and moving the piston portion 11 from the bottom dead center to the top dead center. The piston portion 11 then moves from the top dead center to the bottom dead center, causing the driver blade 16 to descend. In other words, the piston portion 11 reciprocates between the bottom dead center and the top dead center, causing the driver blade 16 to strike the fastener 18 and drive it out. In other words, one driving operation is performed.

[0022] Next, details of the pressure chamber 13 formed in the fastener driving tool 1 of this embodiment will be described. The fastener driving tool 1 is provided with a pressure accumulator vessel 14 that closes the upper end (one side) of the cylinder 10 in the vertical direction (first direction) Z1 and whose interior is in communication with the interior of the cylinder 10. A piston 11 is provided within the cylinder 10 and is movable in the vertical direction Z1. The piston 11 is a member that applies a striking force to the fastener 18 by moving downward (the other side) in the vertical direction Z1 due to the pressure of the gas within the pressure chamber 13. Furthermore, the piston 11 cooperates with the cylinder 10 and the pressure accumulator vessel 14 to define the pressure chamber 13, and is pressed downward by compressed air supplied from the pressure chamber 13.

[0023] Here, the pressure chamber 13 of the driving tool 1 is provided with a partition separating the internal space of the cylinder 10 from the internal space of the pressure accumulator vessel 14. The partition is provided near the upper end of the cylinder 10, and in this embodiment, the partition is a nut 26. As shown in FIG. 2, the nut 26 is composed of a disk portion 26a and a cylindrical portion 26b. The nut 26 is fitted into the upper end of the cylinder 10 and threadedly coupled to the outer periphery of the cylinder 10. Specifically, as shown in FIG. 5, an internal thread groove is formed on the inner periphery 26f of the cylindrical portion 26b of the nut 26, and threadedly coupled to the external thread formed on the outer periphery of the cylinder 10. In this regard, as shown in FIG. 2, a flange (protrusion) 10b is provided on the outer periphery of the cylinder 10, and the pressure accumulator vessel 14 is supported by having its connection end 14a sandwiched between the cylindrical portion 26b of the nut 26 and the flange 10b of the cylinder 10. That is, the nut 26 fixes the cylinder 10 and the pressure accumulator vessel 14. In other words, by fastening the nut 26 to the outer peripheral surface of the cylinder 10, the pressure accumulator vessel 14 is sandwiched between the nut 26 and the flange 10b of the cylinder 10.

[0024] The pressure chamber 13 is also partially defined by the piston portion 11, which reciprocates within the cylinder 10. That is, when the piston portion 11 moves downward within the cylinder 10 due to the pressure of the gas within the pressure chamber 13, it is necessary to maintain an airtight state in the piston chamber 12. For this reason, an X-ring 11a is attached to the outer periphery of the piston portion 11. Furthermore, to improve the slidability of the piston portion 11, a slide ring 11b is attached to the outer periphery of the piston portion 11. Therefore, when the piston portion 11 moves, the piston chamber 12 can be maintained in an airtight state, and the slidability of the piston portion 11 can also be improved.

[0025] Since the piston portion 11 needs to reciprocate smoothly within the cylinder 10, grease (lubricant) 27 is applied to the inner wall 10a of the cylinder 10. However, when the piston portion 11 repeatedly moves up and down during the driving operation, the X ring 11a and the slide ring 11b are in close contact with the inner wall 10a of the cylinder 10, so the grease 27 is scraped out by the X ring 11a and the slide ring 11b, and the grease 27 is gradually lifted to the top of the inner wall 10a of the cylinder 10. As a result, the grease 27 accumulates near the upper surface 11c of the piston portion 11 or near the upper end of the inner wall 10a of the cylinder 10. If the driving operation of the piston part 11 is continued in this state, for example, the piston part 11 will move up and down with the grease 27 adhering to the upper surface 11c of the piston part 11 remaining as it is, or the grease 27 adhering near the upper end of the inner wall 10a of the cylinder 10 will remain near the upper end of the inner wall 10a of the cylinder 10. As a result, the grease 27 will not be supplied to the entire inner wall 10a of the cylinder 10, the sliding resistance of the X-ring 11a and the slide ring 11b when the piston part 11 moves will increase, and the driving force of the driving tool 1 will gradually decrease.

[0026] Therefore, in the driving tool 1 of this embodiment, the nut 26 has through holes 26c that communicate with the internal space of the cylinder 10 and the internal space of the pressure accumulator vessel 14 when viewed in the vertical direction Z1. Specifically, as shown in Fig. 3, a plurality of through holes 26c are provided in the disk portion 26a of the nut 26. As shown in Figs. 4 and 5, the nut 26 is made up of the disk portion 26a and a cylindrical portion 26b, and a thread groove is formed on the inner circumferential surface 26f of the cylindrical portion 26b for threaded coupling with the cylinder 10. Notches 26g are formed in four locations on the outer periphery of the disk portion 26a, and a jig or the like is fitted into these notches 26g to rotate the nut 26 and attach or detach the nut 26.

[0027] As described above, the disk portion 26a of the nut 26 is provided with a plurality of through holes 26c, and further provided with a through hole 26e near the center of the disk portion 26a. Like each of the plurality of through holes 26c, the through hole 26e also communicates with the internal space of the cylinder 10 and the internal space of the pressure accumulator vessel 14. Therefore, as shown in FIG. 2, during the driving operation of the piston portion 11, compressed air P1 and P2 supplied from the pressure chamber 13 are supplied into the cylinder 10 through the through holes 26c and 26e, respectively. At this time, in the driving tool 1, the pressure of the compressed air P2 passing through the plurality of through holes 26c in particular can spread the grease 27 adhering to the upper surface 11c of the piston portion 11 and the grease 27 adhering near the upper end of the inner wall 10a of the cylinder 10 shown in FIG. 6 throughout the area of ​​the inner wall 10a of the cylinder 10 where the piston portion 11 slides. That is, the multiple through-holes 26c are configured to direct the compressed air P2 passing through them toward the inner wall 10a of the cylinder 10, and the compressed air P2 passing through the multiple through-holes 26c is forcefully discharged toward the inner wall 10a of the cylinder 10. As a result, the grease 27 that had accumulated at the top of the cylinder 10 is pushed downward by the pressure of the compressed air P2, and as a result, the grease 27 descends to the range where the piston portion 11 slides, allowing the piston portion 11 to operate smoothly. This reduces the sliding resistance of the X-ring 11a and the slide ring 11b when the piston portion 11 moves, preventing a decrease in the driving force of the driving tool 1. In other words, the driving force of the driving tool 1 can be maintained for a long period of time.

[0028] 2, the piston portion 11 of the driving tool 1 has an inclined surface 11d on its upper surface 11c that slopes outward in the radial direction X1 of the cylinder 10. Because the inclined surface 11d is provided on the upper surface 11c of the piston portion 11, when the piston portion 11 descends and abuts against the damper 15 during the driving operation, the grease 27 that has accumulated on the upper surface 11c of the piston portion 11 moves in the outer circumferential direction Q1 and along the inclined surface 11d due to inertial force and scatters onto the inner wall 10a of the cylinder 10. As a result, the grease 27 adheres to the area of ​​the inner wall 10a of the cylinder 10 where the piston portion 11 slides, allowing the piston portion 11 to operate smoothly.

[0029] Furthermore, the plurality of through holes 26c formed in the disk portion 26a of the nut 26 are preferably provided along the inner wall 10a of the cylinder 10 so that the compressed air P2 passing through the plurality of through holes 26c presses the grease 27 and pushes the grease 27 down along the inner wall 10a of the cylinder 10. The opening shape of the through holes 26c is, for example, circular. As shown in FIG. 3 , each of the plurality of through holes 26c is preferably provided at a position overlapping the inner wall 10a of the cylinder 10 when viewed in the up-down direction Z1. That is, each through hole 26c is preferably positioned so that a portion of the inner wall 10a of the cylinder 10 is visible from above. By positioning each through hole 26c so that a portion of the inner wall 10a of the cylinder 10 is visible from above, the pressure of the compressed air P2 passing through each through hole 26c can be efficiently applied to the grease 27. As a result, the grease 27 can be applied appropriately to the area of ​​the inner wall 10a of the cylinder 10 where the piston portion 11 slides, allowing the piston portion 11 to operate more smoothly.

[0030] 4, the nut 26 has a wall portion 26d on its disk portion 26a that is positioned inward of the through hole 26c in the radial direction X1 of the cylinder 10. That is, the disk portion 26a has the wall portion 26d at a position inside (closer to the center) of the through holes 26c formed along the inner wall 10a of the cylinder 10, and a circular through hole 26e larger than the through hole 26c is formed in the center of the wall portion 26d. In other words, the through hole 26e is formed in the center of the disk portion 26a, the wall portion 26d is formed outside the through hole 26e, and the multiple through holes 26c are further arranged outside the wall portion 26d. This allows the compressed air P2 that hits the wall portion 26d to be appropriately dispersed so that it flows into the multiple through holes 26c. In other words, compressed air P2 is directed against wall portion 26d and dispersed into multiple through holes 26c, resulting in an appropriate amount of grease 27 being applied to the area of ​​inner wall 10a of cylinder 10 where piston portion 11 slides, allowing piston portion 11 to operate smoothly.

[0031] Furthermore, in the driving tool 1, the pressure accumulator vessel 14 is fixed to the cylinder 10 by a nut 26. This allows for easy maintenance of the pressure chamber 13 and part replacement, and also reduces the cost of parts.

[0032] Next, a driving tool 1 according to a modification of the present embodiment will be described. In the driving tool 1 according to a first modification shown in Figures 7 and 8, the plurality of through holes 26c provided in the disk portion 26a are each formed obliquely toward the inner wall 10a of the cylinder 10 so that the compressed air P2 passing through the through holes 26c is directed toward the inner wall 10a of the cylinder 10. Specifically, each of the plurality of through holes 26c is provided inward of the inner wall 10a of the cylinder 10 in the radial direction X1 of the cylinder 10, and further, the cylinder 10-side openings 26h of the through holes 26c are positioned outward of the pressure accumulator vessel 14-side openings 26i of the through holes 26c in the radial direction X1 of the cylinder 10. For example, the cylinder 10-side openings 26h and the pressure accumulator vessel 14-side openings 26i of the through holes 26c are each circular, and the center C1 of the circular openings 26i is offset from the center C2 of the circular openings 26h. Here, the center C2 of the opening 26h on the cylinder 10 side is located outside the center C1 of the opening 26i on the pressure accumulator vessel 14 side in the radial direction X1 of the cylinder 10. In other words, each through hole 26c is formed obliquely toward the inner wall 10a of the cylinder 10, and as a result, the compressed air P2 passing through the through hole 26c can be more powerfully blown toward the inner wall 10a of the cylinder 10. This allows the grease 27 to be appropriately applied to the area of ​​the inner wall 10a of the cylinder 10 where the piston portion 11 slides, allowing the piston portion 11 to operate smoothly.

[0033] 9 and 10, the through-hole 26c is an elongated hole 26j that extends in the circumferential direction S1 of the inner wall 10a of the cylinder 10. As a result, the compressed air P2 that passes through the elongated hole 26j is supplied along the inner wall 10a of the cylinder 10, allowing an appropriate amount of grease 27 to be applied to the area of ​​the inner wall 10a of the cylinder 10 where the piston portion 11 slides, allowing the piston portion 11 to operate smoothly.

[0034] 11 and 12 , a third modified example of the driving tool 1 includes a felt material 28 disposed at the upper end of the cylinder 10. The felt material 28 is, for example, ring-shaped and is fixed by being sandwiched between the nut 26 and the end of the cylinder 10. By impregnating the felt material 28 with grease 27, the grease 27 is dispersed by the compressed air P2 passing through the through-hole 26c, allowing an appropriate amount of grease 27 to be applied to the area of ​​the inner wall 10a of the cylinder 10 where the piston 11 slides. As a result, the piston 11 can operate smoothly.

[0035] 13 and 14 , a fourth modified example of a driving tool 1 includes a nut 29 that secures the pressure accumulator vessel 14 and a partition plate 30 that serves as a partition. Specifically, the nut 29 is cylindrical, and a circular partition plate 30 fitted into the nut 29 is disposed at one end of the inner wall 10a of the cylinder 10. As shown in FIG. 14 , the nut 29 is provided with a notch 29a for fitting a jig or the like. The partition plate 30 has a plurality of through holes 30a arranged along the inner wall 10a of the cylinder 10, and a circular through hole 30b that is larger than the through holes 30a, located more inward (closer to the center) than the plurality of through holes 30a.

[0036] As a result, the compressed air P2 passing through the multiple through holes 30a is supplied along the inner wall 10a of the cylinder 10, so that an appropriate amount of grease 27 can be applied to the area where the piston portion 11 slides on the inner wall 10a of the cylinder 10, allowing the piston portion 11 to operate smoothly.

[0037] The present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention. For example, the number of through-holes 26c provided in the disk portion 26a of the nut 26 is not limited to a plurality of through-holes, but at least one through-hole 26c may be provided, and the large through-hole 26e may not be provided.

[0038] Furthermore, the opening shape of the through holes 26c, 26e, 30a, and 30b is not limited to a circle, but may be a polygon such as a square.

[0039] 1... driving machine (work machine), 2... housing, 3... cylinder case, 4... motor case, 5... handle, 6... striking portion, 7... connecting portion, 8... injection portion, 9... injection passage, 10... cylinder, 10a... inner wall, 10b... flange (projection portion), 11... piston portion, 11a... X ring, 11b... slide ring, 11c... upper surface, 11d... inclined surface, 11e... lower surface, 12... piston chamber, 13... pressure chamber, 14... pressure accumulator vessel, 14a... connection end, 15... damper, 16... driver blade, 17... trigger portion, 17a... trigger switch, 18... stopper, 19... magazine, 20... electric motor, 21... output Force shaft, 22... battery, 23... controller, 24... mating member, 25... push lever, 25a... spring, 26... nut (partition portion), 26a... disk portion, 26b... cylindrical portion, 26c... through hole, 26d... wall portion, 26e... through hole, 26f... inner circumferential surface, 26g... notch portion, 26h, 26i... openings, 26j... elongated hole, 27... grease (lubricant), 28... felt material, 29... nut, 29a... notch portion, 30... partition plate (partition portion), 30a, 30b... through holes, C1, C2... center, P1, P2... compressed air, Q1... outer circumferential direction, S1... circumferential direction, X1... radial direction, Z1... up and down direction (first direction)

Claims

1. A cylindrical cylinder extending in a first direction; a pressure accumulator vessel that closes one end of the cylinder in the first direction and whose interior is in communication with the interior of the cylinder; a piston portion that is provided in the cylinder so as to be movable in the first direction, that cooperates with the cylinder and the pressure accumulator vessel to define a pressure chamber, and that applies a striking force to the stopper by moving to the other side in the first direction due to the pressure of the gas in the pressure chamber; a lubricant supply unit that is provided within the pressure accumulator container, that is disposed in an extension region that extends the cylinder in the first direction, and that supplies lubricant located within the pressure accumulator container along an inner wall of the cylinder to the piston portion.

2. The pressure storage device further includes a partition portion that separates the internal space of the cylinder from the internal space of the pressure storage vessel, The lubricant is applied to an inner wall of the cylinder, The work machine according to claim 1 , wherein the partition portion has a through hole that communicates with the internal space of the cylinder and the internal space of the pressure accumulator vessel and directs air flow passing through the partition portion toward an inner wall of the cylinder.

3. A cylindrical cylinder extending in a first direction; a pressure accumulator vessel that closes one end of the cylinder in the first direction and whose interior is in communication with the interior of the cylinder; a piston portion that is provided in the cylinder so as to be movable in the first direction, that cooperates with the cylinder and the pressure accumulator vessel to define a pressure chamber, and that applies a striking force to the stopper by moving to the other side in the first direction due to the pressure of the gas in the pressure chamber; A partition portion that separates an internal space of the cylinder from an internal space of the pressure accumulator vessel; having A lubricant is applied to the inner wall of the cylinder, The partition portion has a through hole that communicates with the internal space of the cylinder and the internal space of the pressure accumulator vessel and directs the air flow passing through it toward an inner wall of the cylinder, The through hole is provided at a position overlapping with an inner wall of the cylinder when viewed in the first direction, The partition portion has a wall portion that is positioned radially inward of the through hole.

4. The work machine according to claim 3 , wherein a plurality of the through holes are provided along an inner wall of the cylinder.

5. A cylindrical cylinder extending in a first direction; a pressure accumulator vessel that closes one end of the cylinder in the first direction and whose interior is in communication with the interior of the cylinder; a piston portion that is provided in the cylinder so as to be movable in the first direction, that cooperates with the cylinder and the pressure accumulator vessel to define a pressure chamber, and that applies a striking force to the stopper by moving to the other side in the first direction due to the pressure of the gas in the pressure chamber; A partition portion that separates an internal space of the cylinder from an internal space of the pressure accumulator vessel; having A lubricant is applied to the inner wall of the cylinder, The partition portion has a through hole that communicates with the internal space of the cylinder and the internal space of the pressure accumulator vessel and directs the air flow passing through it toward an inner wall of the cylinder, The through hole is provided on the inside of an inner wall of the cylinder in a radial direction of the cylinder, A work machine, wherein an opening of the through hole on the cylinder side is disposed outwardly of an opening of the through hole on the pressure accumulator vessel side in a radial direction of the cylinder.

6. The work machine according to claim 2 , wherein the through hole is an elongated hole extending in a circumferential direction of the inner wall of the cylinder.

7. The work machine according to claim 2 , wherein the partition portion is a nut that fixes the cylinder and the pressure accumulator vessel together.

8. The work machine according to claim 7 , wherein a protrusion is provided on an outer periphery of the cylinder, and the pressure accumulator vessel is clamped between the nut and the protrusion.