JP2014147996A - Driving machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving machine which automatically adjusts a driving depth.SOLUTION: In the case where a nail 5 is not completely driven into a wood 4 even when a piston guide 14 reaches a bottom dead center, compressed air in an accumulator 45 flows continuously, whereby the pressure in a main cylinder 10 is increased. The pressure in a return air chamber 44 is also increased, the compressed air flows into a flange upper chamber 61 through a sub-cylinder control passage 9, a sub-cylinder 32 moves downward, and a sub-cylinder upper exhaust port 27 is closed to intercept the flow of the compressed air from the accumulator 45 into the sub-cylinder 32. At the same time, a second piston lower chamber 48 and the atmosphere communicate with each other to discharge the compressed air in the sub-cylinder 32 to the outside. By the downward movement of the sub-cylinder 32, pressure joining of the sub-cylinder 32 and a piston bumper 35 is released to make the compressed air in the accumulator 45 flow into an upper chamber of a second piston 33. Consequently, the second piston 33 moves downward to push down a main piston 11 until it abuts against a bumper 7.

Description

The present invention relates to a driving machine driven by compressed air.

  FIG. 11 is a cross-sectional view of a conventional driving machine 200 that hits a stopper such as a nail using compressed air as a power source. The cylinder 210 is a cylindrical member containing the piston 211, and the main valve 219 is movable in the vertical direction, and controls the flow path between the pressure accumulation chamber 245 that stores pressure and the inner chamber of the cylinder 210.

The outline of the operation process of nailing with the driving machine 200 will be described below.
Compressed air from a compressor (not shown) is accumulated in the pressure accumulating chamber 245 via an air hose (not shown). When the operator presses the push lever 202 against the wood 204 and operates the trigger 236, the main valve 219 moves upward to leave the cylinder 210, and the pressure accumulation chamber 245 communicates with the inner chamber of the cylinder 210. At the same time, the upper part of the main valve 219 comes into contact with the inner wall of the main body to shut off the inner chamber of the cylinder 210 and the expansion chamber 246.

  The compressed air accumulated in the pressure accumulating chamber 245 flows into the upper chamber of the piston 211 in the cylinder 210, pushes down the piston 211 and drives a nail into the wood 202. As the piston 211 descends, the air compressed in the lower chamber of the piston 211 is filled into the return air chamber through a check valve 212 installed in the middle of the cylinder 210 and a return passage installed below the cylinder 210. The

  When the piston 211 further descends and passes through the check valve 212, high-pressure air in the upper chamber of the piston 211 that pushes down the piston 211 is filled from the check valve 212 into the return air chamber 244.

  The push lever 202 is configured to turn off the trigger valve section when the driving machine body 201 is raised by the reaction of driving, or when the operator releases the trigger 236 and turns off the trigger valve section, the main valve 219 is moved upward. To return to the initial position.

  The main valve 219 comes into contact with the cylinder 210 and blocks the pressure accumulating chamber 245 and the inner chamber 210a of the cylinder 210. The upper portion of the main valve 219 is separated from the inner wall of the main body, and the inner chamber of the cylinder 210 and the expansion chamber 246 are communicated.

  Therefore, the compressed air in the upper chamber of the piston 211 passes through the expansion chamber 246 and is discharged out of the driving machine main body 201. The piston 211 moves upward by the compressed air in the return air chamber 244 and returns to the initial position.

In such a driving machine, it is required to drive a stopper such as a nail into a member to be driven such as wood, and various techniques have been proposed. For example, there is a driving machine that changes the cross section of the injection hole of the stopper and forms an injection hole that matches the size of the stopper to be driven (see Patent Document 1).
JP 2009-83091 A

  By the way, the best construction state using the conventional type driving machine as described above is a state in which the nail head is indented into the wood so that it is flush with or finely aligned with the wood. For this purpose, there are techniques for adjusting the supply pressure and techniques for adjusting the movable range of the push lever at the tip of the driving machine.

  However, since the hardness of wood partially varies depending on the density of nodes and annual rings, there is a problem that the nail cannot be driven completely by a certain adjustment, or that the nail is driven too much.

  For such a problem, for example, it can be assumed that the reaction of the main body is detected by a sensor and the supply pressure of the compressed air is controlled through an arithmetic process, but the entire nail contacts the wood after the nail tip contacts the wood. The time until it is driven is only about 1 ms, and even if the supply pressure is controlled within this time, there is a possibility that the air cannot be followed because it is a compressible fluid. Furthermore, it is expensive because of sensors and arithmetic devices, and a drive power supply for that purpose must be newly prepared. Therefore, there is a part that is not practical for putting a technology for detecting recoil with a sensor into the market, and another technology has been demanded.

  This invention is made | formed in view of the above situations, Comprising: It aims at providing the technique which solves the said subject.

The present invention includes a pressure accumulating chamber for storing compressed air, a cylindrical main cylinder, a main piston capable of reciprocating in the main cylinder, a main valve for controlling communication between the pressure accumulating chamber and the main cylinder, A driving machine that drives a fastening material into a material to be fastened, and includes a second piston that applies an impact to the main piston after the fastening operation of the fastening material by the main piston.
Moreover, you may have a control means which controls on / off of the striking operation | movement of the said 2nd piston.
Further, the control means may automatically perform on / off control of the striking operation of the second piston in accordance with the moving speed of the main piston.
Further, when the second piston is operated, a space below the second piston may be communicated with outside air.
And a return air chamber for storing pressure for returning the main piston to the top dead center. After the operation of the second piston, the space where the compressed air is acting on the second piston is communicated with the outside air. The second piston may be returned to the position before the operation with the pressure stored in the return air chamber.
A sub-cylinder that slidably includes the second piston; and a pressure-receiving surface that receives a pressure of the return air chamber in a part of the sub-cylinder. The communication between the second piston upper chamber in the sub-cylinder, the communication between the sub-cylinder and the outside air of the main body, and the communication between the sub-cylinder and the pressure accumulation chamber can be controlled, and the main valve is connected to the return air chamber and the main air. Communication with the lower chamber of the main piston in the cylinder may be controllable.

  According to the present invention, it is possible to realize a driving machine that stabilizes the driving depth of the nail.

It is sectional drawing which shows the standby state of the driving machine based on this embodiment. It is sectional drawing of the driving machine which shows the state which pressed the push lever to wood based on this embodiment, and set the trigger to ON. It is sectional drawing of the driving machine which shows the state which driven the nail into the wood with low hardness based on this embodiment. It is sectional drawing of the driving machine which shows the state by which the trigger was turned off. It is sectional drawing of the driving machine which shows the state which the piston guide and the main piston returned to the initial position. It is sectional drawing of the driving machine which shows the state where the nail was not completely driven into the timber. It is sectional drawing of the driving machine which shows the state which the 2nd piston act | operated. It is sectional drawing of the driving machine which shows the state by which the trigger was turned off. It is sectional drawing of the driving machine which shows the state which the sub cylinder returned to the initial position. It is sectional drawing of the driving machine which shows the state which the piston guide and the main piston returned to the initial position. It is sectional drawing of the driving machine based on background art.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view of a driving machine 100 according to the present embodiment, and shows a state where an external compressor (not shown) is connected.

  As shown in FIG. 1, the driving machine 100 includes a driving machine main body 1 and a magazine 39. The driving machine main body 1 includes a housing 40, a main valve guide 30 disposed on the upper side of the housing 40, a sub cylinder guide 31 disposed on the upper side of the main valve guide 30, and further disposed on the upper side of the sub cylinder guide 31. The exhaust cover 34 is formed, a handle 38 formed integrally with the housing 40 and extending in a direction substantially orthogonal to the injection direction, and a nose portion 6 positioned at the lower end of the driving machine main body 1. In order to accumulate compressed air from a compressor (not shown), a pressure accumulating chamber 45 is formed inside the handle 38 and the driving machine main body 1. The pressure accumulating chamber 45 is connected to the compressor via an air hose (not shown).

  The driving machine body 1 includes a main cylinder 10, a main piston 11 that can slide up and down (reciprocate) inside the main cylinder 10, and a second piston 33 that is disposed above the main piston 11. Prepare.

  The main cylinder 10 slidably supports the main piston 11 via a piston guide 14 on the inner surface. A return air chamber 44 for storing compressed air for returning the main piston 11 to the top dead center is formed on the outer periphery of the lower end of the main cylinder 10.

  A check valve 12 is provided at a lower portion than the central portion of the main cylinder 10 in the axial direction, and an air passage that allows inflow of compressed air only in one direction from the inside of the main cylinder 10 to the outside return air chamber 44. Is formed. A return passage 8 that is always open to the return air chamber 44 is formed below the main cylinder 10. Furthermore, a cylindrical driver blade 56 that strikes the nail is integrally formed at the tip of the main piston 11, and the lower end of the main cylinder 10 receives the surplus energy of the main piston 11 after the nail is driven. A bumper 7 for absorption is provided.

  A trigger 36 operated by an operator is provided at a connection portion of the handle 38 with the driving machine main body 1. As is well known, when both the pulling operation of the trigger 36 and the pressing operation of the push lever 2 against the wood 4 are performed, the plunger of the trigger valve portion is pushed up by the link mechanism connected to the trigger 36. It is configured.

  On the outer periphery of the main piston 11, a hollow cylindrical piston guide 14 is installed. On the inner diameter of the piston guide 14, a small inner diameter portion 14a is formed on the upper side, and a large inner diameter portion 14b is formed on the lower side. About the upper half of the main piston 11 is accommodated in the small inner diameter portion 14a and the large inner diameter portion 14b. The upper end portion of the main piston 11 is attached to the upper end portion of the inner diameter of the piston guide 14 via an O-ring.

  The small inner diameter portion 14a is formed slightly larger than the outer shape of the upper portion of the main piston 11 to be accommodated. That is, the small inner diameter portion 14a and the upper portion of the main piston 11 are slightly separated from each other. Further, the large inner diameter portion 14 b substantially coincides with the outer diameter of the main piston flange portion 49 formed at a substantially central portion of the upper portion of the main piston 11.

  Similarly, the outer diameter of the piston guide 14 is formed with a small outer diameter portion 14c and a large outer diameter portion 14d.

  The main piston 11 is provided with a main piston flange portion 49 at a position about ¼ of the upper side here. An O-ring is disposed on the outer peripheral surface of the main piston flange portion 49, and the main piston flange portion 49 and the large inner diameter portion 14b are sealed.

  The main piston flange portion 49 is guided by the large inner diameter portion 14 b of the piston guide 14. The upper portion of the main piston 11 is guided by the small inner diameter portion 14a of the piston guide 14 and is slidable in the axial direction.

  In the state where the upper end surface of the main piston 11 is aligned with the upper end surface of the piston guide 14 as shown in FIG. 1, the inner diameter step surface 14e at the boundary between the small inner diameter portion 14a and the large inner diameter portion 14b is the main piston flange portion. It is separated from the upper surface of 49 by a predetermined distance. The main piston 11 can be relatively slid within the piston guide 14 by this distance. The sliding operation will be described later.

  The main cylinder 10 is formed such that the upper part is a large diameter part 10a and the lower part is a small diameter part 10b.

  The piston guide 14 is guided by the small diameter portion 10b of the main cylinder 10 and can be slid toe-legged in the axial direction.

  A second piston 33 is installed above the piston guide 14 and the main piston 11, and the outer periphery is guided by a cylindrical sub-cylinder 32 installed outside the second piston 33. The second piston 33 slides in the axial direction. It is possible to move.

  The sub-cylinder 32 is slidable in the axial direction with its lower portion guided by the large-diameter portion 10a of the main cylinder 10 and its upper portion guided by the sub-cylinder guide 31 respectively.

  The sub-cylinder 32 is formed with a large-diameter flange portion 42 and a small-diameter flange portion 43. The large-diameter flange 42 and the small-diameter flange 43 are each provided with an O-ring on the outer peripheral surface. The large-diameter flange 42 contacts the inner surface of the large-diameter flange lower chamber 29 of the sub-cylinder guide 31, and the small-diameter flange 43 is a small-diameter flange. It is in contact with the inner surface of the lower chamber 28.

  An upward force obtained by the formula (area difference between both flange portions) × (pressure in the large-diameter flange lower chamber 29) acts on the sub cylinder 32.

  A slit 53 that is a notch is formed in a part of the sub cylinder 32 in the axial direction. Specifically, the slit 53 is formed so as to extend from the upper end to the sub cylinder upper exhaust port 27 described later on the inner diameter of the sub cylinder 32.

  A sub cylinder spring 13 is installed below the sub cylinder 32. More specifically, the lower portion of the sub-cylinder spring 13 is disposed in a predetermined arrangement portion formed at the boundary between the large-diameter portion on the inner diameter upper side of the main cylinder 10 and the lower-diameter portion on the lower side. Is in contact with the lower end of the sub cylinder 32. The sub cylinder 32 is urged by a cylinder plate 41 provided at the upper end of the sub cylinder guide 31.

  The pressure accumulating chamber 45 and the large-diameter flange lower chamber 29 communicate with each other through a sub-cylinder guide intermediate hole 50 provided in the sub-cylinder guide 31.

  A sub cylinder upper exhaust port 27 is provided in an intermediate portion of the sub cylinder 32. In the state of this figure, the main valve 19 blocks the pressure accumulating chamber 45 and the inner side of the sub cylinder 32.

  A sub cylinder lower exhaust port 26 is provided below the sub cylinder upper exhaust port 27. In the state of FIG. 1, the second exhaust port 24 and the inside of the sub cylinder 32 communicate with each other.

  A sub cylinder exhaust port 17 is provided below the sub cylinder lower exhaust port 26. In the state of the figure, the cylinder 11 blocks the first exhaust port 15 and the sub cylinder 32 from the inside.

  The upper portion of the sub cylinder 32 is in pressure contact with the outer peripheral surface of the piston bumper 35. Moreover, the upper chamber of the pressure accumulation chamber 45 and the second piston 33 is shut off. As will be described later, when the sub cylinder 32 moves in the axial direction, the communication between the accumulator 45 and the upper chamber of the second piston 33 is selectively switched, whereby the striking operation of the second piston 33 is controlled on / off. Is done. In the present embodiment, the sub-cylinder 32 and the configuration for controlling the movement of the sub-cylinder 32 in the axial direction correspond to the “control unit” of the present invention.

  A main valve 19 is installed outside the intermediate portion of the sub cylinder 32. A main valve rubber 20 is integrally formed at the top.

  A valve spring 22 is installed below the main valve 19. The valve spring 22 biases the main valve 19 upward.

  A main valve lower chamber 21 is formed below the main valve 19, and is connected to a valve portion of the trigger 36 by a main valve control passage 37. Since the configuration is the same as that of the conventional driving machine, details are omitted. However, when the trigger 36 is OFF, the main valve lower chamber 21 and the pressure accumulating chamber 45 communicate with each other. When the trigger 36 is turned ON, the main valve lower chamber 21 and the atmosphere And communicate.

  A main valve guide hole 52 is provided in the main valve guide 30. In the state shown in the drawing, the pressure accumulation chamber 45 and the inner side of the sub cylinder 32 are blocked by the main valve 19.

  A main valve side chamber 23 is installed on the outer peripheral surface of the main valve 19. In the state of this figure, both the return passage 8 and the sub cylinder control passage 9 are coupled to the main valve side chamber 23.

  One end of the return passage 8 is connected to the main piston lower chamber 47 near the bumper 7 through the housing. One end of the sub cylinder control passage 9 is connected to a flange upper chamber 61 between the large diameter flange 42 and the cylinder plate 41 through a sub cylinder guide upper hole 51.

  FIG. 2 shows the driving machine 100 in a state where the push lever 2 of FIG. 1 is pressed against the wood 4 and the trigger 36 is turned on. The compressed air charged in the main valve lower chamber 21 is released from the main valve control passage 37 to the atmosphere. At the same time, the main valve 19 moves downward against the valve spring 22 by the pressure of the pressure accumulating chamber 45 on the upper surface of the main valve 19.

  Therefore, the pressure accumulating chamber 45 and the second piston lower chamber 48 are in communication with the main valve guide hole 52, the space on the upper surface of the main valve 19 (valve rubber 20), and the sub-cylinder upper exhaust port 27. The compressed air in the pressure accumulating chamber 45 passes through the main valve guide hole 52 and the sub cylinder upper exhaust port 27 and flows into the sub cylinder 32 as indicated by an arrow.

  The second piston lower chamber 48 and the return air chamber 44 are not in communication with each other, and the flange upper chamber 61 that is a space between the large-diameter flange 42 and the cylinder plate 41 and the atmosphere are not in communication.

  FIG. 3 is a cross-sectional view showing the driving machine 100 in a state where nails are driven into low-hardness wood. The piston guide 14 is lowered by the compressed air in the sub-cylinder 32, and the inner diameter of the piston guide 14 is large. Part 14b and main piston flange part 49 engage to move main piston 11 downward, and nail 5 is driven completely into the wood.

  At the same time, the air in the main piston lower chamber 47 flows into the return air chamber 44 from the check valve 12, and when the small inner diameter portion 14 a of the piston guide 14 reaches the check valve 12, the compressed air in the sub cylinder 32 returns. The return air chamber 44 is filled with compressed air that flows into the air chamber 44 and returns the main piston 11. At this time, the second piston lower chamber 48 and the return air chamber 44 are in communication with each other via the check valve 12.

  In the case of wood with low hardness, nailing is completed as described above, and the driving machine main body 1 moves upward by reaction. Immediately after this, since the main valve 19 is closed by the return of the push lever 2 to the initial position, the flow of compressed air from the sub cylinder 32 into the return air chamber 44 is slight.

  The pressure of the return air chamber 44 acts on the large diameter flange 42 of the sub cylinder 32 through the return passage 8, but the area ratio of the large diameter flange 42 and the small diameter flange 43 prevents the sub cylinder 32 from moving downward at the pressure. Is set.

  FIG. 4 is a sectional view showing a state of the driving machine 100 in which the push lever 2 is separated from the wood 4 and the trigger 36 is turned off. The main valve lower chamber 21 is filled with compressed air, and the main valve 19 is moved upward. Moving.

  The sub-cylinder lower exhaust port 26 communicates with the second exhaust port 24, and the compressed air in the sub-cylinder 32 is discharged out of the driving machine main body 1. That is, the second piston lower chamber 48 communicates with the atmosphere.

  The return passage 8 and the sub-cylinder control passage 9 are joined by the main valve side chamber 23, and the compressed air filled in the return air chamber 44 flows into the main piston lower chamber 47. Further, since the valve rubber 20 contacts the lower end of the sub cylinder guide 31 and the sub cylinder upper exhaust port 27 is closed, the pressure accumulating chamber 45 and the second piston lower chamber 48 are in a non-communication state.

  FIG. 5 is a cross-sectional view showing the driving machine 100 in which the piston guide 14 and the main piston 11 are returned to the initial positions by the compressed air flowing into the main piston lower chamber 47, and is the same state as FIG. 1 in the standby state. .

  Next, the operation will be described for the case of hard wood. The operation in the case of wood with high hardness is the same as that shown in FIGS. 1 and 2 in the initial stage of the operation. The description is omitted here.

  FIG. 6 is a cross-sectional view showing the driving machine 100 in a state where the nail 5 is not completely driven into the wood 4 even when the piston guide 14 reaches the bottom dead center.

  At this time, although the descending speed of the main piston 11 is reduced or stopped, the compressed air continues to flow into the main cylinder 10 from the pressure accumulating chamber 45, so that the pressure in the main cylinder 10 increases.

  Since the main cylinder 10 communicates with the return air chamber 44 by the check valve 12, the pressure of the return air chamber 44 also increases, and the upper surface of the large-diameter flange portion 42 and the cylinder plate 41 pass through the sub cylinder control passage 9. Compressed air flows into the flange upper chamber 61 therebetween. As a result, the sub cylinder 32 moves downward against the force of the sub cylinder spring 13 urging the sub cylinder 32 upward.

  By moving the sub cylinder 32 downward, the sub cylinder upper exhaust port 27 is closed, and the flow of compressed air from the pressure accumulation chamber 45 into the sub cylinder 32 is blocked. At the same time, the sub-cylinder exhaust port 17 communicates with the first exhaust port 15 so that the second piston lower chamber 48 communicates with the atmosphere, and the compressed air in the sub-cylinder 32 is discharged out of the driving machine body 1.

FIG. 7 is a cross-sectional view showing the driving machine 100 in a state where the second piston 33 is operated.
Due to the downward movement of the sub cylinder 32, the pressure bonding between the upper portion of the sub cylinder 32 and the piston bumper 35 is released, and the compressed air in the pressure accumulating chamber 45 flows into the upper chamber of the second piston 33.

  As a result, the second piston 33 is lowered and pushed down until the main piston 11 contacts the bumper 7. Thereby, the main piston 11 can hit the nail 5 additionally and drive it into the hard wood 4. The nailing is completed as described above, and the driving machine main body 1 moves upward by reaction. As described above, when the hardness of the wood 4 (member to be fastened) is high and the force received by the driver blade 56 from the wood 4 exceeds a predetermined value, the moving speed of the main piston 11 decreases, and the inside of the main cylinder 10 and the return air chamber during the driving operation The pressure in 44 increases. The sub cylinder 32 is driven in accordance with the degree of pressure increase in the main cylinder 10 and the return air chamber 44. That is, the striking operation of the second piston 33 is automatically controlled on / off according to the moving speed of the main piston 11. Thereby, the second piston 33 operates when the force from the fastened member becomes a predetermined value or more.

  FIG. 8 is a cross-sectional view showing the driving machine 100 in a state in which the push lever 2 is separated from the wood 4 and the trigger 36 is turned off. The main valve lower chamber 21 is filled with compressed air, and the main valve 19 is moved upward. Moving.

  The sub-cylinder upper exhaust port 27 communicates with the second exhaust port 24, and the compressed air in the sub-cylinder 32 is discharged out of the driving machine main body 1.

  The return passage 8 and the sub cylinder control passage 9 are communicated with each other by the main valve side chamber 23, and the compressed air filled in the return air chamber 44 flows into the main piston lower chamber 47. As a result, the main piston 11 and the piston guide 14 start to move upward.

  FIG. 9 is a cross-sectional view showing the driving machine 100 in a state where the pressure applied to the large-diameter flange 42 is reduced by reducing the pressure of the return air chamber 44 and the sub cylinder 32 is returned to the initial position.

  The sub cylinder upper exhaust port 27 is closed, the sub cylinder lower exhaust port 26 continues to communicate with the second exhaust port 24, and the compressed air in the sub cylinder 32 is discharged out of the driving machine body 1.

  FIG. 10 is a sectional view showing the driving machine 100 in a state where the piston guide 14 and the main piston 11 are returned to the initial positions by the compressed air flowing into the main piston lower chamber 47.

  Slightly remaining air in the upper chamber of the second piston 33 passes through the slit 53 and moves below the second piston 33 and is discharged from the sub-cylinder lower exhaust port 26. Thus, the driving machine 100 is in the same state as FIG.

  As described above, in the case of wood having low hardness, it is possible to prevent the nail 5 from being driven excessively by hitting with only the main piston 11. On the other hand, in the case of wood with high hardness, it is possible to drive the nail 5 completely by striking and adding with the second piston 33. Since the sub cylinder 18 descends due to the relative pressure difference between the pressure accumulation chamber 45 and the return air chamber 44, the sub cylinder 18 can be stably operated without being influenced by the supply pressure. That is, the above-described driving machine 100 can stabilize the driving depth even if the hardness of the wood 4 changes, and can adjust the supply pressure of the compressed air even when the nodes of the wood 4 are mixed. The desired work can be done without the

  The present invention has been described based on the embodiments. This embodiment is an exemplification, and it is understood by those skilled in the art that various modifications can be made to combinations of the respective components and the like, and such modifications are within the scope of the present invention.

  In the above-described embodiment, the control means controls the hitting operation of the second piston 33 according to the moving speed of the main piston so that the second piston 33 operates in a state where the nail 5 is not driven completely. It is excellent in that the driving depth of the nail 5 can be automatically adjusted as described above. On the other hand, it is possible to provide a switching means that allows the operator to switch on and off the control means so that the operator can select a mode in which the second piston 33 always operates and a mode in which the second piston 33 does not always operate. . Thereby, for example, when it is important to prevent the nail 5 from being driven excessively, the second piston 33 can be prevented from operating regardless of the driving state of the nail 5. Further, in the case where emphasis is placed on reliably driving the nail 5, the second piston 33 can be operated without fail regardless of the driving state of the nail 5. Further, the switching means can switch the control means to the three modes “ON”, “OFF”, and “AUTO”. In the “automatic” mode, the switching means is disposed at a position that does not interfere with the control means, and the driving machine operates in the same manner as in the above-described embodiment.

DESCRIPTION OF SYMBOLS 1 Driving machine main body 2 Push lever 3 Push lever spring 4 Wood 5 Nail 6 Nose 7 Bumper 8 Return passage 9 Sub cylinder control passage 10 Main cylinder 10a Large diameter portion 10b Small diameter portion 11 Main piston 12 Check valve 13 Sub cylinder spring 14 Piston guide 14a Small inner diameter portion 14b Large inner diameter portion 14c Small outer diameter portion 14d Large outer diameter portion 14e Inner diameter step surface 15 First exhaust port 16 Cylinder exhaust port 17 Sub cylinder exhaust port 18 Sub cylinder 19 Main valve 20 Valve rubber 21 Main valve Lower chamber 22 Valve spring 23 Main valve side chamber 24 Second exhaust port 25 Main valve exhaust port 26 Sub cylinder lower exhaust port 27 Sub cylinder upper exhaust port 28 Small diameter flange lower chamber 29 Large diameter flange lower chamber 30 Main valve guide 31 Sub cylinder Guide 32 sub Linda 33 Second piston 34 Exhaust cover 35 Piston bumper 36 Trigger 37 Main valve control passage 38 Handle 39 Magazine 40 Housing 41 Cylinder plate 42 Large diameter flange 43 Small diameter flange 44 Return air chamber 45 Accumulation chamber 47 Main piston lower chamber 48 Second piston lower chamber 49 Main piston flange 50 Sub cylinder guide intermediate hole 51 Sub cylinder guide upper hole 52 Main valve guide hole 53 Slit 56 Driver blade 61 Flange upper chamber 100 Driving machine

Claims (6)

A pressure accumulating chamber for storing compressed air, a cylindrical main cylinder, a main piston capable of reciprocating in the main cylinder, a main valve for controlling communication between the pressure accumulating chamber and the main cylinder, and a predetermined fastening material A driving machine for driving a fastening material,
A driving machine comprising: a second piston that strikes the main piston after the fastening operation of the fastening material by the main piston.   The driving machine according to claim 1, further comprising a control unit that performs on / off control of a hitting operation of the second piston.   3. The driving machine according to claim 2, wherein the control unit automatically performs on / off control of a hitting operation of the second piston in accordance with a moving speed of the main piston.   The driving machine according to any one of claims 1 to 3, wherein when the second piston is operated, a space below the second piston is communicated with outside air. A return air chamber for storing pressure for returning the main piston to top dead center;
After the operation of the second piston, the space where the compressed air is acting on the second piston is communicated with the outside air, and the second piston is returned to the position before the operation by the pressure stored in the return air chamber. The driving machine according to any one of claims 1 to 4, wherein: A sub-cylinder slidably including the second piston;
A pressure receiving surface that receives the pressure of the return air chamber in a part of the sub-cylinder;
Have
The sub-cylinder is capable of controlling communication between the pressure accumulation chamber and a second piston upper chamber in the sub-cylinder, communication between the sub-cylinder and main body outside air, and communication between the sub-cylinder and the pressure accumulation chamber, 2. The driving machine according to claim 1, wherein the main valve can control communication between the return air chamber and a main piston lower chamber in the main cylinder.

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