JP4964624B2 - Driving machine - Google Patents

Description

  The present invention relates to a driving machine that operates using compressed air as a driving source, such as a nailing machine or a screw driving machine.

For example, an air-driven nailing machine includes a main body that includes a piston and a cylinder that reciprocate with compressed air, and a handle that is provided so as to protrude sideways from the main body. A driver guide as a launch port to be ejected is provided in a protruding state. Further, a trigger type switch lever that is operated by a user with a fingertip and a trigger valve that is operated to open and close the cylinder on the main body side are provided at the base of the normal handle portion. When the user pulls the switch lever with his fingertip, the trigger valve is turned on and compressed air is supplied to the cylinder of the main body, whereby the piston moves down and one nail supplied into the driver guide is released. It is hit by a driver and launched.
A contact arm is usually provided at the tip of the driver guide. This contact arm is mainly for preventing malfunction of the driving machine, and can be moved between an off position protruding from the tip of the driver guide by a certain dimension and an on position aligned with the tip, and normally on the off position side. Spring biased. The switch lever pulling operation is effective and the nail is driven out only in the ON state in which the tip of the driver guide as the launch port is pressed against the driving position and the contact arm is moved backward (upward) to the ON position. (Malfunction prevention mechanism).

Various mechanisms have been provided for the malfunction prevention mechanism. For example, in the malfunction prevention mechanism disclosed in Patent Document 1 below, the contact arm is extended along the driver guide toward the main body (upward), and the upper end thereof is connected to the back side of the switch lever (trigger valve side). It is the structure located in the lower surface side of the upper end part of the idler provided in. According to such a conventional configuration, when the contact arm is moved upward and the upper end of the idler is moved by pushing the upper end of the idler to the trigger valve side (upward) and the switch lever is pulled in this state, the idler further moves upward. Then, the valve stem of the trigger valve moves to the on position. When the valve stem is pushed into the on position and the trigger valve is turned on, compressed air is supplied to the cylinder of the main body, and a driving operation is performed.
On the other hand, in the off state where the contact arm is not moved up, the upper end of the idler is not moved to the trigger valve side (upward) by the upper end, so even if the switch lever is pulled in this state, the idler As a result of the insufficient amount of movement, the amount of movement of the valve stem to the on side is insufficient, and therefore the trigger valve is not turned on, so that the driving operation in the main body is not performed.
Patent Document 2 below discloses a configuration in which an intermediate inclusion is disposed between the upper end of a contact arm that extends to the vicinity of the switch lever and the upper end of an idler. According to such a configuration, when the contact arm is moved upward and the intermediate inclusion is pushed by the upper end portion and moved to the operating position side, the upper part of the idler is moved to the valve stem side of the trigger valve by the intermediate inclusion. When the switch lever is pulled with, the idler moves further and the valve stem is pushed to the on position side. When the valve stem is pushed to the on position side, the trigger valve is activated, compressed air is supplied to the cylinder of the main body, and a nail driving operation is performed.
On the other hand, when the contact arm is not moved up, the intermediate inclusion has not moved to the operating position side, so the upper end of the idler has not moved to the valve stem side. Even if the pulling operation is performed, the amount of movement of the idler is insufficient. As a result, the amount of movement of the valve stem to the on side is insufficient, and therefore the trigger valve is not turned on, so that the driving operation in the main body is not performed.
Japanese Patent No. 3670182 Japanese Patent No. 2727960

The conventional malfunction prevention mechanism configured as described above has the following problems. The contact arm is operated to move upward (ON operation) relative to the driver guide when the user presses the driving device against the driving position (for example, the wall side). In this on state, as described above, the upper end of the idler pushes the upper end of the idler to the trigger valve side directly or through an intermediate inclusion, thereby pushing the valve stem of the trigger valve to the on side. . When the trigger is pulled in this state, the idler further moves to move the valve stem to the on position. Normally, the valve stem is biased to the off position side by the spring force of the compression spring or the pressure of the compressed air.
For this reason, when the contact arm is moved upward and then the switch lever is pulled toward the on position, the urging force of the valve stem is strengthened, and this acts directly on the contact arm via the idler as an external force toward the off position. Since this external force acts in the direction of lifting the driving machine main body from the driving material (reactions are received), the user needs to press the driving machine main body in the driving direction with a correspondingly large force. The operability of the driving machine was impaired.
The present invention has been made to solve such a conventional problem, and the urging force of the valve stem to the off position side does not act on the contact arm or greatly reduces it, thereby reducing the reaction at the time of operating the switch lever. The purpose is to improve the operability of the driving machine.

For this reason, this invention was set as the driving device of the structure described in each claim of a claim.
According to the driving machine of the first aspect, when the driving machine main body is pressed to the driving position and the contact arm is held in the on position, the intermediate member is held in the motion transmitting position and the movement of the idler is restricted. When the switch lever is pulled after this restricted state, the idler moves by a sufficiently large distance, and the valve stem of the trigger valve is pushed to the on position against its biasing force. When the valve stem moves to the on position, the trigger valve is turned on and a driving operation is performed in the driving machine body.
Further, the intermediate member is brought into contact with the contact arm in the state of being moved to the ON position from the lateral direction (direction orthogonal to the moving direction of the contact arm, or obliquely forward or obliquely rearward) and held at the operation transmission position. Therefore, the urging force of the valve stem applied to the intermediate member via the idler is the urging force in the moving direction with respect to the contact arm. Therefore, the force acting on the contact arm as an external force in the moving direction is mainly the spring biasing force that biases the contact arm directly to the off position side.
In this way, the urging force of the valve stem applied to the contact arm toward the off position can be eliminated or greatly reduced, so that the reaction of the driving machine body during the switch lever pulling operation can be eliminated or reduced. Thus, the burden on the user can be reduced and the operability of the driving machine can be improved.
Further, according to the driving machine of claim 1, the contact arm advances and retreats between a position (ON position) where the movement of the intermediate member to the operation blocking position (ON position) and a position (OFF position) where the contact member is not controlled by the upper end portion thereof. Therefore, a smaller stroke is sufficient as compared with a case where a part of the movement amount necessary for the idler is secured by the stroke of the contact arm. For this reason, according to the structure of Claim 1, the required stroke of a contact arm can be made smaller than before. Since the stroke to the ON position of the contact arm, that is, the projecting dimension from the tip (launch port) of the driver guide in the OFF position can be reduced, the user can make the tip of the driver guide higher than the driving position. Positioning can be performed with high accuracy, and as a result, more accurate driving can be performed efficiently.
According to the configuration of the second aspect, the intermediate member is pivotally supported, and the intermediate member is fixed at the motion transmission position by moving the contact arm into the movement path of the restricting arm portion, and held in this fixed state. The movement of the idler is restricted by the arm portion, and the valve stem can be moved to the ON position by pulling the switch lever in this restricted state. In a state where the contact arm has entered the movement path of the restriction arm, the movement path of the restriction arm and the movement path of the contact arm intersect each other, so that the restriction arm part is transverse to the movement direction of the contact arm ( The contact is made from the substantially orthogonal direction. For this reason, as described above, the biasing force to the off position side of the valve stem applied to the intermediate member via the idler can be prevented from being applied as an external force in the moving direction to the contact arm. Accordingly, the urging force of the contact arm toward the off position side can be reduced to suppress or eliminate the reaction of the driving machine main body during the switch lever pulling operation.

Next, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a driving machine 1 according to the present embodiment. In the present embodiment, as the driving machine 1, a compressed air type nailing machine that operates using compressed air as a drive source is illustrated. A screwdriver can be provided as well. Moreover, in this specification, it uses for description of each structure and member by making the direction into which a driving tool is driven down.
The driving machine 1 includes a main body 2, a handle 3, and a magazine 4. The main body 2 is internally provided with a piston and a cylinder that are driven into a driving material by hitting a driving tool (nail). A driver for hitting the driving tool is attached to the piston. This driver moves in a driver guide 5 provided in a state of protruding from the lower surface of the main body 2. One driving tool is supplied into the driver guide 5 one by one.
The intake and exhaust of compressed air into the cylinder is performed by opening and closing a head valve (not shown) that is also housed in the main body 2. The head valve is opened and closed by an on / off operation of a trigger valve 10 described later. The main body 2 has a conventionally known configuration and does not require any particular change in the present embodiment, but will be briefly described below. When the head valve is opened, compressed air is supplied to the upper surface side (cylinder upper chamber) of the piston. As a result, the piston is moved downward, whereby the driver moves and the driving tool is driven out from the tip of the driver guide 5. When the head valve is closed, the cylinder upper chamber is opened to the atmosphere, and the piston is returned to the top dead center. In this way, intake and exhaust to the cylinder upper chamber is performed by opening and closing the head valve, and this head valve is opened when a trigger valve 10 described later is turned on and closed when turned off.
The handle portion 3 is provided in a state of protruding from the side portion of the main body portion 2 to the side. In the handle portion 3, there is provided a pressure accumulating chamber 3a in which compressed air supplied from the outside via an air hose 3b is accumulated. The compressed air accumulated in the pressure accumulating chamber 3 a of the handle portion 3 is supplied to the main body portion 2. The trigger valve 10 is arranged at the base part of the handle part 3 (near the joint part with the main body part 2). The trigger valve 10 is also turned on and off using the compressed air in the handle portion 3 as a part of the drive source.
A magazine 4 is placed between the driver guide 5 of the main body 2 and the tip of the handle portion 3 in a spanning state. A large number of driving tools are accommodated in the magazine 4 while being held in parallel with each other. A large number of driving tools are supplied one by one into the driver guide 5 by a feed mechanism interlocked with the main body 2 side.

A detection arm portion 6 a of the contact arm 6 is disposed at the distal end portion (lower end portion) of the driver guide 5. The contact arm 6 includes a detection arm portion 6 a and an operation arm portion 6 b that extends upward along the driver guide 5. The upper end side of the operating arm portion 6 b reaches the vicinity of the trigger switch lever 20 provided to face the trigger valve 10. The operation arm portion 6b is supported by a support base portion 2a provided on the side portion of the main body portion 2 so as to be slidable in the vertical direction.
The detection arm portion 6a and the operation arm portion 6b of the contact arm 6 move integrally in the vertical direction. The detection arm 6 a is positioned in a state surrounding the periphery of the tip of the driver guide 5. The detection arm portion 6a has an off position that protrudes from the tip portion by a small dimension with respect to the position in the axial direction of the driver guide 5 (the driving direction, the vertical direction in FIG. 1), and an on position that is aligned with the tip portion of the driver guide 5. It is provided to be movable between.
Further, the contact arm 6 is biased to the off position side (downward in FIG. 1) by the compression spring 7. For this reason, the contact arm 6 moves to the ON position against the compression spring 7. The relative movement of the contact arm 6 with respect to the driver guide 5 to the ON position is such that the user pushes down the main body 2 toward the driving position of the driving material W and drives the tip end (launching port) of the driver guide 5 to the driving position. It is made by hitting. Therefore, the user pushes down the main body 2 toward the driving position against the spring biasing force of the compression spring 7 that biases the contact arm 6 directly toward the off position. In the driving machine 1 according to the present embodiment, the necessary stroke from the OFF position to the ON position of the contact arm 6 (the pressing stroke of the main body 2) is set to be much smaller than the conventional stroke. This point will be described later.
The contact arm 6 has a foolproof function (malfunction prevention mechanism F) for preventing the main body 2 from malfunctioning even when the switch lever 20 is inadvertently operated as in the prior art. Hereinafter, the malfunction prevention mechanism F will be described. Details of this malfunction prevention mechanism F are shown in FIG.

As described above, the trigger valve 10 is disposed at the base of the handle portion 3, and the trigger type switch lever 20 is disposed below the trigger valve 10. The switch lever 20 is rotatably supported on the side of the main body 2 via a support shaft 21. An idler 22 is supported on the back surface of the switch lever 20 via a support shaft 23 so as to be rotatable up and down. The idler 22 is urged in a direction approaching the trigger valve 10 (clockwise direction in the drawing) by a torsion spring 24 interposed around the support shaft 23. The valve stem 11 of the trigger valve 10 is always abutted against the idler 22.
The idler 22 is urged clockwise by a torsion spring 24, and the valve stem 11 always urged toward the protruding side is abutted against the idler 22 as described later, so that the switch lever 20 is indirectly connected. It is urged in the clockwise direction (off position side) shown in FIG. As shown in FIG. 2, when the switch lever 20 is in the off position (clockwise rotation end position in the drawing), the stopper portion 20a of the switch lever 20 contacts the lower surface (right side surface in the drawing) of the support base portion 2a. It is regulated by.
The trigger valve 10 having a conventionally known configuration is used and is not particularly required to be changed in the present embodiment, but will be briefly described below. The trigger valve 10 includes a rod-shaped valve stem 11, a first valve body 12, and a second valve body 13. The first valve body 12 is fixed to the base portion of the handle portion 3. A second valve body 13 is supported on the inner peripheral side of the first valve body 12 so as to be movable in the vertical direction in the figure. The valve stem 11 is supported so as to be movable in the axial direction (the vertical direction in the figure) in a state of straddling between the first valve body 12 and the second valve body 13.

The valve stem 11 is urged in a direction (off position side) in which the tip end protrudes downward from the first valve body 12 by a compression spring 14 interposed between the rear end portion and the second valve body 13. . Further, a vent hole 13 a is provided at the rear end portion of the second valve body 13. The stem upper chamber 16 (the space around the compression spring 14) in the second valve body 13 is always in communication with the atmosphere via the vent hole 13a and the exhaust passage 3e.
When the valve stem 11 moves to the on position side against the spring biasing force to the off position side by pulling the switch lever 20, the first seal ring 11a is detached from the first valve body 12 as shown in FIG. Thus, the first variable pressure chamber 15 formed between the first valve body 12 and the second valve body 13 and thus the lower surface side of the second valve body 13 are opened to the atmosphere. On the other hand, the compressed air of the pressure accumulating chamber 3a acts on the upper surface side of the second valve body 13 through the air supply holes 3c. For this reason, when the first variable pressure chamber 15 is opened to the atmosphere, the second valve body 13 moves downward. This state is shown in FIG. When the second valve body 13 is moved downward in this manner, the second variable pressure chamber 18 is shut off from the pressure accumulating chamber 3a side by the seal ring 13b, while the seal ring 13c is removed from the inner peripheral surface of the first valve body 12, thereby It communicates with the atmosphere via 3e. When the second variable pressure chamber 18 is opened to the atmosphere, the head valve upper surface side of the main body 2 is opened to the atmosphere via the intake / exhaust passage 3d. On the other hand, since the compressed air of the pressure accumulating chamber 3a is constantly acting on the lower face side of the head valve, when the second variable pressure chamber 18 is opened to the atmosphere, the head valve moves upward and the cylinder upper chamber becomes the pressure accumulating chamber 3a. Open against. When the cylinder upper chamber is opened and compressed air flows in, the piston moves down and the driving tool is driven out.
When the valve stem 11 is returned to the off position by the urging force, the first variable pressure chamber 15 is shut off from the atmosphere and communicated with the pressure accumulating chamber 3a so that compressed air flows into the first variable pressure chamber 15. The compressed air that has flowed into the first variable pressure chamber 15 acts on the lower surface side of the second valve body 13 to move the second valve 13 upward. When the second valve body 13 moves upward, the second variable pressure chamber 18 is shut off from the atmosphere by the seal ring 13c, while compressed air is supplied to the second variable pressure chamber 18. When compressed air is supplied to the second variable pressure chamber 18, this acts on the upper surface side of the head valve via the intake / exhaust passage 3d. When compressed air acts on the upper surface side of the head valve, the head valve is closed and the cylinder upper chamber is opened to the atmosphere, whereby the piston is returned to the top dead center.
Thus, the second valve body 13 is moved up and down by the movement of the valve stem 11 to the on position and the off position, whereby the second variable pressure chamber 18 is sucked and exhausted, and the upper surface side of the head valve is opened to the atmosphere. The state is switched to a state in which compressed air acts.
The valve stem 11 is moved to an on position and an off position by an on / off operation of the switch lever 20. The switch lever 20 is turned on when the user pulls the switch lever 20 upward with a fingertip (rotates counterclockwise in the drawing).

Next, the intermediate member 30 is rotatably supported independently of the switch lever 20 on the support shaft 21 that rotatably supports the switch lever 20 with respect to the main body 2. The intermediate member 30 includes two arm portions 31 and 32 extending in the radial direction at an interval of about 90 ° from each other. In FIG. 2, the arm portion 31 extending downward extends toward the operating arm portion 6 b side of the contact arm 6. Hereinafter, this arm portion 31 is referred to as a restriction arm portion 31. The length of the restriction arm portion 31 is set appropriately. As shown in FIG. 2, the length of the restricting arm 31 is such that the contact arm 6 is located at the off position, and therefore the operating arm 6b is located on the lower side and the protruding amount from the support pedestal 2a is small. In the state where the operating arm portion 6b does not reach and the contact arm 6 is moved up to the on position and the operating arm portion 6b is located at the upper on position as shown by a solid line in FIG. The length is set so as to abut (overlap) the side portion of 6b. In FIG. 3, the upper end of the operating arm portion 6 b located at the off position is indicated by a two-dot chain line.
When the restriction arm 31 of the intermediate member 30 is brought into contact with the operation arm portion 6b of the contact arm 6 from the lateral direction (substantially orthogonal direction), the rotation of the intermediate member 30 toward the operation blocking position is restricted. Therefore, the intermediate member 30 is held at the motion transmission position.
Thus, the required stroke L between the OFF position and the ON position of the contact arm 6 is such that the operating arm portion 6b moves to the OFF position side of the regulating arm portion 31 of the intermediate member 30 (to the left side in FIG. 2). And a position where the intermediate member 30 is prevented from rotating toward the OFF position (on position indicated by a solid line in FIG. 3), and a position where the rotating operation is allowed (FIG. 3). In this case, the dimension is set to a dimension sufficient to move between the two positions indicated by a two-dot chain line in FIG. For this reason, in this embodiment, the movement amount of the contact arm 6 is sufficient with a very small stroke L as compared with a configuration in which a part of the total movement amount of the idler is compensated by the movement of the contact arm. In the driving machine 1 according to the present embodiment, the movement amount of the contact arm 6 does not contribute to the movement amount of the idler 22.
On the other hand, the arm portion 32 that extends to the right in FIG. 2 extends toward the tip of the idler 22. Hereinafter, this arm portion 32 is referred to as a holding arm portion 32. As shown in the figure, the length of the holding arm portion 32 is set to a length dimension that always contacts the tip of the idler 22 (regardless of the operation transmission position or the operation cutoff position). The holding arm 32 holds the tip of the idler 22 at a fixed position.
The intermediate member 30 is urged in a counterclockwise direction (a direction in which the holding arm portion 32 is displaced upward in the drawing) by a torsion spring 33 mounted around the support shaft 21. As shown in FIG. 2, the rotation end (motion transmission position) of the intermediate member 30 in the counterclockwise direction shown in the figure is restricted by the restriction arm portion 31 coming into contact with the support base portion 2a. For this reason, the holding arm portion 32 of the intermediate member 30 is always pressed against the tip portion of the idler 22 from below by the biasing force of the torsion spring 33.

According to the malfunction prevention mechanism F configured as described above, malfunction of the trigger valve 10 and the main body 2 is prevented as follows. First, the case of normal use (normal operation) of the driving machine 1 will be described.
FIG. 2 shows the initial state of the driving machine 1 and the malfunction prevention mechanism F. In this initial state, the contact arm 6 is located at the off position, and therefore, the operating arm portion 6b is lowered with respect to the support pedestal portion 2a and has a small protruding dimension. Further, the switch lever 20 is not pulled, and the stopper portion 20a abuts against the side portion of the support base portion 2a and is held at the off position. The valve stem 11 of the trigger valve 10 is held at the protruding-side off position, and the trigger valve 10 is in an off state (head valve is in a closed state).
In order to perform the driving operation from the initial state, first, the front end portion of the driver guide is positioned at the driving position, and the main body portion 2 is pushed down as it is, so that the contact arm 6 is relatively moved up by the stroke L and turned on. Then, the operating arm portion 6b moves upward with respect to the support base portion 2a, and the protrusion amount increases. This state is shown in FIG. As shown in the figure, when the contact arm 6 is moved upward and turned on, and the protrusion amount from the support base portion 2a of the operating arm portion 6b increases, the operating arm portion 6b moves the restriction arm portion 31 of the intermediate member 30. The intermediate member 30 enters the path, and as a result, the rotation of the intermediate member 30 in the clockwise direction in the figure is restricted, and the intermediate member 30 is fixed at the motion transmission position.
The rotation of the intermediate member 30 in the clockwise direction in the figure is restricted and fixed at the motion transmission position, whereby the downward displacement of the tip of the idler 22 is restricted. At this stage, the urging force (the spring force of the compression spring 14 and the air pressure of the stem upper chamber 16) toward the OFF position of the valve stem 11 acts on the intermediate member 30 as an external force in the clockwise direction in the figure via the idler 22. The external force acts as a pressing force P that presses the regulating arm portion 31 against the operating arm portion 6 b of the contact arm 6 from the side. The pressing force P acts from a direction substantially perpendicular to the moving direction (vertical direction) of the contact arm 6 and therefore does not become an obstacle to restrict the movement except for a slight frictional resistance. From the above, the biasing force of the valve stem 11 toward the off position (mainly the biasing force of the compression spring 14) does not act as a biasing force for moving the contact arm 6 toward the off position. It is sufficient to push down the main body 2 only against the compression spring 7 that directly biases 6 toward the off position, and therefore the main body 2 can be pushed down with a smaller force than before.

As shown in FIG. 4, the user can press the main body 2 with a smaller force than before (the state in which the contact arm 6 is moved to the on position, the rotation of the intermediate member 30 is restricted) as shown in FIG. 4. When the switch lever 20 is pulled upward in the figure, the idler 22 is largely displaced upward as a whole by displacing the rotation support side (support shaft 23 side) upward without substantially displacing the tip portion. The idler 22 is largely displaced upward by the pulling operation of the switch lever 20, so that the valve stem 11 is moved by a sufficient stroke upward in the figure, and the first seal ring 11a is detached from the first valve body 12, thereby causing the first transformation. The chamber 15 is opened to the atmosphere and the second valve body 13 is moved downward, whereby the second variable pressure chamber 18 is opened to the atmosphere and the trigger valve 10 is turned on. Therefore, the head valve is opened in the main body 2 and the driving operation is performed. Made.
When the user releases the pulling operation of the switch lever 20 after the driving operation is completed, the switch lever 20 is returned to the off position by the spring biasing force toward the off position side of the valve stem 11, and thus the valve stem 11 is also in the off position. Returned, the trigger valve 10 is turned off. When the trigger valve 10 is turned off, the first seal ring 11a of the valve stem 11 is airtightly fitted to the inner peripheral side of the first valve body 12, and the first variable pressure chamber 15 is cut off from the atmosphere. 15 is supplied with compressed air from the pressure accumulating chamber 3a. When compressed air is supplied to the first variable pressure chamber 15, the second valve body 13 moves up and compressed air is supplied to the second variable pressure chamber 18, so that the head valve moves down in the main body 2 and the cylinder upper chamber. Is shut off from the pressure accumulating chamber 3a and released to the atmosphere, whereby the piston is returned to the top dead center. This completes a series of driving operations in the main body 2.
After the driving operation of the main body 2 is completed, the user releases the push-down operation of the main body 2 (lifts upward), so that the contact arm 6 is returned to the off position by the urging force of the compression spring 7, and therefore the detection is performed. The arm portion 6a is returned to a state where the arm portion 6a protrudes from the tip of the driver guide 5 by a certain dimension L.

On the other hand, unlike the above procedure, when the user releases the push-down operation of the main body 2 after completing the driving operation and before releasing the pulling operation of the switch lever 20 (while keeping the pulling operation). As shown in FIG. 5, the upper end portion 6 a of the contact arm 6 retracts downward from the side of the regulating arm portion 31 of the intermediate member 30. As a result, the restriction state of the intermediate member 30 is released. As a result, the intermediate member 30 can rotate in the clockwise direction in the figure against the torsion spring 33. On the other hand, an urging force (mainly the spring force of the compression spring 14) is always applied to the idler 22 to the off position side, and this urging force indirectly causes the intermediate member 30 to rotate in the clockwise direction in the drawing (operation cutoff position side). Acting as an external force in the direction of rotation, which is set stronger than the torsion spring 33. From this, as a result, when the restriction state by the operating arm portion 6b is released, the intermediate member 30 rotates in the clockwise direction against the torsion spring 33 to reach the operation cut-off position. When the side is displaced downward, the valve stem 11 is returned to the off position side. However, since the valve stem 11 is not completely returned to the off position at this stage, compressed air is not supplied to the first variable pressure chamber 15, and therefore the second bubble body 13 remains in a lowered state. As a result, since the second variable pressure chamber 18 remains open to the atmosphere, the head valve remains open in the main body 2, so that compressed air is supplied to the piston upper chamber and the piston remains at the bottom dead center. It has become.
Further, when the switch lever 20 is pulled, the main body portion 2 is again pushed down toward another driving position, and the contact arm 6 is moved upward. As shown, since the intermediate member 30 is protruded from the support pedestal 2a by the stroke L, the intermediate member 30 is held in the operation blocking position as it is, so that the movement amount of the idler 22 is insufficient and the trigger valve 10 is maintained in the OFF state. This prevents so-called continuous strike (running continuously at a plurality of locations while the switch lever is pulled).
In this case, when the pulling operation of the switch lever 20 is released, the valve stem 11 is completely returned to the off position, whereby the seal ring 11b is detached from the second valve body 13 and compressed air is supplied to the first variable pressure chamber 15, As a result, the second valve body 13 moves up and compressed air is supplied to the second variable pressure chamber 18, and as a result, the head valve is closed in the main body 2 and the cylinder upper chamber is opened to the atmosphere, whereby the piston is dead. Returning to the point, the series of driving operations in the main body 2 is completed. Further, when the pulling operation of the switch lever 20 is released, the tip end side of the idler 22 can be relatively displaced upward, so that the spring biasing force to the off position side of the valve stem 11 acting indirectly on the intermediate member 30 is exerted. As a result, the intermediate member 30 is returned to the motion transmission position by the torsion spring 33, and is returned to the initial position shown in FIG. As described above, the driving machine 1 according to the present embodiment cannot perform the next driving operation unless the operation of returning both the contact arm 6 and the switch lever 20 to the off position (single driving operation) is performed. It is a hitting machine.

Next, unlike the normal use procedure (single shot operation) described above, the user first pulls the switch lever 20 to the on position side, and then pushes down the main body 2 to turn on the contact arm 6. In the case of relative movement to the position, the driving machine 1 according to the present embodiment does not perform a driving operation (so-called idling mechanism).
When the switch lever 20 is first pulled from the initial state shown in FIG. 2, the operating arm 6b of the contact arm 6 does not move upward as shown in FIG. It is in a state in which it can rotate in the turning direction. On the other hand, the valve stem 11 is always abutted against the upper surface side of the idler 22. For this reason, when the switch lever 20 is pulled, the spring biasing force of the valve stem 11 toward the off side is sufficiently larger than the biasing forces of the torsion springs 23 and 33, so that the idler 22 moves the abutting portion of the valve stem 11. It tilts counterclockwise about the center, and therefore the tip side of the idler 22 is displaced relatively downward. When the front end side of the idler 22 is displaced downward, the holding arm portion 32 of the intermediate member 30 is pushed downward, so that the intermediate member 30 rotates counterclockwise against the torsion spring 33 and is held at the operation blocking position. Is done.
After this state, even if the contact arm 6 is turned on (the operation of pushing down the main body 2) as shown in FIG. 7, the operating arm 6b does not reach the regulating arm 31 of the intermediate member 30, and Since the intermediate member 30 is held at the operation cutoff position, the amount of movement of the idler 22 is insufficient, and as a result, the amount of movement of the valve stem 11 toward the on position is insufficient. Therefore, the first seal ring 11a is connected to the first valve. The first variable pressure chamber 15 is not released to the atmosphere because the second seal ring 11b is not fitted into the second valve body 13 and does not come off the body 12. Since the first variable pressure chamber 15 is not opened to the atmosphere, the second bubble body 13 does not move downward. Therefore, the second variable pressure chamber 18 is not opened to the atmosphere (the trigger valve 10 is not turned on), so the head valve is opened in the main body 2. As a result, since the driving operation is not performed, the pulling operation of the switch lever 20 and the pressing operation of the main body 2 are idle (invalid).
Thus, if the switch lever 20 is pulled before the contact arm 6 is turned on, the intermediate member 30 is rotated to the operation blocking position, so that the amount of movement of the idler 22 is insufficient and the valve stem 11 is turned to the on position. Therefore, the trigger valve 10 is not turned on, so that no driving operation is performed in the main body 2.

The state shown in FIG. 5 is a state in which after the driving operation is completed, the push-down operation of the main body 2 is released while the switch lever 20 is pulled, and the contact arm 6 is returned to the off position, and the state shown in FIG. FIG. 7 shows a state where the switch arm 20 is only pulled first from the initial state shown in FIG. 2 and the contact arm 6 is not turned on. The state shown in FIG. 7 is the state shown in FIG. The state where the on operation is performed is shown. As described above, FIGS. 5 to 6 show different stages, but FIGS. 5 and 6 show the same state except that the position of the second valve body 13 with respect to the first valve body 12 in the trigger valve 10 is different. It has become.
As shown in FIG. 5, in the state where the second valve body 13 is moved downward with respect to the first valve body 12, the second seal ring 11 b of the valve stem 11 is fitted in an airtight manner on the inner peripheral side of the second valve body 13. It is in a state. In this state, since the stem lower chamber 17 and the first variable pressure chamber 15 communicated with the constant pressure accumulating chamber 3a are blocked, the compressed air is not supplied to the first variable pressure chamber 15 as described above. Accordingly, since the second valve body 18 remains in the lowered state, the second variable pressure chamber 18 remains open to the atmosphere. As a result, the head valve is open in the main body 2 and the piston is at bottom dead center. It is in a state stopped at.
On the other hand, as shown in FIG. 6, when the second seal ring 11b of the valve stem 11 is disengaged from the inner peripheral side of the second valve body 13, compressed air is supplied from the stem lower chamber 17 to the first variable pressure chamber 15. In this state, the second valve body 13 moves up and compressed air is supplied to the second variable pressure chamber 18, so that the head valve is maintained closed in the main body 2 and the piston is at the top dead center. It remains in a position.

In the state shown in FIGS. 2 and 3, the second valve body 13 moves up and the stem lower chamber 17 communicates with the first variable pressure chamber 15, and accordingly, compressed air is supplied to the first variable pressure chamber 15. Thus, the second valve body 13 is moved upward, so that compressed air is supplied to the second variable pressure chamber 18 and the head valve is closed. On the other hand, in the state shown in FIG. 4, as a result of the first variable pressure chamber 15 being opened to the atmosphere, the second valve body 13 is moved downward and the second variable pressure chamber 18 is opened to the atmosphere, so the head valve is opened and the piston is opened. It is in a state where it is moved downward and driven in by this.
2 and 3, when the second valve body 13 is moved upward, the seal ring 13b of the second valve body 13 is opened and compressed air is supplied to the second variable pressure chamber 18. It has become. On the other hand, when the second valve body 13 is moved downward as shown in FIG. 4, the second variable pressure chamber 18 is blocked from the pressure accumulating chamber 3a side by the seal ring 13b of the second valve body 13, while the seal By opening the ring 13c with respect to the first valve body 12, the second variable pressure chamber 18 is opened to the atmosphere via the exhaust passage 3e.
As described above, the second valve body 13 moves up and down in accordance with each operation stage, so that the second variable pressure chamber 18 is in a compressed air supply state (FIGS. 2, 3, 6, and 7) and an atmospheric release state ( 4 and 5), whereby the head valve is closed and opened.
6 and 7 show the same state except that the position of the contact arm 6 (the position of the operating arm portion 6b) is different. FIG. 6 shows the off position of the contact arm 6, and FIG. 7 shows the on position. As described above, in the present embodiment, the required stroke between the on position and the off position of the contact arm 6 is set to an extremely small distance.

According to the driving machine 1 of the present embodiment configured as described above, the contact arm 6 is turned on when the normal single shot operation is performed as shown in FIGS. Then, in a state where the rotation of the intermediate member 30 to the operation blocking position side is restricted by the upper end portion of the operation arm portion 6b, the restriction arm portion 31 of the intermediate member 30 is laterally disposed on the side portion of the operation arm portion 6b. Since the state is pressed from the direction, the biasing force (mainly the biasing force of the compression spring 14) of the valve stem 11 applied to the operating arm portion 6b via the idler 22 and the intermediate member 30 is contacted. It acts in a direction substantially perpendicular to the moving direction of the arm 6 and does not act in the moving direction. In contrast to this, conventionally, when the contact arm is moved upward by pushing down the main body, and then the switch lever is pulled, the spring biasing force toward the OFF position of the valve stem biases the contact arm toward the OFF position. Since the spring biasing force acts as a force (reaction force) that pushes up the main body 2, the user can increase the main body so that the main body does not lift when the switch lever is pulled. It was necessary to hold down the main body part with force.
As described above, according to the driving machine 1 of the present embodiment, the urging force of the valve stem 11 toward the off position (the urging force of the compression spring 14) does not act as the urging force that urges the contact arm 6 toward the off position. Therefore, the user does not receive a reaction from the main body when the switch lever is pulled. Therefore, the main body 2 can be held in a pressed state with a lower pressing force than in the prior art, and in this respect, the operability of the driving machine can be improved and the burden on the user can be reduced. Can be done easily.
Further, since the operation arm portion 6b is advanced and retracted in the movement path in order to restrict the movement of the restriction arm 31 of the intermediate member 30, the required stroke L of the contact arm 6 is significantly reduced as compared with the conventional case. The malfunction prevention function can be exhibited with this small stroke L. Since the stroke L of the contact arm 6 is reduced, the amount of pushing down of the main body 2 is reduced during the driving operation, whereby the tip of the driver guide 5 (shooting material launching port) is highly accurate depending on the driving position of the driving material W. In this respect, it is possible to perform more accurate driving.

The embodiment described above can be implemented with various modifications. For example, an example of a driving machine in which the magazine 4 is provided and driving tools are automatically supplied one by one in conjunction with the driving operation is illustrated. However, the user sets nails one by one at the tip of the driver guide. The same applies to the driving machine.
Further, the present invention is not limited to the air-driven driving machine and can be similarly applied to an electric driving machine.
Further, although the intermediate member 30 including the two arm portions 31 and 32 is configured to rotate, an intermediate member that linearly moves in a direction orthogonal to the moving direction of the contact arm may be used. Also in this case, the movement of the contact arm in the movement path of the intermediate member is moved forward and backward to restrict the linear movement to the operation blocking position side, so that the idler moves by a sufficient distance and the trigger valve is moved. It can be configured to switch between an ON state and a state in which the intermediate member is linearly moved to the operation cut-off position and the trigger valve is not turned on as a result of insufficient movement of the idler. Therefore, the urging force of the valve stem can be cut off in the moving direction of the contact arm, and the same effect can be obtained.
Further, as to the contact direction of the intermediate member with respect to the operating arm portion of the contact arm, as illustrated, the contact member is brought into contact with the moving direction of the contact arm from a direction substantially orthogonal to the contact arm, and a constant inclination from obliquely forward or obliquely rearward. It can be configured to contact with an angle, and in any configuration, the urging force of the valve stem against the contact arm can be cut off or significantly reduced.
The urging means for urging the contact arm toward the off position may be configured to use, for example, an air damper or cushion rubber instead of the illustrated compression spring 7.
In addition, the configuration in which the stroke L between the off position and the on position of the contact arm is significantly reduced as compared with the conventional case is exemplified, but the contact arm may be moved with a stroke as large as the conventional one. Even in such a configuration, as a result of not applying the urging force of the valve stem to the contact arm, the reaction of the main body at the time of the switch lever pulling operation can be greatly reduced or eliminated as compared with the conventional one. The operability can be improved.

1 is an overall side view of a driving machine according to an embodiment of the present invention. In this figure, the trigger valve and the internal structure around it are shown in a cutaway view. It is a longitudinal cross-sectional view of the trigger valve and its periphery of the driving machine which concerns on embodiment of this invention. This figure shows these initial states as in FIG. It is a longitudinal cross-sectional view of a trigger valve and its periphery similarly. This figure shows a state in which the contact arm is moved to the ON position by pushing down the main body. It is a longitudinal cross-sectional view of a trigger valve and its periphery. This figure shows a stage in which the main body is pushed down to move the contact arm to the ON position, and then the switch lever is pulled, thereby driving in. It is a longitudinal cross-sectional view of a trigger valve and its periphery. This figure shows a state in which the push-down operation of the main body portion is released with the switch lever being pulled after the driving operation, thereby returning the contact arm to the off position. It is a longitudinal cross-sectional view of the trigger valve and its periphery of the driving machine which concerns on this embodiment. This figure shows a state in which the switch lever is pulled while the contact arm is in the OFF state. It is a longitudinal cross-sectional view of a trigger valve and its periphery similarly. This figure shows an idling state where the driving operation is not performed when the switch lever is first pulled and then the contact arm is moved to the ON position.

Explanation of symbols

W ... Driving material 1 ... Driving machine 2 ... Main body part, 2a ... Support base part 3 ... Handle part, 3a ... Accumulation chamber, 3b ... Air hose 4 ... Magazine 5 ... Driver guide 6 ... Contact arm, 6a ... Detection arm part, 6b ... Actuating arm 7 ... Compression spring F ... Malfunction prevention mechanism (foolproof function)
DESCRIPTION OF SYMBOLS 10 ... Trigger valve 11 ... Valve stem, 11a ... 1st seal ring, 11b ... 2nd seal ring 12 ... 1st valve body 13 ... 2nd valve body, 13a ... Vent hole 14 ... Compression spring 15 ... 1st variable pressure chamber 16 ... Stem upper chamber 17 ... Stem lower chamber 18 ... Second transformer chamber 20 ... Switch lever, 20a ... Stopper portion 21 ... Support shaft 22 ... Idler 23 ... Support shaft 24 ... Torsion spring 30 ... Intermediate member 31 ... Restriction arm portion 32 ... Holding arm 33 ... Torsion spring L ... Stroke P of contact arm ... Pressing force of regulating arm

Claims (2)

A state in which the contact arm which is provided so as to be movable between an on position and an off position with respect to the driving machine main body and is urged toward the off position is moved to the on position against the urging force. the in the operating pull the switch lever, to the switch lever, by idler provided between the effective position and the disabled position movable relative is the switch lever is depressed in a state of being held in the effective position A driving machine in which a valve stem of a trigger valve is pushed to an on position against an urging force through an idler and a driving operation is performed in the driving machine main body,
An intermediate member is provided between the contact arm and the switch lever so as to be movable between an operation transmission position and an operation cutoff position.
When the contact arm is moved to the on position before pulling the switch lever, the intermediate member is held at the operation transmitting position and restricts relative movement of the idler with respect to the switch lever to the effective position. holds, configuration and the driving tool to be held in the motion-transmitting position in contact with the transverse direction to the direction of movement of the contact arm against the contact arm is moved to the oN position. 2. The driving machine according to claim 1, wherein the intermediate member includes a regulation arm portion and a holding arm portion, and is supported so as to be rotatable between the motion transmission position and the motion cutoff position, A driving machine configured to cause a contact arm to enter the movement path of the restriction arm, fix the intermediate member at the motion transmission position, and hold the idler at the effective position by the holding arm portion in the fixed state.

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