JPH0639902Y2 - Operation mode switching device for nailer - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching device for switching a nailing machine to either continuous hammering or single hammering mode.

[0002]

2. Description of the Related Art Some nailing machines are capable of switching between continuous driving and single-shot driving as shown in Japanese Utility Model Publication No. 1-18294 or FIG.

In the continuous hammering mode, as shown in FIG. 11, the switching lever 2 is separated from the contact arm 1 to be applied to the work surface on which the nail is to be hammered, and the contact arm 1 is moved to the front position by the compression coil spring 3. It is obtained by moving to. In this mode, the nail 4 can be nailed continuously any number of times by simply pulling the trigger 4 and pressing the contact arm 1 against the work surface.

In FIG. 11, the contact arm 1 is
The nail extends from the tip of the guide tube 5 to the vicinity of the rotary shaft 6 of the trigger 4, and is constantly urged forward by the compression coil spring 3. Then, when the trigger 4 is pulled, the upper part of the contact lever 8 connected to the lower part of the trigger 4 via the rotary shaft 7 rotates counterclockwise and comes into contact with the rear end 1b of the contact arm 1. When the front end 1a of the contact arm is pressed against the work surface in this state, the contact arm 1 moves rearward against the compression coil spring 3, and the rear end 1b pushes the upper portion of the contact lever 4 rearward.
As a result, the stem 10 of the trigger valve 9 retracts, and the compressed air flows into the cylinder 12 for driving the driver 11. The driver 11 moves forward by the supply of compressed air, and drives the nail sent from the nail supply unit 13 from the guide cylinder 5 toward the work surface.

After that, when the contact arm 1 is separated from the work surface, the restoring force of the compression coil spring 3 causes the contact arm 1 to move forward to release the pressing force of the contact lever 8. As a result of the stem 10 of the trigger valve 9 also being released, the spring 14 in the trigger valve 9 restores the original position and cuts off the supply of compressed air to the cylinder 12 side. The driver 11 returns to its original position by the action of the compressed air in the return air chamber 15.

The next nail driving can be performed immediately by simply pressing the contact arm 1 against the work surface while pulling the trigger 4. In the single shot mode, the switching lever 2 shown in FIG. 11 is slid upward to engage the engaging piece 1c of the contact arm 1 and the contact arm 1
Is moved to a slightly rear position against the compression coil spring 3. This mode is for preventing the next nail from being hit unless the trigger 4 is returned after pulling the trigger 4.

When the front end 1a of the contact arm 1 is pressed against the work surface and the trigger 4 is pulled under this mode, the contact lever 1 rotates integrally with the trigger 4 and pushes the stem 10 of the trigger valve 9 rearward. . As a result, compressed air flows into the cylinder 12, and the driver 11 moves forward by the compressed air to drive the nail out of the guide cylinder 5 toward the work surface.

After that, even if the contact arm 1 is separated from the work surface, the driver 11 maintains the forward state because the contact lever 8 is supported by the rear end 1b of the contact arm 1 and still pushes the stem 10. However, when the trigger 4 is released, the stem 10 of the trigger valve 9 is released and the spring 14 in the trigger valve 9 returns it to its original position. As a result, the supply of compressed air into the cylinder 12 is cut off, and the driver 11 is returned to the rear by the compressed air in the return air chamber 15.

[0009]

However, the above-mentioned conventional operation mode switching device for the nail driving machine is the same as the former one.
The one disclosed in Japanese Patent No. 18294 has a drawback in that the switching lever is only elastically in contact with the trigger, so that the switching lever moves due to an impact during nailing. Further, since the switching lever is provided behind the trigger, there is a problem that it is difficult to put a finger on the trigger and the operation is difficult.

Further, in the latter one shown in FIG. 11, since the switching lever 2 is of a slide type and is locked by the ball 17 urged by the spring 16, it is nailed. There is a problem that it moves freely due to the shock of time.

The present invention aims to solve such problems.

[0012]

In order to achieve the above object, the present invention converts the turning stroke of a contact lever contacting the stem of a trigger valve of a nail driving machine into either continuous or single-shot driving. A contact arm, and a switching operation section arranged in front of a trigger of the nail driving machine for switching the contact arm between two sliding strokes corresponding to two rotational strokes of the contact lever. In the operation mode switching device for a nailing machine, the switching operating portion is loosely fitted to a shaft on the nailing machine main body side that abuts an intermediate portion of the contact arm to switch the contact arm between the two sliding strokes. Cam, an elastic member for urging the cam in the central axis direction of the shaft, an operating lever connected to the cam, and A protrusion fixed to the side where the cam is urged by an elastic member, and the protrusion selectively depending on a sliding operation and a rotating operation of the cam along the axis when switching the sliding stroke. The first and second engaging portions provided on the cam that engage with the above are used.

[0013]

When the mode is switched from one of the continuous striking and the single shot striking to the other mode, the cam is slid along the shaft against the elastic member by holding the turning operation lever, so that the first projection is formed. The engaging portion or the second engaging portion. As a result, the cam becomes rotatable, and then the cam is rotated around the shaft while holding the operation lever so that the other engaging portion faces the protrusion. Therefore, when the operation lever is released, the cam automatically slides along the axis toward the protrusion due to the urging of the elastic member, and the other engaging portion engages with the protrusion.

As a result, the cam switches the contact arm to one of two sliding strokes. If this new mode is continuous striking, the rotation stroke of the contact lever is restricted to that for continuous striking, and continuous striking is possible by operating the trigger and contact arm.

On the other hand, if the new mode is single shot, the rotation stroke of the contact lever is restricted to that for single shot, and the single shot can be made by operating the trigger and the contact arm.

The impact of this single shot is applied to the switching operation portion, but the engagement portion engages with the projection fixed to the shaft, and the engagement state is maintained by the elastic member. There is no risk that the will rotate naturally to switch modes.

Further, since the operation lever of the switching operation portion is provided in front of the trigger, it is easy to put a finger on it and the operation becomes easy.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of a nailing machine according to the present invention will be described below with reference to the drawings. As shown in FIG.
This nailing machine has a hollow housing 1 as its main body.
Have eight.

A cylinder 19 is housed in the housing 18, and a piston 23 holding a nail driving driver 22 is housed in the cylinder 19 so as to be movable back and forth.

An empty space is provided between the housing 18 and the cylinder 19, and the empty space is divided into front and rear by a partition wall 26. The front room serves as a return air chamber 28 that communicates with the inside of the cylinder 19 through a vent hole 27 that penetrates the cylinder wall, and the rear room serves as an air chamber 29 for storing compressed air. There is. The air chamber 29 is provided with a handle portion 30 provided below the housing 18.
It spreads inward and compressed air is supplied from this chamber.

The rear end of the housing 18 and the cylinder 19
Between the rear end and the inside of the cylinder 19, the air chamber 29
And a slide valve 31 for selectively connecting to the atmosphere. On the other hand, a tubular body 32 is provided at the rear end of the housing 18, and an annular groove for guiding sliding of the sliding valve 31 is formed between the tubular body 32 and the housing wall.

The slide valve 31 has a substantially cylindrical shape, and its front edge opens and closes the cylinder 19 by coming into contact with and separating from the valve seat 33 at the rear edge of the cylinder 19. An O-ring 34 for airtightness is attached to the rear part of the annular groove, and a valve chamber 36 is provided on the bottom side of the annular groove. Further, the compression coil spring 3 is provided in the annular groove.
5 is interposed, and the slide valve 31 is the compression coil spring 3
5 and the pressure of the compressed air introduced into the valve chamber 36 shuts off the inside of the cylinder 19 and the air chamber 29 and communicates the inside of the cylinder 19 with the atmosphere.

A vent passage 37 connects the valve chamber 36 and the air chamber 29. The ventilation passage 37 is selectively connected to the inside of the air chamber 29 or the outside of the housing 18 by a trigger valve 38 described later.

Therefore, the trigger valve 38 is connected to the ventilation passage 37.
When the valve is operated to bring the valve 18 into the outside of the housing 18, the inside of the valve chamber 36 becomes the same as the atmospheric pressure, so that the sliding valve 31 is compressed by the compressed air in the air chamber 29 applied to the front edge of the sliding valve 31. Cylinder 19 against spring 35
Pulled away from. As a result, the sliding valve 31 opens the cylinder 19 and shuts off the inside of the cylinder 19 from the atmosphere,
The piston 23 in the cylinder 19 receives the supply of compressed air and moves from the back to the front.

On the contrary, when the trigger valve 38 operates so as to connect the ventilation passage 37 to the air chamber 29, the compressed air flows into the valve chamber 36, and the compression coil spring 3
5 and 5 to move the slide valve 31 to the cylinder 19 side. As a result, the sliding valve 31 moves to the cylinder 19
To close the inside of the cylinder 19 to the atmosphere. As a result of the supply of compressed air being cut off, the piston 23 in the cylinder 19 returns from the front to the rear by the force of the compressed air in the return air chamber 28.

The trigger valve 38 is attached to the base of the handle portion 30 and is constructed as shown in FIG. The trigger valve 38 has a valve cylinder 39 fixed laterally on the housing 18 side. The rear end of the valve cylinder 39 is closed, and the front end is closed by an end plate 41 having an exhaust hole 40. In addition, at the center of the valve cylinder 39, the start end 37 of the air passage 37 is formed.
An air supply / exhaust hole 42 connected to a and an air supply hole 43 connected to the air chamber 29 are provided in the front and rear at a predetermined interval.

A stem 44 is slidably inserted in the valve cylinder 39 in the front-rear direction. The stem 44 is urged forward by a compression coil spring 45 housed in the valve cylinder 39, and its front portion has an end plate 41.
It penetrates through the center of and projects outward. Further, first and second piston portions 46 and 47 are formed at a portion of the stem 44 that has entered the valve cylinder 39.

The front first piston portion 46 has two O
Rings 48 and 49 are attached at a predetermined interval, and when the piston portion 46 is at the top dead center (FIGS. 5 and 6), the rear O-ring 49 causes the air supply hole 43 to supply and exhaust the air. The O-ring 48 on the front side communicates with the hole 42, and when the piston portion 46 is at the bottom dead center (FIG. 7), the exhaust hole 40 communicates with the supply / exhaust hole 42.

Further, the second piston portion 47 on the rear side is also O
The ring 50 is fitted, and the O-ring 50 blocks the conduction between the air supply hole 43 and the stem center hole during the entire stroke of the piston portion 47.

The left side of the stem 44 projects to the outside of the valve cylinder 39, and a trigger 51 is provided in front of that portion. The trigger 51 is provided with a pin 5 on the front side of the housing 18 where the valve cylinder 39 is located.
It is pivotally supported by 2 and can rotate downward. A contact lever 53 is rotatably supported by a pin 54 on the lower portion of the trigger 51, and is rotatable between the trigger 51 and the stem 44 in an upward direction.

As shown in FIG. 1, the housing 1
A guide cylinder 54 that serves as a passage for the driver 22 is connected to the front end plate 20 that closes the front end of the driver 8. The guide tube 54
A nail supply part 55 is connected midway along the guide tube 5
Reference numeral 4 also serves as a passage for guiding the nails sent from the nail supply unit 55.

A contact arm 56 is mounted on the guide cylinder 54 for converting the turning stroke of the contact lever 53 that comes into contact with the stem 44 of the trigger valve 38 into either a continuous striking or a single striking. The contact arm 56 is provided with a guide 51 from the tip of the trigger 51.
Extending to the vicinity of the pin 52, its front end portion 56a projects forward from the guide cylinder 54 and can contact the work surface, and the rear end portion 56b can contact the upper portion of the contact lever 53. .

The contact arm 56 is the trigger 5
An engaging piece 56c is provided between 1 and the nail supply portion 55. The engagement piece 56c is constantly urged by a compression coil spring 58 toward a switching operation portion 57, which will be described later, attached to a housing portion near the nail supply portion 55. Therefore, the contact arm 56 is always urged forward, and stops at the position where the engagement piece 56c abuts on the switching operation portion 57 side.

The switching operation portion 57 is provided in the contact arm 5
6 for switching between two different sliding strokes corresponding to the two different rotational strokes of the contact lever 53. As shown in FIGS. A cam 60 loosely fitted to a shaft 59 on the housing 18 side that abuts on the joint piece 56c to switch the contact arm 56 between the two types of sliding strokes, and biases the cam 60 in the direction of the central axis of the shaft 59. Elastic member 61, an operating lever 62 connected to the cam 60, a projection 63 fixed to the side of the shaft 59 on which the cam 60 is biased by the elastic member 61, and a cam for switching the sliding stroke. The first and second engaging portions 64, 65 provided on the cam 60, which selectively engages the protrusion 63 in accordance with the sliding operation and the rotating operation of the shaft 60 along the shaft 63. There is.

The shaft 63 of the cam 60 is fixed to the lower surface of the housing 18 via a bracket 66 so that its central axis extends in the left-right direction. The cam 60 has a flat portion 60a.
And a flat portion 60b orthogonal thereto, one of which is the engaging piece 56 of the contact arm 56.
It comes into contact with c. When the flat portion 60a comes into contact with the engagement piece 56c, the continuous striking mode is set.
As described above, the contact arm 56 stops at the foremost position, and the rear end portion 56b thereof stops just below the pin 52 of the trigger 51 as shown in FIG. Flat part 60b
Comes into contact with the engagement piece 56c, the single shot mode is set, and as shown in FIG. 9, the contact arm 56 is stopped at a position slightly rearward from that in the continuous shot mode.
The rear end portion 56b is moved over the pin 52 of the trigger 51 and is approached by the contact lever 53.

The elastic member 61, which is a compression coil spring in this case, is attached to the shaft 59 and constantly presses the cam 60 to the left. The operation lever 62 protrudes leftward from the side surface of the flat portion 60b of the cam 60, and protrudes outward from the left bracket 66 so that it can be easily operated with a finger.

The protrusion 63 is a pin and is fixed so as to penetrate the shaft 59 at a right angle. First engaging portion 64
Are formed as stepped portions 64a and 64b integrally provided with the cam 60 at the boundary between the cam 60 and the operating lever 62. The stepped portions 64a and 64b correspond to the pin tip portions 63a and 63b protruding from both sides of the shaft 59, and the cam 60 is provided.
Are located on both sides of the shaft hole.

When the cam 60 is biased toward the pin by the compression coil spring 61, the two pin tips 63a and 63b hit the stepped portions 64a and 64b and engage with each other. Cannot rotate about the shaft 59. On the contrary, when the cam 60 slides on the shaft 59 against the compression coil spring 61 and the engagement is released,
The cam 60 can rotate around the shaft 59.

The second engaging portion 65 is composed of the two step portions 64.
Steps 65a and 6 on both sides of the groove provided between a and 64b
Formed as 5b. Then, after the engagement is released and the cam 60 is rotated about the shaft 59 by 90 ° from the above position, the compression coil spring 61 urges the pin 60 toward the pin tips 63a and 63b. One of the pin tips enters the groove and engages with the step portions 65a and 65b, so that the cam 60 cannot rotate about the shaft 59.

Next, a series of operations of the nailing machine of the above embodiment will be described for each mode of continuous hammering and single shot hammering. In case of continuous striking, as shown in FIGS. 1 and 2, the operation lever 62 is rotated downward. Engagement piece 56c of contact arm 56
Contacts the flat portion 60a of the cam 60, the contact arm 56 stops so that its rear end portion 56b comes close to the pin 52 of the trigger 51, as shown in FIG.

In the state of FIG. 5, the contact lever 53 is merely in contact with the stem 44 of the trigger valve 38, and the nailing machine does not operate. Further, as shown in FIG. 6, the nailer does not operate even if the trigger 51 is simply pulled.

In the state shown in FIGS. 5 and 6, the stem 4
Since the piston portion 46 of No. 4 is at the top dead center, the compressed air in the air chamber 29 flows into the valve chamber 36 (FIG. 1) through the air supply hole 43, the air supply / exhaust hole 42 and the ventilation hole 37, and the sliding valve 31 Is pushed to the cylinder 19 side. Therefore, the cylinder 19 is closed and the piston 23 and the driver 22 remain stationary.

When nailing, the front end portion 56a of the contact arm 56 may be pressed against the work surface while the trigger 51 of FIG. 6 is pulled. As a result, the contact arm 56 slides backward as a whole on the nailing machine, and the rear end portion 56b rotates the contact lever 53 backward, as shown in FIG. The stem 44 is retracted by the rotation of the contact lever 53 to bring the air supply / exhaust hole 42 into conduction with the exhaust hole 40. Therefore, the valve chamber 36 (Fig. 1)
The compressed air inside is discharged, and the slide valve 31 moves to the right side in FIG. 1 against the compression coil spring 35 by the compressed air inside the air chamber 29 that is applied to the front edge of the slide valve 31 and moves to the rear end of the cylinder 19. Is opened, and the inside of the cylinder 19 and the atmosphere are shut off. The compressed air in the air chamber 29 is the cylinder 1
9 enters the cylinder 19 from the rear end and pushes the piston 23 to the left. Therefore, the driver 22 advances in the guide cylinder 54 and drives the nail toward the work surface.

After driving the nail, the contact arm 56
When the contact arm 56 is separated from the work surface, the contact arm 56 causes the engagement piece 56c to move by the action of the compression coil spring 58.
6 returns to the position where it abuts against the flat portion 60a, and the stem 44 also returns to the state of FIG. Therefore, the slide valve 31 closes the cylinder 19 by receiving the force of the compressed air, cuts off the supply of the compressed air into the cylinder 19, and makes the inside of the cylinder 19 communicate with the atmosphere. The piston 23 in the cylinder 19 moves to the right side by the compressed air in the return air chamber 28 and returns to the original position.

When the trigger 51 is released while the contact arm 56 is pressed against the work surface, the stem 44 returns to the intermediate position as shown in FIG.
Since the O-ring 49 is still disconnected between the valve 3 and the air supply / exhaust hole 42, the inside of the valve chamber 36 of the slide valve 31 is kept under atmospheric pressure, and the slide valve 31 puts the cylinder 19 in the released state. .
Therefore, the piston 23 remains stopped at the left end by the compressed air from the air chamber 29. After that, when the contact arm 56 is separated from the work surface, the state similar to that in FIG. 5 is restored, and the piston 23 returns to the original position.

The next nail driving can be performed immediately by simply pressing the contact arm 56 against the work surface while the trigger 51 is pulled. In the case of a single shot, the operating lever 62 is operated to change the state of FIG. 1 to the state of FIG. When operating the operation lever 62, first, in FIG.
Against the first engaging portion 64a, 64b and the protrusion 6
Release the engagement with 3a and 63b. Next, the operation lever 62 is rotated upward by 90 °. This allows the cam 60
Is the flat portion 60b of the engaging piece 5 of the contact arm 56.
6c is retracted. When the pressing force is released, the second engaging portions 65a and 65b engage with the protrusions 63a and 63b to maintain the current posture of the cam 60. The contact arm 56 has a rear end portion 56b as shown in FIG.
Stops at a position slightly rearward of the pin 52 of the trigger 51.

As a result, the conversion to the single shot mode is completed, and the contact arm 5 is operated under the mode.
The front end 56a of 6 is pressed against the work surface, and the trigger 5
When 1 is pulled, the contact lever 53 rotates integrally with the trigger 51 and pushes the stem 44 of the trigger valve 38 rearward. As a result, the same state as in FIG. 7 is obtained,
The air chamber 29 and the cylinder 19 are electrically connected to each other, and the driver 22 is moved forward by the compressed air to drive the nail from the guide cylinder 54 toward the work surface.

Thereafter, as shown in FIG. 10, even if the contact arm 56 is separated from the work surface while the trigger 51 is pulled, the contact lever 53 causes the contact arm 5 to move.
Since the stem 44 is still pushed while being supported by the rear end portion 56b of the driver 6, the driver 22 maintains the forward movement state. That is, since the valve chamber 36 is under the atmospheric pressure and the slide valve 31 keeps the cylinder 19 open, the piston 23 maintains the state of being moved to the left end by the compressed air.

When the trigger 51 is released, the trigger valve 3
The stem 44 of No. 8 is released and returned to its original position by the spring 45 in the trigger valve 38. This allows
The air passage 37 communicates with the air supply hole 43 through the air supply / exhaust hole 42, and the slide valve 31 closes the cylinder 19. Cylinder 19
The supply of the compressed air from the air chamber 29 is cut off, and the compressed air from the return air chamber 28 pushes the compressed air backward to restore the original position.

When the contact arm 56 is pressed against the work surface and the trigger 51 is pulled at the time of nailing, the contact arm 56 and the stem 44 may move to the left due to vibration or recoil during nailing. However, even in such a case, the contact arm 56 still has the flat portion 60b of the cam 60.
The contact lever 53 is prevented from moving further to the left than the position in FIG.
Is stopped at the intermediate position in FIG. Therefore, the air supply hole 43
The air supply / exhaust hole 42 is still blocked by an O-ring 49, the inside of the valve chamber 36 of the slide valve 31 is kept under atmospheric pressure, and the slide valve 31 puts the cylinder 19 in an open state. Then, the piston 2 is compressed by the compressed air from the air chamber 29.
3 remains stopped at the left end. This prevents double strikes. After this, contact arm 5
When 6 is released from the work surface and the trigger 51 is released, the trigger valve 38 returns to the state similar to FIG. 5, and the piston 23 returns to the original position.

The next nail driving can be performed by pulling the trigger 51 and pressing the contact arm 56 against the work surface.

[0052]

Since the present invention is constructed as described above, it is necessary to push or turn the cam along the shaft when changing modes. Therefore, it is possible to prevent the cam from moving due to an impact or the like at the time of nailing, and it is possible to reliably maintain the set mode.

[Brief description of drawings]

FIG. 1 is a partially cutaway vertical sectional view of a nailing machine having an operation mode switching device according to the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a perspective view of a cam of a switching operation unit and its surroundings.

FIG. 5 is a partial cutaway vertical sectional view of a trigger and a peripheral portion of the trigger valve when nailing is not performed in a continuous driving mode.

FIG. 6 is a partial cutaway vertical sectional view when a trigger is pulled in the state of FIG.

FIG. 7 is a partial cutaway vertical sectional view in the case where the contact arm is further pushed to perform nailing from the state of FIG. 6;

8 is a partially cutaway vertical cross-sectional view when only the trigger is returned from the state of FIG.

FIG. 9 is a partial cutaway vertical cross-sectional view of a trigger and a peripheral portion of the trigger valve at the time of non-nail driving in the single shot driving mode.

FIG. 10 is a partial cutaway vertical cross-sectional view when only a trigger is pulled in the state of FIG.

FIG. 11 is a partially cutaway vertical sectional view of a nailing machine provided with a conventional operation mode switching device.

[Explanation of symbols]

 38 ... Trigger valve 44 ... Stem 53 ... Contact lever 56 ... Contact arm 57 ... Switching operation part 59 ... Shaft 60 ... Cam 61 ... Elastic member 62 ... Operation lever 63 ... Projection 64 ... First engaging part 65 ... Second Engagement part

Claims (1)

[Scope of utility model registration request] 1. A contact arm for converting a turning stroke of a contact lever, which comes into contact with a stem of a trigger valve of a nailing machine, into either a continuous striking or a single striking, and the contact arm includes two types of contact arms. A switching operation section arranged in front of a trigger of the nail driving machine for switching between two sliding strokes corresponding to the rotation stroke of the nailing machine. Is a cam loosely fitted on a shaft of the nailing machine main body side that abuts the intermediate portion of the contact arm and switches the contact arm between the two types of sliding strokes; and the cam in the central axis direction of the shaft. An elastic member for biasing, an operation lever connected to the cam, and the cam on the shaft fixed to the side biased by the elastic member. Protrusions, first and second provided on the cam that selectively engages with the protrusion in accordance with a sliding operation and a rotating operation of the cam along the axis when switching the sliding stroke. The operation mode switching device of the nail driving machine is characterized by comprising: