JPS6012705Y2 - pneumatic screwdriver - Google Patents

Description

[Detailed description of the invention] This invention uses compressed air as a power source to rotate an air motor, and this air motor rotates a bit to continuously screw a large number of separate screws one by one into a material to be screwed. Regarding the pneumatic screwdriver that can be used.

Conventionally, pneumatic screwdrivers powered by compressed air,
After the operator of this pneumatic screwdriver sets screws one by one at the forward position of the bit, the screw is rotated by the bit and screwed into the material to be screwed.

Conventional pneumatic screwdrivers are not provided with a screw feeding device that sets individual screws one by one in front of the bit.

An object of the present invention is to provide a pneumatic screwdriver having a screw feeding device for successively setting loose screws one by one into the forward position of the bit.

The present invention, which is distantly related to this purpose, supplies a head screw as appropriate to the tip of a bit rotated by an air motor, rotates the head of the screw with the bit, and screws this screw into the material to be screwed. In the pneumatic screwdriver, a screw alignment guide plate is provided in a screw stirring container that is sealed by a top lid, and is inclined with respect to the top lid. The exhaust air from the air motor is blown into the closed space to form a closed space in which the screws are inserted, and to form a swirling flow of air rising from the bottom of the closed space to the top. The screws that are being stirred in the closed space between the screw stirring container and the top cover are captured one by one, and the screws are sent to the tip of the bit in a unidirectionally aligned state through a notch provided in the peripheral wall of the screw stirring container. It is characterized by

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS. 1 to 5.

FIG. 1 shows a longitudinal cross section of a pneumatic screwdriver 1 of the present invention, which has a pistol-shaped body 2 which includes an air motor 3, a reduction gear device 4, a clutch 5 (however, a 1, the specific structure of the clutch 5 is omitted), an air motor trigger valve 6, and a screw blow-feeding trigger valve 7.
A bit shaft 8 partially protruding from the top, a nose 9 slidably movable in the longitudinal direction with respect to the bit shaft 8, and a screw alignment device 1.
It has 0.

A compressed air storage chamber 11 is provided in the grip 12 of the body 2.
is formed.

A reduction gear 15 of the reduction gear device 4 meshes with a pinion 14 integral with the drive shaft 13 of the air motor 3, and its rotating shaft 16 is formed in a cylindrical shape.

The inner surface of the rotary shaft 16 has a hollow hexagonal cross section, and the input shaft 17 of the clutch 5 is inserted into the rotary shaft 16.

The interlocking plate 18 at the end of the input shaft 17 and the interlocking plate 20 at the end of the output shaft 19 interlock with each other so as to cut off torque transmission at a certain torque or more.

The clutch 5 is of a normal type, and when the bit shaft 8 becomes overtorqued, the rotation shaft 16 of the reduction gear 15 is
Torque transmission from to the bit shaft 8 is cut off.

The output shaft 19 and the bit shaft 8 are integrally connected.

A bit 23 is formed at the tip of the bit shaft 8 and fits into a groove in the head 22 of the screw 21.

The air motor 3, which rotationally drives the bit shaft 8, is started and stopped by manual operation of the air motor trigger valve 6, which is a two-way switching spool valve type.

The exhaust port 24 of the air motor 3 is connected to the screw alignment device 1
0 air supply port 25 and two stop piston cylinders 61 and 62 retraction air supply ports) 61a and 6
2a.

The screw blowing trigger valve 7 is a two-way spool valve, and its manually operated end 26 protrudes behind the grip 12.

In addition, the manual operation end 26 is stopped by a stopper 27 protruding from the grip 12 at the rear thereof while receiving the force of the compression coil spring 28.

The minus port 29 of the trigger valve 7 for screw blowing communicates with the compressed air storage chamber 11, and the other port 30 of the trigger valve 7 for screw blowing communicates with the feed air receiving port 51 of the screw feeding port 51 shown in FIG. is connected to port 58.

The screw feed port 51 is connected to the port 31 through a flexible tube 32, and a screw receiver protruding from the side of the nose 9.

In the screw receiver, the port 31 is formed to protrude obliquely with respect to the nose 9.

The nose 9 is fitted onto the bit shaft 8 and is slidably movable with respect to the bit shaft 8.

Further, the nose 9 is fitted into a cylindrical nose cover 33 extending from the body 2 toward the front.

Slits (not shown) are formed on the upper and lower sides of the nose cover 33, respectively, and these slits allow the screw receiver to move the port 31 and the slide piece 34 fixed to the lower side of the nose 9.

The slide piece 34 is externally fitted onto a sliding guide rod 35 which is fitted into the hole 2a of the body 2.

Compression coil spring 3 externally inserted into this sliding guide rod 35
6 comes into contact with the slide piece 34, and the compression coil spring 3
The other end of 6 is in contact with the body 2.

The nose 9 is accurately guided by the bit shaft 8 and the sliding guide rod 35, and is slid in the longitudinal direction of the bit shaft 8.

As shown in FIG. 1, the screw receiver of the nose 9 has the port 31 positioned ahead of the bit 23, and the stopper flang provided at the rear end of the sliding guide rod 35 keeps the nose 9 stationary. 37 and the body 2 and the restoring force of the compression coil spring 36.

A pair of balls 39 and 40 are fitted onto the inner wall 38 of the nose 9 at regular intervals, and these balls 39 and 40 and rubber rings 39a and 40a constitute a 7-z side screw holding device 63. are doing.

This nose-side screw holding device 63 holds the screw 21 in the nose 9 in a state in which it is ready for screwing.

During the screwing operation of the screw 21, the bit 23 is fitted into the groove of the head 22 of the screw 21 as the 7-piece 9 is pressed against the material to be screwed and retreats.

Details of the screw alignment device 10 are shown in FIGS. 1 and 2.

As seen in these figures, the lower end surface 12 of the grip 12
A cylindrical alignment device casing 42 with an eave is attached to a support member 41 extending from a to the front of the body 2 along the bit axis 8.

This alignment device casing 42 also has a cylindrical screw stirring container 43 with an eave installed therein.

The alignment device casing 42 is provided with an air supply port 25 .

The screw stirring container 43 is arranged concentrically with respect to the alignment device casing 42, and the peripheral wall 4 of the screw stirring container 43 is arranged concentrically with respect to the alignment device casing 42.
A clearance 44 is ensured between the alignment device casing 3a and the peripheral wall 42a of the alignment device casing 42 for the flow of compressed air.

Further, the outer bottom surface 43b of the screw stirring container 43 is provided with a leg portion 45 formed in an annular shape, and the compressed air within the clearance 44 is connected to the outer bottom surface 43b of the screw stirring container 43 and the inner bottom surface 42b of the alignment device casing 42. This prevents it from going around between the two.

The screw stirring container 43 and the alignment device casing 42 are hermetically sealed by a removable cylindrical upper lid 48 with a shallow eave.

This upper cover 48 is removed and a large number of screws 21 are randomly inserted into the screw stirring container 43.

Inside the screw stirring container 43, an inclined oval screw alignment guide plate 46 is disposed.

The screw alignment guide plate 46, the upper lid 48, and the screw stirring container 4
A closed space A is formed by the peripheral wall 43a of No. 3, and a large number of screws 21 are stirred in this closed space A by compressed air.

As shown in FIGS. 1 and 2, the screw alignment guide plate 46 is arranged horizontally with respect to the bit shaft 8, and the highest part thereof is connected to the ceiling surface 48a of the upper cover 48.
A screw alignment plane 47 is provided which is parallel to the screw alignment plane 47 .

A large number of screws 21 are placed on the lower part of the screw alignment guide plate 46 in a random manner.

The distance between the ceiling surface 48a of the upper M4B and the screw alignment plane 47 is equal to the diameter of the head 22 of the screw 21.

With this configuration, when the screws 21 are blown upward along the screw alignment guide plate 46 and climb the screw alignment guide plate 46, the screws 21 are disposed between the screw alignment plane 47 and the ceiling surface 48a of the upper cover 48. Head 22 is restrained.

The peripheral wall 42a of the screw stirring container 42 and the peripheral wall 43a of the alignment device casing 43 located between the ceiling surface 48a of the upper lid 48 and the screw alignment plane 47 have a diameter slightly larger than that through which the head 22 of each screw 21 can pass. A rectangular notch 49 having a wide width is formed (see FIG. 2).

Into this notch 49 are inserted one longitudinal end 50a and one widthwise end 50b of a pair of screw feed guide plates 50, each consisting of a pair of upper and lower plates (see FIG. 3).

The other longitudinal end side 50c of the pair of screw feed guide plates 50
is inserted horizontally into the screw feed port 51.

As shown in FIG. 2, on the peripheral wall 43a of the screw stirring container 43, an upper portion adjacent to the lower end 46a of the screw alignment guide plate 46 has a section that is lateral to the axis of the screw stirring container 43. A first air blowing hole 52 is formed in a direction that matches the projection of the central axis of the guide plate 46 onto the inner bottom surface 43c of the screw stirring container 43.

From this first air blowing hole 52 to the screw alignment guide plate 46
The compressed air is blown out into the closed space A in the direction along the slope of.

Further, as shown in FIGS. 1, 2, and 5, a screw alignment guide plate 46 is provided on the peripheral wall 43a of the screw stirring container 43.
A plurality of (three in this embodiment) second air blowing holes 53 are formed at a position above the second air blowing holes 53 .

The direction of these second air blowing holes 53 is set so that the compressed air rotates clockwise within the screw stirring container 43, as shown in FIG.

The compressed air blown into the screw stirring container 43 from the first air blowing hole 52 and the second air blowing hole 53 forms an inverted conical air swirling flow, and this air swirling flow guides the screw alignment. It exerts an upward thrust along the plate 46.

This upward thrust causes the screw 21 to move to the screw alignment guide plate 46.
along the plane 47 for screw alignment.

The posture in which the screws 21 are pushed up onto the screw alignment plane 47 is not constant.

Therefore, when the threaded portion 54 of any one of the screws 21 is inserted into the screw feed guide plate 50 through the notch 49, the screw 21 is captured.

According to the results of experiments, screw 21 is always removed within a very short time.
was found to be captured on the screw alignment plane 47.

As shown in FIGS. 1 and 3, a total of six screws 21 are held in parallel between a pair of screw feed guide plates 50.

With the heads 22 of these screws 21 in contact with each other,
The screws 21 are aligned, and a pair of screw feed guide plates 50
The screw 21a pushed out into the screw feed port 51 has a lower surface of its head 22a that is connected to the three balls 5 shown in FIG.
It is held in the screw feed port 51 in a state where it is latched by 5.

The upper surface of the head 22a of the screw 21a is connected to a shoulder 57 formed on the inner wall 56a of the screw feed passage 56 in the screw feed port 51.
is brought into contact with.

A feed air receiver port 58 is formed in the screw feed port 51, and the feed air receiver port 58 is connected to the other port 30 of the screw blower trigger valve 7 as described above.

Details of the screw holding device 59 on the screw feeding port side that holds the screw 21a within the screw feeding port 51 are shown in FIGS. 3 and 4.

This screw holding device 59 on the screw feeding port side has three parts that partially protrude into the screw feeding passage 56 with an interval of 1200 mm.
It consists of three balls 55 and three compression coil springs 60 that elastically bias these balls 55 inward in the cross-sectional radial direction of the screw feed passage 56.

These compression coil springs 60 are springs with weak restoring force, and the ball 55 retreats from the screw feed passage 56 due to the force of the compressed air blown into the port 58 pushing the screw 21a, and the compression of the screw 21a It becomes possible to feed by air.

The screw 21a released from the screw holding device 59 on the screw feed port side is sent to the screw holding device 63 on the nose side by the pressure of compressed air.

The stop piston/cylinders 61 and 62 have the same construction, but a stopping stem 64 is provided so as to protrude from the piston 63 of the bent stop piston/cylinder 61 below the upper cover 48 .

This stopping stem 64 comes into contact with the rear side of the head 22b of the last screw 21b of the six screws 21 arranged in parallel on the pair of screw feed guides 50 in the most advanced state.

The stop stem 66, which is provided so as to protrude from the piston 65 of the stop piston/cylinder 62 toward the pair of screw feed guide plates 50, is parallel to the pair of screw feed guide plates 50 in its most advanced state. The screw 21 in the screw feed port 51 contacts the front side of the head 22c of the screw 21c located at the forefront of the six screws 21, and at the same time
It comes into contact with the rear side of the head 22a of the head 22a.

The six screws 21 in the pair of screw feed guide plates 50 are held stationary by the stopping stems 64 and 66.

The operation of the pneumatic screwdriver 1 is performed in the following order.

That is, in a state where the compressed air storage chamber 11 is connected to the compressor, first, the screw blowing trigger valve 7 is opened.
When the manual operation end 26 of (moves to the left in FIG.
Compressed air is supplied to the feed air receiver from 0 to port 58,
The pressure of this compressed air causes the screw feed port side screw holding device 59 to be released, and the screw 21a is sent to the nose side screw holding device 63, and this nose side screw holding device 63
hold it.

Next, by manually operating the air motor trigger valve 6,
When compressed air is supplied to the air motor 3, the air motor 3 starts rotating, thereby starting the bit shaft 8.

By pressing the nose 9 against the material to be screwed, the nose 9 moves backward (moves to the right in FIG. 1), and the screw 21a held by the nose-side screw holding device 63 is fitted into the bit 23. At the same time, it is rotated and screwed into the material to be screwed.

During this time, the exhaust from the air motor 3 passes through the exhaust port 24 and the air supply port 25 of the screw alignment device 10 to the screw stirring container 43.
At the same time as air is blown into the stop piston/cylinder 61 and 62, each retraction air supply port) 61a
and 62a.

Therefore, at the same time that a large number of screws 21 are stirred in the screw stirring container 43, the stop stems 64 and 66 rise, thereby allowing the screws 21 to jump in and move within the pair of screw feeding guide plates 50. ing.

When the screw 21 newly jumps into the notch 49 of the alignment device casing 42 and the screw stirring container 43, the leading screw 21 in the screw feed guide plate 50 is pushed toward the screw holding device 59 on the screw feed port side.

When the threading stroke of the screw 21 is completed, the air motor trigger valve 6 is released, and as a result, the air motor 3 stops rotating, and at the same time, exhaustion of the air motor 3 is completed.
The stopping stems 64 and 66 descend to hold the screws 21 in an aligned state within the pair of screw feeding guide plates 50, and at the same time, agitation of the screws 21 within the screw stirring container 43 is also stopped.

Thereafter, the next screw threading process is repeated by manually operating the screw blowing trigger valve 7 again.

As mentioned above, according to the present invention, the pneumatic screwdriver is equipped with a device for aligning loose screws, so it is possible to perform screwing work using loose screws in succession, and the exhaust air of the air motor can be used as a screw stirring container. Since the air is blown into the air, there is little loss in air consumption.

[Brief explanation of the drawing]

Figure 1 is a vertical sectional view of the pneumatic screwdriver of the present invention, Figure 2
The figure is a sectional view taken along the line ■-■ in Figure 1, Figure 3 is a sectional view taken along the ■-■ line in Figure 2, and Figure 4 is a sectional view taken along the line IV--
FIG. 5 is an end view of the screw holding device on the screw feeding port side taken along the IV line, and is an explanatory view of the air blowing direction of the screw aligning device. 1...Pneumatic screw driver, 3...Curved air motor, 21...Curved screw, 22...---0 part, 23...
-----Human, 43...Screw stirring container, 43
a...Curved peripheral wall, 46...Screw alignment guide plate, 47
...Flat surface for screw alignment, 48... Knock-up lid, 49.
Curve/notch, A... Opening/closing space.

Claims (1)

[Scope of utility model registration request] In a pneumatic screwdriver, a screw head is appropriately supplied to the tip of a bit rotated by an air motor, and the head of the screw is rotated by the bit to screw the screw into the material to be screwed. A screw alignment guide plate is provided in the screw stirring container at an angle with respect to the top lid, and the screw alignment guide plate, the peripheral wall of the screw stirring container, and the top lid form a closed space into which a large number of screws are inserted. The exhaust air from the air motor is blown into the closed space to form a swirling air flow rising from the bottom to the top of the closed space, while the air is being stirred in the closed space between the top end of the screw alignment guide plate and the top cover. A screwdriver that captures certain screws one by one and sends the screws through a notch provided in the peripheral wall of a screw stirring container to the tip of a bit while being aligned in a fixed direction.