JPH11170178A - Automatic thread fastening machine and connected screw case - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically stop a driver having advanced to a thread fastening end position to always keep a fixed screwed depth. SOLUTION: An indicated state is at a halfway position of an automatic thread fastening, and a compressed air advances in an A-direction and is supplied into a driving air chamber 1c, and is moreover supplied to an air motor 12 through a small hole 8a on an input side air supplying sheath-shaped part 8-a small hole on an output side air supply path 1f. A driver 6 drives a top screw 15a in a biting direction by the action of the compressed air in the driving air chamber 1c, and drives the screw 15a in a rotating direction by the action of a bevel gear on an output side of the air motor 12. At the time of thread fastening end, the air supplying sheath-shaped part 8 also moves downward as much as a movement, and an O-ring 8d comes into a close contact with a narrow part of the inner periphery of a valve cap 2 to shut off between the small hole 8b on the output side and the air supply path 1f for stopping the air motor 12. The compressed air in the driving air chamber 1c is also supplied to a screw feeding air chamber 1g (C-direction).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic screw tightening machine for tightening screws with a driver driven by an air motor or the like, and more particularly, to an automatic screw tightening machine capable of continuously tightening connection screws provided in a magazine case. About the machine.

[0002]

2. Description of the Related Art In a conventional automatic screw tightening machine, the supply of air (compressed air) to an air motor or the like, which is a driving source of a screw tightening driver, is exclusively controlled by a trigger lever. Also, the trigger lever was operated when stopping.

[0003]

As described above, the timing for stopping the driver is left to the discretion of the operator who operates the trigger lever. However, it is difficult to determine the timing for shutting off the air by operating the trigger lever. Shut off the air and stop the screwdriver before the screw is completely tightened.
Alternatively, the timing of shutting off the air may be delayed and the screw may be over-tightened, and it is difficult to tighten the screw to a uniform depth.

Accordingly, it is an object of the present invention to always maintain a constant screwing depth by automatically stopping the driver when the driver advances to the screw tightening end position.

It is another object of the present invention to automatically supply a connecting screw to a fixed driver operation position even when screws having different lengths are used, and to always maintain a fixed screwing depth. .

[0006]

In order to achieve the above object, the present invention uses an automatic screw tightening machine having the following structure. In an automatic screw tightening machine that uses air as a drive source of a driver that drives a screw in a biting direction and a rotation direction, an output side of an air motor that is a driving unit of the driver in the rotation direction is driven by the driver in the biting direction. An automatic screw tightening machine having a screw tightening stop means for stopping when the screw tightening end position is reached is used. As the screw tightening stop means, a shutoff unit for shutting off air supply to the air motor is used. An automatic screw tightening machine characterized by using a sealing portion provided on an air supply member interlocked with the driver as the blocking portion, wherein the air motor is used as the screw tightening stopping means. An automatic screw tightening machine characterized by using a transmission control unit that interrupts transmission of output to the driver. A screw feed portion that feeds the driven screw to the driver operation position is configured so that, in association with the movement of the driver in the biting direction, the screw feed portion enters between the screw behind the driven screw and the subsequent screw with air. An automatic screw tightening machine characterized by providing an air supply path for moving the screw.

Further, a connecting screw case having the following structure is used. 'A connecting screw case characterized by providing a height adjusting means for selectively setting a holding plate for controlling a vertical position of a connecting screw to a position at a different height.

[0008] With this configuration, when the driver for driving the screw in the biting direction and the rotation direction moves to the screw tightening end position, the output side of the air motor that is the driving source in the rotation direction of the screw is turned on. It will automatically stop.

Further, by adjusting the position (height) of the holding plate in accordance with the length (height) of the connecting screw housed in the connecting screw case in an upright state, various connecting screws can be shortened or lengthened. Regardless, it is set at a predetermined height of the connection screw case.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an explanatory diagram showing an overall outline of an automatic screw tightening machine, FIG. 2 is an explanatory diagram showing a non-operating state of the automatic screw tightening machine, FIG. 3 is an explanatory diagram showing an initial state of the screw tightening operation, and FIG. FIG. 5 is an explanatory diagram showing an end state of the operation, and FIG.
Is an explanatory diagram showing the return state of the driver after the screw tightening is completed,
6 and 7 are explanatory diagrams showing a screw supply mechanism to a driver operating position, and FIG. 8 is an explanatory diagram showing a height adjusting mechanism of a bottom structure (holding plate) in a connecting screw case.

In these figures, 1 is a body, 1a is an air supply chamber, 1b is a trigger air chamber, 1c is a drive air chamber, 1d is a return air chamber, 1e is a cylinder outside air chamber, and 1f is an air motor. Air supply path, 1g: screw feed air chamber, 1h: screw feed air supply path, 1j: trigger air supply path, 1k: cylinder holder, 1m: trigger air discharge path, 1n: drive air discharge path , 1p is a damper, 1q is an exhaust muffler, 1r is a small hole, 1s is a trigger valve receiver, 2 is a valve cap, 2a is an internal space, 2b is a damper,
2c is a gasket 3 is a head valve, 3a is a spring receiver, 3b is a leg, 3c is a gasket 4 is a spring 5, a piston 6, a driver 7 is a cylinder, 7a is a check valve, 7b is a small hole, 7b is a small hole, and 7c is a vent 8. Is an air supply sheath linked to the driver 6, 8a is an input side small hole, 8b is an output side small hole, 8c is an air passage, 8d is an O-ring 9, 9 is a bevel gear 10, 10 is a bottom cover, 11 is a speed reducer 12, Air motor 13 is a driving nose, 13a is an arm, 13b is a tightening depth adjusting screw 14 is a holding belt 15 is a connecting screw, 15a is a leading screw, 15b is a second screw, 15c is a third screw, and 15c is a third screw 16 is a bottom structure. Body (holding plate), 16a is a bottom plate, 16b is a claw attachment disk, 16c is a concave portion, 16d is a rotating shaft, 16d
e is a bottom plate fixing claw, 16f is a spring, 16g is a knob, 1
6h is a plate screw 17 is a magazine case, 17a is a case side guide, 17
b to 17e are concave grooves, 17b 'to 17e' are tapered end surfaces of each concave groove, 17f is a pin, 17g is a latch, 18 is a magazine case cover, 19 is a feed-side guide, 19a is a spring, and 19b is a rotating shaft. Is a screw detent claw, 20a is a tip portion 21 is a screw feed piston (screw feed portion), 21a is a rotating shaft 22 is a spring 23 is a cylinder 24 is a screw feed claw, 24a is a tip portion 25, and a spring 26 is a spring 26 The contact block 27 is a soft cover 28 is a centering claw 29 is a spring 30 is a trigger valve, 30 a is a spring 31 is a trigger lever 32 is a safety device, 32 a is a rotating shaft 33, and 33 is a screw tightening member.

The automatic screw tightening machine includes: a driver 6 for screwing, a cylinder 7 interlocked with the driver 6, an air motor 12 for rotating the driver 6, an air supply chamber 1a, an air chamber 1b for a trigger, and air for driving. Chamber 1c, return air chamber 1d, air motor air supply path 1f
A bottom cover 10 having a bevel gear 9 for transmitting the output of the air motor 12 to the driver 6; a tightening depth adjusting screw 13b; a screw feed piston 2
1. A driving nose 13 having a screw feed claw 24 or the like.-A magazine case 17 for accommodating a connection screw to be automatically screwed.-A magazine scuba 18-On a surface of a portion to be screwed such as a plate. The contact block 26 is composed of components such as a trigger lever 31 as an operation unit and a safety device 32 for the trigger lever 31.

The body 1 has a sheathed valve cap 2 therein. A damper 2b is provided at an upper end of an internal space 2a, and a space between the outside of the valve cap 2 and the body 1 is defined as an air supply chamber 1a. And

The flange-shaped head valve 3 and the gasket 3c provided in the valve cap 2 are urged downward by a spring 4 in the drawing, and by the action of the gasket 3c,
The air supply chamber 1a and the inside of the cylinder 7 are sealed.

The head valve 3 has a sheath-shaped spring receiver 3a on the upper surface side, and has a leg 3b provided at the outer edge of the lower surface with a predetermined gap, and a gasket 3c inside the leg. The space between the valve cap 2 and the head valve 3 is a trigger air chamber 1b.

A cylinder 7 is fixed in a space on the front side (downward in the drawing) of the body 1 via a cylinder holding portion 1k, and a piston 5 is slidably mounted therein. The piston 5 has an O-ring on its outer peripheral surface and is integrated with the driver 6. The space between the piston 5 and the head valve 3 forms a drive air chamber 1c, the space in the cylinder 7 in front of the piston 5 forms a return air chamber 1d, and the space between the cylinder 7 and the body 1 is formed. The space forms an air reservoir 1e outside the cylinder.

A small hole 7b with a check valve 7a is provided near the middle of the cylinder 7, and a ventilation hole 7c having a larger diameter than the small hole 7b is provided near the lower end. The driver 6 and the piston 5 are integrated, and an air supply sheath 8 is attached to the rear end of the driver 6 protruding from the piston 5. The air supply sheath 8 is inserted into the interior of the valve cap 2, and has an input side small hole 8a and an output side small hole 8b connected to an internal air passage 8c on the front side and the rear side.

A bottom cover 10 containing a bevel gear 9 is attached to the front end of the body 1, and the bevel gear 9 receives an output of an air motor 12 via a speed reducer 11. Further, the air motor 1 is removed from the internal space 2a of the valve cap 2.
Air supply path 1f for air motor that supplies drive air to 2
Is provided on the side surface of the body 1 (in FIGS. 2 to 5, it is shown in a state separated from the body 1).

A feed side guide 19 for guiding the connecting screw 15 and a cylinder 23 containing a screw feed piston 21 and a spring 22 are attached to the arm 13a. A screw feed pawl 24 is attached to the piston 21 so as to be rotatable about the rotation shaft 21a and urged counterclockwise by a spring 25 (see FIGS. 6 and 7).

From the cylinder outer air chamber 1e to the cylinder 23
A screw feed air supply passage 1h for supplying air to the screw feed air chamber 1g is provided on a side surface of the body 1 (a state separated from the body 1 is shown in FIGS. 2 to 5).

The contact block 26 attached to the tip of the driving nose 13 has a soft cover 27 as an outer part, and has a centering claw 28 for holding a driven screw and regulating the position. . The centering claw 28 is divided into a plurality of parts, and each claw part is urged toward the center by a spring 29.

By operating the tightening depth adjusting screw 13b provided on the driving nose 13, the position of the contact block 26 with respect to the driving nose 13 in the front-rear direction changes.

Air supply chamber 1a at the handle of body 1
Is provided with a sheath-shaped trigger valve receiver 1s having a small hole 1r, and a trigger valve 30 is slidably provided therein. The trigger valve 30 is a spring 30
a, the front end is held by the trigger lever 31. The body 1 has a rotating shaft 32a
A safety device 32 is provided which pivots around the lever, and the operation of the safety device allows the trigger lever 31 to be locked in a non-operation state.

In the non-operation state in which the safety device 32 is removed in FIG. 2, the trigger air supply passage 1j is connected to the trigger air discharge passage 1 by two sets of O-rings attached to the trigger valve 30.
m, and the small hole 1r communicates with the trigger air supply passage 1j to fill the trigger air chamber 1b with air (compressed air). (Lower side in the drawing). At this time, the drive air chamber 1c is completely shut off from the air supply chamber 1a by the action of the gasket 3c attached to the lower surface of the head valve 3.

FIG. 3 shows a state in which the safety device 32 is released and the trigger lever 31 shown in FIG. 2 is rotated in the counterclockwise direction, that is, the O-ring portion of the trigger lever 31 moves toward the rear end and the trigger air is released. This is a state in which the supply path 1j and the trigger air discharge path 1m are in communication with each other, and the air in the trigger air chamber 1b is discharged to the outside by this communication.

The discharge of the air causes the trigger air chamber 1b.
When the internal pressure decreases, the pressure of the air accumulated in the gap between the leg portion 3b of the head valve 3 and the cylinder holding portion 1k becomes larger than that of the trigger air chamber 1b.
As a result, the head valve 3 and the gasket 3c are pushed up against the urging force of the spring 4, and air (compressed air) flows from the air supply chamber 1a toward the drive air chamber 1c (direction A).

The air continues to flow into the drive air chamber 1c, which is in communication with the air supply chamber 1a due to the rearward movement of the gasket 3c, and the piston 5 and the driver 6 integrated therewith and the air supply sheath are formed. The part 8 advances.

A part of the air flowing into the drive air chamber 1c is supplied to the input side small hole 8a, the air passage 8c, and the output side small hole 8b.
The internal space 2a of the valve cap 2 is supplied to the air motor 12 via the air supply path 1f for the air motor (direction B). The output of the air motor 12 is transmitted to the bevel gear 9 via the speed reducer 11 and becomes a driving force for rotation of the driver 6.

The leading screw 15a, which has been waiting at the operating position of the driver 6, receives the force in the rotating direction and the biting direction from the driver 6, and is positioned by the centering claw 28 of the contact block 26 so as to be screwed. 33
Will be tightened.

A part of the air flowing into the drive air chamber 1c tends to flow toward the drive air discharge passage 1n through a gap between the head valve 3 and the air supply sheath 8; Since the inner upper end surface of the head valve 3 is sealed by the gasket 2c, the inflow air does not leak from the exhaust muffler 1q to the external space.

The piston 5 advances with the inflow of air into the drive air chamber 1c, and the upper edge of the piston 5
After passing through the position of the small hole 7b,
Through the air chamber 1e outside the cylinder, and from there, it proceeds to the path of the ventilation hole 7c-the air chamber 1d for return and the air supply path 1h for screw feed-the air chamber 1g for screw feed.

The screw feed piston 21 retreats in the direction of the set position of the magazine case 17 (rightward in the figure) against the spring 22 in accordance with the amount of air supplied to the screw feed air chamber 1g. I do.

FIG. 4 shows a state in which the automatic screw tightening operation has been completed. At this time, the piston 5 that drives the driver 6 in the forward direction hits the damper 1p and stops, and the retreat distance of the screw feed piston 21 is maximum.

Further, the air supply sheath 8 which is interlocked with the piston 5 also moves forward, and the portion of the cap 2 corresponding to the O-ring 8d provided at the rear end thereof changes from the long diameter portion to the short diameter portion. Then, the seal between the O-ring 8d and the minor diameter portion is changed.
The output side small hole 8b of the sheath portion 8 for air supply and the air supply passage 1f for the air motor are shut off by the action of air.

By this interruption, the air supply to the air motor 12 is stopped, and the torque transmitted from the air motor 12 to the driver 6 via the reduction gear 11 and the bevel gear 9 also disappears.
The driver 6 stops.

FIG. 5 shows a state in which the trigger lever 31 is released after the automatic screw tightening operation of FIG. 4 is completed. At this time, the trigger lever 31 returns to the position shown in FIG. 1 by the action of the trigger valve 30 and the spring 30a, and the trigger air supply path 1j is cut off from the external space to be in communication with the air supply chamber 1a.

For this reason, air (compressed air) is supplied to the trigger air chamber 1b through the air supply chamber 1a, the small hole 1r, and the trigger air supply path 1j, and the pressure in the air chamber increases with time. When the forward driving force based on the pressure and the elastic force of the spring 4 with respect to the valve 3 exceeds the backward driving force based on the previous pressure of the driving air chamber 1c, the head valve 3 moves forward, the gasket 3c provided at the front end thereof comes into strong contact with the rear edge of the cylinder 7 and the cylinder holding portion 1k of the body 1, and stops there.

By the sealing action based on the pressure contact between the gasket 3c and the cylinder 7, the air from the air supply chamber 1a to the drive air chamber 1c and the subsequent return air chamber 1d and screw feed air chamber 1g. The supply is interrupted.

At the time of this interruption, the pressure in the drive air chamber 1c is higher than that in the return air chamber 1d. Thereafter, the air in the drive air chamber 1c is discharged from the drive air discharge passage 1n to the exhaust muffler. -1q to the external space, and to the return air chamber 1d through the small hole 7b with the check valve 7a and the ventilation hole 7c without the check valve.
The above pressure relationship is reversed.

Due to this pressure difference, the piston 5 and the driver 6 and the air supply sheath 8 which cooperate with the piston 5 return to the rear, and the rear end of the air supply sheath 8 becomes a damper as shown in FIG. 2b.

In connection with the end of the return operation, the air in the return air chamber 1d and the screw feed air chamber 1g is supplied to the outer peripheral surface of the driver 6 and the corresponding inner peripheral surface of the body 1 and the driving nozzle.
Leaks into the external space from a slight gap with the inner peripheral surface of the screw 13 to prepare for the next automatic screw tightening operation.

When the pressure of the screw feed air chamber 1g decreases and the elastic force of the spring 22 becomes stronger than the pressure, the screw feed piston 21 advances and the entire connection screw 15 is screwed. The driver 6 is moved toward the operation position of the driver 6 by one.

In the above description, when the air motor 12 is stopped at the end of the automatic screw tightening operation, the air supply path 1f for the air motor is cut off at a portion interlocked with the piston. Various switches and sensors are used to detect that the piston and its interlocking part have advanced to the position where the automatic screw tightening is completed, and the output thereof controls the operation of the air motor 12 and its output-side clutch. You may.

FIGS. 6 and 7 are explanatory views showing a mechanism for feeding the connecting screw.
5 is fed out while being guided by the case-side guide 17a and the feed-side guide 19, and the leading screw 15a is moved to the operating position of the driver 6.

At this time, the tip portion 24 of the screw feed claw 24
a is in contact with the rear peripheral surface of the second screw 15b from the top, and the distal end portion 20a of the screw detent claw 20 is inserted between the second screw 15b and the third screw 15c from the top to secure the screw 15b. It is in contact with the rear peripheral surface.

The screw feed pawl 24 is attached to the screw feed piston 21 and rotates counterclockwise around the rotation shaft 21a by the action of the spring 25.
It is attached to the feed-side guide portion 19 and rotates clockwise around a rotation shaft 19b by the action of a spring 19a.

With the screw tightening operation of the leading screw 15a by the driver 6, the air is supplied to the screw feed air chamber 1g through the screw feed air supply path 1h as described above, and the screw feed piston 21 Retreats against the elastic force of the spring 22, and at the same time, the screw feed pawl 24
Also rotates backward in the clockwise direction, and the contact partner of the distal end portion 24a thereof is changed from the previous screw 15b to the immediately succeeding screw 1b.
5c (dotted line state).

During the retreat of the screw feed pawl 24, the distal end portion 20a of the screw detent pawl 20 holds the rear peripheral surface of the screw 15b, so that the entire connecting screw 15 does not retreat. It remains in its original condition.

With the end of the screw tightening operation of the leading screw 15a, as described above, the pressure of the air in the screw feed air chamber 1g leaks to the external space, so that the screw feed piston 21 has the elasticity of the spring 22. At the same time, the screw feed claw 24 advances while pushing the rear peripheral surface of the screw 15c with its tip 24a.

By the advance of the screw feed pawl 24, the entire connecting screw 15 is in the screw tightening operation position (left direction in the drawing).
, And the screw 15b is subjected to the next screw tightening operation. Further, the distal end portion 20a of the screw detent claw 20 rotates counterclockwise once it is pressed by the front peripheral surface of the screw 15c, and after the screw 15c gets over the screw, the spring 19
Due to the action of a, the screw 15c is returned in the clockwise direction to hold the rear peripheral surface of the screw 15c.

Magazine case 1 for housing connection screw 15
7 is a bottom structure 1 in which an upper bottom plate 16a and a lower claw mounting disk 16b are integrated with a countersunk screw 16h on the bottom side.
6 are provided. The bottom structure 16 is a magazine case 17
Can be moved up and down and rotatable, and the setting and changing of the up and down position are performed with a knob 16g.

The concave portion 16c of the claw mounting disk 16b is provided with a bottom plate fixing claw 16e having the pivot shaft 16d as a fulcrum and a spring 16f for urging the bottom plate fixing claw counterclockwise (FIG. 6, FIG. 6). The bottom structure 16 is held at a predetermined height in the magazine case 17 with the bottom plate fixing claws 16e inserted in the concave grooves 17a of the magazine case 17 (see FIG. 8).

The casing 18 (omitted in FIG. 7)
Are attached to the magazine case 17 at each of a pin 17f and a latch 17g.

FIG. 8 is an explanatory view showing the relationship between the bottom structure 16 and the magazine case 17. In the illustrated case, the recesses 17b to 17e provided in the magazine case 17 have four stages. The bottom structure 16 is set in the lowermost groove 17b.

Here, when replacing the connecting screw in the magazine case 17 with a lower one, first, the bottom structure 16 is rotated counterclockwise by holding the knob 16g and the bottom plate is Insert the tip of the stopper claw 16e into the groove 17b.
Is moved from the tape-shaped end face 17b 'to the inner circumferential face of the magazine case 17 while rotating the bottom plate fixing claw 16e clockwise against the spring 16f (see FIG. 6). Next, the bottom structure 16 is raised to a height corresponding to the connecting screw to be loaded, for example, to the position of the concave groove 17c. Next, the bottom structure 16 is counterclockwise rotated at the height at the bottom plate fixing claw. What is necessary is just to rotate until 16e enters into the recessed groove 17c.

The tapered end surfaces 17b 'to 17e' are provided only on the counterclockwise front ends of the respective grooves 17b to 17e, and the rear end surfaces in those directions are not tapered.
Therefore, the entirety of the connecting screw 15 placed on the bottom plate 16a of the bottom structure 16 is in the screw tightening operation position (clockwise).
The bottom plate fixing claw 16e of the bottom structure 16 which receives the clockwise turning force when moving to
Does not move beyond the rear end surface to the inner peripheral surface of the magazine case 17. That is, magazine case 1
7, the bottom plate stopper claw 1 which has entered the concave grooves 17b to 17e
6e is locked with respect to its own clockwise rotation.

The connecting screw 1 to the magazine case 17
In the storage form 5, the position of the bottom plate that receives the tip portion is fixed, and the setting position of the holding plate (corresponding to the bottom structure 16) of the head is selected according to the length (height) of the connection screw 15. It may be in the form of doing.

[0057]

As described above, according to the present invention, the air motor for rotation of the driver of the screw tightening machine using air is automatically stopped at the end of the screw tightening. Variations in depth and degree can be eliminated, and screw tightening accuracy can be increased.

Further, the screw mounting plate in the magazine case for accommodating the connecting screws is formed into a vertically movable form, and is moved to a position corresponding to the length of the screws before being held in the magazine case. With this configuration, a single magazine case can handle various connecting screws having different lengths (heights).

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an overall outline of an automatic screw tightening machine.

FIG. 2 is an explanatory view showing a non-operating state of the automatic screw tightening machine.

FIG. 3 is an explanatory diagram showing an initial state of a screw tightening operation.

FIG. 4 is an explanatory diagram showing an end state of a screw tightening operation.

FIG. 5 is an explanatory diagram showing a return state of the driver after screwing is completed.

FIG. 6 is an explanatory view showing a screw supply mechanism to a driver operating position.

FIG. 7 is an explanatory view showing a screw supply mechanism to a driver operating position, and FIG. 7 (b) is a sectional view corresponding to AA in FIG. 7 (a).

FIG. 8: Bottom structure (holding plate) in connection screw case
It is explanatory drawing which shows the height adjustment mechanism.

[Explanation of symbols]

 1: Body 1a: Air supply chamber 1b: Trigger air chamber 1c: Drive air chamber 1d: Return air chamber 1e: Cylinder outside air chamber 1f: Air motor air supply path 1g: Screw feed air chamber 1h: Screw feed Air supply path for use 1j: Air supply path for trigger 1k: Cylinder holding section 1m: Air discharge path for trigger 1n: Air discharge path for drive 1p: Damper 1q: Exhaust muffler 1r: Small hole 1s: Trigger valve receiver 2: Valve cap 2a: Internal space 2b: Damper 2c: Gasket 3: Head valve 3a: Spring receiver 3b: Leg 3c: Gasket 4: Spring 5: Piston 6: Driver 7: Cylinder 7a: Check valve 7b: Small hole 7c: Vent hole 8: Air supply sheath 8a: Input side small hole 8b: Output side small hole 8c: Air passage 8 : O-ring 9: bevel gear 10: bottom cover 11: speed reducer 12: air motor 13: driving nose 13 a: arm 13 b: tightening depth adjusting screw 14: holding belt 15: connecting screw 15 a: leading screw 15 b: second 15c: Third screw 16: Bottom structure 16a: Bottom plate 16b: Claw mounting disk 16c: Recess 16d: Rotating shaft 16e: Bottom plate fixing claw 16f: Spring 16g: Knob 16h: Countersunk screw 17: Magazine Case 17a: Case-side guide portion 17b-17e: Concave groove 17b'-17e ': Tapered end surface 17f: Pin 17g: Latch 18: Magazine case cover 19: Feed-side guide portion 19a: Spring 19b: Rotating shaft 20: Screw Detent claw 20a: Tip 21: Screw feed piston 21a: Rotating shaft 22: Spring 2 : Cylinder 24: Screw feed claw 24a: Tip 25: Spring 26: Contact block 27: Soft cover 28: Centering claw 29: Spring 30: Trigger valve 30a: Spring 31: Trigger lever 32: Safety device 32a: Rotating shaft 33: Screw fastening member

Claims (6)

[Claims] 1. An automatic screw tightening machine using air as a driving source of a driver for driving a screw in a biting direction and a rotating direction, wherein an output side of an air motor which is a driving unit of the driver in the rotating direction is connected to the driver. An automatic screw tightening machine provided with screw tightening stopping means for stopping when the screw moves to the screw tightening end position in the biting direction. 2. An automatic screw tightening machine according to claim 1, wherein said screw tightening stop means includes a cut-off section for cutting off air supply to said air motor. 3. The automatic screw tightening machine according to claim 2, wherein a sealing portion provided on an air supply member interlocked with the driver is used as the blocking portion. 4. The automatic screw tightening machine according to claim 1, wherein a transmission control unit that cuts off transmission of the output of the air motor to the driver is used as the screw tightening stopping unit. 5. A screw feeding portion for feeding a next driven screw in a connecting screw to a driver action position, wherein a screw behind the driven screw is supplied with air in connection with the movement of the driver in the biting direction. 5. The automatic screw tightening machine according to claim 1, further comprising an air supply path for moving the screw between the screw and the subsequent screw. 6. A connecting screw case for storing a connecting screw in an upright state, wherein height adjusting means for selectively setting a holding plate for regulating a vertical position of the connecting screw at a different height is provided. Characteristic connection screw case.