JPH09174354A - Automatic screw fastener - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic screw fastener which is suitable for holding and fastening screws different in length. SOLUTION: This automatic screw fastener is constituted in such a way that a driver unit 2 having a screw fastening tool rotatable by driving of an AC servomotor is arranged so as to be raised and lowered by driving of a raising-lowering driving source, and a chuck unit 3 is arranged so as to be integrally raised and lowered with this driver unit 2 and to be independently raised and lowered, and a chuck claw 12 is arranged in this chuck unit 3. In the chuck unit 3, a supply sleeve 10b to guide a screw to be supplied is arranged in axially parallel to the screw fastening tool, and the chuck claw 12 is constituted so as to reciprocate between a moving passage of the screw fastening tool and the tip of the supply sleeve 10b by actuation of a sliding mechanism 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic screw tightener for tightening a screw on a work.

[0002]

2. Description of the Related Art Conventionally, an automatic screw fastening machine is generally known as a means for fastening a screw to a work. As this automatic screw tightener, a screw tightening tool that rotates by driving a rotary driving source such as a motor, for example, a driver unit equipped with a driver bit, a box bit, etc., is placed on a driver base that can be raised and lowered by driving a lifting drive source. A chuck unit for holding a screw is usually arranged on the screw tightening tool moving path of the driver unit. The chuck unit in this automatic screw tightener is configured to always close the chuck body and arrange a pair of chuck claws.
Holding holes are formed separately so as to guide and hold the screws in the closed state. In addition, a passage for the screw is formed in the chuck main body so that the screw, which is fed from a feeding hose extending from the screw feeding device, can reach the holding hole of the chuck claw.

[0003]

In the above automatic screw tightening machine, the guide sleeve formed on the chuck body and the holding hole for the chuck claw are generally provided so as to communicate with each other in a bent state. For this reason, if the size of the supplied screw becomes long, it is necessary to make the angle of this bent portion as large as possible to reduce the incident angle when supplying the screw, which causes the chuck body to become long and However, in order to reliably take in such a screw, the chuck claw becomes long, and the chuck unit becomes large. In addition, different chuck units are required depending on the length of the screw, which causes a problem that the applicability of one chuck unit is very poor. On the other hand, in the automatic screw tightener having the chuck unit configured such that the guide sleeve and the chuck claw are bent and communicate with each other, the screw is inclined when the screw is transferred from the guide sleeve to the chuck claw, so There is also a problem that the thread directly collides with the holding hole regardless of the length of the screw, and is deformed at that time.

[0004]

SUMMARY OF THE INVENTION An automatic screw tightener according to the present invention is provided with a driver unit having a screw tightening tool that can be rotated by driving a rotary drive source, and the driver unit can be moved up and down by driving an elevator drive source. A chuck unit that can be moved up and down integrally with the driver unit and can be moved up and down independently of the driver unit is provided, and a chuck claw that holds a screw on the movement path of the screw tightening tool is expanded in this chuck unit. It is arranged to be possible. In this automatic screw tightener, a supply sleeve that guides the screw supplied from the screw supply device is provided so as to guide the screw parallel to the screw tightening tool, and the chuck claw is operated by the slide mechanism. It is configured to reciprocate between the moving path and the tip of the supply sleeve. Further, a stopper that can prevent the chuck claws from expanding is also provided on the moving path of the screw tightening tool and at the tip of the supply sleeve.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4, reference numeral 1 denotes an automatic screw tightening machine, which includes a driver unit 2 for fastening a supplied screw to a work, a chuck unit 3 for holding the screw on a moving path of the driver unit 2, and the driver unit. 2 and the lifting / lowering drive unit 4 for controlling the movement operations of the chuck unit 3, respectively.

The driver unit 2 includes a driver base 5
It has an AC servo motor 6 which is an example of a rotary drive source installed above, and an output shaft of this AC servo motor 6 is connected with an internal hollow drive shaft 7 which extends downward and extends downward. There is. In addition, the driver base 5 has a drive shaft 7
A guide portion 8 for guiding the guide shaft 8 is attached, and an external suction device (not shown) is connected to the guide portion 8 during screw tightening work so that air is sucked through the inside of the drive shaft 7. Is configured. Further, a screw tightening tool 9 is connected to the tip of the drive shaft 7. The screw tightening tool 9 has a hollow portion that communicates with the drive shaft 7 and that has a drive portion 9a that engages with an engaging portion of a screw. In the embodiment of the present invention, the screw tightening tool 9
A box bit used when fastening a hexagonal bolt (hereinafter simply referred to as a bolt), which is an example of a screw, is selected as the screw tightening tool 9.
Through hole 9b communicating with the drive shaft 7 is formed so that air can be sucked from the tip.

The chuck unit 3 is provided below the driver unit 2 and has a chuck base 10 having a guide sleeve 10a for guiding the screw tightening tool 9 of the driver unit 2. On this chuck base 10,
Two first slide shafts 11b and 11b capable of reciprocating in the lateral direction (direction orthogonal to the axis of the screw tightening tool) by the operation of the first cylinder 11a, and the first slide shafts 11b and 1
Chuck claw mounting plate 1 attached to the tip of 1b
A slide mechanism 11 including 1c and 11c is provided. The first slide shaft 11b of the slide mechanism 11,
11b and chuck claw mounting plates 11c and 11c correspond to the guide sleeve 10a and a supply sleeve 10b described later.
It is arranged at a position where it reciprocates with the pinch in between, and is configured to be able to move without intersecting the movement path of the screw tightening tool 9.

Further, the chuck claw mounting plate 11c of the slide mechanism 11 has a pair of expandable chuck claws 12,
12 is urged so that it is always closed. The chuck claws 12 and 12 have a structure in which a holding hole 12a for guiding and holding a screw is formed separately on the opposite surfaces, and the holding hole 12a is communicated with the guide sleeve 10a by the operation of the first cylinder 11a. It is configured to reciprocate between a position where the holding hole 12a is communicated with a position where the holding hole 12a communicates with a supply sleeve 10b provided adjacent to the guide sleeve 10a. The supply sleeve 10b is arranged in parallel with the screw tightening tool 9 guided by the guide sleeve 10a in the axial line.
A feed hose 13 extending from an external bolt supply device (not shown) is connected. In addition, these guide sleeves 1
0a, the lower end surface of the supply sleeve 10b is on the same plane,
Further, the upper surface positions of the holding holes 12a of the chuck claws 12, 12 are set to be located on the same surface.

The chuck claw 1 is attached to the chuck base 10 at the leading end position of the supply sleeve 10b and the leading end position of the guide sleeve 10a on the moving path of the screw tightening tool 9.
A stopper is provided to support the blades 2 and 12 so that they cannot be expanded. This stopper is composed of first and second stoppers 15 and 16 positioned before and after the chuck claws 12 and 12 in the moving direction. The first stopper 15 of this stopper is provided below the guide sleeve 10a so as to restrict the expansion of the chuck claws 12, 12, and as shown in FIG. 5, has a trapezoidal notch 17a at the bottom. It is composed of a stop plate 17 and a second cylinder 18 that reciprocates the locking plate 17 up and down. The second stopper 16 is provided below the supply sleeve 10b so as to restrict the expansion of the chuck claws 12, 12, and is a locking plate having a circular engagement hole 19a formed on the side surface of the chuck base 10. It is configured by attaching 19. It should be noted that, corresponding to the first and second stoppers 15 and 16, the engaging members 20 and 21 are provided on the respective surfaces facing the moving direction of the chuck claws 12 and 12.

Regarding the engaging members 20 and 21 provided on the chuck claws 12 and 12, the engaging member 20 provided corresponding to the first stopper 15 is the chuck claws 12 and 12.
Each of the cam followers and the like is provided so as to project, and is configured to engage with the notch portion 17a in the lower portion of the locking plate 17 of the first stopper 15 when the chuck claws 12 are closed. Further, the engaging member 21 provided corresponding to the second stopper 16 includes the chuck claws 12,
When the chuck claw 12 is in the closed state, the chuck claws 12 and 12 are divided and arranged in a substantially cylindrical shape.
It is arranged to engage with the engagement hole 19a of the second stopper 16 when the lower portions 2 and 12 reach the lower portion of the supply sleeve 10b in the closed state.

Further, the chuck unit 3 is provided with a space adjusting mechanism 22 for adjusting the space between the chuck unit 3 and the driver unit 2. This interval adjusting mechanism 22
Third cylinder 2 mounted on the upper surface of the chuck base 10
2a and a shaft 22b which is connected to the rod of the third cylinder 22a and penetrates the upper driver base 5 so as to be inserted therethrough.
And a stopper member 22c fixed to the tip of the shaft 22b protruding above the driver base 5,
The chuck unit 3 is supported so that the stopper member 22c is always locked to the upper surface of the driver base 5 so as to be hung on the driver base 5, and the chuck unit 3 separates from and approaches the driver unit 2 as the rod of the third cylinder 22a expands and contracts. It is configured to be able to.

The elevating control unit 4 comprises an elevating drive source 23 for integrally elevating the driver unit 2 and the chuck unit 3, and a positioning mechanism 24 capable of positioning the chuck unit 3 at an arbitrary position. First, regarding the lifting drive source 23, the lifting drive source 23 has an AC servo motor 26 installed on a base member 25 that can be attached to a moving means such as an XY table (not shown). A ball screw mechanism 27 that operates by driving is arranged. The ball screw mechanism 27 in the up-and-down drive source 23 is configured so that a bearing 27b that moves along the axis of the ball screw mechanism 27, which is arranged perpendicularly to the axis, can move in the vertical direction. Is connected to the driver base 5 of the driver unit 2 and is configured to move the driver base 5 integrally.

The positioning mechanism 24 has two second slide shafts 28, 28 which are guided by the upper and lower side portions of the base member 25 and can move up and down, and the lower ends of the respective second slide shafts 28. The chuck base 10 of the chuck unit 3 is integrally connected to the above. As shown in FIG. 6, each second slide shaft 28 of the positioning mechanism 24 has a structure in which it is connected by a connecting member 29 to operate integrally, and a pinion gear 30 is rotatably attached to the connecting member 29. The brake means 31 is provided and brakes the rotation of the rotating shaft 30a of the pinion gear 30. Further, a rack 32, which meshes with the pinion gear 30 of the connecting member 29, is attached to the base member 25 so as to extend vertically, and the pinion gear 30 is moved by the vertical movement of the second slide shaft 28.
It is configured to move along 2.

In the automatic screw tightener 1 having the above structure,
In the screw tightening work, first, the first cylinder 11a operates to move the chuck claws 12, 12 below the supply sleeve 10b. At this time, the engaging members 21 of the chuck claws 12, 12 are fitted into the engaging holes 19a of the second stopper 16, so that the chuck claws 12, 12 cannot be expanded.
In this state, a hexagonal bolt (hereinafter, simply referred to as a bolt) from a bolt supply device (not shown) through the feed pipe 13.
Is pneumatically fed to hold the chuck jaws 12, 12 in the holding hole 12a.
Supplied and held. At this time, since the length from the supply sleeve 10b to the holding holes 12a of the chuck claws 12, 12 is linear, the supply is not limited by the length of the bolt, and the chuck can be used for any length of bolt. It is possible to satisfactorily supply the claws 12, 12. In addition, the chuck claws 1 are connected to the supply sleeve 10b.
In the supply method in which the holding holes 12a of the nozzles 2 and 12 are linearly formed, the chuck claws are supplied at the time of supplying the bolt, as compared with the conventional chuck unit in which the feed pipe and the chuck claw holding holes are bent and connected. Although the impact applied to 12, 12 increases, in this automatic screw tightening machine 1, the chuck claws 12, 12
Since the second stopper 16 prevents the expansion of
It is possible to prevent the chuck claws 12, 12 from expanding due to an impact when the bolt is supplied, and prevent a problem such that the bolt pops out from the chuck claws 12, 12.

When the bolts are supplied to the chuck claws 12 and 12 as described above, the first cylinder 11a moves back to move the chuck claws 12 and 12 below the guide sleeve 10a, and the chuck claws 12 and 12 are moved. The axis of the held bolt is aligned with the axis of the screw tightening tool 9 guided by the guide sleeve 10a, the second cylinder 18 is operated to lower the locking plate 17, and the notch portion 17a serves as the engaging member 20. The chuck claws 12, 12 are engaged with each other so that they cannot be expanded. When the AC servomotor 26 is driven in this state, the bearing 27b of the ball screw mechanism 27 starts to descend along the screw shaft 27a, and the driver unit 2 is integrated with this.
Is lowered.

When the driver unit 2 is lowered, the chuck unit 3 should also be lowered by its own weight, but at this time, the rotation of the pinion gear 30 is suppressed by the operation of the brake means 31, and the chuck unit 3 is suppressed.
Is unable to descend. Therefore, the screw tightening tool 9 reaches the bolts held by the chuck claws 12, 12 as the driver unit 2 descends, and the screw tightening tool 9 rotates by the driving of the AC servomotor 26 and fits into the bolt. . At this time, chuck claw 1
Since the second and the second stoppers 12 cannot be expanded by the first stopper 15, the screw tightening tool 9 can be securely fitted to the bolt. Further, since air is sucked from the tip of the screw tightening tool 9 by the operation of a suction device (not shown), the bolt is fitted to the screw tightening tool 9 and is sucked at the same time so as not to drop from the screw tightening tool 9. Held in.

When the third cylinder 22a is driven while the screw tightening tool 9 is fitted to the bolt and the bolt is suction-held as described above, the stopper member 22c separated from the driver base 5 due to the lowering of the driver unit 2.
Descends until it comes into contact with the driver stand 5, and the braking means 3
It is adjusted so that the distance between the driver unit 2 and the chuck unit 3 does not change even if the braking by 1 is released.
As a result, the driver unit 2 and the chuck unit 3 can be integrally lowered by driving the AC servomotor 6 while the bolts are held by the chuck claws 12, 12. It is possible to prevent the runout of the bolt that is seen when the bolt is held by the screw tightening tool 9.

After that, when the chuck unit 3 reaches the bolt fastening position of the work, the brake means 31 is activated again to stop the lowering of the chuck unit 3 and lower only the driver unit 2. At this time, the second cylinder operates to pull up the locking plate of the first stopper from the position where it engages with the engaging member, and returns the chuck to a state in which it can be expanded. Therefore, the bolts held by the chuck claws 12, 12 are pushed out by the screw tightening tool 9, and are fastened to the work as the screw tightening tool 9 is rotated by the driving of the AC servomotor 6.

In the automatic screw tightening machine 1, since the first slide shafts 11b and 11b of the slide mechanism 11 and the chuck claw mounting plates 11c and 11c do not intersect the moving path of the screw tightening tool 9, the screw tightening is performed. Even when the tool 9 is expanding the chuck claws 12, 12 and fastening the bolt to the work, the chuck claws 12, 12 are moved to the tip of the supply sleeve 10b by the operation of the first cylinder 11a, and It is possible to supply and hold various bolts.

[0020]

As described above, in the automatic screw tightening machine of the present invention, the supply sleeve is arranged in parallel with the screw tightening tool and the supply pipe extending from the bolt supply device is connected to the supply sleeve. By connecting the chuck claw to the slide mechanism and reciprocating between the guide sleeve tip position and the supply sleeve tip position on the moving path of the screw tightening tool, the screw axis is parallel to the screw tightening tool axis. It is possible to supply in the state, and it is possible to supply well even if the dimension of the screw becomes long, and it is possible to supply corresponding to an extremely wide range of screw lengths. Further, since the first and second stoppers that can prevent the chuck claws from expanding are provided at the positions of the guide sleeve tip and the supply sleeve tip, respectively.
Even if the supply sleeve and the holding hole of the chuck claw are linear like in this automatic screw tightener, and the shock when the pneumatically fed screw is supplied to the chuck claw is large, the shock causes the chuck claw to expand. The screw can be held securely without opening, and when the chuck claw is on the movement path of the screw tightening tool, the screw tightening tool can be fitted to the bolt head before tightening. In particular, when the bolt is held by suction, the bolt can be securely held and the tightening work can be challenged. Further, since the slide mechanism is configured to move the chuck claws in parallel by moving the first slide shaft located with the guide sleeve interposed therebetween, the chuck claws are slid even when the bolts are fastened. It is possible to supply and hold various bolts to the chuck claws, and it is possible to shorten the cycle time related to the fastening work and perform a quick screw fastening work.

[Brief description of the drawings]

FIG. 1 is a front view of an automatic screwing machine according to the present invention.

FIG. 2 is a cross-sectional view showing the internal configuration of the automatic screw tightener according to the present invention.

FIG. 3 is a side view of the automatic screw tightener according to the present invention.

FIG. 4 is a bottom view of the automatic screw tightener according to the present invention.

FIG. 5 is an enlarged sectional view of an essential part showing the vicinity of the first stopper of the automatic screw tightener according to the present invention.

FIG. 6 is an enlarged sectional view of an essential part showing the vicinity of the brake mechanism of the automatic screw tightener according to the present invention.

[Explanation of symbols]

 1 Automatic Screw Tightening Machine 2 Driver Unit 3 Chuck Unit 4 Elevating Drive Unit 5 Driver Stand 6 AC Servo Motor 9 Screw Tightening Tool 10 Chuck Stand 10a Guide Sleeve 10b Supply Sleeve 11 Sliding Mechanism 11a 1st Cylinder 11b 1st Sliding Shaft 11c Chuck Claw Mounting plate 12 Chuck claw 15 First stopper 16 Second stopper 17 Locking plate 18 Second cylinder 19 Locking plate 20 Engaging member 21 Engaging member 22 Interval adjusting mechanism 22a Third cylinder 22b Shaft 22c Stopper member 23 Lifting drive source 24 Positioning Mechanism 25 Base Member 26 AC Servo Motor 27 Ball Screw Mechanism 28 Second Slide Shaft 30 Pinion Gear 31 Brake Means

Claims (5)

[Claims] 1. A driver unit having a screw tightening tool rotatable by driving of a rotary drive source is provided, the driver unit is arranged so as to be able to move up and down by the drive of an elevator drive source, and the driver unit can be raised and lowered integrally with the driver unit. A chuck unit that can move up and down independently of the driver unit is provided, and a chuck claw that holds the screw on the moving path of the screw tightening tool is arranged in this chuck unit, while guiding the screw supplied from the screw supply device. An automatic screw tightening machine, characterized in that a supply sleeve is provided, and the chuck claw is configured to be capable of reciprocating between a movement path of a screw tightening tool and a tip of the supply sleeve by operating a slide mechanism. 2. A driver unit having a screw tightening tool rotatable by driving of a rotary drive source is provided, the driver unit is arranged so as to be able to move up and down by the drive of a lifting drive source, and the driver unit can be raised and lowered integrally with the driver unit. A chuck unit that can move up and down independently of the driver unit is provided, and a chuck pawl that holds a screw on the movement path of the screw tightening tool is arranged in the chuck unit so as to be expandable, while it is supplied from a screw supply device. A supply sleeve for guiding the screw is provided, and the chuck claw is configured to reciprocate between the movement path of the screw tightening tool and the tip of the supply sleeve by the operation of the slide mechanism. A stopper that prevents the chuck claw from expanding at the sleeve tip is provided. Automatic screwing machine, wherein the door. 3. The supply sleeve is arranged parallel to the screw tightening tool in the axis line.
Automatic screw tightener described in. 4. A first stopper capable of preventing the chuck claw from expanding when the chuck claw is positioned on the moving path of the screw tightening tool, and a chuck claw when the chuck claw is positioned at the tip of the supply sleeve. The automatic screw-fastening machine according to claim 2, further comprising a second stopper that prevents expansion of the opening. 5. The automatic screw tightener according to claim 1, wherein the slide mechanism operates without intersecting with a moving path of the screw tightening tool.