JPH09131627A - Screwing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the tightening time of a screw as a whole by providing a suction force producing means to produce the suction force to engage the screw held by a screw holding means with a driver bit. SOLUTION: While a screw is tightened by a screw tightening driver unit 25, a next screw 28 is sucked by the suction force and once held in the constant condition by a screw holding part 24C. After the tightening of the first screw is completed, the screw holding part 24C is moved immediately below the screw tightening driver unit 25, and the screw held by te screw holding part 24C is engaged with a driver bit 25B by the suction force. Thus, the time from the completion of tightening of one screw to the starting of tightening of the next screw can be shortened, and screws can be stably fed to the driver bit 25B.

Description

Detailed Description of the Invention

[0001]

[Table of Contents] The present invention will be described in the following order. BACKGROUND OF THE INVENTION Technical Field of the Invention Conventional Technology (FIGS. 7 to 9) Problems to be Solved by the Invention Means for Solving the Problems Embodiments of the Invention (FIGS. 1 to 6) (1) Overall Configuration (FIG. 1) (2) Configuration of screw tightening driver unit (FIGS. 2 and 3) (3) Configuration of screw holding unit moving unit (FIGS. 4 to 6) (4) Operation and effect of embodiment (5) Other embodiment Invention Effect of

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw tightening device, and more particularly, to a screw aligning and feeding device which conveys a screw to a screw tightening driver unit by means of a screw conveying tube or the like to screw the screw to an object to be screwed. It is suitable for application to a screw tightening device.

[0003]

2. Description of the Related Art Conventionally, as a method of supplying a screw to the tip of a driver bit in a screw tightening device, a method of picking up the screw directly from a screw aligning and supplying device (hereinafter referred to as a first screw supplying method), a screw aligning method. A method of feeding the compressed air from the supply device to the driver section (hereinafter referred to as a second screw supply method) and a method of adhering the screw conveying tube to the tip of the driver bit to directly suck the screw from the driver (hereinafter , Which is referred to as a third screw supply method).

In the first screw supply method, as shown in FIG. 7, after the screws 2 are aligned in a row by the screw alignment supply device 1, the driver 3 is placed above the screw 2A positioned at a predetermined position. Move the driver 3 to screw 2A
The screw 2A is lowered to the position of (3) and the screw 2A is sucked by a screw suction device (not shown) provided in the driver 3 to be engaged with the driver bit.

In the second screw supply method, the screws aligned by a screw alignment supply device (not shown) are used as shown in FIG.
As shown in (A) and (B), the compressed air supply unit of the screw alignment supply device is pressure-fed and supplied to the tip 5A of the driver 5 via the screw conveying unit 4 such as a tube.

In this case, the next screw 2B is supplied to the driver 5 while the screw 2A is fastened to the work (object to be screwed) 7 by the driver bit 6 (FIG. 8A), and the screw 2A When the screw tightening is completed and the driver bit 6 finishes ascending, the next screw 2A is moved to the tip 5 of the driver 5.
When the driver bit 6 moves down to A, the screw 2
B engages with the driver bit 6 (FIG. 8).
(B)). Here, the tip portion 5A of the driver 5 is configured to be openable and closable, and when the screw 2A is screwed to the work 7, the tip portion 5A is opened and the screw tightening is completed and the next screw 2 is screwed.
When B is supplied, the tip 5A is closed.

In the third screw feeding method, as shown in FIG. 9, a screw conveying tube 10 is directly brought into close contact with the tip of a mouthpiece 9 provided outside the driver bit 8. The screws aligned by (not shown) are sucked by a screw suction device (not shown) provided in the driver 11, so that the screws 2A are directly drawn into the mouthpiece 9.

[0008]

However, in the first screw feeding method described above, the driver 3 must be moved to a predetermined position of the screw aligning and feeding device 1 every time the screw 2A is tightened to the work, which is one of the problems. The time from the end of the screw tightening of the screw to the start of the screw tightening of the next screw becomes long, and the time required to screw all the screws on the work becomes long, and the screw aligning and feeding device 1 It is still insufficient as a method of supplying the screw to the tip of the driver bit because it is necessary to accurately position the screwdriver 3 and the driver 3.

In the second screw supply method, unlike the first screw supply method, it is not necessary to move the driver 5 every time the screw 2A is tightened to the work 7, and the screw 2A is tightened while it is tightened. Since the next screw 2B is prepared, the time required to tighten all the screws on the work 7 is significantly reduced as compared with the first screw supply method.

However, in the case of this second screw supply method, there is a problem that the posture of the screw 2A becomes unstable when the screw 2A once supplied to the driver 5 moves and engages with the tip of the driver bit 6. It was Especially when the length of the screw 2A is short, there is a problem that the screw 2A cannot be stably supplied to the driver bit 6 because the direction of the screw 2A may be reversed or the screw 2A may be caught in the middle. .

Further, in this second screw supply method, since the screw is supplied from the screw aligning and supplying device to the driver 5 by compressed air, the screw aligning and supplying device must be provided with a compressed air supply unit, and the screw aligning device is provided. There are problems that the supply device becomes large and complicated, noise is generated due to the exhaust of compressed air, and dust and the like are supplied together with the screw. Furthermore, since the tip portion 5A of the driver 5 must be configured to be openable and closable, the tip portion 5A becomes complicated and the tip portion 5A
Had to be changed according to the shape of the screw, and there was a problem of lacking versatility.

Further, in the third screw supply method, since the screw 2A is directly sucked from the screw aligning and supplying device by the screw suction device provided in the driver 11, the screw aligning and supplying device and the tip portion of the driver 11 are structured. Can be simplified. However, since the screw 2A is directly sucked into the mouthpiece 9, the next screw cannot be supplied while the previous screw is tightened, and accordingly, the first screw supply method is used. Similarly, there is a problem that the time required to tighten all the screws on the work becomes great.

The pressure detector of the screw suction device determines whether or not the screw 2A has reached the mouthpiece 9 (when the screw reaches the mouthpiece 9, the degree of vacuum in the screw suction device is increased. However, there is a problem in that the detection accuracy of the arrival of the screw is low.

The present invention has been made in view of the above points, and it is an object of the present invention to propose a screw tightening device capable of shortening the screw tightening time of the screw as a whole and improving reliability.

[0015]

In order to solve such a problem, in the present invention, a screw for rotating a driver bit by a drive motor and tightening a predetermined screw engaged with the driver bit on an object to be screwed. In the tightening device, a screw holding means for holding a screw conveyed from a screw aligning means for aligning a plurality of screws, a moving means for moving the screw holding means to a position right below a driver bit, and a screw from the screw aligning means to the screw holding means. And a suction force generating means for generating a suction force for engaging the screw held by the screw holding means with the driver bit, and while the screw is tightened on the screwing target by the driver bit. Then, the screws are sucked and conveyed from the screw aligning means to the screw holding means by the suction force generated by the suction force generating means, and the screw tightening by the driver bit is performed. After that, the screw holding means is moved to the position just below the driver bit by the moving means, and the screw held by the screw holding means is engaged with the driver bit by the suction force generated by the suction force generating means. Thus, the control means for controlling the moving means and the suction force generating means are provided.

As described above, while the screw is tightened on the object to be screwed by the driver bit, the screw is sucked and conveyed from the screw aligning means to the screw holding means by the suction force generated by the suction force generating means. After the screw tightening of the screw by the driver bit is completed, the screw holding means is moved to the position just below the driver bit by the moving means and is held by the screw holding means by the suction force generated by the suction force generating means. By engaging the screw tightened with the driver bit, it is possible to shorten the time from the end of screw tightening of one screw to the start of screw tightening of the next screw, and at the same time, the driver bit The screw can be stably supplied.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

(1) Overall Configuration In FIG. 1, reference numeral 20 generally indicates a screw tightening device according to an embodiment of the present invention. The screw tightening device 20 controls a workpiece (not shown) based on the control of a robot 21. While tightening the screw, the next screw is aligned with the screw aligning and feeding device 22.
From the screw holding tube moving unit 24 to the screw holding unit moving unit 24 by suction, and the screw holding unit moving unit 2
4 is held by a screw holding portion (not shown), and at the same time as the screw tightening is completed, the screw holding portion moving unit 24 is moved almost directly below the screw tightening driver unit 25.

The robot 21 has a controller portion 21A for controlling the entire screw tightening device 20, a one-sided surface 21B is provided with a bridge pier portion 21C having a U-shaped cross section, and an arrow is formed substantially at the center thereof. Two rails 21D are provided in the direction indicated by x. Further, on the rail 21D, a plate-like member is configured to be movable on the rail 21D in the x direction and the direction opposite to the x direction (hereinafter, referred to as the front-rear direction) under the control of the controller 21A. The work moving member 21E is provided.

The bridge pier portion 21C is one surface 21 of the robot 21.
Legs 21F and 21G attached to both ends of B substantially perpendicularly to the one surface 21B, a plate-like member 21H provided between upper ends of the legs 21F and 21G, and a side surface of the plate-like member 21H. And a plate-shaped member 21I provided substantially perpendicular to one surface 21B of the robot 21.

In the screw tightening driver unit 25, a plate member 25A provided on the back surface of the screw tightening driver unit 25 is provided on a plate member 21I on the basis of a control signal supplied from the controller unit 21A (see FIG. By moving along a direction (not shown) indicated by an arrow y and a direction opposite to the y direction (hereinafter, referred to as a left-right direction), it is possible to move in the left-right direction.

Further, this screw tightening driver unit 25
Is based on a control signal supplied from the controller section 21A via a wiring 26 by a driver mechanism (not shown) inside the housing, and is opposite to the direction indicated by the arrow z and the z direction along the plate member 25A. It is designed to be movable in a direction (hereinafter referred to as a vertical direction). Accordingly, by moving the work moving member 21E in the front-rear direction and moving the screw tightening driver unit 25 in the left and right direction, it is possible to specify a desired screw tightening position of the work placed on the work moving member 21E. .

The screw holding unit moving unit 24 is a plate-shaped member 2.
5A, so that it can move in the front-rear direction and / or the left-right direction integrally with the screw tightening driver unit 25. Further, the screw holding unit moving unit 24 is a screw aligning and feeding device 2 for aligning screws.
After temporarily holding the screw sucked and conveyed from No. 2 via the screw conveying tube 23 in the screw holding portion (not shown), the screw holding portion is screwed into a screwdriver unit based on a control signal supplied from the controller portion 21A. When the screw is sucked from the screw holding portion by moving the screw holding portion substantially right below the screw holding portion 25, the screw holding portion is returned to the original position.

Thus, the screw tightening device 20 can move the screw tightening driver unit 25 in the left and right direction and the up and down direction, and can move the work moving member 21E in the front and rear direction, so that the screw tightening driver unit 25 can be moved. 25 can be positioned at a desired screw tightening position of the work placed on the work moving member 21E.

(2) Structure of the screw tightening driver unit 25 The structure of the screw tightening driver unit 25 is shown in FIG. The screw tightening driver unit 25 is attached to a driver body portion 25C formed in a cylindrical shape, and the driver bit 25B is rotationally driven by drive control of a motor 25D having an outer diameter slightly smaller than the inner diameter of the driver body portion 25C. By doing so, the screw is tightened in a predetermined screw hole of the work.

The driver bit 25B is attached to the motor 25D via the coupling portion 25E, and is rotated integrally with the coupling portion 25E by the drive control of the motor 25D. A mouthpiece holder 25F is provided inside the driver body 25C. The upper half portion 25F1 housed in the driver body portion 25C of the mouthpiece holder 25F has an outer diameter slightly smaller than the inner diameter of the driver body portion 25C and projects from the tip of the driver body portion 25C of the mouthpiece holder 25F. Lower half 25
F2 is formed at the tip of the driver body 25C and has an outer diameter slightly smaller than the opening 25G having a diameter smaller than the inner diameter of the driver body 25C.

The upper half 2 of the mouthpiece holder 25F
A cavity 25H1 slightly larger than the outer diameter of the coupling portion 25E is formed inside 5F1, and a cavity 25H2 slightly larger than the outer diameter of the driver bit 25B is formed inside the lower half portion 25F2 of the mouthpiece holder 25F. The cavities 25H1 and 25H2 are formed so as to penetrate the upper half portion 25F1 and the lower half portion 25F2 of the mouthpiece holder 25F, respectively. As a result, the driver bit 25B projects from the tip of the mouthpiece holder 25F by a predetermined length through the cavities 25H1 and 25H2.

A mouthpiece 25I having an inner diameter larger than the outer diameter of the driver bit 25B is attached to the tip of the mouthpiece holder 25F with a screw so as to cover the driver bit 25B. Here, as shown in FIG. 3, this screw tightening driver unit 25
Is designed to tighten a screw 28 in a predetermined screw hole of the work 27 with the mouthpiece 25I abutting the work 27. As a result, as the screw 28 is tightened to the work 27, the driver main body 25C Becomes gradually integrated with the motor 25D and gradually descends in a direction (a direction indicated by an arrow a) approaching the work 27.

Further, a screw suction tube 25 is provided on the side surface near the tip of the lower half portion 25F2 of the mouthpiece holder 25F.
J is provided, and a suction force generated from a screw suction device (not shown) provided at a predetermined position of the screw tightening driver unit 25 is generated in the mouthpiece 25I via the screw suction tube 25J. It is done like this. That is, this screw suction tube 25J is a cavity 2 formed in the lower half portion 25F2 of the mouthpiece holder 25F.
This cavity 25H is attached to the 5H3 forming position.
3 is formed by branching from the cavity 25H2. Therefore, the suction force generated by the screw suction device is applied to these cavities 2
It can be generated in the mouthpiece 25I via 5H3 and 25H2.

Here, in this embodiment, a tube is connected to the screw suction device, and this tube has two tubes on the way, namely, a screw suction tube 25J.
It is branched into a screw suction tube which is brought into contact with a screw holding unit moving unit 24 which will be described later, and the suction force generated from the screw suction device is fed to a screw suction tube 25J or a screw suction switching device (not shown). It is possible to switch to the screw suction tube abutting on the screw holding unit moving unit 24.

An opening 25K of a predetermined size is provided along the longitudinal direction of the side surface of the driver main body 25C, and the mouthpiece holder 25 is opened through this opening 25K.
The detection dog portion 25L is attached to the side surface of the upper half portion 25F1 of F. A rod-shaped dog 25L1 whose length can be adjusted is attached to the detection dog portion 25L along the longitudinal direction of the driver main body portion 25C.

Further, the opening 25 of the driver body 25C
A screw suction switching detector 25M is provided on the upper side surface of K, and when the screw tightening by the screw tightening driver unit 25 is performed and the driver main body 25C descends in the direction a by a predetermined distance, The screw suction switching detector 25M also descends in the a direction in association with each other, and the dog 25L of the detection dog portion 25L is provided in the screw suction switching detector 25M.
1 is inserted. In this case, the detection dog portion 25L moves within the range of the opening 25K relative to the driver main body portion 25C.

In this embodiment, as shown in FIG. 3, the screw tightening driver unit 25 allows the screw 27 of the work 27 to be screwed to some extent (for example, even if the screw 28 is not sucked, the screw 28 is screwed into the driver bit 25B). When the screw 28 is tightened to such an extent that it does not fall off from the detection dog part 2
The length of the dog 25L1 is adjusted so that the 5L dog 25L1 is inserted into the screw suction switching detector 25M.

When the dog 25L1 of the detection dog portion 25L is inserted into the screw suction switching detector 25M, the screw suction switching detector 25M sends a dog detection signal to the controller unit 21.
Send to A. The controller unit 21A sends a suction switching signal to the screw suction switching device based on the dog detection signal, and the screw suction switching device, based on the suction switching signal, controls the suction force generated from the screw suction device to be described later in a screw holding unit. It is designed to be generated on the screw suction tube side of the moving unit 24.

Here, in this embodiment, the screw suction switching detector 25M has a light emitting portion and a light receiving portion, and the light emitted from the light emitting portion is received by the light receiving portion.
Therefore, the screw suction switching detector 25M is provided with the dog 25L1.
When is inserted and the light emitted from the light emitting unit is blocked,
The dog 25L1 is detected to be inserted and a dog detection signal is sent to the controller 21A.

(3) Structure of screw holding unit moving unit The structure of the screw holding unit moving unit 24 is shown in FIG.
Shown in (B) and (C). Screw holding unit moving unit 24
Is designed to move the screw holding portion 24C provided at the tip of the cam mechanism portion 24B in a predetermined direction by driving the cam mechanism portion 24B by the screw holding portion moving device 24A having an air cylinder structure. ing.

The screw holding section moving device 24A is controlled by the pressure of the air supplied from the air supply section (not shown) into the cylinder 24E through the air supply port 24D based on the control signal from the controller section 21A. The rod 24F in the cylinder 24E is moved in the direction shown by the arrow b (direction toward the mouthpiece 25I of the screw tightening driver unit 25).

Further, the screw holder moving device 24A includes
A connecting member 24G as shown in FIG. 4 (B) is provided so as to cover the back side of the cylinder 24E in FIG. 4 (A) to the right side surface of the cylinder (screw holding portion 24C side).
The connecting member 24G is configured to be movable in the b direction and the direction opposite to the b direction. A tip portion 24G1 of the connecting member 24G projects from the tip portion of the cylinder 24E, and a tip of a rod 24F that projects from the cylinder 24E is attached to the tip portion 24G1. As a result, air is supplied into the cylinder 24E and the rod 24F
Is moved in the b direction, the linking member 24 is interlocked with this.
G also moves in the b direction.

As shown in FIGS. 4A and 4B, a connecting member 24G for covering the screw holding portion 24C side of the cylinder 24E.
A cam mechanism portion 24B is rotatably attached to the side surface 24G2 by a screw 24H. Also, FIG. 4 (C)
As shown in (side view), the cam mechanism portion 24B has a groove portion 24B1 having a meandering cross-sectional shape.
A cam follower 24B2 is provided in the inside 1.

A screw holding portion 24C is provided at the tip of the cam mechanism portion 24B. As shown in FIG. 5A, a screw transport suction tube 23 is connected to the screw holding portion 24C through a screw transport tube holder 24I, and the screw transport tube holder 24 of the screw holding portion 24C is connected.
The screw 2 that has been sucked and conveyed on the upper surface 24C1 with which I is abutted
8 is formed with a screw holding hole 24C2.

As shown in FIGS. 5 (A) and 5 (B), the screw holding hole 24C2 is provided on the upper surface 24C of the screw holding portion 24C.
1 is formed in the vertical direction with respect to 1, and is bent so as to be substantially horizontal to the upper surface 24C1 inside the screw holding portion 24C and is formed up to the side surface 24C3 side of the screw holding portion 24C. Screw holding hole 2 on this side surface 24C3
A screw suction tube 24J is in contact with the opening position of 4C2. Thereby, the suction force generated from the screw suction device is applied to the screw suction tube 24J and the screw holding hole 24C.
2. Generated on the side of the screw aligning and feeding device 22 via the screw sucking and conveying tube 23, and as a result, the screw holding section 24C from the screw aligning and feeding device 22 via the screw sucking and conveying tube 23.
The screw 28 is retained.

Here, the cross-sectional shape of the screw holding hole 24C2 in the vertical direction is substantially the same as the cross-sectional shape of the screw, and also has a certain depth so that a screw having a certain length can be accommodated. Therefore, since the screw holding portion 24C can always hold the posture of the screw 28 sucked and conveyed in a constant posture, the screw can be stably supplied to the driver bit 25B as described later.

Thus, by supplying air into the cylinder 24E to move the rod 24F in the b direction, the cam mechanism portion 24B can be moved in the b direction in conjunction with this, so that the screw holding portion 24C is moved to the b direction. The driver bit 25B can be moved to a position almost directly below the driver bit 25B.

In this case, the cam mechanism portion 24B moves with the cam follower 24B2 centering on the screw 24H according to the shape of the groove portion 24B1 as the connecting member 24G moves. That is, as shown in FIG. 6, the cam mechanism portion 24B brings the screw holding portion 24C closer to the mouthpiece 25I from a direction substantially perpendicular to the mouthpiece 25I.
The screw holding portion 24C is brought closer to the tip portion of the mouthpiece 25I obliquely from the vicinity thereof so that the screw holding portion 24C is brought into close contact with the tip portion of the mouthpiece 25I. As a result, the screw holding portion 24C can be prevented from colliding with the mouthpiece 25I from the side, and accordingly, the mouthpiece 25I, the screw holding portion 24C, and the cam mechanism portion 24B.
Can be prevented from being damaged.

When the screw holding portion 24C is moved in the b direction, the screw transport tube holder 24I and the screw suction tube 24J are separated from the screw holding portion 24C, and the screw holding portion 24C is returned to its original position. When this is done, the screw transport tube holder 24I will move to the screw holding portion 24C.
The screw suction tube 24J is brought into contact with a predetermined position of the side surface 24C3 of the screw holding portion 24C.

Further, the screw holding portion 24C has a screw detector 2
4C4 and the screw detector 24C5 are provided so as to face each other, and when the screw is sucked from the screw alignment supply device 22 and held in the screw holding hole 24C2, the screw detection signal is sent to the controller unit 21A. Has been done.
The controller unit 21A sends a suction stop signal to the screw suction device based on the screw detection signal, and when the screw suction device receives the suction stop signal, the generation of the suction force is stopped.

In the screw holder 24C, the light emitted from the screw detector 24C4 is supplied to the screw detector 24C5.
When the screw is held in the screw holding portion 24C, the light is shielded by the screw, so that the screw holding portion 24C detects that the screw is held in the screw holding hole 24C2. Lever screw detection signal to controller unit 2
It is designed to be sent to 1A.

Further, in the case of this embodiment, the screw tightening by the screw tightening driver unit 25 is completed, the driver main body portion 25C moves in the direction opposite to the direction a (that is, the direction away from the work), and the next screw tightening is performed. Almost at the same time that the screw tightening driver unit 25 moves to the position, air is supplied into the cylinder 24E under the control of the controller unit 21A so that the screw holding unit 24C moves almost directly below the screw tightening driver unit 25. .

Further, a suction start signal is sent from the controller unit 21A to the screw suction device at the same timing as that when the screw holding portion 24C is moved almost directly under the screw tightening driver unit 25, and at the same time, the screw suction switching device is switched to suction. The signal is sent out. When the screw suction device receives the suction start signal, it generates a suction force, and when the screw suction switching device receives the suction switching signal, the screw suction device transfers the suction force generated from the screw suction device to the screw suction tube 25J side of the screw tightening driver unit 25. generate.

(4) Operation and effects of the embodiment With the above construction, when the work start button (not shown) is pressed, the controller section 21A causes the screw suction device and the screw suction switching device to respectively start the suction start signal and the suction switching. A signal is sent to generate a suction force generated from the screw suction device on the screw suction tube 24J side, whereby the screw aligning and feeding device 22 passes through the screw suction transport tube 23 to the screw holding hole 24C2 of the screw holding portion 24C. Hold the screw.

When the screw is held by the screw holding portion 24C,
The screw holding unit 24C sends a suction stop signal from the screw detector 24C5 to the controller unit 21A, and the controller unit 2
When 1A receives the suction stop signal, 1A stops the suction force from the screw suction device. After that, the screw holder moving device 24A moves the screw holder 2 under the control of the controller 21A.
4C is moved right below the screw tightening driver unit 25 to bring the screw holding hole 24C2 of the screw holding portion 24C into close contact with the mouthpiece 25I (FIG. 6), and the controller portion 24A sucks the screw suction device and the screw suction switching device, respectively. The start signal and the suction switching signal are sent to generate the suction force from the screw suction device on the screw suction tube 25J side.

At this time, the screw tightening driver unit 25
Is moved above the screw tightening position of the workpiece by the movement of the robot 21 and the screw tightening driver unit 25 itself under the control of the controller 21A, and the mouthpiece holder 25F is in the lowest position (shown in FIG. 5). State). Accordingly, the screw holding hole 24C2 of the screw holding portion 24C comes into close contact with the mouthpiece 25I, and at the same time, the suction force generated from the screw suction device is transmitted through the screw suction tube 25J to the mouthpiece 25I.
Which is generated inside, and thereby the screw held by the screw holding portion 24C is sucked and engaged with the driver bit 25B.

Here, the screw holding hole 24 of the screw holding portion 24C
When the screw is sucked from C2, the output from the screw detector 24C5 to the controller unit 21A disappears, whereby the controller unit 21A confirms that the screw has moved from the screw holding unit 24C into the mouthpiece 25I, and The screw holding portion moving device 24A is controlled so as to return the holding portion 24C to the original position (the position shown by the solid line in FIG. 4), and at the same time, the screw tightening by the screw tightening driver unit 25 is started.

When screw tightening by the screw tightening driver unit 25 is started, the driver main body portion 25C gradually descends in the direction a as the screw is tightened on the work. When the screw is tightened to the work by a predetermined amount, as shown in FIG. 3, the dog 25L1 is inserted into the screw suction switching detector 25M, and the screw suction switching detector 25M sends a suction switching signal to the controller unit 21A. The controller unit 21A controls the screw suction switching device based on the suction switching signal.

As a result, the suction force generated by the screw suction device is generated on the screw suction tube 24J side, whereby the next screw is sucked and conveyed from the screw alignment supply device 22 through the screw suction conveyance tube 23 and held by the screw. The screw suction hole 24C2 of the portion 24C holds the screw, and the screw detector 24C5 detects the screw to complete the suction operation by the screw suction device. At this time, the screw tightening operation by the screw tightening driver unit 25 is continuously performed.

Upon completion of screw tightening by the screw tightening driver unit 25, the controller portion 21A moves the driver main body portion 25C in the direction opposite to the direction a, and then the screw tightening driver unit 25 and / or the work moving member 21.
Screw tightening driver unit 2 by moving E
5 is moved to the next screw tightening position, and at the same time, air is supplied to the screw holding unit moving device 24A to supply the screw holding unit 24C.
Is moved almost directly under the screw tightening driver unit 25, and a suction force is generated on the screw suction tube 25J side. Hereinafter, the screw tightening device 20 repeats the above operation until the screw is tightened by the amount necessary for the work.

Therefore, in this screw tightening device 20, while the screw is tightened by the screw tightening driver unit 25, the next screw is sucked by the suction force and temporarily held in the screw holding portion 24C in a constant state. Then, after the screw tightening of the first screw is completed, the screw holding portion 24C is moved to directly below the screw tightening driver unit 25, and the screw held by the screw holding portion 24C is engaged with the driver bit 25B by a suction force. Since it is possible to combine the screws, it is possible to shorten the time from the end of screw tightening of one screw to the start of screw tightening of the next screw, and to stably supply the screw to the driver bit 25B. You can

Further, in the screw tightening device 20, the screw is sucked from the screw aligning and supplying device 22, so that the screw aligning and supplying device 22 is provided with the compressed air generating portion as in the second conventional screw supplying method. Since there is no need, it is possible to simplify the configuration of the screw tightening device 20 as a whole, to avoid noise accompanying exhaust of the compressed air generating portion, and to prevent generation of dust and the like accompanying supply of compressed air.

Further, in the screw tightening device 20, the screws sucked from the screw aligning and supplying device 22 are temporarily held by the screw holding portion 24.
The screw holding portion 24C is moved to the position just below the screw tightening driver unit 25 each time, and the mouthpiece 25 is held.
The screw is driven by the suction force generated in I.
By engaging with 5B, it is not necessary to configure the tip of the driver to match the shape of the screw and open / close unlike the second conventional screw feeding method, and simply screw the mouthpiece 25I. Therefore, the structure of the driver tip can be simplified and the versatility can be improved, and the mouthpiece 25I can be used without changing the driver to match the shape of the screw. Since it is only necessary to replace, it is excellent in terms of cost and exchangeability.

Further, in this screw tightening device 20, the screw detectors 24C4 and 2C are used to confirm the arrival of the screw in the screw holding portion 24C and the engagement of the screw with the driver bit 25B.
By using the 4C5, it is possible to easily and accurately confirm the arrival of the screw and the engagement, and it is possible to easily adjust the degree of the arrival confirmation and the engagement confirmation of the screw.

According to the above construction, while the screw is tightened on the work 27 by the screw tightening driver unit 25, the suction force generated from the screw suction device is generated on the screw suction tube 24J side, and Screw alignment device 2
2 via the screw suction transport tube 23
4C is held in a fixed state in the screw holding hole 24C2, and the screw detectors 24C4 and 24C5 detect that the screw is held in the screw holding portion 24C, and the suction operation is terminated to finish the first screw. Wait until the screw tightening of
After tightening the first screw, the driver body 25
Immediately after C has risen in the direction away from the work 27, the screw holding portion 24C is moved to directly below the screw tightening driver unit 25, and at the same time, the suction force is applied to the screw suction tube 25J.
The screw held by the screw holding part 24C is engaged with the driver bit 25B so that the screw holding part 24C returns to its original position and the screw tightening operation by the screw tightening driver unit 25 is started at the same time. By
The time from the end of screw tightening of one screw to the start of screw tightening of the next screw can be shortened, and the screw can be stably supplied to the driver bit 25B.
Thus, it is possible to realize the screw tightening device 20 that can shorten the screw tightening time of the screw as a whole and improve the reliability.

(5) Other Embodiments In the above embodiment, the screw suction device is provided in the screw tightening driver unit 25, and the suction device is shared by the screw holding portion moving unit 24 and the screw tightening driver unit 25. Although the case has been described, the present invention is not limited to this, and the screw suction device may be provided in another place,
Alternatively, a screw suction device may be separately provided for each of the screw holding unit moving unit 24 and the screw tightening driver unit 25, and the operation of each screw suction device may be controlled by the controller unit 21A.

In the above-described embodiment, the case where the suction operation of the screw suction device is stopped under the control of the controller section 21A when the screw is held by the screw holding section 24C has been described. Alternatively, the suction force may be generated on the screw suction tube 25J side by controlling the suction switching device without stopping the suction force even if the screw is held by the screw holding portion 24C. In this case, when the controller 21A receives the screw detection signal from the screw detector 24C5, it sends a suction switching signal to the screw suction switching device to generate the suction force generated from the screw suction device on the screw suction tube 25J side. .

Further, in the above embodiment, after the screw tightening driver unit 25 is moved to the screw tightening position to be screw tightened, the screw holding portion 24C is brought into close contact with the mouthpiece 25I and at the same time the suction force is applied to the mouthpiece. 25
Although the case where the screw is engaged with the driver bit 25B by being generated in I has been described, the present invention is not limited to this, and the screw tightening driver unit 25 is moved to the screw tightening position to be screw tightened. The screw holding portion 24C may be brought into close contact with the mouthpiece 25I to generate a suction force inside the mouthpiece 25I.

Thus, while the screw tightening driver unit 25 is moving to the next screw tightening position, the screw holding portion 2
Since the screw held in 4C can be engaged with the driver bit 25B, the time from the end of the screw tightening of one screw to the start of the screw tightening of the next screw is set to the above-mentioned embodiment. It can be further shortened.

Further, in the above-mentioned embodiment, the screw aligning and feeding device 2 is used as the screw aligning means for aligning a plurality of screws.
Although the case of using 2 has been described, the present invention is not limited to this, and various other screw aligning means can be applied as the screw aligning means as long as the screws can be aligned. Further, in the above-described embodiment, the case where the screw holding portion 24C is used as the screw holding means for holding the screws conveyed from the screw aligning means has been described, but the present invention is not limited to this, and various other screw holding means may be used. The screw holding means can be applied.

Further, in the above-mentioned embodiment, the case where the cam mechanism portion 24B is used as the moving means for moving the screw holding means directly below the driver bit has been described.
The present invention is not limited to this, and various other moving means can be applied as the moving means. Further, in the above embodiment,
A screw suction device and a screw suction switching device are provided as suction force generating means for conveying a screw from the screw aligning means to the screw holding means and for generating a suction force for engaging the screw held by the screw holding means with a driver bit. Although the case of using it has been described, the present invention is not limited to this, and various other suction force generating means can be applied as long as the suction force is generated.

Further, in the above-described embodiment, while the screw is screwed to the object to be screwed by the driver bit, the suction force generated by the suction force generating means causes the screw aligning means to move the screw holding means. After the screw is sucked and conveyed by the driver bit, and the screw tightening of the screw by the driver bit is completed, the screw holding means is moved to the position just below the driver bit by the moving means, and the suction force generated by the suction force generating means is applied. Although the robot 21 having the controller portion 21A is used as the control means for controlling the moving means and the suction force generating means so that the screw held by the screw holding means is engaged with the driver bit, the present invention has been described. Not limited to this, various other control means can be applied as control means for controlling the moving means and the suction force generating means.

Further, in the above-mentioned embodiment, the detection dog portion 25L and the screw suction switch are used as the screw tightening state detecting means for detecting that the screw engaged with the driver bit is screwed to the screwing target so as not to fall off. Detector 25
Although the case where M is used is described, the present invention is not limited to this, and various other screw tightening state detecting means can be applied as the screw tightening state detecting means.

[0070]

As described above, according to the present invention, while the driver bit is rotated by the drive motor and tightened on the object to be screwed, the suction force generated by the suction force generating means is used. Then, the screws are sucked and conveyed from the screw aligning means to the screw holding means, and after the screw tightening of the screw by the driver bit is completed, the screw holding means is moved by the moving means to the position just below the driver bit, and the suction force generating means Since the screw held by the screw holding means is engaged with the driver bit by the generated suction force, 1
It is possible to shorten the time from the end of tightening one screw to the start of tightening the next screw, and
The screw can be stably supplied to the driver bit,
Thus, it is possible to realize a screw tightening device capable of reducing the screw tightening time of the screw as a whole and improving the reliability.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an overall configuration of a screw tightening device according to an exemplary embodiment of the present invention.

FIG. 2 is a partial cross-sectional view showing the structure of a screw tightening driver unit according to an embodiment.

FIG. 3 is a partial sectional view for explaining the operation of the screw tightening driver unit.

FIG. 4 is a top view (A) and (B) and a side view (C) for explaining a structure and a connecting member of a screw holding unit moving unit according to an embodiment.

FIG. 5 is a cross-sectional view for explaining a screw holding portion.

FIG. 6 is a partial sectional view for explaining the operation of the cam mechanism section.

FIG. 7 is a perspective view for explaining a conventional method of supplying a screw to a driver bit.

FIG. 8 is a sectional view for explaining a conventional method for supplying a screw to a driver bit.

FIG. 9 is a partial cross-sectional view for explaining a conventional method of supplying a screw to a driver bit.

[Explanation of symbols]

20 ... Screw tightening device, 21 ... Robot, 21A ...
Controller part, 21C ... Bridge pier part, 21D ... Rail, 21E ... Work moving member, 22 ... Screw alignment supply device, 23 ... Screw suction transfer tube, 24 ... Screw holding part moving unit, 24A ... Screw Holding unit moving device, 2
4B ... Cam mechanism section, 24C ... Screw holding section, 24C2
...... Screw holding hole, 24C4, 24C5 ...... Screw detector,
24J, 25J ... Screw suction tube, 25 ... Screw tightening driver unit, 25B ... Driver bit, 25
C: driver body, 25D: motor, 25F:
Mouthpiece holder, 25I ... Mouthpiece, 25L
...... Detection dog section, 25M ...... Screw suction switching detector,
26 ... wiring, 27 ... work, 28 ... screw.

Claims (5)

[Claims] 1. A screw tightening device for rotating a driver bit by a drive motor to screw a predetermined screw engaged with the driver bit to an object to be screwed, and a screw aligning means for aligning a plurality of the screws. A screw holding means for holding the screw conveyed from the screw aligning means, a moving means for moving the screw holding means to a position immediately below the driver bit, and a screw conveying means for moving the screw from the screw aligning means to the screw holding means. And a suction force generating means for generating a suction force for engaging the screw held by the screw holding means with the driver bit, and the screw tightening the screw to the screwing target by the driver bit. During the operation, the screw is sucked and conveyed from the screw aligning means to the screw holding means by the suction force generated by the suction force generating means. After the screw tightening of the screw by the driver bit is completed, the screw holding means is moved to a position just below the driver bit by the moving means, and the suction force generated by the suction force generating means causes the screw holding means to move. A screw tightening device comprising: control means for controlling the moving means and the suction force generating means so that the screw held by the screw holding means is engaged with the driver bit. 2. The screw holding means comprises screw detecting means for detecting that the screws sucked and conveyed from the screw aligning means are held, and the control means is based on an output of the screw detecting means. 2. The screw holding means is detected to be engaged with the driver bit by the screw holding means, and the screw holding means is returned to a predetermined position by the moving means. The screw tightening device described in. 3. The screw holding means comprises screw detecting means for detecting that the screws sucked and conveyed from the screw aligning means are held, and the control means is based on an output of the screw detecting means. , The suction force generated by the suction force generation means is generated from the screw holding means side to the driver bit side, or the suction force generated by the suction force generation means is stopped, and the screw holding means is stopped. 2. The screw tightening device according to claim 1, wherein the suction force is generated on the driver bit side when the screw is moved to a position just below the driver bit. 4. A screw tightening state detecting means for detecting that the screw engaged with the driver bit is screwed to the screwing target to the extent that the screw does not fall off, and the control means detects the screw tightening state. 2. The screw tightening device according to claim 1, wherein the suction force generated by the suction force generating means is generated from the driver bit side to the screw holding means side based on the output of the means. 5. The moving means is provided on the outside of the driver bit when the screw holding means is moved directly below the driver bit so that the screw holding means approaches from the direction substantially perpendicular to the driver bit. 2. The screw holding means is brought into close contact with the tip of the mouthpiece by bringing the screw holding means closer to the tip of the mouthpiece obliquely from the vicinity of the mouthpiece. The described screw tightening device.