JPH0650104Y2 - Suction screw tightener - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a suction type screw tightening machine for sucking a screw with a suction sleeve and tightening the screw at a predetermined working position.
The present invention relates to a suction type screw tightener configured to perform screw tightening so that a lower position of a suction sleeve does not collide with a work.

[Prior Art] and [Problems to be Solved by the Invention] Recently, plastic resins have been used for various parts due to the weight reduction of products. Care has been taken to ensure that the surface is not scratched. However,
If the screw is a special screw that cannot be air-fed, or if the work position is in a special position, you must use a suction-type screw tightener. In this case, the suction sleeve that has sucked the screw must be lowered until it comes into contact with the surface of the work, and the suction sleeve damages the surface of the work, resulting in defects such as damage to the work that cannot be prevented. There is.

The present invention is intended to eliminate the above-mentioned drawbacks, and an object of the present invention is to provide a suction-type screw tightening machine configured to stop a suction sleeve for sucking a screw immediately before contacting the work.

[Means for Solving the Problems] In order to achieve the above-mentioned object, a driver bit that is rotated by the rotation of a drive motor is held on a driver base that is moved up and down by the operation of an elevation drive source, and the tip of this driver bit is A suction sleeve is provided so as to be enclosed. Further, the driver bit is configured to advance with respect to the suction sleeve as the driver base descends, and the tip end thereof protrudes from the suction sleeve.

The lifting drive source is composed of a screw shaft that is rotated by the rotation of a servo motor and a bearing base that is held by a driver base and is screwed into the screw shaft.

Further, the rotation of the drive motor is transmitted to the driver bit through a transmission shaft rotatably held on the driver base and a cylinder mechanism that is fixed to the transmission shaft and a sliding sleeve that slides against the transmission shaft. There is.

Further, the servo motor is connected to a control unit that detects the rotation of the servo motor by an encoder and drives the servo motor so that the detected value matches a preset set value.

[Operation] In the above-mentioned suction type screw tightening machine, a value corresponding to a distance slightly shorter than the distance from the tip of the suction sleeve to the work is set as the descending amount of the suction sleeve. After that, the drive motor is driven and the servo motor is driven. The screw shaft rotates with the rotation of the servomotor, and the bearing stand screwed to the screw shaft descends along the screw shaft. At the same time, the driver base descends, and the suction sleeve and the driver bit descend constantly.

On the other hand, the rotation of the servo motor is detected by the encoder, and the amount of lowering of the bearing base and the suction sleeve is detected from the number of rotations. Power is supplied to the servo motor so that the amount of this descending reaches a preset value, the servo motor continues to rotate, and the driver base descends together with the suction sleeve. When the tip of the suction sleeve reaches just before contacting the work and the detected value of the encoder reaches the set value, the power supply to the servo motor is stopped and the driver stand is held at that position. At the same time, a cylinder operation command signal is transmitted, the cylinder mechanism operates, and the sliding sleeve advances with respect to the transmission shaft. Along with this, the driver bit advances with respect to the suction sleeve, and the screw located at the tip thereof can be tightened at a predetermined position on the work. Therefore, even if it is a suction type screw tightening machine, the screw tightening work can be performed without damaging the work, and the suction sleeve can be adjusted according to the type of work or the height of each work position. A stop position can be changed and a highly versatile device can be provided.

Embodiments Embodiments will be described below with reference to the drawings. In FIG. 1 and FIG. 2, reference numeral 1 is a suction type screw tightening machine, which has a hollow pillar 2 fixed to a mounting portion such as an arm portion (not shown) of a robot (not shown). There is. An upper bracket 3 and a lower bracket 4 extending in a direction orthogonal to the pillar 2 are fixed to the upper and lower ends of the pillar 2 in parallel. A servo motor 6 having a drive shaft 6a below is fixed to the upper bracket 3 via a first motor base 5a. A screw shaft 7 rotatably held between the upper bracket 3 and the lower bracket 4 is connected to a drive shaft 6a of the servomotor 6 through a coupling 8, and the screw shaft 7 is provided with a screw shaft 7. Bearing base 9 screwed onto
Is configured to be slidable along its axis. Also,
A driver base 10 extending in a direction intersecting with the screw shaft 7 is fixed to the bearing base 9, and the driver base 10 is configured to move up and down as the servomotor 6 rotates. An encoder 11 is attached to the upper end of the servomotor 6, and the detection value thereof is sent to a control device 12 described later.

A drive motor 13 extending parallel to the servo motor 6 via a second motor base 5b is provided on the driver base 10.
It is fixed with 13a facing down. A transmission shaft 14 rotatably held on the driver base 10 and arranged parallel to the screw shaft 7 is connected to the drive shaft 13a so as to rotate together. The transmission shaft 14 is provided with an air supply / exhaust passage 14a passing through its axis, and the air supply / exhaust passage 14a communicates with an air supply / exhaust port 10a formed in the driver base 10 and will be described later. Air for operating the cylinder mechanism 15 is supplied. Further, a sliding sleeve 16 is arranged on the transmission shaft 14 so as to include it, and a driver bit 17 is attached to the lower end of the sliding sleeve 16 so as to rotate integrally therewith. The sliding sleeve 16 has a steel ball 16a, a part of which protrudes in a guide groove 14b formed along the axis of the transmission shaft 14,
It is configured to be slidable integrally with and along with.
A dog 19 is attached to an upper end of the sliding sleeve 16 via a dog attaching ring 18, and the dog 19 projects from a vertical groove 20a of a storage sleeve 20 described later, and a lower limit of the dog 19 is detected by a sensor (not shown). Is configured to be detected by. The dog mounting ring 18 is biased upward by a spring 21 described later, and the spring 21, the transmission shaft 14 having the air supply / discharge passage 14a, and the sliding sleeve 16 are configured to form a cylinder mechanism 15. There is.

A storage sleeve 20 is fixed to the lower side of the driver base 10 so as to include the sliding sleeve 16, and a guide sleeve into which the driver bit 17 can be inserted at the lower end thereof.
23 is locked. A spring 21 is housed in the guide sleeve 23 and the housing sleeve 20.
Is arranged between the dog mounting ring 18 and the guide sleeve 23 to urge the guide sleeve 23 downward. A suction sleeve 24 that covers the tip of the driver bit 17 is fixed to the lower end of the guide sleeve 23, and the tip of the suction sleeve 24 is located in a chuck unit 25 described later. Also, the guide sleeve
An air suction port 23a is formed in the lower part of 23, and this air suction port 23a is configured to communicate with the inside of the suction sleeve 24 and suck the air inside the suction sleeve 24.

The driver base 10 is fixed between the upper bracket 3 and the lower bracket 4 in parallel with the screw shaft 7.
It is guided by a guide shaft (not shown) of the book, and is structured so as not to rotate when it goes up and down. Also,
A connecting plate 26 is fixed to a side portion of the driver base 10, and one end of the connecting plate 26 is located in a cutout groove 2a cut in the axial direction of the column 2. In this connection plate 26,
A rod 27a of a cylinder 27, which is fixed to the support column 2 so that its axis is aligned, is connected, and the cylinder 27 is configured to act as a balancer for supporting the load applied to the driver base 10 from below.

A chuck unit 25 having a pair of chuck claws 25a is fixed to the lower bracket 4, and a screw 28 supplied from the hose mount 25b to the chuck claw 25a through a screw supply pipe 25c is moved to the driver bit 17. It is configured to be retained on the street.

The servomotor 6 is configured to be driven by a control device 12 which operates upon receiving a servomotor drive command signal. The control device 12 has a control unit 29 composed of a microcomputer, and the control unit 29 includes a setting unit 30 described later.
A storage unit 31 for storing the set value given from is connected. Further, the control unit 29 has an I / 0 interface 32.
The setting unit 30 that sets a value slightly smaller than the distance between the tip of the suction sleeve 24 and the workpiece 33 via the setting unit 30, and the servo motor 6 according to a command value described later.
A drive unit 35 that supplies power from the power distance unit 34 and a cylinder drive unit 36 that operates the cylinder mechanism 15 are connected to the. The control unit 29 waits for 1) a servo motor drive command signal.

2) Read the detected value from the encoder 11 and determine whether this is equal to the set value. If they are equal, jump to 4).

3) Give a command value to the drive unit 35 so that the difference between the detected value and the set value becomes zero, and return to 2).

4) Send the cylinder drive command signal and wait for the screw tightening completion signal.

5) Send a cylinder return command signal to the cylinder drive unit 36.

6) Read the detected value from the encoder 11 and determine whether the detected value is zero. When the detected value is zero, jump to 8).

7) The command value is given to the drive unit 35 so that the detected value becomes zero, and the process returns to 6).

8) Send a cycle completion signal.

9) End.

It is configured like.

In the above suction type screw tightener, the suction sleeve is
From the distance between the tip of 24 and the work 33, the setting unit 30 sets the descending amount that the suction sleeve 24 does not collide with the work 33. After that, the screw supply command signal is transmitted, and the screw 28 is connected to the screw supply pipe 25.
Each drive command signal is transmitted to the drive motor 13 and the servo motor 6 while being supplied to the chuck claw 25a through c. Therefore, the drive motor 13 is driven and rotated, the drive unit 35 of the servo motor 6 is operated, power is supplied from the power supply unit 34 to the servo motor 6, and the servo motor 6 starts rotating. With the rotation of the servomotor 6, the amount of rotation is detected by the encoder 11, and a command value is sent to the drive unit 35 so that the detected value reaches a predetermined set amount, and the power supply unit 34 causes the servo to rotate. Power is supplied to the motor 6. As the servomotor 6 is driven, the screw shaft 7 rotates, the driver base 10 descends along the screw shaft 7, and the suction sleeve 24 and the driver bit 17
Goes down. The suction sleeve 24 descends and the chuck jaws
When approaching the screw 28 held by 25a, the screw 28 is sucked by the suction sleeve 24 and held by the tip of the driver bit 17. In this state, when the driver base 10 further descends, the detected value and the set value match, the driver bit 17 stops at that position, the power supply is stopped, and the driver bit 17 is placed at that position. Power is supplied from the power supply unit 34 so as to hold it. At this time, the driver base 10 and the suction sleeve 24 that moves together with the driver base 10 are lowered by a predetermined lowering amount, and stop immediately before the tip of the suction sleeve 24 collides with the work 33.

After that, a cylinder operation command signal is sent to the cylinder drive unit 36, air is supplied from the air supply / discharge port 10a, and the sliding sleeve 16 advances to the transmission shaft 14. Therefore, the driver bit 17 integrated with this can be advanced with respect to the suction sleeve 24 while being rotated by the rotation of the drive motor 13, and the screw 28 at the tip thereof can be tightened to a predetermined working position on the work 33. .

When the completion of the screw tightening work is detected by some method and a screw tightening completion signal is transmitted, the cylinder drive unit
A return command signal is transmitted to 36, air is discharged from the air supply / discharge port 10a, the sliding sleeve 16 returns by the elastic force of the spring 21, and the driver bit 17 returns into the suction sleeve 24. At the same time, a home position return command signal is transmitted to the drive unit 35 of the servomotor 6, a command value is sent to the drive unit 35 so that the encoder 11 detects the home position, and power is supplied from the power supply unit 34 to the servo. The motor 6 returns to its original position,
Prepare for the next task.

[Advantages of the Invention] As described above, the present invention provides a screw shaft that rotates in response to the rotation of a servomotor to raise and lower a suction sleeve arranged so as to include a driver bit, and a bearing that is screwed and raised to the screw shaft. Since it is configured to be controlled by the table, the suction sleeve can be stopped at any position, and not only does the suction sleeve not damage the surface of the work during tightening work, but also the work There is an advantage that the stop of the suction sleeve can be changed for each type or working position, and a highly versatile device can be provided.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of the present invention, and FIG. 2 is an enlarged view of a cylinder mechanism according to the present invention. 1 ... Suction type screw tightener, 2 ... Strut, 2a ... Notch groove, 3 ... Upper bracket, 4 ... Lower bracket, 5a ... First motor base, 5b ... Second motor base, 6 ... … Servo motor, 6a …… Drive shaft, 7 …… Screw shaft, 8 …… Coupling, 9 …… Bearing stand, 10 …… Driver stand, 10a …… Air supply / exhaust port, 11 …… Encoder, 12 …… Control device, 13 ... Drive motor, 13a ... Drive shaft, 14 ... Transmission shaft, 14a ... Air supply / discharge passage, 14b ... Guide groove, 15 ... Cylinder mechanism, 16 ... Sliding sleeve, 16a ... … Steel ball, 17 …… driver bit, 18 …… dog mounting ring, 19 …… dog, 20 …… storing sleeve, 20a …… vertical groove, 21 …… spring, 22 …………, 23 …… guide sleeve , 23a …… Air suction port, 24 …… Suction sleeve, 25 …… Chuck unit, 25a …… Chuck claw, 25b …… Hose mounting bracket, 25c …… Screw supply pipe, 26 …… Coupling plate, 27 …… Cylinder, 27a …… Rod, 28 …… Screw, 29 …… Control section, 30 …… Setting section, 31 …… Storage section, 32 …… I / 0 interface, 33 …… Workpiece, 34 …… Power supply section, 35 …… Drive section, 36 …… Cylinder drive section,

Claims (1)

[Scope of utility model registration request] 1. A driver base that is moved up and down by the operation of a lifting drive source is provided, and a driver bit that rotates in response to the rotation of a drive motor is held on the driver base, and a suction sleeve is provided so as to enclose the periphery of the driver bit. In a suction type screw tightening machine, which is configured to move the driver bit forward with respect to the suction sleeve as the driver stand descends, a lifting drive source is rotated by the rotation of a servomotor, and a screw shaft and a driver stand are provided. Bearing shaft that is held on the screw shaft and is screwed to the screw shaft, while the transmission shaft that holds the rotation of the drive motor rotatably on the driver base and the slide shaft that is integral with and slidable with the transmission shaft It is transmitted to the driver bit via a cylinder mechanism consisting of a sleeve, and the rotation of the servomotor is Suction type screw driver, characterized in that a control unit for driving the servo motor so that the detection value detected by matching the predetermined set value by da.