JPS6020829A - Automatic screw-tightening apparatus - Google Patents

Abstract

PURPOSE:To improve the using efficiency of a robot and lower the price by installing a guide rail which receives the transmission of the operation from the arm of a robot and moving in slidable ways a holder for holding in a constant direction a driver and installing a spring for holding the driver at a constant position. CONSTITUTION:A holder 2 is fitted onto a guide rail 5 through a slidable part 4 and receives the transmission of the operation in Z-direction from the arm of a robot and transfers a driver in Z-direction along the guide rail and contacts with a screw 9 for fastening the parts 7 and 8 positioned on a jig 6, and thus the screw fastening is carried-out. When the arm of the robot is retreated in Z'- direction, after screw fastening work is completed, the holder 2 is returned back in the Z'-direction by a spring 10, and the driver and the screw for which fastening work is completed are separated. Thus, immediately after the robot completes the transfer and the positioning for parts, the robot performs the transfer operation for propelling the driver, and the power source of the robot and a controller can be effectively utilized directions.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to automatic assembly by robots, and more particularly, to an automatic 4/5 position screw tightening system that allows the robot to be used with high efficiency.

[Background of the invention]

Conventionally, automatic screw tightening devices in automatic assembly equipment have often used well-known automatic screw tightening machines that mainly consist of air cylinders and limit switches, so robots only need to position the parts to be screwed. Since it was not involved in the screw tightening itself at all, it required its own power to obtain thrust as a 1-way υ screw tightening machine, which was expensive, and the screw tightening performance (tightening torque) was limited to a narrow range. LIMITED. Furthermore, IL4 for several seconds to ten seconds during screw tightening work.
1. I was forced to use the inefficient method of waiting for the robot.

[Purpose of Hiki J]

SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic threading device that is inexpensive, highly versatile, and capable of improving the efficiency of robot use.

[Summary of the invention]

To summarize the operating principle of a conventional automatic screw tightening machine, a start command causes the outer cylinder that holds the screw attached to the tip to be pushed out (approaches the part to be threaded) by an air cylinder, and the next command causes A driver bit is rotated by a separate power and is projected from the inside of the outer cylinder concentrically with the screw held in the outer cylinder by another air cylinder, pushing out the screw and plating the target part. In particular, there is no evidence that the magnitude of the thrust by the air cylinder or the ejection speed is controlled. The limit switch simply detects the stroke of the air cylinder and regulates the reciprocating stroke. Despite this, high prices have been maintained, which is difficult to accept based on the common sense of general engineers and the standard of general machinery. By breaking down this principle, we can create a highly functional robot that happens to be forced to stand by.
By being involved in this, it is possible to avoid the limitations of expensive automatic screw-driving machines, and at the same time attract attention to the efficient use of robots. will be explained with reference to FIGS. 1 and 2. 1 (this is a well-known bush-start, torque-controlled electric screwdriver; 2 is a holder that holds a toy and has a contact surface 3 that receives motion (indicated by arrow Z) from the arm of the robot; Yes, this holder 2 is
It was inserted into the Kiterail 5 with "Oshida, Ben 3p Kaon 1",
Holder 2 receives the movement in the Z direction from the robot's arm.
, and the driver is reliably moved in the Z direction along the guide rail. Move in the Z direction! 1Iih The screwdriver is placed on the jig 6 at a predetermined position i<L (6 positions).

It collides with the screw 9 that connects the parts 7 and 8, and performs a predetermined screw tightening operation. 10 Hane f: Force, Su.

The spring 10 plays the role of pulling back the holster in the Z' direction as soon as the robot's arm leaves in the Z' direction after the screw tightening work is completed, and quickly separating the tightened screw from the driver. fulfill.

The cured moss 6 must be placed in the position shown in the figure during the screw tightening operation, but the parts 7.8 must be transported by the robot,
When the driver is placed in the
It must be placed at a position 6' apart from the position 6. Reference numeral 11 denotes an air cylinder that reciprocates the jig between positions 6 and 6'.According to the prior art, a driver 1, a holder 2, a sliding part 4,
The guide rail 5 is integrally assembled and has its own power source (generally an air cylinder) for moving the driver in the Z and Z' force directions, and further has a control device (generally, (It consists of a stroke detector and a relay unit.) Moreover, for example, after the robot has completed the transportation and positioning of the parts 7, 8 to the jig 6', the robot must wait until the screw tightening work is completed by a conventional screw driver. Generally, this waiting time is on the order of several seconds to ten seconds, which is too short for the robot to use this time to perform other tasks in a completely different location. In assembly equipment using robots, consuming such pure waiting time is a great loss.

According to this embodiment, it is possible to eliminate all of the power source for propelling the drive bar in the screw line direction and its control device, which are essential for screw tightening work. In addition, robots transport parts,
Immediately after completing the positioning, you can engage in moving work to propel the driver, and once you complete the threading work, you can immediately start working on moving the picked up assembly to another location. The power source and control device of an expensive robot equipped for "movement" can be effectively utilized without being left unused for even a moment.

FIGS. 3 to 5 show examples of screw feeding, which is essential for screw tightening work, in the first embodiment described above.

Reference numeral 12 indicates a driver gripping portion of the boulder 2, which is connected to the sliding portion 4 at a point 13 so as to be able to rotate with respect to each other in a plane orthogonal to the driver propulsion direction Z.

An overhang 14 as shown in the figure is provided from one of the holding and moving parts, and an air cylinder 16 is mounted between it and a point 15 on the driver holding part 12. During the time period prior to the screw tightening work by the robot, the air cylinder is operated and the driver is moved from the screw tightening work position C to another position (S). In this example, the screw head is placed vertically on three sides.

Figure 4 shows an example in which one screw is vacuum-adsorbed at the tip of the driver. In this embodiment, since a screw 17f with a hexagonal head is used, an attachment 18 with a hexagonal tip as shown in FIG. 5 is used, and an improvement is made by adding a large chamfer to the tip. It was confirmed through experiments that t4+', in which the hexagonal phase is arbitrarily out of order at the initial stage of Un, %ir, can be completely adsorbed even in combination. By attaching an attachment that has been improved from ``Konoshi 1'' to the tip of the screwdriver, it is possible to reliably attract one hexagon head screw at point C. The air cylinder 16 is operated again and moved to the NC point for screw tightening work, completing preparations for the tightening work by the robot described in the first embodiment.

According to this embodiment, while the robot is delaying other assembly work, it is possible to reliably feed a single screw for screw tightening work for the first time in a long time, and to efficiently use the robot at the same level. Demonstrates the effect of

6 and 7 show another embodiment of screw feeding with air suction QK 4'1.

Point D' is the landing point e of the screw located directly below point C' in FIG. 3, and D'' is the point t located below the third point C'.

A screw force feeding device 419 is employed as the screw feeding power.

In general, the screw pumping device 1 is designed to feed pressurized air I/C up to the free end 21 of the hose 20, one screw at a time, from the head to the rear (
(Upper in Fig. 6). The free end of this hose is fixed to the frame 23 via the bracket 22, and J)
// Place the dot and the center as one piece. Arrow P indicates the direction in which the screw is forced to come out.

Reference numeral 24 is a receiver having a hole drilled in a forest pattern with the center aligned with point D.
ct! Without the above pressure air, the screw cannot reach the free end by overcoming the resistance of the hose, and the screw must be hit in the middle of the hose to reliably exert the screw force feeding function. However, on the other hand, since the screw is ejected forcefully into the space at the free end, a 60 degree conical mortar shape is best for the holder.Furthermore, if the screw is an M, 6x14 hexagonal screw with a built-in washer. includes the lower end of the bracket 22 and the receiver 2.
The optimum spatial distance δ from the top surface of the cylindrical member 4 is three.

In this way, the receiver at point D, which has received the force-fed screw, is waiting for the screw to be vacuum-adsorbed by the driver.
At point 7, the receiver is moved by the air cylinder 25 (only the rond is shown), and after being sucked by the driver, the air cylinder 25 returns the empty receiver to point D''.

According to this embodiment, the complicated and expensive return path switching mechanism that is attached to the tip of the driver and used to achieve both screw feeding and driver bit passage is completely eliminated, and screw feeding is extremely inexpensive and reliable. θ′ can be obtained by tightening the screw of the function.

〔Effect of the invention〕

According to the present invention, there is provided an automatic screwing device that is inexpensive, reliable, and has the versatility of being able to change the Mb mounting torque of an extremely wide hole (L-circle) just by replacing the driver. .

[Brief explanation of drawings]

FIG. 1 is a side view of an embodiment of the automatic screw tightening device of the present invention;
・Figure 2 is a cross section taken along the arrows ■-■ of the first part, and Figure 3 is a plan view of another example. 144, No. 1 is a sectional view taken along arrow 1l-IV in FIG. 3, FIG. 6 is a plan view of still another embodiment of the present invention, and FIG. It is an arrow view. 1. Driver, 2. Holder, 3. Rear surface, 5.
・Kite rail, 10...Spring, tt...Robot's arm, Figure 1 Figure 2 Leap Figure 3 Figure 4 Taku 5 Kasumi

Claims (1)

[Scope of Claims] 1. In an automatic assembly device using a robot, a holder that grips a driver and has a contact surface that receives motion from an arm of the robot; a guide rail for sliding this holder in a certain direction; An automatic screw tightening device comprising a spring for holding the holder in a fixed position. 2. A driver capable of vacuum suctioning a screw at its tip, and means for moving the holder that grips the driver in a plane orthogonal to the central axis of screw propulsion to attach one screw;
2. The automatic screw tightening device according to claim 1, further comprising means for completing said movement and said suction and waiting while said robot is performing other assembly operations. 3. A pressure-feeding device for force-feeding one screw, and a mortar-shaped receiver provided close to the hose outlet of the pressure-feeding device;
2. The automatic screw tightening device according to claim 2A''J2, further comprising means for bringing the receiver to a position where the driver will install one screw.