JPH046490B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vacuum suction type fastening device, and in particular, an automatic fastening device that eliminates the adverse effects of debris such as chips generated during fastening on the suction circuit and always performs reliable fastening work at low cost. The purpose is to provide.

A conventional device of this kind will be explained with reference to FIG. 1, taking the case of a screw tightening machine as an example. 1 is a bit, which is interlocked with the piston rod 3 of the cylinder 2, and is connected to a driver (not shown) via a bit holder 4.
is connected to. A vacuum pipe 5 is attached to the outer periphery of the bit 1 so as to be able to slide back and forth with the bit 1. A suction pipe 6 is fixed to the lower part of the vacuum pipe 5, and the upper end of the other end is connected to a vacuum port 10c of a vacuum generator 10 via a tube 7, a vacuum filter 8, and a tube 9.

Further, the tube 9 is connected to the exhaust port 12a of the solenoid valve 12 via the tube 11. Cylinder ports 12b and 12c of the solenoid valve 12 are connected to two ports of the driver upper and lower cylinder 2 by two tubes 13 and 14. or,
A pneumatic port 10a of the vacuum generator 10 is connected to a cylinder port 12b of the solenoid valve 12 via a tube 15.

Next, the operation of the conventional example will be explained. Figure 3 shows a steady state in which the driver section is at its upper limit.When the start signal is input, the driver 16 rotates and the solenoid valve 12 is activated, so compressed air flows into the tubes 13 and 15, and the suction pipe 6, the cylinder 2 descends while attracting the screw S. When the screw tightening is completed, the driver 16 is de-energized to the solenoid valve, so compressed air flows through the tube 14.
flows to On the other hand, the compressed air accumulated in the cylinder 2 and used during the descent passes through the tube 11, the vacuum filter 8 tube 7, and the vacuum pipe 5, and is released from the suction pipe 6, but because it is a small amount, it is not sucked in when tightening the screws. It is too insufficient to remove the chips generated by the friction between the bit 1 and the head of the screw, and even the chips generated when the bit directly hits the workpiece due to screw suction errors. be.

For this reason, these chips and debris remain on the vacuum pipe 5, vacuum filter 8, etc., creating suction resistance and causing the problem of screw suction failure. There was also the problem of suction of air during tightening.

The present invention aims to improve the conventional vacuum suction circuit and provide a highly reliable vacuum suction type automatic screw tightening machine, and one embodiment thereof will be described below with reference to FIGS. 2 to 7.

In the diagram, A is the lifting section, B is the driver section, and C
is the escapement part, D is the supply part, and supply part D
The screws are supplied and aligned, and the escapement C feeds the screws one by one into the catcher 17.
The driver part B is connected to the catcher 17 by the lifting part A.
It descends while suctioning the upper screw S, and returns to the upper limit after completing tightening.

Elevating part A has cylinder 2 and slide shaft 1
8, a driver holder 19, etc., and the driver holder 19 moves up and down on the slide shaft 18 by the operation of the cylinder 2.

Next, the driver part B is fixed to the driver holder 19, and the bit holder 4 and the bit 1
a driver 16 that rotationally drives the vacuum generator 1;
0, and consists of a vacuum pipe 5 and the like to which a suction pipe 6 is fixed at the tip.

Next, the air circuit, which is the key point of the present invention, will be explained.

FIG. 7 is an air circuit diagram, and the flow of air will be explained using this diagram.

20 is an air pressure source, and an integrator 21
It is connected through a tube 22 to a supply port 23a of a solenoid valve 23, which is a switching valve. The cylinder 2 also has air inlets 24a and 25a,
The air inlets 24a, 25a are connected to the cylinder ports 23b, 23c of the solenoid valve 23 through the speed controllers 24, 25 through two tubes 26,
27. 10 is a vacuum generator, and a pneumatic port 10a is connected to a switching valve 2 by a tube 28.
9, and the switching valve 29 is connected to the cylinder port 23b of the solenoid valve 23 by a tube 26. Further, the exhaust port 10b of the vacuum generator 10 is connected to the out port 30a of the quick exhaust valve 30. The import 30b of the quick exhaust valve 30 is connected to the switching valve 32 by a tube 31. The switching valve 32 is connected to the solenoid valve 2 by a tube 33.
It is connected to the cylinder port 23c of No. 3.
On the other hand, the vacuum port 10c of the vacuum generator 10 is connected to the vacuum pipe 5 via the vacuum filter 8, tube 34, and joint 35.

Further, the switching valve 32 is connected to the driver holder 19.
It is arranged so that it switches at the upper limit of .

The switching valve 29 is fixed to an outer pipe 36 fixed to the driver holder 19 so as to be vertically adjustable, and is connected to a lever 37 and a torsion coil spring 3.
It is always running at 8. When the joint 35 is raised, the lever 37 swings in the direction in which the switching valve 29 becomes free.

Next, the effect will be explained. When the activation signal is input, the driver 16 begins to rotate, the solenoid valve 23 is activated, and air flows to the cylinder 2 and the vacuum generator 10. As a result, the driver part B moves downward while attracting the screw S. (See Figure 4)
Next, the suction pipe 6 reaches the surface of the workpiece 39 and becomes the state shown in FIG. 35 stops at that position, but since the lever 37 and the switching valve 29 are lowered in the same way as the bit 1, the lever 37 comes into contact with the joint 35 and the switching valve 29 becomes free.

Therefore, the communication from the tube 26 to the tube 28 is cut off, the suction force of the vacuum generator 10 disappears, and there is no need to suction chips etc. during screw tightening.

Next, when the tightening is completed, a completion signal is issued, the rotation of the driver 16 is stopped, the electromagnetic valve 23 is de-energized, and compressed air flows to the tubes 27 and 33. Therefore, the cylinder 2 rises, and the air flowing into the tube 33 passes through the switching valve 32 and the tube 31, and then passes through the import 30b of the rapid exhaust valve 30.
The air that enters from the exhaust port 10b of the vacuum generator hardly flows to the pneumatic port 10a, which has an orifice and has a large flow resistance, but instead flows to the vacuum port 10c, where it continues to flow to the vacuum pipe 5 and suction pipe 6. It is then released into the atmosphere.

This example describes the case of screw tightening, but the same goes for nut tightening work that uses vacuum suction.Furthermore, when inserting a light object such as a washer by suction, suction using strong air pressure at the same time as the head rises. It unravels and blows out the adsorbed material, allowing for reliable insertion.

Further, in the embodiment shown in FIG. 7, the switching valve 29 is connected to the pneumatic port 10a of the vacuum generator 10, but the switching valve 29 is connected to the exhaust port 10b or the vacuum port 10c of the vacuum generator.
The suction can be stopped in the same way even if the

As described above, according to the present invention, after the driver part begins to descend, it attracts the screw, and when it reaches the tightening surface, the suction is stopped by the switching valve, and further, when the screw tightening is completed and the driver part B begins to rise. Since air enters from the exhaust port of the vacuum generator and goes to the suction pipe and is released, there is no need to absorb dust during work as in the conventional case, and dust sucked in while the driver unit is lowering is completely discharged. Since it is able to securely adsorb screws, it is highly reliable, and there is no need to draw air from a pneumatic source for special chip and dust removal, making it possible to provide an economical and highly reliable automatic screw tightening machine. .

[Brief explanation of drawings]

Fig. 1 is a conventional air circuit diagram, Fig. 2 is a side view of an automatic screw tightening machine according to an embodiment of the present invention, Fig. 3 is a sectional view of the main parts thereof, and Figs. 4 to 6 are main parts of the same device. The sectional view and FIG. 7 are air circuit diagrams of the same device. A... Lifting section, B... Driver section, C... Escapement section, D... Supply section, S... Screw,
1... Bit, 2... Cylinder, 5... Vacuum pipe, 6... Adsorption pipe, 8... Vacuum filter,
10... Vacuum generator, 16... Driver, 19
...Driver holder, 23...Solenoid valve, 29
...Switching valve, 30...Rapid exhaust valve, 32...Switching valve, 35...Joint, 37...Lever.

Claims (1)

[Scope of Claims] 1. A hollow vacuum pipe that is movable up and down, a bit built into the hollow part of the vacuum pipe that is movable up and down and rotatable, an air pressure source that generates compressed air, and pneumatic pressure. a vacuum source that generates a vacuum in the vacuum port by a flow of air from the port to the exhaust port; the air pressure source, the air pressure port and exhaust port of the vacuum source, the vacuum port of the vacuum source and the vacuum pipe; first, second, and third tubes that connect the first and second tubes, and first and second switching valves that are arranged between the first and second tubes and open and close the air passage; The first and second switching valves are controlled in conjunction with the screw tightening operation by the pneumatic port of the vacuum source until the vacuum pipe and bit are lowered and the bit reaches the screwed-in position. Compressed air is supplied to the air pressure port and exhaust port of the vacuum generation source when the screw is tightened by the bit, and the supply of compressed air to the air pressure port and the exhaust port of the vacuum generation source is stopped when the screw is tightened, and the vacuum generation is stopped while the vacuum pipe and the bit are being raised after the screw tightening is completed. A vacuum suction fastening device characterized in that it is configured such that compressed air is supplied to an exhaust port of a source.