JPH059234B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a vacuum suction type insertion device for screw tightening, nut tightening, washer insertion, etc., and for example, in a screw tightening machine, it eliminates chips etc. generated during fastening and always ensures reliable vacuum suction. The purpose of the present invention is to provide a vacuum suction insertion device for performing fastening work etc. at a low cost.

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 an ejector-type 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 activation 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 The cylinder 2 descends while the screw S is sucked by the pipe 6.
When the screw tightening is completed, the electromagnetic valve 12 and the driver 16 are de-energized, so that compressed air flows into the tube 14. On the other hand, the compressed air used for the descent that had accumulated in cylinder 2 was released into tube 1.
1 It passes through the vacuum filter 8, the tube 7, and the vacuum pipe 5, and is released from the suction pipe 6, but because it is a small amount, there are chips sucked in during screw tightening, and minute particles generated by the friction between the bit 1 and the screw head. It is too insufficient to remove powder and even chips generated when the bit directly hits the workpiece due to screw suction errors.

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 above-mentioned conventional vacuum suction circuit and provide a highly reliable vacuum suction type insertion device.One embodiment of the present invention is shown in FIGS. 2 to 11 using a screw tightening machine as an example. explain.

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 after completing tightening, returns to the upper limit.

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 10
It consists of a vacuum pipe 5 and the like, which are connected to each other and have a suction pipe 6 fixed to the tip thereof.

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,
These air inlets 24a, 25a are connected to two tubes 2 through speed controllers 24, 25 to cylinder ports 23b, 23c of the solenoid valve 23.
6 and 27. Reference numeral 10 denotes an ejector-type vacuum generator, and a pneumatic port 10a is connected to a first switching valve 29 through a tube 28.
The switching valve 29 is connected to the cylinder port 23b of the solenoid valve 23 by a tube 26. or,
The exhaust port 10b of the vacuum generator 10 is connected to the outport 30a of the quick exhaust valve 30. The import 30b of the quick exhaust valve 30 is the tube 31
is connected to the second switching valve 32 by. The switching valve 32 is connected to the cylinder port 23c of the solenoid valve 23 by a tube 33. 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.
The lever 37 of the switching valve is arranged so as to come into contact with the inclined surface of the driver holder 19 at the upper limit of the switching valve.

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 FIG. 4).
Next, the suction pipe 6 reaches the surface of the workpiece 39,
When the state shown in Fig. 5 is reached and the bit 1 and screw S are further lowered to the screw-in position, the suction pipe 6, vacuum pipe 5, and coupling 35 stop at that position as shown in Fig. 6, but the lever 37 and the switching valve 29
moves down in the same way as bit 1, so lever 3
7 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 output, the rotation of the screwdriver 16 is stopped, the solenoid valve 23 is de-energized, and the compressed air is supplied to the tubes 27, 33.
flows to 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 30 of the rapid exhaust valve 30.
The air that enters b and further 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.
Flows to the vacuum port 10c and continues as it is to the vacuum pipe 5,
It passes through the adsorption pipe 6 and is released into the atmosphere. Furthermore, when the cylinder 2 rises and reaches its upper limit, the driver holder 19 operates the switching valve 32 to stop the air in the tube 33 from being discharged to the atmosphere. Therefore, air can be used effectively and the time during which noise is generated due to air blowing can be shortened.

In this example, the case of screw tightening has been described, but the nut tightening work using vacuum suction is also very similar.Furthermore, when inserting a light object such as a washer by suction, strong air pressure is applied at the same time as the head rises. It also has the effect of ensuring reliable insertion since the adsorption is released by pressure and the adsorbed material is blown out.

Further, in the embodiment shown in FIG. 7, a quick exhaust valve 30 is provided at the exhaust port 10b of the vacuum generator 10, but it is also effective to provide a chi at the exhaust port 10b as shown in FIG. 9 instead.

Furthermore, if the switching valve 32 is opened before the vacuum pipe descends and picks up the screw, as shown in FIG.
The quick exhaust valve may be omitted.

Also, as shown in FIG. 10, if there is no need to clean the vacuum generator 10, the air from the switching valve 32 is passed in front of the vacuum filter 8, and a quick exhaust valve is connected to the exhaust port 10b of the vacuum generator 10. You can omit it and just use the muffler.

Furthermore, the switching valve 32 is made into a three-way port, and the switching valve 32
Open port during operation and exhaust port 10 of vacuum generator 10
b may be communicated.

Furthermore, in the embodiment of the present invention, in the case of screw tightening work, for example, when the driver part B descends and reaches the tightening surface, the switching valve 29 for stopping suction of dirt is activated, and the screw tightening is completed. A switching valve 32 is also used to discharge the dust in the vacuum pipe 5 and suction pipe 6 while the driver part B is rising, but naturally, these two switching valves 29 and 32 are independent of each other. It can also be used alone.

As described above, according to the present invention, for example, when tightening a screw, the driver part starts descending, then attracts the screw, and when it reaches the tightening surface, the suction is stopped by the switching valve, and furthermore, the screw tightening is completed. When the driver part B begins to rise, air enters from the exhaust port of the vacuum generator, enters the suction pipe, and is released. Debris sucked up during the descent can be completely discharged, ensuring reliable screw suction, high reliability, and economical as there is no need to take special air from a pneumatic pressure source for removing chips and debris. This makes it possible to provide a 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. A cross-sectional view, Figure 7 is an air circuit diagram of the same device, and Figure 8 is a cross-sectional view.
11 are air circuit diagrams of other embodiments of the present invention. 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
...First switching valve, 30... Rapid exhaust valve, 32...
...Second switching valve, 35...Joint, 37...Lever.

Claims (1)

[Claims] 1 A hollow vacuum pipe that can be moved up and down, a suction pipe fixed to the bottom of this vacuum pipe, a bit that can be moved up and down located in the hollow part of this suction pipe and the vacuum pipe, and generates compressed air. an ejector-type vacuum generator that communicates with the vacuum pipe at the vacuum port and generates a vacuum by the flow of compressed air from the pneumatic port to the exhaust port, and the bit, vacuum pipe, and suction pipe. a screwdriver holder to hold the screwdriver holder; an air cylinder connected to the screwdriver holder to raise and lower the screwdriver; a quick exhaust valve having an out port connected to the exhaust port of the vacuum generator; a solenoid valve provided to send air to the rising port of the air cylinder and the import port of the quick exhaust valve during rising, and to send air to the falling port of the air cylinder and the air pressure port of the vacuum generator during falling; It is provided between the compressed air passage connecting the solenoid valve and the quick exhaust valve, and operates at the upper limit of the driver holder to block the passage for sending air from the solenoid valve to the quick exhaust valve, and a second switching valve that returns to operation at other times than the electromagnetic valve and opens a passage for sending the air from the electromagnetic valve to the rapid exhaust valve.