JPH0144194Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an ejector for press-formed products or scraps.

[Background technology and its problems]

Generally, in press machines, an air eject method is used as one method for removing pressed products or scraps. In this method, for example, as shown in FIG. 2, an air blowing nozzle 5 is placed facing a lower mold 2 mounted on a bolster 1 or an upper mold 4 mounted on a slide 3 that moves up and down with respect to the bolster 1. This system blows out compressed air from the nozzle 5 in synchronization with the vertical movement of the slide 3, that is, when the slide 3 rises.

As shown in FIG. 3 or 4, the air piping of the conventional ejector is connected to a 3-port 2-position electromagnetic switching valve 8 or 2-port 2 via a joint 7 between a nozzle 5 and an air source 6 such as a compressor. The position solenoid switching valve 9 is inserted, and the switching valves 8, 9 are activated by a signal from a limit switch operated by a rotary cam attached to the crankshaft 3A for vertical movement of the slide of the press machine shown in FIG.
from the first switching position 8A, 9A to the second switching position 8
B, 9B, and from the second switching positions 8B, 9B to the first switching positions 8A, 9A.

According to this conventional device, when the operation of the press machine is stopped when the switching valves 8 and 9 reach the second switching positions 8B and 9B in order to perform various adjustment operations on the press machine, air is constantly supplied from the blow-off nozzle 5. Because it blows out, energy is wasted.

Also, when the slide 3 of the press machine reaches the bottom dead center and begins to rise, the switching valves 8 and 9 are switched from the first switching valves 8A and 9A to the second switching positions 8B and 9B.
and the second switching position 8B, 9B after ejecting the pressed product or scraps.
The operation speed of the press machine (slide 3) must be switched from
(vertical movement speed) is changed depending on the type of pressed product, etc., and when the operating speed is increased to increase press work efficiency, the time during which the switching valves 8 and 9 are in the second switching position 8B and 9B, That is, the time during which air is blown out from the blow-off nozzle 5 becomes shorter, and as a result, there is a possibility that the press-formed product or the scraps cannot be ejected. For this reason, each time the operating speed of the press machine is changed, for example, by converting the rotary cam, the second switching position 8B, 9B is changed to the second switching position 8B, 9B so that the length of time in which it is in the second switching position 8B, 9B becomes the required length. 1st from 9B
The timing of switching to the switching positions 8A and 8B had to be adjusted, and this work was troublesome.

On the other hand, if the timing of switching from the second switching positions 8B, 9B to the first switching positions 8A, 9A is delayed so that it can cope with all operating speeds of the press machine, during low-speed operation, the pressed product or Air continues to be blown out from the blow-off nozzle 5 for a long time even after the waste has been ejected.
In this case, energy will be wasted.

[Purpose of invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an eject device for a press machine that can save energy and eliminate the need to adjust the switching timing of a switching valve even if the operating speed of the press machine is changed.

[Means and actions for solving problems]

The eject device of the press machine according to the present invention is
In addition to the blowout nozzle and the switching valve, it is equipped with a pressure storage tank, and the switching valve is a 3-port, 2-position switching valve that is switched in synchronization with the vertical movement of the slide of the press machine, and the first port has an air source. A pressure accumulation tank is connected to the second port, and a blowout nozzle is connected to the third port. In the first switching position, the first port and the second port communicate with each other, and the third port is closed, and in the second switching position, the One port is closed and the second and third ports are communicated.

When the switching valve is switched to the first switching position, compressed air from the air source flows into the pressure accumulation tank through the switching valve, and when the air pressure in the pressure accumulation tank increases to the same pressure as the compressed air from the air source, Air flow into the pressure storage tank is automatically stopped. When the slide of the press machine starts to rise after reaching the bottom dead center, the switching valve is switched to the second switching position, and a certain amount of compressed air stored in the pressure storage tank is blown out from the blow-out nozzle through the switching valve. , to eject pressed products or scraps. If the switching timing of the switching valve to the first switching position, which is carried out after this, is delayed, even if the operating speed of the press machine is changed to high speed, the pressure storage tank necessary to eject the pressed product or scraps can be kept in the pressure storage tank. The time for blowing out a certain amount of compressed air from the blow-off nozzle is secured.

〔Example〕

FIG. 1 shows an embodiment of the present invention. In this embodiment, a pressure accumulating tank 23 is connected to an air source 21 such as a compressor via a 3-port 2-position electromagnetic switching valve 22. The air source 21 is connected to the first port 26 of the switching valve 22, and the pressure accumulating tank 23 is connected to the second port 27, which is communicated with the first port 26 when the switching valve 22 is in a non-excited state. 2nd port 27
An air blowing nozzle 25 is connected via a joint 24 to a third port 28 that is communicated when the switching valve 22 is in an energized state.

The switching valve 22 is in the first switching position 22A when it is in a non-excited state, and at this time, the first port 26 and the second port 27 are communicated with each other as described above, and the third port 28 is closed. Further, when the switching valve 22 is in the excited state, it is in the second switching position 22B, and at this time, as described above, the second port 27 and the third port 28 are communicated with each other, and the first port 26 is closed.

In such a configuration, when the switching valve 22 is in the first switching position 22A, the air source 2
The compressed air from 1 passes through the first and second ports 26 and 27 of the switching valve 22 to the pressure accumulator tank 23.
The air pressure inside this pressure storage tank 23 increases. When this air pressure reaches the same pressure as the compressed air from the air source 21, the flow of air into the pressure accumulator tank 23 stops naturally. Eventually, when the slide 3 reaches the bottom dead center and begins to rise, the switching valve 22 is switched to the second switching position 22B, whereby the second and third ports 2 of the switching valve are switched to the second switching position 22B.
7 and 28 communicate with each other, a certain amount of compressed air stored in the pressure accumulating tank 23 is blown out from the air blowing nozzle 25 through the switching valve 22 and the joint 24. As a result, the pressed product or its scraps are ejected from the press machine. After this, the switching valve 22 is moved to the first switching position 22.
It is switched to A and the above operation is repeated.

Therefore, in this embodiment, in order to perform various adjustment operations of the press machine, the operation of the press machine is controlled by switching valve 2.
2 is stopped when the switch is at the second switching position 22, the air blown out from the blow-off nozzle 25 is only the air stored in the pressure accumulation tank 23, and the air from the air source 21 is not blown out, resulting in energy saving. can be realized.

Furthermore, by delaying the timing at which the switching valve 22 is switched from the second switching position 22B to the first switching position 22A, even when the operating speed of the press machine is increased, the switching valve 22 is switched to the second switching position 22B. Since the time required for the product to cool is longer, it becomes possible to secure time for blowing out a certain amount of compressed air from the blow-off nozzle 25 in the pressure storage tank 23, which is necessary to eject the pressed product or scraps. , it becomes unnecessary to adjust the switching timing of the switching valve 22. On the other hand, even if the operating speed of the press machine is lowered and therefore the switching valve 22 remains in the second switching position 22B for a longer time, the air blown out from the blowing nozzle 25 is the air stored in the pressure accumulating tank 23. Since no further air is blown out, energy saving can be achieved in this case.

Further, according to this embodiment, the switching valve is a 3-port 2-position switching valve, and the switching valve is in the second switching position 22B.
When switched to , the first port 26 is closed, and this switching valve 22 also serves as a cutoff valve that cuts off the circuit connecting the air source 21 and the pressure accumulation tank 23.The number of switching valves is 1. Since only one is required, the configuration of the air circuit can be simplified.

In the above embodiment, an electromagnetic switching valve is used as the switching valve, but a mechanical switching valve may also be used. In addition, the capacity of the pressure accumulating tank 23 is appropriately determined based on the necessary amount of air to be blown depending on the number of air blowing nozzles 25, etc. good.

[Effect of idea]

As described above, according to the present invention, it is possible to achieve the effects of saving energy and eliminating the need to adjust the switching timing of the switching valve.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing one embodiment of the present invention;
The figure is a front view showing the external appearance of the press machine, and FIGS. 3 and 4 are piping diagrams showing a conventional eject device. 21...Air source, 22...3 port 2 position electromagnetic switching valve, 22A...1st switching position, 22B
...Second switching position, 23...Accumulator tank, 25...
...Air blowing nozzle, 26...First port, 27
...Second port, 28...Third port.

Claims (1)

[Scope of Claim for Utility Model Registration] An ejecting device for a press machine that ejects pressed products or scraps by air blown from a blowing nozzle, comprising a switching valve and a pressure storage tank, the switching valve being a press machine. It is a 3-port 2-position switching valve that is switched in synchronization with the vertical movement of the slide, and the first port to which an air source is connected, the second port to which the pressure accumulation tank is connected, and the blowout nozzle are connected. a third port, a first switching position in which the first port and the second port communicate with each other and the third port is closed; and a second switching position in which the first port is closed and the second port and the third port communicate with each other. An eject device for a press machine, characterized in that it has a switching position.