JPS5934480B2 - Press machine driving device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an operating device for a press machine with safety measures.

As shown in FIG. 1, the press machine has the upper end of a crank 4 pivotally supported by a shaft 3 on the eccentric part of an eccentric rotating part 2 that rotates around a shaft 1 as a fulcrum, and a slider 5 pivotally supported on the lower end of the crank 4. The slider 5 is guided in the vertical direction by the stator 6, and is placed on the mold 8 by the mold 7 attached to the lower end of the slider 5 due to the vertical movement of the slider 5 as the eccentric rotating part 2 rotates. It processes workpieces.

The eccentric rotating section 2 is connected to a drive source such as a motor, and rotates by transmitting the rotation of a constantly rotating flywheel via a power transmission mechanism such as a clutch.

During operation, the operator operates a switch after placing the workpiece on the mold 8, thereby connecting the power transmission mechanism, transmitting the rotation of the flywheel to the eccentric rotating part 2, and moving the slider 5 downward. When the press of the workpiece is finished at the bottom dead center, the slider 5 rises, and when the slider 5 reaches the top dead center, an automatic operation is performed to disconnect the power transmission mechanism and apply a brake to the eccentric rotating section 2. It looks like this.

The stopping operation of the slider 5 at the top dead center is performed as follows.

That is, a chain 10 is put around a sprocket 9 fixed to the shaft 1 of the eccentric rotating part 2, and another sprocket 11 is rotated by the chain 10, and that sprocket 11 is rotated by the chain 10.
A rotating cam 13 is fixed to the shaft 12 of the rotating cam 13, and a recess 13a is formed in one place on the circumferential surface of the rotating cam 13.
By keeping the rotor 14a of the actuating part of the switch 14 in constant contact with the circumferential surface of the rotating cam 13, and by setting the mounting angle of the rotating cam 13 with respect to the shaft 12, when the slider 5 is located at the top dead center, the rotating cam 13 The rotor 14a of the micro switch 14 is depressed into the recess 13a of the slider 5, and the micro switch 14 is turned on or off when the slider 5 reaches the top dead center, thereby disengaging the power transmission mechanism and applying the brake. It works like this.

In this case, the reason why the rotation of the eccentric rotating portion 2 is transmitted to the rotating cam 13 via the chain 10 is as follows.

In other words, shaft 1 receives a strong impact force (7
(nearly 0G) force of 177D, so if the rotating cam is attached to the shaft 1, it must be able to withstand the impact, but this is quite expensive, so the chain 10 is used to buffer the impact and the rotating cam 13 is The structure is designed to withstand power.

As described above, the operation of the press machine is started by the operator's switch operation, the slider 5 falls, the slider 5 finishes pressing and rises, and automatically ends when the slider 5 reaches the top dead center.

■The cycle is performed as described above.

However, if the slider 5 rises and does not stop when it reaches the top dead center, it may continue to fall, potentially causing an accident for the worker.

Such an accident occurs when the power transmission mechanism that transmits the rotation of the constantly rotating flywheel to the eccentric rotating section 2 is not disconnected. Specifically, the top dead center of the slider 5 due to a chain breakage occurs. This is the case when the arrival cannot be detected.

The same applies when a normal detection signal cannot be obtained due to a failure of the detector itself.

Accidents like the one described above are usually called second-degree falls and are the most likely to result in personal injury.

This invention was made in view of the above points.
To provide an operating device for a press machine that never causes a double drop.

Next, an embodiment of the operating device for a press machine according to the present invention will be described in detail with reference to the drawings.

In FIG. 2, reference numerals 15 to 18 indicate rotary cams, of which rotary cams 15 to 17 are fixed to the shaft 12 of the sprocket 11 in FIG. 1 and rotate simultaneously in response to the rotation of the sprocket 11.

The remaining rotating cam 18 is connected to the shaft 1 of the other sprocket 9.
It is fixed to and rotates by the same angle simultaneously with the rotation of the eccentric rotating part 2.

Therefore, as long as the chain 10 is normal, the rotating cams 15 to 18 rotate synchronously.

The rotating cam 15 has a protrusion 15a on its circumferential surface, the rotating cam 16 has a protrusion 16a on its circumferential surface, and the rotating cam 17 has a protrusion 1 on its circumferential surface.
7a, convex portions 18a are formed on the circumferential surface of the rotating cam 18, and the mutual relationship between these convex portions is as shown in FIG. Micro switches 19 to 22 are installed at angular positions,
These micro switches 19 to 22 switch their contacts and turn on when the convex portions of the corresponding rotating cams come into contact with them.

Here, the rotating cam 18 and micro switch 22, the rotating cam 15 and micro switch 19, and the rotating cam 16
The sets of micro switch 20, rotary cam 17, and micro switch 21 are the first. Second. Third. A fourth position detector is configured.

FIG. 3 is a diagram showing the on/off relationship of the micro switches 19 to 22 by the corresponding rotary cams over one rotation of the rotary cams, that is, the eccentric rotating portion 2. As shown in FIG.

0 degrees and 360 degrees are the rotational positions in FIG.

In this figure, the micro switch 19 is turned on by the convex portion 15a of the rotary cam 15 at an angular position slightly past 0 degrees, and is turned off by coming off the convex portion 15a slightly before 180 degrees, and outputs an output signal 19a. put out.

The micro switch 20 switches the rotating cam 1 just before reaching 0 degrees.
6, it is turned off by the protrusion 16a, and turned on by the protrusion 16a before reaching 180 degrees, producing an output signal 20a.

Micro switches 21 and 22 have corresponding rotary cams 17
The convex portions 17a and 182 of 18 turn on a slight rotation angle interval before 360 degrees, and outputs 21a, 22.
Give out a.

That is, the rotating cam 15 and micro switch 19 pair detects the downward movement of the slider 5 from the top dead center to the bottom dead center, and the rotating cam 16 and micro switch 20 pair detects the downward movement of the slider 5 from the bottom dead center to the bottom dead center. The rising motion toward the dead center is detected, and the rotating cam 17 and micro switch 21 pair and the rotating cam 18 and micro switch 22 pair detect the position of the slider 5 just before the top dead center, that is, stop the slider 5. Detect location.

And rotating cams 15 to 17, micro switch 19
~21 is designed to avoid impact on axis 1 during machining, to reduce costs, and to allow easy adjustment (detection position adjustment) according to the workpiece and tonnage of the press, or according to variations in each machine. As mentioned above, the chain 10 connects the shaft 1.
It is located far away.

The reason why the set of rotating cam 18 and micro switch 22 is provided on the shaft 1 side is because of the above-mentioned reason.
This is to prevent the slider 5 from falling twice when cutting.

FIG. 4 shows a logic circuit which receives ON signals from the micro switches 19 to 22 as H level signals and receives OFF signals as L level signals to control one drive and stop of the press machine.

In this logic circuit, when the output of the OR gate 23 is at H level, the power transmission mechanism is connected and the brake is released to start driving the press machine, and conversely, when the output of the OR gate 23 is at L level, the power transmission mechanism is connected. The connection is released and the brake is applied.

The OR gate 24, the inverter 25, the flip-flop 26, and the AND gate 27°28 constitute a rise control circuit that controls the rise operation of the slider 5.
9, Nand gate 30, flip flop 31.3
2. AND gates 33, 34, and 28 constitute a stop control circuit that controls the stopping operation of the slider 5, and the manual switch 35 and the AND gate 34 constitute a lowering control circuit that controls the lowering operation.

First, when the slider 5 is stopped at the top dead center, any of the output signals 19a to 22 of the micro switches 19 to 22
22a are both at L level, so the outputs Q of flip-flops 26, 31, and 32 are at L level, and each is at H level.

Here, when a sheet metal is set in the mold 8 shown in FIG. becomes L level, but since the output of NAND gate 30 receiving the L level output of Q of flip-flops 31 and 32 does not change from H level, the output of flip-flops 31 and 32 is possible. H of
The output of the AND gate 33 receiving the level becomes H level, the other input of the AND gate 34 becomes low, and the output of the AND gate 34 becomes H level,
It comes to be output via the OR gate 23.

Therefore, the power transmission mechanism of the press machine is connected, the brake is released, and the slider 5 begins to descend.

This downward movement of the slider 5 continues as long as the manual switch 35 is kept pressed.

That is, if the manual switch 35 is turned off during the process, the output of the AND gate 34 becomes L level, the power transmission mechanism is released, and the brake is also activated.

After turning on the manual switch 35 as described above, when the slider 5 is slightly lowered, the output signal 19a of the micro switch 19 goes to H level, becomes L level by the inverter 25, and is applied to the flip-flop 26 as a reset pulse.

Therefore, while receiving this reset pulse, flip-flop 26 does not invert even if it receives an H level signal at its ck terminal.

When the slider 5 reaches a point slightly before descending to the bottom dead center, the output signal 19a becomes L level, thereby releasing the flip-flop 26 from the reset state.

After a while, the output signal 20a of the micro switch 20 will change to H level, and this will cause the flip
The flop 26 is inverted and the output Q changes to H level,
The output becomes one input a of the AND gate 27, and the output signal 20a is directly applied to the other input of the AND gate, so that the output of the AND gate 27 becomes H level and is input to the next stage's AND gate. - Becomes one input a of the gate 28.

Since the other input of this AND gate 28 receives the H level output of the AND gate 33, the output of the AND gate 28 becomes H level and the OR signal is output.
Reach gate 23.

Therefore, even if the manual switch 35 is turned off after this point, the press machine continues to operate and the slider 5 moves upward.

As described above, safety measures are taken to prevent operation from continuing unless the manual switch 35 is pressed until just before the slider 5 reaches the bottom dead center.

When slider 5 continues to rise and reaches near top dead center,
Output signals 21a and 22 of micro switches 21 and 22
2 goes to H level, and inputs them to the ck terminals of flip-flops 31 and 32, respectively, inverting the flip-flops and changing the output Q to L level and Q to H level.

Therefore, the output of AND gate 33 becomes L level and the output of AND gate 28 also becomes L level, resulting in an OR gate.
The output of the press 23 also becomes L level, the power transmission mechanism of the press machine is disconnected, the brake is operated, and the slider 5
stops after reaching top dead center by inertia.

At this time, the output of the inverter 25 also becomes L level,
The flip-flop 26 is reset by the L level, and its output Q changes to the L level.

Note that the flip-flop 3L32 is reset as follows.

That is, the output Q, which changes to H level in response to receiving an H level signal at the ck terminal, becomes two inputs of the NAND gate, and the remaining input corresponds to the operating state of the manual switch 35. level, so if the manual switch 35 is turned off at that time, the inverter 29
Since the output of the NAND gate 30 becomes the H level and becomes the remaining input of the NAND gate 30, the output of the NAND gate 30 becomes the L level, and the flip-flops 31 and 32 are reset to set the output Q to the L level. Return to H level and return to initial state.

However, while the manual switch 35 remains on, the output of the inverter 29 is at the L level, so the output of the NAND gate 30 does not change to the L level, and therefore the flip-flops 31 and 32 cannot be reset. It doesn't cost.

That is, unless the manual switch 35 is turned off once, the flip-flops 31 and 32 will not be reset and the next press machine will not be started.

This prevents the manual switch 35 from being turned on twice.

Furthermore, the following safety measures are taken even if the chain 10 breaks.

First, if the chain 10 breaks while the slider 5 is descending from the top dead center to the bottom dead center, the slider 5 will reach the bottom dead center and move up as long as the manual switch 35 is kept pressed, but the rotating cam Since the output signals 15 to 17 do not rotate, the output signal 20a never becomes H level, and therefore its rising operation is never maintained.

Therefore, when the manual switch 35 is continued to be pressed and the output signal 22a of the micro switch 22 of the rotating rotary cam 18 reaches the H level, the flip-flop 32 is reversed and the output page changes from the H level to the L level. Due to the change to the level, the outputs of the AND gates 33 and 34 become L level, and the output of OR gate 23 also becomes L level, and the press machine stops at the top dead center as described above.

In this case, flip-flops 31, 32 are never reset and therefore cannot be restarted.

Next, if the breakage of the chain 10 occurs while the slider 5 is moving between the bottom dead center and the top dead center, the upward movement is maintained, but the point at which the chain 10 breaks occurs is the micro
The circuit operation differs depending on whether it is before or after the output signal 21a of the switch 21 becomes H level.

First, before the output signal 21a becomes H level, the chain 1
0 is disconnected, only the output signal 22a of the micro switch 22 becomes H level as a stop signal, so
At that point, the outputs of the AND gates 33 and 28 go to the L level, and the press machine stops when the slider 5 reaches the top dead center as described above.

Furthermore, when the chain 10 breaks after the output signal 21a becomes H level, the slider 5 stops at the top dead center and can be started by turning on the manual switch 35 again. Since the output signal 21a does not go to H level when the slider 5 rises, the slider 5 cannot be restarted after it reaches the top dead center and stops.

From the above, if the logic of the signals sequentially obtained by the slider 5 that moves up and down with the rotation of the eccentric rotating section 2 does not hold, the slider 5 will stop at the top dead center and cannot be restarted.

Further, when one press operation is completed and the slider 5 reaches the top dead center, the next activation cannot be performed unless the manual switch is turned off once.

Furthermore, if the chain breaks, the slider 5 will stop when it reaches the top dead center, and the next activation will also be impossible.

Further, in normal operation, when lowering the slider 5, it is necessary to keep pressing the manual switch, and the slider 5 is automatically raised regardless of the manual switch.

As described above, according to the present invention, even if a normal detection signal cannot be obtained due to breakage of the chain or damage to the microswitch during press operation, the slider will always stop at the top dead center, thereby providing safety measures. This is extremely preferable.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the mechanism of a conventional press machine. FIG. 2 is an explanatory diagram of a rotating cam according to an embodiment of the operating device of the present invention. FIG. 3 is a characteristic diagram of the output signal of the micro switch in FIG. 2. FIG. 4 is a circuit diagram of the logic circuit of the operating device. 1... shaft, 2... eccentric rotating part, 3...
...Axis, 4...Crank, 5...
Slider, 6... Stator, 7.8...
...Mold, 9...Sprocket, 10...
・・Chain, 11・・Sprocket, 12・
...Axis, 15-18 ...Rotating cam, 19
~22...Micro switch.

Claims (1)

[Scope of Claims] 1 The eccentric rotating part to which rotational force is applied by the power transmission mechanism descends from the top dead center to the bottom dead center to perform a pressing operation, and then rises to the top dead center again to complete one cycle. In a press machine having a slider at the end of the slider, first to fourth position detectors generate output signals corresponding to the position of the slider, and driving of the slider is controlled based on signals from the four detectors. A first detector fixed to the shaft of the eccentric rotating section sends out a pulse signal just before the top dead center of the slider, and second to fourth detectors are connected to the shaft of the eccentric rotating section. The second detector sends an output signal from just before the slider's top dead center to just before the bottom dead center, and the third detector sends an output signal from just before the slider's bottom dead center to just before the slider's bottom dead center. The fourth detector sends out an output signal just before the top dead center, and like the first detector, the fourth detector sends out a pulse signal just before the slider top dead center and just before the third detector finishes sending out the output signal. On the other hand, the control circuit is composed of a descending control circuit, an ascending control circuit, and a stop control circuit, and the descending control circuit receives the operation signal of the manual switch and the normal signal from the four position detectors, and controls these circuits. It is an AND gate that outputs a descending signal for the slider when each signal is normal, and controls the operation signal from the top dead center to the bottom dead center of the slider. an OR gate receiving the second detection signal; a flip-flop receiving the output signal of this OR gate and a third detector signal; an AND gate receiving the signal of this flip-flop and the second detector signal; The stop control circuit receives the first detector signal and controls the operation signal of the slider from the bottom dead center to the tenth dead center. A flip-flop that sends out a top dead center stop signal for the slider when the switch is disconnected, and a flip-flop that receives the fourth detector signal and sends out a top dead center stop signal for the slider during normal operation together with the flip-flop. A NAND circuit receives the output signals of the flops, each of these flip-flops, and the above operation signal via an inverter.
An operating device for a press machine, comprising a gate and an AND gate receiving an output signal from the other of the flip-flops to control the stopping operation of the slider.