JPS6018520B2 - Speed control device and speed display method in press - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to mechanical presses, and more particularly to flywheel speed control and display thereof.

BACKGROUND OF THE INVENTION Mechanical presses are well known and generally include a slide that reciprocates within a frame in the following manner.

That is, at least one crankshaft is rotatably provided on the ceiling of the frame, and the slide is connected to the crankshaft by a connector so that the slide causes reciprocating motion when the crankshaft rotates. There is. To provide sufficient mechanical rotational inertia to the drive mechanism of such slides, heavy flywheels are commonly used in presses.

This heavy flywheel is connected to the crankshaft via a clutch mechanism, and is given rotational motion by an electric motor. It is also common practice to provide a variable speed coupler, such as an eddy current coupler, between the motor and the flywheel to vary the speed of the flywheel. The above motor is driven.
d) The flywheel rotates continuously, but its rotational motion is interrupted by the clutch being disengaged (deener
(gized), it is not transmitted to the crankshaft.

However, when the clutch is energized, the rotary motion of the flywheel is transferred to the crankshaft, which typically rotates at the same speed as the flywheel.

Of course, a gear mechanism can also be used to make the drive ratio larger or smaller than 1:1. Presses of the type that utilize heavy flywheels for kinetic energy storage have the property that the rotational speed of the flywheel is reduced while the clutch is engaged.

This is because energy is required to start the rotating and reciprocating parts (i.e. the drive mechanism and slides, etc.), and the drive mechanism of a mechanical press is extremely heavy and has an inertial force that must be overcome. This is because it is quite large. For this reason, the rotational speed of the flywheel becomes lower than the preset rotational speed, and it often takes several strokes to reach the predetermined rotational speed.

Therefore, the relationship between press operating speed and time is as follows. First, when the clutch is disengaged and the flywheel is at speed, the rotational speed of the flywheel is at the set normal operating level, but the press is not operating. Next, when the clutch is engaged and the press operation begins, the rotational speed of the flywheel decreases slightly for several cycles to overcome the mechanical inertia of the drive mechanism. Therefore, the press operating speed is also lower than the normal operating speed. Thereafter, the rotational speed of the flywheel reaches the normal operating level, and accordingly the press operation speed also reaches the normal operating speed. In stamping operations, it is important that the press reaches normal operating speed on the first stroke after engagement of the clutch.

For this purpose, it is necessary to prevent the above-mentioned reduction in press operation speed. The amount by which the press operating speed decreases from the set normal operating speed is proportional to the rotational energy gained by the press drive mechanism, which is accelerated from a stationary state to an operating state when the clutch is engaged, and this rotation Energy is provided by the flywheel.

Therefore, a reduction in press operation speed can be prevented by increasing the rotational speed of the flywheel by an amount corresponding to the rotational energy. Furthermore, after overcoming the inertial force, it is necessary to maintain the operating speed of the press at the normal operating speed. [Structure of the Invention] The speed control device, method, and display method for a press according to the present invention can cause the press operation to be performed at the normal operating speed set from the first stroke, and furthermore, such press operation can be performed by the operator. This can be done without putting any strain on the outside.

That is, when the clutch is disengaged, a higher drive voltage than during normal operation is applied to the motor that rotates the flywheel, causing the flywheel to rotate faster than during normal operation.

When the clutch is engaged in this state, the rotational speed of the flywheel is reduced to the normal operating speed due to the inertia of the drive mechanism, as described above, and the first stroke of the slide is performed at the normal operating speed. Of course, the rotational speed of the flywheel in the clutch disengaged state is predetermined so that it becomes the rotational speed during normal operation due to the speed reduction when the clutch is engaged. In addition, so that the operator can set the flywheel rotational speed as high as described above in the clutch-disengaged state, the speedometer that indicates the flywheel rotational speed has a value that is lower than the actual rotational speed of the flywheel. A modified speed voltage is provided to indicate speed.

More specifically, the output voltage of a tachometer directly connected to the flywheel, that is, the speed voltage corresponding to the actual rotational speed of the flywheel, is lowered, and the corrected speed voltage is applied to the speedometer. Therefore, the speedometer will display a lower speed than the actual rotational speed of the flywheel.
However, as described above, when the clutch is engaged and the inertia of the drive mechanism of the press is overcome, the actual rotational speed of the flywheel decreases to the speed during normal operation.

Therefore, the speed voltage applied to the speedometer no longer needs to be modified and is applied as is to the speedometer,
applied to the speedometer, which displays the actual rotational speed of the flywheel. That is, the present invention provides a slide;
A mechanical drive system for reciprocating the slide, and a motor and drive system means that are drivingly connected to the flywheel and continuously rotate the flywheel by driving the slide. a drive means including a clutch that transmits the rotation of the flywheel to the mechanical drive system; a speed controller that controls the rotational speed of the flywheel by changing the rotational speed of the motor in accordance with a speed control voltage; The present invention relates to a mechanical press having a tachometer mechanically connected to the flywheel and providing a speed voltage corresponding to the rotational speed of the flywheel to a speedometer. In the speed control device of the present invention, in the press, when the clutch is not connected, the speed control voltage is corrected so that the flywheel rotates at a speed farther than a set speed during normal operation; When the clutch is connected,
first modifying means for modifying the speed control voltage so that the flywheel rotates at the normal operating speed; and when the clutch is not connected, the flywheel rotates faster than the normal operating speed. A second correction means is provided for correcting the speed voltage so that the speed meter indicates the rotation speed during the normal operation even when the motor is rotating at the same speed.

In the method of the present invention, when the clutch is disengaged,
The flywheel is rotated at a speed higher than a set rotational speed during normal operation, and when the clutch is connected, the flywheel is rotated at the rotational speed during normal operation, and the clutch is in a disengaged state. Even if the flywheel is rotating at a speed far from the rotational speed during the normal operation, the speedometer displays the rotational speed of the flywheel during the normal operation, and when the clutch is in the connected state, The present invention is characterized in that the actual rotational speed of the flywheel is displayed on a speedometer.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is an overview of a press incorporating the flywheel speed control device and speed display circuit of the present invention, and FIG. 2 shows an embodiment of the flywheel speed control device and speed display circuit of the present invention. It is a circuit diagram. Although the flywheel speed control device and speed display circuit in FIG. 2 are incorporated into the mechanical press 2 (FIG. 1), the mechanical press 2 may be any of various conventional presses.

The mechanical press 2 has a slide 3, and the slide 3 is mechanically driven by a drive assembly 41 such as a crankshaft or a connecting mechanism to perform reciprocating motion. The crankshaft 5 is connected to a heavy flywheel 6, which is belt driven by an electric motor 7 via a variable distance mechanism 8.

For example, an eddy current coupler may be used as the variable distance mechanism 8 to control the rotational speed of the output shaft from the motor 7.
Flywheel 6 is continuously rotated by motor 7 at a speed selected by the operator. However, the crankshaft 5 rotates only when the clutch 9 is engaged and the rotational energy of the flywheel 6 is mechanically transmitted, causing the slide 3 to reciprocate through the coupling portion. In FIG. 2, the motor, clutch and flywheel assembly 10 is controlled by a conventional speed controller 12, which drives the flywheel 6 continuously at a preset speed. Rotate to .

A speed control voltage for speed control of the motor is obtained by potentiometer 14 and is input through line 18 to control input terminal 16.

Note that the bias voltage for obtaining the speed control voltage mentioned above is supplied from the terminal 17 to the relay contact 2 through the line 19.
0 and potentiometer 22. motor 7
to rotate the flywheel 6, and the clutch 9
In the disconnected state, the relay contact 20 is closed by the flywheel coil 11.

The flywheel coil 11 is a relay coil that connects normally closed relay contacts 20 and normally open relay contacts 32 according to the connected or disconnected state of the clutch 9 that selectively transmits the rotation of the flywheel 6 to the crankshaft 5. It is something that makes it work.

More specifically, the flywheel coil 6 is connected in series with the clutch drive circuit, and when a voltage that connects the clutch 9 is generated, the flywheel coil 6 is connected to the relay contact 20.
is in the connected state, and the relay contact 32 is in the open state.
Therefore, if the clutch 9 is in the disconnected state, the relay contact 201 is in the closed state, and the potentiometer 22 is in the closed state.
is shorted.

For this purpose, the bias voltage at the terminal 17 is applied via the line 19 and the relay contact 20 to the potentiometer 14 for setting the speed of the motor 7, and the potentiometer 14 adjusts the speed to the normal operating speed. Voltage is input to control input terminal 16 through line 18 . The speed controller 12 determines the rotation speed of the motor 7 according to the input speed control voltage, but the speed control voltage at this time is
The voltage is higher than when the clutch 9 is connected. Therefore, the speed controller 12 drives the motor 7 and rotates the flywheel 6 at a higher speed than when the clutch is engaged.
Tachometer 24 generates a speed voltage on line 26 that is proportional to the actual rotational speed of flywheel 6.

As already mentioned, when the clutch 9 is not engaged, the flywheel 6 rotates at a speed higher than the rotational speed set by the potentiometer 14 during normal operation. In this way, when the clutch 9 is in the disengaged state, the rotational speed of the flywheel 6 is set high.

That is, the rotational speed of the flywheel 6 is controlled by the clutch 9.
It is necessary to set it high so that the first stroke of the press is at the normal operating speed, taking into account the speed reduction when the press is connected. However, in the conventional press, it was necessary to calculate the rotational speed of the flywheel 6 so that the first stroke was at the normal operating speed, or for the operator to refer to an appropriate conversion table. However, according to the present invention, the speedometer 28 always displays the set rotational speed of the flywheel 6 during normal operation, regardless of whether the clutch 9 is connected or not.

In order to perform such an operation, in this embodiment, the output line 26 of the tachometer 24 and the input line 34 of the speedometer 28 are connected to each other.
Relay contact 3 that closes only when energized
2 is connected in parallel with the potentiometer 30. As already mentioned, relay contact 32 is open when clutch 9 is disengaged, and the speed voltage from tachometer 24 is connected to line 26, potentiometer 30,
It is input to the speedometer 28 via line 34.

Therefore, the speedometer 28 is input with the speed voltage reduced by adjusting the potentiometer 30, and the flywheel 6
The displayed rotation speed is lower than the actual rotation speed. In this manner, even if the flywheel 6 is rotating at a higher speed than the rotational speed during normal operation, by adjusting the potentiometer 30, the speedometer 28 can display the rotational speed during normal operation to the operator. On the other hand, the potentiometer 22 connected in parallel with the relay contact 20 is
It is adjusted in consideration of the amount of decrease in the rotational speed of the flywheel 6 due to the inertia force of the press drive mechanism when the clutch 9 is engaged. That is, when the clutch 9 is disconnected, the relay contact 20 is closed, so the bias voltage is directly applied to the potentiometer 14 as a high voltage, but when the clutch 9 is connected, the relay contact 20 is opened and the bias voltage is applied to the adjusted voltage. It is applied to potentiometer 14 as a low voltage which is lowered by tensiometer 22 and provides normal operating speed. Therefore, by simply setting the potentiometer 14 to the normal operating speed position, a high speed control voltage is input to the control input terminal 16 when the clutch 9 is disengaged, causing the flywheel 6 to rotate at high speed as described above. When the clutch 9 is connected, a low speed control voltage is input to the control input terminal 16 to rotate the flywheel 6 at the normal operating speed. The operation of this embodiment can be summarized as follows.

Before the clutch 9 is connected, the potentiometer 22 is short-circuited, and a high speed control voltage is input from the line 18 to the control input terminal 16, and the flywheel 6
rotates at the high speed mentioned above. However, at this time, since the relay contact 32 is open, the speedometer 28 displays a speed lower than the actual rotational speed of the flywheel 6, and the displayed speed is the speed set by the potentiometer 14. In other words, it is the speed during normal operation. next,
When clutch 9 is connected in this state, relay contact 20 opens and relay contact 32 closes. As a result, potentiometer 22 is connected in series with line 18 and a low speed control voltage is input to control input terminal 16.
As a result, the speed controller 12 rotates the flywheel 6, whose high rotational speed has been reduced to the normal operating level due to the inertia of the drive mechanism, at the normal operating speed of the press. Also, since the relay contact 32 is closed, the potentiometer 30 is short-circuited, and the tachometer 2 is connected to the speedometer 28.
The speed voltage generated on the output line 26 of No. 4 is input without modification.

Therefore, the actual rotational speed of the flywheel 6, that is, the rotational speed during normal operation, is displayed on the speedometer 28. By timing the opening of relay contact 20 with the engagement of clutch 9, a low speed control voltage is generated in line 18 as soon as the rotational speed of flywheel 6 has decreased.

Therefore, the speed controller 12 maintains the rotational speed of the flywheel 6 at a reduced level, ie at the rotational speed during normal operation of the press. If the above system is operating correctly, the speedometer 28 will indicate the normal operating speed, regardless of whether the flywheel 6 is rotating at a high speed or at the set normal operating speed. Display speed. For this reason, the operating speed of the press, especially the initial stroke speed of the slider, can be easily adjusted to the normal operating speed while the clutch 9 is not in operation.
Once connected, the preset regular operating speed can be maintained.

[Brief explanation of the drawing]

FIG. 1 is an overview diagram of a press incorporating the flywheel speed control device and speed display circuit of the present invention, and FIG. 2 is a circuit diagram showing an embodiment of the flywheel speed control device and speed display circuit of the present invention. It is a diagram. 2...Press, 3...Slide, 5...Crankshaft, 6...Flywheel, 7...Motor, 9...
Clutch, 12... Speed controller, 14, 22, 30...
Potentiometer, 20, 32...Relay contact, 2
4... Tachometer, 28... Speedometer. "76.1 100.2

Claims (1)

[Scope of Claims] 1. A slide 3, a mechanical drive system for reciprocating the slide, and a flywheel 6, which is drivingly connected to the flywheel 6 to continuously rotate the flywheel. drive means including a clutch 9 for transmitting the rotation of the flywheel to the mechanical drive system in the connected state; a speed controller 12 that controls the rotational speed of the flywheel;
in a mechanical press having a tachometer 24 mechanically coupled to the flywheel and supplying a speed voltage corresponding to the rotational speed of the flywheel to a speedometer 28, when the clutch is not engaged; modifying the speed control voltage so that the flywheel rotates at a speed higher than a set normal operating speed, and when the clutch is engaged, the flywheel rotates at the normal operating speed; first correcting means 20, 22 for correcting the speed control voltage; and even if the flywheel is rotating at a speed higher than the rotational speed during normal operation when the clutch is not engaged, the speedometer A speed control device for a press, comprising: second correction means 30, 32 for correcting the speed voltage so that the rotation speed indicates the rotation speed during normal operation. 2 The first and second correction means are potentiometers 22 and 30, and relay contacts 20 and 32 are connected in parallel to each potentiometer, and both relay contacts are in the open or closed state with respect to each other. Claim 1 characterized in that it is always in an opposite state to
A speed control device for the press described in Section 3. 3. A slide 3, a mechanical drive system for reciprocating the slide, and a motor and drive connection means that are drivingly connected to the flywheel 6 and that drive the flywheel to continuously rotate the flywheel. and a drive means including a clutch 9 for transmitting the rotation of the flywheel to the mechanical drive system in a connected state; a speed controller 12 for controlling;
A tachometer 24 is mechanically connected to the flywheel and supplies a speed voltage corresponding to the rotational speed of the flywheel to a speedometer 28. When the clutch is disconnected, the flywheel is rotated at a speed higher than the set rotational speed during normal operation, and when the clutch is connected, the flywheel is rotated at the rotational speed during normal operation. let me,
Even if the clutch is in the disconnected state and the flywheel is rotating at a faster speed than the rotational speed during the normal operation, the speedometer displays the rotational speed of the flywheel during the normal operation, and the clutch is turned off. A method for controlling and displaying speed in a press, characterized in that in a connected state, the actual rotational speed of the flywheel is displayed on the speedometer.