JPH0444320Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a press braking device that always stops the press at a predetermined position even when the press speed (SPM) changes.

[Prior Art] In an automatic press device equipped with a feeding device, when the workpiece is changed, the press speed is also changed in response to the change in the workpiece.

When the press speed changes, the inertia of the movable parts of the press (flywheel, slide, etc.) increases or decreases, and the braking distance when stopping (for rotating systems such as the flywheel, motor, etc., the sliding angle of the rotating shaft) ) changes.

Further, the start position (stop position) of the automatic press device itself is determined for sequence operation or safety reasons, and the press cannot be started at any other position.

Therefore, when braking the press device, the brake is applied faster by the sliding angle of the rotating shaft in accordance with the press speed at the time, so that the stopped position is always constant.

In conventional press braking devices, when the press speed is changed, the operator determines the slip angle of the rotating shaft corresponding to the changed speed each time from a pre-prepared table. The timing at which the braking signal is issued is adjusted so that the braking is applied earlier by the amount of slip angle.

This braking signal is issued from a micro switch operated by a cam installed on a camshaft that is linked to the crankshaft that drives the slide, so if you want to change the timing at which the braking signal is issued, adjust the position of this cam. are doing.

In addition, the method of creating the table showing the sliding angle of the rotating shaft with respect to the press speed is to divide the press into several stages from the lowest speed to the highest speed, and then apply braking at each stage of press speed to calculate the sliding angle of the rotating shaft. (See Figure 2).

[Problems to be Solved by the Invention] However, with the above-described conventional apparatus, it is necessary to adjust the position of the cam every time there is a change in press speed, making it impossible to perform efficient work.

Further, even if the press speed changes within the range of each stage, the sliding angle of the rotary shaft to be set is constant, so variations occur in the stop position.

Furthermore, when creating the table of the slip angle of the rotating shaft mentioned above, increasing the number of press speed steps will improve the stopping accuracy, but since it is necessary to actually measure the slip angle of the rotating shaft for each step, it is difficult to create the table. In addition to being time-consuming, if the inertia of the movable part changes due to a change in the mold, etc., the table must be re-created.

The present invention was conceived in view of the above-mentioned circumstances, and an object of the present invention is to provide a press braking device that has a function of easily changing the sliding angle of the rotating shaft even when the press speed changes.

[Means for solving the problem] In order to achieve the above purpose, in the press braking device of the present invention, the brake of the press machine is turned on.
- a press control circuit that operates an actuator that is turned off and a drive device that drives a rotating shaft such as a crankshaft of a press machine, and an absolute angle detection encoder that detects the rotation angle of the rotating shaft;
A speed setting device that sets the press speed of the press machine, a correction curve setting device that stores the quadratic regression curve calculation program, and a braking start position setting that sets the braking start position when measuring the slip angle of the rotating shaft. and a correction curve creation switch, and when the signal from the correction curve creation switch is input, the rotation at each press speed is determined based on the signals from the absolute angle detection encoder and the braking start position setting device. A correction curve that calculates the slip angle of the shaft and expresses the relationship between the press speed and the slip angle of the rotary shaft based on the slip angle of the rotary shaft at each press speed and the quadratic regression curve stored in the correction curve setter. a CPU capable of determining the correction curve, storing the correction curve in a storage device, and outputting a signal to the press control circuit based on the correction curve and the signal output from the absolute angle detection encoder; and the correction curve creation switch. When a signal is input through the CPU, the CPU sends a signal to operate the actuator that turns the drive device of the press machine and the brake of the press machine on and off based on each signal from the speed setter and brake start position setter. A microcomputer consisting of a sequence section that outputs output to the press control circuit via the press control circuit is provided.

[Operation] When moving the press, the operator selects a desired press speed at multiple points (measurement points), applies braking while the press is operating at the selected press speed, and
The slip angle of the rotary shaft from the start of braking to the stop is detected by an absolute angle detection encoder, and a correction curve is determined from the slip angle of the rotary shaft determined for each press speed and the quadratic regression curve, and the correction curve is calculated from the quadratic regression curve. Sometimes, the slip angle of the rotating shaft is determined using the correction curve and braking is applied in advance by this slip angle.

[Example] Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 shows an embodiment of the braking device for a press according to the present invention, in which 1 is a driving motor, 2 is a flywheel driven by the motor 1, and 4 is a clutch/brake 3 that connects the flywheel to the press. 2 is a drive shaft to which the rotational force is transmitted; 7 is a crankshaft configured such that the rotational force of the drive shaft 4 is transmitted via a rotary drive gear 5 and a driven gear 6; This is the slide of the moving press device.

A compressed air source is connected to the clutch/brake 3 via a solenoid valve 9.
Clutch/brake 3 is turned on by switching
It's starting to turn off.

Furthermore, an absolute angle detection encoder 10 is connected to the crankshaft 7.

Reference numeral 11 is a correction curve setter in which a calculation program for a quadratic regression curve is stored; 12 is a speed setter for setting the press speed of the press machine; and 13 is for setting the braking start position when measuring the slip angle of the rotating shaft. A braking start position setter, 14 a correction curve creation switch, and 21 a press control circuit for operating the electromagnetic valve 9.

Reference numeral 17 denotes a signal from the absolute angle detection encoder 10 and the braking start position setter 13 which are inputted via the input interface 15 when a signal is inputted from the correction curve creation switch 14 via the input interface 15. The slip angle of the rotating shaft at each press speed is determined based on each signal of A correction curve (see FIG. 2) representing the relationship with the slip angle of the shaft is obtained, and the correction curve is stored in the memory 19, and based on the correction curve and the signal output from the absolute angle detection encoder 10. This is a CPU that can output a signal to the press control circuit 21 via the output interface 20.

Reference numeral 18 indicates that when a signal is input from the correction curve creation switch 14 via the input interface 15 and the CPU 17, the motor 1 of the press machine and the electromagnetic CPU1 sends a signal to operate valve 9.
7. A sequence section that outputs output to the press control circuit 21 via the output interface 20, and the CPU 17, sequence section 18, and storage section 19 constitute a microcomputer 16.

The operation of this embodiment will be explained below.

Before starting regular press work, the sliding angle of the rotating shaft, that is, the crankshaft 7 is detected.

When detecting this slip angle, the speed setter 12 is used to set the lowest press speed, and the braking start position setter 13 is used to set the crankshaft 7.
After setting the braking start position when measuring the slip angle of
Turn it on.

When the correction curve creation switch 14 is turned on, the signal output from the correction curve creation switch 14 is sent to the input interface 15 and the CPU 1.
7 to the sequence unit 18, the sequence unit 18 sends the signals to the press control circuit 2 via the CPU 17 and the interface 20 based on the signals from the speed setter 12 and the braking start position setter 13.
A signal for operating the motor 1 and solenoid valve 9 of the press machine is output to 1, the press machine is operated, and the crankshaft 7 of the press machine is set to the speed setting device 1.
2 and reaches the speed set by crankshaft 7.
When the rotational position of the press is rotated to the position set by the brake start position setter 13, the press control device 21 switches the solenoid valve 9, compressed air is supplied to the clutch/brake 3, and the crankshaft 7 is stopped. .

At this time, the CPU 17 calculates the slip angle of the shaft 7 based on the signals from the absolute angle detection encoder 10 and the braking start position setter 13, and stores it in the memory 19.

Next, the above-mentioned operation is performed two more times by changing the press speed to the maximum speed and then to an intermediate speed.

That is, by performing the above-mentioned operations at different press speeds, the slip angles of the crankshaft 7 at different press speeds are stored in the storage section 19.

When the sliding angle of the crankshaft 7 at each of the three press speeds is stored in the storage device 19,
The CPU 17 calculates a correction curve representing the relationship between the press speed and the slip angle of the crankshaft 7 based on the slip angle of the crankshaft 7 at each press speed and the quadratic regression curve stored in the correction curve setter 11. , the correction curve is stored in the storage device 19.

Once the correction curve is stored in the storage section 19 in this manner, the actual pressing operation is started.

When performing press work, the optimum press speed for the workpiece is set by the speed setting device 12.

The CPU 17 uses the correction curve shown in FIG. 2, the signal output from the absolute angle detection encoder 10,
That is, from the rotational position of the crankshaft 7 and the press speed, the slip angle that is expected to occur when the crankshaft 7 is braked at this press speed is determined.

Furthermore, when the press control circuit 21 outputs a signal to the solenoid valve 9 to stop the rotation of the crankshaft 7, the CPU 17 uses the signal output from the absolute angle detection encoder 10 and the predicted crankshaft 7 described above. Based on the slip angle, a signal is output from the press control circuit 12 to the solenoid valve 9 when the rotational position of the crankshaft 7 moves forward by this slip angle.

Therefore, the braking force applied to the crankshaft 7 by the clutch brake 3 begins to act in advance by the slip angle caused by the rotational speed of the crankshaft 7 at that time, and as a result, the actual stopping position of the crankshaft 7 matches the position where it should be stopped.

Furthermore, there was a change in the workpiece for press work,
When the press speed changes, this press speed is detected by the absolute angle detection encoder 10,
The slip angle corresponding to the press speed is determined from the correction curve stored in the memory 19.

At this time, as described above, the braking start timing is a point in time before the actual stop position by this slip angle.

That is, in order to obtain a correction curve, the operator only needs to set the speed for selecting a measurement point and operate the correction curve creation switch 14.
By taking the slip angle at each type of speed setting, a correction curve can automatically obtain a value approximately approximate to the slip angle for all press speeds, and it is possible to improve the stopping accuracy of the press.

[Effects of the invention] As described above, according to the press braking device of the present invention, approximate values of the slip angle for all press speeds can be obtained with a simple operation, and the required correction curve is also different from that of the conventional one. This is closer to the actual step than the step-like correction line, and can provide an excellent effect of improving the stopping accuracy of the press.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the press braking device of the present invention, and FIG. 2 is a graph showing the relationship between press speed and slip angle when braking is applied. 3 is a clutch brake, 7 is a crankshaft (rotating shaft), 9 is a solenoid valve, 10 is an encoder for absolute angle detection, 11 is a correction curve setting device, 12 is a speed setting device, 13 is a braking start position setting device, 14 16 is a correction curve creation switch, 16 is a microcomputer,
17 is a CPU, 18 is a sequence section, and 19 is a memory device.

Claims (1)

[Scope of utility model registration request] A press control circuit that operates an actuator that turns on and off the brakes of a press machine and a drive device that drives a rotating shaft such as a crankshaft of the press machine, and an absolute angle detection encoder that detects the rotation angle of the rotating shaft. , a speed setting device for setting the press speed of the press machine, and a correction curve setting device in which a quadratic regression curve calculation program is stored.
It is equipped with a braking start position setting device for setting a braking start position when measuring the slip angle of the rotating shaft, and a correction curve creation switch, and when a signal from the correction curve creation switch is input, the absolute angle is set. The slip angle of the rotary shaft at each press speed is determined based on the signals from the detection encoder and the braking start position setter, and the slip angle of the rotary shaft at each press speed and the two stored in the correction curve setter are calculated.
A correction curve representing the relationship between the press speed and the slip angle of the rotating shaft is determined based on the following regression curve, and the correction curve is stored in a storage device, and a signal is output from the correction curve and the absolute angle detection encoder. a CPU capable of outputting a signal to the press control circuit based on the above, and a switch for creating a correction curve.
When a signal is input via the CPU, the speed setting device
Turns on the drive device of the press machine and the brake of the press machine based on each signal from the brake start position setting device.
−Signal that activates the actuator to turn OFF
1. A press braking device comprising a microcomputer comprising a sequence section that outputs output to the press control circuit via a CPU.