JPH04270098A - Method for controlling speed of transfer press - Google Patents

Abstract

PURPOSE:To solve the troubles of breaking of the transfer mechanism or the troubles of remarkable damaging of the durability and the transfer precision on the conventional transfer press, to avoid the transfer mechanism from applying the large impact with the start, the stop and the inching of the press slide before occuring and to protect the transfer mechanism. CONSTITUTION:The transfer press having the transfer mechanism 13 is driven by rotating the eccentric shaft 9 which is the driving shaft of the press slide 5. By observating the driving speed of the above press slide 5, the start or stop of the press slide 5 is allowed only at the time that the driving speed is under the safety limit speed of the prescribed transfer mechanism 13 lower than the stationary press working speed. And the feature is that the press slide driving speed is controlled with the prescribed changing rate so as not to apply the excess impact of the acceleration or decceleration from the speed of starting time of the driving speed to the stationary press working speed against the transfer mechanism.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of controlling the speed of a transfer press, and more particularly to a method of controlling the speed of a transfer press to protect the transfer mechanism.

0002

[Prior Art] A press machine equipped with a transfer mechanism that automatically transports press material in synchronization with the press operation, that is, transfers the press material into and out of a press processing section, that is, a transfer press, is well known in the past. There is.

Generally, the transfer mechanism of a transfer press is drivingly connected to a press slide drive shaft and driven in synchronization with the rotation of the press slide drive shaft. In this case, a transfer action reliably synchronized with the movement of the press slide can be obtained without requiring any special driving means.

0004

[Problems to be Solved by the Invention] However, in the type of transfer mechanism described above, there is a one-to-one relationship between the operation of the transfer mechanism and the drive of the press slide. The rotation of the shaft starts the transfer mechanism, and when the press slide stops, the transfer mechanism stops. Therefore, when the press slide is started, stopped, and inched at a high press slide drive speed (SPM), The impact due to inertial force acts on the transfer mechanism,
There is a risk that the durability and transfer accuracy of this will be significantly impaired. Particularly in high-efficiency transfer presses with a high steady press processing speed, when the press slide is started, stopped, or inched at a steady press processing speed, a large shock that exceeds the safety limit is applied to the transfer mechanism. However, the transfer mechanism may be damaged.

In view of the above-mentioned problems in conventional transfer presses, the present invention prevents large impacts from being applied to the transfer mechanism due to starting, stopping, and inching of the press slide, and protects the transfer mechanism. The purpose of this invention is to provide a method for controlling the speed of a transfer press.

[0006]

[Means for Solving the Problems] According to the present invention, the above object is to provide a speed control method for a transfer press having a transfer mechanism driven in synchronization with the rotation of a press slide drive shaft. Monitors the press slide drive speed, allows the press slide to start or stop only when the press slide drive speed is below the safety limit speed of a predetermined transfer mechanism that is lower than the steady press working speed, and starts the press slide at the press slide drive speed. The press slide drive speed is controlled so that acceleration from the current speed to the steady press working speed, or deceleration from the steady press working speed to the speed at which the press slide stops, is performed at a predetermined rate of change that does not give excessive impact to the transfer mechanism. This is achieved by a transfer press speed control method characterized by:

[0007]

[Operation] According to the transfer press speed control method as described above, the start or stop of the press slide is limited when the press slide drive speed is below the safe limit speed of the transfer mechanism, which is lower than the steady press working speed,
Moreover, the acceleration of the press slide drive speed from the speed at the start of the press slide to the steady press working speed, or the deceleration from the steady press working speed to the speed at the time of stopping the press slide, is maintained at a predetermined rate of change that does not give excessive impact to the transfer mechanism. This is done gradually, thereby preventing large impacts from being applied to the transfer mechanism when the press slide is started and stopped, and further during inching operations in which starting and stopping are repeated.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows an embodiment of a transfer press used to implement the speed control method according to the present invention. The transfer press has a general frame 1, and the frame 1 has a fixed bolster 3 to which a lower mold is attached.
and a movable press slide (ram) 5 on which an upper mold is mounted. The press slide 5 has an eccentric shaft 9 which is a press slide drive shaft attached to the upper frame 7.
The rotation of the eccentric shaft 9 reciprocates in the vertical direction.

Although not shown in the figure, inside the upper frame 7 or on the back side thereof, an electric motor, a flywheel,
A press drive device having a general structure composed of a clutch or the like is provided, and the rotation of a flywheel directly rotated by an electric motor is intermittently transmitted to the eccentric shaft 9 by the clutch, thereby driving the press slide 5. is the SPM (stroke) according to the rotation speed of the flywheel.
per minute).

A transmission shaft 11 for driving the transfer mechanism is drivingly connected to the eccentric shaft 9, and the transmission shaft 11 transfers the rotation of the eccentric shaft 9 to a drive unit 15 of the transfer mechanism 13.
It is designed to be transmitted to The drive unit 15 is configured to change the direction of movement by receiving rotational force from the transmission shaft 11 and drive the slide bar 17 for transfer.

As a result, the transfer mechanism 13 is driven in synchronization with the rotation of the eccentric shaft 9, in other words, in synchronization with the vertical movement of the press slide 5.

[0013] A press start button 1 is located on the side of the frame 1.
9. An operation panel 23 including a press stop button 21, etc., a flywheel rotation speed detection device 25 that detects the flywheel rotation speed as the press slide drive speed, and an operation panel 23
A control device 27 is provided which controls the rotational speed of the electric motor for driving the flywheel and the engagement/disconnection of the clutch according to the signal from the flywheel and the flywheel rotational speed detection signal from the flywheel rotational speed detection device 25.

In order to carry out the control method according to the present invention, the control device 27 performs speed control and clutch engagement control in accordance with a control program as shown in FIG.

Next, an example of a method for controlling the speed of a transfer press according to the present invention will be explained using the flowchart shown in FIG.

First, in step 10, it is determined whether or not the press start signal is on. If the press start switch is on, the process advances to step 20, and step 2
At 0, it is determined whether the flywheel rotation speed is below a predetermined value. This predetermined value is determined according to the safe limit speed of the transfer mechanism 13, and when the flywheel rotation speed is below the predetermined value, that is, when the flywheel rotation speed is below the safe limit speed of the transfer mechanism 13, step 50 is executed, otherwise step 30 is executed.

At step 30, press operation disallowance processing is performed, that is, engagement of the clutch is prohibited, and then at step 40, the flywheel rotation speed is controlled to reduce.

Step 50 is executed when the flywheel rotation speed is below a predetermined value, and in step 50, press operation permission processing, that is, connecting the clutch is performed. As a result, the rotation of the flywheel is transmitted to the eccentric shaft 9, the press slide 5 is started, the transmission shaft 11 is accordingly rotated, and the transfer mechanism 13 starts operating.

Next, in step 60, the flywheel rotation speed is gradually accelerated. The acceleration rate of this acceleration is preset to a value that does not give excessive impact to the transfer mechanism 13.

Next, in step 70, it is determined whether the current flywheel rotation speed is a value corresponding to the steady press working SPM, and whether the flywheel rotation speed is a value corresponding to the steady press working SPM or not is determined. Step 60 is repeatedly executed until the flywheel rotation speed increases to a constant press working SPM, and when the flywheel rotation speed reaches a rotation speed corresponding to the steady press working SPM, further acceleration is stopped and step 80 is executed next.

In step 80, it is determined whether or not the press stop signal is on. If the press stop signal is turned on, step 90 is then executed.

In step 90, the flywheel rotation speed is gradually reduced. The deceleration rate of this deceleration is preset to a value that does not give excessive impact to the transfer mechanism 13.

Next, in step 100, it is determined whether the flywheel rotational speed has decreased to a predetermined value, that is, the safe limit speed of the transfer mechanism 13, and the flywheel rotational speed has decreased to a predetermined value, that is, the safe limit speed of the transfer mechanism 13. The deceleration control is repeated until the flywheel rotational speed decreases to the safe limit speed, and then step 110 is executed.

In step 110, the clutch is disengaged, whereby the rotation of the eccentric shaft 9 is stopped, the vertical movement of the press slide 5 is stopped, and the rotation of the transmission shaft 11 is accordingly stopped. The operation of the transfer mechanism 13 also stops.

Next, in step 120, the flywheel rotational speed is further reduced, and the flywheel is initially driven to rotate at a low speed.

FIG. 3 shows changes in the flywheel rotational speed when the flywheel rotational speed and clutch engagement are performed according to the control program as described above. In FIG. 3, area A is when the press slide is stopped with the clutch brake disengaged, and when the press start button 19 is pressed at time Ta and a press start signal is generated, the flywheel at this time Since the rotational speed is below the safe limit speed of the transfer mechanism, the clutch is engaged at this time Ta, the press slide 5 and the transfer mechanism 13 are started, and the flywheel rotational speed is gradually increased until the time Tb. The flywheel rotational speed becomes the rated speed corresponding to the steady press working SPM. Therefore, region B is an acceleration region. After this, when the press start button 21 is pressed at time Tc and the press stop signal is turned on, the flywheel rotational speed is first gradually reduced, and this rotational speed is reduced to the safe limit speed of the transfer mechanism 13. At time Td, the clutch is disengaged, and the press slide 5 and transfer mechanism 1
3 comes to be stopped. Therefore, region C is a steady press working region, and region D is a deceleration region.

[0027] This ensures that the drive and stop of the press slide 5, in other words, the drive and stop of the transfer mechanism 13, are always performed at a speed below its safe limit speed.

Although the present invention has been described in detail with respect to specific embodiments above, the present invention is not limited thereto, and various embodiments are possible within the scope of the present invention. This will be obvious to those skilled in the art.

[0029]

Effects of the Invention As can be understood from the description of the embodiments as described above, according to the transfer press speed control method according to the present invention, the press slide can be started or stopped when the press slide driving speed is lower than the steady press working speed. It is restricted when the speed is below the safe limit of the transfer mechanism, and the press slide drive speed cannot be accelerated from the speed when the press slide is started to the steady press working speed, or decelerated from the steady press working speed to the speed when the press slide is stopped. Since it is carried out gradually at a predetermined rate of change that does not cause excessive shock to the transfer mechanism, large shocks will not be applied to the transfer mechanism when the press slide starts and stops, and even during inching operations where starting and stopping are repeated. This prevents this from happening, protects the transfer mechanism, and improves its durability.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an embodiment of a transfer press suitable for implementing the speed control method according to the present invention.

FIG. 2 is a flowchart illustrating an example of the procedure for controlling the speed of a transfer press according to the present invention.

FIG. 3 is a graph showing changes over time in the flywheel rotation speed in the transfer press speed control method according to the present invention.

[Explanation of symbols]

1 Frame 3 Bolster 5 Press slide 9 Eccentric shaft 11 Transmission shaft 13 Transfer mechanism 23 Operation panel 25 Flywheel rotation speed detection means 27 Control device

Claims (1)

[Claims] Claim 1. A method for controlling the speed of a transfer press having a transfer mechanism driven in synchronization with the rotation of a press slide drive shaft, in which the press slide drive speed is monitored and the press slide drive speed is determined to be constant during press processing. The press slide is allowed to start or stop only when the speed is below the safe limit speed of the predetermined transfer mechanism, and the press slide drive speed is accelerated to a steady press working speed from the speed at which the press slide is started, or steady press work is performed. A method for controlling the speed of a transfer press, comprising controlling the press slide drive speed so that the speed is reduced from the speed to the speed when the press slide is stopped at a predetermined rate of change that does not give excessive impact to the transfer mechanism.