JPS6021834B2 - Press status detection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for detecting the state of a press, and particularly to detecting an abnormal state of the number of strokes and detecting the number of strokes.

In press working, the rotational speed of the flywheel decreases due to the load applied to the press, but this is generally restored during the interval time between press processes.

However, if processing exceeds the press's capacity, it will no longer be possible to restore the press, and as a result, the flywheel drive motor will be overloaded, leading to problems such as shortened lifespan or burnout. .
In order to deal with such problems, in the past, a thermal relay was provided in the electromagnetic switch of the flywheel drive motor to detect overload and cut off the power to prevent accidents. However, since power interruption by the thermal relay is only caused by a rise in the predetermined temperature of the motor, it has not been possible to completely eliminate the risk of shortening the life of the motor and burning it out. On the other hand, as a method of detecting the number of strokes to determine abnormal conditions in the stroke number of a press, there is a conventional method in which a tachometer generator is installed in the flywheel and the output voltage is converted into a stroke number display. However, with this type of method, the scale corresponding to the output voltage and stroke number of the tachometer fin generator must be changed for each different gear ratio of the mission that connects the flywheel and eccentric re-axis. Not necessarily,
This reduced the workability of the press. Therefore, the present invention is intended to improve the above-mentioned drawbacks of the prior art, and its purpose is to provide a method for detecting the condition of a press by quickly detecting an abnormality in the number of strokes and without causing any harm to the flywheel drive agitator. It is in. Another object of the present invention is to provide a method for detecting the state of a press that can automatically cope with different transmission gear ratios and accurately detect the number of strokes. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention, and reference number 1 indicates a rotating member such as a flywheel of a press. Accordingly, a signal a representing the rotation period of the rotating member 1 is given from the switch 5. Reference numeral 7 denotes an oscillator that provides a reference pulse signal b, and 9 a signal generation circuit that receives the output signal a of the switch 5 and the reference pulse b of the oscillator 7, and generates a count prohibition signal c, a load signal d, and a clear signal e.

The counter 11 receives the reference pulse b from the oscillator 7, the count prohibition signal c and the clear signal e from the signal generation circuit 9, and counts one rotation period of the rotating member 1. counter 11
The count value is sent to the rack 13 by the load signal d of the signal generation circuit 9
latched according to 15 is a detection device for detecting the position of the slide; for example, the position of the slide is detected by detecting the rotation angle of the eccentric shaft (crankshaft) for moving the slide of the press up and down. The vertical position of the slide is directly detected by a rotary encoder provided therein or by a linear scale such as a magnescale provided along the sliding portion of the slide. Reference numeral 17 indicates a microcomputer, which controls the contents of the latch 13 (rotation period of the rotating member 1) and the detection ring 1.
Accept the slide position information in step 5.

Reference numeral 19 denotes a keyboard, which allows the microcomputer 17 to determine the permissible change range nx of the rotational period of the rotating member 1 and the periodic input angle position (timing angle) at which the rotational period T8 of the rotating member 1 is lowered during press drive, which will be described later. is input.

The permissible change range nx of the rotational period is the range of periodic change allowed for the rotating member 1 between when the press is not operated and when the press is loaded.
As will be described in detail later, the microcomputer 17 receives from the latch 13 the rotation period TQ of the rotating member 1 when the press is idling and the rotation period T8 when the press is being driven.
By calculating the difference Ty between these rotation periods and comparing it with a preset allowable change range x, an abnormality in the number of strokes is determined and output. Incidentally, reference numeral 21 is a display section such as a numerical display, which displays the number of strokes of the press. 'FIG. 2 is a timing chart showing the count of one rotation period of a rotary member such as a flywheel of a press, and reference symbols in the diagram correspond to signals with the same symbols in FIG. 1.

That is, a is a detection signal of the switch 5, b is a reference pulse signal of the oscillator 7, c is a count prohibition signal given from the signal generation circuit 9 to the counter 11, d is a load signal given from the signal generation circuit 9 to the latch 13, e is the signal generation circuit 9
From these signals, a count period as shown by f is determined, and one rotation period of the rotating member 1 is counted. FIG. 3 is a flowchart showing an embodiment of the state detection method according to the present invention.
The configuration shown in FIG. i will be used in conjunction with the explanation below. First, after giving initial settings to the microcomputer 7 (step 10)
1) The permissible change range nx of the rotational period of the rotating member 1 and the rotation period T8 of the rotating member 1 during press drive are input to the computer 1 via the keyboard 19.
7 is input and set (steps 103 and 105), after which the actual process for detecting an abnormality in the number of strokes is started.

Once the permissible change range Tx of the rotation period and the period reading angular position are set, it is determined in judgment step 107 whether or not the press is being driven.

If the result of this judgment is "NO", that is, the clutch is OFF and only the rotating member 1 is rotationally driven, the process moves to the next step 109, and the rotation period T of the rotating member 1 when the press is idling.
Q is taken from latch 13 to computer 17 and passed to the next decision step 111. In step 111, a press start command is issued. , and if a start command exists as a result, the clutch is engaged (step 113).
Note that if there is no activation command in step 111, the clutch is turned off and the process returns to step 103. On the other hand, if the determination in step 107 is "YES", that is, the press is being activated, the process jumps to step 113 and the clutch ON state is maintained.

In this way, if the answer is "YES" in step 107, the rotation period TQ during idling has already been reduced in the previous press process, and that TQ is used, so steps 109 and 111 are skipped. Infested. When the idling rotation period TQ of the rotary member 1 is read and the press is started, it is determined in a judgment step 117 whether the position information of the slide position detection device 15 matches the cycle period insertion angle position of the ○ axis. A judgment will be made.

If the result is "YES", that is, the slide moves to the position 119 corresponding to the predetermined cycle input angle position, and if the position has not been reached, the process returns to step 103. In the next step 119,
The driving rotation period T8 of the rotating member during press driving is set.

When the rotation period T8 is read, in the next step 121, a calculation (
Ty=TQ-T8) is performed to find the difference Ty between both periods. Then, in step 123, it is determined whether or not this difference Ty exceeds the permissible change range Tx of the rotation period. If the result is "NO", that is, the tolerance range Tx is exceeded, an abnormality warning such as an alarm is issued (step 12).
5) If the value has not been exceeded, other processing 127 is performed, such as stopping the press when a certain value is reached, and the process returns to step 103 again. According to the above embodiment, an abnormality in the press is detected from a change in the number of strokes of the press based on the difference between the rotation period TQ of the rotating member 1 under no load and the rotation period T8 during press drive. This can be detected, and harmful effects such as burnout of the drive motor of the rotating part can be prevented.

FIG. 4 is a flowchart showing another embodiment of the state detection method according to the present invention, and the configuration for implementing this method is the same as that in FIG. The timing is also as shown in the timing chart of FIG.

The feature of this embodiment shown in FIG. Using the calculation NSPN = Saint 0
By performing ÷K, the number of strokes per minute of the press is detected and displayed, thereby automatically giving an accurate number of strokes even when the gear ratio K of the mission is different.

The above calculation formula is obtained as follows.

First, let T be the period of one rotation of a rotating member such as a flywheel.
Then, the rotation speed Ns per second of the rotating member is as follows.

NS=Main '11 Also, the number of rotations per minute NM of the number of rotating parts is NN=NsX
60 [2].

On the other hand, the slide of the press is held by the crankshaft with a gear ratio of K.
Since the crankshaft is connected to a rotating member through a transmission and a clutch, the number of rotations per minute (NsPN) of the crankshaft is NsPM=NM÷K [3', where NsPM also represents the number of strokes.

Therefore, by substituting equations [1} and (■) into the rigid equation, NSPM
= Saint 0÷K, and the above calculation formula is obtained.

The detection and display of the number of strokes will be explained below with reference to FIG.

First, after initial settings are given to the microcomputer 17 (step 201), the gear ratio K of the transmission interposed between the slide and the rotating member 1 is input and set via the keyboard 19 (step 203).

Next, after starting the driving electric motor (not shown) of the rotating member 1, one rotation period T of the rotating member 1 is loaded from the latch 13 to the computer 17 (step 205), and the above-mentioned calculation formula 0÷K is executed to calculate the number of strokes per minute (NsPM), which is displayed on the display section 21 in the next step 209.

Therefore, even if the transmission gear ratio is different, the number of strokes of the press can be detected and displayed simply by setting the gear ratio.Furthermore, since the number of strokes is obtained from the rotation period of the rotating member, the movement of the slide The number of strokes can be displayed regardless of the number of strokes.

In each of the embodiments described above, one rotation period is measured for measuring the rotation period of a rotating member, but it does not necessarily have to be one rotation, but 1/2 or 1/2 rotation period.
Four rotations or the like can be used as a reference, and it is also possible to measure and use the speed at which the dock of the rotating member passes through the switch.

The second embodiment of detecting and displaying the number of strokes is effective not only for detecting an abnormality in the press due to a decrease in the number of strokes, but also for simply providing a display of the number of strokes.

As explained above, according to the present invention, an abnormal state of the press can be detected from the number of strokes, so it is possible to prevent adverse effects such as competitive damage or shortened life of the flywheel drive motor, and , press strike automatically and accurately even when the mission gear ratio is different.

- It is possible to detect the number of errors and display abnormalities.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram for implementing the present invention, FIG. 2 is a timing chart for counting one rotation period of a rotating member,
FIG. 3 is a flowchart showing one embodiment of the present invention;
The figure is a flowchart showing another embodiment of the invention. 1...Rotating member, 5...Switch, 11...
...Counter, 13...Latch, 15...
・Detection device, 17...Microcomputer,
21...Display section. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. Using a means for detecting the rotation period of a rotating member connected via a clutch mechanism to an eccentric shaft for vertically moving a slide of a press, a means for detecting the position of the slide, and a microcomputer, The permissible change range Tx of the rotational period of the rotating member and the period reading angular position for reading the period of the rotating member when press work is performed by the vertical movement of the slide are preset in the microcomputer, and the rotational period is set in advance in the microcomputer. The rotation period Tα during idling of the press and the rotation period Tβ during press drive when the position information of the position detection means coincides with the cycle read angular position during press drive are input from the detection means to the microcomputer; By calculating the difference Tγ between the two cycles in a computer and comparing it with the change tolerance range Tx inputted into the microcomputer in advance,
A press condition detection method characterized by detecting an abnormality in the number of strokes of a press. 2. Using a means for detecting the rotation period of a rotating member connected via a clutch mechanism to an eccentric shaft for vertically moving the slide of the press, a means for detecting the position of the slide, a means for displaying the number of strokes, and a microcomputer. , the gear ratio K of the transmission interposed between the rotating member and the slide is set in the microcomputer, the rotation period T is determined from the rotation period detecting means of the rotating member, and the calculation formula, N
A press state detection method, characterized in that the number of strokes per minute (N_S_P_M) determined according to _S_P_M=(60)/T÷K is displayed on the display stage.