JPH065196B2 - Rolling bearing rolling bearing abnormality detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a rolling bearing abnormality detecting device for a rolling mill using acoustic emission (AE).

<Prior Art> Conventionally, the following is known as an abnormality detection device for rolling bearings for rolling mills by AE. This rolling bearing abnormality detection device detects AE from the bearing by an AE sensor and
By comparing the output from the E sensor with a reference value by a comparator, when the AE signal exceeds the reference value, it is detected as an abnormality of the bearing.

<Problems to be Solved by the Invention> However, in the conventional rolling bearing abnormality detecting device for a rolling mill, the abnormality of the rolling bearing is determined depending on whether or not the level of the AE signal exceeds the reference value. As shown in FIG. 3, in the rolling mill in which a large AE signal is generated at the time of metal-in and at the time of metal-out, the AE signal generated at the time of metal-in and at the time of metal-out is distinguished from the AE signal indicating the abnormality from the bearing. However, there is a problem that the bearing is normal but is erroneously determined to be abnormal.

Therefore, an object of the present invention is to detect an abnormality of a rolling bearing for a rolling mill, which can accurately detect an abnormality of the bearing without erroneously determining the abnormality of the bearing by stopping the determination of the abnormality of the bearing during metal-in and metal-out. To provide a device.

<Means for Solving Problems> In order to achieve the above object, the rolling bearing abnormality detecting device for a rolling mill of the present invention compares the AE signal from the AE sensor with a reference value to indicate an abnormality of the bearing. It is characterized by comprising a comparing means for outputting an abnormal signal, and a logic circuit for invalidating the output of the comparing means for a predetermined time during metal-in and metal-out based on the rolling signal.

<Operation> With the above configuration, the logic circuit invalidates the output of the comparison means for a predetermined time during metal-in and metal-out based on the rolling signal. Therefore, the determination of the abnormality of the AE signal is stopped at the time of metal-in and at the time of metal-out, and it becomes possible to reliably determine the abnormality of the rolling bearing of the rolling mill.

<Example> Hereinafter, the present invention will be described in detail with reference to an example shown in FIG.

An AE signal detected by an AE sensor (not shown) is amplified by an amplifier, a signal of a predetermined band is passed by a band filter, and envelope detection is performed by an envelope detection circuit. The envelope detection signal is shown in FIG. It is input to the comparator 1 shown. The comparator 1 compares the reference value with the envelope detection signal, and when the envelope detection signal exceeds the reference value, "H"
Signal is output to the memory circuit 2. On the other hand, FIG. 2 (a)
The rolling signal as shown in is input to the storage circuit 2 and the pulse shaping circuit 3. The storage circuit 2 receives the rolling signal and temporarily stores the output of the comparator 1 after the metal-in, that is, during the rolling operation. The waveform shaping circuit 3 cuts off the rolling signal shown in FIG. 2 (a) for a certain time after metal-in and for a certain time before metal-out to perform waveform shaping as shown in FIG. 2 (b). The AND circuit 4 receives the output from the memory circuit 2 and the output from the waveform shaping circuit 3 and has the waveform shown in FIG. 2 (b) excluding the predetermined time after metal-in and the predetermined time before metal-out. AND with the signal output from the memory circuit 2. When both the output of the memory circuit 2 and the output from the pulse shaping circuit 3 output the "H" signal, the "H" signal is output and an alarm is issued.

As described above, this bearing abnormality detecting device captures the signal from the comparator 1 into the memory circuit 2 only during rolling, and does not store the output of the comparator 1 during non-rolling, thus saving the memory capacity. it can. Further, the load on the bearing is small during non-rolling, and even if AE occurs due to an abnormality in the bearing, it is extremely weak and the S / N ratio deteriorates. Therefore, the output of the comparator 1 is stored only during rolling. Since it is incorporated into 2, the S / N ratio is improved.

Further, since the output of the comparator 1 is invalidated in the AND circuit 4 for a predetermined time after the metal-in and before the metal-out as described above, the output from the rolling mill is changed from the rolling mill to the metal-in and the metal-out as shown in FIG. Even if a large AE signal is generated,
There is no erroneous determination as a bearing abnormality.

In the above embodiment, the AND circuit 4 is used as the logic circuit, and the output of the comparator is invalidated in the latter stage of the comparator 1 for a certain period after the metal-in and before the metal-out. It is also possible to provide and stop capturing the envelope detection signal into the comparator 1 for a predetermined time after metal-in and before metal-out. In addition, the alarm signal output from the AND circuit 4 is received, the alarm signal generation cycle is calculated, and it is determined whether or not the total number of occurrences of the alarm signal exceeds a threshold value for each occurrence of the bearing abnormality. May be determined.

<Effects of the Invention> As is apparent from the above, according to the present invention, the comparison means for comparing the AE signal from the AE sensor with the reference value, and the predetermined time during metal-in and metal-out based on the rolling signal, By providing a logic circuit for invalidating the output of the comparison means, the AE signal at the time of metal-in and at the time of metal-out can be excluded from the judgment of the abnormality of the bearing, and the abnormality of the rolling bearing can be detected during the operation of the rolling mill. It can be accurately performed without making an erroneous determination.

Further, if the output of the comparison means is made effective only during rolling in the logic circuit, it is not possible to judge whether the AE is abnormal during non-rolling, thus preventing deterioration of the S / N ratio,
It is possible to efficiently determine the abnormality of the bearing.

[Brief description of drawings]

FIG. 1 is a block diagram of a rolling bearing abnormality detecting device for a rolling mill according to the present invention, FIG. 2 is a diagram showing a rolling signal and a waveform-shaped signal, and FIG. 3 is a waveform diagram of an AE signal and a rolling signal. . 1 ... Comparator, 2 ... Storage circuit, 3 ... Pulse shaping circuit, 4 ... AND circuit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeto Nishimoto, No. 2, Unagiya Nishinomachi, Minami-ku, Osaka-shi, Osaka Within Koyo Seiko Co., Ltd. Address Koyo Seiko Co., Ltd. (72) Inventor Shunji Harada 3-48 Takahatacho, Nishinomiya-shi, Hyogo Kawatetsu Keiki Co., Ltd.

Claims (1)

[Claims] 1. Comparing means for comparing an AE signal from an AE sensor with a reference value to output an abnormality signal indicating an abnormality of a bearing, and a predetermined time during metal-in and metal-out based on a rolling signal. A rolling bearing abnormality detection device for a rolling mill, comprising: a logic circuit for invalidating the output of the comparison means.