JPS59206768A - Creep detector - Google Patents

Abstract

PURPOSE:To improve the detecting sensitivity of the titled device without increasing the diameter of a gear by providing the titled device with plural pairs of gap/voltage converters and differentiators and shifting the setting positions of respective gap/voltage converters slightly from a pitch angle of the gear coupled with a rotary shaft. CONSTITUTION:The gap/voltage converters 2A, 2B are arranged close to the gear 1 coupled with the rotary shaft with a slight shift from the pitch angle of the gear 1. A waveform processing circuit 3b inputs output signals from the converters 2A, 2B and outputs a creep detecting signal C2. Input signal shaping devices 4A, 4B and differentiators 5A, 5B are connected to the circuit 3b in parallel and the differentiators 5A, 5B generate output signals (a), (b) at the rise or fall of a pulse. An output buffer 6 finds out the OR conditions of the signals (a), (b) and outputs the signal C2. Thus, the sensitivity of the creep detector can be set up to an 1/4 pitch angle and the sensitivity of creep detection can be improved without increasing the diameter of the gear 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a creep detection device for detecting creep of a rotating shaft, that is, the start of rotation.

A conventional creep detection device of this type is shown in FIG. In the figure, 1 is a gear that rotates in response to a rotating shaft (not shown). Reference numeral 2 denotes a gap-to-voltage converter disposed close to the gear, which outputs one pulse when one tooth of the gear 1 passes directly below it. 3a is a waveform processing circuit which receives the output signal of the gap-voltage converter 2 as an input and outputs the creep detection signal; 4 is an input signal shaper that shapes the distorted pulse output signal of the gap-voltage converter 2; 5 is a differentiator that generates an output signal at the rising or falling edge of a pulse, and 6 is an output buffer that outputs a creep detection signal CI. This creep detection signal is ultimately applied to activate an alarm device (not shown), such as a lamp, for example.

Next, the operation shown in FIG. 1 will be explained.

Suppose that the gear is rotating 10 times at rest. When the gear 1 starts rotating from this state, one tooth of the gear 1 passes directly under the gap-voltage converter 2, and the gap-voltage converter 2 generates one pulse. A differentiator 5 at a subsequent stage via an input signal shaper 4 detects the rising edge or falling edge of the generated pulse, and outputs a creep detection signal CI.

Here, the operation of the waveform processing circuit 3a, that is, the creep detection sensitivity will be determined. As mentioned above, when the gear 1 rotates by the pitch angle, one pulse is generated from the gap-voltage converter 2. Assuming that the groove width of the gear and the gear are equal, the duty of the pulse becomes 50 inches. Then, the time interval between the rising edge or the falling edge of the pulse is expressed by a period of 1/2 of the pulse repetition time (one cycle).

The pulse repetition time is equal to the time it takes for the gear 1 to rotate by the pitch angle. Therefore, the sensitivity of this creep detection device is 1/2 pitch angle.

Since the conventional creep detection device is configured as described above, the sensitivity of the creep device is only 1/2 pitch angle, and the sensitivity improves by decreasing the pitch angle, but the gap-voltage converter 2 In order to generate a gear detection pulse correctly, the relationship between the tooth width and the groove width of the gear 1 must be equal to or greater than a predetermined value. Further, if the diameter of the gear 1 is constant, the pitch angle cannot be made smaller than the minimum value of the face width and groove width. If the sensitivity of the creep device is to be further improved, the diameter of the gear 1 must be increased.

This invention was made in order to eliminate the drawbacks of the conventional device as described above, and when a gap-voltage converter is set close to a gear, the pitch angle of the gear is slightly shifted, and multiple gap-voltage converters are installed. It is an object of the present invention to provide a creep detection device that can significantly improve the sensitivity of the creep device without increasing the diameter of the gear by arranging the gears.

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 2, the same parts as in FIG. 1 are denoted by the same reference numerals. In FIG. - voltage converter, 3b connects these two gaps - voltage converter 2A,
A waveform processing circuit inputs the output signal of 2B and outputs the creep detection signal C2; 4A and 4B are input signal shapers; 5
A and sB are differentiators that generate output signals a and b at the rising edge or falling edge of the pulse; 6 are differentiators sA and s
This is an output buffer of an OR circuit that receives the output signal of B and takes an OR condition.

Next, the present invention shown in FIG. 2 will be explained in detail. Gap-voltage converters 2A, 2B, input signal shapers 4a, 4
b and differentiators 5A and 5B are connected in parallel, two sets each. The operation of each circuit is the same as that of the conventional creep detection device shown in FIG. However, the output buffer 6 in FIG. 2 receives the output signal a from the two sets of differentiators 5A and 5B.

The OR condition of b is taken and output as the creep detection signal C2.

FIG. 3 shows two sets of cap-voltage converters 2A.

Output pulse signal from 2B, two sets of differentiators 5A.

5B shows the timing relationship between output signals a and b from 5B and the final leap detection signal C2. From the time chart of FIG. 3 of this invention, the sensitivity of the creep detection device is 1
It can be seen that the angle is /4 pitch.

In addition, in the above embodiment, the gap-voltage converters 2A, 2
We have shown the case where two sets of differentiators 5A and 5B are used for B, and the sensitivity of the creep detection device is set to 1/4 pitch angle, but similarly, n sets of gap-voltage converters and n sets of differentiators ( However, if n is an integer), the sensitivity of the creep detection device will be 1/
Significant improvement to 2n pitch angle.

As described above, according to the present invention, a plurality of sets of gap-voltage converters and differentiators are provided, and the setting positions of the respective gap-voltage converters are set to be slightly shifted from the pitch angle of the gear. This has an excellent effect in that the sensitivity of creep detection can be arbitrarily and significantly improved without increasing the diameter.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a conventional creep detection device, FIG. 2 is a block diagram showing the configuration of a creep detection device according to an embodiment of the present invention, and FIG. 3 is a timing diagram showing the output signal of FIG. 2.・It is a chart.

Claims (1)

[Claims] A gear coupled to a rotating shaft, and multiple sets of gaps arranged close to the gear and slightly shifted from the pitch angle of the gear.
a voltage converter, a plurality of differentiators that are paired with the plurality of gap-voltage converters and each shape the waveform of a separate input signal to generate a differential pulse at the edge of the gear; A creep detection device comprising an OR circuit to which an input signal of a differentiator is supplied and which sends out a creep detection signal.