JPS5897619A - Rotation pulse detector - Google Patents

Abstract

PURPOSE:To prevent an erroneous detection pulse generated at an edge part of a gear during low-speed rotation, etc., by providing two pulse detectors corresponding to a gear or slitter fitted to a body of revolution at such positions that their output signals are out of phase by a 90 deg. electric angle. CONSTITUTION:Contactless switches SW2 and SW3 are provided to obtain pulses outputs according to projections and recesses of the tooth part of a gear 1 provided on the shaft of a body of revolution, and their fitting positions are so determined that their generated pulse signals are out of phase by a 90 deg. electric angle. The output A of the SW2 is inputted to a differentiator 4 to obtain a differential output C, which is inputted to a rectifying circuit 6, whose rectification output E (E') is inputted to a terminal S of a flip-flop F.F8. The detection signal B of the SW3, on the other hand, is inputted to a differentiator 5 to obtain a differential output D, which is inputted to a rectifying circuit 7, whose retification output F (F') is inputted to a terminal R of the F.F circuit 8. Thus, the interval between parts H and H' corresponding to a 90 deg. out-of- phase electric angle, so an output waveform G (G') at the output terminal Q of the F.F 8 is detected accurately even when there are parts H and H', and I and I'.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention detects the number of rotations or the rotational speed of a rotating body P! In this case, the present invention relates to a rotation pulse detection device that accurately measures the correct number of rotations t or rotational speed Iζ especially at low speeds and in a stopped state I.

Conventionally, this type of rotational pulse detection device has detected the number of rotations or rotational speed using a gear attached to a rotating body and one pulse generator. When the edge part is reciprocated back and forth due to mechanical vibration or rotational fluctuation, an erroneous detection pulse is generated.In order to prevent the generation of this erroneous detection pulse,
A method must be adopted in which pulses do not occur below a certain low-speed rotation, or a method must be used that ignores data for a certain low-speed rotation, and the rotational speed or number of rotations at the time of mold prevention Ia must be calculated. The present invention has been made to solve the above-mentioned drawbacks, and is a method for accurately measuring the rotation mode or number of rotations, especially at low speeds, in rotating bodies that have mechanical vibrations or small one-turn fluctuations. In order to The signals of two generated pulses are arranged so that they have a phase of 90 degrees in electrical angle, and the pulse signals are passed through a differentiating circuit, then through a rectifier circuit, and then guided through a flop circuit to obtain a stable rotation pulse signal at low speeds. It's a special one.

The present invention will be explained below based on the drawings of the embodiments.

FIG. 1 is a block diagram showing an embodiment of the rotational pulse detection device according to the present invention, and FIG. 2A-G, (1') to
(G') is the output signal A-G of each part in Fig. 1, (lit'
) to (G').
Reference numeral 3' denotes a proximity switch that outputs a pulse output signal using the unevenness of the tooth profile of the gear 1. The mounting positions of the proximity switches 2 and 3 are such that the phase of the generated pulse signal is 90 degrees in electrical angle.
They are arranged so that they are in phase. Figure 2 A and 2
The waveforms in FIG. B show the waveforms of the output signal B of the proximity switch 2 and the output signal B of the proximity switch 3, respectively. 4 is a differentiator which receives the output signal M of the proximity switch 2 as an input, and the waveform of its output signal C becomes the pulse signal shown in FIG. The waveform of the neutral signal is the pulse signal shown in the second diagram.O is the output signal C of the differentiator 4.
1 is a rectifier circuit that receives the output signal of differential 1) 5 as input, R and F are the rectifier circuit 6
．． 7 shows the output signals in the case of a full-wave rectifier, and the waveforms of the output signals E and F become pulse signals shown in FIGS. 2B and PG. In addition, (B') and (P') are output signals when the rectifier circuit 8.7 is a half-wave 11-current device,
The waveforms are shown in Figure 2 (Iii') and (F'), respectively.
The pulse signal will be as shown in . 8 is the output signal 1! of the rectifier viASS and 7! , (E') and F, (F
It is a flip-flop circuit whose input is a signal G when the rectifier circuits 6 and 7 are full-wave rectifiers, and an output signal of G when the rectifier circuits 6 and 7 are half-wave rectifiers.
Figure 2 shows the output signal of G, (G')
The waveforms indicate the waveforms of the output signals G and (G'), respectively. In the following explanation of I, when the Il flow circuit 6.7 is a full-wave rectifier, I will explain it in detail.
When the pulse signal shown in Figure E is applied, the output terminal Q is set to a high potential. On the other hand, when the pulse signal shown in FIG. 2F is applied to the reset side terminal Rj, the output terminal Q is set to a low potential. +
This figure shows the operation of the output terminal Q when the pulse signals shown in FIGS. 2E and 2F are applied to the input terminal 8+6.

Here, in the output waveforms of FIGS. 2A and 2B, H and H', which are indicated by chain lines, or! The portions marked O H In the part shown in Figure 2, several pulse signals are applied to the set side terminal 8 of the flip-flop circuit 8; Even if a pulse signal is applied several times to 8, once it is set, it becomes a high potential and does not change. Similarly to the pulse signal to the set side terminal 8, a pulse signal generated several times or more is applied to the reset side terminal of the flip-flop circuit 8 in the H' portion, and the flip-flop circuit 8 is reset and outputted. The output waveform of terminal Q (FIG. 2G) becomes a low potential. 1
Once the potential is low, it will not reach a high potential unless it is set again.In this way, set the distance between the H and H' portions to 90 degrees in electrical angle.
By setting the phase as H and H as C, unless a small one-turn fluctuation or mechanical vibration in the H part continues up to H', and as long as the H' part does not continue up to the part 1, H and H
', I and I', the output waveform of the output terminal Q of the flip-flop circuit 8 (G in Fig. 2) shows accurate operation. In this case, the output signal G is from the proximity switches 2 and 3. Generated pulse signal - Rectifier circuits 6 and 7
It's gold! In the case of a Pm detector, it is detected accurately as a double frequency.

It is clear that if the rectifier circuits 6 and 7 are half-wave rectifiers, the output signals will be (El'), (P'), and (G'), which can be accurately detected as having the same frequency.

As explained above, according to the present invention, it is possible to stop the generation of false detection pulses that occur at the edge of the IIm car when the rotor rotates at low speed or is stopped. Although we have explained an example in which a gear is attached to the shaft of a rotating body, it is also possible to attach a slitter with notches to the rotating body and detect the rotation of the rotating body using a photoelectric pulse generator. do not have.

[Brief explanation of drawings]

Fig. 1 is a block configuration diagram showing an embodiment of the rotational pulse detection device according to the present invention, and Fig. 2 is a waveform diagram showing the operating waveforms of each part in Fig. 1. gear, 2.3・-
...Proximity switch, 4,5...Differentiator, 6.7
... Rectification port path, 8 ... Frideep flop circuit. Japanese Patent Publication No. 58-97619 (3)

Claims (1)

[Claims] A gear case or a slitter is attached to the rotating body, and the two sets of pulse generators are connected to a rotating pulse detection device equipped with this type of pulse generator so that the phase of the generated pulses is true when the rotating body rotates. two sets of differentiating circuits connected with respective outputs from the pulse generator as input;
A flip-flop circuit is provided in which the output signal of one of the differentiating circuits is connected to the set input side and the output signal of the other differentiating circuit is connected to the reset input side through rectifier circuits, and the rotating body is in a low speed rotation or stopped state. Rotation pulse detection device 0 characterized in that it is designed to prevent the generation of erroneous detection pulses that occur when