JPS61155962A - Apparatus for detecting rotation - Google Patents

Abstract

PURPOSE:To prevent erroneous operation due to rotary vibration, by providing a pair of FFs for latching one of output of a pair of sensors, of which the phases are shifted by a predetermined angle, by the other output at the incremental and decremental edges of one output. CONSTITUTION:A pair of sensors 11, 12 provided to the outer peripheral part of a rotor 10 output detection pulses (a), (b), of which the phases are shifted by 90 deg., with the rotation of the rotor 10. The pulse (a) is supplied to FFs 13, 14 as data and the pulse (b) is supplied to FF13 as it is and supplied to FF14 as a clock pulse in a reversed state. Therefore, FF13 latches the pulse (a) at the incremental edge of the pulse (b) and FF13 latches the same at the decremental edge of said pulse (b). The outputs of FFs 13, 14 are supplied to an exclusive OR gate 15 and the pulse (a) is supplied to a counter 17 only when the outputs of FFs 13, 14 are different. By this method, erroneous operation due to rotary vibration can be prevented.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a rotation detection device, and more particularly to a rotation detection device in which a sensor is provided to face a rotating body and the output pulses of the sensor are used to detect the rotational speed or rotational speed of the rotating body.

[Prior art]

For example, when detecting the rotation speed on the output side of a car transmission, if this rotation is extracted as a pulse signal using a Hall element or MR element, this output pulse can be used to operate various electronic control devices. It becomes possible to do so. Therefore, when performing electronic control of the engine or transmission, it is preferable to extract the rotational speed or rotational speed on the output side of the transmission as an electrical signal. In such cases, conventionally a sensor is provided opposite the outer periphery of the rotor, which rotates in proportion to the rotation speed on the output side of the transmission, and the output of this sensor is shaped into a waveform and directly counted by a counter. I was trying to do that.゛The disadvantage of such conventional rotation detection devices is that even if the rotor, which is transmitted to the output side of the transmission, generates rotational vibration due to vibrations from the engine, etc., the sensor generates pulses due to this rotational vibration. There were cases where the counter would incorrectly count this pulse. Therefore, even when the vehicle is not running, there is a problem in that the rotation is detected as if the rotation speed were present on the output side of the transmission. KObject of the Invention The present invention has been made in view of the above problems, and it is an object of the present invention to provide a rotation detection device that prevents malfunctions caused by rotational vibration. The present invention provides an apparatus in which a first sensor is provided to face a rotating body, and the number of rotations or the rotational speed of the rotating body is detected using output pulses of the sensor.
a second sensor that generates an output signal that is out of phase by a predetermined angle with respect to the output signal of the first sensor; and a second sensor that generates an output signal that is out of phase with the output signal of the first sensor; A pair of 7-lip 70-tubes each latching the output signal of the sensor, and a detection circuit for detecting whether the levels of the outputs of the pair of 7-lip 70-tubes are different. This relates to a rotation detection device characterized in that the rotation number or rotation speed is detected only when a difference is detected by the detection circuit. This is to prevent incorrect detection of the rotational number or rotational speed in the event that a rotational speed occurs. Embodiment] The present invention will be described below with reference to an illustrated embodiment. FIG. 1 shows a rotation detection device according to an embodiment of the present invention, which detects the number of rotations or the rotation speed of a rotating body 10. In FIG. The rotating body 10 is configured to rotate in proportion to the rotational speed of the output side of an automobile transmission, for example, and its outer circumference is alternately magnetized to north and south poles. And this rotating body 1
A first sensor 11 and a second sensor 12 are fixedly arranged opposite to each other on the outer peripheral side of the sensor 0 . These pair of sensors 11 and 12 have output signals whose phases are 90 degrees each other.
° They are arranged so that they are shifted. Of the pair of sensors 11.12, the output side of the first sensor 11 is connected to the data input terminals of the pair of 7-lip 70-tubes 13.14, respectively. On the other hand, the output side of the other sensor 12 is connected to the clock terminals of the pair of flip 70 tabs 13, 14, respectively. Note that the output side of the sensor 12 is directly connected to the clock terminal of the flip-flop 13, whereas it is connected to the clock terminal of the flip-flop 14 via an inverter 18. And the output side of the pair of 7 lip 70 knobs 13.14 is E
It is connected to the input terminal of the XOR gate 15. The output side of the EXOR gate 15 is connected to the input terminal of an AND gate 16. This gate 16
Another input terminal of is connected to the output side of the first sensor 11. The output side of the AND gate 16 is connected to a counter 17, and the counter 17 counts the number of pulses of the pulse signal supplied through the AND gate 16. Next, the operation of this rotation detection device configured as above will be explained. As the rotating body 10 rotates, a pair of sensors 11 and 12 that detect the magnetism of the magnets provided on the outer circumference of the rotating body 10 generate detection pulses as shown in FIGS. 2a and 2b, respectively. There is. The output pulses of the first sensor 11 shown in FIG. 2a are then supplied as data to the flip 70 knobs 13 and 14, respectively. On the other hand, the pulses shown in FIG. On the other hand, the output of the sensor 12 is supplied to the flip-flop 14 via an inverter 18 as a clock signal. Furthermore, the pair of flip-flops 13 and 14 are both designed to latch at the up edge. Therefore, the flip-flop 70 latch 13 latches at the up edge of the pulse shown in FIG. 2, while the second flip-flop 14 latches at the down edge of the pulse shown in FIG. Therefore, the latch timing of the flip 70 knob 13 is as shown in FIG. 2C, whereas the latch timing of the flip 70 knob 14 is as shown in FIG. 2D. As shown in FIG.
Since they are shifted by 0°, the output of the flip-flop 13, which performs the latch operation at the timing shown in FIG. 2C, always latches the high level of the output pulses of the sensor 11. Therefore, the output of the first flip-flop 13 is always maintained at a high level as shown in FIG. 2e. On the other hand, the flip 70 knob 1 performs a latch operation at the timing shown in FIG. 2d.
4 always latches the low level portion of the output of the sensor 11. Therefore, the detection output of the second flip-flop 14 is always at a low level as shown in FIG. 2f. Therefore, the EXOR gate 15 to which the output of the flip-flop 1°3 shown in FIG. 2e and the output of the flip-flop 70 knob 14 shown in FIG. In this case, a high level output will be produced because the values on the input side are different from each other. And the output of this high level gate 15 is AN
Since the output of the sensor 11 is supplied to the D gate 16, when the rotating body 10 is rotating normally, this gate 16 is opened, and the output of the sensor 11 is supplied to the counter 17 through the gate 16, and the output of the sensor 11 is supplied to the counter 17 through the gate 16. Eleven output pulses are counted to detect the number of rotations or rotational speed. On the other hand, if the rotating body 10 does not rotate and is generating rotational vibrations due to vibrations caused by engine operation, for example, as shown by arrows 21 and 22 in FIG. Rotating body 10 for two sensors 12
This will cause vibrations in which the upper magnet performs reciprocating motion. In the case of photographing 21 in the normal rotation direction, this edge becomes a down edge. On the other hand, in the case of vibration 22 in the reverse direction, this edge becomes an up edge. In other words, the same edge may be regarded as an up edge or a down edge due to vibration. Moreover, at this time, the detection output of the other sensor 11 is always at one value, for example, a low level. Therefore, when rotational vibration occurs, flip-flop 1
3.14 will both have the same value, and these same values will be supplied to the EXOR gate 15. Therefore, in this case, the output of EXOR gate 15 will be at a low level, which will cause AND gate 16 to be closed. Therefore, the supply of output pulses from the sensor 11 to the counter 17 is stopped, and the detection operation of the number of rotations or the rotation speed is prohibited. As described above, according to the rotation detection device according to the present embodiment, when the rotating body 10 generates rotational vibration, the pair of flip-flops 13 and 14 both latch one level of the sensor 11, This ensures that the output levels of the pair of flip-flops 13 and 14 are the same. Then, the EXOR gate 15 detects that the output levels of these pair of flip-flops 13 and 14 are the same, and the output of this gate 15 allows the AN
The D gate 16 is closed to block the rotation detection operation and prevent malfunction. Therefore, it is possible to prevent the counter 17 from erroneously counting when the vehicle is stopped and the rotary body 10 is generating rotational vibration due to the engine's rotational motion. Effects of the Invention I As described above. The present invention provides a pair of sensors that generate output signals that are out of phase with each other by a predetermined angle, and an up edge and a down edge of the output signal of one sensor in the pair of sensors, respectively. Equipped with a pair of flip-flops that latch and a detection circuit that detects whether the output levels of the pair of flip-flops are different, and when it is detected by the detection circuit that the outputs of the pair of 7-lip 70-tubes are different. The number of rotations or rotational speed is detected only when the rotational vibration occurs.Therefore, when the outputs of a pair of flip 70 tabs become the same due to rotational vibration, the detection operation is blocked, and this is to prevent malfunction. Therefore, it becomes possible to provide a rotation detection device that has the following characteristics.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a rotation detection device according to an embodiment of the present invention, and FIG. 2 is a waveform diagram showing the operation of this rotation detection device. In the symbols used in the drawings, 10...Rotating body 11...First sensor 12...Second sensor 13...First flip-flop 14...Second 7-lip 70-tube 15...EXOR gate 16...AND gate 17...Counter 18...Inverter.

Claims (1)

[Claims] In an apparatus in which a first sensor is provided to face a rotating body and the output pulse of this sensor is used to detect the rotational speed or rotational speed of the rotating body, the output signal of the first sensor is a second sensor that generates an output signal that is out of phase by a predetermined angle; and an up edge and a down edge of the output signal of one sensor of the pair of sensors respectively latch the output signal of the other sensor. and a detection circuit that detects whether the output levels of the pair of flip-flops are different, and when it is detected by the detection circuit that the outputs of the pair of flip-flops are different. A rotation detection device characterized in that the rotation number or rotation speed is detected only when the rotation speed is detected.