JPS5863680A - Detector for body of door safety device for elevator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an object detection device for an elevator door safety device, and more particularly to an elevator door safety device that extends the door opening time when an object force exists on the closing side of the door when the door is closed. The present invention relates to an improvement of an object detection device that detects the presence or absence of an object on the closed side of a door using the device's ultrasonic waves.

Figure 1 is a block diagram of a conventional object detection device of this type;
FIG. 3 is a time chart of each part signal of FIG. 1. In FIG. 1, the oscillation cycle setting circuit 1 generates one signal in response to the start command signal 8i shown in FIG.
1 is output, the oscillation circuit 2 is operated by this signal T1, and while the signal TI is at the 11" level, it generates the oscillation sound wave signal f shown in FIG. 3 and is applied to the transmitter 4. On the other hand, the signal T□ is applied to the detection distance setting circuit 5, which operates at the rising edge of the signal T1 and outputs Mt at a preset time. , a detection distance setting signal T of 112 levels between ,
[Fig. 2(d)] is output and sent to the detection range setting circuit 6.
give to The detection range setting circuit 6 operates at the falling edge of the signal T, and operates for a preset time t (ts).
's) 1" level The ultrasonic waves transmitted from the transmitter 4 are reflected by the object to be detected 8, and the ultrasonic waves are received by the receiver 9, and the signal from the receiver 9 is transmitted to the received signal amplification circuit 10. is amplified by
The amplified received signal SR shown in FIG. 2(f) is applied to an AND circuit 7 via a comparison (sensitivity setting) circuit 11. The output of the AND circuit 7 is given to the buffer circuit 12,
□Output signal S shown in FIG. 2(g) from the balance circuit 12
Output o.

By the way, as shown in FIG. 2(f), the received signal SR includes a floor reflected received signal SR after the transmitted direct received signal SR1, and when there is an object 8 to be detected, , a reflected reception signal SR from the detected object 8 (large or object) is generated depending on the position of the detected object 8. Therefore, according to the conventional object detection device shown in FIG. When the terminal part of the transmitted and directly received signal SR9 due to the body's sound waves is disturbed, during the period of time t8 when the detection range is set, as shown in (a) and (b) of FIG. There is a drawback that the end portion of the wave signal SRI flows in, and there is a possibility that it will be determined to be the same as the reflected wave from the object to be detected 8, resulting in erroneous detection.

Furthermore, if the comparison level VCOM of the comparison circuit 11 is increased in order to prevent this false detection, a problem arises in that the detection accuracy decreases when the distance from the transmitter 4 to the detected object 8 becomes long.

An object of the present invention is to eliminate the drawbacks of the prior art described above, reduce the influence of disturbances on the received signal due to the shape of the transmitter and receiver, the surrounding door brush, frame, etc., and sending,
To provide an object detection device for a double safety device for an elevator, which can prevent detection accuracy from decreasing even if the distance from a wave receiver to an object to be detected becomes long.

The present invention was made based on the fact that the received signal level is inversely proportional to the distance from the transmitter to the point where the ultrasonic wave enters the receiver, and the detection range setting circuit outputs the detection range setting circuit. As time elapses after the signal reaches the "1" level, the comparison voltage applied to a comparison circuit that compares the level of the received signal from the receiver with a comparison voltage is reduced to a predetermined value; The present invention is characterized in that a gate circuit is provided which then holds the predetermined value and returns the predetermined value at which the detection range-setting signal has reached the "0#" level to the initial comparison voltage.

The present invention will be explained in detail below with reference to the embodiments shown in FIGS. 4, 5, and 7, and FIG. 6.

FIG. 4 is a structural explanatory diagram showing an embodiment of the transmitter and receiver installation portion of the object detection device of the present invention. In Figure 4,
13 is the elevator car, 14 is the car side door, 15 is the hall floor, 16 is the hatch door, and 17 is the transmitter 4 and receiver 9 of FIG. 1 attached to the elevator car 13 as shown. 18 is a pocket cover provided around the transmitter and receiver 17.

, FIG. 5 is a block diagram showing an embodiment of the object detection device of the present invention, and the same parts as in FIG. In the IA5 diagram, a comparison circuit 11 that compares the received signal SR of the received signal amplification circuit 10 is shown.
The comparison voltage vcoM given to .

As shown in the time chart shown in FIG. 6, as time passes after the detection range setting signal °1゛hata from the detection range setting circuit 6 reaches the -1" level, it decreases to a predetermined value vG, and then the above A predetermined value is held at G, and a preset time t is maintained after the signal 1 becomes the "1" level.
8 and the signal T reaches the "0" level, the gate circuit 21 returns the predetermined value to the initial comparison voltage VCOM.
This is provided. The other configurations are the same as in FIG. 1.

Therefore, the comparison voltage applied to the comparison circuit 11 is as shown in FIG. 6(b) with respect to the detection range setting signal T3 in FIG. 6(a).
The voltage changes as follows. For this reason, Fig. 6(C)
As shown in , the terminal part of the transmitted and directly received signal Sat is disturbed by the horn shape of the transmitter and receiver 4.9 and the influence of the surrounding door or frame.
The reflected reception signal SRs from (large or object) can be detected without decreasing the detection accuracy, and the output signal So shown in FIG. 6(d) can be obtained from the buffer 12. Also,
Since the detection distance setting time t set in the detection distance setting circuit 5 can be set shorter, the dead sea 719 shown in FIG. 4 can be set shorter and the detection sea 720 can be wider.

FIG. 7 is a circuit diagram showing an embodiment of the gate circuit 21 shown in FIG. In Fig. 7, 6 is a detection range setting circuit;
22 is a diode, 23.24°28.29 is a resistor,
25 is a capacitor, 26 is a transistor, and 27 is a variable resistor, which are connected as shown in the figure. The transistor 26 has resistors 23 and 24 inserted on its base side.
The on/off time is set by the capacitor 25.

It is designed to generate a comparison voltage that changes with elapsed time.

Note that even if an operational amplifier is used instead of using the transistor 26, a comparison voltage similar to P1 can be generated.

As explained above, according to the present invention, it is possible to reduce the influence of disturbances in each signal received by the door, frame, etc. around the horn shape 5 of the transmitter and receiver.

This has the effect of preventing the detection accuracy from decreasing even if the distance from the transmitter and receiver to the object to be detected becomes longer.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an object detection device of a conventional elevator door safety device, Figs. 2 and 3 are time charts of signals of each part in Fig. 1, and Fig. 4 is a block diagram of an object detection device of a conventional elevator door safety device. Transmission of object detection device. FIG. 2 is a structural explanatory diagram showing an example of an installation part of a wave receiver. FIG. 5 is a block diagram showing one embodiment of the object detection device of the elevator door safety device according to the present invention, and FIG. 6 is a time chart for explaining the operation of the gate circuit of FIG.
FIG. 7 is a circuit diagram showing one embodiment of the gate circuit of FIG. 5. l...Oscillation cycle setting circuit, 2...Oscillation circuit, 3...
・Transmission signal amplifier, 4-... Transmitter, 5... Detection distance setting circuit, 6... Detection range setting circuit, 7...A
IN D circuit, 8... Object to be detected, 9... Receiver,
10... Received signal amplification circuit, 11... Comparison circuit, 1
2...Buffer circuit. 21...Gate circuit. Agent: Patent attorney Takashi Akira. ζbe goose 10 Tsuji 20 F) 3rd eye leaf 40 7 50th (Revised) 5゜-11 Niro - Shima 7 prisoner

Claims (1)

[Claims] 1. If there is an object closing the door when the door is closed, t
In an object detection device for detecting the presence or absence of an object on the closed side of the door using ultrasonic waves of an elevator safety device that extends IC door opening time, from a receiver that receives the ultrasonic waves. The time elapsed since the detection range setting signal outputted from the detection range setting circuit of the comparison voltage input to the comparison circuit that compares the level of the received signal and the comparison voltage reached the ``''1#1# level. and then decreases to a predetermined value, and then holds it at the predetermined value, and the detection movement shelf setting signal becomes ``''
Object detection device 0 for an elevator door safety device, characterized in that it is equipped with a gate circuit that returns the predetermined value to the initial comparison voltage when it reaches the 0″0″ level.