JPS6337032B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a safety device for a passenger conveyor having a speed detection section.

Generally, for safety reasons, it is a big problem to run a passenger conveyor at a higher speed than its rated speed. For this reason, governors have traditionally been used to detect overspeeds above the rated speed, but it is extremely difficult to check whether or not they are working properly because the governor is directly connected to the drive machine. It was hot.

This invention solves the above-mentioned drawbacks, and when abnormal operation such as overspeed of the passenger conveyor is detected,
To provide a safety device for a passenger conveyor that prevents the conveyor from starting.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 1 shows an embodiment of the present invention, in which 1 is an electric motor for a passenger conveyor, 2 is a tachometer generator that generates an output proportional to the rotational speed of this electric motor 1, and 3 is a tachometer generator that generates an output proportional to the rotational speed of the electric motor 1. A low speed detection comparator 4 generates an output when the low speed exceeds a predetermined value, and 4 is an overspeed detection comparator that outputs no output when the low speed exceeds a predetermined value higher than the rated speed. ,4
Governor relays GL and GH for low speed and high speed are connected to the outputs of , respectively, via separate drive amplifiers 5 and 6. 7 is an input setting voltage divider for dividing the output voltage of the tachometer generator 2 and introducing it into the low-speed comparator 3; 8 is an input setting voltage divider for dividing the output voltage of the tachometer generator 2 and introducing it into the high-speed comparator 4;
The output signal from this voltage divider 8 is input to the low speed governor relay.
The signal is applied to the high speed comparator 4 via the GL switching contact GLC. Further, 9 is a voltage divider that generates a voltage higher than a predetermined value V ₂ which is faster than the rated speed of the motor 1. This voltage divider 9 is connected between the + power supply and the ground, and the voltage output from the voltage divider 9 is It is adapted to be applied to the high speed comparator 4 via the switching contact GLC.

FIG. 2 also shows the operation control circuit for the passenger conveyor controlled by the governor relays GL and GH in FIG. Directional operation relay U has normally closed contact Db of relay D, normally closed contact GLb of governor relay GL, GH,
+ via GHb and upward direction start switch SU,
- connected in parallel to the power supply, and further connected in parallel to the + and - power supplies via the normally closed contact Db of the relay U, the normally closed contacts GLc, GHc of the governor relay GL, GH, and the downward direction starting switch SD is connected to the + of this operation relay U, D.
A series circuit of a stop switch STOP, a safety switch S1 provided at the handrail input, and a safety switch S2 provided at the skirt guard are commonly connected to the power supply side circuit. Further, normally open contacts Ua and Da of operation relays U and D are connected in series between the connection point of the normally closed contacts Db and GHb and the connection point of the normally closed contacts Ub and GHc, and the normally open contacts Ua and D are connected in series. Normally open contacts GLa and GHa of governor relays GL and GH are connected in series between the connection point of Da and the connection points of start switches SU and SD. The normally open contacts Uc, Ud and Dc, Dd of the operating relays U and D are connected to the three-phase power line of the motor 1, and the motor 1 is activated in the forward or reverse direction by energizing the operating relays U or D. It's summery.

Figure 3a shows the output characteristics of the comparator 3 for low speed detection, and Figure 3b shows the output characteristics of the comparator 4 for overspeed detection.When the output voltage of the tachogenerator 2 reaches _V1 , the output of the comparator 3 is set to the "H" level, and when the output voltage of the tachogenerator 2 exceeds _V2 , the output of the comparator 4 is set to the "L" level. Also indicates the voltage corresponding to V ₀ rated speed.

Next, the operation of this embodiment configured as described above will be explained.

When the start switch SU is turned on to operate the passenger conveyor in the upward direction, the (+)-start switch
SU - Normally closed contact GLb - Normally closed contact GHb - Normally closed contact Db
- Relay U - (-) closed circuit raises operation relay U
is energized and its normally open contacts Uc and Ud are closed, thereby starting the electric motor 1 to rotate in the normal direction, that is, to enable the passenger conveyor to operate in the upward direction. At this starting point, the output of the tachometer generator 2 is almost equal to zero, and therefore the output of the low speed detection comparator 3 is "L". Furthermore, since the voltage divider 9 is set to output a voltage of V2 _or more as shown in FIG. 3b, even if this output voltage is applied to the overspeed comparator 4 through the switching contact GLd, The output of the comparator 4 is "L".

Next, when the passenger conveyor accelerates and the output of the tachogenerator 2 exceeds _V1 , the output of the low speed detection comparator 3 becomes "H" as shown in Figure 3a.
become the level. Therefore, the cabana relay GL is energized, and its output signal is applied to the overspeed detection comparator 4 by switching the switching contact GLd on the voltage divider 8 side, and the output of the overspeed detection comparator 5 is "L". level changes to “H” level. As a result, cabana relay GH is also energized.
When cabana relay GH is energized, its contacts GHb
is turned off, the circuit of start switch SU is opened, but normally open contacts GLa, GHa and self-holding contact Ua are turned on, so upward direction operation relay U is turned off.
is self-maintained. Note that the normal startup switch SU (or SD) is turned off when startup is completed.

Additionally, when the passenger conveyor is operating, when the speed becomes low, the output of the tachogenerator 2 decreases, and when the speed drops below _V1 , the output of the low speed detection comparator 3 becomes "L" level, so the governor relay GL is deenergized and the relay U is The self-holding circuit is opened and the passenger conveyor stops operating. On the other hand, when the output of the tachometer generator 2 reaches a high speed higher than _V2 , the output of the overspeed detection comparator 4 becomes "L" level, the governor relay GH is deenergized, and the operation of the passenger conveyor is stopped.

Now, if the low speed detection comparator 3 outputs an "H" level output for some reason during startup, the cabana relay GL is energized and the startup circuit is open, so startup is not possible. ,
It is possible to prevent the safety device from starting up in an abnormal condition. Also, when the output of the overspeed detection comparator 4 remains at the "H" level at _V2 or lower, that is, when the overspeed detection function is lost, the governor relay GH is still in suction at startup. Because the starting circuit is open, the device cannot be started and safety is maintained. Furthermore, while the operation is stopped, the voltage divider 9
Since it is possible to check the switching point of the output of the overspeed detection comparator 4 from the "H" level to the "L" level, by comparing it with the output voltage of the tachogenerator 2, the overspeed detection point can be easily checked. can. Furthermore, by adding a circuit for checking the operation of this overspeed detection section, it is possible to check for failures in the detection section.

As explained above, the present invention constantly checks that the speed is within a predetermined range by providing an overspeed detection section and a low speed detection section that generate outputs when the speed of the passenger conveyor is below or above a set value, respectively. This has the great effect of significantly increasing safety, since abnormalities in overspeed control can be checked accurately and quickly.

[Brief explanation of drawings]

1 and 2 are block circuit and wiring diagrams showing one embodiment of the present invention, and FIG. 3 is an operation waveform diagram showing the operation of each part in FIG. 1. 1...Electric motor, 2...Tachogenerator, 3, 4...
Comparator, 5, 6...Amplifier, 7, 8, 9...Voltage divider, GL, GH, U, Q...Relay, SU, SD...Start switch. In addition, in the figures, the same symbols indicate the same parts,
or a corresponding portion.

Claims (1)

[Claims] 1 means for generating an output in response to the speed of the passenger conveyor, a stall detection section for generating an output when the output of the means is above a set value, and an overload detecting section for generating an output when the output of the means is below a set value. a speed detection section; and an operation confirmation circuit that generates an output when there is an abnormality in at least one of the stall detection section and the overspeed detection section due to a startup operation of the passenger conveyor, and the operation confirmation circuit detects the speed of the passenger conveyor. A safety device for a passenger conveyor, characterized in that it prevents activation.