JPS63306181A - 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] [Field of Industrial Application] The present invention issues an alarm when the load at a corner of an elevator significantly exceeds the rated load, and automatically prevents the door at the entrance of the elevator car from closing. This invention relates to improvements to safety devices for elevators.

[Prior art] Passenger and single-sleeper elevators are used by an unspecified number of people, which can cause accidents such as jamming due to inaccurate landing of the elevator car due to overboarding of passengers. (Normally, a weighing device is installed to detect an overload of approximately 110% of the rated carrying load. When this weighing device detects an overload on the elevator car, it will alert the passengers with a buzzer or a red light.) The law requires the elevator to warn passengers that the elevator is overloaded, and at the same time prevent the doors from automatically closing and prevent the elevator from starting, and to maintain this state until the overload is resolved to protect the safety of passengers. There is.

Typical examples of this weighing device are shown in FIGS. 2 and 3.

First, in FIG. 2, 1 is the main rope that suspends the elevator car 10, which mainly consists of the car frame 11 and the car interior 12.
2.2' is a port 7 fixed to the end of the main lobe 1, the lower ends of which pass through a hole (not shown) provided in the upper part of the car frame 11 are connected by the support plate 3, and the lower ends and the support It is fastened to the plate 3 with a dowel 7 and a dowel 4. A spring 5 is inserted into the iron 2.2' between the car frame 11 and the support plate 3, so that the deflection of the spring 5 changes depending on the weight of the elevator car 10.

6 is a cam fixed to the support plate 3, 7 is a microsinch provided at a position facing the cam 6 on the top of the car frame 11, and the cam 6 and this microswitch 7 form a weighing device for detecting overload. When the spring 5 bends in accordance with the weight of the elevator car 10 and the cam 6 engages the microswitch 7, an overload is immediately determined and the above-mentioned safety measures are taken.

Next, in FIG. 3, the same reference numerals as in FIG. A microswitch installed at the bottom of the car frame 11 causes the elastic body 8- to displace downward in accordance with the carrying load when more passengers than the capacity enter the car inner room 12. The floor surface is also displaced downward, and this microswitch 9 is activated. In this case as well, if the microswitch 9 operates, it is immediately determined that an overload has occurred, and similar safety measures are taken.

[Problem that the invention seeks to solve]

However, recent elevator cars have become significantly lighter, especially for four-person elevator cars installed in medium-rise residential buildings of 3 to 5 stories. When a passenger jumps around or becomes violent in the car, the spring 5 shown in FIG. 2 or the elastic body 8 shown in FIG. There is a problem in that the alarm is issued intermittently, distributing noise to the surrounding area, and the operation is prohibited during that time, which seriously impairs operation efficiency.

Further, even if passengers do not jump around inside the car, there is a risk that the elevator car will shake during normal boarding and alighting, causing longitudinal vibrations and causing the scale device to malfunction.

The present invention has been made in view of the above points.It is an object of the present invention to provide a device that accurately detects elevator overload and makes safety measures effective even if the elevator car vibrates.

[Means for solving problems]

The present invention provides that when an elevator car is vibrating, the frequency of vibration is approximately constant regardless of the movement of passengers if it is the same car, and in this case, the output of the well-known weighing device is approximately equal to the natural frequency of this elevator car. The present invention focuses on the occurrence of coincident signals, and attempts to perform more accurate overload detection by determining the time when these signals are generated.

That is, as shown in FIG. 4, the vertical axis represents the deflection y of the spring 5 shown in FIG. 2 or the elastic body 8 such as vibration isolating rubber shown in FIG. If the deflection position of the elastic body when there is no overload is set as the origin O, and the point where the overload microswitch is activated when an overloaded passenger quietly gets into the elevator car is set at the L position, Even when the load N is slightly lower than the load, if a passenger jumps inside the car and the elevator car vibrates, the displacement of the elastic body will depend on the mass m of the car including the live load at that time and the spring constant. It becomes a fixed curve,
Occasionally the overload set point may be exceeded causing the microswitch to trip. However, in this case, since the position of the overload detection point is above the position N where the vibration subsides and the elastic body settles down, the operating time ta of the microswitch is always shorter than % of the natural period T, and in any case When the transient load detection point is set at the position S, which is slightly lower than N, the operating time tb of the microswitch is always longer than 2 of the natural period T, so the load in the elevator car does not exceed the predetermined value. Beyond. In other words, by determining whether the overload detection microswitch has operated continuously for a predetermined period of time or not, the actual overload can be accurately detected, and malfunctions of the weighing device due to car vibration can be effectively prevented. Can be done
Embodiment] Fig. 1 is a digital circuit diagram showing an embodiment of the elevator safety 'AN according to the present invention. The case where 0.6 sec is shown is shown. In the figure, CUTI O and CUTI 1 count the 10 Hz clock pulse signal fO input from the synchronization input terminal C, for example, as long as the clear input terminal CLR is Low Lz bell-shaped B, and when the clear input terminal CLR becomes High level, the count contents are is cleared, clear input terminal C
While LR is in a high level state, the clock pulse signal fO is not counted. Count up to 31 input pulses (3.1 sec) and output terminal Qe ~
Qa (Qo is the output of a 1-digit binary number, Ql is the output of a 2-digit binary number
Digit output, Qz outputs a 3-digit binary number, Q3 outputs a 4-digit binary number.

Q4 outputs the count contents to a 5-digit binary output).

AND1 to AND4 are AND elements, N071 to N0T3
is a negative element, FF is a JK flip-flop having a preset input terminal PR and a clear input terminal CLR, and a terminal Q
When a high-level signal is output, similar to conventional safety devices, an alarm is sounded and the automatic closing of the entrance/exit door at the corner of the elevator is inhibited. R is a resistance, RYa is a normally open contact of a conventional microswitch 7 or 9 which closes when the elevator car is overloaded, and P is a positive power supply voltage.

Next, the operation of the device of the present invention will be explained.

First, if the load inside the elevator car is light and the microswitch does not work at all, that is, if the contact RYa continues to open without closing, the counter CUT
Since the positive power supply voltage P (H4gh level signal) continues to be applied to the clear input terminal CLR of IO through the resistor R, the counter cuTto is connected to the logical product element AND1.
Even if the pulse signal fO is input manually through the terminals, it will not be counted, all terminals Q6 to Q will be in a low level state, and the output of the AND element AND3 will also be in a low level state. Therefore, the preset input terminal P of the JK flip-flop FF
Since no high level signal is input to R, the terminal Q continues to maintain the Lo- level, so there is no possibility of sounding an alarm or prohibiting operation by preventing the door from closing.

Next, even if the load inside the elevator car increases (but does not amount to overload) and vibrates, the microswitch will reset to 0.
．． If the contact RYa continues to close for less than 6 seconds, that is, if the contact RYa continues to close for less than 0.6 seconds, the clear input terminal CLR of the counter CtJT10 remains a contact while the contact RYa is closed. RYa
As long as the gate of the AND element ANDI is open, the counter CUTIO counts the pulse signal fo, but the contact R
According to the above-mentioned principle shown in FIG. 4, if the natural period T of the elevator corner is 1.0 sec, Ya will open within about 0.5 sec, so the terminals Q1 and Q8 of the counter CUTIO
A high level signal is output to the preset input terminal P of the JK flip-flop FF through the AND3 AND3.
Before the old gh level signal is input to R, a positive power supply voltage P (H4gh level Li) is applied to the clear input terminal CLH of the counter CUTIO through the resistor R, and the count contents of the counter CUTIO are periodically cleared. In this case as well, JK flip flop 1
The terminal Q of the FF continues to maintain a low level, so there is no need to sound an alarm or prevent the door from closing to prohibit operation.

However, if the load inside the elevator car increases further and becomes overloaded, the microswitch will continue to operate for 0.6 seconds or more even if the elevator car is vibrating, that is, contact RYa will continue to close for 0.6 seconds or more. In this case as well, while the contact RYa is closed, the clear input terminal CLR of the counter CUTIO becomes zero (Lo-level state) through the contact RYa, so the AND element AN
D Counter CUTIO as long as gate 1 is open
counts the pulse signal fo and outputs the old gh level and L level to the terminals Q0 to Q4 in 0.1 sec steps as shown in FIG.
It will output an OW level signal. Then, the sixth pulse of the pulse signal ro after the contact RYa is closed.

That is, after 0.6 seconds have passed since the contact RYa is closed, the terminals Q, , Q, , Q of the counter Ct1710 become L.
Since the ow level, Q, and Q□ are in the High level state, the AND element AND3 outputs the old gh level signal for the first time, and inputs the old gh level signal to the preset input terminal PR of the JK flip-flop FF. According to J.
The terminal Q of the K flip-flop FF is changed to the old gh level, so that an alarm is sounded to inform passengers of the overload, and closing of the door is prohibited to prevent a jamming accident.

Also, the terminals Q,,Qs of the counter CUTIO.

Q4 is at low level, terminals Q, , Q are in the old gh level state, and the output of the AND element AND3 becomes H4gh for the first time.
When the level state is reached, the gate of the AND element ANDI is closed through the negation element No. 1, so that the pulse signal fO is not applied to the synchronization input terminal C of the counter CUTIO for 7 pulses or more, but the contact RYa is closed. For example, after 0.7 se (after which, the contact RYa is opened and the resistor R is connected to the clear input terminal CLR of the counter CUT10.
When a positive power supply voltage P (High level state) is input through the terminal, all contents of the counter CUTIO are cleared (terminals Q and ~Q4 all become Low level state).
be done. However, even if the output of the AND3 becomes 0@ level and a low level signal is input to the preset input terminal PR of the JK flip-flop FF, the terminal Q of the JK flip-flop FF continues to maintain the old gh level. Therefore, the alarm continues to sound and the elevator operation is prohibited.

On the other hand, if a passenger inquires about this alarm and realizes that there are too many people in the elevator car, and some passengers get off and the load in the elevator car falls below the overload, the microsinch will be reset to 0. The state is inactive for 0.5 seconds or more, that is, the contact RYa remains open for 0.5 seconds or more, and while the contact RYa is open, the clear input terminal CLR of the counter CUTII becomes the negation element N0.
Since it becomes a Low level state through T2, as long as the gate of the AND element AND2 is open, the counter CU
The TII counts the pulse signal fo and outputs high level and low level signals (as shown in FIG. 6) to the terminals Q0 to Q4 in steps of 0.1 sec.

Then, after the contact RYa is opened, the pulse signal fO
0.5 sec after the first pulse, that is, contact RYa opens
After the elapsed time, the terminals Q, , Q, of the counter CUTII become I(high level, Q, , Q3. By inputting a high level signal to the reset input terminal CLR of the FF, the terminal Q of the JK flip-flop FF is changed to a low level state, which silences the alarm and allows the door to be freely closed. , counter CU
T11 terminals Qyu, Q□ are old gh level, terminals Q,,Q
.

, Q4 becomes the Lou level state, and the AND element AND4
When the output of GH becomes the old gh level state, the negative element N0T3
6 to close the gate of AND2 through
For pulses or more, synchronization input terminal C of counter Ct1711
If the pulse signal fo is not applied to the contact RYa and the contact RYa is closed even momentarily, the old g is sent to the clear input terminal CLR of the counter CUTII through the negation element
By inputting the h level signal and clearing all the contents of the counter CUTII (terminals Q and ~Q4 are all set to the Low level state), the output of the AND element AND4 is set to the Low level state, and the output of the JK flip-flop FF is set to the Low level state. It enables presetting and changes to a state where overload can be detected at any time.

In the above explanation, the state in which the amount of displacement of the elastic body that is displaced in response to changes in load within the elevator car is equal to or greater than a predetermined value is 0.
We have described an example in which if the load continues for 6 seconds, it is determined that there is an overload and the safety device is activated, and if the load decreases to Q, 5 seconds, the activation of the safety device is released and the original state is restored. The time shown in the example (0.6 s) can be selected appropriately depending on the period of free vibration of the elevator car.
ec or 0.5 sec) itself has no special meaning, but if you want to set those times more accurately, increase the frequency of the chronograph pulse signal fO (for example, 1
00 Hz, etc.) It is easy to ensure the desired accuracy.

Also, if it is not necessary to set the time so accurately, two delay relays TRY1 and TRY can be used as shown in Figure 7.
A similar function can also be achieved by using 2 or by using a Rage-ken circuit. That is, in the figure, E+ and E- are the power supply busbars, MS is the contact point of the microswitch for overload detection,
When the load in the elevator car is light and the amount of displacement of the elastic body is less than a predetermined value, terminals "c" and "b" are connected,
When the load in the elevator car becomes heavy and the amount of displacement of the elastic body exceeds a predetermined value, terminals "c" and "a" are connected. When voltage is applied to TRYI and TRY2, t+ and tz respectively (however, the period of vibration! tllT≦1.+1.
, 1g≧1+) activation delay relay, TRY
lb is the time-limited normally closed contact of the operation delay relay TRY1, T
RY2a is a time-limited normally open contact of the activation delay relay TRY2, and RYI is an overload detection relay that is energized when voltage is applied, and while this relay is energized,
This system not only sounds an alarm, but also prevents the elevator car from closing and prohibits its operation.

With such a circuit configuration, when the load inside the elevator car is light, the amount of displacement of the elastic body is small, and even if the elevator car vibrates, the contact MS of the microswitch will remain at 1.
Since the terminals "C" and "a" are not connected for more than a period of time, the activation delay relay TRY2 is not activated (therefore, the overload detection relay RYI remains deactivated).

However, when the load inside the elevator car increases and becomes overloaded, even if the elevator car vibrates, terminals "C" and "a" of the contacts MS of the microswitch will be connected for more than t8 hours, so the activation delay relay TRY2 will be activated. It is always energized once, and the contact TRY2a of the activation delay relay TRY2 closes, thereby creating a closed circuit rE+-TRY2a-RYI.
- EJ is generated and the overload detection relay RYl is energized,
It not only sounds an alarm to notify passengers of overload, but also prevents them from closing the doors and prohibiting them from driving.

Normally, once this overload detection relay RYI is energized, the closed circuit rE+-TRYI b-RYI a-RYl-
However, if passengers hear this alarm and realize that there are too many people in the elevator car, and some passengers get off and the amount of displacement of the elastic body decreases, even if the Even though the elevator car is vibrating, the terminals rcJ and rbJ of the contacts MS of the micro-sinch are at t1.
Operation delay relay TR
When Y1 is reversely energized and the contact TRY1b of this activation delay relay TRY1 is opened, the self-holding of the overload detection relay RYI is released, the alarm stops sounding, and the door can be freely closed. This makes it possible to operate the elevator.

In the above explanation, an example using a digital circuit and a relay sequence circuit has been described as a means of embodying the technical idea of the present invention, but there are other methods such as using a microcomputer, and the embodiments include Not limited.

〔Effect of the invention〕

As described above, according to the present invention, overload is determined only when the amount of displacement of the elastic body that displaces in response to load changes in the elevator car continues to be equal to or greater than a predetermined value for a predetermined period of time. Even if the car is vibrating, overload can be accurately determined, greatly improving the reliability of the safety device.

[Brief explanation of drawings]

FIG. 1 is a digital circuit diagram showing an embodiment of the elevator safety device according to the present invention, FIGS. 2 and 3 are diagrams showing a representative example of a weighing device, and FIG. 4 is an explanatory diagram showing the principle of the present invention. , FIG. 5 is an explanatory diagram showing the count contents of the counter CUTIO in FIG. 1, and FIG. 6 is an explanatory diagram showing the count contents of the counter CUTIO in FIG.
An explanatory diagram showing the count contents of II, and FIG. 7 is a relay sequence circuit diagram showing another embodiment of the present invention. 538. Spring (elastic body) 660. Cam 7,9. ,,micro switch 801
0 elastic body 10. ,, Elevator car y000 elastic body variation T90. Elevator cage natural vibration period patent applicant
Fuji Chic Co., Ltd. JyuL diagram-

Claims (2)

[Claims] (1) If it is detected that the carrying load of the elevator car exceeds the rated carrying load based on the amount of displacement of the elastic body that is displaced in response to changes in the load inside the elevator car, an alarm will be issued and the door of the entrance/exit of the elevator car will be issued. A safety device for an elevator, characterized in that the safety device is activated when a state in which the amount of displacement of the elastic body is equal to or greater than a predetermined value continues for a predetermined time or more. (2) The elevator safety device according to claim 1, wherein the predetermined time is 1/2 of the natural vibration period when the elevator car is loaded with a rated load.