JPS6052994B2 - Elevator safety device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a safety device for an elevator.

In an elevator, in case the speed control device malfunctions for some reason and cannot decelerate, when the car goes slightly past the final floor, the car or counterweight collides with the shock absorber to reduce the impact. I'm starting to do that.

The stroke of the shock absorber is selected so that the average deceleration at this time is approximately 1 da. However, in the case of an ultra-high-speed elevator, if an attempt is made to decelerate the vehicle at an average deceleration of 1 g, the stroke of the shock absorber will be long, which is impractical. Therefore, in such a case, it is recognized that the stroke of the shock absorber can be shortened by providing an end stage forced speed reduction device (hereinafter referred to as an ETS device). The ETS device will be explained below with reference to FIGS. 1 to 3.

In the figure, 1 is an elevator car, 2 is a counterweight, 3 is a sheave, 4 is a main rope, 5 is a tension wheel, 6 is a counterbalance lobe, 7 is a governor wheel, and 7a and 7b are installed in the governor wheel 7. 8 is a tension wheel, which opens when the speed exceeds a predetermined speed.
9 is a governor lobe whose both ends are connected to the car 1 and is wrapped around the governor wheel 7 and tension wheel 8; 10 is a cam provided on the car 1; and 11 is a position located in the hoistway and operated by the cam 10. A switch, 12 a shock absorber installed at the bottom of the hoistway, 13 an armature of a hoisting motor that drives the sheave 3, 14 other excitation fields, 15 motor poles, 16 a thyristor, etc. Power conversion device, 17 is a three-phase AC power supply, 18
is a discharge resistor, 19 is a main circuit contactor, 19a and 19b are its normally open contacts, 19c is also a normally closed contact, 20 is a friction brake, and 20a is a brake coil, when the brake coil 20a is deenergized. The friction brake 20 restrains the armature 13 by frictional force, and when the brake coil 20a is energized, the friction brake releases the armature 13.

22 is an ETS detection relay, 22a is its normally open contact, 2
Reference numeral 3 denotes a starting circuit that closes when the car 1 starts and opens after it stops.

When the car 1 is stopped at a certain floor, the position switch 11 and the speed governor contacts 7a and 7b are closed, and the ETS detection relay 22 is energized and the contact 22a is closed.

When the starting circuit 23 is closed by the starting command, (+)-7
The main circuit contactor 19 is energized by the circuit b-22a-23-19-(-), the contact 19a is closed, and the contact 19c is closed.
is open.

As a result, DC power from the power converter 16 is supplied to the armature 13. At the same time, the brake coil 20a with the contact 19b closed is energized and the armature 13 is released. In this way, the car 1 is driven via the sheave 3 and starts running. In FIG. 3, D is a normal deceleration curve, and point C is the lowest floor position.

If, for some reason, car 1 does not decelerate and travels to the bottom floor as shown by curve E, position switch 11 at point A
is opened by a cam 10 provided on the car 1. When car 1 is at a speed above 0, governor contact 7a is open, so ETS detection relay 22 in FIG. 2 is deenergized and contact 2
2a is open. As a result, the main circuit contactor 19 and the brake coil 20a are deenergized, and the friction brake 20 generates braking torque. At the same time, the contact 19a of the main circuit contactor 19 opens and the contact 19c closes. As a result, the electric motor 7 Since the electric braking torque is applied by the discharge resistor 12,
"Car 1 decelerates rapidly. When car 1 reaches the bottom floor, its speed has been reduced below the permissible collision speed of shock absorber 12. Although not shown in the diagram, when the emergency When braking is applied, main circuit contactor 1 is turned off until car 1 stops.
9 is designed not to be reintroduced. As is clear from the above, the first predetermined speed of the governor contact 7a? ? is the permissible collision speed of the shock absorber 12.

Further, the operating speed of contact 7b is 6V, and this contact 7b
Emergency braking occurs whenever the is activated. The above example shows the case of lowering car 1, but if the buffer (not shown) on the counterweight 2 side similarly has only a short stroke, a position switch similar to position switch 11 is provided on the upper floor. .

Now, if the stroke of the shock absorber 12 is made smaller and smaller relative to the speed of the elevator, or if the deceleration during emergency braking is designed to be smaller, the position of point A in Fig. 3 will move further and further away from the terminal floor, and as shown in Fig. 4. Since this interferes with the normal deceleration curve D as shown in FIG.

However, if you configure the circuit by dividing it into multiple stages like this,
A large number of position switches 11 and governor contacts 7a must be provided, leading to increased costs and decreased reliability. Also, E
It takes a long time to check the performance of TS equipment. This invention improves the above-mentioned problems, and even if the stroke of the shock absorber is shortened or the deceleration is reduced during emergency braking, an inexpensive and highly reliable ETS system can be constructed. The purpose is to provide equipment.

An embodiment of the present invention will be described below with reference to FIGS. 1, 5, and 6.

In the figure, 25 is a position switch that is pressed and opened by the cam 10 when car 1 reaches a position one floor above point A, that is, point A+1 in FIG. 6, and 26 is a position switch inside car 1. The load detection device contact 27 opens when the load exceeds the rated load, and the contact 27 is a descending operation relay contact that closes when the car 1 travels downward.

Further, C+1 in FIG. 6 is a floor one floor above the lowest floor.
Note that everything other than the above is the same as in FIG. 2.

In the elevator, the counterweight 2 is set to balance the car 1 when 50 to 50% of the passengers in the car 1 are on board the rated load.

On the other hand, when the car 1 is loaded with more than 120% of the normal rated load, the car 1 is not moved. 6th
Point A+1 in the figure is set at a position where the car load is close to 120% and the speed of car 1 at the time of collision with the shock absorber 12 is less than the allowable collision speed of the shock absorber 12 even when emergency braking is applied. be done. If the load is lighter than this, the required deceleration distance will naturally become shorter. During descending operation with the car load not exceeding the rated load, the load detector contact 26 and descending operation relay contact 27 are both closed, resulting in a circuit similar to that of FIG. 2. That is, when the car 1 reaches point A, if the allowable collision speed of the buffer 12 is exceeded, the position switch 11 and the speed governor contact 7a are both opened, so the ETS detection relay 22 is deenergized. Car 1 comes to an emergency stop. Next, when the in-car load exceeds the rated load, the contacts 26 open. Then, a call for the floor C+1, which is one floor above the lowest floor C, is forcibly registered by a circuit not shown. Then, it is forced to stop on the 11th floor C as shown by curve J. If there is a call from the lowest floor C, it will be restarted and run as shown by curve K. The speed at this time is the buffer 12
What is the permissible collision speed for? It has been lowered considerably. If for some reason the vehicle does not decelerate to the C+1st floor and the A
When the +1 point is reached, the position switch 25 is opened, and if the speed of the car 1 is greater than the speed, the contact 7a is also opened, and the car 1 comes to an emergency stop. In addition, in the above example,
It was decided that the train would temporarily stop on the floor one floor above the bottom floor.
It is not limited to this, but if it is a floor before the bottom floor and the maximum speed when descending from this floor to the bottom floor does not reach the permissible collision speed of the shock absorber. You can achieve your desired goal.

7 and 8 show other embodiments of the invention.

In the figure, 30 is a current detector, and 31 is an overcurrent detector that emits an output 31a when a predetermined overcurrent is detected.

31a1 is the overcurrent detector output when the overload increases, 31a2
is also the case when the rated load increases.

The operating level of overcurrent detector 31 is set to the level of current 1 in FIG. Note that everything other than FIG. 7 is the same as FIG. 1. In Figures 1, 5, and 6, when car 1 is in overload descending operation, the call for floor C+1, which is one floor above the lowest floor C, is forcibly registered and the car is stopped at this floor. explained.

However, at this time, if the load detection device fails and the contacts 26 do not open, the car 1 will not enter deceleration toward the C+1 floor for some reason, and the ETS detection relay 22 will not be deenergized even if it reaches the A+1 point. Detection relay 2 is activated only after reaching point A.
2 is deenergized and an emergency stop occurs. However, since this deceleration distance is insufficient, the car 1 collides with the shock absorber 12 at a speed exceeding the permissible collision speed of the shock absorber 12, which is extremely dangerous.
This is a so-called double failure, and the probability of such an accident occurring is extremely low. However, even if the load detection device does not operate, car 1 normally moves without any problems, so a failure of the load detection device is only discovered when a test weight is loaded on car 1 and tested. . Since such a test is normally conducted once a year, it must be said that there is a fairly high probability that the control device will fail during this period and the above-mentioned ETS operation will occur. Therefore, if the load detection device is automatically checked again and again whether it is normal or not, the probability that the load detection device and the control device will fail at the same time becomes extremely low. This embodiment is one that achieves this. That is, if the car 1 is overloaded and is operated in an upward direction, the overcurrent detector 31 generates an output 31a1.

At this time, if the load detection device is not operating, it means that the load detection device is malfunctioning, so the car 1 is immediately stopped at the nearest floor and is not restarted. Since this circuit can be easily configured, it will be omitted. Note that it is obvious that the current detector 30 may directly detect the current of the armature 13.

As explained above, in the present invention, when a car is operated in an overloaded state, by forcibly stopping it at a floor before the terminal floor, the speed when the car is subsequently operated to the terminal floor is controlled by the shock absorber. The collision speed is set to be below the allowable collision speed, and if the load detection device does not operate even though the motor current is high, the car is stopped.

This allows the ETS device to have a simple configuration without compromising safety and reliability.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of the elevator, Fig. 2 is a control circuit diagram of the ETS device, Figs. 3 and 4 are explanatory diagrams of the operation of the ETS device, and Fig. 5 is an embodiment of the elevator safety device according to the present invention. 6 is an explanatory diagram of the operation of the E'TS device according to FIG. 5, and FIG. 7 is a circuit diagram of the main part of FIG. A current detection circuit diagram, FIG. 8 is an output characteristic curve diagram of the overcurrent detector of FIG. 7. 1...basket, 3...sheave, 7...
...Governor car, 7a, 7b...Governor contact, 10
...Cam, 11...Position switch, 12
...Buffer, 13...Hoisting motor armature, 16...Power converter, 19...Main circuit contactor, 20...Friction type Brake, 20a...
... Brake coil, 22 ... ETS detection relay (means for activating the emergency stop circuit), 25 ... Position switch, 26 ... Load detection device contact, 27
...Downward operation relay contact.

Claims (1)

[Claims] 1. If a car operating at a speed higher than the permissible collision speed of the shock absorber reaches the first predetermined position before the lowest floor and the speed exceeds a predetermined value, an emergency stop occurs. A load detection circuit detects an overloaded state of the above-mentioned car, and the above-mentioned overloaded car is operating downward toward the lowest floor, in which a circuit is activated to bring the above-mentioned car to an emergency stop. When the detection signal of the load detection circuit indicates that the maximum speed at the floor before the lowest floor does not reach the allowable collision speed when starting from this floor and descending to the lowest floor. A safety device for an elevator, comprising a forced stop circuit that stops the car at a floor. 2. If a car that is being operated at a speed higher than the shock absorber's allowable collision speed reaches the first predetermined position before the lowest floor and the speed exceeds the predetermined value, the emergency stop circuit will be activated and the above will occur. In a car that is adapted to make an emergency stop, there is a load detection circuit that detects an overload condition of the car, and a load detection circuit that detects when the overloaded car is descending toward the lowest floor. The detection signal causes the car to be moved to a predetermined floor before the bottom floor, where the maximum speed when descending from this floor to the bottom floor does not reach the allowable collision speed. a forced stop circuit that causes the car to stop; a second position detector that operates when the car reaches a second predetermined position in front of the predetermined floor; and means for activating the emergency stop circuit when the speed of the elevator reaches the predetermined position exceeds the predetermined value. 3. When a car operated at a speed higher than the shock absorber's allowable collision speed is overloaded and is being driven toward the lowest floor, the load detection circuit is activated and the car is operated at a floor before the lowest floor. , for driving the car, in which the car is forced to stop at a predetermined floor where the maximum speed when descending from this floor to the lowest floor does not reach the allowable collision speed. A current detection circuit is provided that operates when the current of the motor is at a value corresponding to the above-mentioned overload condition, and when this current detection circuit is activated but the load detection circuit is not activated, a protection circuit is activated to stop the car. A safety device for an elevator, characterized in that it is configured to