JPH0631143B2 - Elevator safety device - Google Patents

Description

Description: [Industrial application] The present invention relates to an improvement in a safety device for an elevator.

[Prior Art] FIGS. 5 and 6 are an overall circuit configuration diagram and an operation sequence circuit diagram of a conventional elevator safety device disclosed in, for example, Japanese Patent Application Laid-Open No. 53-18157. (1) is an elevator car, (2) is a counterweight, (3) is a hoisting steel car, (4) is a deflector, (5) is a main rope, and (6) is a steel car (3). DC motor armature, (6a) also field, (7) three-phase AC power supply, (8) thyristor converter, (9) ignition control circuit, (10) speed command (10a) Speed command generating circuit, (11) is the main circuit contactor, (11a) is the main circuit contactor (1
1) normally open contact, (11b) its normally closed contact, (12) a braking resistor, (13) a first speedometer generator driven by an armature (6), and (14) also a first 2 speedometer generator, (15) adder, (16) safety circuit described later, (16a) this safety circuit (1
6) Normally closed contact, (17) is the top floor, (18) is the bottom floor, (19) is the cam attached to the car (1), (20) is the car (1) installed in the hoistway The end switch that engages with the cam (19) when reaches the top floor (17), (20a) its normally closed contact, and (21) when the car (1) reaches the bottom floor (18). An end point switch that engages with the cam (19), (21a) its normally closed contact, (22) a forced deceleration relay, (23a) and (23b) a normally open contact of a running relay (not shown), (24) Is a rising operation relay (not shown)
Normally-closed contacts, (25) are normally-closed contacts of a descending operation relay (not shown), and (+) and (-) are positive and negative electrodes of a power supply.

Next, the operation of the conventional safety device for an elevator will be described. When the car (1) start command is issued, the traveling relay contacts (23a) and (23b) are closed. As a result, the forced deceleration relay (22) and the main circuit contactor (11) are energized, the contact (11a) is closed and the contact (11b) is opened. In addition, the speed command generation circuit (1
0) operates to generate a speed command (10a), and the ignition command is supplied from the ignition circuit (9) to the thyristor converter (8). As a result, the three-phase alternating current (7) is converted into variable-voltage direct-current power,
Supplied to the armature (6). The rotation of the armature (6) is detected by the speedometer generator (13) and fed back to the ignition control circuit (9), whereby the traveling speed of the car (1) is controlled with high accuracy.

The speedometer generator (14), the adder (15), and the safety circuit (16) are provided to ensure the safety of the elevator. That is, the adder (15) subtracts the output of the speedometer generator (14) from the speed command (10a) to obtain the deviation (15a). The deviation (15a) is almost zero as long as the elevator is operating normally, but if the deviation (15a) exceeds a predetermined value due to a failure of the device, the safety circuit (16) operates. by this,
The contact (16a) is opened and the main circuit contactor (11) is de-energized.
a) opens and disconnects the armature (6) from the thyristor converter (8). At the same time, the contact (11b) is closed and the braking resistor (12) is connected to the armature (6) to bring the car (1) to an emergency stop.

Now, the safety circuit (16) in the above-mentioned conventional elevator safety device is effective for the following failures.

(A) When the speedometer generator (13) fails and the output voltage decreases, the speed of the car (1) increases and the deviation (15a) increases, so the safety circuit (16) operates.

(B) Even if the ignition control circuit (9) fails, the deviation (15
a) increases and the safety circuit (16) operates.

(C) Armature (6), thyristor converter (8) or contact (1
If the terminals such as 1a) become loose and power cannot be supplied to the armature (6), the deviation (15a) also increases and the safety circuit (1
6) works.

In this way, the safety circuit (16) operates effectively against various failures, but the failures cannot be detected in the following cases.

That is, when the speed command generation circuit (10) fails, the safety circuit (16) is powerless because the car speed is originally designed so that the car speed follows the speed command (10a). In particular, if the polarity of the speed command (10a) is reversed due to a failure of the speed command generation circuit (10), the car (1) will run in the direction opposite to the command direction and will collide with the shock absorber at high speed. Dangerous to.

Generally, an elevator is provided with a forced reduction gear in order to prevent the car (1) from passing through the top floor (17) or the bottom floor (18) at high speed. For example, when the car (1) moves up and reaches the vicinity of the top floor, the cam (19) causes the end switch (20).
, The contact (20a) is opened and the forced deceleration relay (22) is deenergized. As a result, even if the car (1) is traveling at high speed, the deceleration stop operation is immediately performed by deactivating the relay (22). However, if the polarity of the speed command (10a) is reversed due to the failure of the speed command generation circuit (10), the above-mentioned forced deceleration operation is not performed. It is assumed that the command direction is up, but the car (1) is down because the polarity of the speed command (10a) is opposite. Since it is ascending operation, the ascending operation relay contact (24) is open, the descending operation relay contact (25) is closed, and the running relay contact (23a) is closed, so the forced deceleration relay (2
2) is held by the circuit of (+)-(20a)-(25)-(23a)-(22)-(-). On the other hand, since the car (1) is descending, the end point switch (20) cannot operate, and therefore the forced deceleration relay (22) is not deenergized. Therefore, the car (1) may go over the bottom floor and collide with the shock absorber at a high speed, possibly damaging passengers.
The circuit of the forced deceleration relay (22) must be the circuit of Fig. 6 so that it can be operated to descend normally from the top floor and to ascend from the bottom floor.
If the polarity of (10a) is reversed, the above-mentioned dangerous situation will occur.

[Problems to be Solved by the Invention] Since the conventional elevator safety device is configured as described above, it is helpless to the failure of the speed command generation circuit, and especially when the polarity of the speed command reverses. Had the problem of causing serious harm to passengers.

This invention solves the above-mentioned problems, and when the polarity of the speed command reverses and fails, the car can be immediately stopped to guarantee the safety of passengers, and to obtain an elevator safety device with few malfunctions. To aim.

[Means for Solving Problems] In an elevator safety device according to the present invention, a safety circuit monitors a deviation signal between a speed command and an output of a speedometer generator and a polarity monitoring circuit monitors a polarity of the speed command. It is a configuration to monitor.

[Effect] The safety device for an elevator according to the present invention uses the polarity monitoring circuit even when the car travels in the direction opposite to the command because the polarity of the speed command is reversed due to the malfunction, not to mention a general failure. Immediately detect the failure and immediately stop the car emergency.

[Embodiment] An embodiment of the present invention will be described below. In FIGS. 1 and 2, (26) is a polarity monitoring circuit for monitoring the polarity of the speed command (10a), and (111a) is an abnormality detection relay (1
It is a normally closed contact point of 11). Others are the same as those in FIGS. 5 and 6. Further, FIG. 3 shows a circuit configuration diagram of the polarity monitoring circuit (26), in which (24a) is a normally open contact of the ascending operation relay, (25a) is a normally open contact of the descending operation relay, (101) and (Ten
5) is an operational amplifier, (102) to (104) and (107) to (109) are resistors, (106) is a reference voltage, (110) is a transistor, (111) is an abnormality detection relay, (112) and ( 113) is a diode, V _cc
Is a positive power source, (101) to (104) are inverting amplifiers, and (105)
~ (108) are comparators.

Now, it is assumed that the polarity of the speed command (10a) is positive during ascending operation and negative during descending operation. Ascending operation relay contact during ascending operation
Since (24a) is closed, the speed command (10a) is directly connected to the resistor (107). On the other hand, during descending operation, the descending operation relay contact (2
5a) is closed, and the speed command (10a) is connected to the resistor (107) with the same absolute value and only the polarity inverted with the inverting amplifier configured by (101) to (104). Therefore, since the positive speed command is always applied to the resistor (107) in both the ascending operation and the descending operation, the output of the operational amplifier (105) is negative, and therefore the transistor (110) is turned off and the abnormality detection relay (111). ) Is de-energized, and the contact (111a) is closed to allow the elevator to run.

However, a failure occurred in the speed command generation circuit (10a),
When the polarity of the speed command (10a) becomes negative despite the ascending operation or the polarity of the speed command (10a) becomes positive even during the descending operation, a negative voltage is applied to the resistor (107). When this voltage exceeds a predetermined value determined by the reference voltage (106), the output of the operational amplifier (105) is inverted positively, the transistor (110) operates, and the abnormality detection relay (111) is activated. Open the contact (111a). This deenergizes the main circuit contactor (11), opens the contact (11a), disconnects the armature (6) from the thyristor converter (8), and closes the contact (11b) to provide braking resistance. Connect (12) to armature (6) to bring the car (1) to an emergency stop. As a result, even if a failure occurs in which the polarity of the speed command (10a) is reversed, the car (1) can be stopped safely, so that it is possible to prevent a dangerous situation in which the car (1) collides with the shock absorber at high speed.

When the car (1) runs in the opposite direction due to a failure of the ignition control circuit (9), the deviation (15a) increases, so the safety circuit (16)
Can operate and prevent accidents. In this way, the safety circuit that operates when the deviation (15a) exceeds the specified value.
By using (16) and the polarity monitoring circuit (26) together, the safety of the elevator can be greatly improved.

Note that the speed command (10a) is input to the polarity monitoring circuit (26).
However, the output of the speedometer generator (14) may be used instead. However, in that case, even when the car (1) slightly moves in a direction different from the traveling instruction at the time of startup, the monitoring circuit malfunctions, and there is a problem in reliability. For example, consider the case where the car (1) is started in the ascending direction with the rated load. As is well known, the balance weight (2) with an elevator rated load of around 50% is used, so the car (1) is heavier in this case. For this reason, at the time of startup, the car (1) tends to rise once after being pulled downward, and if the polarity is monitored by the output of the speedometer generator (14) at this time, the car (1) will be carelessly operated due to malfunction. This causes a problem that prevents the vehicle from running. In order to prevent this, it is necessary to deteriorate the detection sensitivity or invalidate the detection at the time of start-up or landing, which lowers the reliability of the safety circuit (16). On the other hand, in the present invention, since the polarity of the speed command (10a) is monitored, the above-mentioned inconvenience does not occur and the reliability of the safety circuit (16) can be improved.

FIG. 4 shows another embodiment of the present invention. The polarity of the speed command is constant in both the ascending operation and the descending operation, for example, the polarity is positive, and in the elevator system in which the polarity of the speedometer generator (13) and (14) is switched depending on the operation direction, the inversion consisting of (101) to (104) No amplifier is required, and the circuit configuration is simple.

In the above embodiment of the present invention, the polarity monitoring circuit (26)
Although it is provided with the safety circuit (16), it may be provided with only the polarity monitoring circuit (26).

[Effects of the Invention] As described above, in the present invention, the circuit for monitoring the polarity of the speed command based on the output of the speed command generator is provided. Therefore, when the polarity of the speed command becomes abnormal, the reverse of the car It is possible to provide a safety device for an elevator that can prevent running in advance and that does not malfunction with respect to an operation in a direction different from the running direction that occurs at the time of start-up when the loaded load is heavier than the counterweight.

[Brief description of drawings]

1 is an overall circuit block diagram of an elevator safety device according to an embodiment of the present invention, FIG. 2 is an operation sequence circuit diagram of the elevator safety device shown in FIG. 1, and FIG. 3 is a polarity monitoring circuit. A circuit diagram, FIG. 4 is another circuit diagram of the polarity monitoring circuit, FIG. 5 is an overall circuit block diagram of the conventional device, and FIG. 6 is an operation sequence circuit diagram of the conventional device. (1) …… Elevator basket, (2) …… Balance weight (8) …… Thyristor converter, (9) …… Ignition control circuit, (10) …… Speed command generation circuit, (16) …… Safety circuit, (26) …… Polarity monitoring circuit. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] 1. A speed command generator for instructing a traveling speed of a car, a speedometer generator for detecting the speed of the car, and a deviation between an output of the speed command generator and an output of the speedometer generator is a predetermined value. The safety circuit that operates when the above becomes, a polarity monitoring circuit that detects an abnormality in the polarity of the output of the speed command generator based on the traveling direction of the car, and the car based on the output of the safety circuit or the polarity monitoring circuit. An elevator safety device having a control device for stopping. 2. The polarity monitoring circuit operates when it is determined that the polarity is abnormal when the speed command has a negative polarity during the ascending operation of the elevator car and the speed command has a positive polarity during the descending operation. The safety device for an elevator according to claim 1, wherein: