JP2002037545A - Brake control circuit of elevator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To equalize a direction in which a control contact receives stress by changing a direction of current arc when releasing the control contact each time to suppress transition phenomenon of the contact. SOLUTION: A power supply circuit 4 is connected with both end parts of a series circuit 3 in which a brake excitation coil 1 and the control contact 2 for turning on and off a current to the brake excitation coil 1 of an elevator are connected in series. The power supply circuit 4 consists of a DC power supply 5 and a polarity switching relay 6 for operating the control contact 2 by switching polarities for feeding onto a series circuit 3 side from the DC power supply 5 by inverting an output per brake command.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elevator brake control circuit.

[0002]

2. Description of the Related Art Conventionally, a brake of a traction type elevator (rope hanging type elevator) is configured to operate by sandwiching a brake drum connected to a motor shaft of a motor for driving a traction sheave with a brake shoe. is there.

[0003] The brake is operated during speed control during normal use and during emergency stop when speed is abnormal.

In the above-described elevator brake, a contact arc is generated at the moment when the control contact 32 is turned on / off, particularly when the control contact 32 is turned off, at the control contact 32 of the brake excitation coil 31 in the DC excitation circuit 30 as shown in FIG. .
The brake excitation coil 31 of the elevator needs about 1 A to 10 A, depending on the load capacity (personnel) of the elevator.

[0005] If the arc caused by such a large direct current continues to fly in one direction of the contact, a contact transition phenomenon is induced, and the life of the contact is shortened. That is, a contact transfer phenomenon occurs at a portion indicated by X of the control contact 32 in FIG. 2. When such a contact transfer phenomenon occurs, the contact is caught due to “unevenness” generated at the contact portion due to the transfer. In some cases, the on state may be maintained.

[0006] As a countermeasure, there is a spark killer, but this is not a definitive measure. It is also conceivable to make the contacts AC. However, in this case, the actual movement of the brake is about 3 to 5 times slower than in the case of DC, which is not preferable.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has been made in consideration of the above. It is an object of the present invention to provide an elevator brake control circuit capable of averaging and suppressing a transition phenomenon of a contact.

[0008]

In order to solve the above problems, an elevator brake control circuit according to the present invention comprises an elevator brake exciting coil 1 and a brake exciting coil 1.
A power supply circuit 4 is connected to both ends of a series circuit 3 in which a control contact 2 for turning on / off a current to the series is connected in series,
The power supply circuit 4 includes a DC power supply 5 and a polarity switching relay 6 for inverting the output for each brake command and switching the polarity of power supply from the DC power supply 5 to the series circuit 3 to operate the control contact 2. It is characterized by comprising. With such a configuration, the output is inverted for each brake command, the polarity of power supply from the DC power supply 5 to the series circuit 3 is switched, and the control contact 2 is operated. The direction of the current arc at the time of dissociation can be changed each time, and the direction in which the contacts are stressed can be averaged.

The control contact 2 of the series circuit 3 is constituted by the contact of a DC relay 7 for brake control, and the output is inverted for each brake command to switch the polarity of power supply from the DC power supply 5 to the series circuit 3. It is preferable to provide a flip-flop 8 for operating the control contact 2 of the brake control DC relay 7 and a delay circuit 9 for delaying the switching operation of the control contact 2 of the brake control DC relay 7 for each brake command. . With such a configuration, the time for operating the control contact 2 is delayed by the delay circuit 9, the output is inverted by the flip-flop 8 for each brake command, and power is supplied from the DC power supply 5 to the series circuit 3. By switching the polarity, the control contact 2 can be operated accurately.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments shown in the accompanying drawings.

The elevator apparatus has the following configuration. That is, a continuous elevator hoistway is formed over the upper and lower floors in the building, and a traction sheave rotated by a motor is provided at the upper part of the elevator hoistway, and a wire is wound around this sheave, and the wire An elevator car is suspended from one end of the wire, and a balancer is suspended from the other end of the wire. The traction sheave is rotated by the motor to move the elevator car up and down in the elevator hoistway.

The brake of a traction type elevator (rope suspension type elevator) is configured to operate by sandwiching a brake drum connected to a motor shaft of a motor for driving a traction sheave with a brake shoe. The speed of the elevator car is to be detected by speed detecting means, the brake mechanism detects the speed of the elevator car by the elevator speed detecting means, speed control during normal use and emergency stop when abnormal speed It is supposed to work. That is, a brake command for operating the brake mechanism is output based on the speed of the elevator car detected by the elevator speed detection means, and the brake mechanism operates accordingly.

FIG. 1 shows an elevator brake control circuit for operating a brake mechanism in response to a brake command output.

In FIG. 1, a series circuit 3 is formed by connecting a brake exciting coil 1 of an elevator and a control contact 2 for turning on / off a current to the brake exciting coil 1 in series.
A power supply circuit 4 is provided at both ends of a series circuit 3 in which the brake excitation coil 1 and the control contact 2 are connected in series.
Is connected.

The power supply circuit 4 includes a DC power supply 5 and a polarity switching relay 6 for inverting the output for each brake command and switching the polarity of power supply from the DC power supply 5 to the series circuit 3 to operate the control contact 2. It consists of

Both ends of the series circuit 3 are connected to a first common contact 10 and a second common contact 11 of the polarity switching relay 6, respectively.
2 and the second fixed contact 13 are connected, and the DC power supply 5
The third fixed contact 14 and the fourth fixed contact 15 are connected to the negative electrode side of the first contact. The first common contact 10 is connected to the first fixed contact 12 and the second common contact 11 is connected to the second fixed contact 11. 4 fixed contact 15 and the first common contact 1
A state where 0 is connected to the third fixed contact 14 and a state where the second common contact 11 is connected to the second fixed contact 13 are switched for each brake command described later.

The brake command is input to the flip-flop 8, and the flip-flop 8 is configured so that the output of the relay coil 6a of the polarity switching relay 6 is inverted for each brake command, and the output of the relay coil 6a is inverted. As a result, the first common contact 10 and the second common contact 11 are operated, and as described above, the first common contact 10 is connected to the first fixed contact 12 and the second common contact 11 is The state of being connected to the fourth fixed contact 15 and the first common contact 1
0 is connected to the third fixed contact 14 and the state where the second common contact 11 is connected to the second fixed contact 13 is switched for each brake command.

As shown in FIG. 1, the control contact 2 of the series circuit 3 is constituted by a contact of a DC relay 7 for brake control. The brake command is input not only to the polarity switching relay 6 via the flip-flop 8 as described above, but also to the brake control DC relay 7 via the delay circuit 9 for ON-delay. .
That is, the brake command is configured to be input to two systems of the polarity switching relay 6 and the brake control DC relay 7. The delay time of the delay circuit 9 for ON-delay is about 0.5 seconds. The delay circuit 9 turns on the brake exciting coil 1 with a delay of a predetermined time after receiving a brake command. Therefore, the brake control DC relay 7 is turned on later than the polarity switching relay 6.

By supplying a single brake command, the polarity of the power supply is first reversed by the polarity switching relay 6, and then the brake control DC relay 7 is turned on to release (or engage) the brake. Things. Accordingly, the contact (control contact 2) of the DC relay 7 for brake control can reverse the polarity of the power supply for each operation and suppress the contact transition phenomenon, and average the direction in which the contact receives stress. Is what you can do.

The current flowing to the contact point of the brake control DC relay 7 cannot be said unconditionally because the brake capacity varies depending on the load capacity of the elevator, but is about 1 A to 10 A.

Incidentally, as shown in FIG.
And one end of a relay coil 7a of the brake control DC relay 7 is pulled up (P
(up).

[0022]

As described above, according to the first aspect of the present invention, the brake exciting coil of the elevator and the control contact for turning on / off the current to the brake exciting coil are connected in series. A power supply circuit is connected to both ends of the series circuit, and the power supply circuit operates the control contact by switching the polarity of the DC power supply and the power supply from the DC power supply to the series circuit side by inverting the output for each brake command. And a polarity switching relay for switching the polarity of power supply from the DC power supply to the series circuit side for each brake command to operate the control contact, thereby disengaging the control contact. In this case, the direction of the current arc can be changed each time to average the directions in which the contacts are stressed. As a result,
The present state of contact can be suppressed and contact life can be reduced.

Further, the control contact of the series circuit is constituted by the contact of a DC relay for brake control, and the output is inverted for each brake command to switch the polarity of the power supply from the DC power supply to the series circuit, thereby controlling the DC relay for brake control. A flip-flop for operating the control contact and a delay circuit for delaying the switching operation of the control contact of the DC relay for brake control for each brake command are provided. Delay, invert the output by flip-flop for each brake command, switch the polarity of the power supply from the DC power supply to the series circuit side, operate the control contact accurately, and operate the brake stably Can be done.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of the present invention.

FIG. 2 is a circuit diagram of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Brake excitation coil 2 Control contact 3 Series circuit 4 Power supply circuit 5 DC power supply 6 Polarity switching relay 7 Brake control DC relay 8 Flip-flop 9 Delay circuit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Iwao Shintate 1048 Kazuma Kadoma, Kadoma-shi, Osaka Matsushita Electric Works Co., Ltd. F-term (reference) 3F002 EA10 GA03

Claims (2)

[Claims] 1. A power supply circuit is connected to both ends of a series circuit in which a brake excitation coil of an elevator and a control contact for turning on / off a current to the brake excitation coil are connected in series. The elevator is characterized by comprising a DC power supply and a polarity switching relay for inverting the output for each brake command and switching the polarity of power supply from the DC power supply to the series circuit to operate the control contact. Brake control circuit. 2. The control relay of a series circuit is constituted by the contact of a DC relay for brake control, the output is inverted for each brake command, and the polarity of power supply from the DC power supply to the series circuit is switched to provide a DC relay for brake control. A flip-flop for operating said control contact and a delay circuit for delaying a switching operation of a control contact of a DC relay for brake control for each brake command.
An elevator brake control circuit as described.