JPH01197290A - Control device for elevator - Google Patents

Abstract

PURPOSE:To avoid a trouble due to the fracture of a brake by detecting a brake coil current for supplying a power to an electric motor and actuating a fracture detecting circuit when the electric current does not reach the predetermined value or there is no change in the current. CONSTITUTION:Upon judgement that a signal from a detector 14 for sensing an electric current flowing in a brake coil 57 is inputted and a plunger 56 is properly drawn against a spring 51, a control circuit 11 supplies a power to an electric motor 4 via a drive circuit 3, thereby generating torque. Then, when it is judged that even if a startup instruction contact 12 is turned on, an electric current flowing in the brake coil 57 does not reach the predetermined value and there is no current variation, a fracture detecting circuit is actuated and a report is made accordingly, thereby stopping an elevator concurrently. According to the aforesaid construction, it is possible to limit the propagation of a trouble due to the fracture of a brake.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control device for ensuring the safety of an elevator.

[Conventional technology]

FIG. 5 shows an electromagnetic brake integrally assembled with the first hoist.

Normally, the brake lever (50) is pushed in the direction A in the drawing by the spring (51). Therefore, the brake shoe (52) grips the brake wheel (53) and
It's being stopped. The brake wheel (53) is fixed to a rotating shaft (54) directly connected to the electric motor, and 'rotation of the electric motor,
In turn, the elevator is stopped.

Further, the L-shaped cam (55) rotates in the direction B in the figure as the brake lever (50) moves in the inward direction.
Plunger (56) e is pushing up.

When power is supplied to the brake coil (57).

The plunger (56) is sucked and descends. Along with this descent, the cam (55)' is rotated in the direction C shown in the figure, and the spring (
51) and rotate the brake lever (5o)'ii in the direction shown. Along with this rotation, the brake shoe (
52) releases to the brake car (53)'. By this release, the rotating shaft (54) is driven by the TA machine to move the elevator up and down.

A conventional example of a control device using the elevator brake will be described based on FIG. 6. In the figure, (1) is a three-phase AC power supply, (2) is an electromagnetic contactor that opens and closes the electrical circuit from the AC power supply (1), and (2a) indicates its normally open contact. (3)
(4) is an electric motor drive circuit composed of a thyristor or a transistor, etc., and (4) is an electric motor driven by this drive circuit (3) that rotates one rotation axis (54)'r to drive the elevator up and down. .

(9) is an electromagnetic contactor that supplies power α (l) to the brake coil (57), and (9a) is its normally open contact.
ID is a control circuit that is activated by closing the start command contact z, energizes the electromagnetic contacts (2) and (9), and operates the drive circuit (3); VB is a control power source. (60)
is a wheel connected to the rotating shaft (54), and the main rope (61)
is wrapped around the basket (62) and the weight (63).
)'! i = Driving up and down in a hanging manner.

Next, regarding the operation, when a call occurs in the elevator, the start command contact 0z is closed, the control circuit αυ is activated, and the electromagnetic contacts (2) and (9) are energized. As a result, the contacts (2a) and (9a) are closed, and power is supplied to the drive circuit (3), and the brake coil (57) is also energized by the power source O. Furthermore, when current flows through the brake coil (57), the plunger (56) is attracted, and the brake wheel (53) is released.'8II
'The operation command is sent to the drive circuit (3) and 1%L@
Electric power is supplied to model (4) to generate rotational torque. This rotational torque causes the heel (62) to smoothly start up and down.

[Problem to be solved by the invention]

Since the conventional elevator control device is configured as described above, when the elevator is started, the electric motor may generate torque while the braking force of the brake is still being applied. In this case, the moment the brakes are completely released and there is no braking force, the vehicle suddenly accelerates, resulting in a technical problem that impairs the comfort of the rider.

In addition, if the electric motor (4) is not fully released due to poor contact of the electromagnetic contactor or the plunger (56) causes "warping" and stops midway, the brake wheel (53) may not be fully released.
Power was sometimes supplied to the For this reason, the N motor (4) attempts to rotate while the braking force is applied, causing a large current to flow and causing the motor (4) to burn out or the brake lining to wear abnormally, resulting in the brakes not working. This resulted in an extremely dangerous situation.

This invention was made to solve the above problem, and after confirming that current is flowing through the brake coil, the electric motor is fully energized, thereby smoothly transitioning from braking force to torque generated by the electric motor. In addition, the object of the present invention is to obtain an elevator control device that monitors brake operation and completely prevents motor burnout and abnormal wear of the lining by detecting whether or not the plunger has actually operated the brake current. It is.

[Failure to solve the problem]

An elevator control device according to the present invention.

Detects the current in the brake coil that operates the elevator brake, and depending on the detection result, supplies power to the electric motor that drives the elevator to actually generate rotational torque, or the current in the brake coil is not at the expected value. In addition, the failure detection circuit is activated on the condition that there is no change in current.

[For production]

The elevator control device according to the present invention detects the current in the brake coil and then supplies power to the electric motor to generate rotational torque to continue from the brake to the electric motor, or detects any malfunction of the brake using a failure detection circuit. .

〔Example〕

Generally, the current and voltage of the brake coil (57) have the following relationship.

'd E knee-(Lυten Ri ・・・・・・・・・・・・
... (11i) Here, E is the terminal voltage of the brake coil (57) (constant in this case) 1 L is the same inductance, and R is the same resistance. In equation (1), until the plunger (56) operates Since the inductance L is constant during this period, the current obtained from equation 11 is expressed by the well-known equation below.

The change in this current with respect to time t is as shown in FIG. 4(a). On the other hand, when the brake coil (57) hits the spring (51) and attracts the plunger (56), the inductance L changes. In other words, (from equation 11, d d E = (L) r + (aTi) h+Ri
... (3) t Here, the J-th term differential term on the right side of equation (3) can be rewritten as follows.

Here, X represents the dimension of the air gap of the granger (56), and sD, L(x) means that the inductance L is a function of the dimension X of the air gap.

The velocity and πL(x) represent the rate of change in inductance with respect to a change in air gap, and in this case, it is a negative value. Therefore, when the plunger (56) is attracted, the current changes as shown in FIG. 4(b).

In other words, from point 0 to point (a), current 1 increases according to equation (1), and in the process of attracting the plunger (56), electric current ii increases to point (a) according to equations (3) and (4). decreases from to point (b). When the brassiere (56) has finished being suctioned, the inductance value in that state gradually increases from point (b) according to equation (1).

Therefore, by detecting the change in the current 1 shown in FIG. 4(b), it is possible to fully detect that the brake has been released.

Kazuo embodiments of this invention are shown in Figures 1 to 3 (,) to (f).
).

In the figure, a41 is a current detector that detects the current (i) in the circuit of the brake coil (57). In Figure 2,
12L1 is an output amplifier of the current detector I, Qυ is a capacitor selected to detect only the entire voltage change, and @ is a signal amplification transistor, which together with the capacitor Qυ constitutes the second current detection means. (C) and @ are resistors optimally selected to operate the transistor @ as an amplifier and conduct when the output of the output amplifier ■ is higher than Vk shown in Fig. 3 (a), G is an OIt element, ■ is the RAT flip-flop circuit (hereinafter referred to as F/F circuit), @ is the 5RFiSET signal is input by closing the start command contact Q3, and from that point on, the clock pulse (c/p) ffi is counted and the value exceeds a predetermined value. When it becomes a high potential signal (hereinafter referred to as H signal)
It is a counter that outputs , and functions as a timer means. @ is an AND element, which functions as a failure detection circuit. The wire is an amplification transistor and functions as a first current detection means. clη,c(3 and (to) are transistors G
fl A resistor optimally selected for the specified operation,
3jijN, O, T elements, (to) one-shot multivibrator (hereinafter referred to as OMV), circle is OR element,
071 is a NOT element. VB is the plasmid source, −
VB indicates a negative power supply. (a) to (h) respectively indicate the illustrated position points and illustrate the signals corresponding to FIG.

Next, we will discuss the operation.

When the contact (9a) is closed in the same manner as described in the conventional example, the brake current (1) flows. This current 0) is detected by the current detector, and the signal shown in FIG. 3(a) is outputted to the output point (a) of the output amplifier (2). This indicates that the plunger (56) has been suctioned normally.

41 (a) and (b), the contact (9a) closes at time 1 (, 1 time t).
1, when the voltage at point (a) becomes Vk, 1 transistor (
) becomes conductive, and what was previously an H signal becomes a low potential signal (hereinafter referred to as a low signal). As a result, the output of NOT element C34+ (point (g)) becomes an H signal. This H signal causes OMVi to generate an H signal for a short time (from time t1 to time t12) as shown in FIG. 3(h). OMV(
The H signal of g) is directly input to the set terminal (S) of the F/F circuit (to), and the H signal of the OR element (c) is inputted to the clock terminal (T) and the As shown in FIG. 3(C), the high signal is set.

The voltage at point (a) decreases from time 13 to t4 during the suction process of the plunger (56). During this time, the transistor (2) becomes non-conductive and the point (b) becomes an H signal as shown in FIG. 3(b). The F/F circuit (to) is reset by this H signal, and the point (C) becomes an L signal. On the other hand, after the start command contact α2 is closed, a time limit is counted, and at one time t5, the counter is activated and the point (d) becomes an H signal. However, since point 1 (C) and point (d) do not become H signals at the same time, AND
The output point (e) of the element (to) never becomes an H signal.

This means that the bumps and brakes are normal.

On the other hand, an electromagnetic contactor (
2) One point (f) is an L signal, that is, a start command is issued, and point (C) is also an L signal.

The thumbstick plunger (56) is activated only when suction is detected. Tsumashi.

The output of the OR element (to) becomes an L signal, and the NOT element C3
The output of 71 becomes an H signal and the electromagnetic contactor (2) is energized. This energization causes the drive circuit to be energized via the υ contact (2a), causing the electric motor (4) to generate rotational torque.

In other words, since the electric motor (4) is driven at the same time as the brake is released, the electric motor (4) is driven when the brake is applied.
) is never activated.

After the brake is released, nine rotation torque is not generated.

Next, we will discuss the case where no current flows through the brake coil (57) and the case where the plunger (56) does not operate normally. Masu.

If no current flows through the brake coil (57), point (
If the signal of f) is an H signal, NOT element C (71 is an L signal and remains N), and the electromagnetic contactor (2) is not energized, so the elevator is prevented from starting. Even if current flows, if the plunger (56) is not attracted, the signal at point (a), as shown by the broken line in FIG. 3(a), increases uniformly even after time t3. C24 remains conductive, and one point (1)) maintains [・G].

On the other hand, the F/F circuit is set by the output of O) J V ca, and the point (C) becomes the 11 signal at time t1, and after that, the point (b) remains the L signal. Retain set state. Therefore, 1 point (C) remains 1 (signal N) even after time t3.9 As shown by the broken line in Fig. 3 (C), it becomes l (signal). is H
When it comes to the - circle signal, the output point (e) of the AND element (to) becomes the 's, -#)H signal as shown by the broken line.

Since the point (e) becomes an H signal, it is known that the brake is malfunctioning. Accidents caused by brake malfunction can be prevented by completely stopping the elevator using this signal or by notifying the elevator of a malfunction. Since the specific technology in this regard is well known, the details will be omitted.

Also, since point (c) does not become an L signal, the electromagnetic contactor (
2) is never energized. Therefore, the electric motor (4) is not energized unless the brake is released.
It will not burn out.

In the above embodiment, the electric motor (4) is fully activated after the brake is released, but there is a slight delay from the activation point until the electric motor (4) generates torque. By taking this delay into consideration and fully energizing the electric motor (4) at an appropriate time prior to releasing the brake, the time from the reverse start command to when the elevator actually starts can be shortened. This allows for a smooth transition. For example, in FIG.

The electromagnetic contactor (2) is fully connected directly to point (g), and the circuit is configured so that it is activated by the operation of the transistor circle and fully energizes the motor (4). Then, when the electric motor (4) is energized at time 11 when the transistor (7) operates,
At time t4 when the braking force disappears, the electric motor (4) is adjusted so as to generate a torque that exactly matches the load. To this, l:
#) In addition to smooth startup, you can also get quick startup.

In the above embodiment, the brake coil is excited by direct current, but even if the brake coil is excited by alternating current, as is well known, the exciting current decreases as the pusher is attracted. It can be applied in the same way as by example. For example, the circuit shown in FIG. 2 can be used by rectifying the detection result of the current detector (2) and converting it into direct current.

〔Effect of the invention〕

In this invention, after the first current detection means detects that the current in the brake coil of the brake exceeds a predetermined value, full power is supplied to the electric motor, so that the continuation from the brake to the electric motor is smoothly and quickly performed. be able to.

In addition, a second current detection means is provided to detect that the braking force of the brake is released, and if the brake is normal, it counts a predetermined time period which is longer than the time period for normal detection operation, and within this predetermined time period, a second current detection means is provided. The failure detection circuit is made to operate when the current detection means does not operate.

It is possible to limit the spread of problems caused by brake failure.

[Brief explanation of the drawing]

1 to 4 (a) and (b) show some embodiments of the elevator control device according to the present invention, FIG. 1 is an overall configuration diagram, and FIG. 2 is an electrical and electrical circuit connection of the main parts. Continued, Figure 3 =
→ is a diagram for explaining the operation of Fig. 2. FIGS. 4(a) and 4(b) are diagrams showing the characteristics of the brake. 5 and 6 show conventional elevator control circuits, FIG. 5 is a front view of the brake, and FIG. 6 is a view corresponding to FIG. 1. In the diagram, (1) is an AC power supply, (2) is a magnetic contactor, and (4)
is the electric motor, (9) is the electromagnetic contactor, (tJ is the start command contact, α is the current detector, (2D is the capacitor, @ is the transistor (second current detection means), @ is the counter (timer means), @ is an AND element (failure detection circuit), 9 is a transistor (first current detection means), (52) is a brake shoe, (53) is a brake car, (56)
is the plunger, and (57) is the brake coil. Note that the same reference numerals in Figure 1 indicate the same or equivalent parts.

Claims (2)

[Claims] (1) A brake that generates braking force by deenergizing the brake coil to stop the elevator and energizes the brake coil to release the braking force in response to a start command signal, when the current of the brake coil reaches a predetermined value. A control device for an elevator, comprising: a first current detecting means that operates when the current exceeds the current limit; (2) A brake that generates a braking force by deenergizing a brake coil to stop the elevator, and energizes the brake coil in response to a start command signal to release the braking force; this brake releases the braking force. a second current detection means for detecting a current change in the brake coil that occurs when the start command signal is issued, and a timer means for counting a predetermined time period that is larger than the time period normally detected by the second current detection means after the start command signal is issued. , an elevator control device comprising a failure detection circuit that operates when the second current detection means does not perform a detection operation within the predetermined time period;