JP2001278554A - Magnetic brake control device for elevator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To highly reliably control an electromagnetic brake for an elevator with reduced noise, loss, cost, and size. SOLUTION: A current value obtained by adding/subtracting a current parameter stored by a current parameter storing means 12 to/from a target value I0 of current passed through a brake coil 6 is compared with an actual current value I passed through the brake coil by an on/off control calculating means 10 to output an on/off command 10a. A transistor 5 is thereby on/off-controlled, and the current passed through the brake coil 6 is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for controlling a current flowing through a current brake used for an elevator.

[0002]

2. Description of the Related Art An electromagnetic brake for an elevator restrains a brake wheel fixed to a shaft of a sheave for driving a car by a spring force. When the brake coil is energized, the plunger is sucked to release the brake car, thereby enabling the car to travel. FIG. 5 shows a control circuit of the electromagnetic brake.

When the electromagnetic brake is released, the contact 21 is closed, and the direct current converted by the rectifier 3 from the AC power supply 2 is applied to the brake coil 6. This causes the plunger to start operating. Immediately before the operation is completed (immediately before the plunger emits a mechanical collision sound), the contact 22 closes and the contact 21 opens. As a result, the resistance 23 causes the brake coil 6
Is limited, and the collision noise is controlled to be small.

Thereafter, the contact 24 closes, the contact 22 opens, and the resistance 25 limits the minimum current required to hold the braked vehicle in the released state, that is, the holding current.
Thus, heat generation of the brake coil 6 is suppressed.

[0005]

In the conventional electromagnetic brake control device for an elevator as described above, the voltage applied to the brake coil 6 is set to an optimum value by resistance partial pressure, and the attraction force of the plunger is controlled. However, since the operation sound of the plunger is minimized, there are the following problems. (1) The resistance value differs depending on the type of brake, which makes management complicated. (2) It is difficult to reduce the size of the control panel due to heat generated by the resistors 23 and 25, mounting of the resistors, and the like. (3) The current of the brake coil 6 fluctuates due to the fluctuation of the resistance value due to the heat generation of the resistors 23 and 25 and the fluctuation of the coil resistance due to the heat generation of the brake coil 6, making it difficult to perform stable silent control.

As disclosed in Japanese Patent Publication No. 7-68016, for example, there is a type in which a brake coil current is controlled by a current feedback system. , That is, when the voltage value output with respect to the current to be measured fluctuates, especially when the coefficient becomes small, there is a problem that the current may increase and cause abnormal heating of the brake coil.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a low-noise, low-loss, inexpensive, compact, and highly reliable electromagnetic brake control device for an elevator.

[0008]

According to a first aspect of the present invention, there is provided an electromagnetic brake control device for an elevator, which compares an actual current value of a brake coil with an on / off command by comparing a target value of a current flowing through a brake coil. Is output to control on / off of the current of the brake coil.

An elevator electromagnetic brake control device according to a second aspect of the present invention stores a current parameter, adds or subtracts a current parameter to or from a target value of a current flowing through a brake coil, and calculates an actual current value of the brake coil. And outputs an on / off command to control the on / off of the current of the brake coil.

An electromagnetic brake control device for an elevator according to a third aspect of the invention detects a change in a current conversion coefficient of a current detector for detecting a current flowing through a brake coil, and outputs an abnormal signal when the change is detected. It is something to do.

According to a fourth aspect of the present invention, there is provided the elevator electromagnetic brake control device according to the third aspect, wherein the conversion coefficient fluctuation detecting means calculates the duty ratio of the on / off command,
The average value is output by multiplying the feedback value of the voltage applied to the brake coil by the above duty ratio, and the average voltage is compared with a reference value to output an abnormal signal.

According to a fifth aspect of the present invention, there is provided an elevator electromagnetic brake control device according to the fourth aspect, wherein a temperature of a brake coil corresponding to an ambient temperature is stored as a temperature parameter, and a reference value is stored in the stored temperature parameter. The correction is made by the following.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 1 to 4 show an embodiment of the first and second aspects of the present invention. FIG. 1 is a block diagram, FIG. 2 is a flowchart of an on / off control operation, and FIG. 3 is an on / off control operation. FIG. 4 is an explanatory diagram of an ON / OFF control operation waveform.

In FIG. 1, 1 is a main circuit (hardware circuit) for electromagnetic brake control, 2 is an AC power supply (single-phase AC 80 V), 3 is a rectifier connected to the AC power supply 2, and 4 is a DC of the rectifier 3. Is a switching transistor for controlling a brake current, 6 is an electromagnetic brake coil, and an electromagnetic brake (not shown) has a spring force when the brake coil 6 is deenergized. When the brake coil 6 is energized, the plunger (not shown) is sucked to release the restraining force by the brake shoe (not shown). It is configured.
Reference numeral 7 denotes a current detector that detects a current supplied to the brake coil 6 and outputs a current feedback value I.

Reference numeral 8 denotes a control circuit (a circuit controlled by software) for controlling the electromagnetic brake, and reference numeral 9 denotes a target value I _{0 of the} current flowing through the brake coil 6 (for example, the brake holding current I ₁ is set to the target value I ₀ ). Current command generating means 10 for outputting an ON / OFF control calculating means for outputting an ON / OFF command 10a for the transistor 5; The changing means 12 is connected to the parameter changing means 11 and stores current parameters I ₀ (I ₁ ), △ i ₁ and △ i _2, which will be described later, and outputs them to the current command generating means 9 and the on / off control calculating means 10. This is a current parameter storage unit that performs the operation.

Numeral 13 is connected to the parameter changing means 11, which stores the temperature parameter of the brake coil 6, and outputs the temperature parameter to the reference value setting means 17, which will be described later. Reference numeral 14 is detected from both ends of the smoothing capacitor 4. A filter 15 for removing a noise component from the DC voltage is connected to the on / off control calculation means 10 and outputs an on / off command 1
Averaging means for averaging the duty ratio based on 0a, 16
Is an average voltage calculating means connected to the averaging processing means 15 and the filter 14 to calculate an average voltage.

Reference numeral 17 is connected to the temperature parameter storage means 13, and a reference value setting means for outputting a reference value for judging abnormality of the conversion coefficient. Reference numeral 18 is connected to the average voltage calculating means 16 and the reference value setting means 17, This is a comparison unit that outputs the abnormal signal 18a.

Next, the operation of this embodiment will be described.
The AC power supply 2 is provided by a rectifier 3 and a smoothing capacitor 4.
Rectified to a smooth DC voltage (about 125V)
The brake coil 6 is supplied to the brake coil 6 via the heater 5. Also,
The current flowing through the rake coil 6 is detected by the current detector 7.
And a current feedback value I is output. On / off control hand
The stage 10 has a current target output from the current command generating means 9.
Value I ₀And stored in the current parameter storage means 12.
Current off parameter △ i_TwoAnd current-on parameter △
i₁Is added or subtracted and compared with the current feedback value I to turn on.
/ Off command 10a is output. With this, transistor 5
Turns on / off to control the brake coil current.

The on / off control calculation will be described with reference to FIGS. Captures the current target value I ₀ in step S1 in FIG. 2, takes in the current feedback value I in step S2. Current off parameter current feedback value I is the current target value I ₀ at step S3 △ i ₂ added value (hereinafter referred to as the upper limit.) Greater or the determining than. If it is larger than the upper limit, the process proceeds to step S4, in which an off signal is output to turn off the transistor 5 (see FIG. 3). If less than the upper limit value, step S5
Proceed to.

The current off parameter current feedback value I from the current target value I ₀ in step S5 △ i ₁ a value obtained by subtracting (hereinafter referred to the lower limit value.) Or smaller to determine than. If it is not less than the lower limit, the process proceeds to step S6, and the output of the off signal is held. If it is smaller than the lower limit, the process proceeds to step S7, where an ON signal is output to turn on the transistor 5 (see FIG. 3). FIG. 4 shows the relationship between the on / off command 10a and the current feedback value I, that is, the brake coil current.

That is, although a pulse train is output as the ON / OFF command 10a, the time applied to the brake coil 6 changes as the duty ratio changes, and the current flowing through the brake coil 6 is controlled accordingly. You.
At this time, the DC main circuit voltage and current parameters {i ₁ , △
i ₂ and the electrical time constant inherent to the electromagnetic brake determine the switching period, ie, the frequency, of the transistor 5. Depending on the switching frequency, magnetic noise from the electromagnetic brake is generated, and when the frequency is high, the switching loss of the transistor 5 increases.

[0022] Therefore, in this embodiment, for example and model holding current value I ₁ of the brake is known in advance, the current parameters for the holding current value I ₁ △
Automatic setting is performed using i ₁ and △ i ₂ . The current parameters △ i ₁ and △ i ₂ may be determined as absolute values, respectively, or may be obtained by multiplying a current target value I ₀ by a coefficient. (For example, △ i ₁ = k ₁ I ₀ , △ i ₂ = k ₂ I ₀ ,
Here, k ₁ and k ₂ are coefficients) Even if the current target value I ₀ is different from the holding current value I ₁ , the same control may be obtained.

Also, the holding current value I of the electromagnetic brake₁Not yet
For a known model, the parameter changing means 11
The current parameter stored in the current parameter storage means 12
TA I ₀, △ i₁, △ i_TwoTo change individually. Sand
In addition, magnetic noise from the electromagnetic brake (flowing through the brake coil 6)
The current ripple frequency is affected. ) Does not occur
And the current parameter so that the switching frequency is low.
Data @ i₁, △ i_TwoSelect

For example, the target value I ₀ stored as a current parameter is gradually lowered, and the lower limit value is reduced, thereby obtaining a current target value I ₀ at the time when the brake plunger starts to move due to vibration or the like. , A predetermined margin may be set as the new holding current value I ₁ . In addition, by the above control, as a countermeasure against noise when the brake is released, the switching frequency is optimized by adjusting the software parameters without providing a special resistor or the like in hardware, and the software is stabilized. Control becomes possible.

Embodiment 2 This is an embodiment of the third invention of the present invention, and shares FIGS. However, FIG.
The feedback circuit of the DC voltage via the filter 14 is not used. Next, the operation of this embodiment will be described. The operation by each of the components 1 to 12 is the same as that of the
Is the same as An on / off command 10a (pulse train) output from the on / off control calculation means 10 is input to the averaging processing means 15 and averaged by software (in this embodiment, averaging by a primary filter). , Its output is the duty ratio.

The average voltage calculating means 16 multiplies the average value of the pulse train output from the averaging means 15, that is, the duty ratio by the voltage gain (125 V) of the main circuit 1, and calculates the average applied to the brake coil 6. Calculate the voltage. The average voltage is compared by the comparing means 18 to determine whether the average voltage is within the reference value range set by the reference value setting means 17, and if the average voltage is out of the range, an abnormal signal 18a is output.

For example, if the current conversion coefficient of the current detector 7 is 1
/ 2, the brake coil current is flowing at 10A with respect to the target value of 10A, for example.
Is detected. The on / off control calculation means 10 recognizes that the feedback current value I is smaller than the target value, and turns on the transistor 5 until the current value reaches 10A. As a result, the duty ratio of the pulse train increases, and the output value of the average voltage calculation means 16 also increases. That is, since a current of 20 A actually flows, a voltage corresponding to the current is applied.

As described above, since the average output voltage changes depending on the conversion coefficient, it becomes possible to detect when the conversion coefficient of the current detector 7 becomes abnormal. That is, when the time ratio of the on / off time is out of the specified range, the abnormal signal 18
a is output. However, since the averaged voltage is a primary filter method, a certain time constant is required in principle, so it is necessary to judge the presence or absence of an abnormality at a stable place (when the electromagnetic brake is in the holding state). Is desirable. For example, the time constant is set to 1 second, and abnormality detection is set to 5 seconds after the electromagnetic brake release command.

Embodiment 3 This is an embodiment of the fourth invention of the present invention, and shares FIGS. Embodiment 2
In the above, the voltage gain (output value of the rectifier 3) was fixed, but actually the output voltage of the rectifier 3 (the smoothing capacitor 4
Of the AC power supply 2 fluctuates.
In other words, when controlling to the same current value, if the power supply voltage is high, the duty ratio of the pulse is controlled to be small, but if the voltage is low, the duty ratio of the pulse is controlled to be large. Need to take.

In the third embodiment, the DC main circuit voltage output from the rectifier 3 is fed back via the filter 14, and the value is used as the voltage gain. As a result, the output of the average voltage calculation means 16 is obtained as an absolute value, so that abnormality can be detected with higher accuracy.

Embodiment 4 FIG. This is an embodiment of the fifth invention of the present invention, and shares FIGS. Embodiment 2
Then, the resistance value of the brake coil 6 changes due to the temperature fluctuation (the higher the temperature, the higher the resistance value. If the same current is tried to flow, the voltage becomes higher). The output voltage of the voltage calculation means 16 also fluctuates. Therefore, when the temperature of the brake coil 6 is high (11
(0 ° C.), the output voltage of the average voltage calculation means 16 is adopted as a reference value.

In the fourth embodiment, the coil temperature (ambient temperature) at the time of adjustment is output from the temperature parameter storage means 13 to the reference value setting means 17 as a parameter.
A function is provided for automatically correcting the temperature coefficient of copper to a reference value at high temperatures. Here, the temperature coefficient of copper is 0.00
Assuming that 390 / deg and the ambient temperature are Ta, the reference value after correction = the reference value set at the time of adjustment × ｛1 + 0.0039 ×
(110-Ta)}. Thus, since the reference value is corrected to a value corresponding to the temperature of the brake coil 6, it is possible to detect an abnormality with higher accuracy.

[0033]

As described above, according to the first aspect of the present invention, the target value of the brake coil current is compared with the actual current value of the brake coil to output an on / off command to turn on the current of the brake coil. Since the on / off control is performed, the brake current is optimally controlled, and the operation sound and loss of the electromagnetic brake can be minimized.

In the second invention, the current parameter is stored, and an on / off command is output by comparing the current value obtained by adding or subtracting the current parameter to or from the target value of the brake coil current with the actual current of the brake coil. Since the current of the brake coil is controlled to be turned on / off, the optimum switching frequency can be easily set even for a model whose holding current value of the electromagnetic brake is unknown.

In the third invention, the variation of the current conversion coefficient for detecting the current flowing through the brake coil is detected, and in the fourth invention, the duty ratio of the on / off command is calculated and applied to the brake coil. The average value is output by multiplying the feedback value of the voltage by the above duty ratio, and an abnormal signal is output by comparing each with the reference value.If the current conversion coefficient fluctuates, this can be easily detected. Can be.

In the fifth invention, the temperature of the brake coil corresponding to the ambient temperature is stored as a temperature parameter.
Since the reference value is corrected based on the stored temperature parameter, the abnormality can be detected with higher accuracy.

[Brief description of the drawings]

FIG. 1 is a block diagram showing Embodiment 1 of the present invention.

FIG. 2 is an on / off control operation flowchart showing the first embodiment of the present invention;

FIG. 3 is an explanatory diagram of an on / off control operation showing the first embodiment of the present invention.

FIG. 4 is an ON / OFF control operation waveform diagram showing the first embodiment of the present invention.

FIG. 5 is a circuit diagram showing a conventional elevator electromagnetic brake control device.

[Explanation of symbols]

Reference Signs List 4 smoothing capacitor, 5 switching transistor, 6 brake coil, 7 current detector, 9 current command generating means, 10 on / off control calculating means, 11 parameter changing means, 12 current parameter storing means, 1
3 temperature parameter storage means, 14 filters, 15
Averaging processing means, 16 average voltage calculating means, 17 reference value setting means, 18 abnormality detecting means (comparing means), 18a
Abnormal signal, S1-S7 ON / OFF control calculation means

Claims (5)

[Claims] 1. An elevator having an electromagnetic brake that restrains the movement of a car when a brake coil is deenergized and releases the restraint when the brake coil is energized. And an on / off control calculation means for comparing the current value of the brake coil with the actual current value of the brake coil and outputting an on / off command to control the current of the brake coil on / off. Brake control device. 2. An elevator having an electromagnetic brake that restrains the movement of a car when a brake coil is deenergized and releases the restraint when the brake coil is energized. And a current value obtained by adding or subtracting the current parameter to or from a target value of the current flowing through the brake coil, and an actual current value of the brake coil, and output an ON / OFF command to reduce the current of the brake coil. An electromagnetic brake control device for an elevator, comprising: on / off control calculation means for performing on / off control. 3. An elevator having an electromagnetic brake for restraining the movement of a car when a brake coil is deenergized and releasing the restraint when the brake coil is energized detects a current flowing through the brake coil. A current detector, a conversion coefficient fluctuation detecting means for detecting a change in a current conversion coefficient of the current detector, and an abnormality detecting means for outputting an abnormality signal when a change in the current conversion coefficient is detected. Characteristic electromagnetic brake control device for elevators. 4. A conversion coefficient variation detecting means for averaging processing means for calculating a duty ratio of an on / off command, and an average voltage obtained by multiplying a feedback value of a voltage applied to a brake coil by the output duty ratio. 4. The electromagnetic brake control device for an elevator according to claim 3, comprising: average voltage calculating means for outputting the average voltage; and comparing means for comparing the output average voltage with a reference value to output an abnormal signal. 5. A temperature parameter storing means for storing a temperature of a brake coil corresponding to an ambient temperature as a temperature parameter, and a reference value correcting means for correcting a reference value based on the stored temperature parameter. The electromagnetic brake control device for an elevator according to claim 4, wherein