JPS62151637A - Device for controlling electromagnetic brake - Google Patents

Abstract

PURPOSE:To reduce the cost of a device by providing a chopper element in an electric passage from a DC power source to a solenoid for braking and eliminating the need for using two types of high and low power sources. CONSTITUTION:When a brake-ON command is externally given, a chopper element is kept an ON condition during a time T1. When a timer for the set time T1 is started (step 303) and, after the time has elapsed (step 304 YES), the chopper element is turned OFF. After that, the chopper element repeats intermittent operations at an OFF time T2 and an ON time T3. Accordingly, two types of high and low power sources are not necessary, leading to reduction in the cost of a device.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to a control device for an electromagnetic brake used, for example, in braking.

(Summary of the Invention) In this invention, the voltage applied to the brake solenoid is intermittent using a chopper element, so that the average drive current for a certain period of time immediately after the start of braking is high, and the average drive current after the above-mentioned certain period of time has elapsed is low. This makes it possible to simplify the circuit configuration and reduce costs compared to the conventional example in which similar characteristics were obtained by switching the applied voltage between high and low levels.

(Prior art and its problems) Conventionally, in a control device for an electromagnetic brake used in a brake motor, etc., a strong friction torque is required immediately after the start of braking, as shown in Figure 5 (a). On the other hand, after braking is complete, a very large friction torque is not required, so by switching the voltage applied to the brake solenoid in two stages, high and low, as shown in Figure 5(b), An attempt was made to obtain the necessary frictional 1-lux characteristics.

However, in order to switch the voltage applied to the brake solenoid into two stages, high and low, it is necessary to have two types of power supplies (high and low), or a charging capacitor to generate high voltage, so the circuit configuration must be There was a problem in that it became complicated and led to a loss of 1 hair.

(Objective of the Invention) The object of the invention is to provide a circuit with a simple circuit configuration, which can be manufactured at low cost, and which can reliably obtain the desired friction (~retention) corresponding to the start of braking and after the completion of braking. An object of the present invention is to provide a control device for an electromagnetic brake.

(Structure and Effects of the Invention) In order to achieve the above object, the present invention uses a chopper element to intermittent the voltage applied to the brake solenoid, so that the average driving current for a certain period of time immediately after the start of braking is high, and This is characterized in that the average drive current after the elapse of time is low.

With this configuration, a chopper element is simply interposed in the current-carrying path from the DC power source to the brake solenoid, and this can be controlled by switching, so there is no need to have two types of power sources, high and low. Since there is no need to provide a capacitor to generate high voltage, the cost of this type of device can be reduced compared to conventional devices.

(Description of Embodiments) FIG. 1 is a longitudinal sectional view showing the basic structure of an electromagnetic brake device according to the present invention.

In the figure, a shaft 71 connected to a motor (not shown)
A disk 2 made of magnetic material is attached to ~1.

On the other hand, a fixed plate 3 is fixed integrally with the motor housing.
A case 4 is fixed to the case 4, and a brake solenoid 5 is built into the case 4.

Then, by energizing the solenoid 5, the disk 2 and the retainer 6 fixed to the end face of the case 4 perform a separating operation via the gap 7, and the rotation of the shaft 1 is braked.

In the present invention, the following improvements have been added to the energization control circuit for the solenoid 5.

FIG. 2 is a diagram showing the electrical system configuration of the control device according to the present invention.

As shown in the figure, in the present invention, a chopper element 9 is interposed in the current-carrying path leading from the DC power source to the brake solenoid 5,
This is transmitted via the interface 12 to the microprocessor 10. Switching is controlled by the output of a microcomputer consisting of a memory 11. In addition, 1
3 is a flywheel diode.

FIG. 3 is a flowchart 1 showing the structure of a control system program stored in the memory 11 of the microcomputer, and the operation of the apparatus of the present invention will be systematically explained in accordance with flowchart 1.

Assume now that the motor connected to the electromagnetic brake is in a rotating state. In this state, if a brake ON command is given from outside to stop the rotation of the motor (
Step 30HA determination), as shown in FIG. 4(b),
During the time T1 (the chopper element 9 is kept in the ON state).

This is done in step 30 to start the timer for the set time T1.
3) After the time has elapsed (step 304), the chopper element 9 is turned off (step 305).

Thereafter, the chopper element 9 repeats the intermittent operation after the OFF time - 2.ON time T3.

This is done by starting a timer for the set time T2 (step 3).
06), wait for the time up (step 307)
4 constant) and turn on the chopper element 9 (step 308).
, then step 30 to start the timer for the set time T3.
9), wait for the time-up (step 3104), and turn off the chopper element 9 (step 3).
11), is done by repeating.

Next, in order to start rotating the motor, the brake ON command is released (No in step 312), the above intermittent operation is stopped, and the chopper element 9 is turned OFF while the motor is rotating.
(step 312).

When the above processing is carried out, as shown in FIG. 4 (a), the average j drive current for a certain period of time immediately after the start of braking is high, and the average drive current after the elapse of the above certain period of time becomes low.
The friction torque generated in the electromagnetic brake follows a curve almost similar to that of the conventional example, in other words, a large braking torque is applied immediately after braking is started, and a relatively small braking torque is applied after braking is completed. It is possible to generate this and maintain the stopped state.

In addition, especially in this embodiment, since the intermittent control of the chopper element 9 is performed by software control of a microcomputer, even if the structure of the electromagnetic brake to be controlled is changed, it can be handled simply by changing the software. This has the advantage of not requiring any major changes in the design h1.

In addition, only one type of DC power supply is required as a power source, and there is no need to prepare two types of power supplies, high and low, as in conventional equipment, and there is no need to provide a condenser for high voltage generation, so the circuit configuration The cost can be reduced by simplifying the process.

Furthermore, since the drive current is controlled by chopper control, there are advantages such as low resistance loss and low heat generation.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view schematically showing the structure of an electromagnetic brake according to the present invention, FIG. 2 is a circuit diagram showing the electrical hardware configuration of the device of the present invention, and FIG. 3 is the software 1 to software configuration. Figure 4 shows the voltage applied to the brake solenoid and the friction generated in the electromagnetic brake.
Fig. 5 is a time chart showing the relationship between applied voltage and friction torque in a conventional device. 1... Shaft 2... Disk 3... Fixed plate 4... Case 5... Solenoid 6... Friction plate 7... Gap 8... Electromagnetic brake 9... Chopper element 10 ...Microprocessor 11...Memory 12...Interface 13...Flywheel diode Fig. 1 Fig. 2 Fig. 3 Fig. 4

Claims (1)

[Claims] (1) The voltage applied to the brake solenoid is intermittent by a chopper element, so that the average drive current for a certain period of time immediately after braking is started is high, and the average drive current after the certain period of time has elapsed is low. An electromagnetic brake control device.