JP2007330047A - Power-generating braking device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power-generating braking device capable of maintaining a posture of a slider, and shortening a braking distance during operation of a braking. <P>SOLUTION: This power-generating braking device has a load inputted with a motor current by regenerative power generated after exciting current shut-down to a motor, and includes a DC power supply for supplying a constant current to an exciting coil of the motor. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a power generating brake device having a load for inputting a motor current by regenerative power generated after interruption of an excitation current to a motor.

  In a planar positioning device that controls the slider in a two-dimensional manner on the platen, the slider is moved and controlled in a state of being lifted by an air bearing, so that friction is small. Therefore, when the slider speed is decreased and the stop operation is rapidly performed in the event of an abnormality, the power generation type uses regenerative power based on the back electromotive force generated in the excitation coil after the excitation current to the motor provided on the slider is cut off. A brake device is used.

  A power generation brake device that uses regenerative electric power generated from a motor after the excitation current is cut off is disclosed in Patent Document 1. FIG. 5 is a functional block diagram showing a configuration example of a conventional power generation brake device.

  The motor unit 1 is formed of a three-phase AC motor having excitation coils La, Lb, and Lc. The counter coils Ea, Eb, and Ec are applied to the excitation coils La, Lb, and Lc of each phase due to the rotation of the motor. appear.

  The motor driver 2 supplies excitation currents Ia, Ib, and Ic whose phases are shifted by 120 degrees to the excitation coils La, Lb, and Lc of each phase in the drive mode. Although not shown, the motor driver 2 includes control means such as an inverter that controls the rotational speed of the motor by changing the frequency of the excitation current.

  A block 3 is a power generation brake device, which comprises two switch means 4 and 5, a switch control means 6, a speed detection means 7, a current sensor 8, three sets of capacitors C, and a resistor R connected in parallel to these capacitors. A resonant circuit load is provided.

  The switch means 4 includes three sets of changeover switches that are switched by an operation signal M1 from a switch control means 6 that inputs a brake command W. The excitation coils La, Lb, and Lc of each phase are connected to the D contact in the drive mode in the steady operation state, and input excitation currents Ia, Ib, and Ic from the motor driver.

  When the switch means 4 receives the operation signal M1 from the switch control means 6, the switch means 4 selects the B contact in the brake mode and cuts off the exciting current to the motor unit 1. The motor currents ia, ib, ic using the back electromotive voltages Ea, Eb, Ec generated in the excitation coils La, Lb, Lc of the respective phases due to the rotation of the motor after being cut off as regenerative power are supplied from the B contact to the switch means 5 And a brake force is generated in the direction of reverse rotation of the motor by flowing to the load via the switch means 5.

  The switch means 5 switches between two types of loads. When the motor is rotating at a high speed, the C contact shown in the figure is selected, and braking is applied in a capacitor mode in which a resonance circuit composed of a capacitor C and a resistor R is used as a load. When the rotation speed is lower than the predetermined value, the operation signal M2 switches to the S contact side, and the brake is applied in the short mode in which the excitation coils La, Lb, and Lc are short-circuited.

  The switch control means 6 receives the output of the speed detection means 7 for converting the excitation current value detected by the current sensor 8 into a speed signal, and outputs the operation signal M2 to the switch means 5 when the rotational speed falls below a predetermined value. To do.

  FIG. 6 is a moving image diagram after a brake operation of a slider provided with a conventional power generation brake device. FIG. 6A shows the movement after the brake operation at time t0 on the slider 10 indicated by the solid line moving in the P direction on the platen 9 by the dotted line. FIG. 6B shows the change characteristics of the slider speed V and the movement distance L after the brake operation.

JP-A-53-080517

T.IEE Japan, Vol.115-D. No.3 '95 P348 to P353 “Floating-type railway vehicle induction current collection PWM converter by instantaneous current detection”

The conventional power generation brake device has the following problems.
(1) After the brake operation, if the speed of the slider 10 decreases to some extent, the braking force becomes weak, and the posture is affected by the unbalance of the center of gravity of the slider 10 and the external tension of the connected cable bear (not shown). May be difficult to maintain, and may rotate as indicated by θ.

(2) When the slider rotates, the teeth with the platen 9 are not aligned, a closed magnetic path cannot be formed, and no braking force is generated. For this reason, the braking distance of the slider is extended and there is a danger of a collision.

(3) Further, since the closed magnetic circuit cannot be configured, automatic re-servo control cannot be started, and a complicated operation for correcting the posture of the slider 10 to the normal position by manual operation is required.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to realize a power generating brake device capable of maintaining the posture of the slider during braking and shortening the braking distance.

In order to achieve such a subject, the present invention has the following configuration.
(1) In a power generation brake device having a load for inputting a motor current by regenerative electric power generated after the excitation current to the motor is interrupted,
A power generating brake device comprising: a DC power source for supplying a constant current to an excitation coil of the motor when the motor drops below a predetermined speed.

(2) converter means to which the load is connected, which is operated by a power supply voltage obtained from the regenerative power, and which inputs the motor current;
Switching means for supplying the DC power supply voltage to the converter means when the power supply voltage drops below a predetermined value;
The power generating brake device according to (1), comprising:

(3) The power generating brake device according to (2), wherein the DC power supply is supplied via a DC / DC converter connected to a storage battery that stores the regenerative power.

(4) The power generating brake device according to (2) or (3), further comprising constant current control means for controlling the converter means so that a current supplied to an excitation coil of the motor is constant. .

(5) Supplying the motor current to a resonance circuit load, and comprising switch means for connecting the DC power source to an excitation coil of the motor when the motor drops below a predetermined speed (1) The power generating brake device described in 1.

As is apparent from the above description, the present invention has the following effects.
(1) The braking distance is shortened and the danger of a collision can be avoided.
(2) The attitude of the slider can be maintained and stopped while avoiding rotation.
(3) By controlling the attitude of the slider when the servo is not operating, it can be activated by automatic re-servo control.
(4) No manual work is required to start and stop the servo control, and work safety and system operation efficiency can be expected to increase.

  Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a functional block diagram showing an embodiment of a power generation brake device to which the present invention is applied. The same elements as those of the conventional apparatus described with reference to FIG.

  The embodiment of FIG. 1 is a configuration in which the present invention is applied to a power generating brake device that supplies regenerative power to a load via converter means having a function of shifting the resonance frequency of the equivalent resonance circuit according to the speed of the motor. It is an example.

  Regarding the equivalent CR circuit by the PWM converter, Non-Patent Document 1 discloses the operation principle and application in detail. In this embodiment, this equivalent CR circuit is used as an equivalent resonance circuit of the power generation brake device.

  The equivalent resonance circuit is represented by an equivalent capacitor C and resistor R series circuit. By changing the time constant of the CR circuit, the resonance frequency can be matched with the frequency of the motor current corresponding to the rotation speed of the motor.

  By this resonance frequency control, the equivalent reactance component of the motor current circuit can be made zero, and the phase difference between the counter electromotive voltage and the motor current can be made zero. As a result, the motor current always maintains the maximum current, and the braking force can be optimally controlled.

  Converter means 11 forming an equivalent resonance circuit inputs motor currents ia, ib, ic via switch means 4. The current values of the motor currents ia and ib are detected by the current sensors 12 and 13.

  The integrating means 14a and 14b receive the detected values of the motor currents ia and ib detected by these current sensors and execute incomplete integration calculation.

  The power supply voltage of the converter means 11 is indicated by Vc. This power supply voltage Vc is obtained from regenerative power generated from the motor. The voltage control means 15 controls the power supply voltage Vc so as to obtain a voltage that provides optimum resonance characteristics in relation to the rotational speed of the motor.

  The speed detection means 16 inputs the detection value of the motor current ia detected by the current sensor 12 to calculate a speed signal Vs indicating the motor rotation speed, and outputs this as a set value for the voltage control means 15.

  The voltage control means 15 inputs a voltage Vi obtained by dividing the power supply voltage Vc with the resistors R1 and R2 as a measured value, and controls the switching element Q0 to be turned on / off based on a deviation from the set value Vs to change the resistance R3 from the power supply voltage Vc. Is controlled so that Vc follows Vs.

  The converter means 11 includes switching elements Q1 to Q6 composed of six FETs and a commutation auxiliary capacitor C1. The switching elements Q1 and Q2 connected in series for switching the motor current ia are controlled to be opened and closed by a gate drive circuit 18a driven by the PWM control means 17a.

  The switching elements Q3 and Q4 connected in series for switching the motor current ib are controlled to open and close by a gate drive circuit 18b driven by the PWM control means 17b. The switching elements Q5 and Q6 connected in series for switching the motor current ic are controlled to be opened and closed by a gate drive circuit 18c driven by the PWM control means 17c.

  The incomplete integration calculation output of the integration unit 14a that inputs the detected value of the motor current ia is input to the PWM control unit 17a. The incomplete integration calculation output of the integration unit 14b that inputs the detected value of the motor current ib is input to the PWM control unit 17b. The adding means 19 adds the incomplete integration calculation output of the integration means 14a and the incomplete integration calculation output of the integration means 14b, and inputs the added value to the PWM control means 17c.

  A thick line block 100 is a stop control means added according to the present invention. This stop control means 100 has a DC power supply 101 and a switching diode 102 for supplying a constant current to a specified exciting coil of the motor, and the DC power supply 101 is supplied to the power supply voltage Vc of the PWM converter via the switching diode 102. Connected in parallel.

  The voltage V0 of the DC power supply 101 has a voltage value lower than the power supply voltage Vc of the PWM converter, and V0 <Vc during a period when the motor speed is high, and the switching diode 102 is off.

  When the motor speed falls below a predetermined speed, the power supply voltage Vc decreases and V0> Vc, the switching diode 102 is turned on, and the DC power supply 101 is connected as the power supply voltage V0 of the PWM converter.

  Further, the stop control unit 100 includes a constant current control unit 103. The constant current control means 103 inputs and monitors the detection value Vs of the speed detection means 16 and enters a constant current mode when the motor speed is below a predetermined speed, and the direct current supplied to the designated excitation coil of the motor The switching elements Q1 to Q6 of the converter means 11 are controlled via the gate drive circuits 18a to 18c so as to be constant.

  If an example of constant current control is shown, switching element Q1 and Q4 will be made into the object of switching control, and other switching elements Q2, Q3, Q5, and Q6 will be forced off. The current I0 from the DC power source 101 flows through the excitation coils La and Lb designated from the switching element Q1, and flows through the path returning to the DC power source 101 via the switching element Q4.

  The constant current control means 103 controls the on / off ratio of the switching elements Q1 and Q4 so that the direct current I0 is constant.

  By supplying a constant current to the exciting coil of the motor in the constant current mode, the slider is rapidly stopped by the binding force of the magnetic circuit between the teeth of the slider and the teeth of the platen. The rapid stop makes it possible to shorten the brake distance and maintain the posture, and to prevent the rotation that has occurred in the conventional apparatus.

  FIG. 2 is a movement image diagram after the brake operation of the slider provided with the power generation brake device of the present invention, corresponding to FIG. When an abnormality occurs at time t0, the driver output to the motor is turned off and the power generation brake mode is set.

  In the power generation brake mode, the kinetic energy of the motor is regenerated and consumed by heat energy due to a load such as resistance, and the speed of the slider is reduced. When the motor falls below a predetermined speed at time t1, the power generation brake mode is switched to the constant current mode.

  As a result, a constant current flows through the excitation coil of the motor, and the slider rapidly stops at time t1 due to the binding force of the magnetic circuit with the platen teeth. At this time, the teeth of the slider and the teeth of the platen face each other while maintaining a posture without relatively rotating.

  FIG. 3 is a functional block diagram showing another embodiment of the power generating brake device to which the present invention is applied. The feature of this embodiment compared with FIG. 1 resides in an energy storage type brake device configuration.

  The regenerative power that has passed through the converter means 11 is stored in the storage battery 105 via the switching diode 104 instead of the form in which the regenerative energy is thermally consumed by the load resistor R3 shown in FIG.

  A DC / DC converter 106 is connected to the storage battery 105, and an output voltage V 0 of the DC / DC converter 106 supplies a DC power supply and a power supply voltage of the converter means 11 in the constant current mode.

  According to such a configuration, since it is not necessary to connect a DC power supply in the constant current mode from the outside, the cost of the entire apparatus is reduced and there is no resistive load that generates heat, so that an effect of suppressing a temperature rise can be expected.

  Further, by controlling the output voltage V0 of the DC / DC converter 106 according to the power generation brake mode and the constant current mode by the operation signal Vf from the constant current control means 103, the brake braking characteristic and the slider attitude control characteristic can be obtained. It is possible to improve.

  FIG. 4 is a functional block diagram showing still another embodiment of the power generating brake device to which the present invention is applied. A feature of this embodiment is that a constant current mode using a DC power source 101 is introduced in place of the short mode in the power generation type brake device in the conventional capacitor mode and short mode shown in FIG.

When the switch means 5 is switched from the capacitor mode (C contact) to the constant current mode (J contact) by the operation signal M2 of the switch control means 6, the current I0 from the DC power source 101 flows as follows. When the open / close switch 20 is closed, the current I0 flows through the exciting coil La and then flows into the exciting coils Lb and Lc. When the open / close switch 20 is opened, the current I0 flows through the exciting coil La and then flows into the exciting coil Lb.
The open / close switch 20 is provided to switch the coil phase through which the current I0 flows.

  In this embodiment, since the constant current control means employed in the embodiments of FIGS. 1 and 3 is not provided, the constant current characteristics are slightly deteriorated, but the present invention can be implemented at a low cost because the structure is simple. .

It is a functional block diagram showing one embodiment of a power generation brake device to which the present invention is applied. It is a movement image figure after the brake operation of the slider provided with the power generation type brake device of the present invention. It is a functional block diagram which shows other embodiment of the electric power generation type brake device to which this invention is applied. It is a functional block diagram which shows other embodiment of the electric power generation type brake device to which this invention is applied. It is a functional block diagram which shows the structural example of the conventional electric power generation type brake device. It is a movement image figure after the brake operation of the slider provided with the conventional electric power generation type brake device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor part 2 Driver 4 Switch means 6 Switch control means 11 Converter means 12, 13 Current sensor 14a, 14b Integration means 15 Voltage control means 16 Speed detection means 17a, 17b, 17c PWM control means 18a, 18b, 18c Gate drive circuit 19 Adding means 100 Stop control means 101 DC power supply 102 Switching diode 103 Constant current control means 106 DC / DC converter

Claims (5)

In a power generating brake device with a load that inputs motor current due to regenerative power generated after the excitation current to the motor is cut off,
A power generating brake device comprising: a DC power source for supplying a constant current to an excitation coil of the motor when the motor drops below a predetermined speed. Converter means connected to the load, operated by a power supply voltage obtained from the regenerative power, and for inputting the motor current;
Switching means for supplying the DC power supply voltage to the converter means when the power supply voltage drops below a predetermined value;
The power generating brake device according to claim 1, further comprising:   The power generation brake device according to claim 2, wherein the DC power is supplied via a DC / DC converter connected to a storage battery that stores the regenerative power.   4. The power generating brake device according to claim 2, further comprising constant current control means for controlling the converter means so that a current supplied to the excitation coil of the motor is constant. 2. The switch means for supplying the motor current to a resonant circuit load and connecting the DC power source to an excitation coil of the motor when the motor drops below a predetermined speed. Power generation brake device.

Images