JP2581317Y2 - Circuit breaker - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker such as a level crossing circuit breaker, a parking lot circuit breaker, etc., and more particularly to an emergency process when the motor is locked.

[0002]

2. Description of the Related Art Heretofore, in this type of circuit breaker, a DC brushless motor (also simply referred to as a brushless motor) has been used for driving the blocking rod because of a large starting torque and maintenance-free operation.

[0003]

However, since this type of circuit breaker is installed outdoors, a failure such as phase loss may occur due to a power failure or the like. However, in a multi-phase brushless motor of a three-phase full-wave type or the like, the rotation angle range in which the rotational force is lost even if one phase out of the three-phase full-wave type is lost is, for example, 60 ° in the three-phase full-wave type. The angle range for locking is only a small angle out of 60 °, and the motor often appears to rotate normally. This is called open phase rotation. If left unattended, the motor may lock up depending on the starting position, which will hinder traffic. Open phase rotation needs to be known promptly. The lock due to this phase loss
This is because there is a range where almost no rotational force is generated only by the restraining force due to the excitation of the phase that is not missing.

The present invention has been made under such circumstances, and enables the rotation of the DC brushless motor when the lock of the DC brushless motor fails due to phase loss or the like, and immediately shuts off when the rotation of the motor is impossible. An object of the present invention is to provide a circuit breaker that can lower a rod by its own weight and can immediately know lock and open-phase rotation.

[0005]

As described above, since the angle range in which the DC brushless motor locks due to phase loss is small, when the motor drive current is cut off during locking, the motor rotates due to the weight of the cut-off rod. Out of the angle range,
There is a high possibility that the motor can be driven by re-input of the motor drive current. In the present invention, based on this idea, in order to achieve the above object, a circuit breaker is configured as in the following (1) to (4).

(1) A circuit breaker for raising and lowering a blocking rod by a DC brushless motor, comprising: lock detecting means for detecting lock of the DC brushless motor; and DC brushless motor in response to an output signal of the lock detecting means. A circuit breaker provided with a breaking / re-closing means for breaking and re-closing a drive current of a motor.

(2) The circuit breaker according to the above (1), wherein the cut-off / re-start means cuts off the control power supply of the DC brushless motor in response to an output signal of the lock detection means and turns on again.

(3) In addition to the lock detecting means, there is provided an open-phase rotation detecting means for detecting an open-phase rotation, and a display means for performing a required display in accordance with an output signal of these detecting means. Or the circuit breaker according to the above (2).

(4) The shut-off / re-entry means stops the re-entry when the lock is not released irrespective of interruption / re-entry of a predetermined number of motor drive currents at the time of the shut-off rod lowering command. ).

[0010]

According to the constitutions (1) to (4), when the DC brushless motor is locked, the drive current of the DC brushless motor is cut off and turned on again. In the configuration of the above (3), the lock detecting means,
A required display is performed according to the output signal of the phase loss rotation detecting means. According to the configuration of (4), when the lock is not released irrespective of the predetermined number of times of the motor drive current being interrupted / re-input, the re-input is stopped, and the weight of the shut-off rod is lowered.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments.
FIG. 1 is a block diagram of an electric system of a "railroad crossing circuit breaker" according to an embodiment, and FIG.
It is a circuit diagram of a descending cam switch part.

In FIG. 1, a 24 VDC power supply is supplied to a drive circuit (inverter circuit) of a DC brushless motor (hereinafter referred to as a motor) 1 via a normally closed contact 23a of a relay 23 (see FIG. 2). The control circuit of the motor 1 is connected to the control circuit of the motor 1 through the closed contact 7a.
And supplied to a CPU (central processing unit) 5.

The lock and open phase rotation of the motor are detected by a current sensor 3 which extracts a voltage of a motor current detection resistor 2 connected in series to a motor power supply and detected by an amplification / detection circuit 4. That is, when the motor is locked, a larger motor current flows than in the normal state, and this is detected by the amplification / detection circuit 4 by comparing it with a value slightly larger than the upper limit value of the motor current in the normal state. Since the motor current periodically becomes zero, it is detected by the amplifying / detecting circuit 4 by comparing it with a value slightly smaller than the lower limit value of the motor current during normal rotation. The open-phase rotation detection signal 4a and the lock detection signal 4b from the amplifying / detecting circuit 4 are sent to the CPU 5, and the CPU 5 turns off / on the motor control power supply and displays an alarm on the display 8, which will be described later.

The condition 8a of the presence / absence of the motor drive power source is determined by the photocoupler 8 driven by the voltage of the motor drive power source.
The condition of lifting / lowering of the shut-off rod (not shown) transmitted to PU5
0a is transmitted to the CPU 5 by the photocoupler 10 driven by the rise / fall command voltage.

In FIG. 2, reference numeral 21-1 denotes an ascending cam switch which is turned on when the shut-off rod approaches a vertical position.
Reference numeral 21-2 denotes a descending cam switch which is turned on when the shut-off rod reaches near the horizontal position, and reference numeral 22 denotes a movable contact which closes to the ascending cam switch side during the ascending condition and to the descending cam switch side during the descending condition. 23 is a movable contact 22 and a DC power supply O
A relay connected between the V terminals. When the relay is energized, the shut-off rod is braked by a relay contact (not shown), and when the relay is not energized, the motor drive power is turned on by the relay contact 23a.

Next, the operation of the embodiment will be described with reference to the flowchart of FIG. 3 showing the operation of the CPU 5, and the timing charts of the signals of the respective parts of FIGS.

At step 1 (hereinafter referred to as S1) in FIG. 3, an alarm output to the display 8 is set to an initial state, and at S2, the relay 7 is de-energized and the motor control power is turned on. S3
To determine whether or not the motor drive power is turned on based on a signal from the photocoupler 8.
Return to step 2 and wait for the motor drive power supply.

As is apparent from FIG. 2, when the ascending command is issued when the shut-off rod is near the horizontal position, or when the descending command is issued when the shut-off rod is near the vertical position, the relay 23 is turned off. When the braking of the blocking rod is released, the contact 23a is closed and the motor driving power is turned on.

When it is determined in S3 that the motor drive power is turned on, it is determined in S4 whether or not the motor lock has failed based on the presence or absence of the lock detection signal 4b. In the event of a lock failure, an alarm is displayed on the display 8 in S7 within one second after the up / down command, and the motor control power supply is shut off in S9 or S15.

In step S8, it is determined whether the lock failure at the time of ascending or the lock at the time of descending has been determined with reference to the signal from the photocoupler 10.
In the event of a lock failure at descent, the relay 7 is energized for one second via the relay driver 6 in S9, the relay contact 7a is opened, and the motor control power supply is cut off for one second. In step S10, the relay 7 is deenergized, the relay contact 7a is closed, and the motor control power is turned on again. In step S11, it is determined whether or not the motor lock is continued based on the lock detection signal 4b.

When the relay contact 7a is opened and the motor control power supply is cut off by the temporary energization of the relay 7, the switching elements of each phase of the motor drive circuit are turned off, and the motor is in a non-constrained (free) state and cut off. The motor rotates slightly due to the weight of the rod. For this reason, when the lock is performed due to the phase loss, the lock range is lost, the lock is released by turning on the motor control power supply again in S10, the motor rotation is continued, and the blocking rod starts to descend.

If the lock failure continues in S11, the relay 7 is energized via the relay driver 6 in S12 within one second after the motor control power supply is turned on again, and the relay contact 7
Open a and shut off the motor control power supply again. In S13, it is determined whether or not the motor drive power is turned on based on a signal from the photocoupler 8. If it is turned on, it is determined in S14 whether the condition is a rising condition based on a signal from the photocoupler 10. If not, the process returns to S13. Thereafter, S13 and S14 are repeated, and when the motor drive power supply is cut off or an ascending command is received and the ascending condition is satisfied, the process returns to S2. That is, the motor drive current is cut off by the cutoff of the motor control power supply in S12, the motor is in an unconstrained state, the cutoff rod descends by its own weight, reaches near the horizontal position, the descending cam switch is turned on, the relay 23 is energized, and its contact The shutoff of the motor control power continues until 23a is opened and the motor drive power is shut off. Alternatively, if the shut-off rod does not lower its own weight for some reason, the motor control power supply continues to shut off until an ascending command is received and the ascending condition is satisfied.

If a lock failure has occurred in S8, the motor control power supply is shut off for 0.7 seconds in S15, the motor control power supply is turned on again in S16, and it is determined in S17 whether the lock failure has continued. .

In S15, when the motor control power supply is cut off and the motor is brought into the non-restrained state, the breaking rod has already been braked, so that its own weight slightly drops from the horizontal position and the motor rotates.
When locked due to an open phase, it is out of the lock range and S
The lock is released by turning on the motor control power supply 16 again,
The rotation of the motor continues and the blocking rod starts to rise. When the lock failure is eliminated in this way, the process returns from S17 to S2.

If the lock failure continues in S17, it is determined in S18 whether the retry is three times. Since this time is one retry, the process returns to S15 and cuts off the motor control power.
In step S6, it is determined whether the lock failure has continued. If the lock failure is eliminated, the process returns to S2. If the lock failure continues, S18 is two retries, so S15
Then, the operation of S15 and S16 is repeated. S17
If the lock failure has been resolved, the flow returns to S2.

If the lock failure has continued at S17, S
Since the retry is performed three times in step 18, the process proceeds to step S19, in which the motor control power supply is cut off. Thereafter, steps S20 and S21 are repeated.
When the condition for shutting down or lowering the motor drive power source is satisfied, the process returns to S2.

If there is no lock failure in step S4, it is determined in step S5 whether or not a phase loss rotation has occurred based on the phase loss rotation detection signal 4a.
When the rotation is not the phase loss rotation, that is, when the rotation is normal, the process returns to S2. In the case of phase loss rotation, the process proceeds to S6, an alarm is displayed on the display 8 within one second from the start of the operation, and the process returns to S2.

The alarm display on the display 8 continues until the power switch (not shown) of the circuit breaker is turned off. Note that these displays can be made on the display 8 and an alarm can be sent to the outside using a relay or the like.

FIGS. 4 to 7 are timing charts of the embodiment at the time of normal operation and at the time of failure. FIG. 4 shows a normal operation. Open phase rotation detection signal 4a, lock detection signal 4
b becomes the illustrated level in the normal state due to the circuit configuration of the amplification / detection circuit 4.

FIG. 5 shows the state during the open phase rotation. At the time of phase loss rotation, the motor current periodically becomes zero as described above.
The detection circuit 4 detects an open-phase rotation detection signal that repeats “H” and “L” as shown in FIG.
The CPU 5 determines in S5 that the phase rotation has occurred.
The alarm output shown in FIG.

FIG. 6 shows a case in which the lock failure at the time of falling causes an operation with a retry, and the operation with a lock failure at the time of rise operates with a second retry. Regardless of the down command, the motor current is increased as compared with the normal rotation by the motor lock as described above, and the "H" signal as shown in the figure is detected by the amplification / detection circuit 4 and supplied to the CPU 5. The CPU 5 determines that a lock failure has occurred in S4,
At 7, a lock failure is displayed on the display 8. In S8, it is determined that the lock failure at descent occurs.
At 10, the motor control power supply is turned on again (retry). When the motor control power supply is cut off, the motor drive current is cut off and the motor current becomes zero, so that the lock detection signal 4b returns to "L". When the motor control power supply is turned on again, the lock is released, phase rotation is performed, and when the descent is completed, the descent cam switch is turned on, the relay 23 is energized, and the motor drive power supply is cut off. Next, an ascending command comes, but S1 because it is locked
In steps S5 to S18, the motor control power supply is repeatedly cut off and turned on again. The second phase is turned on again, phase rotation is started, and when the ascending is completed, the ascending cam switch is turned on and the motor drive power supply is cut off.

FIG. 7 shows a case in which the lock failure at the time of lowering does not cause a retry operation, the blocking rod lowers by its own weight, and the phase-out operation at the time of ascending occurs. In spite of the descending command, the motor is locked and the lock detection signal 4b becomes "H", the lock failure is determined in S4, and an alarm is displayed in S7. In steps S9 and S10, the motor control power is cut off and turned on again. However, the lock failure has not been resolved and the lock failure is determined in step S11. In step S12, the motor control power supply is cut off, the motor drive current is cut off, and the blocking rod descends by its own weight. To start. When the self-weight lowering is completed, the lowering cam switch is turned on, the relay 23 is energized, and the motor drive power supply is cut off, and
Returning to step 2, the motor control power is turned on. When an ascending command is received, the movable contact 22 is inverted, the relay 23 is de-energized, the motor drive power is turned on, the motor rotates out of phase, and the shut-off rod starts to ascend.

As shown in FIGS. 5 to 7, once the alarm is displayed on the display 8, it disappears until the power of the circuit breaker is turned off, regardless of whether the motor control power or the motor drive power is turned on or off. There is no oversight.

The above-described open-phase rotation due to the retry after the lock failure has been confirmed by the test of the actual machine.

In the embodiment, when the motor is locked, the motor control power supply is cut off and turned on again to cancel the lock. However, the present invention is not limited to this.
For example, after the control signals to the switching elements of the motor drive circuit are temporarily turned off when the motor is locked, the motor drive current can be sequentially turned on to cut off and reapply the motor drive current. Can be directly shut off and re-input. That is, in the present invention, when the motor is locked, the drive current of the motor is cut off, and the motor is turned on again to cancel the lock. The number of retries for shut-off / re-input is not limited to one at the time of descending and three times at the time of ascending, but can be freely set.

Further, in the embodiment, the lock or the missing phase rotation which occurred first is detected and an alarm is given to the display. However, the present invention is not limited to this. Is also good.

[0037]

[Effects of the Invention] As described above, according to the present invention,
The motor can be rotated even when locked due to phase loss or the like, and lock or phase loss rotation can be detected immediately.
Further, when the motor is locked at the time of the shut-off rod lowering command and the motor cannot be rotated even after a predetermined number of retries, the shut-off rod is immediately lowered by its own weight, and safety can be ensured.

[Brief description of the drawings]

FIG. 1 is a block diagram of an electric system according to an embodiment.

FIG. 2 is a circuit diagram of an ascending cam switch and a descending cam switch.

FIG. 3 is a flowchart showing the operation of the embodiment.

FIG. 4 is a timing chart during normal operation.

FIG. 5 is a timing chart in a case where one phase of the motor has failed and apparently operates normally.

FIG. 6 is a timing chart in the case of locking at descent → operation at retry → lock at ascent → operation at second retry

FIG. 7 is a timing chart in the case of lock at descent → does not operate in retry → lower weight drop → open phase operation at ascent

[Explanation of symbols]

 Reference Signs List 1 DC brushless motor 2 Motor current detection resistor 4 Amplification / detection circuit 5 CPU 7 Relay

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Toshio Takano 1-13-8 Kamikizaki, Urawa-shi, Saitama Nihon Signal Co., Ltd. Yono Office (56) References JP-A-4-19053 (JP, A) JP-A-4-55163 (JP, A) JP-A-4-29594 (JP, A) JP-A-3-195389 (JP, A) JP-A-2-159994 (JP, A) JP-A-63-99794 (JP, A) JP-A-58-224590 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B61L 29/00-29/28 H02P 6/00-6/02

Claims (4)

(57) [Scope of request for utility model registration] 1. A circuit breaker for raising and lowering a blocking rod by a DC brushless motor, comprising: lock detecting means for detecting lock of the DC brushless motor; and the DC brushless motor according to an output signal of the lock detecting means. A circuit breaker comprising: a circuit for cutting off and re-closing the drive current of the motor. 2. The circuit breaker according to claim 1, wherein the cut-off / re-turn-off means cuts off and re-turns on a control power supply of the DC brushless motor in response to an output signal of the lock detection means. 3. An open-phase rotation detecting means for detecting an open-phase rotation in addition to the lock detecting means, and a display means for performing a required display in accordance with an output signal of the detecting means. The circuit breaker according to claim 1. 4. The shut-off / re-entry means is adapted to stop the re-entry when the lock is not released irrespective of the shut-off / re-entry of a predetermined number of motor drive currents at the time of a shut-off rod lowering command. The circuit breaker according to claim 1, wherein