JP2013225416A - Electromagnetic relay - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce power consumption by surely maintaining closed state of a contact point, regardless of simple and low-cost configuration.SOLUTION: An electromagnetic relay includes an electromagnet 4 in which a coil 10 is wound on an iron core through a spool 9, a movable iron member 5 which is rotated when attracted to a magnetic pole part of an iron core 8 when the coil 10 is energized, a contact opening/closing mechanism 6 which drives a movable contact member 13 by rotational action of the movable iron member 5, to cause a movable contact point 14 to open/close a fixed contact point 16 of a fixed contact member 15, and a low power consumption circuit 1 which contains a timer IC17 which is connected in parallel to the coil 10, to start counting when the coil 10 is energized, and outputs a signal when a preset operation completion time expires, and decreases an application voltage to the coil 10 based on an output signal from the timer IC17.

Description

  The present invention relates to an electromagnetic relay, and more particularly to an electromagnetic relay having a low power consumption circuit.

  Conventionally, as an electromagnetic relay, the rated current is applied to the coil until the armature is attracted to the electromagnet, and if the motion detection element detects that the armature is attracted to the electromagnet, the amount of current applied to the coil is reduced. Therefore, there is one that suppresses power consumption (see, for example, Patent Document 1).

  However, in the conventional electromagnetic relay, an operation detection element for detecting whether or not the armature has operated is essential. In addition, since the detection by the motion detection element can only detect the rotation state of the armature, the following problem occurs. That is, when the armature is attracted to the electromagnet, even if the movable contact is not completely closed to the fixed contact, the energization amount to the coil is suppressed. In this case, after the movable contact comes into contact with the fixed contact, it may be opened and closed by bounce. If the amount of energization to the coil is suppressed during the time when the contact opens and closes, the contact may open again.

Japanese Patent Laid-Open No. 4-43524

  An object of the present invention is to provide an electromagnetic relay capable of reducing power consumption by reliably maintaining a closed state of a contact despite a simple and inexpensive configuration.

As a means for solving the above problems, the present invention provides:
Electromagnetic relay
An electromagnet formed by winding a coil around an iron core;
A movable iron piece that operates by being attracted to the magnetic pole portion of the iron core by energizing the coil;
A contact opening and closing mechanism that drives the movable contact piece by the operation of the movable iron piece and opens and closes the movable contact to the fixed contact of the fixed contact piece;
The timer IC is connected in parallel to the coil, starts counting when the coil is energized, and outputs a signal when a preset operation completion time elapses. Based on the output signal from the timer IC A low power consumption circuit for lowering the applied voltage to the coil,
It is set as the structure provided with.

  With this configuration, when a voltage is applied to the coil, the timer IC starts counting, and when the operation completion time has elapsed, a signal is output to lower the applied voltage to the coil. Since the time required for the operation completion time, that is, the movable iron piece to rotate and be attracted to the magnetic pole part of the iron core, and the bounce to disappear at the closed contact has elapsed, the applied voltage to the coil is lowered, so the contact The power consumption can be suppressed in a stable state that does not open.

A base on which the electromagnet, the movable iron piece, and the contact opening / closing mechanism are provided;
A case that is mounted on the base and covers the component;
The low power consumption circuit is preferably unitized and integrated with the case or the base.

  With this configuration, an energy saving electromagnetic relay can be obtained simply by providing a unitized low power consumption circuit in the case. The electromagnetic relay itself can be easily accommodated without requiring special design changes due to its structure.

  According to the present invention, the timer IC outputs a signal when the operation completion time elapses after the voltage is applied to the coil to reduce the applied voltage to the coil. Power consumption can be smoothly suppressed while maintaining the contact closed state.

It is a circuit diagram which shows the low power consumption circuit employ | adopted as the electromagnetic relay which concerns on this embodiment. 3 is a time chart for explaining the operation of the low power consumption circuit of FIG. 1. It is an exploded perspective view in the state where a case showing an outline of an electromagnetic relay concerning this embodiment was removed.

  Embodiments according to the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 shows a low power consumption circuit 1 employed in an electromagnetic relay 2 according to this embodiment. This low power consumption circuit 1 is connected in parallel with the electromagnetic relay 2 (coil 10 thereof).

  For example, as shown in FIG. 3, the electromagnetic relay 2 is configured by attaching an electromagnet 4, a movable iron piece 5, and a contact opening / closing mechanism 6 to a base 3 and covering the base 3 with a case 7. The electromagnet 4 is obtained by winding a coil 10 around an iron core 8 via a spool 9 and is excited when a voltage is applied to the coil 10 from a power source 11 via a coil terminal 12 provided on the spool 9. As a result, the movable iron piece 5 is attracted and rotated by the magnetic pole part of the iron core 8 (the lower end in FIG. 3: not shown), and the contact opening / closing mechanism 6 is driven. That is, the movable contact piece 13 is driven and the movable contact 14 is closed to the fixed contact 16 of the fixed contact piece 15.

  The low power consumption circuit 1 includes a timer IC 17 (Integrated Circuit), a switching signal generation circuit 18, and a switching circuit 19.

  The timer IC 17 is connected in parallel to the coil 10 of the electromagnetic relay 2 and starts counting when a voltage is applied to the coil 10. During this time, an off signal is output from the output terminal (Vout) of the timer IC 17. The counting time is from when the voltage is applied to the coil 10 and the excitation of the electromagnet 4 is started, and then the movable iron piece 5 is rotated and attracted to the magnetic pole portion of the iron core 8 until the bounce disappears at the closed contact. The time required, that is, the operation completion time (here, 50 ms, where 20 ms is the minimum value of the operation completion time that can be set). The timer IC 17 outputs an ON signal from the output terminal when the operation completion time has elapsed.

The switching signal generation circuit 18 includes a first transistor Tr1 and a first resistor R1.
The emitter and collector of the first transistor Tr1 are connected in parallel to the coil 10 of the electromagnetic relay 2 and the first resistor R1 connected in series. The output terminal of the timer IC 17 is connected to the base of the first transistor Tr1 via the resistor R3. A base of a second transistor Tr2, which will be described later, is connected between the collector of the first transistor Tr1 and the first resistor R1.

The switching circuit 19 includes a second transistor Tr2 and a second resistor R2.
The emitter and collector of the second transistor Tr2 are connected in parallel to the coil 10 of the electromagnetic relay 2 and the first resistor R1 connected in series. The base of the second transistor Tr2 is connected between the first transistor Tr1 and the first resistor R1, and the diode D is connected to the collector. The diode D is in antiparallel with the coil 10.

  The low power consumption circuit 1 having the above configuration can be unitized and provided on the upper surface of the case 7. By making the unit, it is only necessary to form an installation place in the case 7 and to electrically connect the low power consumption circuit 1 and the coil terminal 12 to each other without substantially changing the structure of the existing electromagnetic relay 2.

Next, the operation of the low power consumption circuit 1 having the above configuration will be described.
That is, as shown in FIG. 2, when a voltage is applied from the power source 11 to the coil 10 of the electromagnetic relay 2, in the low power consumption circuit 1, the timer IC 17 outputs the output terminal based on the applied voltage to the input terminal (Vin). An off signal is output from (Vout). As a result, the first transistor Tr1 of the switching signal generation circuit 18 is turned off and the second transistor Tr2 of the switching circuit 19 is turned on, so that the first resistor R1 is bypassed from the coil 10 to the second transistor Tr2 side. And current flows. In this state, there is no voltage drop outside the coil, and the rated voltage is applied to the coil 10. At the same time, the timer IC 17 starts counting.

  When the operation completion time elapses due to the count in the timer IC 17, an ON signal is output from the output terminal (Vout). Since the timer IC 17 is used, the responsiveness is poor as in the conventional circuit using a capacitor with discharge, and the time characteristic does not change due to the influence of heat generated by the coil 10. The ON signal is output immediately after the set operation completion time has elapsed.

  When the on signal is output from the timer IC 17, the first transistor Tr 1 is turned on in the switching signal generation circuit 18. Then, the second transistor Tr2 is turned off by the switching circuit 19. As a result, a current flows from the coil 10 to the first resistor R1, the voltage value applied to the coil 10 is reduced by the voltage drop at the first resistor R1, and the amount of current is reduced. As a result, power consumption in the coil 10 is suppressed. At this time, since the operation completion time has already passed and the contact does not bounce, even if the voltage applied to the coil 10 decreases, the contact is maintained in a closed state without any problem.

  Thus, according to the embodiment, since the timer IC 17 is used, the circuit configuration can be simplified. If a voltage is input from the power supply 11, the power is accurately driven when the operation completion time has elapsed, and there is almost no variation in the operation time. Further, even when the coil 10 generates heat, the operating characteristics do not change due to the thermal effect. Furthermore, even if an instantaneous stop (instantaneous interruption) in which the voltage input from the power supply 11 is interrupted for a moment occurs and an OFF signal is output from the output terminal, the signal immediately returns to the ON signal. Therefore, even if an impact or the like is applied and the contact is opened, the original state can be restored.

  In addition, this invention is not limited to the structure described in the said embodiment, A various change is possible.

  For example, in the above-described embodiment, the low power consumption circuit 1 is unitized and provided on the upper surface of the case 7. However, the low power consumption circuit 1 may be provided on the side surface of the case 7 or the lower surface of the base 3. 3 and the case 7 can be disposed in an internal space (for example, the inner surface of the case 7).

DESCRIPTION OF SYMBOLS 1 ... Low power consumption circuit 2 ... Electromagnetic relay 3 ... Base 4 ... Electromagnet 5 ... Movable iron piece 6 ... Contact opening / closing mechanism 7 ... Case 8 ... Iron core 9 ... Spool 10 ... Coil 11 ... Power supply 12 ... Coil terminal 13 ... Movable contact piece 14 ... movable contact 15 ... fixed contact piece 16 ... fixed contact 17 ... timer IC
18 ... switching signal generation circuit 19 ... switching circuit

Claims (2)

An electromagnet formed by winding a coil around an iron core;
A movable iron piece that operates by being attracted to the magnetic pole portion of the iron core by energizing the coil;
A contact opening and closing mechanism that drives the movable contact piece by the operation of the movable iron piece and opens and closes the movable contact to the fixed contact of the fixed contact piece;
The timer IC is connected in parallel to the coil, starts counting when the coil is energized, and outputs a signal when a preset operation completion time elapses. Based on the output signal from the timer IC A low power consumption circuit for lowering the applied voltage to the coil,
An electromagnetic relay characterized by comprising: A base on which the electromagnet, the movable iron piece, and the contact opening / closing mechanism are provided;
A case that is mounted on the base and covers the component;
The electromagnetic relay according to claim 1, wherein the low power consumption circuit is unitized and integrated with the case or the base.