JPH02216726A - Reclosing delay relay - Google Patents

Abstract

PURPOSE:To prevent contacts from being brought into contact with each other for a specific time even if an input signal is applied to a coil again immediately after the cutting-off thereof by setting each value of a capacitor and resistances in such a manner that a charge current for turning off a switching element is not supplied for a predetermined time after the cutting-off when the input signal is cut off and is applied immediately. CONSTITUTION:A coil 3 is de-energized upon cutting off the input signal thereof. Immediately at this moment, if the switch of the input signal is turned on again, a charge current is nearly supplied because the discharge of a capacitor 15 is not advanced. Accordingly, a relatively lower control current is supplied into the control terminal of a switching element 14 through second and first resistances 17, 16. As a result, the element 14 is half turned on so that the coil 3 is weakly energized. At this stage, a movable contact 11 cannot be brought into contact with a stationary contact 9 since the control current is higher than a released ampere-turn and lower than a working ampere-turn. Namely, a predetermined time from the cutting-off time of the input signal to the discharge of the capacitor is necessary for both the contacts to be brought into contact with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a re-opening delay relay in which a contact device operates with a delay when an input signal is applied again immediately after cutting off an input signal to a coil.

[Prior Art] A general electromagnetic relay has as basic elements an electromagnet device having a coil and an armature, and a contact device consisting of movable and fixed contacts that perform contact and separation operations in response to the armature.

Such electromagnetic relays apply and cut off input signals to the coil (
(excitation and demagnetization), the contact device quickly performs contact and separation operations, and efforts are usually made to further speed up these operations and improve responsiveness.

[Problems to be solved by the invention] However, when a numerical electromagnetic relay is used to rotate or stop a motor that is not special, such as one equipped with a clutch brake, the following problems arise. be. In other words, in an electromagnetic relay equipped with a normally open contact device,
If the input signal to the coil is cut off (demagnetized) to stop the motor, and then the input signal is immediately applied to the coil again (excited), the motor will not stop due to inertial force. In other words, it is impossible to satisfy the demand for reliably stopping the motor once.

The present invention has been made in view of the above reasons, and its purpose is to keep the contacts of the load circuit in contact (closed) for a certain period of time even if the input signal is reapplied immediately after the input signal is cut off.
It is an object of the present invention to provide a re-opening delay relay which can prevent such occurrences and is therefore suitable for rotation/stopping of a motor, etc.

[Means for Solving the Problems] In order to achieve the above object, the re-closing delay relay of the present invention includes an electromagnetic device that drives the armature to an actuation position or a return position by excitation or demagnetization of a coil, and an electromagnetic device that drives the armature in response to the armature. The relay body consists of a contact device in which a movable contact connects and separates from a fixed contact, and the relay body is connected in series to a coil, with a switching element having a control terminal, and one end of the coil and a switching element connected in parallel to the coil. A series circuit consisting of a capacitor and a first resistor connected between the control terminals of the element, a second resistor connected in parallel to the capacitor, and a third resistor connected between the control terminal of the switching element and the power supply. is added so that when the capacitor in the series circuit is charged, when the input signal to the coil is cut off and then applied, the charging current that turns on the switching element will not flow for a predetermined period of time from the point of cutoff. This is done by setting the values of the capacitor and each resistor.

[Operation] According to the configuration of the present invention, when the input signal switch is turned on to apply an input signal to the coil for the first time, that is, when the capacitor is completely discharged, the switching element changes according to the time constant of the series circuit. A control current flows through the control terminal of the coil, turning it on and energizing the coil. In other words, in this case, the current is greater than the impressive ampere turn and both the movable and fixed contacts come into contact (closed).

If this state continues, charging of the capacitor will eventually be completed,
This time, a slightly smaller control current flows through the second and first resistors to the control terminal of the switching element. The switching element is therefore in a half-on state and the coil is weakly excited. That is, in this case, since there is a larger ampere turn than the open ampere turn, both the movable and fixed contacts can maintain a contact (closed) state.

Next, when the input signal to the coil is cut off, current no longer flows through the control a terminal of the switching element, turning it off and demagnetizing the coil. In this case, the voltage becomes below the release ampere turn and both the movable and fixed contacts separate (open). Further, from the time when the input signal is cut off, the capacitor starts discharging according to the time constant of the capacitor and the second resistor.

When the input signal switch is immediately turned on again at this time, almost no charging current flows because the capacitor has hardly discharged, and a rather small control current flows to the control terminal of the switching element via the second and first resistors. . The switching element is therefore in a half-on state and the coil is weakly excited. In this case, since the ampere turn is larger than the open ampere turn but smaller than the moving ampere turn, both the movable and fixed contacts cannot be brought into contact (closed) state.

Therefore, in order to bring both the movable and fixed contacts into contact (closed) state, a charging current flows for a predetermined period of time from when the input signal is cut off until the capacitor is sufficiently discharged, and more specifically, a charging current that turns on the switching element flows. It is necessary for a predetermined period of time to pass until this happens.

Note that this predetermined time is determined (in the range of several seconds to about 1 degree) depending on what kind of load circuit is to be opened or closed, and if the required time can be determined, the values of the capacitor and each resistor can be easily set.

[Example] Hereinafter, an example of the present invention will be described based on FIGS. 1 and 2.

First, the configuration of a general relay body, which is the premise of the present invention, will be explained.

1 is an electromagnetic device, which includes a coil 3 wound around a coil frame 2;
It consists of a yoke 4, an armature 5, a return spring 6, etc., and a device stand 7.
will be installed on the

The yoke 4 has a 5-shape, and a long piece 4a is inserted and fixed into the inner hole of the coil frame 2, and its tip is thin. The short piece 4b is positioned such that a predetermined gap is interposed between the short piece 4b and the outer periphery of the coil 3.

The armature 5 also has a 5-shape, and a short piece 5a is rotatably supported at the tip of a long piece 4a of the yoke. The long piece 5b extends within a predetermined gap between the short piece 4b of the yoke and the outer periphery of the coil 3, and is positioned so as to be attracted to the inner surface of the short piece 4b. One end of the return spring 6 is fixed to the long piece 5b of the armature, the other end is fixed to the table 7, and the long piece 5b is fixed to the short piece 4.
The armature 5 is spring-biased in the direction away from b.

This electromagnet device 1 is placed in an operating position in which the long piece 5b of the armature is attracted to the short piece 4b of the yoke by excitation of the coil 3, which becomes more than the impressed ampere turn, and by demagnetization of the coil 3, the value becomes less than the released ampere turn. Then, the long piece 5b returns to the return position where it is separated from the short piece 4b.
Each armature 5 is driven.

8 is a contact device, which includes a fixed contact plate 10 provided with fixed contacts 9;
A movable contact plate 12 provided with movable contacts 11, and a card 1
Consists of 3rd class.

The fixed contact plate 10 and the movable contact plate 12 have both contacts 9.11.
Each proximal end is connected to a fixed part 7a,
? Cantilevered by a.

The card 13 has a base end 13a that is a rotation support portion 7b of the device stand 7.
A driven part 13b that contacts the long piece 5b of the armature and an actuating part 13c that contacts the movable contact plate 12 are provided in the intermediate part. Therefore, the card 13 responds to the armature 5, and when it is in the return position as shown in the second figure, the movable contact 11 is separated from the fixed contact 9, and if it is driven to the operating position, the armature is activated. The portion 13c presses the movable contact plate 12 and the movable contact 11 comes into contact with the fixed contact 9.

The electromagnet device 1 and the contact device 8 constitute a relay body.

Next, the present invention will be explained in detail.

Reference numeral 14 denotes a switching element such as an N-P-N type transistor, the collector and emitter of which are connected in series to the coil 3.

15 is a capacitor, and 16 is a first resistor, which form a series circuit. This series circuit is connected between one end of the coil 3 and the base, which is a control terminal of the switching 14, so as to be parallel to the coil 3.

A second resistor 17 is connected in parallel to the capacitor 15.

A third resistor 18 is connected between the base and emitter of the switching element 14, that is, the power supply.

The values of these capacitors 15 and each of the resistors 16, 17, 18, etc. are set to a predetermined value from the point of interruption when the input signal to the coil 3 is cut off and then applied when the capacitor 15 in the series circuit is charged. time, switching element 1
Set so that the charging current that turns on 4 does not flow.

In addition, these capacitors 15 and each resistor 16°17.1
8 is housed in a recess 2a formed in a part of the outer peripheral surface of the winding drum of the coil frame 2. Note that this accommodation location is not limited to this, and may be any other suitable location, and may also be connected to from outside the relay.

This re-opening delay relay has a DC power supply E connected to the series circuit of the coil 3 and the switching element 14 via the input signal switch SW, and a load such as a motor and its power supply connected in series to both contacts 9 and 11. Connected. and,[
It operates as explained in the section ``Operation''.

FIG. 3 is a characteristic diagram of the attraction force and spring load with respect to the stroke of the armature 5, where Ql is the attraction force characteristic due to the impressive ampere turn, Q2 is the attraction force characteristic due to the ampere turn when the switching element 14 is in a half-on state,
Q3 is the attraction force characteristic due to the release ampere turn, and Q4 is the spring load due to the return spring 6.

Note that the relay body to which the present invention can be applied is not limited to the one described in this embodiment, but can be applied to any type of relay body.

[Effects of the Invention] The re-turning delay relay of the present invention has the advantage that even if the input signal switch is cut off and then turned on again immediately, the delay time from the time when the input signal is cut off until the capacitor is sufficiently discharged, more specifically. , the contacts can be prevented from contacting (closing) until a predetermined period of time has elapsed before the charging current that turns on the switching element flows, and is therefore suitable for rotating and stopping the motor, etc. becomes.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, and FIG. 2 is a circuit diagram showing an embodiment of the present invention.
FIG. 3, a vertical cross-sectional view of the overall configuration, is a characteristic diagram of the attraction force and spring load with respect to the stroke of the armature. l・-electromagnet device, 2-coil frame, 3・-coil, 5-・-armature, 8-one contact device, 9-fixed contact, 11-movable contact, 14-switching element, 15-capacitor, 17-th 2 resistor, 16-first resistor, 18-third resistor.

Claims (1)

[Claims] (1) The relay body consists of an electromagnetic device that drives the armature to the operating position or return position by excitation or demagnetization of the coil, and a contact device that moves the movable contact to and from the fixed contact in response to the armature, connected in series to the coil. a switching element having a control terminal; a series circuit consisting of a capacitor and a first resistor connected between one end of the coil and the control terminal of the switching element so as to be parallel to the coil; A second resistor connected in parallel and a third resistor connected between the control terminal of the switching element and the power supply are added, and when the capacitor in the series circuit is charged, the input signal to the coil is A re-opening delay relay in which the values of a capacitor and each resistor are set so that when the current is cut off and then applied, the charging current that turns on the switching element does not flow for a predetermined period of time after the cut-off.