JP2527480Y2 - Electromagnetic relay with fail-safe structure - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is an improvement of an electromagnetic relay, more specifically, for returning a movable contact piece of an armature to a state separated from a make contact without exciting a coil. In the event that the return spring means provided in the device does not work due to breakage or the like, the electromagnetic path of the fail-safe structure that automatically and reliably establishes the conductive path including the movable contact piece and the make contact is immediately opened. It relates to a relay.

[Conventional technology and problems]

2. Description of the Related Art Electromagnetic relays are widely used for remote control, sequential control, supply control of large current, and the like of various electric devices. Especially in applications where malfunctions such as control of industrial robots and signal systems of train monitoring equipment lead to danger of human life or large-scale damage, conductive paths that form closed circuits when energized by electromagnetic relays, so-called make contacts, are used. The main devices are controlled via the controller, and in an emergency, the power supply to each unit is stopped simultaneously by stopping the excitation of the electromagnetic relay. As a matter of course, the electromagnetic relay used for such an application requires a high degree of reliability.

FIG. 4 shows a conventional electromagnetic relay and an example of such use. The hinged electromagnetic relay (50) is a yoke.
A magnetic circuit is formed by (2), an iron core (3) fixed thereto, and an armature (4) hinged to the upper end of the yoke (2), and a coil (6) wound around the iron core (3). The armature (4) is attracted to the iron core (3) by an electromagnetic attraction force generated when the current is excited. At this time, the movable contact (C1) provided at one end of the contact spring (C2) attached to the armature (4) via the insulating base (5) moves and contacts the make contact (A1). (C2) side terminal (C) and make contact (A
1) The terminal (A) is electrically connected to form a conductive path. (1) is a case of an electromagnetic relay. When the coil (6) is not excited, the armature (4) is configured to return to the break contact (B1) side by the tensile force of the return spring means (7). Various controlled devices (12) are connected to the power supply (11) via the terminals (C) and (A) (through so-called make contacts), and these controlled devices are turned on and off by the electromagnetic relay (50). The operation and non-operation of the device (12) are controlled. The break contact (B1) and the terminal (B) following the break contact (B1) are not used in the illustrated example.

The exciting coil (6) of the electromagnetic relay (50) is connected to a power supply (or control circuit output) (8) via two types of switches (9) and (10). The operation switch (9) is used for normal ON / OFF of the electromagnetic relay (50), while the emergency switch (10) is provided in the vicinity of the controlled device (12) or other places as necessary. The operation of the controlled device (12) can be stopped at any time in an emergency.

However, the conventional electromagnetic relay (50) has a structure in which the armature (4) is returned to the break contact (B1) side by the tensile force of the return spring means (7). If 7) is deteriorated and the urging action is weakened, or if the function is completely lost due to breakage, the operation of the relay becomes unstable (for example, greatly depends on the mounting posture, etc.), and the armature (4) Cannot be reliably returned to the break contact (B1) side. In such a case, even if the emergency switch (10) is operated to stop the controlled device (12) or the operation switch (9) is operated to stop the excitation of the electromagnetic relay (50), the return spring means (7) is stopped. ) Is not functioning properly, the conductive path (make contact) via the make contact remains conductive, and the power supply to the controlled device (12) does not stop, so the operation continues without stopping the controlled device Can lead to accidents. This is inconvenient and dangerous.

The present invention is made in view of the difficulties of such a conventional electromagnetic relay, and in the event that the return spring means fails, the conductive path through the make contact is automatically and surely made. An object of the present invention is to provide an electromagnetic relay that can be notified of a failure of the electromagnetic relay by stopping the controlled device in an open state, and thus can be used in various control circuits in a safe and fail-safe manner.

[Means for solving the problem]

In order to solve the above problem, an electromagnetic relay according to the first invention of the present application will be described with reference to FIG. 1 of the accompanying drawings. A movable contact (C1) at the end of a contact spring fixed to an armature in a normal state, The electromagnetic relay having a return spring means for urging the fixed make contact (A1) opposed to the movable contact so as to keep the fixed contact point separated from the movable contact is caused solely by the urging action in the normal state of the return spring means. A conductive second conductive path is interposed in series with the first conductive path including the make contact.

In addition, the electromagnetic relay according to the second invention of the present application will be described with reference to FIG. 2 of the accompanying drawings. A movable contact at an end of an abutting spring which is fixed to an armature in a normal state, and a fixed opposite to the movable contact The return spring means, which has a return spring means for urging it so as to keep the applied make contact in a separated state, includes the return spring means itself between the two action points where the tension urging force of the spring means acts. A second conductive path is formed, and is interposed in series with the first conductive path.

[Action]

In the electromagnetic relay of the first invention configured as described above, when the return spring means does not work, that is, when it cannot be said that it is in a normal state, only the urging action of the return spring means is performed only in the normal state. Since the second conductive path that is brought into a conductive state due to the current becomes a non-conductive state immediately, the first conductive path (make contact) on the make contact side including this conductive path in series is provided.
Is open even if the coil of the electromagnetic relay is excited. Therefore, the controlled device stops.

Further, in the electromagnetic relay of the second invention, when the return spring means is cut and separated into two parts and does not exhibit a spring action, that is, when it is difficult to say that it is normal, the conductive path portion of the return spring means Is inevitably separated into two, so that the conductive path (make contact) on the make contact side including this part inevitably becomes open even when the coil of the electromagnetic relay is excited. Therefore, the controlled device stops.

[Example of the invention]

Hereinafter, the present invention will be described with reference to the drawings based on an embodiment.
Note that, in the following drawings, portions denoted by the same reference numerals indicate the same or equivalent portions.

In FIG. 1, (20) is an embodiment of the electromagnetic relay according to the first invention of the present application. In the figure, (1) is a case of an electromagnetic relay, (2) is a yoke, (3) is an iron core, and (4)
Is hinged to the upper end of the yoke (2) and fixed to the opposite side of the iron core (3) via an insulating member (5).
The other end has a movable contact (C1), the other end is an armature as a terminal (C), and (6) is a coil wound around the iron core (3) via a bobbin. The yoke (2), the iron core (3), and the armature (4) form a magnetic circuit, and the armature (4) is formed by an electromagnetic attraction force generated when a coil (6) wound around the iron core (3) is energized and excited. 4) is adsorbed to the iron core (3). At this time,
The movable contact (C1) moves and comes into contact with the make contact (A1).

When the coil (6) is not excited, the armature (4) is configured to return to the break contact (B1) side by the tensile force of the return spring means (7). The return spring means (7) is a return spring means which is engaged with the ends of the armature (4) and another armature (A5) described later and pulls and urges both. (B1) is a break contact which comes into contact with the movable contact (C1) by the action of the return spring means (7) when the coil (6) is not excited.

Now, (A5) is a movable iron piece hinged to the lower end of the yoke (2). Like the above-mentioned armature (4), a movable iron piece is provided on the opposite side of the yoke (2) via an insulating member (A6). The movable contact (A4) is provided at the end of the contact spring (A8). This movable contact (A4) applies the urging force (tensile force) of the return spring means (7).
, So as to come into contact with the additional contact (A3) provided to face it. The movable iron piece (A5) is also urged by the second spring means (A7), but the two urging forces are in opposite directions, and the urging force of the second spring means (A7) is restored. It is set weaker than the urging force of the spring means (7). As a result, in a normal state, the movable contact (A4) of the movable iron piece (A5) is always in contact with the additional contact (A3). This additional contact (A3) and the make contact (A
1) is fixed to the same conductive member (A2) and is electrically connected. After all, in the present embodiment, the conductive path (first conductive path) on the make contact (A1) side is formed including a contact made of a movable iron piece. That is, the second conductive path including the contact by the additional contact (A3) and the movable contact (A4) is connected in series.

Since the device controlled by the electromagnetic relay (20) of the present embodiment is connected to the power supply via the first conductive path, the return spring means (7) of the electromagnetic relay (20) is disconnected or the spring force is reduced. When it becomes extremely weak, that is, when the original urging force is lost or becomes insufficient, the second conductive path is opened, so that the power supply to the controlled device is stopped, Since the operation of the device is stopped, an operator or the like can clearly know the occurrence of the abnormality.

As described above, when the electromagnetic relay (20) of the present embodiment is used, the operation of the controlled device is automatically stopped when a failure occurs.
Therefore, a fail-safe control system can be constructed.

Next, FIG. 2 shows an electromagnetic relay (3
0) shows an embodiment. This embodiment is substantially similar to the fourth embodiment.
The configuration is the same as that of the conventional electromagnetic relay (50) shown in the figure, but a terminal (A) on the make contact side is provided on the way with the return spring means (7) interposed as an electrical conductive path. ing. That is, the insulating member (C3) and the conductive member (C4) are fixed in order at the rear end of the armature (4), and the return spring means (7) applies the conductive member (C4) to one action. Another conductive member (C6) fixed at an appropriate distance from the yoke (2) via an insulating member (C5) is defined as the other working point. A tensile urging force acts on both points of action. The rear end of the contact spring (C2) and the conductive member (C4) are connected by a conductive wire, and the conductive member (C6)
Is connected to a terminal (C) fixed to the case (1) by a conducting wire. Further, as described above, since the conductive member (C4) and the conductive member (C6) are connected by the return spring means (7) made of a conductive material, the terminal (C) is eventually changed from the make terminal (A) to the terminal (C). The first conductive path on the entire make-up side is formed by connecting the portion itself between the two points of action of the return spring means (7) where the tensile urging force acts as a second conductive path in series. Therefore, when the return spring means (7) is broken and cut, the return spring means is separated into two parts by its contraction force, and the conductive path is cut (opened) at this part and connected. Power supply to the controlled device stops. Therefore, this electromagnetic relay (30) is also a fail-safe electromagnetic relay capable of constructing a fail-safe control system.

FIG. 3 shows an electromagnetic relay (40) according to another embodiment of the present invention. The schematic configuration of the magnetic circuit, the armature (4), etc. is similar to that of the conventional electromagnetic relay (50) in FIG. In this embodiment, a return spring means (13) is embodied by fixing one end of the spring contact piece itself fixed to the armature (4) to the case (1). Normally, the movable contact (A2) is separated from the make contact (A2) by being urged by the pulling force indicated by the arrow.
The terminal (C) uses the end of the return spring means (13) itself. Accordingly, as in the previous embodiment, the first conductive path on the makeup side is acted upon by the tension urging force of the return spring means (13).
It is formed by connecting the portions themselves between the two action points in series. For this reason, when the return spring means (13) is cut off, the conductive path is cut off at this part because it is separated into two parts by the spring action, and the supply of power to the controlled device is stopped. Therefore, the electromagnetic relay (40) of the present embodiment is also a fail-safe electromagnetic relay capable of constructing a fail-safe control system.

[Effect of the invention]

As described above with reference to the embodiments, according to the first invention of the present application, in the electromagnetic relay having the return spring means for urging the coil to open the first conductive path including the make contact when the coil is not excited. Since the second conductive path which is in a conductive state only in a normal state solely due to the urging action of the spring means is interposed in series with the first conductive path, when the spring means is no longer in the normal state, Then, even when the coil is immediately excited, the conductive path including the make contact is automatically opened. Therefore, a fail-safe control system can be constructed.

Further, according to the second invention of the present application, in the electromagnetic relay having the return spring means for urging the first conductive path including the make contact to be opened when the coil is not energized, between the two operating points which operate. Since a part of a certain spring means itself is formed as a second conductive path and interposed in series with the first conductive path, if the return spring means is cut off, even if the coil is immediately energized, a make contact is made. Are automatically opened. Therefore, a fail-safe control system can be constructed.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional side view showing the structure of an electromagnetic relay according to an embodiment of the first invention of the present application, and FIG. 2 is a view showing the structure of an electromagnetic relay according to an embodiment of the invention of the second invention. FIG. 3 is a partial cross-sectional side view showing the structure of an electromagnetic relay according to another embodiment of the present invention, and FIG. 4 is an example of the structure of a conventional electromagnetic relay. The partial cross-sectional side views shown are shown respectively. 20, 30, 40 ... electromagnetic relay, 2 ... yoke, 3 ... iron core, 4 ... armature, 6 ... coil, 7, 13 ... return spring means, C1 movable contact, A1 make contact,

Claims (2)

(57) [Scope of request for utility model registration] An iron core (3), a yoke (2), and an armature (4) constituting a magnetic circuit, a coil (6) wound around the iron core, and the coil (6) when the coil is not excited. The pole is moved away from the iron core, and a contact spring (C
2) It has a movable contact piece (C1) at the end and a return spring means (7) that urges the fixed contact point (A1) opposed to the movable contact piece so as to keep them apart. When the coil is excited, the armature is attracted to the iron core, so that the movable contact piece of the armature and the make contact are brought into contact with each other to conduct the first conductive path including both. In the electromagnetic relay, having a second conductive path that is in a conductive state solely due to the urging action of the return spring means in a normal state, this second conductive path is interposed in series with the first conductive path. An electromagnetic relay characterized in that: 2. An iron core (3), a yoke (2) and an armature (4) constituting a magnetic circuit, a coil (6) wound on the iron core, and the coil when the coil is not excited. The pole is moved away from the iron core, and a contact spring (C
2) It has a movable contact piece (C1) at the end and a return spring means (7) that urges the fixed contact point (A1) opposed to the movable contact piece so as to keep them apart. When the coil is excited, the armature is attracted to the iron core, so that the movable contact piece of the armature and the make contact are brought into contact with each other to conduct the first conductive path including both. In the electromagnetic relay, a portion of the spring means between the two action points where the tension urging force of the spring means acts as a second conductive path, and is interposed in series with the first conductive path. An electromagnetic relay characterized by the following.