JP2525972Y2 - Electromagnetic relay with fail-safe structure - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is an improvement of a hinge type electromagnetic relay.
When the return spring that returns the armature to the break contact side is no longer applied when the coil is not energized and no load is applied, the armature is securely returned to the break contact side, and the conduction between the contact spring and the make contact is established. The present invention relates to an electromagnetic relay having a fail-safe structure that can shut off an electromagnetic wave.

[Problems to be solved by conventional technology and device]

As is well known, in a hinge type electromagnetic relay, an armature is moved to a make contact side by an electromagnetic force obtained by exciting a coil wound on an iron core, and in a no-load state where the coil is not excited. The armature is configured to return to the break contact side by the tensile force of the return spring.

However, as shown in FIG. 3, the electromagnetic relay has a structure in which the armature hinged to the yoke (yoke) is returned to the break contact side by the pulling force of the return spring. When the spring breaks and does not work, it becomes impossible to return the armature to the break contact side. Therefore, when the coil is excited by turning on the emergency stop button (ON) of an industrial robot or machine tool, it functions normally as a relay. However, the coil is excited by turning off the emergency stop button (OFF). When interrupted, the armature does not return to the break contact, and there is a problem that the contact spring of the armature and the make contact are maintained in a conductive state.

The present invention has been made in view of the above-described disadvantages of the conventional electromagnetic relay, and when the return spring is cut off or does not work, the armature is moved to the break contact side. An object of the present invention is to provide an electromagnetic relay having a fail-safe structure that can be reliably restored.

[Means for solving the problem]

The means adopted by the present invention to solve the above-described technical problem will be described below with reference to the accompanying drawings.

That is, according to the present invention, the armature (4) is moved to the make contact (a) side by the electromagnetic force obtained by exciting the coil (3) wound around the iron core (3a), and the coil (3) The armature (4) is returned to the break contact (b) side by the pulling force of the return spring (5) in a no-load state where the armature is not excited. While the ferromagnetic material (6) is fixed to (4), the ferromagnetic material (6) is weaker than the electromagnetic force of the coil (3).
Is disposed on the break contact side of the case (1), or between the coil (3) and the armature (4) with a force weaker than the electromagnetic force of the coil (7). 4)
The above-mentioned technical problem has been solved by adopting means for arranging a spring means (9) for urging the spring toward the break contact side.

[Action]

In the electromagnetic relay configured as described above, when the return spring (5) does not work, the magnet (7) arranged on the break contact side of the case (1) turns the ferromagnetic of the armature (4). The body (6) is sucked and the armature is returned to the break contact (b) side. On the other hand, a spring means (9) disposed between the coil (3) and the armature (4) is used. (4) is returned to the break contact (b) side.

〔Example〕

Hereinafter, the present invention will be described in more detail based on embodiments shown in the accompanying drawings. FIG. 1 is an explanatory view showing the structure of the first embodiment relay according to the present invention, and FIG. 2 is an explanatory view showing the structure of the second embodiment relay.

In the drawing, reference numeral (1) indicates a relay case, reference numeral (2) indicates a yoke, reference numeral (3) indicates a coil wound around an iron core (3a) via a bobbin (3b), and reference numeral (4) Is an armature hinged to the yoke (2), reference numeral (5) is a return spring connected to the yoke (2) and the armature (4), reference numeral (a) is a make contact, and reference numeral (b) is a break. The contact, symbol (c), is a contact spring fixed and fixed to the armature (4) via an insulating mold (4a), and these are all components of a conventional electromagnetic relay.

The most important feature of the present invention is that, as shown in FIG. 1, a ferromagnetic material (6) such as iron or nickel is fixed on the insulating mold (4a) of the armature (4). The magnet (7) for attracting the body (6) is provided at the break contact (b) side of the case (1). As the magnet (7), a magnet that attracts the ferromagnetic material (6) with a weaker force than the electromagnetic force when the coil (3) is excited is used.

When the return spring (5) is cut off in the relay of the first embodiment having such a configuration, the emergency stop button (8) of an industrial robot or a machine tool is turned off, and the coil (3) is turned off. When the excitation of () is interrupted, the ferromagnetic material (6) of the armature (4) is attracted to the magnet (7).
Therefore, the armature (4) returns to the break contact (b) side, and the conduction state between the contact spring (c) and the make contact (a) is cut off.

In the relay of the second embodiment, a pair of compression coil springs (9) are arranged at positions on the upper flange (3b1) of the bobbin (3b) of the coil (3) facing the armature (4). Therefore, in the relay of the second embodiment, the case (1) is not always necessary. The compression coil spring (9) urges the armature (4) toward the break contact (b) with a force weaker than the electromagnetic force of the coil (3).

Thus, in the relay of the second embodiment, the return spring (5)
If the machine stops working, turn off the emergency stop button (8) of the industrial robot or machine tool (OFF)
When the excitation of the coil (3) is interrupted, the armature (4) returns to the break contact (b) side by the urging force of the compression coil spring (9), and the contact spring (c) and the make contact (a)
Is cut off.

Although the relay of this embodiment is generally configured as described above, the present invention is by no means limited to the above-described embodiment, and various changes can be made in the "claims for registering a utility model". For example, in the relay of the first embodiment, a magnet (7) is disposed in the case (1), and the ferromagnetic material (6) attracted by the magnet (7) is used as an insulating mold (4a) for the armature (4). Although the example in which the ferromagnetic material (6) is fixed to the case (1) and the magnet (7) is fixed to the insulating mold (4a) of the armature (4) is described. Also, the example in which the compression coil spring (9) is arranged on the bobbin (3b) of the coil (3) in the relay of the second embodiment has been described, but the compression coil spring (9) is inserted into the blind hole formed in the iron core (3a). Design changes such as placement naturally belong to the technical scope of the present invention.

[Effect of the invention]

As described above with reference to the embodiments, according to the present invention, the magnet that fixes the ferromagnetic material to the armature and attracts the ferromagnetic material with a weaker force than the electromagnetic force of the coil is provided on the break contact side of the case. Since the spring means is provided between the coil and the armature and biases the armature toward the break contact with a force weaker than the electromagnetic force of the coil, even if the return spring does not operate, the contact is established. The pole can be reliably returned to the break contact side. Therefore, even if the emergency stop button is turned off (OFF) and the excitation of the coil is cut off, as in the case of the well-known electromagnetic relay, the armature remains on the break contact side. The problem of maintaining the conductive state between the contact spring and the make contact without returning to the normal state can be solved.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing the structure of a first embodiment relay according to the present invention, FIG. 2 is an explanatory view showing the structure of a second embodiment relay according to the present invention, and FIG. 3 is the structure of a conventionally known electromagnetic relay. FIG. (1): case, (3): coil, (3a): iron core,
(4): armature, (5): return spring, (6): ferromagnetic, (7): magnet, (9): compression coil spring, (a):
Make contact, (b): break contact.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Akira Oki 1-13-8 Kamikizaki, Urawa-shi, Saitama Nihon Signal Co., Ltd. Yono Office (56) References JP-A-59-158506 (JP, A) JP-A-56-63733 (JP, A)

Claims (2)

(57) [Scope of request for utility model registration] 1. An armature (4) is made into contact with a make contact (a) by an electromagnetic force obtained by exciting a coil (3) wound around an iron core (3a).
(1) with the case (1) for returning the armature (4) to the break contact (b) side by the pulling force of the return spring (5) in a no-load state where the coil (3) is not excited and the coil (3) is not excited. In the relay, the ferromagnetic material (6) is fixed to the armature (4) while the ferromagnetic material (6) is weaker than the electromagnetic force of the coil (3).
A magnet (7) for attracting the magnet is arranged on the break contact side of the case (1) so that the armature (4) returns to the break contact (b) side when the return spring (5) stops working. An electromagnetic relay having a fail-safe structure, characterized by being configured. 2. An armature (4) is made into contact with a make contact (a) by an electromagnetic force obtained by exciting a coil (3) wound around an iron core (3a).
Side, and the armature (4) is returned to the break contact (b) side by the tensile force of the return spring (5) in a no-load state where the coil (3) is not excited. Armature (4) with a weaker force than the electromagnetic force of (3)
Is disposed between the coil (3) and the armature (4) so as to urge the armature (4) toward the break contact, so that the armature (4) is actuated when the return spring (5) stops working. Characterized in that it is configured to return to the break contact (b) side.