Relay

Abstract

Relay, comprising a magnetic armature (5) with a magnetic core (6), wherein a permanent magnet (15) is attached to the magnetic armature (5) for detecting the position of the magnetic armature (5), the magnetic armature (5) has a recess (16) and the permanent magnet (15) is designed as a ring magnet and is at least partially arranged in the recess (16).

Description

[0001] The present invention relates to a relay. A relay is defined as an electromagnetically operated switch powered by an electric current, which has at least two switch positions.

[0002] The relay is used, for example, in circuits with high voltages. The relay can be designed as a gas-filled contactor. For safety reasons, it can be useful to detect the switching position of the relay contacts. This allows, for example, in the case of a stuck contact, appropriate measures to be taken to correct the malfunction.

[0003] Document US 2014 / 0002092A1 describes an electromagnetic switching device in which the switching state of a movable contact is determined using a measuring element that includes a permanent magnet and a reed switch.

[0004] It is an object of the present invention to provide a relay with improved properties.

[0005] According to a first aspect of the present invention, a relay is provided. The relay has a magnetic armature with a magnetic core. A permanent magnet is arranged on the magnetic armature for detecting the position of the magnetic armature.

[0006] The permanent magnet generates a magnetic field that can be detected by a magnetic sensor. The magnetic sensor can detect the position of the permanent magnet and thus the position of the magnetic armature. In particular, the magnetic sensor can detect whether the relay contacts are open.

[0007] In one embodiment, the relay has a housing. The housing can be closed, in particular hermetically sealed. For example, the magnetic armature and the permanent magnet are arranged in the housing. In particular, the contacts of the relay can also be arranged in the housing. The housing can be filled with a gas, in particular a protective gas. The gas is intended to prevent the formation of arcs. Arcs can occur when the contacts open and lead to damage to the contacts. In particular, this can cause the contacts to "stick" together and no longer be able to be separated.

[0008] In one embodiment, the magnetic sensor is located outside the housing. This allows the switching position to be detected through the housing wall without the need for cables to pass through the housing. Furthermore, this enables easy retrofitting of the relay with a magnetic sensor, provided the relay is already equipped with the permanent magnet.

[0009] When the relay is activated, the movement of the magnetic core, and thus the entire magnetic armature, is generated by the flow of current in a coil. This movement is, for example, axial. The change in position of the magnetic armature causes the relay contacts to close. For example, in one position of the magnetic armature, the relay is in a rest state, with the contacts open. In a second position of the magnetic armature, the relay is in an active state, with the contacts closed.

[0010] The relay can have at least one fixed contact. For example, the relay has two fixed contacts. Furthermore, the relay can have at least one movable contact. The movable contact is, for example, formed as part of the magnetic armature. For example, the movable contact is formed in the form of a plate. The movable contact can be located at an axial end of the magnetic armature. The movable contact forms, for example, an end face of the magnetic armature. The magnetic core forms, for example, an opposite axial end of the magnetic armature.

[0011] In one embodiment, the magnetic sensor is a switch that is actuated by the magnetic field. In particular, it can be a magnetic sensor that does not require an additional power supply. For example, the magnetic sensor could be a reed switch or reed sensor. Alternatively, it could also be a Hall sensor.

[0012] The magnetic sensor, for example a reed switch, can be configured as a single-pole switch, a normally closed switch, or a changeover switch. A single-pole switch is open in its resting state and is closed by the application of a magnetic field. A normally closed switch is closed in its resting state and is opened by the application of a magnetic field. A changeover switch has a normally closed contact and a normally open contact, with the normally closed contact being closed in the switch's resting state.

[0013] The application of a magnetic field opens the normally closed contact and closes the normally open contact.

[0014] In one embodiment, the relay incorporates such a magnetic sensor. However, it is also possible to supply the relay with the permanent magnet and retrofit it with a magnetic sensor later.

[0015] In particular, the permanent magnet is attached to the magnetic core. For example, the permanent magnet is arranged at a first axial end of the magnetic armature. In particular, the permanent magnet can be arranged at an end face of the magnetic armature.

[0016] Furthermore, the magnetic armature has a recess. The permanent magnet is at least partially positioned in this recess. The recess is located, for example, on one end face of the magnetic armature.

[0017] In one embodiment, the permanent magnet is symmetrical with respect to a longitudinal axis of the relay. This allows for particularly easy positioning of the magnetic sensor, especially if the permanent magnet is not visible during positioning. For example, the permanent magnet is designed as a disc magnet.

[0018] Furthermore, the permanent magnet has an opening or recess. A component of the relay can be at least partially accommodated in this opening or recess, at least in certain positions of the magnetic armature. The opening or recess also allows for weight reduction, which is particularly advantageous for a moving part of the relay. The permanent magnet is designed as a ring magnet.

[0019] Several aspects of an invention are described in the present disclosure. All properties disclosed with respect to one embodiment are also disclosed with respect to other embodiments, even if the respective property is not explicitly mentioned in the context of another embodiment.

[0020] The following section provides a more detailed explanation of the items described here, using a schematic example.

[0021] It shows: Fig. 1 An embodiment of a relay in sectional view.

[0022] Fig. Figure 1 shows a relay 1, which is used, for example, to switch strong electrical currents and / or high electrical voltages.

[0023] Relay 1 has two fixed contacts 2, 3 and one movable contact 4. The movable contact 4 is designed as a contact plate. Fig.Figure 1 shows relay 1 in a rest state. The movable contact 4 is spaced apart from the fixed contacts 2 and 3, so that contacts 2, 3, and 4 are galvanically isolated from each other. The fixed contacts 2 and 3, together with the movable contact 4, form the relay contacts. The relay contacts can also be configured alternatively. For example, only one of the relay contacts can be fixed.

[0024] Relay 1 has a movable magnetic armature 5. The magnetic armature 5 has a magnetic core 6. The magnetic core 6 is made of a ferromagnetic material. The magnetic armature 5 has a first axial end 7 and an opposite second axial end 8. The magnetic core 6 forms the first axial end 7 of the magnetic armature 5. The movable contact 4 forms the second axial end 8 of the magnetic armature 5.

[0025] The magnetic armature 5 has a shaft 9 that is guided through the magnetic core 6 and is firmly connected to the magnetic core 6. The magnetic core 6 is surrounded by a coil (not shown).

[0026] A current flowing in the coil causes the magnetic core 6, and thus the entire magnetic armature 5, to move axially until the movable contact 4 makes contact with the stationary contacts 2, 3. The magnetic armature 5 thus moves from a first position to a second position. The relay 1 is then in the active state, so that contacts 2, 3, 4 are galvanically connected. In another embodiment, the magnetic armature 5 can also perform a rotary movement. The magnetic armature 5 can, in particular, be designed as a pull-type or hinged armature.

[0027] When the current flow in the coil is interrupted, the magnetic armature 5 is moved back to its first position by springs 10a, 10b. The relay 1 is then in its rest state, in which contacts 2, 3, 4 are open.

[0028] When contacts 2, 3, 4 open, an arc can occur which can damage the contact surfaces. This can cause contacts 2, 3, 4 to "stick" together and no longer be able to separate. To prevent the formation of such arcs, contacts 2, 3, 4 are arranged in a hermetically sealed housing 11 filled with a gas 12. The housing 11 completely surrounds the magnetic armature 5 and contacts 2, 3, 4. The component is thus designed as a gas-filled relay 1 or gas-filled contactor.

[0029] For safety reasons, relay 1 has a device for detecting the position of the magnetic armature 5 and thus for detecting the position of the movable contact 4. This is particularly useful when relay 1 is used in circuits with life-threatening voltages. This allows appropriate measures to be taken to correct a malfunction, for example, in the event of a stuck contact.

[0030] In particular, relay 1 has a magnetic sensor 13 that is actuated by a magnetic field. The magnetic sensor 13 is located outside the housing 11. The magnetic sensor 13 is, for example, a switch 14, in particular a reed switch. A reed switch has one or more movable switching reeds that move towards each other or towards a stationary contact under the influence of a magnetic field. The switching reeds and contacts are, for example, arranged in a glass tube. Alternatively, it could also be, for example, a Hall sensor.

[0031] The switch 14 is actuated by a permanent magnet 15. The permanent magnet 15 is located inside the hermetically sealed housing 11. The permanent magnet 15 is rigidly connected to the magnetic armature 5. In particular, the permanent magnet 15 can be directly attached to the magnetic core 6. The permanent magnet 15 is significantly smaller than the magnetic core 6. The permanent magnet 15 is made of a different material than the magnetic core 6. The permanent magnet 15 is arranged on an end face of the magnetic armature 5. In particular, the magnetic armature 5, and especially the magnetic core 6, has a recess 16 in which the permanent magnet 15 is at least partially arranged.

[0032] The permanent magnet 15 is arranged, for example, such that its north-south direction runs in the axial direction of the magnetic armature 5. The permanent magnet 15 can also be arranged such that its north-south direction runs in the radial direction of the magnetic armature 5. The arrangement of the magnetic sensor 13 depends on the arrangement of the permanent magnet 15. The permanent magnet 15 is preferably designed and arranged symmetrically with respect to rotation about a longitudinal axis 18 of the relay 1. This allows for any positioning of the magnetic sensor 13 with respect to the longitudinal axis. In particular, positioning the magnetic sensor 13 is facilitated when the housing 11 is closed, i.e., when the permanent magnet 15 is no longer visible from the outside.

[0033] The permanent magnet 15 has an opening 17. The permanent magnet 15 is designed as a ring magnet. Other components of the relay 1, for example, project into the opening 17. In particular, the relay 1 can have a pump stem 19 which, at least temporarily in the first position of the permanent magnet 15, extends into the opening 17 of the permanent magnet 15. The pump stem 19 serves for gas evacuation and subsequent filling of the relay 1 with the gas 12, in particular a protective gas.

[0034] After filling with the gas 12, the housing 11 is tightly sealed, for example by squeezing the pump stem 19.

[0035] When the magnetic armature 5 moves, the permanent magnet 15 moves along with it. For example, when the magnetic armature 5 moves from its second position to its first position, the switch 14 closes. The magnetic field of the permanent magnet 15 then acts on a movable switching tongue of the switch 14. Thus, the switch 14 is closed when the relay 1 is in its rest state and contacts 2, 3, and 4 are open. This allows for the detection of "stuck" contacts 2, 3, and 4, as the switch 14 will not close in this case. Alternatively, the switch 14 can also be arranged and configured such that it is open in the first position of the magnetic armature 5.

[0036] Alternatively, the switch 14 can also be configured as a changeover switch. For example, in the rest state of relay 1, a normally open contact of switch 14 is closed. When the magnetic armature 5 moves from its first position to its second position, in which the relay contacts are closed, the normally open contact of switch 14 opens and the normally closed contact of switch 14 closes.

[0037] The permanent magnet 15 and the magnetic sensor 13 or switch 14 are arranged relative to each other, and the permanent magnet 15 is sufficiently strong, that it can activate the magnetic sensor 13 through the wall of the housing 11 in a rest position. Furthermore, the magnetic sensor 13 and the permanent magnet 15 must be arranged such that their function is not impaired by the electromagnetic field of the coil and the magnetic core 6. For example, the magnetic sensor 13 is located on the underside of the housing 11, in particular at least partially below the magnetic armature 5.

[0038] To detect the switching position of the movable contact 4, no cable penetrations through the housing 11 are required. Furthermore, if the magnetic armature 5 is equipped with a permanent magnet 15, a simple retrofit with a magnetic sensor 13, in particular with a magnetically actuated switch 14, is possible.

[0039] The magnetic sensor 13 is, for example, permanently connected to the housing 11. For instance, the magnetic sensor 13 can be glued to the housing 11 or otherwise fixed to it. Alternatively, the magnetic sensor 13 is connected to an additional support that ensures a fixed position of the magnetic sensor 13 relative to the housing 11. Reference symbol list 1 relay 2 first confirmed contact 3 second fixed contact 4 movable contacts 5 magnetic anchors 6 magnetic core 7 first axial end 8 second axial end 9 shaft 10a spring 10b spring 11 cases 12 Gas 13 Magnetic sensor 14 switches 15 permanent magnet 16 In-depth study 17 Opening 18 Longitudinal axis 19 pump handles

Claims

Relay comprising a magnetic armature (5) with a magnetic core (6), wherein a permanent magnet (15) is attached to the magnetic armature (5) for detecting the position of the magnetic armature (5), the magnetic armature (5) has a recess (16) and the permanent magnet (15) is designed as a ring magnet and is at least partially arranged in the recess (16). Relay according to claim 1, comprising a housing (11), wherein the magnetic armature (5) and the permanent magnet (15) are arranged in the housing (11). Relay according to one of the preceding claims, comprising a magnetic sensor (13) for detecting the magnetic field of the permanent magnet (15). Relay according to claim 3, comprising a housing (11) in which the magnetic sensor (13) is arranged outside the housing (11). Relay according to one of the preceding claims, wherein the permanent magnet (15) is attached to the magnetic core (6). Relay according to one of the preceding claims, wherein the permanent magnet (15) is arranged at a first axial end (7) of the magnetic armature (5). Relay according to claim 6, comprising a movable contact (4) forming a second axial end (8) of the magnetic armature (5), wherein the second axial end (8) is opposite the first axial end (7). Relay according to one of the preceding claims, wherein the permanent magnet (15) is symmetrical with respect to a longitudinal axis (18) of the relay (1). Relay according to one of the preceding claims, wherein the permanent magnet (15) is designed as a disc magnet. Relay according to claim 3 or one of claims 4 to 9 with reference to claim 3, wherein the magnetic sensor (13) is designed as a Hall sensor. Relay according to claim 3 or one of claims 4 to 9 with reference back to claim 3, wherein the magnetic sensor (13) is designed as a switch (14). Relay according to claim 11, wherein the switch (14) is designed as a reed switch. Relay according to one of claims 11 or 12, comprising several contacts (2, 3, 4), wherein the switch (14) is closed when the contacts (2, 3, 4) are open, or wherein the switch (14) is open when the contacts (2, 3, 4) are closed. Relay according to one of claims 11 to 13, wherein the magnetic sensor (13) is designed as a changeover switch.

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