Contactor, in particular for disconnecting batteries in electrical wiring systems on board vehicles |
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申请号 | EP12158601.0 | 申请日 | 2012-03-08 | 公开(公告)号 | EP2521155B1 | 公开(公告)日 | 2014-05-14 |
申请人 | MENBER'S S.p.A.; | 发明人 | Forsberg, Per Anders; Crovetti, Claudio; Tinto, Massimiliano; | ||||
摘要 | |||||||
权利要求 | |||||||
说明书全文 | The present invention relates to a contactor, in particular of the type designed for use as battery disconnector in electrical wiring systems on board vehicles. The aforesaid contactors are normally used for connecting selectively a load, i.e., the electrical wiring system on board a vehicle, to a supply source, i.e., the battery of a vehicle. Contactors of this type generally have a casing bearing two or more fixed contacts and a mobile shaft axially bearing a mobile contact that co-operates with the fixed contacts. The shaft is typically coupled to an electromagnetic control device designed to displace the shaft from an operative first position, where the contacts are open, to an operative second position, where the contacts are closed. For example, the document No. For instance, the electromagnetic control device can comprise for this purpose an electric coil. In this way, one of the operative positions of the contactor (position of contacts open or of contacts closed) is an unstable configuration that is maintained, against the thrust of the elastic means, by keeping the electric coil energized, which produces an electromagnetic force of return on the shaft bearing the mobile contacts. To prevent this problem, the document No. For reasons of safety, frequently coupled to the contactor is a mechanical mechanism for manual switching of the electrical connection between the battery and the load. For example, a switch connected in series to the contactor can be used for this purpose. Document The inventors have found that said mechanical interruption of the electrical connection between the battery and the load can cause various problems. For example, when the contactor is in the position of contacts closed and supply of the vehicle is activated, a high current can pass through the contactor and the switch. In these conditions, when the electrical connection is interrupted manually, electric arcs that can damage the contacts of the switch can be set up and/or interfere with operation of the electrical wiring system. For example, in the presence of an inductive active load, said electric arcs can be set up when the user is performing the interruption slowly. Instead, in the presence of a capacitive load, the electric arcs can be set up on account of bouncing effects, for example, when the user is modifying the grip of the actuator that operates the manual interruption. The object of the invention is to overcome the drawbacks outlined above. According to the invention, said object is achieved thanks to a contactor having the characteristics recalled in the ensuing claims. The claims form an integral part of the technical teaching provided herein in relation to the invention. In various embodiments, the contactor comprises a stationary casing bearing at least two fixed contacts. Said contacts are electrically closed by means of at least one mobile contact co-operating with the fixed contacts. For example, an electromagnetic control device coupled to the mobile contact can be used for selectively displacing the mobile contact into an operative first position, where the mobile contact and the fixed contacts are connected electrically, or into an operative second position, where the mobile contact and the fixed contacts are disconnected. According to the invention, the contactor also comprises mechanical means designed to interrupt the electrical connection between the fixed contacts, and a sensor configured for detecting an actuation of the mechanical means before these effectively interrupt the electrical connection between the fixed contacts. In various embodiments, a control device is used, such as for example a microcontroller, which controls the electromagnetic control device in such a way that the mobile contact is displaced into the open position, when the mechanical means are operated. In various embodiments, the mechanical means are set within the casing and are operated via an actuator set outside the casing. For example, the actuator can be a handle that activates a descender for transmitting a movement of translation on the mobile contact. The invention will now be described, purely by way of non-limiting example, with reference to the annexed drawings, wherein:
In the ensuing description, various specific details are illustrated aimed at providing an in-depth understanding of the embodiments. The embodiments may be obtained without one or more of the specific details, or with other methods, components, materials, etc. In other cases, known structures, materials, or operations are not illustrated or described in detail so that various aspects of the embodiments will not be obscured. The reference to "an embodiment" or "one embodiment" in the framework of the present description is intended to indicate that a particular configuration, structure, or characteristic described in relation to the embodiment is included in at least one embodiment. Hence, phrases such as "in an embodiment" or "in one embodiment" that may be present in different points of this description do not necessarily refer to one and the same embodiment. Moreover, particular conformations, structures, or characteristics can be combined adequately in one or more embodiments. The references used herein are provided merely for convenience and hence do not define the sphere of protection or the scope of the embodiments. With reference to For example, in the embodiment considered, the lid carries four fixed contacts 162a, 162b, 162c and 162d for connection to a battery and to a load. For example, said connections can be obtained via conventional electric cables 30, which can also be fixed to the fixed contacts 162 by means of appropriate fixing means, such as for example locknuts 32, where each nut 32 comprises an internal thread that co-operates with a corresponding thread of the respective contact 162. In particular, in the embodiment considered, the contacts 162a and 162d are connected to the negative terminal and to the positive terminal, respectively, of the battery of the vehicle, whereas the contacts 162b and 162c are connected to the negative terminal and to the positive terminal, respectively, of the load. In this case, to connect the load to the battery of the vehicle the contactor is configured for selectively closing the electrical connection between the contacts 162a and 162b and between the contacts 162c and 162d. For example, in the embodiment considered, the contactor 10, preferably the lid 16, comprises a pushbutton 164 that can govern switching of the contactor 10. For example, said pushbutton could even close only, and hence never open, the contacts of the contactor 10. Moreover, control of the contactor 10 can also be remote. For example, in the embodiment considered, the contactor comprises for this purpose at least one connector 18 for transmitting and/or receiving supply signals and/or control signals and/or command signals. For example, in the embodiment considered, the contactor 10 comprises two connectors 18a and 18b, where each connector comprises seven contacts, such as pins. For instance, in the embodiment considered, the contactor 10 can receive through the connectors 18a and 18b at least one remote-control signal or command signal that indicates the fact that the contactor must open or close the electrical connection between the contacts. In particular, in the embodiment considered, the connectors 18 of the contactor 10 can comprise:
In the embodiment considered, the contactor 10 also comprises an optional rigid protection 20, such as for example a protection plate made of a plastic material, which has a shape configured for protecting the fixed contacts 162 when the protection 20 is fixed to the casing 12. For example, in the embodiment considered, said protection 20 is fixed to the lid 16 of the casing 12 via appropriate fixing means in such a way as to cover the fixed contacts 162. For example, in the embodiment considered, said fixing means are screws 22 that co-operate with corresponding threaded holes 168 in the lid 16. Preferably, the screws 22 are screwed into threaded inserts secured by expansion into the lid 16, because a possible thread made directly in the plastic of the lid could in the long run lose its thread. As mentioned previously, the lid 16 of the contactor 10 comprises a plurality of fixed contacts 162. For example, in the case where the lid 16 is made of a plastic material, it can be injection moulded directly on the fixed contacts 162. Instead, in the embodiment illustrated in As mentioned previously, the contactor 10 is configured for selectively closing, for example in response to a signal received from the pushbutton 164, the electrical connection between the fixed contacts 162, i.e., between the contacts 162a and 162b and between the contacts 162c and 162d. In one embodiment, the contactor 10 comprises for this purpose at least one electromagnetic control device 142 and at least one mobile contact 144, which co-operates with the fixed contacts 162. For example, when the electromagnetic control device 142 is actuated, the mobile contact or contacts 144 are pushed from beneath against the fixed contacts 162 and close the electrical connection between the fixed contacts 162. In particular, in the embodiment considered, two electromagnetic control devices 142a and 142b, and respectively two mobile contacts 144a and 144b, are used, where each mobile contact 144 is coupled to the shaft of the respective electromagnetic control device 142. In the embodiment considered, the electromagnetic control device 142 comprises a stationary casing 1428 and a shaft 1422 axially mobile with respect to the casing 1428; i.e., the shaft 1422 can translate in the direction of its own longitudinal axis, and the movement of the shaft can be controlled by means of the electromagnetic device 142. For example, in the embodiment considered, the shaft 1422 can be actuated via a coil 1424 set within the casing 1428. The coil 1424 can, for example, be a solenoid comprising two electrical contacts 1426. In one embodiment, the electromagnetic control device 142 is of the "electrical latching" or "monostable" type. In this case, the electromagnetic control device 142 comprises inside it an elastic element, such as for example a spring, which tends to push (or pull) the shaft towards an operative first position. Instead, when a current is applied to the coil 1424 of the electromagnetic control device 142, a force is generated that pushes the shaft 1422 in an operative second position that is maintained against the tensile stress of the elastic element. This means that one of the two positions is stable, i.e., is a resting position (without supply), whereas the other (with the device supplied) is a position forced as a result of the electromagnetic field. Instead, in the embodiment considered here, electromagnetic control devices 142 of the "mechanical latching" or "bistable" type are used. Said devices are characterized by two stable positions, i.e., a retention position in which the mobile contact 144 is in the open position and a retention position in which the mobile contact 144 is in the closed position. In particular, said positions are kept stable in a mechanical way thanks to anchorage means, such as for example a cam. Consequently, these electromagnetic control devices consume current only for switching (from on to off, and vice versa) but, once they have reached one or the other position, do not require supply. In the embodiment considered, the mobile contact 144 is not rigidly fixed to the shaft 1422, but the electromagnetic control device 142 comprises an elastic element 150, such as for example a spring, which tends to push (or pull) the mobile contact 142 upwards, i.e., in the direction of the fixed contacts 162. For example, in the embodiment considered, the shaft 1422 comprises on its upper side a stop ring 148, and the spring 150 tends to push the mobile contact 144 against said stop ring 148. Consequently, the spring 150 is always in a state of compression, even when the mobile contact 144 is in the closed position. In said position, the mobile contact 144 will encounter the obstacle of the fixed contacts 1622, and the spring 150 will guarantee a sufficient pressure of the former on the latter so as to ensure adequate closing of the contact and hence passage of current. In one embodiment, the contactor 10 also comprises an electrical circuit, mounted, for example, on a printed circuit 146. For example, In the embodiment considered, the circuit 146 comprises a driver 1462 for driving the electromagnetic control devices 142a and 142b, contacts 1464 for the connectors 18a and 18b, and a processing circuit, such as for example a microcontroller 1466 configured for controlling operation of the driver 1462 and communication through the connectors 18a and 18b. According to the invention, the contactor 10 also comprises mechanical means for manual switching of the electrical connection between the fixed contacts 162 of the contactor 10. In the embodiment considered, the contactor 10 comprises an actuator that can be operated by a user, such as for example a handle 24, where the actuator 24 operates a mechanism within the contactor 10 for interrupting the electrical connection between the contacts mechanically. In the embodiment considered, said mechanism intervenes directly on the connection between the fixed contacts 162 and the mobile contacts 144. For example, in the embodiment considered, the mechanism is configured for pushing the mobile contacts 144 downwards, or in general away from the fixed contacts 162, when a user turns the handle 24 from an operative first position to an operative second position. In the embodiment considered, the mechanism comprises for this purpose mechanical means that convert the rotational movement of the handle 24 into a movement of translation along the axis of rotation of the handle 24, i.e., in a direction that is parallel to the axes 1422 of the electromagnetic control devices 142. For example, in the embodiment considered, the mechanical conversion means comprise an actuator 242, a shaft with cam 244, and elastic means, such as for example a spring 246, configured for pressing the shaft with cam 244 against the actuator 242. The shaft 244 is thus axially mobile and is pushed by the spring 246 against the actuator 242. With reference to In the embodiment considered, the actuator 242 comprises, on its upper side, a cut 2424, which co-operates with a corresponding portion of the handle 24 in such a way as to receive the motion of rotation of the handle 24. In the embodiment considered, the actuator 242 comprises on its under side at least one projection 2422, which co-operates with the cam 2442 of the shaft 244. Consequently, when the handle 24 is turned, the actuator 242 is also turned, and the projections 2422 co-operate with the cam 2442 to push the shaft 244 axially downwards against the force of the spring 246. In the embodiment considered, the entire mechanism, i.e., the actuator 242, the shaft with cam 244, and the spring 246, is inserted into a substantially cylindrical hollow portion 166 of the lid 16 and then closed from beneath via a plate 248 comprising an opening in such a way that only the portion 2444 of the shaft 244 projects from the under side of the plate 248 and the plate provides a rest for the spring 246. For example, in the embodiment considered, the plate 248 is fixed to the lid 16 via screws 250. In the embodiment considered, the cylindrical portion 166 of the lid 16 comprises on its upper side an opening 1662, into which a portion of the handle 24 for operating the actuator 242 can be inserted. In one embodiment, further means are provided for transmitting the axial movement of the shaft 242 to the mobile contacts 144. For example, in the embodiment considered, a lamella 252 is used, fixed to the portion 2444 of the shaft 244. For example, the lamella 252 can comprise an opening 2522, in which the portion 2444 of the shaft 244 is inserted, and then the lamella 252 is clamped to the portion 2444 by means of appropriate fixing means, such as for example a nut 254, which co-operates with a corresponding external thread of the portion 2444. In this case, it may also be envisaged that the portion 2444 of the shaft 244 has a cross section configured so as to guarantee that the coupling between the lamella 254 and the shaft 244 is blocked with respect to movements of rotation. With reference to As mentioned previously, each shaft 244 of the electromagnetic devices 142 can translate in the direction of its own longitudinal axis, and the movement of the shaft 1422 can be controlled via actuation of the respective electromagnetic device 142. In one embodiment, each shaped portion 2524 is configured for pushing the shaft 1422 of the respective mobile contact 144 downwards. However, as mentioned previously, the electromagnetic control devices 142 can also comprise anchorage means that define two stable retention positions. In this case, the shaft 1422 cannot be pushed manually downwards, because it is always in a stable position. To prevent this problem, each shaped portion 2524 can have a slot or opening that allows passage of the shaft 1422 of the respective electromagnetic control device 142 in such a way that the movement of the shaft 244 is transmitted directly onto the mobile contacts 144, which are then pushed downwards against the force of the springs 150. The inventors have found that a manual interruption of the electrical connection between the contacts can cause various problems. For example, when the contacts are closed and supply of the vehicle is activated, a high current can pass through the contacts. In these conditions, when the electrical connection is interrupted manually, electric arcs can be set up that can damage the contacts and/or the electrical wiring system on board the vehicle. In one embodiment, to prevent this problem, a sensor 1468 is provided that detects an activation of the manual interruption before this interrupts the electrical connection mechanically. For example, in one embodiment, the mechanism of manual interruption comprises an operative first position, where the contactor is ready, i.e., where the electrical connection between the fixed contacts 162 can be closed by means of the electromagnetic control devices 142, and an operative second position, where the mechanism interrupts the electrical connection between the fixed contacts 162. In this case, the sensor detects the fact that the actuator or another component of the mechanism has been displaced into a position intermediate between the operative first and second positions. In one embodiment, the signal received by the sensor 1468 is used by a control unit, for example the microcontroller 1466, for controlling the electromagnetic device or devices 142 in such a way that the shaft 1422 of the respective electromagnetic control device is displaced into the position in which the respective mobile contact 144 is open, i.e., the fixed contacts 162 are disconnected via the electromagnetic control devices 142, and the manual switching mechanism ensures only the mechanical interruption of the electrical connection. Preferably, the microcontroller 1466 is also configured, after driving the electromagnetic control devices 142 in such a way that the respective mobile contact 144 is pushed into the open position, for activating the electromagnetic control devices 142 in such a way as to prevent any possible interference with the manual switching mechanism. For example, the microcontroller 1466 can de-activate or inhibit activation of the electromagnetic control device 142 once the mobile contact has reached the open position. For example, said de-activation of the electromagnetic control devices 142 can be made for a predetermined time interval or for the entire duration of activation of manual interruption, possibly being based also on a filtered signal to prevent bouncing effects. Consequently, the manual switching mechanism, in particular the lamella 252, has two functions:
For example, in the embodiment considered, the sensor 1468 is an optical sensor, such as for example a sensor comprising an infrared transmitter and an infrared receiver. However, also other types of sensors can be used, such as for example magnetic or contact sensors. In the embodiment considered, the sensor 1468 is electrically coupled to the driver 1462 of the electromagnetic control devices 142. For example, the sensor 1468 can be connected to the microcontroller 1466 via an interface circuit of the sensor 1470, and the microcontroller 1466 can be configured for controlling operation of the electromagnetic control devices 142 in response to the signal detected by the sensor 1468. In one embodiment, the sensor 1468, and possibly also the interface circuit 1470, are mounted directly on one and the same printed circuit 146. In the embodiment considered, the microcontroller 1466 hence receives at input the signal detected by the sensor 1468 and supplies at output a signal that instructs the driver 1462 in such a way that the shaft 1422 of each electromagnetic control device 142 is displaced from the closed position to the open position, i.e., the mobile contacts 144a and 144b are disconnected from the fixed contacts 162a to 162d. As described previously, this switching can include a brief actuation of the coils 1424 for displacing the shaft 1422 from one stable retention position into the other stable retention position. In general, the sensor 1468 is configured for detecting activation of manual interruption before this interrupts the electrical connection mechanically. For example, in the embodiment considered, the sensor 1468 is pre-arranged for detecting a movement of translation of the shaft 244 or of the lamella 252. In the embodiment considered, the lamella 252 comprises for this purpose a projection or a prolonged portion 2526 that co-operates with the sensor 1468. In particular, when the handle is in an operative first position, the prolonged portion 2526 does not interfere with the radiation generated by the transmitter of the sensor 1468; i.e., the receiver of the optical sensor 1468 receives the radiation generated by the transmitter of the sensor 1468. Instead, when the handle is in an operative second position, a part of the prolonged portion 2526 is inserted between the transmitter and the receiver of the optical sensor 1468; i.e., the receiver of the optical sensor 1468 receives a lower amount of radiation. In the embodiment considered, the prolonged portion 2526 of the lamella 2526 comprises an opening 2528 set in such a way that the receiver of the optical sensor 1468 receives the radiation generated by the transmitter of the sensor 1468 when the handle is activated. For example, when the handle is in the position in which the contactor 10 is ready for being activated (see In the embodiment considered, the microcontroller detects this event and generates the respective control signals for opening the mobile contacts 144a and 144b by means of the electromagnetic control devices 142a and 142b. Consequently, the electrical connection is interrupted before the shaped portions 2524 come into contact with the mobile contacts 144. Completion of rotation of the handle 24 hence serves only to bring the handle into a stable position, where the shaped portions 2524 keep the mobile contacts 144 in the open position. In any case, even a failure of the sensor 1468 does not create any danger for the user because in this case the mechanical mechanism of interruption intervenes effectively as described previously and displaces the mobile contacts 144 downwards, i.e., opens the connection between the mobile contacts 144 and the fixed contacts 162. In general, the sensor described previously can be applied to any manual switch, even if it is a switch separate from the contactor 10. However, the switching mechanism described herein presents the advantage that the switch for manual disconnection and the electromagnetic control device use the same contacts; i.e., additional contacts are not necessary to provide a switch dedicated exclusively to manual interruption. |