Patent Grant
7021950
1. Field of the Invention
The present invention refers to a system for preventing the formation of electric arcs in connectors interspersed in an electric power distribution network, particularly applicable to a network assembled in an automotive vehicle for feeding power loads, such as a 42V network of a vehicle with two voltage levels (14V and 42V, or dual voltage system) for the purpose of preventing that, when the connector components are fortuitously or accidentally separated, or due to a lack of warning of a handler, an electric arc between contact points is generated which causes destruction or early deterioration of said contacts, or of the connector itself, an ill-timed interruption of the feed to certain loads of the network, or a fire situation with more or less severe damage, especially during the disconnection of the two electroinsulating parts or supports, components of a connector, bearing the electroconductive contact terminals.
The invention is also especially interesting for electric vehicles in which a set of batteries is used to provide power to an electric motor intended for driving the vehicle, and in which the current levels are in the range of 400 A at 400 V for DC, and 40 A at 220 V for AC, which current and voltage values require the incorporation of a series of safety measures for minimizing the risk of injuries to users, mechanics and safety technicians.
The invention also refers to a method for preventing the formation of electric arcs, as well as to a connector used in said system and method.
2. Description of the Invention
There are numerous documents which tackle the drawback of electric arc formation, both upon connecting as well as, especially, upon disconnecting the two component parts of a connector incorporated in a load feed network, at a voltage level susceptible to generating said electric arcs.
Patents EP-A-697751, EP-A-673085 and U.S. Pat. No. 6,146,160 disclose connectors with means for an effective mechanical clamping of the connection terminals, typically pins and electroconductive sockets, such that an accidental disconnection thereof cannot occur.
U.S. Pat. Nos. 3,945,699, 4,749,357 and 5,676,571 disclose means associated to the electroconductive pin receiver females, provided for obstructing or minimizing electric arc formation when connecting the two connector components.
U.S. Pat. No. B1-6,225,153 discloses a universal charge port connector for electric vehicles, in which a mechanism is provided for cutting off the current susceptible to generating an arc during disconnection of the male and female terminals of the connector before decoupling of the two component parts of said connector, particularly for preventing the disconnection of the connectors while charging vehicle batteries, which mechanism includes a mechanical lock of said two parts actuated by a lever which is associated to a switch coupled to a power source for the connector assembly, through which switch, and when the lever is actuated by a user, current circulation towards the power load to be fed is disabled before enabling the disconnection of the male-female power terminal or terminals of the connector.
U.S. Pat. No. 5,542,425 discloses an apparatus and method for preventing the deterioration of the contacts in electric equipment, specifically in image acquisition equipment with an ultrasound system in which several probes can be linked to the acquisition system with no risk of an electric arc being able to jump when disconnecting said probes, in which system the connector includes a mechanically actuated element for actuating and deactivating a connection interface between components, including a sensor or detector determining when the connector is going to be disconnected by one of the components, and provides a signal used by one of the components for disabling the electric power feed to the connector and thus preventing electric arc formation upon physically separating the male-female terminals thereof. In the different examples illustrated by this patent, said element is a rotating shaft which the user must act on, and said sensor is an optical sensor, magnetic sensor or simple switch.
In the last two background examples, the feed source disconnection is carried out either by the user (as in U.S. Pat. No. B1-6,225,153) or by means of the addition of a sensor associated to a mechanism likewise actuated by the user (as in U.S. Pat. No. 5,542,425), being necessary to always act on the connector with means for suitably moving its contacts, delay generation being essential for suitable functioning due to the mechanical actuation conditions.
Unlike said background, in the system, method and connector of the present invention, the connector itself includes passive means, such as additional terminals associated to an auxiliary circuit which, due to their configuration or position in the connector, constitute detection means susceptible to generating a signal indicating a situation prior to disconnection of the power terminals of the connector during the decoupling run thereof. From said signal, a disconnection protection device disables the electric power feed to the connector at hand before the physical separation of the power terminals occurs. The connector of the present invention is of a conventional structure, including two socket coupling electroinsulating blocks, generally of multiple contacts.
The system provides for an electronic unit susceptible to individually controlling a plurality of different connectors interspersed at different points of the network for electric current distribution towards the power loads.
The system according to the invention, which is provided for preventing electric arc formation in connectors feeding power loads, is implemented on the basis of connectors interspersed in an electric power supply and distribution network. Each connector is of the type comprising first and second electroinsulating connection supports susceptible to releasable socket coupling, which supports carry at least a pair of power terminals, although they will generally have multiple contacts. The first and second electroinsulating supports can adopt a first definitive coupling position A in which said power terminals are electrically coupled together, forming an electric power through channel towards a corresponding power load. The first and second electroinsulating supports can adopt a second decoupling position C in which the power terminals are physically separated, preventing electric power passing towards the corresponding power load. As previously mentioned, the voltage level of said network is such that when the separation of the power terminals occurs, an electric arc can be generated. According to the invention, said connector comprises at least a pair of additional electroconductive elements for detection functions which, upon exceeding a preset threshold in an intermediate position B corresponding to a point of a decoupling run of the electroinsulating supports between said first position A and said second position C, form or interrupt an auxiliary electric circuit through which an electric warning signal is generated concerning said displacement of the supports towards the decoupling situation corresponding to second position C. At least one disconnection protection device, such as a power relay or FET power transistor, has been provided, connected to said auxiliary circuit, prepared so that, upon receiving said electric warning signal, it immediately cuts off the electric feed towards said channel formed by the power terminals of the connector before these reach said second position C, that is, before physical separation between them occurs, preventing an arc from being generated. In the case that the connector has multiple power contacts, a single pair of additional electroconductive elements serves for generating a single warning signal which triggers cutting off the current to all of the power contacts.
According to a preferred embodiment of the system according to the invention, said disconnection protection device, of which there is at least one, is integrated in an electronic unit adapted for controlling a plurality of connectors interspersed in different load feed lines. Said electronic unit comprises a circuit for identification of the connector or connectors in transition towards decoupling position B, which circuit is connected to a microprocessor controlling said disconnection protection device, which is linked to the electric power feed source and from which corresponding circuits or channels are formed which pass through a distribution connector and from this, they branch off towards the corresponding connectors and their electrically coupled terminals.
According to said embodiment, a line of the corresponding auxiliary circuit of each connector is received through said distribution connector, which lines are fed to said connector identification circuit which, according to which is the connector from which the warning signal is received, acts on the microprocessor sending a preferential interruption which generates a corresponding order to the disconnection protection device to disconnect the feed towards the power channel or lines passing through the corresponding connector.
In order to better understand the invention, it will be described with the aid of several sheets of drawings which show several non-limiting embodiment examples of a possible implementation, according to the following detail:
a, 4b and 4c show sectional schematic views respectively showing positions A, B and C of the electroinsulating supports of the connector of the present invention according to a first embodiment example;
a, 5b and 5c show sectional schematic views respectively showing positions A, B and C of the electroinsulating supports of the connector of the present invention according to a second embodiment example;
a, 6b and 6c show sectional schematic views respectively showing positions A, B and C of the electroinsulating supports of the connector of the present invention according to a third embodiment example; and
a, 7b and 7c show sectional schematic views respectively showing positions A, B and C of the electroinsulating supports of the connector of the present invention according to a fourth embodiment example.
First making reference to
To prevent the formation of said electric arc, the system of the invention includes a pair of additional electroconductive elements 12, 13 in the connector 11 which carry out a detection function of an intermediate position B of the electroinsulating supports 1, 2 located at a point of the decoupling displacement or run thereof between said first and second positions A and C. In said intermediate position B, it is essential that the power terminals 3, 4 are still coupled together. Said intermediate position B detection is carried out by means described below in reference to
Said additional electroconductive elements 12, 13 are associated to an auxiliary electric circuit 14, 15 through which, and when detection of intermediate position B of the electroinsulating supports 1, 2 is carried out, an electric warning signal will be generated by virtue of which said disconnection protection device 7 immediately interrupts the electric feed towards the load 10 through said channel 5, 6 and, accordingly, the terminals 3, 4, before these reach said second position C of mutual physical separation. Therefore, when the decoupling run continues between the electroinsulating supports 1, 2 from intermediate position B, there is no longer current passing through the terminals 3, 4, and an electric arc jump is impossible when the physical separation between both of them is carried out upon having reached the second position C.
In the example of
In the diagram in
The diagram in
With the configuration shown in
It will be seen that in this arrangement, some of the connectors 11a, . . . , 11e are of multiple contacts, besides the additional detection contacts, which are assembled through a series of terminal pairs. However, in the connectors 11c and 11d, only a pair of terminals 3, 4 are power terminals, whereas the other pair of terminals serves to connect detection lines of other connectors, whereas the distribution connector 11e is connected to two feed channels 5, 6 of power loads 10a, 10b through other pairs of power terminals 3, 4, including a single pair of additional detection terminals 12, 13 which protect all the power terminals 3, 4 of said distribution connector 11e from the formation of electric arcs in cooperation with the electronic unit 20. The other pairs of terminals in the distribution connector 11e serve only for the connection of the lines coupled to ground connections 14 in other system connectors. Accordingly, it is possible to provide connectors according to the present invention provided with multiple power contacts and generally with a single detection contact.
The different positions A, B and C which the terminal supports can adopt and the manner in which the pair of additional terminals 12, 13 detects the intermediate position B is described below with reference to
a to 6c show first, second and third embodiment examples of the connector 11 of the present invention. In all of them, the connector 11 always comprises two supports 1, 2 of an electroinsulating material, which carry, in the example shown, two pairs of power terminals 3, 4 connected to respective power feed channel spans 5, 6 and a pair of additional terminals 12, 13 connected respectively to the detection line 15 and ground connection 14. Each one of the terminals is composed of a male pin 3, 12 and a female base 4, 13 susceptible to being coupled together. The elements of the pairs of terminals 3, 4 and 12, 13 are arranged on the mutually facing respective supports 1, 2 such that when said supports 1,2 are coupled, all the terminal pair elements are connected together.
The first and second electroinsulating supports 1, 2 of the connector 11 comprise mechanical closure means of mutual coupling thereof consisting of projections 21 formed on several resilient arms 22 joined to the first support 1 and first and second notches 23a, 23b incorporated on the second support 2. When the first and second supports are coupled together, the projections 21, by virtue of the resilient force of the arms 22, are first housed in the first notches 23a, momentarily retaining the supports 1, 2 in this position, and then in the second notches 23b. Similarly, decoupling is carried out in two steps: a first step in which a displacement occurs until the projections 21 are housed in the second notches 23b, and a second step until the complete separation of the supports 1, 2.
In the first embodiment example shown in
In a first definitive coupling position A shown in
In an intermediate position B shown in
In a second position C shown in
In the second embodiment example shown in
Positions A, B and C of this second embodiment example, shown respectively in
In the third embodiment example shown in
Positions A, B and C of this third embodiment example, shown respectively in
a to 7c show a fourth embodiment example in which the power terminals adopt the shape of two pairs of male pin 3 and female base 4, whereas the detection terminals include an electroconductive part 30 fixed to the first electroinsulating support 1 of the connector 11 and two spaced conducting strips 32a, 32b fixed to the second support 2 of the connector 11 in a position such that said electroconductive part 30, during the coupling and decoupling of the first and second supports 1, 2, overlaps and bridges said strips 32a, 32b. Inside of the second support 2, two branches 31a, 31b of the electric detection circuit connected to the ground connection 14 and the connection channel 15 to the electronic unit 20 are arranged. In this fourth embodiment example, the second support 2 incorporates a single resilient arm 22 with a projection 21, and the first support 1 incorporates said first and second notches 23a and 23b on the corresponding side.
In a first position A shown in
In an intermediate position B shown in
In a second position C shown in
It can be seen that in all the disclosed embodiment examples, detection contacts 12, 13 and 30, 31a, 31b associated to an auxiliary circuit are included in addition to the power terminals 3, 4. The decoupling action of the first and second electroinsulating supports 1, 2 of the connector 11 is preferably carried out in two steps, with the aid of said notch configurations. In a first step, a displacement between the first and second supports 1, 2 occurs until overcoming a threshold in the decoupling run which generates a momentary or permanent disconnection or connection of detection contacts 12, 13; 30, 31a, 31b without there being a disconnection of the power terminals 3, 4. Said momentary or permanent disconnection or connection of the detection contacts 12, 13; 30, 31a, 31b generates a signal used by the control unit to cut off the current to the power terminals 3, 4. In a second decoupling step, the definitive disconnection of the pair of power terminals 3, 4 is produced with no risk of an electric arc being generated, since current no longer passes through them.
The essential features of the invention are detailed in the following claims.
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| Number | Date | Country | |
|---|---|---|---|
| 20040192092 A1 | Sep 2004 | US |
