Electrical distribution unit

Abstract

An electrical distribution unit (1) comprising at least two electrical connection regions, having respectively at least a first and a second fixed electrical contact element that can be electrically connected and disconnected via at least a third movable electrical contact element (6a-6g), pre-stressed in a switching position (A, B) via at least one elastic element (7), and actuated in at least one other switching position (A, B) via an actuator unit (8) having at least one actuator (9) and at least one commutator shaft (10) movable via the actuator, the actuator unit (8) driving a commutator wheel (32) via a drive wheel (30), and the commutator wheel (32)-drive wheel (30) combination constituting a stepper transmission (41). [Fig 3]

Description

Title of the invention: Electrical distribution unit technical field

[0001] The invention relates to an electrical distribution unit. State of the art

[0002] Electrical distribution units for motor vehicles, in particular hybrid or electric motor vehicles, have, in addition to safety units such as voltage and current measurement systems, also switching devices which prevent or allow the flow of electricity through an electrical current circuit of the vehicle.

[0003] As a general rule, these switching devices consist of at least three relays (depending on the embodiment, at least two high-current relays and one pre-charge relay are installed). On a case-by-case basis, other relays may also be installed to connect and disconnect drive units, DC load contacts, battery bank switching, and to perform other functions.

[0004] The relays used consist respectively of a contact and an actuator which are controlled by corresponding terminal stages of a control device and monitored via specific circuits.

[0005] In addition to the high costs, the use of several individual relays and actuators results in increased space requirements and weight. Furthermore, the relays themselves usually have two high-current connections that can only be passively cooled via the connected busbars. This has an adverse effect on the installation space and the weight of the contact technology. The requirements for electrical conductivity and opening / closing speed also necessitate adaptation of the actuators. This has an adverse effect on the overall weight, overall volume, and energy efficiency. Moreover, it results in complex control and monitoring systems for each individual relay in order to detect or prevent malfunctions occurring in each individual relay.The sum of all these disadvantages prompts the search for an improved switching device that is suitable for use in an electrical distribution unit of a battery-electric vehicle.

[0006] The high-current relays used are generally of identical construction and consist respectively of a contact and an actuator which are controlled by corresponding terminal stages of a control device and monitored by through specific circuits. Each of these relays has, in this case, integrated the necessary technology to interrupt the current flow even under load.

[0007] A switching device is known from the unpublished document DE 10 2023 209 219. This device features a camshaft or crankshaft as the central actuation element for actuating the contacts. Depending on the number of switching positions, various switching positions of the actuation shaft are produced. Since this is a spring-loaded unit, it is important that the contacts and shaft remain in the defined switching position. The springs are subject to external environmental influences such as vibrations and acceleration spikes, so a mechatronic actuation concept for the camshaft or crankshaft is necessary to ensure that the switching position of the individual switches remains securely connected or open.

[0008] Due to the requirement for switching under load in given situations, the switch contacts must open or close within a defined time, as otherwise excessive arcing occurs at the contacts. This arcing leads to wear of the components. Summary of the invention

[0009] An object of the invention is to provide an improved electromechanical switching device, in which the switches are connected in a safe and simple manner.

[0010] The objective is achieved by means of an electrical distribution unit comprising at least two electrical connection regions, namely at least a first electrical connection region and at least a second electrical connection region, the first electrical connection region having at least one first fixed electrical contact element and the second electrical connection region having at least one second fixed electrical contact element, the first electrical contact element and the second electrical contact element being able to be electrically connected and disconnected by means of at least one third movable electrical contact element, the third electrical contact element being pre-stressed in a switching position by means of at least one elastic element and being able to be actuated in at least one other switching position by means of an actuator unit,the actuator unit having at least one actuator and at least one mechanical interface with respect to a commutator shaft which can be moved via the actuator and which, depending on the actuated commutator position, leaves the third electrical contact element in the pre-stressed commutator position or moves it into at least one other commutator position against the force, of spring of the elastic element, characterized in that the actuator unit drives a commutator wheel via a drive wheel and in that the commutator-drive wheel combination constitutes a step-by-step transmission.

[0011] The objective is also achieved by means of an electrical distribution unit comprising at least two electrical connection regions, namely at least a first electrical connection region and at least a second electrical connection region, the first electrical connection region having at least one first fixed electrical contact element and the second electrical connection region having at least one second fixed electrical contact element, the first electrical contact element and the second electrical contact element being able to be electrically connected and disconnected by means of at least one third movable electrical contact element, the third electrical contact element being pre-stressed in a switching position by means of at least one elastic element and being able to be actuated in at least one other switching position by means of an actuator unit,the actuator unit having at least one actuator and at least one commutator shaft which can be moved via the actuator and which, depending on the actuated commutator position, leaves the third electrical contact element in the pre-stressed commutator position or moves it into at least one other commutator position against the spring force of the elastic element, characterized in that the commutator shaft respectively operates a commutator wheel and in that the commutator wheel-commutator shaft combination constitutes a step-by-step transmission.

[0012] The solution ensures that the commutator shaft rotates through a defined angular value of the actuation path. This rotation can be variably performed in steps of 30°, 60°, or 90°, based on the geometry and the requirements for the commutator positions. The solution further ensures that the camshaft is held in a defined position. Additional holding force by means of an electric actuator is not required.

[0013] Preferably, the switching wheel has an outer contour having concave wing surfaces between the grooves, in particular between grooves and wing tips.

[0014] Preferably, the distribution of grooves along equal or unequal degree spacings extends radially in the direction of the center of rotation of the commutator wheel.

[0015] Preferably, the drive wheel has a pin intended to engage in the grooves of the commutator wheel and a convex contour intended to support the concave wing surfaces of the commutator wheel.

[0016] Preferably, the cams of the commutator shaft press the third electrical contact element against the spring force of the elastic element.

[0017] Preferably, the cam or the commutator shaft is pre-stressed by means of a compression spring against the third contact element 6a-6g.

[0018] The compression spring is for example a leaf spring or a helical spring.

[0019] The objective is also achieved through a method of actuation of a unit of electrical distribution, wherein, by rotation of the drive wheel, the pin engages in one of the grooves of the commutator wheel and rotates it, wherein, in the event of further rotation, the pin slips out of the groove and the commutator wheel rotates again to a starting position in which the commutator wheel is supported by a convex surface on the drive wheel. Description of figures

[0020] Other features and advantages of the invention will become apparent from the following description, which is purely illustrative and not limiting and should be read in conjunction with the accompanying drawings, on which: - Figure [1] illustrates a state-of-the-art electrical distribution unit, - Figure [Fig. 2] illustrates a cross-section along line AA, - Figure 3 illustrates one implementation of the switching according to the invention, - Fig. 4 illustrates the switching sequence of the embodiment.

[0021] An electrical distribution unit, which is described by way of example in [Fig.1], is at the basis of the invention.

[0022] An alternative embodiment of the electromechanical switching device 1 is shown in [Fig. 1]. The electromechanical switching device 1 has a first electrical connection region 2 and a second electrical connection region 3. The first electrical connection region 2 and the second electrical connection region 3 are arranged side by side on a cooling unit 13 in a first construction plane X.

[0023] The first electrical connection region 2 has several first fixed electrical contact elements 4a-4g, namely seven first electrical contact elements 4a-4g.

[0024] The second electrical connection region 3 has several second fixed electrical contact elements 5a-5g, namely seven second electrical contact elements 5a-5g.

[0025] A first respective electrical contact element 4a-4g of the first electrical connection region 2 can be connected to a second respective electrical contact element 5a-5g of the second connection region 3, and disconnected from it, via a third respective contact element 6a-6g.

[0026] The respective third contact element 6a-6g can be controlled for this purpose in two switching positions A, B by means of an actuator unit 8, namely in a first switching position A and in a second switching position B.

[0027] In the embodiment according to figures 1 and 2, the first switching position A corresponds to a switching position in which a first respective electrical contact element 4a-4g is electrically connected to a second respective electrical contact element 5a-5g via a third respective electrical contact element 6a-6g.

[0028] In the embodiment according to [Fig.1], the second switching position B corresponds to a switching position in which a first respective electrical contact element 4a-4g is electrically disconnected from the second respective electrical contact element 5a-5g, as shown in [Fig.2].

[0029] The actuator unit 8 comprises an actuator 9 which is realized in the form of an electric motor 9a, and a commutator shaft 10 comprising several commutator elements 11, namely seven commutator elements 11. The commutator shaft 10 is realized in the form of a camshaft 10a and the individual commutator elements 11 of the commutator shaft 10 are formed by cams fixed to the camshaft 10a.

[0030] A switching element 11 of the switching shaft 10 is in this respect functionally associated respectively with a third electrical contact element 6a-6g respective.

[0031] The switching shaft 10 is disposed in a region between the first electrical connection region 2 and the second electrical connection region 3 also in the first construction plane X and extends axially between the two electrical connection regions 2, 3.

[0032] The direction indication "axially" means a direction along the central longitudinal axis 12 of the commutator shaft 10 or parallel to this axis.

[0033] The first electrical connection region 2 and the second electrical connection region 3 are partially arranged in a housing 14, such that the first electrical contact elements 4a-4g and the second elements of electrical contacts 5a-5g are arranged inside the housing 14 and connection points 20 of the respective electrical connection area 2, 3 are made outside the housing 14.

[0034] Respective connection points 20 are electrically connected respectively to at least one first or second electrical contact element 4a-4g, 5a-5g respective of the connection region 2, 2', 3, 3' respective.

[0035] The commutator shaft 10 is substantially mounted in the housing 14 and is made so that it can be driven in rotation by means of the electric motor 9a disposed outside the housing 14.

[0036] The third electrical contact elements 6a-6g are arranged on an internal wall 15 of the housing 14 in a second construction plane Y by means of two elastic elements 7 respectively, namely compression springs 7a in the present case, and in such a way that respectively a third electrical contact element 6a-6g is arranged substantially parallel to the two electrical connection regions 2, 3 using its respective electrical contact elements 4a-4g, 5a-5g.

[0037] The second construction plane Y corresponds to a spatial plane parallel to the first construction plane X.

[0038] The third electrical contact elements 6a-6g and the camshaft 10a are arranged such that respectively a cam of the camshaft 10a can control respectively a third electrical contact element 6a-6g in the two switching positions A, B.

[0039] In the first switching position A, a first respective electrical contact element 4a-4g is electrically connected to a second respective electrical contact element 5a-5g via a third respective electrical contact element 6a-6g. This is achieved in the embodiment shown in Figures 1 and 2, by the fact that the third respective contact element 6a-6g is pre-stressed, via springs 7a, radially in the direction of the first respective electrical contact element 4a-4g associated with it and the second respective electrical contact element 5a-5g associated with it, i.e. in a closed position.

[0040] In the second switching position B, see [Fig.2], a first respective electrical contact element 4a-4g is electrically disconnected from the second respective electrical contact element 5a-5g, by the fact that the associated third respective contact element 6a-6g is, via the cam of the camshaft 10a associated with it, moved radially against the spring force of the springs 7a towards the inner wall 15 of the housing 14 and thus an open position is caused.

[0041] In the first switching position A, a first respective electrical contact element 4a-4g is electrically connected to a second respective electrical contact element 5a-5g via a third respective contact element 6a-6g.

[0042] In the embodiment according to the invention of Figures 3 and 4, the actuator unit 8 comprises an actuator 9 which can be in the form of a DC motor, a brushless DC motor, a stepper motor or other rotating machines.

[0043] In addition, the actuator unit 8 includes an interposed transmission which can be in the form of a cylindrical gear, a planetary transmission or other reduction gears and provides a reduction for the electric motor of the actuator 9. A stepper transmission is mounted downstream of the transmission, stepper transmission by means of which a type of intermittent displacement device is represented.

[0044] Fig. 3 illustrates a front side view of the electrical distribution unit, with only parts of the actuator unit 8 shown.

[0045] The actuator unit 8 includes a drive wheel 30, which is connected to the actuator 9 via the interposed transmission. The drive wheel 30 is mounted in the front region of the housing 14 and rotates about the axis 40. The commutator shaft 10 is also mounted in the front region of the housing 14.

[0046] [Fig.4] illustrates the operation, but in a view of the rear side of the drive wheel 30 of [Fig.3].

[0047] The drive wheel 30 has a pin 31 and an edge 35 that extends radially inward with respect to the axis of rotation. The edge 35 forms a convex circular segment, which allows it to mesh with a commutator wheel 32. Thus, the defined commutator position is fixed by means of the geometry. No additional external retaining force is required.

[0048] The commutator wheel 32, shaped like a Maltese cross, has grooves 33 distributed regularly around its periphery. The commutator wheel 32 rests on the commutator shaft 10.

[0049] In the embodiment shown in [Fig.4], four grooves 33 extend in a manner offset by 90 degrees from each other in the direction of the axis of rotation of the commutator wheel 32, i.e. in the direction of the commutator shaft 10. For the latching of the commutator position, the commutator wheel 32 has on its periphery, between the grooves 33, circular segment-type recesses which form the concave wing surfaces 36.

[0050] The drive wheel 30 forms, together with the switching wheel 32, the step-by-step transmission 46.

[0051] The switching operation is shown in [Fig.4]. From the top, the switching wheel 32 is in a position in which one of the concave wing surfaces rests against the ring 35 of the switching wheel 32 and the pin 31 is not yet received in one of the grooves 33.

[0052] When the drive wheel 30 rotates, the raised pin 31 engages in one of the grooves 33 on the commutator wheel 32.

[0053] While the drive wheel 30 continues to rotate, the pin 31 moves along one of the grooves 33, such that the commutator wheel 32 rotates by a fixed angle, usually in whole divisions of 360°. This can be seen from above in [Fig. 4], second image. Thus, the commutator wheel 32 rotates in the opposite direction to the drive wheel 30. Due to the connection of the commutator wheel 32 to the commutator shaft 10, this results in rotation of the commutator shaft and consequently of the cams on the commutator shaft. The movement of the cams causes the contact elements 6a-6g to open and close.

[0054] In the third image from the top of [Fig.4], we can see the continuation of the rotation, by the fact that the commutator wheel 32 continues to rotate and tends to occupy again the position in which the concave wing surface 36 is opposite the edge 35 of the drive wheel 30.

[0055] As soon as the pin 31 reaches the end of the groove 33, it disengages from the commutator wheel 32, resulting in a pause in movement or intermittent movement. The edge 35 of the drive wheel, shaped like a convex circular segment, engages with the commutator wheel, as shown in the lower figure in [Fig. 4]. Thus, the defined commutator position is fixed by means of the geometry. No additional external retaining force is required. Furthermore, the dynamic behavior of the position control can be improved. Overloading the actuator no longer has any effect on the angular position of the commutator shaft, as this is already fixed by the engaged circular segment.

[0056] The movement sequence remains the same for other switching positions, with the pin 31 engaging in other grooves 33 on the switching wheel respectively. In this case as well, it does not matter whether the drive wheel is rotated clockwise or counterclockwise. On the contrary, this allows for distinct and reproducible opening and closing of the contacts of the electromechanical switching device.

Claims

Demands

1. Electrical distribution unit (1) comprising at least two electrical connection regions, namely at least a first electrical connection region (2, 2') and at least a second electrical connection region (3, 3'), the first electrical connection region (2, 2') having at least one first fixed electrical contact element (4a-4g) and the second electrical connection region (3, 3') having at least one second fixed electrical contact element (5a-5g), the first electrical contact element (4a-4g) and the second electrical contact element (5a-5g) being electrically connected and disconnected via at least one third movable electrical contact element (6a-6g), the third electrical contact element (6a-6g) being pre-stressed in a switching position (A,B) pre-stressed by means of at least one elastic element (7) and capable of being actuated in at least one other switching position (A, B) by means of an actuator unit (8), the actuator unit (8) having at least one actuator (9) and at least one mechanical interface with respect to a commutator shaft (10) which can be moved by means of the actuator and which, depending on the actuated switching position (A, B), leaves the third electrical contact element (6a-6g) in the pre-stressed switching position (A, B) or moves it to at least one other switching position (A, B) against the spring force of the elastic element (7), characterized in that the actuator unit (8) drives a commutator wheel (32) by means of a drive wheel (30) and in that the commutator wheel (32)-drive wheel (30) combination constitutes a transmission step-by-step (46).

2. Electrical distribution unit (1) according to claim 1, characterized in that the switching wheel (32) has an outer contour comprising concave wing surfaces (36) between grooves (33).

3. Electrical distribution unit (1) according to claim 2, characterized in that the distribution of grooves along equal degree spacings extends radially in the direction of the center of rotation of the commutator wheel (32).

4. Electrical distribution unit (1) according to any one of claims 2 or 3, characterized in that the drive wheel (30) has a pin (31) intended to engage in the grooves of the commutator wheel and a convex contour (35) intended to support the concave wing surfaces (36) of the commutator wheel.

5. Electrical distribution unit (1) according to any one of the preceding claims, characterized in that cams of the switching shaft (10) press the third electrical contact element (6a-6g) against the spring force of the elastic element (7).

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