WO2021023330A1

WO2021023330A1 - Electric-motor drive unit for motor-vehicle applications

Info

Publication number: WO2021023330A1
Application number: PCT/DE2020/100550
Authority: WO
Inventors: Claus Töpfer; Fatih ÖZDOGAN; Tim SONNENSCHEIN
Original assignee: Kiekert Ag
Priority date: 2019-08-02
Filing date: 2020-06-25
Publication date: 2021-02-11
Also published as: DE102019120962A1

Abstract

The invention relates to an electric-motor drive unit for motor-vehicle applications, in particular a locking unit for an electric charging device (1, 2, 3, 4) of a motor vehicle. The drive unit comprises a movable adjusting element (1), in particular a locking element (1) which is provided for example, to releasably lock a charging plug (2) in a charging socket (3) of the electric charging device (1, 2, 3, 4). A motorised drive with an electric motor (4) for the preferable linear adjustment of the adjusting element (1) is provided, wherein at least one bearing (6a, 6b) is provided for guiding the adjusting element (1). According to the invention, the bearing (6a, 6b) is arc-shaped in the cross-section with different arcs (R₁, R₂) in the direction of actuation (B) of the actuating element (1).

Description

description

Electromotive drive unit for automotive engineering

Applications

The invention relates to an electromotive drive unit for motor vehicle technical applications, in particular a locking unit for an electric charging device of a motor vehicle, with a movable adjusting element, in particular locking element, which is provided, for example, to releasably lock a charging plug in a charging socket of the electric charging device, and with a Motor drive with electric motor for the preferably linear adjustment of the adjusting element, at least one bearing being provided for guiding the adjusting element.

Electromotive drive units for automotive applications are known in various forms. Thus, among other things, the generic DE 4225478 A1 concerns a drive device for adjusting a mirror glass carrier pivotably mounted in a mirror housing of a motor vehicle rearview mirror. In addition, such drive units are used on and in connection with motor vehicle fitters. Also for seat adjustments, window lifters, tank flap locks, headlight adjustments, etc., to name just a few examples.

The present invention is primarily concerned with a locking unit for an electric charging device of a motor vehicle. With the aid of the locking unit, the charging plug can be releasably locked with respect to the charging socket of the electric charging device in order to accompany and ensure an electric charging process of an electric or flybridge motor vehicle. In fact, batteries in electric or hybrid vehicles have to be regularly supplied with electrical energy. This is done with recourse to a charging infrastructure, which typically includes charging stations. For the charging process with electrical energy, the charging plug of the charging column is generally coupled to a charging socket on the motor vehicle side and is releasably locked. In principle, it is also possible to proceed in reverse. The charging station is then equipped with a charging socket, whereas the charging plug is on the vehicle side.

In any case, the locking is necessary to avoid health risks, for example, since high voltage is generally used at this point. In addition, the locking ensures that only previously identified users draw the energy made available by the charging station lawfully and that misuse is prevented. For this purpose, an identification of the operator and an authorization check with the aid of an identification signal usually take place before such a loading process, as is basically described in WO 2010/149426 A1.

The adjustment of the adjusting element and in particular the locking element is carried out in the state of technology according to CN 2020695855 U with the help of an electric motor drive. The electric motor drive itself consists of an electric motor and a downstream multi-stage gear. The multi-stage gear works on the locking element via a cam. The locking element is in turn received in an annular bearing and guided through the bearing and is designed like a pin or bolt for this purpose.

In addition, comparable solutions are known in the further and also generic prior art according to DE 10 2011 010 809 A1. A locking device that works with a mechanical bolt is implemented at this point. The mechanical latch can be powered by an electric motor operate. In this way, the mechanical bolt engages in grooves in the charging plug and thus ensures that the plug or charging plug is locked with the aid of the locking device inside the charging socket.

A similar solution is described in DE 10 2009 030 092 A1. In this case too, a plug or charging plug is provided which can be locked in a socket or charging socket. The user can also be identified via the plug or charging plug. In addition, locking means are provided with the help of which the charging plug can be locked in the charging socket of the charging station. An electromotive drive is used to drive the locking means.

In this way, the two positions “unlocked” and “locked” of the locking element can be implemented and specified, at least and in principle. In the "unlocked" position of the locking element, the charging plug can be removed from the charging socket. The "locked" position, on the other hand, ensures that the charging plug is locked and secured in relation to the charging socket. This position is typically only assumed when a previously provided user identification has been successfully completed and payment for the electrical energy drawn is also ensured. The charging process is only started after the locking element has ensured that the charging plug has been locked with respect to the charging socket.

In general, the charging socket on the motor vehicle side is arranged and mounted together with the drive or the electromotive drive unit and in particular the locking unit for the charging device of the motor vehicle on or in a body of the motor vehicle, mostly in a body opening or body recess, which is also closed with an additional flap may be. In this context, the adjusting element or locking element, like a housing accommodating the electromotive drive unit, is mostly off Made of plastic in order to be able to provide additional electrical insulation from the mostly metallic body of the motor vehicle. For this purpose, the adjusting element or locking element and also the housing are mostly produced in the course of a plastic molding process and in particular a plastic injection molding process.

When designing such plastic parts and the associated injection molding tools, various design rules to be observed in practice must be taken into account. In addition to the general endeavors to work with the lowest possible wall thicknesses when designing the housing and to avoid large and flat areas, so-called draft angles are typically used. Such draft angles, as components of injection molding tools, ensure that the frictional forces that inevitably occur during the removal of the aforementioned plastic parts are kept low. In fact, such draft angles are often used for structures inside the housing. For this purpose, the corresponding walls of the molded part are generally beveled slightly, the associated angles mostly being determined empirically.

In order to keep costs low, in the prior art according to CN 2020695855 U and also in practice, the bearing for the actuating element or locking element is also made of plastic. In view of the not inconsiderable coefficients of friction "plastic-plastic" of approx. 0.4 to 0.9 depending on the plastic used (for sliding friction) observed in this context, increased wear is to be expected in the area of such a bearing, if only comes to a punctual abutment of the adjusting element or locking element on the bearing in question. In addition, a punctual abutment for a mostly intended linear guidance of the adjusting element or locking element is disadvantageous and can lead to functional impairments under certain circumstances. The invention aims to provide a remedy here overall. The invention is based on the technical problem of further developing such an electromotive drive unit for motor vehicle applications in such a way that production and wear as well as permanent functionality are optimized.

To solve this technical problem, the invention proposes in a generic electromotive drive unit that the bearing is arcuate in cross section with different arcs or radii in the direction of actuation of the locking element.

Most of the time, the bearing has a circular arc shape in cross section. In addition, the bearing has at least two radii that differ from one another and are different in cross-section and in the direction of actuation of the actuating element or locking element. The two or the at least two radii of the bearing, which is arcuate in cross section, advantageously touch in the contact area with the actuating element.

In this way, first of all, a bearing for the generally linearly displaceable adjusting element and in particular locking element is made available which combines optimal friction conditions, reduced wear and improved guidance of the adjusting element during its completed linear adjustment path. Because at least in the contact area of the two radii with the adjusting element, a demolding tool or demolding tool part used at this point and responsible for the definition of the bearing can be dimensioned and designed as a component of an injection molding tool in such a way that no demolding bevel is required in the contact area in question.

This means first of all that the bearing is made of plastic or is designed as a plastic molded part and in particular a plastic injection molded part. In addition, in this context, the bearing is regularly attached to a housing, also made of plastic, for the electromotive drive unit connected or formed in one piece with this. In a preferred embodiment, the bearing is composed on the one hand of a bearing rib connected to the housing and, on the other hand, a bearing wall on the adjusting element side supported with the aid of the bearing rib, which has the special circular arc-shaped character described in cross section. In addition, the bearing wall is advantageously designed in the direction of the adjusting element in a convex arcuate or convex arcuate shape. In an alternative embodiment, the bearing wall can also be supported on a housing wall instead of on a special bearing rib.

As a result, the adjusting element or locking element rests in the contact area on the circular arc-shaped bearing wall or generally the bearing. In addition, the design is usually made in such a way that the bearing and the housing are formed in one piece, that is to say are produced in a common plastic molding process and, in particular, a plastic injection molding process. That is, both the bearing and the housing are each designed as a plastic injection molded part.

The special inventive design of the bearing or the bearing wall with the two different radii which is convex in the direction of the actuating element and has the two different radii now defines the special contact area according to the invention with the locking element. Because the two different radii of the circular arc-shaped bearing wall touch in the contact area in question with the adjusting element. The design is additionally and advantageously made in such a way that the bearing in question has a smaller radius in the actuation direction and in a plan view of the bearing and at the origin of the movement of the actuating element or on the head side than in the course of the movement. In principle, the reverse can of course also be used.

In this way, a demolding necessary for the definition of the specially designed bearing according to the invention in or on the housing can be Manufacture and design the tool or demolding tool part as part of an injection molding tool in such a way that the relevant demolding tool has no drafting angle in the contact area in question, or the drafting angle 0 ° is observed in the contact area. An inclined position of the wall or the bearing wall on the adjusting element side, which must be maintained during manufacture, is therefore not necessary in the contact area. As a result, the actuating element or locking element rests against the contact area over the entire length of the contact area and practically over its entire linear actuating path, which overall defines a contact line or a contact strip which extends from the head of the bearing wall to the base at the bottom of the housing extends.

Since, in addition, the larger radius is advantageously used at the bottom of the bearing wall compared to the smaller radius at the head of the bearing wall, the bearing wall has - except for the contact area - against the actuation direction of the actuating element via a conical upward direction towards the head of the bearing wall tapering character. Since the demoulding tool required to manufacture the bearing and consequently the bearing wall is moved out of the manufactured shape of the housing after the injection molding process against the actuation direction of the adjusting element, optimized and comparably low frictional forces are observed in the area of the bearing wall, as in the case that the bearing wall would have been beveled overall.

As a result of this, the actuating element or locking element is properly guided in its actuation direction and also against the actuation direction. Because here the adjusting element, which generally completes the linear adjusting path, lies against the bearing in question over the entire contact line or the previously mentioned and defined contact strip. In this context, work is usually carried out with at least two opposing bearings that accommodate and guide the actuating element between them. At the same time, the Friction conditions are optimized so that not only long-term operation can be expected, but also high functional reliability over long time scales. This is where the main advantages can be seen.

In the following the invention is explained in more detail with reference to a drawing showing only one embodiment; show it:

1 shows the electromotive drive unit according to the invention in a schematic plan view,

FIG. 2 shows the object according to FIG. 1 in a side view,

3A shows a detailed view of the object according to FIG. 1,

3B shows a schematic plan view of the object according to FIGS. 3A and

FIG. 3C shows a view X of the object according to FIG. 3A.

In the figures, an electric motor drive unit for motor vehicle applications is shown. Specifically and according to the execution example, it is a locking unit for an electric charging device 1, 2, 3, 4 of a motor vehicle, not shown in detail. The motor vehicle may be designed as an electric or hybrid motor vehicle.

The electric charging device 1, 2, 3, 4 is composed of an actuating element 1 in the form of a locking element 1, a charging plug 2 and finally a charging socket 3. The charging socket 3 is mounted on the motor vehicle side together with the locking unit accommodated in a housing 5, for example in the previously mentioned recess in the motor vehicle body. With the aid of the adjusting element or locking element 1, the charging connector 2 on the column side can be releasably locked in the charging socket 3, as was already described in the introduction. Corresponding adjusting movements of the adjusting element or locking element 1 are effected with the aid of an electric motor 4, which works on the adjusting element or locking element 1 with the interposition of a gear that is not specified in detail and can be seen in particular in FIG. Consequently, the locking element 1, the charging plug 2, the charging socket 3 and the drive 4 for the locking element 1 define the charging device 1, 2, 3, 4.

The locking element 1 is moved downwards in its actuating direction B, shown in particular by an arrow in FIG. 2. A linear travel of the locking element 1 corresponds to this. During this process, the charging plug 2 inserted into the charging socket 3 can be releasably locked with respect to the charging socket 3. In order to unlock the charging plug 2, the locking element 1 must be moved against its actuation direction B upwards in FIG. 2 with the aid of the electric motor 4.

In order to be able to represent and implement the linear adjustment path of the locking element 1 already mentioned and connected to the actuation direction B of the locking element 1, the housing 5 has several bearings 6a, 6b on the inside for guiding the locking element 1. In this way, the motor drive with the electric motor 4 can provide the desired linear adjustment of the locking element 1 in the actuation direction B and against the actuation direction B, as indicated in FIG. 2 by the corresponding arrows.

The housing 5 is a plastic injection molded part. The bearing 6a, 6b is also designed as a plastic injection-molded part. The bearing 6a, 6b and the housing 5 are designed in one piece. In addition, the housing 5 together with the bearing 6a, 6b or the multiple bearings 6a, 6b for the adjusting element or control element 1 is in one go in an injection molding tool (not shown) made of thermoplastic such as polyethylene (PE), polypropylene (PP) or polyamide (PA). Based on Enlarged representations of a bearing in FIGS. 3A to 3C show that the bearing 6a, 6b according to the exemplary embodiment has a bearing rib 6a connected to the housing 5 on the one hand and a bearing wall 6b on the adjusting element or locking element side on the other. With the aid of the bearing rib 6a, the bearing wall 6b, which for the most part extends perpendicularly in cross section, is supported with respect to the bearing rib 6a. In addition, it can be seen from the enlarged representations that the bearing wall 6b supported in this way with the aid of the bearing rib 6a is designed in the direction of the locking element 1 in a convex arcuate shape and in particular a convex arcuate shape.

According to the invention, the bearing 6a, 6b is not only designed in cross-section in the form of an arc and in particular in the form of a circular arc. But the bearing 6a, 6b also has different arcs or radii Ri, R2 in the actuating direction B of the adjusting element or locking element 1. In fact, in the cross section of the bearing 6a, 6b in the actuation direction B, at least two radii Ri, R2 that differ from one another are implemented. Based on the enlarged illustration in FIG. 3B, it can be seen that both radii Ri, R2 touch in a contact area 7 with the locking element 1.

In addition, the design is such that the bearing 6a, 6b has the smaller radius R2 in the actuation direction B at the origin of the movement of the locking element 1 or on the head side of the bearing 6a, 6b. In contrast, the larger radius Ri is realized on the foot side of the bearing 6a, 6b. It can be seen that the convex circular arc shaped bearing wall 6b in the direction of the locking element 1 is equipped in this way with the different radii Ri, R2.

The design is such that a lower area 6bi on the foot side of the bearing 6a, 6b or the convexly curved bearing wall 6b has the larger radius Ri. In contrast, the head-side upper area 6b2 of the bearing 6a, 6b or the bearing wall 6b is equipped with the smaller radius R2. The center points belonging to the respective radii Ri, R2 meet the contact area 7 in their extension. In the contact area 7, the differing radii Ri, R2 or the different areas 6bi, 6b2 of the bearing wall 6b touch each other, namely in cross section and in plan, as can be seen in FIG. 3B recognizes.

In this way, a demolding tool which is necessary in the production of the bearing 6a, 6b in question can be equipped with a non-existent demolding bevel in the contact area 7. As a result, a contact line or a contact strip to the locking element 1 is formed in the contact area 7 in plan view and over the entire length of the bearing wall 6b, which provides for a large contact area between the bearing 6a, 6b and the locking element 1. This is accompanied by reduced friction, reduced wear and a particularly high level of functional reliability when completing the linear travel, as already described in the introduction.

List of reference symbols:

1 locking element / adjusting element

1, 2, 3, 4 electric charger 2 charging plugs

3 charging socket

4 electric motor

5 housing

6a bearing rib

6a, 6b bearings

6b storage wall

6bi lower area

6b2 upper area

7 Contact area

B direction of actuation

Ri larger radius

Ri, R2 radii (arcs) R2 smaller radius

Claims

1. Electromotive drive unit for automotive applications, in particular a locking unit for an electric charging device (1, 2, 3, 4) of a motor vehicle with a movable adjusting element (1), in particular a locking element (1), which is provided, for example, to a charging plug (2 ) to be releasably locked in a charging socket (3) of the electric charging device (1, 2, 3, 4), and with a motor drive with an electric motor (4) for preferably linear adjustment of the actuating element (1), with at least one bearing (6a, 6b) is provided for guiding the adjusting element (1), d ad urchge ke nnzeich that the bearing (6a, 6b) is arcuate in cross section with different arcs (Ri, R2) in the actuating direction (B) of the adjusting element (1).

2. Drive unit according to claim 1, characterized in that the bearing (6a, 6b) is formed in the shape of a circular arc in cross section.

3. Drive unit according to claim 1 or 2, characterized in that the bearing (6a, 6b) in cross section in the actuating direction (B) has at least two radii (Ri, R2) which differ from one another.

4. Drive unit according to claim 3, characterized in that the two radii (Ri, R2) touch in the contact area (7) with the adjusting element (1).

5. Drive unit according to one of claims 1 to 4, characterized in that the bearing (6a, 6b) in the actuating direction (B) has a smaller radius (R2) on the head side than on the foot side (Ri).

6. Drive unit according to one of claims 1 to 5, characterized in that the bearing (6a, 6b) is designed as a bearing rib (6a) connected to a housing (5) with a bearing wall (6b) on the adjusting element.

7. Drive unit according to claim 6, characterized in that the bearing wall (6b) in the direction of the adjusting element (1) is convexly arc-shaped and in particular convexly arc-shaped.

8. Drive unit according to one of claims 1 to 7, characterized in that the bearing (6a, 6b) and the housing (5) are made in one piece.

9. Drive unit according to one of claims 1 to 8, characterized in that the housing (5) is designed as a plastic injection molded part.

10. Drive unit according to one of claims 1 to 9, characterized in that the bearing (6a, 6b) is produced without a draft angle in the contact area (7).