FR2750811A1 - Power supply connection terminal for windscreen wiper motor - Google Patents

Abstract

The connection terminal (100) includes a conducting component (10) and two insulating components (120,130). The conducting element is obtained from a folded thin metal band with a central elongated arm (119). A conductor extremity is soldered to the extremity of the arm. The opposite extremity of the conducting component is shaped as a female connector which receives a male connector attached to a thermal protection module (21). The insulating components are made of plastic and mounted on the central conducting component.

Description

 The present invention relates generally to geared motors for driving the wiper arms of a motor vehicle or the like.

 Conventionally, such a gear motor comprises a metal base housing in a housing a reducing gear train, and comprising a flange for fixing a cover housing the electric motor.

 Such a gear motor, powered by the DC voltage of the vehicle's on-board network, includes a ground terminal which is generally provided directly on this metal base, the whole of which is therefore grounded.

 This known arrangement has certain drawbacks.

 First of all, the fact that the entire base is grounded imposes a unique polarity for the supply of the electric motor.

 This is disadvantageous in that, in certain cases, it may be desirable to connect the terminal normally dedicated to ground to the supply voltage, while the other supply terminal, constituted by a connection piece which conventionally passes through the base being surrounded by an insulating material, will be connected to ground. This is desirable in particular when it is desired to reverse the direction of rotation of the motor to bring the wiper arms to the rest position (called "parking") or even for reasons of compatibility with the electrical wiring practiced in certain countries, in particular in Japan.

 Then, the fact that the ground terminal is in electrical, and therefore thermal, contact with the base, which constitutes a relatively large metallic mass, poses problems when connecting to the ground terminal of a flexible ground conductor by welding. .

 In fact, the heat losses in the base impose significant power on the welding equipment, and failing this, it is frequent that the welding of the ground conductor is therefore imperfectly carried out, due to a temperature welding too low.

 The present invention aims to overcome these two drawbacks.

 To this end, it offers a geared motor for driving at least one wiper arm, in particular of a motor vehicle, comprising a metal base housing components of a reducer and capable of receiving an envelope of an electric motor, said metal base receiving a support for at least a first brush supplied by a positive voltage supplied by at least one electrical supply terminal and at least one second brush connected to ground by another electrical supply terminal, each electrical supply terminal being constituted by a metal part projecting outside the base, characterized in that each metal part passes through the base while being surrounded by an insulator.

Preferred, but not limiting, aspects of the geared motor according to the invention are the following
- The metal part constituting said other electrical supply terminal is part of a conductive element in one piece extending between the outside of the base and a connection part with the motor supply circuit.

 - Said conductive element carries a first insulating part extending at the level of the crossing of the base and a second insulating part extending adjacent to the connection part.

 - Said first and second insulating parts are produced by overmolding on said conductive element.

 - Said connection part is a pin or clamp for connecting a terminal of a motor thermal protection component.

 - An intermediate part of said conductive element extends in a non-insulated way along a component carrying plate of the engine, and said first and second insulating parts comprise regions forming spacers to hold said intermediate part away from said component carrying plate.

 the insulator situated at the level of the crossing of said base comprises a barrel in which said metal part is embedded, said barrel extending outside by a cradle above which a free end part of said part is supported metallic.

 - Said end part of the metal part has a "V" profile.

 According to a second aspect, the invention provides a method of mounting a power supply terminal in a through opening of a metal base of a geared motor for driving at least one wiper arm, in particular of a motor vehicle, said base housing reducer components and being capable of receiving an engine casing, characterized in that said supply terminal can be electrically isolated from said base or else in electrical contact with the base, and in that, according to the type of terminal, the said through opening is widened or not by breaking fragile areas surrounding it.

Other aspects, aims and advantages of the present invention will appear better on reading the following detailed description of a preferred embodiment thereof, given by way of example and made with reference to the appended drawing, in which
Figure 1 is a perspective view of a connection piece according to the invention
FIG. 2 is an elevation view of the rear of a motor-reducer base comprising said connection piece, and
Figure 3 is a perspective view of the gear motor base comprising said connection piece.

 Referring to the drawing, there is shown a base 10 of a gear motor intended for driving one or more wiper arms of a motor vehicle.

 Conventionally in itself, this base, made of a metal alloy such as an aluminum alloy, comprises a part 12 in the form of a bowl defining a housing 11 for a train of reduction gears (not shown), a part 14 for receiving the components (brushes, brush holder, connectors, thermal protection components, etc.) of an electric motor, surrounded by a flange 15 for fixing a motor cover (not shown), and a part connecting 13 between these two parts, crossed by a cylindrical bore (not visible) for the passage of the motor output shaft.

 Figure 2 shows the component holder plate 20 housed in part 14 of the base. In known manner, this plate 20 carries three brushes 27, 28, 29, for supplying the motor, namely two brushes 27, 28 for positive supply (two-speed motor) and a brush 29 for earth.

 The two brushes 27, 28 are respectively connected to two connection elements 24, 25 which pass through the base through an oblong opening, being surrounded by an insulator 26.

 I1 is provided a connection piece, generally designated by the reference 100, which is intended to provide the electrical connection between a first connection terminal, in this case a soldering terminal, intended to receive the end of a flexible conductor motor supply (not shown), and a second connection terminal, in this case a female connection element for plugging, intended to be connected to the motor supply circuit, and more particularly to one of the two male terminals of a motor thermal protection component, conventional in itself, the other terminal of which is connected to the brush 29.

 This connection piece 100 is shown in detail in FIG. 1.

 It comprises a conductive element 110 preferably produced by folding a thin strip of metal alloy, and two insulating elements 120, 130.

 The element 110 comprises an elongated central branch 119. At its upper end in FIG. 1, the central part undergoes a bend at approximately 900 to form a part 118 whose free end zone, as will be seen below, constitutes a terminal for welding power wire.

 In addition, during the shaping of the conductive element 110, this part 118 adopts a profile in the general shape of a flattened "V", opening upwards, with two wings 118a, 118b. At the free end of the branch 118 is also provided, in its axis, a short projecting tab 118c, for purposes explained below.

 At its opposite end, the central branch 119 joins an annular part 119a from which extends, obliquely to the branch 119, another branch 119b.

 This branch 119b, bent in its plane at an intermediate level, is extended by a branch 112 folded at right angles, a branch 113 folded at 1800 below (in the figure) of branch 112, and a branch 114 folded at 1800 below and at a distance from the branch 113, with a rounded transition part slightly projecting downwards.

 The branch 114 ends with a beak 116 curved downwards.

 The branch 114 is also bordered by two wings 115 folded upwards and laterally delimiting the space between the branches 113 and 114.

 The parts 112 to 116 of the element 110 thus constitute a female connector in which a male connection terminal in the form of a blade of a thermal protection component, designated by the reference 21 in FIG. 2, will be able to be inserted.

 On the metal element 110 are overmolded two plastic bodies.

 A first of these bodies 120 is located at the level of the annular part 119a. It comprises an annular central part 122 in which said annular part 119a is embedded and in which a through opening 121 is coaxial with the opening formed centrally in the annular part 119a of the element 110.

 From the central part 122 extends a projecting part 123 in which is embedded an initial section of the branch 119, and another projecting part 124 in which is embedded an initial section of the branch 119b.

 At the periphery of the part 122 are also formed three wedging lugs 125, substantially evenly distributed, which adopt a generally L-shaped profile projecting in the same direction as the female connector 112-116 and that the branch 118.

 The other body produced by overmolding, generally designated by the reference 130, extends in the region of the upper end of the branch 119 and of the branch 118. It has a main part 131 in the shape of a barrel whose axis is located substantially along the bottom of the branch 118, and which is extended by a truncated portion 132 at the upper surface of which the free end portion of said branch 118 is clear. It will be observed here that the projecting tab 118c provided at the free end of the branch 118 improves the mechanical cohesion between said free part of the branch 118 and said truncated part 132 of the molded body.

 At its rear end, the body 130 has an enlargement 133 of substantially semi-circular section.

Finally, axial ribs 134 are formed, approximately equally distributed, at the periphery of the barrel-shaped part 131.

 The connecting piece 100 is put in place on the inside of the base 10 equipped with the component-holding plate, by introducing the truncated part 132 and a front part of the barrel 131 into a circular housing provided in the base, and also engaging time the female connector 112-116 on the associated male pin of component 21.

 Previously, the opening formed in the base was widened to the appropriate dimension by breaking a veil occupying part of said opening using an appropriate tool.

 During this movement the grooves 134 deform elastically and / or plastically to anchor the barrel in its opening while the lugs 125 come to hang around a damper 23 making it possible to elastically support the component-carrying plate 20 in the part 14 of the base. A fixing screw 22 is then inserted into the opening 121 of the part 100 to immobilize said part 100 on the part 14 of the base.

 In addition, the part 133 of the body 130 and the part 122 of the body 120 constitute end-of-travel stops during the mounting movement, in particular in order to prevent the intermediate, bare part 119 of the part 100 from coming into contact. contact with conductive parts of the component holder plate 20.

 Thus, by simple and economical means, a ground terminal is isolated from the base which is easy to set up and fix.

 Once the assembly has been carried out, the free end region of the branch 118 projects outside the base, being electrically isolated from the latter by the parts 131 and 132 of the body. The bowl shape defined by the wings 118a, 118b also facilitates the connection of the gearmotor to a flexible conductor of the electric harness of the vehicle by welding.

 When the gearmotor must be provided with an ordinary earth terminal, that is to say in electrical contact with the base 10, this terminal can simply be added in the opening of the base, initially provided with its veil of in one piece, so as to be in contact with the base.

 Of course, the present invention is in no way limited to the embodiment described and shown, but a person skilled in the art will know how to make any variant or modification in accordance with his spirit.

 In particular, the connection elements 112-116 on the one hand, and 118 on the other hand, provided at the two ends of the connection piece 100, can take any other form, to make the connections by welding or by simple contact. Thus, for example, the branch 118 can be replaced by a male or female terminal for a corresponding connector of the vehicle harness.

Claims (9)

 1. Geared motor for driving at least one wiper arm, in particular of a motor vehicle, comprising a metal base (10) housing components of a reducer and capable of receiving an envelope of a electric motor, said metal base receiving a support (20) for at least one first brush (27, 28) supplied by a positive voltage supplied by at least one electrical supply terminal (24, 25) and at least one second brush ( 29) connected to ground by another electrical supply terminal (118), each electrical supply terminal being constituted by a metal piece (24, 25, 118) projecting outside the base, characterized in that each metal part crosses the base while being surrounded by an insulator (26, 131, 132).  2. Geared motor according to claim 1, characterized in that the metal part (118) constituting said other electrical supply terminal is part of a conductive element in one piece (110) extending between the exterior of the base and a connection part (112116) with the motor supply circuit.  3. Gear motor according to claim 2, characterized in that said conductive element carries a first insulating part (130) extending at the level of the crossing of the base and a second insulating part (120) extending adjacent to the connection part (112116).  4. Gear motor according to claim 3, characterized in that said first and second insulating parts (130, 120) are produced by overmolding on said conductive element (110).  5. Gear motor according to one of claims 2 to 4, characterized in that said connection part (112116) is a pin or clamp for connecting a terminal of a component (21) of thermal protection of the motor.  6. Geared motor according to one of claims 2 to 5, characterized in that an intermediate part (119) of said conductive element (110) extends in a non-isolated manner along a component-carrying plate (20 ) of the motor, and in that said first and second insulating parts comprise regions forming spacers (133, 122) for holding said intermediate part away from said component-carrying plate.  7. Gear motor according to one of claims 1 to 6, characterized in that the insulator (130) located at the crossing of said base comprises a barrel (131) in which is embedded said metal part, said barrel is extending outside by a cradle (132) above which rests a free end portion of said metal part (118).  8. Gear motor according to claim 7, characterized in that said end portion of the metal part (118) has a "V" profile.  9. Method for mounting a power supply terminal in a through opening of a metal base of a geared motor for driving at least one wiper arm, in particular of a motor vehicle, said base housing components of reducer and being able to receive a motor casing, characterized in that said supply terminal (118) can be electrically isolated from said base or else in electrical contact with the base, and in that, depending on the type of terminal, or extending said through opening or not by breaking fragile areas surrounding it.