ACTUATOR FOR A SIDE DOOR OF A MOTOR VEHICLE

Abstract

An actuator for a side door of a motor vehicle is described. The actuator brings about automatic opening or closing of the side door depending on a signal. The actuator has an electric motor which, depending on an activation, generates a torque which acts on a hinge of the side door via a transmission. Furthermore, it has a device for holding the side door in any open position, which holding device is realized by a function of the electric motor itself which is designed in such a way that, in the currentless state, it has an increased cogging torque which is configured to a value required as a holding torque for holding the door open. In this way, the actuator is distinguished by a simple and inexpensive design.

Claims

1. An actuator for a side door of a motor vehicle, which brings about automatic opening or closing of the side door depending on a signal, comprising: a transmission; an electric motor which is activated by a signal via a control device and which, depending on the signal, generates a torque which acts on a hinge of the side door via the transmission; and a holding device for holding the side door in any open position, the holding device further comprising: a function of the electric motor; wherein during a currentless state of the electric motor, the electric motor has an increased cogging torque which is configured to a value required as a holding torque for holding the door open.

2. The actuator of claim 1, the electric motor further comprising a brushless direct current motor.

3. The actuator of claim 1, wherein the air gap of the electric motor is small.

4. The actuator of claim 1, the electric motor further comprising particularly few grooves and poles.

5. The actuator of claim 1, further comprising a sensor device which specifies specific holding positions of the side door.

6. The actuator of claim 1, wherein the cogging torque of the electric motor is converted via the associated transmission into a holding torque of the door in a desired position.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The invention will be explained in detail below with reference to an exemplary embodiment in conjunction with the drawing, in which:

[0017] FIG. 1 shows an exemplary embodiment of an actuator which is installed in a motor vehicle;

[0018] FIG. 2 shows a highly schematized side view of the actuator;

[0019] FIG. 3 shows a highly schematized top view of the actuator in the closed position of the door;

[0020] FIG. 4 shows a highly schematized top view of the actuator when the door is open;

[0021] FIG. 5 shows a highly schematized section through an electric motor of the actuator; and

[0022] FIG. 6 shows a diagram showing the cogging torque depending on the angle of rotation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0023] The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

[0024] The exemplary embodiment described here involves an actuator for a side door of a motor vehicle, which, depending on a signal, causes the side door to open or close automatically. The actuator has an electric motor which is activated by the signal via a control device and which, depending on the signal, generates a torque which acts on a hinge of the side door via a transmission.

[0025] FIG. 1 shows the actuator 1 installed on the A-pillar of a motor vehicle.

[0026] FIG. 2 shows the actuator 1 in a highly schematized side view. The actuator 1 has an electric motor (not specifically shown) which has a drive shaft 2 which extends upward in the figure and exerts a corresponding torque. The shaft 2 actuates a rotary arm 6 which is mounted on a sliding element 3 and is fastened in a vehicle door. The corresponding mechanism is held via an arm 7 fastened to the Apillar of a motor vehicle, as shown at 4.

[0027] Rotation of the motor shaft 2 therefore causes the rotary arm 6 to pivot and thus opens or closes the vehicle door.

[0028] FIGS. 3 and 4 each show a schematized top view of the actuator 1 with a corresponding actuating mechanism (transmission) for the vehicle door, with FIG. 3 showing the arm 6 with the door closed and FIG. 4 showing the arm 6 with the door open.

[0029] The actuator 1 illustrated and described here furthermore has a device for holding the vehicle side door in any open position, which holding device is realized by a function of the electric motor itself. In this case, the electric motor is designed in such a way that, in the currentless state, it has an increased cogging torque which is configured to a value required as a holding torque for holding the vehicle door open. Here, the cogging torque of the motor is intensified further to the holding torque via the transmission mechanism provided.

[0030] FIG. 5 shows a schematized partial section through an electric motor of the actuator 1. The motor has a rotor 9 and a stator 8 which are separated from one another by an air gap 10. By a correspondingly small configuration of the air gap 10, a cogging torque of the electric motor is generated, which, optionally by being intensified via the associated transmission, becomes a holding torque of the vehicle door, which is sufficient to hold the door open in a specific latching position. The diagram in FIG. 6 shows the cogging torque of the motor depending on the angle of rotation, with a maximum cogging torque of 0.14 Nm being generated here as the holding torque.

[0031] In the present exemplary embodiment, the maximum cogging torque of 0.14 Nm is multiplied by the transmission ratio of the associated transmission of 375, resulting in a door holding torque of 52 Nm. The torque required to open the door or to move the door further from a holding position is 62 Nm. The holding torque of 52 Nm generated by the cogging torque and intensified by the transmission is therefore sufficient to hold the door open.

[0032] The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.