ACTUATOR FOR A SIDE DOOR OF A MOTOR VEHICLE WITH HOLDING FUNCTION

Abstract

An actuator for a side door of a motor vehicle is described, which brings about automatic opening or closing of the side door depending on a signal and has a device for holding the side door in any open position. The holding device is realized by a function of the electric motor itself, according to which function the control device initiates a short-circuit function of the motor phases when the motor is activated, which causes a high current flow and thus a high torque for holding the side door open. By short-circuiting the motor phases, no additional components are required, since this is a special activation function of the motor.

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 the signal via a control device and which, depending on said 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 an open position, the holding device further comprising: a function of the electric motor; wherein according to the function, the control device initiates a short-circuit function of the electric motor phases when the electric motor is activated, which causes a high current flow and thus a high torque, holding the side door open.

2. The actuator of claim 1, the electric motor further comprising a three-phase motor.

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

4. The actuator of claim 1, wherein the electric motor has a minimized cogging torque.

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

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The invention will be explained in detail below with reference to an exemplary embodiment in conjunction with the drawing, in which:

[0020] FIG. 1 shows an exemplary embodiment of an actuator which is installed in a motor vehicle;

[0021] FIG. 2 shows a highly schematized side view of the actuator;

[0022] FIG. 3 shows a highly schematized top view of the actuator in the closed position of the door;

[0023] FIG. 4 shows a highly schematized top view of the actuator when the door is open; and

[0024] FIG. 5 shows a diagram showing the increase in torque when the motor is short-circuited.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] 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.

[0026] 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.

[0027] FIG. 1 shows the actuator 1 installed on the A-pillar of a motor vehicle.

[0028] 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 A-pillar of a motor vehicle, as shown at 4.

[0029] Rotation of the motor shaft 2 therefore causes the rotary arm 6 to pivot and thus opens or closes the vehicle door.

[0030] 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.

[0031] The actuator 1 shown and described here also has a device for holding the vehicle side door in any open position, which is realized by a function of the electric motor itself. In this case, the electric motor together with the control device is configured in such a way that the door holding function is realized by short-circuiting the motor phases via the control device (activation electronics). The motor controller therefore has a short-circuit function. Such a short circuit is deliberately brought about, as a result of which the motor holds the door in the desired position with a high torque. The short circuit induces a current in the motor phases, the current generating the corresponding torque of the motor, which is used here, optionally increased via a transmission, as a holding torque.

[0032] FIG. 5 shows a diagram of the increase in torque when the motor is short-circuited, with the corresponding short-circuit torque and the corresponding short-circuit current being shown. It is seen that the short-circuiting of motor phases results in a significant increase in motor torque, which ensures the corresponding holding function of the door.

[0033] By skillful configuration of the short-circuit torque, the holding function of the door is thus fulfilled.

[0034] 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.