Vehicle door opening device

A door is open and held by engaging a latch with a striker of a vehicle body. The door has a release actuator connected to the latch. The vehicle body includes a power drive and a control module. An operating unit instructs the control module to close the door. The control module instructs the release actuator to disengage the latch from the striker. After the control module instructs the power drive to start closing of the door, releasing of the release actuator is stopped by the control module at a door position determined by actual voltage of a power source.

BACKGROUND OF THE INVENTION

The present invention relates to a vehicle door opening device for moving a door to close from a fully-open position.

In a vehicle door opening device in JP 3,931,572 B2, when a sliding door in a vehicle body is closed from a fully-open position, a release actuator is driven with a switch to allow a fully-open latch for holding the sliding door in the fully-open position to be released, and a power drive is driven to allow the sliding door to close from the fully-open position. When a certain time passes after the release actuator is driven, the release actuator is instructed to stop and the fully-open latch is controlled to return to the rest before releasing.

However, in the vehicle door opening device in the patent, to ensure a series of actions of the fully-open latch from release starting of the release actuator to the rest, a time for controlling the release actuator is set to be longer, so that a returning sound comes out in a little time after the sliding door starts to close when the release actuator and fully-open latch return to the rest from the release state. Thus, after an initial sound comes out when the sliding door starts, a returning sound comes out of the release actuator and the fully-open latch, so that the sound is noticeable thereby decreasing its quality. The initial sound stands for a sound when a ricketying between the power drive and the sliding door and loosening of a cable for transmitting power of the power drive to the sliding door are absorbed. If a certain time is set to be shorter in order that time for generating initially actuating sound and returning sound is shortened, the release actuator is driven and stopped although the fully-open latch does not move to a position where the latch completely leaves the striker when actual voltage of a power source is low and when closing velocity of the sliding door is slow, so that the fully-open latch is likely to engage with the striker of the vehicle body and to make it impossible for the sliding door to close.

SUMMARY OF THE INVENTION

In view of the disadvantages as above, it is an object of the invention to provide a vehicle door opening device ensuring a series of actions of a fully-open latch when a door is closed from a fully-open position, a returning sound of a release actuator and a fully-open latch being not noticeable.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

A sliding door1for minivans or station wagons is supported by upper, middle and lower guide rails3,4,5fixed on a vehicle body2and can move manually or by a power drive6from a fully-closed position inFIG. 2in which an entrance7at the side of the vehicle body2is closed, to a fully-open position inFIG. 1in which the door1is moved rearward along the side and is in the back of the vehicle body2and vice versa.

A fully-closed latch8is provided at the rear end within the sliding door1and engages with a striker (not shown) fixed to the vehicle body2allowing the sliding door1to be held in the fully-closed position.

At the lower end of the front part of the sliding door1, there is a lower roller (not shown) that can move along the lower guide rail5. The lower latch has a fully-open latch9that engages with a striker9aat the rear end of the lower guide rail to allow the sliding door1to be held in the fully open position.

The fully-open latch9is connected to an exterior handle10on the sliding door1outside the vehicle and an interior handle (not shown) and a fully-open releasing actuator11within the sliding door1; and disengaged from the striker manually with the exterior handle10or interior handle or with the fully-open release actuator11to enable the sliding door1to be closed.

The fully-open release actuator11includes a power drive source comprising a motor or a solenoid. The power drive source is driven with a switch13such as a wireless switch or a switch by a driver's seat or the vehicle body2. So a release lever (not shown) of the fully-open latch9is moved from a rest position to a release position to allow the fully-open latch9to disengage from the striker. While an electric current flows through the fully-open release actuator11by the power drive source, the fully-open latch9is held in a release state in which it cannot engage with the striker.

The power drive6within the side of the vehicle body2comprises a reversible PSD (power sliding door) motor61; a rotary drum62that can be rotated by the PSD motor61via a reduction gear (not shown); an electromagnetic clutch63that connects and disconnects a power transmission path between the PSD motor61and the rotary drum62; and a power-transmission cable64which is wound on and out of the rotary drum62, extends along the middle guide rail4and is coupled to the rear end of the sliding door1.

When the electromagnetic clutch63disconnects the power transmission path, the sliding door1can be opened manually by a small force without subjecting to resistance for reversing the PSD motor61. While the PSD motor61does not work, the power transmission path is connected by the electromagnetic clutch, and a braking force is exerted to the sliding door1which opens and closes, by a resistant force for reversing the PSD motor61.

On the rotary drum62that rotates together with opening and closing of the sliding door1, there is provided a rotation sensor65for detecting a rotation angle of the rotary drum62at high resolution. The rotation sensor65comprises a rotary encoder for generating a pulse signal corresponding to the rotation angle of the rotary drum62(corresponding to a travel of the sliding door1) and a turning direction (corresponding to a traveling direction of the sliding door1).

A control module12in the vehicle body2controls drive and stop of the power drive6and the fully-open release actuator11.

InFIG. 3, the control module12comprises a CPU121, drive circuits122,123,124, a pulse detecting circuit125, a voltage detecting circuit126and an SW input circuit127, and is electrically connected to the fully-open release actuator11via the actuator release drive circuit122, to the PSD motor61via the PSD motor drive circuit123, to the electromagnetic clutch63via the clutch drive circuit124and to the rotation sensor65via the pulse detecting circuit125. The voltage detecting circuit126detects an actual voltage of the power source14having DC12V as rated voltage.

The CPU121comprises a door-position detecting circuit for detecting the present position of the sliding door1based on a signal output from the pulse detecting circuit125for converting a pulse signal from the rotation sensor65, and a door velocity measuring circuit. In the CPU121, as shown by a broken line A inFIG. 4, a target velocity is formerly set and stored corresponding to the traveling direction and position of the sliding door1. Furthermore, depending on the traveling direction and position of the sliding door1, a value is calculated on the basis of a voltage coefficient etc. determined by the target velocity and actual voltage of the power source, and stored. A solid line B inFIG. 4is the calculated maximum value corresponding to the velocity calculated when the actual voltage value of the power source14is the maximum such as 16V. A two-dot-dash line C is the calculated minimum value corresponding to the velocity when the actual voltage value of the power source14is the minimum such as 11 V.

A release-stop door position for stopping the fully-open release actuator11is determined by a position where a value calculated based on the target velocity and actual voltage of the power source14reaches formerly determined judgment threshold value. For example, when the actual voltage of the power source14is the maximum voltage, the release-stop door position is a position D, and when the actual voltage of the power source14is the minimum voltage, the release-stop door position is a position E away from the position D in a closing direction. The area between the positions D and E is formerly set as release stop area for stopping the fully-open release actuator11.

For example, when the actual voltage of the power source14is 16 V, the door closing velocity is greater than that of 11 V, so that the door traveling distance from the calculated value to the threshold value gets shorter. As actual voltage of the power source14increases, a release-stop door position for stopping the fully-open release actuator gets closer to the fully-open position in the release stop area. Thus, when the actual voltage of the power source14is high and when the sliding door closes faster, a returning sound when the fully-open release actuator11and the fully-open latch9returns from the release state to the rest comes out just after the sliding door1starts closing. The sound gets less noticeable. Even if the sliding door1is instructed to stop just after the sliding door1starts to close, the fully-open latch9does not engage with the striker again because the sliding door1closes faster, ensuring a series of actions in which the fully-open latch9returns from the release state to the rest.

During predetermined initial term after the sliding door1starts to close from the fully-open position, the closing of the sliding door1is not stable and it is very difficult to detect the present position of the sliding door1exactly because the path between the power drive6and the sliding door gets rickety and the cable64loosens. Accordingly, in this embodiment, in order to detect the release-stop door position exactly, the releasing stop area is set beyond the unstable area corresponding to the initial period. However, the present invention is not limited thereto. For example, by ignoring the unstable area, it is possible to set the release stop area to a position closer to the fully-open position.

Then, the closing of the sliding door1will be described with respect to the flowcharts inFIGS. 5 and 6. When the sliding door1is held in the fully-open position, the fully-open latch9engages with the striker and the fully-open position of the sliding door1is detected with the door-position detection circuit. In the step S1, when the switch13is actuated to close the door, the control module12instructs connecting of the electromagnetic clutch63of the power drive6according to a closing signal from the switch13. With the electromagnetic clutch63, an operating force transmission path between the PSD motor61and the rotary drum62in the power drive6is connected, thereby exerting a driving force to the sliding door1. Furthermore, the control module12formerly determines the release-stop door position based on the present actual voltage of the power source14.

In the step S3, since the electromagnetic clutch63instructs connecting, a timer of the control module12instructs time t1such as 100 msec, and in the step S4, the control module12instructs the fully-open release actuator11of the releasing. Thus, the fully-open latch9is disengaged from the striker with the fully-open release actuator11, enabling the sliding door1to close.

After the control module12instructs the fully-open release actuator11to be driven for releasing, a predetermined time t2passes and in the step S5, the PSD motor of the power drive6is instructed to be driven for closing the door1. Thus, the power drive6starts closing the door1based on the instructions for closing, making the sliding door1to close from the fully-open position.

The door-position detecting circuit counts a pulse signal tapped off from the rotation sensor65which rotates with the rotary drum62, so that the direction of motion and the present position of the sliding door1are detected.

When it is detected that the sliding door1is moved to the release stop area, the control module12compares whether or not the present position of the sliding door1is in the release stop area determined by the actual voltage of the power source14. If the present position of the sliding door1is in the release-stop door position, it is judged that there is a stop request in the fully-open release actuator, so that the fully-open release actuator11is instructed to stop the release in the step S7. Thus, with the stop of the release in the fully-open release actuator11, the fully-open latch9returns to the rest from the release state. In the step S8, the sliding door1is moved to the fully-open position by the power drive6.

In the step S6, if it is not detected that the sliding door1is in the release-stop door position, it proceeds to the step S9. If a predetermined time t3such as 2.6 sec passes in the step S9after the electromagnetic clutch63is instructed of connection, it proceeds to the step S10in which the fully-open release actuator11is instructed of releasing. Thus, even if the sliding door1does not move to the release-stop door position within the predetermined time t3of starting of the power drive6, release of the fully-open release actuator11is stopped to allow the fully-open latch9to return to the rest.

The foregoing merely relates to an embodiment of the invention. Various changes and modifications may be made by those skilled in the art without departing from the scope of claims wherein: