1. Field of the Invention
The present invention is related to a power sliding mini-van door, and in particular, to a motor which can be used to drive both a power drive assembly and a lock cinching assembly of the door.
2. Background of the Related Art
Conventional systems for automatically opening and closing a sliding door in a vehicle include a power drive assembly for moving the door and a latch assembly for cinching the door so that the door can be moved into a fully locked position. A first motor drives the power drive assembly and a second motor drives the latch assembly. The use of these multiple motors leads to a number of difficulties. For example, the use of the multiple motors increases the cost of the system and further necessitates additional corresponding circuitry to be added to the system, thereby further increasing costs. Moreover, the increase in components as a result of using multiple motors results in an undesirable increase in the weight of the door.
When the door of the vehicle is being opened or closed, it will often encounter an obstacle which will resist or hinder the door""s movement. This obstacle can be, for example, a user of the vehicle. Thus, it is desirable for a system which automatically opens or closes the door to be able to reverse direction upon the detection of the obstacle. Unfortunately, these detection systems can fail, sometimes without previous notification of its defective state being provided to the vehicle""s users. Accordingly, it would be desirable to have at least two systems to detect obstacles of the door""s movement in case one of the systems fails.
In conventional systems, changes in motor speed are a direct function of the effective voltage of an input signal. When the opening or closing of the door is initiated, the rapidly changing input signal causes an in-rush current. This in-rush current is known to demagnetize motor magnets, which reduces horsepower and is detrimental to the life of any motor. Thus, it would be desirable to reduce or eliminate the in-rush current.
It is therefore an object of the present invention to use a single motor to drive both the power drive assembly and a latch assembly of a vehicle door. This will decrease the number of required parts and hence, simplify and lower the cost of manufacture, while reducing the weight of the door.
This object is achieved by providing power sliding door for a motor vehicle that comprises a door structure, a power drive assembly, a latch assembly, and a single motor for operating both the latch assembly and the power drive assembly. The door structure is mounted on a track associated with the motor vehicle, the door structure being movable along the track between opened and closed positions. The power drive assembly is connected with the door and capable of being driven to move the door along the track between the opened and closed positions. The latch assembly is mounted on the door and movable between latched and unlatched positions. The single motor is mounted on the door structure operatively connected with both the power drive assembly and the latch assembly. The motor drives the power drive assembly and thus enables the power drive assembly to move the door along the track between the opened and closed positions. The motor assists movement of the latch assembly to the latched position after the power drive assembly moves the door to the closed position.
It is another object of the present invention to provide two systems for detecting an obstacle to the door""s movement. One of two systems includes at least one Hall effect sensor to measure the speed of the motor. If the detected speed is less than a predetermined threshold, then it is assumed that an obstacle is in the way of the door and hence, the direction of the motor is reversed. The second system of the present invention includes a tape switch mounted on the edge of the door. The tape switch has two electrical strips which will contact each other if the tape switch contacts an obstacle and will provide a signal to reverse the direction of the motor. These two systems operate independently of one another. Therefore, if one of the systems fails, the other would still enable the motor to reverse direction upon detection of an obstacle. Thus, the safety of all users of the vehicle is maintained.
It is another object of the invention to include a controller to provide a signal to the motor which slowly ramps up the effective voltage, and hence the speed of the motor, when the opening or closing of the door is initiated. This will reduce or eliminate the in-rush current caused by a rapid start sequence. Thus, the life and performance of the motor is enhanced.
These and other objects, features and characteristics of the present invention, will be more apparent upon consideration of the detailed description and appended claims with reference to the accompanying drawings.