Automatic slide door

Automatic slide door mechanism includes a slide rail secured to a slide door of a vehicle and which is extended in the fore-aft-direction of the vehicle, a slide rail guide holding the slide rail and held by an arm rotatably coupled to a main vehicle body, swing driving actuator for rotating the arm towards inside or outside of the vehicle, and slide driving actuator separate from the swing driving actuator, the slide driving actuator being held by the slide rail guide and adapted for actuating the slide door and the slide rail in the fore-and-aft direction of the vehicle. This assures smooth and prompt operation during movement of the slide door in the fore-and-aft direction of the vehicle and a sufficiently large torque during movement of the slide door towards inside or outside.

FIELD OF THE INVENTION 
This invention relates to a slide type door for a vehicle and, more 
particularly, to an automatic slide door which may be opened and closed by 
driving actuator. 
BACKGROUND 
An example of conventional slide doors of this type is a slide door device 
for a vehicle as described in JP Utility Model Kokoku Publication No. 
4-21703 (1992). FIGS. 14 to 16 show a slide door device disclosed in the 
JP UM Kokoku Publication. Thus, FIGS. 14 to 16 show an opened state of the 
slide door, a closed state of the slide door and a cross-section taken 
along a line 16--16 of FIG. 14, respectively. 
In FIGS. 14 to 16, a mounting bracket 21 is mounted on a main vehicle body. 
Each of the link plates 23A, 23B of a parallel link 2 has its proximal end 
pivotally mounted on the mounting bracket 21 and has its distal end 231, 
232 pivotally supported on a holding member 3. In FIG. 16, the link plate 
23A is provided with a driving motor 26. The torque of the driving motor 
26 is transmitted to a pinion 25 via a gear box 27 and a shaft 251. 
In FIG. 16, a slide rail 1 is made up of a guide rail 12, an extension 14 
and a main member 15, and is secured to a slide door S at the extension 
14. In FIG. 14, a rack 13 having rack teeth 13a is provided within the 
guide rail 12, and has its rear end 131 bent at a larger angle into the 
inside of the main member 19. 
The rack teeth 13a are engaged with a pinion 25. Rotation of the pinion 25 
imparts a driving force to the slide rail 1 being in unison with the rack 
13 and the slide door S, such that the slide door S is linearly movable in 
the fore-and-aft direction (left-and rightward direction in FIG. 14), 
basically along a straight section of the rack 13. 
For closing the slide door S, it is moved forwardly (towards the right in 
FIG. 14). When a curved rear end 131 of the rack 13 reaches the pinion 25, 
forward movement of the slide door S ceases. The curved rear end 131 then 
travels along its curve by operation of a pinion 25, while the link plate 
23A is rotated about a distal end 231 forming the proximal end of the link 
plate 23A, as a result of which the parallel link 2 in its entirety is 
swung towards the inner side of the vehicle, with the slide door S being 
moved towards the inner side in a direction at right angles to a pivotal 
(link) shaft of the main member (as seen in FIG. 14) and closed. FIG. 15 
shows such closed state of the slide door S. 
DISCUSSION OF THE RELATED ART 
According to eager investigation of the inventors of the present invention 
the following problems were found in the related art. 
With the above-described conventional slide door device, a sole driving 
actuator is employed and the driving force of the driving actuator is 
transmitted to a rack via a pinion gear. The slide door is moved towards 
the inside and outside and in the fore-and-aft direction by the movement 
of the rack having one bent end relative to the pinion gear. 
However, when the slide door is moved in the fore-and-aft direction, it 
needs to be moved at some elevated speed in order to shorten the door 
opening and closing time. On the other hand, a larger torque is required 
and hence the pinion gear has to be decelerated in order to cause the 
movement of the slide door towards the inside or outside, thus it is 
difficult for the sole driving actuator to control the movement time and 
the driving force for the slide door in the respective direction. 
That is, if the rotation of the driving motor is set so as to conform to 
the movement of the slide door in the fore-and-aft direction, torque 
shortage is incurred when the slide door is to be moved towards the inner 
side or the outer side. Conversely, if the rotation of the driving motor 
is set so as to conform to the movement of the slide door towards the 
inside or outside, speed of movement in the fore-and-aft direction is 
retarded. If a driving mechanism having a uniform speed of movement is 
employed as the driving actuator, and an electrical control system needs 
to be employed in order to eliminate the deficiency, resulting in the 
complicated control system. 
SUMMARY OF THE DISCLOSURE 
It is therefore an object of the present invention to provide a novel 
automatic slide door of a simplified structure which is capable of 
performing a smooth and prompt operation and developing a sufficiently 
large torque when moving the slide door towards the inside or outside. 
Further objects will become apparent in the entire disclosure and claims. 
For accomplishing the above object, the present invention generally 
provides a driving actuator for moving a slide door towards the inside or 
outside, and another driving actuator, different from the firstly-stated 
driving actuator, for moving the slide door in the fore-and-aft direction. 
In addition, the present invention controls the changeover timing of the 
two driving actuators in order to effect smooth and prompt sliding and 
positive closure, thereby controlling optimum driving timing of the 
respective driving actuators and the required driving power. 
The present invention provides an automatic slide door comprising 
(a) a slide rail secured to a slide door of a vehicle and extended in a 
fore-and-aft direction of the vehicle, 
(b) a slide rail guide holding the slide rail and held by an arm rotatably 
coupled to a main body of the vehicle, 
(c) a swing driving actuator for rotating the arm towards inside or outside 
of the vehicle, and 
(d) a slide driving actuator separate from the swing driving actuator, 
wherein the slide driving actuator is held by the slide rail guide and is 
adapted for actuating the slide door and the slide rail in the 
fore-and-aft direction of the vehicle. (Aspect 1, may be referred to as a 
"basic structure", hereinafter) 
Further, according to the present invention, the swing driving actuator is 
adapted to be operative between a bracket rotatably coupling the arm to 
the vehicle and the arm pivotally supported on the brackets. The swing 
driving actuator causes swinging movement of the arm, the slide rail being 
adapted to be moved only in the fore-and-aft direction with respect to the 
slide rail guide. (Aspect 2) 
The swing driving actuator and the slide driving actuator include a 
relative position detector operated between the slide rail and the slide 
rail guide, and are driven by an output signal of the relative position 
detector. (Aspect 3) 
According to the present invention, there is also provided a control unit 
for simultaneously actuating the swing driving actuator and the slide 
driving actuator for a pre-set time responsive to an output signal of the 
relative position detector. (Aspect 4) 
More specifically, the automatic slide door of the present invention 
comprises 
(a) a slide rail secured to a slide door of a vehicle and extended in a 
fore-and-aft direction of the vehicle, 
(b) a slide rail guide holding the slide rail and held by an arm rotatably 
coupled to a main body of the vehicle, 
(c) a swing driving actuator for rotating the arm towards inside or outside 
of the vehicle, 
(d) a slide driving actuator held by the slide rail guide and adapted for 
actuating the slide door and the slide rail in the fore-and-aft direction 
of the vehicle, 
(e) a relative position detector including a switch for selecting a 
changeover position at which switching is to be made between rotation of 
the arm and the actuation of the slide rail, and a cam mechanism for 
holding an operating state of the switch, and 
(f) a control unit controlling the operation of the swing driving actuator 
and the slide driving actuator responsive to an output detection signal of 
the relative position detector, the control unit causing simultaneous 
operation of the swing driving actuator and the slide driving actuator for 
a pre-set-time on detection of the output detection signal. (Aspect 5) 
The following basic function and operation are carried out by the present 
invention. 
According to the basic structure of the present invention, an optimum 
driving force and an optimum operating time may be independently set in 
connection with the movement in the fore-and-aft direction and rotation 
towards inside or outside of the slide door, whereby a basic structure may 
be achieved in which prompt and smooth movement in the fore-and-aft 
direction and positive closure by the movement under a larger torque in 
the direction towards inside or outside during the final stage of door 
closure may be realized together. 
At the time of changeover from the movement in the fore-and-aft direction 
of the door and the rotation towards inside or outside on the basis of the 
above-described basic structure, the two driving actuators are actuated 
simultaneously (i.e., overlapping each other) for a pre-set time duration, 
in order to effect smooth reliable transition between the operating period 
in the fore-and-aft direction at an elevated operating speed and the 
operating period in the direction towards inside or outside of the vehicle 
at a retarded operating speed. (Aspects 4 and 5) 
According to the basic structure of the present invention, as shown in the 
schematic skeletonic view of FIG. 13, the basic principle for smooth and 
positive opening and closure of the automatic slide door is given by an 
extremely simple structure, so that the constituent elements may be 
selectively combined depending on the intended use on the basis of the 
above principle. 
That is, it suffices if the bracket 1 is such as can pivotally mount arms 
and can be mounted on a vehicle. A swing driving actuator 11A is 
interposed between the arm and the bracket 11. In addition to the screw 
rod and nut type driving actuator, shown herein, a pressure medium 
actuating type swing driving actuator 11A, such as a pneumatic or 
hydraulic driving actuator, or other mechanical swing driving mechanism, 
may also be employed. In any case, the swing driving actuator is 
preferably controllable directly or indirectly by electrical signals. 
Although the arm of the parallel arm type as shown in the Figures is 
preferred, the arm may also be other than linear or parallel, provided 
that the door can be thereby securely retained and held movably towards 
the inside or the outside of the vehicle. 
The slide rail and the slide rail guide are not limited to the shape shown, 
provided that the slide rail and the slide rail guide are slidable 
relative to each other and of retentive force and toughness sufficient to 
hold the door. The same may be said of the rail orientation and the 
direction of engagement between the slide rail and the slide rail guide. 
The following embodiments meet these points and are satisfactory in 
assembling and stability. 
The relative position detector includes slide rail position detection and 
arm angle detection. Although a combination of a cam and the limit switch 
as shown is simplest in structure, position sensors, such as optical, 
photo-electric or electro-magnetic position sensors, may be used alone or 
in combination. So-called proximity switches may also be employed. 
The slide driving actuator of the roll type as shown which is pressure 
contacted to a slide rail surface, is simplest in structure. However, it 
is also possible to employ a slide driving actuator of any known type, 
such as a rack-and-pinion type or an endless belt type (i.e., wire or 
chain type) as a slide driving actuator. 
A safety stopper for the slide driving actuator may also be disposed, which 
is preferred. 
According to the structures of aspects 2 and 3, there may be realized 
embodiments meeting the objects by a simplified structure based upon the 
basic structure, respectively. 
SUMMARY OF THE PREFERRED EMBODIMENTS 
The preferred embodiments will be outlined hereinbelow generally, the 
relative position detector includes a switch for detecting a changeover 
position at which switching is to be made between rotation of said arm and 
the actuator of said slide rail, and includes a cam arrangement for 
holding an operating state of said switch. 
The cam arrangement comprises a (first) lever (or engagement member) which 
is engageable with a cam disposed at a distal end of the arm to latch the 
open state of the door at a predetermined angle, the first lever being 
retained at a predetermined position defining the open state of the door 
by means of a spring force. 
The lever is retained in the predetermined position defining the open state 
of the door by a further (second) lever which is urged by a spring against 
unlatching the latching to the open state of the door. 
The second lever is associated with the switch for detecting a changeover 
position. 
At least one of the first and second levers is unlatched by an actuating 
member disposed on the slide rail so as to bring the arm rotatable 
relative to the slide rail guide. 
The unlatching is made when the slide rail is slid to its end position 
ready for rotating the arm for closing the door. 
Thus the switch serves as a relative position detector, and the switch is 
switched over upon abutment of the actuating member disposed on the slide 
rail. 
The second lever is an L-shaped lever retained swingable about a rotation 
center of the lever, with its first leg (or end) serving to abut with the 
first lever and with its second leg (or end) serving to engage a cam 
portion (surface) of the actuating member disposed on the slide rail so as 
to retain the angular position of the slide rail relative to the slide 
rail guide during the rotation of the arm for closing and opening the 
door. 
The second leg has a pin protruding from the second leg, said pin engaging 
a back-slope of the cam portion of the actuating member so as to retain 
the cam at the engaged position, when the actuating member urges the 
L-shaped lever to swing about its rotation center. The L-shaped lever is 
urged by a spring toward a direction for retaining the first lever to a 
locking position against the cam of the arm. 
The swing driving actuator comprises a screw rod assembly operating between 
the arm and a bracket to be secured to the main body of the vehicle for 
rotatably supporting said arm. 
More preferably, the slide rail driving actuator comprises a motor-driven 
roll driving the slide rail. 
The simultaneous operation of the swing and slide driving actuator is 
controlled by the switch acting on a lever which serves to retain the 
angular position between said arm and the door. 
The switch acts on the second lever which is urged by a spring toward the 
open state of the door, the second lever retaining the first lever which 
is engageable with the cam disposed on the arm. 
The pre-set time of simultaneous operation may be initiated with a delay 
time after the detection of the output signal of the relative position 
detector. 
In summary, the present invention provides the following meritorious 
effects. 
According to the basic structure of the present invention, separate 
independent driving actuators are provided which take charge of (i) 
movement in the fore-and-aft direction and (ii) rotation towards the 
inside or outside of the slide door, whereby an optimum driving force and 
an optimum moving time may be set such that an increased speed and a 
retarded speed may be realized for the movement in the fore-and-aft 
direction and for the movement towards the inside or the outside, 
respectively, with a consequence that premises for time reduction in slide 
door movement are satisfied. (Aspect 1) 
In addition, by providing an overlap period at the time of switching 
between the movement in the fore-and-aft direction and that towards the 
inside or outside of the vehicle, smooth and secured transition of the 
changeover operations is achieved without the necessity of strictly 
setting the changeover position by the changeover position detection 
switch. (Aspects 4 and 5) 
With the construction of the Aspects 2 and 3, the present invention may be 
implemented by a simplified structure on the basis of the basic structure 
of the present invention. The relative position detector can be simpler in 
structure if it is comprised of a limit switch and a cam in combination 
therewith.