WO2014043780A1

WO2014043780A1 - Closure panel drive system with third position hold

Info

Publication number: WO2014043780A1
Application number: PCT/CA2012/000870
Authority: WO
Inventors: Dan Cosmin; Borys SHCHOKIN
Original assignee: Magna Closures Inc.
Priority date: 2012-09-20
Filing date: 2012-09-20
Publication date: 2014-03-27

Abstract

In an aspect, a drive system is provided for a closure panel for a vehicle. The drive system is capable of supporting the closure panel in an intermediate position between open and closed positions. The drive system supports the closure panel against a closing force.

Description

CLOSURE PANEL DRIVE SYSTEM WITH THIRD POSITION HOLD

FIELD

[0001] This disclosure relates to a drive system for moving a vehicle closure panel between an open position and a closed position and for holding the closure panel in an intermediate position between the open position and the closed position.

BACKGROUND

[0002] Some vehicles are equipped with a closure panel such as a lift gates, that is driven between an open position and a closed position using an electric drive system. Systems have been proposed to provide such vehicles with the capability of stopping the closure panel in an intermediate position, between the open position and the closed position. Such proposed systems are, in some instances, complex and expensive.

SUMMARY

[0003] In an aspect, a closure panel drive system is provided, for moving a vehicular closure panel between an open position and a closed position. The drive system includes a closure panel actuation motor that is operatively connectable to the closure panel and that is operable to drive the closure panel between the open position and the closed position. The drive system further includes a toothed wheel that is rotatable by the closure panel actuation motor about a toothed wheel axis between a first position corresponding to a closed position of the closure panel and a second position corresponding to an open position of the closure panel, and that is operatively connectable to a vehicular closure panel. The toothed wheel has a plurality of wheel teeth spaced apart circumferentially about the toothed wheel axis by a plurality of valleys. The drive system further includes a toothed wheel that has a locking member tooth, and that is pivotable about a locking member pivot axis for movement along a path between a locking position wherein the locking member tooth is in one of the valleys of the toothed wheel and an unlocking position wherein the locking member tooth is out of the valleys of the toothed wheel. When the locking member is in the unlocking position the toothed wheel has a first resistance to rotation to the first position. When the locking member is in the locking position the toothed wheel has a second resistance to rotation to the first position. The second resistance to rotation to the first position is higher than the first resistance to rotation to the first position. The drive system further includes a locking member actuator that is operatively engageable with the locking member and is selectively operable to drive the locking member between the locking and unlocking positions.

[0004] In another aspect, a closure panel assembly is provided, which includes a closure panel and the drive system described above.

[0005] In yet another aspect, amethod of operating a closure panel drive system on a closure panel for a vehicle is provided, comprising: a) moving the closure panel towards one of a closed position or an open position, wherein a toothed wheel is operatively connected to the closure panel and rotates during movement of the closure panel; and b) moving a locking member to a locking position wherein the locking member is engaged with the toothed wheel to stop the movement of the closure panel at an intermediate position between the open and closed positions.

[0006] In yet another aspect, a drive system is provided for a closure panel for a vehicle. The drive system is capable of supporting the closure panel in an intermediate position between open and closed positions. The drive system supports the closure panel against a closing force, and optionally also supports the closure panel against an opening force.

[0007] Other aspects, including methods of operation, and other embodiments of the above aspects will be evident based on the following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Reference is made, by way of example only, to the attached figures, wherein: [0009] Figure 1 is a side view of a vehicle with a closure panel assembly;

[0010] Figure 2 is a perspective view of a drive system for the closure panel assembly in the vehicle shown in Figure 1 ;

[0011] Figures 3 and 4 are additional perspective views of the drive system shown in Figure 2; [0012] Figures 5-7 are plan views of the drive system in different positions; and [0013] Figure 8 is a plan view of the drive system when being manually overridden.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS [0014] In this specification and in the claims, the use of the article "a", an , or

"the" in reference to an item is not intended to exclude the possibility of including a plurality of the item in some embodiments. It will be apparent to one skilled in the art in at least some instances in this specification and the attached claims that it would be possible to include a plurality of the item in at least some embodiments. [0015] Reference is made to Figure 1 which shows a vehicle 10 with a vehicle body 11 and a closure panel assembly 12. The closure panel assembly 12 includes a closure panel 14 and a closure panel drive system 16. The closure panel 14 may be a lift gate as shown in Figure 1 , or it may be some other kind of closure panel, such as, for example, an upward-swinging vehicle door (i.e. what is sometimes referred to as a gull- wing door). The closure panel 14 is movable between a closed position (shown in dashed outline in Figure 1) and an open position (shown in solid outline in Figure 1). In the embodiment shown, the closure panel 14 pivots between the open position and the closed position about a closure panel pivot axis 18, which is horizontal. In other embodiments, the pivot axis 18 may have some other orientation (e.g. vertical). In still other embodiments, the closure panel 14 may move in a manner other than pivoting. For example, the closure panel 14 may translate or may undergo a combination of translation and rotation between the open and closed positions.

[0016] The closure panel drive system 16 is provided for driving the closure panel 14 between the open position and the closed position. Referring to Figures 2, 3 and 4,

) the drive system 16 includes a closure panel actuation motor 20 (Figure 2), a housing 21 , a toothed wheel 22 (Figures 3 and 4), a locking member 24 (Figure 4), a locking member biasing member 26 (Figure 4) and a locking member actuator 28 (Figures 2, 3 and 4). Referring to Figure 2, the closure panel actuation motor 20 may be a bidirectional electric motor, and drives a gear train 30, which, in turn, drives a closure

) panel actuation arm 32. The actuation arm 32 pivots about an actuation arm pivot axis 33, and pivotally connects at pivot connection 34 to one end of a pushrod 35. The other end of the pushrod 35 pivotally connects to the closure panel 14 (Figure 1) at pivot connection 36. Thus, the closure panel actuation motor 20 is operatively connected to the closure panel 14. Rotation of the closure panel actuation motor 20 in a first direction

> drives the closure panel 14 towards the open position and rotation of the closure panel actuation motor 20 in a second direction drives the closure panel 14 towards the closed position.

[0017] Referring to Figure 1 , one or more closure panel biasing members 37 may be provided which urge the closure panel 14 towards the open position throughout at ⁾ least some portion of the path between the open position and the closed position and which assist in holding the closure panel 14 in the open position. The closure panel biasing members 37 may be, for example, gas struts which are pivotally connected at one end to the closure panel 14 and at another end to the vehicle body 1 . In the embodiment shown there are two biasing members 37 (one on the left side of the vehicle 10 and one on the right side of the vehicle 10), however one biasing member 37 is obscured by the other in the view shown in Figure 1. As the closure panel 14 moves

5 between the open and closed positions, the torques exerted thereon by the biasing members 37 and by the weight of the closure panel 14 itself will vary. In an embodiment, the closure panel 14 may have some position between the open and closed positions at which the torque exerted thereon by the biasing members 37 cancels out the torque exerted thereon by the weight of the panel 14. Above this point

) (which may be referred to as a balance point), the torque exerted by the biasing members 37 may overcome the torque exerted by the weight of the panel 14 thus resulting in a net torque upwards, towards the open position. Below this point, the torque exerted by the weight of the panel 14 may overcome the torque exerted by the biasing members 37 thus resulting in a net torque downwards, towards the closed

> position.

[0018] A helical coil spring 39 is shown in Figure 2. The spring 39 may serve several functions and is optional. For example, during manufacture of the closure panel drive system 16, there will be some small amount of play between the components of the drive system 16 due to the tolerances in the manufacture of the components. The ⁾ play between the components however, can lead to noise as the components rattle and contact each other intermittently during operation of the vehicle 10. The spring 39 may hold the components of the closure panel drive system 16 in engagement with one another with a selected force so as to reduce the likelihood of such noise. Additionally, the spring 39 may apply some amount of biasing force urging the drive system 16 in a direction that drives the closure panel 14 towards the open or closed position. The spring 39 may be used in this capacity as a way of tailoring the balancing of the closure ) panel 14 that is described above in relation to the biasing members 37.

[0019] The toothed wheel 22 (Figure 4) cooperates with the locking member 24 to provide a way of releasably locking the closure panel 14 at a range of positions between the open position and the closed position. The toothed wheel 22 is driven about a toothed wheel rotation axis 38 by the closure panel actuation motor 20. In the

) embodiment shown, one of the gears in the gear train 30 is mounted on a shaft 40. The shaft 40 also holds the toothed wheel 22 thereon. The toothed wheel 22 may rotate between a first position (identified by dashed radial line 42) which corresponds to the closed position of the closure panel 14, and a second position (identified by dashed radial line 44) which corresponds to the open position of the closure panel 14. The

) toothed wheel 22 may rotate through a plurality of revolutions when moving from one of the first and second positions 42 and 44 to the other of the positions 42 and 44. The first and second positions 42 and 44 are shown in Figure 4 as being angularly offset from each other, however, because the toothed wheel 22 may rotate through a plurality of revolutions when rotating between the two positions 42 and 44, the first and second

⁾ positions 42 and 44 may be considered different positions even if the first and second positions were not angularly offset about the axis 38. The toothed wheel 22 has a plurality of wheel teeth 46 that are spaced apart circumferentially about the axis 38 by a plurality of valleys 48.

[0020] The locking member 24 is pivotable about a locking member pivot axis 50 for movement along a path 52 shown in Figure 5 between a locking position (Figure 5) and an unlocking position (Figure 7). In Figure 5, the path 52 is bounded by a radial line 54 representing the locking position and a radial line 56 representing the unlocking position for the locking member 24. As shown in Figure 4, a mushroom pin 57 may be provided on the housing 21. The mushroom pin 57 passes through a slot 59 in the locking member 24 to help capture the locking member 24 for pivoting movement along the path 52.

[0021] The locking member 24 has a locking member tooth 58. When the locking member 24 is in the locking position the locking member tooth 58 is in one of the valleys 48 of the toothed wheel 22, and blocks movement of the toothed wheel 22 in a first rotational direction shown by arrow 60 and in a second rotational direction 62. The first direction 60 may correspond to the direction of rotation of the toothed wheel 22 when the closure panel 14 is moving towards the closed position. The second direction 62 may correspond to the direction of rotation of the toothed wheel 22 when the closure panel 14 is moving towards the open position. The locking member tooth 58 may have any suitable shape for the purpose of releasably blocking the movement of the toothed wheel 22. For example, the tooth 58 may have a generally V-shaped profile (as shown in Figure 4) with a radiused corner. Alternatively, the tooth 58 may, for example, have a generally arcuate (optionally circular) profile as shown in Figures 5-8. [0022] When the locking member 24 is in the unlocking position as shown in Figure 7, the tooth 58 is out of the valleys 48 of the toothed wheel 22. In some embodiments, there may be a clearance gap G between the tooth 58 and the toothed wheel 22, so that the tooth 58 does not impose any frictional drag on the rotation of the toothed wheel 22.

[0023] The locking member 24 is held in the locking position by the locking member biasing member 26. The locking member biasing member 26 may be any suitable type of biasing member, such as, for example, a compression spring. In the example embodiment shown in Figure 4, the locking member biasing member 26 has a first end 64 that is pivotally mounted to a portion of the housing 21 and a second end 66 that is pivotally mounted to the locking member 24. A limit surface 61 prevents the movement of the locking member 24 past the unlocking position under the urging of the biasing member 26.

[0024] Referring to Figure 5, when the locking member 24 is in the locking position, the locking member biasing member 26 applies a force (represented by F) on the locking member 24, which exerts a first selected holding torque (represented by T) on the locking member 24 that holds the locking member tooth 58 in place in one of the valleys 48 of the toothed wheel 22 and that therefore holds the locking member 24 in the locking position. Figures 5, 6 and 7 show a progression of movement of the locking member 24 between the locking position and the unlocking position. As can be seen in Figure 7, when the locking member 24 is in the unlocking position, the locking member biasing member 26 applies a force F on the locking member 24 (which may be a different amount of force than is applied in the locking position), which exerts a second selected holding torque T (which may be a different amount of torque than is applied in the locking position) on the locking member 24 that holds the locking member tooth 58 out of the valleys 48 and thus holds the locking member 24 in the unlocking position.

[0025] When the locking member 24 is in the unlocking position, the toothed wheel 22 has a first resistance to rotation to the first position, that is the resultant resistance taking into account all the forces acting on the toothed wheel 22, including, for example, the force on the toothed wheel 22 that results from the force of the closure panel biasing member 18 urging the closure panel 14 upwards, the weight of the closure panel 14 urging the closure panel downwards, and frictional resistance in the gear train 30. Additionally, the toothed wheel 22 has a first resistance to rotation to the second position (which may be different than the first resistance to rotation in the closing direction to the first position), taking into account the aforementioned forces.

[0026] When the locking member 24 is in the locking position, the toothed wheel 22 has a second resistance to rotation to the first position. The second resistance to rotation to the first position is higher than the first resistance to rotation to the first position due to the engagement of the locking member tooth 58 with one of the valleys 48 of the toothed wheel 22. Additionally, when the locking member 24 is in the locking position the toothed wheel 22 has a second resistance to rotation to the second position (which may be different than the second resistance to rotation to the first position), taking into account the aforementioned forces. The second resistance to rotation to the second position is higher than the first resistance to rotation to the second position.

[0027] As shown in Figures 5 and 7, the movement of the locking member 24 from the locking position to the unlocking position changes the orientation of the biasing member 26, and thus changes the direction in which the force F is directed, so that in the locking position the force generates a torque in a first direction and in the unlocking position the force generates a torque in a second direction that is opposite to the first direction. Similarly, movement of the locking member 24 from the unlocking position to the locking position changes the direction in which the torque T is applied on the locking member 24 from the second direction to the first direction.

[0028] As a result of the pivoting movement of the biasing member 26, the biasing member 26 is configured to urge the locking member 24 towards the locking position when the locking member 24 moves beyond a transition position along the path 52 towards the locking position, and the biasing member 26 is configured to urge the locking member 24 towards the unlocking position when the locking member 24 moves beyond the transition position along the path 52 towards the unlocking position. The transition position would be a position wherein the force F exerted by the biasing member 26 on the locking member 24 passes directly through the center of rotation of the locking member 24, which is the pivot axis 38, and thus as a result the biasing member 26 would exert no torque on the locking member 24 (i.e. a torque of zero). Any movement past the transition position towards the locking position would cause the direction of the force from the biasing member 26 to exert a torque on the locking member 24 that urges the locking member 24 towards the locking position. Similarly, any movement past the transition position towards the unlocking position would cause the direction of the force from the biasing member 26 to exert a torque on the locking member 24 that urges the locking member 24 towards the unlocking position. The specific position of the transition position may be anywhere suitable. In an embodiment, the transition position is between the position shown in Figure 5 and the position shown in Figure 6. The position shown in Figure 6 shows an intermediate position between the locking position and the unlocking position, wherein the locking member 24 has been rotated just out of the valley 48 in which it was previously in, such that the locking member tooth 58 engages one of the wheel teeth 46. As can be seen from the direction of the force F and the resultant torque T shown in Figure 6, by the time the locking member 24 has rotated to bring the tooth 58 out of the valley 48, the locking member 24 has already passed the transition position and is therefore biased towards the unlocking position by the biasing member 26. The transition position is represented by a radial line 68 in Figure 5 along the path 52.

[0029] A benefit of arranging the drive system 16 so that the transition position is passed by the time the tooth 58 leaves the valley 48 is described further below in relation to manually overriding the locking member 24.

[0030] The locking member 24 may be driven between the locking position and the unlocking position by the locking member actuator 28. The locking member actuator 28 is operatively engageable with the locking member 24 and is selectively operable to drive the locking member 24 between the locking position and the unlocking position. The locking member actuator 24 includes a locking member actuator motor 70 and a locking member driver 72. The locking member actuator motor 70 is a bi- directional electric motor. The locking member driver 72 includes a first driver arm 74 and a second driver arm 76. The locking member driver 72 is rotatable by the motor 70 between a first position (Figure 7) and a second position (Figure 5). When the locking member driver 72 is in the first position, the locking member 24 is, under normal circumstances, in the unlocking position. Rotation of the locking member driver 72 from the first position to the second position can be divided into two portions. During a first portion of the rotation, the first driver arm 74 engages a drive surface 78 on the locking member 24 and drives the locking member 24 to the locking position. In the embodiment shown, the locking member driver 72 causes the first driver arm 74 to rotate into a slot 80 in the locking member 24 thereby engaging the drive surface 78 which is in the slot 80. As rotation of the locking member driver 72 continues the locking member driver 72 begins to drive the locking member 24 to pivot away from the unlocking position towards the locking position. At some point in the rotation of the locking member driver 72 the locking member 24 is pivoted past the transition position and the locking member biasing member 26 urges the locking member 24 towards the locking position, and thus assists the locking member actuator 28 in bringing the locking member 24 to the locking position once the transition position has been passed.

[0031] Optionally, during a subsequent second portion of the rotation of the locking member driver 72 from the first position to the second position, the first driver arm 74 is rotated out of the slot 80 so that the first driver arm 74 disengages from the drive surface 78 on the locking member 24, so as to permit movement of the locking member 24 out of the locking position without backdriving the locking member driver 72. A benefit of this disengagement will be described further below in relation to manually overriding the locking member 24.

[0032] Rotation of the locking member driver 72 may continue until the second driver arm 76 contacts a stop surface 82 on the locking member 24. A control system 84 that may be provided for controlling the operation of the locking member actuator motor 70 may be configured to detect a current spike in the motor 70 that occurs when the stop surface 82 is encountered by the second driver arm 76, preventing further rotation of the locking member driver 72. Upon such detection, the control system 84 may be configured to cut power to the motor 70. Upon reaching the second position (Figure 5) a resilient locking member driver holding member 86 (Figure 4) may optionally be provided to engage a first detent 88a (Figure 4) on the locking member driver 72 to hold the locking member driver 72 in the second position.

[0033] During pivoting of the locking member 24 towards the locking position, it is possible that a position as shown in Figure 6 could occur, whereby the toothed wheel 22 is positioned such that the locking member tooth 58 encounters a tooth 46 instead of a valley 48. However, during pivoting of the locking member 24 to the locking position, the closure panel 14 is being driven by the closure panel actuation motor 20 either towards the open position or towards the closed position. As a result, the toothed wheel 22 is rotating, either towards the first position or towards the second position. Thus, even if, momentarily, during movement of the locking member 24 towards the locking position, the locking member tooth 58 comes to rest against a wheel tooth 46 (as shown in figure 6), further rotation of the toothed wheel 22 will present a valley 48 into which the locking member tooth 58 can enter so as to complete the movement of the locking member 24 to the locking position, thereby locking the toothed wheel 22 in position. Upon detection of the locking member 24 reaching the locking position, the control system 84 may cut power to the closure panel actuation motor 20.

[0034] Rotation of the locking member driver 72 from the second position (Figure 5) to the first position (Figure 7) by the motor 70 may be carried out by driving the motor 70 in the opposite direction to the direction which brought the driver 72 to the second position. During a first portion of the rotation from the second position to the first position, the locking member driver 72 the first driver arm 74 enters the slot 80 and engages the drive surface 78 on the locking member 24 and drives the locking member 24 to the unlocking position. As the locking member 24 is pivoted past the transition position the locking member biasing member 26 urges the locking member 24 towards the unlocking position, and thus assists the locking member actuator 28 in bringing the locking member 24 to the unlocking position once the transition position has been passed.

[0035] During an optional subsequent second portion of the rotation of the locking member driver 72 from the second position to the first position, the first driver arm 74 is rotated out of the slot 80 so that the first driver arm 74 disengages from the drive surface 78. Upon reaching the first position, the driver 72 may be held in the first position by engagement of the holding member 86 (Figure 4) with the second detent 88b (Figure 4).

[0036] Thus, the closure panel drive system 16 permits the closure panel 14 to be stopped in an intermediate position between the open position and the closed position and supports the closure panel 14 against both closing movement and opening movement (i.e. against movement towards the closed position and against movement towards the open position). More particularly when the intermediate position is a position in which the weight of the closure panel 14 overcomes the biasing members 37, locking the toothed wheel 22 with the locking member 24 supports against the net torque on the toothed wheel 22 in the first direction. When the intermediate position is a position in which the biasing members 37 overcome the weight of the closure panel 14, locking the toothed wheel 22 with the locking member 24 supports against the net torque on the toothed wheel 22 in the second direction. The intermediate position may be referred to as a third position.

[0037] It may also be possible to lock the toothed wheel 22 with the locking member 24 when the closure panel 14 is in the open position, and not just in the intermediate position.

[0038] During operation of the vehicle 10, the vehicle 10 may incur a power failure while the locking member 24 is in the locking position and the closure panel 14 is in an intermediate position or in the open position. During such an event, the locking member 24 would remain in the locking position, so that the closure panel 14 would continue to be supported in the intermediate position or open position. In some embodiments, the toothed wheel 22 and the locking member 24 may be configured so that the locking member 24 may be manually overridden so as to permit a user to close the closure panel 14 (i.e. to manually bring the closure panel 14 to the closed position). To provide this manual override capability, the valleys 48 on the toothed wheel 22 and the locking member tooth 58 may be shaped so that a closing torque applied to the toothed wheel 22 (i.e. a torque applied to the toothed wheel 22 urging the toothed wheel 22 towards the first position) causes a locking member backdriving force to be exerted on the locking member 24 in a selected direction. This backdriving force generates an unlocking torque on the locking member 24. If the unlocking torque is sufficiently high, the unlocking torque will overcome the holding torque that the locking member biasing member 26 exerts on the locking member 24, and as a result, the toothed wheel 22 will rotate towards the first position. This rotation of the toothed wheel 22 will drive the locking member tooth 58 out of the valley 48 in which the tooth 58 was engaged. Such movement is shown in Figure 8. As can be seen, because the first driver arm 74 on the driver 72 is disengaged from the drive surface 78 on the locking member 24, the driver 72 (and thus the motor 70) is not backdriven when the locking member 24 is being manually driven towards the unlocking position. At some point during travel of the tooth 58 out of the valley 48 the locking member 24 passes the transition position, and as a result, the locking member biasing member no longer resists the pivoting movement of the locking member 24 and instead urges the locking member 24 towards to the unlocking position shown in Figure 7. Thus, once the transition position is passed, closure of the closure panel 14 is no longer resisted by the locking member 24.

[0039] The selected closing torque that is applied to the toothed wheel 22 may be applied by a user applying a closing force (i.e. a downward force) on a handle 90 (Figure 1) of the closure panel 14. One or more parameters including the shapes of the valleys 48 and the tooth 58, the arrangement of the locking member 24 and the biasing member 26, and the gear ratio between the closure panel 14 and the toothed wheel 22 may be selected in order to permit the locking member 24 to be manually overridden and for the closure panel 14 to be manually closed by a person. In an example embodiment, the parameters may be selected so that a closing force (i.e. a downward force) at the handle 90 of the closure panel 14 that is sufficient to manually override the locking member 24 may be less than about 90 Newtons.

[0040] As shown in Figure 4, the control system 84 may include a microprocessor 92 and a memory 94 that contains programming that is configured to carry out the method steps described herein, and may be configured to receive inputs and transmit outputs as described herein. While the control system 84 has been shown as a single block, it will be understood by persons skilled in the art that in practice the control system 84 may be a complex distributed control system having multiple individual controllers connected to one another over a network.

[0041] In addition to receiving signals that are indicative of the current being sent to the motors 70 and 20, the control system 84 may also receive signals from one or more sensors, including, for example, a limit switch 96. The limit switch 96 may be positioned to send a signal to the control system 84 when the locking member 24 reaches the locking position. Additionally, a position sensor may be provided (not shown) that sends signals to the control system 84 that is indicative of the position of the closure panel 14 throughout the range of motion of the closure panel 14 between the open position and the closed position. Such a position sensor may be, for example a Hall-effect sensor that detects a feature on the motor output shaft or on one of the shafts within the gear train 30. Other sensors may additionally be provided.

[0042] By providing the control system 84 with the capability to determine the position of the closure panel 14 the control system 84 can be configured to permit a user to select a desired intermediate position at which the control system 84 is to lock the toothed wheel 22 so as to hold the closure panel 14 in the intermediate position. For example, the user could manually move the closure panel 14 to the desired intermediate position and can then press a button on the key fob to instruct the control system 84 to store the current position of the closure panel 14 in the memory 94 so that during future uses of the vehicle 10, the control system 84 can be programmed to open the closure panel 14 to the intermediate position instead of the open position (e.g. to accommodate a low ceiling in a garage).

[0043] The control system 84 may be able to detect when the locking member 14 has been manually overridden. For example, the control system 84 may store the direction in which the motor 70 was last driven. Thus the control system 84 can determine whether the locking member driver 72 is in the first position or the second position. If the locking member driver is determined to be in the second position, corresponding to the locking position of the locking member 24, but the locking member 24 is not in the locking position (based on, for example, a lack of any signals coming from the limit switch 96, and/or based on, for example, an indication that the closure panel 14 is moving, the control system 84 may determine that the locking member 24 has been manually overridden. In such an instance, the control system 84 may prevent further powered operation of the locking member actuator 28 until such time that the vehicle 10 has been brought into a service center for servicing. Alternatively, in embodiments wherein the first and second driver arms 74 and 76 are substantially the same, the control system 84 could treat the second driver arm 76 as the first driver arm 74 and could operate the actuator 28 so as to rotate the second driver arm 74 into the slot 80 to drive the locking member 24 back to the locking position when desired, and to use the second driver arm 76 as the first driver arm 74 thereafter (until another situation occurs where the locking member 24 is manually overridden again).

[0044] It will be noted that the drive system 16 shown and described provides the capability of stopping the closure panel 14 in an intermediate position between the first and second positions and to be manually overridden without the need to incorporate a clutch into its structure. This reduces the size, complexity and cost of the drive system 16 as compared to some drive systems that include a clutch.

[0045] The drive system 16 has been found to perform well during testing, such that a consistent force was able to manually override the locking member 24 over a broad range of temperatures, and over a broad range of intermediate positions.

[0046] While not described in detail above, it will be understood that, in embodiments wherein the closure panel 14 is latched by a vehicular latch to the vehicle body 11 when in the closed position, the latch would have to be opened prior to movement of the closure panel away from the closed position.

[0047] The above-described embodiments are intended to be examples only, and alterations and modifications may be carried out to those embodiments by those of skill in the art.

Claims

Claims:

1. A closure panel drive system for moving a vehicular closure panel between an open position and a closed position, comprising:

a closure panel actuation motor that is operatively connectable to the closure panel and that is operable to drive the closure panel between the open position and the closed position;

a toothed wheel that is rotatable by the closure panel actuation motor about a toothed wheel axis between a first position corresponding to a closed position of the closure panel and a second position corresponding to an open position of the closure panel, and that is operatively connectable to a vehicular closure panel, wherein the toothed wheel has a plurality of wheel teeth spaced apart circumferentially about the toothed wheel axis by a plurality of valleys;

a locking member having a locking member tooth, and that is pivotable about a locking member pivot axis for movement along a path between a locking position wherein the locking member tooth is in one of the valleys of the toothed wheel and an unlocking position wherein the locking member tooth is out of the valleys of the toothed wheel, wherein, when the locking member is in the unlocking position the toothed wheel has a first resistance to rotation to the first position, and wherein, when the locking member is in the locking position the toothed wheel has a second resistance to rotation to the first position, wherein the second resistance to rotation to the first position is higher than the first resistance to rotation to the first position;

21

709493PCT a locking member actuator that is operatively engageable with the locking member and is selectively operable to drive the locking member between the locking and unlocking positions. 2. A closure panel drive system as claimed in claim 1 , wherein, when the locking member is in the unlocking position the toothed wheel has a first resistance to rotation to the second position, and wherein, when the locking member is in the locking position the toothed wheel has a second resistance to rotation to the second position, wherein the second resistance to rotation to the second position is higher than the first resistance to rotation to the second position.

3. A closure panel drive system as claimed in claim 1 , wherein in the locking position the locking member permits a selected closing torque on the toothed wheel to drive rotation of the toothed wheel to the first position.

4. A closure panel drive system as claimed in claim 3, wherein the selected closing torque is selected to correspond to a closing force on the closure panel that is manually exertable by a person. 5. A closure panel drive system as claimed in claim 4, further comprising a locking member biasing member configured to apply a selected holding torque on the locking member to hold the locking member in the locking position, wherein exertion of the selected closing torque on the toothed wheel pivots the locking member out of the valleys of the toothed wheel against the selected holding torque.

6. A closure panel drive system as claimed in claim 5, wherein the locking member biasing member is configured to urge the locking member towards the locking position when the locking member moves beyond a transition position along the path towards the locking position, and to urge the locking member towards the unlocking position when the locking member moves beyond the transition position along the path toward the unlocking position.

7. A closure panel drive system as claimed in claim 5, wherein the locking member actuator is operatively disengaged from the locking member when the locking member is in the locking position. 8. A closure panel drive system as claimed in claim 6, wherein the locking member actuator is operatively disengaged from the locking member when the locking member is in the locking position and when the locking member is in the unlocking position.

9. A closure panel drive system as claimed in claim 6, wherein the locking member biasing member includes a compression spring that is pivotally mounted at a first end to a support member and that is pivotally mounted at a second end to the locking member, wherein movement of the locking member past the transition position towards the locking position pivots the compression spring to exert a torque on the locking member in a first rotational direction about the locking member pivot axis, and wherein movement of the locking member past the transition position towards the unlocking position pivots the compression spring to exert a torque on the locking member in a second rotational direction about the locking member pivot axis.

10. A closure panel drive system as claimed in claim 5, wherein the locking member actuator includes a locking member actuator motor, a locking member driver that is drivable by the locking member actuator motor, wherein the locking member driver has a first driver arm, wherein during a first portion of rotation of the locking member driver from a first position to a second position the first driver arm engages a drive surface on the locking member and drives the locking member to the locking position.

11. A closure panel drive system as claimed in claim 10, wherein during a subsequent second portion of rotation of the locking member driver from the first position to the second position the first driver arm disengages from the drive surface on the locking member so as to permit movement of the locking member out of the locking position without backdriving the locking member driver.

12. A closure panel drive system as claimed in claim 11 , wherein the locking member driver includes a second driver arm, and wherein when the locking member driver is in the second position the second driver arm engages a stop surface on the locking member.

13. A closure panel drive system as claimed in claim 12, wherein during a first portion of rotation of the locking member driver from the second position to the first position the first driver arm engages the drive surface on the locking member and drives the locking member to the unlocking position, wherein during a subsequent second portion of rotation of the locking member driver from the first position to the second position the first driver arm disengages from the drive surface on the locking member so as to permit movement of the locking member out of the unlocking position without backdriving the locking member driver. 14. A closure panel drive system as claimed in claim 13, wherein the position of the first driver arm when the locking member driver is in the second position is substantially the same as the position of the second driver arm when the locking member driver is in the first position, and wherein the first driver arm and the second driver arm are substantially identical in shape. 5. A closure panel drive system as claimed in claim 14, further comprising a control system that is configured to control the operation of the locking member actuator motor, wherein the control system is programmed to control the direction of rotation of the locking member driver based on the position of the locking member.

16. A closure panel drive system as claimed in claim 10, further comprising a control system that disables the locking member actuator motor when the locking member driver reaches the second position.

17. A closure panel drive system as claimed in claim 1 , further comprising a control system that is configured to operate the locking member actuator to drive the locking member to the locking position in response to receiving an indication that the closure panel has reached a selected intermediate position between the open position and the closed position.

18. A closure panel drive system as claimed in claim 1 , wherein the control system is configured to receive signals from a closure panel position sensor that are indicative of the position of the closure panel between the open position and the closed position, and wherein the indication is received from the closure panel position sensor.

19. A closure panel drive system as claimed in claim 6, wherein movement of the locking member from the locking position to a position in which the locking member tooth is engaged with one of the wheel teeth brings the locking member past the transition position.

20. A closure panel assembly for a vehicle, comprising:

a closure panel that is movable between an open position and a closed position; and a closure panel drive system, including:

a closure panel actuation motor that is operatively connectable to the closure panel and that is operable to drive the closure panel between the open position and the closed position; a toothed wheel that is rotatable by the closure panel actuation motor about a toothed wheel axis between a first position corresponding to a closed position of the closure panel and a second position corresponding to an open position of the closure panel, and that is operatively connectable to a vehicular closure panel, wherein the toothed wheel has a plurality of wheel teeth spaced apart circumferentially about the toothed wheel axis by a plurality of valleys;

a locking member actuator that is operatively engageable with the locking member and is selectively operable to drive the locking member between the locking and unlocking positions. 21. A closure panel assembly as claimed in claim 20, wherein in the locking position the locking member permits a selected closing torque to drive rotation of the toothed wheel to the first position.

22. A closure panel assembly as claimed in claim 21 , wherein the selected closing torque is selected to correspond to a closing force on the closure panel that is manually exertable by a person. 23. A closure panel assembly as claimed in claim 22, further comprising a locking member biasing member configured to apply a selected holding torque on the locking member to hold the locking member in the locking position, wherein exertion of the first selected closing torque on the toothed wheel pivots the locking member out of the valleys of the toothed wheel against the selected holding torque.

24. A closure panel assembly as claimed in claim 23, wherein the closure panel has a handle, and wherein at least a selected downward force on the closure panel at the handle generates at least the selected closing torque on the toothed wheel.

25. A closure panel assembly as claimed in claim 23, wherein the selected downward force is less than about 90 Newtons.

26. A method of operating a closure panel drive system on a closure panel for a vehicle, comprising:

a) moving the closure panel towards one of a closed position or an open position, wherein a toothed wheel is operatively connected to the closure panel and rotates during movement of the closure panel; and b) moving a locking member to a locking position wherein the locking member is engaged with the toothed wheel to stop the movement of the closure panel at an intermediate position between the open and closed positions. 27. A method as claimed in claim 26, further comprising applying a holding force from a spring on the locking member to hold the locking member in the locking position.

28. A method as claimed in claim 27, applying at least a selected closing torque on the toothed wheel while the locking member is in the locking position, wherein the selected closing torque is sufficient overcome the holding force and to drive the toothed wheel in a direction to move the closure panel towards the closed position and to drive the locking member from the locking position to an unlocking position in which the locking member is disengaged from the toothed wheel. 29. A method as claimed in claim 28, wherein during movement of the locking member from the locking position to the unlocking position the locking member passes a transition position beyond which the locking member biasing member biases the locking member towards the unlocking position. 30. A method as claimed in claim 29, wherein the selected closing torque is generatable by applying a selected downward force on a handle of the closure panel.

31. A method as claimed in claim 28, wherein the selected downward force is less than about 90 Newtons.