JP2001253241A - Power operation system for vehicle lift gate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple power operation system capable of moving a lift gate at an optional position between a completely closed position and a completely opened position without obstructing a loading region. SOLUTION: This power operation system for opening or closing the lift gate 12 of a vehicle is provided with a pair of drive units 22 supported by vehicle pillar parts provided on both sides of a lift gate opening part. Each drive unit is provided with a vertically arranged channel 24 and a rack bar 34 moving in the channel. A link 40 is fitted connectably to the rack bar at one end part and connectably to the lift gate at the opposite side end part. The rack bar is lifted or lowered by a power unit 46 having a driven pinion gear 56 coupled with the lift gate. The lift gate is opened or closed via the link when the rack bar is lifted or lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a power actuation system for a vehicle liftgate pivotally mounted on a vehicle roof for pivotal movement about a generally horizontal hinge axis, and more particularly to a complete power actuation system. And a power actuation system for moving the lift gate from an open position to a fully open position and from an open position to a fully closed position.

[0002] This application claims the benefit of US Provisional Application No. 60 / 184,194, filed February 22, 2000, the disclosure of which is incorporated by reference.
The whole is incorporated into the text as if it were all described.

[0003]

BACKGROUND OF THE INVENTION Sports cars and vans with lift gauges pivoted about a generally horizontal hinge axis at the top,
Used by a very large number of people today. Some of these lift gauges are large and heavy. Their size and weight make it difficult to open and close these lift gauges. Some lift gauges are spaced a large distance above the ground when they are fully open. For some people, their height above the ground makes them very difficult to close. For these and other reasons, many people desire to have a power actuation system for opening and closing a lift gauge.

[0004] In recent years, a number of different lift gauge opening mechanisms have been attempted. Some of these lift gauge opening mechanisms have a single cable that opens and closes the lift gauge connected to a counterbalance system, such as a gas cylinder. A lift gauge with a single cable opening and closing mechanism is typically a lightweight trunk lid and moves over a relatively small range.

[0005] The output of a gas cylinder varies with temperature. This complicates power lift gauge systems that rely on gas cylinders to open the lift gauge.
One or more gas cylinders may be used on coldest days (-40 ° C)
Must be strong enough to release the lift gauge. This results in a gas cylinder which substantially increases the resistance to closing on warmest days (80 ° C.). Therefore,
A very large electric motor must be used to close the lift gauge.

[0006] Lift gauges having two or more lift gauges are common for counterbalance systems. These gas cylinders occupy a position such that their axis is substantially parallel to the lift gauge, thereby hiding the gas cylinder when the lift gauge is closed. In this closed position, the movable arm of the gas cylinder is very small. In such systems, the lift gates move about one-third of their full range of travel before the gas cylinders exert sufficient force to further open the lift gates without the application of an independent lift force. be able to. There are even some systems that bias the liftgate toward a closed position when the gas cylinder passes through the center and the liftgate is closed. In these self-closing systems, the lift gate may need to be opened more than a third before the gas cylinder opens the lift gate further.

US Pat. No. 4,903,435 issued to Werner Bitman et al. On Feb. 27, 1990.
Discloses an apparatus for automating the opening and closing of a pivoting body panel of a motor vehicle including an actuation rod. The actuation rod is pivotally mounted at one end to a pivoting body panel and at an opposite end to a slide block. The slide block is moved in a rectilinear track tilted by a control cable driven in a closed loop by a cable drum driven by an electric vehicle. The device of the Bitman '435 patent is bulky and cumbersome and relies on gravity to completely close the pivoting body panel.

[0008] US Patent No. 5,588,258, issued December 31, 1996 to Kevin Wright et al.
A power actuator is disclosed for a pivoting closure element that includes two gas-filled struts and an extendable strut adapted to be extended by a cable drive. The power actuator of the '258 patent by light opens and closes the pivot closure element completely. However, extendable struts and cable drives are complex and expensive and require a large amount of vertical space.

[0009] US Patent No. 6,055,775, issued to Timony Delling et al. On May 2, 2000, discloses a lift gate self-closing device that includes a pneumatic actuator. The pneumatic actuator is pivotally mounted at one end to a lift gate and at the opposite end to tape. The tape is a substantially elongated belt member having a rack formed on the lower side.
The rack is driven by a pinion gear located in the truck and mounted on the output shaft of the electric motor. Alternatively, the tape can be an endless member. In either case, the lift gate is manually opened until the off center condition is achieved with the pneumatic actuator. Next, the pneumatic actuator automatically opens the lift gate. The lift gate is closed by energizing the motor to drive the tape and actuator down until the lift gate is closed by gravity. Deling's device requires manual intervention to open the lift gate and relies on gravity to completely close the lift gate.

US Pat. No. 6,09, issued Jul. 25, 2000 to Joseph Michael Johnson et al.
No. 2,337 discloses a vehicle liftgate power actuation system having two drive units. In these drive units, a segmented sector rides in the truck with an end sector attached to the lift gate. The segmented sectors are driven by pinion gears mounted on the output shaft of the electric motor. This power actuation system opens and closes the lift gate completely and is fully satisfactory for its intended purpose. However, the drive unit reduces overhead headroom in the cargo space, which may be opposed by some users.

[0011]

It is an object of the present invention to provide an improved vehicle liftgate power actuation system.

[0012]

SUMMARY OF THE INVENTION A feature of the present invention is that a vehicle liftgate power actuation system can move a liftgate from a closed position to a fully open position, and from an open position to a fully closed position. That's what it means.

Another feature of the present invention is that the lift gate power actuation system does not reduce overhead headroom in the loading area. Another feature of the present invention is that the lift gate power actuation system is compact, durable and economical to manufacture.

Yet another feature of the present invention is that the drive unit of the lift gate power actuation system is composed of fewer parts and is less complex than other power actuation systems.

Yet another feature of the present invention is that the power actuation system of the liftgate minimizes vertical protrusion into the loading area of the vehicle and into unobstructed load widths at the liftgate opening. And coordinated with the D-pillar.

Yet another feature of the present invention is that the power actuation system can be used in conjunction with a counterbalance system for a manual actuation system without any modification of the counterbalance system.

[0017] The above and other objects, features and advantages of the present invention will become more apparent from the following description of preferred embodiments, taken in conjunction with the accompanying drawings.

[0018]

DETAILED DESCRIPTION OF THE INVENTION A sports car 10 has a lift gate 12 attached to the rear end of the vehicle roof by two hinge assemblies 13.
Pivots about the axis of the substantially horizontal hinge 15 from the closed position shown in FIGS. 1 and 2 to the raised open position shown in FIGS. Hinge shaft 15 is substantially horizontal and lift gate 12 is allowed to pivot about 90 ° about a pivot axis between a substantially horizontal open position and a substantially vertical closed position. I have. However, the range of movement can vary from one vehicle model to another.

The lift gate 12 is opened and closed by a power actuation system comprising at least one and preferably two identical lift mechanisms 22. The lift mechanism 22
At the rear end of the vehicle at the D pillar,
The pillar defines an open rear width for the cargo area closed by the lift gate 12. One exemplary lift mechanism 22 is shown in detail in FIGS.

The lift mechanism 22 includes an annular rectangular linear channel 24 having a longitudinal slot 26 in a top portion of a side wall 28 thereof. The channel 24 has a window 30 on the opposite side wall 32 that is aligned with the bottom portion of the slot 26, as best shown in FIG. A rack bar 34 is disposed within the channel 24 for linear movement within the channel 24 and the rack bar 34
Serving as a guide or track for Rack bar 34
Has teeth 36 on one side facing the side wall 32 so that the window 30 provides access to the teeth 36. So that ball stud 38 extends through slot 26,
A ball stud 38 is mounted at the top end opposite the rack bar 34. The rack bar 34 is preferably
U-shaped shoe 39 of low friction material adjacent each end to facilitate sliding movement of rack bar 34 of channel 24
Having.

The lift mechanism 22 includes a link 40 having a ball socket 42 provided at the lowermost end and a ball socket 44 provided at the uppermost end. The ball stud 38 is disposed in the ball socket 42, so that the lowermost end of the link 40 is freely attached to the rack bar 34. The opening of the ball socket 44 is perpendicular to the opening of the ball socket 42. The ball socket 44 accommodates the ball stud 38 as described further below.
By means of ball studs which are substantially perpendicular to the lift gate 1
2 is used to attach the top end of the link 40.

The lift mechanism 22 includes a power unit 4 for raising and lowering a rack bar 34 in the channel 24.
6 is provided. The power unit 46 includes an electric motor 48
, A first gear set 50, an electromagnetic clutch 52, and a second gear set 54 having an output pinion gear 56. The electric motor 48 has a worm gear output 49 that changes the drive shaft by 90 ° and drives a gear set 50 with an output pinion gear 51. The output pinion gear 51 drives the input side of the electromagnetic clutch 52, and its output side drives the gear 53. The gear 53 is, as described above, a gear set 5 having an output pinion gear 56.
4 is driven. Power unit 46 is channel 2
4 so that the pinion gear 56
Project into the window 30 and engage the teeth 36 of the rack bar 34, as best shown in FIG. Gear set 5
The housing cover 4 includes a guard and bearing support 58 for the pinion gear 56.

The lift mechanism 22 is mounted on the vehicle 1 with the channel 24 secured to the vehicle at the D-pillar 60 by appropriate brackets, fasteners, welds, etc. (not shown).
Set to 0. The channel 24 is supported in a substantially vertical orientation and preferably is as vertical as possible in both the longitudinal and lateral directions of the vehicle. The deviation from vertical depends on the shape of the particular vehicle model. For example, in the vehicle shown, the channel 25 is inclined forward by about 10 ° in the longitudinal direction, as best seen in FIGS. On the other hand, the channel 24 slopes approximately 10 ° laterally inward, as best seen in FIGS.

The lift mechanism 22 is also mounted so that the ball stud 38 faces rearward on an axis substantially parallel to the longitudinal axis of the vehicle. The teeth 36 are rectangular rack bars 3
4 on the opposite side, facing forward. The power unit 46 is attached to the outside of the channel 24 on the vehicle.

The link 40 is attached to a ball stud 38 facing rearward at the lowermost end by a ball socket 42 opened in the longitudinal direction so as to be connected freely. The top end of the link 40 is attached to a ball stud 62 at the side edge of the lift gate 12 by a top ball socket 44 that opens laterally. The ball stud 62 has a hinge shaft 15
Mounted on the side edge of the vehicle liftgate 12 so as to be spaced from and essentially perpendicular to the longitudinal axis of or parallel to the vehicle. Thus, the link 40 is connected to the rack bar 34 and the lift gate 1.
2 freely pivots in any direction. This freedom of movement reduces the side loads on ball studs 38 that tend to twist the rack bar 34 so that the substantially twist free rack bar 34 slides smoothly within the channel 24. , Channel 24 or pinion gear 56
Do not restrain.

The power actuation system further includes a conventional power source, such as a vehicle battery (not shown), and appropriate motor control circuitry for energizing and deactivating the reversible electric motor 48. I have. The motor control circuit is
It is well known to those skilled in the art and thus need not be described in detail here.

The power actuation system operates as follows. The lift gate 12 is closed as shown in FIGS. 1 and 2, and the electric motor 48 and the electromagnetic clutch 52 are urged to open the lift gate 12. When energized, the electric motor 48 rotates the pinion gear 51 clockwise via the gear set 50. Next, the pinion gear 51 rotates the output gear 53 clockwise through the engaged electromagnetic clutch 52. The gear 53 moves the rack bar 34 from the retracted position shown in FIGS.
The gear 56 is rotated clockwise through the gear set 54 until it is driven to the raised position shown in FIG. This raises the lift gate 12 via the link 40 from the closed position shown in FIGS. 1 and 2 to the raised open position shown in FIGS. When the lift gate 12 is completely opened, limit switches and the like are actuated to stop the electric motor 48 and the electromagnetic clutch 52. The lift gate 12 is closed by reversing the electric motor 48 so that the gear 56
Then, the rack bar 34 is driven to return to the retracted position shown in FIG.

The lift gate 12 can easily be manually moved even when the power is reduced. This is because the de-energized clutch 52 allows the clutch output gear 53 to move freely with respect to the electric motor 48 and gear set 50.

The power actuation system can be designed to function alone. Alternatively, if the primary adjustment is the size of the electric motor 48, it may be designed to work in conjunction with gas cylinders known in the art.

The power actuation system described above preferably comprises two identical drive units 22 for balanced operation and reduced manufacturing costs. However, the drive units need not be identical, and in some cases a single drive unit may be sufficient.

Although the preferred embodiment has a rearwardly facing ball stud 38 to minimize the twist on the rack bar 34, the ball stud 38 can face in any direction. In one aspect, it is an advantage that ball stud 38 faces inward. this is,
Allow the lift mechanism 22 to move outward to make room. Moreover, the preferred embodiment also includes an electromagnetic clutch. However, it is also possible to omit the electromagnetic clutch and use a back driveable electric motor to reduce costs. In other words,
Many modifications and variations of the present invention can be made in light of the above teachings. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

[Brief description of the drawings]

FIG. 1 is a rear view of a sports vehicle with a liftgate power actuation system of the present invention, with the liftgate shown in a closed position.

FIG. 2 shows a line 2-2 of FIG. 1 viewed in the direction of the arrow;
FIG. 3 is a cross-sectional view taken along the outline.

FIG. 3 is a cross-sectional view of a sports vehicle similar to FIG. 2, but with the lift gate shown in an open position.

FIG. 4 is a rear view of the sports car of FIG. 1,
It is a figure showing a lift gate of an open position.

FIG. 5 is an isometric view of one of the lift mechanisms shown in FIGS. 1-4.

FIG. 6 is a vertical section of the lift mechanism shown in FIG. 5;

FIG. 7 is an exploded view of the lift mechanism shown in FIG. 5;

[Explanation of symbols]

 Reference Signs List 12 lift gate 15 hinge shaft 24 annular channel 26 longitudinal slot 28 side wall 30 window 34 rack bar 36 tooth 38 stud 39 U-shaped shoe 40 link 42 one end of link 44 other end of link 46 power unit 48 electric motor 52 Electromagnetic clutch 56 output pinion gear

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Lloyd Walker Rogers, Jr. 48316, Michigan, USA, Shelby Township, Wolf Drive 53601 (72) Inventor Ronald James Wild, 48081, Michigan, USA Cent Claire Shores, Flatsho 21908

Claims (8)

[Claims] A power for opening and closing a vehicle lift gate pivotally mounted on a rear end of a vehicle roof by pivoting between an open position and a closed position about a substantially horizontal hinge axis. An actuation system comprising: an annular channel (24); a longitudinal slot (26) provided in a side wall (28) of the annular channel.
And an annular channel (24) having a window (30) in the side wall of the annular channel opposite the longitudinal slot; and in the channel to move within the channel. A stud (38) extending through a longitudinal slot in the side wall of the annular channel and teeth (36) facing the window in the side wall of the annular channel. A link (40) having an end (42) connectably connected to the studs, the link (40) having a rack bar (34), the link (40) being spaced apart from the hinge shaft (15). The link (40) having an opposite end (44) splicably attached to the lift gate (12); a first position for holding the lift gate of the vehicle in the open position; Re Togeto having the second within the annular channel between a position meshing with the rack bar teeth for moving the rack bar output pinion gear to retain in the closed position (56), the power unit (4
6) and a power actuation system comprising: 2. The power unit fixed to the annular channel and comprising an electric motor (48) driving the output pinion gear (56) via an electromagnetic clutch (52). Item 2. A power actuation system according to Item 1. 3. The power actuation system according to claim 1, wherein the annular channel is arranged in the vehicle in a vertical configuration. 4. The power actuation system according to claim 3, wherein the annular channel (24) is a rectangular channel fixed to the vehicle in a vertical configuration at a pillar of the vehicle. 5. The power actuation system according to claim 4, wherein the power unit is fixed to an outer wall of the channel. 6. The rectangular channel (24) has a longitudinal slot in a side wall of the rectangular channel facing rearward toward the lift gate, and the rack bar is formed in the side wall of the channel. The power actuation system of claim 5, having a stud extending through the longitudinal slot. 7. The power actuation system according to claim 6, wherein the rack bar has a U-shaped shoe (39) made of a low-friction material at each end. 8. The power actuation system according to claim 6, wherein the rectangular channel (24) is straight.