LIFT ASSIST SYSTEMS FOR MOTOR VEHICLES

Lift assist systems are provided for use with motor vehicle assemblies. An exemplary lift assist system may include features for reducing the rate at which a tailgate pivots open and reducing the amount of force required to pivot the tailgate closed.

TECHNICAL FIELD

This disclosure relates generally to motor vehicles, and more particularly to lift assist systems for a closure member of the vehicle.

BACKGROUND

Many vehicles include a tailgate disposed at a rear of the vehicle. The tailgate can include added features that increase the weight of the tailgate, thereby making the tailgate open too quickly or be too difficult to close.

SUMMARY

In some aspects, the techniques described herein relate to a vehicle assembly, including: a tailgate configured to pivot between a closed position and an open position; and a lift assist system connected to the tailgate and including a torsion rod and a nitrogen gas strut, wherein the lift assist system is configured such that, when the tailgate is pivoted from the open position to the closed position, the torsion rod applies a first force on the tailgate and the nitrogen gas strut applies a second force on the tailgate.

In some aspects, the techniques described herein relate to a vehicle assembly, wherein the torsion rod extends between a first end that is rotatably attached to a support assembly and a second end that is fixedly attached to a clamp box.

In some aspects, the techniques described herein relate to a vehicle assembly, wherein the support assembly includes a flange and a shaft that extends through the flange and rotates relative to the flange, and the first end includes an attachment sleeve that is configured to receive the shaft.

In some aspects, the techniques described herein relate to a vehicle assembly, wherein the clamp box is secured to a lower wall of the tailgate.

In some aspects, the techniques described herein relate to a vehicle assembly, wherein, when the tailgate is pivoted between the closed position and the open position, the second end does not rotate relative to the clamp box.

In some aspects, the techniques described herein relate to a vehicle assembly, wherein the nitrogen gas strut includes a first end that is pivotably attached to a support assembly and a second end that is fixedly attached to a vehicle endwall.

In some aspects, the techniques described herein relate to a vehicle assembly, wherein the vehicle endwall is a laterally extending surface of a vehicle sidewall.

In some aspects, the techniques described herein relate to a vehicle assembly, wherein the second end is above a vehicle bumper.

In some aspects, the techniques described herein relate to a vehicle assembly, wherein the support assembly includes a bracket, a support, a cup, a flange, and a bell crank.

In some aspects, the techniques described herein relate to a vehicle assembly, wherein the nitrogen gas strut is mounted in an open area defined by a vehicle sidewall and an outer panel of a vehicle body.

In some aspects, the techniques described herein relate to a vehicle assembly, including: a tailgate positioned between a first vehicle sidewall and a second vehicle sidewall, the tailgate configured to pivot between a closed position and an open position; a torsion rod rotatably attached at a first end to the first vehicle sidewall and fixedly attached at an opposite, second end to a clamp box; and a nitrogen gas strut pivotably attached at a first end to the tailgate and fixedly attached at an opposite, second end to a portion of the second vehicle sidewall.

In some aspects, the techniques described herein relate to a vehicle assembly, wherein the first end of the torsion rod extends through a first side of the tailgate and is attached to a support assembly that is secured to the first vehicle sidewall.

In some aspects, the techniques described herein relate to a vehicle assembly, wherein the support assembly includes a flange and a shaft that extends through the flange and rotates relative to the flange, and the shaft is received within an attachment sleeve of the first end.

In some aspects, the techniques described herein relate to a vehicle assembly, wherein the second end of the torsion rod includes an attachment section that is received within a channel of the clamp box so that the second end does not rotate relative to the clamp box.

In some aspects, the techniques described herein relate to a vehicle assembly, wherein the first end of the nitrogen gas strut is attached to a support assembly that is secured to the tailgate.

In some aspects, the techniques described herein relate to a vehicle assembly, wherein the support assembly includes a bracket, a support, a cup, a flange, and a bell crank.

In some aspects, the techniques described herein relate to a vehicle assembly, wherein the support includes a slot that is configured to receive a shaft that extends through a second side of the tailgate and the bracket.

In some aspects, the techniques described herein relate to a vehicle assembly, wherein a drive rod extends through the support and the bell crank, and the bell crank includes a post that is attached the second end of the nitrogen gas strut.

In some aspects, the techniques described herein relate to a vehicle assembly, wherein the second end of the nitrogen gas strut is above a vehicle bumper.

In some aspects, the techniques described herein relate to a vehicle assembly, wherein the nitrogen gas strut is mounted in an open area defined by the second vehicle sidewall and an outer panel of a vehicle body. LIFT ASSIST SYSTEMS FOR MOTOR VEHICLES

DETAILED DESCRIPTION

This disclosure details lift assist systems for controlling movement of vehicle tailgates. Exemplary lift assist systems may include a torsion rod and a nitrogen gas strut. The torsion rod and the nitrogen gas strut may include features for reducing the force needed to move the vehicle tailgate from an open position to a closed position. In some implementations, the torsion rod may be configured to apply a first force on the tailgate, and the nitrogen gas strut may be configured to apply a second force on the tailgate. These and other features are discussed in greater detail in the following paragraphs of this detailed description.

FIG.1schematically illustrate select portions of a vehicle10. The vehicle10may include a closure member, here a tailgate14, a torsion rod18, and a nitrogen gas strut22. As discussed further below, the torsion rod18and the nitrogen gas strut22may be configured to establish a lift assist system24that can both reduce the rate at which the tailgate14pivots open and reduce the amount of force required to pivot the tailgate14closed. Together, the tailgate14and the lift assist system24establish a vehicle assembly of the vehicle10.

In the illustrated embodiment, the vehicle10is depicted as a pickup truck. However, the vehicle10could alternatively be a car, a van, sports utility vehicle (SUV), or any other vehicle configuration. Although a specific component relationship is illustrated in the figures of this disclosure, the illustrations are not intended to limit this disclosure. The placement and orientation of the various components of the vehicle10are shown schematically and could vary within the scope of this disclosure. In addition, the various figures accompanying this disclosure are not necessarily drawn to scale, and some features may be exaggerated or minimized to emphasize certain details of a particular component or system.

The tailgate14is located at the rear of the vehicle10, in this example, and may be positioned between a pair of vehicle sidewalls of a vehicle body26. More specifically, one end of the tailgate14is adjacent a first vehicle sidewall30and another, opposite end of the tailgate14is adjacent a second vehicle sidewall34.

The tailgate14may be pivoted relative to the vehicle body26between a closed position shown inFIG.1and an open position shown inFIG.2. When in the closed position, the tailgate14provides a barrier between the exterior of the vehicle10and a vehicle cargo space38, such as a vehicle bed. When in the open position, the tailgate14permits users to access the vehicle cargo space38.

The tailgate14may include an integrated accessory component42, such as a step ladder, for example, which may be deployed when the tailgate14is in the open position. In some examples, the accessory component42may increase the weight of the tailgate14, thereby making the tailgate14open more quickly or be more difficult to close. The lift assist system24may therefore be provided on the vehicle10for facilitating a more positive user experience when opening or closing the tailgate14.

The torsion rod18of the lift assist system24may be mounted at least partially within the tailgate14. In this example, the torsion rod18extends longitudinally within the tailgate14.

The nitrogen gas strut22of the lift assist system24may be mounted outboard of the tailgate14. In this example, the nitrogen gas strut22is mounted adjacent to the second vehicle sidewall34.

FIGS.3-5illustrate additional details associated with the torsion rod18of the exemplary lift assist system24ofFIG.1. The torsion rod18may extend between a first end46and a second end50. The first end46may extend through a first side54of the tailgate14, and then through a bracket58, which may be secured (e.g., bolted, welded, adhered, etc.) to the first side54.

The first end46of the torsion rod18may include an attachment sleeve62for rotatably attaching to the first vehicle sidewall30via a support assembly66. The support assembly66may include a rotatable shaft70and a flange74. The rotatable shaft70extends through the flange74, in this example. The rotatable shaft70may rotate relative to the flange74. The attachment sleeve62is generally cylindrically shaped and may include a bore78for receiving the rotatable shaft70. The rotatable shaft70may be constructed to correspond to the shape of the attachment sleeve62. The flange74may include a groove82for retaining the rotatable shaft70against the flange74. The flange member74may be secured (e.g., bolted, welded, adhered, etc.) to the first vehicle sidewall30of the vehicle body26so that the torsion rod18can rotate relative to the first vehicle sidewall30.

The second end50of the torsion rod18may include an attachment section78for fixedly attaching to a clamp box82. The clamp box82may be secured (e.g., bolted, welded, adhered, etc.) to a surface, here a lower wall86of the tailgate14in this example. In other examples, the clamp box82could be secured to other portions of the vehicle body26including but not limited to the second vehicle sidewall34, inner panel sheet metal sections, and inner and/or outer hinge reinforcements. The attachment section78may include a curved portion90and a flat portion94that is substantially flat relative to the curved portion90and the generally cylindrical shape of the torsion rod18.

The clamp box82may include a first section98and a second section102that cooperate for receiving the attachment section78of the second end50. A lower side106of the first section98may provide a channel110for receiving the flat portion94, and an upper side114of the second section102may provide a channel118for receiving the curved portion90. In this example, the channel110is generally U-shaped, and the channel118is generally arc-shaped.

When the attachment section78is installed between the first section98and the second section102, the flat portion94may abut an upper wall122of the channel110, opposed sidewalls126of the channel110may abut opposed sidewalls130of the channel118, and the curved portion90of the attachment section78may abut a lower wall134of the channel118so that the attachment section78is fixed from rotation relative to the clamp box82. However, the clamp box82may cause the torsion rod18to pivot with the tailgate14. For example, if the clamp box82is secured to the lower wall86of the tailgate14, the clamp box82may pivot with the tailgate14between the closed position and the open position. With the attachment section78unable to rotate within the clamp box82, the torsional force is transferred to the first end46of the torsion bar18, which then causes the attachment sleeve62to rotate with the rotatable shaft70relative to the first vehicle sidewall30of the vehicle body26(seeFIG.4).

The torsion rod18may be configured to assist a user when lifting the tailgate14. For example, when a user pivots the tailgate14from the closed position to the open position, the second end50of the torsion rod18and the clamp box82move with the tailgate14, which causes the first end46of the torsion rod18and the attachment sleeve62to rotate with the rotatable shaft70relative to the first vehicle sidewall30(seeFIG.4). This action causes internal components of the torsion rod18to store torsional energy. When the user subsequently pivots the closure member14from the open position back to the closed position, the torsion rod18releases the stored energy and applies a first force on the tailgate14. The first force may be a spring-like force that reduces the external force needed for the user to move the closure member14back to the closed position.

FIGS.6-9illustrate additional details associated with the nitrogen gas strut22of the exemplary lift assist system24ofFIG.1. The nitrogen gas strut22may be mounted within an open area142defined by the second vehicle sidewall34and an outer panel146of the vehicle body26. The outer panel146may form an outer contour of the vehicle body26. The nitrogen gas strut22may be concealed by other components (e.g., a taillight) and is therefore generally not visible from exterior of vehicle10.

The nitrogen gas strut22may include a first end150and a second end154. The first end150may be pivotably attached to a support assembly158. The support assembly158may include a bracket162, a support166, a cup170, a flange174, and a bell crank178.

The bracket162may be secured (e.g., bolted, welded, adhered, etc.) at a second side182of the tailgate14and thus may move with the tailgate14relative to the second vehicle sidewall34. The bracket162may include a shaft186for attaching to the support166. The shaft186is fixed and thus does not pivot relative to the bracket162. The shaft186extends through an opening defined at the second side182and then through the bracket162in this example. A portion of the shaft186may be received in a slot190of the support166. The support166may include a first section194and a second section198. The first section194may extend laterally outward away from an inboard facing side202of the flange174. The first section194may be pivotably attached to the bracket162when the shaft186is in the slot190. The second section198may extend laterally outward away from an outboard facing side206of the flange174. The second section198may be pivotably attached to the bell crank178via a drive rod210. The drive rod210may extend through the cup170, the flange174, and the bell crank178.

The cup170may be secured (e.g., welded, adhered, etc.) to the flange174, which is secured (e.g., bolted, welded, adhered, etc.) to the second vehicle sidewall34. As a result, the cup170does not rotate relative to the support166and the flange174. The cup170may include one or more portions214that extend laterally outward away from the inboard facing side202of the flange174and at least partially surround the support166.

The bell crank178may include a post216for pivotably attaching the support assembly158to the first end150of the nitrogen gas strut22.

When the tailgate14is pivoted between the closed position (seeFIGS.1and6) and the open position (seeFIGS.2and3), the bracket162and the shaft186rotate relative to the second vehicle sidewall34. The support166rotates with the shaft186and thus also the bracket162, which causes the bell crank178to rotate relative to the flange174.

The second end154of the nitrogen gas strut22may be fixedly attached to a vehicle endwall218of the vehicle body26. The vehicle endwall218may be a laterally extending surface of the vehicle sidewall34. In this example, the second end154of the nitrogen gas strut22is attached at a location that is above a bumper222of the vehicle10. However, other implementations are contemplated within the scope of this disclosure.

The nitrogen gas strut22may be configured as a compressive gas strut with damping capabilities. As shown inFIGS.10and11, for example, the first end150may include a sealed container226containing pressurized nitrogen gas G, and the second end154may include a rod230and a piston234. Nitrogen gas G in the sealed container226may pass through an opening238provided between a first side242of the piston234and a second side246of the piston234.

FIG.10shows the nitrogen gas strut22in a first position when the tailgate14is in the closed position (seeFIGS.1and6), andFIG.11shows the nitrogen gas strut22in a second position when the tailgate14is in the open position (seeFIGS.2and3). When a user pivots the tailgate14from the closed position to the open position, the bracket162, the shaft186, the support166, and the bell crank178pivot relative to the second vehicle sidewall34(seeFIGS.6-9). As the bell crank178pivots, the first end150of the nitrogen gas strut22is pulled in tension away from the second end154of the nitrogen gas strut22, and the nitrogen gas G passes though the opening238from the second side246of the piston234to the first side242of the piston234. The volume of the nitrogen gas G on the first side242thereby increases, which in turn increases the amount of pressure applied on the first side242and decreases the amount of pressure applied on the second side246. This pressure differential between the first side242and the second side246causes the nitrogen gas strut22to dampen or control the rate at which the first end150moves away from the second end154. As a result, the nitrogen gas strut22may cause the tailgate14to pivot more slowly from the closed position to the open position.

When a user pivots the tailgate14from the open position to the closed position, the first end150of the nitrogen gas strut22is pushed in compression toward the second end154, and the nitrogen gas G passes through the opening238from the first side242of the piston234to the second side246of the piston234. The volume of the nitrogen gas G on the second side246thereby increases, which in turn increases the amount of pressure applied on the second side246and decreases the amount of pressure applied on the first side242. This pressure differential between the first side242and the second side246cause the nitrogen gas strut22to apply a second force on the tailgate14. The second force may be a compressive force that reduces the external force needed for the user to move the tailgate14to the closed position.

In this disclosure, like reference numerals designate like elements where appropriate and reference numerals with the addition of one-thousand or multiples thereof designate modified elements that are understood to incorporate the same features and benefits of the corresponding elements.

FIG.12illustrates another example vehicle1010. The vehicle1010may include a tailgate1014, a torsion rod1018, and a nitrogen gas strut1022. The torsion rod1018may be rotatably attached at one end1046to a first vehicle sidewall and fixedly attached at an opposite end1050to a clamp box1082. The nitrogen gas strut1022may be pivotably attached at a first end1150to the tailgate1014and fixedly attached at a second end1154to a vehicle body1026. In this example, the second end1154may be attached at a location that is vertically below the tailgate1014. In a particular example, the nitrogen gas strut1022is vertically aligned in parallel with the tailgate1014.

The torsion rods and the nitrogen gas struts of this disclosure are capable of establishing a lift assist system of the vehicle. For example, the torsion rods and the nitrogen gas struts may include features that cooperate for reducing the force needed to move a closure member from an open position to a closed position. The nitrogen gas struts may also include feature for reducing the rate at which a closure member moves from the closed position to the open position.