GB2375998A

GB2375998A - Tailgate assembly

Info

Publication number: GB2375998A
Application number: GB0113305A
Authority: GB
Inventors: Martin Charles Halliwell
Original assignee: Ford Global Technologies LLC
Current assignee: Ford Global Technologies LLC
Priority date: 2001-06-01
Filing date: 2001-06-01
Publication date: 2002-12-04
Anticipated expiration: 2021-06-01
Also published as: GB0113305D0; GB2375998B

Abstract

A tailgate assembly is disclosed in which a gas strut 8 used to support an upper tailgate 4 is connected to part of the body structure 3 of a motor vehicle by a movable mounting. In a first position indicated by the line X-X the gas strut 8 operates normally to assist opening of the upper tailgate 4 but in a second position indicated by the line Y-Y the mounting is position so as to further compress the gas strut 8 which can then be used to partially open the upper tailgate 4 without manual assistance. When the mounting 25 is in the second position the pressure in the gas strut 8 is such that it prevents full closure of the upper tailgate 4 thereby preventing the lower tailgate 6 from being closed upon it.

Description

A motor vehicle and a tailgate assemblv therefor The invention relates to motor vehicles and in particular to a tailgate assembly for a motor vehicle.

It is well known to provide a motor vehicle with a horizontally split tailgate assembly having an upper tailgate hingedly connected along an upper edge thereof to part of the body structure of the motor vehicle and a lower tailgate member hingedly connected along a lower edge thereof to part of the body structure of the motor vehicle.

It is normal for the upper tailgate to overlie the lower tailgate so that the upper tailgate can be opened without opening the lower tailgate. This is useful to put shopping into the motor vehicle without having to open both tailgates.

It is an object of this invention to provide a tailgate assembly of the type described above with improved functionality.

According to the invention there is provided a motor vehicle having a body structure and a rear mounted tailgate assembly connected to the body structure, the tailgate assembly comprising an upper tailgate member pivotally connected at an upper edge thereof to the body structure for movement between a closed position and an open position, a lower tailgate member pivotally connected at a lower edge thereof to the body structure for movement between a closed position and an open position, at least one gas strut connected at one end by a first mounting to the body structure and connected at an opposite end by a second mounting to the upper tailgate wherein at least one first mounting is movable relative to the body structure between a first position in which the upper tailgate can move to said closed position so as to overlie the lower tailgate and a second position in which the upper tailgate is prevented from moving into said closed position.

The first mounting may be movable between said first and second positions by means of an electronically controlled actuator.

The electronically controlled actuator may be an electric motor.

The electric motor may be controlled by an electronic control unit arranged to receive signals from an operator controlled switch and a sensor arranged to indicate whether the lower tailgate may be closed.

The control unit may be arranged to receive a signal indicative of first mounting position.

The switch may be part of a remote handset having a transmitter to transmit a signal to a receiver connected to the electronic control unit.

The switch may be operable to move the first mounting from said first position to said second position and release an electronic latch holding the upper tailgate closed.

The invention will now be described by way of example with reference to the accompanying drawing in which :- Fig. 1 is a side view of a motor vehicle including a rear tail gate assembly according to the invention; Fig. 2 is a partly cut-away and partly cross-sectioned view of a rear part of the motor vehicle shown in Fig. 1 showing the tailgate assembly in greater detail ; Fig. 3 is a cross-section along the line Y-Y on Fig. 2; Fig. 4 is a rear view of an electronically controlled actuator associated with a first mounting forming part of the tailgate assembly ;

Fig. 5 is a block diagram of a control circuit associated with the electronically controlled actuator; and Fig. 6 is a flow chart showing the primary logic associated with an electronic control unit use to control operation of the electronically controlled actuator.

With reference to Figs 1 to 6 there is shown a motor vehicle 2 having a body structure 3 defining a passenger compartment. A tailgate assembly is connected to the body structure 3 at the rear of the motor vehicle 2 to provide access to the passenger compartment. The rear portion of the passenger compartment is used as a luggage compartment in which goods or articles can be carried.

The tailgate assembly comprises an upper tailgate 4 which is pivotally connected at an upper edge thereof by means of two spaced apart hinges 5 to part of the body structure 3 and a lower tailgate 6 which is pivotally connected at a lower edge thereof by means of two spaced apart hinges 7 to the body structure 3.

The upper and lower tailgates 4,6 are movably between a closed position in which the upper tailgate 4 overlies the lower tailgate 6 so that access to the rear of the passenger compartment is closed off and an open position in which full access is provided to the rear of the passenger compartment.

In addition, the upper tailgate 4 can be opened without the need to open the lower tailgate 6. This is useful when it is required to place a small article into the luggage space in the rear of the passenger compartment.

The terms upper and lower edges referred to above relate to those respective edges of the upper and lower tailgates 4,6 when the tailgates 4,6 are in their closed positions.

A pair of gas struts 8 are connected between the upper tailgate 4 and the body structure 3 to assist with opening of the upper tailgate 4.

Each of the gas struts 8 is connected at one end by a first mounting 9 to the body structure and at an opposite end by a second mounting in the form of threaded fastening 18 which is engaged with an aperture in an upstanding flange 19 fixed to the upper tailgate 4.

One of the first mountings 9 is a fixed mounting providing a pivotal connection between the associated gas strut 8 and the body structure 3 and the other of the first mountings 9 is movable relative to the body structure 3 by an electronically controlled actuator in the form of an electric motor 28.

The electronically controlled first mounting 25 comprises the electric motor 28 which drives a threaded drive shaft 29 supported at one end by an end support 30 and a slider 13 slideably mounted on a track 12 defined be a slot 11 formed in part of the body structure 3.

The slider 13 has a threaded bore 14 in which is threadingly engaged the drive shaft 29 an a post 15 used to attach the slider 13 to the gas strut 8 by means of a flange 17 fixed to one end of the gas strut 8. The post 15 extends through an aperture in the flange 17 and is secured in place by a nut 16 threadingly engaged with the post 15.

A sensor wheel 31 is connected to the drive shaft 29 to provide in combination with a sensor 22 a signal that can be used to indicate the position of the slider 13.

The post 15 is movable between a first position indicated by the line X-X on Fig. 2 in which the upper tailgate 4 is free to moved to its closed position and a second position indicated by the line Y-Y on Fig. 2 in which the upper tailgate 4 is prevented from returning to its closed position. In the second position the pressure in the gas strut 8 is

sufficient to prevent further closing of the upper tailgate 4 and balances the load applied to the strut 8 by the weight of the upper tailgate 4. If an attempt is made to further close the upper tailgate 4 this is strongly resisted by the gas strut 8 and in an extreme case may result in the gas strut 8 bottoming out.

An electronic control unit 20 controls the operation of the movable mounting 25 and is connected to the electric motor 28. The electronic control unit 20 is provided with a number of input signals which it uses to determine the location of the movable mounting 25 and also the desired position of the movable mounting 25.

A first input signal is received by the control unit 20 from a micro-switch 21 used to sense whether the lower tailgate 6 is closed, a second input signal is received from the drive shaft sensor 22 which is used to indicate the position of the slider 13 and hence the position of the movable mounting 25 and a third input signal is receivable from an operator controllable switch 27.

The operator controllable switch 27 forms part of a remote handset 24 used to selectively unlock the upper tailgate 4. The handset 24 includes a lower power transmitter which is operable to send a signal to a receiver 23 connected to the control unit 20. The signal sent can be a radio signal or an infra-red signal.

The control unit 20 is arranged not only to send a control signal to the movable mounting 25 but also to an electrically controlled latch 26 used to hold the upper tailgate 4 in a closed position.

Operation is as follows, when the upper and lower tailgates 4,6 are both in their closed positions the movable mounting 25 is in its first position corresponding to the line X-X on Fig. 2. In this position the upper tailgate 4 can be manually opened and closed

normally and the gas struts 8 will assist with the opening movement of the upper tailgate 4 and partly compensate for its weight.

Operation of the switch 27 will cause the control unit 20 to send an unlocking signal to the latch 26 to release the upper tailgate 4 and also send a signal to the electric motor 28 thereby energising the electric motor 28. The electric motor 28 will rotate the drive shaft 29 in a direction producing motion of the slider 13 towards the second position corresponding to the line Y-Y on Fig. 2. This motion will increase the gas pressure within the gas strut 8 so that the upper tailgate 4 will spring open.

The continued motion of the first mounting 25 towards the second position continues to compress the gas within the gas strut 8 thereby urging the upper tailgate 4 into a partially or fully opened position. After a pre-determined time delay the control unit 20 will move the first mounting 25 back to its first position unless the lower tailgate 6 is sensed to be open.

If the lower tailgate 6 is open then the movable first mounting 25 is maintained in the second position. With the movable first mounting 25 in the second position it is not possible to close the upper tailgate 4 because the pressure build up in the gas strut 8 is too great and the upper tailgate 6 is thereby prevented from closing fully.

When the lower tailgate 6 is sensed to be closed then the movable mounting 25 is returned to its first position and the upper tailgate 4 can be fully closed and brought into latching co-operation with the latch 26.

In this way the movable mounting is able to provide automatic remote opening of the upper tailgate 4 and also a safety stop to prevent the upper tailgate 4 from being closed before the lower tailgate 6 is closed.

It will be appreciated that if the upper tailgate 4 were closed before the lower tailgate 6 then the upper tailgate 4 could be damaged by the incorrect closing of the lower tailgate 6 onto it.

Although the invention has been described with reference to the use of only one movable first mounting 25 it will be appreciated that both gas struts could be connected to the body structure by means of a movable mounting which would enable a greater opening load to be be applied to the upper tailgate 4 and also greater resistance to incorrect closing.

It will also be appreciated that the remote handset could be replaced by a switch located in the passenger compartment or both types of switch could be provided to permit automatic opening of the upper tailgate.

Claims

CLAIMS 1. A motor vehicle having a body structure and a rear mounted tailgate assembly

connected to the body structure, the tailgate assembly comprising an upper i CAIIUCLL u tailgate member pivotally connected at an upper edge thereof to the body structure for movement between a closed position and an open position, a lower tailgate member pivotally connected at a lower edge thereof to the body structure for movement between a closed position and an open position, at least one gas strut connected at one end by a first mounting to the body structure and connected at an opposite end by a second mounting to the upper tailgate wherein at least one first mounting is movable relative to the body structure between a first position in which the upper tailgate can move to said closed position so as to overlie the lower tailgate and a second position in which the upper tailgate is prevented from moving into said closed position.
2. A motor vehicle as claimed in Claim 1 in which the first mounting is movable between said first and second positions by means of an electronically controlled actuator.
3. A motor vehicle as claimed in Claim 2 in which the electronically controlled actuator is an electric motor.
4. A motor vehicle as claimed in Claim 3 in which the electric motor is controlled by an electronic control unit arranged to receive a signal from an operator controlled switch.
5. A motor vehicle as claimed in Claim 4 in which the control unit is arranged to receive a signal from a sensor arranged to indicate whether the lower tailgate is closed.

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6. A motor vehicle as claimed in Claim 4 or in Claim 5 in which the control unit is arranged to receive a signal indicative of first mounting position.
7. A motor vehicle as claimed in Claim 4 or in Claim 5 in which the switch is part of a remote handset having a transmitter to transmit a signal to a receiver connected to the electronic control unit.
8. A motor vehicle as claimed in any of Claims 4 to 6 in which the switch is operable to move the first mounting from said first position to said second position and release an electronic latch holding the upper tailgate closed.
9. A motor vehicle substantially as described herein with reference to the accompanying drawing.