Strut assembly

Abstract

Aspects of the present invention relate to a strut assembly (10) for a powered vehicle closure. The strut assembly comprises a closure mounting structure (12) for coupling the strut assembly to a vehicle closure, and a body mounting structure (14) for coupling the strut assembly to a vehicle body. The strut assembly comprises an active portion (16) arranged between the closure mounting structure and the body mounting structure. The active portion comprises an actuator (18) configured to move the strut assembly between a retracted state and an extended state in response to a control signal. The strut assembly also comprises a passive portion (20) arranged between the closure mounting structure and the body mounting structure. The passive portion is configured to permit extension of the strut assembly independently of the control signal.

Description

[0001] STRUT ASSEMBLY

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to a strut assembly. Aspects of the invention relate to a strut assembly, a vehicle system, and a vehicle.

[0004] BACKGROUND

[0005] It is known to provide a vehicle closure (e.g., bonnet / hood or boot / tailgate) which is hingedly coupled to a vehicle body. It is also known to provide an extendable strut assembly which is coupled to the vehicle body and the vehicle closure in order to assist with and / or control pivoting of the vehicle closure about its hinge(s).

[0006] One type of known strut assembly includes a gas spring which uses compressed gas to support some of the weight of a vehicle closure when it is opened. This reduces the effort required to lift the vehicle closure. Another type of known strut assembly includes an actuator which is configured to extend and retract the strut assembly in response to a control signal. This enables the strut assembly to automatically open and close the vehicle closure, or otherwise reduce the user effort required to open / dose the vehicle closure, for example in response to a button or switch activation.

[0007] It is an aim of the present invention to address one or more of the disadvantages associated with the prior art.

[0008] SUMMARY OF THE INVENTION

[0009] Aspects and embodiments of the invention provide a strut assembly, a vehicle system, and a vehicle as claimed in the appended claims.

[0010] According to an aspect of the present invention there is provided a strut assembly for a powered vehicle closure. The strut assembly comprises a closure mounting structure for coupling the strut assembly to a vehicle closure, and a body mounting structure for coupling the strut assembly to a vehicle body. The strut assembly comprises an active portion arranged between the closure mounting structure and the body mounting structure and operable to move the strut assembly between a retracted state and an extended state in response to a control signal. The strut assembly also comprises a passive portion arranged between the closure mounting structure and the body mounting structure and configured to permit extension of the strut assembly independently of the control signal. The active portion may comprise an actuator configured to move the strut assembly between the retracted state and the extended state.

[0011] With this arrangement, the active portion is operable to extend and retract the strut assembly during opening and closing of the vehicle closure. This enables the strut assembly to automatically open and close the vehicle closure, for example in response to a button or switch activation, or otherwise reduce the user effort required to open / dose the vehicle closure under normal conditions (i.e., following receipt of a control signal). Furthermore, having such a passive portion allows extension of the strut assembly independently of the control signal when required. For example, the passive portion may allow rapid extension of the strut assembly when an active pedestrian safety mechanism is deployed to urge the vehicle closure away from the vehicle body, without the need for the active portion to operate. This can be particularly beneficial where the passive portion permits extension of the strut assembly more rapidly than the active portion. Additionally, the passive portion may allow extension of the strut assembly when an object is placed under the vehicle closure and would otherwise obstruct normal closing of the vehicle closure. In other words, the passive portion may extend from a retracted position of the passive portion to an extended position of the passive portion while the active portion retracts, to avoid pinching or crushing of the object and / or damage to the actuator. As used herein, the term extension of the strut assembly refers to an increase in the distance between the closure mounting structure and the body mounting structure along the length of the strut assembly, i.e., parallel to and / or along the longitudinal axis of the strut assembly. The extension of the strut assembly permitted by the passive portion may be less than, equal to, or greater than the extension of the strut assembly when the active portion moves the strut assembly from the retracted state to the extended state. For example, the extension of the strut assembly permitted by the passive portion may be 5%, 10%, 15%, 20%, 30%, 40%, 50%, 60%, 70%, 80% or 90% of the extension of the strut assembly when the active portion moves the strut assembly from the retracted state to the extended state. In this manner, the passive portion can still permit extension of the strut assembly independently of the control signal without the need to extend the strut assembly to the fully extended state. This can facilitate a more compact arrangement.

[0012] As used herein, the term “active portion” refers to a portion of the strut assembly which generates, transfers, or otherwise exerts a longitudinal force to extend and / or retract the strut assembly in response to a control signal. In other words, when the active portion receives an appropriate control signal, it may use a source of power (e.g., an electrical, pneumatic, hydraulic, or other suitable source of power) to provide the longitudinal force to extend and / or retract the strut assembly.

[0013] As used herein, the term “passive portion” refers to a portion of the strut assembly which is configured to move between extended and retracted states of the passive portion in response to external forces (i.e., forces not produced by the strut assembly) acting to move the closure and body mounting structures towards or away from each other. As such, the state of the passive portion is not controlled by a control signal. For example, the passive portion may be urged to a retracted state of the passive portion by the weight of the vehicle closure urging the closure and body mounting structures towards each other and / or via a spring (e.g., gas or mechanical spring), and may be urged to an extended state of the passive portion when an upward force is applied to the vehicle closure (e.g., by an explosive charge of an active pedestrian safety system, or a reactive force of an obstruction under the vehicle closure as the active portion of the strut assembly retracts).

[0014] Optionally, the passive portion is configured to permit both extension and retraction of the strut assembly independently of the control signal. The passive portion being configured to permit retraction as well as extension of the strut assembly allows the strut assembly to return to a fully retracted state after extension of the passive portion (e.g., after a force which led to extension of the passive portion, such as a pinched object, is removed). This contrasts with arrangements where the passive portion is configured to permit extension only, which may require replacement of the strut assembly after the passive portion has been extended.

[0015] Optionally, the actuator is configured to extend or retract the strut assembly at a first rate of movement and the passive portion is configured to permit extension of the strut assembly at a second rate of movement, wherein the second rate of movement is faster than the first rate of movement. It will be understood that it is desirable for vehicle closures to move relatively slowly when being opened / closed during normal use in response to a control signal (e.g., to give time to move any obstructions out of the path of the vehicle closure). However, it will also be understood that vehicle closures need to move comparatively much faster when deployed as part of an active pedestrian safety mechanism. Therefore, having the second rate of movement being faster than the first rate of movement facilitates suitable rates of movement of the vehicle closure in normal and active pedestrian safety conditions.

[0016] Optionally, the passive portion is configured to permit transition from a fully retracted position to a fully extended position in less than 20ms, optionally less than 15ms. That is, the passive portion is configured to transition from a fully retracted position of the passive portion to a fully extended position of the passive portion in less than 20ms, optionally less than 15ms. In some embodiments, the passive portion comprises one or more extendable elements which can extend freely under the influence of external forces acting to urge the closure and body mounting structures away from each other. In other words, there is no mechanical or electromechanical mechanism which needs to be actuated to extend the passive portion. This allows the passive portion to permit rapid extension when subjected to large external forces (e.g., such as those provided by an explosive charge of an active pedestrian safety mechanism).

[0017] In some embodiments, the passive portion comprises a plurality of extendable elements which are slidable relative to each other to extend the passive portion. In some embodiments, the passive portion comprises a low-friction interface between the plurality of extendable elements (e.g., a lubricated interface), to permit rapid extension of the passive portion. In some embodiments, the extendable elements include a shaft slidable relative to a passive housing part, wherein the shaft can move freely relative to the passive housing part to permit rapid extension of the passive portion. In some embodiments, the shaft comprises a first end with a piston located within the passive housing part, wherein there is a low-friction interface (e.g., a lubricated interface) between the piston and an internal wall of the passive housing part to permit rapid extension of the passive portion.

[0018] In some embodiments, the passive portion comprises a resilient arrangement or spring (e.g., a gas spring or mechanical spring) which biases the passive portion towards the fully retracted position or the fully extended position. It will be understood that in such embodiments, although the spring may exert a longitudinal force to extend or retract the strut assembly, the longitudinal force is not applied in response to a control signal or using an external source of power, and is therefore not an “active” extension or retraction force.

[0019] In some embodiments, the passive portion comprises a resilient arrangement or spring (e.g. gas spring or mechanical spring) which biases the passive portion towards the fully retracted position. In this way, the normal unloaded condition of the passive portion (i.e., the condition when no forces are applied to urge the body and closure mounting structures towards or away from each other) is to the retracted position. It will be understood that, in such embodiments, transition to the fully extended state of the passive portion would still be permitted when external forces are applied to the strut assembly (e.g., to urge the closure and body mounting structures apart), when the external forces are greater than the biasing force provided by the spring. It will be understood that in such embodiments, although the spring may exert a longitudinal force to retract the strut assembly when the passive portion is extended, the longitudinal force is not applied in response to a control signal or using an external source of power, and is therefore not an “active” retraction force.

[0020] In some embodiments, the passive portion comprises a resilient arrangement or spring (e.g., a gas spring or mechanical spring) which biases the passive portion towards the fully extended position to facilitate rapid extension of the passive portion. It will be understood that in such embodiments, the biasing force of the spring may be less than a weight of the vehicle closure that is applied to the strut assembly so that the passive portion stays in its fully retracted position during normal use. However, when the vehicle closure is urged upwards (e.g., by an explosive charge of an active pedestrian safety mechanism) the spring may work with the explosive charge to facilitate more rapid extension of the passive portion than would be achieved by the explosive charge alone. It will be understood that in such embodiments, although the spring may exert a longitudinal force to extend the strut assembly when the passive portion is retracted, the longitudinal force is not applied in response to a control signal or using an external source of power, and is therefore not an “active” extension force. Optionally, the active portion comprises an active housing part arranged between the closure and body mounting structures, and a shaft slidable relative to the active housing part to move the strut assembly between the retracted and extended states. Such an arrangement with a shaft slidable relative to a housing part facilitates controlled extension / retraction. For example, using screw mechanisms, pistons, gas springs, dampers or other mechanisms coupled to the shaft and arranged within the housing.

[0021] Optionally, the passive portion comprises a passive housing part arranged between the closure and body mounting structures, and a shaft slidable relative to the passive housing part to permit extension of the strut assembly independently of the active portion. Such an arrangement with a shaft slidable relative to a housing part facilitates controlled extension / retraction of the passive portion. For example, using screw mechanisms, pistons, gas springs, dampers or other mechanisms coupled to the shaft and arranged within the housing.

[0022] Optionally, the strut assembly comprises a single housing which defines the active housing part and the passive housing part, and which comprises an internal divider which separates the active housing part from the passive housing part. Such an arrangement provides a compact arrangement and reduces the number of required components.

[0023] Optionally, the active housing part and the passive housing part are discrete housings coupled to each other. Such an arrangement facilitates the use of off-the-shelf housings, which may simplify manufacturing of the strut assembly.

[0024] Optionally, the shaft of the active portion and the shaft of the passive portion are separate shafts which protrude from the respective housing parts in opposite directions.

[0025] Optionally, the strut assembly comprises a common shaft which defines the shaft of the active portion and the shaft of the passive portion, wherein the common shaft comprises a first end moveable within the active housing part and a second end moveable within the passive housing part. In other words, the active and passive housing parts may be coupled to each other via the common shaft.

[0026] Optionally, the active and passive housing parts are telescopically arranged with respect to each other. This may provide a compact strut assembly with a reduced fully retracted length.

[0027] Optionally, the shaft of the active portion defines the passive housing part of the passive portion. In other words, the passive portion is provided telescopically inside the active portion. Since the passive portion does not require an actuator, it is easier to fit the passive portion inside a larger active portion than vice versa.

[0028] Optionally, the passive portion and / or active portion comprises a fluid within the respective housing part and a piston at a first end of the respective shaft, wherein the fluid is configured to be compressed as the piston moves within the respective housing part. Such a compressed fluid may facilitate a controlled extension and retraction of the strut assembly. For example, where the passive portion has such a fluid, compression of the fluid may provide a slower retraction of the passive portion following extension of the passive portion due to a trapped object, which may avoid sudden slamming shut of the vehicle closure after removal of the obstruction. As another example, where the active portion has such a fluid, compression of the fluid may resist movement of the vehicle closure (e.g., due to the weight of the vehicle closure) which may reduce the power requirements of the actuator. Optionally, the active and passive portions are arranged in series along the length of the strut assembly. This may provide a compact arrangement in a direction transverse to the longitudinal axis.

[0029] Optionally, the active and passive portions are coaxially aligned, optionally along a longitudinal axis which passes through the closure mounting structure and the body mounting structure.

[0030] Alternatively, the active and passive portions may each have respective longitudinal axes which are arranged parallel to but spaced apart from each other. In other words, at least part of the active and passive portions may be arranged side-by-side. This may provide a compact arrangement in a direction parallel to the longitudinal axes.

[0031] Optionally, the actuator comprises an electric motor coupled to a screw mechanism. Such an actuator provides a simple means for active extension / retraction of the strut assembly. Furthermore, such an actuator can be supplied by an electrical source on a vehicle (e.g., a battery) which removes the need for a separate power source (e.g., an air compressor in a pneumatic actuator).

[0032] Alternatively, any other type of suitable actuator may be used, such as a double-acting hydraulic or pneumatic cylinder.

[0033] Optionally, the minimum distance between the closure and body mounting structures, i.e., when the active portion and the passive portion are both fully retracted, is in the range of 100 mm to 1500 mm (e.g., 100 mm to 300 mm, 200 mm to 500 mm, 400 mm to 900 mm, 800 mm to 1200 mm, or 1100 mm to 1500 mm) and the maximum distance between the closure and body mounting structures, i.e., when the active portion is fully extended and the passive portion is fully extended, is in the range of 175mm to 2750 mm (e.g., 175 mm to 425 mm, 350 mm to 800 mm, 700 mm to 1300 mm, 1200 mm to 1900 mm, or 1800 mm to 2750 mm). The active extended distance between the closure and body mounting structures (i.e., the distance between the closure and body mounting structures when the active portion is fully extended and the passive portion is fully retracted) may be in the range of 150 mm to 2500 mm (e.g., 150 mm to 400 mm, 300 mm to 700 mm, 600 mm to 1100 mm, 1000 mm to 1600 mm, or 1500 mm to 2500 mm). The passive extended distance between the closure and body mounting structures (i.e., the distance between the closure and body mounting structures when the passive portion is fully extended and the active portion is fully retracted) may be in the range of 125mm to 1750 mm (e.g., 125mm to 300mm, 250mm to 600mm, 500mm to 1000mm, 900mm to 1400mm, or 1200mm to 1750mm) . Such distances are suitable for opening and closing typical vehicle closures.

[0034] Optionally, the distance between the closure and body mounting structures when the active portion is fully extended and the passive portion is fully retracted minus the distance between the closure and body mounting structures when the active portion and the passive portion are both fully retracted defines an active extension range. Optionally, the distance between the closure and body mounting structures when the passive portion is fully extended and the active portion is fully retracted minus the distance between the closure and body mounting structures when the active portion and the passive portion are both fully retracted defines a passive extension range. Optionally, the sum of the active and passive extension ranges defines a maximum extension range of the strut assembly (i.e., the distance between the closure and body mounting structures when the active portion and the passive portion are both fully extended minus the distance between the closure and body mounting structures when the active portion and the passive portion are both fully retracted). The active extension range may be greater than 10%, greater than 20%, greater than 30%, greater than 40%, greater than 50%, greater than 60%, greater than 70%, greater than 80% or greater than 90% of the maximum extension range, with the passive extension range providing the remainder of the maximum extension range (i.e., being less than 90%, less than 80%, less than 70%, less than 60%, less than 50%, less than 40%, less than 30%, less than 20% or less than 10% of the maximum extension range). Put another way, the active extension range may be less than 90%, less than 80%, less than 70%, less than 60%, less than 50%, less than 40%, less than 30%, less than 20% or less than 10% of the maximum extension range, with the passive extension range providing the remainder of the maximum extension range (i.e., being greater than 10%, greater than 20%, greater than 30%, greater than 40%, greater than 50%, greater than 60%, greater than 70%, greater than 80% or greater than 90% of the maximum extension range).

[0035] According to another aspect of the invention, a vehicle system is provided. The vehicle system comprises a vehicle closure hingedly coupled to a vehicle body, and at least one strut assembly as disclosed herein. The closure mounting structure of the at least one strut assembly may be coupled to the vehicle closure and the body mounting structure of the at least one strut assembly may be coupled to the vehicle body. Such a vehicle system benefits from the advantages of the strut assembly outlined above.

[0036] Optionally, the vehicle closure comprises a front or rear vehicle closure (e.g., a bonnet / hood or tailgate).

[0037] Optionally, the at least one strut assembly is arranged so that a weight of the vehicle closure acts against extension of the passive portion. Such an arrangement avoids unwanted extension of the passive portion.

[0038] Optionally, the vehicle system further comprises an active pedestrian safety mechanism configured to be deployed to urge the vehicle closure away from the vehicle body, wherein the passive portion of the at least one strut assembly is configured to be extended when the active pedestrian safety mechanism is deployed. Such a vehicle system allows the vehicle closure to be raised to cushion a pedestrian in the event of an impact.

[0039] Optionally, the active pedestrian safety mechanism comprises an explosive charge configured to break the hinged coupling between the vehicle closure and the vehicle body when urging the vehicle closure away from the vehicle body. Such an explosive charge may facilitate a rapid deployment when a pedestrian impact is imminent).

[0040] According to another aspect of the invention, a vehicle is provided. The vehicle comprises a vehicle system as disclosed herein. Such a vehicle benefits from the advantages of the vehicle system outlined above.

[0041] Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and / or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and / or features of any embodiment can be combined in any way and / or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and / or incorporate any feature of any other claim although not originally claimed in that manner.

[0042] BRIEF DESCRIPTION OF THE DRAWINGS

[0043] One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0044] Figure 1 shows a strut assembly in accordance with an embodiment of the invention, in which active and passive portions are fully retracted; Figure 2 shows the strut assembly of Figure 1 with the active portion extended and the passive portion retracted;

[0045] Figure 3 shows the strut assembly of Figures 1 and 2 with the active portion retracted and the passive portion extended;

[0046] Figure 4 shows a strut assembly in accordance with a further embodiment of the invention;

[0047] Figure 5A shows a strut assembly in accordance with a further embodiment of the invention, in which active and passive portions are fully retracted;

[0048] Figure 5B shows the strut assembly of Figure 5A with the active portion extended and the passive portion retracted;

[0049] Figure 5C shows the strut assembly of Figures 5A and 5B with the active portion retracted and the passive portion extended;

[0050] Figure 6A shows a strut assembly in accordance with a further embodiment of the invention, in which active and passive portions are fully retracted;

[0051] Figure 6B shows the strut assembly of Figure 6A with the active portion extended and the passive portion retracted;

[0052] Figure 6C shows the strut assembly of Figures 6A and 6B with the active portion retracted and the passive portion extended;

[0053] Figure 7A shows a schematic representation of a vehicle system with a vehicle closure and a strut assembly in a fully retracted state;

[0054] Figure 7B shows a schematic representation of a vehicle system with a vehicle closure and a strut assembly having an active portion in an extended state;

[0055] Figure 7C shows a schematic representation of a vehicle system with a vehicle closure and a strut assembly having a passive portion which has been extended due to an object obstructing shutting of the vehicle closure;

[0056] Figure 7D shows a schematic representation of a vehicle system with a vehicle closure and a strut assembly having a passive portion which has been extended due to a body portion obstructing shutting of the vehicle closure;

[0057] Figure 7E shows a schematic representation of a vehicle system with a vehicle closure and a strut assembly having a passive portion which has been extended by deployment of an active pedestrian safety mechanism; and

[0058] Figure 8 shows a vehicle in accordance with an embodiment of the invention.

[0059] DETAILED DESCRIPTION

[0060] A strut assembly in accordance with an embodiment of the present invention is described herein with reference to the accompanying Figures 1 to 3. As shown in Figures 7A to 7E and Figure 8, the strut assembly may be part of a vehicle system 100 and of a vehicle 200. With reference to Figures 1 to 3, a strut assembly for a powered vehicle closure is indicated at 10. The strut assembly 10 has a closure mounting structure 12 for coupling the strut assembly 10 to a vehicle closure, and a body mounting structure 14 for coupling the strut assembly 10 to a vehicle body. The closure and body mounting structures 12, 14 are configured to permit rotation of the strut assembly 10 relative to the closure and body in a conventional manner, for example via a ball stud or a pivot pin.

[0061] The strut assembly 10 has an active portion 16 arranged between the closure mounting structure 12 and the body mounting structure 14. As will be described in more detail below, the active portion 16 may have an actuator 18 configured to move the strut assembly 10 between a retracted state (as illustrated in Figure 1) and an extended state (as illustrated in Figure 2) in response to a control signal. With this arrangement, the active portion 16 is operable to extend and retract the strut assembly 10 during opening and closing of the vehicle closure. This enables the strut assembly 10 to automatically open and close the vehicle closure, for example in response to a button or switch activation, or otherwise reduce the user effort required to open / dose the vehicle closure under normal conditions (i.e., following receipt of the control signal).

[0062] The strut assembly 10 also has a passive portion 20 arranged between the closure mounting structure 12 and the body mounting structure 14. As will be described in more detail below, the passive portion 20 is configured to permit extension of the strut assembly 10 independently of the control signal to which the actuator 18 responds (as illustrated in Figure 3). Having such a passive portion 20 allows extension of the strut assembly 10 independently of the control signal when required. For example, the passive portion 20 may allow rapid extension of the strut assembly 10 when an active pedestrian safety mechanism is deployed to urge the vehicle closure away from the vehicle body, thereby preventing slow extension of the strut assembly from stopping the deployment of the safety mechanism. Additionally, the passive portion 20 may allow extension of the strut assembly 10 when an object is trapped under the vehicle closure. In other words, the passive portion 20 may extend while the active portion 16 retracts to avoid pinching of the object and / or damage to the actuator 18.

[0063] The passive portion 20 may be configured to permit both extension and retraction of the strut assembly 10 independently of the control signal to which the actuator 18 responds. This allows the strut assembly 10 to return to a fully retracted state after extension of the passive portion 20 (e.g. , after a force which led to extension of the passive portion 20, such as a pinched object, is removed). In other words, the strut assembly 10 can transition from the state shown in Figure 3 back to the state shown in Figure 1. This contrasts with arrangements where the passive portion is configured to permit extension only (i.e., from the state of Figure 1 to the state of Figure 3, but not vice versa), which may require replacement of the strut assembly 10 after the passive portion 20 has been extended.

[0064] The active portion 16 has an active housing part 22A arranged between the closure and body mounting structures 12, 14 and a shaft 24A slidable relative to the active housing part 22A to move the strut assembly 10 between the retracted and extended states. Similarly, the passive portion 20 has a passive housing part 22B arranged between the closure and body mounting structures 12, 14 and a shaft 24B slidable relative to the passive housing part 22B to permit extension of the strut assembly 10 independently of the active portion 16.

[0065] In the embodiment of Figures 1 to 3, the strut assembly 10 has a single housing 22 which defines the active housing part 22A and the passive housing part 22B. The single housing 22 has an internal divider 25 which separates the active housing part 22A from the passive housing part 22B. In alternative embodiments, the active housing part 22A and the passive housing part 22B may be discrete housings coupled to each other (e.g., fixed together via welding, fasteners, or any other suitable coupling means, or coupled via one or more intermediate components, such as a common shaft as in the embodiment of Figures 6A to 6C described below).

[0066] In the embodiment of Figures 1 to 3, the shaft 24A of the active portion 16 and the shaft 24B of the passive portion 20 are separate shafts which protrude from the respective housing parts 22A, 22B in opposite directions. In particular, each of the shafts 24A, 24B has a first end 26A, 26B which is moveable within the respective housing part 22A, 22B and a second end 28A, 28B which is external to the respective housing part 22A, 22B. The second ends 28A, 28B of the shafts 24A, 24B are positioned at opposite ends of the strut assembly 10 to each other. In the illustrated embodiment, the closure mounting structure 12 is provided at the second end 28A of the shaft 24A of the active portion 16 (e.g., integrally formed or attached thereto), and the mounting structure 14 is provided at the second end 28B of the shaft 24B of the passive portion 20 (e.g., integrally formed or attached thereto). In alternative embodiments, the closure and body mounting structures 12, 14 are provided at the opposite ends.

[0067] In alternative embodiments, the shaft 24A of the active portion 16 and the shaft 24B of the passive portion 20 may be separate shafts which protrude from the respective housing parts 22A, 22B in the same direction. For example, the body mounting structure 14 may be fixed to the passive housing part 22B, the second end 28B of the shaft 24B of the passive portion 20 may be coupled to the active housing part 22A, and the closure mounting structure 12 may be provided at the second end 28A of the shaft 24A of the active portion 16.

[0068] In the embodiment of Figures 1 to 3, the active and passive portions 16, 20 are arranged in series along the length of the strut assembly 10. In particular, the active and passive portions 16, 20 are coaxially aligned along a longitudinal axis which passes through the closure mounting structure 12 and the body mounting structure 14. In alternative embodiments, the active and passive portions 16, 20 may be coaxially aligned along a longitudinal axis, but with one or both of the closure and body mounting structures 12, 14 offset from the longitudinal axis.

[0069] In alternative embodiments, the active and passive portions 16, 20 each have respective longitudinal axes which are arranged parallel to but spaced apart from each other. In other words, at least part of the active and passive portions 16, 20 may be arranged side-by- side.

[0070] In the embodiment of Figures 1 to 3, the actuator 18 has an electric motor 30 in the active housing part 22A coupled to a screw mechanism 32, which provides a simple means for active extension / retraction of the strut assembly 10. In particular, the screw mechanism 32 includes a threaded screw or spindle 34 which is rotated by the electric motor 30 and a threaded nut 36 which is fixed relative to the shaft 24A of the active portion 16 and secured against rotation relative to the active housing part 22A by any suitable anti-rotation means. The threaded screw or spindle 34 engages the threaded nut 36 so that rotation of the threaded screw or spindle 34 by the motor 30 is translated to linear movement of the threaded nut 36 along the threaded screw or spindle 34.

[0071] The motor 30 has power connectors 38 for coupling to an electrical source on a vehicle (e.g., a battery) to power the actuator 18. For example, the power connectors 38 may be supplied with power from an actuator control system 40 to power the motor 30 in response to the actuator control system 40 receiving a control signal to extend or retract the strut assembly 10. It will be understood that the power connectors 38 connect the motor 30 to an electrical circuit. When power flows through the electrical circuit in a first direction, the motor 30 rotates the threaded screw or spindle 34 in a first direction. When power flows through the electrical circuit in a second direction (i.e., opposite to the first direction), the motor 30 rotates the threaded screw or spindle 34 in a second direction. In some embodiments, the screw mechanism 32 also includes a gear arrangement 42 which changes the rate of rotation of the threaded screw or spindle 34 relative to the rate of rotation of the motor 30. For example, the gear arrangement 42 may decrease the rate of rotation of the threaded screw or spindle 34 relative to the rate of rotation of the motor 30. In this way, a relatively high-speed but low torque motor rotation is translated to a relatively slow-speed but higher torque screw / spindle rotation, which increases the extension force of the strut assembly 10 to facilitate lifting of the vehicle closure 102. In other embodiments, the gear arrangement 42 may increase the rate of rotation of the threaded screw or spindle 34 relative to the rate of rotation of the motor 30 (e.g., to facilitate faster opening / closing of the vehicle closure).

[0072] In alternative embodiments, any other type of suitable actuator may be used, such as a double-acting hydraulic or pneumatic cylinder, or a linear motor.

[0073] It will be understood that the actuator 18 is configured to extend or retract the strut assembly 10 at a first rate of movement which is dependent on the structure of the actuator 18. For example, in the embodiment of Figures 1 to 3, the rate of rotation of the threaded screw or spindle 34 as well as the pitch of the threads of the threaded screw or spindle 34 and the threaded nut 36 will determine the rate of extension and retraction of the strut assembly 10.

[0074] The passive portion 20 may be configured to permit extension of the strut assembly 10 at a second rate of movement which is faster than the first rate of movement. In particular, the passive portion 20 is configured to permit transition from its fully retracted position to its fully extended position in less than 20ms, optionally less than 15ms. For example, in the embodiment of Figures 1 to 3, the first end 26B of the shaft 24B of the passive portion 20 can move freely within the passive housing part 22B under the influence of external forces urging the closure and body mounting structures 12, 14 away from each other. This means that when a large force is applied (e.g., an upwards force applied to a vehicle closure by an explosive charge of an active pedestrian safety mechanism), the passive portion 20 can extend rapidly from the retracted position illustrated in Figure 1 to the extended position illustrated in Figure 3.

[0075] In some embodiments, the passive portion 20 comprises a low-friction interface (e.g., a lubricated interface) between the first end 26B of the shaft 24B of the passive portion 20 and the passive housing part 22B, to facilitate the rapid extension of the passive portion 20. For example, the interface between piston 44 (described below) and the passive housing part 22B may be a lubricated interface.

[0076] In some embodiments, the passive portion 20 has a fluid within the passive housing part 22B and a piston 44 at a first end 26B of the shaft 24B of the passive portion 20. The fluid is configured to be compressed as the piston 44 moves within the passive housing part 22B. Such a compressed fluid may facilitate a controlled extension and retraction of the strut assembly 10. For example, compression of the fluid may bias the shaft 24B of the passive portion 20 to an extended or retracted state. Alternatively, compression of the fluid may provide a slower retraction of the passive portion 16 following extension due to a trapped object, which may avoid sudden slamming shut of the vehicle closure after removal of the obstruction. In some embodiments, the piston 44 includes a valve or other opening which permits a slow bleed of the compressed fluid to facilitate controlled retraction of the passive portion 20.

[0077] In some embodiments, a fluid-tight arrangement is provided in which compressed fluid is provided within the passive housing part 22B to urge the shaft 24B of the passive portion 20 to a retracted state. In this way, the natural unloaded condition of the passive portion 20 is to the retracted state, but transition to an extended state is permitted when external forces are applied to the strut assembly 10 that are greater than the biasing force provided by the compressed fluid. This may help to keep the passive portion 20 retracted during normal use. In other words, the passive portion 20 may include a gas spring which biases the shaft 24B of the passive portion 20 towards a retracted state. In other embodiments, the passive portion 20 may include a different kind of spring (e.g., a mechanical coil spring) for the same purpose.

[0078] In some embodiments, a fluid-tight arrangement is provided in which the fluid remains compressed when the passive portion 20 is in a retracted state (e.g., due to weight of the vehicle closure). Such a compressed fluid may facilitate faster extension of the passive portion 20 (e.g., when an active pedestrian safety mechanism is deployed). In other words, the passive portion 20 may include a gas spring which biases the passive portion 20 towards an extended state. In other embodiments, the passive portion 20 may include a different kind of spring (e.g., a mechanical coil spring) for the same purpose.

[0079] In some embodiments, the active portion 16 has a fluid within the active housing part 22A and a piston 44 at a first end 26B of the shaft 24B of the active portion 16. The fluid is configured to be compressed as the piston 44 moves within the active housing part 22A. Such a compressed fluid may facilitate a controlled extension and retraction of the strut assembly 10. For example, compression of the fluid may resist movement of the vehicle closure (e.g., due to the weight of the vehicle closure) which may reduce the power requirements of the actuator 18. In other words, the active portion 16 may include a gas spring which contributes towards movement of the vehicle closure. In other embodiments, the active portion 16 may include a different kind of spring (e.g., a mechanical coil spring) for the same purpose.

[0080] It will be understood that the strut assembly 10 has a minimum distance between the closure and body mounting structures 12, 14 when the active and passive portions 16, 20 are both fully retracted, as in Figure 1. In some embodiments, the minimum distance may be in the range of 100 mm to 1500 mm (e.g., 100 mm to 300 mm, 200 mm to 500 mm, 400 mm to 900 mm, 800 mm to 1200 mm, or 1100 mm to 1500 mm). The strut assembly 10 also has an active extended distance between the closure and body mounting structures 12, 14 when the active portion 16 is fully extended and the passive portion 20 is fully retracted, as in Figure 2. In some embodiments, the active extended distance may be in the range of 150 mm to 2500 mm (e.g., 150 mm to 400 mm, 300 mm to 700 mm, 600 mm to 1100 mm, 1000 mm to 1600 mm, or 1500 mm to 2500 mm). The strut assembly 10 also has a passive extended distance between the closure and body mounting structures 12, 14 when the passive portion 20 is fully extended and the active portion 16 is fully retracted, as in Figure 3. In some embodiments, the passive extended distance may be in the range of 125mm to 1750 mm (e.g., 125mm to 300mm, 250mm to 600mm, 500mm to 1000mm, 900mm to 1400mm, or 1200mm to 1750mm). The strut assembly 10 also has a maximum extended distance between the closure and body mounting structures 12, 14 when the active and passive portions 16, 20 are both fully extended. In some embodiments, the maximum extended distance may be in the range of 175mm to 2750 mm (e.g., 175 mm to 425 mm, 350 mm to 800 mm, 700 mm to 1300 mm, 1200 mm to 1900 mm, or 1800 mm to 2750 mm).

[0081] It will be understood that the active extended distance between the closure and body mounting structures 12, 14 minus the minimum distance between the closure and body mounting structures 12, 14 defines an active extension range R1 (as illustrated on Figure 2). Similarly, the passive extended distance between the closure and body mounting structures 12, 14 minus the minimum distance between the closure and body mounting structures 12, 14 defines a passive extension range R2 (as illustrated on Figure 3). The sum of the active and passive extension ranges R1, R2 defines a maximum extension range (i.e., the maximum distance between the closure and body mounting structures 12, 14 minus the minimum distance between the closure and body mounting structures 12, 14). In some embodiments, the active extension range R1 may be greater than 10%, greater than 20%, greater than 30%, greater than 40%, greater than 50%, greater than 60%, greater than 70%, greater than 80% or greater than 90% of the maximum extension range, with the passive extension range R2 providing the remainder of the maximum extension range (i.e., being less than 90%, less than 80%, less than 70%, less than 60%, less than 50%, less than 40%, less than 30%, less than 20% or less than 10% of the maximum extension range). Put another way, in some embodiments the active extension range R1 may be less than 90%, less than 80%, less than 70%, less than 60%, less than 50%, less than 40%, less than 30%, less than 20% or less than 10% of the maximum extension range, with the passive extension range R2 providing the remainder of the maximum extension range (i.e., being greater than 10%, greater than 20%, greater than 30%, greater than 40%, greater than 50%, greater than 60%, greater than 70%, greater than 80% or greater than 90% of the maximum extension range). For example, in the embodiment of Figures 1 to 3 the active extension range R1 is approximately 70% of the maximum extension range and the passive extension range R2 is approximately 30% of the maximum extension range.

[0082] In the illustrated embodiment, the active portion 16 has a longer extension range than the passive portion 20. In other words, the shaft 24A of the active portion 16 can protrude from the active housing part 22A to a greater extent than the shaft 24B of the passive portion 20 can protrude from the passive housing part 22B. Put another way, the active housing part 22A is longer than the passive housing part 22B. In alternative embodiments, the passive portion 20 may have a longer extension range or the active and passive portions 16, 20 may have a roughly equal extension range.

[0083] In some embodiments, the closure and body mounting structures 12, 14 are ball stud sockets for receiving corresponding ball studs on the vehicle closure and vehicle body. Alternatively, the closure and body mounting structures 12, 14 may be ball studs for locating in corresponding ball stud sockets on the vehicle closure and vehicle body. In other embodiments, the closure and body mounting structures 12, 14 are any other kind of suitable mounting structure, such as a lug for receiving a pin, bolt or other fastener.

[0084] A strut assembly in accordance with a further embodiment of the present invention is illustrated in Figure 4. Features which are common to the embodiment of Figure 4 and the previous embodiment of Figures 1 to 3 are given the same reference numerals, and only differences are discussed in detail.

[0085] In the embodiment of Figure 4, the actuator 18 has a different configuration to the actuator 18 of Figures 1 to 3. In particular, the electric motor 30 is provided in the shaft 24A rather than the active housing part 22A, and the threaded nut 36 is fixed relative to the active housing part 22A rather than fixed relative to the shaft 24A. Such an arrangement may facilitate easier access for electrical wiring of the power connectors 38. Further, the embodiment of Figure 4 differs from the previous embodiment of Figures 1 to 3 in that the gear arrangement 42 is omitted.

[0086] In the embodiment of Figure 4, the threaded nut 36 is fixed to an end of an inner projection 37 which extends from the internal divider 25. In other embodiments, the inner projection 37 may extend from a side wall of the active housing part 22A. The illustrated inner projection 37 extends to a free end which is proximal to an end of the active housing part 22A distal the internal divider 25. In this way, the threaded nut 36 is provided close to the motor 30 when the active portion 20 is retracted, which facilitates suitable linear movement of the threaded screw or spindle 34 to an extended position when required. In other embodiments, the inner projection 37 has a shorter length (i.e., the nut 36 may be positioned further from the motor 30 than in the illustrated embodiment). In the illustrated embodiment, the inner projection 37 is provided inside the shaft 24A of the active portion 20. In other words, the shaft 24A surrounds the inner projection 37.

[0087] In the embodiment of Figure 4, the active portion 16 has a spring 39 which contributes towards movement of the vehicle closure. In particular, the illustrated spring 39 is a mechanical coil spring which is compressed within the active portion 16 when the active portion 16 is in the retracted state, so that the shaft 24A of the active portion is biased by the spring 39 towards the extended state. In this way, the spring 39 works to counter a weight of the vehicle closure pushing the shaft 24A of the active portion 16 into the active housing part22A, which reduces the power requirements of the electric motor 30 when extending the active portion 16 in use (i.e., when raising the vehicle closure in use). In the illustrated embodiment, the spring 39 is arranged between the inner projection 37 and the shaft 24A of the active portion 16.

[0088] As shown in Figures 7A to 7E and Figure 8, the strut assembly 10 of Figure 4 may be part of a vehicle system 100 and of a vehicle 200.

[0089] A strut assembly in accordance with a further embodiment of the present invention is illustrated in Figures 5A to 5C. Features which are common to the embodiment of Figures 5A to 5C and the previous embodiments of Figures 1 to 4 are given the same reference numerals, and only differences are discussed in detail.

[0090] In the embodiment of Figures 5A to 5C, the passive portion 20 is provided telescopically inside the active portion 16. In other words, the active and passive housing parts 22A, 22B are telescopically arranged with respect to each other. In particular, the shaft 24A of the active portion 16 defines the passive housing part 22B of the passive portion 20. In more detail, the shaft 24A of the active portion 16 has an internal volume and the shaft 24B of the passive portion 20 is moveable within the internal volume of the shaft 24A of the active portion 16. The internal volume of the shaft 24A of the active portion 16 has an internal divider 25 part-way along the shaft 24A, which separates the shaft 24A of the active portion 16 into the passive housing part 22B above the internal divider 25 and the remainder of the shaft 24A below the internal divider (e.g., for accommodating a screw mechanism 32 as described above).

[0091] In alternative embodiments, the active portion 16 may be provided telescopically inside the passive portion 20.

[0092] In the embodiment of Figures 5A to 5C, the actuator is not shown for simplicity. However, it will be understood that an actuator 18 similar to that illustrated in Figures 1 to 3, or any other suitable actuator, may be provided to extend the active portion 16 in response to a control signal.

[0093] As shown in Figures 7A to 7E and Figure 8, the strut assembly 10 of Figures 5A to 5C may be part of a vehicle system 100 and of a vehicle 200.

[0094] A strut assembly in accordance with a further embodiment of the present invention is illustrated in Figures 6A to 6C. Features which are common to the embodiment of Figures 6A to 6C and the previous embodiments of Figures 1 to 5C are given the same reference numerals, and only differences are discussed in detail.

[0095] In the embodiment of Figures 6A to 6C, the active housing part 22A and the passive housing part 22B are discrete housings coupled to each other. In particular, the strut assembly 10 has a common shaft 24 which defines the shaft of the active portion 16 and the shaft of the passive portion 20. The common shaft 24 has a first end 26 which is moveable within the active housing part and a second end 28 which is moveable within the passive housing part 22B. In other words, the active and passive housing parts 22A, 22B are coupled to each other via the common shaft 24. In the embodiment of Figures 6A to 6C, the actuator is not shown for simplicity. However, it will be understood that an actuator 18 similar to that illustrated in Figures 1 to 3, or any other suitable actuator, may be provided to extend the active portion 16 in response to a control signal.

[0096] As shown in Figures 7A to 7E and Figure 8, the strut assembly 10 of Figures 6A to 6C may be part of a vehicle system 100 and of a vehicle 200.

[0097] A vehicle system 100 in accordance with an embodiment of the present invention is described herein with reference to the accompanying Figures 7A to 7E. As shown in Figure 8, the vehicle system 100 may be part of a vehicle 200.

[0098] The vehicle system 100 has a vehicle closure 102 hingedly coupled to a vehicle body 104 by a hinge arrangement 106. The vehicle system 100 also has a strut assembly 10. The strut assembly 10 may be of the kind described above (e.g., as illustrated in Figures 1 to 3, as illustrated in Figures 5A to 5C, or as illustrated in Figures 6A to 6C). The closure mounting structure 12 of strut assembly 10 is coupled to the vehicle closure 102 and the body mounting structure 14 of the strut assembly is coupled to the vehicle body 104.

[0099] In the illustrated embodiment, the vehicle closure 102 is a front vehicle closure (e.g., a bonnet or hood). In alternative embodiments, the vehicle closure 102 is a rear vehicle closure (e.g., a boot or tailgate).

[0100] The strut assembly 10 is arranged so that a weight of the vehicle closure 102 acts against extension of the passive portion 20. In particular, the strut assembly 10 is arranged underneath the vehicle closure 102 and the body mounting structure 14 is fixed to the vehicle body 104 below the vehicle closure 102 so that the weight of the vehicle closure 102 urges the closure and body mounting structures 12, 14 towards each other.

[0101] Referring to Figure 7A, the strut assembly 10 is fully retracted (e.g., to the position shown in Figures 1, 5A or 6A). In this way, the vehicle closure 102 is in a closed position.

[0102] Referring to Figure 7B, the active portion 16 of the strut assembly 10 is extended by the actuator 18 (e.g., to the position shown in Figures 2, 5B or 6B). In this way, the vehicle closure 102 is in an open position to provide access to the area of the vehicle body 104 below the vehicle closure 102 (e.g., an engine bay on an internal combustion engine-powered vehicle, or a front storage area / ”frunk” on an electric vehicle).

[0103] In the embodiment of Figures 7C and 7D, the area of the vehicle body 104 below the vehicle closure 102 is a front storage area or “trunk”. In Figure 7C an oversized object 108 is located within the front storage area so that the vehicle closure 102 is obstructed from being fully closed. Similarly, in Figure 7D a body portion 108, such as a hand, is located at an edge of the vehicle body 104 so that the vehicle closure 102 is obstructed from being fully closed. Therefore, when the active portion 16 of the strut assembly 10 is retracted by the actuator 18 in response to a retracting control signal, the passive portion 20 of the strut assembly 10 extends (e.g., to the position shown in Figures 3, 5C or 6C). In this way, crushing of the object or pinching of the body portion 108 and / or damage to the actuator 18 is inhibited.

[0104] The vehicle system 100 has an active pedestrian safety mechanism 150 which is configured to be deployed to urge the vehicle closure 102 away from the vehicle body 104. In particular, the active pedestrian safety mechanism has an explosive charge 152 configured to break the hinge arrangement 106 and to urge the vehicle closure 102 away from the vehicle body 104 to the position illustrated in Figure 7E. In order to permit movement of the vehicle closure 102 to the deployed state, the passive portion 20 of the strut assembly 10 is rapidly extended (e.g., to the position illustrated in Figures 3, 5C or 6C).

[0105] In the deployed position illustrated in Figure 7E, a rear end 154 of the vehicle closure 102 is raised to provide a cushion in the event of an impact with a pedestrian. It will be understood that a front end 156 of the vehicle closure 102 may remain secured to the vehicle body 104 (e.g., via a latch) when the active pedestrian safety mechanism 150 is deployed.

[0106] The vehicle system 100 may include an active pedestrian safety control system 158. The active pedestrian safety control system 158 may include one or more sensors 160 indicative of an imminent crash with a pedestrian (e.g., bumper sensors, camera sensors with image processing to identify pedestrians, or any other suitable sensors). In response to receiving a signal from the one or more sensors 160, the active pedestrian safety control system 158 may be configured to activate the explosive charge 152.

[0107] Although only one strut assembly 10 is shown in the schematic representations of Figures 7A to 7E, it will be understood that the vehicle system 100 may have more than one strut assembly 10. For example, there may be two strut assemblies 10 located on opposite sides of the vehicle closure 102, or more than two strut assemblies distributed around a perimeter of the vehicle closure. Similarly, the active pedestrian safety mechanism 150 may include two explosive charges 152 located on opposite sides of the vehicle body 104.

[0108] Figure 8 illustrates a vehicle 200 according to an embodiment of the present invention. The vehicle 200 has a vehicle system 100 of the kind described above. In the illustrated embodiment, there are two strut assemblies 10 located on opposite sides of the vehicle closure 102 and vehicle body 104. In the illustrated view, the strut assemblies 10 are extended by the actuator 18 of the active portion 16 so that the vehicle closure 102 is pivoted relative to the vehicle body 104 to an open position (e.g., corresponding to the state of the vehicle system 100 illustrated in Figure 7B). However, it will be understood that the vehicle system 100 of the vehicle 200 can also be put into the other states illustrated in Figures 7A, and 7C to 7E. It will be appreciated that various changes and modifications can be made to the present invention without departing from the scope of the present application. It should also be noted that whilst the appended claims set out particular combinations of features described above, the scope of the present disclosure is not limited to the particular combinations hereafter claimed, but instead extends to encompass any combination of features herein disclosed.

Claims

CLAIMS1. A strut assembly for a powered vehicle closure, the strut assembly comprising: a closure mounting structure for coupling the strut assembly to a vehicle closure; a body mounting structure for coupling the strut assembly to a vehicle body; an active portion arranged between the closure mounting structure and the body mounting structure, wherein the active portion comprises an actuator configured to move the strut assembly between a retracted state and an extended state in response to a control signal; and a passive portion arranged between the closure mounting structure and the body mounting structure, wherein the passive portion is configured to permit extension of the strut assembly independently of the control signal.

2. The strut assembly of claim 1 , wherein the passive portion is configured to permit both extension and retraction of the strut assembly independently of the control signal.

3. The strut assembly of claim 1 or 2, wherein the actuator is configured to extend or retract the strut assembly at a first rate of movement, and wherein the passive portion is configured to permit extension of the strut assembly at a second rate of movement, wherein the second rate of movement is faster than the first rate of movement; optionally, wherein the passive portion is configured to permit transition from a fully retracted position to a fully extended position in less than 20ms, optionally less than 15ms.

4. The strut assembly of any preceding claim, wherein the active portion comprises an active housing part arranged between the closure and body mounting structures, and a shaft slidable relative to the active housing part to move the strut assembly between the retracted and extended states; and / or wherein the passive portion comprises a passive housing part arranged between the closure and body mounting structures, and a shaft slidable relative to the passive housing part to permit extension of the strut assembly independently of the active portion.

5. The strut assembly of claim 4, comprising a single housing which defines the active housing part and the passive housing part, and which comprises an internal divider which separates the active housing part from the passive housing part.

6. The strut assembly of claim 4, wherein the active housing part and the passive housing part are discrete housings coupled to each other.

7. The strut assembly of any of claims 4 to 6, wherein the active and passive housing parts are telescopically arranged with respect to each other.

8. The strut assembly of claim 7, wherein the shaft of the active portion defines the passive housing part of the passive portion.

9. The strut assembly of any of claims 4 to 8, wherein the passive portion and / or active portion comprises a fluid within the respective housing part and a piston at a first end of the respective shaft, wherein the fluid is configured to be compressed as the piston moves within the respective housing part.

10. The strut assembly of any preceding claim, wherein the active and passive portions are arranged in series along the length of the strut assembly.

11. The strut assembly of any preceding claim, wherein the actuator comprises an electric motor coupled to a screw mechanism.

12. A vehicle system comprising: a vehicle closure hingedly coupled to a vehicle body; and at least one strut assembly according to any preceding claim, wherein the closure mounting structure of the at least one strut assembly is coupled to the vehicle closure and the body mounting structure of the at least one strut assembly is coupled to the vehicle body.

13. The vehicle system of claim 12, wherein the at least one strut assembly is arranged so that a weight of the vehicle closure acts against extension of the passive portion.

14. The vehicle system of claim 13, further comprising an active pedestrian safety mechanism configured to be deployed to urge the vehicle closure away from the vehicle body, wherein the passive portion of the at least one strut assembly is configured to be extended when the active pedestrian safety mechanism is deployed.

15. A vehicle comprising the vehicle system of any of claims 12 to 14.

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