EP2956316A1 - Vehicle suspension system - Google Patents

Vehicle suspension system

Info

Publication number
EP2956316A1
EP2956316A1 EP14703612.3A EP14703612A EP2956316A1 EP 2956316 A1 EP2956316 A1 EP 2956316A1 EP 14703612 A EP14703612 A EP 14703612A EP 2956316 A1 EP2956316 A1 EP 2956316A1
Authority
EP
European Patent Office
Prior art keywords
controller
suspension system
sense
switching device
move
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP14703612.3A
Other languages
German (de)
French (fr)
Inventor
Christian Schering
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Haldex Brake Products GmbH
Original Assignee
Haldex Brake Products GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from GB201302438A external-priority patent/GB201302438D0/en
Priority claimed from GBGB1315675.7A external-priority patent/GB201315675D0/en
Application filed by Haldex Brake Products GmbH filed Critical Haldex Brake Products GmbH
Publication of EP2956316A1 publication Critical patent/EP2956316A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G11/00—Resilient suspensions characterised by arrangement, location or kind of springs
    • B60G11/26—Resilient suspensions characterised by arrangement, location or kind of springs having fluid springs only, e.g. hydropneumatic springs
    • B60G11/27—Resilient suspensions characterised by arrangement, location or kind of springs having fluid springs only, e.g. hydropneumatic springs wherein the fluid is a gas
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G17/00—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load
    • B60G17/015—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements
    • B60G17/0152—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements characterised by the action on a particular type of suspension unit
    • B60G17/0155—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements characterised by the action on a particular type of suspension unit pneumatic unit
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G17/00—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load
    • B60G17/015—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements
    • B60G17/018—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements characterised by the use of a specific signal treatment or control method
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G2202/00—Indexing codes relating to the type of spring, damper or actuator
    • B60G2202/10—Type of spring
    • B60G2202/15—Fluid spring
    • B60G2202/152—Pneumatic spring
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G2300/00—Indexing codes relating to the type of vehicle
    • B60G2300/04—Trailers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G2500/00—Indexing codes relating to the regulated action or device
    • B60G2500/30—Height or ground clearance
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G2600/00—Indexing codes relating to particular elements, systems or processes used on suspension systems or suspension control systems
    • B60G2600/20—Manual control or setting means

Definitions

  • the present invention relates to a vehicle suspension system particularly, but not exclusively to a suspension system for a commercial or heavy goods vehicle.
  • EP2125398 An alternative system is disclosed in EP2125398, and this system includes a raise button which when actuated raises the trailer body, and a lower button which when actuated, lowers the vehicle body.
  • these buttons are mechanically connected to a pneumatic valve so that actuation of the button causes the movement of the valve which either releases compressed air from the suspension bellows (the lower button) or facilitates the supply of
  • Electronically control air suspension systems are also known, and examples are WABCO GmbH's ECAS and Haldex Brake Products GmbH's ColasTronic® system.
  • the raise and lower buttons are electrically connected to the trailer's electronic braking system (EBS) electronic control unit (ECU). Actuation of either of the buttons causes an electrical signal to be transmitted to the EBS ECU, and the EBS ECU to control the supply of power to the appropriate electrically operated valve or valves to cause release or supply of compressed air from or to the suspension bellows.
  • EBS electronic braking system
  • ECU electronic control unit
  • An electronically controlled air suspension system using the ColasTronic® system is shown in EP2540536A1 . This application shows the electrical connections to the raise and lower buttons (17, 18), but the buttons themselves are not illustrated in this application.
  • a vehicle suspension system including a suspension element, a controller, and manually operable switching device which is connected to the controller, the suspension element having a first attachment portion and a second attachment portion, the attachment portion be adapted, in use, to be attached to different portions of a vehicle, and being operable by the controller to move in a first sense to increase the separation of two attachment portions or a second sense to decrease the separation of the two attachment portions, wherein the controller is configured to move the suspension element in the first sense when the switching device is actuated according to a first actuation scheme and to move the suspension element in the second sense when the switching device is actuated according to a second actuation scheme, the first actuation scheme being different to the second actuation scheme.
  • a single switch or button may be used to achieve manual raising or lowering of a vehicle suspension.
  • the switching device is preferably actuated in an actuation direction when actuated according to the first and second actuation schemes.
  • the direction of actuation for the first and second actuation schemes may be given by a translational degree of freedom.
  • the controller may be configured to operate the suspension element to move in the first sense when the switching device is actuated a first number of times in a designated period of time and to move in the second sense when the switching device is actuated a second number of times in a designated period of time, the first number of times being different to the second number of times.
  • the first number of times may be less than the second number of times.
  • the first number of times may be one, and the second number of times may be two.
  • the second number of times may be one and the first number of times may be two.
  • the controller may be configured such that the length of time for which the switching device is activated determines whether it operates the suspension element to move in the first sense or the second sense.
  • the controller may be configured to operate the suspension element to move in the first sense when the switching device is activated for a first length of time and to move in the second sense when the switching device is activated for a second length of time, the first length of time being different to the second length of time.
  • the controller may be configured to operate the suspension element to move in the first sense when the switching device is activated for a length of time which is less than a first predetermined level, and to move in the second sense when the switching device is activated for a length of time which is greater than the first predetermined level.
  • the controller may be configured to operate the suspension element to move in the first sense when the switching device is activated for a length of time which is less than a first predetermined level, and to move in the second sense when the switching device is activated for a length of time which is greater than a second predetermined level, the second predetermined level being greater than the first predetermined level.
  • the controller may include a valve assembly and a programmable electronic control unit.
  • the controller may be programmed to measure a parameter determined by the separation of two attachment portions when the switching device is activated for a length of time which is less than or greater than a third predetermined level.
  • the controller may have a memory and be programmed to store in its memory the measured parameter.
  • the controller may be configured such that the force with which the switching device is operated by a user determines whether the controller operates the suspension element to move in the first sense or the second sense.
  • the controller may be configured to operate the suspension element to move in the first sense when the switching device is operated with a first force level and to move in the second sense when the switching device is operated with a second, different, force level.
  • the controller may be configured to operate the suspension element to move in the first sense when the switching device is operated with a force which is less than a first predetermined level, and to move in the second sense when the switching device is operated with a force which is greater than the first predetermined level.
  • the controller may be configured to operate the suspension element to move in the first sense when the switching device is operated with a force which is less than a first predetermined level, and to move in the second sense when the switching device is operated with a force which is greater than a second predetermined level, the second predetermined level being greater than the first predetermined level.
  • the controller may include a valve assembly and a programmable electronic control unit.
  • the controller may be programmed to measure a parameter determined by the separation of two attachment portions when the switching device is operated with a force which is less than or greater than a third predetermined level.
  • the controller may have a memory and be programmed to store in its memory the measured parameter.
  • the controller may be configured such that the distance the switching device is moved when actuated determines whether the controller operates the suspension element to move in the first sense or the second sense.
  • the controller may be configured to operate the suspension element to move in the first sense when the switching device is moved a first distance and to move in the second sense when the switching device is moved a second, different, distance.
  • the controller may be configured to operate the suspension element to move in the first sense when the switching device is moved a distance which is less than a first predetermined level, and to move in the second sense when the switching device is moved a distance which is greater than the first predetermined level.
  • the controller may be configured to operate the suspension element to move in the first sense when the switching device is moved a distance which is less than a first predetermined level, and to move in the second sense when the switching device is moved a distance which is greater than a second predetermined level, the second predetermined level being greater than the first predetermined level.
  • the controller may include a valve assembly and a programmable electronic control unit.
  • the controller may be programmed to measure a parameter determined by the separation of two attachment portions when the switching device is moved a distance which is less than or greater than a third predetermined level.
  • the controller may have a memory and be programmed to store in its memory the measured parameter.
  • the suspension element may include a fluid operated actuator which moves in the first sense when connected to a supply of pressurised fluid, and in the second sense which connected to a lower pressure region.
  • the suspension system may further include a pressurised fluid source, the controller being operable to connect the suspension to either the pressurised fluid source or the low pressure region.
  • the suspension element may comprise air bellows.
  • the switching device may comprise a push button or switch which is electrically connected to the controller, and which transmits an electrical signal to the controller when pressed by a user.
  • the transmission of the electrical signal to the controller may be maintained until the user releases the switching device, at which point the transmission of the electrical signal to the controller ceases.
  • the suspension system may be a trailer vehicle suspension system.
  • the controller may include a valve assembly and a programmable electronic control unit.
  • FIGURE 1 shows a schematic illustration of an electronic suspension system according to the invention
  • FIGURE 2 shows a schematic illustration of a vehicle fitted with the electronic suspension system shown in Figure 1
  • FIGURE 3 shows a flow chart illustrating a first possible method of operation of the electronic control unit of the system shown in Figure 1
  • FIGURE 4 shows a flow chart illustrating a second possible method of operation of the electronic control unit of the system shown in Figure 1
  • FIGURE 5 shows a flow chart illustrating an alternative version of the method illustrated in Figure 3
  • FIGURE 6 shows a flow chart illustrating a third possible method of operation of the electronic control unit of the system shown in Figure 1 ,
  • FIGURE 7 shows a flow chart illustrating an alternative version of the method illustrated in Figure 6.
  • FIGURE 8 shows a flow chart illustrating a fourth possible method of operation of the electronic control unit of the system shown in Figure 1
  • FIGURE 9 shows a flow chart illustrating a fifth possible method of operation of the electronic control unit of the system shown in Figure 1 .
  • an electronic suspension system 10 comprising a levelling valve assembly 12, a plurality (in this example 6) of suspension bellows 14, and a compressed air reservoir 16.
  • the suspension system 10 is designed for use on a trailer 28 of a commercial vehicle, in particular a heavy goods vehicle, and the suspension bellows 14 are, in use, mounted between the chassis 32 and the body 30 of the trailer 28, as illustrated in Figure 2.
  • the levelling valve assembly 12 is operable to connect the suspension bellows 14 to the compressed air reservoir 16 so as to inflate the air bellows 14, and raise the trailer body 30 relative to its chassis 32, or to release compressed air from the suspension bellows 14 to lower the trailer body 30 relative to its chassis 32.
  • the system is provided with a raise/lower lever 18, the lever 18 being connected to a rotary valve such that rotation of the lever in a first direction releases compressed air from the suspension bellows 14 and rotation of the lever 18 in the opposite direction connects the compressed air reservoir 16 to the suspension bellows 14.
  • the system 10 also includes an electronic control unit (ECU) 20, which may be the electronic braking control unit for the trailer.
  • the levelling valve assembly 12 includes a raise input 22, and a lower input 24, which are electrically connected to the ECU 20, and is configured such that the supply of electrical power to the raise input 22 connects the compressed air reservoir 16 to the suspension bellows 14 to raise the trailer body 30 relative to the chassis 32, whilst the supply of electrical power of the lower input 24 releases compressed air from the suspension bellows 14 so as to lower the trailer body 30 relative to the chassis 32.
  • the suspension level may therefore be controlled electronically, for example, using an input from a distance sensor, to maintain the trailer at a desired ride height.
  • An example of a suitable levelling valve assembly is described in EP2540536.
  • the control of the suspension level is intended to be achieved electronically by means of the ECU 20, with the levelling lever being provided as a secondary or emergency means of pneumatic control of the suspension level in case of the failure of the electronic control system.
  • the suspension system 10 is also provided with an electronic actuator 26, which in this example comprises a button, which is also electrically connected to the ECU 20.
  • the ECU 20 is programmed such that when the button is actuated once, the vehicle body is raised, and when the button is actuated twice, the vehicle body is lowered.
  • the control buttons are typically mounted on the inside wall of the trailer body 30, the use of a single button instead of two buttons could be particularly advantageous where space on the trailer body 30 wall is limited, for example in a thermally lined refrigerated trailer.
  • the button 26 is of the type which, when depressed by a user, and electrical signal is transmitted to the ECU 20, and electrical signal continuing to be transmitted to the ECU 20 until the user releases the button.
  • the ECU 20 may be programmed as illustrated in Figure 3.
  • the ECU 20 monitors for the receipt of a signal from the button 26.
  • the ECU 20 advances a timer whilst monitoring for the receipt of a further signal from the button 26.
  • the ECU 20 transmits a signal to the raise input 22 of the levelling valve assembly 12 so that compressed air is supplied to the suspension bellows 14 and the trailer body 30 is raised relative to its chassis 32.
  • the ECU 20 continues to monitor for receipt of a signal from the button 26, and maintains the signal to the raise input 22 of the levelling valve assembly 12 so the supply of pressurised fluid to the suspension bellows 14 continues.
  • the user depresses and then releases the button 26 again, and the ECU 20 is programmed to terminate the signal to the raise input 22 of the levelling valve assembly 12 so that the levelling valve assembly operates to cease the supply of further compressed air to the suspension bellows 14 and to hold the bellows 14 at their current pressure.
  • the ECU 20 then returns to monitoring for receipt of a signal from the button 26 as before.
  • the ECU 20 is programmed to transmit a signal to the lower input 24 of the levelling valve assembly 12 so that compressed air is released from the suspension bellows 14 and the trailer body 30 is lowered relative to its chassis 32.
  • the ECU 20 continues to monitor for receipt of a signal from the button 26, and maintains the signal to the lower input 22 of the levelling valve assembly 12 so the release of pressurised fluid to the suspension bellows 14 continues.
  • the user depresses and then releases the button 26 again, and the ECU 20 is programmed to terminate the signal to the lower input 24 of the levelling valve assembly 12 so that the levelling valve assembly operates to cease the release of further compressed air to the suspension bellows 14 and to hold the bellows 14 at their current pressure.
  • the ECU 20 then returns to monitoring for receipt of a signal from the button 26 as before.
  • the suspension system is operated on a "press to stop" basis.
  • An alternative way of programming the ECU 20 is illustrated Figure 4.
  • the ECU 20 monitors for the receipt of a signal from the button 26.
  • the ECU 20 advances a timer whilst checking that the signal from the button 26 is still being received (i.e. that the user has not released the button 26). If, after a designated time limit (say 2 seconds), the signal from the button 26 is still being received (i.e.
  • the ECU 20 transmits a signal to the raise input 22 of the levelling valve assembly 12 so that compressed air is supplied to the suspension bellows 14 and the trailer body 30 is raised relative to its chassis 32.
  • the ECU 20 continues to monitor the receipt of the signal from the button 26, and maintains the signal to the raise input 22 of the levelling valve assembly 12 so the supply of pressurised fluid to the suspension bellows 14 continues.
  • the user releases the button 26, and the ECU 20 is programmed to terminate the signal to the raise input 22 of the levelling valve assembly 12, when it stops receiving a signal from the button 26, so that the levelling valve assembly operates to cease the supply of further compressed air to the suspension bellows 14 and to hold the bellows 14 at their current pressure.
  • the ECU 20 then returns to monitoring for receipt of a signal from the button 26 as before.
  • the ECU 20 is programmed to monitor for receipt of a further signal from the button 26. If, no further signal is received within the designated time limit, and process restarts, and the ECU 20 returns to monitoring for receipt of a signal from the button 26. If the user presses the button 26 again within the designated time limit, the ECU 20 is programmed to transmit a signal to the lower input 24 of the levelling valve assembly 12 so that compressed air is released from the suspension bellows 14 and the trailer body 30 is lowered relative to its chassis 32.
  • the ECU 20 continues to monitor for receipt of a signal from the button 26, and maintains the signal to the lower input 22 of the levelling valve assembly 12 so the release of pressurised fluid to the suspension bellows 14 continues.
  • the user releases the button 26, and the ECU 20 is programmed to terminate the signal to the lower input 24 of the levelling valve assembly 12, when the signal from the button 26 ceases, so that the levelling valve assembly operates to cease the release of further compressed air to the suspension bellows 14 and to hold the bellows 14 at their current pressure.
  • the ECU 20 then returns to monitoring for receipt of a signal from the button 26 as before.
  • the embodiment of the invention illustrated in Figure 4 therefore operates on a "release to stop” basis, or, in other words, as a "dead man's switch". It will be appreciated that the suspension can only be safely raised or lowered by a certain amount - there is a maximum and minimum safe separation of the trailer body 30 from the chassis 32, and in both embodiments of the invention, the ECU 20 will be programmed to stop the raising or lowering of the suspension when either of these limits is reached even if the user has not actuated the button 26 in the manner required to stop the raising or lowering process. This may be achieved by the connection to the ECU 20 of a distance sensor which provides an output representative of the separation of the trailer body 30 and chassis 32. The ECU 20 may be programmed to move the suspension between predefined levels.
  • the ECU 20 may be programmed to stop the raising of the suspension when the next defined level is reached even if the user has not actuated the button 26 in the manner required to stop the raising process. The same could apply to the lowering process.
  • the ECU 20 When programmed as described in relation to Figure 3, the ECU 20 could also be programmed to store in its memory the height of the trailer body 30 relative to the chassis 32 when the user presses the button 26 for a predetermined length of time (5 seconds say). This is illustrated in Figure 5.
  • the ECU 20 could also be programmed to return the trailer body 30 automatically to the stored height when the vehicle has been parked (e.g. when the parking brake is applied) or when the vehicle ignition is turned off. A user may thus store the height when the trailer body 30 is at the best height for loading or unloading from a particular docking bay.
  • the ECU 20 is programmed to raise the suspension after a single actuation of the button 26 and to lower the suspension after a double actuation of the button 26, it may equally be programmed to operate the other way round. In other words, the ECU 20 may be programmed to lower the suspension after a single actuation of the button 26, and to raise the suspension after a double actuation of the button 26. In any alternative embodiment, the ECU 20 is programmed such that when the button is actuated for a first length of time, the body is raised, and when the button is actuated for a second length of time, the vehicle body is lowered.
  • buttons are typically mounted on the inside wall of the trailer body 30, the use of a single button instead of two buttons could be particularly advantageous where space on the trailer body 30 wall is limited, for example in a thermally lined refrigerated trailer.
  • the button 26 is of the type which, when depressed by a user, and electrical signal is transmitted to the ECU 20, and electrical signal continuing to be transmitted to the ECU 20 until the user releases the button.
  • the ECU 20 may be programmed as illustrated in Figure 6.
  • the ECU 20 monitors for the receipt of a signal from the button 26.
  • the ECU 20 advances a timer whilst monitoring for the receipt of a further signal from the button 26.
  • the ECU 20 transmits a signal to the raise input 22 of the levelling valve assembly 12 so that compressed air is supplied to the suspension bellows 14 and the trailer body 30 is raised relative to its chassis 32.
  • the ECU 20 continues to monitor for receipt of a signal from the button 26, and maintains the signal to the raise input 22 of the levelling valve assembly 12 so the supply of pressurised fluid to the suspension bellows 14 continues.
  • the user depresses and then releases the button 26 again, and the ECU 20 is programmed to terminate the signal to the raise input 22 of the levelling valve assembly 12 so that the levelling valve assembly operates to cease the supply of further compressed air to the suspension bellows 14 and to hold the bellows 14 at their current pressure.
  • the ECU 20 then returns to monitoring for receipt of a signal from the button 26 as before.
  • the ECU 20 is programmed to transmit a signal to the lower input 24 of the levelling valve assembly 12 so that compressed air is released from the suspension bellows 14 and the trailer body 30 is lowered relative to its chassis 32.
  • the ECU 20 continues to monitor for receipt of a signal from the button 26, and maintains the signal to the lower input 22 of the levelling valve assembly 12 so the release of pressurised fluid to the suspension bellows 14 continues.
  • the user depresses and then releases the button 26 again, and the ECU 20 is programmed to terminate the signal to the lower input 24 of the levelling valve assembly 12 so that the levelling valve assembly operates to cease the release of further compressed air to the suspension bellows 14 and to hold the bellows 14 at their current pressure.
  • the ECU 20 then returns to monitoring for receipt of a signal from the button 26 as before.
  • the suspension system is operated on a "press to stop" basis. It will be appreciated that the suspension can only be safely raised or lowered by a certain amount - there is a maximum and minimum safe separation of the trailer body 30 from the chassis 32, and in both embodiments of the invention, the ECU 20 will be programmed to stop the raising or lowering of the suspension when either of these limits is reached even if the user has not actuated the button 26 in the manner required to stop the raising or lowering process. This may be achieved by the connection to the ECU 20 of a distance sensor which provides an output representative of the separation of the trailer body 30 and chassis 32. The ECU 20 may be programmed to move the suspension between predefined levels.
  • the ECU 20 may be programmed to stop the raising of the suspension when the next defined level is reached even if the user has not actuated the button 26 in the manner required to stop the raising process. The same could apply to the lowering process.
  • the ECU 20 When programmed as described in relation to Figure 6, the ECU 20 could also be programmed to store in its memory the height of the trailer body 30 relative to the chassis 32 when the user presses the button 26 for a third predetermined length of time (less than 1 second say). This is illustrated in Figure 7.
  • the ECU 20 could also be programmed to return the trailer body 30 automatically to the stored height when the vehicle has been parked (e.g. when the parking brake is applied) or when the vehicle ignition is turned off. A user may thus store the height when the trailer body 30 is at the best height for loading or unloading from a particular docking bay.
  • the ECU 20 is programmed to raise the suspension after actuation of the button 26 for the shorter period of time and to lower the suspension after actuation of the button 26 for a longer period of time, it may equally be programmed to operate the other way round. In other words, the ECU 20 may be programmed to lower the suspension after actuation of the button 26 for the shorter period of time, and to raise the suspension after actuation of the button 26 for the longer period of time.
  • the ECU 20 could be programmed to initiate raising of the suspension if the button is actuated for less than a first predetermined time period (say 2 seconds), and to initiate lowering of the suspension if the button is actuated for more than a second, higher, predetermined time period (say 2.5 seconds), or vice versa.
  • a first predetermined time period say 2 seconds
  • a second, higher, predetermined time period say 2.5 seconds
  • the ECU 20 is programmed to do nothing other than return to monitoring for receipt of a signal from the button 26.
  • the user can then actuate the button 26 again.
  • the embodiments of the invention described in relation to Figures 6 and 7 use a button which returns automatically to the "off position" when released by the user, i.e. ceases sending an electrical signal to the ECU 20 when released by the user, this need not be the case.
  • the button 26 may be configured to maintain the electrical signal to the controller after it is released by the user, and to cease the electrical signal to the controller when it is pressed and released again.
  • system is configured to distinguish between the raise and lower command based on the force applied to actuate the button 26, or the displacement of the button 26. Examples of how the ECU 20 could be programmed to operated are illustrated in Figures 8 and 9.
  • Figure 8 shows an example in which the system is configured to raise the suspension if the force applied to the button 26 is below a predetermined level, and to lower the suspension if the force applied to the button 26 is above a predetermined level.
  • the system could also be programmed to operate in an analogous way to that shown in Figure 4, with the suspension height being stored if the force used to actuate the button 26 is below a first threshold, and to raise the suspension if the force is above the first threshold but below a second, higher, threshold, and to lower the suspension if the force is above the second threshold.
  • This system could also be programmed to initiate raising of the suspension if the button is actuated with a force less than a first predetermined level, and to initiate lowering of the suspension if the button is actuated with a force of more than a second, higher, predetermined force level, or vice versa. If the button is actuated with a force which falls between these two levels, the ECU 20 is programmed to do nothing other than return to monitoring for receipt of a signal from the button 26. The user can then actuate the button 26 again.
  • Figure 9 shows an example in which the system is configured to raise the suspension if the button 26 is moved less than a predetermined amount, and to lower the suspension if the button 26 is moved more than that predetermined amount.
  • the system could also be programmed to operate in an analogous way to that shown in Figure 4, with the suspension height being stored if the button 26 is moved less than a first threshold amount, and to raise the suspension if the button 26 is moved more than the first threshold amount but below a second, higher, threshold amount, and to lower the suspension if the button 26 is moved more than the second threshold amount.
  • This system could also be programmed to initiate raising of the suspension if the button is moved less than a first predetermined amount, and to initiate lowering of the suspension if the button is moved more than a second, higher, predetermined amount, or vice versa. If the button is moved by an amount which falls between these two levels, the ECU 20 is programmed to do nothing other than return to monitoring for receipt of a signal from the button 26. The user can then actuate the button 26 again.
  • the switching device in these embodiments could, in these embodiments, comprise a push button which has two sets of contacts - one set being made when the button is half pressed and the other when it is fully pressed.
  • Such buttons are, for example, commonly used as the shutter button on a digital camera.
  • the ECU 20 could be programmed to raise the suspension if the button 26 is fully depressed, and to lower the suspension of the button 26 is half-pressed, or vice versa.
  • the invention is described in relation to an air suspension system, it should be appreciated that it may equally be employed in a suspension system using any fluid - hydraulic or pneumatic, and any form of suspension element - hydraulic or pneumatic - may be employed instead of bellows to raise or lower the trailer body 30.
  • the invention is also described as using a button for manual control of the suspension level. It should be appreciated that any other form of manually operable switching device - including a switch which pivots on an axis of rotation when actuated - may be used instead of a push button. Moreover, whilst the embodiments of the invention described in relation to Figures 3, 4 and 5 use a switching device which returns automatically to the "off position" when released by the user, i.e. ceases sending an electrical signal to the ECUU 20 when released by the user, this need not be the case. The switching device may be configured to maintain the electrical signal to the controller after it is released by the user, and to cease the electrical signal to the controller when it is pressed and released again.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Vehicle Body Suspensions (AREA)

Abstract

A vehicle suspension system (10) including a suspension element (14), a controller (12, 20), and manually operable switching device (26) which is connected to the controller (12, 20), the suspension element (14) having a first attachment portion and a second attachment portion, the attachment portion be adapted, in use, to be attached to different portions of a vehicle, and being operable by the controller (12, 20) to move in a first sense to increase the separation of two attachment portions or a second sense to decrease the separation of the two attachment portions, wherein the controller (12, 20) is configured to move the suspension element (14) in the first sense when the switching device is actuated (26) according to a first actuation scheme and to move the suspension element in the second sense when the switching device (26) is actuated according to a second actuation scheme, the first actuation scheme being different to the second actuation scheme.

Description

Title: Vehicle Suspension System Description of Invention
The present invention relates to a vehicle suspension system particularly, but not exclusively to a suspension system for a commercial or heavy goods vehicle.
In commercial trailer vehicles fitted with air suspension, it is known to provide means for the manual raising or lowering of the suspension (for example for adjusting the trailer height when the vehicle is in a loading bay or dock) by the supply or release of compressed air to or from the air suspension support bellows, in addition to an automatic system for maintaining a desired ride height during vehicle travel. It is known for the manual raise and lower function to be achieved using a handle connected to a rotary valve such that rotation of the handle in a first direction releases compressed air from the suspension bellows and rotation of the handle in the opposite direction facilitates the supply of compressed air to the suspension bellows.
An alternative system is disclosed in EP2125398, and this system includes a raise button which when actuated raises the trailer body, and a lower button which when actuated, lowers the vehicle body. In this case, these buttons are mechanically connected to a pneumatic valve so that actuation of the button causes the movement of the valve which either releases compressed air from the suspension bellows (the lower button) or facilitates the supply of
compressed air to the suspension bellows (the raise button).
Electronically control air suspension systems are also known, and examples are WABCO GmbH's ECAS and Haldex Brake Products GmbH's ColasTronic® system. In these, the raise and lower buttons are electrically connected to the trailer's electronic braking system (EBS) electronic control unit (ECU). Actuation of either of the buttons causes an electrical signal to be transmitted to the EBS ECU, and the EBS ECU to control the supply of power to the appropriate electrically operated valve or valves to cause release or supply of compressed air from or to the suspension bellows. An electronically controlled air suspension system using the ColasTronic® system is shown in EP2540536A1 . This application shows the electrical connections to the raise and lower buttons (17, 18), but the buttons themselves are not illustrated in this application.
According to a first aspect of the invention we provide a vehicle suspension system including a suspension element, a controller, and manually operable switching device which is connected to the controller, the suspension element having a first attachment portion and a second attachment portion, the attachment portion be adapted, in use, to be attached to different portions of a vehicle, and being operable by the controller to move in a first sense to increase the separation of two attachment portions or a second sense to decrease the separation of the two attachment portions, wherein the controller is configured to move the suspension element in the first sense when the switching device is actuated according to a first actuation scheme and to move the suspension element in the second sense when the switching device is actuated according to a second actuation scheme, the first actuation scheme being different to the second actuation scheme.
By virtue of this arrangement, a single switch or button may be used to achieve manual raising or lowering of a vehicle suspension.
The switching device is preferably actuated in an actuation direction when actuated according to the first and second actuation schemes.
The direction of actuation for the first and second actuation schemes may be given by a translational degree of freedom. The controller may be configured to operate the suspension element to move in the first sense when the switching device is actuated a first number of times in a designated period of time and to move in the second sense when the switching device is actuated a second number of times in a designated period of time, the first number of times being different to the second number of times.
The first number of times may be less than the second number of times.
The first number of times may be one, and the second number of times may be two. Alternatively, the second number of times may be one and the first number of times may be two.
The controller may be configured such that the length of time for which the switching device is activated determines whether it operates the suspension element to move in the first sense or the second sense.
In other words, the controller may be configured to operate the suspension element to move in the first sense when the switching device is activated for a first length of time and to move in the second sense when the switching device is activated for a second length of time, the first length of time being different to the second length of time.
The controller may be configured to operate the suspension element to move in the first sense when the switching device is activated for a length of time which is less than a first predetermined level, and to move in the second sense when the switching device is activated for a length of time which is greater than the first predetermined level.
The controller may be configured to operate the suspension element to move in the first sense when the switching device is activated for a length of time which is less than a first predetermined level, and to move in the second sense when the switching device is activated for a length of time which is greater than a second predetermined level, the second predetermined level being greater than the first predetermined level.
The controller may include a valve assembly and a programmable electronic control unit. The controller may be programmed to measure a parameter determined by the separation of two attachment portions when the switching device is activated for a length of time which is less than or greater than a third predetermined level. In this case, the controller may have a memory and be programmed to store in its memory the measured parameter. The controller may be configured such that the force with which the switching device is operated by a user determines whether the controller operates the suspension element to move in the first sense or the second sense.
In other words, the controller may be configured to operate the suspension element to move in the first sense when the switching device is operated with a first force level and to move in the second sense when the switching device is operated with a second, different, force level.
The controller may be configured to operate the suspension element to move in the first sense when the switching device is operated with a force which is less than a first predetermined level, and to move in the second sense when the switching device is operated with a force which is greater than the first predetermined level.
The controller may be configured to operate the suspension element to move in the first sense when the switching device is operated with a force which is less than a first predetermined level, and to move in the second sense when the switching device is operated with a force which is greater than a second predetermined level, the second predetermined level being greater than the first predetermined level. The controller may include a valve assembly and a programmable electronic control unit.
The controller may be programmed to measure a parameter determined by the separation of two attachment portions when the switching device is operated with a force which is less than or greater than a third predetermined level. In this case, the controller may have a memory and be programmed to store in its memory the measured parameter.
The controller may be configured such that the distance the switching device is moved when actuated determines whether the controller operates the suspension element to move in the first sense or the second sense.
In other words, the controller may be configured to operate the suspension element to move in the first sense when the switching device is moved a first distance and to move in the second sense when the switching device is moved a second, different, distance. The controller may be configured to operate the suspension element to move in the first sense when the switching device is moved a distance which is less than a first predetermined level, and to move in the second sense when the switching device is moved a distance which is greater than the first predetermined level. The controller may be configured to operate the suspension element to move in the first sense when the switching device is moved a distance which is less than a first predetermined level, and to move in the second sense when the switching device is moved a distance which is greater than a second predetermined level, the second predetermined level being greater than the first predetermined level.
The controller may include a valve assembly and a programmable electronic control unit. The controller may be programmed to measure a parameter determined by the separation of two attachment portions when the switching device is moved a distance which is less than or greater than a third predetermined level. In this case, the controller may have a memory and be programmed to store in its memory the measured parameter.
The suspension element may include a fluid operated actuator which moves in the first sense when connected to a supply of pressurised fluid, and in the second sense which connected to a lower pressure region. In this case, the suspension system may further include a pressurised fluid source, the controller being operable to connect the suspension to either the pressurised fluid source or the low pressure region.
The suspension element may comprise air bellows.
The switching device may comprise a push button or switch which is electrically connected to the controller, and which transmits an electrical signal to the controller when pressed by a user. In this case, the transmission of the electrical signal to the controller may be maintained until the user releases the switching device, at which point the transmission of the electrical signal to the controller ceases.
The suspension system may be a trailer vehicle suspension system. The controller may include a valve assembly and a programmable electronic control unit.
Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, of which,
FIGURE 1 shows a schematic illustration of an electronic suspension system according to the invention, FIGURE 2 shows a schematic illustration of a vehicle fitted with the electronic suspension system shown in Figure 1 ,
FIGURE 3 shows a flow chart illustrating a first possible method of operation of the electronic control unit of the system shown in Figure 1 , FIGURE 4 shows a flow chart illustrating a second possible method of operation of the electronic control unit of the system shown in Figure 1 ,
FIGURE 5 shows a flow chart illustrating an alternative version of the method illustrated in Figure 3,
FIGURE 6 shows a flow chart illustrating a third possible method of operation of the electronic control unit of the system shown in Figure 1 ,
FIGURE 7 shows a flow chart illustrating an alternative version of the method illustrated in Figure 6.
FIGURE 8 shows a flow chart illustrating a fourth possible method of operation of the electronic control unit of the system shown in Figure 1 , and FIGURE 9 shows a flow chart illustrating a fifth possible method of operation of the electronic control unit of the system shown in Figure 1 .
Referring now to Figure 1 , there is shown an electronic suspension system 10 comprising a levelling valve assembly 12, a plurality (in this example 6) of suspension bellows 14, and a compressed air reservoir 16. The suspension system 10 is designed for use on a trailer 28 of a commercial vehicle, in particular a heavy goods vehicle, and the suspension bellows 14 are, in use, mounted between the chassis 32 and the body 30 of the trailer 28, as illustrated in Figure 2. The levelling valve assembly 12 is operable to connect the suspension bellows 14 to the compressed air reservoir 16 so as to inflate the air bellows 14, and raise the trailer body 30 relative to its chassis 32, or to release compressed air from the suspension bellows 14 to lower the trailer body 30 relative to its chassis 32. The system is provided with a raise/lower lever 18, the lever 18 being connected to a rotary valve such that rotation of the lever in a first direction releases compressed air from the suspension bellows 14 and rotation of the lever 18 in the opposite direction connects the compressed air reservoir 16 to the suspension bellows 14.
The system 10 also includes an electronic control unit (ECU) 20, which may be the electronic braking control unit for the trailer. The levelling valve assembly 12 includes a raise input 22, and a lower input 24, which are electrically connected to the ECU 20, and is configured such that the supply of electrical power to the raise input 22 connects the compressed air reservoir 16 to the suspension bellows 14 to raise the trailer body 30 relative to the chassis 32, whilst the supply of electrical power of the lower input 24 releases compressed air from the suspension bellows 14 so as to lower the trailer body 30 relative to the chassis 32. The suspension level may therefore be controlled electronically, for example, using an input from a distance sensor, to maintain the trailer at a desired ride height. An example of a suitable levelling valve assembly is described in EP2540536.
The control of the suspension level is intended to be achieved electronically by means of the ECU 20, with the levelling lever being provided as a secondary or emergency means of pneumatic control of the suspension level in case of the failure of the electronic control system.
The suspension system 10 is also provided with an electronic actuator 26, which in this example comprises a button, which is also electrically connected to the ECU 20. In one example, the ECU 20 is programmed such that when the button is actuated once, the vehicle body is raised, and when the button is actuated twice, the vehicle body is lowered. By programming the ECU 20 to operate in this way, electronic raising and lowering of the suspension can be achieved using only a single button instead of a separate raise and lower button. The control buttons are typically mounted on the inside wall of the trailer body 30, the use of a single button instead of two buttons could be particularly advantageous where space on the trailer body 30 wall is limited, for example in a thermally lined refrigerated trailer.
In this embodiment of the invention, the button 26 is of the type which, when depressed by a user, and electrical signal is transmitted to the ECU 20, and electrical signal continuing to be transmitted to the ECU 20 until the user releases the button. The ECU 20 may be programmed as illustrated in Figure 3. In this embodiment of the invention, the ECU 20 monitors for the receipt of a signal from the button 26. When the user depresses and then releases the button 26, the ECU 20 advances a timer whilst monitoring for the receipt of a further signal from the button 26. If no further signal is received within a designated time limit (say 2 seconds), the ECU 20 transmits a signal to the raise input 22 of the levelling valve assembly 12 so that compressed air is supplied to the suspension bellows 14 and the trailer body 30 is raised relative to its chassis 32. The ECU 20 continues to monitor for receipt of a signal from the button 26, and maintains the signal to the raise input 22 of the levelling valve assembly 12 so the supply of pressurised fluid to the suspension bellows 14 continues. When the desired level is achieved, the user depresses and then releases the button 26 again, and the ECU 20 is programmed to terminate the signal to the raise input 22 of the levelling valve assembly 12 so that the levelling valve assembly operates to cease the supply of further compressed air to the suspension bellows 14 and to hold the bellows 14 at their current pressure. The ECU 20 then returns to monitoring for receipt of a signal from the button 26 as before.
Alternatively, if after the initial actuation of the button 26, the user depresses and releases the button 26 again within the designated time limit, the ECU 20 is programmed to transmit a signal to the lower input 24 of the levelling valve assembly 12 so that compressed air is released from the suspension bellows 14 and the trailer body 30 is lowered relative to its chassis 32. The ECU 20 continues to monitor for receipt of a signal from the button 26, and maintains the signal to the lower input 22 of the levelling valve assembly 12 so the release of pressurised fluid to the suspension bellows 14 continues. When the desired level is achieved, the user depresses and then releases the button 26 again, and the ECU 20 is programmed to terminate the signal to the lower input 24 of the levelling valve assembly 12 so that the levelling valve assembly operates to cease the release of further compressed air to the suspension bellows 14 and to hold the bellows 14 at their current pressure. The ECU 20 then returns to monitoring for receipt of a signal from the button 26 as before.
Thus, in the embodiment of the invention illustrated in Figure 3, the suspension system is operated on a "press to stop" basis. An alternative way of programming the ECU 20 is illustrated Figure 4. In this embodiment of the invention, the ECU 20 monitors for the receipt of a signal from the button 26. When the user depresses the button 26, the ECU 20 advances a timer whilst checking that the signal from the button 26 is still being received (i.e. that the user has not released the button 26). If, after a designated time limit (say 2 seconds), the signal from the button 26 is still being received (i.e. the button 26 is still depressed), the ECU 20 transmits a signal to the raise input 22 of the levelling valve assembly 12 so that compressed air is supplied to the suspension bellows 14 and the trailer body 30 is raised relative to its chassis 32. The ECU 20 continues to monitor the receipt of the signal from the button 26, and maintains the signal to the raise input 22 of the levelling valve assembly 12 so the supply of pressurised fluid to the suspension bellows 14 continues. When the desired level is achieved, the user releases the button 26, and the ECU 20 is programmed to terminate the signal to the raise input 22 of the levelling valve assembly 12, when it stops receiving a signal from the button 26, so that the levelling valve assembly operates to cease the supply of further compressed air to the suspension bellows 14 and to hold the bellows 14 at their current pressure. The ECU 20 then returns to monitoring for receipt of a signal from the button 26 as before.
Alternatively, if after the initial pressing of the button 26, the user releases the button 26 within the designated time limit, the ECU 20 is programmed to monitor for receipt of a further signal from the button 26. If, no further signal is received within the designated time limit, and process restarts, and the ECU 20 returns to monitoring for receipt of a signal from the button 26. If the user presses the button 26 again within the designated time limit, the ECU 20 is programmed to transmit a signal to the lower input 24 of the levelling valve assembly 12 so that compressed air is released from the suspension bellows 14 and the trailer body 30 is lowered relative to its chassis 32. The ECU 20 continues to monitor for receipt of a signal from the button 26, and maintains the signal to the lower input 22 of the levelling valve assembly 12 so the release of pressurised fluid to the suspension bellows 14 continues. When the desired level is achieved, the user releases the button 26, and the ECU 20 is programmed to terminate the signal to the lower input 24 of the levelling valve assembly 12, when the signal from the button 26 ceases, so that the levelling valve assembly operates to cease the release of further compressed air to the suspension bellows 14 and to hold the bellows 14 at their current pressure. The ECU 20 then returns to monitoring for receipt of a signal from the button 26 as before.
The embodiment of the invention illustrated in Figure 4 therefore operates on a "release to stop" basis, or, in other words, as a "dead man's switch". It will be appreciated that the suspension can only be safely raised or lowered by a certain amount - there is a maximum and minimum safe separation of the trailer body 30 from the chassis 32, and in both embodiments of the invention, the ECU 20 will be programmed to stop the raising or lowering of the suspension when either of these limits is reached even if the user has not actuated the button 26 in the manner required to stop the raising or lowering process. This may be achieved by the connection to the ECU 20 of a distance sensor which provides an output representative of the separation of the trailer body 30 and chassis 32. The ECU 20 may be programmed to move the suspension between predefined levels. So, for example, when raising the trailer body 30, instead of continuing to raise the trailer body 30 until the maximum safe height is reached, the ECU 20 may be programmed to stop the raising of the suspension when the next defined level is reached even if the user has not actuated the button 26 in the manner required to stop the raising process. The same could apply to the lowering process.
When programmed as described in relation to Figure 3, the ECU 20 could also be programmed to store in its memory the height of the trailer body 30 relative to the chassis 32 when the user presses the button 26 for a predetermined length of time (5 seconds say). This is illustrated in Figure 5. The ECU 20 could also be programmed to return the trailer body 30 automatically to the stored height when the vehicle has been parked (e.g. when the parking brake is applied) or when the vehicle ignition is turned off. A user may thus store the height when the trailer body 30 is at the best height for loading or unloading from a particular docking bay.
It should be appreciated that, whilst in this example, the ECU 20 is programmed to raise the suspension after a single actuation of the button 26 and to lower the suspension after a double actuation of the button 26, it may equally be programmed to operate the other way round. In other words, the ECU 20 may be programmed to lower the suspension after a single actuation of the button 26, and to raise the suspension after a double actuation of the button 26. In any alternative embodiment, the ECU 20 is programmed such that when the button is actuated for a first length of time, the body is raised, and when the button is actuated for a second length of time, the vehicle body is lowered. By programming the ECU 20 to operate in this way, electronic raising and lowering of the suspension can be achieved using only a single button instead of a separate raise and lower button. The control buttons are typically mounted on the inside wall of the trailer body 30, the use of a single button instead of two buttons could be particularly advantageous where space on the trailer body 30 wall is limited, for example in a thermally lined refrigerated trailer.
In this embodiment of the invention, the button 26 is of the type which, when depressed by a user, and electrical signal is transmitted to the ECU 20, and electrical signal continuing to be transmitted to the ECU 20 until the user releases the button. For this embodiment, the ECU 20 may be programmed as illustrated in Figure 6. In this embodiment of the invention, the ECU 20 monitors for the receipt of a signal from the button 26. When the user depresses the button 26, the ECU 20 advances a timer whilst monitoring for the receipt of a further signal from the button 26. If the signal ceases (because the user has released the button) within a designated time limit (less than 2 seconds, say), the ECU 20 transmits a signal to the raise input 22 of the levelling valve assembly 12 so that compressed air is supplied to the suspension bellows 14 and the trailer body 30 is raised relative to its chassis 32. The ECU 20 continues to monitor for receipt of a signal from the button 26, and maintains the signal to the raise input 22 of the levelling valve assembly 12 so the supply of pressurised fluid to the suspension bellows 14 continues. When the desired level is achieved, the user depresses and then releases the button 26 again, and the ECU 20 is programmed to terminate the signal to the raise input 22 of the levelling valve assembly 12 so that the levelling valve assembly operates to cease the supply of further compressed air to the suspension bellows 14 and to hold the bellows 14 at their current pressure. The ECU 20 then returns to monitoring for receipt of a signal from the button 26 as before.
Alternatively, if after the initial actuation of the button 26, the user releases the button 26 after a longer period of time than the designated time limit (greater than 2 seconds in this example), the ECU 20 is programmed to transmit a signal to the lower input 24 of the levelling valve assembly 12 so that compressed air is released from the suspension bellows 14 and the trailer body 30 is lowered relative to its chassis 32. The ECU 20 continues to monitor for receipt of a signal from the button 26, and maintains the signal to the lower input 22 of the levelling valve assembly 12 so the release of pressurised fluid to the suspension bellows 14 continues. When the desired level is achieved, the user depresses and then releases the button 26 again, and the ECU 20 is programmed to terminate the signal to the lower input 24 of the levelling valve assembly 12 so that the levelling valve assembly operates to cease the release of further compressed air to the suspension bellows 14 and to hold the bellows 14 at their current pressure. The ECU 20 then returns to monitoring for receipt of a signal from the button 26 as before.
Thus, in the embodiment of the invention illustrated in Figure 6, the suspension system is operated on a "press to stop" basis. It will be appreciated that the suspension can only be safely raised or lowered by a certain amount - there is a maximum and minimum safe separation of the trailer body 30 from the chassis 32, and in both embodiments of the invention, the ECU 20 will be programmed to stop the raising or lowering of the suspension when either of these limits is reached even if the user has not actuated the button 26 in the manner required to stop the raising or lowering process. This may be achieved by the connection to the ECU 20 of a distance sensor which provides an output representative of the separation of the trailer body 30 and chassis 32. The ECU 20 may be programmed to move the suspension between predefined levels. So, for example, when raising the trailer body 30, instead of continuing to raise the trailer body 30 until the maximum safe height is reached, the ECU 20 may be programmed to stop the raising of the suspension when the next defined level is reached even if the user has not actuated the button 26 in the manner required to stop the raising process. The same could apply to the lowering process.
When programmed as described in relation to Figure 6, the ECU 20 could also be programmed to store in its memory the height of the trailer body 30 relative to the chassis 32 when the user presses the button 26 for a third predetermined length of time (less than 1 second say). This is illustrated in Figure 7. The ECU 20 could also be programmed to return the trailer body 30 automatically to the stored height when the vehicle has been parked (e.g. when the parking brake is applied) or when the vehicle ignition is turned off. A user may thus store the height when the trailer body 30 is at the best height for loading or unloading from a particular docking bay.
It should be appreciated that, whilst in this example, the ECU 20 is programmed to raise the suspension after actuation of the button 26 for the shorter period of time and to lower the suspension after actuation of the button 26 for a longer period of time, it may equally be programmed to operate the other way round. In other words, the ECU 20 may be programmed to lower the suspension after actuation of the button 26 for the shorter period of time, and to raise the suspension after actuation of the button 26 for the longer period of time. It should also be appreciated that it may be difficult for a user to judge exactly how long the button 26 has been held down for, and it may be actuated for longer than the user realises, resulting (in the example illustrated in Figure 6) in the suspension being lowered, when the user actually intended it to be raised (or vice versa when the system is configured to operate the opposite way round). To reduce the likelihood of this occurring, the ECU 20 could be programmed to initiate raising of the suspension if the button is actuated for less than a first predetermined time period (say 2 seconds), and to initiate lowering of the suspension if the button is actuated for more than a second, higher, predetermined time period (say 2.5 seconds), or vice versa. If the button is actuated for a time which falls between these two time periods, the ECU 20 is programmed to do nothing other than return to monitoring for receipt of a signal from the button 26. The user can then actuate the button 26 again. Whilst the embodiments of the invention described in relation to Figures 6 and 7 use a button which returns automatically to the "off position" when released by the user, i.e. ceases sending an electrical signal to the ECU 20 when released by the user, this need not be the case. The button 26 may be configured to maintain the electrical signal to the controller after it is released by the user, and to cease the electrical signal to the controller when it is pressed and released again.
In alternative embodiments, the system is configured to distinguish between the raise and lower command based on the force applied to actuate the button 26, or the displacement of the button 26. Examples of how the ECU 20 could be programmed to operated are illustrated in Figures 8 and 9.
Figure 8 shows an example in which the system is configured to raise the suspension if the force applied to the button 26 is below a predetermined level, and to lower the suspension if the force applied to the button 26 is above a predetermined level. The system could also be programmed to operate in an analogous way to that shown in Figure 4, with the suspension height being stored if the force used to actuate the button 26 is below a first threshold, and to raise the suspension if the force is above the first threshold but below a second, higher, threshold, and to lower the suspension if the force is above the second threshold. This system could also be programmed to initiate raising of the suspension if the button is actuated with a force less than a first predetermined level, and to initiate lowering of the suspension if the button is actuated with a force of more than a second, higher, predetermined force level, or vice versa. If the button is actuated with a force which falls between these two levels, the ECU 20 is programmed to do nothing other than return to monitoring for receipt of a signal from the button 26. The user can then actuate the button 26 again.
Figure 9 shows an example in which the system is configured to raise the suspension if the button 26 is moved less than a predetermined amount, and to lower the suspension if the button 26 is moved more than that predetermined amount. The system could also be programmed to operate in an analogous way to that shown in Figure 4, with the suspension height being stored if the button 26 is moved less than a first threshold amount, and to raise the suspension if the button 26 is moved more than the first threshold amount but below a second, higher, threshold amount, and to lower the suspension if the button 26 is moved more than the second threshold amount. This system could also be programmed to initiate raising of the suspension if the button is moved less than a first predetermined amount, and to initiate lowering of the suspension if the button is moved more than a second, higher, predetermined amount, or vice versa. If the button is moved by an amount which falls between these two levels, the ECU 20 is programmed to do nothing other than return to monitoring for receipt of a signal from the button 26. The user can then actuate the button 26 again.
It will be appreciated, of course, that the system could be configured to operate the other way round in terms of the circumstances under which is raises or lowers the suspension.
The switching device in these embodiments could, in these embodiments, comprise a push button which has two sets of contacts - one set being made when the button is half pressed and the other when it is fully pressed. Such buttons are, for example, commonly used as the shutter button on a digital camera. In this case, the ECU 20 could be programmed to raise the suspension if the button 26 is fully depressed, and to lower the suspension of the button 26 is half-pressed, or vice versa. Whilst the invention is described in relation to an air suspension system, it should be appreciated that it may equally be employed in a suspension system using any fluid - hydraulic or pneumatic, and any form of suspension element - hydraulic or pneumatic - may be employed instead of bellows to raise or lower the trailer body 30. The invention is also described as using a button for manual control of the suspension level. It should be appreciated that any other form of manually operable switching device - including a switch which pivots on an axis of rotation when actuated - may be used instead of a push button. Moreover, whilst the embodiments of the invention described in relation to Figures 3, 4 and 5 use a switching device which returns automatically to the "off position" when released by the user, i.e. ceases sending an electrical signal to the ECUU 20 when released by the user, this need not be the case. The switching device may be configured to maintain the electrical signal to the controller after it is released by the user, and to cease the electrical signal to the controller when it is pressed and released again.
When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components. The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

1 . A vehicle suspension system including a suspension element, a controller, and manually operable switching device which is connected to the controller, the suspension element having a first attachment portion and a second attachment portion, the attachment portion be adapted, in use, to be attached to different portions of a vehicle, and being operable by the controller to move in a first sense to increase the separation of two attachment portions or a second sense to decrease the separation of the two attachment portions, wherein the controller is configured to move the suspension element in the first sense when the switching device is actuated according to a first actuation scheme and to move the suspension element in the second sense when the switching device is actuated according to a second actuation scheme, the first actuation scheme being different to the second actuation scheme.
2. A vehicle suspension system according to claim 1 the switching device is actuated in an actuation direction when actuated according to the first and second actuation schemes.
3. A vehicle suspension system according to claim 2 wherein the direction of actuation for the first and second actuation schemes is given by a translational degree of freedom.
4. A vehicle suspension system according to any preceding claim wherein the controller is configured either to operate the suspension element to move in the first sense when the switching device is actuated a first number of times in a designated period of time and to move in the second sense when the switching device is actuated a second number of times in a designated period of time, the first number of times being different to the second number of times.
5. A vehicle suspension system according to claim 4 wherein the first number of times is less than the second number of times.
6. A vehicle suspension system according to claim 5 wherein the first number of times is one, and the second number of times is two.
7. A vehicle suspension system according to claim 4 wherein the second number of times is one and the first number of times is two.
8. A vehicle suspension system according to and one of claim 1 to 3 wherein the controller is configured such that the length of time for which the switching device is activated determines whether it operates the suspension element to move in the first sense or the second sense.
9. A vehicle suspension system according to claim 8 wherein the controller is configured to operate the suspension element to move in the first sense when the switching device is activated for a length of time which is less than a first predetermined level, and to move in the second sense when the switching device is activated for a length of time which is greater than the first predetermined level.
10. A vehicle suspension system according to claim 8 wherein the controller is configured to operate the suspension element to move in the first sense when the switching device is activated for a length of time which is less than a first predetermined level, and to move in the second sense when the switching device is activated for a length of time which is greater than a second predetermined level, the second predetermined level being greater than the first predetermined level.
1 1 . A vehicle suspension system according to any one of claims 8, 9 or 10 wherein the controller is programmed to measure a parameter determined by the separation of two attachment portions when the switching device is activated for a length of time which is less than or greater than a third predetermined level.
12. A vehicle suspension system according to claim 1 1 wherein the controller has a memory and is programmed to store in its memory the measured parameter.
13. A vehicle suspension system according to any one of claims 1 to 3 wherein the controller is configured such that the force with which the switching device is operated by a user determines whether the controller operates the suspension element to move in the first sense or the second sense.
14. A vehicle suspension system according to claim 13 wherein the controller is configured to operate the suspension element to move in the first sense when the switching device is operated with a force which is less than a first predetermined level, and to move in the second sense when the switching device is operated with a force which is greater than the first predetermined level.
15. A vehicle suspension system according to claim 13 wherein the controller is configured to operate the suspension element to move in the first sense when the switching device is operated with a force which is less than a first predetermined level, and to move in the second sense when the switching device is operated with a force which is greater than a second predetermined level, the second predetermined level being greater than the first predetermined level.
16. A vehicle suspension system according to any one of claims 13, 14 or 15 wherein the controller is programmed to measure a parameter determined by the separation of two attachment portions when the switching device is operated with a force which is less than or greater than a third predetermined level.
17. A vehicle suspension system according to claim 16 wherein the controller has a memory and be programmed to store in its memory the measured parameter.
18. A vehicle suspension system according to any one of claims 1 to 3 wherein the controller is configured such that the distance the switching device is moved when actuated determines whether the controller operates the suspension element to move in the first sense or the second sense.
19. A vehicle suspension system according to claim 18 wherein the controller is configured to operate the suspension element to move in the first sense when the switching device is moved a distance which is less than a first predetermined level, and to move in the second sense when the switching device is moved a distance which is greater than the first predetermined level.
20. A vehicle suspension system according to claim 18 wherein the controller is configured to operate the suspension element to move in the first sense when the switching device is moved a distance which is less than a first predetermined level, and to move in the second sense when the switching device is moved a distance which is greater than a second predetermined level, the second predetermined level being greater than the first predetermined level.
21 . A vehicle suspension system according to any one of claims 18, 19 or 20 wherein the controller is programmed to measure a parameter determined by the separation of two attachment portions when the switching device is moved a distance which is less than or greater than a third predetermined level.
22. A vehicle suspension system according to claim 21 wherein the controller has a memory and is programmed to store in its memory the measured parameter.
23. A vehicle suspension system according to any preceding claim wherein the controller includes a valve assembly and a programmable electronic control unit.
24. A vehicle suspension system according to any preceding claim wherein the suspension element includes a fluid operated actuator which moves in the first sense when connected to a supply of pressurised fluid, and in the second sense which connected to a lower pressure region.
25. A vehicle suspension system according to claim 24 wherein the suspension system further includes a pressurised fluid source, the controller being operable to connect the suspension to either the pressurised fluid source or the low pressure region.
26. A vehicle suspension system according to any preceding claim wherein the suspension element comprises air bellows.
27. A vehicle suspension system according to any preceding claim wherein the switching device comprises a push button or switch which is electrically connected to the controller, and which transmits an electrical signal to the controller when pressed by a user.
28. A vehicle suspension system according to claim 27 wherein the transmission of the electrical signal to the controller is maintained until the user releases the switching device, at which point the transmission of the electrical signal to the controller ceases.
29. A vehicle suspension system according to any preceding claim wherein the suspension system is a trailer vehicle suspension system.
30. A vehicle suspension system substantially as hereinbefore described with reference to and as shown in the accompanying drawings.
31 . A vehicle including a suspension system according to any preceding claim.
32. A trailer vehicle including a suspension system according to any preceding claim.
EP14703612.3A 2013-02-12 2014-02-11 Vehicle suspension system Withdrawn EP2956316A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GB201302438A GB201302438D0 (en) 2013-02-12 2013-02-12 Vehicle suspension system
GBGB1315675.7A GB201315675D0 (en) 2013-09-03 2013-09-03 Vehicle suspension system
PCT/EP2014/052659 WO2014124944A1 (en) 2013-02-12 2014-02-11 Vehicle suspension system

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EP2956316A1 true EP2956316A1 (en) 2015-12-23

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EP14703612.3A Withdrawn EP2956316A1 (en) 2013-02-12 2014-02-11 Vehicle suspension system

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WO (1) WO2014124944A1 (en)

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EP3208120A1 (en) 2016-02-18 2017-08-23 Haldex Brake Products Aktiebolag Electronic control unit and control circuit for a pneumatic suspension system of a commercial vehicle

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