SE537661C2 - Hydraulic system for controlling the clutch as well as the piston of a vehicle - Google Patents

Hydraulic system for controlling the clutch as well as the piston of a vehicle Download PDF

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Publication number
SE537661C2
SE537661C2 SE1450110A SE1450110A SE537661C2 SE 537661 C2 SE537661 C2 SE 537661C2 SE 1450110 A SE1450110 A SE 1450110A SE 1450110 A SE1450110 A SE 1450110A SE 537661 C2 SE537661 C2 SE 537661C2
Authority
SE
Sweden
Prior art keywords
clutch
shifting piston
pressure
piston
hydraulic system
Prior art date
Application number
SE1450110A
Other languages
Swedish (sv)
Other versions
SE1450110A1 (en
Inventor
Bo Lundström
Kristoffer Nilsson
Gustaf Lagunoff
Per-Olof Davidsson
Original Assignee
Borgwarner Torqtransfer Systems Ab
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
Application filed by Borgwarner Torqtransfer Systems Ab filed Critical Borgwarner Torqtransfer Systems Ab
Priority to SE1450110A priority Critical patent/SE537661C2/en
Priority to KR1020167022879A priority patent/KR20160117495A/en
Priority to EP15702254.2A priority patent/EP3099569B1/en
Priority to PCT/EP2015/052025 priority patent/WO2015114125A2/en
Priority to US15/114,189 priority patent/US10408284B2/en
Priority to JP2016548306A priority patent/JP2017506724A/en
Priority to CN201580006671.1A priority patent/CN105960536B/en
Publication of SE1450110A1 publication Critical patent/SE1450110A1/en
Publication of SE537661C2 publication Critical patent/SE537661C2/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
    • B60K17/00—Arrangement or mounting of transmissions in vehicles
    • B60K17/34—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles
    • B60K17/344—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles having a transfer gear
    • B60K17/346—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles having a transfer gear the transfer gear being a differential gear
    • B60K17/3467—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles having a transfer gear the transfer gear being a differential gear combined with a change speed gearing, e.g. range gear
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
    • B60K23/00—Arrangement or mounting of control devices for vehicle transmissions, or parts thereof, not otherwise provided for
    • B60K23/08—Arrangement or mounting of control devices for vehicle transmissions, or parts thereof, not otherwise provided for for changing number of driven wheels, for switching from driving one axle to driving two or more axles
    • B60K23/0808—Arrangement or mounting of control devices for vehicle transmissions, or parts thereof, not otherwise provided for for changing number of driven wheels, for switching from driving one axle to driving two or more axles for varying torque distribution between driven axles, e.g. by transfer clutch
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W10/00—Conjoint control of vehicle sub-units of different type or different function
    • B60W10/02—Conjoint control of vehicle sub-units of different type or different function including control of driveline clutches
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W10/00—Conjoint control of vehicle sub-units of different type or different function
    • B60W10/10—Conjoint control of vehicle sub-units of different type or different function including control of change-speed gearings
    • B60W10/11—Stepped gearings
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W10/00—Conjoint control of vehicle sub-units of different type or different function
    • B60W10/119—Conjoint control of vehicle sub-units of different type or different function including control of all-wheel-driveline means, e.g. transfer gears or clutches for dividing torque between front and rear axle
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D25/00—Fluid-actuated clutches
    • F16D25/06—Fluid-actuated clutches in which the fluid actuates a piston incorporated in, i.e. rotating with the clutch
    • F16D25/062—Fluid-actuated clutches in which the fluid actuates a piston incorporated in, i.e. rotating with the clutch the clutch having friction surfaces
    • F16D25/063—Fluid-actuated clutches in which the fluid actuates a piston incorporated in, i.e. rotating with the clutch the clutch having friction surfaces with clutch members exclusively moving axially
    • F16D25/0635—Fluid-actuated clutches in which the fluid actuates a piston incorporated in, i.e. rotating with the clutch the clutch having friction surfaces with clutch members exclusively moving axially with flat friction surfaces, e.g. discs
    • F16D25/0638—Fluid-actuated clutches in which the fluid actuates a piston incorporated in, i.e. rotating with the clutch the clutch having friction surfaces with clutch members exclusively moving axially with flat friction surfaces, e.g. discs with more than two discs, e.g. multiple lamellae
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D48/00—External control of clutches
    • F16D48/06—Control by electric or electronic means, e.g. of fluid pressure
    • F16D48/10—Preventing unintentional or unsafe engagement
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
    • F16H61/26—Generation or transmission of movements for final actuating mechanisms
    • F16H61/28—Generation or transmission of movements for final actuating mechanisms with at least one movement of the final actuating mechanism being caused by a non-mechanical force, e.g. power-assisted
    • F16H61/30—Hydraulic or pneumatic motors or related fluid control means therefor
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D48/00—External control of clutches
    • F16D48/02—Control by fluid pressure
    • F16D2048/0257—Hydraulic circuit layouts, i.e. details of hydraulic circuit elements or the arrangement thereof
    • F16D2048/0287—Hydraulic circuits combining clutch actuation and other hydraulic systems
    • F16D2048/0293—Hydraulic circuits combining clutch and transmission actuation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H57/00—General details of gearing
    • F16H57/02—Gearboxes; Mounting gearing therein
    • F16H2057/02039—Gearboxes for particular applications
    • F16H2057/02043—Gearboxes for particular applications for vehicle transmissions
    • F16H2057/02052—Axle units; Transfer casings for four wheel drive

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Hydraulic Clutches, Magnetic Clutches, Fluid Clutches, And Fluid Joints (AREA)

Abstract

ABSTRACT A hydraulic system is provided, comprising a hydraulically actuatedclutch, a hydraulically actuated shifting piston, and a pressure source foractuating the clutch as Well as the shifting piston. The movement of the shiftingpiston also controls a valve function Which serves to open a connection from thepressure source to the clutch only When the shifting piston has reached one of its end positions. To be published With Pig. 2

Description

A HYDRAULIC SYSTEM FOR A VEHICLE Technical FieldThe present invention related to a hydraulic system for a vehicle. Moreparticularly, the present invention relates to a hydraulic system for controlling an AWD coupling as well as low/high range gear of a transfer case.
BackgroundAWD vehicles with a drivetrain topology including a Transfer Case with a selectable low range gear have existed on the market for many years. ln thesimplest form the low range gear is selected with an additional shift lever. Inmodern vehicles there is an increasing need for controllability and functionalityof the low range gear. Such requirements can include the ability to “shift on themove", i.e. the possibility to change low/high range without a complete stand-still of the vehicle. lt°s also desirable that the shifting of low/high range can beperformed without actuating the AWD Clutch at the same time, as that mightinfluence the vehicle behavior negatively, as for example locking up the front andrear axle in a parking maneuver.
To meet the new requirements the shifting is normally controlled by anactuator rather than a manual lever. When combined with controllable AWD, suchsystems tend to be complex, heavy and include several actuators, mechanismsand sensors.
There are existing electromechanical systems utilizing just one actuatorfor both shifting and clutch actuation. The drawback of these electromechanicalsystems are that they tend to by heavier, be less flexible for packaging, haveworse torque accuracy and controllability, need a more complex control strategyand have a higher peak current consumption.
There are also existing hydraulic solutions as shown in Fig. l, illustratingan example of an existing hydraulic solution for 2-Speed Transfer Cases using apressure controlling pump, like e.g. a pump as described in WO20ll043722, forboth shift actuation and AWD-Clutch actuation. The drawback of the existingdesigns are that they tend utilize multiple actuators which results in higher cost,weight and packaging size. Normally they are also designed with a slide valve which requires high cleanliness and an oil filter.
Summary An object of the present invention is to provide a hydraulic system Whichuses the movement of a shifting piston to also achieve a valve function. Thehydraulic system is preferably used in applications requiring torque controlbetween a coupling and a gear switch, such as transfer case applications whereinthe hydraulic system serves to open a connection from the pressure source to theAWD clutch piston only when the shifting piston has reached one of its endpositions.
According to aspects of the present invention, a hydraulic system isprovided in accordance with the features set forth in the independent claims.
Preferred embodiments are defined by the appended dependent claims.
Brief Description of Drawings Embodiments of the invention will be described in the following;reference being made it the appended drawings which illustrate non-limitingexamples of how the inventive concept can be reduced into practice.
Fig. l shows an example of existing hydraulic solution for 2-SpeedTransfer Cases using a pressure controlling pump for both shift actuation andAWD-Clutch actuation; Fig. 2 is a hydraulic scheme of a reversible pump combined withmechanically actuated piston valves; Fig. 3 is a hydraulic scheme of a pump combined with direction valve andpiston valve. The solenoid actuated direction valve is preferably of a seat valveWPC; Fig. 4 is a hydraulic scheme of a pilot controlled ball valve enabling theuse of only two piston sealings; Fig. 5 is a hydraulic scheme of a reversible pump combined with pistonvalves; Fig. 6 and 7 show a piston valve function realized with piston seals andsleeve; Fig. 8 shows a piston valve function realized with spring valves in thepiston; Fig. 9 shows a piston valve realized as mechanically activated seat valve; Fig. l0 shows a piston valve function realized with check valvescontrolled by pins; Fig. ll shows a piston valve function realized as a part of the gearretention mechanism; Fig. l2 shows a pilot controlled ball valve with dual inputs; Fig. 13 shows a hydraulic actuator according to an embodiment; and Fig. 14 shows a hydraulic actuator according to a further embodiment.
Detailed DescriptionAlthough the hydraulic system will be described mainly with reference to transfer case applications, it should be realized that the inventive concept is notlimited to such applications but could be implemented for various vehicleapplications in which torque control between a coupling and a gear shift isrequired.
Now turning to the transfer case application, one of the challenges usingone actuator for both the AWD Clutch and the shift function is to meet therequirement to not have any AWD Clutch torque when shifting range gear. ln theexisting hydraulic solution shown in Fig. 1 this is solved by a separate valvewhich will divert the flow/pressure to either shifting or the AWD Clutch piston.
The invention described here is to use the movement of the shifting pistonto also achieve a valve function, which serves to open a connection from thepressure source (i.e. a pump) to the AWD Clutch piston only when the shiftingpiston has reached one of its end positions, i.e. when the shifting maneuver iscomplete.
By reducing the pressure once the shifting has been completed theactivation of unintentional torque transfer in the AWD Clutch can be avoidedduring shifting.
As a pressure source for shifting a reversible pressure regulating pump canbe used or as an alternative a one directional pressure regulating pump incombination with a 4/2-direction valve to reverse the flow directions.
The valve function activated by the piston movement can be realized inmany ways, but a seat type valve is preferable due to its lower sensitivity tocontamination. ln the figures some examples using the piston sealings themselvesare shown to achieve the valve function, some examples using the pistonmovement to actuate separate valves, and an example of using a pilot controlledvalve.
Starting with Fig. 2 a reversible pump is provided to apply a pressure onboth sides of a shifting piston. Moving the piston will urge one of the valves toopen, thereby allowing hydraulic pressure to be applied to the AWD clutch.
Fig. 3 shows another embodiment in which a pump is arranged in serieswith a directional valve. When the shifting piston moves a channel will open allowing hydraulic pressure to be applied to the AWD clutch.
Pig. 4 shows a modification of the embodiment shown in Pig. 3, whereinthe hydraulic pressure from the shifting piston channels is used to control a ballvalve, instead of actuating the AWD clutch.
Pig. 5 shows a modification of the embodiment shown in Pig. 3, in whichthe pump and the directional valve are replaced by a reversible pump.
Pig. 6 shows an embodiment in which the shifting piston is surrounded bya plastic insert having several holes along its periphery. Moving the shiftingpiston will allow fluid to flow through the holes for actuating the AWD clutch.
Pig. 7 shows a modification of the embodiment shown in Pig. 6, in whichthe plastic insert has been removed and the piston itself has been provided withcircumferential holes.
Pig. 8 shows a further embodiment. The shifting piston is connected withtwo springs on opposite sides, each spring sealing off a fluid channel inside thepiston. When the piston is urged to move one of the springs will deflect and openthe channel. A ball inside the piston acts as a valve for directing the fluid flow tothe AWD clutch.
Pig. 9 shows an example of a valve to be used with the system of Pig. 2.When the piston moves the valve pin will be allowed to move downwards, thusopening a channel to the AWD clutch. The movement of the pin may e.g. beaccomplished by a cam surface.
Pig. l0 shows a yet further embodiment of a system in which the valvefunctionality is provided by two separate check valves, each check valve beingcontrolled by a respective pin.
Pig. ll shows an embodiment in which the valve functionality forms partof the gear retention mechanism. The spring-biased ball is used to keep theshifting piston at a desired position. Purther, the fluid channel connecting thepressure source with the AWD clutch is arranged such that it will be blocked bythe ball during shifting.
Pig. l2 shows a yet further embodiment of a valve to be used with thesystem of Pig. 2. ln this embodiment the pilot controlled ball valve has dualinputs whereby the channel to the AWD clutch will open once the pilot pressureis sufficient to move the valve.
Pig. l3 shows an embodiment of a hydraulic actuator using a reversiblepump assembly having a first port for providing pressure to one actuator, and asecond port for providing pressure to a second actuator. A third port is providedand connected to the pressure overflow valve. This embodiment uses the third port to provide pressure to the AWD coupling, while the first and second ports are used to provide pressure to both sides of the shifting piston. In thisembodiment the shifting piston Will be pressurized simu1taneous1y as the AWDcoup1ing is actuated. Such embodiment may be advantageous in cases wherethere are no requirements on “shift on the move”.
In Fig. 14 a further embodiment is shown using two pump assemb1ies. Afirst pump assembly is the same as being described with reference to e.g. Fig. 13,and used to actuate the AWD coup1ing. A sma11 reversib1e pump, preferab1y of1ow cost gerotor type with 2 in1et check va1ves, is provided for shifting the pistonbetween 1ow and high range.
As an option the shifting piston wi11 have sea1ings that in end positionpass sma11 out1et ho1es sop the pressure = current goes down and end positions wi11 be detected.

Claims (8)

1. A hydraulic system for a vehicle, comprising a hydraulically actuated clutch, a hydraulically actuated shifting piston, and a pressure source for actuating the clutch as well as the shifting piston,characterized in that the movement of the shifting piston also controls a valve function whichserves to open a connection from the pressure source to the clutch only when the shifting piston has reached one of its end positions.
2. A hydraulic system for a vehicle, comprising a hydraulically actuated clutch, a hydraulically actuated shifting piston, and a pressure source for actuating the clutch as well as the shifting piston,characterized in that the shifting piston forms a valve which, when arranged in an end position,allows the pressure source to apply a pressure to the clutch, and, when movingbetween two end positions, prevents the pressure source to apply a pressure tothe clutch.
3. The hydraulic system according to claim 1 or 2, wherein the pressure source is a reversible pump.
4. The hydraulic system according to claim 1 or 2, wherein the pressure source is a non-reversible pump arranged in series with a directional valve.
5. The hydraulic system according to any one of the preceding claims,further comprising a pilot controlled ball valve arranged between the pressuresource and the clutch, and wherein the shifting piston is configured to open a pressure channel for providing the pilot pressure to the ball valve.
6. A transfer case, comprising a hydraulic system according to any one of the preceding claims.
7. The transfer case of claim 6, wherein the hydraulically actuated clutch is an AWD coupling configured to change driving mode between two wheel drive and four wheel drive, and the hydraulically actuated shifting piston is configured to change between low range gear and high range gear of the transfer case.
8. A method for operating a transfer case comprising a hydraulicallyactuated clutch for changing driving mode between two wheel drive and fourwheel drive, a hydraulically actuated shifting piston for changing between lowrange gear and high range gear, and a pressure source for actuating the clutch aswell as the shifting piston, wherein the method comprises the step of: moving the shifting piston between two end positions, wherein the shiftingpiston forms a valve which, when arranged in an end position, allows thepressure source to apply a pressure to the clutch, and, when moving between two end positions, prevents the pressure source to apply a pressure to the clutch.
SE1450110A 2014-01-31 2014-01-31 Hydraulic system for controlling the clutch as well as the piston of a vehicle SE537661C2 (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
SE1450110A SE537661C2 (en) 2014-01-31 2014-01-31 Hydraulic system for controlling the clutch as well as the piston of a vehicle
KR1020167022879A KR20160117495A (en) 2014-01-31 2015-01-31 A hydraulic system for a vehicle
EP15702254.2A EP3099569B1 (en) 2014-01-31 2015-01-31 A hydraulic system for a vehicle
PCT/EP2015/052025 WO2015114125A2 (en) 2014-01-31 2015-01-31 A hydraulic system for a vehicle
US15/114,189 US10408284B2 (en) 2014-01-31 2015-01-31 Hydraulic system for a vehicle
JP2016548306A JP2017506724A (en) 2014-01-31 2015-01-31 Hydraulic system for vehicle
CN201580006671.1A CN105960536B (en) 2014-01-31 2015-01-31 A kind of hydraulic system for vehicle

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE1450110A SE537661C2 (en) 2014-01-31 2014-01-31 Hydraulic system for controlling the clutch as well as the piston of a vehicle

Publications (2)

Publication Number Publication Date
SE1450110A1 SE1450110A1 (en) 2015-08-01
SE537661C2 true SE537661C2 (en) 2015-09-29

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Family Applications (1)

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SE1450110A SE537661C2 (en) 2014-01-31 2014-01-31 Hydraulic system for controlling the clutch as well as the piston of a vehicle

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Publication number Publication date
SE1450110A1 (en) 2015-08-01

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