EP2006509A2 - Verbrennungsmotor mit variabler Verdichtung - Google Patents

Verbrennungsmotor mit variabler Verdichtung Download PDF

Info

Publication number
EP2006509A2
EP2006509A2 EP20080251215 EP08251215A EP2006509A2 EP 2006509 A2 EP2006509 A2 EP 2006509A2 EP 20080251215 EP20080251215 EP 20080251215 EP 08251215 A EP08251215 A EP 08251215A EP 2006509 A2 EP2006509 A2 EP 2006509A2
Authority
EP
European Patent Office
Prior art keywords
piston
coupler
pivot
pivot member
engager
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Withdrawn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
EP20080251215
Other languages
English (en)
French (fr)
Inventor
Michael Von Mayenburg
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.)
Individual
Original Assignee
Individual
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 US12/011,494 external-priority patent/US7946260B2/en
Application filed by Individual filed Critical Individual
Publication of EP2006509A2 publication Critical patent/EP2006509A2/de
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B75/00—Other engines
    • F02B75/04—Engines with variable distances between pistons at top dead-centre positions and cylinder heads
    • F02B75/045—Engines with variable distances between pistons at top dead-centre positions and cylinder heads by means of a variable connecting rod length

Definitions

  • the technology disclosed herein relates to methods and apparatus for adjusting the compression ratio of an internal combustion engine, such as for gasoline and diesel fueled engines.
  • Gasoline engines are typically designed so that under full load (open throttle) no uncontrolled combustion (knocking) occurs which limits the combustion ratio. Under throttled conditions, the gasoline engine is under compressed which can reduce engine efficiency. Diesel engines are typically over compressed to enhance starting in cold conditions. Diesel engines that have warmed up would be more efficient if they had a lower compression ratio. Thus, a variable compression ratio engine can be operated under various operating conditions to vary the engine compression so as to, for example, increase engine efficiency. A need exists for an improved variable compression ratio engine and related methods.
  • a piston coupler is pivotable about a first axis and pivotally couples a piston to a connecting rod with the piston being slidable in an associated piston cylinder in response to rotation of a crank shaft coupled to the connecting rod.
  • the piston is reciprocated between top dead center and bottom dead center positions.
  • the piston coupler comprises a first coupling portion pivotally coupled to the piston such that the piston is pivotable about a first axis and a second coupler portion pivotally coupled to the connecting rod such that the connecting rod is pivotable about a second axis.
  • One of the first and second coupler portions comprises an eccentric portion operable such that pivoting of the piston coupler about the first axis from a first coupler position to a second coupler position pivots the eccentric portion from a first eccentric position to a second eccentric position and shifts the second axis relative to the first axis to thereby vary the compression ratio of the associated piston cylinder.
  • the piston coupler can also comprise a pivot member engager.
  • a pivot member comprises a pivot coupler engager movable from a first pivot coupler engager position to a second pivot coupler engager position and positioned to engage the pivot member engager to pivot the piston coupler from the first coupler position to the second coupler position as the piston approaches the bottom dead center position and in response to such movement of the pivot coupler engager.
  • the pivot coupler engager is disengaged from the pivot member engager as the piston travels away from bottom dead center position.
  • a pivot member can be pivotable about a pivot member axis for pivoting movement from first to second pivot member positions in response to movement of the pivot coupler engager from first to second positions so as to result in corresponding movement of the piston coupler from first to second coupler positions to thereby vary the compression of the engine.
  • the pivot member engager can comprise at least one pivot member engagement surface which, for example, can be flat or planar and the pivot member can comprise at least one pivot member engagement surface which can also be flat or planar.
  • the pivot member is pivotable about a pivot member axis and comprises two pivot member engagement surfaces respectively positioned at opposite sides of the pivot member axis and the first axis and wherein there is a first set of two pivot coupler engagement surfaces on opposite sides of the pivot member axis.
  • a plurality of pistons are provided with a common pivot member being provided to engage the pivot member engagement surfaces of the couplers associated with the pistons in the respective first and second piston cylinders.
  • a first bracket positioned at least in part in the first cylinder and a second bracket positioned at least in part within the second cylinder can be used to support respective ends of the common pivot member.
  • a first set of two pivot coupler engagement surfaces can be provided at one end portion of the common pivot member and a second set of two pivot coupler engagement surfaces can be provided at the opposite end portion of the common pivot member.
  • the piston coupler can comprise a piston pin pivotable about the first axis with exemplary forms of piston pins being described in greater detail below.
  • the piston pins include internal cavities. These internal cavities can include a first cavity at one end portion of the piston pin that can be at least in part conical, a second cavity at an opposite end portion of the pivot pin that can also be at least in part conical, and an internal passageway extending therebetween. These passageways can be dimensioned and positioned to provide a homogeneous bending line in response to the application of force by the piston to the piston pin and the counterforce applied by the connecting rod during operation of an engine.
  • the piston coupler comprises a piston pin.
  • a piston associated with a cylinder can comprise a body having an upper cylindrical piston ring supporting portion of a first diameter and a lower body portion sized to create a pivot member engager receiving space between the lower body portion and the associated cylinder.
  • One end portion of the piston pin can extend outwardly from the lower body portion into the pivot member engager receiving space, said one end portion of the piston pin can comprise a pivot member engager.
  • the pivot members can be selectively driven to cause pivoting of the pivot members to thereby vary the compression ratio of the engine.
  • a motor can be coupled to a worm gear which operably engages a pivot member to pivot the pivot member between various positions to adjust the compression ratio to a plurality of values depending upon the position to which the pivot member has been pivoted.
  • a single motor can be coupled to a plurality of pivot member drivers, such as to plural worm gears, such as a respective worm gear for driving each pivot member.
  • a worm gear associated with a pivot member can engage a pivot member to restrict movement of a pivot member in either direction along a pivot member axis about which the pivot member can be pivoted.
  • the pivot member can define a recess extending in a direction perpendicular to the pivot member axis with the worm gear being positioned at least partially in the recess and engaging the pivot member to restrict movement of the pivot member in either direction along the pivot member axis.
  • Pivoting of the pivot member can be limited to be within predetermined limits such as by configuring a worm gear drive for the pivot member.
  • a mechanism can be provided for limiting the extent of pivoting of the pivot coupler about the first axis to be within a predetermined limit.
  • a piston coupler retainer can be coupled to the piston coupler to apply a retention force to resist pivoting of the piston coupler.
  • the piston coupler retainer can also limit pivoting of the pivot coupler about the first axis to be within a predetermined limit.
  • the piston coupler retainer can comprise a friction brake having a braking surface received within a braking surface defining cavity of the piston coupler.
  • an internal combustion engine wherein a piston cylinder has a longitudinal centerline and wherein the maximum eccentricity is defined as E and corresponds to the maximum offset between the first and second axes, wherein an origin of a reference coordinate system is at the intersection of the longitudinal centerline of the at least one piston cylinder and a bottom dead centerline corresponding the second axis when the second axis is in the bottom dead center position, wherein the Z dimension is along the longitudinal center line of the piston cylinder from the origin and the X dimension is along the bottom dead centerline from the origin, wherein the pivot member axis is parallel to the first axis and, wherein the pivot member axis intersects an area wherein X is from -0.5E to -0.8E and Z is from -0.25E to 0.25E.
  • an internal combustion engine comprises at least one piston cylinder with a longitudinal centerline, wherein the longitudinal centerline is positioned between a first line parallel to the longitudinal centerline that intersects the first axis and a second line parallel to the longitudinal centerline that intersects the second axis when the eccentric portion is pivoted to the maximum allowed extent.
  • an internal combustion engine wherein the maximum eccentricity is defined as E and corresponds to the maximum offset between the first and second axes arising from pivoting the eccentric portion
  • the piston coupler comprises a piston pin comprising first and third portions and a second portion intermediate the first and third portions, the first and third portions having longitudinal centerlines that are aligned with the first axis, the second portion comprising the eccentric portion and having a longitudinal center line that is aligned with the second axis, the first, second and third portions comprising right cylindrical surfaces, the second portion having a right cylindrical surface of a first diameter defined as R CR , one of the first and third portions having a right cylindrical surface of a diameter R 1 , wherein R 1 ⁇ (R CR + E), and the other of the first and third portions having a right cylindrical surface of a diameter R 2 , wherein R 2 ⁇ (R CR - E).
  • an internal combustion engine wherein there are first and second of said piston cylinders, a respective associated first piston slidably received by the first of said piston cylinders, a respective associated second piston slidably received by the second of said piston cylinders, a respective connecting rod and piston coupler associated with and coupled to said first piston, a respective connecting rod and piston coupler associated with and coupled to the second piston, and wherein there is a common pivot member for engaging the piston couplers associated with the first and second pistons.
  • the common pivot member can comprise a first set of two pivot coupler engagement surfaces for engaging two pivot member engagement surfaces of the piston coupler associated with the first piston and a second set of two pivot coupler engagement surfaces for engaging two pivot member engagement surfaces of the piston coupler associated with the second piston.
  • the common pivot member can comprise a first pivot member end portion extending into a first region defined by the first cylinder and a second pivot member end portion extending into a second region defined by the second cylinder.
  • a first bracket can be coupled to the first cylinder in a position to pivotally support the first pivot member end portion and a second bracket can be coupled to the second cylinder in a position to pivotally support the second pivot member end portion.
  • the first and second brackets can be fastened together with a portion of the first cylinder and a portion of the second cylinder positioned between the first and second brackets.
  • the first and second brackets are configured to provide clearance for the respective pivot member engagement surfaces and pivot coupler engagement surface to engage one another.
  • the piston coupler can define a piston coupler braking surface.
  • a spring biased friction brake can be coupled to the at least one piston and can comprise a friction brake with a braking surface positioned to frictionally engage the piston coupler braking surface.
  • each of the piston coupler braking surface and friction brake braking surface can be at least partially conical.
  • the piston coupler can comprise a piston pin with a first end portion comprising a brake receiving cavity defining the piston coupler braking surface with the friction brake being inserted at least partially into the brake receiving cavity.
  • the piston pin can comprise a second end portion that defines a cavity that is at least partially conical with the pivot member engager comprising an outwardly projecting portion of the second end portion.
  • An internal cavity can be provided that interconnects the second end portion cavity and the brake receiving cavity.
  • the internal cavity, the second end portion cavity and the brake receiving cavity can be shaped and dimensioned to achieve a homogenous bending line in response to the application of force by the piston to the piston pin and the counterforce applied by the connecting rod during operation of the engine.
  • the friction brake can comprise a stop portion positioned to engage the piston coupler to limit the extent of pivoting of the piston coupler to within a predetermined limit.
  • the invention encompasses all novel and non-obvious assemblies, sub-assemblies and individual elements, as well as method acts, that are novel and non-obvious and that are disclosed herein.
  • the embodiments described below to illustrate the invention are examples only as the invention is defined by the claims set forth below.
  • the term “coupled” and “coupling” encompasses both a direct connection of elements as well as the indirect connection of elements through one or more other elements.
  • the terms "a” and “an” encompass both the singular and the plural. For example, if an element or a element is referred to, this includes one or more of such elements. For example, if a plurality of specific elements of one type present, there is also an element of the type described.
  • the invention is also not limited to a construction which contains all of the features described herein.
  • Adjustable compression ratio engines can be operated to improve the efficiency of the engine by varying the compression ratio appropriately.
  • FIG. 1 illustrates a vertical sectional view through a portion of an internal combustion engine, in this case a six cylinder engine.
  • Table 1 Various dimensions of an exemplary engine are set forth in Table 1 below. It is to be understood that these dimensions are for example only and do not limit the scope of this disclosure.
  • the engine 10 of FIG. 1 comprises a portion of an engine block 12 having respective end walls 14,16 that pivotally support a crank shaft 20 for rotation about an axis 24.
  • Respective bearings 26,28 pivotally couple the crank shaft to the respective housing walls.
  • Additional support bearings or bushings 30,32 couple the crank shaft to the engine housing at locations intermediate the ends of the crank shaft for further support.
  • FIG. 1 For purposes of clarity only, portions of three pistons 40,42 and 44 are shown in FIG. 1 , the other three pistons of this illustrative engine are not shown.
  • the technological developments disclosed herein are not limited to six cylinder engine applications as engines with any number of cylinders can utilize the technology.
  • a piston or connecting rod 60 is coupled by bearings or bushings 62 at a lower end portion 64 of the connecting rod to a connecting rod mounting location 66 of the crank shaft 20.
  • the upper end portion 70 of connecting rod 60 is provided with an opening 72 extending therethrough, the opening having a longitudinal axis 74 that is parallel to the longitudinal axis 24 of the crank shaft.
  • opening 72 is of a right cylindrical shape.
  • a piston coupling bushing or bearing 76 can be positioned within opening 72.
  • Bushing 76 has a centrally extending coupler receiving opening 78 extending therethrough.
  • Opening 78 is of a right cylindrical configuration in this example and has a longitudinal axis concentric with the axis 74.
  • a coupler such as a coupling or piston pin 80 extends through the opening 78 and couples the piston 40 to the connecting rod 60.
  • the piston 40 comprises a body having an upper cylindrical piston ring supporting portion 81 of a first diameter and a lower body portion sized to create a pivot member engager receiving space between the lower body portion 83.
  • One end portion of the piston pin 40 extends outwardly from the lower body portion 83 and into a pivot member engager receiving space 85, said one end portion of the piston pin can comprise a pivot member engager (e.g., including engagement surface 170') as explained below.
  • a pivot member engager comprises an outwardly projecting portion of a pivot coupler.
  • Coupler 80 in this configuration comprises an eccentric that can be pivoted to cause relative motion of the piston 40 relative to the connecting rod 60 to thereby vary the combustion chamber volume and thereby the compression ratio of the cylinder.
  • Suitable couplers can assume shapes other than the shape of an elongated pin and comprise an eccentric operable to selectively shift the pivot axis of the connecting rod where it is coupled to the piston relative to the pivot axis about which the piston and pivot pin pivots.
  • Exemplary constructions of an eccentric coupler 80 in the form of piston pins are described below.
  • a coupler retaining mechanism for example a friction brake 82, an example of which is explained below, can be used to retain the coupler 80 in, or resist the motion of the coupler 88 from, a desired position to which it has been pivoted.
  • the piston coupler such as the pin
  • the piston coupler can interfit tightly enough with the piston to resist motion from a desired position to which it has been pivoted until such time as the resistance is overcome by engaging a pivot member that has been shifted to a different position.
  • a cavity 84 is provided in the head of piston 40 to accommodate the relative movement of the piston and connecting rod.
  • a pivot mechanism is utilized to pivot the coupler 80 to a desired position of eccentricity to adjust the combustion ratio.
  • An exemplary form of pivot member 90 is shown in FIG. 1 and is described in more detail below.
  • a modified form of pivot member 90a is shown for selective coupling to the couplers for pistons 42 and 44 and is also described below.
  • the pivot member 90a is an example of, a single or common pivot member for engaging the piston couplers 80 associated with first and second pistons (e.g., pistons 42,44), the pivot member 90a comprising a first set of two pivot coupler engagement surfaces (e.g., 210a', 210a" of FIG. 9 ) for engaging the two pivot member engagement surfaces (e.g., 170',170" of FIG. 5B ) of the piston coupler 80 associated with the piston 42 and a second set of two pivot coupler engagement surfaces (e.g., 210b', 210b" of FIG. 9 ) for engaging the two pivot member engagement surfaces (e.g., 170',170") of the piston coupler 80 associated with the piston 44.
  • a first set of two pivot coupler engagement surfaces e.g., 210a', 210a" of FIG. 9
  • the two pivot member engagement surfaces e.g., 170',170" of FIG. 5B
  • pivot member operable to pivot the pivot coupler of more than one piston.
  • the piston coupler 80 engages the pivot member 90 and, if the pivot member 90 has been pivoted to adjust the eccentricity of the associated coupler, the coupler engages the pivot member and is pivoted to the desired eccentricity position.
  • the friction applied by friction brake 82 if included, is overcome to allow such pivoting.
  • the friction brake 82 retains the coupler 80 in position relative the connecting rod 60 until further adjustment of the pivot member to adjust the eccentricity position.
  • the coupler 80 is again adjusted to the desired position of eccentricity by engagement of the pivot engager portion of the coupler with the pivot member 90.
  • the pivot members 90,90a can be pivoted together so that their positions are maintained at the same rotational position.
  • the eccentricity of the cylinder is adjusted if the pivot member has been turned. For example, in FIG. 1 , piston 42 is at the bottom dead center position with surface 170" of piston coupler 80 shown engaging a surface 210a" of pivot member 90a.
  • pivot member 90a has been turned to adjust the eccentricity of the associated coupler 80, upon such engagement of surfaces 210a" and 170", the coupler 80 for piston 42 turns to adjust the relative position of piston 42 to its associated connecting rod 60.
  • the other pistons 40,44 reach their bottom dead center positions, they would likewise be adjusted to the desired compression ratio by pivoting their associated couplers 80.
  • an exemplary internal combustion engine comprises a rotatable crank shaft 24; at least one piston cylinder (e.g., in one example, six cylinders including cylinders receiving pistons 40,42 and 44) with each piston being slidably received by its associated cylinder so as to reciprocate between top dead center and bottom dead center positions within the receiving cylinder.
  • the piston comprises a first piston coupler portion receiving bore defining a first axis (e.g., axis 74 explained below) (see e.g., FIG. 7 ).
  • the connecting rod 60 comprises a first crank coupling end portion 64 pivotally coupled to the crank shaft such that rotation of the crank shaft causes the connecting rod to reciprocate.
  • the connecting rod 60 also comprises a second piston coupling end portion 70 comprising a second piston coupler receiving bore defining a second axis 160.
  • a piston coupler e.g., a piston pin 80
  • the piston coupler comprises a connecting rod coupler portion (e.g. 78) pivotally received by the second piston coupler receiving bore to couple the connecting rod 60 to the piston (e.g., 40).
  • One of the piston coupler portion and connecting rod coupler portion comprises an eccentric portion such that reciprocation of the connecting rod causes the piston to reciprocate between the top dead center and bottom dead center positions.
  • pivoting of the piston coupler about the first axis from a first coupler position to a second coupler position pivots the eccentric portion from a first eccentric position to a second eccentric position and shifts the second axis relative to the first axis to thereby vary the compression ratio of the associated cylinder.
  • the portion 78 of pin 80C an be considered an eccentric portion.
  • the piston coupler portion can be the eccentric portion.
  • the piston coupler also comprises a pivot member engager that can comprise an end portion of a piston pin (e.g., surfaces 170', 170") and a pivot member (e.g., 90, 90a) comprising a pivot coupler engager (e.g., surfaces 210', 210"; 210a', 210a"; 210b', 210b") movable from a first pivot coupler engager position to a second pivot coupler engager position and positioned to engage the pivot member engager to pivot the piston coupler from the first coupler position to the second coupler position as the piston approaches the bottom dead center position and in response to such movement of the pivot coupler engager from the first pivot coupler engager position to the second pivot coupler engager position.
  • the pivot coupler engager is also operable in one embodiment to disengage the pivot member engager as the piston travels away from the bottom dead center position.
  • the pivot member can be pivotable about a pivot member axis.
  • the pivot member can be pivotable about the pivot member axis from a first pivot member position to a second pivot member position to pivot the pivot coupler engager from the first pivot couple engager position to the second pivot coupler engager position.
  • the piston coupler is pivoted from a first coupler position to a second coupler position as the piston approaches the bottom dead center position in response to the pivoting of the pivot coupler engager from the first pivot coupler engager position to the second pivot coupler engager position.
  • the pivot member engager can comprise at least one pivot member engagement surface (e.g., surface 170') and the pivot coupler engager can comprise at least one pivot coupler engagement surface (e.g. surface 210').
  • the at least one pivot coupler engagement surface can be pivoted from a first position to a second position in response to pivoting of the pivot member from the first pivot member position to the second pivot member position.
  • the at least one pivot member engagement surface and at least one pivot coupler engagement surface are desirably positioned to engage one another as the piston approaches the bottom dead center position to pivot the piston coupler from the first coupler position to the second coupler position in response to the pivoting of the at least one pivot coupler engagement surface from the pivot coupler engager first position to the pivot coupler engager second position.
  • the at least one pivot coupler engagement surface and the at least one pivot member engagement surface can each be a flat surface and such surfaces can be planar.
  • there are two of said pivot member engagement surfaces e.g., 170', 170" positioned on opposite sides of the first axis.
  • there can be a first set of two pivot coupler engagement surfaces on opposite sides of the pivot member axis see surfaces 210', 210" of pivot member 90 and either surfaces 210a', 210a" or 210b', 210b" ofpivot member 90a).
  • the pivot member engager comprises downwardly facing first and second pivot member engagement surfaces of one end portion of a piston pin.
  • the couplers 80 can, for example, have an eccentricity of 1.8 mm.
  • the turning angle of the pivot member 90,90a can be limited to a predetermined amount or extent. In a specific example, the turning angle can be limited to 110 degrees to thereby provide a maximum 3 mm piston movement.
  • Table 1 a variable combustion chamber volume is provided and a variable combustion ratio of from 10-16 results. These dimensions can be varied.
  • FIG. 2 illustrates the piston 40 without the coupler 80 and without the connecting rod 60 coupled thereto.
  • the piston 40 comprises a first bore section 110 of circular cross-section and having a longitudinal axis aligned with the longitudinal axis 74 in this example.
  • Friction brake engagers are provided adjacent to the bore 110. These engagers can take numerous forms and are designed to engage a friction brake in the illustrated example to prevent rotation of the friction brake relative to the piston.
  • recesses and other interfitting arrangements can be used, in FIG. 2 a plurality of projections, in this case radially extending projections 114,116 and 118 are provided. These projections extend in an outward direction from the edge of bore 110 at locations spaced 120 degrees about the center of the bore 110. These projections extend outwardly away from a surface 112 of the piston.
  • FIG. 3 a vertical sectional view through piston 40 of FIG. 2 , the bore 110 is shown along with the projections 114 and 118.
  • a second bore 124 having a longitudinal axis corresponding to the axis 74 in this example, is also shown.
  • the bores 110 and 124 are coaxial and are of right cylindrical shape.
  • FIGs. 4 , 4B , 5, 5A and 5B illustrate an exemplary eccentric piston coupler 80 in the form of a piston pin for coupling the piston 40 to the associated connecting rod 60.
  • Coupler 80 comprises a first end portion 130, a second end portion 140 and a central section 150 intermediate the first and second end portions 130,140.
  • End portion 130 comprises an exterior right cylindrical surface 152.
  • End section 140 comprises a right cylindrical surface 154.
  • the central portion 150 comprises a right cylindrical surface 156.
  • the axis of cylindrical surface 156 is centered on the axis 160.
  • FIG. 4a illustrates an end view of the coupler 80 of FIG. 4 .
  • at least one portion of the piston coupler of this example can comprise an eccentric portion that is eccentric relative to at least one other portion of the piston coupler.
  • the maximum eccentricity of this form of coupler can be defined as E and corresponds to the maximum offset between the first and second axes 74,160 arising from pivoting the eccentric portion 150.
  • the piston coupler 80 comprises a piston pin comprising first and third portions 130,140 and a second portion 150 intermediate the first and third portions, the first and third portions have longitudinal centerlines that are aligned with the first axis 160.
  • the second portion 150 comprises the eccentric portion and has a longitudinal center line that is aligned with the second axis 160.
  • the first, second and third portions comprise right cylindrical surfaces 152,154.
  • the second portion comprises a right cylindrical surface 156 of a first radius defined as R CR
  • one of the first and third portions e.g., portion 140
  • R 1 ⁇ (R CR + E)
  • R 2 ⁇ (R CR - E)
  • a second end portion 140b of the piston pin defines a second cavity 193 that is at least partially conical.
  • a pivot member engager comprises (e.g., including surface 170b") an outwardly projecting portion of the second end portion of the piston pin.
  • a first end portion 130b of this form of pivot pin also defines a first cavity 195 that is at least partially conical with a surface 213b" operable as explained below in connection with surface 213 of FIG. 7 .
  • An internal cavity 182b interconnects the first and second cavities 193,195.
  • the internal cavity and the first and second cavities can be shaped and dimensioned to achieve a homogenous bending line 201 ( FIG. 5D ) in response to the application of force by the piston to the piston pin (forces F p , F p applied to end portions of the piston pin) and the counterforce applied by the connecting rod during operation of the engine.
  • the piston coupler can comprise a first end portion 130 ( FIG. 7 ) comprising a piston coupler braking surface and a second end portion 140, the pivot member engager can comprise an outwardly projecting portion of the second end portion.
  • FIG. 7 illustrates the coupler 80 installed in place. With this exemplary construction, turning of the coupler 80 shifts the piston relative to the piston rod to thereby vary the combustion ratio.
  • FIGs. 4C and 7B illustrate an alternative form of coupler 80a.
  • first and third portions 130a, 140a have respective first and third diameters that are equal.
  • portion 150a has a second diameter that is greater than the first and third diameters.
  • the piston coupler receiving bore comprises right cylindrical first and second piston bore portions 110a, 124a having a diameter that is greater than the second diameter such that the piston pin is insertable in one direction through one of the first and second piston bore portions and the connecting rod bore.
  • a first bushing 171 is mounted to the first piston pin portion 130a and positioned within the first piston bore portion 110a and second bushing 173 is mounted to the third piston pin portion 140a and is positioned within the second piston bore portion 124a.
  • One or both of the bushings 171,173 are desirably mounted in place after the piston pin has been inserted into the piston and through the connecting rod.
  • the first and second bushings 171,173 restrict the piston pin against motion along the axis 74.
  • an exemplary pivot member engager can comprise at least one pivot member engagement surface (e.g., two surfaces 170' and 170").
  • the pivot coupler engager can comprise at least one pivot coupler engagement surface (see FIG. 9 ).
  • the at least one pivot coupler engagement surface can be pivoted from a first position to a second position in response to pivoting of the pivot member from the first pivot member position to the second pivot member position.
  • the at least one pivot member engagement surface and at least one pivot coupler engagement surface are desirably positioned to engage one another as the piston approaches the bottom dead center position to pivot the piston coupler from the first coupler position to the second coupler position in response to the pivoting of the at least one pivot coupler engagement surface from the pivot coupler engager first position to the pivot coupler engager second position.
  • FIG. 5 illustrates a vertical sectional view through the exemplary coupler 80.
  • FIGs. 5a and 5b are respective end views of the coupler.
  • FIG. 5 also illustrates a pivot member engaging element, in this case a surface 170" positioned to engage the pivot member 90 to turn the coupler 80 to adjust the eccentricity of the coupler and thereby the compression ratio as explained below.
  • the internal combustion engine can also comprise a piston coupler retainer coupled to the piston coupler to apply a retention force to resist pivoting of the piston coupler.
  • the piston coupler retainer can also limit the pivoting of the pivot coupler about the first axis (e.g., axis 74) to be within a predetermined limit.
  • a mechanism for retaining the piston coupler in a location to which it has been pivoted or turned comprises a friction brake.
  • the illustrated coupler comprises a brake engaging surface, such as a partially conical or frusto conical recess 180 extending inwardly into the end portion 130 of coupler 80.
  • An internal bore 182 is provided at the base of recess 180.
  • An exemplary friction brake 184 is shown in FIGs.
  • the illustrated friction brake comprises a body 185 with a generally conical braking component 186 having an external braking surface 186a shaped to engage the braking surface 180 of the coupler 80.
  • the body 185 can comprise a generally triangular base portion 187 from which the braking portion 186 projects.
  • the base 185 can also be provided with interfitting members that mate with or interfit with corresponding interfitting members of the piston.
  • the base can comprise plural indentations or recesses 190,192,194 for engaging the respective projections 118, 114 and 116 of the piston (see FIG. 2 ). When engaged in this manner, relative rotation between the brake 184 and the piston 42 is prevented. As can be seen in FIG.
  • a biasing spring 196 can be positioned within the conical portion 186 of the break 184.
  • a braking force adjustment screw 198 having a head 197 threadedly received and captured in a threaded bore 182 of coupler 80 is provided.
  • a nut 199 coupled to screw 198 can be rotated to adjust the braking force by changing the axial position of the screw in bore 182 to thereby change the compression of the spring 196.
  • the nut 199 can be fastened to or otherwise mounted so as to be retained on the screw so as not to be dislodged during operation of the engine.
  • Surfaces 213,215 ( FIG. 4A ) of the piston pin cooperate with the friction brake to limit the extent of pivoting of the piston pin to within a predetermined angular limit, such as 110 degrees. Other mechanisms can be used to limit such pivoting.
  • each of the piston coupler braking surface and friction brake braking surface is at least partially conical.
  • the piston coupler in this example, comprises a piston pin with first and second end portions, the first end portion comprising a brake receiving first cavity defining the piston coupler braking surface. Also, a friction brake being inserted at least partially into the brake receiving cavity in this example.
  • FIGs. 8 and 8a illustrate an exemplary pivot member 90.
  • the illustrated pivot member comprises a body 202 having an outer surface 204 which can be of a right cylindrical shape for insertion into a bore 206 in the end wall 16 of the engine housing 12 ( FIG. 13 ).
  • a recess 209 can be provided in the body 202.
  • recess 209 is an arcuate recess having a radius and centered about the axis 24.
  • a worm gear 200 is positioned and captured or formed within recess 209. As can be seen in FIG. 8a , the illustrated recess 209 does not extend entirely around the circumference of the body 202.
  • the recess 209 and worm gear is of a limited length, in this example, although this can be varied, the length is limited to "2" + ")", such as 110 degrees (e.g., in the example where "2" is equal to ")" and equal to 55 degrees, 55 degrees either side of vertical).
  • the pivot member also comprises first and second eccentric coupler engaging surfaces 210', 210" (only one, namely 210", of which is shown in FIG. 8 , and with both of these surfaces being shown in FIG. 13 ). The operation of these surfaces to engage and pivot the eccentric coupler will be understood from the description below.
  • the worm gear drivenly is coupled to the pivot member.
  • a motor can be coupled to the worm gear and is operable to pivot the pivot member from plural first positions to plural second positions to adjust the compression ratio to a plurality of values.
  • the pivot member can define a recess extending in a direction perpendicular to the pivot member axis, the worm gear being positioned at least partially in the recess.
  • the worm gear engages the pivot member to restrict movement of the pivot member in either direction along the pivot member axis.
  • the worm gear can be configured to restrict pivoting of the pivot member to be within a predetermined limit.
  • the predetermined limit can be, in one example, approximately one hundred and ten degrees.
  • the center position of the limit can correspond to the pivot coupler being pivoted to a position that aligns the first axis 74 and the second axis 160.
  • FIGs. 9, 9A and 9B illustrate another exemplary form of pivot member 90a.
  • Components of the FIG. 90a example of pivot member in common with those of pivot member 90 are assigned the same numbers as in FIGs. 8 and 8a with the letter "a" following the number.
  • the illustrated form of pivot member 90a provides two coupler engaging surfaces 210a', 210a" in position to engage the piston coupler 80 that couples piston 42 to its associated piston rod 60 and two coupler engaging surfaces 210b' and 210b" in position to engage the coupler 80 that couples piston 44 to its piston rod 60. These engaging surfaces are also shown in FIG. 13 .
  • Pivot member supports 220,222 shown in FIGs. 10, 10a, 11, 11a and 12 can be mounted to engine block 12 as shown in FIG.
  • pivot member 90a comprises one form of a common pivot member comprising a first pivot member end portion extending into a first region defined by the first cylinder and a second pivot member end portion extending into a second region defined by the second cylinder.
  • a first bracket can be coupled to the first cylinder in a position to pivotally support the first pivot member end portion.
  • a second bracket can be coupled to the second cylinder in a position to pivotally support the second pivot member end portion.
  • the first and second brackets can be fastened together (e.g., using bolts 227,229) with a portion of the first cylinder and a portion of the second cylinder positioned between the first and second brackets.
  • the first and second bracket can be shaped to provide clearance for the respective pivot member engagement surfaces and pivot coupler engagement surface to engage one another.
  • a shaft 300 having a distal end portion with a worm gear drive portion 302 engages the worm gear 200 of pivot member 90 such that rotation of the shaft 300 in respective opposite directions pivots the pivot member 90 in respective opposite directions within the limits of the worm gear 200.
  • a similar shaft (not shown) can be used to drive the worm gear 209a of pivot member 90a.
  • These shafts 300 are respectfully driven by worm gears 304,306 coupled thereto.
  • FIGs. 14A, 14B, and 14C illustrate exemplary positions of the pivot member driven by the associated worm gear.
  • a motor 360 controlled by control signals via a connector 362 can be controlled to drive the shaft 308 and thereby the mechanism as explained above.
  • Motor 360 can be any suitable motor, such as a stepper motor.
  • Control signals for motor 360 can come from, for example, a microprocessor or electronic control module via an electrical signal carrying bus of a vehicle. The interaction of these components will be more apparent from FIG. 14 wherein corresponding elements are given corresponding numbers.
  • coupler 90 has been turned counterclockwise (in this example, in the direction of arrow 370) a certain amount to adjust the compression ratio.
  • the amount of turning has been exaggerated in these figures for purposes of illustration.
  • a portion of one of the coupler surfaces, in this example surface 170" engages a portion of one of the pivot member turning surfaces. in this example surface 210".
  • Continued downward movement of the piston results in rotation (pivoting) of the coupler (in this example in the direction of arrow 372).
  • the surfaces 170', 170" of the coupler have been rotated to a position that matches the position of the surfaces 210', 210" of the pivot member 90.
  • the coupler 80 has been adjusted to vary the compression rate (note the position of surfaces 170', 170") and can be retained in adjustment by the friction brake as previously explained.
  • a piston cylinder shown with a longitudinal centerline 400.
  • the longitudinal centerline is desirably positioned between a first line parallel to the longitudinal centerline that intersects the first axis and a second line parallel to the longitudinal centerline that intersects the second axis when the eccentric portion is pivoted to the maximum allowed extent.
  • a piston cylinder is illustrated with a longitudinal centerline and wherein the maximum eccentricity is defined as E and corresponds to the maximum offset between the first and second axes, wherein an origin of a reference coordinate system 430 is at the intersection of the longitudinal centerline of the at least one piston cylinder and a bottom dead centerline 432 corresponding the second axis when the second axis is in the bottom dead center position, wherein the Z dimension is along the longitudinal center line of the piston cylinder from the origin and the X dimension is along the bottom dead centerline from the origin, wherein the pivot member axis is parallel to the first axis and, wherein the pivot member axis (into the page and intersecting point 433) intersects an area 434 wherein X is from -0.5E to -0.8E and Z is from -0.25E to 0.25E.
  • an exemplary motor 360 is shown for driving worm gear shaft 308 to pivot the pivot members and adjust the compression ratio of the engine such as previously described.
  • Motor 360 can be a stepper motor or other form of motor and can provide feedback to an engine controller 370 which provides drive signals to the motor.
  • Motor 360 is simply one example of a mechanism for driving a worm gear or other pivot member drive mechanism.
  • Engine controller 370 can be a conventional engine controller, such as programmable controller, used in a vehicle which captures various vehicle parameter signals on a system bus utilized in the vehicle. These parameter signals can be used by the engine controller to generate motor control signals should conditions exist where it is desirable to selectively adjust the pivot members to vary the stroke of the piston cylinders. These control signals can be responsive to one or more engine operating parameters.
  • a throttle angle sensor 374 can be used to deliver a throttle angle signal via a data bus to the engine controller.
  • the motor 360 can drive worm gear 308 in clockwise or counterclockwise directions in response to control signals from the engine controller 370 in response to the throttle angle sensor signals.
  • the compression ratio would typically be reduced.
  • the compression ratio would typically be increased.
  • the combustion air temperature can be sensed by temperature sensor 376. In general, higher combustion air temperatures can be used to lower thresholds of alternatively used signals to control the motor to reduce the compression ratio.
  • lower temperature sensed signals can be used to increase the threshold to increase the compression ratio.
  • a pressure sensor 377 can be used to sense the cylinder head pressure. Above a pre-defined pressure level at a certain crank shaft position, for example the top dead center position, the compression ratio would typically be decreased. Below this pre-determined pressure level, the compression ratio can be increased.
  • the crank shaft position can be sensed by a crank shaft position sensor 379.
  • an ionization sensor typically integrated into an ignition plug, senses in the moment of ignition the grade of the ionization of the air/fuel mixture of the internal combustion engine. Above a pre-determined threshold, the compression ratio is typically decreased. Below the pre-determined threshold, the compression ratio is typically increased.
  • An ignition plug with an ionization sensor is indicated at 378 in FIG. 18 .
  • a knocking sensor indicated schematically at 380 typically mounted to a cylinder block, senses vibration spikes caused by uncontrolled ignition of the combustion mix, corresponding to the engine knocking. In response to such signals, the engine controller 370 can control motor 360 to decrease the compression ratio. Control signals derived from combinations of sensed engine parameter conditions can also be used.
EP20080251215 2007-06-22 2008-03-31 Verbrennungsmotor mit variabler Verdichtung Withdrawn EP2006509A2 (de)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US93674107P 2007-06-22 2007-06-22
US95835207P 2007-07-03 2007-07-03
US349807P 2007-11-16 2007-11-16
US12/011,494 US7946260B2 (en) 2007-06-22 2008-01-25 Internal combustion engine with variable compression ratio

Publications (1)

Publication Number Publication Date
EP2006509A2 true EP2006509A2 (de) 2008-12-24

Family

ID=39735328

Family Applications (1)

Application Number Title Priority Date Filing Date
EP20080251215 Withdrawn EP2006509A2 (de) 2007-06-22 2008-03-31 Verbrennungsmotor mit variabler Verdichtung

Country Status (2)

Country Link
EP (1) EP2006509A2 (de)
WO (1) WO2009002379A2 (de)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010108582A1 (de) * 2009-03-26 2010-09-30 Ixetic Bad Homburg Gmbh Vorrichtung zur veränderung des verdichtungsverhältnisses in einem verbrennungsmotor
US8851030B2 (en) 2012-03-23 2014-10-07 Michael von Mayenburg Combustion engine with stepwise variable compression ratio (SVCR)
KR101510324B1 (ko) 2009-10-06 2015-04-08 현대자동차 주식회사 가변 압축비 장치
KR101510323B1 (ko) 2009-10-06 2015-04-08 현대자동차 주식회사 가변 압축비 장치

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1386114A (en) * 1919-10-24 1921-08-02 Jedrzykowski Edmund Internal-combustion engine
US1463474A (en) * 1920-07-19 1923-07-31 Arthur A Lazier Timing device for internal-combustion engines
US4215660A (en) * 1978-04-28 1980-08-05 Finley Donald G Internal combustion engine
DE69108572T2 (de) * 1990-01-17 1995-08-17 Mitsubishi Motors Corp Vorrichtung zum Ändern des Kompressionverhältnisses für Brennkraftmaschine.
US5025757A (en) * 1990-09-13 1991-06-25 Larsen Gregory J Reciprocating piston engine with a varying compression ratio
CA2089815A1 (en) * 1993-02-18 1994-08-19 John F. E. Beattie Variable compression piston
ATE174661T1 (de) * 1995-02-28 1999-01-15 Tk Design Ag Verbrennungsmotor vom typ hubkolbenmotor mit variablem verdichtungsverhältnis
DE19703948C1 (de) * 1997-02-03 1998-06-18 Meta Motoren Energietech Vorrichtung zur Veränderung der Verdichtung einer Hubkolbenbrennkraftmaschine
JP3968967B2 (ja) * 2000-07-07 2007-08-29 日産自動車株式会社 レシプロ式内燃機関の可変圧縮比機構
US7191741B2 (en) * 2002-12-16 2007-03-20 Nissan Motor Co., Ltd. Pin connected link mechanism
JP4084718B2 (ja) * 2003-07-31 2008-04-30 本田技研工業株式会社 内燃機関の圧縮比可変装置
US7028647B2 (en) * 2004-01-09 2006-04-18 Ford Global Technologies, Llc Variable compression ratio connecting rod for internal combustion engine

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010108582A1 (de) * 2009-03-26 2010-09-30 Ixetic Bad Homburg Gmbh Vorrichtung zur veränderung des verdichtungsverhältnisses in einem verbrennungsmotor
KR101510324B1 (ko) 2009-10-06 2015-04-08 현대자동차 주식회사 가변 압축비 장치
KR101510323B1 (ko) 2009-10-06 2015-04-08 현대자동차 주식회사 가변 압축비 장치
US8851030B2 (en) 2012-03-23 2014-10-07 Michael von Mayenburg Combustion engine with stepwise variable compression ratio (SVCR)

Also Published As

Publication number Publication date
WO2009002379A3 (en) 2009-02-26
WO2009002379A2 (en) 2008-12-31

Similar Documents

Publication Publication Date Title
US20110192379A1 (en) Internal combustion engine with variable compression ratio
DE60127919T2 (de) Mechanismus für das variable Verdichtungsverhältnis einer Brennkraftmaschine
US20110023834A1 (en) Internal combustion engine with variable compression ratio
EP2006509A2 (de) Verbrennungsmotor mit variabler Verdichtung
KR101180953B1 (ko) 가변 압축비 장치
EP2464866B1 (de) Hochdruckpumpe
DE10350018A1 (de) Anschlussplatte für eine Axialkolbenpumpe
WO2002081920A1 (de) Einstempel-einspritzpumpe für ein common-rail-kraftstoffeinspritzsystem
EP2016265B1 (de) Brennkraftmaschine mit variablem kompressionsverhältnis
CN1291255A (zh) 轴向柱塞机
US6412453B1 (en) System and method for varying the compression ratio of an internal combustion engine
CN101490386B (zh) 内燃机
EP1312777B1 (de) Brennkraftmaschine mit variablem Verdichtungsverhältnis
WO2006133452A2 (en) Piston assembly for barrel engine
EP1300564B1 (de) Pleuelstangenvorrichtung
US6408804B1 (en) Apparatus for varying the compression ratio of an internal combustion engine
US10443490B1 (en) Variable compression ratio engine
WO2011107130A1 (de) Verfahren zum betreiben einer hubkolbenmaschine
DE10352737A1 (de) Verbrennungskraftmaschine mit einem veränderbaren Verdichtungsraum
US20040213689A1 (en) Fuel injection pump and rotation-linear motion transforming mechanism with safeguard
WO2019162528A1 (de) Sensoreinrichtung für eine längenverstellbare pleuelstange
DE202010001019U1 (de) Verbrennungsmotor mit elektrisch einstellbarer Kompression
JPS6043128A (ja) 過給式デイ−ゼル内燃機関のための燃料噴射ポンプ
DE10304685A1 (de) Verbrennungsmotor mit veränderbarem Verdichtungsverhältnis
EP1813791B1 (de) Brennkraftmaschine

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20080331

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MT NL NO PL PT RO SE SI SK TR

AX Request for extension of the european patent

Extension state: AL BA MK RS

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20121002