EP1179657B1 - Variable event timing mechanism - Google Patents
Variable event timing mechanism Download PDFInfo
- Publication number
- EP1179657B1 EP1179657B1 EP20010000338 EP01000338A EP1179657B1 EP 1179657 B1 EP1179657 B1 EP 1179657B1 EP 20010000338 EP20010000338 EP 20010000338 EP 01000338 A EP01000338 A EP 01000338A EP 1179657 B1 EP1179657 B1 EP 1179657B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- drive shaft
- cam sleeve
- pin
- rotation
- drive member
- 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.)
- Expired - Lifetime
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/26—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of two or more valves operated simultaneously by same transmitting-gear; peculiar to machines or engines with more than two lift-valves per cylinder
- F01L1/267—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of two or more valves operated simultaneously by same transmitting-gear; peculiar to machines or engines with more than two lift-valves per cylinder with means for varying the timing or the lift of the valves
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/02—Valve drive
- F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
- F01L1/047—Camshafts
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/34—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift
- F01L1/344—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift changing the angular relationship between crankshaft and camshaft, e.g. using helicoidal gear
- F01L1/356—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift changing the angular relationship between crankshaft and camshaft, e.g. using helicoidal gear making the angular relationship oscillate, e.g. non-homokinetic drive
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/02—Valve drive
- F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
- F01L1/047—Camshafts
- F01L1/053—Camshafts overhead type
- F01L2001/0537—Double overhead camshafts [DOHC]
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- 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
- F02B2275/00—Other engines, components or details, not provided for in other groups of this subclass
- F02B2275/18—DOHC [Double overhead camshaft]
Definitions
- the present invention to relates to a mechanism for enabling the duration of a valve event in an internal combustion engine to be varied.
- valve event the proportion of an engine cycle measured in crankshaft angle during which the valve remains open
- cam profile the proportion of an engine cycle measured in crankshaft angle during which the valve remains open
- the valve event durations could not be optimised for performance over the entire load/speed operating range of the engine and instead the fixed cam profiles were selected to provide an acceptable compromise over the engine operating range.
- VET variable event timing
- the geometry of the cams is variable but the cams always rotate at half crankshaft speed.
- Such mechanisms tend to be complex and expensive.
- the cams In the second category, to which the mechanisms of the present invention belong, the cams have fixed profile but their phase is cyclically varied as the engine turns so that during each engine cycle the phase is advanced and retarded relative to the crankshaft. In other words, a variable amplitude oscillation is superimposed on the rotation of the cams so as to vary event duration dynamically.
- the present invention seeks to provide a variable event timing mechanism that is compact, reliable and capable of being fitted to existing engines without the need for major alterations to the engine block or cylinder head.
- a mechanism for enabling the duration of a valve event in an internal combustion engine to be varied comprising a drive shaft rotatable in synchronism with the engine crankshaft, a cam sleeve (12) concentrically mounted for rotation about the drive shaft (10) and carrying a cam for opening and closing an engine valve and a drive member (14) coupled to the drive shaft (10) and to the cam sleeve (12), wherein the drive member is mounted for rotation about an axis parallel to that of the drive shaft and the axis of the drive member is variably offset from the drive shaft axis, the extent of the offset serving to vary the phase of the cam sleeve relative to the drive shaft cyclically thereby superimposing a variable amplitude oscillation on the steady rotation of the cam sleeve by the drive shaft to vary the valve event duration, characterised in that the means for coupling the drive member for rotation with the drive shaft includes a pin slidable in and out of a radial bore
- the drive member may be coupled to the cam sleeve by way of a doubly articulated link that is pivotably secured at one end to the drive member and at the other end to the cam sleeve.
- the drive member may conveniently be connected to a cylindrical ring surrounding the drive shaft and journalled in a block that is mounted for sliding movement towards and away from the surface of the engine to which the pillow blocks supporting the drive shaft bearings are secured.
- a mechanism for enabling the duration of a valve event in an internal combustion engine to be varied comprising a drive shaft rotatable in synchronism with the engine crankshaft, a rotatably mounted cam sleeve surrounding the drive shaft with clearance and carrying a cam for opening and closing an engine valve, means for coupling the cam sleeve for rotation with the drive shaft, and means for moving the cam sleeve and the drive shaft relative to one another between concentric and eccentric positions, the extent of the offset between the axes of rotation of the cam sleeve and the drive shaft serving to vary the phase of the cam sleeve relative to the drive shaft cyclically thereby superimposing a variable amplitude oscillation on the steady rotation of the cam sleeve by the drive shaft to vary the valve event duration, characterised in that the means for coupling the cam sleeve for rotation with the drive shaft includes a pin slidable in and out of a radial bore
- the radial pin is slidably received in the drive shaft, and moves in and out of its bore to accommodate the eccentric motion of the drive member or cam sleeve relative to the drive shaft, making it possible to pivot the projecting end of the pin on the drive member or cam sleeve.
- a VET mechanism of a first embodiment of the invention comprises a drive shaft 10 that is driven in the normal manner from the engine crankshaft.
- the illustrated mechanism serves to vary event duration and phase in a fixed relationship to one another (as shown in the valve lift diagram of Figure 4) but should it additionally be required to vary the phase of the valve events independently of any change in event duration, then it is possible to incorporate a known phase change mechanism in the pulley driving the drive shaft 10.
- the VET mechanism comprises a cam sleeve 12 that is fitted over the drive shaft 10 and can rotate freely relative to it.
- Drive is transmitted from the drive shaft 10 to the cam sleeve 12 by a crescent shaped drive member 14.
- the drive member 14 is formed integrally with a ring 16 that is journalled in a block 18.
- the ring 16 surrounds the drive shaft 10 with clearance and can be moved by sliding the block 18 up and down from a position where it is concentric with the drive shaft 10 to eccentric positions.
- Each end of the crescent of the drive member 14 is bifurcated and receives a pivot pin between its jaws.
- One of the ends 14a is pivotably connected by a pin 28 to a lollipop-shaped element 20 having a stem which is slidably received in a radial bore 22 in the drive shaft 10.
- the opposite end 14b of the drive member 14 is connected by way of a link 23 to the cam sleeve 12.
- the link 23 is doubly articulated, being pivotable about a first pin 24 relative to the drive member 14 and about a second pin 26 relative to the cam sleeve 12.
- Circlips 30 and 32 received in grooves 34 and 36 on the drive shaft 10 serve to retain the cam sleeve 12 and its drive member 14 axially on the drive shaft 10.
- the ring 16 By moving the block 18 either up or down from this position, the ring 16 will be forced to rotate about an axis that is vertically offset from the axis of the drive shaft 10. As a result, as the drive member 14 rotates, the distance of the driven end 14a from the centre of the drive shaft centre will vary cyclically during each revolution. Hence the lollipop-shaped element 20 will move in and out of the bore 22 in synchronism with the rotation of the drive shaft 10 causing a rotational oscillation of the drive member 14 around the drive shaft.
- the opposite end 14b of the drive member 14 connects to the cam sleeve 12 via the doubly articulated link 23 which moves during each revolution to compensate for the drive member 14 and cam sleeve 12 having different centres of rotation.
- This motion causes a further rotational oscillation of the cam sleeve 12 relative to the drive member 14 which superimposes upon the oscillation of the drive member 14 around the drive shaft 10 such that the phase of the cam sleeve is varied cyclically as the drive shaft rotates.
- This will result in the curves 100 and 114 at the extreme of adjustment of the block 18 in one direction and in the curves 104 and 110 at the extreme of adjustment in the opposite direction.
- the various blocks 18 for the different valves must all be movable in synchronism with one another and this can be achieved by mounting each block 18 on pins 40 that extend vertically from the cylinder head, i.e. from the face of the cylinder head on which the pillow blocks supporting the drive shaft bearings are mounted. Eccentrics 50 received in the bores 42 in the blocks 18 can be rotated in unison to raise and lower all the blocks 18 simultaneously by the same amount.
- one of the guide pins 40 may be formed with a bore 42 that communicates with an oil gallery 44 in the cylinder head. Further bores 46 in the block 18 connected to the bore 42 serve to guide the oil to the bearing surface of the ring 16, to the eccentric 50 and to the outer surfaces of the guide pins 40.
- the drive shaft 10 and the cam sleeve 12 are always concentric and they are coupled to one another by an intermediate drive member 14 that can be moved to an eccentric position.
- the intermediate drive member is omitted and instead the drive shaft 110 can be moved to an eccentric position relative to the cam sleeve 112.
- all the embodiments operate in any analogous manner to one another.
- inventions of Figures 5 to 7 also have in common with the embodiment of Figures 1 to 3, the fact that the coupling between the drive shaft 110 and the cam sleeve includes a pin slidably received in a radial bore in the drive shaft 110 and the fact that all the coupling forces acts in the same plane normal to the axis of rotation of the mechanism.
- the bearing blocks that support the drive shaft may furthermore be constructed in a similar manner to the blocks 18.
- a pin 220 is slidably received in a radial bore 122 in the drive shaft 110 the pin 220 having a tangentially extending arm 223.
- a single pivot pin 224 connects the arm 223 to the cam sleeve 112. The slidable pin 220 reciprocates radially within the bore 122 as the mechanism rotates.
- the slidable pin 320 has a cylindrical head 324 of which the axis lies parallel to the axis of rotation of the mechanism.
- the head 324 is received in a block 326 that is a force fit in a bore 328 in the cam sleeve 112.
- the pin 320 needs to move in the bore 122 to take up the eccentricity.
- the pin 420 again has a part cylindrical head 424 but this is received in a cap 426 that is retained in a cut-out 432 in the cam sleeve 112 by a clamping band 430.
- the head 424 of the pin 420 cannot move radially in relation to the cam sleeve 112 and the pin 420 must once again reciprocate within the bore 122 in the drive shaft 110.
Description
- The present invention to relates to a mechanism for enabling the duration of a valve event in an internal combustion engine to be varied.
- In an internal combustion engine having cam operated intake and exhaust valves, the duration of a valve event (the proportion of an engine cycle measured in crankshaft angle during which the valve remains open) is determined by the cam profile. Conventionally, internal combustion engines have cams with fixed profiles and the duration of the valve events cannot therefore be modified to suit the engine operating conditions. The valve event durations could not be optimised for performance over the entire load/speed operating range of the engine and instead the fixed cam profiles were selected to provide an acceptable compromise over the engine operating range.
- Proposals have in the past been put forward to allow event duration to be varied during engine operation and these can be regarded as falling into two categories. In the first category of variable event timing (VET) mechanisms, the geometry of the cams is variable but the cams always rotate at half crankshaft speed. Such mechanisms tend to be complex and expensive. In the second category, to which the mechanisms of the present invention belong, the cams have fixed profile but their phase is cyclically varied as the engine turns so that during each engine cycle the phase is advanced and retarded relative to the crankshaft. In other words, a variable amplitude oscillation is superimposed on the rotation of the cams so as to vary event duration dynamically.
- In its various aspects, the present invention seeks to provide a variable event timing mechanism that is compact, reliable and capable of being fitted to existing engines without the need for major alterations to the engine block or cylinder head.
- According to a first aspect of the invention, there is provided a mechanism for enabling the duration of a valve event in an internal combustion engine to be varied, comprising a drive shaft rotatable in synchronism with the engine crankshaft, a cam sleeve (12) concentrically mounted for rotation about the drive shaft (10) and carrying a cam for opening and closing an engine valve and a drive member (14) coupled to the drive shaft (10) and to the cam sleeve (12), wherein the drive member is mounted for rotation about an axis parallel to that of the drive shaft and the axis of the drive member is variably offset from the drive shaft axis, the extent of the offset serving to vary the phase of the cam sleeve relative to the drive shaft cyclically thereby superimposing a variable amplitude oscillation on the steady rotation of the cam sleeve by the drive shaft to vary the valve event duration, characterised in that the means for coupling the drive member for rotation with the drive shaft includes a pin slidable in and out of a radial bore in the drive shaft and the end of the pin projecting from the drive shaft is pivotably mounted on the drive member.
- Preferably, the drive member may be coupled to the cam sleeve by way of a doubly articulated link that is pivotably secured at one end to the drive member and at the other end to the cam sleeve.
- The drive member may conveniently be connected to a cylindrical ring surrounding the drive shaft and journalled in a block that is mounted for sliding movement towards and away from the surface of the engine to which the pillow blocks supporting the drive shaft bearings are secured.
- The ability to adjust the event timing by movement of blocks that are mounted on the same surface as the drive shaft bearing pillow blocks once again makes for a compact arrangement and avoids the need for extensive modification to the engine block or cylinder head.
- As an alternative to providing an intermediate drive member that can be moved to an eccentric position in relation to the cams, it is possible to provide a mechanism in which he drive shaft can itself be moved to an eccentric position in relation to the cams.
- Thus, according to a second aspect of the invention, there is provided a mechanism for enabling the duration of a valve event in an internal combustion engine to be varied, comprising a drive shaft rotatable in synchronism with the engine crankshaft, a rotatably mounted cam sleeve surrounding the drive shaft with clearance and carrying a cam for opening and closing an engine valve, means for coupling the cam sleeve for rotation with the drive shaft, and means for moving the cam sleeve and the drive shaft relative to one another between concentric and eccentric positions, the extent of the offset between the axes of rotation of the cam sleeve and the drive shaft serving to vary the phase of the cam sleeve relative to the drive shaft cyclically thereby superimposing a variable amplitude oscillation on the steady rotation of the cam sleeve by the drive shaft to vary the valve event duration, characterised in that the means for coupling the cam sleeve for rotation with the drive shaft includes a pin slidable in and out of a radial bore in the drive shaft and the end of the pin projecting from the drive shaft is pivotably mounted on the cam sleeve.
- In all the embodiments, the radial pin is slidably received in the drive shaft, and moves in and out of its bore to accommodate the eccentric motion of the drive member or cam sleeve relative to the drive shaft, making it possible to pivot the projecting end of the pin on the drive member or cam sleeve.
- In prior art mechanisms that superimpose an oscillation on a cam to vary the valve event duration, as exemplified by US 5,979,381 and EP 0801213, drive is taken from the crankshaft driven drive shaft by means of a radial pin that is permanently fixed to the drive shaft. However a sliding connection is then required somewhere else along the path through which torque is transmitted to the cams from the drive shaft. Hence, in US 5,979,381 a sliding connection is provided between the radial pin and an eccentric drive member, while EP 0801213 uses a sliding connection between an eccentric drive member and a cam sleeve. Such sliding connections are difficult to lubricate, complicate assembly and add to manufacturing cost.
- The invention will now be described further, by way of example, with reference to the accompanying drawings, in which:
- Figure 1 is a perspective assembled view of a mechanism of the invention,
- Figure 2 is an exploded view of the same mechanism,
- Figure 3 is a section through a cylinder head fitted with the mechanism of Figures 1 and 2, taken in a plane normal to the drive shaft of the mechanism,
- Figure 4 is a diagram of valve lift versus crankshaft angle for an engine having a mechanism of the invention fitted to both the intake and exhaust valves, and
- Figures 5 to 7 are exploded views similar to the view of Figure 2 showing three further alternative embodiments of the invention.
- Referring to Figures 1 and 2, a VET mechanism of a first embodiment of the invention comprises a
drive shaft 10 that is driven in the normal manner from the engine crankshaft. The illustrated mechanism serves to vary event duration and phase in a fixed relationship to one another (as shown in the valve lift diagram of Figure 4) but should it additionally be required to vary the phase of the valve events independently of any change in event duration, then it is possible to incorporate a known phase change mechanism in the pulley driving thedrive shaft 10. - The VET mechanism comprises a
cam sleeve 12 that is fitted over thedrive shaft 10 and can rotate freely relative to it. Drive is transmitted from thedrive shaft 10 to thecam sleeve 12 by a crescentshaped drive member 14. At its axial end, thedrive member 14 is formed integrally with aring 16 that is journalled in ablock 18. Thering 16 surrounds thedrive shaft 10 with clearance and can be moved by sliding theblock 18 up and down from a position where it is concentric with thedrive shaft 10 to eccentric positions. - Each end of the crescent of the
drive member 14 is bifurcated and receives a pivot pin between its jaws. One of theends 14a is pivotably connected by apin 28 to a lollipop-shaped element 20 having a stem which is slidably received in aradial bore 22 in thedrive shaft 10. Theopposite end 14b of thedrive member 14 is connected by way of alink 23 to thecam sleeve 12. Thelink 23 is doubly articulated, being pivotable about afirst pin 24 relative to thedrive member 14 and about asecond pin 26 relative to thecam sleeve 12. Circlips 30 and 32 received ingrooves drive shaft 10 serve to retain thecam sleeve 12 and itsdrive member 14 axially on thedrive shaft 10. - When the
ring 16 of thedrive member 14 is positioned by theblock 18 to be concentric with thedrive shaft 10, then the cam sleeve 12, thedrive shaft 10 and thedrive member 14 all rotate in unison without moving relative to one another. This will produce the events represented by thecurves curves cam sleeve 12. - By moving the
block 18 either up or down from this position, thering 16 will be forced to rotate about an axis that is vertically offset from the axis of thedrive shaft 10. As a result, as thedrive member 14 rotates, the distance of the drivenend 14a from the centre of the drive shaft centre will vary cyclically during each revolution. Hence the lollipop-shaped element 20 will move in and out of thebore 22 in synchronism with the rotation of thedrive shaft 10 causing a rotational oscillation of thedrive member 14 around the drive shaft. - The
opposite end 14b of thedrive member 14 connects to thecam sleeve 12 via the doubly articulatedlink 23 which moves during each revolution to compensate for thedrive member 14 andcam sleeve 12 having different centres of rotation. This motion causes a further rotational oscillation of thecam sleeve 12 relative to thedrive member 14 which superimposes upon the oscillation of thedrive member 14 around thedrive shaft 10 such that the phase of the cam sleeve is varied cyclically as the drive shaft rotates. This will result in thecurves block 18 in one direction and in thecurves block 18 to any position between these extremes to give continuous control of the duration of the valve events. - It will be seen from Figure 4 that by suitable selection of the geometry of the mechanism, it is possible to ensure that the opening and closing times of the valves are substantially unaltered and that only the duration of events is modified. In Figure 4, the
lines - The
various blocks 18 for the different valves must all be movable in synchronism with one another and this can be achieved by mounting eachblock 18 onpins 40 that extend vertically from the cylinder head, i.e. from the face of the cylinder head on which the pillow blocks supporting the drive shaft bearings are mounted. Eccentrics 50 received in thebores 42 in theblocks 18 can be rotated in unison to raise and lower all theblocks 18 simultaneously by the same amount. - The mounting of the
blocks 18 onguide pins 40 in the cylinder head is also advantageous in that is permits lubrication of the various bearing surfaces of theblock 18. To this end, as shown in Figure 3, one of theguide pins 40 may be formed with abore 42 that communicates with anoil gallery 44 in the cylinder head.Further bores 46 in theblock 18 connected to thebore 42 serve to guide the oil to the bearing surface of thering 16, to the eccentric 50 and to the outer surfaces of theguide pins 40. - In the embodiment of Figures 1 to 3, the
drive shaft 10 and thecam sleeve 12 are always concentric and they are coupled to one another by anintermediate drive member 14 that can be moved to an eccentric position. By contrast, in the embodiments of Figures 5 to 7, the intermediate drive member is omitted and instead thedrive shaft 110 can be moved to an eccentric position relative to thecam sleeve 112. In other respects, all the embodiments operate in any analogous manner to one another. The embodiments of Figures 5 to 7 also have in common with the embodiment of Figures 1 to 3, the fact that the coupling between thedrive shaft 110 and the cam sleeve includes a pin slidably received in a radial bore in thedrive shaft 110 and the fact that all the coupling forces acts in the same plane normal to the axis of rotation of the mechanism. The bearing blocks that support the drive shaft may furthermore be constructed in a similar manner to theblocks 18. - In the embodiment of Figure 5, a
pin 220 is slidably received in aradial bore 122 in thedrive shaft 110 thepin 220 having a tangentially extendingarm 223. Asingle pivot pin 224 connects thearm 223 to thecam sleeve 112. Theslidable pin 220 reciprocates radially within thebore 122 as the mechanism rotates. - In the embodiment of Figure 6, the
slidable pin 320 has acylindrical head 324 of which the axis lies parallel to the axis of rotation of the mechanism. Thehead 324 is received in ablock 326 that is a force fit in abore 328 in thecam sleeve 112. Once again in this embodiment, thepin 320 needs to move in thebore 122 to take up the eccentricity. - Lastly, in the embodiment of Figure 7, the
pin 420 again has a partcylindrical head 424 but this is received in acap 426 that is retained in a cut-out 432 in thecam sleeve 112 by aclamping band 430. Thehead 424 of thepin 420 cannot move radially in relation to thecam sleeve 112 and thepin 420 must once again reciprocate within thebore 122 in thedrive shaft 110.
Claims (9)
- A mechanism for enabling the duration of a valve event in an internal combustion engine to be varied, comprising a drive shaft (10) rotatable in synchronism with the engine crankshaft, a cam sleeve (12) concentrically mounted for rotation about the drive shaft (10) and carrying a cam for opening and closing an engine valve and a drive member (14) coupled to the drive shaft (10) and to the cam sleeve (12), wherein the drive member (14) is mounted for rotation about an axis parallel to that of the drive shaft (10) and the axis of the drive member (14) is variably offset from the drive shaft axis (10), the extent of the offset serving to vary the phase of the cam sleeve (12) relative to the drive shaft (10) cyclically thereby superimposing a variable amplitude oscillation on the steady rotation of the cam sleeve (12) by the drive shaft (10) to vary the valve event duration, characterised in that the means for coupling the drive member for rotation with the drive shaft includes a pin (20) slidable in and out of a radial bore (22) in the drive shaft (10) and the end of the pin (20) projecting from the drive shaft (10) is pivotably mounted on the drive member (14).
- A mechanism as claimed in claim 1, wherein the drive member (14) is coupled to the cam sleeve (12) by way of a doubly articulated link (23) that is pivotably secured at one end to the drive member (14) and at the other end to the cam sleeve (12).
- A mechanism as claimed in claim 1 or 2, wherein the drive member (14) is connected to a cylindrical ring (16) surrounding the drive shaft (10) and journalled in a block (18) that is mounted for sliding movement towards and away from the surface of the engine to which are secured the pillow blocks supporting bearings of the drive shaft (10).
- A mechanism as claimed in claim 3, wherein the block (18) within which the cylindrical ring (16) is journalled is mounted on guide pins (40) of which at least one has a bore (42) that communicates with an oil gallery (44) of the engine, the block (18) being formed with further bores (46) for connecting the bore (42) in the guide pin (40) to bearing surfaces of the block (18).
- A mechanism for enabling the duration of a valve event in an internal combustion engine to be varied, comprising a drive shaft (110) rotatable in synchronism with the engine crankshaft, a rotatably mounted cam sleeve (112) surrounding the drive shaft (110) with clearance and carrying a cam for opening and closing an engine valve, means for coupling the cam sleeve for rotation with the drive shaft, and means for moving the cam sleeve (112) and the drive shaft (110) relative to one another between concentric and eccentric positions, the extent of the offset between the axes of rotation of the cam sleeve and the drive shaft serving to vary the phase of the cam sleeve relative to the drive shaft cyclically thereby superimposing a variable amplitude oscillation on the steady rotation of the cam sleeve (112) by the drive shaft (110) to vary the valve event duration, characterised in that the means for coupling the cam sleeve (112) for rotation with the drive shaft (110) includes a pin (220,320,420) slidable in and out of a radial bore (122) in the drive shaft (110) and the end of the pin (122) projecting from the drive shaft (110) is pivotably mounted on the cam sleeve (112).
- A mechanism as claimed in claim 5, wherein the pin (220) is formed with a rigid tangentially extending arm (223), the end of which is connected by way of a pivot pin (224) to the cam sleeve (112).
- A mechanism as claimed in claim 5, wherein the pin (320) has a cylindrical head (324) of which the axis lies parallel to the axis of rotation of the mechanism, the head (324) being received in a block (326) that is a force fit in a bore (328) in the cam sleeve (112).
- A mechanism as claimed in claim 5, wherein the pin (420) has a part cylindrical head (424) is received in a cap (426) that is retained in a cut-out (432) in the cam sleeve (112) by a clamping band (430).
- A mechanism as claimed in any preceding claim, wherein the coupling elements connecting the drive member to the drive shaft and the cam sleeve, respectively, intersect a common plane normal to the axis of rotation of the drive shaft.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB0019325A GB2365508A (en) | 2000-08-08 | 2000-08-08 | Variable valve timing mechanism |
GB0019325 | 2000-08-08 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP1179657A1 EP1179657A1 (en) | 2002-02-13 |
EP1179657B1 true EP1179657B1 (en) | 2006-06-21 |
Family
ID=9897107
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP20010000338 Expired - Lifetime EP1179657B1 (en) | 2000-08-08 | 2001-08-02 | Variable event timing mechanism |
EP01000345A Expired - Lifetime EP1234955B1 (en) | 2000-08-08 | 2001-08-02 | Variable event timing mechanism |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP01000345A Expired - Lifetime EP1234955B1 (en) | 2000-08-08 | 2001-08-02 | Variable event timing mechanism |
Country Status (3)
Country | Link |
---|---|
EP (2) | EP1179657B1 (en) |
DE (2) | DE60120852T2 (en) |
GB (1) | GB2365508A (en) |
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GB2424257A (en) * | 2005-03-18 | 2006-09-20 | Mechadyne Plc | Single cam phaser camshaft with adjustable connections between the inner shaft and associated cam lobes |
DE102012008219B4 (en) * | 2012-04-25 | 2019-05-16 | Audi Ag | Valve gear of an internal combustion engine |
DE102013215560A1 (en) * | 2013-08-07 | 2015-02-12 | Mahle International Gmbh | Variable camshaft |
DE102016201264A1 (en) * | 2016-01-28 | 2017-08-03 | Mahle International Gmbh | operating procedures |
JP2021071049A (en) * | 2018-02-28 | 2021-05-06 | 日立Astemo株式会社 | Valve timing control device of internal combustion engine |
GB202005068D0 (en) * | 2020-04-06 | 2020-05-20 | Pattakos Manousos | Continous variable valve duration apparatus |
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GB2066361B (en) * | 1980-01-02 | 1984-07-11 | Nat Res Dev | Valve timing mechanisms of internal combustion engines |
GB2165885B (en) * | 1984-10-20 | 1987-12-23 | Austin Rover Group | I c engine variable valve timing mechanism |
GB2252130B (en) * | 1989-10-13 | 1994-03-30 | Rover Group | An internal combustion engine camshaft drive mechanism |
GB9021270D0 (en) * | 1990-10-01 | 1990-11-14 | Mitchell Stephen W | Improvements in or relating to driving connections between two rotatable bodies |
JP3177532B2 (en) * | 1992-01-27 | 2001-06-18 | 株式会社ユニシアジェックス | Intake and exhaust valve drive control device for internal combustion engine |
DE4220668C1 (en) * | 1992-06-24 | 1993-12-09 | Daimler Benz Ag | Actuating device for a flap in motor vehicles |
DE4413406C2 (en) * | 1994-04-18 | 1999-05-06 | Korostenski Erwin | Internal combustion engine with variable valve timing |
DE4419557C1 (en) * | 1994-06-03 | 1995-10-19 | Korostenski Erwin | IC with variable valve control |
AU4252496A (en) * | 1994-12-13 | 1996-07-03 | Erwin Korostenski | Valve gear mechanism for an internal combustion engine |
JPH08240109A (en) * | 1995-03-03 | 1996-09-17 | Unisia Jecs Corp | Intake/exhaust valve driving control device for internal combustion engine |
WO1997007324A2 (en) * | 1995-08-19 | 1997-02-27 | Erwin Korostenski | Internal combustion engine and process for operating the valve gear mechanism of an internal combustion engine |
US5687681A (en) * | 1995-10-18 | 1997-11-18 | Unisia Jecs Corporation | Phase changing mechanism for camshaft of internal combustion engine |
GB9523742D0 (en) * | 1995-11-21 | 1996-01-24 | Mitchell Stephen W | Valve timing phase changer |
DE19546366C2 (en) * | 1995-12-12 | 2002-01-17 | Erwin Korostenski | Valve train of an internal combustion engine |
JP3612379B2 (en) * | 1996-04-10 | 2005-01-19 | 三菱自動車工業株式会社 | Variable valve mechanism drive device and hydraulic actuator |
JP3899576B2 (en) * | 1997-02-07 | 2007-03-28 | 三菱自動車工業株式会社 | Variable valve mechanism and internal combustion engine with variable valve mechanism |
-
2000
- 2000-08-08 GB GB0019325A patent/GB2365508A/en not_active Withdrawn
-
2001
- 2001-08-02 DE DE2001620852 patent/DE60120852T2/en not_active Expired - Fee Related
- 2001-08-02 EP EP20010000338 patent/EP1179657B1/en not_active Expired - Lifetime
- 2001-08-02 DE DE2001625321 patent/DE60125321T2/en not_active Expired - Fee Related
- 2001-08-02 EP EP01000345A patent/EP1234955B1/en not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
DE60120852D1 (en) | 2006-08-03 |
GB2365508A (en) | 2002-02-20 |
DE60125321D1 (en) | 2007-02-01 |
EP1234955A1 (en) | 2002-08-28 |
EP1179657A1 (en) | 2002-02-13 |
EP1234955B1 (en) | 2006-12-20 |
DE60120852T2 (en) | 2007-01-11 |
GB0019325D0 (en) | 2000-09-27 |
DE60125321T2 (en) | 2007-07-05 |
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