GB2097084A - Hydraulic device for actuating gas change - Google Patents

Hydraulic device for actuating gas change Download PDF

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Publication number
GB2097084A
GB2097084A GB8211151A GB8211151A GB2097084A GB 2097084 A GB2097084 A GB 2097084A GB 8211151 A GB8211151 A GB 8211151A GB 8211151 A GB8211151 A GB 8211151A GB 2097084 A GB2097084 A GB 2097084A
Authority
GB
United Kingdom
Prior art keywords
valve
actuating
piston
transmission
lever
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Withdrawn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
GB8211151A
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.)
MAN AG
Original Assignee
MAN Maschinenfabrik Augsburg Nuernberg AG
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 MAN Maschinenfabrik Augsburg Nuernberg AG filed Critical MAN Maschinenfabrik Augsburg Nuernberg AG
Publication of GB2097084A publication Critical patent/GB2097084A/en
Withdrawn legal-status Critical Current

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Classifications

    • 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
    • F01L9/00—Valve-gear or valve arrangements actuated non-mechanically
    • F01L9/10—Valve-gear or valve arrangements actuated non-mechanically by fluid means, e.g. hydraulic
    • F01L9/11—Valve-gear or valve arrangements actuated non-mechanically by fluid means, e.g. hydraulic in which the action of a cam is being transmitted to a valve by a liquid column
    • 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
    • F01L1/3442—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 using hydraulic chambers with variable volume to transmit the rotating force
    • F01L2001/34423—Details relating to the hydraulic feeding circuit
    • F01L2001/34446—Fluid accumulators for the feeding circuit

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanically-Actuated Valves (AREA)
  • Valve Device For Special Equipments (AREA)
  • Valve-Gear Or Valve Arrangements (AREA)
  • Compressor (AREA)
  • Control Of Transmission Device (AREA)

Abstract

The hydraulic device for actuating a gas change valve (12) comprises an actuating piston (6) movable by a cam-operated transmission piston (2) via a fluid control line (4) the line (4) incorporating a permanent vent (5) and housing an automatic oil refilling system (8-11) to ensure that the fluid is gas free. In order to prevent leaking control fluid from reaching hot engine parts, and to ensure accurate stepless adjustment of the valve lift, a transmission lever (13) is provided and there is relative displacement between the actuating cylinder (7) to vary the pivotal movement of the lever (13) and hence vary the lifting motion of the valve (12). Preferably, it is the lever (13) which is displaceable at right angles to the cylinder (7). <IMAGE>

Description

SPECIFICATION Hydraulic device for actuating gas change valves This invention relates to an internal combustion engine, engine compressor or similar machine having a hydraulic device for actuating inlet and outlet valves. German patent publication No. 2840445 discloses a hydraulic device in which an actuating piston is associated with each variable-lift valve. Each valve is movable against the force of a closing spring by a cam-operated transmission piston via a control line containing control fluid. At the highest point of the hydraulic system means are provided for permanent venting of the control fluid. The transmission cylinder is connected to a device for replenishing control fluid.
In this disclosure, the cam actuating the transmission piston features a pre-lift cam and a post-lift cam in order to control appropriately the pressure buildup in the hydraulic system and, in particular, to match pressure transmission to the desired motion of the valve. The actuating piston is arranged immediately above and acts directly on the valve.
Varying the opening lift of the valve in the closure is by means of a restrictor provided in the hydraulic transmission circuit which limits the pressure transmitted to the valve and thereby the valve movement to a greater or iesser degree.
Reducing the valve lift is apt to improve the performance of the engine during starting and at part loads. The known method of control by means of a restrictor axiomatically involved a more or less slow response in matching the valve lift to the prevailing conditions, and this constitutes a certain drawback.
An added disadvantage in that system is that the valve is actuated directly from above by the actuating piston. In such an arrangement, oil leaking from the actuating cylinder unavoidably passes downwards along the valve stem and contacts the hot engine parts, forms carbon deposits or burns inside the cylinder.
An object of the present invention is to avoid the drawback referred to and to improve the known hydraulic system in a manner that no control fluid can reach the hot engine parts and accurate, stepless adjustment of the valve lift is possible with instant response.
The invention provides an internal combustion engine, compressor or similar machine having a hydraulic device for actuating inlet and outlet valves, the device comprising an actuating piston associated with each valve and being movable against the force of a closing spring by a transmission piston operable by a cam via a control duct containing control fluid and means for permanent venting of the control fluid, the transmission cylinder being connected to a device for replenishing control fluid, wherein a transmission lever pivotable about a fulcrum is provided between the actuating piston and the valve, the transmission lever and the actuating cylinder being relatively displaceable so as to vary the pivotal movement of the transmission lever and hence the lift of the valve.
In other words, a transmission lever which is generally known in mechanical linkages for this purpose is re-introduced, this lever being preferably of the single-arm type and various arrangements are possible to realize this. The actuating cylinder thus acts from the top on the lever so that control fluid is prevented from reaching the valve stem.
In order to enable a varying valve lift to be obtained, the fulcrum of the actuating lever or the actuating cylinder can be shifted horizontally, i.e.
perpendicular to the lifting motion of the valve relative to the other, so that the same amount of stroke of the actuating plunger or piston can as a result of the varying lever arm, produce a different lift of the valve.
As a further embodiment of the invention, it is proposed, that the free end of the one-armed transmission lever be made to bear on the valve so that it can be shifted on the latter within given limits. The shifting is preferably achieved by arranging the fulcrum of the transmission lever on the rod of the hydraulic plunger or piston which is movable by the hydraulic fluid against the force of the spring. This arrangement is preferred in order to effect the displacement of the fulcrum in a simple manner, and, especially, in correct timing with the movement of the actuating plunger or piston. Of course, displacements of the fulcrum can also be effected by any suitable alternative means.
An embodiment of the invention will now be described with reference to a part-sectional schematic view shown in the accompanying drawing.
In the drawing, an actuating piston 6 arranged in an actuating cylinder 7 is movable by a control fluid via a cam 1, a transmission piston 2 in a transmission cylinder 3 and a control line 4 having a permanent vent 5. The actuating piston 6 acts on a transmission lever 13 pivoted on afulcrum 14. The free end of the lever bears against a valve 12. The point of application of the actuating piston 6 is between the fulcrum 14 and the free end of the transmission lever 13.
The fulcrum 14 is provided on a piston rod 15 connected to a piston 16 movable in a hydraulic cylinder 17. As the piston 16 is acted upon by control medium in the line 19, the piston rod 15 moves away from a stop 18 to shift the transmission lever 13 horizontally so as to vary the distance between the valve 12 and the point of application of the piston 6 and thus to vary the lift of the valve 12. Of course, the same effect would be obtained if, instead of moving the fulcrum 14, the actuating cylinder7 were displaced in the direction of the arrow 20.
The hydraulic circuit also includes a check valve 8, a relief valve 10 and an accumulator 11.
1. An internal combustion engine compressor or similar machine having a hydraulic device for actuating inlet and outlet valves, the device comprising an actuating piston associated with each valve and being movable against the force of a closing spring by a transmission piston operable by a cam via a control duct containing control fluid and means for permanent venting of the control fluid, the transmission cylinder being connected to a device for replenishing control fluid, wherein a transmission lever
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Hydraulic device for actuating gas change valves This invention relates to an internal combustion engine, engine compressor or similar machine having a hydraulic device for actuating inlet and outlet valves. German patent publication No. 2840445 discloses a hydraulic device in which an actuating piston is associated with each variable-lift valve. Each valve is movable against the force of a closing spring by a cam-operated transmission piston via a control line containing control fluid. At the highest point of the hydraulic system means are provided for permanent venting of the control fluid. The transmission cylinder is connected to a device for replenishing control fluid. In this disclosure, the cam actuating the transmission piston features a pre-lift cam and a post-lift cam in order to control appropriately the pressure buildup in the hydraulic system and, in particular, to match pressure transmission to the desired motion of the valve. The actuating piston is arranged immediately above and acts directly on the valve. Varying the opening lift of the valve in the closure is by means of a restrictor provided in the hydraulic transmission circuit which limits the pressure transmitted to the valve and thereby the valve movement to a greater or iesser degree. Reducing the valve lift is apt to improve the performance of the engine during starting and at part loads. The known method of control by means of a restrictor axiomatically involved a more or less slow response in matching the valve lift to the prevailing conditions, and this constitutes a certain drawback. An added disadvantage in that system is that the valve is actuated directly from above by the actuating piston. In such an arrangement, oil leaking from the actuating cylinder unavoidably passes downwards along the valve stem and contacts the hot engine parts, forms carbon deposits or burns inside the cylinder. An object of the present invention is to avoid the drawback referred to and to improve the known hydraulic system in a manner that no control fluid can reach the hot engine parts and accurate, stepless adjustment of the valve lift is possible with instant response. The invention provides an internal combustion engine, compressor or similar machine having a hydraulic device for actuating inlet and outlet valves, the device comprising an actuating piston associated with each valve and being movable against the force of a closing spring by a transmission piston operable by a cam via a control duct containing control fluid and means for permanent venting of the control fluid, the transmission cylinder being connected to a device for replenishing control fluid, wherein a transmission lever pivotable about a fulcrum is provided between the actuating piston and the valve, the transmission lever and the actuating cylinder being relatively displaceable so as to vary the pivotal movement of the transmission lever and hence the lift of the valve. In other words, a transmission lever which is generally known in mechanical linkages for this purpose is re-introduced, this lever being preferably of the single-arm type and various arrangements are possible to realize this. The actuating cylinder thus acts from the top on the lever so that control fluid is prevented from reaching the valve stem. In order to enable a varying valve lift to be obtained, the fulcrum of the actuating lever or the actuating cylinder can be shifted horizontally, i.e. perpendicular to the lifting motion of the valve relative to the other, so that the same amount of stroke of the actuating plunger or piston can as a result of the varying lever arm, produce a different lift of the valve. As a further embodiment of the invention, it is proposed, that the free end of the one-armed transmission lever be made to bear on the valve so that it can be shifted on the latter within given limits. The shifting is preferably achieved by arranging the fulcrum of the transmission lever on the rod of the hydraulic plunger or piston which is movable by the hydraulic fluid against the force of the spring. This arrangement is preferred in order to effect the displacement of the fulcrum in a simple manner, and, especially, in correct timing with the movement of the actuating plunger or piston. Of course, displacements of the fulcrum can also be effected by any suitable alternative means. An embodiment of the invention will now be described with reference to a part-sectional schematic view shown in the accompanying drawing. In the drawing, an actuating piston 6 arranged in an actuating cylinder 7 is movable by a control fluid via a cam 1, a transmission piston 2 in a transmission cylinder 3 and a control line 4 having a permanent vent 5. The actuating piston 6 acts on a transmission lever 13 pivoted on afulcrum 14. The free end of the lever bears against a valve 12. The point of application of the actuating piston 6 is between the fulcrum 14 and the free end of the transmission lever 13. The fulcrum 14 is provided on a piston rod 15 connected to a piston 16 movable in a hydraulic cylinder 17. As the piston 16 is acted upon by control medium in the line 19, the piston rod 15 moves away from a stop 18 to shift the transmission lever 13 horizontally so as to vary the distance between the valve 12 and the point of application of the piston 6 and thus to vary the lift of the valve 12. Of course, the same effect would be obtained if, instead of moving the fulcrum 14, the actuating cylinder7 were displaced in the direction of the arrow 20. The hydraulic circuit also includes a check valve 8, a relief valve 10 and an accumulator 11. CLAIMS
1. An internal combustion engine compressor or similar machine having a hydraulic device for actuating inlet and outlet valves, the device comprising an actuating piston associated with each valve and being movable against the force of a closing spring by a transmission piston operable by a cam via a control duct containing control fluid and means for permanent venting of the control fluid, the transmission cylinder being connected to a device for replenishing control fluid, wherein a transmission lever pivotable about a fulcrum is provided between the actuating piston and the valve, the transmission lever and the actuating cylinder being relatively displaceable so as to vary the pivotal movement of the transmission lever and hence the lift of the valve.
2. An engine as claimed in claim 1, wherein the fulcrum is at one end ofthe transmission lever and the other end of the transmission lever bears against the valve, the actuating piston acting on the transmission lever at a point between the valve and the fulcrum in the direction of valve opening.
3. An engine as claimed in claim 2, wherein the transmission lever is pivotal ly connected to the piston rod of a hydraulic piston displaceable by the hydraulic fluid against spring bias in a direction per pendiculartothe lifting motion of the valve.
4. An internal combustion engine, compressor or similar machine substantially as herein described with reference to the embodiment shown in the accompanying drawing.
GB8211151A 1981-04-16 1982-04-16 Hydraulic device for actuating gas change Withdrawn GB2097084A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19813115422 DE3115422A1 (en) 1981-04-16 1981-04-16 HYDRAULIC DEVICE FOR ACTUATING GAS EXCHANGE VALVES

Publications (1)

Publication Number Publication Date
GB2097084A true GB2097084A (en) 1982-10-27

Family

ID=6130291

Family Applications (1)

Application Number Title Priority Date Filing Date
GB8211151A Withdrawn GB2097084A (en) 1981-04-16 1982-04-16 Hydraulic device for actuating gas change

Country Status (7)

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JP (1) JPS57181910A (en)
DD (1) DD207398A1 (en)
DE (1) DE3115422A1 (en)
FR (1) FR2504188A1 (en)
GB (1) GB2097084A (en)
IT (1) IT8220026A0 (en)
SE (1) SE8202383L (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1988002059A1 (en) * 1986-09-09 1988-03-24 Wride, Marlene, Alfreda Variable lift cam follower
WO1990003499A1 (en) * 1988-09-28 1990-04-05 Siemens Aktiengesellschaft Modular, self-contained hydraulic valve timing systems for internal combustion engines
EP0405187A1 (en) * 1989-06-27 1991-01-02 FEV Motorentechnik GmbH &amp; Co. KG Electromagnetic positioning device

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102013113815A1 (en) 2013-12-11 2015-06-11 Pierburg Gmbh Transmission arrangement for a mechanically controllable valve train

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE369394C (en) * 1921-06-07 1923-02-19 Maybach Motorenbau G M B H Control of valves, in particular injection valves for constant pressure motors
GB213894A (en) * 1923-04-05 1924-09-18 Henry Farman Improvements relating to the regulation of internal-combustion engines for aircraft
DE2363891A1 (en) * 1973-07-13 1975-06-26 Daimler Benz Ag Valve control system for ic engine - valve rod is controlled by action of lever on adjustable curved surface
DE2337885A1 (en) * 1973-07-26 1975-02-06 Daimler Benz Ag Adjusting device for I.C. engine valves - using stop, regulated by pressure medium piston, to adjust valve lift
DE2448311B2 (en) * 1974-10-10 1978-03-23 Maschinenfabrik Augsburg-Nuernberg Ag, 8500 Nuernberg Adjustable hydraulic valve control for reciprocating piston engines or machines
DE2840445C2 (en) * 1978-09-16 1984-10-04 M.A.N. Maschinenfabrik Augsburg-Nürnberg AG, 8500 Nürnberg Hydraulic device for operating a gas exchange valve for internal combustion engines

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1988002059A1 (en) * 1986-09-09 1988-03-24 Wride, Marlene, Alfreda Variable lift cam follower
WO1990003499A1 (en) * 1988-09-28 1990-04-05 Siemens Aktiengesellschaft Modular, self-contained hydraulic valve timing systems for internal combustion engines
EP0405187A1 (en) * 1989-06-27 1991-01-02 FEV Motorentechnik GmbH &amp; Co. KG Electromagnetic positioning device

Also Published As

Publication number Publication date
DD207398A1 (en) 1984-02-29
FR2504188A1 (en) 1982-10-22
DE3115422A1 (en) 1982-11-11
SE8202383L (en) 1982-10-17
IT8220026A0 (en) 1982-03-09
DE3115422C2 (en) 1989-12-14
JPS57181910A (en) 1982-11-09

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WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)