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
  • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
  • F01L1/12—Transmitting gear between valve drive and valve
  • F01L1/14—Tappets; Push rods
  • F01L1/146—Push-rods
• • 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
  • F01L1/20—Adjusting or compensating clearance
  • F01L1/22—Adjusting or compensating clearance automatically, e.g. mechanically
  • F01L1/24—Adjusting or compensating clearance automatically, e.g. mechanically by fluid means, e.g. hydraulically
  • F01L1/245—Hydraulic tappets
  • F01L1/255—Hydraulic tappets between cam and rocker arm
• • 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
  • F01L9/12—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 with a liquid chamber between a piston actuated by a cam and a piston acting on a valve stem
  • F01L9/14—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 with a liquid chamber between a piston actuated by a cam and a piston acting on a valve stem the volume of the chamber being variable, e.g. for varying the lift or the timing of a valve
• • 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
  • F01L1/12—Transmitting gear between valve drive and valve
  • F01L1/14—Tappets; Push rods
  • F01L1/16—Silencing impact; Reducing wear
• • 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
  • F01L13/00—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations
  • F01L13/0015—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for optimising engine performances by modifying valve lift according to various working parameters, e.g. rotational speed, load, torque
  • F01L2013/0089—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for optimising engine performances by modifying valve lift according to various working parameters, e.g. rotational speed, load, torque with means for delaying valve closing

Definitions

• the invention relates to a control arrangement for a valve operating assembly in a piston engine according to preamble of claim 1 as well as to a method for controlling the closing movement of a valve operating assembly in a piston engine according to preamble of claim 6.
• An object of the invention is to provide a control arrangement for a valve operating assembly and a method for controlling the closing movement of a valve operating assembly, which solve the above mentioned problems of the prior art.
• a specific object of the invention is further to provide an efficient, straightforward and reliable braking method and arrangement to be adapted for the closing phase of a valve operating assembly in connection with the delay function of the inlet valve.
• the guide member includes a third chamber, which is arranged to be in communication with the first duct for releasing of pressure in the first chamber, and a control piston located in said third chamber and movably arranged with regard to the guide member for controlling pressure medium flow through said third chamber.
• the guide member is provided with a second duct for communication between the first duct and the third chamber and a third duct for releasing of pressure in said third chamber.
• the control piston is then arranged to control the opening and closing of said third duct.
• Efficient operation of the arrangement can be achieved if the diameter of the third duct is smaller that the diameter of the second duct.
• the control piston is arranged to partly extend out from the guide member after releasing of pressure in the first chamber for engaging with the piston device and braking its movement toward the guide member.
• the outward extending movement of the control piston is with advantage accomplished by means of the hydraulic medium entering from the first chamber into the third chamber.
• the braking function takes place in the upper part as well as in the lower part of the piston device included in the control arrangement of the valve operating assembly making the operation efficient and smooth.
• the braking function is available always when also the delay function for delaying the closing of the inlet valve is in use, and it is practically independent on the operating speed on the engine. Since the operation of the control piston can be accomplished by making use of the hydraulic medium normally utilised for the inlet valve delay function, an uncomplicated construction and reliable operation can be achieved.
• the invention is further defined by a method for controlling the closing movement of a valve operating assembly in accordance with claims 6 and 7.
• FIG. 1 shows a piston engine and a skeleton diagram of its valve mechanism
• FIG. 2 - 6 show an embodiment of a control arrangement according to the invention in separate consecutive stages of operation with the delay function for the delayed closing of the inlet valve being on, and
• FIG. 7 shows the embodiment of figures 2 - 6 in a certain stage of operation with the delay function for the delayed closing of the inlet valve being off.
• FIG. 1 shows a schematic view of a piston engine 1 as far as it is relevant to the understanding of the invention.
• the gas exchange of the cylinders (not shown) in the piston engine 1 is carried out under the control of gas exchange valves, i.e. inlet valves and exhaust valves, located on a cylinder head 2. Only inlet valves 3 are shown and they are operated by means of valve mechanisms 6 which are typically guided by the cam profiles of cam devices 5 arranged on a camshaft 4 of the engine.
• the force transmission connection between each valve mechanism 6 and the corresponding cam device 5 is realised by a control arrangement 7.
• the control arrangement 7 is shown in more detail in Figures 2 - 6.
• the control arrangement 7 comprises a body part 8, which is typically attached to the en- gine body.
• a piston device 9 is movably arranged within the body part 8.
• the upper end of the piston device 9 is arranged in force transmission connection with the valve mechanism 6 (not shown closer). This connection may be mechanical or hydraulic.
• the movements of the piston device 9 are controlled by a guide member 10 arranged at the lower end of the piston device within the body part 8.
• the guide member 10 is in engagement with and urged by a spring 1 1 towards a roller 12, which receives its guidance from the cam profile of the cam device 5.
• the body part 8 and the piston device 9 together define a first chamber 13, into which hydraulic medium can be selectively fed for providing a delay in the closing of the inlet valve 3.
• the feed line is provided with a shut-off valve 14 and a non-return valve 15.
• the shut-off valve 14 By means of the shut-off valve 14 the feed line to the first chamber 13 may be connected or disconnected, depending on whether or not the aim is to use the delay function for the delayed closing of the inlet valve 3.
• Due to the non-return valve 15 the control arrangement cannot cause any pulsations in the source of hydraulic medium. This is of importance when lubricat- ing oil is used as a hydraulic medium.
• the body part 8 is additionally provided with a duct 16 for releasing of pressure in the first chamber 13 and with a second chamber 17, which encloses the guide member 10, the spring 1 1 as well as the lower end of the piston device 9.
• the guide member 10 includes a groove 10a in its mantle surface and is addi- tionally provided with a third chamber 18.
• a duct 19 connects the groove 10a to the third chamber 18.
• a control piston 20 is movably arranged in the third chamber 18 and said chamber is further connected with ducts 21 and 22 to an oil sump providing lubrication for the camshaft and the parts connected therewith.
• figure 7 illustrates the operation of the arrangement according to the invention under normal load situations of the engine.
• the situation of figure 7 corresponds to the one disclosed in figure 4, but in this case the feed line 14 and 15 is closed.
• no hydraulic medium is fed into the chamber 13.
• the guide member 10 and the piston device 9 remain in direct contact through the whole operation cycle and the control pis- ton is inoperative, since the chambers and ducts are mainly filled with air.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Valve Device For Special Equipments (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=39924659

Family Applications (1)

Country Status (4)

Cited By (2)

Families Citing this family (1)

Citations (8)

Family Cites Families (1)

• 2008
  • 2008-10-29 FI FI20086021A patent/FI121245B/fi not_active IP Right Cessation
• 2009
  • 2009-10-09 WO PCT/FI2009/050804 patent/WO2010049583A1/en active Application Filing
  • 2009-10-09 EP EP09744424A patent/EP2340362B1/en active Active
  • 2009-10-09 CN CN2009801418498A patent/CN102197200B/zh active Active

Patent Citations (8)

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