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
  • F01L1/02—Valve drive
  • F01L1/024—Belt drive
• • 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
• • 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]
• • 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
  • F01L2303/00—Manufacturing of components used in valve arrangements
  • F01L2303/01—Tools for producing, mounting or adjusting, e.g. some part of the distribution
• • 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
  • F02B2275/06—Endless member is a belt
• • 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 relates to a method, where shafts are driven via a transmission by a drive shaft, for setting the rotational position of the shafts in relation to that of the drive shaft.
• the method is particularly intended for applying to the setting of camshafts.
• a further disadvan ⁇ tage is that the belts which are mounted on the positioned drive wheels have relatively large intrinsic error toleran ⁇ ces, which affects the total error to a large degree so that an exact setting is difficult to achieve.
• the object of the invention is to achieve a method of cam ⁇ shaft setting which does not have the mentioned disadvan ⁇ tages, and an apparatus for carrying out the method.
• the error tolerances can be reduced, compared with the use of keyways and the like on the transmission wheels and the co-acting markings on the cylinder block or crankcase, and the use of tools results in that errors due to working by eye are elimina ⁇ ted, thus permitting the setting accuracy to increase by more than what is involved in solely the decrease of manu ⁇ facturing tolerances.
• Fig. 1 is a view from the front and partially in cross-sec ⁇ tion of an embodiment of the apparatus in accordance with the invention
• Fig. 2 is a view from the rear and partly in cross-section of the apparatus in Fig. 1;
• Figs. 3 and -4 illustrate a tool for the angular setting of camshafts in an engine having dual camshafts.
• FIG. 1 A conventional engine is illustrated in Fig. 1, as seen from the front.
• the crankshaft has a transmission wheel 1 which, when the engine is in operation, drives two cam ⁇ shafts via a toothed belt 2 by co-action with their trans ⁇ mission wheels 3 , ⁇ "
• the belt 2 further runs over a jockey pulley 5 and over a hydraulic belt tightener 6, which auto ⁇ matically ensures that correct belt tension is maintained.
• the transmission wheels 3 and i. are fixed to the camshafts by a suitable type of releasable frictional joint so that the wheels are readily made rotatable relative the respec ⁇ tive shaft.
• the basic concept of the invention is thus enabled, namely of utilizing machined surfaces on the shafts for achieving a more accurate setting.
• an abutment 7 on the rear counterweight 8 of the crankshaft for setting the angular position of the crankshaft.
• this abutment is illustrated as being in engagement with a tool 9, which is inserted in a bore in the crankcase.
• crankshaft 1 other surfaces of a crankshaft can be utilized together with a complemental tool for setting the crankshaft 1 in a welldefined angular position.
• the abutment on the rear counterweight of the crankshaft is a particularly suitable surface, since this also constitutes a reference surface in the production of the crankshaft.
• the engine to which the invention is applied in the embodiment example has dual camshafts 10,11.
• the same principle can be used for the camshafts as for the crankshafts, for their indivi ⁇ dual setting, e.g. by allowing a cam surface on the cam ⁇ shaft to co-act with a complemental tool inserted in an opening in the cylinder block, a combination tool 12 is preferably used for simultaneously setting the angular position of both camshafts 10, 11, as indicated in Fig. 2.
• the combination tool 12 is shown to a larger scale in Figs. 3 and , and principally comprises two levers 13, 14 with rectangular cross-section, the opposing end portions of the levers being unrotatably connectable to the rear ends of the respective camshafts 8,11, the other end portions of these levers engaging flat against each other in the set position of the camshafts, whereby a well defined angular position of the latter is achieved.
• the un-rotatable connection between camshaft end and lever can be achieved by the camshaft end being provided with a transverse slot, which co-acts with a complemental transverse projection 16 arranged on the corresponding lever end portion and is screwed into a thread in the camshaft end for fixing the lever axially.
• the camshafts can be locked in their set positions with the aid of a nut 18 screwed onto a bolt 17 projecting out from the lever 14 and accommodated in a hole in the lever 13.
• the transmission wheels 3 and 4 are rigidly connected to their respective shafts and the belts are tensioned.
• the first step of the method is to loosen the respective friction joint on the camshafts so that these can be turned relative the transmission wheels.
• the angular positions of the camshafts are then set by the levers 13 » 1*4 being taken into engagement against each other as illustrated in Fig. 2 by full lines, and the levers are locked in this position with the aid of the nut 18.
• the crankshaft is then turned to the position illustrated in Fig. 1 with the abutment 7 in engagement against the tool 9. While maintaining the set position of the crankshaft the friction joints between transmission wheels and shafts are then tightened, and the tools 9 and 12 are removed.
• the camshaft setting is thus completed.
• the crankshaft transmission wheel 1 does not need to be rotatable relative the crankshaft, since the rotation of wheels 3, -4 caused by this wheel do not affect the setting of the camshafts.
• setting by eye is completely avoided in the inventive method, and the accura ⁇ cy will be solely dependent on the manufacturing tolerances for the machined setting surfaces on the shafts and for the tools, and it is therefore possible to achieve very high setting accuracy.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Valve-Gear Or Valve Arrangements (AREA)
• Friction Gearing (AREA)
• Paper (AREA)
• Control Of Motors That Do Not Use Commutators (AREA)
• Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
• Control And Other Processes For Unpacking Of Materials (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (2)

Family

ID=20368494

Family Applications (1)

Country Status (6)

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Family Cites Families (3)

• 1987
  • 1987-05-13 SE SE8701959A patent/SE458137B/sv not_active IP Right Cessation
• 1988
  • 1988-05-10 WO PCT/SE1988/000241 patent/WO1988008918A1/en active IP Right Grant
  • 1988-05-10 DE DE8888904695T patent/DE3875123T2/de not_active Expired - Lifetime
  • 1988-05-10 JP JP63504519A patent/JPH02503459A/ja active Pending
  • 1988-05-10 EP EP88904695A patent/EP0417086B1/de not_active Expired - Lifetime
  • 1988-05-10 AT AT88904695T patent/ATE81186T1/de active

Non-Patent Citations (1)

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