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
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D15/00—Varying compression ratio
  • F02D15/02—Varying compression ratio by alteration or displacement of piston stroke
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
  • F16C23/00—Bearings for exclusively rotary movement adjustable for aligning or positioning
  • F16C23/10—Bearings, parts of which are eccentrically adjustable with respect to each other
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
  • F16C7/00—Connecting-rods or like links pivoted at both ends; Construction of connecting-rod heads
  • F16C7/06—Adjustable connecting-rods
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
  • F16C9/00—Bearings for crankshafts or connecting-rods; Attachment of connecting-rods
  • F16C9/04—Connecting-rod bearings; Attachments thereof
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
  • F16C2360/00—Engines or pumps
  • F16C2360/22—Internal combustion engines

Definitions

• the connecting rod may be of the telescopic type, as is for example known from US2016237889 or of the eccentric type.
• the connecting rod is provided with a device, often of a hydromechanical nature, allowing its length to be adjusted.
• the control of the connecting rod consists in controlling the hydromechanical device for adjusting its length to a target length, so as to give the engine a set volumetric ratio.
• the piloting system comprises:
• At least one linear hydraulic spool arranged in a housing of the connecting rod head, and capable of occupying a first rest position and at least a second position, each position making it possible to open or close fluid communication with the circuit.
• At least one of the pads comprises end-of-travel stops, to limit its possible displacement along the transverse axis;
• the (at least one) slide makes it possible, depending on the position it occupies, to establish an oil circulation between a hydraulic chamber and an oil supply, or to establish an oil circulation between a hydraulic chamber and an oil evacuation, or to establish an oil circulation between the two hydraulic chambers, or to block all oil circulation with the two hydraulic chambers;
• Figures 5c and 5d show a variant of the control system of a telescopic connecting rod according to the invention, and the associated hydraulic diagram for a “three-rate” operation, with transfer between the hydraulic chambers;
• Figures 7a, 7b, 7c and 7d show the control system of a telescopic connecting rod according to the invention, and the associated hydraulic diagram for operation in "continuous rate", with transfer between the hydraulic chambers;
• Figures 8a, 8b and 8c show control members carried by the crankshaft and configured to cooperate with a connecting rod according to the invention;
• Figure 8d shows the control system of a connecting rod according to the invention cooperating with a control member carried by the crankshaft.
• the connecting rod 10 comprises a body 101 extending along a longitudinal axis z.
• the connecting rod 10 according to the invention can be of the telescopic type (figure la) or of eccentric type (figure lb, lc): a central cylinder mechanism or an eccentric mechanism is then fitted in the body 101 of the connecting rod 10.
• These mechanisms form part of a hydraulic control circuit 104, included in the connecting rod 10.
• the hydraulic circuit 104 preferably comprises at least two hydraulic chambers 1041, 1042 associated with at least one hydraulic piston.
• the hydraulic chambers 1041,1042 are associated with a central piston 1045 in the case of a telescopic connecting rod (figure la), and the chambers 1041,1042 are respectively associated with a first piston and with a second piston in the case of a telescopic rod. of an eccentric connecting rod (figure le).
• the modification of the supply, evacuation or circulation of oil in or between these two hydraulic chambers 1041,1042 will induce the displacement of the piston (s) hydraulic (s), which displacement allows the rod length to be modified along the longitudinal axis z.
• the connecting rod 10 also comprises a connecting rod end 102, intended to establish a pivot connection, along a transverse axis y perpendicular to the longitudinal axis z, with a crankpin 2 of the crankshaft 200 of the piloted volumetric ratio engine.
• bearings 103 are provided to limit the friction between the big end 102 and crankpin 2.
• the control system 110 comprises at least one linear hydraulic spool 111, arranged in a housing 112 of the head 102 of the connecting rod 10 ( Figure 2a).
• the piloting system 110 is in fluid connection with the hydraulic circuit 104 by means of at least one duct 104a arranged in the big end 102 and communicating with the housing 112.
• the drawer 111 is said to be linear because it is able to move along the transverse axis y, in the housing 112. Thus, it is capable of occupying a first rest position PI and at least a second position P2. A position of drawer 111 will allow:
• the front section 112a of the housing 112 is configured to partially accommodate the first pad 113.
• the front section 112a has an enlarged housing allowing the first pad 113 to establish a sliding connection according to the transverse axis y, with the big end 102.
• the control system 110 also comprises a return means 114 (FIG. 2a), for example springs, for returning the spool 111 to the first rest position PI, in the absence of the support force exerted on the first pad. 113.
• the piloting system 110 also includes a second shoe 115 disposed on the same side of the big end 102 as the first shoe 113 ( Figures la and lb).
• the second pad 115 is also able to withstand the support force exerted by the external pilot member 50. It is advantageously configured to balance the support force exerted by the external pilot member 50 and prevent the appearance of parasitic torque between the first pad 113 and the control member 50.
• the first 113 and second 115 pads are arranged so that the barycenter of the forces undergone by said pads when the support force is applied to them is located substantially in the center of the big end 102.
• the second shoe 115 is symmetrical to the first shoe 113 with respect to the center of the big end 102 and has a contact surface equivalent to the first shoe 113.
• the first 113 and second 115 pads may be aligned along the longitudinal axis z, the first as close as possible to the body 101 of the connecting rod 10 and the second at the level of the cap of the bie head 102.
• several second pads 115 could be arranged on the blank of the big end 102, and arranged so as to balance the forces.
• FIG. 3a illustrates a piloting system comprising two spools 111a, 111b, suitable for an eccentric connecting rod
• FIG. 3b illustrates the same piloting system for a telescopic connecting rod.
• the piloting system 111 remains identical in both cases and thus consists of a first pad 113 (and a second pad 115 - not shown), on which an external pilot member 50 exerts a support force, allowing The actuation of a first spool 111a and a second spool 111b, which control the supply and discharge of oil respectively from the first hydraulic chamber 1041 and from the second hydraulic chamber 1042.
• the control system 111 does not allow oil to be transferred between the two chambers 1041, 1042 of the hydraulic circuit 104.
• variable-length connecting rod The operating mode of the piloting system 111 illustrated in FIGS. 3a and 3b is detailed below, with reference to a connecting rod of variable length with eccentric operating at “two-rate”. Another important aspect of the variable-length connecting rod according to the present invention relates to the desire or not to transfer part of the oil from one chamber 1041,1042 of the hydraulic circuit 104 into the other, when the length of the cylinder is changed. connecting rod.
• this fluidic connection may be independent or dependent on the position of the drawer (s) 111a, 111b.
• the fluid connection can be provided by a transfer pipe 104c.
• the transfer pipe 104c advantageously comprises a device for orienting the oil flow 1046 such as for example a non-return valve.
• the length of the connecting rod 10 is maximum in the absence of a bearing force applied to the first pad 113, the spool 111 then being in its rest position PI and allowing the circulation of oil from the first hydraulic chamber 1041 to the second hydraulic chamber 1042; the transfer of oil between the second chamber 1042 to the first chamber 1041 is also possible via the transfer line 104c.
• a return or repel element 1042a (illustrated by a spring 1042a arranged in the hydraulic chamber 1042 in FIGS. 3c, 3d) makes it possible to guarantee the elongation of the connecting rod 10 thanks to a force, independent of the external forces applied to the connecting rod, during an engine cycle.
• the second chamber 1042 by the action of the spring 1042a, will extend by pushing back the piston 1045.
• the return or pushing element 1042a may be located outside the chamber 1042 (in particular in the case of the eccentric connecting rod) and perform the same function as described above.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Shafts, Cranks, Connecting Bars, And Related Bearings (AREA)
• Output Control And Ontrol Of Special Type Engine (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=69468833

Family Applications (1)

Country Status (7)

Family Cites Families (25)

• 2019
  • 2019-11-04 FR FR1912336A patent/FR3102814B1/fr not_active Expired - Fee Related
  • 2019-11-19 FR FR1912874A patent/FR3102813A1/fr not_active Ceased
• 2020
  • 2020-11-04 US US17/755,606 patent/US20230042411A1/en not_active Abandoned
  • 2020-11-04 KR KR1020227018993A patent/KR20220090575A/ko not_active Withdrawn
  • 2020-11-04 EP EP20817454.0A patent/EP4055256A1/de not_active Withdrawn
  • 2020-11-04 WO PCT/FR2020/051987 patent/WO2021089940A1/fr not_active Ceased
  • 2020-11-04 JP JP2022526707A patent/JP2023500949A/ja active Pending
  • 2020-11-04 CN CN202080089946.3A patent/CN115298426A/zh active Pending

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