EP3884141A1 - Ensemble culbuteur pour freinage de moteur - Google Patents

Ensemble culbuteur pour freinage de moteur

Info

Publication number
EP3884141A1
EP3884141A1 EP19817590.3A EP19817590A EP3884141A1 EP 3884141 A1 EP3884141 A1 EP 3884141A1 EP 19817590 A EP19817590 A EP 19817590A EP 3884141 A1 EP3884141 A1 EP 3884141A1
Authority
EP
European Patent Office
Prior art keywords
assembly
valve
rocker arm
lever
exhaust
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.)
Pending
Application number
EP19817590.3A
Other languages
German (de)
English (en)
Inventor
Mark VANWINGERDEN
Douglas J. NIELSEN JR.
James E. Mccarthy Jr.
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.)
Eaton Intelligent Power Ltd
Original Assignee
Eaton Intelligent Power Ltd
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
Priority claimed from US16/195,120 external-priority patent/US10690024B2/en
Application filed by Eaton Intelligent Power Ltd filed Critical Eaton Intelligent Power Ltd
Publication of EP3884141A1 publication Critical patent/EP3884141A1/fr
Pending legal-status Critical Current

Links

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
    • F01L1/18—Rocking arms or levers
    • 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
    • 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
    • F01L1/18—Rocking arms or levers
    • F01L1/181—Centre pivot rocking arms
    • 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
    • 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
    • F01L13/06—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for braking
    • 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
    • F01L13/06—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for braking
    • F01L13/065—Compression release engine retarders of the "Jacobs Manufacturing" type

Definitions

  • the present disclosure relates generally to a rocker arm assembly for use in a valve train assembly and, more particularly, to a rocker arm assembly having an engine braking bridge.
  • Compression engine brakes can be used as auxiliary brakes in addition to wheel brakes, for example, on relatively large vehicles powered by heavy or medium duty diesel engines.
  • a compression engine braking system is arranged, when activated, to provide an additional opening of an engine cylinder’s exhaust valve when the piston in that cylinder is near a top-dead-center position of its compression stroke so that compressed air can be released through the exhaust valve. This causes the engine to function as a power consuming air compressor which slows the vehicle.
  • the exhaust valve is actuated by a rocker arm which engages the exhaust valve by means of a valve bridge.
  • the rocker arm rocks in response to a cam on a rotating cam shaft and presses down on the valve bridge which itself presses down on the exhaust valve to open it.
  • a hydraulic lash adjuster may also be provided in the valve train assembly to remove any lash or gap that develops between the components in the valve train assembly.
  • an exhaust valve rocker arm assembly selectively opening first and second exhaust valves.
  • the assembly includes an exhaust rocker arm and a valve bridge operably associated with the rocker arm and including a main body and a lever rotatably coupled to the main body.
  • the main body is configured to engage the first exhaust valve
  • the lever is configured to engage the second exhaust valve.
  • the exhaust valve rocker arm assembly may include one or more of the following features: wherein the lever is disposed at least partially within the main body; wherein the lever is disposed between opposed flanges of the main body; wherein the valve bridge main body is configured to have an interference fit with a valve tip of the first exhaust valve; and a hydraulic lash adjuster (HLA) assembly coupled between the exhaust rocker arm and the valve bridge, wherein the interference fit is configured to transfer relative motion to the HLA assembly and the second exhaust valve.
  • HLA hydraulic lash adjuster
  • the exhaust valve rocker arm assembly may include one or more of the following features: a valve shoe rotatably coupled to the lever; wherein the valve shoe is rotatably coupled to the lever by a valve shoe pin extending through the lever; wherein the valve shoe is configured to have an interference fit with a valve tip of the second exhaust valve; and a hydraulic lash adjuster (HLA) assembly coupled between the exhaust rocker arm and the valve bridge, wherein the interference fit is configured to transfer relative motion to the HLA assembly and the first exhaust valve.
  • HLA hydraulic lash adjuster
  • the exhaust valve rocker arm assembly may include one or more of the following features: wherein the lever is coupled to the main body such that rotation of the lever and engagement of the second exhaust valve occurs without rotation of the main body; wherein the main body includes an aperture, the lever at least partially disposed within the aperture, and wherein the lever is rotatably coupled to the main body by a bridge pin extending through the main body; and wherein the lever includes an engagement surface and an opposed side opposite the engagement surface, wherein the engagement surface is configured to be engaged by an engine brake rocker arm, and the opposed side is configured to move upwardly against the main body when the engagement surface is moved downward.
  • a valve train assembly in another aspect of the present disclosure, includes a first exhaust valve, a second exhaust valve, and an exhaust valve rocker arm assembly selectively opening the first and second exhaust valves.
  • the exhaust valve rocker arm assembly including an exhaust rocker arm, and a valve bridge operably associated with the rocker arm and including a main body and a lever rotatably coupled to the main body.
  • the main body is configured to engage the first exhaust valve
  • the lever is configured to engage the second exhaust valve.
  • An engine brake rocker arm assembly includes an engine brake rocker arm configured to selectively engage and rotate the lever to open the second exhaust valve.
  • valve train assembly may include one or more of the following features: wherein the lever is disposed at least partially within the main body between opposed flanges of the main body; wherein the exhaust wherein the valve bridge main body has an interference fit with a valve tip of the first exhaust valve; and a hydraulic lash adjuster (HLA) assembly coupled between the exhaust rocker arm and the valve bridge, wherein the interference fit is configured to transfer relative motion to the HLA assembly and the second exhaust valve.
  • HLA hydraulic lash adjuster
  • valve train assembly may include one or more of the following features: a valve shoe rotatably coupled to the lever by a valve shoe pin extending through the lever; wherein the valve shoe has an interference fit with a valve tip of the second exhaust valve; and a hydraulic lash adjuster (HLA) assembly coupled between the exhaust rocker arm and the valve bridge, wherein the interference fit is configured to transfer relative motion to the HLA assembly and the first exhaust valve.
  • HLA hydraulic lash adjuster
  • the valve train assembly may include one or more of the following features: wherein the engine brake rocker arm assembly further comprises an engine brake capsule coupled to the engine brake rocker arm, the engine brake capsule movable between a retracted position and an extended position, wherein in the retracted position the engine brake capsule does not engage the lever, and in the extended position the engine brake capsule selectively engages the lever, wherein the engine brake capsule includes an outer housing, a plunger, and a pin assembly, wherein the plunger is disposed in a lower chamber of the outer housing, and the pin assembly is at least partially disposed within an upper chamber of the outer housing, and wherein the engine brake capsule includes a check ball assembly disposed within the lower chamber, the pin assembly operatively associated with the check ball assembly to selectively enable a hydraulic fluid into the lower chamber to move the plunger from the retracted position to the extended position.
  • FIG. 1 is a plan view of a valve train assembly incorporating a rocker arm assembly that includes an intake rocker arm assembly, an exhaust rocker arm assembly, and an engine brake rocker arm assembly constructed in accordance to one example of the present disclosure;
  • FIG. 2 is a perspective view of the valve train assembly shown in FIG. 1 without the intake rocker arm assembly;
  • FIG. 3 is an exploded view of the exhaust valve rocker arm assembly and the engine brake rocker arm assembly of FIG. 1 ;
  • FIG. 4 is a cross-sectional view of the engine brake rocker arm assembly shown in FIG. 3 and taken along line 4-4;
  • FIG. 5 is a perspective view of a portion of the rocker arm assembly shown in FIG. 1 ;
  • FIG. 6 is a perspective view of a valve bridge assembly of the exhaust valve rocker arm assembly shown in FIG. 1 , constructed in accordance to one example of the present disclosure
  • FIG. 7 is a plan view of a portion of the valve bridge assembly shown in FIG. 6;
  • FIG. 8 is a cross-sectional view of the rocker arm assembly shown in FIG. 5 taken along line 8-8 and during a normal exhaust event actuation;
  • FIG. 9 is a cross-sectional view of the rocker arm assembly shown in FIG. 5 taken along line 8-8 and during a brake event actuation;
  • FIG. 10 is a cross-sectional view of another exhaust rocker arm assembly during a normal exhaust event actuation that may be used with the rocker arm assembly shown in FIG. 1 , and constructed in accordance to one example of the present disclosure;
  • FIG. 1 1 is a cross-sectional view of the exhaust rocker arm assembly shown in FIG. 10 during a brake event actuation;
  • FIG. 12 is a perspective view of a valve train assembly incorporating a rocker arm assembly that includes an intake rocker arm assembly, an exhaust rocker arm assembly, and an engine brake rocker arm assembly constructed in accordance to another example of the present disclosure
  • FIG. 13 is a sectional view of the valve train assembly shown in FIG. 12 in a first mode
  • FIG. 14 is a sectional view of the valve train assembly shown in FIG. 12 in a second mode
  • FIG. 15 is a cross-sectional view of an engine brake capsule shown in FIG. 13;
  • FIG. 16 is a cross-sectional view of an engine brake capsule shown in FIG. 14;
  • FIG. 17 is a perspective view of an example valve bridge assembly shown in FIG. 12
  • FIG. 18 is a sectional view of the valve train assembly shown in FIG. 12 with one example valve bridge assembly.
  • FIG. 19 is a sectional view of the valve train assembly shown in FIG. 12 with another example valve bridge assembly.
  • a partial valve train assembly constructed in accordance to one example of the present disclosure is shown and generally identified at reference 10.
  • the partial valve train assembly 10 utilizes engine braking and is shown configured for use in a three-cylinder bank portion of a six- cylinder engine. It will be appreciated however that the present teachings are not so limited. In this regard, the present disclosure may be used in any valve train assembly that utilizes engine braking.
  • the partial valve train assembly 10 is supported in a valve train carrier 12 and can include three rocker arms per cylinder.
  • each cylinder includes an intake valve rocker arm assembly 14, an exhaust valve rocker arm assembly 16, and an engine brake rocker arm assembly 18.
  • the exhaust valve rocker arm assembly 16 and the engine brake rocker arm assembly 18 cooperate to control opening of the exhaust valves and are collectively referred to as a dual rocker arm assembly 20 (FIG. 2).
  • the intake valve rocker arm assembly 14 is configured to control motion of the intake valves
  • the exhaust valve rocker arm assembly 16 is configured to control exhaust valve motion in a drive mode
  • the engine brake rocker arm assembly 18 is configured to act on one of the two exhaust valves in an engine brake mode, as will be described herein.
  • a rocker shaft 22 is received by the valve train carrier 12 and supports rotation of the exhaust valve rocker arm assembly 16 and the engine brake rocker arm assembly 18. As described herein in more detail, the rocker shaft 22 can communicate oil to the assemblies 16, 18 during operation.
  • a cam shaft 24 includes lift profiles or cam lobes configured to rotate assemblies 16, 18 to activate first and second exhaust valves 26 and 28, as is described herein in more detail.
  • exhaust valve rocker arm assembly 16 can generally include an exhaust rocker arm 30, a valve bridge assembly 32, and a hydraulic lash adjuster (FILA) assembly 36.
  • FILA hydraulic lash adjuster
  • the exhaust rocker arm 30 includes a body 40, an axle 42, and a roller 44.
  • Body 40 can receive the rocker shaft 22 and defines a bore 48 configured to at least partially receive the FILA assembly 36.
  • the axle 42 can be coupled to the body 40 and can receive the roller 44, which is configured to be engaged by an exhaust lift profile or cam lobe 50 (FIG. 2) of the cam shaft 24.
  • an exhaust lift profile or cam lobe 50 FIG. 2
  • the exhaust rocker arm 30 is rotated downward, causing downward movement of the valve bridge assembly 32, which engages the first and second exhaust valve 26 and 28 (FIG. 2) associated with a cylinder of an engine (not shown).
  • the FILA assembly 36 is configured to take up any lash between the FILA assembly 36 and the valve bridge assembly 32.
  • the FILA assembly 36 can comprise a plunger assembly 52 including a leak down plunger or first plunger body 54 and a ball plunger or second plunger body 56.
  • the plunger assembly 52 is received by bore 48 defined in rocker arm 30, and can have a first closed end defining a spigot 58, which is received in a socket 60 that acts against the valve bridge assembly 32.
  • the second plunger body 56 has an opening that defines a valve seat 62, and a check ball assembly 64 can be positioned between the first and second plunger bodies 54, 56.
  • the check ball assembly 64 can be configured to hold oil within a chamber 66 between the first and second plunger bodies 54, 56.
  • a biasing mechanism 68 e.g., a spring biases second plunger body 56 upward (as shown in FIGS. 8 and 9) to expand the first plunger body 54 to take up any lash.
  • oil can be supplied from rocker shaft 22 through a channel (not shown) to the chamber within second plunger 56, and downward pressure can cause downward movement of the first plunger body 54 due to the oil in the chamber 66.
  • HLA assembly 36 may have any other suitable configuration that enables assembly 36 to take up lash between the assembly and the valve bridge assembly 32.
  • the engine brake rocker arm assembly 18 can generally include an engine brake rocker arm 70, an axle 72, a roller 74, an actuator or piston assembly 76, and a check valve assembly 78.
  • Engine brake rocker arm 70 can receive the rocker shaft 22 and can define a first bore 80 and a second bore 82.
  • the first bore 80 can be configured to at least partially receive the piston assembly 76
  • the second bore 82 can be configured to at least partially receive the check valve assembly 78.
  • the axle 72 can be coupled to the rocker arm 70 and can receive the roller 74, which is configured to be engaged by a brake lift profile or cam lobe 84 (FIG. 2) of the cam shaft 24. As such, when the roller 74 is engaged by the cam lobe 84, the brake rocker arm 70 is rotated downward, causing downward movement of the piston assembly 76.
  • the actuator or piston assembly 76 can include a first actuator or piston body 86, a second actuator or piston body 88, a socket 90, a biasing mechanism 92, a stopper 94, and a nut 96.
  • the piston assembly 76 can be received by the first bore 80 of the rocker arm 70.
  • the first piston body 86 can include a first closed end that defines a spigot 98, which is received in socket 90 that acts against the valve bridge assembly 32.
  • the second piston body 88 can be secured to rocker arm 70 by nut 96, and stopper 94 can be secured to the second piston body 88.
  • the second piston body 88 and the nut 96 can act as a fine adjustment screw to set the initial position of piston assembly 76.
  • the biasing mechanism 92 e.g., a spring
  • the stopper 94 can be configured to limit upward movement of the first piston body 86.
  • Pressurized oil is selectively supplied through a channel 100 (FIG. 4) to a chamber 102 of the first piston body 86 to move the piston body 86 downward and outward from the bore 80 to an extended position. When the oil supply to channel 100 is suspended, the first piston body 86 returns to the retracted position by the biasing mechanism 92.
  • the check valve assembly 78 is at least partially disposed in the second bore 82 and can include a spool or check valve 1 10, a biasing mechanism 1 12, a cover 1 14, and a clip 1 16.
  • the check valve assembly 78 is configured to selectively supply oil from a channel 1 18 (FIG. 4) in the rocker shaft 22 to the channel 100.
  • the check valve 1 10 can be biased into a closed position by the biasing mechanism 1 12 such that oil is not supplied to channel 100.
  • the oil pressure in channel 1 18 is sufficient to open the check valve 1 10
  • the oil is supplied via the channel 100 to actuate the piston assembly 76 into the extended position.
  • Clip 1 16 can nest in a radial groove provided in the second bore 82 to retain the check valve assembly 78 therein.
  • assembly 10 includes valve bridge assembly 32 having a movable lever assembly 130 integrated therein.
  • the lever assembly 130 can pass some of the valve actuation force back to the HLA assembly 36 (via bridge 32), thereby preventing unintended extension of the HLA assembly during the braking event.
  • lever assembly 130 allows the valve 26 to open during the engine braking operation without allowing downward motion of the valve bridge assembly 32.
  • lever assembly 130 significantly reduces the actuation force required for the braking event compared to known systems.
  • the valve bridge assembly 32 comprises the lever assembly 130 disposed within a main bridge main body 132.
  • the bridge main body 132 includes a first end 134 and a second end 136.
  • the first end 134 can be configured to engage valve 28, and the second end 136 can include a first aperture 138, a second aperture 140, and a third aperture 142.
  • the lever assembly 130 can generally include a lever 150, a bridge pin 152, a valve shoe 154, and a valve shoe pin 156.
  • the lever 150 can be disposed within the first aperture 138 and is rotatably coupled to the bridge main body 132 by the bridge pin 152, which extends through the second and third apertures 140, 142 of the bridge main body 132.
  • the lever 150 includes an engagement surface 158, first opposed openings 160, second opposed openings 162, and a stop flange 164.
  • the engagement surface 158 is configured to be selectively engaged by socket 90 of piston assembly 76.
  • First opposed openings 160 can receive the bridge pin 152, and the second opposed openings 162 can receive the valve shoe pin 156.
  • the stop flange 164 can be configured to engage a bar 166 (FIGS. 6 and 7) of the bridge main 132 to limit downward movement of the lever 150 (as shown in FIG. 6).
  • the valve shoe 154 includes a main body portion 168 and a connecting portion 170 having an aperture 172 formed therein.
  • the main body portion 168 is configured to receive a portion of the valve 26, and the connecting portion 170 is at least partially disposed within lever 150 such that the connecting portion aperture 172 receives the valve shoe pin 156 to rotatably couple the valve shoe 154 to the lever 150.
  • lever 150 can be selectively engaged at the engagement surface 158, which can cause rotation about pin 156 and upward movement of an opposed side 174 of the lever that is opposite surface 158 (see FIG. 9). This upward movement of lever end 174 causes upward movement of bridge main body 132 toward FILA assembly 36 to prevent extension thereof.
  • the exhaust rocker arm assembly 16 can selectively engage the valve bridge main body 132 to actuate valves 26, 28 and perform a normal exhaust event (combustion mode); whereas, the engine brake rocker arm assembly 18 can selectively engage the lever assembly 130 to only actuate valve 26 and perform a brake event actuation (engine braking mode).
  • the piston assembly 76 is configured to move the first piston body 86 between the retracted position and the extended position. In the retracted position, the first piston body 86 is withdrawn into the bore 80 such that the socket 90 is spaced apart from and does not contact the lever engagement surface 158 even when the cam lobe 84 of camshaft 24 engages the engine brake rocker arm 70.
  • FIG. 4 shows engine brake rocker arm assembly 18 with piston assembly 76 in the extended position as a result of oil being supplied from rocker shaft 22 through channel 100.
  • engine brake event actuation is active, and piston assembly 76 is configured to engage the lever assembly 130 of the valve bridge assembly 32 (FIG. 9).
  • the engine brake event actuation capability may be deactivated by ceasing the oil supply through channel 100 and/or 1 18, thereby causing the piston assembly 76 to move to the retracted position.
  • FIG. 8 shows portions of assemblies 16, 18 during a normal exhaust event actuation where the exhaust rocker arm 30 is engaged by cam lobe 50 of cam shaft 24.
  • cam lobe 50 engages roller 44, which causes the exhaust rocker arm 30 to rotate about the rocker shaft 22.
  • the exhaust rocker arm 30 pushes through the HLA assembly 36 and moves the valve bridge main body 132 downward to open the first and second exhaust valves 26, 28.
  • FIG. 9 illustrates portions of assemblies 16, 18 during a brake event actuation where the engine brake rocker arm 70 is engaged by the cam lobe 84 of cam shaft 24.
  • cam lobe 84 engages roller 74, which causes the brake rocker arm 70 to rotate about the rocker shaft 22.
  • the brake rocker arm 70 pushes socket 90 downward to engage and cause downward movement of lever engagement surface 158.
  • lever engagement surface 158 This in turn can cause downward movement of the valve shoe 154, which opens valve 26 to brake the engine.
  • lever end 174 moves upward against bridge main body 132, which pushes against the HLA assembly 36 to prevent extension thereof during the brake event.
  • FIGS. 10 and 1 1 illustrate a valve bridge assembly 200 constructed in accordance to one example of the present disclosure.
  • the valve bridge assembly 200 may be utilized with valve train assembly 10 and may be similar to valve bridge assembly 32 except that it can include a hydraulic actuator assembly 202 instead of the lever assembly 130.
  • the valve bridge assembly 200 comprises the hydraulic actuator assembly 202 and a valve bridge main body 204, which includes a first end 206 and a second end 208.
  • the first end 206 can be configured to engage valve 28, and the second end 208 can include an aperture 210.
  • the hydraulic actuator assembly 202 can be at least partially disposed within aperture 210 and can generally include a capsule or outer housing 212, a first actuator or piston body 214, a second actuator or piston body 216, a check ball assembly 218, and a biasing mechanism 220.
  • the outer housing 212 defines an upper aperture 222, a lower aperture 224, and a central chamber 226. At least a portion of the second piston body 216 extends through the upper aperture 222, and the lower aperture 224 is configured to receive at least a portion of the exhaust valve 26.
  • the central chamber 226 defines a space between the first and second piston bodies 214, 216 that is configured to receive oil or other fluid from the brake rocker arm 70.
  • the first piston body 214 can be disposed within the outer housing 212 and can include a valve receiving slot 228 and a seat 230.
  • the valve receiving slot 228 is configured to receive an end of the exhaust valve 26, and seat 230 can be configured for seating at least a portion of the biasing mechanism 220.
  • the second piston body 216 can be disposed at least partially within the outer housing 212 and can include an oil supply channel 232 and a check ball assembly seat 234.
  • the oil supply channel 232 is fluidly connected to a capsule 236, which is coupled to the brake rocker arm 70 and configured to selectively receive a pressurized oil supply form the channel 1 18 of rocker shaft 22.
  • the check ball assembly 218 can be disposed at least partially within the check ball seat 234.
  • the check ball assembly 218 can generally include a retainer 238, a check ball 240, and a biasing mechanism 242.
  • the retainer 238 can be seated within seat 234 and is configured to maintain check ball 240 therein.
  • the biasing mechanism 242 can bias the check ball against seat 234 to seal oil supply channel 232. As such, check ball assembly 218 is in the normally closed position. However, assembly 18 may be configured to have a normally open position.
  • the biasing mechanism 220 can have a first end seated in the seat 230 of the first piston 214, and a second end seated in the seat 234 of the second piston 216.
  • the biasing mechanism 220 can be configured to bias the first and second pistons 214, 216 apart from each other, and can secure check ball assembly retainer 238 within seat 234.
  • the biasing apart of first and second pistons 214, 216 can act to draw oil from channel 232 into central chamber 226 to assure oil is stored therein.
  • FIG. 10 shows portions of assemblies 16, 18 during a normal exhaust event actuation where the exhaust rocker arm 30 is engaged by cam lobe 50 of cam shaft 24 (see FIG. 2).
  • cam lobe 50 engages roller 44, which causes the exhaust rocker arm 30 to rotate about the rocker shaft 22.
  • the exhaust rocker arm 30 pushes through the HLA assembly 36 and moves the bridge main body 204 downward to open the first and second exhaust valves 26, 28.
  • FIG. 1 1 illustrates portions of assemblies 16, 18 during a brake event actuation where the engine brake rocker arm 70 is engaged by the cam lobe 84 of cam shaft 24 (see FIG. 2).
  • cam lobe 84 engages roller 74, which causes the brake rocker arm 70 to rotate about the rocker shaft 22.
  • Pressurized oil is supplied through capsule 236 to oil supply chamber 232.
  • the pressurized fluid and/or biasing mechanism 220 opens check ball assembly 218 such that oil fills the central chamber 226.
  • a partial valve train assembly constructed in accordance to another example of the present disclosure is shown and generally identified at reference 300.
  • the partial valve train assembly 300 can be similar to the structure and function of partial valve train assembly 10 described herein.
  • the partial valve train assembly 300 utilizes engine braking and is shown configured for use in a three-cylinder bank portion of a six-cylinder engine. It will be appreciated however that the present teachings are not so limited. In this regard, the present disclosure may be used in any valve train assembly that utilizes engine braking.
  • the partial valve train assembly 300 is supported in a valve train carrier 312 and can include three rocker arms per cylinder.
  • each cylinder includes an intake valve rocker arm assembly 314, an exhaust valve rocker arm assembly 316, and an engine brake rocker arm assembly 318.
  • the exhaust valve rocker arm assembly 316 and the engine brake rocker arm assembly 318 cooperate to control opening of the exhaust valves and are collectively referred to as a dual rocker arm assembly 320.
  • the intake valve rocker arm assembly 314 is configured to control motion of the intake valves
  • the exhaust valve rocker arm assembly 316 is configured to control exhaust valve motion in a drive mode
  • the engine brake rocker arm assembly 318 is configured to act on one of the two exhaust valves in an engine brake mode, as will be described herein.
  • a rocker shaft 322 is received by the valve train carrier 312 and supports rotation of the exhaust valve rocker arm assembly 316 and the engine brake rocker arm assembly 318. As described herein in more detail, the rocker shaft 322 can communicate oil to the assemblies 316, 318 during operation.
  • a cam shaft 324 includes lift profiles or cam lobes configured to rotate assemblies 316, 318 to activate first and second exhaust valves 326 and 328, as is described herein in more detail.
  • Exhaust valve rocker arm assembly 316 is similar to exhaust valve rocker arm assembly 16 and can generally include an exhaust rocker arm 330, a valve bridge assembly 332, and an HLA assembly 336, which can be similar to HLA assembly 36.
  • Engine brake rocker arm assembly 318 can generally include an engine brake rocker arm 370 and an engine brake capsule 376.
  • the engine brake rocker arm 370 can receive the rocker shaft 322 and can define a bore 380 configured to at least partially receive the engine brake capsule 376.
  • the rocker arm 370 is configured to be engaged by a brake lift profile or cam lobe (e.g., lobe 84) of the cam shaft 324 to rotate the brake rocker arm 370 downward, thereby causing downward movement of the engine brake capsule 376.
  • a brake lift profile or cam lobe e.g., lobe 84
  • the actuator or engine brake capsule 376 can generally include an outer housing 500, a plunger 502, and a cap 504.
  • the outer housing 500 can be received by the bore 380 of the rocker arm 370 and can generally include a lower chamber 506, an intermediate chamber 508, and an upper chamber 510.
  • the plunger 502 is slidably received within lower chamber 506 and is configured to act against the valve bridge assembly 332.
  • a check ball assembly 512 can be disposed in the lower chamber 506.
  • the check ball assembly 512 can be configured to hold oil within a space or area 514 between the plunger 502 and the intermediate chamber 508.
  • a pin assembly 516 is disposed in the upper chamber 510 and includes a main body 518 and a pin arm 520.
  • the main body 518 defines a seat 522 configured to receive a biasing mechanism 524 (e.g., a spring), and pin arm 520 extends downwardly from the main body into the intermediate chamber 508.
  • the biasing mechanism 524 is configured to rest against the cap 504 and bias the pin assembly 516 downward into contact with the check ball assembly 512.
  • Oil can be supplied to the intermediate chamber 508 via, for example, the rocker shaft 322 and through ports 526.
  • the upward pressure of the fluid supply compresses the biasing mechanism 524 such that pin assembly 516 is moved away from the check ball assembly 512.
  • This movement allows the oil in intermediate chamber 508 to fill area 514 and move plunger 502 downward and outward into an extended position to engage the valve bridge assembly 332 (e.g., a brake mode).
  • the oil in intermediate chamber 508 can be at least partially evacuated and plunger 502 is able to slide upward into lower chamber 506 when the plunger 502 comes into contact with the valve bridge assembly 332 (e.g., drive mode).
  • valve train assembly 300 includes valve bridge assembly 332 to overcome the potentially undesirable events described above in relation to conventional valve bridges.
  • valve bridge assembly 332 includes a movable lever assembly 430 integrated therein that can pass some of the valve actuation force back to HLA assembly 336 (via bridge 332), thereby preventing unintended extension of the HLA during the braking event.
  • lever assembly 330 allows the valve 326 to open during the engine braking operation without allowing downward motion of the valve bridge assembly 332.
  • lever assembly 430 significantly reduces the actuation force required for the braking event compared to known systems.
  • the valve bridge assembly 332 comprises the lever assembly 430 disposed within a bridge main body 432.
  • the bridge main body 432 includes a first end 434 and a second end 436.
  • the first end 434 can be configured to engage valve 328, and the second end 436 can include a cutout 438 and opposed apertures 440 and 442.
  • the lever assembly 430 can generally include a lever 450, a bridge pin 452, a valve shoe 454, and a valve shoe pin 456.
  • the lever 450 can be disposed at least partially within the cutout 438 and is rotatably coupled to and within the bridge main body 432 by the bridge pin 452, which extends through the opposed apertures 440, 442 of the bridge main body 432.
  • the lever 450 can be disposed between opposed flanges 444 of the bridge main body 432.
  • the lever 450 includes an engagement surface 458, first opposed openings 460, and second opposed openings 462.
  • the engagement surface 458 is configured to be selectively engaged by plunger 502 of piston assembly 376.
  • First opposed openings 460 can receive the bridge pin 452, and the second opposed openings 462 can receive the valve shoe pin 456.
  • the valve shoe 454 includes a main body portion 468 having an aperture 472 formed therein.
  • the main body portion 468 is configured to receive a portion of the valve 326, and also receive the valve shoe pin 456 to rotatably couple the valve shoe 454 to the lever 450.
  • lever 450 can be selectively engaged at the engagement surface 458, which can cause rotation about pin 456 and upward movement of an opposed side 474 of the lever that is opposite surface 458 (see FIGS. 18 and 19). This upward movement of lever end 474 causes upward movement of bridge main body 432 toward HLA assembly 336 to prevent extension thereof.
  • the exhaust rocker arm assembly 316 can selectively engage the valve bridge main body 432 to actuate valves 326, 328 and perform a normal exhaust event (combustion mode); whereas, the engine brake rocker arm assembly 318 can selectively engage the lever assembly 430 to only actuate valve 326 and perform a brake event actuation (engine braking mode).
  • the engine brake capsule 376 is configured to move the plunger 502 between the retracted position and the extended position. In the retracted position, the plunger 502 is withdrawn into the outer housing lower chamber 504 such that the plunger 502 is spaced apart from and does not contact the lever engagement surface 458 even when the cam lobe (e.g., lobe 84) of camshaft 324 engages the engine brake rocker arm 370.
  • cam lobe e.g., lobe 84
  • FIGS. 14 and 16 show engine brake capsule 376 in the extended position as a result of oil being supplied through ports 526.
  • engine brake event actuation is active, and engine brake capsule 376 is configured to engage the lever assembly 430 of the valve bridge assembly 332.
  • the engine brake event actuation capability may be deactivated by ceasing the oil supply through ports 526, thereby causing the engine brake capsule 376 to move to the retracted position.
  • valve tip motion of valve 326 can be constrained (e.g., tight tolerance or interference fit) within valve shoe 454.
  • the pivot arm will create relative motion between the valve 326 and valve bridge assembly 332.
  • the brake valve 326 is constrained and relative motion is transferred to the HLA 336 and valve 328.
  • valve tip motion of valve 328 can be constrained within the valve bridge main body 432. As such, during braking operation, the brake valve 328 is constrained and relative motion is transferred to the HLA 336 and valve 326.
  • the system includes an exhaust valve rocker arm that engages a valve bridge to actuate two valves to perform an exhaust event.
  • the valve bridge includes a main body and a lever integrated therein, the internal lever being rotatable relative to a valve bridge main body.
  • the rotatable lever can be selectively engaged and rotated by an engine brake rocker arm to actuate one of the two valves to perform an engine brake event.
  • the lever can simultaneously pass some of the valve actuation force back to the HLA assembly, thereby preventing unintended extension of the HLA assembly during the braking event.
  • the internal lever allows the valve to open during the engine braking operation without cocking or rotating the main body, which can cause the unintended extension.
  • lever assembly significantly reduces the actuation force required for the braking event compared to known systems.
  • the valve bridge can include a hydraulic actuator assembly, which utilizes a hydraulic intensifier to multiply load (reduce stroke), while transferring some of the load to the bridge and the HLA.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Valve Device For Special Equipments (AREA)
  • Valve-Gear Or Valve Arrangements (AREA)

Abstract

L'invention concerne un ensemble culbuteur de soupape d'échappement qui ouvre sélectivement des première et seconde soupapes d'échappement. L'ensemble comprend un culbuteur d'échappement et une crosse de soupapes fonctionnellement associée au culbuteur et comprenant un corps principal et un levier couplé de façon rotative au corps principal. Le corps principal est configuré pour venir en prise avec la première soupape d'échappement, et le levier est configuré pour venir en prise avec la seconde soupape d'échappement.
EP19817590.3A 2018-11-19 2019-11-19 Ensemble culbuteur pour freinage de moteur Pending EP3884141A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US16/195,120 US10690024B2 (en) 2015-01-21 2018-11-19 Rocker arm assembly for engine braking
PCT/EP2019/025401 WO2020104057A1 (fr) 2018-11-19 2019-11-19 Ensemble culbuteur pour freinage de moteur

Publications (1)

Publication Number Publication Date
EP3884141A1 true EP3884141A1 (fr) 2021-09-29

Family

ID=68841048

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19817590.3A Pending EP3884141A1 (fr) 2018-11-19 2019-11-19 Ensemble culbuteur pour freinage de moteur

Country Status (3)

Country Link
EP (1) EP3884141A1 (fr)
CN (2) CN117386475A (fr)
WO (1) WO2020104057A1 (fr)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE112022001502T5 (de) * 2021-04-26 2024-05-23 Eaton Intelligent Power Limited Kipphebelbaugruppe
CN118805018A (zh) * 2022-03-15 2024-10-18 伊顿智能动力有限公司 用于可变气门致动的液压胶囊
WO2024153459A1 (fr) * 2023-01-19 2024-07-25 Eaton Intelligent Power Limited Capsule de frein de moteur dotée de patin de piston

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017160379A1 (fr) * 2016-03-16 2017-09-21 Eaton Corporation Ensemble bras basculant
JP2018503025A (ja) * 2015-01-21 2018-02-01 イートン コーポレーションＥａｔｏｎ Ｃｏｒｐｏｒａｔｉｏｎ エンジンブレーキ用ロッカーアームアセンブリ
CN109154216B (zh) * 2016-04-07 2021-08-17 伊顿智能动力有限公司 摇臂组合件

Also Published As

Publication number Publication date
WO2020104057A1 (fr) 2020-05-28
CN113167137A (zh) 2021-07-23
CN113167137B (zh) 2023-11-03
CN117386475A (zh) 2024-01-12

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