CN1444690A - Improvements in cam contacting devices - Google Patents

Improvements in cam contacting devices Download PDF

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Publication number
CN1444690A
CN1444690A CN01813624A CN01813624A CN1444690A CN 1444690 A CN1444690 A CN 1444690A CN 01813624 A CN01813624 A CN 01813624A CN 01813624 A CN01813624 A CN 01813624A CN 1444690 A CN1444690 A CN 1444690A
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CN
China
Prior art keywords
cam
contacting devices
cam contacting
lift valve
devices according
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Pending
Application number
CN01813624A
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Chinese (zh)
Inventor
丹尼尔·G·波默利尤
马克·沃格赫尔
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NZTEC Inc
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NZTEC Inc
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Publication of CN1444690A publication Critical patent/CN1444690A/en
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    • 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
    • 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
    • F01L1/143—Tappets; Push rods for use with overhead camshafts
    • 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
    • F01L1/08—Shape of cams
    • 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
    • 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
    • F01L1/12—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
    • 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
    • F01L3/00—Lift-valve, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces; Parts or accessories thereof
    • F01L3/06—Valve members or valve-seats with means for guiding or deflecting the medium controlled thereby, e.g. producing a rotary motion of the drawn-in cylinder charge
    • 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
    • F01L3/00—Lift-valve, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces; Parts or accessories thereof
    • F01L3/22—Valve-seats not provided for in preceding subgroups of this group; Fixing of valve-seats
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M57/00—Fuel-injectors combined or associated with other devices
    • F02M57/04—Fuel-injectors combined or associated with other devices the devices being combustion-air intake or exhaust valves
    • 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
    • F01L2001/0535—Single overhead camshafts [SOHC]
    • 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
    • F01L2301/00—Using particular materials
    • 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
    • F01L2301/00—Using particular materials
    • F01L2301/02—Using ceramic materials
    • 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
    • F01L2305/00—Valve arrangements comprising rollers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M69/00—Low-pressure fuel-injection apparatus ; Apparatus with both continuous and intermittent injection; Apparatus injecting different types of fuel
    • F02M69/04—Injectors peculiar thereto
    • F02M69/042—Positioning of injectors with respect to engine, e.g. in the air intake conduit
    • F02M69/045—Positioning of injectors with respect to engine, e.g. in the air intake conduit for injecting into the combustion chamber
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Valve-Gear Or Valve Arrangements (AREA)
  • Gears, Cams (AREA)
  • Valve Device For Special Equipments (AREA)

Abstract

The invention relates to improved cam contacting devices for use in internal combustion engines and preferably for use in internal combustion engines having variable valve timing. In particular, the use of ceramics including silicon nitride and silicon carbide have been demonstrated as providing effective cam contacting surfaces allowing an axially displaceable cam shaft having a variable profile cam to be run with resulting improvements in idle speed and volumetric efficiency.

Description

The improvement of cam contacting devices
Related application
This application relates to the Canadian patent application 2257437 that is incorporated herein by reference.
Technical field
The present invention relates to that internal-combustion engine uses, have preferably that the internal-combustion engine of vario valve timing uses, improved cam contacting devices.Particularly, use the pottery that comprises silicon nitride and silicon carbide to be proved to be each effective cam contact surface can be provided, allow to move axially a camshaft, finally improve idling and volumetric efficiency with cam that is rotated of a deformable line.
Background of the present invention
Internal combustion (IC) Engine Design need be carried out a large amount of relatively balances between the particularly relevant design of valve timing between the design with contradiction or each performance parameter.
For example, in an internal combustion (IC) Engine Design, an artificer may wish the Economy that makes minimum emissions and increase fuel, and does not wish satisfied engine performance is made compromise.In the past, the design of this motor has been subjected to the restriction of these contradiction parameters, thereby causes the artificer to compromise in design, to obtain the balance between each parameter.Like this, the frequent emphasis of artificer is a main performance target (for example reducing discharging) of noting the ideal performance (for example moment of torsion or idle stability) of definite motor.But this compromise usually be because the artificer with air-breathing property (breathability), promptly the best of fuel and air enter and burn the back waste gas discharge, the shortage that is attached to the ability in this motor produces.
The air-breathing property of one motor mainly is by camshaft, cam, and air valve lift valve spare (with relevant tappet, rocking arm, determine by physical arrangement if you are using).Particularly, the timing that duration and each air valve are closed is opened in the unlatching timing of the relative positioning decision air inlet and exhaust valve between the physical form of each cam or shape line reach relative to each other, they in the axial location of cam, have determined the power diagram of this cylinder according to each air inlet and exhaust valve.
Because the high temperature of working environment, high pressure and machinery quicken, and the complexity of these component, therefore it is difficult regulating air valve at the motor run duration, therefore most motors all use a stationary cam timing system, in this system, the relative timing of air valve opening and closing does not change with engine speed.The result is that this stationary cam timing motor need carry out balance between each engine parameter.
More particularly, the effect of camshaft is exactly in order to open and close each air valve in suitable time, thereby before burning cylinder is full of, and after burning, makes the cylinder emptying.Each cam is installed on this camshaft, and has definite air valve unlatching timing, opens duration and the shape line of closing timing.Each lift valve spare closely contacts with cam face, and strides and lean against on the cam face, so that On/Off power is imposed on each air valve.Therefore, the opening and closing of air valve are by the rotation timing of this camshaft, and this camshaft is by this bent axle control.
Therefore, the physical size of each cam and lift valve spare or shape and each cam location each other all are the parameters that can change, so that obtain the ideal engine performance.
As for the physical size or the design of cam, following term is generally used for describing the shape of a cam and the physical motion of an air valve.For example, the basic circle of this cam limits closing the duration of this air valve, this smooth bevel defines the transient time between closing of air valve and the measurable lift, this side or inclined-plane provide the air valve opening time and open performance, this protruding top limits the time and the maximum unlatching displacement of air valve standard-sized sheet, and this duration defines the time that this air valve leaves its valve seat.
Therefore at the motor run duration, each in these parameters of a cam all can not be controlled separately, need compromise between each situation that the physical size of a cam and the relation of other parameters are permitted.For example, thereby the duration is an air valve opens the sufficiently long time and cylinder is full of and/or emptying, thereby and because of the compromise between the loss of the oversize generation of this opening of valves powered compressor, and the lift that increases increases power, but be subjected to the restriction of the diameter of lift valve spare.
As for the design of lift valve spare (or tappet), the technology of lift valve spare is variable between each motor.Usually, the main purpose that designs a lift valve spare is to keep in touch in order to make between this lift valve spare surface and the cam face, makes the noise minimum of run duration simultaneously.Lift valve spare with two kinds of main types, solid and lift valve spare hydraulic pressure, every kind of lift valve spare has each variable contact jaw, this end comprises flat, mushroom-like with roller shape.Use hydraulic pressure lift valve spare can reduce the impact and the noise of air valve usually.In order to compensate the lift valve spare hole that does not have alignment, because corresponding tappet end face more or less projection normally, therefore flat tappet-cam has slightly a taper usually in its surface.
The lift valve spare of another kind of type is a roll-type lift valve spare, and this lift valve spare comprises the running roller or the roller that contact with this cam.This roller lift valve spare allows to be used for high resistive drag force angular surface type line, and the result is to need high spring for valve tension force, so that this roller is contacted with this cam.Each roller lift valve spare also can reduce the frictional loss between this lift valve spare and the cam, therefore will increase the comprehensive power or the efficient of this motor.
The end of mushroom-like lift valve spare has a ridge, and is used for providing in each duration more lift.
Air inlet and exhaust cam relative positioning each other helps forming engine power figure.Particularly, the flange angle of departure or the overlapping time of having determined that air inlet and exhaust valve is opened simultaneously, wherein, the wideer flange angle of departure is improved idling performance usually, idling vacuum and top power, and the narrow flange angle of departure will reduce idling performance, but better intermediate range moment of torsion is provided.
It also is a parameter that is used for influencing engine performance that one cam is carried out calibration, and calibration is also referred to as and changes the position of cam with respect to this each air valve of camshaft actuated.Specifically, camshaft is postponed, that is, this camshaft makes air valve delay unlatching can make this power that the rotating speed band is risen relatively, and can increase power, reduces the low side moment of torsion simultaneously.The ground of comparing, make camshaft in advance (air valve is opened in advance) have reverse effect.
In order to overcome some problems relevant, various variable cam timing systems have been designed with the stationary cam timing.Usually, these systems provide a cam flange with threedimensional cam surface and one lift valve spare that can axial motion on this threedimensional cam surface.Therefore, the axial position of this camshaft will be determined the concrete cam-shaped line of one control air valve timing.So allow its performance change to the run duration that is complementary with its operating mode at motor, variable valve timing allows to change valve timing.Variation in a variable cam system cam relative shape can be to intake cam, exhaust cam, and independently phase adjusted is carried out in air inlet and exhaust respectively, perhaps independently intake and exhaust cam is regulated mutually.
For example, enter characteristic and make air-fuel mixture enleanment in the cylinder, will improve fuel economy and reduce the moment of torsion reaction of motor thereby reduce fuel by means of shorter fuel entry time is provided.The ground of comparing thickens the mixed gas in the cylinder thereby increase the fuel entry time by means of bigger lift and longer duration are provided, and will cause the increase of horsepower.A variable valve timing system can make the purpose of these contradictions obtain being in harmonious proportion by means of the different timing shape lines that provide according to engine speed, thereby improves the air-breathing property of this motor and increase mainfold presure.
In high performance application, current prior art recognizes that with single axial roller or running roller be the optimum performance raising device of the lift valve spare on basis as this valve gear operation usefulness.Yet, along with the hope of engine speed forms gradually, have been found that under the situation of spring of the pretightening force that in higher engine speed use is higher, will lose efficacy based on the lift valve spare of running roller.Typically, losing efficacy occurs in two aspects, and promptly the roller bearing in the running roller itself lost efficacy and/or the catastrophic inefficacy of lift valve spare, and the both is because the result of " sensitive spot (the flat spotting) " of the generation lift valve spare of running roller and valve gear vibration.
In addition, present various lift valve spare designs based on running roller directly are not transported to lubricant oil on the roller bearing, but carry out lubricating indirectly, and this will reduce the heat dissipation potential of each bearing surface.Therefore, when running roller directly contacted with race ring and have minimum oil film between two surfaces, bearing life may reduce.
One based on the system of single axle in order to obtain maximum bearing life, if this running roller diameter reaches maximum in the scope of this lift valve body, necessary three parameters of balance of artificer then.These three parameters are: roller bearing diameter, shaft diameter and running roller thickness.Each parameter all must change, and makes compression and contact stress minimum on each bearing surface, makes the stress minimum in this, and makes direct this distortion minimum that influences contact stress in each roller bearing.
Although the various variable valve timing system in past is for example in U.S. Pat 2969051, German patent DE 19755937, disclose in German patent DE 304494 that Switzerland publishes and the U.S. Pat 2307926, but various lift valve spare/cam contact system or not extensively enforcement or not success.In other words, under the harsh operating mode of internal-combustion engine, the various variable valve timing system before can be alike is unsuccessful in their bearing/race ring.
General introduction of the present invention
According to the present invention, it provides a kind of cam contacting devices, and this device is used in has improved thermal performance in the internal-combustion engine.The cam contact material that can make it the various performances that obtain utilizing has been disclosed.These materials comprise so material or their combination, the performance that is these materials is, density is less than 6g/cc (preferably about 3.1-3.2g/cc), Young's modulus is greater than 310Gpa (preferably 310-450Gpa), Vickers (Vichers) hardness is greater than 1150 (Hv) (preferably 1650-2850Hv), and thermal expansion coefficient is less than 10.5 * 10 -6/ ℃ (preferably about 3.1-5.5 * 10 -6/ ℃), heat conductivity is less than 50W/mK (preferably about 22-26W/mK), and reed matting (Weibull) modulus is greater than 12 (preferably about 12-18), and tear resistance is greater than 900 (preferably about 947-1263).
In embodiment more specifically, this cam contacting devices is a ball bearing in a race ring and supporting member, wherein, the thermal expansion coefficient of this ball bearing is less than the thermal expansion coefficient of this race ring and supporting member, more particularly, this cam contacting devices is a ceramic balls bearing in steel race ring and supporting member.
In one embodiment, this cam contacting devices is a silicon nitride or silicon carbide ball bearing.
Concrete cam contact material can comprise CERALLOY 147-31E, 147-31N, any among 147-1E or the 147-1.
In a further embodiment, this cam contacting devices comprises that one is used for providing lubricated lubrication system to this cam contacting devices/cam interface.
In a further embodiment, the present invention relates to above-mentioned cam contacting devices in Application on Internal Combustion Engine with each deformable line cam.
Further, the invention provides a kind of internal-combustion engine, this internal-combustion engine has each cylinder, one rotating cam axle, each air valve and the lift valve spare that formation work connects between each air valve and rotating cam axle, this internal-combustion engine also comprises a deformable line cam axle and each other can linearly moving each lift valve spare, wherein each lift valve spare comprises that is used for a silicon nitride bearing that contacts with this rotating cam axle formation work, and it can comprise a valve seat with fuel injection orifice, and fuel is spurted in each cylinder in this valve seat.
Brief description of drawings
These or other characteristic of the present invention will become clearer from the explanation of making below with reference to each appended accompanying drawing, wherein:
Figure 1A is the schematic representation of an expression roller lift valve spare of the present invention;
Figure 1B is one and represents that lift valve spare in the present invention is equipped with and does not install the schematic representation of ball bearing;
Fig. 1 C is the schematic representation of a solid lift valve spare of hemisphere of the present invention;
Fig. 1 D represents to have the end view of the variable valve timing camshaft of a fixed center line and a variable center line;
Fig. 2 is a schematic representation that has a combination overhead cam axle system of a ball bearing air valve chamber and valve seat fuel injector;
Fig. 3 is the wearing and tearing form of a steel ball bearing lift valve spare that has moved in a motor of an expression, the photo of comparing with the steel ball bearing lift valve spare that does not move in motor;
Fig. 4 is the photo of the wearing and tearing form of expression one a ceramic bearing lift valve spare and steel bearing lift valve spare.
Fig. 5 is the photo of the wearing and tearing form of an expression rounding running roller lift valve spare of one steel and a ceramic bearing lift valve spare.
The detailed description of the embodiment of the invention
Bright in general
Each accompanying drawing represents to be used for each internal-combustion engine, particularly be applicable to the various different designs of each cam contacting devices in the vario valve timing motor, and use cam contacting devices according to the present invention in a vario valve timing motor, to test the various test result that draw.
Figure 1A, 1B and 1C represent three kinds of designs according to cam contacting devices of the present invention, i.e. rounding running roller lift valve spare, the design of ball bearing lift valve spare and solid hemisphere bearing lift valve spare.Fig. 1 D represents an end elevation that has the vario valve timing camshaft of a fixed center line 1 and a variable center line 2.In this specification, cam contacting devices is meant and contacts with the outer surface of a rotating cam in the internal-combustion engine or move thereupon, thereby directly or indirectly influences any device of the opening and closing of air valve.Therefore, cam contacting devices comprises air valve lift valve spare, rocking arm or the cam follower that directly contacts with a valve rod.
Referring to accompanying drawing 1A, show the side view and the front view of the running roller lift valve spare 3 of a rounding.In this design, a running roller is fixed on the end of this lift valve spare, and each bearing allows the fixed axis rotation of this running roller in this lift valve spare substrate.
Referring to accompanying drawing 1B, a ball bearing lift valve spare 4 is illustrated in the builtup member 10, and each exploded representation one hydraulic damping system 5, bearing holder 6 and ball bearing 7.35 expression grease channels, the interior admittance surface of 36 these lift valve spares of expression.
Referring to Fig. 1 C, the solid hemisphere lift valve spare 8 shown in the figure has a domed ends, and this end has and is used for lubricant oil being carried the grease channel 37 at this cam-contact device/cam interface.
Fig. 2 represents a schematic representation that has a combination overhead cam axle system of a ball bearing air valve damper 16 and valve seat fuel injector 20.This system comprises: the variable cam 15 of shape line in an overhead cam structure has head valve damper 16, one cylinder heads, 17, one air valves 18 and a spring for valve 19 of ball bearing (or running roller or hemisphere of an above-mentioned rounding).This valve seat 20 can comprise the fuel nozzle 21 that has transport pipe 22.Intake duct 23 delivers air in the cylinder by valve 18.Air valve damper 16 can comprise ball bearing circle 24 and the spring for valve holder 26 that is located on the bearing support 25.
The material of cam contacting devices
Have the fixing internal-combustion engine of the camshaft of shape line (ICE) and having in the internal-combustion engine of camshaft of deformable line respectively, the various specific designs of the lift valve spare that comprises the ceramic bearing of choosing from silicon nitride and silicon carbide are being tested.For the ease of comparing, other stupaliths and their performance are illustrated in the table 1.
Table 1---Bearing Steel/ceramic comparison sheet
The product alloy Unit Silicon nitride Si 3N 4CeralloY ?147-31N Silicon carbide SiC Aluminium oxide Al 2O 3 Zirconium oxide ZrO 2Y-PSZ Bearing Steel AISI 52100
Reference (face as follows) ??(1) ???(1)(2) ?????(3) ??(1)(2) ??(3)(6) ??(3)(6) ???(2)(3) ???(4)
Density ???(g/cc) ??3.2 ??3.14- ??3.20 ???3.70- ???3.99 ??5.9 ????7.8
Young's modulus ???(Gpa) ??310 ??390-450 ???350-460 ??205-210 ????208-210
Compression strength ???(Mpa) ??2500(6) ???3900 ??3000
Poisson's ratio ??0.27 ??0.14??- ??0.17 ???0.22??- ???0.23 ??0.31 ????0.3
The fracture rigidity ???(Mpa. ??M) 1/2?? ??5.8 ??2.5???- ??6.7 ???3.8-5.2 ??7.5-12 ????18
Vickers hardness ????(Hv) ??1800 ??1650??- ??2850 ???2000 ??1150- ??1400 ????700
Thermal expansion coefficient ??(10 -6/ ????℃) ??3.1 ??3.3-5.5 ???5.5- ???10.2 ??10-10.5 ????12.5
Heat conductivity ??(W/m.K) ??26 ??22-200 ???28-35 ??＞2.0- ??3.1 ????50
Flexible intensity ???(Mpa) ??800 ??375-634 ???350-460 ??1100- ??1300 ????2500
Thermal shock resistance ????(℃) ??610 ??157-500 ???200-280 ??280-300
The reed matting modulus ??＞15 ??12-18 ???12-13 ??25 ????0.24- ????7.87
Tear resistance ????(7) ??1110 ??947- ??1263 ???610 ????689
Reference
(1) the silicon nitride performance of Ceradyne company
(2) be used for the Hiroyuki Ito and the shigeki Matsunaga of precision bearing portion of the research and development of the bearing of particular surroundings-basis research and development centre of NSK Website association
(3) be used for stupalith--the ShinNiizeki at NSK Website association bearing technology center of particular surroundings
(4) in the oiling agent extreme pressure agent to the H.P.Nixon of the influence-Timken company of Ohio website association of bearing fatigue life
(5) heat conductivity-author Andrew Slifka of pottery and ceramic coating, website: http://www.boulder.nist.gov/div853/Annual%20Report%202000%HTML/ P23.html
(6) website: http://www.doceram.com/e_mat3.htm
(7)Awr＝FT 1/2×H 1.43×Em -0.8
The initial assessment of this ceramic balls lift valve spare design is that the Isky cam company in Los Angeles county carries out.The lift valve spare of the ceramic bearing that use obtains from Ceradyne company (below be referred to as lift valve spare 1) is made by material C eralloy 147-31N.
When this machine provides best assessment chance not have motor damage dangerous when lift valve spare lost efficacy for lift valve spare, utilize the SPINTRON control system, when motor does not burn, in this motor, lift valve spare 1 is carried out initial assessment.Assessment for the first time is when spring for valve pressure is low, and promptly 200 pounds/inch are carried out, thereby whether the high contact load of surface of contact of initially determining the surface of lift valve spare/cam can cause camshaft to produce cut.Test cycle was finished in 8 hours, and lift valve spare or this camshaft significantly do not damage.Then, assessment for the second time is the spring for valve that utilizes a NASCAR (the common dolly in North America) to use, and carries out under up to 800 pounds/inch pressure.This test was also carried out 8 hours, did not all find to damage in this lift valve spare or cam flange.
The assessment of second stage is carried out under practical operation situation on a ZZ4P/N24502609 Chevrolet V8 motor.Two different lift valve spares designs are used in this test, i.e. the running roller of ball bearing and rounding, thus the variation of material in this ball bearing design is assessed.Fig. 3, the result of 4 and 5 these tests of expression, and table 2 has been summarized this lift valve spare/experimental design.
Table 2
Lift valve spare Design Material Supplier
???1 The ball bearing lift valve spare that race ring is lubricated The Ceralloyl47-31N silicon nitride Lift valve body-Shaver motor ball bearing-Ceradyne
???2 The ball that race ring is lubricated The 52-100 alloyed steel Lift valve body-Shaver motor
Bearing lift valve spare Ball bearing-Timken
???3 The lift valve spare of rounding The 52-100 alloyed steel Lift valve body and running roller-Shaver motor
Test is to carry out on the Shever of California Torrance motor equipment.Three kinds of different designs are arranged on this use high-performance spring (with 3561 pounds/inch, in test engine p/n10134358).Start this motor, and under part throttle characteristics, the control rotating speed, and be set in 2000rpm.After 2 minutes, detect a mistake that perceives, and motor is stopped.Take this motor immediately apart, detect each component.
The wearing and tearing that Fig. 3 represents steel ball bearing lift valve spare (2) and original steel ball bearing relatively.Fig. 4 represents lift valve spare 1 (left side) and lift valve spare 2 (right side).As shown in the figure, lift valve spare 1 does not have material unaccounted-for (MUF), and the flange of camshaft does not all have to degenerate in any case.Lift valve spare 2 has excessive fret wear, and the flange of camshaft has suitably been degenerated.
Fig. 5 represents lift valve spare 3 (left side and centre) and lift valve spare 1 (the right).In this case, we notice: lift valve spare in the test or camshaft flange all do not have to damage.
Then, this motor assembles with lift valve spare 1 and 3 again, and the new cam axle of same size is installed, and continues test 6 hours under different rotating speeds (idling to 6000) and load.This test engine produces the identical horsepower and the moment of torsion of prescribed level, does not detect what problem in engine operation.After test is finished, this motor is taken apart, and measured the wearing and tearing of each lift valve spare and camshaft.On this lift valve spare and camshaft flange, all there are not significantly wearing and tearing.
Variable cam flange-shape thread test
Carry out following Total Test with a motor that has deformable line cam axle:
Test engine: Chevrolet (Xue Folai) LS-15.7L head valve pushrod engine
Compression ratio: 10: 1
Cylinder aperture * stroke: 99.00 * 92.00mm
Spray in order
Before improving, motor has the horsepower rate of 345@5400rpm, and idling speed is 700rpm.
Revising this motor makes it to comprise a deformable line cam axle and is used to make the linear hydraulic driving system that moves of this camshaft.The deformable line flange of this camshaft can make this lift, and duration and angle (7 degree) change.Modification is used for the cam contacting devices of all 16 valves of this motor, makes it to comprise silicon nitride ball bearing (Ceralloyl47-31N).Use 350 pounds spring pressure.
This motor initial launch 5 minutes is shut down, and then is moved 45 minutes, and during this period, when motor moved from low speed to high speed, this camshaft moved axially between the two ends of this flange.
Utilize this improved camshaft, the horsepower rate of this motor is measured to be 420hp@5400rpm, and obtainable minimum idling is 400rpm.What calculate volumetric efficiency (VE) increases to 25% altogether.
When the adjusting that applies was offset on electronic control module (ECM) the harmony ground that this motor is used, it was unsuccessful attempting idling speed is reduced under the 400rpm.In other words, when attempting to be reduced to idling speed under the 400rpm, the idle air control module (ICM) of this controller will increase idling speed with fuel.According to the cam-shaped line that idling is used, it is contemplated that idling speed can be reduced under the 200rpm.
Then, the motor operation is opened afterwards and detects.This camshaft and cam contacting devices do not demonstrate tangible wearing and tearing.
Discuss:
Original lift valve spare test explanation: have the cam contacting devices of a minutia that contacts with a camshaft, when in an internal-combustion engine, moving, can bear very high point pressure.Particularly, use silicon nitride bearing to provide and have fixedly effective cam contacting devices of the camshaft of shape line.Each original lift valve spare test further specifies: using a lubricated steel bearing is invalid as a cam contacting devices, and causes this cam contacting devices to lose efficacy rapidly.
Each deformable line cam shaft experiment shows: the cam contacting devices with trickle point of contact can make the variable valve timing system with a continuous variable cam shape line carry out work effectively.The result of these tests shows: compare with a stationary cam shape line motor, idling can be considerably reduced, and the comprehensive volumetric efficiency of motor can significantly rise.
The discussion of steel and ceramic bearing
The inefficacy of steel ball is that the welding partly of killing promptly by this steel ball and steel valve body forms.Once you begin kill, ball will slide immediately, and roll on cavity and camshaft.This ball this killed and the slip effect can be explained wearing and tearing (.042 ") reason uniformly.This do not wish the ball that exists relatively the slip effect of this camshaft cause this camshaft to produce as can be seen badly damaged (being groove).
The success of pottery (silicon nitride) ball should be given the credit to the low coefficient of friction of pottery and superior thermal diffusivity.Because ceramic balls can not kill, thus it will be in its cavity continuous rolling, and can keep contacting with the rolling of camshaft.This can explain the minimum reason of damage/wearing and tearing on the camshaft.When ball rolled on this camshaft, it must slide in the cavity of this lift valve body.Therefore in this design, can there be certain friction inherently, and produces heat.Yet because the friction factor of pottery is low, the heat of therefore comparing generation with steel still less.In addition, the lubricant oil that offers the slidingsurface between this ball and the lift valve body by lift valve spare will further reduce this friction, and cool off this ball.
Further, because ceramic balls is better than the rigidity of metal balls, therefore it is not easy distortion under the load effect.Therefore, the inner heat aspect that produces of this ball also can be still less in this ceramic balls.
The steel roll assembly wherein has roller.Therefore, there is the roller rolling action of this camshaft relatively.As the ceramic balls situation, so the wearing and tearing on the camshaft drop to minimum.Because the effect of contact stress, camshaft is hardened.This is exactly to form on the camshaft and the reason of the arrowband that is used for roller and ceramic balls as can be seen probably.Because this steel ball assembly mainly is to roll, do not slide, therefore, friction and reach minimum because of fricative heat.
Concerning the silicon nitride ball:
A) the total friction on the ball is less than the friction of a steel ball.
B) friction of reduced levels will produce than the littler heat of a steel ball at this ball contact surface place.
C) be starkly lower than the heat conductivity of this cup shell when the heat conductivity of this ball, when utilizing the lubricant oil of supplying with this ball/lift valve spare further to cool off simultaneously, the main heat dissipation path of the heat that produces at the interface surface place of ball-cam and ball-cup shell (36) is by this steel interface, rather than by this ball.
D) thus each steel contact surface than this ball hot faster.
E) because heat increases and expansion coefficient is higher, so each steel contact surface expands more than this ball.
F) if the expansion coefficient difference, then this ball always less than around cup shell.Therefore, this ball can not block because of heating.
G) mark on the cam may be because the heat of contact interface effectively heats the result who makes this cam sclerosis.
Concerning the steel ball:
A) the total friction on the ball is greater than the friction of a silicon nitride ball.
B) high-caliber friction will produce than a silicon nitride ball more heat at this ball contact surface place.
C) lubricant oil that utilize to supply with the interface of this ball/lift valve spare further cools off, will the dispelling the heat by this ball and each surface of contact of the heat that produces at the interface surface place of ball-cam and ball-cup shell (36).
D) so each steel contact surface is the same with this ball heats.
E) the steel ball that contacts with cup shell with this cam is because of warm sooner with this cup shell of contact gear ratio of this cam.Must be faster if hot than cup shell, then this ball expands sooner than this cup shell, thus increase rubs and may begin to be stuck in this cup shell.
F) if expansion coefficient is identical, if then ball is warmmer sooner than cup shell, then ball can be stuck in this cup shell.
G) cam, the wearing and tearing on ball and the cup shell may be because ball begins to block (killing) in this cup shell, thereby increase the result of whole three lip-deep friction and wears greatly.
Concerning steel (rounding) running roller:
A) the total friction on the steel running roller is greater than the friction of a silicon nitride ball.
B) high-caliber friction will produce than a silicon nitride ball more heat at this running roller contact surface place.
C) any heat that produces at each interface surface place of running roller-cam and running roller-roller (4) all passes through this running roller wheel rim and the heat radiation of each surface of contact.
D) so each steel contact surface is the same with this ball heats.
Therefore e) this steel running roller has littler point of contact than this silicon nitride ball, will produce than this ball more heat concerning a given spring-load.
F) this steel running roller has a large amount of gaps in this supporting lift valve spare surface relatively.
G) running roller under thermal expansion will can not contact any lift valve spare surface on every side, so this steel running roller will can not block (killing) as the steel ball.
H) heat that produces in the running roller wheel rim can only not have the forced-oil-cooling passage by cam and the heat radiation of each roller bearing.
I) because higher levels of friction and still less lubricated, so the steel running roller is warmmer than silicon nitride ball.
J) mark on the cam may be to produce because the high level at running roller-cam interface place conducts heat.This cam can effectively be hardened by the heat that friction and contact pressure produce.Because at the high temperature and high pressure at cam point of contact place, so this mark wider than silicon nitride ball.
Conclusion, when shown in other properties of materials and the table 1 not simultaneously because heat and heat conductivity that pottery and Metal Contact produce, the thermal expansion coefficient reason, the success of silicon nitride may be the result that cam flange metal hardens.

Claims (26)

1. one kind has improved thermal performance and is used in cam contacting devices in the internal-combustion engine.
2. cam contacting devices according to claim 1, its density is less than 6g/cc.
3. as cam contacting devices as described in the claim 2, its density is about 3.1-3.2g/cc.
4. cam contacting devices according to claim 1, its Young's modulus is greater than 310Gpa.
5. as cam contacting devices as described in the claim 4, its Young's modulus is approximately 310-450Gpa.
6. cam contacting devices according to claim 1, its Vickers hardness is greater than 1150 (Hv).
7. as cam contacting devices as described in the claim 6, its Vickers hardness is approximately 1650-2850 (Hv).
8. cam contacting devices according to claim 1, its thermal expansion coefficient is less than 10.5 * 10 -6/ ℃.
9. as cam contacting devices as described in the claim 8, its thermal expansion coefficient is approximately 3.1-5.5 * 10 -6/ ℃.
10. cam contacting devices according to claim 1, its heat conductivity is less than 50W/mK.
11. as cam contacting devices as described in the claim 10, its heat conductivity is approximately 22-26W/mK.
12. cam contacting devices according to claim 1, its reed matting modulus is greater than 12.
13. as cam contacting devices as described in the claim 12, its reed matting modulus is approximately 12-18.
14. cam contacting devices according to claim 1, its tear resistance is greater than 900.
15. as cam contacting devices as described in the claim 14, its tear resistance is approximately 947-1263.
16. cam contacting devices according to claim 1, wherein this cam contacting devices is a ball bearing with arbitrary performance among the claim 1-15 or each performance combination.
17. cam contacting devices according to claim 1, wherein this cam contacting devices is a ball bearing in a race ring and supporting member, and the thermal expansion coefficient of this ball bearing is less than the thermal expansion coefficient of this race ring and supporting member.
18. cam contacting devices according to claim 1, wherein this cam contacting devices is a ceramic balls bearing in a steel race ring and supporting member.
19. as cam contacting devices as described in the claim 18, wherein this ball bearing is one of silicon nitride or silicon carbide.
20. cam contacting devices according to claim 1, wherein this cam contact material is from CERALLOY 147-31E, 147-31N, any that choose among 147-1E or the 147-1.
21. cam contacting devices according to claim 1, wherein this cam contacting devices is the running roller of a rounding, any one in a ball bearing or the hemisphere surface.
22. as cam contacting devices as described in the claim 21, wherein this cam contact material is from CERALLOY 147-31E, 147-31N, any that choose among 147-1E or the 147-1.
23. as cam contacting devices as described in arbitrary among the claim 1-22, wherein this cam contacting devices comprises that one is used for providing lubricated lubrication system to this cam contacting devices/cam interface.
24. aforesaid right required arbitrary described cam contacting devices is used in the internal-combustion engine with each deformable line cam among the 1-23.
25. have each cylinder a kind of, one rotating cam axle, in the internal-combustion engine of each air valve and the lift valve spare that formation work connects between each air valve and rotating cam axle, its improvement comprises a deformable line cam axle and each other can linearly moving each lift valve spare, and wherein each lift valve spare comprises that is used for a silicon nitride bearing that contacts with this rotating cam axle formation work.
26. as internal-combustion engine as described in the claim 25, it also comprises a valve seat with fuel injection orifice, fuel is spurted in each cylinder in this valve seat.
CN01813624A 2000-08-08 2001-08-07 Improvements in cam contacting devices Pending CN1444690A (en)

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CA002315595A CA2315595A1 (en) 2000-08-08 2000-08-08 Improvements in variable valve timing systems
CA2,315,595 2000-08-08

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CN108180047A (en) * 2017-12-05 2018-06-19 力帆实业(集团)股份有限公司 The admission cam of supercharged direct-injection engine

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CN108180047B (en) * 2017-12-05 2023-11-07 力帆实业(集团)股份有限公司 Cam group of supercharged direct injection engine

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