CN108397251B - Intake cam and molded line design method thereof - Google Patents

Intake cam and molded line design method thereof Download PDF

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CN108397251B
CN108397251B CN201810146913.2A CN201810146913A CN108397251B CN 108397251 B CN108397251 B CN 108397251B CN 201810146913 A CN201810146913 A CN 201810146913A CN 108397251 B CN108397251 B CN 108397251B
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cam
engine
profile
closing angle
thermodynamic
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CN108397251A (en
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欧阳宪林
黄贤龙
曾小春
段翔
陈劼
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Jiangling Motors Corp Ltd
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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
    • F01L1/02—Valve drive
    • F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
    • F01L1/08—Shape of cams
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00—Computer-aided design [CAD]
    • G06F30/10—Geometric CAD
    • G06F30/17—Mechanical parametric or variational design
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
    • G06F2119/06—Power analysis or power optimisation
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
    • G06F2119/08—Thermal analysis or thermal optimisation
    • 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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Abstract

An intake cam and a method of designing a profile thereof, the method comprising: determining a delay closing angle of an air inlet valve of the engine by adopting a thermodynamic calculation method and through engine performance simulation calculation; calculating an acceleration curve of the air inlet cam by adopting a kinematics calculation method according to the delay closing angle, and performing secondary integration on the acceleration curve to obtain a cam profile of the air inlet cam; and checking the cam profile, and adjusting the cam profile by adjusting the delayed closing angle so as to enable the cam profile to meet the dynamic performance requirement and the thermodynamic performance requirement of the engine. The invention designs the air inlet cam of the engine suitable for the Atkinson cycle by simulating and calculating the performance of the engine and adopting a kinetic and thermodynamic analysis method.

Description

Intake cam and molded line design method thereof
Technical Field
The invention relates to the technical field of engines, in particular to an air inlet cam of an engine and a molded line design method thereof.
Background
With the gradual deterioration of energy forms and increasingly strict fuel consumption regulations, domestic passenger car market users pay more attention to the fuel consumption of vehicles, and the improvement of the efficiency of gasoline engines becomes an urgent problem for the development of gasoline engines. With the increase of market demand, engines are continuously developed, and on the basis of the traditional Otto cycle engine, an Atkinson cycle engine is developed.
Otto-cycle engines are characterized by a compression ratio that is consistent with the expansion ratio. The Atkinson cycle engine reduces the displacement of the gasoline engine by delaying the closing of the inlet valve, so that the expansion ratio is larger than the compression ratio, the pumping loss is reduced, and the heat efficiency can be effectively improved. However, moving from a conventional otto-cycle engine to an atkinson-cycle engine, late intake valve closing techniques may be employed. In order to achieve ideal thermal efficiency of the atkinson cycle engine, the intake cam needs to be redesigned to achieve an ideal valve closing delay angle.
Disclosure of Invention
In view of the above situation, an intake cam and a profile design method thereof are provided to solve the problem of achieving the atkinson cycle through intake cam control in the prior art.
A method of designing a profile of an intake cam that is applied to an atkinson cycle engine, the method comprising:
determining a delay closing angle of an air inlet valve of the engine by adopting a thermodynamic calculation method and through engine performance simulation calculation;
calculating an acceleration curve of the air inlet cam by adopting a kinematics calculation method according to the delay closing angle, and performing secondary integration on the acceleration curve to obtain a cam profile of the air inlet cam;
and checking the cam profile, and adjusting the cam profile by adjusting the delayed closing angle so as to enable the cam profile to meet the dynamic performance requirement and the thermodynamic performance requirement of the engine.
Further, in the above-described profile designing method, the step of calculating an acceleration curve of the intake cam according to the retarded closing angle by using a kinematic calculation method includes:
simplifying the valve actuating mechanism of the engine into a single mass vibration model, and carrying out dynamic calculation according to the delayed closing angle to obtain an acceleration curve of the cam.
Further, in the above-mentioned profile design method, the step of checking the cam profile and adjusting the cam profile by adjusting the retarded closing angle so that the cam profile meets the dynamic performance requirement and the thermodynamic performance requirement of the engine includes:
establishing a multi-mass vibration model of the valve train according to the mass, rigidity and damping characteristics of each part of the valve train;
determining whether the cam profile meets the dynamic performance requirements of the engine according to the multi-mass vibration model;
when the cam profile meets the dynamic performance requirement, calculating by using a valve actuating mechanism to obtain an actual delay angle;
performing thermodynamic calculation according to the actual delay angle, and judging whether a thermodynamic calculation result meets the thermodynamic performance requirement of the engine;
if not, adjusting the delayed closing angle within a preset amplitude range, and returning to the step of calculating the acceleration curve until the thermodynamic calculation result meets the thermodynamic performance requirement.
Further, the above profile designing method, wherein the step of determining whether the cam profile meets the dynamic performance requirement of the engine according to the multi-mass vibration model further includes:
and when the cam profile does not meet the dynamic performance requirement, adjusting the delayed closing angle within the preset amplitude range, and returning to the step of calculating the acceleration curve until the cam profile meets the dynamic performance requirement of the engine.
Further, in the above-described profile designing method, the step of calculating an acceleration curve of the intake cam according to the retarded closing angle by using a kinematic calculation method includes:
calculating a wrap angle of the cam based on the retarded closing angle and a rocker arm ratio of a rocker arm connecting between the intake valve and the cam;
and performing dynamic calculation according to the wrap angle to obtain an acceleration curve of the air inlet cam.
Further, in the above molded line design method, the kinetic calculation formula is:
Figure GDA0002459217570000031
in the formula: m mass parameters of a valve train of the engine; c is a mass damping parameter of the valve train; k is a mass stiffness parameter of the valve train; x is displacement;
Figure GDA0002459217570000032
is the speed;
Figure GDA0002459217570000033
is the acceleration; f is the stress.
Further, in the above molded line design method, the thermodynamic calculation formula is:
Figure GDA0002459217570000034
wherein m iscMass of the working medium in the cylinder; u is the specific internal energy; pcIs the in-cylinder pressure; v is the cylinder volume; qFHeat released for fuel combustion is injected; qWFor cylinder wall heat loss, α for retarded closing angle of inlet valve, hBBIs the leakage enthalpy;
Figure GDA0002459217570000035
is a mass flow of gas.
Further, in the above molded line design method, the dynamic performance requirement is as follows: and the speed, the acceleration and the stress of the air inlet cam meet preset conditions.
The embodiment of the invention also provides an intake cam, and the intake cam adopts the molded line designed by any one of the methods.
Further, in the intake cam, a wrap angle of the cam profile is 130 ° to 150 ° of a cam angle.
In the embodiment of the invention, the engine performance is simulated and calculated, and a dynamic and thermodynamic analysis method is adopted to design the air inlet cam suitable for the engine with the Atkinson cycle. The cam profile is adjusted by adjusting the delay angle of the inlet valve, so that the cam profile meets the thermodynamic and dynamic performance requirements of the engine, and therefore when the designed inlet cam is applied to the Atkinson cycle engine, the opening time and the closing time of the inlet valve are reasonably controlled, and the heat efficiency of the engine is effectively improved.
Drawings
Fig. 1 is a block diagram illustrating a method for designing a cam profile according to a first embodiment of the present invention;
FIG. 2 is a block diagram illustrating a method of designing a cam profile according to a second embodiment of the present invention;
fig. 3 is a partial structural schematic diagram of an engine in an embodiment of the invention, and shows the working principle of an intake cam.
Description of the main elements
Air inlet cam 10
Transmission assembly 20
Rocker arm 21
Tappet column 22
Air inlet valve 23
Detailed Description
To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Embodiments of the invention are presented in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, this embodiment is provided so that this disclosure will be thorough and complete.
It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
Referring to fig. 1, a method for designing a profile of an intake cam applied to an atkinson cycle engine according to a first embodiment of the present invention is shown. The method includes steps S11-S14.
And step S11, determining the delayed closing angle of the engine intake valve by adopting a thermodynamic calculation method and through engine performance simulation calculation.
The molded line design method in the embodiment may be performed by using engine simulation analysis software, for example, may be performed by using a Boost simulation program, which may not only predict the steady-state performance of the engine at the design stage, but also analyze the thermodynamic process of the molded engine. Firstly, a preliminary delayed closing angle of an intake valve and a lift of the intake valve are determined according to a thermodynamic calculation method so as to achieve the aim of realizing an Atkinson cycle.
The thermodynamic calculation method generally adopts the following thermodynamic formula:
Figure GDA0002459217570000051
wherein m iscMass of the working medium in the cylinder; u is the specific internal energy; pcIs in the cylinderPressure; v is the cylinder volume; qFHeat released for fuel combustion is injected; qWFor cylinder wall heat loss, α for retarded closing angle of inlet valve, hBBIs the leakage enthalpy;
Figure GDA0002459217570000052
is a mass flow of gas.
In the above-mentioned formula,
Figure GDA0002459217570000053
the internal energy of the working medium of the cylinder is changed;
Figure GDA0002459217570000054
the work done by the working medium to the piston;
Figure GDA0002459217570000055
heat released for fuel combustion is injected;
Figure GDA0002459217570000056
the heat of the working medium exchanging heat with the cylinder cover, the cylinder sleeve and the piston;
Figure GDA0002459217570000057
enthalpy flow due to air leakage. M is directly influenced by delayed closing angle of an inlet valve and inlet valve processcAnd u, when
Figure GDA0002459217570000058
The retarded closing angle of the intake valve can be preliminarily determined when the requirements are all satisfied.
And step S12, calculating an acceleration curve of the intake cam according to the delayed closing angle by adopting a kinematics calculation method, and performing secondary integration on the acceleration curve to obtain the cam profile of the intake cam.
Specifically, the lift and wrap angle of the cam are first calculated from the retarded closing angle of the intake valve. An air inlet valve of the engine is connected with an air inlet cam through a rocker arm, and the delay closing angle and the lift of the air inlet valve and the lift and wrap angle of the cam can be converted through a lever principle. And calculating an acceleration curve of the intake cam by using the lift and wrap angle of the intake cam and a kinematic calculation method. And performing secondary integration on the acceleration curve to obtain the cam profile of the air inlet cam.
And step S13, checking the cam profile, and adjusting the cam profile by adjusting the delay closing angle so that the cam profile meets the requirements of the engine on the dynamic performance and the thermodynamic performance.
The cam profile obtained in step S12 is a preliminary cam profile, and a check is performed to determine whether the cam profile meets thermodynamic and dynamic requirements of the engine. The retarded closing angle of the intake valve can be finely adjusted during cam profile verification. A preliminary retarded closing angle of the intake valve is obtained in step S11, which is calculated to be 30 cam angle in the present embodiment, and the adjustment is made on the basis of this angle value. The adjustment of the delayed closing angle of the inlet valve is controlled within a preset adjustment range. The preset adjustment range may be set in advance, for example, within a cam angle of plus or minus 10 °, that is, within a range of 20 ° to 40 ° of cam angle, to adjust the retarded closing angle of the intake valve.
The lift of the intake valve and the lift of the cam are fixed, and the delayed closing angle of the intake valve only needs to be adjusted within a certain range. And recalculating the cam profile once every time the delayed closing angle is adjusted until the cam profile meets the dynamic requirement and the thermodynamic requirement of the engine, and determining the profile of the intake cam.
In the embodiment, an intake cam suitable for an engine of an Atkinson cycle is designed by performing simulation calculation on the performance of the engine and adopting a dynamic and thermodynamic analysis method. The cam profile is adjusted by adjusting the delay angle of the inlet valve, so that the cam profile meets the thermodynamic and dynamic performance requirements of the engine, and therefore when the designed inlet cam is applied to the Atkinson cycle engine, the opening time and the closing time of the inlet valve are reasonably controlled, and the heat efficiency of the engine is effectively improved.
Referring to fig. 2, the method for designing the profile according to the second embodiment of the present invention is applied to an engine with an atkinson cycle. The method includes steps S21-S29.
And step S21, determining the delayed closing angle of the engine intake valve by adopting a thermodynamic calculation method and through engine performance simulation calculation.
Step S22, calculating a wrap angle of the cam based on the delayed closing angle.
In particular implementations, the wrap angle of the cam may be calculated based on a rocker ratio of a rocker arm connecting between the intake valve and the cam.
And step S23, simplifying a valve actuating mechanism of the engine into a single mass vibration model, performing dynamic calculation according to the wrap angle to obtain an acceleration curve of the intake cam, and performing secondary integration on the acceleration curve to obtain a cam profile of the intake cam.
When the cam profile is calculated by adopting kinematics, the valve actuating mechanism of the engine is simplified into a single mass vibration model, and the single mass model is to design the mass, the damping and the rigidity of the valve actuating mechanism of the engine into equivalent values. And calculating an acceleration curve of the cam by the wrap angle of the cam, wherein the dynamics calculation formula is as follows:
Figure GDA0002459217570000061
in the formula: m1Is equivalent mass; c1Equivalent damping is adopted; k1Is the equivalent stiffness; x is displacement;
Figure GDA0002459217570000062
is the speed;
Figure GDA0002459217570000071
is the acceleration; f is the stress. The cam acceleration curve can be calculated according to Newton's second law
Figure GDA0002459217570000072
To the cam acceleration curveAnd obtaining the cam profile of the air inlet cam by twice integration.
And step S24, establishing a multi-mass vibration model of the valve train according to the mass, the rigidity characteristic and the damping characteristic of each part of the valve train.
And step S25, determining whether the cam profile meets the dynamic performance requirement of the engine according to the multi-mass vibration model, if so, executing step S26, otherwise, executing step S29.
After the cam profile is obtained according to the single mass vibration model, the cam profile needs to be checked to determine whether the cam profile meets the practical application. When checking is carried out, the mass, rigidity characteristic and damping characteristic of each part of the valve train are considered in detail, the mass, rigidity matrix and damping matrix of the valve train system are obtained, and a multi-mass vibration model of the valve train is established. Wherein, in the multi-mass vibration model, the mass matrix M2Comprises the following steps:
Figure GDA0002459217570000073
wherein m 1-m 5 are the masses of 5 parts in the valve train respectively.
Damping matrix C2Comprises the following steps:
Figure GDA0002459217570000074
wherein, -c1,2，c1,2，……c5,6Damping of individual components in the valve train.
Stiffness matrix K2Comprises the following steps:
Figure GDA0002459217570000075
wherein-k1,2，k1,2，……k5,6Is the stiffness of the individual components in the valve train. It will be appreciated that in practice, the various components of the valve train and their mass and damping may be arranged according to the actual conditions.
In step S25, the dynamics performance of the cam profile can be checked by applying the intake cam lift curve to a dynamics calculation method, and specifically, the dynamics calculation formula is as follows:
Figure GDA0002459217570000081
in the formula: m2Is a quality matrix; c2Is a damping matrix; k2Is a stiffness matrix; x is displacement;
Figure GDA0002459217570000082
is the speed;
Figure GDA0002459217570000083
is the acceleration; f is the stress. Calculating the displacement, stress, speed and acceleration of each part (including a valve, a rocker arm, a valve spring and the like) of the accessory mechanism, and evaluating whether the calculation result meets preset conditions or not, wherein the preset conditions are set according to actual use requirements. Various characteristic indexes of the valve train model are as follows: when the speed, the acceleration and the stress meet the use requirements, the cam profile meets the dynamic performance requirements of the engine.
And step S26, calculating the actual delay angle through the valve train.
And step S27, performing thermodynamic calculation according to the actual delay angle, and judging whether the thermodynamic calculation result meets the thermodynamic performance requirement of the engine.
And step S28, when the thermodynamic calculation result does not meet the thermodynamic performance requirement of the engine, adjusting the delayed closing angle within a preset amplitude range, and returning to execute the step S22 until the cam profile meets the thermodynamic performance requirement of the engine.
And step S29, adjusting the delayed closing angle within a preset amplitude range, and returning to execute the step S22 until the cam profile meets the dynamic performance requirement of the engine.
Compared with the first embodiment, the method has the advantages that the multi-mass vibration model of the valve train is established according to the mass, the rigidity characteristic and the damping characteristic of each part of the valve train, the preliminarily established cam profile is checked according to the multi-mass vibration model, and the cam profile meets the checking requirement by adjusting the delayed closing angle of the inlet valve, so that the inlet cam suitable for the Atkinson cycle engine is obtained. The molded line of the obtained air inlet cam accurately meets the actual requirement and can achieve ideal thermal efficiency.
Referring to fig. 3, a schematic diagram of a portion of an engine according to an embodiment of the present invention is shown, in which the operation principle of an intake cam is shown. As shown in fig. 3, the engine includes a cam 10 and a transmission assembly 20, and the transmission assembly 20 is connected to a cylinder (not shown) of the engine and can transmit the force of the intake cam 10 to a piston of the cylinder. The transmission assembly 20 includes a rocker arm 21, a lifter 22 connected to the rocker arm 21, and an intake valve 23. The cam profile of the intake cam 10 is obtained according to the profile designing method in the above embodiment, and the wrap angle thereof is 145 ° cam angle. Specifically, the cam profiles obtained in the present invention are shown in table 1.
TABLE 1 intake cam profile line table
Figure GDA0002459217570000091
Wherein the intake cam rotation angle is 0 °, indicating the starting point of the intake cam lift. Table 1 shows: the air inlet cam is gradually increased from a starting point of 0 degrees to a maximum lift point and then gradually decreased to an air inlet cam lift end point, and the rotation angle of the air inlet cam and the corresponding lift of the air inlet cam are recorded.
It can be understood that the wrap angle of the cam obtained by the method in the above embodiment can realize the atkinson cycle at the cam rotation angle of 130 ° to 150 ° to improve the heat use efficiency, so that the wrap angle of the intake cam in the embodiment of the present invention can also be 130 ° or 150 ° cam rotation angle, which is not limited herein.
When the intake cam 10 operates, the intake cam 10 rotates around the wheel center, the rocker arm 21 rotates around the contact point of the rocker arm and the lifter 22, the intake valve 23 moves along the valve center line direction, and the lifter 22 is fixed. When the intake cam 10 rotates, the pressure rocker arm 21 rotates around the contact point of the rocker arm 21 and the tappet 22, the intake valve 23 is pressed to move downwards due to the fixed tappet 22, the intake valve 23 is separated from the contact with the cylinder head, and the valve is opened. The piston also moves up and down in cooperation with the rotation of the intake cam.
In the embodiment, the Atkinson cycle cam can enable the intake valve to be closed in a delayed mode, the intake valve is closed after the piston is at the bottom dead center, and the compression stroke of the piston is after the bottom dead center. And the expansion stroke of the piston starts from top dead center, so the engine compression stroke is smaller than the otto-cycle cam. Therefore, the effective compression ratio of the engine is smaller than the expansion ratio, and the aim of realizing the Atkinson cycle is fulfilled.
The above-mentioned embodiments only express the embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1. A method of designing a profile of an intake cam that is applied to an engine of an atkinson cycle, the method comprising:
determining a delay closing angle of an air inlet valve of the engine by adopting a thermodynamic calculation method and through engine performance simulation calculation;
calculating an acceleration curve of the air inlet cam by adopting a kinematics calculation method according to the delay closing angle, and performing secondary integration on the acceleration curve to obtain a cam profile of the air inlet cam;
and checking the cam profile, and adjusting the cam profile by adjusting the delayed closing angle so as to enable the cam profile to meet the dynamic performance requirement and the thermodynamic performance requirement of the engine.
2. The profile designing method according to claim 1, wherein the step of calculating an acceleration curve of the intake cam based on the retarded closing angle using a kinematic calculation method includes:
simplifying the valve actuating mechanism of the engine into a single mass vibration model, and carrying out dynamic calculation according to the delayed closing angle to obtain an acceleration curve of the cam.
3. The profile design method of claim 2, wherein said steps of checking the cam profile and adjusting the cam profile by adjusting the retarded closing angle to meet the dynamic and thermodynamic performance requirements of the engine comprise:
establishing a multi-mass vibration model of the valve train according to the mass, rigidity and damping characteristics of each part of the valve train;
determining whether the cam profile meets the dynamic performance requirements of the engine according to the multi-mass vibration model;
when the cam profile meets the dynamic performance requirement, calculating by using a valve actuating mechanism to obtain an actual delay angle;
performing thermodynamic calculation according to the actual delay angle, and judging whether a thermodynamic calculation result meets the thermodynamic performance requirement of the engine;
if not, adjusting the delayed closing angle within a preset amplitude range, and returning to the step of calculating the acceleration curve until the thermodynamic calculation result meets the thermodynamic performance requirement.
4. A profile design method according to claim 3, wherein the step of determining whether the cam profile meets the dynamic performance requirements of the engine based on the multi-mass vibration model is further followed by:
and when the cam profile does not meet the dynamic performance requirement, adjusting the delayed closing angle within the preset amplitude range, and returning to the step of calculating the acceleration curve until the cam profile meets the dynamic performance requirement of the engine.
5. The profile designing method according to claim 1, wherein the step of calculating an acceleration curve of the intake cam based on the retarded closing angle using a kinematic calculation method includes:
calculating a wrap angle of the cam based on the retarded closing angle and a rocker arm ratio of a rocker arm connecting between the intake valve and the cam;
and performing dynamic calculation according to the wrap angle to obtain an acceleration curve of the air inlet cam.
6. The method of profile design according to claim 1, wherein the kinetic calculation formula is:
Figure FDA0002413112700000021
in the formula: m mass parameters of a valve train of the engine; c is a mass damping parameter of the valve train; k is a mass stiffness parameter of the valve train; x is displacement;
Figure FDA0002413112700000022
is the speed;
Figure FDA0002413112700000023
is the acceleration; f is the stress.
7. The mold line design method of claim 1, wherein the thermodynamic calculation formula is:
Figure FDA0002413112700000024
wherein m iscFor tools in cylindersThe mass of the mass; u is the specific internal energy; pcIs the in-cylinder pressure; v is the cylinder volume; qFHeat released for fuel combustion is injected; qWFor cylinder wall heat loss, α for retarded closing angle of inlet valve, hBBIs the leakage enthalpy;
Figure FDA0002413112700000025
is a mass flow of gas.
8. A method of profile design according to claim 1, wherein the dynamic performance requirements are: and the speed, the acceleration and the stress of the air inlet cam meet preset conditions.
9. An intake cam, characterized in that the profile designed by the method according to any one of claims 1 to 7 is used for the intake cam.
10. The intake cam of claim 9, wherein the cam profile has a wrap angle of 130 ° to 150 ° cam angle.
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Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2145340A5 (en) * 1971-07-08 1973-02-16 Hinderks M V
DE2429708C3 (en) * 1974-06-20 1978-05-18 Maschinenfabrik Augsburg-Nuernberg Ag, 8500 Nuernberg Cam for controlling the valves of an internal combustion engine
JP2003083099A (en) * 2001-09-06 2003-03-19 Yanmar Co Ltd Control method for internal combustion engine
JP2004176668A (en) * 2002-11-28 2004-06-24 Fuji Heavy Ind Ltd Intake cam device for engine
CN101787909B (en) * 2009-11-06 2011-09-07 北京理工大学 Optimal design method for valve cam profile
CN202202909U (en) * 2011-06-17 2012-04-25 广州汽车集团股份有限公司 Turbo supercharging gasoline engine and cam axle and air inlet cam
CN102720554A (en) * 2012-06-08 2012-10-10 重庆银钢一通凸轮科技有限公司 Smooth optimization design method of cam profile
CN103336886B (en) * 2013-06-03 2016-12-28 北京理工大学 A kind of method for designing of flexible air distribution cam curve
DE102014225054A1 (en) * 2014-12-05 2016-06-09 Mahle International Gmbh Adjustable camshaft
CN105975693B (en) * 2016-05-06 2019-07-16 哈尔滨工程大学 A kind of prediction technique of valve actuating mechanism rocker arm bracket dynamic load
CN205669418U (en) * 2016-05-23 2016-11-02 吉林大学 A kind of Atkinson circulates type range extender engine admission cam shaft
CN106677852B (en) * 2016-12-30 2019-02-26 北京理工大学 A kind of Valve-train Cam design method

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