CN203669952U - Gas distribution cam profile of diesel engine for automobile - Google Patents

Abstract

The utility model discloses a gas distribution cam profile of a diesel engine for an automobile. Gas distribution cams comprise a gas inlet cam and a gas outlet cam, and the cam profile of the gas inlet cam and the cam profile of the gas outlet cam are respectively composed of a cam base circle, a rising buffer section, a rising section, a falling section and a falling buffer section. According to the gas distribution cam profile of the diesel engine for the automobile, the combined type cam profile is adopted, the rising section and the falling section of the cam profile are respectively composed of five sections of displacement equations of different mathematical expressions, the falling section and the rising section are symmetrical about the radial center line of the cam, the rising section is connected with the cam base circle through the constant-speed and constant-acceleration rising buffer section, and the falling section is connected with the cam base circle through the constant-speed and constant-acceleration falling buffer section. By improving the cam profile of a gas distribution mechanism, the low-speed torque of the diesel engine is improved.

Description

A kind of Diesel Engines Valve Cam

Technical field

The utility model relates to the component of motor car engine, is specifically related to a kind of Valve-train Cam for diesel engine for automobile.

Background technique

Sports type multipurpose automobile (Sport Utility Vehicle-SUV) is very popular in the market vehicle, the power plant of increasing producer using diesel engine for automobile as SUV, main purpose is to bring into play the feature that the diesel engine thermal efficiency is high, its usage economy is good, and how therefore one of emphasis that the low speed torque of diesel engine for automobile is user to be paid close attention to improve low speed torque and become the Important Problems that design will solve.

Model utility content

The purpose of this utility model is to provide a kind of Diesel Engines Valve Cam, by improving the cam design of distribution device, coordinates with measures such as exhaust gas turbocharge the low speed torque that has improved diesel engine.

The purpose of this utility model is achieved through the following technical solutions:

A kind of Diesel Engines Valve Cam is provided, valve cam comprises intake cam and exhaust cam, the cam profile of intake cam and exhaust cam is by cam base circle, lifting buffering section, ascent stage, descending branch and decline breeze way composition, it adopts Combined cam molded line, the ascent stage of cam profile becomes by five sections of shifted systems of different mathematic(al) representations with descending branch, and descending branch and ascent stage are about cam radial centre lines symmetry, ascent stage is connected with cam base circle with accelerating type decline breeze ways such as constant speed by accelerating type lifting buffering sections such as constant speed respectively with descending branch.

The improvement technological scheme of a kind of Diesel Engines Valve Cam that the utility model provides, the described ascent stage becomes by five sections of shifted systems of different mathematic(al) representations with descending branch, and each section of displacement equation representation is as follows:

In formula,

H _i, unit: mm, represents that each section of ascent stage or descending branch are with cam angle degree

shift value, i=1～5;

unit: deg, i=1～5,

span: 0～β _i,

β _irepresent ascent stage or each section of cornerite of descending branch, unit: deg, i=1～5;

C ₁～C ₂₁be every coefficient of each section of equation, obtain by solving equations according to boundary conditions.

The improvement technological scheme of a kind of Diesel Engines Valve Cam that the utility model provides, described lifting buffering section and decline breeze way are about cam radial centre lines symmetry, lifting buffering section and decline breeze way are by accelerating sections compositions such as constant speed Duan He, and its molded line equation representation is:

Constant speed section: H _y1=H ₀-V ₀x;

Deng accelerating sections: $H_{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HDA0000454739660000011.png"\; state="\{\{state\}\}">y</figure-callout>}2}=\frac{A}{2}{(x-Q_2)}^2+B(x-Q_2)+C;$

In formula,

H ₀represent the end of a period height of breeze way, unit: mm;

V ₀represent the end of a period speed of default breeze way, unit: mm/deg;

Q ₂represent the cornerite of constant speed section, unit: deg;

A, B, C are equation coefficient, calculate by actual boundary condition.

The improvement technological scheme of a kind of Diesel Engines Valve Cam that the utility model provides, the molded line basic design parameters of described intake cam is as follows: lifting buffering section cornerite φ ₁be 10, unit: deg; Decline breeze way cornerite φ ₂be 10, unit: deg; Breeze way constant speed section cornerite Q ₂be 5, unit: deg; Maximum cam lift Hmax is 4.42, unit: mm; Lifting buffering section height H ₀₁be 0.15, unit: mm; Decline breeze way height H ₀₂be 0.15, unit: mm; Lifting buffering section speed V ₀₁be 0.02, unit: mm/deg; Decline breeze way speed V ₀₂for-0.02, unit: mm/deg; When lift, basal area is 262.23, unit: deg.mm; Molded line fullness coefficient Fu is 0.55.

The improvement technological scheme of a kind of Diesel Engines Valve Cam that the utility model provides, the molded line basic design parameters of described exhaust cam is as follows: lifting buffering section cornerite φ ₁be 10, unit: deg; Decline breeze way cornerite φ ₂be 10, unit: deg; Breeze way constant speed section cornerite Q ₂be 5, unit: deg; Maximum cam lift Hmax is 4.79, unit: mm; Lifting buffering section height H ₀₁be 0.15, unit: mm; Decline breeze way height H ₀₂be 0.15, unit: mm; Lifting buffering section speed V ₀₁be 0.02, unit: mm/deg; Decline breeze way speed V ₀₂for-0.02, unit: m/deg; When lift, basal area is 305.2, unit: deg.mm; Molded line fullness coefficient Fu is 0.55.

Compared with prior art, the beneficial effects of the utility model are:

1, the ascent stage of cam profile of the present utility model and descending branch symmetry, is connected with cam generating circle is round and smooth by breeze way, and each section of curve second order, three order derivatives are continuous, has guaranteed the stable working of distribution device.

2, cam profile of the present utility model has adopted less intake and exhaust overlapping angle and less air inlet cornerite, is conducive to improve low speed torque and the idling work stationarity of diesel engine.

3, cam profile of the present utility model has adopted suitable breeze way, is conducive to reduce air valve drop noise and impact.

Accompanying drawing explanation

Fig. 1 is diesel engine for automobile inlet and outlet cam gabarit schematic diagram described in the utility model;

Fig. 2 is that the inlet and outlet door of diesel engine for automobile valve cam described in the utility model control opens and closes schematic diagram (being port timing);

Fig. 3 is the air inlet tappet characteristics of motion curve of Diesel Engines Valve Cam control described in the utility model; Wherein, Fig. 3 a is intake cam tappet displacement diagram, and Fig. 3 b is intake cam tappet velocity and acceleration curve;

Fig. 4 is the exhaust tappet characteristics of motion curve of Diesel Engines Valve Cam control described in the utility model; Wherein, Fig. 4 a is exhaust cam tappet displacement diagram, and Fig. 4 b is exhaust cam tappet velocity and acceleration curve.

In figure: 1, cam base circle 2, lifting buffering section 3, ascent stage 4, descending branch 5, decline breeze way 6, exhauxt valve opens advance angle 7, exhaust valve closing retardation angle 8, IO Intake Valve Opens advance angle 9, IC Intake Valve Closes retardation angle

Embodiment

With reference to Fig. 1, valve cam comprises intake cam and exhaust cam, and the cam profile of intake cam and exhaust cam forms by five parts, is respectively cam base circle 1, lifting buffering section 2, ascent stage 3, descending branch 4 and decline breeze way 5.The technical program adopts Combined cam molded line, and the ascent stage 3 of cam profile becomes by five sections of shifted systems of different mathematic(al) representations with descending branch 4, and descending branch 4 and ascent stage 3 are about cam radial centre lines (symmetrical center line) symmetry; Ascent stage 3 is connected with cam base circle 1 with accelerating type decline breeze ways 5 such as constant speed by accelerating type lifting buffering sections 2 such as constant speed respectively with descending branch 4.

Ascent stage 3 and descending branch 4 are all called active section, and active section is become by five sections of shifted systems respectively, and each section of displacement equation representation is as follows:

In formula, h _i(unit: mm) represents that each section with cam angle degree

(span: 0～β _i) shift value, i=1～5; C ₁～C ₂₁be every coefficient of each section of equation, obtain by solving equations according to boundary conditions.

Lifting buffering section 2 and decline breeze way 5 are about cam radial centre lines (symmetrical center line) symmetry, and lifting buffering section 2 and decline breeze way 5 are all made up of accelerating sections such as constant speed Duan He, and the molded line equation representation of breeze way is as follows:

Constant speed section: H _y1=H ₀-V ₀x

Deng accelerating sections: $H_{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HDA0000454739660000011.png"\; state="\{\{state\}\}">y</figure-callout>}2}=\frac{A}{2}{(x-Q_2)}^2+B(x-Q_2)+C$

In formula, H ₀(unit: mm) is the end of a period height of breeze way; V ₀(unit: mm/deg) is the end of a period speed of default breeze way, given by artificer; Q ₂for the cornerite of constant speed section, unit: deg; A, B, C are equation coefficient, are calculated and are obtained by actual boundary condition.

In embodiment, lift unit is mm, and speed unit is mm/deg, and unit of acceleration is mm/deg ², angular unit is deg.

In Fig. 1, R2 represents the radius of cam base circle, unit: mm; φ 1 represents the cornerite of lifting buffering section 2, and φ 2 represents the cornerite of decline breeze way 5, in the present embodiment, and φ 1=φ 2.

In Fig. 1, θ ₁represent ascent stage work cornerite, θ ₂represent descending branch work cornerite, in the present embodiment, θ ₁=θ ₂=θ=β ₁+ β ₂+ β ₃+ β ₄+ β ₅, be half cornerite of active section.

In the present embodiment, the molded line basic design parameters of intake cam and exhaust cam is (in table, numerical value adopts scientific notation counting) as shown in table one and table two.

The molded line basic design parameters of table one intake cam

The molded line basic design parameters of table two exhaust cam

Table three inlet and outlet cam lift table

The opening and closing of intake cam control intake valve, the opening and closing of exhaust cam control exhaust valve.

With reference to Fig. 2, bent axle is rotated in a clockwise direction.The angle of IO Intake Valve Opens advance angle 8 is 5 °; The angle of IC Intake Valve Closes retardation angle 9 is 39 °; The corresponding crank angle of IO Intake Valve Opens is 224 °.The angle of exhauxt valve opens advance angle 6 is 53 °; The angle of exhaust valve closing retardation angle 7 is 5 °; The corresponding crank angle of exhauxt valve opens is 238 °.The intake and exhaust cam work relationship of design, is 10 ° by the overlapping angle that makes inlet and exhaust valve like this.

The natural gas engine of the present embodiment adopts side single camshaft, and the interval angle of intake and exhaust cam peach point is that intake cam lags behind 110.5 ° of exhaust cams.

Claims (5)

1. a Diesel Engines Valve Cam, valve cam comprises intake cam and exhaust cam, the cam profile of intake cam and exhaust cam is by cam base circle (1), lifting buffering section (2), ascent stage (3), descending branch (4) and decline breeze way (5) composition, it is characterized in that, adopt Combined cam molded line, the ascent stage (3) of cam profile becomes by five sections of shifted systems of different mathematic(al) representations with descending branch (4), and descending branch (4) and ascent stage (3) are about cam radial centre lines symmetry, ascent stage (3) is connected with cam base circle (1) with accelerating type decline breeze ways (5) such as constant speed by accelerating type lifting buffering sections (2) such as constant speed respectively with descending branch (4).

2. according to a kind of Diesel Engines Valve Cam claimed in claim 1, it is characterized in that, the described ascent stage (3) becomes by five sections of shifted systems of different mathematic(al) representations with descending branch (4), and each section of displacement equation representation is as follows:

In formula,

H _i, unit: mm, represents that ascent stage (3) or each section of descending branch (4) are with cam angle degree

shift value, i=1～5;

unit: deg, i=1～5,

span: 0～β _i,

β _irepresent ascent stage (3) or each section of cornerite of descending branch (4), unit: deg, i=1～5;

C ₁～C ₂₁be every coefficient of each section of equation, obtain by solving equations according to boundary conditions.

3. according to a kind of Diesel Engines Valve Cam claimed in claim 1, it is characterized in that, described lifting buffering section (2) and decline breeze way (5) are about cam radial centre lines symmetry, lifting buffering section (2) and decline breeze way (5) are by accelerating sections compositions such as constant speed Duan He, and its molded line equation representation is:

Constant speed section: H _y1=H ₀-V ₀x;

Deng accelerating sections: $H_{y2}=\frac{A}{2}{(x-Q_2)}^2+B(x-Q_2)+C;$

In formula,

H ₀represent the end of a period height of breeze way (2,5), unit: mm;

V ₀represent the end of a period speed of default breeze way (2,5), unit: mm/deg;

Q ₂represent the cornerite of constant speed section, unit: deg;

A, B, C are equation coefficient, calculate by actual boundary condition.

4. according to a kind of Diesel Engines Valve Cam claimed in claim 1, it is characterized in that, the molded line basic design parameters of described intake cam is as follows: lifting buffering section (2) cornerite φ ₁be 10, unit: deg; Decline breeze way (5) cornerite φ ₂be 10, unit: deg; Breeze way (2,5) constant speed section cornerite Q ₂be 5, unit: deg; Maximum cam lift Hmax is 4.42, unit: mm; Lifting buffering section (2) height H ₀₁be 0.15, unit: mm; Decline breeze way (5) height H ₀₂be 0.15, unit: mm; Lifting buffering section (2) speed V ₀₁be 0.02, unit: mm/deg; Decline breeze way (5) speed V ₀₂for-0.02, unit: mm/deg; When lift, basal area is 262.23, unit: deg.mm; Molded line fullness coefficient Fu is 0.5503.

5. according to a kind of Diesel Engines Valve Cam claimed in claim 1, it is characterized in that, the molded line basic design parameters of described exhaust cam is as follows: lifting buffering section (2) cornerite φ ₁be 10, unit: deg; Decline breeze way (5) cornerite φ ₂be 10, unit: deg; Breeze way (2,5) constant speed section cornerite Q ₂be 5, unit: deg; Maximum cam lift Hmax is 4.79, unit: mm; Lifting buffering section (2) height H ₀₁be 0.15, unit: mm; Decline breeze way (5) height H ₀₂be 0.15, unit: mm; Lifting buffering section (2) speed V ₀₁be 0.02, unit: mm/deg; Decline breeze way (5) speed V ₀₂for-0.02, unit: m/deg; When lift, basal area is 305.2, unit: deg.mm; Molded line fullness coefficient Fu is 0.5530.

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