CN1114017A - Cam used as a substitute for crankshaft link mechanism - Google Patents

Abstract

The present invention features that the profile of the cam is composed of two sections of curve, the first is circular arc curve and the second is the fixed point passing equal chord length curve. The axis of the cam passes through said fixed point and is perpendicular to the plane of the cam profile. This plan is applied to the double stroke gasoline engine of motocycle to replace the traditional crankshaft link mechanism, the obvious results of simple structure and lowering oil consumption is obtained.

Description

Cam used as a substitute for crankshaft link mechanism

What the present invention relates to is the mechanical engineering element, in particular for replacing the cam member of crankshaft ﹠ connecting.

In the mechanical structure of routine, mostly application to cam is to drive cam rotation by camshaft, and the parts that contact with cam then move along with the rotation of cam, but seldom have, by the parts that contact with cam is the active movement part, drives the mechanism that camming movement is rotated camshaft.In addition, have the mechanism of reciprocating motion of the pistons, be mostly to adopt crankshaft ﹠ connecting to make the to-and-fro motion of piston become the rotation of bent axle, or the rotation of bent axle makes piston produce to-and-fro motion by connecting rod in classes such as existing internal-combustion engine or air compressors.And this conventional construction of crankshaft-link rod, the problem that the size that all has parts is big, weight is big, and the technology of structure is also complicated.

In view of the situation of prior art, the purpose of this invention is to provide a kind of new cam member that is used to replace crankshaft ﹠ connecting, this cam not only can drive cam by camshaft and make the motion of cam contact; Also can be by the active movement of cam contact, and cam and camshaft are rotated.This cam can be applicable on the internal-combustion engine, air compressor of reciprocating motion of the pistons, replaces traditional crankshaft ﹠ connecting.

The present invention adopts following technical measures to realize: at the cam member that is made of camshaft 1 and cam 2, the characteristics of this programme are that the profile line of cam 2 is made up of two sections curve acb curves and adb curve; Described acb curve is to be that the center of circle is the circular curve of radius with R with O ' in the right-angle plane coordinate,

Curvilinear equation is:

X ²+Y ²+2αRX＝（1-α ²）R ²

O≤X≤(1-α) R 0＜α＜1 wherein,

Described adb curve then is to cross O the chord length curves such as mistake fixed point of chord length ab such as order in the X-Y coordinate, and its curvilinear equation is:

$\sqrt{{\mathrm{<figure-callout\; id="2"\; label="X"\; filenames="941106918\_DRIMG1.png,941106918\_DRIMG3.png"\; state="\{\{state\}\}">X</figure-callout>}}^2+{\mathrm{<figure-callout\; id="2"\; label="Y"\; filenames="941106918\_DRIMG1.png,941106918\_DRIMG3.png"\; state="\{\{state\}\}">Y</figure-callout>}}^2}+\sqrt{(1-a^2)R^2-2\mathrm{aR}(2R\sqrt{\frac{1-a^2}{X^2+Y^2}}-1)}X$ $=2R\sqrt{1-a^2}$

Wherein-( -1+ α) R≤X≤O 0＜α＜1;

In addition, the axis normal of described camshaft 1 is in the X-Y coordinate plane at cam 2 profile line places, and by true origin O.In addition, this programme gives its characteristics more specifically, promptly the variable α in described cam 2 its profile line equations is provided the concrete numerical value of α=1/2, so the acb curve's equation is become:

X ²+Y ²+RX＝3/4R ²

0≤X≤1/2R wherein,

The adb curvilinear equation then becomes:

$\sqrt{{\mathrm{<figure-callout\; id="2"\; label="X"\; filenames="941106918\_DRIMG1.png,941106918\_DRIMG3.png"\; state="\{\{state\}\}">X</figure-callout>}}^2+{\mathrm{<figure-callout\; id="2"\; label="Y"\; filenames="941106918\_DRIMG1.png,941106918\_DRIMG3.png"\; state="\{\{state\}\}">Y</figure-callout>}}^2}+\sqrt{3/4R^2-\frac{\sqrt{3}{R}^{2}X}{\sqrt{X^2+{\mathrm{<figure-callout\; id="2"\; label="Y"\; filenames="941106918\_DRIMG1.png,941106918\_DRIMG3.png"\; state="\{\{state\}\}">Y</figure-callout>}}^2}}+\mathrm{RX}}=\sqrt{3}R$

Wherein-( -1/2) R≤X≤O.

In this programme,, and be symmetrical to X-axis, and the axis of camshaft pass origin at X-Y coordinate cam profile line because the profile line of cam is to be made of two excessive curves of slyness.The cam of this structure promptly can drive cam rotation by camshaft makes the parts that contact with cam obtain to-and-fro motion, resembles the used for air compressor cam structure and replaces crankshaft ﹠ connecting, makes the piston of air compressor obtain regular to-and-fro motion.In addition, the cam of this structure also can go actuating cam to rotate by the parts active to-and-fro motion that contacts with cam, as the to-and-fro motion of internal combustion engine, promotes to replace the cam rotation of crankshaft ﹠ connecting, and by camshaft it is exported work done.Owing in internal-combustion engine or air compressor, replaced crankshaft ﹠ connecting with cam mechanism, make that designs simplification, size are dwindled, weight saving, adopt cam mechanism can obtain efficient preferably to same cylinder diameter and stroke.As seen, this programme has remedied the vacancy of prior art, and implementation result also is extremely significant.

Description of drawings:

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the schematic top plan view of Fig. 1;

Fig. 3 is the X-Y coordinate diagram of cam profile of the present invention;

Fig. 4 is used for the example structure schematic representation of internal-combustion engine for the present invention.

Now the embodiment who uses on the motorcycle two-stroke gasoline engine with a present invention and in conjunction with its accompanying drawing is further elaborated technological scheme of the present invention.As shown in Figure 4, one piston that is mated 4 is arranged in petrolic cylinder sleeve 5, be processed with the promotion groove 6 that can hold and can rotate for cam 2 at the middle part of piston 4, in promoting groove 6, cam 2 be housed, and promote to lean on bearing 3 to contact between groove 6 and the cam 2.In addition, on the diameter on the vertical cam of the sidewall 2 profile line planes of cylinder sleeve 5, be processed with the axis hole that matches with camshaft 1, camshaft 1 also passes from this hole, and on the perpendicular sidewall of cylinder sleeve 5 and its axis hole and corresponding with the promotion groove 6 on the piston 4, also be processed with for cam 2 and rotate and piston 4 moves required slotted hole 7.The profile line of described cam 2 is made up of two sections curve acb and adb as shown in Figure 3, and two curvilinear equations in variable α be decided to be α=1/2, so its curvilinear equation is respectively:

X ²+ Y ²+ RX=3/4R ²O≤X≤1/2R wherein,

With

$\sqrt{{\mathrm{<figure-callout\; id="2"\; label="X"\; filenames="941106918\_DRIMG1.png,941106918\_DRIMG3.png"\; state="\{\{state\}\}">X</figure-callout>}}^2+{\mathrm{<figure-callout\; id="2"\; label="Y"\; filenames="941106918\_DRIMG1.png,941106918\_DRIMG3.png"\; state="\{\{state\}\}">Y</figure-callout>}}^2}+\sqrt{3/4R^2-\frac{\sqrt{3}{R}^{2}X}{\sqrt{X^2+{\mathrm{<figure-callout\; id="2"\; label="Y"\; filenames="941106918\_DRIMG1.png,941106918\_DRIMG3.png"\; state="\{\{state\}\}">Y</figure-callout>}}^2}}+\mathrm{RX}}=\sqrt{3}R$

Wherein-( -1/2) R≤X≤O.

Petrolic in the present embodiment cylinder diameter * stroke is 40 * 39.6.So can determine R=32.14.Can determine the concrete profile of cam 2 thus.Its implementation result has obvious result simple in structure and that oil consumption reduces than the petrol engine of the traditional crankshaft ﹠ connecting that adopts identical bore and stroke.

Claims (2)

1, being used to replace the cam of crankshaft ﹠ connecting is to be made of camshaft [1] and cam [2], the invention is characterized in that the profile line of described cam [2] is made up of two sections curve acb curves and adb curve; Described acb curve is to be the center of circle with O ' in X-Y right-angle plane coordinate, is the circular curve of radius with R, and its curvilinear equation is:

X ²+Y ²+2aRX=(1-a ²)R ²

R 0＜α＜1 of 0≤X≤(1-a) wherein,

Described adb curve then is to cross O the chord length curves such as mistake fixed point of chord length ab such as order in the X-Y coordinate, and its curvilinear equation is:

$\sqrt{X^2+Y^2}+\sqrt{(1-a^2)R^2-2\mathrm{aR}(2R\sqrt{\frac{1-a^2}{X^2+Y^2}}-1)}X$ $=2R\sqrt{1-a^2}$

Wherein $-(2\sqrt{1-a^2}-1+a)R\&le;X\&le;O$ 0＜α＜1；

In addition, the axis normal of described camshaft [1] is in the X-Y coordinate plane at cam [2] profile line place, and by true origin O.

2, according to the described cam of claim 1, it is characterized in that variable α=1/2 in its profile line equation of described cam [2], so the acb curve's equation then is:

X ²+Y ²+RX＝3/4R ²

0≤X≤1/2R wherein,

The adb curvilinear equation then is:

$\sqrt{X^2+Y^2}+\sqrt{3/4R^2-\frac{\sqrt{3}{R}^{2}X}{\sqrt{X^2+Y^2}}+\mathrm{RX}}=\sqrt{3}R$

Wherein-( -1/2) R≤X≤0.

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