CN104972901A - Design method for clutch pedal torsion and helical spring power-assisted system - Google Patents

Abstract

The invention provides a design method for a clutch pedal torsion and helical spring power assisted system. The design method comprises the expression 1 of the deflection of a torsion spring being determined by geometrical principles. According to force exerted on the torsion spring, the expression 2 of the force Fn exerted on a mounting point B of a pedal by the torsion spring is analyzed and built. According to geometrical principles, the expression 3 of the imposing force Fn exerted on the mounting point B of the pedal by the torsion spring to the force arm Ln of a rotation point (O) of the pedal is built. Based on the expression 1,the expression 2, the expression 3 and the principle of moment balance, the equality 1 is determined and the expression 4 is built for a torsion spring power assisted model. According to the expression 4 of the torsion spring power assisted model, a clutch pedal torsion spring power assisted system is built. The design method provided by the invention corrects the problem in the prior art that the direction of the imposing force of a torsion spring to its pedal on the pedal by the torsion spring is wrongly defined and avoids large error in the clutch pedal torsion spring power assisted system.

Description

The method of designing of clutch pedal torsion and coil spring force aid system

Technical field

The present invention relates to the Design of Auto Parts field, particularly relate to the method for designing of the torsion of a kind of clutch pedal and coil spring force aid system.

Background technology

Current clutch pedal power assistant spring is widely used, but the design process of majority is only on pedal by different spring fittings, trample or measure by tester the quality that treadle effort feels power-assisted effect, thus determine the design plan of clutch pedal power assistant spring, the change of any one parameter all needs to re-start test to verify power-assisted effect like this, process is more loaded down with trivial details, and measurement discrete so also cannot reach the optimization of power-assisted effect.

Along with computer aided design is at the application development of field of automobile design, when carrying out the design of clutch pedal power assistant spring, the math modeling setting up clutch pedal spring boost system can be considered, namely the expression formula of pedal tread by power-assisted acting force of the spring is constructed, to find the key parameter of spring design, and carry out quantitative optimal design.

In general, clutch pedal spring boost system mainly comprises pedal, pedal support and power assistant spring, and power assistant spring can be cylindrically coiled spring or torsion spring.The principle of clutch pedal spring boost system is made it to produce deformation by pedal rotary compression power assistant spring, thus produce antagonistic force, for pedal provides support power or power-assisted to pedal.

Such as Authorization Notice No. is the method for designing that the Chinese patent of CN101397977B discloses a kind of spring boost system, establishes torsion spring (power assistant spring) to the math modeling of pedal effort in this method of designing.See the Fig. 3 to Fig. 5 in CN101397977B, by the directed force F of spring to pedal in this method of designing _nbe defined as the direction vertical with torsion spring one hold-down arm.

But be through present inventor and study discovery, as shown in Figure 1, can learn according to balance between two forces, F _ndirection should along the line direction of torsion spring two attachment points (attachment point B and attachment point C), therefore, in CN101397977B, be equivalent to make use of a wrong F _nobtain torsion spring force aid system math modeling, the torsion spring force aid system according to this Design of Mathematical Model will produce larger error, and torsion spring power-assisted effect will be had a greatly reduced quality, thus have impact on the traveling comfort that clutch pedal tramples.

Summary of the invention

Technical matters to be solved by this invention is the defect that the torsion spring force aid system error that obtains for the method for designing of existing clutch pedal spring boost system is larger, provides a kind of method of designing of clutch pedal torsion spring force aid system.

The present invention solves the problems of the technologies described above adopted technical scheme, and provide a kind of method of designing of clutch pedal torsion spring force aid system, described method comprises:

According to geometrical principle determination torsion spring deflection expression formula 1 be:

Wherein, θ is pedal corner, a ₀for pedal initial angle, L ₁for distance, the L of the attachment point C to pedal pivot point O of torsion spring on pedal support ₂for distance, the d of the attachment point B to pedal pivot point O of torsion spring on pedal ₀for torsion spring free state angle, r be the radius of torsion spring, l is torsion spring brachium, in described expression formula 1, ignore the deadweight of torsion spring, ignore the radius r of torsion spring because of compression or the flexure deformation drawing high produced change in radius and torsion spring hold-down arm;

The directed force F of torsion spring to its attachment point B on pedal is set up according to torsion spring force analysis _nexpression formula 2 be:

Wherein, K ₂for torsion spring rigidity;

The directed force F of torsion spring to its attachment point B on pedal is set up according to geometrical principle _nto the arm of force L of pedal pivot point O _nexpression formula 3 be:

$L_n=\frac{L_1\×L_2\×\sin (a_0-\mathrm{\θ})}{\sqrt{{L_1}^2+{L_2}^2-{2L}_1{L}_2\cos (a_o-\mathrm{\θ})}};$

According to expression formula 1, expression formula 2, expression formula 3 and based on the equation 1 that principle of moment balance is determined, setting up torsion spring power-assisted model expression 4 is:

$T=\frac{K_2{L}_1{L}_2\sin (a_0-\mathrm{\θ})\{d_0-\arccos [1-\frac{{L_1}^2+{L_2}^2-2L_1{L}_2\cos (a_0-\mathrm{\θ})}{2(r^2+l^2)}\left]\right\}}{L_{p}l\sqrt{{L_1}^2+{L_2}^2-2L_1{L}_2\cos (a_0-\mathrm{\θ})}};$

Wherein, equation 1 is: T × L _p=F _n× L _n, L _pfor torsion spring to the application force T of the pedal tread A point of pedal to the arm of force of pedal pivot point O;

Clutch pedal torsion spring force aid system is designed according to torsion spring power-assisted model expression 4.

Further, on described pedal tread, A point is the center of pedal tread.

Further, described method also comprises:

Obtain the disengaging of clutch power-clutch pedal rotation curve representing disengaging of clutch power and θ corresponding relation;

Determine a ₀, L ₁, L ₂, L _pand K ₂value;

Set d respectively ₀, r and l initial value;

The span of selected θ, according to the torsion spring power-assisted model set up, obtains the torsion spring power-assisted curve representing T and θ corresponding relation;

Adjustment d ₀, r and l initial value at least one, make the pedal corner corresponding to the peak value of the pedal corner corresponding to peak value of T in described torsion spring power-assisted curve and disengaging of clutch power described in described disengaging of clutch power-clutch pedal rotation curve identical, thus determine d ₀, r and l end value, complete the design of clutch pedal torsion spring force aid system.

Further, a ₀determined value be 1.8 °, L ₁determined value be 64mm, L ₂determined value be 50mm, L _pdetermined value be that the span of 323mm, θ is chosen to be 0 ~ 25 °, K ₂determined value be 200N/mm.

Further, the initial value of l is set as 24mm, and the initial value of r is set as 10mm, d ₀initial value be set as 70 °.

According to the method for designing of clutch pedal torsion spring force aid system of the present invention, to correct in existing method torsion spring to the problem of the force direction definition error of pedal, thus, the torsion spring power-assisted model obtained is more accurate, avoids the design error that clutch pedal torsion spring force aid system is larger.

In addition, present invention also offers a kind of method of designing of clutch pedal coil spring force aid system, described method comprises:

According to geometrical principle determination coil spring deflection L _xexpression formula 5 be:

$L_x=L_0-\sqrt{{L_1}^2+{L_2}^2+2L_1{L}_2\cos (a_0-\mathrm{\θ})};$

Wherein, θ is pedal corner, a ₀for pedal initial angle, L ₁for distance, the L of the attachment point C to pedal pivot point O of torsion spring on pedal support ₂for distance, the L of the attachment point B to pedal pivot point O of torsion spring on pedal ₀for coil spring drift, in described expression formula 5, ignore helical spring deadweight;

The directed force F of coil spring to its attachment point B on pedal is set up according to coil spring force analysis _nexpression formula 6 be:

F _n＝K ₁×L _x；

Wherein, K ₁for rigidity of helical spring;

The directed force F of coil spring to its attachment point B on pedal is set up according to geometrical principle _nto the arm of force L of pedal pivot point O _nexpression formula 7 be:

$L_n=\frac{L_1\×L_2\×\sin (a_0-\mathrm{\θ})}{\sqrt{{L_1}^2+{L_2}^2-{2L}_1{L}_2\cos (a_o-\mathrm{\θ})}};$

According to expression formula 5, expression formula 6 and expression formula 7 and based on the equation 2 that principle of moment balance is determined, setting up coil spring power-assisted model expression 8 is:

$T=\frac{K_2{L}_1{L}_2\sin (a_0-\mathrm{\θ})[L_0-\sqrt{{L_1}^2+{L_2}^2-2L_1{L}_2\cos (a_0-\mathrm{\θ})}]}{L_p\sqrt{{L_1}^2+{L_2}^2-2L_1{L}_2\cos (a_0-\mathrm{\θ})}};$

Wherein equation 2 is expressed as: T × L _p=F _n× L _n, L _pfor coil spring to the application force T of the pedal tread A point of pedal to the arm of force of pedal pivot point O;

Clutch pedal coil spring force aid system is designed according to coil spring power-assisted model expression 8.

Further, on described pedal tread, A point is the center of pedal tread.

Further, described method also comprises:

Obtain the disengaging of clutch power-clutch pedal rotation curve representing disengaging of clutch power and θ corresponding relation;

Determine a ₀, L ₁, L ₂, L _pand K ₁value;

Setting L ₀initial value;

The span of selected θ, according to the coil spring power-assisted model set up, obtains the coil spring power-assisted curve representing T and θ corresponding relation;

Adjustment L ₀initial value, make the pedal corner corresponding to the peak value of the pedal corner corresponding to peak value of T in described coil spring power-assisted curve and disengaging of clutch power described in described disengaging of clutch power-clutch pedal rotation curve identical, thus determine L ₀end value, complete the design of clutch pedal coil spring force aid system.

Further, a ₀determined value be 1.8 °, L ₁determined value be 64mm, L ₂determined value be 50mm, L _pdetermined value be that the span of 323mm, θ is chosen to be 0 ~ 25 °, K ₁determined value be 10N/mm.

Further, L ₀initial value be set as 40mm.

According to the method for designing of clutch pedal coil spring force aid system of the present invention, to correct in existing method torsion spring to the problem of the force direction definition error of pedal, thus, the coil spring power-assisted model obtained is more accurate, avoids the design error that clutch pedal coil spring force aid system is larger.

Accompanying drawing explanation

Fig. 1 is the stress balance figure of clutch pedal;

The reduced graph of the clutch pedal torsion spring force aid system that the method for designing that Fig. 2 is the clutch pedal torsion spring force aid system provided according to one embodiment of the invention obtains;

Disengaging of clutch power-clutch pedal rotation curve that Fig. 3 obtains for one embodiment of the invention;

The torsion spring power-assisted curve that the method for designing that Fig. 4 is the clutch pedal torsion spring force aid system provided according to one embodiment of the invention obtains;

The reduced graph of the clutch pedal coil spring force aid system that the method for designing that Fig. 5 is the clutch pedal coil spring force aid system provided according to one embodiment of the invention obtains;

The coil spring power-assisted curve that the method for designing that Fig. 6 is the clutch pedal coil spring force aid system provided according to one embodiment of the invention obtains.

Reference numeral in Figure of description is as follows:

1, pedal; 2, torsion spring; 21, torsion spring hold-down arm; 3, coil spring.

Detailed description of the invention

In order to make technical matters solved by the invention, technical scheme and beneficial effect clearly understand, below in conjunction with drawings and Examples, the present invention is described in further detail.Should be appreciated that specific embodiment described herein only in order to explain the present invention, be not intended to limit the present invention.

The method of designing of the clutch pedal torsion spring force aid system that one embodiment of the invention provides, comprises the steps:

101, according to geometrical principle determination torsion spring deflection expression formula 1 be:

Wherein, θ is pedal corner, a ₀for pedal initial angle, L ₁for distance, the L of the attachment point C to pedal pivot point O of torsion spring on pedal support ₂for distance, the d of the attachment point B to pedal pivot point O of torsion spring on pedal ₀for torsion spring free state angle, r be the radius of torsion spring, l is torsion spring brachium, in described expression formula 1, ignore the deadweight of torsion spring, ignore the radius r of torsion spring because of compression or the flexure deformation drawing high produced change in radius and torsion spring hold-down arm; In the embodiment shown in Fig. 1 and Fig. 2, ignore the shape of pedal 1 simultaneously, be reduced to the straight line OA rotated around pedal pivot point O.Certainly, in other embodiments, pedal 1 also can not be reduced to straight line, but designs according to the shape of itself.

In the present embodiment, torsion spring deflection be specifically calculated as follows:

As shown in Figure 2, under a certain pedal rotational angle theta, the distance L of the torsion spring attachment point C on pedal support to pedal pivot point O ₁for the line segment CO in figure, the distance L of the torsion spring attachment point B on pedal to pedal pivot point O ₂for the line segment BO in figure, according to the cosine law, can in the hope of the distance of line segment BC (namely under a certain pedal corner, the distance L of attachment point B and attachment point C _m), namely obtain following formula (1):

L _m ²=L ₁ ²+ L ₂ ²-2L ₁l ₂cosa(1); Wherein a is under this pedal rotational angle theta, the angle of line segment CO and line segment BC, and angle a is pedal initial angle a ₀with the difference of pedal rotational angle theta, namely there is following formula (2):

a＝a ₀-θ （2）；

According to Pythagorean theorem, then the distance CD of attachment point C and attachment point B to torsion spring axle center D and BD is had to be $\sqrt{r^2+l^2};$

According to the cosine law, then have:

${L_m}^2={\left(\sqrt{r^2+l^2}\right)}^2+{\left(\sqrt{r^2+l^2}\right)}^2-2\sqrt{r^2+l^2}\×\sqrt{r^2+l^2}\cos d;$ Formula (3) is obtained after simplification:

L _m ²＝2(r ²+l ²) ²-2(r ²+l ²)cosd （3）；

Wherein, d is under this pedal rotational angle theta, the angle of torsion spring.

In conjunction with formula (1), (2) and (3), formula (4) can be obtained:

Can in the hope of under this pedal rotational angle theta by formula (4), the angle d of torsion spring, it is represented by formula (5):

$d=\arccos [1-\frac{{L_1}^2+{L_2}^2-2L_1{L}_2\cos (a_0-\mathrm{\θ})}{2(r^2+l^2)}]---\left(5\right);$

Then by torsion spring free state angle d ₀deduct torsion spring angle d now, torsion spring deflection can be obtained expression formula 1 be:

102, the directed force F of torsion spring to its attachment point B on pedal is set up according to torsion spring force analysis _nexpression formula 2 be:

Wherein, K ₂for torsion spring rigidity.

103, as shown in Figure 2, the directed force F of torsion spring to its attachment point B on pedal is set up according to geometrical principle _nto the arm of force L of pedal pivot point O _nexpression formula 3 be:

$L_n=\frac{L_1\×L_2\×\sin (a_0-\mathrm{\θ})}{\sqrt{{L_1}^2+{L_2}^2-{2L}_1{L}_2\cos (a_o-\mathrm{\θ})}}.$

In the present embodiment, arm of force L _nbe specifically calculated as follows:

As shown in Figure 2, under a certain pedal rotational angle theta, the distance L of the torsion spring attachment point C on pedal support to pedal pivot point O ₁for the line segment CO in figure, the distance L of the torsion spring attachment point B on pedal to pedal pivot point O ₂for the line segment BO in figure, according to the characteristic of right-angled triangle, then there is formula (7):

L _n＝L ₁sinc（7）；

Wherein c is the angle of line segment CO and line segment CB;

According to sine, then have:

and then obtain formula (8):

$\sin c=\frac{L_2\×\sin a}{L_m}---\left(8\right);$

Formula (7), (8), (1) and (2) combine, and can obtain expression formula 3:

$L_n=\frac{L_1\×L_2\×\sin (a_0-\mathrm{\θ})}{\sqrt{{L_1}^2+{L_2}^2-{2L}_1{L}_2\cos (a_o-\mathrm{\θ})}}.$

104, according to power expression formula 1, expression formula 2 and expression formula 3 and based on the equation 1 that principle of moment balance is determined, setting up torsion spring power-assisted model expression 4 is:

$T=\frac{K_2{L}_1{L}_2\sin (a_0-\mathrm{\θ})\{d_0-\arccos [1-\frac{{L_1}^2+{L_2}^2-2L_1{L}_2\cos (a_0-\mathrm{\θ})}{2(r^2+l^2)}\left]\right\}}{L_{p}l\sqrt{{L_1}^2+{L_2}^2-2L_1{L}_2\cos (a_0-\mathrm{\θ})}};$

Wherein equation 1 is: T × L _p=F _n× L _n, L _pfor torsion spring to the application force T of the pedal tread A point of pedal to the arm of force of pedal pivot point O, i.e. L _pfor A point on pedal tread is to the vertical distance of pedal pivot point O.Preferably, on described pedal tread, A point is the center of pedal tread.

105, clutch pedal torsion spring force aid system is designed according to above-mentioned torsion spring power-assisted model expression 4.

In addition, the method for designing of the clutch pedal torsion spring force aid system that one embodiment of the invention provides, can further include step 106, this step 106 is as follows:

Obtain the disengaging of clutch power-clutch pedal rotation curve representing disengaging of clutch power and described pedal rotational angle theta corresponding relation;

Determine a ₀, L ₁, L ₂, L _pand value;

Set d respectively ₀, r and l initial value;

The span of selected θ, according to the torsion spring power-assisted model set up, obtains the torsion spring power-assisted curve representing T and θ corresponding relation;

Adjustment d ₀, r and l initial value at least one, make the pedal corner corresponding to the peak value of the pedal corner corresponding to peak value of T in described torsion spring power-assisted curve and disengaging of clutch power described in described disengaging of clutch power-clutch pedal rotation curve identical, thus determine d ₀, r and l end value, complete the design of clutch pedal torsion spring force aid system.

In one embodiment, in described step 106, a ₀determined value be 1.8 °, L ₁determined value be 64mm (millimeter), L ₂determined value be 50mm, L _pdetermined value be that the span of 323mm, θ is chosen to be 0 ~ 25 °, K ₂determined value be 200N/mm (Newton per millimeter).The initial value of l is set as 24mm, and the initial value of r is set as 10mm, d ₀initial value be set as 70 °.By above-mentioned a ₀, L ₁, L ₂, L _pand K ₂determined value and d ₀, r and l initial value all substitute into above-mentioned torsion spring power-assisted model expression 4, then obtain the definite expression formula of T about θ, and within the scope of the θ of 0 ~ 25 °, utilize this exact expression formula to draw out the torsion spring power-assisted curve representing T and θ corresponding relation, described torsion spring power-assisted curve as shown in Figure 4.

Clutch pedal spring design criterion is: the last period plays drag effect, ensures that clutch pedal can normal return when hydraulic pressure is less; Latter one section is played power-assisted effect, and in order to ensure power-assisted best results, spring assist peak value should tried one's best on same pedal corner with disengaging of clutch power peak value.In the present embodiment, as shown in Figure 3, it is obtained by emulation or is obtained by practical measurement disengaging of clutch power-clutch pedal rotation curve.

Therefore, if the pedal corner corresponding to peak value of T is identical with the pedal corner corresponding to the peak value of disengaging of clutch power described in the disengaging of clutch power-clutch pedal rotation curve in Fig. 3 in the torsion spring power-assisted curve in Fig. 4, then d is described ₀, r and l initial value be optimal selection, without the need to adjustment.

If the pedal corner corresponding to peak value of T is not identical with the pedal corner corresponding to the peak value of disengaging of clutch power described in the disengaging of clutch power-clutch pedal rotation curve in Fig. 3 in the torsion spring power-assisted curve in Fig. 4, then d is described ₀, r and l initial value be not optimal selection; Now, d is adjusted ₀, r and l initial value at least one, make the pedal corner corresponding to the peak value of the pedal corner corresponding to peak value of T in described torsion spring power-assisted curve and disengaging of clutch power described in described disengaging of clutch power-clutch pedal rotation curve identical, thus determine d ₀, r and l end value, complete the design of clutch pedal torsion spring force aid system.

In figure 3, the disengaging of clutch power peak value of described disengaging of clutch power-clutch pedal rotation curve is positioned at pedal corner 11.6 ° place, and the peak value of T does not appear at pedal corner 11.6 ° place in torsion spring power-assisted curve described in the diagram, visible, the clutch pedal torsion spring force aid system that Fig. 4 represents is not optimal design, can by adjustment d ₀, r and l initial value at least one, make the peak value of T in described torsion spring power-assisted curve also at pedal corner 11.6 ° place, thus obtain optimum clutch pedal torsion spring force aid system design plan.

Should be understood that, in torsion spring power-assisted curve, the pedal corner corresponding to peak value of T is identical with the pedal corner corresponding to the peak value of disengaging of clutch power described in disengaging of clutch power-clutch pedal rotation curve, comprise the situation that the pedal corner corresponding to peak value of T in torsion spring power-assisted curve is substantially identical with the pedal corner corresponding to the peak value of disengaging of clutch power described in disengaging of clutch power-clutch pedal rotation curve, namely allow rational error limit.

The method of designing of clutch pedal torsion spring force aid system according to the above embodiment of the present invention, to correct in existing method torsion spring to the problem of the force direction definition error of pedal, thus, the torsion spring power-assisted model obtained is more accurate, avoids the design error that clutch pedal torsion spring force aid system is larger.

In addition, present invention also offers a kind of method of designing of clutch pedal coil spring force aid system, described method comprises:

201, according to geometrical principle determination coil spring deflection L _xexpression formula 5 be:

$L_x=L_0-\sqrt{{L_1}^2+{L_2}^2+2L_1{L}_2\cos (a_0-\mathrm{\θ})};$

Wherein, θ is pedal corner, a ₀for pedal initial angle, L ₁for distance, the L of the attachment point C to pedal pivot point O of torsion spring on pedal support ₂for distance, the L of the attachment point B to pedal pivot point O of torsion spring on pedal ₀for coil spring drift, in described expression formula 5, ignore helical spring deadweight; In the present embodiment, as shown in Figures 1 and 5, ignore pedal 1 shape simultaneously, be reduced to the straight line OA rotated around pedal pivot point O; Certainly, in other embodiments, pedal 1 also can not be reduced to straight line, but designs according to the shape of itself.In the present embodiment, preferably, selected coil spring is cylindrically coiled spring, certainly, in other embodiments, also can select the coil spring of other form according to different demands, such as Reducing screw spring.

In the present embodiment, coil spring deflection L _xbe specifically calculated as follows:

As shown in Figure 5, under a certain θ, L ₁for the line segment CO in figure, L ₂for the line segment BO in figure, according to the cosine law, can in the hope of the distance of line segment BC (namely under a certain pedal corner, the distance L of attachment point B and attachment point C _m), this distance L _mbe coil spring under this θ by the length after compressing, namely obtain following formula (9):

(9); Wherein a is under this θ, the angle of line segment CO and line segment BC, and angle a is a ₀with the difference of θ, namely there is following formula (10):

a＝a ₀-θ（10）；

In conjunction with formula (9) and formula (10), then obtain coil spring under this θ by the length L after compressing _m:

$L_m=\sqrt{{L_1}^2+{L_2}^2-2L_1{L}_2\cos (a_0-\mathrm{\θ})};$

Then have:

Helical spring deflection $L_x=L_0-L_m=L_0-\sqrt{{L_1}^2+{L_2}^2-2L_1{L}_2\cos (a_0-\mathrm{\θ})}.$

202, the directed force F of coil spring to its attachment point B on pedal is set up according to coil spring force analysis _nexpression formula 6 be:

F _n＝K ₁×L _x；

Wherein, K ₁for rigidity of helical spring.

203, the F of coil spring to its attachment point B on pedal is set up according to geometrical principle _nto the arm of force L of pedal pivot point O _nexpression formula 7 be:

$L_n=\frac{L_1\×L_2\×\sin (a_0-\mathrm{\θ})}{\sqrt{{L_1}^2+{L_2}^2-{2L}_1{L}_2\cos (a_o-\mathrm{\θ})}};$

In the present embodiment, arm of force L _nbe specifically calculated as follows:

As shown in Figure 2, under a certain pedal rotational angle theta, the distance L of the coil spring attachment point C on pedal support to pedal pivot point O ₁for the line segment CO in figure, the distance L of the coil spring attachment point B on pedal to pedal pivot point O ₂for the line segment BO in figure, according to the characteristic of right-angled triangle, then there is formula (11):

L _n＝L ₁sinc（11）；

Wherein c is the angle of line segment CO and line segment CB;

According to sine, then have:

and then obtain formula (12):

$\frac{L_2\×\sin a}{L_m}---\left(12\right);$

In conjunction with formula (9), (10), (11) and (12), expression formula 7 can be obtained:

$L_n=\frac{L_1\×L_2\×\sin (a_0-\mathrm{\θ})}{\sqrt{{L_1}^2+{L_2}^2-{2L}_1{L}_2\cos (a_o-\mathrm{\θ})}}.$

204, according to expression formula 5, expression formula 6 and expression formula 7 and based on the equation 2 that principle of moment balance is determined, setting up coil spring power-assisted model expression 8 is:

$T=\frac{K_2{L}_1{L}_2\sin (a_0-\mathrm{\θ})\{d_0-\arccos [1-\frac{{L_1}^2+{L_2}^2-2L_1{L}_2\cos (a_0-\mathrm{\θ})}{2(r^2+l^2)}\left]\right\}}{L_{p}l\sqrt{{L_1}^2+{L_2}^2-2L_1{L}_2\cos (a_0-\mathrm{\θ})}};$

Wherein equation 2 is: T × L _p=F _n× L _n, L _pfor coil spring to the application force T of the pedal tread A point of pedal to the arm of force of pedal pivot point O, i.e. L _pfor A point on pedal tread is to the vertical distance of pedal pivot point O.Preferably, on described pedal tread, A point is the center of pedal tread.

205, clutch pedal coil spring force aid system is designed according to above-mentioned coil spring power-assisted model expression 8.

In addition, the method for designing of the clutch pedal coil spring force aid system that one embodiment of the invention provides, can further include step 206, this step 206 is as follows:

Obtain the disengaging of clutch power-clutch pedal rotation curve representing disengaging of clutch power and θ corresponding relation;

Determine a ₀, L ₁, L ₂, L _pand K ₁value;

Setting L ₀initial value;

The span of selected θ, according to the coil spring power-assisted model set up, obtains the coil spring power-assisted curve representing T and θ corresponding relation;

Adjustment L ₀initial value, make the pedal corner corresponding to the peak value of the pedal corner corresponding to peak value of T in described coil spring power-assisted curve and disengaging of clutch power described in described disengaging of clutch power-clutch pedal rotation curve identical, thus determine L ₀end value, complete the design of clutch pedal coil spring force aid system.

In one embodiment, in described step 206, a ₀determined value be 1.8 °, L ₁determined value be 64mm, L ₂determined value be 50mm, L _pdetermined value be that the span of 323mm, θ is chosen to be 0 ~ 25 °, K ₁determined value be 10N/mm.L ₀initial value be set as 40mm.By above-mentioned a ₀, L ₁, L ₂, L _pand K ₁determined value and L ₀initial value all substitute into above-mentioned coil spring power-assisted model expression 8, then obtain the definite expression formula of application force T about pedal rotational angle theta, and within the scope of the pedal rotational angle theta of 0 ~ 25 °, utilize this exact expression formula to draw out the coil spring power-assisted curve representing described application force T and described pedal rotational angle theta corresponding relation, described coil spring power-assisted curve as shown in Figure 6.

In the present embodiment, as shown in Figure 3, it is obtained by emulation or is obtained by practical measurement disengaging of clutch power-clutch pedal rotation curve.

Therefore, if the pedal corner corresponding to peak value of T is identical with the pedal corner corresponding to the peak value of disengaging of clutch power described in the disengaging of clutch power-clutch pedal rotation curve in Fig. 3 in the coil spring power-assisted curve in Fig. 6, then L is described ₀initial value be optimal selection, without the need to adjustment.

If the pedal corner corresponding to peak value of T is not identical with the pedal corner corresponding to the peak value of disengaging of clutch power described in the disengaging of clutch power-clutch pedal rotation curve in Fig. 3 in the coil spring power-assisted curve in Fig. 6, then L is described ₀initial value be not optimal selection; Now, L is adjusted ₀initial value, make the pedal corner corresponding to the peak value of the pedal corner corresponding to peak value of T in described coil spring power-assisted curve and disengaging of clutch power described in described disengaging of clutch power-clutch pedal rotation curve identical, thus determine L ₀end value, complete the design of clutch pedal coil spring force aid system.

In figure 3, the disengaging of clutch power peak value of described disengaging of clutch power-clutch pedal rotation curve is positioned at pedal corner 11.6 ° place, and the peak value of T does not appear at pedal corner 11.6 ° place in coil spring power-assisted curve described in figure 6, visible, the clutch pedal coil spring force aid system that Fig. 6 represents is not optimal design, can by adjustment L ₀initial value, make the peak value of T in described coil spring power-assisted curve also at pedal corner 11.6 ° place, thus obtain optimum clutch pedal coil spring force aid system design plan.

The method of designing of clutch pedal coil spring force aid system according to the above embodiment of the present invention, to correct in existing method torsion spring to the problem of the force direction definition error of pedal, thus, the coil spring power-assisted model obtained is more accurate, avoids the design error that clutch pedal coil spring force aid system is larger.

The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, all any amendments done within the spirit and principles in the present invention, equivalent replacement and improvement etc., all should be included within protection scope of the present invention.

Claims (10)

1. a method of designing for clutch pedal torsion spring force aid system, is characterized in that, described method comprises:

According to geometrical principle determination torsion spring deflection expression formula 1 be:

Wherein, θ is pedal corner, a ₀for pedal initial angle, L ₁for distance, the L of the attachment point C to pedal pivot point O of torsion spring on pedal support ₂for distance, the d of the attachment point B to pedal pivot point O of torsion spring on pedal ₀for torsion spring free state angle, r be the radius of torsion spring, l is torsion spring brachium, in described expression formula 1, ignore the deadweight of torsion spring, ignore the radius r of torsion spring because of compression or the flexure deformation drawing high produced change in radius and torsion spring hold-down arm;

The directed force F of torsion spring to its attachment point B on pedal is set up according to torsion spring force analysis _nexpression formula 2 be:

Wherein, K ₂for torsion spring rigidity;

The directed force F of torsion spring to its attachment point B on pedal is set up according to geometrical principle _nto the arm of force L of pedal pivot point O _nexpression formula 3 be:

$L_n=\frac{L_1\×L_2\×\sin (a_0-\mathrm{\θ})}{\sqrt{{L_1}^2+{L_2}^2-{2L}_1{L}_2\cos (a_o-\mathrm{\θ})}};$

According to expression formula 1, expression formula 2, expression formula 3 and based on the equation 1 that principle of moment balance is determined, setting up torsion spring power-assisted model expression 4 is:

$T=\frac{K_2{L}_1{L}_2\sin (a_0-\mathrm{\θ})\{d_0-\arccos [1-\frac{{L_1}^2+{L_2}^2-2L_1{L}_2\cos (a_0-\mathrm{\θ})}{2(r^2+l^2)}\left]\right\}}{L_{p}l\sqrt{{L_1}^2+{L_2}^2-2L_1{L}_2\cos (a_0-\mathrm{\θ})}};$

Wherein, equation 1 is: T × L _p=F _n× L _n, L _pfor torsion spring to the application force T of the pedal tread A point of pedal to the arm of force of pedal pivot point O;

Clutch pedal torsion spring force aid system is designed according to torsion spring power-assisted model expression 4.

2. the method for designing of clutch pedal torsion spring force aid system according to claim 1, is characterized in that, on described pedal tread, A point is the center of pedal tread.

3. the method for designing of clutch pedal torsion spring force aid system according to claim 1, it is characterized in that, described method also comprises:

Obtain the disengaging of clutch power-clutch pedal rotation curve representing disengaging of clutch power and θ corresponding relation;

Determine a ₀, L ₁, L ₂, L _pand K ₂value;

Set d respectively ₀, r and l initial value;

The span of selected θ, according to the torsion spring power-assisted model set up, obtains the torsion spring power-assisted curve representing T and θ corresponding relation;

Adjustment d ₀, r and l initial value at least one, make the pedal corner corresponding to the peak value of the pedal corner corresponding to peak value of T in described torsion spring power-assisted curve and disengaging of clutch power described in described disengaging of clutch power-clutch pedal rotation curve identical, thus determine d ₀, r and l end value, complete the design of clutch pedal torsion spring force aid system.

4. the method for designing of clutch pedal torsion spring force aid system according to claim 3, is characterized in that, a ₀determined value be 1.8 °, L ₁determined value be 64mm, L ₂determined value be 50mm, L _pdetermined value be that the span of 323mm, θ is chosen to be 0 ~ 25 °, K ₂determined value be 200N/mm.

5. the method for designing of the clutch pedal torsion spring force aid system according to claim 3 or 4, it is characterized in that, the initial value of l is set as 24mm, and the initial value of r is set as 10mm, d ₀initial value be set as 70 °.

6. a method of designing for clutch pedal coil spring force aid system, is characterized in that, described method comprises:

According to geometrical principle determination coil spring deflection L _xexpression formula 5 be:

$L_x=L_0-\sqrt{{L_1}^2+{L_2}^2+2L_1{L}_2\cos (a_0-\mathrm{\θ})};$

Wherein, θ is pedal corner, a ₀for pedal initial angle, L ₁for distance, the L of the attachment point C to pedal pivot point O of torsion spring on pedal support ₂for distance, the L of the attachment point B to pedal pivot point O of torsion spring on pedal ₀for coil spring drift, in described expression formula 5, ignore helical spring deadweight;

The directed force F of coil spring to its attachment point B on pedal is set up according to coil spring force analysis _nexpression formula 6 be:

F _n＝K ₁×L _x；

Wherein, K ₁for rigidity of helical spring;

The directed force F of coil spring to its attachment point B on pedal is set up according to geometrical principle _nto the arm of force L of pedal pivot point O _nexpression formula 7 be:

$L_n=\frac{L_1\×L_2\×\sin (a_0-\mathrm{\θ})}{\sqrt{{L_1}^2+{L_2}^2-{2L}_1{L}_2\cos (a_o-\mathrm{\θ})}};$

According to expression formula 5, expression formula 6 and expression formula 7 and based on the equation 2 that principle of moment balance is determined, setting up coil spring power-assisted model expression 8 is:

$T=\frac{K_2{L}_1{L}_2\sin (a_0-\mathrm{\θ})[L_0-\sqrt{{L_1}^2+{L_2}^2-2L_1{L}_2\cos (a_0-\mathrm{\θ})}]}{L_p\sqrt{{L_1}^2+{L_2}^2-2L_1{L}_2\cos (a_0-\mathrm{\θ})}};$

Wherein equation 2 is expressed as: T × L _p=F _n× L _n, L _pfor coil spring to the application force T of the pedal tread A point of pedal to the arm of force of pedal pivot point O;

Clutch pedal coil spring force aid system is designed according to coil spring power-assisted model expression 8.

7. the method for designing of clutch pedal coil spring force aid system according to claim 6, is characterized in that, on described pedal tread, A point is the center of pedal tread.

8. the method for designing of clutch pedal coil spring force aid system according to claim 6, it is characterized in that, described method also comprises:

Obtain the disengaging of clutch power-clutch pedal rotation curve representing disengaging of clutch power and θ corresponding relation;

Determine a ₀, L ₁, L ₂, L _pand K ₁value;

Setting L ₀initial value;

The span of selected θ, according to the coil spring power-assisted model set up, obtains the coil spring power-assisted curve representing T and θ corresponding relation;

Adjustment L ₀initial value, make the pedal corner corresponding to the peak value of the pedal corner corresponding to peak value of T in described coil spring power-assisted curve and disengaging of clutch power described in described disengaging of clutch power-clutch pedal rotation curve identical, thus determine L ₀end value, complete the design of clutch pedal coil spring force aid system.

9. the method for designing of clutch pedal coil spring force aid system according to claim 8, is characterized in that, a ₀determined value be 1.8 ^°, L ₁determined value be 64mm, L ₂determined value be 50mm, L _pdetermined value be that the span of 323mm, θ is chosen to be 0 ~ 25 ^°, K ₁determined value be 10N/mm.

10. the method for designing of clutch pedal coil spring force aid system according to claim 8 or claim 9, is characterized in that, L ₀initial value be set as 40mm.