CN1912420A - Vabrition damper for semi-active electromagnetic suspension of electric vehicle - Google Patents

Abstract

A vibration absorber used on half active electromagnetic suspension in driven automobile is prepared as applying electromagnetic vibration absorber to generate a vibration damping according to relative movement speed between spring loaded mass and under spring mass, setting said absorber to double sleeves structure and winding a numbers of excitation coils in gap between internal and external cylinders, setting piston rod and piston as well as hydraulic oil cavity in internal cylinder, setting piston rod or piston to be strip magnetic iron and opening a numbers of damping holes being used to pass-flow hydraulic oil on piston.

Description

Be used for the initiatively vibration damper of electromagnetic suspension of electric vehicle half

[technical field]

The present invention relates to a kind of initiatively vibration damper of electromagnetic suspension of electric vehicle half that is used for.

[background technique]

When automobile running is on the road surface, has some and allow the people feel ill and the vibration of the Vertical direction that is harmful to health is added on vehicle body and passenger's the health.The essence of this vibration is exactly the acceleration of spring carried mass, traditional suspension mainly is that the vibration damper by the hydraulic pressure form absorbs this part energy, but this part energy has normally fallen as heat dissipation, so there is the people to begin to consider that the mode with electromagnetism replaces dydraulic shock absorber.

For example, in the articles that the people delivered " Energy Recovery from an Electrical Suspension for EV " such as Portuguese Ismenio Martins, Jorge Esteves and Fernando Pina da Silva a kind of like this electromagnetic suspension (this project is supported by JNICT project n.PBIC/C/CEG/2363/95) has just been proposed, as shown in Figure 1, this suspension comprises an electromagnetic damper and a cover energy-recuperation system.

But because technology is ripe not enough, present stage the working stability of electromagnetic suspension also can not show a candle to traditional suspension, limited its application.

[summary of the invention]

The objective of the invention is to, overcome the not enough problem of the stability of a system that exists in the prior art, a kind of new vibration damper that is used for electric vehicle half active electromagnetic suspension is provided, better suppresses the vibration of spring carried mass, and guarantee that when electromagnetism lost efficacy vibration damper did not lose efficacy.

For achieving the above object, the vibration damper that is used for electric vehicle half active electromagnetic suspension that the present invention proposes comprises electromagnetic damper, be used for producing a vibration damping according to the speed of related movement between spring carried mass and the unsprung weight, it is characterized in that: described electromagnetic damper is a double-sleeve structure, in the gap of inner core and urceolus, be wound with some field coils, have piston rod, piston and hydraulic oil to store the chamber in inner core, one of them is a bar magnet at least for described piston rod and piston; Also have some damping holes of allowing hydraulic oil therefrom flow through of being used on the piston.

According to preferred version of the present invention, this suspension also comprises filler opening, oil outlet and oil storage tank, and described filler opening links to each other with oil storage tank with oil drain valve by priming valve respectively with oil outlet.

Also comprise automatically controlled piston, be positioned at the oil storage tank top, its control end links to each other with control unit ECU

Also comprise floating piston, be positioned at the oil storage tank below.

There is sealing nitrogen described floating piston below.

Because the present invention has adopted such scheme, emerging electromagnetic suspension and traditional hydraulic suspension are organically combined, the two works simultaneously, the advantage that had both had the electromagnetic suspension recoverable energy, the advantage that has the traditional suspension stable performance again, can better suppress the vibration of spring carried mass, and guarantee that when electromagnetism lost efficacy vibration damper did not lose efficacy.

[description of drawings]

Fig. 1 is the electromagnetic damper schematic representation of prior art recoverable energy.

Fig. 2 a is the internal structure rough schematic view of permanent magnetism linear incentive vibration damping generator of the present invention.

Fig. 2 b is a damper piston cross sectional representation of the present invention.

Fig. 3 is a vibration damper of the present invention and the situation that the is connected schematic representation of control unit and electronic circuit breaker, storage battery, outer oil circuit.

[embodiment]

Shown in Fig. 2 a, what the vibration damper in this suspension adopted is double-sleeve structure, is wound with some field coils 1 and shows in the gap of inner core and urceolus.Piston rod 2 is bar permanent magnets, and it is fixedly connected in the center hole of piston 3.What piston 3 adopted is iron material, helps to increase the permeability between coil and the permanent magnet like this.

4 and 5 are respectively filler opening and oil outlet, link to each other with oil storage tank 9 with oil drain valve 7 by a priming valve 6 respectively, also have some damping holes 31 on the piston, shown in Fig. 2 b.Their employing is in order to make this suspension become mixing suspension system in conjunction with electromagnetic vibration damping and conventional hydraulic vibration damping.What wherein damping hole 31 adopted is the very little damping hole of diameter, in fact because the conventional suspension that this cover replenishes only just adopted when electromagnetic suspension loses efficacy, therefore adopt the simplest damping hole to get final product, if use the flowing valve on the traditional suspension certainly instead, effect can be better, but cost can rise.32 is center hole among the figure, is used to connect bar permanent magnet.

Fig. 3 represents is vibration damper and the situation that is connected of control unit and electronic circuit breaker, storage battery, outer oil circuit.As seen from the figure, filler opening 4 links to each other with oil storage tank 9 with oil drain valve 7 by priming valve 6 respectively with oil outlet 5.Also comprise automatically controlled piston 8, be positioned at the oil storage tank top, its control end links to each other with control unit ECU; Floating piston 10 is positioned at the oil storage tank below, and there is sealing nitrogen described floating piston 10 belows.

Working condition is as follows: permanent magnetism linear incentive vibration damping generator is operated in alternator mode.When relative movement took place between piston rod 2, piston 3 and the bitubular cylinder body, the magnetic flux by field coil 1 will change, and that is to say that field coil will certainly cut the magnetic line of force that permanent magnet produces, and produces electromagnetic force.Because coil when cutting magnetic line, radially is being symmetrical, so electromagnetic force component diametrically is equal and opposite in direction, direction is opposite, thereby we may safely draw the conclusion, and making a concerted effort of electromagnetic force is axial force.According to Lenz's law, when producing flux change between coil and the permanent magnet, it is to want to suppress this variation that coil produces induction electromotive force, promptly produces counter magnetic flux, this is to suppress this relative movement to take place with regard to the electromagnetic force that means generation, so can be used as the damping force of this cover vibration damping equipment.

When between coil and permanent magnet relative movement being arranged, because coil cutting magnetic line has certainly led to induction electromotive force, link to each other with external circuit, just produced induction current, in fact, this device is regulated damping force by adjusting induction current.In Fig. 3, the electric bridge that is constituted by a diode is used for adjusting the faradic phase place of output, and inductance is as energy buffer, stored energy during switch on, and switch disconnects to be transferred to energy in the battery again, thereby finishes the charging process to battery.Above among Fig. 3 and independent diode that battery directly links to each other in fact be a one-way valve to electric current, it passes through the control to current direction, the assurance suspension can only be to battery charge, and can not cause battery discharge, thereby has reached purpose of energy saving.

According to pertinent literature, can get the formula of damping force:

$F_A=-i\·\mathrm{K\Φ}\·\mathrm{sign}({\stackrel{\·}{z}}_s-{\stackrel{\·}{z}}_u)=-\frac{{\left(\mathrm{K\Φ}\right)}^2({\stackrel{\·}{z}}_s-{\stackrel{\·}{z}}_u)}{R_{\mathrm{\Σ}}}$

Wherein, Φ represents the magnetic flux by coil winding, and K is a structural coefficient, and they have determined the output voltage u of permanent magnetism linear incentive vibration damping generator jointly,

Relative velocity between expression spring carried mass and the nonspring carried mass, the in fact speed of related movement between coil and the permanent magnet just.R _∑What represent is the all-in resistance of entire circuit, if vibration damper is operated in the pure resistance pattern, this is a definite value.Induction electromotive force: $e=\left|\mathrm{K\Φ}({\stackrel{\·}{z}}_s-{\stackrel{\·}{z}}_u)\right|,$ And induction current: i=e/R _∑

If following formula is write as the form of traditional damping force, we can draw the formula of damping:

b _s＝(KΦ) ²/R _∑

If excitation is operated in the pure resistance pattern, vibration damper will have a fixing damping, suspension is the passive type suspension just, yet excitation is not to be operated in the pure resistance pattern, and the damping force that system produces is regulated by electric current, electric current can be changed the switch gear by control unit and be regulated, in fact, also be that conversion by the switch gear realizes to the charging of battery, therefore can realize becoming damping.

Below be the change damping that we prepare realization:

$b_s=-{\left({\stackrel{\&CenterDot;\&CenterDot;}{z}}_s\right)}^2\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="B"\; filenames="A20051002148600101.png"\; state="\{\{state\}\}">B</figure-callout>}}_1+{\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="A20051002148600101.png"\; state="\{\{state\}\}">C</figure-callout>}}_1\&DoubleLeftArrow;b_s>0$

$b_s=B\&DoubleLeftArrow;b_s\&le;0$

We can with $F_{\mathrm{ref}}=\left|b_s({\stackrel{\&CenterDot;}{z}}_s-{\stackrel{\&CenterDot;}{z}}_u)\right|$ Pre-set, be stored in the control unit, as the test value of damping force, when | F _A|＜F _RefThe time, control unit gets out of the way and closes closure, and induction current increases, and damping force increases; When | F _A|＞F _RefThe time, control unit gets out of the way to close and disconnects, and induction current reduces, and damping force reduces.This controlling method is not that this device adopts, but the control that this device adopts is to be based upon on the basis of this method, therefore is necessary to hand over.

We directly control damping force by the test value of electric current.Usually, the suspension system on the automobile can not be too responsive to reacting condition on every side.Take place for fear of some too sensitive inductions, be necessary some parameter values are estimated.Because $({\stackrel{\&CenterDot;}{z}}_s-{\stackrel{\&CenterDot;}{z}}_u)=\frac{e}{\mathrm{K\&Phi;}}=\frac{u+i\&CenterDot;R_A}{\mathrm{K\&Phi;}},$ Wherein e represents induction electromotive force, and R _AThe resistance value of the permanent magnetism linear incentive vibration damping generator of expression.The test value that this formula and damping force have been arranged, we can estimate a value, as the test value of electric current, thereby directly electric current are controlled, and are not needed to compare with damping force again, this makes control become and is more prone to.Below be the estimation result of electric current test value:

$i_{\mathrm{ref}}=u\frac{b_s}{{\left(\mathrm{K\&Phi;}\right)}^2-b_s{R}_a}$

The control procedure of this device can be described like this:

As i＜i _RefThe time, switch on, electric current increases, and damping force increases; As i＞i _RefThe time, switch disconnects, and electric current reduces, and damping force reduces.

The process of suspension recovered energy can be described like this: system has adopted a cover electronic circuit breaker to link to each other with electric bridge, is used for realizing the transition of voltage.When switch on (S=1), energy is deposited in inductance; When switch disconnected (S=0), the energy in the inductance was transferred to storage battery, promptly charges the battery.

In conjunction with Fig. 2, from following formula as can be seen electric-power damper be recovered energy how: $e-i\&CenterDot;(R_A+R_L)-L\frac{\mathrm{di}}{\mathrm{dt}}=0,$ (S=1) when switch on, energy is deposited in inductance $e-i\&CenterDot;(R_A+R_L+R_{\mathrm{bat}})-L\frac{\mathrm{di}}{\mathrm{dt}}-E_{\mathrm{bat}}=0,$ (S=0, i＞0), when switch disconnected, the energy in the inductance was transferred to storage battery, promptly charges the battery

Wherein, subscript A represents the physical quantity on the field coil, and subscript L represents the physical quantity on the inductance L, and subscript bat represents the physical quantity on the battery, and e and E represent electromotive force.

Because excitation can not accomplish to be operated in generator mode always, in some specific moment, it also can come work with electric motor mode, electrical signal at this moment will occur and interrupt and cause the unreliable of system works this moment.In addition, owing to the technology that present electromagnetic suspension is present is also very immature, the possibility that inefficacy is arranged under abominable operating conditions, if but automobile is in the process of travelling, suspension must guarantee to have the function of vibration damping, so we have increased a set of equipment on the basis of electromagnetic suspension, make that suspension still can be realized the function of vibration damping when electromagnetic suspension lost efficacy.

Shown in Fig. 2 a, filler opening 4 links to each other with oil storage tank 9 by oil drain valve 7 by priming valve 6, oil outlet 5, and the controlled unit ECU of priming valve and oil drain valve is by 8 controls of the automatically controlled piston in the oil storage tank; Piston 3 peripheries also have some damping holes, shown in Fig. 2 b; The annexation of ECU and each element as shown in Figure 3.When control unit receives signal that acceleration transducer transmits greater than the maximum value that is stored in the spring carried mass acceleration in the control unit in advance, thereby control unit then output signal makes automatically controlled piston to close clutch release slave cylinder one lateral movement, thereby back down the clutch release slave cylinder that priming valve is pressed into fluid vibration damper, when oil pressure reaches threshold value in the cylinder, there is pressure transducer that signal is transferred to ECU, the ECU output order is given automatically controlled piston, by force that automatically controlled piston is locked, the oil pressure difference that automatically controlled piston still exists up and down in the oil storage tank is adjusted by floating piston at this moment.Equally, if when the acceleration of spring carried mass less than the minimum value that is stored in the spring carried mass acceleration in the control unit in advance, in fact start auxiliary traditional suspension inhibition spring carried mass acceleration this moment and do not have too big practical significance for improving run smoothness, and owing to reasons such as friction have been lost a large amount of heat energy, in line with purpose of energy saving, at this moment control unit will be given automatically controlled piston one signal, make it to away from clutch release slave cylinder one lateral movement, thereby cause degree of vacuum to back down oil drain valve fluid sucking-off clutch release slave cylinder.When oil pressure is lower than threshold value in the cylinder, there is pressure transducer that signal is passed to ECU, the automatically controlled piston motion of ECU output control command locking makes pressure balance by the floating piston adjustment, and automatically controlled piston should adopt high-abrasive material.

The foregoing description is used for just that the present invention will be described, and in addition, the present invention can also have some modification:

Such as, if do not consider energy-conservation purpose, can make closed pattern to the inner core of double-sleeve structure, fill hydraulic oil therein with.Like this, much no matter the acceleration of spring carried mass has, liquid-springing all works.That is: major-minor vibration damping all works simultaneously.For another example, priming valve and oil drain valve can control with other modes, such as, can control with an automatically controlled piston respectively, or control with oil pump.For another example, permanent magnet also can consider to adopt electromagnet.

Claims (5)

1, a kind of initiatively vibration damper of electromagnetic suspension of electric vehicle half that is used for, comprise electromagnetic damper, be used for producing a vibration damping according to the speed of related movement between spring carried mass and the unsprung weight, it is characterized in that: described electromagnetic damper is a double-sleeve structure, in the gap of inner core and urceolus, be wound with field coil, have piston rod (2), piston (3) and hydraulic oil to store the chamber in inner core, one of them is a bar magnet at least for described piston rod (2) and piston (3); Also have some damping holes (31) of allowing hydraulic oil therefrom flow through of being used on the piston.

2, the initiatively vibration damper of electromagnetic suspension of electric vehicle half that is used for as claimed in claim 1 is characterized in that: also comprise filler opening (4), oil outlet (5) and oil storage tank (9), the described priming valve (6) that passes through respectively links to each other with oil storage tank (9) with oil drain valve (7).

3, the initiatively vibration damper of electromagnetic suspension of electric vehicle half that is used for as claimed in claim 2, it is characterized in that: also comprise automatically controlled piston (8), be positioned at the oil storage tank top, its control end links to each other with control unit (ECU)

4, as claim 2 or the 3 described initiatively vibration dampers of electromagnetic suspension of electric vehicle half that are used for, it is characterized in that: also comprise floating piston (10), be positioned at the oil storage tank below.

5, the initiatively vibration damper of electromagnetic suspension of electric vehicle half that is used for as claimed in claim 4, it is characterized in that: there is sealing nitrogen described floating piston (10) below.

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