CN105156542A - Piezoelectric energy-feed type shock absorber - Google Patents

Abstract

A piezoelectric energy-feed type shock absorber comprises a shock absorber body, a universal drive shaft and a piezoelectric mechanism. The two ends of the universal drive shaft are connected with a gear shaft of the shock absorber body and a cam shaft of the piezoelectric mechanism through cross universal joints; the piezoelectric mechanism mainly comprises a shell, a piezoelectric beam, a cam, the cam shaft and a fixed end. The shock absorber body mainly comprises a gear, a rack, an inner sleeve, an outer sleeve, a piston, a floating piston, a compression valve, an expansion valve, a guide base, hydraulic oil, the gear shaft and lifting lugs. The piezoelectric energy-feed type shock absorber can generate electric energy and damp needed by vibration reduction of a vehicle, reduce fuel consumption of a vehicle engine and reduce pollution of the vehicle to the environment.

Description

The energy vibration damper of piezoelectricity

Technical field

The present invention relates to a kind of vehicle shock absorber, particularly a kind of energy vibration damper.

Technical background

Automobile industry grow continuously and fast while pulling economy, uplifting the people's living standard, day by day serious to the pollution of environment, exacerbate the shortage problem of automobile available energy.Energy saving, protection of the environment be automotive industry the present and the future develop must faced by two themes.Therefore, recycling is carried out to the portion of energy consumed in vehicle traveling process significant.

Suspension connects vehicle bridge and vehicle body, and its function relaxes road excitation to bring the impact of vehicle body and the vibration of decay vehicle body, ensures ride of vehicle and control stability.The stochastic vibration energy of suspension system under road surface and motor equal excitation is converted into form of thermal energy by suspension shock-absorber and consumes.If reclaimed needing the energy of vibration damper consumption; be converted into form of energy that vehicle can directly utilize as electric energy, hydraulic energy etc.; and produce the damping of Vehicle damper needs; just can reduce the fuel consume of vehicle while ensureing vehicle run smoothness, reach the object of energy saving and protection of the environment.

Current automobile vibrational energy recovery method mainly contains mechanical type and electromagnetic type.Mechanical type energy regenerative method utilizes liquid (gas) to press accumulator, and vibrational energy is stored into this device with the form of hydraulic energy or air pressure energy, but speed of response is comparatively slow, response frequency is lower.Electromagnetic type energy regenerative method utilizes electromagnetic generator, the coil cutting magnetic induction line of generator, is electric energy by changes mechanical energy, but volume is comparatively large, easily the problem such as electromagnetic interference and leakage field occurs.

Piezoelectric material has piezoelectric effect, and piezoelectric effect is the phenomenon that mechanical energy and electric energy are changed by piezoelectric material mutually.Utilize the direct piezoelectric effect of piezoelectric material that the vibrational energy of external environment is converted into electric energy and the theory carrying out storing has become current study hotspot, be suitable for the recovery of Vehicular vibration energy.Relative electromagnetic principle, electrostatic principle and hydraulic principle, it is good that piezoelectric energy conversion equipment is embodied in data-collection performance, not only has the simple advantage of structure, also comprises without heating, without electromagnetic interference, inertia is little and easily realize the plurality of advantages such as integrated.

Reclaim about Vehicular vibration energy at present in the patent documentation of piezoelectric device, piezoelectric device is all power-actuated, do not consider the relation of energizing frequency and piezoelectric device natural frequency, cannot accomplish that the natural frequency of energizing frequency and piezoelectric device is close, therefore cannot give full play to the performance of piezoelectric device.And only considered the characteristic of piezoelectric device generating, do not consider its damping characteristic, if replace former ride-control with piezoelectric device, the damping of piezoelectric device does not reach the damping needed for vehicle far away, if install piezoelectric device on the basis of former ride-control, will change the damping characteristic of vehicle, this all can make the smoothness of vehicle and travelling comfort decline.

Summary of the invention

The object of the present invention is to provide a kind of energy vibration damper of piezoelectricity that Vehicular vibration energy can be converted into electric energy, produce the damping needed for Vehicle damper simultaneously.

Technological scheme of the present invention is as follows:

The present invention includes vibration damper body, universal drive shaft and piezoelectric device, universal drive shaft two ends are connected with the gear shaft of vibration damper body and the camshaft of piezoelectric device respectively by Hooke's joint.

Described piezoelectric device mainly comprises housing, piezoelectric beam, cam, camshaft and fixed end.Axial surface both sides outside housing are respectively equipped with two corresponding housing hangers, and piezoelectric device is connected with vehicle body by four hangers; In casing, camshaft is through casing longitudinal center line, and this camshaft is fixed on casing by the deep groove ball bearing be located on casing two side shaft holder, and bearing (ball) cover is bolted on the casing outside bearing, for seal shaft socket end; One end of described camshaft is stretched out casing and is connected with universal drive shaft, cam is arranged on camshaft by key, the camshaft of cam both sides is respectively equipped with cam snap ring, these cam both sides are equipped with straight trough, the unfolded drawing of this straight trough two cell wall is the waveform curved surface be parallel to each other, and this straight trough on cam can increase the energizing frequency of piezoelectric beam; The upper lower box both sides inwall of bearing support is respectively equipped with fixed end, and one end of 15-30 piezoelectric beam is separately fixed on fixed end, and the other end of this piezoelectric beam is placed in the straight trough of above-mentioned cam by needle bearing.

The intermediate portion of described piezoelectric beam is divided into three layers, middle one deck is metal substrate, upper and lower two layers is all the piezo-electric sheets be made up of piezoceramic material, an electrode is respectively provided with in the both sides up and down of piezoelectric beam, be connected with external equipment or energy accumulating device by lead-in wire, reach the recycling function of energy.One end of piezoelectric beam is fixed block, piezoelectric beam intermediate portion and fixed block is bonded together by epoxy resin, and by bolt, fixed block is connected with the fixed end on piezoelectric device.The other end of piezoelectric beam and rotating shaft bond, by needle bearing Spielpassung between rotating shaft and cam mechanism.Length by the piezoelectric beam of universal drive shaft side is 3/5 of opposite side piezoelectric beam length.

Described vibration damper body mainly comprises: gear, tooth bar, inner sleeve, outer sleeve, piston, floating piston, compression valve, flexible valve, guide holder, hydraulic oil, gear shaft, hanger.Be provided with upper rings on the top of inner sleeve, be provided with sealed air chamber at inner sleeve top, the hydraulic pressure pasta below sealed air chamber is provided with the floating piston floating over pasta band seal ring, in sealed air chamber, is full of nitrogen; Below floating piston, be provided with piston, this piston is provided with upper and lower two circular holes, and compression valve is located in circular hole, and rebound valve is located in lower circular hole, and piston is also provided with piston outer ring, is mutually flowed by inwall for preventing the hydraulic oil in upper and lower two cavitys; The lower end of outer sleeve is provided with lower lift ring, the lower end of inner sleeve is enclosed within outer sleeve, tooth bar upper end is connected by bolt and piston, lower end and the outer sleeve of this tooth bar are connected, the lower end of inner sleeve is provided with seal ring, between inner sleeve and tooth bar lower end, be provided with guide holder, tooth bar is by producing linear relative movement between the guiding of guide holder and piston and inner sleeve; A cavity is provided with near the position of rack tooth at inner sleeve, pinion stand, bearing and gear is provided with in cavity, bearing and gear are located on the gear shaft that is connected with universal drive shaft, snap ring is respectively equipped with in gear both sides and bearing both sides, this wheel and rack tooth is meshed, opening is provided with sealing cover, and sealing lid and inner sleeve are connected.Below the floating piston of inner sleeve, be filled with hydraulic oil, hydraulic oil is flowed by compression valve and rebound valve and produces damping between the oil pocket that piston is upper and lower; The nitrogen that is filled with above of floating piston forms the difference that sealed air chamber carrys out the upper and lower oil chamber volume change of compensating piston.

The present invention compared with prior art tool has the following advantages:

1, while automobile vibrational energy being converted to electric energy, producible damping vibration attenuation body vibrations, utilizes the vibration of the damping vibration attenuation vehicle of vibration damper body and piezoelectric device, can not reduce smoothness and the travelling comfort of vehicle.

2, make energizing frequency close to the first natural frequency of piezoelectric beam by the method for the velocity ratio and increase cam lobe number that arrange gear rack, arrange around the piezoelectric beam of employing various structures size, a cam and multiple piezoelectric beam and camshaft arrange that the measures such as multiple cams make the natural frequency of piezoelectric beam cover the frequency of ground excitation, the generated energy of effective raising piezoelectric device and efficiency, reduce the fuel consume of vehicle motor, play the effect of energy saving and reduction vehicle environmental pollution.

Accompanying drawing explanation

Fig. 1 is structural representation sketch of the present invention.

Fig. 2 is the structural representation sketch of piezoelectric device of the present invention.

Fig. 3 is the structural representation sketch of piezoelectric device cam of the present invention.

Fig. 4 is the longitudinal section of Fig. 3.

Fig. 5 is that the master of piezoelectric beam in piezoelectric device of the present invention looks simplified schematic diagram.

Fig. 6 is the plan view of Fig. 5.

Fig. 7 is the rise movement profiles of driven member needle bearing of the present invention.

Fig. 8 is the graph of a relation of driven member needle bearing of the present invention and groove.

Fig. 9 is the kinematic relation figure of cam mechanism groove of the present invention and needle bearing.

Figure 10 is the structural representation sketch of vibration damper body of the present invention.

Figure 11 is the A-A sectional view of Figure 10.

In figure, 1. piezoelectric device, 2. universal drive shaft, 3. vibration damper body, 101. camshaft, 102. deep groove ball bearing, 103. bearing (ball) cover, 104. housing, 105. fixed end, 106. piezoelectric beam, 107. needle bearing, 108. cam, 109. piezoelectric beam, 110. housing hangers, 111. bolt, 112. bearing (ball) cover, 113. fixed block, 114. metal substrate, 115. contact conductor, 116. piezo-electric sheet, 117. rotating shaft, 118. through hole, 119. groove, 120. keyway, 301. bearing, 302. snap ring, 303. gear shaft, 304. sealing cover, 305. gear, 306. inner sleeve, 307. tooth bar, 308. compression valve, 309. floating piston, 310. upper rings, 311. sealed air chamber, 312. seal ring, 313. rebound valve, 314. piston, 315. piston outer rings, 316. hydraulic oil, 317. outer sleeve, 318. guide holder, 319. Sealing shield ring, 320. lower lift ring.

Embodiment

In the energy vibration damper schematic diagram of the piezoelectricity shown in Fig. 1, universal drive shaft 2 two ends are connected with the gear shaft of vibration damper body 3 and the camshaft of piezoelectric device 1 respectively by Hooke's joint.

As shown in Figure 2, the axial surface both sides outside the housing 104 of described piezoelectric device are respectively equipped with two corresponding housing hangers 110, and piezoelectric device is connected with vehicle body by four hangers; In casing, camshaft 101 is through casing longitudinal center line, and this camshaft is fixed on casing by the deep groove ball bearing 102 be located on casing two side shaft holder, and bearing (ball) cover 103 is bolted on the casing outside bearing, for seal shaft socket end; One end of described camshaft is stretched out casing and is connected with universal drive shaft, as shown in Figure 3 and Figure 4, cam 108 is arranged on camshaft by keyway 121 and internal key, the camshaft of cam both sides is respectively equipped with cam snap ring, these cam both sides are equipped with straight trough 119, the unfolded drawing of this straight trough two cell wall is the waveform curved surface be parallel to each other, and this straight trough on cam can increase the energizing frequency of piezoelectric beam; The upper lower box both sides inwall of bearing support is respectively equipped with fixed end 105, and one end of 30 piezoelectric beams 106 is separately fixed on fixed end, and the other end of this piezoelectric beam is placed in the straight trough of above-mentioned cam by needle bearing 107.

As shown in Figure 5 and Figure 6, the intermediate portion of described piezoelectric beam is divided into three layers, middle one deck is metal substrate 114, upper and lower two layers is all the piezo-electric sheets 116 be made up of piezoceramic material, a contact conductor 115 is respectively provided with in the both sides up and down of piezoelectric beam, be connected with external equipment or energy accumulating device by lead-in wire, reach the recycling function of energy.One end of piezoelectric beam is fixed block, piezoelectric beam intermediate portion and fixed block 113 is bonded together with epoxy resin, changes fixed block and is provided with through hole 120, and bolt makes the fixed block of piezoelectric beam connect together with the fixed end on piezoelectric device through through hole.The other end of piezoelectric beam and rotating shaft bond, by needle bearing Spielpassung between rotating shaft and cam mechanism.Length by the piezoelectric beam of universal drive shaft side is 3/5 of opposite side piezoelectric beam length.

Described piezoelectric device core parts are piezoelectric beam, and the design of the other end of above-mentioned piezoelectric beam and piezoelectric beam simply supported end supporting structure also determine excitation can with f (x, t)=Asin (ω t) sine function form passes to piezoelectric beam, to remain with cam mechanism to make piezoelectric beam simply supported end and contact, adopt groove type cam mechanism.When designing cam mechanism, cam mechanism profilogram need be drawn according to the characteristics of motion of its actual job requirement determination driven member, because sine function curve is relatively more steady, there is no acceleration shock, sinusoidal acceleration characteristics of motion representation theory profile can be used.Can be obtained by Der Grundsatz der Maschinen cam mechanism relevant knowledge, driven member sinusoidal acceleration displacement movement equation is

$\begin{array}{c}s=h\[\frac{\mathrm{\δ}}{{\mathrm{\δ}}_0}-\frac{1}{2\mathrm{\π}}sin\left(2\mathrm{\π}\frac{\mathrm{\δ}}{{\mathrm{\δ}}_0}\right)\]\\ \left(0\≤\mathrm{\δ}\≤{\mathrm{\δ}}_0\right)\end{array}---\left(1-1\right)$

H in formula---driven member rise working stroke (mm);

δ ₀---driven member motion angle for actuating travel (°).

Primary election piezoelectric beam displacement excitation amplitude is 3mm, requires that driven member needle bearing is also that therefore need to improve formula (1-1), after improving, formula is according to the motion of piezoelectric beam end exiting form

$\begin{array}{c}{s}^{\′}=h\[\frac{{\mathrm{\δ}}^{\′}}{{\mathrm{\δ}}_0}+\frac{1}{2\mathrm{\π}}sin\left(2\mathrm{\π}\frac{{\mathrm{\δ}}^{\′}}{{\mathrm{\δ}}_0}\right)\]\\ \left(-{\mathrm{\δ}}_0/2\≤{\mathrm{\δ}}^{\′}\≤{\mathrm{\δ}}_0/2\right)\end{array}---\left(1-2\right)$

H in formula---driven member working stroke is 6mm;

δ ₀---driven member motion angle is 18 °.

Formula (1-2) is carried out MATLAB programming, and export driven member rise Motion curves, as shown in Figure 7, as can be known from Fig. 7, the profilogram after improvement is more smooth-going, and sudden change, can not meet piezoelectric beam tip displacement excitation function.The design of cam straight trough profilogram adopts method of direct coordinate, can obtain theoretical contour right angled coordinates

x _B＝(s ₀+s′)sinδ′+ecosδ′

(1-3)

y _B＝(s ₀+s′)cosδ′-esinδ′

E, s in formula ₀---cam mechanism offset distance and Base radius, wherein offset distance is 0.

As shown in Figure 8, theoretical contour B point corresponding Ditermination of cam profile A, C 2 point, three points are all on normal, and in figure, β is the polar angle of groove normal n-n, i.e. normal and horizontal line angle.Can obtain according to inside and outside contour curve in Fig. 8 and theoretical contour relation, on outer drop center wheel profile, the relative B point coordinates of C point is

x _C＝x _B+r _rcosβ

(1-4)

y _C＝y _B+r _rsinβ

R in formula _r---the radius of needle bearing.

On inner groovy profile line, the relative B point coordinates of A point is

x _A＝x _B-r _rcosβ

(1-5)

y _A＝y _B-r _rsinβ

By formula (1-4), (1-5) in conjunction with formula (1-3), utilize MATLAB software programming, each coordinate points is outputted in Excel form, and then builds cam mechanism mockup dimensional parameters data sheet, as shown in table 1-1.

Table 1-1 cam mechanism dimensional parameters

Theoretical contour can be obtained according to cam mechanism relevant knowledge, because piezoelectric beam is flexible body, parts can be in contact with it according to piezoelectric beam structural design and be rigid body, in piezoelectric beam rotating shaft, needle bearing and piezoelectric beam form an angle and cam mechanism recess width are changed, be stuck to prevent bearing and groove fit place, as shown in Figure 9, recess width must be greater than 8mm.Cantilever beam deflection can be obtained and end face corner is by the mechanics of materials

$\begin{array}{c}{f}_B=-\frac{{\mathrm{Fl}}^3}{3EI}\\ {\mathrm{\θ}}_B=-\frac{{\mathrm{Fl}}^2}{2EI}\end{array}---\left(1-6\right)$

By formula (1-6) and displacement excitation amplitude f _b=A=3mm can obtain piezoelectric beam simply supported end corner

${\mathrm{\θ}}_B=\frac{3A}{2l}---(1-7)$

Recess width can be obtained according to formula (1-7)

b＝8×(sinθ _B+cosθ _B)(1-8)

When piezoelectric beam length is 85mm, b=8.5mm; When piezoelectric beam length is 145mm, b=8.3mm.

Have two kinds of length due to piezoelectric beam and make cam mechanism easy accessibility on camshaft, outputing groove at disk two ends, side is 145mm piezoelectric beam simply supported end, and opposite side is 85mm piezoelectric beam simply supported end, as shown in Figure 4.

As shown in Figure 10 and Figure 11, the top of the inner sleeve 306 of described vibration damper is provided with upper rings 310, be provided with sealed air chamber 311 at inner sleeve top, 316, the hydraulic oil below sealed air chamber be provided with the floating piston 309 floating over pasta band seal ring 312, in sealed air chamber, be full of nitrogen; Piston 314 is provided with below floating piston, this piston is provided with upper and lower two circular holes, and compression valve 308 is located in circular hole, and rebound valve 313 is located in lower circular hole, piston being also provided with piston outer ring 315, mutually being flowed by inwall for preventing the hydraulic oil in upper and lower two cavitys; The lower end of outer sleeve 317 is provided with lower lift ring 320, the lower end of inner sleeve is enclosed within outer sleeve, tooth bar 307 upper end is connected by bolt and piston, lower end and the outer sleeve of this tooth bar are connected, the lower end of inner sleeve is provided with seal ring 319, also be provided with guide holder 318 and connecting part, tooth bar lower end in the lower end of inner sleeve, tooth bar is by producing linear relative movement between the guiding of guide holder and piston and inner sleeve; A cavity is provided with near the position of rack tooth at inner sleeve, pinion stand, bearing 301 and gear 305 is provided with in cavity, bearing and gear are arranged on the gear shaft 303 that is connected with universal drive shaft, snap ring 302 is respectively equipped with in gear both sides and bearing both sides, this wheel and rack tooth is meshed, opening is provided with sealing cover 304, and sealing lid and inner sleeve are connected.Be respectively used to be connected vehicle body and vehicle bridge at vibration damper inner sleeve and the suspension ring on outer sleeve.

Claims (3)

1. the energy vibration damper of piezoelectricity, it is characterized in that: it comprises vibration damper body, universal drive shaft and piezoelectric device, universal drive shaft two ends are connected with the gear shaft of vibration damper body and the camshaft of piezoelectric device respectively by Hooke's joint.

2. the energy vibration damper of piezoelectricity according to claim 1, is characterized in that: described piezoelectric device mainly comprises housing, piezoelectric beam, cam, camshaft and fixed end; Axial surface both sides outside housing are respectively equipped with two corresponding housing hangers, and piezoelectric device is connected with vehicle body by four hangers; In casing, camshaft is through casing longitudinal center line, and this camshaft is fixed on casing by the deep groove ball bearing be located on casing two side shaft holder, and bearing (ball) cover is bolted on the casing outside bearing, for seal shaft socket end; One end of described camshaft is stretched out casing and is connected with universal drive shaft, cam is arranged on camshaft by key, the camshaft of cam both sides is respectively equipped with cam snap ring, these cam both sides are equipped with straight trough, the unfolded drawing of this straight trough two cell wall is the waveform curved surface be parallel to each other, and this straight trough on cam can increase the energizing frequency of piezoelectric beam; The upper lower box both sides inwall of bearing support is respectively equipped with fixed end, and one end of 15-30 piezoelectric beam is separately fixed on fixed end, and the other end of this piezoelectric beam is placed in by needle bearing in the straight trough of above-mentioned cam;

The intermediate portion of described piezoelectric beam is divided into three layers, middle one deck is metal substrate, upper and lower two layers is all the piezo-electric sheets be made up of piezoceramic material, an electrode is respectively provided with in the both sides up and down of piezoelectric beam, be connected with external equipment or energy accumulating device by lead-in wire, one end of piezoelectric beam is fixed block, by epoxy resin, piezoelectric beam intermediate portion and fixed block are bonded together, and by bolt, fixed block is connected with the fixed end on piezoelectric device, the other end of piezoelectric beam and rotating shaft bond, by needle bearing Spielpassung between rotating shaft and cam mechanism, length by the piezoelectric beam of universal drive shaft side is 3/5 of opposite side piezoelectric beam length.

3. the energy vibration damper of piezoelectricity according to claim 1, it is characterized in that: described vibration damper body mainly comprises: gear, tooth bar, inner sleeve, outer sleeve, piston, floating piston, compression valve, flexible valve, guide holder, hydraulic oil, gear shaft, hanger, upper rings is provided with on the top of inner sleeve, sealed air chamber is provided with at inner sleeve top, hydraulic pressure pasta below sealed air chamber is provided with the floating piston floating over pasta band seal ring, in sealed air chamber, is full of nitrogen; Below floating piston, be provided with piston, this piston is provided with upper and lower two circular holes, and compression valve is located in circular hole, and rebound valve is located in lower circular hole, and piston is also provided with piston outer ring, is mutually flowed by inwall for preventing the hydraulic oil in upper and lower two cavitys; The lower end of outer sleeve is provided with lower lift ring, the lower end of inner sleeve is enclosed within outer sleeve, tooth bar upper end is connected by bolt and piston, lower end and the outer sleeve of this tooth bar are connected, the lower end of inner sleeve is provided with seal ring, between inner sleeve and tooth bar lower end, be provided with guide holder, tooth bar is by producing linear relative movement between the guiding of guide holder and piston and inner sleeve; A cavity is provided with near the position of rack tooth at inner sleeve, pinion stand, bearing and gear is provided with in cavity, bearing and gear are located on the gear shaft that is connected with universal drive shaft, snap ring is respectively equipped with in gear both sides and bearing both sides, this wheel and rack tooth is meshed, opening is provided with sealing cover, and sealing lid and inner sleeve are connected.Below the floating piston of inner sleeve, be filled with hydraulic oil, hydraulic oil is flowed by compression valve and rebound valve and produces damping between the oil pocket that piston is upper and lower; The nitrogen that is filled with above of floating piston forms the difference that sealed air chamber carrys out the upper and lower oil chamber volume change of compensating piston.