汽車座椅輕量化和舒適性的研究與分析
汽車座椅輕量化和舒適性的研究與分析,汽車座椅,量化,以及,舒適,研究,鉆研,分析
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譯文題目:The analysis and improvement of the engineering vehicle seats
工程車輛座椅舒適性分析與改進(jìn)
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THE ANALYSIS AND IMPROVEMENT OF THE
ENGINEERING VEHICLE SEAT
ABSTRACT
Traditional Engineering Vehicles were emphasized on the completion of the task while pay less attentions on the driver. Recently, with the development of science and technology,during the routine work, people are increasingly laying stress on the health and comfort. Take the traditional agricultural machine for example, it has no seat for the tiller, people realized that one person chasing behind a machine is a tiring work. During the following engineering machines, the seat for the driver appears. However, the primary seats are rigid ones, leaving a space for the worker and paying less attention to the comfort of the driver. The research and fact show that the rigid seat hardly absorbs vibration, sometimes, it would amplify the shaking. To gain good quality of comfort of seat, some laws were implemented to supervise the seat or vehicle manufacturers to produce seat in good quality. For example, GBT 14779一1997 was issued to constraint the sitting posture of the seat. For the manufacturers, it
is essential to highlight the comfort of the seats, for the purpose of producing good products according with the factory standard, the local standard and the national standard. The thesis will do some analysis and researches as follows.Firstly, a kind of seat suspension is designed, which is to absorb the vibration of the vehicle. The seat suspension is designed by the three demensional soft of CATIA. In the paper,the CATIA is made some introduction to the reader, then the three demension view of the seat suspension and the engineering view are made. Also, the stiffness of the spring has been designed and the damper has been made of some experiment. Secondly, in this paper, the factors which have influence on the comfotable of the driver. Except the influence of the vehicle itself, the driver's comfotable is influenced by the vehicle speed and the road roughness. The road condition is usually expressed by the frequency-domain model, whie what the vehicle needs is usually the time-domain model. So the frequency-domain model should be changed into the time-domain model, and the road-roughness is gained. The vehiche velocity and road-roughness ratio are made to be the input parameters in analysising the vehicle comfortable which with seat suspension and which without. By researching them, they can act as theory for the existance of the seat suspension.
Finally, the parameters of the seat suspension are simulated. To illustrate the reasonable of the spring and damper parameters, the upper acceleration of the seat panel is measured.
Being different weight of different drivers, the related parameters of spring and damper are used. By researching this, it can help to ground the theory of selecting the value of the spring and damper and instruct the practice.
Key Words: Engineering Vehicle; Seat Suspension; Design; Sping Stiffness; Absober Damping; Comfort
1.2.1 the birth of the seat suspension
Car seat is on the car directly in contact with the driver's hip a part that is also a vehicle vibration transmitted to the driveDrive part of the last link, thus an important influence on the driver's seating comfort.In the original car,Car seats and mouth is often used in life of seats were similar, all use a bucket.Compared with the wooden block in their livesChairs and plastic seat car seat the difference is that the car seat in order to more convenient and car floorConnections, and to make the seat with the whole vehicle form a solid whole, steel structure or commonly used car seatSteel structure, forming a frame.And then over the surface of the upper frame and the driver's hip contact install a seatFight for the driver in the vehicle to provide a more convenient operation space, this is the first car seat.As the, the improvement of people to use cars frequency, it was found that for a long period of time and contact rigidity of car seats, can make hip to produceLarger load.In addition, compared with people in daily life "sit", cars drive in the process,In under the effect of road roughness and vehicle speed, can pass the vibration of dynamic transfer through the seat to the driver's hip, come inAnd the vibration is passed to the driver's body, it is added to the car seat to the drivers, especially professionalThe influence of the driver.Many professional drivers and suffer from occupational diseases, such as cervical spondylosis, lumbar disease, head, shoulder,Upper limb pain, swell, etc.
Directly to the driver to slow the car seat vibration and the influence of fatigue, people start to look for in a rigidSeat at the top of the seat skeleton bucket with a soft cloth or sponge and other flexible material, the method for the driverVibration and the friction between seat and hips brings a certain improvement.Later, people also found at the bucket seatFlexible material such as with a cloth or sponge between suspension some fine spring wire, can bring a better damping effect to the driver,So this way also widely promotion and has been in use today, also used the most modern carsThis kind of cheap comfort and a better seat.
For carrying passengers and their belongings as the main purpose, to occupant as the center, emphasize the comfort of car is concerned, its early in the design have a strict standard for comfort, vibration from the engine to the control of tires, car body, shock absorption performance of suspension, etc, all has the very high request.And, as a result of cars to meet the needs of people reach their destination quickly, the car's chassis is generally low, which determines the car you must drive on the road the good pavement, in view of the above some of the requirements, for the car, on the seat frame to add some cloth or sponge and other flexible material can meet its good ride comfort.But, for long-term driving on poor road conditions and road engineering vehicles (including military vehicles), due to its original the most main purpose is for the completion of the project or task is to transport the goods as the main purpose, so the vehicle suspension damping of shock absorber and spring stiffness values are very big, so it is difficult to give attention to two or morethings arrives the driver's comfort requirements.In addition, because of the construction vehicle which is often only a few drivers or several crew members, thus engineering vehicle driver to take comfort in the past been attention and rarely mentioned.
With the development of the society and the needs of the project construction, a growing number of researchers engaged in construction vehicle driving, traditionalEngineering vehicles to be engaged in construction vehicle driver had a larger hurt both physically and mentally, with the progress of science and technologyAs well as people living standard rise, people are not only satisfied with its cargo and the completion of tasks of homework, the driver aboardComfort, more and more attention and concern.The engineering vehicle is now expected to meet with the completion of tasks of the homeworkCan, like a car with good comfort, or close to the car's comfort, is due to the load truckA main job, and therefore cannot reduce vehicle suspension parameters, thus people imagine to add a set of similar on the seatIn vehicle suspension shock absorber and spring mechanism, thus have appeared on the vehicle seat suspension.
According to linear seat suspension by some itself is difficult to avoid the above problems, through special scientific research personnelDevice to the structure and the linear characteristics is transformed into nonlinear characteristics, so as to make the seat suspension has better performance of vibration isolation.The common linear seat suspension is transformed into nonlinear methods are: by adding a specific shape, and makeConnected to the elastic element, so as to realize the established nonlinear characteristics;Using changes pitch, diameter, helix Angle changeImplementation of spiral springs;Using multiple spring combination or use magnetic spring to realize nonlinear.GermanyGrammer company pioneered in CAM and elastic element device to realize the nonlinear characteristics of a given. In addition, the UKBostrum company also use CAM and spring and shock absorber was developed institutions such as a nonlinear shear type seat suspension.Enterprises and colleges and universities in our country have made related research in this field, and get the good vibration damping performance.Such as xi 'an huatai automobile seat co., LTD. The use of shock absorber and spring, the scissors mechanism, chute, rubber pieces and other agencies also developed with non-linear characteristics of seat suspension, henan university of science and technology, using spring, shock absorber, such as surface plate mechanism of mutual cooperation, also developed a similar function of seat suspension.
Comfort, starting in the 1980 s, our country has begun to adopt by a certain stiffness of spring and dampingVibration system which has the function of reducing vibration of seat suspension, called elastic seat suspension.Elastic seat suspension in the vertical directionThan the rigid seat suspension vibration isolation effect is much better, resilient seat suspension according to their characteristics is linear or nonlinear elastic is divided into linear and nonlinear seat suspension seat suspension.Seat suspension rigidity and elasticity suspension are collectively referred to as passive seat suspension, research has shown that linear seat suspension for attenuation vibration plays a role, but there is some linear seat suspension: if the seat suspension stiffness is bigger, so the seat suspension system becomes larger, the natural frequency of the driver inHomework by vibration damage mainly comes from the low frequency vibration, so the low frequency vibration attenuation caused by itThe purpose of less, not improve the driver's comfort.On the other hand, if the stiffness is small, so the driver seat contactWhen will make the seat of larger displacement, if strong vibration of vehicles on the road, will lead to greater vibrationCheng, contact the driver seat when the larger displacement brought seat suspension layout space constraints, andExcessive vibration trip will lead to the direction of the driver of vehicle control ability, make manipulation of the disorder.
Car seat is on the car directly in contact with the driver's hip a part that is also a vehicle vibration transmitted to the driveDrive part of the last link, thus an important influence on the driver's seating comfort.In the original car,Car seats and seat were used in daily life, using a bucket.Compared with the wooden block in their livesChairs and plastic seat car seat the difference is that the car seat in order to more convenient and car floorConnections, and to make the seat with the whole vehicle form a solid whole, steel structure or commonly used car seatSteel structure, forming a frame.And then over the surface of the upper frame and the driver's hip contact install a seatFight for the driver in the vehicle to provide a more convenient operation space, this is the first car seat.
The above mentioned seat suspension because of its simple structure, low cost, implementation is easy, damping effect is obvious, thereforeIn the life has been widely used in production, in the slow due to the damage caused by vehicle vibration plays a very importantThe role of.However, as people life quality further improve, people no longer satisfied with their current passive seat suspension,For when the seat suspension shock absorber damping value and spring stiffness value was determined, you can't get to change, and the driver in the process of driving, due to the effect of road roughness and the speed of the car, driver load on the seatIs to change all the time, if you want to get the best effect of vibration reduction, would require seat suspension and shock absorber damping valuesSpring stiffness value of moment adjustment, to adapt the demand of working condition of the road.So people began to the semi-active seatSuspension and active seat suspension, the semi-active seat suspension and active seat suspension is built on a vehicle semi-active suspensionAnd the basis of vehicle active suspension, semi-active seat suspension technology and active seat suspension technology is with the carThe semi-active suspension and vehicles of generation and development of active suspension.At present, the semi-active suspension and active seat suspensionTechnology is not mature, and there are many technical problems to overcome.For example, the semi-active seat suspension used in electrorheological fluid andMagnetorheological fluid exists particle deposition and flow variations of temperature change constantly, with air spring for a halfActive seat suspension, due to the use of air as power transmission medium, and has the characteristics of easy to compress air, so it is difficult toDo instant inflated and deflated, limited to the slow response of MRF liquidity problems.Active seat suspensionIs due to their large energy consumption, the structure is complex, high cost of restricting its application in vehicle.
工程車輛座椅舒適性分析與改進(jìn)
摘要
傳統(tǒng)工程車輛側(cè)重對工作的完成,對駕駛員的影響考慮較少。近年來,隨著科學(xué)進(jìn)步和人們生活水平的提高,在口常工作中,除了對工作的完成度之外,人們還對在工作中的健康和舒適性提出了更高的要求。如傳統(tǒng)的農(nóng)用機(jī)械不提供駕駛員座位,人跟著機(jī)器走是一件很耗體力的事情,隨后供駕駛員乘坐的座位便出現(xiàn)了。起初的僅是一個剛性的座斗,對乘坐舒適性并沒有很多要求。研究和事實表明,這種座斗乘坐舒適性很差,無法緩沖車輛工作過程中所產(chǎn)生的振動,甚至對車輛的振動起到放大,作為提高其舒適性,有關(guān)部門出臺了標(biāo)準(zhǔn)來約束制造商,例如GBT 14779-1997就是又姿人體模板功能設(shè)計要求的一種約束。
本文圍繞以下幾方面進(jìn)行分析和研究。
首先,對影響駕駛員的乘坐舒適性的因素進(jìn)行了分析,不考慮車輛自身參數(shù),乘員的乘坐舒適性受車速和路面不平度系數(shù)的影響,路面的狀況一般是以路面的頻域棒表達(dá),而車輛需要的往往是時域模型,把頻域模型轉(zhuǎn)化成相應(yīng)的時域模型,在此基礎(chǔ)上得到路面不平度。文章還把車速和路面不平度系數(shù)作為輸入分別分析有座椅懸架和無懸架對人體舒適性的影響,為座椅懸架的存在和合理利用提供理論依據(jù)。
其次,設(shè)計了一款具有減振功能的座椅懸架,此座椅懸架采用CATIA三維造型進(jìn)行設(shè)計。對CATIA軟件進(jìn)行了簡要的介紹,然后對座椅懸架的三維圖工程進(jìn)行了制作,并對座椅懸架中的彈簧進(jìn)行了參數(shù)設(shè)計,對選購的彈簧進(jìn)行了實驗分析。
最后,對座椅懸架的參數(shù)進(jìn)行了仿真分析,通過測得座椅上面板的加速度的衰祠況來評價座椅懸架中彈簧剛度和減振器阻尼值的合理性。針對不同體重的駕駛員,分析得到不同體重等級的駕駛員所應(yīng)該配備的相應(yīng)的彈簧剛度值和減振器阻尼值坐椅懸架。為座椅懸架參數(shù)取值的合理性提供理論基礎(chǔ)和實際指導(dǎo)。
關(guān)鍵詞:工程車輛;座椅懸架;設(shè)計;彈簧剛度;減振器阻尼;舒適性
1.2.1座椅懸架的誕生
汽車座椅是汽車上與駕駛員的臀部直接相接觸的一個部件,也是車輛振動傳遞到駕駛員的最后一個環(huán)節(jié),因而對駕駛員的乘坐舒適性產(chǎn)生很重要的影響。在最初的汽車上,汽車座椅與口常生活中所使用的座椅相差不大,都采用一個座斗。相比生活中的木質(zhì)座椅與塑料座椅,汽車上的座椅其不同之處在于,汽車上的座椅為了更方便的與汽車地板連接,也為使座椅與整個車輛形成一個牢固的整體,汽車上的座椅一般采用鋼制結(jié)構(gòu)或鐵制結(jié)構(gòu),形成一個座椅骨架。然后在骨架上部與駕駛員臀部相接觸的表面安裝一個座斗,為駕駛員在駕駛車輛提供一個比較方便的操作空間,這便是最初的汽車座椅。隨著人們使用汽車頻率的提高,人們發(fā)現(xiàn)長時間的與剛性的汽車座椅相接觸,會使臀部產(chǎn)生比較大的負(fù)荷。此外,相比人們在日常生活中的“靜坐”的不同,汽車在行駛過程中,在路面不平度與車速的共同作用下,會通過座椅把動態(tài)的振動傳遞到駕駛員的臀部,進(jìn)而把這種振動傳遞到駕駛員的全身,這就加劇了人們對汽車座椅對駕駛員,特別是職業(yè)駕駛員的影響。很多職業(yè)駕駛員因此而患上了職業(yè)病,如頸椎病,腰椎病,頭部、肩部、上肢疼痛發(fā)脹等。
為減緩由于汽車座椅給駕駛員帶來的直接振動與疲勞的影響,人們開始尋求在剛性的座椅骨架上端的座椅斗上鋪一層柔軟的布料或是海綿等柔性物質(zhì),這種方法對駕駛員的振動以及座椅與臀部之間的摩擦帶來了一定的改善。再后來,人們還發(fā)現(xiàn)在座椅座斗與布料或海綿等柔性物質(zhì)之間斜拉一些細(xì)彈簧絲,能給駕駛員帶來比較好的減振效果,于是這種方式也得到普遍的推廣,并且一直沿用至今,現(xiàn)代汽車上也大部分都用采用的這種成本低廉的舒適性又較好的座椅。
對于作為以載運(yùn)人員及其隨身物品為主要目的,以乘員為中心,強(qiáng)調(diào)舒適性的轎車而言,其在設(shè)計之初就對舒適性有著嚴(yán)格的標(biāo)準(zhǔn),從發(fā)動機(jī)振動的控制到輪胎、車身、懸架等方面的減振性能都具有很高的要求。并且,由于轎車要滿足人們快速到達(dá)目的地的需要,轎車的底盤一般都比較低,這就決定了轎車必須在路面良好的路面上行駛,鑒于上述的一些要求,對于小轎車而言,在座椅骨架上添加一些布料或海綿等柔性物質(zhì)已經(jīng)可以滿足其較好的乘坐舒適性。但是,對于長期行駛在路面狀況較差甚至無路的工程車輛(包括軍用車輛),由于其最初最主要目的在于對工程或任務(wù)的完成,是以運(yùn)輸貨物為主要目的,因而車輛懸架的減振器阻尼和彈簧剛度取值往往都很大,這樣就很難兼顧到駕駛員的舒適性要求。此外,由于工程車輛這類車往往是只有駕駛員或少量幾個乘員,因而工程車輛駕駛員乘座舒適性在以往很少被關(guān)注和提及。
隨著社會的發(fā)展和工程建設(shè)的需要,越來越多的人員從事工程車輛的駕駛,傳統(tǒng)的工程車輛對長期從事工程車輛的駕駛員身心產(chǎn)生了較大的傷害,隨著科學(xué)和技術(shù)的進(jìn)步以及人們生活水平的提高,人們不再只滿足于其載貨和作業(yè)任務(wù)的完成,駕駛員的乘坐舒適性越來越多的受到關(guān)注和重視。人們希望工程車輛在滿足其對作業(yè)任務(wù)的完成的同時,能夠像轎車一樣具有良好的舒適性,或者接近小轎車的舒適性,由于載重是工程車輛的主要工作,因而車輛的懸架參數(shù)無法減小,因而人們設(shè)想在座椅上再添加一套類似于車輛懸架上的減振器和彈簧的機(jī)械裝置,因而車輛座椅懸架便出現(xiàn)了。
針對線性座椅懸架所存在的上述一些自身難以避免的問題,科研人員通過一些特殊的結(jié)構(gòu)和裝置把線性特性轉(zhuǎn)化為非線性特性,從而使得座椅懸架具備較好的隔振性能。常見的把線性座椅懸架轉(zhuǎn)化為非線性的方法有:通過添加某一特定的形狀的機(jī)構(gòu),并使之與彈性元件相連,從而實現(xiàn)既定的非線性特性;采用螺距變化、直徑變化、螺旋角變化的螺旋彈簧實現(xiàn)非線性;運(yùn)用多個彈簧進(jìn)行組合或運(yùn)用磁力彈簧來實現(xiàn)非線性。德國的 Grammer 公司率先采用凸輪和彈性元件等裝置實現(xiàn)了給定的非線性特性.另外,英國Bostrum公司也利用凸輪、彈簧和減振器等機(jī)構(gòu)研制了一款非線性的剪式座椅懸架。我國的企業(yè)和高校也做過相關(guān)這方面的研究,并且獲得了比較好的減振性能。如西安華泰汽車座椅有限公司運(yùn)用減振器、彈簧、剪式機(jī)構(gòu)、滑槽、橡膠塊等機(jī)構(gòu)也研制了具有非線特性的座椅懸架,河南科技大學(xué)運(yùn)用彈簧、減振器、曲面板等機(jī)構(gòu)的相互配合,也研制了相類似功能的座椅懸架。
舒適性,從上世紀(jì)八十年代開始,我國已經(jīng)開始采用由一定剛度的彈簧和一定阻尼的減振器構(gòu)成的具有減振功能的座椅懸架,稱為彈性座椅懸架。彈性座椅懸架在垂直方向上比剛性座椅懸架的隔振效果要好得多,彈性座椅懸架根據(jù)其彈性特性是線性的還是非線性的又分為線性座椅懸架和非線性座椅懸架。剛性座椅懸架和彈性座椅懸架統(tǒng)稱為被動座椅懸架,研究表明,線性座椅懸架對衰減振動起了一定的作用,但線性座椅懸架存在著一些不足:如果座椅懸架的剛度比較大,那么座椅懸架系統(tǒng)的固有頻率就變大,而駕駛員在作業(yè)時所受到的振動的傷害主要來自于低頻振動,這樣對低頻所引起的振動的衰減就很少,起不到提高駕駛員舒適性的目的。另一方面,如果剛度較小,那么駕駛員接觸座椅時將會使座椅產(chǎn)生較大的位移,如果車輛在行駛中的振動強(qiáng)烈,將會帶來更大的振動行
程,駕駛員接觸座椅時產(chǎn)生的較大的位移給座椅懸架的布置帶來了空間上的限制,并且過大的振動行程將會導(dǎo)致駕駛員對車輛方向的掌控能力下降,使得操縱紊亂.
汽車座椅是汽車上與駕駛員的臀部直接相接觸的一個部件,也是車輛振動傳遞到駕駛員的最后一個環(huán)節(jié),因而對駕駛員的乘坐舒適性產(chǎn)生很重要的影響。在最初的汽車上,汽車座椅與日常生活中所使用的座椅相差不大,都采用一個座斗。相比生活中的木質(zhì)座椅與塑料座椅,汽車上的座椅其不同之處在于,汽車上的座椅為了更方便的與汽車地板連接,也為使座椅與整個車輛形成一個牢固的整體,汽車上的座椅一般采用鋼制結(jié)構(gòu)或鐵制結(jié)構(gòu),形成一個座椅骨架。然后在骨架上部與駕駛員臀部相接觸的表面安裝一個座斗,為駕駛員在駕駛車輛提供一個比較方便的操作空間,這便是最初的汽車座椅。
上述所提到的座椅懸架由于結(jié)構(gòu)簡單,成本低廉,實現(xiàn)容易,減振效果明顯,因而在生活生產(chǎn)中已經(jīng)得到了廣泛的應(yīng)用,在減緩由于車輛振動帶給人們的傷害發(fā)揮著重要的作用。但是,隨著人們生活質(zhì)量的進(jìn)一步提高,人們不再滿足于現(xiàn)有的被動座椅懸架,因為這種座椅懸架一旦減振器的阻尼值和彈簧的剛度值確定之后,就不能再進(jìn)行變化了,而駕駛員在行車過程中,由于受到路面不平度和車速的影響,駕駛員對座椅的載荷是時刻發(fā)生變化的,如果要想獲得最佳的減振效果,就要求座椅懸架的減振器阻尼值和彈簧的剛度值時刻進(jìn)行調(diào)節(jié),以適應(yīng)路面工況的要求。于是人們便開始了對半主動座椅懸架和主動座椅懸架的研究,半主動座椅懸架和主動座椅懸架是建立在車輛半主動懸架和車輛主動懸架的基礎(chǔ)之上的,因而半主動座椅懸架技術(shù)和主動座椅懸架技術(shù)是隨著車輛半主動懸架和車輛主動懸架的產(chǎn)生而發(fā)展的。目前,半主動座椅懸架和主動座椅懸架技術(shù)還未成熟,還有很多技術(shù)問題要去克服。例如,半主動座椅懸架中使用電流變液和磁流變液存在粒子容易發(fā)生沉積和流變體的溫度經(jīng)常發(fā)生變化,對于帶有空氣彈簧的半主動座椅懸架,由于運(yùn)用空氣作為動力傳遞的介質(zhì),而空氣具有易壓縮的特點(diǎn),因而很難做到瞬間充氣與放氣,受到響應(yīng)速度慢的限制磁流變液的流動性問題。主動座椅懸架則是由于其能量消耗大,結(jié)構(gòu)復(fù)雜,成本高制約了其在車輛上的應(yīng)用。
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