盤式制動器 外文翻譯
Automobile Brake System
The braking system is the most important system in cars. If the brakes fail, the result can be disastrous. Brakes are actually energy conversion devices, which convert the kinetic energy (momentum) of the vehicle into thermal energy (heat).When stepping on the brakes, the driver commands a stopping force ten times as powerful as the force that puts the car in motion. The braking system can exert thousands of pounds of pressure on each of the four brakes.
Two complete independent braking systems are used on the car. They are the service brake and the parking brake.
The service brake acts to slow, stop, or hold the vehicle during normal driving. They are foot-operated by the driver depressing and releasing the brake pedal. The primary purpose of the brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by when a separate parking brake foot pedal or hand lever is set.
The brake system is composed of the following basic components: the “master cylinder” which is located under the hood, and is directly connected to the brake pedal, converts driver foot’s mechanical pressure into hydraulic pressure. Steel “brake lines” and flexible “brake hoses” connect the master cylinder to the “slave cylinders” located at each wheel. Brake fluid, specially designed to work in extreme conditions, fills the system. “Shoes” and “pads” are pushed by the slave cylinders to contact the “drums” and “rotors” thus causing drag, which (hopefully) slows the car.
The typical brake system consists of disk brakes in front and either disk or drum brakes in the rear connected by a system of tubes and hoses that link the brake at each wheel to the master cylinder (Figure).
Basically, all car brakes are friction brakes. When the driver applies the brake, the control device forces brake shoes, or pads, against the rotating brake drum or disks at wheel. Friction between the shoes or pads and the drums or disks then slows or stops the wheel so that the car is braked.
In most modern brake systems (see Figure 15.1), there is a fluid-filled cylinder, called master cylinder, which contains two separate sections, there is a piston in each section and both pistons are connected to a brake pedal in the driver’s compartment. When the brake is pushed down, brake fluid is sent from the master cylinder to the wheels. At the wheels, the fluid pushes shoes, or pads, against revolving drums or disks. The friction between the stationary shoes, or pads, and the revolving drums or disks slows and stops them. This slows or stops the revolving wheels, which, in turn, slow or stop the car.
The brake fluid reservoir is on top of the master cylinder. Most cars today have a transparent r reservoir so that you can see the level without opening the cover. The brake fluid level will drop slightly as the brake pads wear. This is a normal condition and no cause for concern. If the level drops noticeably over a short period of time or goes down to about two thirds full, have your brakes checked as soon as possible. Keep the reservoir covered except for the amount of time you need to fill it and never leave a cam of brake fluid uncovered. Brake fluid must maintain a very high boiling point. Exposure to air will cause the fluid to absorb moisture which will lower that boiling point.
The brake fluid travels from the master cylinder to the wheels through a series of steel tubes and reinforced rubber hoses. Rubber hoses are only used in places that require flexibility, such as at the front wheels, which move up and down as well as steer. The rest of the system uses non-corrosive seamless steel tubing with special fittings at all attachment points. If a steel line requires a repair, the best procedure is to replace the compete line. If this is not practical, a line can be repaired using special splice fittings that are made for brake system repair. You must never use copper tubing to repair a brake system. They are dangerous and illegal.
Drum brakes, it consists of the brake drum, an expander, pull back springs, a stationary back plate, two shoes with friction linings, and anchor pins. The stationary back plate is secured to the flange of the axle housing or to the steering knuckle. The brake drum is mounted on the wheel hub. There is a clearance between the inner surface of the drum and the shoe lining. To apply brakes, the driver pushes pedal, the expander expands the shoes and presses them to the drum. Friction between the brake drum and the friction linings brakes the wheels and the vehicle stops. To release brakes, the driver release the pedal, the pull back spring retracts the shoes thus permitting free rotation of the wheels.
Disk brakes, it has a metal disk instead of a drum. A flat shoe, or disk-brake pad, is located on each side of the disk. The shoes squeeze the rotating disk to stop the car. Fluid from the master cylinder forces the pistons to move in, toward the disk. This action pushes the friction pads tightly against the disk. The friction between the shoes and disk slows and stops it. This provides the braking action. Pistons are made of either plastic or metal. There are three general types of disk brakes. They are the floating-caliper type, the fixed-caliper type, and the sliding-caliper type. Floating-caliper and sliding-caliper disk brakes use a single piston. Fixed-caliper disk brakes have either two or four pistons.
The brake system assemblies are actuated by mechanical, hydraulic or pneumatic devices. The mechanical leverage is used in the parking brakes fitted in all automobile. When the brake pedal is depressed, the rod pushes the piston of brake master cylinder which presses the fluid. The fluid flows through the pipelines to the power brake unit and then to the wheel cylinder. The fluid pressure expands the cylinder pistons thus pressing the shoes to the drum or disk. If the pedal is released, the piston returns to the initial position, the pull back springs retract the shoes, the fluid is forced back to the master cylinder and braking ceases.
The primary purpose of the parking brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by the driver when a separate parking braking hand lever is set. The hand brake is normally used when the car has already stopped. A lever is pulled and the rear brakes are approached and locked in the “on” position. The car may now be left without fear of its rolling away. When the driver wants to move the car again, he must press a button before the lever can be released. The hand brake must also be able to stop the car in the event of the foot brake failing. For this reason, it is separate from the foot brake uses cable or rods instead of the hydraulic system.
Anti-lock Brake System
Anti-lock brake systems make braking safer and more convenient, Anti-lock brake systems modulate brake system hydraulic pressure to prevent the brakes from locking and the tires from skidding on slippery pavement or during a panic stop.
Anti-lock brake systems have been used on aircraft for years, and some domestic car were offered with an early form of anti-lock braking in late 1990’s. Recently, several automakers have introduced more sophisticated anti-lock system. Investigations in Europe, where anti-lock braking systems have been available for a decade, have led one manufacture to state that the number of traffic accidents could be reduced by seven and a half percent if all cars had anti-lock brakes. So some sources predict that all cars will offer anti-lock brakes to improve the safety of the car.
Anti-lock systems modulate brake application force several times per second to hold the tires at a controlled amount of slip; all systems accomplish this in basically the same way. One or more speed sensors generate alternating current signal whose frequency increases with the wheel rotational speed. An electronic control unit continuously monitors these signals and if the frequency of a signal drops too rapidly indicating that a wheel is about to lock, the control unit instructs a modulating device to reduce hydraulic pressure to the brake at the affected wheel. When sensor signals indicate the wheel is again rotating normally, the control unit allows increased hydraulic pressure to the brake. This release-apply cycle occurs several time per second to “pump” the brakes like a driver might but at a much faster rate.
In addition to their basic operation, anti-lock systems have two other things in common. First, they do not operate until the brakes are applied with enough force to lock or nearly lock a wheel. At all other times, the system stands ready to function but does not interfere with normal braking. Second, if the anti-lock system fail in any way, the brakes continue to operate without anti-lock capability. A warning light on the instrument panel alerts the driver when a problem exists in the anti-lock system.
The current Bosch component Anti-lock Braking System (ABSⅡ), is a second generation design wildly used by European automakers such as BWM, Mercedes-Benz and Porsche. ABSⅡ system consists of : four wheel speed sensor, electronic control unit and modulator assembly.
A speed sensor is fitted at each wheel sends signals about wheel rotation to control unit. Each speed sensor consists of a sensor unit and a gear wheel. The front sensor mounts to the steering knuckle and its gear wheel is pressed onto the stub axle that rotates with the wheel. The rear sensor mounts the rear suspension member and its gear wheel is pressed onto the axle. The sensor itself is a winding with a magnetic core. The core creates a magnetic field around the winding, and as the teeth of the gear wheel move through this field, an alternating current is induced in the winding. The control unit monitors the rate o change in this frequency to determine impending brake lockup.
The control unit’s function can be divided into three parts: signal processing, logic and safety circuitry. The signal processing section is the converter that receives the alternating current signals form the speed sensors and converts them into digital form for the logic section. The logic section then analyzes the digitized signals to calculate any brake pressure changes needed. If impending lockup is sensed, the logic section sends commands to the
Modulator assembly
The hydraulic modulator assembly regulates pressure to the wheel brakes when it receives commands from the control utuit. The modulator assembly can maintain or reduce pressure over the level it receives from the master cylinder, it also can never apply the brakes by itself. The modulator assembly consists of three high-speed electric solenoid valves, two fluid reservoirs and a turn delivery pump equipped with inlet and outlet check valves. The modulator electrical connector and controlling relays are concealed under a plastic cover of the assembly.
Each front wheel is served by electric solenoid valve modulated independently by the control unit. The rear brakes are served by a single solenoid valve and modulated together using the select-low principle. During anti-braking system operation, the control unit cycles the solenoid valves to either hold or release pressure the brake lines. When pressure is released from the brake lines during anti-braking operation, it is routed to a fluid reservoir. There is one reservoir for the front brake circuit. The reservoirs are low-pressure accumulators that store fluid under slight spring pressure until the return delivery pump can return the fluid through the brake lines to the master cylinder.
譯 文：
汽車制動系統(tǒng)
制動系統(tǒng)是汽車重要的系統(tǒng)組成。 如果制動失靈，結(jié)果損失可能是非常慘重的。制動器實際就是能量轉(zhuǎn)換裝置，它將汽車的動能（動量）轉(zhuǎn)化成熱能（熱量）。當(dāng)駕駛員踩下制動踏板，所產(chǎn)生的制動力能達到汽車運動時動力的10倍。制動系統(tǒng)能對轎車四個車輪中的每個車輪施加數(shù)千磅的制動力。
每輛汽車上使用兩個完全獨立的制動系統(tǒng)，即行車制動器和駐車制動器。
行車制動器起到減速、停車、或保持車輛正常行駛。制動器是由司機用腳踩、松制動器踏板來控制的。駐車制動器的主要作用就是當(dāng)車內(nèi)無人的時候，汽車能夠保持靜止。當(dāng)獨立的駐車制動器—踏板或手桿，被安裝時，駐車制動器就會被機械地操作。
制動系統(tǒng)是由下列基本的成分組成:位于發(fā)動機罩下方，而且直接地被連接到制動踏板的“制動主缸”把駕駛員腳的機械力轉(zhuǎn)變?yōu)橐簤毫Αｄ撝频摹爸苿庸苈贰焙陀腥嵝缘摹爸苿榆浌堋卑阎苿又鞲走B接到每個輪子的“制動輪缸”上。 制動液, 特別地設(shè)計為的是工作在極端的情況，填充在系統(tǒng)中?！爸苿颖P”和“襯塊”是被制動輪缸推動接觸“圓盤”和“回轉(zhuǎn)體”如此引起緩慢的拖拉運動, (希望)使汽車減慢速度。
典型的制動系統(tǒng)布置有前后盤式，前盤后鼓式，各個車輪上的制動器通過一套管路系統(tǒng)連接到制動主缸上。
基本上講，所有的汽車制動器都是摩擦制動器。當(dāng)司機剎車時，控制裝置會迫使制動蹄，或制動襯片與車輪處的旋轉(zhuǎn)的制動鼓或制動盤接觸。接觸后產(chǎn)生的摩擦使車輪轉(zhuǎn)動減慢或停止，這就是汽車的制動。
在最基本的制動系統(tǒng)中，有一個制動主缸，這個主缸內(nèi)部填充制動液，并包含兩個部分，每個部分里都有一個活塞，兩個活塞都連接駕駛室里的制動踏板。當(dāng)制動踏板被踩下時，制動液會從制動主缸流入輪缸。在輪缸中，制動液推動制動蹄或制動襯片與旋轉(zhuǎn)的制動鼓或制動盤接觸。靜止的制動蹄或制動襯片與旋轉(zhuǎn)的制動鼓或制動盤之間產(chǎn)生摩擦力使汽車的運動逐漸減緩或停止。
制動液的裝置位于主缸的頂部。目前大多數(shù)的車都有一個容易看見的裝制動液的裝置，為的是不用打開蓋子就可以看得見制動液的油面。隨著制動踏板的運動制動液就會緩慢的下降，正常情況下是這樣的。如果制動液在很短的時間內(nèi)下降得明顯或者下降了三分之二，那么就要盡快的檢查你的制動系統(tǒng)了。保持制動液裝置充滿制動液除非你需要維修它，制動液必須保持很高的沸點。位于在空氣中的制動液就會吸收空氣中的潮氣引起制動液低于沸點。
制動液通過一系列的管路從主缸到達各車輪。橡膠軟管只用在需要彈力的地方，比如應(yīng)用在前輪。在車的行進中上下來回運動。系統(tǒng)的其它部分在所有的連接點上都應(yīng)用了無腐蝕性的無縫鋼管。如果鋼線需要修理的話，最好的方法就是代替這條線。如果這不符合實際，那么為了制動系統(tǒng)可以用特殊的裝置修理它。你不可以用銅管來修理制動系。它們是危險也是不正確的。
鼓式制動器包括制動鼓，一個輪缸，回拉彈簧，一個制動底版，兩個帶摩擦層的制動蹄。制動底版固定在輪軸外部的法蘭或轉(zhuǎn)向節(jié)。制動鼓固定在輪轂上。制動鼓的內(nèi)部表面與制動蹄的內(nèi)層之間有空隙。要使用制動器時，司機就要踩下踏板，這時輪缸擴大制動片，對其施加壓力，是制動蹄觸碰制動鼓。制動鼓與摩擦片之間產(chǎn)生的摩擦制動了車輪，從而使汽車停止。要釋放制動器時，司機松開踏板，回拉彈簧拉回制動片，這樣車輪會自由轉(zhuǎn)動。
盤式制動器包括制動盤而不是鼓，在它的兩面上各有一個薄的制動片或叫盤式制動器的制動片。制動片是靠擠住旋轉(zhuǎn)的制動盤來停住汽車。制動主缸里流出的制動液迫使活塞向里部的金屬盤移動，這便使摩擦片緊緊地貼住制動盤。這時制動片與制動盤產(chǎn)生的摩擦使汽車減速、停止，出現(xiàn)了制動行為?；钊纸饘倩蛩芰?。盤式制動器主要有三種，即：浮動卡鉗型、固定卡鉗型和滑動卡鉗型。浮動卡鉗型和滑動卡鉗型盤式制動器使用單活塞。固定卡鉗型盤式制動器既可以使用兩個活塞有可以使用四個活塞。
制動系統(tǒng)是由機械能，液壓能或氣壓能裝置驅(qū)動的。在機械杠桿適合所有的汽車的駐車制動器中使用。當(dāng)踩下制動踏板時，杠桿就會推動制動器主缸的活塞給制動液施加壓力，制動液通過油管流入輪缸。制動液的壓力施加到輪缸活塞以使制動片被壓到制動鼓或制動盤上。如果松開踏板，活塞回到原來的位置上，回拉彈簧拉回制動片，制動液返回制動主缸，這樣制動停止。
駐動制動器的主要作用是車內(nèi)無人時，使汽車靜止不動。如果車內(nèi)安裝的是獨立的駐車制動器，那么駐車制動器是由司機手動的控制。駐車制動器正常是當(dāng)車已經(jīng)停止時使用的。向后拉手閘，并把手柄卡在正確的位置上?，F(xiàn)在，即使離開汽車也不用害怕它會自己滑走。如果司機要再次啟車時，他必須在松開手桿之前按下按鈕。在行車制動器失靈的情況下，手閘必須能停住車。正因為這樣，手閘與腳閘分開，手閘使用的是繩索或杠桿而不是液力系統(tǒng)。
防抱死制動系統(tǒng)是使汽車制動更安全、更方便的制動裝置，它既有調(diào)節(jié)制動系統(tǒng)的壓力來防止車輪被完全抱死的功能，又有防止輪胎在滑的路面上行駛或緊急停車時的滑動。
防抱死制動系統(tǒng)最早應(yīng)用在航空飛行器上，而且在二十世紀 90年代一些國內(nèi)的汽車內(nèi)也安裝了這種系統(tǒng)。近來，幾個汽車制造商引進了更為復(fù)雜的防抱死系統(tǒng)。歐洲使用這種系統(tǒng)已有幾十年的時間，通過對其的調(diào)查，一位汽車制造商坦言，如果所有的汽車都安裝上防抱死制動系統(tǒng)，那么交通事故的發(fā)生率會降低7.5%。同時，一些權(quán)威人士預(yù)測這種系統(tǒng)會提高汽車的安全性。
防抱死制動系統(tǒng)可以在一秒鐘內(nèi)調(diào)節(jié)幾次制動時車輪上的受力，使車輪的滑移受到控制，而且所有的系統(tǒng)基本上都以相同的方式完成。每個車輪都會有一個傳感器，電子控制裝置能連續(xù)檢測來自車輪傳感器傳來的脈沖電信號，并將它們處理轉(zhuǎn)換成和輪速成正比的數(shù)值；如果其中一個傳感器的信號不斷下降，那么這就表明了相應(yīng)的輪胎趨于抱死，這時電子控制裝置向該車輪的制動器發(fā)出降低壓力的指令。當(dāng)信號顯示車輪轉(zhuǎn)速恢復(fù)正常時，電子控制裝置會增加制動器的液壓。這種循環(huán)像司機一樣調(diào)節(jié)制動器，但它的速度更快，達到了每秒循環(huán)數(shù)次。
防抱死制動系統(tǒng)除了上面基本操作，還有兩個特點。首先，當(dāng)制動系統(tǒng)的壓力上升到使輪胎抱死或即將抱死的時候，防抱死制動系統(tǒng)才會啟動；當(dāng)制動系統(tǒng)在正常情況下，防抱死制動系統(tǒng)停止運作。其次，如果防抱死制動系統(tǒng)有問題時，制動器會獨立地繼續(xù)運行。但控制板上的指示燈亮起提醒司機系統(tǒng)出現(xiàn)問題。
目前歐洲汽車生產(chǎn)商，如：寶馬、奔馳、寶時捷等廣泛使用的是波許（Bosch）防抱死制動系統(tǒng)。這種系統(tǒng)基本組成包括車輪轉(zhuǎn)速傳感器，電子控制裝置和調(diào)節(jié)裝置。
每個有一個向電子控制裝置發(fā)出車輪轉(zhuǎn)動情況的信號的傳感器，它一般由磁感應(yīng)傳感頭和齒圈組成。前面的傳感器安在輪轂上，齒圈安在輪網(wǎng)上。后面的傳感器安在后部的監(jiān)測系統(tǒng)上，齒圈安在輪軸上。傳感器本身是纏繞電磁核的電線圈，電磁核才線圈的周圍產(chǎn)生磁場。當(dāng)齒圈的齒移動到磁場時，就會改變線圈的電流。電子控制裝置會監(jiān)測這種變化，然后判斷車輪是否即將抱死。
電子控制裝置有三個作用，即：信號的處理，編輯和安全防護。信號的處理起到轉(zhuǎn)換器的作用，它是將接受的脈沖電信號處理轉(zhuǎn)換成數(shù)值，為編輯做準備。編輯就是分析這些數(shù)值，計算出需要制動壓力。如果檢測出車輪即將抱死，電控裝置就會計算出數(shù)值向調(diào)節(jié)裝置發(fā)出指令。
調(diào)節(jié)裝置
當(dāng)接受到電子控制裝置的指令后，液壓執(zhí)行裝置會調(diào)節(jié)制動輪缸的液壓的大小。調(diào)節(jié)裝置能保持或減小來自制動主缸的液壓，而裝置本身是不能啟用制動器的。這種裝置有三個高速率的電磁閥，兩個油液存儲器和一個帶有內(nèi)外檢測閥的傳動泵。調(diào)節(jié)裝置中的電子連接器隱藏在塑料蓋下。
每個電磁閥都是其獨立控制的，并作用于前輪。后部的制動輪缸受到一個電磁閥控制，并依照------的原理進行調(diào)節(jié)。當(dāng)防抱死制動系統(tǒng)運行時，電子控制裝置會使電磁閥循環(huán)運作，這樣既能收回又能釋放制動器的壓力。當(dāng)壓力釋放時，它會釋放到液壓單元。前部的制動器電路有一個單元。存儲器低壓存儲器，它在低壓下存儲油液，直到回流泵打開，油液流經(jīng)制動輪缸進入制動主缸。
1.課題研究的目的及意義
汽車的設(shè)計與生產(chǎn)涉及到許多領(lǐng)域，其獨有的安全性、經(jīng)濟性、舒適性等眾多指標，也對設(shè)計提出了更高的要求。汽車制動系統(tǒng)是汽車行駛的一個重要主動安全系統(tǒng)，其性能的好壞對汽車的行駛安全有著重要影響。隨著汽車的形式速度和路面情況復(fù)雜程度的提高，更加需要高性能、長壽命的制動系統(tǒng)。其性能的好壞對汽車的行駛安全有著重要影響，如果此系統(tǒng)不能正常工作，車上的駕駛員和乘客將會受到車禍的傷害。
汽車是現(xiàn)代交通工具中用得最多、最普遍、也是運用得最方便的交通工具。汽車制動系統(tǒng)是汽車底盤上的一個重要系統(tǒng)，它是制約汽車運動的裝置，而制動器又是制動系中直接作用制約汽車運動的一個關(guān)鍵裝置，是汽車上最重要的安全件。汽車的制動性能直接影響汽車的行駛安全性。隨著公路業(yè)的迅速發(fā)展和車流密度的日益增大，人們對安全性、可靠性的要求越來越高，為保證人身和車輛安全，必須為汽車配備十分可靠的制動系統(tǒng)。
車輛在形式過程中要頻繁進行制動操作，由于制動性能的好壞直接關(guān)系到交通和人身安全，因此制動性能是車輛非常重要的性能之一，改善汽車的制動性能始終是汽車設(shè)計制造和使用部門的重要任務(wù)。
現(xiàn)代汽車普遍采用的摩擦式制動器的實際工作性能是整個制動系中最復(fù)雜、最不穩(wěn)定的因素，因此改進制動器機構(gòu)、解決制約其性能的突出問題具有非常重要的意義。
2.汽車制動器的國內(nèi)外現(xiàn)狀及發(fā)展趨勢
對制動器的早期研究側(cè)重于試驗研究其摩擦特性，隨著用戶對其制動性能和使用壽命要求的不斷提高，有關(guān)其基礎(chǔ)理論與應(yīng)用方面的研究也在深入進行。
目前，汽車所用的制動器幾乎都是摩擦式的，可分為鼓式和盤式兩大類。盤式制動器被普遍使用。但由于為了提高其制動效能而必須加制動增力系統(tǒng)，使其造價較高，故低端車一般還是使用前盤后鼓式。汽車制動過程實際上是一個能量轉(zhuǎn)換過程，它把汽車行駛時產(chǎn)生的動能轉(zhuǎn)換為熱能。高速行駛的汽車如果頻繁使用制動器，制動器因摩擦?xí)a(chǎn)生大量的熱量，使制動器溫度急劇升高，如果不能及時的為制動器散熱，它的效率就會大大降低，影響制動性能，出現(xiàn)所謂的制動效能熱衰退現(xiàn)象。
在中高級轎車上前后輪都已經(jīng)采用了盤式制動器。不過，時下還有不少經(jīng)濟型轎車采用的還不完全是盤式制動器，而是前盤后鼓式混合制動器（即前輪采用盤式制動器、后輪采用鼓式制動器），這主要是出于成本上的考慮，同時也是因為轎車在緊急制動時，負荷前移，對前輪制動的要求比較高，一般來說前輪用盤式制動器就夠了。當(dāng)然，前后輪都使用盤式制動器是一種趨勢。在貨車上，盤式制動器也有被采用的，但離完全取代鼓式制動器還有相當(dāng)長的一段距離。
現(xiàn)代汽車制動器的發(fā)展起源于原始的機械控制裝置，最原始的制動控制只是駕駛員操縱一組簡單的機械裝置向制動器施加作用力，那時的汽車重量比較小，速度比較低，機械制動已經(jīng)能夠滿足汽車制動的需要，但隨著汽車自身重量的增加，助力裝置對機械制動器來說越來越顯得非常重要,從而開始出現(xiàn)了真空助力裝置。另外，近年來則出現(xiàn)了一些全新的制動器結(jié)構(gòu)形式，如磁粉制動器、濕式多盤制動器、電力液壓制動臂型盤式制動器、濕式盤式彈簧制動器等。
3.課題研究的內(nèi)容
制動器是制動系中最主要的一個部件，是制動系統(tǒng)中用以產(chǎn)生阻礙車輛的運動或運動趨勢的力的部件。
凡是利用固定元件與旋轉(zhuǎn)元件工作表面的摩擦而產(chǎn)生制動力矩的制動器都稱為摩擦制動器，摩擦制動器可分為鼓式和盤式兩大類。前者的摩擦副中的旋轉(zhuǎn)元件為制動鼓，其工作表面為圓柱面；后者的旋轉(zhuǎn)元件則為圓盤狀的制動盤，以端面為工作表面。
目前廣泛使用的是摩擦式制動器,盤式制動器的摩擦力產(chǎn)生于同汽車固定部位相連的部件與一個或幾個制動盤兩端面之間。其中摩擦材料僅能覆蓋制動盤工作表面的一小部分的盤式制動器稱為鉗盤式制動器；摩擦材料覆蓋制動盤全部工作表面盤式制動器稱為全盤式制動器?，F(xiàn)代汽車中以單盤單鉗式的鉗盤式制動器應(yīng)用最為廣泛，僅有個別大噸位礦用自卸車采用單盤三鉗和雙盤單鉗的鉗盤式制動器，以及全盤式制動器。鉗盤式制動器中定鉗盤式為制動鉗固定在制動盤兩側(cè)，且在其兩側(cè)均設(shè)有加壓機構(gòu)。浮鉗盤式制動器僅在制動盤一側(cè)設(shè)有加壓機構(gòu)的制動鉗，借其本身的浮動，而在制動盤的另一側(cè)產(chǎn)生壓緊力。又分為制動鉗可相對于制動鉗可相對于制動盤軸向滑動鉗盤式制動器；與制動鉗可在垂直于制動盤的平面內(nèi)擺動的擺動鉗盤式制動器。
鼓式制動器摩擦副中的旋轉(zhuǎn)元件為制動鼓，鼓式制動器根據(jù)其結(jié)構(gòu)都不同，又分為：雙向自增力蹄式制動器、雙領(lǐng)蹄式制動器、領(lǐng)從蹄式制動器、雙從蹄式制動器。
正如上面我們看的一樣，制動器器的類型很多，那么每種類型的制動器器都適用什么類型的車呢？是不是有種減速器是完美無缺的？本課題就是來解決這些問題的。其實每種類型都有它的優(yōu)缺點，我們本課題要研究的內(nèi)容就是要通過分析設(shè)計，找出不同類型的減速器的優(yōu)缺點。了解了他們的優(yōu)缺點后我們就能更好更充分的利用它們，為汽車優(yōu)化設(shè)計提供方便。
4.完成課題的實驗條件、預(yù)計設(shè)計過程中可能遇到的問題以及解決的方法和措施
由于對專業(yè)知識的不熟練，可能需要查閱眾多的資料。根據(jù)設(shè)計車型的特點，合理計算該車型制動系統(tǒng)制動力及制動器最大制動力矩、鼓式制動器的結(jié)構(gòu)形式及選擇、鼓式制動器主要參數(shù)的計算與確定、摩擦襯塊的磨損特性計算、制動器熱容量和溫升的核算、制動力矩的計算與校核、在二維或三維設(shè)計平臺AUTO CAD中完成鼓式制動器零件圖以及裝配圖的繪制、設(shè)計合理性的分析和評價等。
本次設(shè)計的目的是通過合理整和已有的設(shè)計，閱讀大量文獻，掌握機械設(shè)計的基本步驟和要求，以及傳統(tǒng)的機械制圖的步驟和規(guī)則；掌握鼓式制動器總成的相關(guān)設(shè)計方法，以進一步扎實汽車設(shè)計基本知識；學(xué)會用AUTO CAD,CATIA等三維軟件進行基本的二維或三維建模和制圖，同時提高分析問題及解決問題的能力。提出將各種設(shè)計方法互相結(jié)合,針對不同的設(shè)計內(nèi)容分別應(yīng)用不同的方法,以促進其設(shè)計過程方法優(yōu)化、設(shè)計結(jié)果精益求精。
5.畢業(yè)設(shè)計實施計劃
第1-4周：查閱資料，分析課題研究的內(nèi)容，外文翻譯，寫開題報告；
第5-6周：比較分析各種不同類型主減速器的優(yōu)缺
第7-8周：分析確定幾種不同類型的主減速器，并繪制出草圖
第9-10周：具體數(shù)據(jù)計算
第11-15周：確定主減速器總裝配圖并繪制總裝配圖：
均為計算機繪圖；
第16-17周：撰寫畢業(yè)論文，準備答辯。
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