花冠汽車電器實驗臺設計【帶圖紙和說明書】
花冠汽車電器實驗臺設計【帶圖紙和說明書】,帶圖紙和說明書,花冠,汽車電器,實驗,試驗,設計,圖紙,以及,說明書,仿單
附 錄1:英文文獻
AUTO ELECTRIC APPLIANCES
1、Starting System
Automobile engines are not self-starts. In order to start them, the engine crankshaft must be turned over. To do this, the starter motor receives electrical power form the storage battery. The starter motor then converts this energy into mechanical energy, which it transmits through the drive mechanism to the engine’s fly wheel.
The starter motor draws a great deal of electrical current from the battery. A large starter motor might require 300 to 400 amperes of current. This current flows through the heavy gauge cables that connect the battery to the starter.
The drive controls the flow of this current using the starting switch. However, if the cables were routed from the battery to the starting switch and then on to the starter motor, the voltage drop caused b resistance in the cables would be too great. To avoid this problem, the system is designed with two connected circuits: the starter circuit and the control circuit.
1.1 The starting safety switch
The starting safety switch is also called a neutral start switch. It is a normally open switch that prevents the starting system from opening when the automobile’s transmission is in gear. If the car has no starting safety switch, it is possible to spin the engine with the transmission in gear. This will make the car lurch forward or backward which could be dangerous. Safety switches or interlock devices are used with all automatic transmissions and on many late-model cars with manual transmissions. The safety switch can be an electrical switch that opens the control circuit if the car is in gear. It can also be a mechanical interlock device that will not let the ignition switch turn to start if the car is in the gear.
1.2 Magnetic Switch (Relays and Solenoids)
A magnetic switch in the starting system allows the control circuit to open and close the starter circuit. The switch can be a:
（１）Relay which uses the electromagnetic field of a coil to attract an armature and close the contact points.
（２） Solenoid which uses the electromagnetic field of a coil to pull a plunger into the coil and close the contact points. The plunger’s movement can also be used to do a mechanical job, such as shifting the starter motor gear in a solenoid-actuated drive.
1.3 Starter Motor
The starter motor converts electrical energy from the battery into mechanical energy to turn the engine. It does this through the interaction of magnetic fields. When current flows through a conductor, a magnetic field is formed around the conductor. If the conductor is placed in another magnetic field, the two fields will be weakened at one side and strengthened at the other side. An automotive starter motor has many conductors and uses a lot of current to create enough rotational force to crank the engine.
The armature is the collection of conductors that will spin to crank the engine. The starter drive gear is mounted on the armature shaft. The pole pieces are the stationary magnetic fields. The motor housing encloses the armature and pole pieces, holds the bearings that support the armature shaft, and provides the terminals for connecting the motor to the rest of the staring system.
2.I gniting System
The ignition system on an internal combustion engine provides the spark that ignites the combustible air/fuel mixture in the combustion chamber. The spark consists of an electric are produced by applying a high voltage across the electrodes of a spark plug. This spark must occur near the end of the compression stroke, as the position approaches top dead center (TDC). The cylinders must fire in the proper order and at a precise instant, depending on engine speed, load and temperature conditions.
A spark plug consists of a pair of electrodes called the center and ground electrodes, separated by a gap. A spark is produced by applying a high voltage (from approximately 6 KV to 40 KV) between the center electrode and ground. Once the arc is started, a much lower voltage is required to sustain the arc to ignite the air/fuel mixture.
The ignition system is divided into two circuits: the primary and the secondary. The primary circuit is the low-voltage side of the system and controls the secondary circuit, which is the high-voltage side of the system.
The following are the basic parts of the primary ignition circuit:
（１）Battery and/or alternator. Supplies the low voltage (12V) used to operate the primary circuit.
（２） Ignition switch. Key-operated switch used to feed battery voltage to the primary circuit.
（３） Primary wires. Low voltage wires used to connect the electrical components of the primary circuit.
（４） Ignition coil primary winding. Current flow through the coil produces an electromagnetic field, which is used to induce a high voltage in the secondary coil.
（５） Electronic control unit. Contains a switching transistor controlled by a speed sensor and is used to open and close the primary circuit.
（５）Speed sensor, or pickup. Produces a pulsating voltage that signals the generation of an ignition spark.
The following are the basic parts of a secondary ignition circuit:
（１）Ignition coil secondary winding. Has a high voltage (40,000 V or more) induced in it each time the primary magnetic field collapses.
（２）Coil wire. Heavily insulated wire that feeds high voltage from the ignition coil to distributor cap.
（３） Distributor rotor. Operates in conjunction with the distributor cap to distribute the high voltage from the ignition coil to the individual spark plug wires in the firing order.
（４） Distributor cap. Insulated cap that transfers high voltage from the distributor rotor to spark plug wires.
（５） Spark plug wire. Heavily insulated wire that carries high voltage from the distributor to the spark plugs.
（６）Spark plug. Provides the air gap within the combustion chamber for the high voltage to arc across, thus igniting the air/fuel mixture.
３、Lighting Circuit
The lighting system in a typical automobile includes the headlight, parking lights, direction-signal lights, side marker, stoplights, tail lights, and interior lights.
3.1 Main Lighting Switch
The main lighting switch (sometimes called the headlight switch) is the heart of the lighting systems. It controls the headlights, parking lights, side marker lights, taillights, license plate light, instrument panel lights, and interior lights.
Individual switches are provided for special purpose lights such as directional signals, hazard warning flashers, back up lights, and courtesy lights. The main lighting switch may be of either the “push-pull” or “push-pull with rotary contact” types. A typical switch will have three positions: off, parking, and headlamps. Some switches also contain a rheostat to control the brightness of the instrument panel lights. The rheostat is operated by rotating the control knob, separating it from the push-pull action of the main lighting switch.
When the main lighting switch completes the circuit to the headlamps, the low beam lights the way for city driving and for use when meeting oncoming traffic on the highway. When the dimmer switch is actuated, the single filament headlamps go “on”, along with the high beam of the two filament headlamps. The next actuation of the dimmer switch returns the headlight system to low beams only on the two filament lamps. Some cars are equipped with and electronic headlight dimming device, which automatically switches the headlights from high beam to low in response to light from an approaching vehicle or light from the taillight of a vehicle being overtaken. The dimmer switch in the automatic headlamp dimming system is a special override type. It is located in the steering column as part of a combination dimmer, horn, and turn signal switch. The override action occurs when a slight pull toward the driver on the switch lever providers high beam headlights regardless of the amount of light on the sensor-amplifier.
For some years there has been discussion about the advantages of a polarized headlight system. Such a system comprises headlights which produce polarized light in a particular plane. The windscreens of all cars would be fitted with polarizing glass, which would be oriented so that glare from an approaching vehicle would be essentially eliminated, while the forward vision would still be kept at the present levels. The advantages the system appear attractive, but the practical problems of making the transition are very great, since it would not be practical to convert all existing vehicles to this type of lighting. Also, any benefits would only be marginal because glare itself is not a frequent cause of accidents. However, many cars now have refracting or colored glass to cut down on glare.
3.2 Directional Signal Switch
The directional signal switch is installed just below the hub of the steering wheel. A manually controlled lever projecting from the switch permits the driver to signal the direction in which he wants to turn. Moving the switch handle down will light the “turn signal” lamps on the left front and left rear of the car, signaling a left turn. Moving the switch upward will light the turn signal lamps on the right (front and rear), signaling a right turn. With the switch in a position to signal a turn, lights are alternately turned “on” and “off” by a turn signal flasher. Incorporated in the directional signal switch is a “l(fā)ane change switch mechanism”. This feature provides the driver the opportunity to signal a lane change by holding the turn lever against a dent, then releasing it so cancel the signal immediately after the maneuver is completed.
3.3 Stoplight Switch
In order to signal a stop, a brake pedal operated “stoplight switch” is provided to operate the vehicle’s stop lamps. In addition to lighting the conventional rear lights, the switch also operates the center high-mounted stop lamp, which became mandatory on later models. Cruise control equipped vehicles may also utilize a vacuum release valve. In this case, both the vacuum release valve and the stoplight switch are actuated by movement of the brake pedal.
汽車電器
1、啟動系統(tǒng)
汽車發(fā)動機是不能自動啟動的。為了啟動發(fā)動機，曲軸必須先運轉起來。為此，啟動機必須從蓄電池得到足夠的電能。接著啟動機將這部分電能轉化成機械能，通過驅動機構傳到發(fā)動機曲軸飛輪上。
啟動機需要蓄電池提供大量的電流。一個大型的啟動機需要大約300~400安培的電流。電流通過重型電纜從蓄電池連接到啟動機上。
駕駛員通過啟動開關來控制這個電流。如果導線從蓄電池經過啟動開關連接到啟動機上，在導線上會產生大量的電壓降。為了避免這個問題，啟動系統(tǒng)設計有兩套電路：啟動機電路和控制電路。
1.1安全啟動開關
啟動安全開關又稱為空檔啟動開關。它是一個常開開關，用來防止在汽車掛擋后啟動系統(tǒng)工作。如果沒有安全啟動開關，啟動系統(tǒng)很可能在掛擋后工作。這種情況是非常危險的，將會使汽車前進或后退。安全開關或者互鎖裝置在所有的自動排擋或手動排擋的汽車上都有應用。安全開關可以是一種電子開關，當汽車掛擋后，它斷開控制電路。同樣，安全開關也可以是機械互鎖裝置，當汽車掛擋后不允許點火開關轉到啟動位置。
1.2電磁開關
啟動系統(tǒng)的電磁開關用于控制控制電路斷開或接通啟動機電路。開關形式如下：
（１）繼電器： 利用吸引線圈產生磁場，吸引銜鐵并閉合觸點。
（２）電磁線圈：利用吸引線圈產生磁場，推動柱塞進入線圈并閉合觸點。柱塞通常是機械運動，就如使啟動機掛擋的電磁驅動裝置一樣。
1.3啟動機
啟動機將蓄電池的電能轉化為驅動發(fā)動機啟動的機械能。它是利用電磁互感的原理制成的。通有電流的導體在其周圍會產生磁場。當這樣的導體被放置到另一個磁場中時，兩個磁場將有一側被加強而另一側被減弱。當大電流流過汽車啟動機的線圈時，可以產生足以讓發(fā)動機曲軸轉動的力矩。
電樞由線圈組成用以使發(fā)動機曲軸轉動。啟動機驅動安裝在電樞轉軸上的齒輪。磁極產生穩(wěn)定磁場。啟動機外殼內裝入電樞與磁極，外殼兩端的軸承支撐電樞轉軸，并將啟動機與啟動系統(tǒng)支架相連。
2、點火系統(tǒng)
內燃機的點火系統(tǒng)產生電火花，點燃燃燒室的可燃混合氣體?；鸹ㄓ呻娀‘a生，是由經過火花塞電極的高電壓形成的?；鸹☉撛诮咏鼔嚎s行程終了的時候產生，即活塞位于接近上止點（TDC）。各缸的點火應該有合適的順序和精確的時間，這取決于發(fā)動機的轉速、負荷和溫度。
火花塞由一對電極組成，稱為中心電極和塔鐵（旁）電極由一個間隙分開?；鸹ㄓ稍谥行碾姌O和旁電極之間的高電壓（大約6千伏到40千伏）產生。一旦電弧產生，必須有一個較低的電壓來維持電弧點燃混合氣。
點火系統(tǒng)分為兩條回路：初級和次級。初級回路是系統(tǒng)的低壓端，并控制這次級回路，而次級回路是系統(tǒng)的高壓端。
初級回路由以下基本部分組成：
（１）蓄電池和發(fā)電機。提供低壓電（12伏）讓低壓電路正常工作。
（２）點火開關。通過點火開關的控制，把蓄電池電壓提供給初級電路。
（３）初級導線。低壓導線用來連接初級回路的各個部件。
（４）點火線圈初級繞組。電流通過線圈，產生一個電磁場，用來在次級線圈中產生高電壓。
（５）電子控制單元。包括由轉速傳感器控制的開關晶體管，用來斷開或接通初級電路。
（６）轉速傳感器或者感應線圈。產生一組脈沖電壓，給點火火花的產生提供信號。
次級回路由以下基本部分組成：
（１）點火線圈次級繞組。當初級回路的電磁場每一次消失的時候，會產生一個高電壓（40 000伏或更高）。
（２）（線圈）高壓導線（中央高壓線）。導線必須確保絕緣，以保證高電壓從點火線圈傳輸到分電器蓋。
（３）分電器的分火頭。作用是與分電器蓋相連，把高電壓從點火線圈分配到需要點火的火花塞導線上。
（４）分電器蓋。該蓋子是絕緣的，確保高電壓從分火頭傳輸到火花塞導線上。
（５）火花塞導線（分缸高壓線）。導線必須確保絕緣，以保證高電壓從分電器傳輸到火花塞。
（６） 火花塞。在燃燒室里提供空氣間隙，保證高電壓的電弧通過，來點燃混合氣。
3、照明線路
普通車的照明系統(tǒng)包括前照燈、泊車燈、轉向信號燈、輪廓燈、制動燈、倒車燈、尾燈以及車內燈。
3.1燈光總開關
燈光總開關（有時叫做前照燈開關）是照明系統(tǒng)的心臟。它控制前照燈、泊車燈、輪廓燈、尾燈、牌照燈、儀表板燈和車內燈。
個別的開關被提供作為控制特別的燈，像是轉向信號、危險警告閃爍裝置、倒車燈和禮貌燈。燈光總開關可能是“拉桿式的”或“拉桿及旋鈕式”類型。一個典型的開關一般有三個位置：關閉、泊車和前照燈。一些開關也包含一個可變電阻器，控制儀表板燈的燈光亮度?？勺冸娮杵饔尚D的控制手柄操縱，與燈光總開關的推一拉的操縱是分開的。
當燈光總開關接通前照燈線路的時候，近光燈絲點亮，為在城市道路駕駛和在高速公路上輛車交會時提供照明。在變光開關工作時，單絲前照燈打開，同時雙絲前照燈的遠光燈也一起打開。變光開關的另一個接通時，雙絲前照燈上只有近光燈打開。一些汽車裝備了前照燈電子變光裝置，當接收到一輛逐漸靠近的汽車的燈光時，或接收到前面被趕上的車的尾燈燈光時，能自動地將前照燈從遠光轉變到近光。自動前照燈的變光開關是一種特別的開關。它位于轉向柱上，作為組合變光開關、喇叭和轉向信號開關的一部分。輕輕朝著駕駛員的方向拉動開關控制桿這一動作，就可以使前照燈遠光燈泡點亮，而不用顧及燈的數量。
近年來，人們開始討論有關偏振光的前照燈系統(tǒng)的優(yōu)勢。一個這樣的系統(tǒng)包括能產生偏振光的特殊面的前照燈。所有的汽車擋風玻璃會配備有偏振光玻璃，這樣，來自某一正在接近的汽車的眩目的光線會被定向除去，于是向前的視角就能夠保持當前的水平方向。該系統(tǒng)的有時顯得很有吸引力，但是實際的制造上的問題非常大，因為將現存汽車全部改換成這種系統(tǒng)顯然不實際。這些益處只是次要的，因為眩目本身并不是意外事件發(fā)生的常見因素。因此，許多汽車現在裝備使光線折射的玻璃或把玻璃染色來減少眩目的影響。
3.2轉向開關
轉向開關就安裝在轉向柱轂的下面。從開關上突出的一個用手控制的杠桿使駕駛員能根據所轉的方向顯示轉向信號。向下移動開關柄將會點亮車輛左前和左后的“轉向信號燈”，表示向左轉。向上移動開關將會點亮車輛右邊（前面和后面）的燈，表示向右轉。籍由一個轉向開關表示方向信號，轉向燈被一個轉向信號閃光器交替地控制“ON”和“OFF”。合并在轉向開關中的是一個“變換開關機構”。該特征提供給駕駛員一個機會來握住轉向桿，靠向一個爪來表示一個變換信號，在操縱完之后，釋放它就可以立刻取消該信號。
3.3制動燈開關
為了要表示停車，由剎車踏板操縱“制動燈開關”控制汽車的制動燈、除了傳統(tǒng)照明的后燈，開關也控制中央高位剎車燈，在最新的車型中是強制性安裝的。裝備了巡航控制的汽車也可能利用一個真空釋放閥。在這種情況下，真空釋放閥和制動燈開關都有剎車踏板的運動控制。
附 錄2：實驗指導書
實驗一：汽車照明以及信號系統(tǒng)原理分析及故障檢修
一、實驗目的與要求
１、了解與掌握汽車照明系統(tǒng)的結構與工作原理，熟悉汽車照明系統(tǒng)電路特征。
２、掌握汽車電路測試．方法，熟練使用檢測儀器儀表，進行工作過程信號測試。
３、結合實驗設備，進行故障模擬，并加以排除，總結排除故障的方法。
４、結合試驗儀器，按照汽車照明系統(tǒng)布線原則，查找不同系統(tǒng)的電路組成。
二、實驗儀器及設備
１、花冠汽車電器實驗臺(1臺)
２、汽車萬用表2只
３、各用車用繼電器、保險片一組。
三、實驗內容
１、查找汽車燈系電路，繪制汽車部分照明系統(tǒng)電路接線圖。
（１）將電量充足的蓄電池接入電路中，紅色的夾子接蓄電池的“+”極，黑色的夾子接蓄電池的“一”極。閉和所有的電器開關，故障開關復位。使整個電路系統(tǒng)處于通路狀態(tài)。
（２）在花冠電器實驗臺上根據導線顏色及連線位置關系，參照花冠汽車電路圖進行查找，并且利用萬用表進行檢測，查找電路接點電壓，將測量值紀錄，并總結節(jié)點電壓特征。主要紀錄繼電器盒端子電壓以及端子控制電路。
（３）查找不同燈系電路(設計性)：
要求向學們結合花冠汽車電路圖進行設計查找，同時能夠在實驗臺中找出不同電路控制開關以及保險，將電路接線圖進行簡化。布置如下工作任務，根據不同要求進行電路分析：
１）結合實驗臺，查找并分析前照燈(大燈、小燈)電路，并且使用燈光變光控制開關控制近光、遠光變化。 ．
２）查找并分析轉向燈電路，同時結合實驗臺進行紀錄燈系工作特征。拆卸轉向信號燈，紀錄燈泡功率及特征。
３）查找并分析汽車霧燈控制電路，查找電路相關繼電器以及保險容量。
４）查找并分析儀表燈電路，并設計出合理方案控制儀表燈工作。
５）查找倒車燈電路。
６）查找并分析制動燈電路。
７）查找并分析尾燈電路。
２、結合實驗臺，使用實驗臺故障設置開關，設置出不同汽車照明系統(tǒng)故障，并進行分析，總結結論。
要求設計出不同方案進行故障演示。必要時，可以改變故障控制開關電路，進行紀錄。要求同學們自己設計方案，每人至少設計1～2個故障。
３、課后作業(yè)
根據實驗內容，紀錄測量數據，將結果以及電路圖記入實驗報告。
（１）根據設置故障點，總結故障規(guī)律，分析可能形成原因。
（２）將實驗臺一側前轉向燈泡拆下，使用轉向燈開關控制轉向燈工作，紀錄工作特征，并進行分析。
（３）分析制動燈不工作的原因。
（４）分析一個前照燈不工作的原因。
４、考核內容
（１）結合實驗臺，教師設置不同照明系統(tǒng)電路故障，要求同學們在規(guī)定時間內排除，并分析原因。
（２）結合實驗臺繼電器盒，查找教師指出端子的含義。包括：端子所屬于電器系統(tǒng)；端子連接導線性質；端子電壓變化規(guī)律等。
實 驗 報 告
課程名稱：
系部名稱：
專業(yè)班級：
學生姓名：
學 號：
指導教師：
實驗項目
汽車照明以及信號系統(tǒng)原理分析及故障檢修
實驗日期
實驗地點
同組人數
實驗臺號
實驗類型
□驗證性 □ 綜合性 □ 設計性 □ 其 他
一、實驗目的
二、實驗儀器設備
三、實驗原理
四、實驗內容或步驟
五、數據表格
六、數據處理結果（結論）
七、實驗中存在的問題、解決方法及進一步的想法等
八、教師評語
成 績
指導教師簽字：
年 月 日
注：1、此報告為參考格式，各欄項目可根據實際情況進行調整；
2、“實驗儀器設備”一欄：設計性實驗根據實驗條件對實驗儀器設備提出具體要求；
3、“實驗內容或步驟”一欄：設計性實驗需填寫設計方案。
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