離合器壓盤總成高速破壞試驗臺設計,離合器壓盤總成高速破壞試驗臺設計,離合器,總成,高速,破壞,損壞,試驗臺,設計 附 錄 The Spin Tester for the Automobile Clutch Test with High Speed Photography System Abstract:The development of a new type spin tester for the automobile clutch test is introduced.A vertical flexible shaft system with rubber damper is applied to the tester.The crushing test of the clutch assembly can be done frequently on the spin tester,and the high speed photography system adopting ordinary camera can record the crushing wink.The crushing test of a clutch on this tester is also introduced.and the weak link of the clutch assembly can be found from the photograph of crushing wink. Key words:spin tester　automobile clutch　high speed photography Clutch by gland assembly and platen assembly which, in their rotation strength is the key parts of the quality evaluation car is an important index, rules and regulations should be acceleration in their state of the rotating speed is higher than speeding strength test to determine the safety and reliability of the clutch disc. For example, santana clutch disc assembly and driven plate total chengdu in ordinary temperature requirements in a = rad/s2 acceleration of 50 acc to 12 000 r/min, and platen assembly also requires in high temperature (250 ℃) at a = rad/s2 acceleration of 50 acc to 10 000 r/min without fracture. These tests require in the specialized testing machine. At present, the domestic is no clutch assembly strength test on the special equipment. This paper introduces the author developed a vertical multi-function of clutch rotating strength tester (see chart 1). It has a strong drive ability (1), can generate enough acceleration, the maximum weight 50 kg, with the highest speed 18 000 r/min, maximum acceleration 20 rad PI/s2 the clutch assembly strength test; (2) the strong vibration absorber system, to absorb the clutch assembly high speed rotating vibration energy; (3) the reliable and steady automation control system and absolute safety of lead brick protection recessed; (4) to observe the clutch assembly rotation experiment process and the rupture instantaneous state surveillance and high-speed photography system. To all sorts of clutch assembly, the machine can strength test, especially for high speed can be frequently do destructive testing, use convenient, safe and reliable. Figure 1 clutch rotating strength tester photos 1.The main structure characteristics 1.1 With rubber damping bearing on the "flexible shaft type This kind of test enginery due to frequent, high-speed destructive testing, the host axis should be able to complete the clutch assembly rose quickly to the whole process of destruction, so we used on the vertical "with rubber damper flexible shaft of [1], the structure see FIG. 2). Due to the vertical axis, one soft critical speed is low, order only 1800 to 2000 r/min or so, make whole high-speed area are on supercritical of smooth state. At the same time in soft shaft with a middle with "O" type of rubber ring damping bearing shaft system, when the critical speed or because the clutch assembly brought serious imbalance fierce, the vibration damping bearing can absorb vibration energy, attenuation shaft vibration [2], ensure the clutch assembly continue to rise until the complete destruction, ensure speed high-speed damage test. This structure is simple, easy to adjust, damping range. In order to prevent the clutch assembly damage time, great instantaneous vibration energy cause shaft and the lower the destruction of the transmission system, in the gentle shaft with a limit bearing, head to prevent soft shaft bending big and the bottom of the drive shaft damage components. Soft axis adopt plug-in installation, when the clutch assembly, the most serious destruction is replaced the soft shaft, head bent to the whole machine didn't have any effect, operation loading and unloading is very convenient, and ensure the tester can frequently in the clutch assembly destructive test. The vertical axis, facilitate "on the cover from the Windows of the testing process and observe specimens of installation and removal. Figure 2 rubber damper with flexible shaft 1.2 The clutch assembly damage moments of high-speed photography system The clutch assembly by many parts assembly and become, the parts quality is directly related to the quality of the assembly. If can through the high-speed strength test find assembly parts the weak links, had better be to be in test chamber to take the parts assembly by deformation and destruction and yield spread to the whole process of, that will be very significant. Although currently not at a close range in advance, do not know when the clutch assembly of the damage happened produced high speed the whole process of destruction, but they can take to destroy the moment alone photos. Foreign is widely accepted in the specimen outside trigger coil rotor set, as the rotor fly crack, debris flying out of line, met trigger trigger circuit triggered by high speed camera shutter open, took a damage the image of the rotor moment. Obviously this design requirements must have taken the camera very high speed. For example the clutch assembly destruction speed than 10 000 r/min, the linear velocity in the 200 m/s above, if want to take clear debris flying out of the instantaneous movement condition when, captured fragments of the distance from the 2 mm moving images. So, the camera at least should have t = 2 mm / (200 m/s) = 1 x 10-5 s shooting speed, for ordinary camera it is clearly the deficits. In order to solve this problem, we developed a common cameras with the high-speed photography in the technology, with the clutch high-speed strength test machine, took the clutch assembly destruction of photographs. The moment The high-speed photography work principle of the system is shown in figure 3. The specific practices for ordinary camera, will cover the Windows in testing machine in the darkness of the test chamber outside, open shutter, in advance for shooting state. At the same time, add the rear cover outside the window between the two steel ball must high pressure of the capacitor voltage. When the clutch assembly, high speed rotating parts fly crack damage, cut off the assembly line, the periphery of the trigger that set up light source line work trigger pin, triggering a trigger pulse, so that the air between two steel ball, a steel ball capacitor in ionization produced strong, between discharge pulse light source, then the camera narrow photographic plate, get the clutch assembly destruction of photographs. The moment The technology of the method is simple, save expensive high-speed cameras, the shooting accuracy is high. Figure 3 high-speed photography system work principle diagram 2.Experimental study We in the testing machine to clutch cover plate assembly and made a large destructive testing. Now to the santana gland assembly damage test as an example. First, take the santana clutch cover assembly state of rest; Then, the gland assembly, and to destroy the damage process using high-speed photography system to shoot, have the following results: (1) santana clutch cover assembly in speed for 11 560 r/min, gland spring of fly out, cut off the trigger coil, took a high-speed photography photos (see chart 4), photos are the right off about 20 ° position on a spring of the flying out of the shadows. After parking the tray found not damage, but find spring of crack, the obvious skeleton spring of centrifugal force along the role in the first bending fly out broken. (2) this gland assembly continue to rise in speed for speed test, 14 010 r/min happened when the tray destruction, like on high-speed photography photos (see chart 5). Photos of the moment by damage, the whole clutch cover visible assembly gland produces serious warping deformation, radial on turn over the close (see photo) and cut off the trigger coil. As gland warping, clutch the tray imbalances fly crack damage. But did not see the gland cast iron rings (cover parts can't photographed) fly out of the shadow of the fracture. (3) from gland assembly destroyed the crack of photos skeleton (see figure 6) can see, gland serious warping deformation in spring of installation, the gaps, but pulled gland and without breaking into several pieces, although gland lower part of the cast iron ring has fractured into seven pieces, but found no gland inside surface, cast iron rings pieces the trace of the impact. The result shows the santana car clutch cover the failure process of the instantaneous assembly for local parts, (spring of) fly out-gland serious warping deformation, in local weak section and pulled in the bottom of the gland cast iron rings and the whole gland assembly fracture failure. This tester has been put into use of factory three years, because the function is all ready, performance stability, price cheap, and solve the clutch a lot of detection, the development, and the research question, is expected to replace the imported, application. Figure 4 gland assembly spring of fly out of the moment photos Figure 5 gland assembly moments of photos. Damage Figure 6 gland assembly after damage remains of the photo Reference [1] WuDaWen. "O" type rubber ring experimental study of the dynamic characteristics of the master's degree thesis: [Master's degree thesis]. Hangzhou, zhejiang university, 1998 [2] QianLiXin. Ultra-high speed rotor test development speeding some issues of the study: [Ph.D. Thesis]. Hangzhou, zhejiang university, 1998 帶高速攝影系統(tǒng)的汽車離合器旋轉破壞強度試驗機 摘要：提供了一種帶高速攝影系統(tǒng)的汽車離合器旋轉破壞強度試驗機，該機可以頻繁地做離合器總成的破壞性試驗，并可拍攝到離合器總成破壞瞬間的獨幅照片，以利找出總成零件的薄弱環(huán)節(jié)。 關鍵詞：旋轉破壞性試驗　試驗機　汽車離合器　高速攝影 汽車離合器由壓蓋總成和從動盤總成組成，它們的旋轉強度是評價汽車關鍵零件質量的重要指標，規(guī)范規(guī)定它們都應在加速度狀態(tài)下進行高于工作轉速的超速強度試驗，以確定離合器盤的安全性和可靠性。例如，桑塔納轎車的離合器壓盤總成與從動盤總成都要求在常溫下以a=50 rad/s2的加速度升速至12 000 r/min,而從動盤總成還要求在高溫(250℃)下以a=50 rad/s2的加速度升速至10 000 r/min而不發(fā)生破裂。這些試驗都要求在專門的試驗機上進行。 　　目前，國內尚缺少進行汽車離合器總成強度試驗的專用設備。本文介紹筆者研制的一種立式多功能的汽車離合器旋轉強度試驗機(見圖1)。它具有①較強的驅動能力，可產生足夠大的加速度，進行最大重量50 kg、最高轉速18 000 r/min、最大加速度20π rad/s2的離合器總成強度試驗；②強大的減振系統(tǒng)，以吸收離合器總成高速旋轉時的振動能量；③可靠而平穩(wěn)的自控系統(tǒng)和絕對安全的鉛磚防護腔體；④可供觀察離合器總成旋轉試驗過程和破裂瞬時狀態(tài)的監(jiān)視與高速攝影系統(tǒng)。對各種汽車離合器總成，該機可進行高速強度試驗，尤其可頻繁地做破壞性試驗，使用方便、安全可靠。 圖1　汽車離合器旋轉強度試驗機照片 1.主要結構特色 1.1 帶橡膠阻尼支承的上托式柔性軸系 　　這類試驗機由于要頻繁地進行高速破壞性試驗，主機軸系應能順利完成離合器總成升速至破壞的全過程，因此我們采用立式上托的帶橡膠阻尼器的柔性軸系［1］，其結構見圖2。由于采用立式柔軸，其一階臨界轉速很低，只有1800～2000 r/min左右，使整個高速區(qū)域均處在超臨界的平穩(wěn)狀態(tài)。同時在柔軸中間設有一個用“O”型橡膠圈組成的阻尼支承，當軸系通過臨界轉速或者由于離合器總成發(fā)生嚴重失衡帶來激烈振動時，該阻尼支承能吸收振動能量，衰減軸系振動［2］，確保離合器總成繼續(xù)升速直至破壞，保證完成高速破壞試驗。此結構簡單、容易調整、減振范圍大。為了防止離合器總成破壞時刻，巨大的瞬時振動能量造成下部軸系和傳動系統(tǒng)的破壞，在柔軸頭部設有一限位支座，防止柔軸彎曲變形過大而破壞軸系下部的傳動部件。柔軸采用插入式安裝，當離合器總成破壞嚴重時，最多是更換頭部彎曲的柔軸，對整個機器沒有任何影響，操作裝卸十分方便，從而保證了該試驗機可以頻繁地進行離合器總成的破壞性試驗。采用立式上托軸系，便于從頂蓋視窗觀察試驗過程以及試件的安裝與拆卸。 圖2　帶橡膠阻尼器的柔性軸系 1.2　離合器總成破壞瞬間的高速攝影系統(tǒng) 　　離合器總成由許多零件組裝而成，各零件質量的好壞直接關系到總成的質量。若能通過高速強度試驗找出總成零件的薄弱環(huán)節(jié)，最好是在試驗腔內拍攝到總成各零件由變形→屈服→散架→破壞的全過程，那將是十分有意義的。雖然目前無法在近距離內，在事先不知道離合器總成何時發(fā)生破壞的情況下拍攝高速破壞的全過程，然而卻可以拍攝到破壞瞬間的獨幅照片。 　　國外普遍采用的是在試件轉子外設置觸發(fā)線圈，當轉子飛裂時，碎片飛出碰到觸發(fā)線，由觸發(fā)電路觸發(fā)高速照相機打開快門，拍下轉子破壞瞬間的形象。顯然這種設計要求照相機必須有很高的拍攝速度。例如離合器總成的破壞轉速多大于10 000 r/min，其線速度在200 m/s以上，若要拍攝清楚碎片飛出時的瞬時運動狀況，捕捉到碎片移動2 mm距離的圖像。那么，照相機起碼應具有t=2 mm/(200m/s)=1×10-5 s的拍攝速度，對于普通照相機這顯然是望塵莫及的。 　　為了解決這個難題，我們開發(fā)了一種用普通照相機拍攝的高速攝影技術，用在汽車離合器 高速強度試驗機上，拍到了離合器總成破壞瞬間的獨幅照片。此高速攝影系統(tǒng)的工作原理見圖3。具體做法為，將普通照相機置于試驗機頂蓋視窗外，在黑暗的試驗腔外，預先打開快門，處于待拍攝狀態(tài)。同時，加足頂蓋側視窗外反光鏡兩鋼球間的高壓電容器的電壓。當離合器總成高速旋轉，零件飛裂破壞時，切斷總成外圍設置的觸發(fā)線，使光源觸發(fā)線路工作，觸發(fā)針發(fā)出觸發(fā)脈沖，使兩鋼球間的空氣電離，引發(fā)電容器在鋼球間放電，產生強的窄脈沖光源，于是照相機底片感光，獲得離合器總成破壞瞬間的獨幅照片。此技術方法簡便，省去昂貴的高速照相機，拍攝精度也高。 圖3　高速攝影系統(tǒng)工作原理圖 2.試驗研究 　　我們在此試驗機上對離合器蓋及盤總成作了大量破壞性試驗。今以桑塔納轎車壓蓋總成的破壞試驗為例說明。首先，拍下桑塔納轎車離合器壓蓋總成靜止時的狀態(tài)；然后，對壓蓋總成進行破壞，并對破壞過程用高速攝影系統(tǒng)進行拍攝，獲得以下結果： 　　(1)桑塔納離合器壓蓋總成在轉速為11 560 r/min時，壓蓋彈簧片飛出，切斷觸發(fā)線圈，拍下高速攝影照片(見圖4)，照片正右偏上約20°位置有一彈簧片飛出的陰影。停車后發(fā)現整盤尚未破壞，但找到彈簧片裂骸，明顯可見彈簧片在離心力作用下沿根部先彎斷飛出。 　　(2)以此壓蓋總成繼續(xù)升速試驗，在轉速為14 010 r/min時發(fā)生整盤破壞，拍得高速攝影照片(見圖5)。由破壞瞬間的照片可見，整個離合器壓蓋總成的壓蓋發(fā)生嚴重翹曲，徑向變形上翻拉平(見照片上部)并切斷觸發(fā)線圈。隨著壓蓋翹曲后，離合器整盤失衡飛裂破壞。但未看出壓蓋下部鑄鐵圓環(huán)(遮住部位無法拍攝到)斷裂飛出的影子。 　　(3)從壓蓋總成破壞后的裂骸照片(見圖6)可看出，壓蓋嚴重翹曲變形，在安裝彈簧片的缺口處拉斷，但壓蓋并沒有破斷成幾塊，雖然壓蓋下部的鑄鐵圓環(huán)已斷裂成7塊，但沒有發(fā)現壓蓋內側面上有鑄鐵圓環(huán)碎塊撞擊的痕跡。 　　由上結果可見桑塔納轎車離合器壓蓋總成瞬時的破壞過程為，局部零件(彈簧片)飛出→壓蓋嚴重翹曲變形，在局部薄弱截面處拉斷→壓蓋下部的鑄鐵圓環(huán)斷裂→整個壓蓋總成破壞。 　　本試驗機已投入工廠使用達3年之久，由于功能齊全、性能穩(wěn)定、價格低廉，且解決了汽車離合器大量的檢測、開發(fā)與研究問題，有望替代進口，推廣應用。 圖4　壓蓋總成彈簧片飛出瞬間的照片 圖5　壓蓋總成破壞瞬間的照片 圖6　壓蓋總成破壞后殘骸的照片 參考文獻 [1] 吳大文.“O”型橡膠圈動態(tài)特性的實驗研究：［碩士學位論文］.杭州：浙江大學，1998 [2] 錢立新.超高速轉子超速試驗臺研制中若干問題的研究：［博士學位論文］.杭州：浙江大學，1998