【摘要】：機(jī)油冷卻器(簡(jiǎn)稱油冷器)主要功能是用于發(fā)動(dòng)機(jī)潤(rùn)滑油的冷卻,是汽車發(fā)動(dòng)機(jī)冷卻系統(tǒng)的重要零配件。如今,車用油冷器多采用多層密集排列的鋸齒型錯(cuò)列翅片全鋁油冷器,此類型的油冷器體積小,重量輕,冷卻效率高,但油冷器整體結(jié)構(gòu)復(fù)雜,同時(shí)又對(duì)油冷器的密封性和耐腐蝕等性能又有著非�？量痰囊�,為實(shí)現(xiàn)該類型油冷器翅片同芯板、芯板同前后密封板之間精密和高質(zhì)量的連接,最終實(shí)現(xiàn)油冷器同冷卻系統(tǒng)精密與可靠的連接,其連接方法已經(jīng)成為備受關(guān)注的研究課題。本文以CA型板翅式鋁合金油冷器為研究對(duì)象,首先,制定了油冷器頂板結(jié)構(gòu)的電阻點(diǎn)焊工藝和芯體的Nocolok爐中釬焊工藝。其次,焊后分別對(duì)點(diǎn)焊焊接接頭進(jìn)行了宏觀形貌、顯微組織、顯微硬度、拉伸性能和撕裂分析等實(shí)驗(yàn)分析,研究了不同工藝參數(shù)對(duì)點(diǎn)焊焊接接頭各性能的影響規(guī)律。同時(shí),研究了釬焊工藝參數(shù)對(duì)油冷器釬焊接頭顯微組織的影響,并對(duì)油冷器進(jìn)行了綜合性能檢測(cè),為該類型的板翅式鋁合金油冷器的焊接提供了關(guān)于焊接工藝的理論基礎(chǔ)。實(shí)驗(yàn)研究表明:1)點(diǎn)焊焊接接頭由熔核、塑性環(huán)和母材三部分組成,熔核屬于典型的“柱狀晶+等軸晶”組織。隨著電流和焊接周波的增大,焊核中心等軸晶組織逐漸粗化,柱狀晶組織數(shù)量隨著焊接電流的增大而減少,隨著電極壓力的增大而增多。2)焊接電流、焊接周波和電極壓力對(duì)點(diǎn)焊接頭的顯微硬度和拉伸載荷的影響規(guī)律均有所不同,柱狀晶區(qū)的顯微硬度大于焊核中心,顯微硬度最小值出現(xiàn)在熱影響區(qū)。3)當(dāng)焊接電流、周波和電極氣壓分別為22 kA、8 cyc和0.20 MPa,且預(yù)壓時(shí)間和維持時(shí)間分別為25 cyc和15 cyc時(shí),點(diǎn)焊焊接接頭性能達(dá)到最佳值,其平均顯微硬度為40.64 Hv,拉剪力為2.103 kN。4)釬縫區(qū)的組織是典型的α(Al)固溶體和Al+Si共晶相組織。釬焊工藝的最優(yōu)工藝參數(shù)是:六個(gè)分區(qū)溫度依次為600℃-605℃-610℃-615℃-620℃-615℃,釬焊區(qū)網(wǎng)帶速度為320 mm/min。對(duì)油冷器進(jìn)行綜合性能檢測(cè)試驗(yàn),檢測(cè)發(fā)現(xiàn)產(chǎn)品合格率高,滿足生產(chǎn)和使用要求,表明該最優(yōu)工藝參數(shù)可用于指導(dǎo)實(shí)際焊接生產(chǎn)。
[Abstract]:The main function of the oil cooler is to cool the engine lubricating oil, which is an important part of the automobile engine cooling system. Nowadays, automotive oil coolers are mostly made of multi-layer, dense arrangement of jagged staggered fin all aluminum oil coolers. This type of oil cooler is small in volume, light in weight and high in cooling efficiency, but the overall structure of the oil cooler is complex. At the same time, the sealing performance and corrosion resistance of the oil cooler are very demanding. In order to realize the precise and high quality connection between the fin of the oil cooler and the core plate, the core plate and the front and rear sealing plates, Finally, the precise and reliable connection between oil cooler and cooling system is realized. In this paper, the CA type plate-fin aluminum alloy oil cooler is taken as the research object. Firstly, the resistance spot welding process of the oil cooler roof structure and the brazing process of the core body in the Nocolok furnace are established. Secondly, the macroscopic morphology, microstructure, microhardness, tensile properties and tear analysis of spot welded joints were analyzed respectively after welding, and the effects of different process parameters on the properties of spot welded joints were studied. At the same time, the effect of brazing process parameters on the microstructure of the brazed joint of the oil cooler is studied, and the comprehensive properties of the oil cooler are tested, which provides a theoretical basis for the welding of this type of plate-fin aluminum alloy oil cooler. The experimental results show that: 1) the spot welding joint consists of three parts: nugget, plastic ring and base metal. The nugget belongs to the typical "columnar equiaxed crystal" structure. With the increase of current and Zhou Bo, the equiaxed structure of the center of the nugget gradually coarsened, the number of columnar structure decreased with the increase of welding current, and increased with the increase of electrode pressure. 2) Welding current. The effect of welding Zhou Bo and electrode pressure on the microhardness and tensile load of spot welding joint is different. The microhardness of columnar crystal zone is larger than that of the core of the welding, and the minimum value of microhardness appears in the heat affected zone. 3) when welding current, When Zhou Bo and electrode pressure were 22 kA,8 cyc and 0.20 MPa, preloading time and maintaining time were 25 cyc and 15 cyc, respectively, the properties of spot welding joint reached the optimum value, and the average microhardness was 40.64 Hv,. The microstructure of brazing seam region with tensile shear force of 2.103 kN.4 is typical of 偽 (Al) solid solution and Al Si eutectic phase. The optimum parameters of brazing process are as follows: the six zone temperatures are 600 鈩，

本文編號(hào)：2360300