中置雙頂液壓油缸導向限位結構研究

陳志斌

摘 要：本文提出了一種自卸車中置雙頂液壓油缸導向限位結構，是把油缸缸筒卡鍵由圓形改為方形結構（圓形結構力量是發散型的，易滾動;而方形結構力量聚集型的，不易滾動），包括一級缸筒、二級缸筒、三級缸筒等每級缸筒的兩個圓形卡鍵改為方形卡鍵，油缸頭部增加一L型支撐環不僅有利于油缸更好的定位，防塵圈也不被擠出，還有利于保證油缸行程，缸筒總長在原有基礎上增加30mm，使油缸舉升更加穩定;在油缸尾部每級缸筒上增加兩個方形卡鍵和一個支撐環，有利于油缸更好的導向、限位，安全性更高，油封密封更嚴實等優點。改進后中雙油缸不僅可以抑制油壓壓力過大造成油缸缸筒限位失效造成脫落質量問題，還解決了油缸密封不嚴，導致漏油問題;大大提高了油缸的安全性能，延長了油缸的使用壽命，保證了油缸舉升的穩定性;該結構具有工藝簡單、安全可靠，便于推廣應用的優點。

關鍵詞：中雙頂液壓油缸 導向限位 研究

Research on the Guiding and Limiting Structure of Center Mounted Double Top Hydraulic Cylinder

Chen Zhibin

Abstract：In this paper， a kind of guiding and limiting structure of double top hydraulic cylinder in dump truck is proposed. The clamping key of oil cylinder is changed from circular to square structure （the force of circular structure is divergent and easy to roll; while the force of square structure is concentrated， which is not easy to roll）， including the first stage cylinder， the second stage cylinder and the third stage cylinder， and the two round bayonets of each stage cylinder are changed into square ones. Adding an L-shaped support ring is not only conducive to the better positioning of the oil cylinder， while the dust ring is not squeezed out， but also conducive to ensuring the oil cylinder stroke. The total length of the cylinder barrel is increased by 30mm on the original basis to make the lifting of the oil cylinder more stable; two square keys and a support ring are added on each stage of the cylinder at the tail of the oil cylinder， which is conducive to the better guide and limit of the oil cylinder， higher safety and tighter oil seal and so on. After the improvement， the middle and double oil cylinders can not only restrain the excessive oil pressure which causes the cylinder barrel limit failure， resulting in falling off quality problems， but also solves the oil cylinder sealing problem， which leads to oil leakage; greatly improves the safety performance of the oil cylinder， extends the service life of the oil cylinder， and ensures the stability of the oil cylinder lifting; the structure has the advantages of simple process， safety and reliability， and is easy to be popularized and applied.

Key words：double-top hydraulic cylinder， guide limit， research

1 中置雙頂液壓缸結構概述

自卸車汽車用中置液壓缸結構分為中置單頂液壓缸結構和中置雙頂液壓缸結構二種，中置雙頂液壓缸又分為單活塞桿和多級活塞桿（一般3級）見圖1，中置雙頂多級油缸在4×2自卸車包括輕型自卸車中應用廣泛，良好的經濟性和舉升穩定性在市場中有很好的口碑。

2 中雙多級液壓缸使用問題

2.1 問題原因

由于用戶的操作不當和載荷偏心及運輸粘時采用急剎急停卸載，勢必造成油缸漏油、活塞桿拉脫現象經常發生。據行業不完全統計此類故障率高達4.5%。