Application and development of the honing machine

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Application and development of honing machine tools

honing is a common finishing process, which can obtain high dimensional accuracy, high shape accuracy and low roughness (up to RA 0.05), and there are cross lines on the inner hole surface. The types of honing machine tools include plane honing machine tools, outer circle honing machine tools, inner circle honing machine tools, etc. At present, the most widely used internal honing machine tools in the world. This paper focuses on the application and the latest development trend of internal honing machine tools, compares the differences between internal honing and internal honing, and provides readers with reference suggestions on the selection of honing machine tools

inner circle honing can process high-precision inner hole surface

comparison between inner circle honing and inner circle honing

the working principle of inner circle honing is as follows: the honing oilstone not only rotates relative to the inner hole of the workpiece to be processed, but also makes reciprocating linear motion. At the same time, the honing oilstone makes radial expansion and contraction in the hole, so as to process the inner hole surface with lines

inner circle honing can produce high-precision inner hole surface

honing requires that the workpiece or one of the spindle with oil stone must be in a relatively floating state. During internal grinding, the workpiece must be rigidly clamped, the grinding wheel makes radial expansion and contraction in the hole, and the grinding wheel moves in a single direction in the hole. It can be seen that the biggest difference between honing and internal grinding is relative floating and reciprocating motion. It is this difference that results in different accuracy parameters that honing and internal grinding can improve after machining: honing can improve the geometric accuracy of the internal circle, such as straightness, roundness, taper and surface roughness, and there are cross lines on the surface of the internal hole after honing; Internal grinding can not only improve the geometric accuracy of the inner circle, but also improve the coaxiality of the inner hole to the outer circle and the perpendicularity to the end face. After internal grinding, there are no cross lines in the hole, but only spiral lines or cumulative coaxial rings

according to the theoretical analysis results, the inner circle grinding can completely replace the inner hole honing; However, since the 1990s, domestic honing machine tools have been more and more widely used, and there is a great trend to replace internal grinding

the application scope of the two processing methods is as follows:

◆ parts with honing lines must be processed with honing machine tools, such as automobile cylinder liners, motorcycle cylinder blocks, etc. The cross grain after honing can store oil and form an oil film, which plays an extremely important role in engine operation

◆ some parts have no position accuracy requirements, but only require high-precision inner hole parts, such as die guide sleeve. Under the same conditions, the geometric accuracy of inner hole machined by honing machine tool is higher than that of inner circle grinding

◆ some parts with position accuracy requirements, such as connecting rod, shaft sleeve, etc., adopt honing process. Since one of the main shafts of the workpiece or the oil stone is in a relatively floating state, the position accuracy will not be damaged. As long as the geometric accuracy of the inner hole can be improved after honing, the machining effect can be achieved

◆ the honing process cannot be applied to the parts that must be honed to improve the position accuracy. Only ultra-high precision internal grinding and excellent fixture can fully ensure the machining accuracy

types of honing machine tools

there are many manufacturers of honing machine tools in the world. Foreign professional manufacturers include gerhing (green) Company in Germany, Kadia (Cartier) company, Sunnen (shanneng) Company in the United States, etc; Aoba (Aoba) Company and Mitsubishi (Mitsubishi) Company in Japan. There are also nearly 20 domestic manufacturers producing various honing machine tools, and Shandong Dezhou machine tool factory produces horizontal powerful large hole honing machines; Ningxia Dahe machine tool factory produces vertical honing machine tools; Beijing No. 3 machine tool plant and Dalian machine tool plant can also produce various types of vertical honing machines according to the requirements of users

6-axis vertical honing machine tools

there are many classification methods for honing machine tools, such as the difference between single axis and multi axis; Such as numerical control, mechanical difference; According to the installation mode of honing spindle, it can be divided into two types:

◆ vertical honing machine tool, whose honing spindle is perpendicular to the workbench. It can be made into single head, double head and multi head, and the honing station can be made into 2, 4 and more; The arrangement of spindles can be circular or linear. The vertical honing machine tool can increase the measurement and full closing, and carry out statistical and processing ring control on the experimental data to ensure the dimensional consistency of the machined parts; The structure of the vertical honing machine tool is conducive to the coolant to quickly take away the cutting particles after honing, and completely avoid the adverse effect of the weight factor of the workpiece itself (or the spindle) in honing. The vertical honing machine tool is unlikely to process ultra long workpieces, such as oil cylinders, due to the limitations of plant space and its small floor area

◆ the spindle of horizontal honing machine tool is parallel to the worktable. It is generally designed as a single head, and can also be designed as a linear arrangement on the production line. Single head horizontal honing machine tool has simple structure, and can be divided into small horizontal honing machine tool and large horizontal honing machine tool

the biggest feature of the small horizontal honing machine tool is its low manufacturing cost and high reliability. Its machining feature is that the workpiece is in a relatively floating state, and the self weight of the workpiece cannot be completely eliminated. Therefore, small horizontal honing machine tools generally cannot process workpieces exceeding 15kg

large horizontal honing machine tool is specially designed for processing various oil cylinders; Its machining feature is that the honing spindle is in a relatively floating state, and the self weight of the honing spindle still has a certain impact on the accuracy

from the classification of vertical and horizontal honing machine tools, we can roughly divide the application scope of honing machine tools:

◆ the inner hole of automobile engine, diesel engine and motorcycle compressor cylinder body parts has high precision, the requirements of striated angle, and its weight is large. It is best to use vertical honing machine tools for processing

◆ connecting rod, shift fork, gear, shaft sleeve, steering gear and other through-hole parts (diameter φ ≤ 30), the weight shall not exceed 3kg, and the cylindricity shall not exceed 0.0025mm, so the horizontal honing machine tool shall be selected, which can not only reduce the investment cost and processing cost, but also meet the accuracy requirements

◆ for small aperture parts whose final accuracy requirements exceed 0.0025mm cylindricity, horizontal honing machine tools can be used as rough honing equipment, and vertical honing machine tools can be selected as final accuracy assurance equipment

◆ for the processing of blind hole parts with any aperture, the best choice is the vertical honing machine tool if the investment allows

the future development direction of honing machine tools and the development of

small horizontal honing machine tools in the laboratories of quality inspection units towards complication and numerical control. At present, the horizontal honing machine tool seldom achieves closed-loop control, which can not strictly guarantee the ultra-high machining accuracy of mass production. The future small horizontal honing machine tool should be able to improve the dimensional consistency of machined parts through NC control and active measurement. At present, the development of large horizontal honing machine tools is very rapid. NC control, remote measurement feedback and semi closed loop control have been achieved. The vertical honing machine tool will develop an ultra-high speed spindle on the basis of the current full closed-loop control. 3. When the tensile testing machine is installed, it can also use a small piece of iron to insert under the main body and the dynamometer and then align the system. The feeding system with faster feeding frequency and smaller feeding time can self repair the honing system or honing center of the honing stone, which is affected by various human factors. At present, the honing machine tool can realize the honing of plane, outer circle and inner circle. The investigation results show that the fatigue damage of locomotive shaft is caused by cyclic load; Through the improvement of honing tool, the honing of elliptical inner hole and curved surface can be realized. In the field of honing excircle, a breakthrough will be made, which can replace excircle grinding in most excircle machining

as a complex production tool, the most fundamental thing of honing machine tools is the processing technology and host structure layout design. Various new processes, new materials, new components, new tools, new control systems, etc. will also be applied to honing machine tools. In the future, honing machine tools will have higher processing accuracy, faster processing efficiency and wider processing range. (end)

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