China Shenzhen Perfect Precision Product Co., Ltd. company news

CNC indexing head can provide a lot of convenience for some multi-sided products, it can process the workpiece at multiple angles at one time, so it can obviously reduce the process of processing   However, when the workpiece itself (especially when machining the side of the workpiece) is relatively high, or the fixture height is relatively high, there may be interference between the tool and fixture when changing the tool, which may cause damage to the tool or even the tool changing system, to prevent this problem, we should pay attention to the following points Placement of workpieces and fixtures on the table   Since the disc type tool changer is usually installed on the upper left side of the machine, the tool change will also take place on the left side of the spindle. When changing tools, a section of space under the tool arm will be temporarily used, so workpieces and fixtures should not be present here.   The table can be moved left and right, if the mounting position of workpiece and fixture is chosen on the left side of the table, then no matter how the table is moved, the workpiece and fixture will be on the left side of the spindle, which may not be a problem when the height of the workpiece and fixture is low, but once the workpiece and fixture conflict with the tool change action due to the height, then the workpiece and fixture will have to be removed and re-tuned.   Therefore, it is a good choice to use the right side of the table space as a priority. Selection of tool change point   Due to the condition, the tool change action has to be done at a specific point, and this point can be preferred to the upper left corner of the table.   Consistency of the tool change point   We have mounted the workpiece on the right side of the table and the safe tool change point has been set in the program, however, when the operator is resharpening or changing the tool, it is likely to forget about the tool change point and cause damage to the workpiece or tool.

In fact, a workpiece to see not only the strength of a manufacturer, but also to see his approach to some details. For cnc cnc lathe machining parts, if the manufacturer is not handled well, then this machining parts are not available, then in processing for manufacturers, should pay attention to what? First, the price surface burr, it can be said that for this point is a lot of manufacturers are easy to ignore, many people say this part out of what kind of time, that the finished package is what kind of time. In fact, otherwise, for a part, cnc cnc lathe machining parts is done through the equipment, then injection molding will produce cloak, and this burr is also generated at this time, if not timely trimming, or will be this part scrap. Otherwise will be in use will also affect the other links.   Second, the accuracy of the parts, for cnc cnc lathe machining parts, her accuracy is very strict, only to meet the required accuracy, can be used, and judge it this accuracy, mainly to see his ability to control the size, if the tolerance can fluctuate within the provisions, then this part is qualified, if beyond the tolerance, then it is not qualified. Third, the analysis of the test results, for a component, he will inevitably go through a performance test before leaving the factory, if the performance is qualified, then it will be factory, if not, then some of the reasons should be analyzed, so as to avoid the scrapping of large quantities, processing industry manufacturers will basically be so to deal with, they will be based on some of the performance of many homes, will Make a certain quality control chart, so as to analyze the causes.

Focus on CNC lathe   After selecting the processing method and dividing the process, the next step is to reasonably arrange the sequence of the process. The machining process of the parts usually includes cutting process, heat treatment process and auxiliary process. Reasonable arrangement of the order of cutting process, heat treatment and auxiliary process, and solving the connection problem between processes can improve the processing quality and productivity of the parts and reduce the processing cost. In the CNC lathe processing parts, should be divided into processes according to the principle of process concentration, the arrangement of parts turning processing order generally follows the following principles. 1. CNC lathe in the parts processing first coarse and then fine   According to the order of rough turning → semi-finishing turning → finishing turning, gradually improve the machining accuracy of the parts. Rough turning will cut off most of the machining margin on the surface of the workpiece in a shorter period of time, which not only improves the metal removal rate, but also meets the uniformity requirements of the finish turning margin. If the uniformity of the residual left after rough turning does not meet the requirements of finishing, semi-finishing turning should be arranged in order to make the finishing residual small and uniform. When finishing turning, the tool is finished along the contour of the part at one time to ensure the machining accuracy of the part.   2. CNC lathe in the parts processing first near and then far   The far and near mentioned here is according to the distance of the processing part relative to the tool change point. Usually in rough machining, the parts near the tool change point are processed first, and the parts far from the tool change point are processed afterwards, in order to shorten the tool movement distance, reduce the empty travel time, and help to maintain the rigidity of the blank or semi-finished parts and improve their cutting conditions.   3. CNC lathe in the parts processing inside and outside cross   For parts with both inner surface (inner type, inner cavity) and outer surface, when arranging the processing sequence, the inner and outer surface should be roughly processed first, and then the inner and outer surface should be finely processed.   When machining the inner and outer surfaces, the inner type and cavity are usually machined first, and then the outer surface is machined. The reason is that it is more difficult to control the size and shape of the inner surface, the tool rigidity is correspondingly poor, the durability of the tool tip (edge) is easily affected by cutting heat and reduced, and it is more difficult to remove the chips in the processing.   4. CNC lathe in the parts processing tool concentration   Tool concentration refers to the use of a tool after processing the corresponding parts, and then change another tool to process the corresponding other parts, in order to reduce the empty stroke and tool change time.   5. CNC lathe in the parts processing base surface first The surface used as the fine reference should be processed first, because the more accurate the surface as the positioning reference, the smaller the clamping error. For example, when processing shaft parts, always process the center hole first, and then process the outer surface and end face with the center hole as the fine reference. CNC lathe in the parts processing to determine the feed route Feed route refers to the path that the tool starts moving from the starting point until it returns to the point and ends the processing program, including the path of cutting processing and the non-cutting empty stroke such as tool introduction and cutting out. 1. CNC lathe in the parts processing tool introduction, cutting out When processing on the CNC lathe, especially fine turning, to properly consider the tool attraction, cut out route, try to make the tool tip along the contour of the tangential direction of the introduction, cut out, so as to avoid sudden changes in cutting force and elastic deformation, resulting in a smooth connection contour surface scratches, sudden changes in shape or stagnant tool marks and other problems.   2. CNC lathe in the parts processing to determine the shortest empty stroke route Determine the shortest empty stroke route in addition to rely on a large number of practical experience, should be good at analysis, if necessary, can be supplemented by some simple calculations. In the manual preparation of more complex contour machining program, the programmer (especially beginners) will sometimes finish processing each tool by executing the "return to zero" (i.e., return to the tool change point) instruction, so that it returns to the tool change point position, and then execute the subsequent program. This will increase the distance of the tool path, thus greatly reducing productivity. Therefore, the "return to zero" instruction should not be used when executing the retreat action without changing the tool. When arranging the tool route, the distance between the end of the previous tool and the starting point of the next tool should be shortened as much as possible in order to meet the requirements of the shortest tool route. CNC lathe tool change point position to change the tool does not touch the workpiece as the principle.   3. CNC lathe in the parts processing to determine the shortest cutting feed route Short cutting feed route can effectively improve productivity and reduce the amount of tool wear. In the arrangement of roughing or semi-finishing cutting feed route, should take into account the rigidity of the machined parts and the process of processing and other requirements, do not lose sight of the other.

Focus on CNC lathe   Clamping the workpiece means positioning and clamping the workpiece on the CNC lathe or in the fixture CNC lathe in the turning process, the workpiece must rotate with the CNC lathe spindle, therefore, it is required that when clamping on the CNC lathe, the axis of the workpiece to be machined and the axis of the CNC lathe spindle must be coaxial, and the workpiece should be clamped to avoid the workpiece loosening or falling off under the action of the cutting force and causing accidents.   According to the shape, size and processing quantity of the workpiece, different clamping methods can be used to clamp the workpiece on the CNC lathe. The attachments used to load workpieces on CNC lathe are the same as self-centering chuck/single-action chuck, center, arbor, center frame, follow tool holder, chuck and angle iron, etc. 1. CNC lathe self-centering chuck clamping work   CNC lathe self-centering chuck is mounted on the spindle through the flange to clamp the workpiece. The small bevel gear rotates by inserting a square-head wrench into the square hole of the self-centering chuck, which drives the large bevel gear to rotate, and the large bevel gear drives the three jaws which are threaded with the disc on the back to move along the radial direction synchronously.   The characteristics of CNC lathe self-centering chuck are that the three jaws can automatically center the workpiece, and it is easy to clamp and correct the workpiece, but the clamping force is small, and it cannot clamp large and irregular workpieces.   The method of CNC lathe self-centering chuck to load workpieces has positive grip and reverse grip to load workpieces, when reverse grip clamping, the three grips will be removed and jumping installation can reverse grip to load larger diameter workpieces.   The jaws of the chuck are called hard jaws, which are hardened to have hardness. The claw made of non-hardened steel or copper and aluminum is called soft claw, generally welded on the hard claw, which is well positioned and not easy to pinch the workpiece, to be processed before use, turning or grinding can be. 2. CNC lathe single-action chuck for clamping workpiece   The four jaws of CNC lathe single-action chuck can move independently, because the back of each jaw has a half-flap internal thread and the screw engages, and the screw has a hole at the end.   When the chuck wrench is used to turn a certain side hole, the corresponding screw is driven to turn, and the jaws can be clamped or loosened. Therefore, the single-action chuck of CNC lathe can clamp workpieces with square/rectangular/elliptical cross-section and irregular shape, and can also turn eccentric shafts and holes. Therefore, the clamping force of single-action chuck for CNC lathe is larger than that of self-setting new chuck master long for clamping normal round workpiece with larger diameter.   CNC lathe with single-action chuck for clamping workpiece, because the four jaws are not synchronized can not be automatically centered, it needs to be carefully corrected so that the axis of the workpiece is aligned with the spindle rotation axis. The positioning accuracy is 0.2-0.5mm with the scribing disc according to the inner and outer round surface of the workpiece or the pre-drawn processing line; the positioning accuracy of 0.01-0.02mm can be achieved with the percentage table according to the finishing surface of the workpiece. When the machining allowance of each part of the workpiece is uneven, focus on the part with less allowance, otherwise the workpiece will be easily scrapped.   CNC lathe single-action chuck can all use the positive grip or reverse grip to clamp the workpiece, but also can use one or two reverse grips, the rest still use the positive grip to clamp the workpiece.

Frontier CNC   In the cutting process, the thin wall by the cutting force, easy to produce deformation, resulting in oval or small in the middle, the two ends of the "waist-shaped" phenomenon. In addition, thin-walled casing due to poor heat dissipation during processing, very easy to produce thermal deformation, it is not easy to ensure the quality of parts processing. The following parts are not only inconvenient to clamp, but also difficult to process parts, so it is necessary to design a special thin-walled sleeve and guard shaft. Process analysis   According to the technical requirements provided in the drawing, the workpiece is processed by seamless steel pipe, and the surface roughness of the inner hole and outer wall is Ra1.6μm, which can be achieved by turning, but the cylindricity of the inner hole is 0.03mm, which is a high requirement for thin-walled parts. In mass production, the process route is roughly as follows: material - heat treatment - turning end face - turning external circle - turning internal hole - quality inspection.   The "bore machining" process is the key to quality control. We put aside the outer circle, thin-walled casing on the inner hole cutting is difficult to ensure that 0.03mm of the cylinder.   Key technology of turning holes   The key technology of turning holes is to solve the problem of rigidity and chip removal of the internal hole turning tool. Increase the rigidity of the internal hole turning tool, take the following measures.   (1) Try to increase the cross-sectional area of the tool shank, usually the tip of the internal hole turning tool is located on the top of the tool shank, so that the cross-sectional area of the tool shank is less than 1/4 of the cross-sectional area of the hole, as shown in the figure on the left below. If the tip of the internal hole turning tool is located on the center line of the shank, then the cross-sectional area of the shank in the hole can be greatly increased as follows   (2) The shank extension length can be 5-8mm longer than the workpiece length to increase the rigidity of the shank and reduce the vibration in the cutting process. Solve the problem of chip removal   Mainly control the direction of cutting outflow, coarse turning tool requires chip flow to the surface to be machined (front chip discharge), for this reason, use the positive edge inclination of the bore turning tool, as shown in the figure below.   When fine turning, the chip flow is required to centerward tilting front chip discharge (hole center chip discharge), so when grinding the tool, pay attention to the grinding direction of the cutting edge, to the front tilting arc chip discharge method, as shown in the figure below Fine turning tool alloy with YA6, the current M type, its bending strength, wear resistance, impact toughness and anti-adhesion and temperature with steel are better.   When sharpening the front angle grinding to round to arc-like angle 10-15 °, the rear angle according to the processing of the arc from the wall 0.5-0.8mm (tool bottom line along the arc), c cutting edge angle k to § 0.5-1 for along the chip edge B point trimmed edge for R1-1.5, vice rear angle grinding into 7-8 ° for the appropriate, E inner edge of the A-A point grinding into the round outward chip evacuation. Machining method   (1) Before processing, you must do a shaft guard. The main purpose of the shaft guard: to turn the thin-walled sleeve of the inner hole to the original size of the set, with the front and rear of the top fixed so that it is not deformed in the case of processing the outer circle, to maintain the quality and accuracy of the outer circle processing. Therefore, the processing of the shaft guard is the key link to the process of processing thin-walled casing   The processing of guard shaft embryo with 45 ﹟ carbon steel; turning end face, open two B-type top hole, rough turning outer circle, leaving a margin of 1mm. by heat treatment tempering shape, and then fine turning leaving a margin of 0.2mm grinding. Re-heat treatment crushed fire surface, hardness HRC50, and then by cylindrical grinding machine into the following figure, the accuracy to meet the requirements, after completion to be used.   (2) In order to make the workpiece finished at one time, the embryo left clamping position and cut off allowance.   (3) First, the embryo is heat-treated and tempered to a hardness of HRC28-30 (the hardness of the machinable range).   (4) Turning tool using C620, first put the front center into the spindle taper position fixed, in order to prevent the workpiece deformation when clamping thin-walled sleeve, add an open ring thick sleeve, as shown in the figure below. In order to maintain mass production, one end of the outer circle of the thin-walled sleeve is machined to a uniform size d, t the ruler is axial clamping position, a thin-walled sleeve pressed to improve the quality of the inner hole when turning, to maintain the size. Considering that there is cutting heat generated, the workpiece expansion size is difficult to grasp. Need to pour sufficient cutting fluid to reduce the thermal deformation of the workpiece.   (5) Clamp the workpiece firmly with auto-centering three-jaw chuck, turn the end face and rough turn the inner circle. Leave a margin of 0.1-0.2mm finish turning, replace the finish turning tool to cut the margin of processing to the guard shaft full over fit and roughness requirements. Remove the bore turning tool, insert the guard shaft to the front top, clamp with the tailstock top according to the length requirement, change the external turning tool to rough turn the external circle, and then finish turning to the drawing requirements. After passing the inspection, use the cutting tool to cut off the workpiece according to the required length. In order to make the workpiece disconnected when the cut is flat, the knife edge to be beveled grinding, so that the workpiece end face flat; guard shaft grinding small section is to cut off to leave a gap and grinding small, guard shaft to reduce the deformation of the workpiece, to prevent vibration, as well as cut off when falling touch the original cause.

What is stability? Stability is divided into process stability and production stability. Process stability refers to meet the production of qualified products with stability of the process plan; production stability refers to the production process with stability of production capacity.   As most of the domestic mold manufacturing enterprises are small and medium-sized enterprises, and a considerable part of them are still in the traditional workshop production management stage, often ignoring the stability of the mold, resulting in long mold development cycle, high manufacturing costs, which seriously restricts the pace of development of enterprises. First, let's look at the main factors affecting the stability of hardware stamping parts, which are: the method of using the die material; the strength requirements of the structural parts of the die; the stability of the performance of the stamping material; the fluctuation characteristics of the material thickness; the range of change of the material; the size of the resistance of the tensile bar; the range of change of the crimping force; and the choice of lubricant.   As we all know, the metal materials used in stamping dies involve many kinds, and because of the different roles played by various parts in the dies, the requirements and selection principles for their materials are not the same. Therefore, how to reasonably choose the mold material becomes one of the very important work in the mold design.   When choosing the mold material, in addition to the requirement that the material must have high strength, high wear resistance and appropriate toughness, but also must take into account the characteristics of the processed product material and yield requirements, so as to achieve the stability of the mold forming requirements.   In practice, due to the tendency of mold designers to select mold materials based on personal experience, the problem of unstable mold forming due to improper selection of materials for mold parts often occurs in hardware stamping.   It is worth noting that in the process of hardware stamping, as each stamping plate has its own chemical composition, mechanical properties and characteristics closely related to the stamping performance, the unstable performance of stamping materials, fluctuations in the thickness of stamping materials and changes in stamping materials not only directly affect the accuracy and quality of hardware stamping processing, but also may lead to damage of the die.   Take stretching bar for example, it occupies a very important position in hardware stamping. In the stretch forming process, the product needs to be formed with a certain size and properly distributed tension along the fixed perimeter, which comes from the force of the stamping equipment, the deformation resistance of the edge part of the material, and the flow resistance on the surface of the crimped circle. If the flow resistance is generated by the crimping force alone, the friction between the die and the material is not sufficient. For this reason, it is also necessary to set up the stretching tendons on the crimp ring that can produce larger resistance to increase the resistance of the feeding material, so as to produce larger plastic deformation of the material to meet the requirements of plastic deformation and plastic flow of the material. At the same time, by changing the size and distribution of the resistance of the stretching tendons and controlling the speed of material flow into the die and the amount of feed, effective regulation of the tension and its distribution in each deformation area of the stretched part is realized, so as to prevent the rupture, wrinkling, and quality problems such as deformation of the product during stretching and forming. As can be seen from the above, in the process of developing stamping process and die design, it is necessary to consider the size of tensile resistance, arrange the tensile tendons and determine the form of tensile tendons according to the change range of crimping force, so that each deformation area can complete forming according to the required deformation mode and degree of deformation.   In order to solve the problem of hardware stamping die stability, strict control is needed from the following aspects.   ① In the process formulation stage, by analyzing the product, anticipating the defects that may arise in the manufacturing of the product, so as to develop a manufacturing process plan with stability.   ② Implementing the standardization of the production process and the standardization of the production process.   ③Establish a database and continuously summarize and optimize it; with the help of CAE analysis software system, come up with the most optimal solution.  

Stamping is a forming process that relies on presses and dies to apply external forces to plates, strips, pipes and profiles to produce plastic deformation or separation to obtain workpieces of the desired shape and size (stampings). The blanks for stamping are mainly hot-rolled and cold-rolled steel plates and strips. So what are the technical requirements of hardware stamping parts? Stamped parts have the following technical requirements in the process of production, storage and transportation.   1、Size and shape: The size and shape of the stamping parts should be basically in accordance with the product design drawings and technical documents of the stamping parts.   2、Burr: The stamping parts which are sheared or blanked will generally have burr, and then they need to be polished according to "Burr Height of Stamping Parts".   3、Surface quality: Except for punching and cutting, the surface condition of the stamped parts is required to be the same as that of the plate used, and only small surface area unevenness and slight hair pulling can appear in the process of forming, and at the same time, it cannot affect the quality of the finished products in the next process into the assembly.   4、Heat treatment: After forming and welding of stamping parts, heat treatment is generally not required.   5、Punching and cutting surface: The condition of punching and cutting surface is not specified.   6、Supply good: The supply of stamping parts should ensure their basic quality status and conform to the product chart and inspection card of stamping parts.  

CNC lathe machining is a small part of machining, so what forms of machining are there in CNC lathe machining? One: Turning tool fixation, mainly for machining unformed workpieces in rotation.   The second is: workpiece fixation, through the high-speed rotation of the workpiece, the turning tool's horizontal and vertical movement for precision machining. In the lathe also available drill, reaming drill, reamer, tap, plate and knurling tool for corresponding processing. Lathe is mainly used for processing shafts, discs, sleeves and other workpieces with rotary surfaces, is the most widely used in machinery manufacturing and repair factories in a class of machine tool processing. The reason why CNC machining should have a wide range is that it has great advantages compared to ordinary lathe machining.   1, CNC lathe processing accuracy is high, high stability, so it can ensure the high quality of processing.   2, a high degree of automation, CNC machining is executed by program decoding, which largely reduces the intensity of manual repetitive work.   3, CNC lathe processing parts change, only need to change the CNC program, which greatly reduces the production preparation time.   4、Multi-coordinate linkage can be carried out, which can process parts with complex shapes.   5, CNC lathe for the operator's quality requirements are also high.

CNC machining center in the process of high-speed machining, to maintain the smoothness of the load throughout the cutting process, to avoid sudden changes in direction, and also to avoid sudden changes in direction when reducing the amount of feed or tool stop. So what strategies should be followed during CNC machining? When the tool path is determined, the CNC machining center should be dominated by smooth milling during high-speed machining to reduce tool wear and improve machining accuracy. According to the principle of shallow cutting and small layer depth of layering, a reasonable layering route is used to achieve the rationality of machining and smoothness of load. In the corner should increase the circular arc walking tool, to prevent the corner speed vector direction of the sudden change, to avoid sharp changes in the tool load.   In the CNC machining center plane two-way cutting processing, can be in the adjacent two rows of tool trajectory between the additional arc transfer, in order to form a smooth lateral shift. In the space two-way cutting processing, you can use the space arc transfer, space inside the arc transfer, space outside the arc transfer and "golf" type transition transfer and other forms of extended transition, which not only ensures the smoothness of the tool trajectory, but also effectively avoid the phenomenon of turning hard bend between the two lines, this transfer method is commonly used in a variety of Curved surface high-speed milling. In order to avoid the CNC machining center in the shape of the contour of the normal direct feed and retreat, should be used spiral, arc and diagonal way into and out of the tool, to ensure smooth into and out of the tool, the steep wall surface and non-steep wall surface finishing, in order to prevent sharp changes in cutting load, CNC machining center to apply different methods of steep wall surface and non-steep wall surface separate processing, can improve the cutting speed, while making the roughness of the surface of the part uniform.

The unique tool magazine of CNC machining center can realize the function of automatic tool change and spindle orientation. Compared with the general machine tool cost is higher, of course, the processing accuracy and efficiency is also higher. So to choose the right machining center, so as to ensure that the CNC machining center to play the most - the greatest benefit. So for companies to choose the machining center model is also to be quite careful, so what specifically to pay attention to? First, the selection procedure should be reasonable, the premise is to have a comprehensive understanding of the processing center - center, including its performance, characteristics, type, the main parameters applicable range, etc. Only on the basis of a full understanding of the following procedures can be launched.   Second, choose the right type. When choosing the type of CNC machining process, processing objects, scope, price and other factors should be taken into account. For example, single-sided processing of the workpiece, such as a variety of plate parts, etc., should choose the vertical machining worker - center; more than two sides of the processing of the workpiece or in the surrounding radially radiating row of holes, face processing, should choose horizontal processing; complex surface processing, such as the guide wheel, the engine on the whole impeller, etc., you can choose five-axis machining center; for the workpiece of high precision requirements, the use of bedroom machining center - center. When processing larger size workpiece, such as machine bed, column, etc., you can choose gantry type machining center. Of course the above methods are only as a reference, the final decision should be made under the conditions of process requirements and financial balance.