Yearly Archive September 27, 2020

The following machining center for you to introduce the machining center disordered tool solution (solve).

1. This situation may be caused by the upper and lower machining ports of the machining center. The operator will use the reset button to change the calculation method or simply press the emergency stop button.
2. At the same time, the typical PLC program of machining center (PLC programming is an electronic system of digital operation, specially designed for application in industrial environment) refreshes the tool list after the modification. Your program should be like this, but after you have a problem with the tool cover, you just need to put the knife down. After repairing, I think there should be no problem on the original tool holder, and there will be a confused knife.
3. Communicate with the manufacturer you purchased. If the manufacturer has after-sales service or after-sales maintenance, you can ask their technicians to check the security. In addition, do not operate the keyboard on the operation panel of the machining center after the tool is out of order. If you do not know PLC, please try to use external force to help the tool sleeve complete the action. Pay attention to safety during operation. Try to get the machining center tool library itself to complete the entire M6 cycle, so it certainly won’t be messy.
4. During normal tool change, the tool change process is stuck due to insufficient air pressure. After manual tool magazine reset (reset), the tool magazine may be disordered.
5. When the manipulator of machining center changes tool, the operator presses the reset key or emergency stop key. As a result, the tool change is terminated unexpectedly and the tool magazine may be disordered.
6. Due to the damage of the mechanical structure of the machine tool (damage), or the loss of the parameters of the CNC system, disordered failure caused by the phenomenon of tool disorder.

Processing method for disordered tools in tool magazine of machining center:

1) Check whether the switch of the counter is loose and whether there is knife jamming. If there is, it is easy to mess the knife.

2) Check your clamping loose tool signal, tool sleeve up and down signal, spindle position signal.

3) If there is a shift function between high and low gears, check the low and high gear signals. When an alarm appears, see which signal does not arrive or is caused by a flicker. Another possibility is that the authorized t diagram is not strict.

4) If the machining center is used by others, ask them if they have adjusted the phase sequence of the forward and reverse motors of the magazine. If they do, the magazine can only rotate in one direction, so the tool magazine can not be found nearby and the magazine will be in disorder.

The so-called CNC machining is also known as CNC machining, which refers to a kind of processing which is operated by CNC machining operators after the programmer uses the computer to program the work order to be processed. There are three kinds of guide rails for CNC machining center. The differences between these three kinds of guides are quite big. Therefore, if you need to select the guide rails of CNC machining centers, it is better to have a detailed understanding of these three kinds of guides in advance, so that we can better select the guide rails for our CNC machining centers. The following is an introduction to the guide rails of CNC machining centers:

According to the motion track, the guide rail can be divided into linear motion guide rail and circular motion guide rail; according to the working nature, it can be divided into main motion guide rail, feed motion guide rail and adjustment guide rail; according to the friction property of contact surface, it can be divided into sliding guide rail, rolling guide rail and hydrostatic guide rail.

Slide guide

The sliding guide has the advantages of simple structure, convenient manufacturing, good stiffness and high vibration resistance. The traditional cast iron cast iron and cast iron quenched steel guide rail has the disadvantages of large static friction coefficient, dynamic friction coefficient changes with the speed, and the friction loss is large. It is easy to crawl at low speed / (1-60mm / min /), which reduces the positioning accuracy of moving parts. Therefore, it is not used in other CNC machine tools except economical CNC machine tools.

At present, most CNC machine tools use plastic guide, that is, a layer of plastic film soft belt composed of plastic and other chemical materials is pasted on the friction surface of moving guide rail.

There are two kinds of guide rail Plastics: PTFE soft belt and epoxy wear-resistant rail coating. The characteristics of plastic sliding guide are good friction characteristics, good wear resistance, smooth movement, good vibration damping and good technology.

Rolling guide

Rolling guide is to place ball, roller, needle and other rolling elements between the guide surfaces, so that the sliding friction between the guide surfaces becomes rolling friction. Compared with sliding guide rail, rolling guide has the advantages of high sensitivity and little difference between dynamic friction coefficient and static friction coefficient, so it can move stably, and it is not easy to crawl when moving at low speed; (high positioning accuracy, repeated positioning accuracy can reach 02um; low friction resistance, light movement, small wear, good accuracy retention and long service life. However, the anti vibration performance of rolling guide is poor, which requires high protection.

The rolling guide rail is especially suitable for the working parts of machine tools requiring uniform movement, sensitive motion and high positioning accuracy. This is the reason why rolling guide is widely used in CNC machine tools.

Hydrostatic guideway

There is an oil cavity between the two working faces of the hydrostatic guideway. After the lubricating oil with certain pressure is injected, the hydrostatic oil film can be formed, so that the working surface of the guide rail is in pure liquid friction, without wear, and has good accuracy retention; at the same time, the friction coefficient is also very low, which greatly reduces the driving power; at low speed, there is no creeping, the bearing capacity is large, and the rigidity is good; In addition, the oil has the function of vibration absorption and good vibration resistance. Hydrostatic guideway can be divided into hydrostatic guideway and aerostatic guideway.

Its disadvantage is that the structure is complex, there must be an oil supply system, and the cleanliness of the oil is required to be high. Hydrostatic guideway is widely used in machine tools. The hydrostatic guideway of CNC turret punch press can be divided into open type and closed type

1. With the development of science and technology of rotation and temperature rise, the spindle speed of CNC machining of aluminum cavity is higher and higher, and the range of speed change is wider and wider.

Therefore, the requirements of bearing high-speed operation stability are higher and higher. The temperature rise of machine tool spindle bearing is an important factor to limit the bearing speed. Generally, the correct selection of bearing type, worse grade, configuration mode, clearance (preload), lubricant and lubrication mode can improve the high-speed performance of rolling bearing to a certain extent.

1. Service life and bearing capacity for heavy machine tools or heavy cutting machines, the bearing capacity of air filter bearing should be the first.

Because for general machine tools, the life of the spindle assembly refers to the service life to maintain the accuracy of the spindle. Therefore, the bearing accuracy is required to meet the life requirements of the spindle assembly.

1. Stiffness and vibration resistance in order to ensure the machining quality of aluminum cavity CNC machining, the spindle system must have enough stiffness, otherwise there will be a large re mapping error or even vibration.

Anti vibration refers to the ability to resist forced vibration and self-excited vibration. The anti vibration performance of the main shaft depends on the stiffness and damping of the spindle and bearing. The stiffness of the spindle system can be effectively improved by using preloaded rolling bearings.

1. Noise in high-speed grinding machine, the noise of grinding head bearing is an important part of the whole noise, and it is advantageous to select low-noise rolling bearing.

In the fault detection of CNC machining of aluminum cavity, reasoning can be carried out from two aspects: forward and backward. Forward: that is, from the cause of the fault, explore its functional relationship, and check the impact of the cause on the results.

In other words, according to the possible causes of the fault, to see whether it is consistent with the fault phenomenon, to determine the fault point.

By using reasoning method, the object of reasoning analysis is often vague, because in many fault causes or phenomena, we should find out their common characteristics.

So as to determine the fault point, with the deepening of reasoning step by step, we will realize that the personality characteristics of reasoning analysis object is the fault to be found.

Grinding methods can be divided into cylindrical grinding, internal grinding, centerless grinding, surface grinding, form grinding, gear grinding, thread grinding, east-west grinding, general lathe surface grinding, etc. With the development of NC technology, CNC grinding method plays an increasingly important role in grinding.

CNC grinder can process some special parts (such as axis parts with special curve, special-shaped parts with more than three coordinate requirements, mold, etc.) which cannot be processed on general grinder. Therefore, it is used to machining parts in a wide range. In order to maximize the economic benefits of CNC grinding machine, the following processing objects can be given priority.

（1） The parts put into production repeatedly have better benefit

The use of CNC grinding machine process preparation time occupies a higher share. For example, preparation of process analysis, programming, adjustment and trial cutting of the first part of parts.

The sum of these inductive working hours is often dozens to hundreds of times of the working hours of a single part. However, the operation contents of the NC lathe (such as special general lathe fixtures, process documents, programs, etc.) can be saved and used repeatedly. Therefore, when a part is successfully trial produced on a CNC grinder and put into production repeatedly, the production cycle is greatly reduced, and the cost is also less, which can achieve better results Economic benefits.

（2） It is required to guarantee the processing quality and produce the key parts in medium and small batches with high efficiency

Controlled grinding machine can realize high precision, high quality and high efficiency grinding under the control of computer. Compared with special grinding machine, it can save a lot of special process equipment, and has strong flexible manufacturing ability and good economic benefits.

Compared with the general grinding machine, it can remove many artificial disturbing factors in the long process of disorderly processing, and has good accuracy consistency and interchangeability, and high processing efficiency.

（3） The processing batch of parts should be greater than that of general grinder

When NC grinding machine is used to process medium and small batch parts, due to various reasons, the pure cutting time only accounts for 10% – 30% of the actual working hours. When machining on the CNC grinding machine of grinding center, which is a kind of multi process convergence, this share may rise to 70% – 80%, but the preparation adjustment time is often much longer, so the parts batch size will become uneconomical.

（4） The processed parts should fit in with the process characteristics of CNC grinding machine with multi process convergence

When CNC grinding machine is used to process parts, the condition of grinding wheel cutting workpiece is completely the same as that of corresponding non CNC grinding machine, but it can carry out some complex machining with machining accuracy requirements. For example, in the grinding range, the general grinder is mainly used for grinding the end face of cylindrical surface, conical surface or stepped shoulder.

In addition, CNC cylindrical grinder can also grind toroidal surface (including convex and concave surface), as well as the above various forms of disordered combined surface.

（5） Balance of inductive processing capability of parts

As a single CNC grinding machine, it is difficult to complete all the processing contents of a part, and it needs to transfer and cooperate with the processing procedures of other equipment, so it has the requirements of production rhythm and workshop production capacity balance.

Therefore, it is necessary to give full play to the processing characteristics of CNC grinding machine, and reasonably organize matching balance process on other processing equipment.

（6） Some special parts processing considerations

Although the processing batch of some parts is very small, ordinary lathes have disordered shapes, high quality and good interchangeability, which can not meet the above requirements on non CNC grinding machines, and can only be organized to be processed on CNC grinding machines, such as parabola, cycloid cam and special reflector mirror

CNC lathe is a kind of high-precision and high-efficiency automatic machine tool. The use of CNC lathe can improve the processing efficiency and create more value. The emergence of CNC lathe makes enterprises get rid of backward processing technology.

The processing technology of CNC lathe is similar to that of ordinary lathe. However, since CNC lathe is a kind of clamping device, which can complete all turning process continuously and automatically, attention should be paid to the following aspects.

For efficient metal cutting, machining materials, cutting tools and cutting conditions are the three main factors. These factors determine the processing time, tool life and machining quality. An economical and effective machining method must be a reasonable choice of cutting conditions.

Three factors of cutting conditions: cutting speed, feed and cutting depth directly lead to tool damage. With the increase of cutting speed, the tool tip temperature increases, resulting in mechanical, chemical and thermal wear. When the cutting speed is increased by 20%, the tool life is reduced by 1 / 2.

The relationship between feed condition and tool wear is very small. However, when feeding, the cutting temperature increases and the wear occurs. It has less effect on the tool than on the cutting speed. Although the influence of cutting depth on cutting speed and feed rate is not as great as that of cutting speed and feed rate, the hardened layer produced by cutting material will also affect the tool life when cutting at small cutting depth.

The user should select the cutting speed according to the material, hardness, cutting state, material type, feed rate and cutting depth.

According to these factors, select the most suitable processing conditions. The ideal state is to wear regularly and stably to reach the service life.

But in practice, the choice of tool life is related to tool wear, size change, surface quality, cutting noise, processing heat and so on. When determining the processing conditions, it is necessary to study according to the actual situation. For refractory materials such as stainless steel and heat resistant alloy, coolant or hard blade can be used.

(1) Point control CNC lathe processing robot. The CNC lathe robot of CNC equipment can only control the moving parts of the lathe from one position to another accurately, that is to say, only the value of controlling the end point of coordinate travel does not have any reduction in the moving process, as for the speed and path between the relevant two points depends on the productivity.

In order to locate accurately on the basis of as high productivity as possible, the movement between the two related points is first to move quickly to the new position, and then slow down the 1-3 stage, let it slowly locate the point, so as to ensure its positioning accuracy.

(2) Point line control CNC lathe processing robot. This kind of NC lathe robot processing, not only to control the position between the two related points, but also to control the movement speed and route between the two related points.

Its route usually consists of straight lines parallel to each axis. The difference between the control and the point of NC lathe robot is that when the moving parts of the machine tool move, it can be processed along an axis direction (generally it can be cut at 45 ° oblique line, but not any slope linear cutting). The auxiliary function is the position control of the NC lathe robot, such as improving the spindle speed control, feed processing cycle, tool selection, and other functions.

(3) Contour control CNC lathe processing robot. The control device of this kind of CNC lathe can control two or more coordinate axes continuously at the same time.

In the process of machining, we should not only control the starting point and the end point, but also control the speed and position of each point in the whole processing process, so that the CNC lathe robot can process complex shaped parts according to the drawing requirements. Its auxiliary functions are also relatively complete.