Talking about how to correctly understand the quality of machine tools

Old gold press: For the understanding of machine quality, there may be different opinions from different angles. However, things always have their roots, and the quality of machine tools will have a recognized standard of judgment.

Have asked a customer, what is the quality of the machine? The customer said with ease: "A machine tool that is not easy to break and has good precision is a good machine tool." Lao Jin asked: "If the machine tool accuracy is not very high, but it meets your needs, the machine tool with a low failure rate is not counted. Good machine?" The answer after the customer scratched for half a day was: Yes.

I have also asked a sales peer, what is the quality of the machine tool? The answer from peers is: "The machine tool that customers can purchase twice is a good machine tool." Lao Jin asked: "If the customer is forced to repurchase the machine with frequent failure rate due to the pressure of funds, can this machine be a good machine? "The peers are stunned.

I also asked a machine tool designer, what is the quality of the machine tool? The designer has been thoughtful: “The failure rate, stability, and reliability represent the quality of the machine.” Lao Jin asked: “If the machine has a low failure rate, good stability, and good reliability, but the technical level is low, it can be said that High quality?” The designer’s answer is no.

Behind the question and answer is deep thought. After careful analysis, Laojin believes that the quality of machine tools should be measured by two parts and five elements. Part of the performance is simply the ability of the machine tool, including accuracy, rigidity, and technical level; part of it is quality, which represents the satisfaction of users using the product, including reliability and stability.

Two flowers are blossomed, one for each table. Let's analyze the five elements of machine quality one by one.

The machine tool accuracy is divided into two pieces. One piece is the machine's own motion accuracy, including positioning accuracy and repeat positioning accuracy, which is generally proportional to the actual machining accuracy; the other is the machine tool's machining accuracy, which is the dimensional accuracy obtained after the workpiece is actually loaded, this indicator and The positioning accuracy and repeat positioning accuracy on the manufacturer's sample are two concepts. High-precision machine tools are generally high-performance, but they do not represent high-quality, high-precision machine tools with high failure rates abound.

Rigidity refers to the ability of a machine tool to withstand loads and is proportional to cutting efficiency. High-rigidity machine tools mean high efficiency. Note that the efficiency here refers to the volume of metal removed per unit time. The large depth of cut is not necessarily efficient, and the small depth of cut is not necessarily inefficient. Highly rigid machines are not necessarily high performance and do not represent high quality.

The technical level of the machine tool is relative. For example, the ball screw technology belongs to cutting-edge technology 20 years ago, but now it is a conventional technology, and the linear motor drive is high technology. The development of machine tool technology is changing with each passing day, new technologies are emerging one after another. New technologies often mean high precision, high rigidity or high quality, but things are impermanent, and new technologies are also very likely to die.

The reliability of a machine tool refers to the ability or possibility of performing a specified function without failure under certain conditions within a certain period of time. The reliability of the machine tool is basically equivalent to the low failure rate, which is the most important indicator for users.

The specificity of the stability on the machine tool refers to how long the physical capacity of the machine tool, such as precision and rigidity, is maintained, that is, the length of the machine performance retention time. It is also a major indicator that affects the user's choice of machine tool.

The result of the analysis is that high-performance machines and high-quality machines cannot be directly drawn with equal signs. A high-quality machine is equal to the sum of a high-performance machine and a high-quality machine.

It should be pointed out that to evaluate the quality of a machine tool, a reference standard is required. It is ridiculous to take a 30,000-yuan machine to compare the quality with a machine of 1 million yuan.