Improve clean production and enhance the reliability of hydraulic systems

When you open the product samples of advanced foreign enterprises or visit them, the first impression you get is that the Windows are bright and clean, without a speck of dust. However, in most of our industrial enterprises, the production environment can be described as dusty everywhere. The construction machinery industry is no exception.

Machinery is generally made of steel. In the eyes of Chinese people, steel is "not afraid" of dust and other pollutants, so there is no need to keep it so clean.

This notion is wrong. Hydraulic transmission is widely adopted in construction machinery. As the medium of hydraulic transmission, hydraulic oil can be said to be cleaner than the edible oil we consume. Fortunately, more and more business managers have recognized the problem and are making improvements - this is clean production.

With the development of society and the intensification of competition, the requirements for product quality are getting higher and higher. To enhance the reliability of the entire machine, most construction machinery enterprises prefer to use imported parts. However, even with exactly the same imported parts, our failure rate is still much higher than that of foreign products. Why is that? Some enterprises' hydraulic systems frequently malfunction, but they have no idea how to improve them. In fact, all of this is closely related to clean production.

Clean production is a comprehensive set of pollution prevention measures throughout the entire production process and the entire life cycle of products. It involves aspects such as product research and development, design, manufacturing, process flow/parameters, equipment, operating procedures, and product performance during use. Therefore, enterprises should study and analyze the possibility of reducing pollutant generation from each link in the above process. Seek opportunities and potential for clean production.

Statistics show that 75% to 80% of the faults in hydraulic systems are caused by contamination. For the lubrication system of mechanical transmission, contaminants also act as abrasives. The cleanliness and significance of the hydraulic system itself have been discussed many times in relevant journals. This article focuses on how to improve the cleanliness of the hydraulic system assembly from the perspective of production management.

The assembly of the hydraulic system is mainly carried out in the assembly workshop. Enterprises should pay special attention to the following aspects:

1. Prevent dust from entering the assembly and final assembly workshops

The components of dust are diverse, including soil, smoke and dust, etc.

Firstly, there should be an assembly workshop with good dust-proof performance to prevent dust from entering the workshop through doors and Windows, especially in areas with heavy sand and dust and poor air quality.

The main channels for dust to enter the workshop are the gaps around the workshop door and the open Windows. The author once saw a workshop. When the north wind blew in winter, even the fallen leaves outside would enter the workshop through the gap under the door. It could be said that "one night the north wind blew, and all the items were covered with dust."

When necessary, sealing measures should be taken for doors and Windows, and filters should be installed on ventilation Windows.

Of course, a smooth and flat workshop floor is even more essential.

Secondly, it is necessary to prevent dust from being brought into the workshop by racks and other equipment. Due to the insufficient technical capital capacity of Chinese enterprises and the various small-batch production characteristics of the construction machinery industry, after the paint on structural components such as frames is completed, most of them cannot be immediately placed in the assembly workshop but are left outdoors for a period of time, which inevitably leads to dust accumulation. Once these dusts enter the workshop, they will become secondary sources of pollution.

Therefore, for items placed outdoors, they should be cleaned before entering the workshop.

Thirdly, efforts should be made to minimize the introduction of dust by personnel and vehicles.

Anyone who has read the introduction of the Shenzhou spacecraft knows that the personnel entering the rocket and spacecraft assembly workshop all wear white coats. In fact, this is the case in industries such as aerospace, high-tech electronics and electrical appliances, pharmaceuticals and chemicals. Some hydraulic component manufacturing enterprises in the machinery industry, such as Guizhou Liyuan, have long achieved assembly in white coats. In the assembly workshop of Rexira Company in Beijing, not only are the workshop Windows double-layered, but personnel must also wear clean coats when entering the assembly workshop. The cloths used to wipe hydraulic components must be special lint-free cloths that do not shed threads.

Second, avoid pollution during the production process

The main pollutants at this stage include rust, welding slag, iron filings, oil stains, etc

Most of the stronger enterprises in our country have already achieved pre-treatment of structural components and the like. After painting, they are transferred to the assembly workshop, and there is basically no possibility of rust entering the assembly workshop. However, enterprises with weak strength still have this problem.

To prevent welding slag from contaminating the production site, on-site welding should be avoided during the design process.

The substandard structural components often require on-site grinding. Iron filings may enter the machine interior along with the assembly, and the iron filings milled by the air milling cutter also pose a threat to personal safety.

Iii. Packaging, Storage and Handling

Hydraulic components should be properly packaged to prevent dust, rust and bumps. Most professional manufacturers can achieve this, but non-professional manufacturers often neglect packaging requirements, resulting in components being covered with dust, even rusting, and the sealing surface failing due to bumps before assembly. Therefore, the packaging requirements and even the cleanliness requirements should be specified on the design drawings. The author once saw a fabric-reinforced rubber hose used for the oil suction port of a hydraulic pump. As the user did not specify the packaging requirements, the supplier only wrapped it with a layer of plastic film. After the film was damaged, it was covered with dust and could not be used normally.

Just like workshops, warehouses must also do a good job in dust prevention management. During handling, handle with care to avoid bumps and knocks, especially to prevent cracking of the hydraulic pump motor housing. Do not unpack before assembly.

Iv. Other issues

Debugging, major overhauls and new product trial production can be carried out in one workshop and must be separated from the assembly workshop.