Precision liquid expansion fixture boost gear intelligent upgrade

"Made in China 2025" proposes to implement the development strategy of building a strong manufacturing country in China. The equipment manufacturing industry as a strategic and basic industry is an important guarantee for industrial upgrading and technological progress in various industries and a comprehensive manifestation of the country's comprehensive strength. As the core and basic components of major equipment, gears are related to the performance, level and reliability of major equipment and mainframes, and are the bottleneck restricting the development of major equipment. To become a powerful country in equipment manufacturing, China must first become a strong manufacturing country for gears and other basic components. In the "13th Five-Year Plan for Development of China's Gear Industry", it is also proposed that the gear industry should be upgraded from "gear manufacturing" to "gear intelligence" and "gear creation" to achieve a transformation from large to strong. In the gear processing, high-precision, high-reliability and high-efficiency automatic clamping and positioning gears are important prerequisites for the upgrade of “Gear Gear”.

Traditional mechanical clamps cannot meet the requirements of high efficiency, high precision and high reliability in the gear processing industry due to their low precision and difficulty in automation. The precision liquid expansion clamp has a series of advantages such as high repetitive clamping precision, large clamping force, good precision retention, long service life and convenient use. It is an effective technology to solve the long-life efficient manufacturing process of gears, vibration reduction and noise reduction of gear transmission. The foundation, especially its ability to cooperate with the machine tool to achieve automatic clamping, is suitable for the automated production line of gear processing, to achieve intelligent gear manufacturing. Therefore, precision fluid expansion fixtures are increasingly being used by the gear processing industry.

Since the research and production of hydraulic shank in 2007, Sentai Yingge has accumulated rich experience in isostatic expansion technology. In order to meet the needs of users of intelligent manufacturing, high-efficiency manufacturing and high-precision manufacturing, the background of precision liquid swell fixture is monopolized by foreign countries. Next, Sentai Yingge successfully designed and manufactured a high-precision positioning and clamping type internal expansion type and external expansion type liquid expansion clamp, which has anti-vibration, anti-loose, fast and strong locking end-face expansion hydraulic nut, etc. The high-end liquid expansion fixture series replaces the import, shortens the delivery time, reduces the cost, and is widely recognized by users.

The precision liquid expansion fixture is different from the traditionally defined hydraulic clamp. The hydraulic clamp is mainly used in CNC numerical control machine tools. The hydraulic components replace the mechanical parts to realize the positioning, support and compression of the workpiece. The liquid expansion clamp uses the static pressure expansion technology. According to the machine configuration, the manual or automatic pressing mechanism is used to pressurize the clamp. The hydraulic medium pre-stored inside the clamp cavity generates a great pressure under the action of the pressing mechanism, forcing the thin-wall deforming element to 360° over the entire clamping range. Uniform elastic deformation in the circumferential direction, the expansion of the workpiece positioning hole/shaft is achieved, and the clamping accuracy is high, which greatly improves the machining accuracy and quality stability of the workpiece. The liquid expansion clamp can realize the workpiece positioning and transmission torque at the same time, without other structural devices, providing users with good reliability and safety. The variable diameter clamping can be realized by selecting the variable diameter sleeve, in response to the flexible production requirements, the flexible adjustment method and the quick clamping, the replacement time is reduced, the production efficiency is greatly improved, and the cost is reduced.

According to the actual needs of customers, Sentai Yingge Co., Ltd. tailors the individualized liquid expansion fixtures for customers. According to the different types of workpieces, it can be divided into external expansion type, internal expansion type and end expansion type liquid expansion clamp.

After the Sentai Yingge® external expansion type liquid expansion clamp is pressurized by the internal hydraulic medium, the thin-wall deformation element on the mandrel expands outward, eliminating the gap between the hole and the inner hole of the workpiece, thereby expanding the inner hole to achieve positioning and guarantee. The radial and end face runout of the workpiece are both ≤0.005mm. Figure 1 shows the external expansion type liquid expansion clamp used for gear grinding. The clamp pushes the piston top rod of the clamp through the hydraulic push rod of the machine tool to realize automatic pressurization, and cooperates with the industrial robot to realize the automatic clamping of the workpiece. The whole dressing + Processing time ≤ 30s, life up to 100,000 times workpiece clamping; compared to gear processing, the detection of gear workpiece has higher requirements on its positioning accuracy, Figure 2 is the liquid expansion mandrel for gear detection, the mandrel is After manually screwing the compression Screw, the inner hole of the gear is expanded, and the mandrel and the workpiece reference hole are accurately centered and clamped without gaps, and the radial and end jumps are ≤0.003 mm.

In the Sentai Yingge® internal expansion type liquid expansion clamp, the thin-wall deformation element shrinks toward the inner hole under the static pressure expansion, and the clearance gap with the workpiece shaft is continuously reduced, and finally the workpiece shaft is clamped and positioned. Fig. 3 is an internal expansion type liquid expansion clamp for automatic gear loading and unloading for triple gear grinding. The clamp is provided with a booster cylinder. The machine tool only needs to provide about 2 MPa of hydraulic oil for the clamp to automatically clamp. The workpiece is also equipped with a pressure indicating mechanism, and the field operator can judge the operation of the fixture without using other auxiliary conditions, thereby improving the safety of the operation; FIG. 4 is a manual liquid expansion clamp for the rotor grinding of the compressor, Before the transformation, the enterprise adopts four-claw centering mechanical clamps. Every time the workpiece is clamped, the workpiece needs to be corrected, the efficiency is extremely low, and the precision is not high. After adopting the customized liquid expansion clamp, the radial and end face runout of the workpiece is ≤0.005mm, and the precision is stable, which greatly improves the production efficiency and product qualification rate.

Sentai Yingge® end-expansion type liquid expansion clamp - hydraulic nut is mainly used in fastening occasions with higher compression requirements. Figure 5 shows the hydraulic nut. When the nut is screwed into the screw, the screw used to drive the pressurizing piston can be tightened to provide a great preload on the end face of the nut. The utility model has the characteristics of reliable fastening and labor saving, and the hydraulic nut has the function of preventing looseness even under the condition of strong vibration shock. Because it uses the built-in piston to pressurize, there is no need for an external hydraulic pump, so it is compact in structure, easy to use, simple in operation, low in cost, and the hydraulic nut also has a pressure indicator, which is convenient for the user to select the appropriate output pressure, and also for the user. The safe and reliable use of the hydraulic power lock nut provides a basis for judgment; Figure 6 shows the shaving cutter grinding fluid expansion clamp, which has high requirements on the verticality of the end face during the grinding process, so While the inner hole of the razor is being expanded and centered, it is necessary to press the end face. The clamp adopts a hydraulic nut to press the end face thereof. Compared with the ordinary nut, the hydraulic nut is more convenient to operate and the locking force is stronger and more uniform, and the grinding precision is better ensured. The precision of the shaving cutter clamping diameter The accuracy of the jump to the end face and the end face is ≤0.003mm.

Figure 1 External expansion type liquid expansion fixture

Figure 2 gear detection liquid expansion mandrel

Figure 3 Internal expansion type liquid expansion fixture

Figure 4 Compressor rotor grinding fluid expansion fixture

Figure 5 hydraulic nut

Figure 6 Shaving cutter grinding fluid expansion fixture

With the goal of “leading high-end tools localization”, Sentai Yingge provides users with various types of liquid expansion clamps for high-precision positioning and clamping, designing and producing non-standard customized products for customers, and providing them with mechanical processing. A full set of technical services, to promote the gear to upgrade, and strive to contribute to the "Made in China 2025."

(Received date)