A plug-in throttle valve group for a rod-type hydrostatic cylinder

Abstract

The invention discloses a plug-in throttle valve group for a tie-rod type static pressure oil cylinder. The through hole is used as the center hole for pressure measurement. The cartridge valve body is also provided with an oil supply transfer hole and a static pressure oil pad connection hole. The restrictor is provided with an inner seal ring and an outer seal ring at intervals. A capillary tube is wound between the sealing rings, and a radial connection hole connected to the pressure measuring center hole is opened on the restrictor. One end of the capillary tube is connected to the oil supply transfer hole, and the other end is connected to the radial connection hole. , so that the high-pressure oil entering through the oil supply transfer hole can only be throttled by the capillary, and then flow through the radial connection hole and the pressure measurement center hole in turn, and flow into the connection hole of the static pressure oil pad. The performance of the actuator is improved, the cost of the actuator is reduced, on-site maintenance is convenient, and the service life is long.

Description

technical field [0001] The invention relates to the technical field of testing equipment, in particular to a throttle installation structure for a tie-rod type static pressure oil cylinder. Background technique [0002] Hydraulic servo actuators are widely used in testing in the fields of automobiles, aviation, rail and civil engineering. They can simulate the loads on components during use and complete performance, strength and fatigue tests. The actuator is the center of the entire test bench. key components. Existing actuators are mainly divided into tie-rod type and flange type. The tie-rod type is generally an ordinary polymer guide bearing due to its compact structure, and the lip type is combined with high-pressure sealing; the flange type can be designed with static pressure support and gap seal because the external size is sufficient. Capable of providing high speed and withstanding large side loads. [0003] The performance of the existing rod-type actuators is m...

AI Technical Summary

Problems solved by technology

[0003] The performance of the existing rod-type actuators is mainly limited by the performance of the sealing ring. Some high-pressure seals can reach higher speeds, but they cannot withstand reciprocating high-frequency movements; the friction generated by the high-pressure seal changes with the pressure of the oil chamber. Changes have a great impact on motion control accuracy; there is always relative friction between the oil seal and the guide ring and the piston rod, and the seal needs to be replaced regularly

The combined seal requires high hardness of the piston rod. If the hardness does not reach a certain level, the surface of the piston rod will be easily worn by the combined seal ring. Especially in some fatigue tests, the piston rod is required to move at a small amplitude and high frequency, which is very easy to cause local wear of the piston rod. Rod wear is generally difficult to repair, and the cost of repair will be far greater than replacing the oil seal

Therefore, high-performance flanged static pressure cylinders are often selected, resulting in high cost of test benches, and the testing of components by general manufacturers is unaffordable

In addition to the high cost, the high-performance flange-type static pressure cylinder has a larger stroke and tonnage than the tie-rod type, and the overall structure is heavier. The structure design and motion control process need to consider the influence of the structure weight on the test process, which is more complicated to use.

The existing high-performance static pressure cylinder has complex mechanical structure and hydraulic oil circuit. The maintenance process has high requirements for the workshop environment and the experience of technicians. When it is damaged, it generally needs to be dismantled and shipped back to the manufacturer for maintenance; the structure of the tie-rod actuator is relatively simple. Suitable for on-site seal replacement with low maintenance requirements

[0004] At present, some manufacturers design the oil distribution channel in the end cover of the tie rod type actuator, and add a throttle to realize the static pressure support and guiding function, but this greatly increases the processing difficulty of the end cover, and at the same time increases the size of the actuator end cover. The size makes the compactness of the tie-rod cylinder worse, and it is essentially the same as the flange-type static pressure cylinder, and the cost performance is not significantly improved.

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