Asymmetric cylinder closed-loop speed system controlled by electro-hydraulic proportional pump

Abstract

The invention relates to a control system of electric liquid ratio pump control asymmetry cylinder. Wherein, the oil gate A1 of electric liquid ratio pump (1) with closed-loop flux control system is connected to the single valve (4) oil gate A2, the single valve (7) oil gate A3, the overflow valve (8) oil gate A4, the overflow valve (9) oil gate A5, the flux division overflow valve (19) oil gate A6 and the asymmetry oil cylinder (18) rod chamber; the oil gate B1 of electric liquid ratio pump (1) is connected to the single valve (11) oil gate B2, the single valve (10) oil gate B3, the overflow valve (8) oil gate B4, the overflow valve (9) oil gate B4, and the liquid control single valve (17) oil gate B5; and the oil gate B6 of liquid control single valve (17) is connected to the non-rod chamber of asymmetry oil cylinder (18) and the maintenance-safety circuit. The oil feeding circuit, main pump zero flux unload circuit and pressure-limited circuit are arranged between the non-rod chamber and the rod chamber oil pip.

Description

1. Technical field [0001] The invention belongs to an electro-hydraulic speed control system. In particular, it relates to a speed control system for an electro-hydraulic proportional pump to control an asymmetrical cylinder. 2. Background technology [0002] At present, there are mainly two ways in the commonly used speed control system. One is an open system using an electro-hydraulic proportional valve to control the actuator (Liu Jianzhong. Discussion on a high-precision synchronous system for pump control and valve control compensation. Mechanical Development, 1998 (4)), and its disadvantages are large throttling losses, The efficiency is low, and it is easy to cause the system oil to heat up. It can only be applied to occasions with low power and medium and low pressure or occasions with high power but short working hours (Ming Zilin. Energy consumption analysis and energy-saving design of stepping furnace hydraulic system. Hydraulic and Pneumatic, 2002 (8)); the oth...

AI Technical Summary

Problems solved by technology

One is an open system that uses an electro-hydraulic proportional valve to control the actuator (Liu Jianzhong. Discussion on a high-precision synchronous system for pump control and valve control compensation. Mechanical Development, 1998 (4)), and its disadvantages are large throttling losses, The efficiency is low, and it is easy to cause the system oil to heat up. It can only be applied to occasions with low power and medium and low pressure or occasions with high power but short working hours (Ming Zilin. Energy consumption analysis and energy-saving design of stepping furnace hydraulic system. Hydraulic and Pneumatic, 2002 (8)); the other is a closed volume speed control system that uses a variable pump to control an oil motor or a symmetrical oil cylinder (Cao Xinming. Hydraulic Servo System. Metallurgical Industry Press). This speed control circuit has no throttling and Overflow loss, the system is not easy to heat, and the efficiency is high. It is suitable for occasions with large power, but there are two problems: one is that the closed volume speed regulation system that uses variable pumps to control oil motors or symmetrical oil cylinders is difficult to apply When the actuator is an asymmetrical oil cylinder, especially in the speed control system with heavy load, large flow and high frequency, it is necessary to ensure that the reciprocating speed is consistent; the second is that the flow adjustment of the variable pump is mainly based on the machine-hydraulic servo control The pressure step variable, its hydraulic system and flow control system are complicated, the control is backward, and there are many failure points

Images