Slider Crank Feedback Digital Hydraulic Cylinder

Abstract

The invention discloses a crank slide block feedback digital hydraulic cylinder. The crank slide block feedback digital hydraulic cylinder comprises a slide valve, a hydraulic cylinder and a stepper motor; the hydraulic cylinder includes a hydraulic cylinder cavity and a piston; the hydraulic cylinder cavity is divided into an upper cavity and a lower cavity; the slide valve includes a valve cavity and a valve element; one end of the valve element is connected with the stepper motor, and the other end of the valve element is fixed with one end of the lead screw; a feedback nut is arranged at the other end of the lead screw; and the feedback nut and the lead screw form a screw nut pair. The feedback digital hydraulic cylinder further comprises a crank slide block mechanism; the crank slide block mechanism includes a piston rod, a connecting rod, a crank, a connecting piece and a rotating shaft; the lower end of the piston rod is fixed with the piston, and the upper end of the piston rod extends above the upper cavity from the internal of the upper cavity of the hydraulic cylinder; the upper end of the piston rod is hinged to one end of the connecting rod through the connecting piece; the other end of the connecting rod is hinged to the crank; and the crank is connected with the feedback nut through the rotating shaft. The digital hydraulic cylinder not only can precisely control the operating speed and the displacement thereof, but also has the characteristics of simple structure, quick feedback response and continuity.

Description

technical field [0001] The invention relates to the field of digital hydraulic cylinders, in particular to a crank slider type feedback digital hydraulic cylinder. Background technique [0002] The hydraulic cylinder is the core part of the hydraulic system, a hydraulic actuator, and an energy conversion device. As the needs of society and industry put forward higher requirements for the control accuracy of hydraulic components, it is obvious that traditional hydraulic technology cannot meet the existing industrial production requirements in terms of accuracy and control. [0003] Therefore, in order to overcome the problem of poor accuracy of traditional hydraulic cylinders, digital hydraulic cylinders came into being. Digital hydraulic cylinders integrate stepping motors, hydraulic slide valves, and feedback mechanisms inside the hydraulic cylinders. When in use, the hydraulic oil source is connected , all functions directly control the moving length vector of each compon...

AI Technical Summary

Problems solved by technology

[0004] At present, digital hydraulic cylinders mainly include stepper motors or servo motors, hydraulic cylinders, hydraulic slide valves, sensors, and feedback mechanisms. Digital technology controls the angular displacement of stepper motors to control the opening of hydraulic slide valves, and then controls oil flow. The oil volume and flow rate can finally control the operating speed and displacement of the hydraulic cylinder. Among them, the feedback mechanism mainly collects the displacement speed information of the hydraulic cylinder through the sensor and feeds it back to the stepping motor, and then adjusts the angular displacement of the stepping motor to achieve precise control. Hydraulic cylinder, this process is the closed-loop control of the stepper motor, this kind of closed-loop control of the stepper motor has problems such as complexity, hysteresis, nonlinearity and poor anti-interference, and usually the structure of this feedback mechanism is relatively complicated

In order to overcome the shortcomings of the stepper motor closed-loop control, a closed-loop digital control of the displacement of the hydraulic cylinder appears. For example, the Chinese invention patent (authorized announcement date CN103148047 B authorized announcement date 2016.03.02) discloses the internal feedback digital servo hydraulic cylinder. The spool of the valve is driven and controlled by the first motor, and the feedback screw sleeve of the slide valve is driven and controlled by the second motor. The hysteresis telescopic displacement sensor feeds back the displacement signal of the hydraulic cylinder to the corresponding driver of the second motor, and the driver controls the operation of the second motor. By controlling the relative movement of the feedback screw sleeve and the spool, the closed-loop digital control of the displacement of the hydraulic cylinder is realized. This invention includes a first motor that drives the displacement of the slide valve and a second motor that executes the feedback command. Because the second motor The motor driver needs to pass the sensor to perform the feedback action. Therefore, this feedback mechanism still has the disadvantage of feedback response lag

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