proportional cartridge valve with variable flow gain

The invention discloses a proportional cartridge valve with variable flow gain, which comprises a valve sleeve, a hollow valve core with a damping hole, a control cover plate, a valve cover, a displacement transducer and a pilot control valve, and is characterized in that: the lower part of the hollow valve core is arranged in the valve sleeve and is linearly sealed with the valve sleeve; the upper part of the hollow valve core is matched with the control cover plate; the upper end of the control cover plate is connected with the valve cover; the displacement transducer is arranged on the valve cover; the pilot control valve is arranged on a side face of the control cover plate; a semicircular hole is machined on a port at the bottom of the valve core; and four symmetrical waist-shaped holes are machined on the valve sleeve. The invention has the advantages that: the proportional cartridge valve has small valve opening, low flow gain and high linearity, and high-precision linear control at low flow can be realized; the valve has large valve opening, high flow gain and high linearity, and high-precision linear control at high flow can be realized; and due to low flow fluctuation and low pressure shock of the valve, the service life of the valve can be prolonged.