Patent ID: 9726296
Date: 2017-08-08
CPC Classifications: F16K,Y10T

Claim:
1. A hydraulic cartridge valve, comprising: a sleeve having a first longitudinal bore that extends along a longitudinal axis, the first longitudinal bore configured to form a working port via an end opening; a plunger accommodated for linear motion in the first longitudinal bore; at least one first radial bore penetrating the sleeve in the region of an inlet port and extending radially with respect to the longitudinal axis; at least one second radial bore penetrating the sleeve in the region of a return port, the at least one second radial bore extending radially with respect to the longitudinal axis and being arranged at a distance from the at least one first radial bore in the direction of the longitudinal axis; a first fluid flow path extending from the inlet port to the working port; a second fluid flow path extending from the working port to the return port, and a third fluid flow path extending from the working port via a restrictor and an adjustable pilot valve to the return port, wherein the plunger is configured such that one or more of the first fluid flow path and the second fluid flow path are blocked, depending on the position of the plunger, while the one or more of the first fluid flow path and the second fluid flow path are otherwise open, wherein the plunger has at least one third radial bore that extends radially with respect to the longitudinal axis and forms part of the first fluid flow path, wherein the plunger has at least one fourth radial bore that (i) extends radially with respect to the longitudinal axis, (ii) forms part of the second fluid flow path, and (iii) is arranged at a distance from the at least one third radial bore in the direction of the longitudinal axis, wherein the plunger has a second longitudinal bore that extends along the longitudinal axis, wherein the second longitudinal bore is open towards the working port, wherein the at least one third and fourth radial bores open into the second longitudinal bore, and wherein the second longitudinal bore forms part of the first, second, and third fluid flow paths, and wherein the plunger has a third longitudinal bore extending along the longitudinal axis on the side facing away from the second longitudinal bore, wherein the second and third longitudinal bores are connected to one another via the restrictor, and wherein an actuating pressure between the restrictor and the pilot valve loads the plunger in the direction of the working port.