Hydraulic distributor with compensation device for directional valves

An open-center valve device for operating machines comprising:

• a first section and a second section, the sections being configured to be connected to respective pairs of work ports to operate a respective actuator of the operating machine,
• a high-pressure line configured in such a way as to be connected to a pump to supply a flow rate of an operating fluid to the sections, and
• a discharge line configured to be connected to an outlet for the operating fluid,
• each of the sections comprising a spool control element, configured in such a way as to send the flow rate to the respective work ports,
• the valve device further comprising:
• one or more free flow segments configured in such a way as to define a free flow line connecting in successive sequence each of the spool control elements, each of the spool control elements including a free-circulation passage configured in such a way that, when all the spool control elements are in a neutral position, the high-pressure line is connected to the discharge line without sending the flow rate to the work ports,
• a series duct configured in such a way that, upon a movement from the neutral position of one of the spool control elements for operating one of the actuators, a return flow rate from a respective use is supplied to a subsequent spool control element, progressively closing the respective free flow passage, the spool control elements comprising respective return passages configured to receive the return flow rate, respective non-return valves being provided downstream of the return passages of the spool control elements and upstream of the series duct,
• wherein at least one of the spool control elements comprises at least one bypass passage, the spool control elements being configured in such a way that, when a spool control element is in the neutral position, the bypass passage is closed and, when the spool control element is moved from the neutral position to operate the respective actuator, the spool control element progressively puts the bypass passage into communication with the outlet via the discharge line or a low-pressure line directly connected to the outlet, wherein the sections comprise a return line configured in such a way that, when one of the spool control elements is moved from the neutral position to operate the respective actuator, the return flow rate from a driven actuator is fed to the respective return passage, and wherein the valve device further comprises a bypass duct, the bypass duct being arranged as a bypass to the return line in such a way as to bring the return flow rate to the bypass passage in parallel with the return passages and wherein the valve device further comprises a maximum pressure valve arranged along the bypass duct.

An open-center valve device for operating machines comprising:

• a first section and a second section, the sections being configured to be connected to respective pairs of work ports to operate a respective actuator of the operating machine,
• a high-pressure line configured in such a way as to be connected to a pump to supply a flow rate of an operating fluid to the sections, and
• a discharge line configured to be connected to an outlet for the operating fluid,
• each of the sections comprising a spool control element, configured in such a way as to send the flow rate to the respective work ports,
• the valve device further comprising:
• one or more free flow segments configured in such a way as to define a free flow line connecting in successive sequence each of the spool control elements, each of the spool control elements including a free-circulation passage configured in such a way that, when all the spool control elements are in a neutral position, the high-pressure line is connected to the discharge line without sending the flow rate to the work ports,
• a series duct configured in such a way that, upon a movement from the neutral position of one of the spool control elements for operating one of the actuators, a return flow rate from a respective use is supplied to a subsequent spool control element, progressively closing the respective free flow passage, the spool control elements comprising respective return passages configured to receive the return flow rate, respective non-return valves being provided downstream of the return passages of the spool control elements and upstream of the series duct,
• wherein at least one of the spool control elements comprises at least one bypass passage, the spool control element being configured in such a way that, when the spool control element is in the neutral position, the bypass passage is closed and, when the spool control element is moved from the neutral position to operate the respective actuator, the spool control element progressively puts the bypass passage into communication with the outlet via the discharge line or a low-pressure line directly connected to the outlet, and wherein the valve device further comprises a two-way sequence slide valve through which the return flow rate is discharged.