Regulating valve, in particular for the electroproportional regulation of the pivot angle of a hydraulic machine

1. A regulating valve, comprising:

a valve housing defining a piston bore;

a regulating piston guided slidably in the piston bore, the regulating piston being configured to be displaced axially in an adjusting direction via an actuator;

a counterspring configured to act upon the regulating piston with a spring force opposite to the adjusting direction, the counterspring being supported on a spring plate that is supported, via its side pointing away from the counterspring, on a supporting spring supported on the valve housing; and

an adjusting device configured to act upon the spring plate with an adjustable adjusting force counter to a supporting force of the supporting spring, the adjusting device acting on that side of the spring plate which points toward the counterspring.

2. The regulating valve according to claim 1 , wherein the adjusting device includes a pin arranged axially displaceably in the valve housing and engaging on that side of the spring plate which points toward the counterspring, the pin being configured to act upon the spring plate with the adjusting force.

3. The regulating valve according to claim 1 , wherein the supporting spring is configured as a cup spring.

4. The regulating valve according to claim 1 , wherein the spring plate is configured as a bush and the counterspring is at least partially surrounded by the bush.

5. The regulating valve according to claim 2 , wherein the pin is arranged in an oblique bore of the valve housing, the oblique bore being formed obliquely to the longitudinal axis of the regulating piston and extending from the spring plate in a direction away from the supporting spring.

6. The regulating valve according to claim 5 , wherein the pin is screwed into the oblique bore via a threaded portion.

7. The regulating valve according to claim 5 , further comprising a further oblique bore issuing into the oblique bore, wherein a setscrew is screwed in the further oblique bore, and wherein the pin is supported on the setscrew and configured to be displaced axially by the setscrew.

8. The regulating valve according to claim 7 , wherein an expander is inserted into the oblique bore or into the oblique bore and the further oblique bore.

9. The regulating valve according to claim 1 , further comprising:

a connection between a tank duct and an actuating pressure duct being controllable by the regulating piston in the adjusting direction; and

a connection between a delivery pressure duct and the actuating pressure duct being controllable by the regulating piston in the opposite direction, the regulating piston being configured to be acted upon opposite to the adjusting direction by a spring force of a measuring spring.

10. The regulating valve according to claim 7 , wherein the actuator is configured as a lifting magnet with a magnet coil, and wherein the oblique bore of the pin or the oblique bore of the setscrew is at least partially covered by the magnet coil from an outside of the valve housing.

11. The regulating valve according to claim 4 , wherein the regulating piston includes a radial projection via which the counterspring acts with the spring force upon the regulating piston, the radial projection being configured to penetrate into the bush.

12. The regulating valve according to claim 1 , wherein the piston bore has a guide portion configured to slidably guide the regulating piston, the guide portion having a radially widened step adjoining it in the region of an actuator-side end portion of the regulating piston, the radially widened step having a step face which points toward the actuator and on which the supporting spring is supported.

13. The regulating valve according to claim 12 , wherein the piston bore has a threaded portion which adjoins the step and into which the actuator is screwed.

14. The regulating valve according to claim 1 , wherein the adjusting device is accessible from outside when the valve housing is in a state inserted into a housing.

15. A hydraulic system, comprising:

a variable-displacement pump of the swashplate type; and

a regulating valve configured as a pivot-angle regulator, the regulating valve including:

a valve housing defining a piston bore;

a regulating piston guided slidably in the piston bore, the regulating piston being configured to be displaced axially in an adjusting direction via an actuator;

a counterspring configured to act upon the regulating piston with a spring force opposite to the adjusting direction, the counterspring being supported on a spring plate that is supported, via its side pointing away from the counterspring, on a supporting spring supported on the valve housing; and

an adjusting device configured to act upon the spring plate with an adjustable adjusting force counter to a supporting force of the supporting spring, the adjusting device acting on that side of the spring plate which points toward the counterspring.

16. The regulating valve according to claim 10 , further comprising:

a connection between a tank duct and an actuating pressure duct being controllable by the regulating piston in the adjusting direction; and

a connection between a delivery pressure duct and the actuating pressure duct being controllable by the regulating piston in the opposite direction, the regulating piston being configured to be acted upon opposite to the adjusting direction by a spring force of a measuring spring.

17. The regulating valve according to claim 14 , wherein the housing is a hydraulic machine housing.