WO-2026093765-A1 - A HYDRAULIC CONTROL SYSTEM

WO2026093765A1WO 2026093765 A1WO2026093765 A1WO 2026093765A1WO-2026093765-A1

Abstract

A system for controlling the pressure of a control fluid provided to a hydraulically operated pilot input unit, the system comprising: a hydraulically operated pilot input unit for controlling the movement of at least one hydraulic service, wherein the hydraulically operated pilot input unit is operable upon receipt of a control fluid; a pilot pressure pump configured to pump the control fluid from a tank to the hydraulically operated pilot input unit via a fluid channel; and a proportional control valve located within the fluid channel and being moveable from and between a fully open position, at least one partially open position, and a fully closed position to regulate the pressure of the control fluid provided to the hydraulically operated pilot input unit.

Inventors

GUEST, Jonathan Keith

Assignees

SAFETY SHIELD AI LTD

Dates

Publication Date: 20260507
Application Date: 20251103
Priority Date: 20241104

Claims (12)

1. A system for controlling the pressure of a control fluid provided to a hydraulically operated pilot input unit, the system comprising: a hydraulically operated pilot input unit for controlling the movement of at least one hydraulic service, wherein the hydraulically operated pilot input unit is operable upon receipt of a control fluid; a pilot pressure pump configured to pump the control fluid from a tank to the hydraulically operated pilot input unit via a fluid channel; and a proportional control valve located within the fluid channel and being moveable from and between a fully open position, at least one partially open position, and a fully closed position to regulate the pressure of the control fluid provided to the hydraulically operated pilot input unit.
2. The system according to any preceding claim, wherein the proportional control valve is electronically controllable, and wherein the system comprises an electronic control unit configured to move the proportional control valve from and between the fully open, partially open, and fully closed position.
3. The system according to any preceding claim, wherein: when in the fully open position, the proportional control valve is configured to allow the control fluid to flow from the tank to the hydraulically operated pilot input unit at a nominal pressure; when in the fully closed position, the proportional control valve is configured to prevent the control fluid from flowing from the tank to the hydraulically operated pilot input unit; and when in the at least one partially open position, the proportional control valve is configured to allow the control fluid to flow from the tank to the hydraulically operated pilot input unit at a pressure below the nominal pressure.
4. The system according to any preceding claim, wherein the proportional control valve comprises: a proportional control valve inlet configured to receive control fluid from the tank; a pilot input unit outlet configured to convey control fluid to the pilot input unit; and a tank outlet configured to convey control fluid to the tank, wherein, when in the fully open position, the proportional control valve directs all control fluid received from the proportional control valve inlet through the pilot input unit outlet; when in the fully closed position, the proportional control valve directs all control fluid received from the proportional control valve inlet to the tank outlet; and, when in the at least one partially open position, the proportional control valve directs some of the control fluid received from the proportional control valve inlet through each of the pilot input unit outlet and the tank outlet.
5. The system according to any preceding claim, further comprising a pilot isolation valve located within the fluid channel and being moveable from a fully open position to a fully closed position to prevent the control fluid from flowing from the tank to the hydraulically operated pilot input unit.
6. The system according to claim 5, wherein the proportional control valve is located between the pilot isolation valve and the hydraulically operated pilot input unit.
7. The system according to any preceding claim, further comprising a pressure sensor configured to measure the pressure within the fluid channel, wherein the proportional control valve is configured to automatically move between its fully open position, at least one partially open position, and fully closed position based on the measured pressure.
8. The system according to any preceding claim, further comprising a risk detection unit configured to automatically move the proportional control valve towards its fully closed position upon detection of a risk.
9. The system according to claim 8, wherein the risk detection unit comprises at least one camera configured to generate and send video data to a processor for analysis, wherein the processor is configured to identify a risk within the video data and generate a signal corresponding thereto, and wherein the signal is configured to automatically move the proportional control valve towards its fully closed position.
10. The system according to claim 8 or 9, wherein the risk detection unit is configured to determine a severity of the risk and move the proportional control valve towards its fully closed position by an amount that is based upon the determined severity.
11. The system according to any preceding claim, further comprising an override button configured to move the proportional control valve from and between its fully open position, at least one partially open position, and fully closed position.
12. Machinery or equipment comprising the system according to any preceding claim.

Description

A HYDRAULIC CONTROL SYSTEM FIELD OF THE INVENTION The present invention relates to improvements in or relating to a hydraulic control system and, more specifically, to a system for controlling the pressure of a control fluid provided to a hydraulically operated pilot input unit. BACKGROUND TO THE INVENTION Many hydraulically actuated systems comprise safety mechanisms configured to bring the system to a stop. However, such safety mechanisms are often very abrupt, which can lead to risks and dangers associated with the stoppage of the system. Moreover, hydraulically actuated systems typically comprise a plurality of hydraulic services, each having a separate safety mechanism. The use of multiple safety mechanisms increases the cost and complexity of the system, while also increasing the risk associated with an operable hydraulic service causing harm or damage even when other hydraulic services within the system have been stopped. It is against this background that the present invention has arisen. SUMMARY OF THE INVENTION According to the present invention there is provided a system for controlling the pressure of a control fluid provided to a hydraulically operated pilot input unit, the system comprising: a hydraulically operated pilot input unit for controlling the movement of at least one hydraulic service, wherein the hydraulically operated pilot input unit is operable upon receipt of a control fluid; a pilot pressure pump configured to pump the control fluid from a tank to the hydraulically operated pilot input unit via a fluid channel; and a proportional control valve located within the fluid channel and being moveable from and between a fully open position, at least one partially open position, and a fully closed position to regulate the pressure of the control fluid provided to the hydraulically operated pilot input unit. The use of a proportional control valve, which may also be called a modulating control valve, enables the pressure of the control fluid provided to the hydraulically operated pilot input unit to be varied from and between a maximum and minimum pressure. The proportional control valve can, therefore, be used to bring the hydraulically operated pilot input unit, and all the associated hydraulic services, to a controlled stop simultaneously and at a desired rate. This capability, which is not present in traditional hydraulic systems, is particularly beneficial in an emergency, and is crucial for applications requiring precise control over machinery operations, ensuring both efficiency and safety. The hydraulically operated pilot input unit may control the movement of the at least one hydraulic service by controlling the flow of a working fluid provided thereto. The hydraulically operated pilot input unit may comprise one or more travel lever and/or joystick manipulator. The travel lever(s) and/or joystick manipulator(s) may be hydraulically operated. The hydraulically operated pilot input unit may be located within the cab of construction machinery. The pilot pressure pump may be a variable pump. More specifically, the pump may be a variable displacement pump. The pilot pressure pump may be configured to pump the control fluid within the fluid channel at a pressure of up to 100 bar, 50 bar, 40 bar, or more specifically, 38 bar. The control fluid may be configured to flow from the tank to the hydraulically operated pilot input via the pump. As such, the pump may be in fluid communication with the fluid channel. The fluid channel may be a conduit. The fluid channel may be a plurality of separate fluid channels connected together. There may be a network of fluid channels. The fluid channel, or network thereof, may comprise a filter. The filter may be configured to filter the control fluid entering and/or exiting the tank. The system may be a dead-headed system. As such, an increase in flow rate may cause a decrease in pressure and vice versa. Therefore, the proportional control valve may regulate the pressure and/or flow rate of the control fluid provided to the hydraulically operated pilot input unit. The control fluid may be a hydraulic fluid. The proportional control valve may be electronically controllable. The system may comprise an electronic control unit configured to move the proportional control valve from and between the fully open, partially open, and fully closed position. An electronically controllable proportional control valve enables the pressure of the control fluid provided to the pilot input unit to be selected based on a dynamic set point, which, in turn, enables dynamic control of each of hydraulic service. The electronic control unit may be configured to automatically move the proportional control valve in response to an event. The event may be the receipt of a signal. The signal may be generated by a processor, or a risk detection unit. As such, the event may be a risk. Alternatively, or in addition, the proportional control valve may be manually controllable. F