Hydraulic control assembly for a crane

Abstract

The utility model provides a crane hydraulic control assembly, including power takeoff, double variable pump, oil tank, swivel, first proportional valve and second proportional valve, through power takeoff drive double variable pump, and via swivel constructs two sets of working circuit which is independent of each other in hydraulic pressure to the first proportional valve and second proportional valve with pressure oil independently supplies, thereby. This parallel architecture of double pump double valve avoids the flow and pressure interference among each execution mechanism when the traditional single pump system executes the composite action from the root, makes different actions be able to carry out smoothly, accurately, efficiently simultaneously, greatly improves the operating performance and work efficiency of equipment.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic control technology, specifically to hydraulic control components for cranes. Background Technology

[0002] In the field of construction machinery and special vehicles, it has become common practice to use crane hydraulic control components as the core of power transmission and control. Such systems typically obtain power from the chassis engine via a power take-off (PTO) to drive a hydraulic pump, which then operates multiple actuators through control valve groups to complete complex actions. However, in traditional single-pump, multi-valve systems, the flow and pressure between actuators interfere with each other when performing complex actions, resulting in sluggish and uncoordinated movements and low overall efficiency. Furthermore, simply using multiple independent pump stations to meet the requirements of complex actions leads to a bloated system structure, high costs, and fails to solve the problem of unified management and distribution of the power source.

[0003] Especially in equipment where the upper part requires continuous rotation relative to the chassis, the hydraulic circuit needs to be transitioned through a rotary joint. In existing technology, if the oil supply and return circuits of multiple valve groups are concentrated through a single rotary joint, the total power may exceed the load-bearing limit of the chassis power take-off when the system faces high-pressure conditions, posing a significant risk of engine stalling or component damage. Although some systems have attempted to introduce power limiting mechanisms, these mostly focus on controlling the engine or a single pump. In complex systems with dual pumps, multiple actuator circuits, and rotary connections, how to achieve efficient composite motion control and reliable total system power management remains an unresolved technical challenge. Utility Model Content

[0004] This utility model proposes a hydraulic control component for cranes. It utilizes different variable pumps to control different actuators of the crane, thereby improving work efficiency and the micro-motion performance of multi-action linkage. At the same time, through power cross-control between multiple variable pumps, it avoids the problem of engine stalling due to overpower when multiple pumps work in combination.

[0005] The technical solution of this utility model is implemented as follows: The crane hydraulic control components include a power take-off (PTO), a dual variable pump, an oil tank, a rotary joint, a first proportional valve, and a second proportional valve. The output end of the power take-off is connected to the input end of the dual variable pump. The oil inlet of the dual variable pump is fluidly connected to the oil tank; The outlet of the dual variable pump is fluidly connected to the lower inlet of the rotary joint; The upper oil outlet of the rotary joint is fluidly connected to the oil inlet of the first proportional valve and the second proportional valve, respectively. The return ports of the first and second proportional valves are fluidly connected to the upper return port of the rotary joint. The lower oil return port of the rotary joint is fluidly connected to the oil tank; The dual variable pump includes a power control module for automatically adjusting the displacement and / or pressure when the system pressure increases, in order to limit the total power of the system.

[0006] Furthermore, the dual variable pump includes two independent variable pump units, the oil inlet of which is fluidly connected to the oil tank, and the oil outlet of which is fluidly connected to the first proportional valve and the second proportional valve respectively through the rotary joint.

[0007] Furthermore, the power control module is configured to reduce the displacement of the dual variable pump when the system pressure reaches or exceeds a preset threshold, so as to keep the input power from exceeding the rated power of the power take-off.

[0008] Furthermore, the rotary joint is a multi-channel rotary joint, with at least two independent oil inlet channels and oil outlet channels respectively provided in its lower and upper parts.

[0009] Furthermore, the first proportional valve and the second proportional valve are each configured to independently control one or more actuators to achieve compound actions.

[0010] Furthermore, the power take-off unit and the dual variable pump are connected by a drive shaft and a coupling.

[0011] Furthermore, the dual variable pump is fluidly connected to the oil tank, the rotary joint, the first proportional valve, and the second proportional valve via hydraulic pipelines.

[0012] The beneficial effects of the technical solution provided in this application are as follows: 1. The hydraulic control component of this crane drives the dual variable pump through the power take-off and independently supplies pressurized oil to the first proportional valve and the second proportional valve via the rotary joint, thereby constructing two hydraulically independent working circuits. This parallel architecture of dual pumps and dual valves fundamentally avoids the flow and pressure interference between actuators when performing compound actions in traditional single pump systems, enabling different actions to be performed simultaneously, smoothly, accurately, and efficiently, greatly improving the operational performance and work efficiency of the equipment; 2. The crane's hydraulic control assembly integrates the power control module into the dual variable pump. This module automatically adjusts the displacement and / or pressure in response to increases in system pressure. This design achieves intelligent closed-loop management of the system's total power, effectively preventing chassis engine stalling or hydraulic component damage due to power overload under high-pressure conditions, ensuring the reliability and safety of the entire system. Crucially, this power limiting function is located at the source of power transmission and works in conjunction with the multi-actuator circuits connected via the rotary joint. This ensures efficient composite actions while solving the long-standing problems of power distribution and overload protection in complex systems with slewing operation requirements, achieving a balance between efficiency and safety. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the hydraulic control component for the crane according to this utility model.

[0015] In the diagram: 1 Power Take-Off, 2 Dual Variable Pump, 3 Oil Tank, Rotary Joint, 5 First Proportional Valve, 6 Second Proportional Valve. Detailed Implementation

[0016] The technical solution of this utility model will be clearly and completely described below with reference to its embodiments. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0017] This utility model provides a hydraulic control component for a crane, which is integrated between the crane chassis and the upper working mechanism. It is primarily used to solve the technical problems of poor coordination of complex actions and system power overload under complex working conditions. Figure 1 As shown, the system adopts a modular hydraulic control approach. Through the coordinated operation of the power take-off 1, dual variable pump 2, oil tank 3, rotary joint 4, first proportional valve 5 and second proportional valve 6, a highly efficient and safe hydraulic power and control system is constructed.

[0018] Specifically, the power take-off (PTO) 1 is installed at the output end of the crane chassis engine, and its output shaft is rigidly connected to the input shaft of the dual variable pump 2 via a drive shaft and coupling. This direct drive method ensures that the engine power is efficiently and reliably transmitted to the crane's hydraulic control components. The dual variable pump 2 adopts a swashplate or swashplate-shaft variable structure, which integrates two independent variable pump units, each with its own independent suction port and discharge port, together forming the system's dual hydraulic power source.

[0019] Regarding the hydraulic circuit connections, the two inlet ends of the dual variable pump 2 are connected to the oil tank 3 via two independent suction pipes, and a coarse filter is installed on the suction pipe to prevent contaminants from entering the pump. The two outlet ends of the dual variable pump 2 are connected to two high-pressure oil supply pipes, which ultimately converge to two independent inlet channels at the bottom of the rotary joint 4. It is worth noting that this design of independent inlet and outlet for the dual pumps lays the physical foundation for subsequent interference-free compound actions.

[0020] The rotary joint 4, as a key component connecting the fixed part of the chassis and the rotating part of the upper vehicle, adopts a multi-channel rotary sealing structure. Its lower housing has two oil inlet channels and two oil return channels, respectively connected to the dual oil outlet and dual oil return pipelines from the chassis; the upper rotating body has corresponding two oil outlet channels and two oil return channels, which rotate together with the upper vehicle mechanism. The rotary joint 4 uses a precisely fitted rotary sealing pair to ensure reliable sealing during the transfer of hydraulic oil between the fixed and rotating components.

[0021] Two pressure oil lines leading from the oil outlet at the top of the rotary joint 4 are connected to the inlets of the first proportional valve 5 and the second proportional valve 6, respectively. Both proportional valves adopt electro-hydraulic proportional control, which can receive minute electrical signals from the controller to precisely adjust the valve opening and output flow. The first proportional valve 5 is typically used to control the hoisting or luffing movements of the crane, while the second proportional valve 6 is used to control the telescoping or slewing movements. Each proportional valve can independently operate one or more actuators.

[0022] During operation, when a compound action is required, the controller simultaneously sends control signals to the first proportional valve 5 and the second proportional valve 6. Since the oil supply source for the two proportional valves is two independent variable pump units in the dual variable pump 2, the flow and pressure of the two working circuits do not interfere with each other, realizing the smooth and precise execution of compound actions such as hoisting and slewing, luffing and telescopic movements, and completely solving the problem of mutual interference in compound actions of traditional single pump systems.

[0023] The integrated power control module within the dual variable pump 2 is one of the core innovations of this system. This module monitors the system's operating pressure in real time via a pressure sensor. When the detected pressure reaches a preset threshold (e.g., 90% of the crane's rated operating pressure), the power control module automatically reduces the displacement of the dual variable pump 2 by adjusting the swashplate angle or controlling the piston displacement. This displacement adjustment is based on a constant power control algorithm, ensuring that the pump's output power (pressure × displacement) never exceeds the rated input power of the power take-off 1.

[0024] In the return oil circuit design, the return ports of the first proportional valve 5 and the second proportional valve 6 are connected to the two return oil channels on the upper part of the rotary joint 4 via return oil pipelines. After the actuator has worked, the hydraulic oil returns through the proportional valve return ports, the upper return oil channel of the rotary joint 4, and the lower return oil channel, finally returning to the oil tank 3 via the main return oil pipeline. A cooler and a fine filter are installed on the return oil pipeline to ensure that the hydraulic oil is adequately cooled and purified before returning to the oil tank.

[0025] For high-pressure operating conditions, a special protection mechanism is in place. When the crane performs heavy lifting or executes multiple high-pressure actions simultaneously, the system pressure increases significantly. At this time, the power control module responds quickly by reducing the displacement of the dual variable pump 2 to limit the output flow. Although the actuator speed will be appropriately reduced, it ensures that the total system power does not exceed the limit, effectively preventing the chassis engine from shutting down due to overload, and avoiding damage to hydraulic components due to overpressure.

[0026] In this embodiment, all hydraulic connections utilize high-pressure hydraulic pipelines conforming to GB / T standards, including both rigid and flexible hoses. Pipeline connections employ 24° cone seals or flange seals to ensure no leakage occurs across the entire operating pressure range. The system's operating pressure range is designed to be 0-35 MPa, and the total displacement of the dual variable pump 2 can be selected within the range of 50-200 ml / rev, depending on the crane's tonnage.

[0027] In summary, this crane hydraulic control assembly, through a unique combination of power take-off 1, dual variable pump 2, rotary joint 4, and two proportional valves 5 and 6, along with the power control module built into the dual variable pump 2, achieves efficient and coordinated control of the crane's hydraulic control assembly under complex operations and intelligent limitation of system power. This design not only improves operational efficiency but, more importantly, ensures the safe and reliable operation of the equipment, making it particularly suitable for crane applications requiring frequent complex operations and heavy-duty work.

[0028] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A hydraulic control assembly for a crane, characterized in that: Including a power take-off (1), a dual variable pump (2), an oil tank (3), a rotary joint (4), a first proportional valve (5), and a second proportional valve (6), characterized in that: The output end of the power take-off (1) is connected to the input end of the dual variable pump (2) via a transmission connection; The oil inlet of the dual variable pump (2) is fluidly connected to the oil tank (3); The oil outlet of the dual variable pump (2) is fluidly connected to the lower oil inlet of the rotary joint (4); The upper oil outlet of the rotary joint (4) is fluidly connected to the oil inlet of the first proportional valve (5) and the second proportional valve (6). The oil return ports of the first proportional valve (5) and the second proportional valve (6) are fluidly connected to the upper oil return port of the rotary joint (4). The lower oil return port of the rotary joint (4) is fluidly connected to the oil tank (3); The dual variable pump (2) includes a power control module for automatically adjusting the displacement and / or pressure when the system pressure increases, in order to limit the total power of the system.

2. The crane hydraulic control assembly according to claim 1, characterized in that, The dual variable pump (2) includes two independent variable pump units. The oil inlet of each variable pump unit is fluidly connected to the oil tank (3), and the oil outlet is fluidly connected to the first proportional valve (5) and the second proportional valve (6) respectively through the rotary joint (4).

3. The crane hydraulic control assembly according to claim 2, characterized in that, The power control module is configured to reduce the displacement of the dual variable pump (2) when the system pressure reaches or exceeds a preset threshold, so as to keep the input power from exceeding the rated power of the power take-off (1).

4. The crane hydraulic control assembly as described in claim 1, characterized in that, The rotary joint (4) is a multi-channel rotary joint, with at least two independent oil inlet channels and oil outlet channels in its lower and upper parts, respectively.

5. The crane hydraulic control assembly as described in claim 1, characterized in that, The first proportional valve (5) and the second proportional valve (6) are each configured to independently control one or more actuators to achieve compound actions.

6. The crane hydraulic control assembly according to claim 1, characterized in that, The power take-off (1) and the dual variable pump (2) are connected by a drive shaft and a coupling.

7. The crane hydraulic control assembly according to claim 1, characterized in that, The dual variable pump (2) is fluidly connected to the oil tank (3), the rotary joint (4), the first proportional valve (5), and the second proportional valve (6) through hydraulic pipelines.

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