Dual pump split flow control system, method and crane

Abstract

The application discloses a double-pump split-flow combination control system and method and a crane. The system comprises a combination valve, a shuttle valve, a first electromagnetic reversing valve and a hydraulic control reversing valve. A control oil port of the hydraulic control reversing valve is connected with a pilot oil source of a first actuator control valve. A first oil inlet of the hydraulic control reversing valve is connected with a stable pressure oil source. An oil outlet of the hydraulic control reversing valve is connected with a first oil inlet of the first electromagnetic reversing valve. An oil outlet of the first electromagnetic reversing valve is connected with a first oil inlet of the shuttle valve. An oil outlet of the shuttle valve is connected with a control oil port of the combination valve. A second oil inlet of the first electromagnetic reversing valve and a second oil inlet of the hydraulic control reversing valve are respectively connected with a back oil port. The crane comprises the double-pump split-flow combination control system. By introducing the pilot oil source of the actuator control valve, the combination valve is closed first and then the actuator control valve is reversed during the actuation of the actuator, so that the actuator is completely supplied with oil by the single pump during the actuation, and the smoothness of the starting process is ensured.

Description

Technical Field

[0001] This invention relates to engineering machinery, specifically to a dual-pump merging and splitting control system, method, and crane. Background Technology

[0002] Currently, the dual-pump confluence control scheme adopted by the domestic crane industry is mainly based on the technical solution disclosed in "CN104564868B, Confluence Control System, Method and Crane". It can realize dual-pump confluence operation when working under single load and dual-pump diversion operation when performing compound actions, which not only improves the control accuracy of compound actions, but also ensures the operation efficiency.

[0003] Based on this, "CN112128155B, a dual-pump merging and splitting control system and its control method" further solved the problem of large speed changes of the actuator during the switching of compound actions, and improved the smoothness of operation during the switching of compound actions.

[0004] However, in practical applications, the CN112128155B technical solution still experiences some impact during the initial stage of the actuator's operation, when the system switches from dual-pump oil supply to single-pump oil supply, affecting the smoothness of the actuator's operation.

[0005] Therefore, it is necessary to further improve the technical solution of CN112128155B. Summary of the Invention

[0006] Purpose of the Invention: The purpose of this invention is to solve the impact problem that occurs during the switching from dual-pump oil supply to single-pump oil supply, and to improve the smoothness of the actuator's operation. To this end, a dual-pump flow splitting and merging control system, method, and crane are proposed.

[0007] Technical Solution: The first aspect of this invention provides a dual-pump merging and splitting control system, including a merging valve, a shuttle valve, a first solenoid directional valve, and a hydraulic directional valve. The control port of the hydraulic directional valve is connected to the pilot oil source of the first actuator control valve; the first inlet of the hydraulic directional valve is connected to a stable pressure oil source; the outlet of the hydraulic directional valve is connected to the first inlet of the first solenoid directional valve, the outlet of the first solenoid directional valve is connected to the first inlet of the shuttle valve, and the outlet of the shuttle valve is connected to the control port of the merging valve; the second inlet of the first solenoid directional valve and the second inlet of the hydraulic directional valve are respectively connected to return ports.

[0008] Furthermore, in the technical solution of CN112128155B, since the oil source for switching the confluence valve comes from the load pressure of the actuator, when the system malfunctions and the actuator does not operate, it cannot switch to the non-confluence state, making it inconvenient to disconnect the dual-pump system for troubleshooting.

[0009] Therefore, the aforementioned dual-pump flow splitting and merging control system also includes a reversing valve. The first inlet of the reversing valve is connected to a stable pressure oil source; the second inlet of the reversing valve is connected to a return port; and the outlet of the reversing valve is connected to the second inlet of a shuttle valve. The reversing valve can be a second solenoid reversing valve or a manual reversing valve.

[0010] Optionally, the above-mentioned dual-pump merging and splitting control system also includes adjustable damping, which is set on the connecting pipeline between the stable pressure oil source and the second oil inlet of the shuttle valve.

[0011] In the above technical solution, when the system malfunctions or the operating status of the first and second hydraulic pumps needs to be checked separately, a stable pressure oil source can be introduced into the control chamber of the confluence valve through the second solenoid directional valve, manual directional valve, or adjustable damping. This enables the dual-pump system to be forcibly disconnected when the actuator is not in operation, i.e., the first and second hydraulic pumps are cut off. This facilitates troubleshooting or monitoring of the operating status of the dual-pump system and improves the maintainability of the system.

[0012] A second aspect of the present invention provides a crane including the dual-pump merging and splitting control system described in the first aspect. This crane possesses the beneficial effects of the dual-pump merging and splitting control system.

[0013] A third aspect of the present invention provides a dual-pump merging and splitting control method, employing the dual-pump merging and splitting control system described in the first aspect, the control method comprising:

[0014] Before the pilot oil pressure reaches the opening pressure of the first actuator control valve, the hydraulic control directional valve is opened first, so that the stable pressure oil source acts on the control chamber of the confluence valve through the hydraulic control directional valve, the first solenoid directional valve and the shuttle valve. The confluence valve works in the shut-off position. At this time, the first hydraulic pump and the second hydraulic pump are cut off and are in a non-confluence state.

[0015] When the pilot oil pressure continues to rise, the pressure oil in the first inlet circuit acts on the first actuator through the first actuator control valve. When the first actuator is activated, it is supplied with oil entirely by the first hydraulic pump. At this time, if it is necessary to operate the second actuator, the second actuator is supplied with oil entirely by the second hydraulic pump.

[0016] When the combined action is performed, the first solenoid directional valve is energized, and the pressure oil in the control chamber of the confluence valve is unloaded through the shuttle valve and the first solenoid directional valve. The confluence valve is in the open position, and at this time the first hydraulic pump and the second hydraulic pump are in the confluence state.

[0017] Furthermore, when the system malfunctions or the operating status of the first and second hydraulic pumps needs to be checked separately, the stable pressure oil source is applied to the control chamber of the confluence valve by adjusting the directional valve or adjustable damping. The confluence valve operates in the shut-off position, thereby cutting off the first and second hydraulic pumps.

[0018] As mentioned earlier, the dual-pump split-flow and merging control method can improve the smoothness of actuator operation and enhance system maintainability.

[0019] The principle of this invention is as follows:

[0020] For actuators in cranes that require smooth start-up, the pilot oil source of the first actuator control valve is connected to the control terminal of the reversing control valve. This allows the confluence valve to close first during actuator operation, followed by the reversing of the first actuator control valve. This ensures that the actuator is fully supplied with oil by the first hydraulic pump during startup, guaranteeing a smooth start-up process. Simultaneously, the operation speed of the first actuator is not affected when the second actuator is activated. Therefore, this invention can simultaneously guarantee smoothness during both the moment of actuator startup and during combined operations.

[0021] When the system malfunctions or the operating status of the first and second hydraulic pumps needs to be checked separately, a stable pressure oil source can be introduced into the control chamber of the confluence valve through, for example, the second solenoid directional valve, to cut off the first and second hydraulic pumps, which facilitates troubleshooting or monitoring of the operating status of the dual-pump system.

[0022] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: it can improve the smoothness of the actuator's operation. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of a dual-pump flow splitting and merging control system according to an embodiment of this application;

[0025] Figure 2 This is a schematic diagram of the structure of another dual-pump flow splitting and merging control system in the embodiments of this application;

[0026] Figure 3 This is a schematic diagram of another dual-pump flow splitting and merging control system in an embodiment of this application;

[0027] Reference numerals in the attached diagram: 1, merging valve; 2, shuttle valve; 3-1, first solenoid directional valve; 3-2, second solenoid directional valve; 4, hydraulically controlled directional valve; 5-1, first actuator control valve; 5-2, second actuator control valve; 6-1, first actuator; 6-2, second actuator; 7, manual directional valve; 8, adjustable damping; P1, first oil inlet; P2, second oil inlet; Pi, stable pressure oil source; a1 / a2 / b1 / b2, pilot oil source. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0029] Figure 1 The diagram shown is a structural schematic of a dual-pump merging and splitting control system provided in an embodiment of this application. The dual-pump merging and splitting control system includes a merging valve 1, a shuttle valve 2, a first electromagnetic directional valve 3-1, a second electromagnetic directional valve 3-2, a hydraulically controlled directional valve 4, a first actuator control valve 5-1, a second actuator control valve 5-2, a first actuator 6-1, and a second actuator 6-2.

[0030] The first oil inlet circuit P1 connects to the first hydraulic pump, and the second oil inlet circuit P2 connects to the second hydraulic pump. The stable pressure oil source Pi is used to provide the stable pressure required for the control of the confluence valve 1. a1 and b1 are the pilot oil sources for the first actuator control valve 5-1, and a2 and b2 are the pilot oil sources for the second actuator control valve 5-2.

[0031] The pilot oil source a1 of the first actuator control valve 5-1 is connected to the control port of the hydraulic directional valve 4. The stabilizing pressure oil source Pi is connected to the first inlet of the hydraulic directional valve 4 and the first inlet of the second solenoid directional valve 3-2. The outlet of the hydraulic directional valve 4 is connected to the first inlet of the first solenoid directional valve 3-1, the outlet of the first solenoid directional valve 3-1 is connected to the first inlet of the shuttle valve 2, the outlet of the second solenoid directional valve 3-2 is connected to the second inlet of the shuttle valve 2, and the outlet of the shuttle valve 2 is connected to the control port of the confluence valve 1. The second inlets of the first solenoid directional valve 3-1, the second solenoid directional valve 3-2, and the second inlet of the hydraulic directional valve 4 are all connected to the return ports.

[0032] This application provides a dual-pump merging and splitting control method, which adopts the above-mentioned dual-pump merging and splitting control system. The specific details of the dual-pump merging and splitting control method are as follows.

[0033] When the pilot oil source a1 provides pilot oil, before the pressure of the pilot oil source a1 reaches the opening pressure of the first actuator control valve 5-1, the hydraulic control directional valve 4 is opened first. The hydraulic control directional valve 4 is in the left position. The stable pressure oil source Pi acts on the control chamber of the confluence valve 1 through the hydraulic control directional valve 4, the first solenoid directional valve 3-1 and the shuttle valve 2. The confluence valve 1 is in the shut-off position (lower position). At this time, the first hydraulic pump and the second hydraulic pump are cut off and are in a non-confluence state.

[0034] When the pressure of the pilot oil source a1 continues to rise, the first actuator control valve 5-1 operates in the lower position. The pressure oil in the first inlet oil circuit P1 acts on the first actuator 6-1 through the first actuator control valve 5-1, thus ensuring that the first actuator 6-1 is fully supplied with oil by the first hydraulic pump when it operates, and the start-up process is smooth and shock-free. At this time, if it is necessary to operate the second actuator 6-2, the second actuator 6-2 is fully supplied with oil by the second hydraulic pump, and the combined actions do not interfere with each other.

[0035] If it is necessary to increase the operating speed of the first actuator 6-1, the first solenoid directional valve 3-1 can be energized and operated in the left position. The pressure oil in the control chamber of the confluence valve 1 is unloaded through the shuttle valve 2 and the first solenoid directional valve 3-1, and the confluence valve 1 is operated in the conducting position (upper position). At this time, the first hydraulic pump and the second hydraulic pump are in a confluence state, thereby increasing the operating speed of the first actuator 6-1.

[0036] When the system malfunctions or when it is necessary to check the operating status of the first and second hydraulic pumps separately, the second solenoid directional valve 3-2 is energized and operates in the left position. The stable pressure oil source Pi acts on the control chamber of the confluence valve 1 through the second solenoid directional valve 3-2, and the confluence valve 1 operates in the lower position, thereby cutting off the first and second hydraulic pumps and realizing the separate monitoring of the operating status of the first and second hydraulic pumps.

[0037] Figure 2 The diagram shown is a structural schematic of another dual-pump merging and splitting control system provided in this application embodiment. This dual-pump merging and splitting control system replaces the aforementioned second electromagnetic directional valve 3-2 with a manual directional valve 7. The function of the manual directional valve 7 is the same as that of the second electromagnetic directional valve 3-2, except that the control method is changed from electromagnetic control to manual control.

[0038] Figure 3 The diagram shows another structural schematic of a dual-pump merging and splitting control system provided in this application embodiment. This dual-pump merging and splitting control system replaces the aforementioned second electromagnetic directional valve 3-2 with an adjustable damper 8. The adjustable damper 8 has an internal oil passage with an inlet and an outlet at its two ends. Inside the adjustable damper 8 is a screw that can be screwed in and out. The end of the screw has a piston structure, and the flow area and on / off state of the internal oil passage can be adjusted by rotating the screw. Although the adjustable damper 8 can have different structural forms, their essence is the same: adjusting the degree of on / off state between the inlet and outlet oil through a thread.

[0039] This application also provides a crane that includes any of the above-mentioned dual-pump merging and splitting control systems, thereby providing the crane with the beneficial effects of the dual-pump merging and splitting control system.

[0040] This embodiment of the application introduces a pilot oil source for the actuator control valve, enabling the confluence valve to be closed first during actuator operation, and then the actuator control valve to be switched. This ensures that the actuator is supplied with oil entirely by a single pump during operation, guaranteeing a smooth start-up process. A stable pressure oil source is introduced into the confluence valve control chamber via a second solenoid directional valve, a manual directional valve, or an adjustable damper, forcibly cutting off P1 and P2, facilitating troubleshooting or operational status monitoring of the dual-pump system.

[0041] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A dual-pump flow splitting and merging control method, employing a dual-pump flow splitting and merging control system, characterized in that, The dual-pump merging and splitting control system includes a merging valve (1), a shuttle valve (2), a first electromagnetic directional valve (3-1), and a hydraulic directional valve (4). The control port of the hydraulic directional valve (4) is connected to the pilot oil source of the first actuator control valve (5-1); the first inlet of the hydraulic directional valve (4) is connected to a stable pressure oil source; the outlet of the hydraulic directional valve (4) is connected to the first inlet of the first electromagnetic directional valve (3-1), the outlet of the first electromagnetic directional valve (3-1) is connected to the first inlet of the shuttle valve (2), and the outlet of the shuttle valve (2) is connected to the control port of the merging valve (1); the second inlet of the first electromagnetic directional valve (3-1) and the second inlet of the hydraulic directional valve (4) are respectively connected to the return port. The control method includes: Before the pilot oil source pressure reaches the opening pressure of the first actuator control valve (5-1), the hydraulic control directional valve (4) is opened first, so that the stable pressure oil source acts on the control chamber of the confluence valve (1) through the hydraulic control directional valve (4), the first solenoid directional valve (3-1) and the shuttle valve (2). The confluence valve (1) is working in the cut-off position. At this time, the first hydraulic pump and the second hydraulic pump are cut off and in a non-confluence state. When the pilot oil pressure continues to rise, the pressure oil in the first inlet circuit acts on the first actuator (6-1) through the first actuator control valve (5-1). When the first actuator (6-1) is activated, it is supplied with oil entirely by the first hydraulic pump. At this time, if it is necessary to operate the second actuator (6-2), the second actuator (6-2) is supplied with oil entirely by the second hydraulic pump. When the combined action is performed, the first solenoid directional valve (3-1) is energized, and the pressure oil in the control chamber of the confluence valve (1) is unloaded through the shuttle valve (2) and the first solenoid directional valve (3-1). The confluence valve (1) is in the open position, and at this time the first hydraulic pump and the second hydraulic pump are in the confluence state.

2. The dual-pump flow splitting and merging control method according to claim 1, characterized in that, The dual-pump flow splitting and merging control system also includes a second electromagnetic reversing valve (3-2) or a manual reversing valve (7) or an adjustable damper (8). The first oil inlet of the second electromagnetic reversing valve (3-2) or the manual reversing valve (7) is connected to a stable pressure oil source; the second oil inlet of the second electromagnetic reversing valve (3-2) or the manual reversing valve (7) is connected to a return oil port; the oil outlet of the second electromagnetic reversing valve (3-2) or the manual reversing valve (7) is connected to the second oil inlet of the shuttle valve (2); the adjustable damper (8) is installed on the connecting pipeline between the stable pressure oil source and the second oil inlet of the shuttle valve (2). When the system malfunctions or the operating status of the first hydraulic pump and the second hydraulic pump needs to be checked separately, the stable pressure oil source is applied to the control chamber of the confluence valve (1) by adjusting the second solenoid directional valve (3-2), the manual directional valve (7), or the adjustable damper (8). The confluence valve (1) is then in the shut-off position, thereby cutting off the first hydraulic pump and the second hydraulic pump.

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