A multi-way valve, a crane hydraulic system and a crane

Abstract

The application discloses a multi-way valve, a crane hydraulic system and a crane, and relates to the technical field of cranes, in particular to a multi-way valve, a crane hydraulic system and a crane. The multi-way valve comprises: an extension joint, an amplitude joint and a hoist joint; each joint comprises a reversing valve, a pressure compensator, an electric proportional pilot valve and an overflow valve; the control end of a hydraulic control reversing valve is connected with the working port of the reversing valve, the inlet of the hydraulic control reversing valve is connected with the LS oil way of the pressure compensator, and the outlet of the hydraulic control reversing valve is connected with the oil return port through the overflow valve; the hoist joint comprises a main hoist and an auxiliary hoist, and the main hoist and the auxiliary hoist share the overflow valve through a shuttle valve. The application takes the pressure of each oil outlet of the multi-way valve as a feedback condition to determine which overflow valve on the hydraulic system feedback oil way works, thereby playing a role in limiting the pressure of the load feedback oil way. In the overflow working condition, the upper car reduces the oil pump displacement by limiting the pressure of the oil pump feedback oil way, thereby avoiding the problem that a large amount of oil flows to the oil tank through the overflow valve, and improving the energy-saving performance of the hydraulic system while having the advantages of good composite action performance.

Description

Technical Field

[0001] This invention belongs to the field of engineering machinery technology, specifically relating to a multi-way valve, a crane hydraulic system, and a crane. Background Technology

[0002] As a core component of the hydraulic system of a wheeled crane, the multi-way valve enables switching between multiple actions of the upper structure. By controlling the displacement of each valve stem of the multi-way valve, the flow direction is determined to different actuators; each oil circuit of the multi-way valve has a corresponding safety valve that controls the maximum pressure of the corresponding oil circuit. Because the multi-way valve is a core component of the hydraulic system, its safety, economy, and operability are all closely related to it.

[0003] Multi-way valves with post-valve compensation for the main valve have certain advantages in compound operation, but when the overflow pressure is reached, the system energy loss is large, resulting in poor energy efficiency. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a multi-way valve, a crane hydraulic system, and a crane, which can effectively improve the energy efficiency of the downstream compensation multi-way valve, thereby meeting the dual requirements of the entire machine for complex actions and energy saving.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] Firstly, a multi-way valve is provided, comprising: a telescopic link, a variable amplitude link, and a hoist link; the telescopic link includes: a telescopic directional valve, a pressure compensator I disposed downstream of the telescopic directional valve, an electro-proportional pilot valve I and an electro-proportional pilot valve V for controlling the switching of the telescopic directional valve; the control end of the hydraulically controlled directional valve I is connected to the working port A1 of the telescopic directional valve, the inlet of the hydraulically controlled directional valve I is connected to the LS oil circuit of the pressure compensator I, and the outlet of the hydraulically controlled directional valve I is connected to the return oil port through a relief valve I; the control end of the hydraulically controlled directional valve II is connected to the working port B1 of the telescopic directional valve, the inlet of the hydraulically controlled directional valve II is connected to the LS oil circuit of the pressure compensator I, and the outlet of the hydraulically controlled directional valve II is connected to the return oil port through a relief valve II; the variable amplitude link includes: a telescopic directional valve, a variable amplitude link, and a hoist link; the telescopic link includes: a telescopic directional valve, a pressure compensator I disposed downstream of the telescopic directional valve, an electro-proportional pilot valve I disposed downstream of the telescopic directional valve, an electro-proportional pilot valve I disposed downstream of the pressure compensator ... The luffing control unit includes: a luffing directional valve, a pressure compensator II located downstream of the luffing directional valve, and electro-proportional pilot valves II and VI for controlling the switching of the luffing directional valve; the control terminal of hydraulic directional valve III is connected to the working port A2 of the luffing directional valve, the inlet of hydraulic directional valve III is connected to the LS oil circuit of pressure compensator II, and the outlet of hydraulic directional valve III is connected to the return oil port through relief valve III; the control terminal of hydraulic directional valve IV is connected to the working port B2 of the luffing directional valve, the inlet of hydraulic directional valve IV is connected to the LS oil circuit of pressure compensator II, and the outlet of hydraulic directional valve IV is connected to the return oil port through relief valve IV; the winch control unit includes: a main winch directional valve, a pressure compensator III located downstream of the main winch directional valve, and a pressure compensator II for controlling the switching of the luffing directional valve. The system includes two electro-proportional pilot valves: valve three and valve seven, which control the switching of the main winch directional valve; a secondary winch directional valve; a pressure compensator four located downstream of the secondary winch directional valve; and two electro-proportional pilot valves, valve four and valve eight, used to control the switching of the secondary winch directional valve. The control terminal of hydraulic directional valve five is connected to the outlet of shuttle valve one. Hydraulic directional valve five controls the low-pressure port pressure of the main and secondary winch connections. When the main and secondary winch connections operate simultaneously, to prevent the high-pressure port pressure from flowing away from relief valve five and thus failing to build up pressure, the pressure from the working ports B3 and B4 of the main and secondary winch directional valves is introduced into the spring chamber of hydraulic directional valve five for logical limitation. The inlet of shuttle valve one is connected to the working port of the main winch directional valve. Port A3 connects to the inlet of hydraulic directional valve five, which is connected to the LS oil circuit of pressure compensator three and pressure compensator four. The outlet of hydraulic directional valve five is connected to the return port through relief valve five. Hydraulic directional valve six is ​​a high-pressure side directional valve for the hoist. The outlet of shuttle valve two is connected to the control end of hydraulic directional valve six and the spring chamber of hydraulic directional valve five. The inlet of shuttle valve two is connected to the working port B3 of the main hoist directional valve. The inlet of hydraulic directional valve six is ​​connected to the LS oil circuit of pressure compensator three and pressure compensator four. The outlet of hydraulic directional valve six is ​​connected to the return port through relief valve six. The working port A4 of the auxiliary hoist directional valve is connected to the inlet two of shuttle valve one. The working port B4 of the auxiliary hoist directional valve is connected to the inlet two of shuttle valve two.

[0007] Furthermore, the LS oil circuits of pressure compensators one, two, three, and four are respectively connected to the LS oil circuits of the multi-way valve via check valves; the LS oil circuit of pressure compensator three is connected to the inlet of hydraulic directional valve five and the inlet of hydraulic directional valve six via check valves; the LS oil circuit of pressure compensator four is connected to the inlet of hydraulic directional valve five and the inlet of hydraulic directional valve six via check valves.

[0008] Furthermore, when the electro-proportional pilot valve one is energized and reverses, pilot oil enters the valve stem spring chamber of the telescopic directional valve through the electro-proportional pilot valve one, causing the telescopic directional valve to reverse. High-pressure oil enters the actuator through the valve stem of the telescopic directional valve, pressure compensator one, and the working port B1 of the telescopic directional valve. At the same time, high-pressure oil enters the control end of the hydraulically controlled directional valve two from the working port B1 of the telescopic directional valve, causing the hydraulically controlled directional valve two to reverse. When the LS pressure of pressure compensator one exceeds the set pressure of relief valve two, relief valve two depressurizes the LS oil circuit of pressure compensator one and feeds back to the LS port of the load-sensitive pump. Based on the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of pressure compensator one, the displacement of the load-sensitive pump is reduced.

[0009] Furthermore, when the electro-proportional pilot valve five is energized and reverses, pilot oil enters the valve stem spring chamber of the telescopic directional valve through the electro-proportional pilot valve five, causing the telescopic directional valve to reverse. High-pressure oil enters the actuator through the valve stem of the telescopic directional valve, pressure compensator one, and the working port A1 of the telescopic directional valve. At the same time, high-pressure oil enters the control end of the hydraulic directional valve one from the working port A1 of the telescopic directional valve, causing the hydraulic directional valve one to reverse. When the LS pressure of pressure compensator one exceeds the set pressure of relief valve one, relief valve one depressurizes the LS oil circuit of pressure compensator one and feeds back to the LS port of the load-sensitive pump. Based on the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of pressure compensator one, the displacement of the load-sensitive pump is reduced.

[0010] Furthermore, when the electro-proportional pilot valve two is energized and reverses, pilot oil enters the valve stem spring chamber of the luffing directional valve through the electro-proportional pilot valve two, causing the luffing directional valve to reverse. High-pressure oil enters the actuator through the valve stem of the luffing directional valve, pressure compensator two, and the working port B2 of the luffing directional valve. At the same time, high-pressure oil enters the control end of the hydraulic directional valve four from the working port B2 of the luffing directional valve, causing the hydraulic directional valve four to reverse. When the LS pressure of pressure compensator two exceeds the set pressure of relief valve four, relief valve four depressurizes the LS oil circuit of pressure compensator two and feeds back to the LS port of the load-sensitive pump. Based on the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of pressure compensator two, the displacement of the load-sensitive pump is reduced.

[0011] Furthermore, when the electro-proportional pilot valve six is ​​energized and reverses, pilot oil enters the valve stem spring chamber of the luffing directional valve through the electro-proportional pilot valve six, causing the luffing directional valve to reverse. High-pressure oil enters the actuator through the valve stem of the luffing directional valve, pressure compensator two, and the working port A2 of the luffing directional valve. At the same time, high-pressure oil enters the control end of the hydraulic directional valve three from the working port A2 of the luffing directional valve, causing the hydraulic directional valve three to reverse. When the LS pressure of pressure compensator two exceeds the set pressure of relief valve three, relief valve three relieves pressure on the LS oil circuit of pressure compensator two and feeds back to the LS port of the load-sensitive pump. Based on the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of pressure compensator two, the displacement of the load-sensitive pump is reduced.

[0012] Furthermore, when the electro-proportional pilot valve three is energized and reverses, pilot oil enters the valve stem spring chamber of the main winch directional valve through the electro-proportional pilot valve three. The main winch directional valve reverses, and high-pressure oil enters the actuator through the valve stem of the main winch directional valve, pressure compensator three, and the working port A3 of the main winch directional valve. At the same time, high-pressure oil enters the inlet one of shuttle valve one from the working port A3 of the main winch directional valve, and enters the control end of the hydraulic directional valve five from the outlet of shuttle valve one, pushing the hydraulic directional valve five to reverse. When the LS pressure of pressure compensator three exceeds the set pressure of relief valve five, relief valve five relieves pressure on the LS oil circuit of pressure compensator three and feeds back to the LS port of the load-sensitive pump. Based on the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of pressure compensator three, the load-sensitive pump... Displacement; When the electro-proportional pilot valve four is energized and reverses, pilot oil enters the valve stem spring chamber of the auxiliary winch directional valve through the electro-proportional pilot valve four. The auxiliary winch directional valve reverses, and high-pressure oil enters the actuator through the valve stem of the auxiliary winch directional valve, pressure compensator four, and working port A4 of the auxiliary winch directional valve. At the same time, high-pressure oil enters the inlet two of shuttle valve one from the working port A4 of the auxiliary winch directional valve, and enters the control end of the hydraulic directional valve five from the outlet of shuttle valve one, pushing the hydraulic directional valve five to reverse; When the LS pressure of pressure compensator four exceeds the set pressure of relief valve five, relief valve five relieves pressure on the LS oil circuit of pressure compensator four and feeds back to the LS port of the load-sensitive pump. The displacement of the load-sensitive pump is reduced according to the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of pressure compensator four.

[0013] Furthermore, when the electro-proportional pilot valve seven is energized and reverses, pilot oil enters the valve stem spring chamber of the main winch directional valve through the electro-proportional pilot valve seven. The main winch directional valve reverses, and high-pressure oil enters the actuator through the valve stem of the main winch directional valve, pressure compensator three, and the working port B3 of the main winch directional valve. At the same time, high-pressure oil enters the inlet one of shuttle valve two from the working port B3 of the main winch directional valve, and enters the control end of hydraulic directional valve six from the outlet of shuttle valve two, pushing hydraulic directional valve six to reverse. When the LS pressure of pressure compensator three exceeds the set pressure of relief valve six, relief valve six relieves pressure on the LS oil circuit of pressure compensator three and feeds back to the LS port of the load-sensitive pump. Based on the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of pressure compensator three, the load-sensitive pump... Displacement; When the electro-proportional pilot valve 8 is energized and reverses, pilot oil enters the valve stem spring chamber of the auxiliary winch directional valve through the electro-proportional pilot valve 8. The auxiliary winch directional valve reverses, and high-pressure oil enters the actuator through the valve stem of the auxiliary winch directional valve, pressure compensator 4, and working port B4 of the auxiliary winch directional valve. At the same time, high-pressure oil enters the inlet 2 of shuttle valve 2 from the working port B4 of the auxiliary winch directional valve, and enters the control end of hydraulic directional valve 6 from the outlet of shuttle valve 2, pushing hydraulic directional valve 6 to reverse; When the LS pressure of pressure compensator 4 exceeds the set pressure of relief valve 6, relief valve 6 relieves pressure on the LS oil circuit of pressure compensator 4 and feeds back to the LS port of the load-sensitive pump. The displacement of the load-sensitive pump is reduced according to the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of pressure compensator 4.

[0014] In a second aspect, a crane hydraulic system is provided, wherein the crane hydraulic system is equipped with the multi-way valve described in the first aspect.

[0015] Thirdly, a crane is provided, the crane being equipped with the crane hydraulic system described in the second aspect.

[0016] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: The present invention uses the pressure of each oil outlet of the telescopic link, the luffing link, and the hoisting link as feedback conditions to determine which relief valve in the hydraulic system feedback oil circuit is active, thereby limiting the pressure of the load feedback oil circuit; in the overflow condition, by limiting the pressure of the oil pump feedback oil circuit, the oil pump displacement is reduced, thereby avoiding the problem of a large amount of hydraulic oil overflowing into the oil tank through the relief valve, improving the energy efficiency of the hydraulic system while having the advantage of good compound action performance. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the principle of a multi-way valve provided in an embodiment of the present invention;

[0018] In the diagram: 101. Main relief valve; 102. Diverter valve; 103. Buffer valve; 104. Electro-proportional pilot valve 1; 105. Hydraulic directional valve 1; 106. Relief valve 1; 107. Hydraulic directional valve 2; 108. Relief valve 2; 109. Electro-proportional pilot valve 2; 110. Hydraulic directional valve 3; 111. Relief valve 3; 112. Hydraulic directional valve 4; 113. Relief valve 4; 114. Electro-proportional pilot valve 3; 115. Hydraulic directional valve 5; 116. Relief valve 5; 11 7. Shuttle Valve I; 118. Electro-proportional Pilot Valve IV; 119. Hydraulic Directional Control Valve VI; 120. Relief Valve VI; 121. Shuttle Valve II; 122. Pilot-operated Relief Valve; 123. Pressure Reducing Valve; 124. Electro-proportional Pilot Valve V; 125. Pressure Compensator I; 126. Electro-proportional Pilot Valve VI; 127. Pressure Compensator II; 128. Pressure Compensator III; 129. Electro-proportional Pilot Valve VII; 130. Pressure Compensator IV; 131. Electro-proportional Pilot Valve VIII; 132. Three-position four-way valve. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0020] Example 1

[0021] like Figure 1 As shown, a multi-way valve mainly includes: a telescopic coupling, a luffing coupling, and a hoisting coupling. The oil source for port P (P1 or P2, or P1+P2) comes from a load-sensitive pump. A main relief valve 101 is installed on the main line to prevent hydraulic system pressure overload, a flow divider valve 102 is used for flow diversion, and a buffer valve 103 is used to absorb impact pressure and prevent vibration when the hydraulic system experiences shocks. A pilot module is also integrated, where a pressure reducing valve 123 reduces the main line pressure to the pilot pressure range, providing pressure for pilot reversal; when the pressure reducing valve 123 pressure does not drop to the settable range, the pilot relief valve 122 overflows to provide safety protection.

[0022] The telescopic linkage includes: a telescopic directional valve, a pressure compensator 125 located downstream of the telescopic directional valve, and electro-proportional pilot valves 104 and 124 for controlling the switching of the telescopic directional valve. The control terminal of the hydraulically controlled directional valve 105 is connected to the working port A1 of the telescopic directional valve; the inlet of the hydraulically controlled directional valve 105 is connected to the LS oil circuit of the pressure compensator 125; and the outlet of the hydraulically controlled directional valve 105 is connected to the return port via a relief valve 106. The control terminal of the hydraulically controlled directional valve 107 is connected to the working port B1 of the telescopic directional valve; the inlet of the hydraulically controlled directional valve 107 is connected to the LS oil circuit of the pressure compensator 125; and the outlet of the hydraulically controlled directional valve 107 is connected to the return port via a relief valve 108. The LS oil circuit of the pressure compensator 125 is connected to the LS oil circuit of the multi-way valve via a check valve.

[0023] The oil source at port P (P1 or P2, or P1+P2) is connected to the telescopic valve. When the electro-proportional pilot valve 104 is energized and reversed, the pilot oil enters the valve stem spring chamber of the telescopic directional valve through the electro-proportional pilot valve 104, and the telescopic directional valve reverses. The high-pressure oil enters the actuator through the valve stem of the telescopic directional valve, the pressure compensator 125, and the working port B1 of the telescopic directional valve. At the same time, the high-pressure oil enters the control end of the hydraulic directional valve 107 from the working port B1 of the telescopic directional valve, and the hydraulic directional valve 107 reverses. When the LS pressure of the pressure compensator 125 exceeds the set pressure of the relief valve 108, the relief valve 108 relieves the pressure of the LS oil circuit of the pressure compensator 125 and feeds back to the LS port of the load-sensitive pump. Based on the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator 125, the displacement of the load-sensitive pump is reduced, and the oil pump flow is reduced to reduce energy loss during overload.

[0024] When the electro-proportional pilot valve 5124 is energized and reverses, pilot oil enters the valve stem spring chamber of the telescopic directional valve through the electro-proportional pilot valve 5124, causing the telescopic directional valve to reverse. High-pressure oil enters the actuator through the valve stem of the telescopic directional valve, pressure compensator 125, and the working port A1 of the telescopic directional valve. At the same time, high-pressure oil enters the control end of the hydraulic directional valve 105 from the working port A1 of the telescopic directional valve, causing the hydraulic directional valve 105 to reverse. When the LS pressure of the pressure compensator 125 exceeds the set pressure of the relief valve 106, the relief valve 106 relieves pressure on the LS oil circuit of the pressure compensator 125 and feeds back to the LS port of the load-sensitive pump. Based on the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator 125, the displacement of the load-sensitive pump is reduced, thereby reducing the oil pump flow and energy loss during overload.

[0025] The luffing control unit includes: a luffing directional valve, a pressure compensator 127 located downstream of the luffing directional valve, and electro-proportional pilot valves 109 and 126 for controlling the switching of the luffing directional valve; the control terminal of the hydraulic directional valve 110 is connected to the working port A2 of the luffing directional valve, the inlet of the hydraulic directional valve 110 is connected to the LS oil circuit of the pressure compensator 127, and the outlet of the hydraulic directional valve 110 is connected to the return port through the relief valve 111; the control terminal of the hydraulic directional valve 112 is connected to the working port B2 of the luffing directional valve, the inlet of the hydraulic directional valve 112 is connected to the LS oil circuit of the pressure compensator 127, and the outlet of the hydraulic directional valve 112 is connected to the return port through the relief valve 113. The LS oil circuit of the pressure compensator 127 is connected to the LS oil circuit of the multi-way valve through a check valve.

[0026] When the P-port oil source is connected to the luffing valve, and the electro-proportional pilot valve 2 109 is energized and reversed, the pilot oil enters the valve stem spring chamber of the luffing directional valve through the electro-proportional pilot valve 2 109, causing the luffing directional valve to reverse. The high-pressure oil enters the actuator through the valve stem of the luffing directional valve, the pressure compensator 2 127, and the working port B2 of the luffing directional valve. At the same time, the high-pressure oil enters the control end of the hydraulic directional valve 4 112 from the working port B2 of the luffing directional valve, causing the hydraulic directional valve 4 112 to reverse. When the LS pressure of the pressure compensator 2 127 exceeds the set pressure of the relief valve 4 113, the relief valve 4 113 relieves the pressure of the LS oil circuit of the pressure compensator 2 127 and feeds back to the LS port of the load-sensitive pump. Based on the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator 2 127, the displacement of the load-sensitive pump is reduced, thereby reducing the flow rate and energy loss during overload.

[0027] When the electro-proportional pilot valve 6 126 is energized and reverses, pilot oil enters the valve stem spring chamber of the luffing directional valve through the electro-proportional pilot valve 6 126, causing the luffing directional valve to reverse. High-pressure oil enters the actuator through the valve stem of the luffing directional valve, pressure compensator 2 127, and the working port A2 of the luffing directional valve. At the same time, high-pressure oil enters the control end of the hydraulic directional valve 3 110 from the working port A2 of the luffing directional valve, causing the hydraulic directional valve 3 110 to reverse. When the LS pressure of pressure compensator 2 127 exceeds the set pressure of relief valve 3 111, relief valve 3 111 depressurizes the LS oil circuit of pressure compensator 2 127 and feeds back to the LS port of the load-sensitive pump. Based on the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of pressure compensator 2 127, the displacement of the load-sensitive pump is reduced, thereby reducing the flow rate and energy loss during overload.

[0028] The hoisting unit includes: a main hoisting directional valve, a pressure compensator 3128 located downstream of the main hoisting directional valve, an electro-proportional pilot valve 3114 and an electro-proportional pilot valve 7129 for controlling the switching of the main hoisting directional valve, an auxiliary hoisting directional valve, a pressure compensator 4130 located downstream of the auxiliary hoisting directional valve, and an electro-proportional pilot valve 4118 and an electro-proportional pilot valve 8131 for controlling the switching of the auxiliary hoisting directional valve. The control terminal of hydraulic directional valve 5115 is connected to the outlet of shuttle valve 117. Hydraulic directional valve 5115 controls the low-pressure port pressure of the main and auxiliary winches. When the main and auxiliary winches operate simultaneously, to prevent the high-pressure port pressure from flowing away through overflow valve 5116 and thus failing to build up pressure, the pressure from the working ports B3 and B4 of the main and auxiliary winch directional valves is introduced into the spring chamber of hydraulic directional valve 5115 for logical limitation. The inlet of shuttle valve 117 is connected to the working port A3 of the main winch directional valve. The inlet of hydraulic directional valve 5115 is connected to the LS oil circuit of pressure compensator 3128 and the LS oil circuit of pressure compensator 4130. The outlet of the main winch is connected to the return port via relief valve 5 116; the hydraulic directional valve 6 119 is the high-pressure side directional valve for the winch; the outlet of shuttle valve 2 121 is connected to the control end of hydraulic directional valve 6 119 and the spring chamber of hydraulic directional valve 5 115; the inlet of shuttle valve 2 121 is connected to the working port B3 of the main winch directional valve; the inlet of hydraulic directional valve 6 119 is connected to the LS oil circuit of pressure compensator 3 128 and the LS oil circuit of pressure compensator 4 130; the outlet of hydraulic directional valve 6 119 is connected to the return port via relief valve 6 120; the working port A4 of the auxiliary winch directional valve is connected to the inlet 2 of shuttle valve 1 117; the working port B4 of the auxiliary winch directional valve is connected to the inlet 2 of shuttle valve 2 121. The LS oil circuits of pressure compensator 3 128 and pressure compensator 4 130 are respectively connected to the LS oil circuit of the multi-way valve via check valves. The LS oil circuit of pressure compensator 3 128 is connected to the inlet of hydraulic directional valve 5 115 and the inlet of hydraulic directional valve 6 119 via a check valve. The LS oil circuit of pressure compensator 4 130 is connected to the inlet of hydraulic directional valve 5 115 and the inlet of hydraulic directional valve 6 119 via a check valve.

[0029] The main hoist and auxiliary hoist share the same relief valve. Relief valve 5 116 is the low-pressure side relief valve for hoisting, and relief valve 6 120 is the high-pressure side relief valve for hoisting. The P port oil source is connected to the hoisting system (main hoist + auxiliary hoist).

[0030] When the electro-proportional pilot valve 314 is energized and reverses, pilot oil enters the valve stem spring chamber of the main winch directional valve through the electro-proportional pilot valve 314. The main winch directional valve reverses, and high-pressure oil enters the actuator through the valve stem of the main winch directional valve, pressure compensator 3128, and the working port A3 of the main winch directional valve. At the same time, high-pressure oil enters the inlet of shuttle valve 117 from the working port A3 of the main winch directional valve, and enters the control end of hydraulic directional valve 515 from the outlet of shuttle valve 117, pushing hydraulic directional valve 5115 to reverse. When the LS pressure of pressure compensator 3128 exceeds the set pressure of relief valve 516, relief valve 5116 relieves pressure on the LS oil circuit of pressure compensator 3128 and feeds back to the LS port of the load-sensitive pump. Based on the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of pressure compensator 3128, the displacement of the load-sensitive pump is reduced, reducing the flow rate and energy loss during overload.

[0031] When the electro-proportional pilot valve 4 118 is energized and reverses, pilot oil enters the valve stem spring chamber of the auxiliary winch directional valve through the electro-proportional pilot valve 4 118. The auxiliary winch directional valve reverses, and high-pressure oil enters the actuator through the valve stem of the auxiliary winch directional valve, pressure compensator 4 130, and working port A4 of the auxiliary winch directional valve. At the same time, high-pressure oil enters the inlet 2 of shuttle valve 1 117 from the working port A4 of the auxiliary winch directional valve, and enters the control end of hydraulic directional valve 5 115 from the outlet of shuttle valve 1 117, pushing hydraulic directional valve 5 115 to reverse. When the LS pressure of pressure compensator 4 130 exceeds the set pressure of relief valve 5 116, relief valve 5 116 relieves pressure on the LS oil circuit of pressure compensator 4 130 and feeds back to the LS port of the load-sensitive pump. Based on the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of pressure compensator 4 130, the displacement of the load-sensitive pump is reduced, reducing the flow rate and energy loss during overload.

[0032] When the electro-proportional pilot valve 7 129 is energized and reverses, pilot oil enters the valve stem spring chamber of the main winch directional valve through the electro-proportional pilot valve 7 129. The main winch directional valve reverses, and high-pressure oil enters the actuator through the valve stem of the main winch directional valve, pressure compensator 3 128, and working port B3 of the main winch directional valve. At the same time, high-pressure oil enters the inlet of shuttle valve 2 121 from working port B3 of the main winch directional valve, and enters the control end of hydraulic directional valve 6 119 from the outlet of shuttle valve 2 121, pushing hydraulic directional valve 6 119 to reverse. When the LS pressure of pressure compensator 3 128 exceeds the set pressure of relief valve 6 120, relief valve 6 120 relieves pressure on the LS oil circuit of pressure compensator 3 128 and feeds back to the LS port of the load-sensitive pump. Based on the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of pressure compensator 3 128, the displacement of the load-sensitive pump is reduced, reducing the flow rate and energy loss during overload.

[0033] When the electro-proportional pilot valve 8131 is energized and reverses, pilot oil enters the valve stem spring chamber of the auxiliary winch directional valve through the electro-proportional pilot valve 8131. The auxiliary winch directional valve reverses, and high-pressure oil enters the actuator through the valve stem of the auxiliary winch directional valve, the pressure compensator 4130, and the working port B4 of the auxiliary winch directional valve. At the same time, high-pressure oil enters the inlet 2 of shuttle valve 2121 from the working port B4 of the auxiliary winch directional valve, and enters the control end of the hydraulic directional valve 619 from the outlet of shuttle valve 2121, pushing the hydraulic directional valve 619 to reverse. When the LS pressure of the pressure compensator 4130 exceeds the set pressure of the relief valve 6120, the relief valve 6120 relieves the pressure of the LS oil circuit of the pressure compensator 4130 and feeds back to the LS port of the load-sensitive pump. Based on the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator 4130, the displacement of the load-sensitive pump is reduced, and the flow rate is reduced to reduce energy loss during overload. The main roll lifting and the auxiliary roll lifting share the same relief valve. During combined operation, the oil in the main roll or auxiliary roll oil circuit is selected by the shuttle valve. The oil in the main roll lifting or auxiliary roll lifting circuit with higher oil pressure is selected.

[0034] In this invention, the telescopic directional valve, the luffing directional valve, the main winch directional valve, and the auxiliary winch directional valve are all three-position four-way valves 132 with the same structure.

[0035] To address the issues of poor energy efficiency in post-valve compensation multi-way valves and poor composite action in pre-valve compensation multi-way valves, this invention innovates from a fundamental principle. It uses the pressure at each outlet of the multi-way valve as a feedback condition to determine which relief valve (limiting the maximum pressure in each direction of movement) in the hydraulic system's feedback oil circuit is activated, thus limiting the pressure in the load feedback oil circuit. During relief operation, the pressure in the four main systems and eight directions of motion of the vehicle is limited in the oil pump feedback oil circuit to reduce the pump displacement, thereby preventing a large amount of oil from flowing back to the oil tank through the relief valve. This improves the energy efficiency of the hydraulic system while maintaining good composite action performance. For example, during winch lowering, the pressure at the winch lowering port of the multi-way valve is used as feedback oil to control the opening of the two-position two-way valve. If the overflow pressure value for winch lowering is reached, the relief valve opens, limiting the pressure at the hydraulic system's feedback port, thereby limiting the pump displacement and preventing a large amount of oil from flowing back to the oil tank during winch lowering.

[0036] This invention integrates the pilot module and pilot oil circuit within a multi-way valve, reducing assembly piping and thus lowering costs and failure rates. The hydraulically controlled directional valves between the various outlets of the multi-way system are interlocked, allowing different pressure levels to be used between ports A and B of each port, meeting usage requirements while enhancing safety.

[0037] This invention interlocks the outlet circuits of each section of a multi-way valve by installing a hydraulically controlled directional valve and a relief valve at the outlet of a three-position four-way directional valve. Specifically, when each section of the multi-way valve is operating, only one hydraulically controlled directional valve at port A or port B is active, ensuring that at most one relief valve corresponding to the hydraulically controlled directional valve is active. During combined operations, the high-pressure isolation of the check valve allows the pressure feedback from the high-pressure section to adjust the load-sensitive pump displacement. The oil from the outlet of each pressure compensator passes through the hydraulically controlled directional valve and then reaches the relief valve.

[0038] Example 2

[0039] Based on the multi-way valve described in Embodiment 1, this embodiment provides a crane hydraulic system, wherein the crane hydraulic system is equipped with the multi-way valve described in Embodiment 1.

[0040] Example 3

[0041] Based on the crane hydraulic system described in Embodiment 2, this embodiment provides a crane equipped with the crane hydraulic system described in Embodiment 2.

[0042] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A multi-way valve characterized by, Comprise: Telescopic joint, amplitude joint and winch joint; The telescopic joint comprises: a telescopic reversing valve, a pressure compensator one (125) arranged behind the telescopic reversing valve, an electric proportional pilot valve one (104) and an electric proportional pilot valve five (124) for controlling the reversing of the telescopic reversing valve; a control end of a hydraulic control reversing valve one (105) is connected to a working port A1 of the telescopic reversing valve, an inlet of the hydraulic control reversing valve one (105) is connected to an LS oil way of the pressure compensator one (125), and an outlet of the hydraulic control reversing valve one (105) is connected to a return oil port through an overflow valve one (106); a control end of a hydraulic control reversing valve two (107) is connected to a working port B1 of the telescopic reversing valve, an inlet of the hydraulic control reversing valve two (107) is connected to the LS oil way of the pressure compensator one (125), and an outlet of the hydraulic control reversing valve two (107) is connected to the return oil port through an overflow valve two (108); The amplitude joint comprises: an amplitude reversing valve, a pressure compensator two (127) arranged behind the amplitude reversing valve, an electric proportional pilot valve two (109) and an electric proportional pilot valve six (126) for controlling the reversing of the amplitude reversing valve; a control end of a hydraulic control reversing valve three (110) is connected to a working port A2 of the amplitude reversing valve, an inlet of the hydraulic control reversing valve three (110) is connected to an LS oil way of the pressure compensator two (127), and an outlet of the hydraulic control reversing valve three (110) is connected to a return oil port through an overflow valve three (111); a control end of a hydraulic control reversing valve four (112) is connected to a working port B2 of the amplitude reversing valve, an inlet of the hydraulic control reversing valve four (112) is connected to the LS oil way of the pressure compensator two (127), and an outlet of the hydraulic control reversing valve four (112) is connected to the return oil port through an overflow valve four (113); The winch joint comprises: A main winch reversing valve, a pressure compensator three (128) arranged behind the main winch reversing valve, an electric proportional pilot valve three (114) and an electric proportional pilot valve seven (129) for controlling the reversing of the main winch reversing valve; A sub winch reversing valve, a pressure compensator four (130) arranged behind the sub winch reversing valve, an electric proportional pilot valve four (118) and an electric proportional pilot valve eight (131) for controlling the reversing of the sub winch reversing valve; The control end of the hydraulic control reversing valve five (115) is connected with the outlet of the shuttle valve one (117), the hydraulic control reversing valve five (115) is used for controlling the main and auxiliary winch low-pressure port pressure, when the main and auxiliary winches are simultaneously operated, in order to prevent the pressure of the high-pressure port from flowing away from the overflow valve five (116) and thus the pressure from not being established, the pressure of the working port B3 of the main winch reversing valve and the working port B4 of the auxiliary winch reversing valve is introduced into the spring cavity of the hydraulic control reversing valve five (115) to perform logical restriction, the inlet one of the shuttle valve one (117) is connected with the working port A3 of the main winch reversing valve, the inlet of the hydraulic control reversing valve five (115) is connected with the LS oil way of the pressure compensator three (128) and the LS oil way of the pressure compensator four (130), and the outlet of the hydraulic control reversing valve five (115) is connected with the return oil port through the overflow valve five (116); the hydraulic control reversing valve six (119) is a winch high-pressure side reversing valve, the outlet of the shuttle valve two (121) is connected with the control end of the hydraulic control reversing valve six (119) and the spring cavity of the hydraulic control reversing valve five (115), the inlet one of the shuttle valve two (121) is connected with the working port B3 of the main winch reversing valve, the inlet of the hydraulic control reversing valve six (119) is connected with the LS oil way of the pressure compensator three (128) and the LS oil way of the pressure compensator four (130), and the outlet of the hydraulic control reversing valve six (119) is connected with the return oil port through the overflow valve six (120); the working port A4 of the auxiliary winch reversing valve is connected with the inlet two of the shuttle valve one (117), and the working port B4 of the auxiliary winch reversing valve is connected with the inlet two of the shuttle valve two (121).

2. The multi-way valve of claim 1, wherein, the LS oil ways of the pressure compensator one (125), the pressure compensator two (127), the pressure compensator three (128) and the pressure compensator four (130) are respectively connected with the LS oil way of the multi-way valve through the one-way valves; the LS oil way of the pressure compensator three (128) is connected with the inlet of the hydraulic control reversing valve five (115) and the inlet of the hydraulic control reversing valve six (119) through the one-way valve; the LS oil way of the pressure compensator four (130) is connected with the inlet of the hydraulic control reversing valve five (115) and the inlet of the hydraulic control reversing valve six (119) through the one-way valve.

3. The multi-way valve of claim 2, wherein, when the electric proportional pilot valve one (104) is powered on and reversed, the pilot oil enters the valve rod spring cavity of the telescopic reversing valve through the electric proportional pilot valve one (104), the telescopic reversing valve is reversed, the high-pressure oil enters the actuator through the valve rod of the telescopic reversing valve, the pressure compensator one (125) and the working port B1 of the telescopic reversing valve, at the same time, the high-pressure oil enters the control end of the hydraulic control reversing valve two (107) from the working port B1 of the telescopic reversing valve, and the hydraulic control reversing valve two (107) is reversed; when the LS pressure of the pressure compensator one (125) exceeds the set pressure of the overflow valve two (108), the overflow valve two (108) bleeds the LS oil way of the pressure compensator one (125) and feeds back to the LS port of the load-sensitive pump, and the displacement of the load-sensitive pump is reduced according to the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator one (125).

4. The multi-way valve of claim 2, wherein, When the electric proportional pilot valve five (124) is energized, the pilot oil enters the spool spring chamber of the telescopic directional valve through the electric proportional pilot valve five (124), the telescopic directional valve is reversed, the high pressure oil enters the actuator through the spool of the telescopic directional valve, the pressure compensator one (125), and the working port Al of the telescopic directional valve, at the same time, the high pressure oil enters the control end of the hydraulic control directional valve one (105) from the working port Al of the telescopic directional valve, the hydraulic control directional valve one (105) is reversed; when the LS pressure of the pressure compensator one (125) exceeds the set pressure of the overflow valve one (106), the overflow valve one (106) bleeds the LS oil circuit of the pressure compensator one (125) and feeds back to the LS port of the load sensing pump, and the displacement of the load sensing pump is reduced according to the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator one (125).

5. The multi-way valve of claim 2, wherein, When the electric proportional pilot valve two (109) is energized, the pilot oil enters the spool spring chamber of the luffing directional valve through the electric proportional pilot valve two (109), the luffing directional valve is reversed, the high pressure oil enters the actuator through the spool of the luffing directional valve, the pressure compensator two (127), and the working port B2 of the luffing directional valve, at the same time, the high pressure oil enters the control end of the hydraulic control directional valve four (112) from the working port B2 of the luffing directional valve, the hydraulic control directional valve four (112) is reversed; when the LS pressure of the pressure compensator two (127) exceeds the set pressure of the overflow valve four (113), the overflow valve four (113) bleeds the LS oil circuit of the pressure compensator two (127) and feeds back to the LS port of the load sensing pump, and the displacement of the load sensing pump is reduced according to the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator two (127).

6. The multi-way valve of claim 2, wherein, When the electric proportional pilot valve six (126) is energized, the pilot oil enters the spool spring chamber of the luffing directional valve through the electric proportional pilot valve six (126), the luffing directional valve is reversed, the high pressure oil enters the actuator through the spool of the luffing directional valve, the pressure compensator two (127), and the working port A2 of the luffing directional valve, at the same time, the high pressure oil enters the control end of the hydraulic control directional valve three (110) from the working port A2 of the luffing directional valve, the hydraulic control directional valve three (110) is reversed; when the LS pressure of the pressure compensator two (127) exceeds the set pressure of the overflow valve three (111), the overflow valve three (111) bleeds the LS oil circuit of the pressure compensator two (127) and feeds back to the LS port of the load sensing pump, and the displacement of the load sensing pump is reduced according to the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator two (127).

7. The multi-way valve of claim 2, wherein, When the electric proportional pilot valve three (114) is energized, the pilot oil enters the valve rod spring chamber of the main winch directional valve through the electric proportional pilot valve three (114), the main winch directional valve is reversed, the high pressure oil enters the actuator through the valve rod of the main winch directional valve, the pressure compensator three (128), the working port A3 of the main winch directional valve, at the same time, the high pressure oil enters the inlet one of the shuttle valve one (117) from the working port A3 of the main winch directional valve, and enters the control end of the hydraulic control directional valve five (115) from the outlet of the shuttle valve one (117), and drives the hydraulic control directional valve five (115) to reverse; when the LS pressure of the pressure compensator three (128) exceeds the set pressure of the overflow valve five (116), the overflow valve five (116) is de-energized to the LS oil circuit of the pressure compensator three (128), and is fed back to the LS port of the load sensing pump, and the displacement of the load sensing pump is reduced according to the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator three (128); When the electric proportional pilot valve four (118) is energized, the pilot oil enters the valve rod spring chamber of the auxiliary winch directional valve through the electric proportional pilot valve four (118), the auxiliary winch directional valve is reversed, the high pressure oil enters the actuator through the valve rod of the auxiliary winch directional valve, the pressure compensator four (130), the working port A4 of the auxiliary winch directional valve, at the same time, the high pressure oil enters the inlet two of the shuttle valve one (117) from the working port A4 of the auxiliary winch directional valve, and enters the control end of the hydraulic control directional valve five (115) from the outlet of the shuttle valve one (117), and drives the hydraulic control directional valve five (115) to reverse; when the LS pressure of the pressure compensator four (130) exceeds the set pressure of the overflow valve five (116), the overflow valve five (116) is de-energized to the LS oil circuit of the pressure compensator four (130), and is fed back to the LS port of the load sensing pump, and the displacement of the load sensing pump is reduced according to the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator four (130).

8. The multi-way valve of claim 2, wherein, When the electric proportional pilot valve seven (129) is energized, the pilot oil enters the valve rod spring chamber of the main winch directional valve through the electric proportional pilot valve seven (129), the main winch directional valve is reversed, the high pressure oil enters the actuator through the valve rod of the main winch directional valve, the pressure compensator three (128), the working port B3 of the main winch directional valve, at the same time, the high pressure oil enters the inlet one of the shuttle valve two (121) from the working port B3 of the main winch directional valve, and enters the control end of the hydraulic control directional valve six (119) from the outlet of the shuttle valve two (121), and drives the hydraulic control directional valve six (119) to reverse; when the LS pressure of the pressure compensator three (128) exceeds the set pressure of the overflow valve six (120), the overflow valve six (120) is de-energized to the LS oil circuit of the pressure compensator three (128), and is fed back to the LS port of the load sensing pump, and the displacement of the load sensing pump is reduced according to the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator three (128). When the electric proportional pilot valve eight (131) is powered, the pilot oil enters the valve rod spring cavity of the auxiliary winch reversing valve through the electric proportional pilot valve eight (131), the auxiliary winch reversing valve reverses, the high pressure oil enters the actuator through the valve rod of the auxiliary winch reversing valve, the pressure compensator four (130), the working port B4 of the auxiliary winch reversing valve, at the same time, the high pressure oil enters the inlet two of the shuttle valve two (121) from the working port B4 of the auxiliary winch reversing valve, and enters the control end of the hydraulic control reversing valve six (119) from the outlet of the shuttle valve two (121), and pushes the hydraulic control reversing valve six (119) to reverse; when the LS pressure of the pressure compensator four (130) exceeds the set pressure of the overflow valve six (120), the overflow valve six (120) releases the LS oil way of the pressure compensator four (130), and feeds back to the LS port of the load sensing pump, and the displacement of the load sensing pump is reduced according to the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator four (130).

9. A crane hydraulic system characterized by The crane hydraulic system is configured with the multi-way valve of any one of claims 1-8.

10. A crane, characterized in that The crane is configured with the crane hydraulic system of claim 9.

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