Multi-way valve, crane hydraulic system and crane

Abstract

The invention discloses a multi-way valve, a crane hydraulic system and a crane. The multi-way valve comprises a telescopic unit, a variable amplitude unit and a winch unit. Each unit comprises a reversing valve, a pressure compensator, an electric proportional pilot valve and an overflow valve; the control end of the hydraulic control reversing valve is connected with a working port of the reversing valve, an inlet of the hydraulic control reversing valve is connected with an LS oil way of the pressure compensator, and an outlet of the hydraulic control reversing valve is connected with an oil return port through an overflow valve. The winch unit comprises a main winch and an auxiliary winch, and the main winch and the auxiliary winch share an overflow valve through a shuttle valve. According to the invention, the pressure of each oil outlet of the multi-way valve is used as a feedback condition to determine which overflow valve on a feedback oil way of a hydraulic system works according to innovation from a bottom-layer principle, so that the effect of limiting the pressure of a load feedback oil way is achieved. Under the overflow working condition, the upper vehicle reduces the displacement of the oil pump by limiting the pressure of the oil pump feedback oil way, so that the problem that a large amount of oil flows to the oil tank through the overflow valve is avoided, the energy-saving performance of the hydraulic system is improved, and meanwhile, the hydraulic system has the advantage of good composite action performance.

Description

Technical Field

[0001] The invention belongs to the technical field of engineering machinery, and in particular relates to a multi-way valve, a crane hydraulic system and a crane. Background Art

[0002] As the core component of the hydraulic system of wheeled cranes, the multi-way valve can realize the switching of multiple actions on the vehicle. By controlling the displacement of each valve stem of the multi-way valve, the flow can flow to different actuators; each oil circuit of the multi-way valve has a corresponding safety valve to control the maximum pressure of the corresponding oil circuit. Since the multi-way valve is the core component of the hydraulic system, safety, economy, control and other characteristics are closely related to it.

[0003] The multi-way valve with post-main valve compensation has certain advantages in compound action, but if the overflow pressure is reached, the system energy loss is large and there is a disadvantage of poor energy saving. Summary of the invention

[0004] In order to solve the deficiencies in the prior art, the present invention provides a multi-way valve, a crane hydraulic system and a crane, which can effectively improve the energy saving of the post-valve compensation multi-way valve, thereby meeting the dual requirements of the whole machine for compound action and energy saving.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: In the first aspect, a multi-way valve is provided, including: a telescopic link, a variable amplitude link and a winch link; the telescopic link includes: a telescopic reversing valve, a pressure compensator 1 arranged behind the telescopic reversing valve, an electric proportional pilot valve 1 and an electric proportional pilot valve 5 for controlling the reversing of the telescopic reversing valve; the control end of the hydraulically controlled reversing valve 1 is connected to the working port A1 of the telescopic reversing valve, the inlet of the hydraulically controlled reversing valve 1 is connected to the LS oil circuit of the pressure compensator 1, and the outlet of the hydraulically controlled reversing valve 1 is connected to the return oil port through the overflow valve 1; the control end of the hydraulically controlled reversing valve 2 is connected to the working port B1 of the telescopic reversing valve, the inlet of the hydraulically controlled reversing valve 2 is connected to the LS oil circuit of the pressure compensator 1, and the outlet of the hydraulically controlled reversing valve 2 is connected to the return oil port through the overflow valve 2; the variable The amplitude connection includes: a variable amplitude reversing valve, a pressure compensator 2 arranged behind the variable amplitude reversing valve, an electric proportional pilot valve 2 and an electric proportional pilot valve 6 for controlling the reversing of the variable amplitude reversing valve; the control end of the hydraulic control reversing valve 3 is connected to the working port A2 of the variable amplitude reversing valve, the inlet of the hydraulic control reversing valve 3 is connected to the LS oil circuit of the pressure compensator 2, and the outlet of the hydraulic control reversing valve 3 is connected to the return oil port through the relief valve 3; the control end of the hydraulic control reversing valve 4 is connected to the working port B2 of the variable amplitude reversing valve, the inlet of the hydraulic control reversing valve 4 is connected to the LS oil circuit of the pressure compensator 2, and the outlet of the hydraulic control reversing valve 4 is connected to the return oil port through the relief valve 4; the winch connection includes: a main winch reversing valve, a pressure compensator 3 arranged behind the main winch reversing valve, a The electric proportional pilot valve three and the electric proportional pilot valve seven control the reversing direction of the main winch reversing valve; the auxiliary winch reversing valve, the pressure compensator four arranged behind the auxiliary winch reversing valve, the electric proportional pilot valve four and the electric proportional pilot valve eight for controlling the reversing direction of the auxiliary winch reversing valve; the control end of the hydraulic control reversing valve five is connected to the outlet of the shuttle valve one, the hydraulic control reversing valve five is used to control the pressure of the low-pressure port of the main and auxiliary winch joints. When the main and auxiliary winch joints are actuated at the same time, in order to prevent the pressure of the high-pressure port from flowing away from the relief valve five and thus failing to establish pressure, the pressure of the working port B3 of the main winch reversing valve and the working port B4 of the auxiliary winch reversing valve are introduced into the spring chamber of the hydraulic control reversing valve five for logical restriction, and the inlet one of the shuttle valve one is connected to the working port of the main winch reversing valve Port A3, the inlet of the hydraulically controlled reversing valve five is connected to the LS oil circuit of the pressure compensator three and the LS oil circuit of the pressure compensator four, and the outlet of the hydraulically controlled reversing valve five is connected to the oil return port through the overflow valve five; the hydraulically controlled reversing valve six is ​​the reversing valve on the high-pressure side of the winch, the outlet of the shuttle valve two is connected to the control end of the hydraulically controlled reversing valve six and the spring chamber of the hydraulically controlled reversing valve five, the inlet one of the shuttle valve two is connected to the working port B3 of the main winch reversing valve, the inlet of the hydraulically controlled reversing valve six is ​​connected to the LS oil circuit of the pressure compensator three and the LS oil circuit of the pressure compensator four, and the outlet of the hydraulically controlled reversing valve six is ​​connected to the oil return port through the overflow valve six; the working port A4 of the auxiliary winch reversing valve is connected to the inlet two of the shuttle valve one, and the working port B4 of the auxiliary winch reversing valve is connected to the inlet two of the shuttle valve two.

[0006] Furthermore, the LS oil circuits of pressure compensator one, pressure compensator two, pressure compensator three and pressure compensator four are respectively connected to the LS oil circuit of the multi-way valve through a one-way valve; the LS oil circuit of pressure compensator three is connected to the inlet of hydraulically controlled reversing valve five and the inlet of hydraulically controlled reversing valve six through a one-way valve; the LS oil circuit of pressure compensator four is connected to the inlet of hydraulically controlled reversing valve five and the inlet of hydraulically controlled reversing valve six through a one-way valve.

[0007] Furthermore, when the electric proportional pilot valve 1 is electrically switched, the pilot oil enters the valve stem spring chamber of the telescopic reversing valve through the electric proportional pilot valve 1, the telescopic reversing valve is switched, and the high-pressure oil enters the actuator through the valve stem of the telescopic reversing valve, the pressure compensator 1, and the working port B1 of the telescopic reversing valve. At the same time, the high-pressure oil enters the control end of the hydraulically controlled reversing valve 2 from the working port B1 of the telescopic reversing valve, and the hydraulically controlled reversing valve 2 is switched; when the LS pressure of the pressure compensator 1 exceeds the set pressure of the relief valve 2, the relief valve 2 relieves the pressure on the LS oil circuit of the pressure compensator 1 and feeds back to the LS port of the load-sensitive pump, thereby reducing the displacement of the load-sensitive pump according to the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator 1.

[0008] Furthermore, when the electric proportional pilot valve five is electrically switched, the pilot oil enters the valve stem spring chamber of the telescopic reversing valve through the electric proportional pilot valve five, the telescopic reversing valve is switched, and the high-pressure oil enters the actuator through the valve stem of the telescopic reversing valve, the pressure compensator one, and the working port A1 of the telescopic reversing valve. At the same time, the high-pressure oil enters the control end of the hydraulically controlled reversing valve one from the working port A1 of the telescopic reversing valve, and the hydraulically controlled reversing valve one is switched; when the LS pressure of the pressure compensator one exceeds the set pressure of the relief valve one, the relief valve one releases the pressure on the LS oil circuit of the pressure compensator one and feeds back to the LS port of the load-sensitive pump, thereby reducing the displacement of the load-sensitive pump according to the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator one.

[0009] Furthermore, when the electric proportional pilot valve 2 is electrically switched, the pilot oil enters the valve stem spring chamber of the variable amplitude reversing valve through the electric proportional pilot valve 2, the variable amplitude reversing valve is switched, and the high-pressure oil enters the actuator through the valve stem of the variable amplitude reversing valve, the pressure compensator 2, and the working port B2 of the variable amplitude reversing valve. At the same time, the high-pressure oil enters the control end of the hydraulically controlled reversing valve 4 from the working port B2 of the variable amplitude reversing valve, and the hydraulically controlled reversing valve 4 is switched; when the LS pressure of the pressure compensator 2 exceeds the set pressure of the relief valve 4, the relief valve 4 relieves the pressure on the LS oil circuit of the pressure compensator 2 and feeds back to the LS port of the load-sensitive pump, thereby reducing the displacement of the load-sensitive pump according to the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator 2.

[0010] Furthermore, when the electric proportional pilot valve six is ​​electrically switched, the pilot oil enters the valve stem spring chamber of the variable amplitude reversing valve through the electric proportional pilot valve six, the variable amplitude reversing valve is switched, and the high-pressure oil enters the actuator through the valve stem of the variable amplitude reversing valve, the pressure compensator two, and the working port A2 of the variable amplitude reversing valve. At the same time, the high-pressure oil enters the control end of the hydraulically controlled reversing valve three from the working port A2 of the variable amplitude reversing valve, and the hydraulically controlled reversing valve three is switched; when the LS pressure of the pressure compensator two exceeds the set pressure of the relief valve three, the relief valve three relieves the pressure on the LS oil circuit of the pressure compensator two and feeds back to the LS port of the load-sensitive pump, and reduces the displacement of the load-sensitive pump according to the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator two.

[0011] Furthermore, when the electric proportional pilot valve three is electrically switched, the pilot oil enters the valve stem spring chamber of the main winch reversing valve through the electric proportional pilot valve three, the main winch reversing valve is switched, and the high-pressure oil enters the actuator through the valve stem of the main winch reversing valve, the pressure compensator three, and the working port A3 of the main winch reversing valve. At the same time, the high-pressure oil enters the inlet one of the shuttle valve one from the working port A3 of the main winch reversing valve, and enters the control end of the hydraulic control reversing valve five from the outlet of the shuttle valve one, pushing the hydraulic control reversing valve five to switch; when the LS pressure of the pressure compensator three exceeds the set pressure of the relief valve five, the relief valve five relieves the pressure on the LS oil circuit of the pressure compensator three, and feeds back to the LS port of the load-sensitive pump, and reduces the pressure of the load-sensitive pump according to the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator three. Displacement; when the electric proportional pilot valve four is electrically reversed, the pilot oil enters the valve stem spring chamber of the auxiliary winch reversing valve through the electric proportional pilot valve four, the auxiliary winch reversing valve is reversed, and the high-pressure oil enters the actuator through the valve stem of the auxiliary winch reversing valve, the pressure compensator four, and the working port A4 of the auxiliary winch reversing valve. At the same time, the high-pressure oil enters the inlet two of the shuttle valve one from the working port A4 of the auxiliary winch reversing valve, and enters the control end of the hydraulic control reversing valve five from the outlet of the shuttle valve one, pushing the hydraulic control reversing valve five to reverse; when the LS pressure of the pressure compensator four exceeds the set pressure of the relief valve five, the relief valve five relieves the pressure on the LS oil circuit of the pressure compensator four and feeds back to the LS port of the load-sensitive pump, and reduces the displacement of the load-sensitive pump according to the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator four.

[0012] Furthermore, when the electric proportional pilot valve seven is electrically switched, the pilot oil enters the valve stem spring chamber of the main winch reversing valve through the electric proportional pilot valve seven, the main winch reversing valve is switched, and the high-pressure oil enters the actuator through the valve stem of the main winch reversing valve, the pressure compensator three, and the working port B3 of the main winch reversing valve. At the same time, the high-pressure oil enters the inlet one of the shuttle valve two from the working port B3 of the main winch reversing valve, and enters the control end of the hydraulic control reversing valve six from the outlet of the shuttle valve two, pushing the hydraulic control reversing valve six to switch; when the LS pressure of the pressure compensator three exceeds the set pressure of the relief valve six, the relief valve six relieves the pressure on the LS oil circuit of the pressure compensator three, and feeds back to the LS port of the load-sensitive pump, reducing the pressure of the load-sensitive pump according to the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator three. Displacement; when the electric proportional pilot valve eight is electrically reversed, the pilot oil enters the valve stem spring chamber of the auxiliary winch reversing valve through the electric proportional pilot valve eight, the auxiliary winch reversing valve is reversed, and the high-pressure oil enters the actuator through the valve stem of the auxiliary winch reversing valve, the pressure compensator four, and 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 from the working port B4 of the auxiliary winch reversing valve, and enters the control end of the hydraulic control reversing valve six from the outlet of the shuttle valve two, pushing the hydraulic control reversing valve six to reverse; when the LS pressure of the pressure compensator four exceeds the set pressure of the relief valve six, the relief valve six relieves the pressure on the LS oil circuit of the pressure compensator four and feeds back to the LS port of the load-sensitive pump, and reduces the displacement of the load-sensitive pump according to the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator four.

[0013] 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.

[0014] According to a third aspect, a crane is provided, wherein the crane is equipped with the crane hydraulic system according to the second aspect.

[0015] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: the present invention uses the pressure of the oil outlets of the telescopic link, the luffing link and the winch link as feedback conditions to determine which overflow valve on the hydraulic system feedback oil circuit is effective, thereby playing a role in limiting the load feedback oil circuit pressure; in the overflow condition, the oil pump displacement is reduced by limiting the pressure of the oil pump feedback oil circuit, thereby avoiding the problem of a large amount of hydraulic oil overflowing into the oil tank through the overflow valve, thereby improving the energy saving of the hydraulic system and having the advantage of good compound action performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 1 is a schematic diagram of the principle of a multi-way valve provided by an embodiment of the present invention; In the figure: 101, main relief valve; 102, diverter valve; 103, buffer valve; 104, electric proportional pilot valve 1; 105, hydraulic control reversing valve 1; 106, relief valve 1; 107, hydraulic control reversing valve 2; 108, relief valve 2; 109, electric proportional pilot valve 2; 110, hydraulic control reversing valve 3; 111, relief valve 3; 112, hydraulic control reversing valve 4; 113, relief valve 4; 114, electric proportional pilot valve 3; 115, hydraulic control reversing valve 5; 116, relief valve 5; 11 7. Shuttle valve one; 118. Electric proportional pilot valve four; 119. Hydraulic controlled reversing valve six; 120. Overflow valve six; 121. Shuttle valve two; 122. Pilot overflow valve; 123. Pressure reducing valve; 124. Electric proportional pilot valve five; 125. Pressure compensator one; 126. Electric proportional pilot valve six; 127. Pressure compensator two; 128. Pressure compensator three; 129. Electric proportional pilot valve seven; 130. Pressure compensator four; 131. Electric proportional pilot valve eight; 132. Three-position four-way valve. DETAILED DESCRIPTION

[0017] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0018] Embodiment 1 like Figure 1 As shown, a multi-way valve mainly includes: telescopic joint, variable amplitude joint and winch joint. The oil source of the P (P1 or P2, or P1+P2) port comes from a load-sensitive pump. A main relief valve 101 is provided on the main line to prevent the hydraulic system from overloading pressure, a diverter valve 102 is used for diversion, and a buffer valve 103 is used to absorb the impact pressure and prevent shaking when the hydraulic system is impacted. A pilot module is integrated, in which the pressure reducing valve 123 reduces the main line pressure to the available range of the pilot pressure to provide pressure for the pilot reversing; when the pressure of the pressure reducing valve 123 does not drop to the settable range, the pilot relief valve 122 overflows to play a safety protection role.

[0019] The telescopic reversing valve includes: a telescopic reversing valve, a pressure compensator 125 arranged behind the telescopic reversing valve, an electric proportional pilot valve 104 and an electric proportional pilot valve 5 124 for controlling the reversing of the telescopic reversing valve. The control end of the hydraulic control reversing valve 105 is connected to the working port A1 of the telescopic reversing valve, the inlet of the hydraulic control reversing valve 105 is connected to the LS oil circuit of the pressure compensator 125, and the outlet of the hydraulic control reversing valve 105 is connected to the oil return port through the relief valve 106; the control end of the hydraulic control reversing valve 2 107 is connected to the working port B1 of the telescopic reversing valve, the inlet of the hydraulic control reversing valve 2 107 is connected to the LS oil circuit of the pressure compensator 125, and the outlet of the hydraulic control reversing valve 2 107 is connected to the oil return port through the relief valve 2 108. The LS oil circuit of the pressure compensator 125 is connected to the LS oil circuit of the multi-way valve through a one-way valve.

[0020] The oil source at the P (P1 or P2, or P1+P2) port is connected to the telescopic link. When the electric proportional pilot valve 104 is electrically switched, the pilot oil enters the valve stem spring chamber of the telescopic reversing valve through the electric proportional pilot valve 104, the telescopic reversing valve is switched, and the high-pressure oil enters the actuator through the valve stem of the telescopic reversing valve, the pressure compensator 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 107 from the working port B1 of the telescopic reversing valve, and the hydraulic control reversing valve 107 is switched; when the LS pressure of the pressure compensator 125 exceeds the set pressure of the relief valve 108, the relief valve 108 releases the pressure of the LS oil circuit of the pressure compensator 125 and feeds back to the LS port of the load-sensitive pump, and reduces the displacement of the load-sensitive pump according to the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator 125, and reduces the oil pump flow to reduce energy loss when overloaded.

[0021] When the electric proportional pilot valve 124 is electrically switched, the pilot oil enters the valve stem spring chamber of the telescopic reversing valve through the electric proportional pilot valve 124, the telescopic reversing valve is switched, and the high-pressure oil enters the actuator through the valve stem of the telescopic reversing valve, the pressure compensator 125, and the working port A1 of the telescopic reversing valve. At the same time, the high-pressure oil enters the control end of the hydraulic control reversing valve 105 from the working port A1 of the telescopic reversing valve, and the hydraulic control reversing valve 105 is switched; when the LS pressure of the pressure compensator 125 exceeds the set pressure of the relief valve 106, the relief valve 106 relieves the pressure on the LS oil circuit of the pressure compensator 125 and feeds back to the LS port of the load-sensitive pump, and reduces the displacement of the load-sensitive pump according to the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator 125, and reduces the oil pump flow rate to reduce energy loss when overloaded.

[0022] The variable amplitude link includes: a variable amplitude reversing valve, a pressure compensator 2 127 arranged behind the variable amplitude reversing valve, an electric proportional pilot valve 2 109 and an electric proportional pilot valve 6 126 for controlling the reversing of the variable amplitude reversing valve; the control end of the hydraulic control reversing valve 3 110 is connected to the working port A2 of the variable amplitude reversing valve, the inlet of the hydraulic control reversing valve 3 110 is connected to the LS oil circuit of the pressure compensator 2 127, and the outlet of the hydraulic control reversing valve 3 110 is connected to the oil return port through the relief valve 3 111; the control end of the hydraulic control reversing valve 4 112 is connected to the working port B2 of the variable amplitude reversing valve, the inlet of the hydraulic control reversing valve 4 112 is connected to the LS oil circuit of the pressure compensator 2 127, and the outlet of the hydraulic control reversing valve 4 112 is connected to the oil return port through the relief valve 4 113. The LS oil circuit of the pressure compensator 2 127 is connected to the LS oil circuit of the multi-way valve through a one-way valve.

[0023] The oil source at port P is connected to the variable amplitude link. When the electric proportional pilot valve 109 is electrically switched, the pilot oil enters the valve stem spring chamber of the variable amplitude reversing valve through the electric proportional pilot valve 109, the variable amplitude reversing valve is switched, and the high-pressure oil enters the actuator through the valve stem of the variable amplitude reversing valve, the pressure compensator 127, and the working port B2 of the variable amplitude reversing valve. At the same time, the high-pressure oil enters the control end of the hydraulic control reversing valve 112 from the working port B2 of the variable amplitude reversing valve, and the hydraulic control reversing valve 112 is switched; when the LS pressure of the pressure compensator 127 exceeds the set pressure of the relief valve 113, the relief valve 113 releases the pressure on the LS oil circuit of the pressure compensator 127 and feeds back to the LS port of the load-sensitive pump, and reduces the displacement of the load-sensitive pump according to the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator 127, and reduces the flow rate to reduce energy loss when overloaded.

[0024] When the electric proportional pilot valve 6 126 is electrically switched, the pilot oil enters the valve stem spring chamber of the variable amplitude reversing valve through the electric proportional pilot valve 6 126, the variable amplitude reversing valve is switched, and the high-pressure oil enters the actuator through the valve stem of the variable amplitude reversing valve, the pressure compensator 2 127, and the working port A2 of the variable amplitude reversing valve. At the same time, the high-pressure oil enters the control end of the hydraulic control reversing valve 3 110 from the working port A2 of the variable amplitude reversing valve, and the hydraulic control reversing valve 3 110 is switched; when the LS pressure of the pressure compensator 2 127 exceeds the set pressure of the relief valve 3 111, the relief valve 3 111 relieves the pressure on the LS oil circuit of the pressure compensator 2 127 and feeds back to the LS port of the load-sensitive pump, and reduces the displacement of the load-sensitive pump according to the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator 2 127, thereby reducing the flow rate and reducing energy loss when overloaded.

[0025] The winch unit includes: a main winch reversing valve, a pressure compensator 3 128 arranged behind the main winch reversing valve, an electric proportional pilot valve 3 114 and an electric proportional pilot valve 7 129 for controlling the reversing of the main winch reversing valve, an auxiliary winch reversing valve, a pressure compensator 4 130 arranged behind the auxiliary winch reversing valve, an electric proportional pilot valve 4 118 and an electric proportional pilot valve 8 131 for controlling the reversing of the auxiliary winch reversing valve. The control end of the hydraulically controlled reversing valve 5 115 is connected to the outlet of the shuttle valve 117. The hydraulically controlled reversing valve 5 115 is used to control the pressure of the low-pressure port of the main and auxiliary winches. When the main and auxiliary winches are actuated at the same time, in order to prevent the pressure of the high-pressure port from flowing away from the relief valve 5 116 and thus failing to build up pressure, the pressure of the working port B3 of the main winch reversing valve and the working port B4 of the auxiliary winch reversing valve are introduced into the spring chamber of the hydraulically controlled reversing valve 5 115 for logical restriction. The inlet 1 of the shuttle valve 117 is connected to the working port A3 of the main winch reversing valve. The inlet of the hydraulically controlled reversing valve 5 115 is connected to the LS oil circuit of the pressure compensator 3 128 and the LS oil circuit of the pressure compensator 4 130. The hydraulically controlled reversing valve 5 115 The outlet of the hydraulic control reversing valve 6 119 is connected to the oil return port through the relief valve 5 116; the hydraulic control reversing valve 6 119 is the reversing valve on the high pressure side of the winch, the outlet of the shuttle valve 2 121 is connected to the control end of the hydraulic control reversing valve 6 119 and the spring chamber of the hydraulic control reversing valve 5 115, the inlet 1 of the shuttle valve 2 121 is connected to the working port B3 of the main winch reversing valve, the inlet of the hydraulic control reversing valve 6 119 is connected to the LS oil circuit of the pressure compensator 3 128 and the LS oil circuit of the pressure compensator 4 130, and the outlet of the hydraulic control reversing valve 6 119 is connected to the oil return port through the relief valve 6 120; the working port A4 of the auxiliary winch reversing valve is connected to the inlet 2 of the shuttle valve 1 117, and the working port B4 of the auxiliary winch reversing valve is connected to the inlet 2 of the shuttle valve 2 121. The LS oil circuits of the pressure compensator 3 128 and the pressure compensator 4 130 are respectively connected to the LS oil circuit of the multi-way valve through a one-way valve. The LS oil circuit of the pressure compensator 3 128 is connected to the inlet of the hydraulic control reversing valve 5 115 and the inlet of the hydraulic control reversing valve 6 119 through a one-way valve. The LS oil circuit of the pressure compensator 4 130 is connected to the inlet of the hydraulic control reversing valve 5 115 and the inlet of the hydraulic control reversing valve 6 119 through a one-way valve.

[0026] The main hoisting and lowering and the auxiliary hoisting and lowering share the same relief valve. Relief valve five 116 is the relief valve on the low-pressure side of the hoisting descent, and relief valve six 120 is the relief valve on the high-pressure side of the hoisting rise. The oil source at port P is connected to the hoisting link (main hoisting + auxiliary hoisting).

[0027] When the electric proportional pilot valve 3 114 is electrically switched, the pilot oil enters the valve stem spring chamber of the main winch reversing valve through the electric proportional pilot valve 3 114, the main winch reversing valve is switched, and the high-pressure oil enters the actuator through the valve stem of the main winch reversing valve, the pressure compensator 3 128, and the working port A3 of the main winch reversing valve. At the same time, the high-pressure oil enters the inlet 1 of the shuttle valve 117 from the working port A3 of the main winch reversing valve, and enters the control end of the hydraulic control reversing valve 5 115 from the outlet of the shuttle valve 117, pushing the hydraulic control reversing valve 5 115 to switch. When the LS pressure of the pressure compensator 3 128 exceeds the set pressure of the relief valve 5 116, the relief valve 5 116 releases the pressure on the LS oil circuit of the pressure compensator 3 128 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 the pressure compensator 3 128, and the flow rate is reduced to reduce energy loss when overloaded.

[0028] When the electric proportional pilot valve 4 118 is electrically switched, the pilot oil enters the valve stem spring chamber of the auxiliary winch reversing valve through the electric proportional pilot valve 4 118, the auxiliary winch reversing valve is switched, and the high-pressure oil enters the actuator through the valve stem of the auxiliary winch reversing valve, the pressure compensator 4 130, and the working port A4 of the auxiliary winch reversing valve. At the same time, the high-pressure oil enters the inlet 2 of the shuttle valve 117 from the working port A4 of the auxiliary winch reversing valve, and enters the control end of the hydraulic control reversing valve 5 115 from the outlet of the shuttle valve 117, pushing the hydraulic control reversing valve 5 115 to switch. When the LS pressure of the pressure compensator 4 130 exceeds the set pressure of the relief valve 5 116, the relief valve 5 116 relieves the pressure on the LS oil circuit of the pressure compensator 4 130 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 the pressure compensator 4 130, and the flow rate is reduced to reduce energy loss when overloaded.

[0029] When the electric proportional pilot valve 7 129 is electrically switched, the pilot oil enters the valve stem spring chamber of the main winch reversing valve through the electric proportional pilot valve 7 129, the main winch reversing valve is switched, and the high-pressure oil enters the actuator through the valve stem of the main winch reversing valve, the pressure compensator 3 128, and the working port B3 of the main winch reversing valve. At the same time, the high-pressure oil enters the inlet 1 of the shuttle valve 2 121 from the working port B3 of the main winch reversing valve, and enters the control end of the hydraulic control reversing valve 6 119 from the outlet of the shuttle valve 2 121, pushing the hydraulic control reversing valve 6 119 to switch; when the LS pressure of the pressure compensator 3 128 exceeds the set pressure of the relief valve 6 120, the relief valve 6 120 relieves the pressure of the LS oil circuit of the pressure compensator 3 128 and feeds back to the LS port of the load-sensitive pump, and reduces the displacement of the load-sensitive pump according to the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator 3 128, and reduces the flow rate to reduce energy loss when overloaded.

[0030] When the electric proportional pilot valve eight 131 is electrically switched, the pilot oil enters the valve stem spring chamber of the auxiliary winch reversing valve through the electric proportional pilot valve eight 131, the auxiliary winch reversing valve is switched, and the high-pressure oil enters the actuator through the valve stem of the auxiliary winch reversing valve, the pressure compensator four 130, and 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, pushing the hydraulic control reversing valve six 119 to switch; when the LS pressure of the pressure compensator four 130 exceeds the set pressure of the relief valve six 120, the relief valve six 120 relieves the pressure of the LS oil circuit of the pressure compensator four 130, and feeds back to the LS port of the load-sensitive pump, and reduces the displacement of the load-sensitive pump according to the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator four 130, and reduces the flow rate to reduce energy loss when overloaded. The main roll lifting and lowering and the auxiliary roll lifting and lowering share the same overflow valve. During compound action, the shuttle valve is used to select the oil in the main roll or auxiliary roll oil circuit. The oil in the main roll lifting and lowering or auxiliary roll lifting and lowering circuit with higher oil pressure will be selected.

[0031] In the present invention, the telescopic reversing valve, the variable amplitude reversing valve, the main hoisting reversing valve, and the auxiliary hoisting reversing valve are all three-position four-way valves 132 with the same structure.

[0032] In order to solve the problems of poor energy saving of the post-valve compensation multi-way valve and poor compound action of the pre-valve compensation multi-way valve, the present invention innovates from the underlying principle and uses the pressure of each oil outlet of the multi-way valve as a feedback condition to determine which overflow valve (limiting the maximum pressure of each action direction) on the hydraulic system feedback oil circuit works, thereby playing a role in limiting the load feedback oil circuit pressure. In the overflow working condition, the four major systems and eight major movement directions of the vehicle reduce the oil pump displacement by limiting the pressure of the oil pump feedback oil circuit, thereby avoiding the problem of a large amount of oil flowing into the oil tank through the overflow valve, improving the energy saving of the hydraulic system while having the advantage of good compound action performance. For example, when the winch falls, the pressure of the winch drop 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 of the winch falls is reached, the overflow valve opens to limit the pressure of the hydraulic system feedback port, thereby limiting the displacement of the oil pump, and a large amount of oil will not flow back to the oil tank when the winch falls.

[0033] The pilot module and the pilot oil circuit of the present invention are integrated in the multi-way valve, which reduces the assembly pipeline, thereby reducing the cost and failure rate. The hydraulic control reversing valves between the outlets of the multi-way are interlocked, so that different pressure levels are used between the A and B ports of each link, which not only meets the use requirements but also improves safety.

[0034] The present invention realizes interlocking of the outlet circuits of each link of the multi-way valve by setting a hydraulically controlled reversing valve and a relief valve at the outlet of the three-position four-way reversing valve, that is, when each link of the multi-way valve is working, only one hydraulically controlled reversing valve at port A or port B is working, so that at most only one relief valve corresponding to the hydraulically controlled reversing valve is working. During the compound action, the pressure fed back from the high-pressure link is selected to adjust the displacement of the load-sensitive pump through the high-pressure isolation of the one-way valve. The oil at the outlet of each link of the pressure compensator passes through the hydraulically controlled reversing valve and reaches the relief valve.

[0035] Embodiment 2 Based on the multi-way valve described in the first embodiment, this embodiment provides a crane hydraulic system, and the crane hydraulic system is equipped with the multi-way valve described in the first embodiment.

[0036] Embodiment 3 Based on the crane hydraulic system described in the second embodiment, this embodiment provides a crane, and the crane is equipped with the crane hydraulic system described in the second embodiment.

[0037] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A multi-way valve, characterized in that: include: Telescopic coupling, luffing coupling and winch coupling; The telescopic link comprises: a telescopic reversing valve, a pressure compensator 1 (125) arranged behind the telescopic reversing valve, an electric proportional pilot valve 1 (104) and an electric proportional pilot valve 5 (124) for controlling the reversing of the telescopic reversing valve; the control end of the hydraulically controlled reversing valve 1 (105) is connected to the working port A1 of the telescopic reversing valve, the inlet of the hydraulically controlled reversing valve 1 (105) is connected to the LS oil circuit of the pressure compensator 1 (125), and the outlet of the hydraulically controlled reversing valve 1 (105) is connected to the oil return port via the relief valve 1 (106); the control end of the hydraulically controlled reversing valve 2 (107) is connected to the working port B1 of the telescopic reversing valve, the inlet of the hydraulically controlled reversing valve 2 (107) is connected to the LS oil circuit of the pressure compensator 1 (125), and the outlet of the hydraulically controlled reversing valve 2 (107) is connected to the oil return port via the relief valve 2 (108); The variable amplitude link comprises: a variable amplitude reversing valve, a second pressure compensator (127) arranged behind the variable amplitude reversing valve, a second electric proportional pilot valve (109) and a sixth electric proportional pilot valve (126) for controlling the reversing of the variable amplitude reversing valve; the control end of the third hydraulic control reversing valve (110) is connected to the working port A2 of the variable amplitude reversing valve, the inlet of the third hydraulic control reversing valve (110) is connected to the LS oil circuit of the second pressure compensator (127), and the outlet of the third hydraulic control reversing valve (110) is connected to the return oil port through the third overflow valve (111); the control end of the fourth hydraulic control reversing valve (112) is connected to the working port B2 of the variable amplitude reversing valve, the inlet of the fourth hydraulic control reversing valve (112) is connected to the LS oil circuit of the second pressure compensator (127), and the outlet of the fourth hydraulic control reversing valve (112) is connected to the return oil port through the fourth overflow valve (113); The winch includes: 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; Auxiliary winch reversing valve, a pressure compensator four (130) arranged behind the auxiliary winch reversing valve, an electric proportional pilot valve four (118) and an electric proportional pilot valve eight (131) for controlling the reversing of the auxiliary winch reversing valve; The control end of the hydraulically controlled reversing valve 5 (115) is connected to the outlet of the shuttle valve 1 (117). The hydraulically controlled reversing valve 5 (115) is used to control the pressure of the low-pressure port of the main and auxiliary winch joints. When the main and auxiliary winch joints are actuated simultaneously, in order to prevent the pressure of the high-pressure port from flowing away from the relief valve 5 (116) and thus failing to build up pressure, the pressure of the working port B3 of the main winch reversing valve and the working port B4 of the auxiliary winch reversing valve are introduced into the spring chamber of the hydraulically controlled reversing valve 5 (115) for logical restriction. The inlet 1 of the shuttle valve 1 (117) is connected to the working port A3 of the main winch reversing valve. The inlet of the hydraulically controlled reversing valve 5 (115) is connected to the LS oil circuit of the pressure compensator 3 (128) and the LS oil circuit of the pressure compensator 4 (130). The outlet of the hydraulically controlled reversing valve 5 (115) is connected to the LS oil circuit of the pressure compensator 3 (128) and the LS oil circuit of the pressure compensator 4 (130). The oil return port is connected through the overflow valve five (116); the hydraulically controlled reversing valve six (119) is the reversing valve on the high-pressure side of the winch, the outlet of the shuttle valve two (121) is connected to the control end of the hydraulically controlled reversing valve six (119) and the spring chamber of the hydraulically controlled reversing valve five (115), the inlet one of the shuttle valve two (121) is connected to the working port B3 of the main winch reversing valve, the inlet of the hydraulically controlled reversing valve six (119) is connected to the LS oil circuit of the pressure compensator three (128) and the LS oil circuit of the pressure compensator four (130), and the outlet of the hydraulically controlled reversing valve six (119) is connected to the oil return port through the overflow valve six (120); the working port A4 of the auxiliary winch reversing valve is connected to the inlet two of the shuttle valve one (117), and the working port B4 of the auxiliary winch reversing valve is connected to the inlet two of the shuttle valve two (121).

2. The multi-way valve according to claim 1, characterized in that: The LS oil circuits of the pressure compensator 1 (125), the pressure compensator 2 (127), the pressure compensator 3 (128) and the pressure compensator 4 (130) are connected to the LS oil circuit of the multi-way valve through the one-way valves respectively; The LS oil circuit of the pressure compensator 3 (128) is connected to the inlet of the hydraulic control reversing valve 5 (115) and the inlet of the hydraulic control reversing valve 6 (119) through a one-way valve; The LS oil circuit of the pressure compensator 4 (130) is connected to the inlet of the hydraulically controlled reversing valve 5 (115) and the inlet of the hydraulically controlled reversing valve 6 (119) through a one-way valve.

3. The multi-way valve according to claim 2, characterized in that: When the electric proportional pilot valve 1 (104) is electrically switched, the pilot oil enters the valve stem spring chamber of the telescopic reversing valve through the electric proportional pilot valve 1 (104), the telescopic reversing valve is switched, and the high-pressure oil enters the actuator through the valve stem of the telescopic reversing valve, the pressure compensator 1 (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 2 (107) from the working port B1 of the telescopic reversing valve, and the hydraulic control reversing valve 2 (107) is switched. When the LS pressure of the pressure compensator 1 (125) exceeds the set pressure of the relief valve 2 (108), the relief valve 2 (108) releases the pressure of the LS oil circuit of the pressure compensator 1 (125) and feeds back to the LS port of the load sensing pump, and reduces the displacement of the load sensing pump according to the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator 1 (125).

4. The multi-way valve according to claim 2, characterized in that: When the electric proportional pilot valve 5 (124) is electrically switched, the pilot oil enters the valve stem spring chamber of the telescopic reversing valve through the electric proportional pilot valve 5 (124), the telescopic reversing valve is switched, and the high-pressure oil enters the actuator through the valve stem of the telescopic reversing valve, the pressure compensator 1 (125), and the working port A1 of the telescopic reversing valve. At the same time, the high-pressure oil enters the control end of the hydraulic control reversing valve 1 (105) from the working port A1 of the telescopic reversing valve, and the hydraulic control reversing valve 1 (105) is switched. When the LS pressure of the pressure compensator 1 (125) exceeds the set pressure of the relief valve 1 (106), the relief valve 1 (106) releases the pressure of the LS oil circuit of the pressure compensator 1 (125) and feeds back to the LS port of the load sensing pump, thereby reducing the displacement of the load sensing pump according to the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator 1 (125).

5. The multi-way valve according to claim 2, characterized in that: When the electric proportional pilot valve 2 (109) is electrically switched, the pilot oil enters the valve stem spring chamber of the variable amplitude reversing valve through the electric proportional pilot valve 2 (109), the variable amplitude reversing valve is switched, and the high-pressure oil enters the actuator through the valve stem of the variable amplitude reversing valve, the pressure compensator 2 (127), and the working port B2 of the variable amplitude reversing valve. At the same time, the high-pressure oil enters the control end of the hydraulic control reversing valve 4 (112) from the working port B2 of the variable amplitude reversing valve, and the hydraulic control reversing valve 4 (112) is switched; 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) releases the pressure of the LS oil circuit of the pressure compensator 2 (127) and feeds back to the LS port of the load sensing pump, and reduces the displacement of the load sensing pump according to the pressure difference between the inlet pressure of the multi-way valve and the LS pressure of the pressure compensator 2 (127).

6. The multi-way valve according to claim 2, characterized in that: When the electric proportional pilot valve six (126) is electrically switched, the pilot oil enters the valve stem spring chamber of the variable amplitude reversing valve through the electric proportional pilot valve six (126), the variable amplitude reversing valve is switched, and the high-pressure oil enters the actuator through the valve stem of the variable amplitude reversing valve, the pressure compensator two (127), and the working port A2 of the variable amplitude reversing valve. At the same time, the high-pressure oil enters the control end of the hydraulic control reversing valve three (110) from the working port A2 of the variable amplitude reversing valve, and the hydraulic control reversing valve three (110) is switched; when the LS pressure of the pressure compensator two (127) exceeds the set pressure of the relief valve three (111), the relief valve three (111) releases the pressure of the LS oil circuit of the pressure compensator two (127) and feeds back to the LS port of the load sensing pump, and reduces the displacement of the load sensing pump 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 according to claim 2, characterized in that: When the electric proportional pilot valve 3 (114) is electrically switched, the pilot oil enters the valve stem spring chamber of the main winch reversing valve through the electric proportional pilot valve 3 (114), the main winch reversing valve is switched, and the high-pressure oil enters the actuator through the valve stem of the main winch reversing valve, the pressure compensator 3 (128), and the working port A3 of the main winch reversing valve. At the same time, the high-pressure oil enters the inlet 1 of the shuttle valve 1 (117) from the working port A3 of the main winch reversing valve, and enters the outlet of the shuttle valve 1 (117). The control end of the hydraulically controlled reversing valve five (115) drives the hydraulically controlled reversing valve five (115) to change direction; when the LS pressure of the pressure compensator three (128) exceeds the set pressure of the relief valve five (116), the relief valve five (116) releases the pressure of the LS oil circuit of the pressure compensator three (128) and feeds back to the LS port of the load sensing pump, thereby reducing the displacement of the load sensing pump 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 4 (118) is electrically switched, the pilot oil enters the valve stem spring chamber of the auxiliary winch reversing valve through the electric proportional pilot valve 4 (118), the auxiliary winch reversing valve is switched, and the high-pressure oil enters the actuator through the valve stem of the auxiliary winch reversing valve, the pressure compensator 4 (130), and the working port A4 of the auxiliary winch reversing valve. At the same time, the high-pressure oil enters the inlet 2 of the shuttle valve 1 (117) from the working port A4 of the auxiliary winch reversing valve, and enters the outlet of the shuttle valve 1 (117). The control end of the hydraulically controlled reversing valve five (115) drives the hydraulically controlled reversing valve five (115) to change direction; when the LS pressure of the pressure compensator four (130) exceeds the set pressure of the relief valve five (116), the relief valve five (116) releases pressure to the LS oil circuit of the pressure compensator four (130) and feeds back to the LS port of the load-sensitive pump, thereby reducing the displacement of the load-sensitive pump 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 according to claim 2, characterized in that: When the electric proportional pilot valve 7 (129) is electrically switched, the pilot oil enters the valve stem spring chamber of the main winch reversing valve through the electric proportional pilot valve 7 (129), the main winch reversing valve is switched, and the high-pressure oil enters the actuator through the valve stem of the main winch reversing valve, the pressure compensator 3 (128), and the working port B3 of the main winch reversing valve. At the same time, the high-pressure oil enters the inlet 1 of the shuttle valve 2 (121) from the working port B3 of the main winch reversing valve, and enters the outlet of the shuttle valve 2 (121). The control end of the hydraulically controlled reversing valve six (119) drives the hydraulically controlled reversing valve six (119) to change direction; when the LS pressure of the pressure compensator three (128) exceeds the set pressure of the relief valve six (120), the relief valve six (120) releases the pressure of the LS oil circuit of the pressure compensator three (128) and feeds back to the LS port of the load sensing pump, and reduces the displacement of the load sensing pump 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 8 (131) is electrically switched, the pilot oil enters the valve stem spring chamber of the auxiliary winch reversing valve through the electric proportional pilot valve 8 (131), the auxiliary winch reversing valve is switched, and the high-pressure oil enters the actuator through the valve stem of the auxiliary winch reversing valve, the pressure compensator 4 (130), and the working port B4 of the auxiliary winch reversing valve. At the same time, the high-pressure oil enters the inlet 2 of the shuttle valve 2 (121) from the working port B4 of the auxiliary winch reversing valve, and enters the outlet of the shuttle valve 2 (121). The control end of the hydraulically controlled reversing valve six (119) drives the hydraulically controlled reversing valve six (119) to reverse; when the LS pressure of the pressure compensator four (130) exceeds the set pressure of the relief valve six (120), the relief valve six (120) releases the pressure of the LS oil circuit of the pressure compensator four (130) and feeds back to the LS port of the load-sensitive pump, thereby reducing the displacement of the load-sensitive pump 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 in that: The crane hydraulic system is equipped with a multi-way valve as described in any one of claims 1 to 8.

10. A crane, characterized in that: The crane is equipped with the crane hydraulic system according to claim 9.

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