An open hydraulic system for a dredger

Abstract

The present invention provides an open-type hydraulic system for a dredger, relating to the field of hydraulic technology. The system comprises a first power source, a second power source, a first pump group, a second pump group, a third pump group, a fourth pump group, an oil circuit switching valve group, a grab support winch motor drive assembly, a grab opening and closing winch motor drive assembly, a luffing winch motor drive assembly, and a slewing motor drive assembly. One of the oil inlet and outlet lines of the grab support winch motor drive assembly and the grab opening and closing winch motor drive assembly is equipped with a balancing valve, and the other is connected to the control port of the balancing valve. The first power source simultaneously drives the first and second pump groups, while the second power source simultaneously drives the third and fourth pump groups. The present invention can achieve stable operation of the dredger.

Description

Technical Field

[0001] The present invention relates to the field of hydraulic technology, in particular to an open hydraulic system for a dredge. Background Art

[0002] Grab dredgers are primarily used in areas and situations where cutter-suction and trailing-suction dredgers are unsuitable for deployment. They feature a small operating radius, high flexibility, shallow draft, and high positioning accuracy. To ensure the grab bucket has a certain overload capacity, conventional dredgers use a "torque converter + hydraulic clutch" system to drive the dredger. Torque converters, in particular, can achieve a torque conversion of 1.8 to 2.6 times. However, dredgers using this "torque converter + hydraulic clutch" system have operational stability issues. For example, the grab bucket is prone to stalling when lowering. Furthermore, because existing dredger hydraulic systems rely on a single power pack for power, they cannot function properly if a fault occurs. Summary of the Invention

[0003] The problem solved by the present invention is how to reasonably design the hydraulic system of a dredge to achieve stable operation of the dredge.

[0004] To solve the above problems, the present invention provides an open hydraulic system for a dredger, comprising a first power source, a second power source, a first pump group, a second pump group, a third pump group, a fourth pump group, an oil circuit switching valve group, a grab support winch motor drive assembly, a grab opening and closing winch motor drive assembly, a luffing winch motor drive assembly, and a slewing motor drive assembly;

[0005] One of the oil inlet and oil outlet passages of the grab support winch motor drive assembly and the grab opening and closing winch motor drive assembly is provided with a balancing valve, and the other is connected to the control port of the balancing valve;

[0006] The first power source drives the first pump group and the second pump group simultaneously, and the second power source drives the third pump group and the fourth pump group simultaneously; the first pump group and the third pump group are connected to the grab bucket opening and closing winch motor drive assembly through the oil circuit switching valve group, and the second pump group and the fourth pump group are connected to the grab bucket opening and closing winch motor drive assembly through the oil circuit switching valve group; the first pump group is also connected to the variable amplitude winch motor drive assembly and the rotary motor drive assembly respectively through the oil circuit switching valve group; the third pump group is also connected to the rotary motor drive assembly through the oil circuit switching valve group; the fourth pump group is also connected to the variable amplitude winch motor drive assembly through the oil circuit switching valve group.

[0007] Optionally, the first pump group includes a first variable pump, the third pump group includes a third variable pump, and the oil circuit switching valve group includes a first solenoid reversing valve, a second solenoid reversing valve, a third solenoid reversing valve, a fourth solenoid reversing valve, a fifth solenoid reversing valve and a sixth solenoid reversing valve;

[0008] The outlet of the first variable displacement pump is connected to the inlet of the first solenoid reversing valve. The outlet of the first solenoid reversing valve is divided into two paths, one of which is connected in sequence to the second solenoid reversing valve and the luffing winch motor drive assembly, and the other is connected in sequence to the third solenoid reversing valve, the fourth solenoid reversing valve, and the slewing motor drive assembly; the oil return ports of the first solenoid reversing valve, the second solenoid reversing valve, the third solenoid reversing valve, and the fourth solenoid reversing valve are respectively connected to the oil tank;

[0009] The inlet of the fifth solenoid reversing valve is divided into two paths, one path is connected to the outlet of the first variable pump, and the other path is connected to the outlet of the sixth solenoid reversing valve and the third variable pump in sequence. The outlet of the fifth solenoid reversing valve is connected to the rotary motor drive assembly, and the return oil ports of the fifth solenoid reversing valve and the sixth solenoid valve are respectively connected to the oil tank.

[0010] Optionally, the second pump group further includes a second variable pump, the fourth pump group further includes a fourth variable pump, and the oil circuit switching valve group further includes a seventh solenoid reversing valve and an eighth solenoid reversing valve;

[0011] The outlet of the second variable pump is connected to the inlet of the seventh solenoid reversing valve, the outlet of the fourth variable pump is connected to the inlets of the eighth solenoid reversing valve and the seventh solenoid reversing valve in sequence, the two outlets of the seventh solenoid reversing valve are respectively connected to the grab support winch motor drive assembly, and the return oil ports of the seventh solenoid reversing valve and the eighth solenoid reversing valve are respectively connected to the oil tank.

[0012] Optionally, the open hydraulic system of the dredger further includes an air-cooled cooler, the air-cooled cooler includes a fan drive motor and a cooling channel, the first pump group further includes a first cooling pump, the second pump group further includes a first circulating cooling pump, the third pump group further includes a second cooling pump, and the fourth pump group further includes a second circulating cooling pump;

[0013] The outlets of the first cooling pump and the second cooling pump are connected to the fan drive motor and the oil tank in sequence respectively, and the outlets of the first circulating cooling pump and the second circulating cooling pump are connected to the cooling channel and the oil tank in sequence respectively.

[0014] Optionally, the dredger open hydraulic system further includes a control valve group, a supporting winch brake, a supporting winch brake valve, an opening and closing winch brake, an opening and closing winch brake valve, a luffing winch brake, a luffing winch brake valve, a slewing winch brake, and a slewing winch brake valve; the first pump group further includes a first control pump; and the third pump group further includes a second control pump.

[0015] The inlet of the control valve group is connected to the outlet of the first control pump and the second control pump respectively. The outlet of the control valve group is divided into four routes. The first route is connected to the supporting winch brake valve and the supporting winch brake in sequence, the second route is connected to the opening and closing winch brake valve and the opening and closing winch brake in sequence, the third route is connected to the variable amplitude winch brake valve and the variable amplitude winch brake in sequence, and the fourth route is connected to the slewing winch brake valve and the slewing winch brake in sequence; the return oil ports of the supporting winch brake valve, the opening and closing winch brake valve, the variable amplitude winch brake valve and the slewing winch brake valve are respectively connected to the oil tank.

[0016] Optionally, the open hydraulic system of the dredger further includes an oil supply valve group, the second pump group further includes a first oil supply pump, the third pump group further includes a second oil supply pump, and two oil supply check valves are connected in series between the oil inlet and oil outlet circuits of the grab support winch motor drive assembly, the grab opening and closing winch motor drive assembly, the luffing winch motor drive assembly, and the slewing motor drive assembly, and the inlets of the two oil supply check valves are connected;

[0017] The inlet of the oil supply valve group is connected to the outlet of the first oil supply pump and the second oil supply pump respectively. The outlet of the oil supply valve group is divided into four routes. The first route is connected to the inlet of the two oil supply check valves of the grab support winch motor drive assembly, the second route is connected to the inlet of the two oil supply check valves of the grab opening and closing winch motor drive assembly, the third route is connected to the inlet of the two oil supply check valves of the variable amplitude winch motor drive assembly, and the fourth route is connected to the inlet of the two oil supply check valves of the rotary motor drive assembly.

[0018] Optionally, the first pump group further includes a first electromagnetic proportional relief valve, the second pump group further includes a second electromagnetic proportional relief valve, the third pump group further includes a third electromagnetic proportional relief valve, and the fourth pump group further includes a fourth electromagnetic proportional relief valve;

[0019] The inlet and outlet of the first electromagnetic proportional relief valve are connected to the control port of the first variable pump and the oil tank respectively; the inlet and outlet of the second electromagnetic proportional relief valve are connected to the control port of the second variable pump and the oil tank respectively; the inlet and outlet of the third electromagnetic proportional relief valve are connected to the control port of the third variable pump and the oil tank respectively; the inlet and outlet of the fourth electromagnetic proportional relief valve are connected to the control port of the fourth variable pump and the oil tank respectively.

[0020] Optionally, the grab bucket supporting winch motor drive assembly further includes a supporting winch hydraulic motor, a ninth solenoid reversing valve, a first electric proportional speed regulating valve, and a first relief valve;

[0021] One working port of the ninth solenoid reversing valve is respectively connected to the balancing valve, the outlet of one of the oil replenishing one-way valves, the outlet of the first overflow valve and a working port of the supporting winch hydraulic motor; another working port of the ninth solenoid reversing valve is connected to a working port of the first electric proportional speed control valve; another working port of the first electric proportional speed control valve is respectively connected to the outlet of another oil replenishing one-way valve and another working port of the supporting winch hydraulic motor.

[0022] Optionally, the grab bucket opening and closing winch motor drive assembly further includes an opening and closing winch hydraulic motor, a tenth electromagnetic reversing valve, a second electric proportional speed regulating valve and a second relief valve;

[0023] One working port of the tenth solenoid reversing valve is respectively connected to the balancing valve, the outlet of one of the oil-supplying one-way valves, the outlet of the second overflow valve and a working port of the opening and closing winch hydraulic motor; another working port of the tenth solenoid reversing valve is connected to a working port of the second electric proportional speed control valve; another working port of the second electric proportional speed control valve is respectively connected to the outlet of another oil-supplying one-way valve and another working port of the opening and closing winch hydraulic motor.

[0024] Optionally, the other outlet of the oil replenishing valve group is divided into two paths, one path is connected to the supporting winch hydraulic motor and the oil tank in sequence, and the other path is connected to the opening and closing winch hydraulic motor and the oil tank in sequence.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] One of the oil inlet and outlet lines of the grab support winch motor drive assembly and the grab opening and closing winch motor drive assembly is equipped with a balancing valve, and the other is connected to the control port of the balancing valve. The opening of the balancing valve is controlled by the pilot pressure of the oil inlet at the winch lowering end. The greater the pilot pressure, the more the balancing valve opens, the greater the flow, and the faster the winch lowering speed. Conversely, the smaller the pilot pressure, the smaller the balancing valve opening, the smaller the flow, and the slower the winch lowering speed. Therefore, the size of the balancing valve after opening is controlled by the active oil supply pressure at the winch lowering end oil port, rather than being opened or closed arbitrarily. This avoids the possibility of stalling the winch due to rapid lowering due to gravity after the balancing valve is opened, and realizes the balancing valve's anti-stall function during grab lowering. At the same time, the oil switching valve group rationally combines and cuts off the oil output from the first, second, third, and fourth pump groups, fully ensuring sufficient oil supply to each winch during normal operation. In addition, if one power source fails, the other power source can complete all corresponding actions at half speed, thus realizing the mutual backup of the first and second power sources, ultimately achieving stable operation of the dredger. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A hydraulic principle diagram of an embodiment of an open hydraulic system for a dredger according to the present invention;

[0028] Figure 2 This is a hydraulic principle diagram of an embodiment of the first pump group in the present invention;

[0029] Figure 3 This is a hydraulic principle diagram of an embodiment of the second pump group in the present invention;

[0030] Figure 4 This is a hydraulic principle diagram of an embodiment of the third pump group in the present invention;

[0031] Figure 5 This is a hydraulic principle diagram of an embodiment of the fourth pump group in the present invention;

[0032] Figure 6 This is a hydraulic principle diagram of an embodiment of the oil circuit switching valve group in the present invention;

[0033] Figure 7 A schematic diagram of an embodiment of a grab support winch motor drive assembly of the present invention;

[0034] Figure 8 This is a schematic diagram of an embodiment of the grab bucket opening and closing winch motor drive assembly of the present invention.

[0035] Description of reference numerals:

[0036] 100, first power source; 200, second power source; 300, first pump group; 301, first variable displacement pump; 302, first cooling pump; 303, first control pump; 304, first electromagnetic proportional relief valve; 400, second pump group; 401, second variable displacement pump; 402, second cooling pump; 403, second control pump; 404, second electromagnetic proportional relief valve; 500, third pump group; 501, third variable displacement pump; 502, first circulating cooling pump; 503, first charge pump; 504, third electromagnetic proportional relief valve; 600, fourth pump group; 601, fourth variable displacement pump; 602, second circulating cooling pump; 603, second oil supply pump; 604, fourth electromagnetic proportional relief valve; 700, oil circuit switching valve group; 701, first electromagnetic reversing valve; 702, second electromagnetic reversing valve; 703, third electromagnetic reversing valve; 704, fourth electromagnetic reversing valve; 705, fifth electromagnetic reversing valve; 706, sixth electromagnetic reversing valve; 707, seventh electromagnetic reversing valve; 708, Eighth solenoid reversing valve; 800, grab support winch motor drive assembly; 801, support winch hydraulic motor; 802, ninth solenoid reversing valve; 803, first electric proportional speed control valve; 804, first relief valve; 900, grab opening and closing winch motor drive assembly; 901, opening and closing winch hydraulic motor; 902, tenth solenoid reversing valve; 903, second electric proportional speed control valve; 904, second relief valve; 110, luffing winch motor drive assembly; 120, slewing motor drive assembly; 1 30. Air-cooled cooler; 131. Fan drive motor; 132. Cooling channel; 140. Control valve group; 150. Support winch brake valve; 160. Support winch brake; 170. Open and close winch brake valve; 180. Open and close winch brake; 190. Luffing winch brake valve; 210. Luffing winch brake; 220. Slewing winch brake valve; 230. Slewing winch brake; 240. Oil supply valve group; 250. Oil tank; 260. Balance valve; 270. Oil supply check valve. DETAILED DESCRIPTION

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0038] It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, such that the embodiments of the present invention described herein can be practiced in an order other than that illustrated or described herein.

[0039] like Figure 1As shown, an open hydraulic system for a dredger according to an embodiment of the present invention includes a first power source 100, a second power source 200, a first pump group 300, a second pump group 400, a third pump group 500, a fourth pump group 600, an oil circuit switching valve group 700, a grab support winch motor drive assembly 800, a grab opening and closing winch motor drive assembly 900, a luffing winch motor drive assembly 110 and a rotary motor drive assembly 120; one of the oil inlet and oil outlet oil circuits of the grab support winch motor drive assembly 800 and the grab opening and closing winch motor drive assembly 900 is provided with a balancing valve 260, and the other is connected to the control port of the balancing valve 260; the first power source 100 simultaneously drives the first pump group 300 and the second pump group 40 0, the second power source 200 simultaneously drives the third pump group 500 and the fourth pump group 600; the first pump group 300 and the third pump group 500 are connected to the grab bucket opening and closing winch motor drive assembly 900 through the oil circuit switching valve group 700, and the second pump group 400 and the fourth pump group 600 are connected to the grab bucket opening and closing winch motor drive assembly 900 through the oil circuit switching valve group 700; the first pump group 300 is also connected to the variable amplitude winch motor drive assembly 110 and the rotary motor drive assembly 120 respectively through the oil circuit switching valve group 700; the third pump group 500 is also connected to the rotary motor drive assembly 120 through the oil circuit switching valve group 700; the fourth pump group 600 is also connected to the variable amplitude winch motor drive assembly 110 through the oil circuit switching valve group 700.

[0040] In this embodiment, a balancing valve 260 is installed in one of the oil inlet and outlet lines of the grab support winch motor drive assembly 800, and the other is connected to the control port of the balancing valve 260. A balancing valve 260 is installed in one of the oil inlet and outlet lines of the grab opening and closing winch motor drive assembly 900, and the other is connected to the control port of the balancing valve 260. The opening of the balancing valve 260 is controlled by the pilot pressure at the oil inlet at the drawworks lowering end. The greater the pilot pressure, the greater the opening of the balancing valve 260, which increases the flow rate and increases the drawworks lowering speed. Conversely, the smaller the pilot pressure, the smaller the opening of the balancing valve 260, which decreases the flow rate and decreases the drawworks lowering speed. Therefore, the opening of the balancing valve 260 is controlled by the active oil supply pressure at the drawworks lowering end, rather than being opened or closed arbitrarily. This prevents the drawworks from stalling due to rapid gravity lowering after the balancing valve 260 is opened, thus ensuring that the balancing valve 260 counteracts stall during the grab lowering process. At the same time, the oil switching valve group 700 rationally combines and cuts off the oil output from the first pump group 300, the second pump group 400, the third pump group 500, and the fourth pump group 600, fully ensuring sufficient oil supply to each winch during normal operation. In addition, if one power source fails, the other power source can complete all corresponding operations at half speed, thereby realizing mutual backup between the first power source 100 and the second power source 200. Ultimately, stable operation of the dredger is achieved.

[0041] Alternatively, as Figures 2 to 6 As shown, the first pump group 300 includes a first variable displacement pump 301, the third pump group 500 includes a third variable displacement pump 501, and the oil circuit switching valve group 700 includes a first solenoid reversing valve 701, a second solenoid reversing valve 702, a third solenoid reversing valve 703, a fourth solenoid reversing valve 704, a fifth solenoid reversing valve 705, and a sixth solenoid reversing valve 706;

[0042] The outlet of the first variable displacement pump 301 is connected to the inlet of the first solenoid reversing valve 701. The outlet of the first solenoid reversing valve 701 is divided into two paths. One path is connected in sequence to the second solenoid reversing valve 702 and the luffing winch motor drive assembly 110, and the other path is connected in sequence to the third solenoid reversing valve 703, the fourth solenoid reversing valve 704, and the slewing motor drive assembly 120. The oil return ports of the first solenoid reversing valve 701, the second solenoid reversing valve 702, the third solenoid reversing valve 703, and the fourth solenoid reversing valve 704 are respectively connected to the oil tank 250.

[0043] The inlet of the fifth solenoid reversing valve 705 is divided into two paths, one path is connected to the outlet of the first variable pump 301, and the other path is connected to the outlet of the sixth solenoid reversing valve 706 and the third variable pump 501 in sequence. The outlet of the fifth solenoid reversing valve 705 is connected to the rotary motor drive assembly 120, and the return oil ports of the fifth solenoid reversing valve 705 and the sixth solenoid valve are respectively connected to the oil tank 250.

[0044] Optionally, the second pump group 400 further includes a second variable pump 401 , the fourth pump group 600 further includes a fourth variable pump 601 , and the oil circuit switching valve group 700 further includes a seventh solenoid reversing valve 707 and an eighth solenoid reversing valve 708 ;

[0045] The outlet of the second variable pump 401 is connected to the inlet of the seventh solenoid reversing valve 707, the outlet of the fourth variable pump 601 is connected to the inlets of the eighth solenoid reversing valve 708 and the seventh solenoid reversing valve 707 in sequence, the two outlets of the seventh solenoid reversing valve 707 are respectively connected to the grab support winch motor drive assembly 800, and the return oil ports of the seventh solenoid reversing valve 707 and the eighth solenoid reversing valve 708 are respectively connected to the oil tank 250.

[0046] In this embodiment, the first power source 100 drives the first transfer case, whose two output ports simultaneously drive the first pump assembly 300 and the second pump assembly 400. The second power source 200 drives the second transfer case, whose two output ports simultaneously drive the third pump assembly 500 and the fourth pump assembly 600.

[0047] Under normal circumstances, the hydraulic oil output by the second variable pump 401 and the hydraulic oil output by the fourth variable pump 601 are combined after being switched by the seventh electromagnetic reversing valve 707, and jointly provide driving pressure oil to the grab bucket supporting winch motor drive assembly 800; the hydraulic oil output by the first variable pump 301 and the hydraulic oil output by the third variable pump 501 are combined after being switched by the fifth electromagnetic reversing valve 705, and jointly provide driving pressure oil to the grab bucket opening and closing winch motor drive assembly 900;

[0048] When luffing and slewing are required, the hydraulic oil output by the fourth variable displacement pump 601 is switched by the second solenoid reversing valve 702 and supplied to the luffing winch motor drive assembly 110. The hydraulic oil output by the third variable displacement pump 501 is switched by the sixth solenoid reversing valve 706 and supplied to the slewing motor drive assembly 120. At this time, due to the oil supply from the third and fourth variable displacement pumps 501 and 601, the dredger's grab support winch motor drive assembly 800 and grab opening and closing winch motor drive assembly 900 operate at half speed.

[0049] When the first power source 100 fails, at this time, the hydraulic oil output by the fourth variable pump 601 is powered on and switched by the eighth electromagnetic reversing valve 708, and then the driving pressure oil is provided to the grab support winch motor drive assembly 800 alone; the hydraulic oil output by the third variable pump 501 is powered on and switched by the sixth electromagnetic reversing valve 706, and then the driving pressure oil is provided to the grab opening and closing winch motor drive assembly 900 alone; the oil supply to other components of the hydraulic system is also halved, which will not be repeated here.

[0050] When luffing and slewing are required, the hydraulic oil output by the fourth variable displacement pump 601 is switched by the sixth solenoid reversing valve 706 and supplied to the luffing winch motor drive assembly 110. The hydraulic oil output by the third variable displacement pump 501 is switched by the eighth solenoid reversing valve 708 and supplied to the slewing motor drive assembly 120. The luffing and slewing actions can be synchronized.

[0051] When the second power source 200 fails, the hydraulic oil output by the first variable pump 301 is used to provide driving pressure oil to the grab bucket opening and closing winch motor drive assembly 900 through the first electromagnetic reversing valve 701 alone; the hydraulic oil output by the second variable pump 401 is used to provide driving pressure oil to the grab bucket supporting winch motor drive assembly 800 through the seventh electromagnetic reversing valve 707 alone; the oil supply to other components of the hydraulic system is also halved, which will not be repeated here.

[0052] When luffing and slewing are required, the hydraulic oil output by the first variable displacement pump 301 is supplied to the luffing winch motor drive assembly 110 after being energized by the first solenoid reversing valve 701. The hydraulic oil output by the first variable displacement pump 301 is supplied to the slewing motor drive assembly 120 after being energized by the first solenoid reversing valve 701 and the third solenoid reversing valve 703. Luffing and slewing are only single-action.

[0053] Optionally, the dredger open hydraulic system further includes an air-cooled cooler 130, the air-cooled cooler 130 includes a fan drive motor 131 and a cooling channel 132, the first pump group 300 further includes a first cooling pump 302, the second pump group 400 further includes a first circulating cooling pump 502, the third pump group 500 further includes a second cooling pump 402, and the fourth pump group 600 further includes a second circulating cooling pump 602;

[0054] The outlets of the first cooling pump 302 and the second cooling pump 402 are connected to the fan drive motor 131 and the oil tank 250 in sequence, respectively. The outlets of the first circulating cooling pump 502 and the second circulating cooling pump 602 are connected to the cooling channel 132 and the oil tank 250 in sequence, respectively.

[0055] In this embodiment, the first cooling pump 302 and the second cooling pump 402 are electric proportional constant pressure variable piston pumps; the first circulating cooling pump 502 and the second circulating cooling pump 602 are fixed displacement pumps. Figure 1 As shown, the first cooling pump 302 and the second cooling pump 402 are used to drive the fan drive motor 131 of the air-cooled cooler 130 to operate for circulating cooling of the hydraulic system oil.

[0056] Optionally, the dredger open hydraulic system further includes a control valve group 140, a supporting winch brake 160, a supporting winch brake valve 150, an opening and closing winch brake 180, an opening and closing winch brake valve 170, a luffing winch brake 210, a luffing winch brake valve 190, a slewing winch brake 230, and a slewing winch brake valve 220; the first pump group 300 further includes a first control pump 303; and the third pump group 500 further includes a second control pump 403;

[0057] The inlet of the control valve group 140 is connected to the outlet of the first control pump 303 and the second control pump 403 respectively. The outlet of the control valve group 140 is divided into four routes. The first route is connected to the supporting winch brake valve 150 and the supporting winch brake 160 in sequence, the second route is connected to the opening and closing winch brake valve 170 and the opening and closing winch brake 180 in sequence, the third route is connected to the variable amplitude winch brake valve 190 and the variable amplitude winch brake 210 in sequence, and the fourth route is connected to the slewing winch brake valve 220 and the slewing winch brake 230 in sequence; the return oil ports of the supporting winch brake valve 150, the opening and closing winch brake valve 170, the variable amplitude winch brake valve 190 and the slewing winch brake valve 220 are respectively connected to the oil tank 250.

[0058] In this embodiment, the first control pump 303 and the second control pump 403 are quantitative pumps, which are used to provide opening pressure oil for each winch brake.

[0059] Optionally, the open hydraulic system of the dredger further includes an oil supply valve group 240, the second pump group 400 further includes a first oil supply pump 503, the third pump group 500 further includes a second oil supply pump 603, and two oil supply check valves 270 are connected in series between the oil inlet and oil outlet circuits of the grab support winch motor drive assembly 800, the grab opening and closing winch motor drive assembly 900, the luffing winch motor drive assembly 110, and the rotary motor drive assembly 120, and the inlets of the two oil supply check valves 270 are connected;

[0060] The inlet of the oil replenishing valve group 240 is connected to the outlet of the first oil replenishing pump 503 and the second oil replenishing pump 603 respectively. The outlet of the oil replenishing valve group 240 is divided into four routes. The first route is connected to the inlet of the two oil replenishing check valves 270 of the grab support winch motor drive assembly 800, the second route is connected to the inlet of the two oil replenishing check valves 270 of the grab opening and closing winch motor drive assembly 900, the third route is connected to the inlet of the two oil replenishing check valves 270 of the variable amplitude winch motor drive assembly 110, and the fourth route is connected to the inlet of the two oil replenishing check valves 270 of the rotary motor drive assembly 120.

[0061] Alternatively, as Figures 2 to 5 As shown, the first pump group 300 further includes a first electromagnetic proportional relief valve 304 , the second pump group 400 further includes a second electromagnetic proportional relief valve 404 , the third pump group 500 further includes a third electromagnetic proportional relief valve 504 , and the fourth pump group 600 further includes a fourth electromagnetic proportional relief valve 604 ;

[0062] The inlet and outlet of the first electromagnetic proportional relief valve 304 are connected to the control port of the first variable pump 301 and the oil tank 250, respectively. The inlet and outlet of the second electromagnetic proportional relief valve 404 are connected to the control port of the second variable pump 401 and the oil tank 250, respectively. The inlet and outlet of the third electromagnetic proportional relief valve 504 are connected to the control port of the third variable pump 501 and the oil tank 250, respectively. The inlet and outlet of the fourth electromagnetic proportional relief valve 604 are connected to the control port of the fourth variable pump 601 and the oil tank 250, respectively. In this way, by controlling the opening sizes of the first electromagnetic proportional relief valve 304, the second electromagnetic proportional relief valve 404, the third electromagnetic proportional relief valve 504, and the fourth electromagnetic proportional relief valve 604, the flow rates of the first variable pump 301, the second variable pump 401, the third variable pump 501, and the fourth variable pump 601 can be controlled.

[0063] Alternatively, as Figure 7 As shown, the grab bucket supporting winch motor drive assembly 800 further includes a supporting winch hydraulic motor 801, a ninth electromagnetic reversing valve 802, a first electric proportional speed regulating valve 803 and a first relief valve 804;

[0064] One working port of the ninth solenoid reversing valve 802 is respectively connected to the balancing valve 260, the outlet of one of the oil-replenishing one-way valves 270, the outlet of the first overflow valve 804 and a working port supporting the winch hydraulic motor 801; another working port of the ninth solenoid reversing valve 802 is connected to a working port of the first electric proportional speed control valve 803; another working port of the first electric proportional speed control valve 803 is respectively connected to the outlet of another oil-replenishing one-way valve 270 and another working port supporting the winch hydraulic motor 801.

[0065] Alternatively, as Figure 8 As shown, the grab bucket opening and closing winch motor drive assembly 900 also includes an opening and closing winch hydraulic motor 901, a tenth electromagnetic reversing valve 902, a second electric proportional speed regulating valve 903 and a second relief valve 904;

[0066] One working port of the tenth solenoid reversing valve 902 is respectively connected to the balancing valve 260, the outlet of one of the oil-replenishing one-way valves 270, the outlet of the second overflow valve 904 and a working port of the opening and closing winch hydraulic motor 901; another working port of the tenth solenoid reversing valve 902 is connected to a working port of the second electric proportional speed control valve 903; another working port of the second electric proportional speed control valve 903 is respectively connected to the outlet of another oil-replenishing one-way valve 270 and another working port of the opening and closing winch hydraulic motor 901.

[0067] Optionally, another outlet of the oil replenishing valve group 240 is divided into two paths, one path is connected to the supporting winch hydraulic motor 801 and the oil tank 250 in sequence, and the other path is connected to the opening and closing winch hydraulic motor 901 and the oil tank 250 in sequence.

[0068] For the grab support winch, when the grab is suspended in the air, the brake of the grab support winch is opened, and the gravity of the grab will generate a driving torque on the support winch hydraulic motor 801 through the grab support winch. This driving torque will form a high-pressure chamber between A051 of the support winch hydraulic motor 801 and the corresponding port b of the balance valve 260, the port a of the first overflow valve 804, and the port b of the ninth electromagnetic reversing valve 802. During the lowering operation of the grab support winch, as the displacement of the second variable pump 401 and the fourth variable pump 601 gradually decreases, the pilot pressure at port C of the balancing valve 260 will inevitably decrease. Consequently, the balancing valve 260 will close accordingly under the action of the spring force, thereby hindering the lowering of the grab support winch. In particular, when the second variable pump 401 and the fourth variable pump 601 stop supplying oil, the corresponding pilot pressure at port C of the balancing valve 260 will completely disappear, causing the balancing valve 260 to completely close. At this time, the lowering of the grab support winch will be completely stopped due to the blocked oil circuit. This is unacceptable when the grab is lowered for dredging, as it will prevent the grab from entering the mud. In order to avoid the influence of the opening change of the balance valve 260 on the descending inertia of the grab bucket when approaching a certain height of the mud entry point, the second variable pump 401 and the fourth variable pump 601 will stop supplying oil at this time. Then the lowering inertia of the grab bucket needs to communicate the A051 and B051 ports of the support winch hydraulic motor 801 to a certain extent, so that the support winch hydraulic motor 801 becomes a free wheel with a certain speed. Different mud entry depths determine the setting of the free wheel speed of the support winch hydraulic motor 801.

[0069] Therefore, in order to prevent the influence of the free wheel supporting the winch hydraulic motor 801 on the inertia of the grab bucket when the balance valve 260 is completely disconnected and then opened, when the second variable pump 401 and the fourth variable pump 601 gradually stop the oil supply control, the ninth electromagnetic reversing valve 802 must be synchronously controlled to be energized and the first electric proportional speed control valve 803 must proportionally increase the control current, so that the inertia of the grab bucket supporting the winch is maintained until the grab bucket is completely put into the mud.

[0070] When the grab bucket is fully immersed in the mud, the tension in the grab bucket support winch wire rope decreases. At this point, the tension change signal is directly fed into the dredger's PLC control system. To prevent the grab bucket support winch from continuing to release the rope due to inertia, the dredger's control system PLC proactively sends a control signal to the first electric proportional speed control valve 803, rapidly reducing the control current to zero and blocking the freewheel of the support winch hydraulic motor 801. This reestablishes high-pressure oil between the support winch hydraulic motor 801 and the closed chamber of the balancing valve 260, hindering the continued operation of the support winch hydraulic motor 801 and preventing the grab bucket support winch from continuing to release the rope. When the current in the first electric proportional speed control valve 803 decreases to zero, the ninth solenoid reversing valve 802 loses power, completely shutting off the freewheel control of the support winch hydraulic motor 801.

[0071] Through the above control, stopping the oil supply of the second variable pump 401 and the fourth variable pump 601 cuts off the obstruction of the winch lowering by the balance valve 260, and opening the ninth electromagnetic reversing valve 802 and the first electric proportional speed control valve 803 supports the free operation of the winch hydraulic motor 801 within the required speed range, effectively ensuring the inertia of the grab bucket entering the mud.

[0072] When the free wheel control is performed on the supporting winch hydraulic motor 801, the supporting winch hydraulic motor 801 will leak during operation due to the lack of main system oil supply, which will inevitably cause air suction. In order to prevent this situation, the system adds two oil replenishment one-way valves 270 between the A051 and B051 ports of the supporting winch hydraulic motor 801. The two oil replenishment one-way valves 270 actively replenish oil to the A051 and B051 sides of the supporting winch hydraulic motor 801, effectively avoiding the existence of air suction.

[0073] When freewheeling the support winch hydraulic motor 801, its self-circulation inevitably generates a significant amount of heat. However, due to the low leakage rate, this heat is dissipated insignificantly. To prevent overheating and malfunction of the support winch hydraulic motor 801, the system incorporates active cold oil flushing at flush port BH2 of the support winch hydraulic motor 801, ensuring sufficient heat dissipation during both normal operation and freewheeling.

[0074] For the grab bucket opening and closing winch, when the grab bucket is suspended in the air, the brake of the grab bucket opening and closing winch is opened, and the gravity of the grab bucket will generate a driving torque on the opening and closing winch hydraulic motor 901 through the grab bucket opening and closing winch. This driving torque will form a high-pressure chamber between A071 of the opening and closing winch hydraulic motor 901 and the b port of the balance valve 260, the a port of the second overflow valve 904, and the b port of the tenth electromagnetic reversing valve 902. During the lowering operation of the grab bucket opening and closing winch, as the displacement of the first variable pump 301 and the third variable pump 501 gradually decreases, the pilot pressure at port C of the corresponding balancing valve 260 will inevitably decrease. Consequently, the balancing valve 260 will close accordingly under the action of the spring force, thereby hindering the lowering of the grab bucket opening and closing winch. In particular, when the first variable pump 301 and the third variable pump 501 stop supplying oil, the pilot pressure at port C of the balancing valve 260 will completely disappear, causing the balancing valve 260 to completely close. At this time, the lowering of the grab bucket opening and closing winch will be completely stopped due to the blocked oil circuit. This is unacceptable when the grab bucket is lowered for dredging, as it will prevent the grab bucket from entering the mud. In order to avoid the influence of the opening change of the balance valve 260 on the descending inertia of the grab bucket when approaching a certain height of the mud entry point, the first variable pump 301 and the third variable pump 501 will stop supplying oil at this time. Then the lowering inertia of the grab bucket needs to communicate the A071 and B071 ports of the opening and closing winch hydraulic motor 901 to a certain extent, so that the opening and closing winch hydraulic motor 901 becomes a free wheel with a certain speed. Different mud entry depths determine the setting of the free wheel speed of the opening and closing winch hydraulic motor 901.

[0075] Therefore, in order to prevent the influence of the free wheel of the opening and closing winch hydraulic motor 901 on the inertia of the grab bucket when the balance valve 260 is completely disconnected, when the first variable pump 301 and the third variable pump 501 gradually stop the oil supply control, it is also necessary to synchronously control the tenth electromagnetic reversing valve 902 to be energized and the second electric proportional speed control valve 903 to proportionally increase the control current, so that the inertia of the grab bucket opening and closing winch is maintained until the grab bucket is completely put into the mud.

[0076] When the grab bucket is fully immersed in the mud, the tension of the grab bucket opening and closing winch wire rope will inevitably decrease. At this time, the tension change signal is directly input into the dredger control system PLC. To prevent the grab bucket opening and closing winch from continuing to release the rope due to inertia, the dredger control system PLC will actively send a control signal to the second electric proportional speed control valve 903, rapidly reducing the control current to zero, blocking the freewheel of the opening and closing winch hydraulic motor 901. This will re-establish high-pressure oil between the opening and closing winch hydraulic motor 901 and the closed chamber of the balance valve 260, blocking the continued operation of the opening and closing winch hydraulic motor 901 and thus preventing the grab bucket opening and closing winch from continuing to release the rope. When the current of the second electric proportional speed control valve 903 decreases to zero, the tenth electromagnetic reversing valve 902 loses power, completely shutting off the freewheel control of the opening and closing winch hydraulic motor 901.

[0077] Through the above control, stopping the oil supply of the first variable pump 301 and the third variable pump 501 cuts off the obstruction of the winch lowering by the balance valve 260, and opening the tenth electromagnetic reversing valve 902 and the second electric proportional speed control valve 903 allows the opening and closing winch hydraulic motor 901 to operate freely within the required speed range, effectively ensuring the inertia of the grab bucket entering the mud.

[0078] When the opening and closing winch hydraulic motor 901 is under free wheel control, the opening and closing winch hydraulic motor 901 will leak during operation due to the lack of oil supply from the main system, which will inevitably cause air suction. In order to prevent this situation, the system adds two oil replenishment one-way valves 270 between the A071 and B071 ports of the opening and closing winch hydraulic motor 901. The two one-way valves actively replenish oil to the A071 and B071 sides of the opening and closing winch hydraulic motor 901, effectively avoiding the existence of air suction.

[0079] When the opening and closing winch hydraulic motor 901 is freewheeling, its self-circulation inevitably generates a significant amount of heat. However, due to the low leakage rate, little heat is removed. To prevent overheating and malfunction of the opening and closing winch hydraulic motor 901, the system has added active cold oil flushing at the flushing port BH3 of the opening and closing winch hydraulic motor 901, ensuring sufficient heat dissipation during normal operation and freewheeling.

[0080] The reader should understand that in the description of this specification, reference to the terms "one embodiment", "some embodiments", "examples", "specific examples" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, different embodiments or examples described in this specification and features of different embodiments or examples can be combined and combined by those skilled in the art without contradiction.

[0081] Although the present disclosure is disclosed as above, the protection scope of the present disclosure is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present disclosure, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. An open hydraulic system for a dredger, characterized in that: The invention comprises a first power source (100), a second power source (200), a first pump group (300), a second pump group (400), a third pump group (500), a fourth pump group (600), an oil circuit switching valve group (700), a grab support winch motor drive assembly (800), a grab opening and closing winch motor drive assembly (900), a luffing winch motor drive assembly (110), and a slewing motor drive assembly (120); One of the oil inlet and oil outlet passages of the grab bucket supporting winch motor drive assembly (800) and the grab bucket opening and closing winch motor drive assembly (900) is provided with a balancing valve (260), and the other is connected to a control port of the balancing valve (260); The first power source (100) drives the first pump group (300) and the second pump group (400) simultaneously, and the second power source (200) drives the third pump group (500) and the fourth pump group (600) simultaneously; the first pump group (300) and the third pump group (500) are connected to the grab bucket opening and closing winch motor drive assembly (900) through the oil circuit switching valve group (700), and the second pump group (400) and the fourth pump group (600) are connected to the grab bucket opening and closing winch motor drive assembly (900) through the oil circuit switching valve group (700). The first pump group (300) is connected to the grab bucket opening and closing winch motor drive assembly (900); the first pump group (300) is also connected to the luffing winch motor drive assembly (110) and the rotary motor drive assembly (120) respectively through the oil circuit switching valve group (700); the third pump group (500) is also connected to the rotary motor drive assembly (120) through the oil circuit switching valve group (700); the fourth pump group (600) is also connected to the luffing winch motor drive assembly (110) through the oil circuit switching valve group (700).

2. The open hydraulic system for dredger according to claim 1, characterized in that: The first pump group (300) includes a first variable displacement pump (301), the third pump group (500) includes a third variable displacement pump (501), and the oil circuit switching valve group (700) includes a first electromagnetic reversing valve (701), a second electromagnetic reversing valve (702), a third electromagnetic reversing valve (703), a fourth electromagnetic reversing valve (704), a fifth electromagnetic reversing valve (705), and a sixth electromagnetic reversing valve (706); The outlet of the first variable displacement pump (301) is connected to the inlet of the first electromagnetic reversing valve (701). The outlet of the first electromagnetic reversing valve (701) is divided into two paths, one path is connected to the second electromagnetic reversing valve (702) and the luffing winch motor drive assembly (110) in sequence, and the other path is connected to the third electromagnetic reversing valve (703), the fourth electromagnetic reversing valve (704) and the rotary motor drive assembly (120) in sequence; the oil return ports of the first electromagnetic reversing valve (701), the second electromagnetic reversing valve (702), the third electromagnetic reversing valve (703) and the fourth electromagnetic reversing valve (704) are respectively connected to the oil tank (250); The inlet of the fifth electromagnetic reversing valve (705) is divided into two paths, one path is connected to the outlet of the first variable pump (301), and the other path is connected to the outlet of the sixth electromagnetic reversing valve (706) and the outlet of the third variable pump (501) in sequence. The outlet of the fifth electromagnetic reversing valve (705) is connected to the rotary motor drive assembly (120), and the oil return ports of the fifth electromagnetic reversing valve (705) and the sixth electromagnetic reversing valve (706) are respectively connected to the oil tank (250).

3. The open hydraulic system for dredger according to claim 2, characterized in that: The second pump group (400) further includes a second variable displacement pump (401), the fourth pump group (600) further includes a fourth variable displacement pump (601), and the oil circuit switching valve group (700) further includes a seventh electromagnetic reversing valve (707) and an eighth electromagnetic reversing valve (708); The outlet of the second variable pump (401) is connected to the inlet of the seventh electromagnetic reversing valve (707), the outlet of the fourth variable pump (601) is connected to the inlets of the eighth electromagnetic reversing valve (708) and the seventh electromagnetic reversing valve (707) in sequence, the two outlets of the seventh electromagnetic reversing valve (707) are respectively connected to the grab support winch motor drive assembly (800), and the oil return ports of the seventh electromagnetic reversing valve (707) and the eighth electromagnetic reversing valve (708) are respectively connected to the oil tank (250).

4. The open hydraulic system for dredger according to claim 3, characterized in that: The system further comprises an air-cooled cooler (130), the air-cooled cooler (130) comprising a fan drive motor (131) and a cooling channel (132), the first pump group (300) further comprising a first cooling pump (302), the second pump group (400) further comprising a first circulating cooling pump (502), the third pump group (500) further comprising a second cooling pump (402), and the fourth pump group (600) further comprising a second circulating cooling pump (602); The outlets of the first cooling pump (302) and the second cooling pump (402) are connected to the fan drive motor (131) and the oil tank (250) in sequence, respectively; the outlets of the first circulating cooling pump (502) and the second circulating cooling pump (602) are connected to the cooling channel (132) and the oil tank (250) in sequence, respectively.

5. The open hydraulic system for dredger according to claim 2, characterized in that: The system further comprises a control valve group (140), a supporting winch brake (160), a supporting winch brake valve (150), an opening and closing winch brake (180), an opening and closing winch brake valve (170), a luffing winch brake (210), a luffing winch brake valve (190), a slewing winch brake (230), and a slewing winch brake valve (220); the first pump group (300) further comprises a first control pump (303); and the third pump group (500) further comprises a second control pump (403); The inlet of the control valve group (140) is connected to the outlet of the first control pump (303) and the outlet of the second control pump (403) respectively. The outlet of the control valve group (140) is divided into four paths. The first path is connected to the supporting winch brake valve (150) and the supporting winch brake (160) in sequence. The second path is connected to the opening and closing winch brake valve (170) and the opening and closing winch brake (180) in sequence. The third path is connected to the luffing winch brake valve (190) and the luffing winch brake (210) in sequence. The fourth path is connected to the slewing winch brake valve (220) and the slewing winch brake (230) in sequence. The oil return ports of the supporting winch brake valve (150), the opening and closing winch brake valve (170), the luffing winch brake valve (190) and the slewing winch brake valve (220) are respectively connected to the oil tank (250).

6. The open hydraulic system for dredger according to claim 2, characterized in that: The invention also includes an oil replenishment valve group (240), the second pump group (400) further includes a first oil replenishment pump (503), the third pump group (500) further includes a second oil replenishment pump (603), and two oil replenishment check valves (270) are connected in series between the oil inlet and oil outlet passages of the grab support winch motor drive assembly (800), the grab opening and closing winch motor drive assembly (900), the luffing winch motor drive assembly (110), and the slewing motor drive assembly (120), and the inlets of the two oil replenishment check valves (270) are connected; The inlet of the oil replenishing valve group (240) is connected to the outlet of the first oil replenishing pump (503) and the outlet of the second oil replenishing pump (603) respectively. The outlet of the oil replenishing valve group (240) is divided into four routes. The first route is connected to the inlet of the two oil replenishing check valves (270) of the grab bucket supporting winch motor drive assembly (800), the second route is connected to the inlet of the two oil replenishing check valves (270) of the grab bucket opening and closing winch motor drive assembly (900), the third route is connected to the inlet of the two oil replenishing check valves (270) of the variable amplitude winch motor drive assembly (110), and the fourth route is connected to the inlet of the two oil replenishing check valves (270) of the rotary motor drive assembly (120).

7. The open hydraulic system for dredger according to claim 3, characterized in that: The first pump group (300) further includes a first electromagnetic proportional relief valve (304), the second pump group (400) further includes a second electromagnetic proportional relief valve (404), the third pump group (500) further includes a third electromagnetic proportional relief valve (504), and the fourth pump group (600) further includes a fourth electromagnetic proportional relief valve (604); The inlet and outlet of the first electromagnetic proportional relief valve (304) are respectively connected to the control port of the first variable pump (301) and the oil tank (250); the inlet and outlet of the second electromagnetic proportional relief valve (404) are respectively connected to the control port of the second variable pump (401) and the oil tank (250); the inlet and outlet of the third electromagnetic proportional relief valve (504) are respectively connected to the control port of the third variable pump (501) and the oil tank (250); and the inlet and outlet of the fourth electromagnetic proportional relief valve (604) are respectively connected to the control port of the fourth variable pump (601) and the oil tank (250).

8. The open hydraulic system for dredger according to claim 6, characterized in that: The grab bucket supporting winch motor drive assembly (800) further includes a supporting winch hydraulic motor (801), a ninth electromagnetic reversing valve (802), a first electric proportional speed regulating valve (803), and a first overflow valve (804); One working port of the ninth solenoid reversing valve (802) is respectively connected to the balancing valve (260), the outlet of one of the oil replenishing one-way valves (270), the outlet of the first overflow valve (804), and a working port of the supporting winch hydraulic motor (801); another working port of the ninth solenoid reversing valve (802) is connected to a working port of the first electric proportional speed control valve (803); another working port of the first electric proportional speed control valve (803) is respectively connected to the outlet of another oil replenishing one-way valve (270) and another working port of the supporting winch hydraulic motor (801).

9. The open hydraulic system for dredger according to claim 8, characterized in that: The grab bucket opening and closing winch motor drive assembly (900) also includes an opening and closing winch hydraulic motor (901), a tenth electromagnetic reversing valve (902), a second electric proportional speed regulating valve (903) and a second overflow valve (904); One working port of the tenth electromagnetic reversing valve (902) is respectively connected to the balance valve (260), the outlet of one of the oil-supplying one-way valves (270), the outlet of the second overflow valve (904), and a working port of the opening and closing winch hydraulic motor (901); another working port of the tenth electromagnetic reversing valve (902) is communicated with a working port of the second electric proportional speed control valve (903); another working port of the second electric proportional speed control valve (903) is respectively connected to the outlet of another oil-supplying one-way valve (270) and another working port of the opening and closing winch hydraulic motor (901).

10. The open hydraulic system for dredger according to claim 9, characterized in that: Another outlet of the oil replenishing valve group (240) is divided into two paths, one path is connected to the supporting winch hydraulic motor (801) and the oil tank (250) in sequence, and the other path is connected to the opening and closing winch hydraulic motor (901) and the oil tank (250) in sequence.

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