Confluence control hydraulic system of loading machine

Abstract

The utility model discloses a loader confluence control hydraulic system which comprises a working hydraulic system, and the working hydraulic system comprises an oil tank, a gear pump, an unloading valve, a pilot oil supply valve, a pilot valve, a shuttle valve, a control valve, a multi-way valve, a movable arm oil cylinder, a rotating bucket oil cylinder, a flow control conversion valve and a variable pump. An oil port b2 of the pilot valve is connected with an oil port b2 of the shuttle valve, the oil port b2 of the shuttle valve is further connected with an oil port a2 of the multi-way valve, meanwhile, the oil port a2 of the pilot valve bypasses the shuttle valve and is directly connected with the oil port b2 of the multi-way valve, two oil outlets, corresponding to the oil port a2 and the oil port b2, of the multi-way valve are connected with a rodless cavity of the movable arm oil cylinder, and therefore a circulating oil way is formed and used for controlling the movable arm oil cylinder to act. Therefore, when the movable arm descends, the variable pumps do not converge, the descending operation comfort is improved, and the use energy consumption is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of loader hydraulic systems, in particular to a loader confluence control hydraulic system. Background Art

[0002] As a widely used construction machinery, loaders have different uses and complex working conditions, which determine the complexity of their hydraulic systems. Currently, common loader hydraulic systems mainly include dual fixed-displacement pump systems, combined fixed-displacement pump and variable-displacement pump systems, and dual variable-displacement pump systems.

[0003] There is a semi-variable confluence hydraulic system for loaders disclosed in Chinese patent announcement number CN218148627U. In this scheme, the variable pump and gear pump are controlled to merge, which can improve work efficiency. However, when the working pressure is high, the confluence of large flow and high pressure will cause large power consumption and waste energy; moreover, when the pilot valve handle is slightly moved (the expected working speed is slow), the variable pump has a large flow confluence, the mid-position loss is large, and the micro-movement performance of the operation is poor; moreover, when the boom is lowered, the variable pump and the gear pump merge to participate in the descent. At this time, as long as the handle is moved and the reversing valve core is opened, the large flow will participate in the descent work. Due to the impact of the large flow, the front section of the descent will be smashed, the driver's operation experience is poor, and the large flow loss causes excess energy loss. Utility Model Content

[0004] The utility model aims to provide a loader confluence control hydraulic system, which can solve the above-mentioned technical problems and has the advantage of reducing the energy consumption of the whole machine.

[0005] In order to achieve the above purpose, the solution of the utility model is:

[0006] A loader confluence control hydraulic system includes a working hydraulic system, the working hydraulic system includes an oil tank, a gear pump, an unloading valve, a pilot oil supply valve, a pilot valve, a shuttle valve, a control valve, a multi-way valve, a boom cylinder, a bucket cylinder, a flow control conversion valve and a variable pump;

[0007] The oil suction port of the gear pump is connected to the oil tank, and the oil outlet of the gear pump is connected to the multi-way valve via the unloading valve;

[0008] The oil suction port of the variable pump is connected to the oil tank; an oil outlet of the variable pump is simultaneously connected to the P port of the flow control conversion valve, the pilot oil supply valve and the P3 port of the control valve;

[0009] The EF port of the flow control conversion valve is connected to the oil circuit between the unloading valve and the multi-way valve, forming a confluence of the variable pump and the working quantitative gear pump, and supplying oil to the multi-way valve;

[0010] The pilot oil supply valve is connected to the P port of the pilot valve; the oil ports a1 and b1 of the pilot valve are connected to the oil ports a1 and b1 of the shuttle valve, and the oil ports a1 and b1 of the shuttle valve are connected to the oil ports b1 and a1 of the multi-way valve, and the two oil outlets of the multi-way valve corresponding to the oil ports b1 and a1 are connected to the rodless chamber of the bucket cylinder, thereby forming a circulating oil circuit for controlling the action of the bucket cylinder;

[0011] The oil port b2 of the pilot valve is connected to the oil port b2 of the shuttle valve, and the oil port b2 of the shuttle valve is connected to the oil port a2 of the multi-way valve. At the same time, the oil port a2 of the pilot valve bypasses the shuttle valve and is directly connected to the oil port b2 of the multi-way valve, and the two oil outlets of the multi-way valve corresponding to the oil ports a2 and b2 are connected to the rodless chamber of the boom cylinder, thereby forming a circulating oil circuit for controlling the action of the boom cylinder.

[0012] The oil inlet P1 of the control valve is connected to an oil outlet c of the shuttle valve to collect the pressure signal from the shuttle valve; an oil outlet P4 of the control valve is connected to an oil inlet of the variable pump to control the flow of the variable pump;

[0013] The oil outlet P5 of the control valve is connected to the LS port of the flow control switching valve;

[0014] The T ports of the unloading valve, pilot valve, pilot oil supply valve, flow control conversion valve, multi-way valve and control valve are all connected to the oil tank; the oil return port of the steering constant power variable piston pump is also connected to the oil tank.

[0015] Furthermore, it also includes a steering hydraulic system, which includes the variable pump, the flow control conversion valve, a high-pressure steering gear, a pressure reducing valve, the control valve and a steering cylinder;

[0016] The oil outlet of the variable pump is also connected to the P1 port of the pressure reducing valve;

[0017] The oil outlet P2 of the pressure reducing valve is connected to the port a and port b of the flow control conversion valve through the high-pressure steering gear, and the port A and port B of the flow control conversion valve are connected to the rodless chamber of the steering cylinder;

[0018] The oil outlet P2 of the control valve is connected to the LS port of the high-pressure steering gear;

[0019] The T port of the pressure reducing valve is connected to the oil tank.

[0020] Furthermore, the variable displacement pump adopts a steering constant power variable displacement piston pump, and the gear pump is a working fixed displacement gear pump.

[0021] Furthermore, the oil suction port of the gear pump and the oil tank are provided with an oil suction filter.

[0022] Furthermore, the T-ports of the unloading valve, the pilot valve, the pilot oil supply valve, the flow control conversion valve, the multi-way valve and the pressure reducing valve are all connected to the oil tank through the hydraulic radiator and the oil return valve core.

[0023] After adopting the above technical solution, the utility model has the following technical effects:

[0024] The variable pump for lowering the boom does not merge, which improves the comfort of lowering operation and reduces energy consumption. The use of a steering constant power variable piston pump reduces the energy consumption of the entire machine on the basis of a fixed variable hydraulic system; 3. A control valve is used to control the combined flow of the steering constant power variable piston pump to avoid high-pressure unloading, overflow loss, mid-position bypass loss, and throttling loss, reduce the heat generated by the hydraulic system, reduce energy consumption, improve the reliability of hydraulic components, and at the same time improve the controllability of the vehicle's working device; BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A system schematic diagram of an embodiment of the utility model;

[0026] Figure 2 This is a test data diagram of an embodiment of the present utility model.

[0027] Explanation of reference numerals: oil tank 1, variable pump 2, steering constant power variable piston pump 2a, gear pump 3, working quantitative gear pump 3a, control valve 4, high-pressure steering gear 5, flow control conversion valve 6, pressure reducing valve 7, steering cylinder 8, unloading valve 9, multi-way valve 10, shuttle valve 11, pilot valve 12, pilot oil supply valve 13, boom cylinder 14, bucket cylinder 15, oil suction filter element 16, hydraulic radiator 17, oil return valve core 18. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0029] like Figure 1 As shown, the utility model is a loader confluence control hydraulic system, which is mainly composed of an oil tank 1, a variable pump 2, a gear pump 3, a control valve 4, a high-pressure steering gear 5, a flow control conversion valve 6, a pressure reducing valve 7, a steering cylinder 8, an unloading valve 9, a multi-way valve 10, a shuttle valve 11, a pilot valve 12, a pilot oil supply valve 13, a boom cylinder 14, a bucket cylinder 15 and the like.

[0030] In this embodiment, the variable displacement pump 2 is a steering constant power variable displacement piston pump 2a, and the gear pump 3 is a working fixed displacement gear pump 3a.

[0031] The oil suction port of the working quantitative gear pump 3 a is connected to the oil tank 1 , and the oil outlet of the working quantitative gear pump 3 a is connected to the multi-way valve 10 via the unloading valve 9 .

[0032] The oil suction port of the steering constant power variable displacement piston pump 2a is connected to the oil tank 1, and an oil suction filter element 16 may be provided between the two for filtering.

[0033] An oil outlet of the steering constant power variable displacement piston pump 2a is simultaneously connected to the P port of the flow control conversion valve, the P1 port of the pressure reducing valve 7, the pilot oil supply valve 13 and the P3 port of the control valve.

[0034] The EF port of the flow control conversion valve 6 is connected to the oil circuit between the unloading valve 9 and the multi-way valve 10, forming a confluence of the steering constant power variable piston pump 2a and the working quantitative gear pump 3a and supplying oil to the multi-way valve 10.

[0035] The oil outlet P2 of the pressure reducing valve 7 is connected to the a port and the b port of the flow control conversion valve 6 through the high-pressure steering gear 5 , and the A port and the B port of the flow control conversion valve 6 are connected to the rodless chamber of the steering cylinder 8 .

[0036] The pilot oil supply valve 13 is connected to the P port of the pilot valve 12;

[0037] The oil ports a1 and b1 of the pilot valve 12 are connected to the oil ports a1 and b1 of the shuttle valve 11, and the oil ports a1 and b1 of the shuttle valve 11 are connected to the oil ports b1 and a1 of the multi-way valve 10. The two oil outlets of the multi-way valve 10 corresponding to the oil ports b1 and a1 are connected to the rodless chamber of the bucket cylinder 15, thereby forming a circulating oil circuit for controlling the action of the bucket cylinder 15.

[0038] The oil port b2 of the pilot valve 12 is connected to the oil port b2 of the shuttle valve 11, and the oil port b2 of the shuttle valve 11 is connected to the oil port a2 of the multi-way valve 10. At the same time, the oil port a2 of the pilot valve 12 bypasses the shuttle valve 11 and is directly connected to the oil port b2 of the multi-way valve 10, and the two oil outlets of the multi-way valve 10 corresponding to the oil ports a2 and b2 are connected to the rodless chamber of the boom cylinder 14, thereby forming a circulating oil circuit for controlling the movement of the boom cylinder 14.

[0039] The oil inlet P1 of the control valve 4 is connected to an oil outlet c of the shuttle valve 11 to collect the pressure signal from the shuttle valve 11; an oil outlet P4 of the control valve 4 is connected to an oil inlet of the steering constant power variable piston pump 2a to control the flow of the steering constant power variable piston pump 2a; the other two oil outlets P5 and P2 of the control valve 4 are respectively connected to the LS port of the flow control conversion valve 6 and the LS port of the high-pressure steering gear 5; the T port of the control valve 4 is connected to the T port of the flow control conversion valve 6.

[0040] The T ports of the unloading valve 9, the pilot valve 12, the pilot oil supply valve 13, the flow control conversion valve 6, the multi-way valve 10 and the pressure reducing valve 7 are all connected to the oil tank 1 through the hydraulic radiator 17 and the oil return valve core 18 for returning oil; the oil return port of the steering constant power variable piston pump 2a is also connected to the oil tank 1.

[0041] In combination with the above, the working principle of the utility model is:

[0042] The confluence control hydraulic system of the utility model comprises a steering hydraulic system and a working hydraulic system.

[0043] The steering hydraulic system is mainly composed of a steering constant power variable piston pump 2a, a flow control conversion valve 6, a high-pressure steering gear 5, a pressure reducing valve 7, a control valve 4 and a steering cylinder 8. When steering, the steering constant power variable piston pump 2a supplies oil on demand according to the steering speed and angle change, and the high-pressure signal oil output by the high-pressure steering gear 5 and the high-pressure oil output by the flow control conversion valve 6 enter the steering cylinder 8 together to participate in steering, thereby reducing energy consumption loss.

[0044] The working hydraulic system is mainly composed of a working quantitative gear pump 3a, an unloading valve 9, a pilot oil supply valve 13, a pilot valve 12, a shuttle valve 11, a control valve 4, a multi-way valve 10, a boom cylinder 14, a bucket cylinder 15, a flow control conversion valve 6 and a steering constant power variable piston pump 2a. When the working system pressure reaches a high level, a high pressure and a small flow rate can meet the normal operation of the system, and the working quantitative gear pump 3a is unloaded by low pressure to avoid high pressure overflow loss.

[0045] The utility model can have at least the following benefits:

[0046] 1. The steering constant power variable piston pump 2a can be controlled to a kw. When the power consumption of the steering constant power variable piston pump 2a of the confluence control hydraulic system is less than a kw, at this time (a kw (power consumption) = P (pressure) * Q (flow) / 600 < akw) the steering constant power variable piston pump 2a will not adjust the output flow Q due to the change of load P. When the power consumption of the hydraulic system reaches akw, at this time (a kw = P * Q / 600 = a kw) the steering constant power variable piston pump 2a will adjust the output flow Q according to the real-time load P change to maintain the hydraulic system a kw constant. If the load P increases, the flow Q decreases, and if the load P decreases, the flow Q increases.

[0047] The constant power control function of the constant power variable piston pump 2a can adjust the output flow Q of the constant power variable piston pump 2a according to the real-time load P, maintain constant power consumption, reduce the mid-position bypass energy loss, and improve the energy consumption economy.

[0048] 2. The output pressure of the pilot valve 12 is 0 - Px bar. By adjusting the opening pressure of the control valve 4 to be Py bar (0 < Py < Px), as long as the handle of the pilot valve is slightly moved (the output pressure of the pilot valve 12 is less than Py bar), the shuttle valve 11 will feedback the pilot pressure signal to the control valve 4 (through the oil circuit between port c of the shuttle valve 11 and port P1 of the control valve 4). At this time, the pilot pressure is less than the opening pressure of the control valve 4, and the control valve 4 does not open, and the steering constant power variable piston pump 2a operates at the minimum displacement. If the handle is moved significantly (the output pressure of the pilot valve 12 is greater than Py bar), the shuttle valve 11 will feedback this pilot pressure signal to the control valve 4. At this time, the pilot pressure is greater than the opening pressure of the control valve 4, and the spool of the control valve 4 moves leftward, and the steering constant power variable piston pump 2a confluences at the maximum displacement. In this way, when the handle is slightly moved (expecting a slower working speed), the confluence flow of the variable pump 2 can be reduced, and the energy consumption waste of the middle bypass can be reduced. When the handle is moved significantly (expecting a faster working speed), the two pumps can confluence at the maximum displacement, enabling fast operation and improving production efficiency.

[0049] 3. Since the oil port a2 of the pilot valve 12 bypasses the shuttle valve 11 and is directly connected to the oil port b2 of the multi-way valve 10, that is, the descending pilot pressure signal of the pilot valve 12 does not access the shuttle valve 11, and the descending pilot pressure signal will not be feedback to the control valve 4, that is, the control valve 4 does not open, and the steering constant power variable piston pump 2a operates at the minimum displacement, avoiding the slamming phenomenon that occurs in the front section of the descent due to the large-flow impact when the reversing spool of the multi-way valve 10 just opens, improving the driver's operating experience and reducing the redundant energy consumption caused by flow loss. At the same time, when the boom descends rapidly, it can achieve rapid descent only by relying on the self-weight of the working device, and the flow of the steering constant power variable piston pump 2a will not confluence into the working hydraulic system, reducing the energy consumption waste of the middle bypass.

[0050] In this state, when the boom descends rapidly, since the steering constant power variable piston pump 2a does not participate in the confluence operation, it may cause the rod chamber of the boom cylinder 14 to have a suction void (negative pressure) phenomenon. However, through actual testing, no suction void (negative pressure) occurred in the rod chamber during the whole process. The test data is as Figure 2 shown. During the peak segment (10 - 12) of the pilot pressure in the small chamber of the boom, the corresponding value of the pressure in the small chamber of the boom is always greater than 0 and does not drop below 0, thus proving that no suction void situation occurred.

[0051] The above is only the preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for those of ordinary skill in the art in this technical field, equivalent changes and modifications made without departing from the principle of the present invention should still fall within the protection scope of the present invention.

[0052] In the description of the embodiments of the present application, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

Claims

1. A loader confluence control hydraulic system, characterized in that: It includes a working hydraulic system, which includes an oil tank, a gear pump, an unloading valve, a pilot oil supply valve, a pilot valve, a shuttle valve, a control valve, a multi-way valve, a boom cylinder, a bucket cylinder, a flow control conversion valve and a variable pump; The oil suction port of the gear pump is connected to the oil tank, and the oil outlet of the gear pump is connected to the multi-way valve via the unloading valve; The oil suction port of the variable pump is connected to the oil tank; an oil outlet of the variable pump is simultaneously connected to the P port of the flow control conversion valve, the pilot oil supply valve and the P3 port of the control valve; The EF port of the flow control conversion valve is connected to the oil circuit between the unloading valve and the multi-way valve, forming a confluence of the variable pump and the working quantitative gear pump, and supplying oil to the multi-way valve; The pilot oil supply valve is connected to the P port of the pilot valve; the oil ports a1 and b1 of the pilot valve are connected to the oil ports a1 and b1 of the shuttle valve, and the oil ports a1 and b1 of the shuttle valve are connected to the oil ports b1 and a1 of the multi-way valve, and the two oil outlets of the multi-way valve corresponding to the oil ports b1 and a1 are connected to the rodless chamber of the bucket cylinder, thereby forming a circulating oil circuit for controlling the action of the bucket cylinder; The oil port b2 of the pilot valve is connected to the oil port b2 of the shuttle valve, and the oil port b2 of the shuttle valve is connected to the oil port a2 of the multi-way valve. At the same time, the oil port a2 of the pilot valve bypasses the shuttle valve and is directly connected to the oil port b2 of the multi-way valve, and the two oil outlets of the multi-way valve corresponding to the oil ports a2 and b2 are connected to the rodless chamber of the boom cylinder, thereby forming a circulating oil circuit for controlling the action of the boom cylinder. The oil inlet P1 of the control valve is connected to an oil outlet c of the shuttle valve to collect the pressure signal from the shuttle valve; an oil outlet P4 of the control valve is connected to an oil inlet of the variable pump to control the flow of the variable pump; The oil outlet P5 of the control valve is connected to the LS port of the flow control switching valve; The T ports of the unloading valve, pilot valve, pilot oil supply valve, flow control conversion valve, multi-way valve and control valve are all connected to the oil tank; the variable pump adopts a steering constant power variable piston pump, and the return oil port of the steering constant power variable piston pump is also connected to the oil tank.

2. A loader confluence control hydraulic system according to claim 1, characterized in that: It also includes a steering hydraulic system, which includes the variable pump, the flow control conversion valve, a high-pressure steering gear, a pressure reducing valve, the control valve and a steering cylinder; The oil outlet of the variable pump is also connected to the P1 port of the pressure reducing valve; The oil outlet P2 of the pressure reducing valve is connected to the port a and port b of the flow control conversion valve through the high-pressure steering gear, and the port A and port B of the flow control conversion valve are connected to the rodless chamber of the steering cylinder; The oil outlet P2 of the control valve is connected to the LS port of the high-pressure steering gear; The T port of the pressure reducing valve is connected to the oil tank.

3. A loader confluence control hydraulic system according to claim 1 or 2, characterized in that: The gear pump is a fixed displacement gear pump.

4. A loader confluence control hydraulic system according to claim 1 or 2, characterized in that: The oil suction port of the gear pump and the oil tank are provided with an oil suction filter element.

5. A loader confluence control hydraulic system according to claim 2, characterized in that: The T ports of the unloading valve, the pilot valve, the pilot oil supply valve, the flow control conversion valve, the multi-way valve and the pressure reducing valve are all connected to the oil tank through the hydraulic radiator and the oil return valve core.

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