Large-flow load-sensitive multi-way valve and control system thereof

Abstract

The utility model discloses a high-flow load-sensitive multi-way valve and a control system thereof. The problems that an existing loader control system is unreliable in compound action and large in impact during confluence are solved. The system comprises a large-flow load-sensitive multi-way valve; the valve body is provided with a first oil inlet, a feedback oil way, an oil return port, a first working oil port and a second working oil port; the second oil inlet is connected with the first pump and used for feeding oil; the first oil inlet and the second oil inlet are matched with each other and convey oil to the first reversing valve and / or the second reversing valve; the anti-impact valve comprises an unloading valve element, a first damper and a second damper. The second oil inlet is connected with the oil return port through the unloading valve core; pressure oil of the first damping oil outlet, pressure oil of the second damping oil outlet and set elastic force of the unloading valve element spring cavity interact to control an opening of the unloading valve element. The utility model has the advantages of simple structure, reliable action, long service life and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to an engineering vehicle control system, concretely relates to a large flow load sensitive multiway valve and control system thereof. BACKGROUND

[0002] Engineering vehicles are the main force of a construction project, and the appearance of engineering vehicles has multiplied the progress of the construction project and greatly reduced manpower. Existing engineering vehicles include loaders, bulldozers, road rollers and the like. Taking a loader as an example, the loader is an important component in engineering machinery, and the energy saving of the whole machine is of great significance to the low-carbon and environmentally-friendly economic transformation of the whole engineering machinery industry. Energy saving and high efficiency have become an important development direction of the loader industry. With the full implementation of the "national fourth" standard and the rapid development of engineering machinery, engineering machinery vehicles are exported in large quantities, and customers have higher and higher requirements on the efficiency, controllability and energy saving of the whole machine. However, the domestic key core hydraulic components are lacking and immature, especially the large flow load sensitive multiway valve, which has long relied on imports, and the host factory has long been plagued by high component cost and long supply cycle.

[0003] At present, most of the existing loaders adopt open center multiway valves, and the principle is as shown in Figure 1 、 2 The existing open center multiway valve directly connects the boom working link and the bucket working link, and the rotating working link action is unreliable during the composite action. The control system using the multiway valve has a very complex structure, and the structure is unreliable when the two pumps are combined. The impact is also large when the flow is too large. Although the system has the advantages of simple structure and low price, there are still several problems: on the one hand, the work efficiency is low, the overflow loss is large, and the heat generation is large, which leads to low work efficiency, and more fuel is consumed for the same work load of loading and unloading; on the other hand, the instantaneous pressure impact is large; thirdly, there is no compensation function, the flow is greatly affected by the load and the inlet pressure, and the composite action effect of the boom and the bucket is poor. UTILITY MODEL CONTENTS

[0004] In order to solve the problem of unreliable composite action and large impact when combining of the existing loader control system in the background art, the utility model provides a large flow load sensitive multiway valve and control system thereof.

[0005] The technical scheme of the utility model is: a large flow load sensitive multiway valve, comprising a valve body, a first oil inlet, a feedback oil way, a return oil port, a first working oil port and a second working oil port are arranged on the valve body; further comprising:

[0006] A first reversing valve is arranged in the valve body and is in sliding cooperation with the valve body, and the first reversing valve is arranged corresponding to the first working oil port;

[0007] The second reversing valve is arranged in the valve body and is in sliding cooperation with the valve body, and the second reversing valve is arranged correspondingly to the second working oil port;

[0008] The second oil inlet is connected with the first pump for oil inlet, and the first oil inlet and the second oil inlet are matched with each other and deliver oil to the first reversing valve and / or the second reversing valve.

[0009] The shock resistance valve comprises an unloading valve core, a first damping and a second damping, the second oil inlet is connected with the oil return port through the unloading valve core, pressure oil of the second oil inlet is connected with the unloading valve core control cavity through the first damping, pressure oil of the feedback oil path is connected with the spring cavity of the unloading valve core through the second damping, and pressure oil of the first damping oil outlet and pressure oil of the second damping oil outlet interact with the set elastic force of the spring cavity of the unloading valve core to control the opening of the unloading valve core.

[0010] As a further improvement of the utility model, the third reversing valve is arranged between the second oil inlet and the first damping.

[0011] As a further improvement of the utility model, the feedback oil path is connected with the control cavity of the third reversing valve, pressure oil of the feedback oil path and the set elastic force of the third reversing valve are matched to control the opening of the third reversing valve.

[0012] As a further improvement of the utility model, the third reversing valve is arranged between the second oil inlet and the first damping.

[0013] The first pressure compensator, pressure oil of the second oil inlet and / or the first oil inlet is connected with the first pressure compensator through the first reversing valve, and the oil outlet of the first pressure compensator is connected with the feedback oil path and the first working oil port through the first reversing valve.

[0014] The second pressure compensator, pressure oil of the second oil inlet and / or the first oil inlet is connected with the second pressure compensator through the second reversing valve, and the oil outlet of the second pressure compensator is connected with the feedback oil path and the second working oil port through the second reversing valve.

[0015] As a further improvement of the utility model, the compensating check valve is arranged between the oil outlet of the first pressure compensator and the feedback oil path and between the oil outlet of the second pressure compensator and the feedback oil path, and is used for picking up feedback oil pressure of the feedback oil path.

[0016] As a further improvement of the utility model, the overload valve is arranged between the second oil port and the oil return port, and is used for overload protection.

[0017] As a further improvement of the utility model, the third reversing valve is arranged between the second oil inlet and the first damping.

[0018] A main overflow valve is arranged to receive pressure oil from the first inlet and / or the second inlet, and the outlet of the main overflow valve is connected to the return port to improve the safety of the system.

[0019] A feedback overflow valve is arranged between the feedback oil path and the return port to provide overload protection.

[0020] As a further improvement of the utility model, the feedback oil path comprises a first feedback channel and a second feedback channel, the feedback overflow valve is arranged on the second feedback channel, a third damper is arranged between the first feedback channel and the second feedback channel, and a constant flow valve is arranged on the first feedback channel and connected to the return port.

[0021] As a further improvement of the utility model, the utility model further comprises an extension link, the extension link is provided with a fourth reversing valve and a third working oil port, the extension link is arranged on the valve body and detachably connected to the valve body, the fourth reversing valve is in sliding cooperation with the extension link, and the fourth reversing valve receives pressure oil from the first inlet and / or the second inlet and is correspondingly arranged with the third working oil port.

[0022] A control system comprises:

[0023] The large-flow load-sensitive multi-way valve described above;

[0024] A second pump is arranged to provide pressure oil;

[0025] A steering power source is arranged to control the steering of the product;

[0026] A steering priority valve is connected to the second pump and connected to the steering power source and the first inlet respectively, and is arranged to preferentially supply oil to the steering power source;

[0027] A selection shuttle valve is arranged to select feedback oil from the steering priority valve and the feedback oil path and connected to the second pump, and is arranged to control the output of the second pump;

[0028] A pilot control oil source is arranged to provide a pilot oil source.

[0029] The utility model has the advantages that the impact-resistant valve is arranged to protect the system from pressure impact and prolong the service life of elements. BRIEF DESCRIPTION OF DRAWINGS

[0030] ATTACHMENT Figure 1 It is a structural schematic view of the existing loader multi-way valve.

[0031] ATTACHMENT Figure 2It is a structural schematic diagram of an existing loader control system.

[0032] Attached Figure 3 It is a structural schematic diagram of an embodiment of the utility model.

[0033] Attached Figure 4 It is a hydraulic principle schematic diagram of the loader control system of an embodiment of the utility model.

[0034] Attached Figure 5 It is a hydraulic principle schematic diagram of a multi-way valve of an embodiment of the utility model.

[0035] In the figure, 1, valve body; 11, first working oil port; 12, second working oil port; 2, first reversing valve; 3, second reversing valve; 4, impact-resistant valve; 41, unloading valve core; 42, first damping; 43, second damping; 44, third reversing valve; 51, first pressure compensator; 52, second pressure compensator; 53, compensating check valve; 54, overload valve; 6, main overflow valve; 71, feedback overflow valve; 72, first feedback channel; 73, second feedback channel; 74, third damping; 75, constant flow valve; 8, expansion link; 81, fourth reversing valve; 82, third working oil port; 91, second pump; 92, steering power source; 93, steering priority valve; 94, selection shuttle valve; 95, pilot control oil source; 96, first pump; 97, multi-way valve; P1, first oil inlet; P2, second oil inlet; LS, feedback oil circuit; T, oil return port. DETAILED DESCRIPTION

[0036] The embodiments of the utility model are further described below in combination with the drawings:

[0037] By Figure 3 In combination Figures 4-5 As shown in the figure, a large-flow load-sensitive multi-way valve comprises a valve body 1, the valve body is provided with a first oil inlet P1, a feedback oil circuit LS, an oil return port T, a first working oil port 11 and a second working oil port 12; further comprising:

[0038] A first reversing valve 2 is arranged in the valve body and is in sliding cooperation with the valve body, and the first reversing valve is arranged in correspondence with the first working oil port;

[0039] A second reversing valve 3 is arranged in the valve body and is in sliding cooperation with the valve body, and the second reversing valve is arranged in correspondence with the second working oil port;

[0040] A second oil inlet P2 is connected with the first pump 96 and is used for oil inlet; the first oil inlet and the second oil inlet cooperate with each other and deliver oil to the first reversing valve and / or the second reversing valve;

[0041] The anti-impact valve 4 includes an unloading valve core 41, a first damper 42, and a second damper 43. The second oil inlet is connected to the return oil port through the unloading valve core. The pressure oil in the second oil inlet is connected to the control chamber of the unloading valve core through the first damper. The pressure oil in the feedback oil circuit is connected to the spring chamber of the unloading valve core through the second damper. The pressure oil at the first damper outlet, the pressure oil at the second damper outlet, and the set elastic force of the unloading valve core spring chamber interact to control the opening of the unloading valve core. The beneficial effects of this invention are that the anti-impact valve protects the system from pressure shocks and extends the service life of components. When the system encounters sudden heavy loads, rapid movement, or frequent cylinder extension and retraction, the variable pump may not respond to the load change in time to adjust the output pressure. The anti-impact valve can respond quickly and eliminate pressure peaks. This invention also has the advantages of simple structure, reliable operation, and long service life. The multi-way integrated anti-impact valve of this invention has a low-pressure unloading function, making the system more energy-efficient; it also has high-pressure overflow, improving product safety performance. This system significantly reduces the number of parts, resulting in a cost reduction of approximately 40% compared to existing systems.

[0042] This invention also includes a third directional valve 44, which is located between the second oil inlet and the first damper. Specifically, the feedback oil circuit is connected to the control chamber of the third directional valve, and the pressure oil in the feedback oil circuit and the elastic force of the third directional valve cooperate to control the opening of the third directional valve. In this invention, P2 is connected to a fixed displacement gear pump, and P1 is connected to the EF port of the variable displacement pump in the steering system. Under the premise of ensuring priority steering, flow merging can be achieved. That is, when steering is not in progress, the variable displacement pump picks up the load pressure through the shuttle valve, and the variable displacement pump oil enters P1 through the priority valve stem, merging with the gear pump, greatly increasing the flow rate of the working system and improving the overall working efficiency. The first-connect integrated anti-shock valve is set at a low pressure (approximately 10-15 bar) as a three-way flow valve to ensure the pressure differential at the outlet of the fixed displacement pump. When not in operation, it unloads at low pressure. When connected to a variable displacement pump, the anti-shock valve is set at a slightly higher pressure than the differential pressure valve of the load-sensitive pump (approximately 30-35 bar). After the valve core quickly returns to the neutral position, the P port pressure oil seals the valve. The variable displacement pump mechanism requires time to respond. According to tests, the anti-shock valve can eliminate the pressure peak from the pump outlet to the valve, eliminating hydraulic shock and extending the service life of the pump and valve. In this invention, the bridge circuit composed of the unloading valve core and the first and second dampers can be designed to match the vehicle's operating conditions. The dynamic response of the working structure is good, allowing for precise control and a wide range of applicability.

[0043] This utility model also includes:

[0044] The first pressure compensator 51, the pressure oil of the second oil inlet and / or the first oil inlet is connected with the first pressure compensator through the first reversing valve, and the oil outlet of the first pressure compensator is connected with the feedback oil path and the first working oil inlet through the first reversing valve respectively;

[0045] The second pressure compensator 52, the pressure oil of the second oil inlet and / or the first oil inlet is connected with the second pressure compensator through the second reversing valve, and the oil outlet of the second pressure compensator is connected with the feedback oil path and the second working oil inlet through the second reversing valve respectively. Specifically, the compensating check valve 53 is arranged between the oil outlet of the first pressure compensator and the feedback oil path and between the oil outlet of the second pressure compensator and the feedback oil path, and is used for picking up the feedback oil pressure of the feedback oil path. The load-sensitive control of the multi-way valve has good fine-tuning performance, can realize simultaneous action of multiple execution structures, and is irrelevant to flow and load. Each valve core (the first reversing valve, the second reversing valve and the fourth reversing valve) can be independently arranged with flow and pressure, can realize rapid and accurate control on each control mechanism, and improves the stability and reliability of the whole machine action. The compensating valve core (the pressure compensator) of the multi-way valve is provided with the check valve (the compensating check valve) function, and can prevent load action from sliding down. When the complex action of the bucket and the boom is performed, when there is a difference between the load pressures of the two actions, the load pressure demand of one of the two is high, and the action of the one can slide down due to the fact that the pressure is not established enough to overcome the load; the compensating valve core is provided with the check valve function, can be opened only when the P port pressure is greater than the load demand pressure, and ensures the safety of the loader operation. When the complex action is performed, the LS picks up the pressure, the boom and the rotating bucket all feed the load pressure to the pump, the pump adjusts the swash plate swing angle to control the output after picking up the highest pressure, and if the check valve is not arranged, the high-pressure oil can press the compensator at the low load end, and the compensator cannot be opened.

[0046] The utility model further includes the overload valve 54, is arranged between the second oil port and the oil return port, is used for load overload protection. Usually overload valve setting and rotating bucket work are connected, avoid rotating bucket to exceed setting down work, improve system and operator safety performance. Actually the utility model further sets up boom big cavity load keeps check valve, prevents boom from automatic retraction, and boom small cavity oil supplement check valve is used for oil supplement.

[0047] The utility model further includes:

[0048] The main overflow valve 6 is used for receiving the pressure oil of the first oil inlet and / or the second oil inlet, the oil outlet of the main overflow valve is connected with the oil return port, and is used for improving the safety performance of the system.

[0049] A feedback overflow valve 71 is arranged between the feedback oil path and the oil return port for overload protection.

[0050] The utility model further includes an extension link 8, fourth reversing valve 81 and third working oil port 82 are equipped on the extension link, the extension link is equipped on the valve body and is with the valve body can detachable connection, fourth reversing valve and extension link slip fit, fourth reversing valve receives the pressure oil of first oil inlet and / or second oil inlet and is with third working oil port corresponding setting.

[0051] A control system comprising:

[0052] The large-flow load-sensitive multi-way valve 97 described above;

[0053] A second pump 91 for providing pressure oil;

[0054] A steering power source 92 for controlling product steering;

[0055] A steering priority valve 93 connected to the second pump and connected to the steering power source and the first oil inlet respectively for preferentially supplying oil to the steering power source;

[0056] A selection shuttle valve 94 selecting the feedback oil at the steering priority valve and the feedback oil path and connected to the second pump for controlling the second pump output;

[0057] The pilot control oil source 95 is used for providing a pilot oil source. The utility model discloses a high -efficient energy -conserving hydraulic system, and the steering system is load -sensitive variable system, and the working system is quantitative pump system. That is, the first pump is a quantitative pump, and the second pump is a variable pump, and specifically, the second pump is a load -sensitive variable pump. The hydraulic system variable pump outlet of the utility model is equipped with an anti -shock valve, protects the system from pressure impact, prolongs the service life of element, when the steering joint or the working joint oil cylinder suddenly encounters huge load, fast movement or the oil cylinder frequently telescopes etc. Working condition, the variable pump has not changed the output pressure in time in response to load change, and the anti -shock valve can respond quickly, and eliminate the pressure peak value. The utility model discloses a hydraulic system steering pressure cut -off function load -sensitive pump, when the oil cylinder reaches the limit working condition, the quantitative pump unloads first, and the pump carries out pressure cut -off again, under the condition that the system pressure and flow requirement are satisfied, there is no redundant flow loss, and the whole system efficiency is very high, and the valve is combined with the compensation main valve, and the composite action is good, and the control precision is high. The utility model discloses a hydraulic system solves the effect of boom and bucket composite action and realizes perfect composite of multiple actions, improves operation efficiency. The utility model discloses a hydraulic system simple structure, low maintenance cost has great cost advantage. The utility model discloses a multiway valve and hydraulic system can be applied to engineering vehicles such as loader, bulldozer, road roller.

[0058] In the description of the utility model, it need explanation, the orientation or positional relation that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" indicate are based on the orientation or positional relation shown in the drawing, only for the convenience of describing the utility model and simplifying the description, and not indicate or imply that the indicated device or element must have a particular orientation, construct and operate in a particular orientation, therefore can not be understood as the limitation to the utility model. In addition, the terms "first", "second" are only for the purpose of description, and can not be understood as indicating or implying relative importance.

[0059] In the description of the utility model, it need explanation, unless another explicit provision and limitation, the terms "installation", "connection", "connect" should be broad -based understanding, for example, can be fixed connection, can be detachable connection, or integrally connected, can be mechanical connection, can be electrical connection, can be directly connected, can be indirectly connected through the intermediate medium, can be the intercommunication of two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances. In addition, in the description of the utility model, unless otherwise stated, the meaning of "multiple" is two or more than two.

[0060] Skilled persons should know: although the utility model has been described according to the above specific embodiment, the utility model idea of the utility model is not limited to this utility model, and any modification using the utility model idea will be included in the utility model patent protection range.

Claims

1. A high flow load sensing multi-way valve comprising a valve body, characterized by: The valve body is provided with a first oil inlet, a feedback oil path, an oil return port, a first working oil port and a second working oil port; further comprising: A first reversing valve is arranged in the valve body and in sliding cooperation with the valve body, and the first reversing valve is arranged in correspondence with the first working oil port; A second reversing valve is arranged in the valve body and in sliding cooperation with the valve body, and the second reversing valve is arranged in correspondence with the second working oil port; A second oil inlet is connected with the first pump for oil inlet; the first oil inlet and the second oil inlet cooperate with each other and deliver oil to the first reversing valve and / or the second reversing valve; An impact-resistant valve comprises an unloading valve core, a first damper and a second damper; the second oil inlet is connected with the oil return port through the unloading valve core, the pressure oil of the second oil inlet is connected with the unloading valve core control cavity through the first damper, and the pressure oil of the feedback oil path is connected with the spring cavity of the unloading valve core through the second damper; the pressure oil of the first damper outlet and the pressure oil of the second damper outlet interact with the set elastic force of the spring cavity of the unloading valve core to control the opening of the unloading valve core.

2. The high flow load sensing multiple spool valve of claim 1, wherein Further comprising a third reversing valve arranged between the second oil inlet and the first damper.

3. The high flow load sensing multi-way valve of claim 2, wherein The feedback oil path is connected with the control cavity of the third reversing valve, and the pressure oil of the feedback oil path cooperates with the set elastic force of the third reversing valve to control the opening of the third reversing valve.

4. The high flow load sensing multiple spool valve of claim 1, wherein Further comprising: A first pressure compensator, the pressure oil of the second oil inlet and / or the first oil inlet is connected with the first pressure compensator through the first reversing valve, and the outlet of the first pressure compensator is connected with the feedback oil path and the first working oil port through the first reversing valve; A second pressure compensator, the pressure oil of the second oil inlet and / or the first oil inlet is connected with the second pressure compensator through the second reversing valve, and the outlet of the second pressure compensator is connected with the feedback oil path and the second working oil port through the second reversing valve.

5. The high flow load sensing multi-way valve of claim 4, wherein Further comprising a compensating check valve arranged between the outlet of the first pressure compensator and the feedback oil path and arranged between the outlet of the second pressure compensator and the feedback oil path, for picking up the feedback oil pressure of the feedback oil path.

6. The high flow load sensing multiple spool valve of claim 1, wherein Further comprising an overload valve arranged between the second oil port and the oil return port, for overload protection.

7. The high-flow load-sensing multiple spool valve of claim 1, wherein Further comprising: A main relief valve for receiving the pressure oil of the first oil inlet and / or the second oil inlet, the outlet of the main relief valve is connected with the oil return port, for improving the safety performance of the system; A feedback relief valve arranged between the feedback oil path and the oil return port, for overload protection.

8. The high flow load sensing multi-way valve of claim 7, wherein The feedback oil path comprises a first feedback channel and a second feedback channel, the feedback relief valve is arranged on the second feedback channel, a third damper is arranged between the first feedback channel and the second feedback channel, a constant flow valve is arranged on the first feedback channel, and the constant flow valve is connected with the oil return port.

9. The large-flow load-sensitive multi-way valve according to claim 1, further comprising an expansion link, wherein the expansion link is provided with a fourth reversing valve and a third working oil port, and the expansion link is arranged on the valve body and detachably connected with the valve body. The fourth reversing valve is in sliding cooperation with the expansion link, and the fourth reversing valve receives the pressure oil of the first oil inlet and / or the second oil inlet and is arranged in correspondence with the third working oil port. ​ 10. A control system characterized by: ​ The large-flow load-sensitive multi-way valve according to any one of claims 1-9; a second pump for providing pressure oil; a steering power source for controlling product steering; a steering priority valve connected with the second pump and connected with the steering power source and the first oil inlet respectively, for preferentially supplying oil to the steering power source; a selector shuttle valve for selecting feedback oil from the steering priority valve and the feedback oil path and connected with the second pump, for controlling the second pump output; a pilot control oil source for providing a pilot oil source.

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