Hydraulic system and working machine

Abstract

The utility model belongs to the technical field of hydraulic transmission, and discloses a hydraulic system and an operation machine, the hydraulic system comprises an oil pumping unit, an execution unit, a detection unit and a control unit; the oil pumping unit comprises a hydraulic pump and a driving device in transmission connection with the hydraulic pump, the execution unit comprises an execution element connected to an output oil way of the hydraulic pump and a reversing control valve arranged between the output oil way and the execution element, and the detection unit is used for detecting the position of a valve element of the reversing control valve. The control unit is in communication connection with the detection unit and used for controlling the rotating speed of the driving device. The system is simple in structure and can be matched with a specific algorithm to realize low-energy-consumption flow matching adjustment.

Description

Technical Field

[0001] This utility model belongs to the field of hydraulic transmission technology, specifically relating to a hydraulic system and working machinery. Background Technology

[0002] Hydraulic systems, as a widely used form of power transmission in modern machinery, directly affect their energy efficiency level depending on whether their input and output flow rates are matched. Current mainstream technologies primarily rely on two architectural approaches to achieve input-output flow matching and regulation: one is an opening-flow regulation mechanism centered on a proportional valve. This method places a proportional valve between the pump and the actuator, with the pump always outputting a constant flow rate, and the flow rate to the actuator is adjusted by changing the flow area of ​​the proportional valve's orifice. The other is a load feedback-pump displacement (speed) regulation mechanism centered on a load-sensitive pump. This mechanism dynamically adjusts the pump's output by sensing the load pressure in real time. While the former has a simple structure, it incurs significant throttling losses when implementing flow regulation, resulting in high energy consumption and low efficiency. The latter, although improving energy efficiency through closed-loop control, requires the integration of numerous precision components such as pressure sensors, electronic controllers, and variable displacement pumps. This not only increases the complexity of the hydraulic circuit but also significantly increases costs, making it difficult to promote in the low-to-mid-end market or small-to-medium-sized equipment. Utility Model Content

[0003] In view of the above-mentioned defects or deficiencies, this utility model provides a hydraulic system and working machinery, which aims to solve the technical problems of complex structure and high component cost of existing hydraulic systems with low energy consumption flow matching and adjustment functions.

[0004] To achieve the above objectives, this utility model provides a hydraulic system, which includes a pumping unit, an execution unit, a detection unit, and a control unit. The pumping unit includes a hydraulic pump and a drive unit that is driven by the hydraulic pump. The execution unit includes an actuator connected to the output oil circuit of the hydraulic pump and a reversing control valve disposed between the output oil circuit and the actuator. The detection unit is used to detect the valve core position of the reversing control valve. The control unit is communicatively connected to the detection unit and is used to control the rotational speed of the drive unit.

[0005] In embodiments of this invention, the detection unit may be a Hall sensor.

[0006] In embodiments of this utility model, the detection unit may also be at least one of an ultrasonic detection element, an eddy current detection element, an optical detection element, a magnetic detection element, a circuit continuity detection element, or an infrared detection element.

[0007] In embodiments of this utility model, the detection unit may also be at least one of a mechanical switch, a contact switch, a potentiometer, a strain gauge, or a pressure sensor.

[0008] In an embodiment of this utility model, the reversing control valve includes a valve body and a valve core, the valve core being movably disposed within the valve body, and a detection unit being mounted on the valve body and used to monitor the position of the valve core relative to the valve body.

[0009] In an embodiment of this utility model, the reversing control valve includes a valve body and a valve core, the valve core being movably disposed within the valve body, and a detection unit being disposed independently of the valve body and used to monitor the position of the valve core relative to the valve body.

[0010] In an embodiment of this utility model, the reversing control valve includes a valve body and a valve core. The valve core is movably disposed in the valve body and at least one end is a handle control end. The handle control end is connected to an external operating handle. The detection unit is used to detect the position of the operating handle, and the control unit is used to convert the position of the operating handle into the position of the valve core according to the preset relationship between the "operating handle position and the valve core position".

[0011] In the embodiments of this utility model, the hydraulic pump is a fixed displacement pump, and the driving device is an engine.

[0012] In embodiments of this utility model, the engine and the hydraulic pump are coaxially and directly connected, or a speed transmission unit is provided between the engine and the hydraulic pump.

[0013] To achieve the above objectives, this utility model also provides a working machine, wherein the working machine includes the hydraulic system described above.

[0014] Through the above technical solution, the hydraulic system provided by this utility model embodiment has the following beneficial effects:

[0015] From a system architecture perspective, this hydraulic system only requires the addition of a detection unit for detecting the valve core position to the existing system architecture, and then the injection of the corresponding control algorithm into the control unit to achieve low-energy flow matching and regulation. Very few components need to be added or modified, and there is no need for complex feedback oil circuits or precision components. This greatly reduces the cost and difficulty of upgrading and modifying the hydraulic system. It has excellent compatibility and can be adapted to the installation and upgrade of almost all small and medium-sized operating machinery on the market.

[0016] Other features and advantages of this invention will be described in detail in the following detailed description section. Attached Figure Description

[0017] The accompanying drawings are provided to illustrate the present invention and form part of the specification. They are used together with the following detailed description to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0018] Figure 1 This is a hydraulic schematic diagram of the hydraulic system according to an embodiment of the present utility model;

[0019] Figure 2 This is a control connection architecture diagram of a first embodiment of the hydraulic system according to the present utility model.

[0020] Figure 3 This is a control connection architecture diagram of a second embodiment of the hydraulic system according to the present utility model.

[0021] Explanation of reference numerals in the attached figures

[0022] 11. Actuating element; 12. Reversing control valve; 2. Oil pump unit; 21. Hydraulic pump; 22. Engine; 3. Detection unit; 4. Control unit; 41. ECU controller; 5. Operating handle. Detailed Implementation

[0023] The specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of this utility model.

[0024] The hydraulic system of this utility model is described below with reference to the accompanying drawings.

[0025] When operating machinery performs different actions, the demand for hydraulic flow varies. If effective input-output flow matching and adjustment are not carried out, the hydraulic system is prone to problems such as slow response and excessive speed, making it difficult to meet the requirements of precision operation. Therefore, it is necessary to design an input-output flow matching and adjustment mechanism.

[0026] Common flow matching and regulation mechanisms on the market are generally based on proportional valve opening, which works by changing the flow area of ​​the valve orifice to regulate the output flow. While these mechanisms are simple in structure and low in cost, they result in significant throttling losses and high energy consumption.

[0027] There are also some more intelligent and precise flow regulation methods on the market, such as load feedback flow regulation mechanisms based on variable pumps or servo pumps. These control methods require the integration of a large number of precision components, resulting in complex structures and very high costs, which limits their promotion in the low-end market or small and medium-sized equipment.

[0028] In view of this, the present invention discloses a hydraulic system. For example... Figure 1 , Figure 2 and Figure 3 As shown, the hydraulic system includes an oil pump unit 2, an execution unit, a detection unit 3, and a control unit 4.

[0029] The oil pumping unit 2 includes a hydraulic pump 21 and a drive unit that is driven by the hydraulic pump 21. The execution unit includes an execution element 11 connected to the output oil circuit of the hydraulic pump 21 and a reversing control valve 12 disposed between the output oil circuit and the execution element 11. The detection unit 3 is used to detect the valve core position of the reversing control valve 12. The control unit 4 is communicatively connected to the detection unit 3 and is used to control the speed of the drive unit according to the position of the valve core.

[0030] To achieve flow matching and regulation, this system requires a specific flow control method, which includes:

[0031] S100: Determine the valve position of the reversing control valve 12 based on the valve core position of the reversing control valve 12 of each execution unit;

[0032] S200: Determine the action to be performed by the hydraulic system based on the valve position of the directional control valve 12;

[0033] S300: Determine the required flow rate of the hydraulic system to perform the current action based on the first preset mapping relationship between "target action - flow rate required to perform target action";

[0034] S400: Adjust the drive speed of the drive components to match the output flow of the hydraulic pump 21 with the required flow of the hydraulic system.

[0035] The hydraulic system in this invention is mainly used in construction machinery, such as truck-mounted cranes, excavators, loaders, and tractors.

[0036] Taking a boom-type aerial work platform as an example, the actuator 11 of the boom-type aerial work platform mainly includes a boom telescopic drive cylinder, a boom luffing drive cylinder, a slewing drive motor, and a platform lifting drive cylinder. When the platform needs to telescopicate the boom, the reversing control valve 12 between the telescopic drive cylinder and the output oil circuit of the hydraulic pump 21 will switch from the shut-off valve position to the open valve position. Similarly, when the platform needs to control boom luffing, vehicle rotation, and platform lifting, the corresponding reversing control valve 12 needs to switch positions. Therefore, when the platform is in operation, it only needs to obtain the valve position status of each reversing control valve 12 to determine the action that the hydraulic system needs to perform.

[0037] Different actions performed by the platform require different flow rates. During equipment commissioning, a preliminary mapping relationship between the different actions performed and the required flow rates can be calculated in advance. For example, the preliminary mapping relationship could be: Q1 is the flow rate required for performing boom extension or luffing alone; Q2 is the flow rate required for performing boom extension and platform lifting simultaneously; and Q3 is the flow rate required for performing slewing and boom retraction simultaneously. Once the action that the hydraulic system is about to perform is known, the required flow rate for performing the current action can be determined based on the preliminary mapping relationship.

[0038] The second preset mapping relationship between the rotational speed of hydraulic pump 21 and the output flow of hydraulic pump 21 is a factory-known parameter. Therefore, after knowing the required flow of the system, it is only necessary to adjust the driving speed of the driving device accordingly to achieve a rough matching adjustment of the system's output flow and required flow. Even if a throttle valve is used for further flow matching adjustment, the resulting throttling loss is very small.

[0039] In summary, from a system architecture perspective, this hydraulic system only requires the addition of a detection unit 3 for detecting the valve core position to the existing system architecture, and then the injection of the corresponding control algorithm into the control unit 4 to achieve low-energy flow matching and regulation. Very few components need to be added or modified. Compared with the existing load-sensitive pump type load feedback hydraulic system, it does not require the intervention of complex feedback oil circuits or precision components, which greatly reduces the cost and difficulty of upgrading and modifying the hydraulic system. It has excellent compatibility and can be adapted to the installation and upgrade of almost all small and medium-sized operating machinery on the market.

[0040] In terms of flow matching regulation, the method first determines the action to be performed by the hydraulic system by detecting the valve position of the directional control valve 12. Then, based on the action to be performed by the hydraulic system, the required flow rate of the system can be obtained. Finally, the speed of the hydraulic pump 21 is adjusted according to the required flow rate. Although flow matching regulation can only achieve approximate flow matching, the control logic is simple, it relies on fewer components, and it can be used in conjunction with a throttle valve to achieve more precise flow regulation with very little throttling loss. Thus, for low-end or small-to-medium-sized products, it can achieve the addition of low-energy flow matching regulation function while effectively controlling costs. In addition, this method is an open-loop control, which, compared to the lag and delay of the traditional pressure / flow feedback closed-loop control mechanism, enables rapid response in flow regulation and has higher control efficiency.

[0041] In this embodiment, the reversing control valve 12 mainly consists of a valve body and a valve core, with the valve core movably disposed within the valve body. By moving the valve core, the valve position of the reversing control valve 12 can be switched.

[0042] In this embodiment, the detection unit 3 can be a Hall sensor. Hall sensors primarily detect changes in magnetic field strength or polarity. These devices are small in size and can be integrated with the valve core of the reversing control valve 12, making them suitable for use in narrow spaces within the valve body. Furthermore, because Hall sensors are non-contact sensors, they experience no mechanical wear, have a long lifespan, and are highly resistant to oil and vibration. Additionally, the valve core moves rapidly during reversal, and the high sensitivity of the Hall sensor makes it better suited for position detection during high-speed valve core movement.

[0043] In this embodiment, based on the detection method, the detection unit 3 can detect the valve core position of the reversing control valve 12 in a non-contact manner. For example, the detection unit 3 can be at least one of an ultrasonic detection element, an eddy current detection element, an optical detection element, a magnetic detection element, a circuit continuity detection element, or an infrared detection element.

[0044] In this embodiment, the detection unit 3 can also detect the valve core position of the reversing control valve 12 through physical contact or physical transmission. For example, the detection unit 3 can be a mechanical switch, contact switch, potentiometer, strain gauge, or pressure sensor, etc.

[0045] like Figure 2 As shown, in this embodiment, the detection unit 3 can be installed in multiple locations. For example, when the detection unit 3 is a small component, a corresponding mounting structure can be provided on the valve body, and the detection unit 3 can be installed on the valve body to achieve integration between the detection unit 3 and the valve body.

[0046] Alternatively, the detection unit 3 can be set independently of the valve body and fixedly placed at the end of the valve body. In this case, the end of the valve core needs to extend out of the valve body to facilitate the detection by the detection unit 3. The detection unit 3 can determine the position of the valve core by detecting the distance to the end of the valve core, whether the end of the valve core is in contact with the detection unit 3, or the pressure exerted by the end of the valve core on the detection unit 3.

[0047] like Figure 3 As shown, the reversing of certain types of directional control valves 12 is controlled by an operating handle 5. At least one end of the valve core of such directional control valves 12 is the handle control end, which is mechanically connected to the external operating handle 5. When the operator operates the corresponding operating handle 5 in the control box or in the cab, the operator can control such directional control valves 12 to reverse.

[0048] For this type of directional control valve 12, when the detection unit 3 is large and the space around the directional control valve 12 is relatively narrow, such as Figure 3 As shown, the detection unit 3 can be placed near the operating handle 5. By detecting the position of the operating handle 5, the position of the valve core can also be indirectly reflected.

[0049] In addition, when the detection unit 3 is a contact sensing device, the detection unit 3 can be mechanically connected by a connecting rod, a pull rope, or a spring.

[0050] With the development of new energy technologies, the construction machinery industry is gradually transforming towards electrification and intelligence. However, at present, especially for the low-to-mid-end market, traditional power systems still dominate with the transmission form of a fuel engine driving a fixed displacement pump. This phenomenon is mainly due to its significant cost and size advantages: the combination of the engine and the fixed displacement pump has a simple structure and a small overall size. Moreover, the fixed displacement pump is more technologically mature and has a lower manufacturing cost compared to variable displacement pumps or servo pumps. Therefore, this combination can effectively reduce the overall production cost and has high compactness, meeting the needs of the low-to-mid-end market or small and medium-sized equipment.

[0051] In hydraulic systems with engine 22-driven fixed displacement pumps, mainstream solutions mostly use proportional valves to regulate the flow rate of the hydraulic system. However, as mentioned earlier, this regulation method has drawbacks such as high energy consumption and low system efficiency. Although there are better load feedback flow regulation mechanisms in existing technologies, they require modification of the fixed displacement pump and the introduction of complex feedback mechanisms, resulting in high costs. Therefore, this modification solution is rarely considered in the low-to-mid-end market or for small and medium-sized equipment.

[0052] In this embodiment, the hydraulic system can be powered by an engine 22 plus a fixed displacement pump. This retains the absolute cost advantage of traditional power systems while also allowing for the addition of low-energy flow matching and adjustment functions. Of course, the driving component can also be an electric motor.

[0053] In this embodiment, the engine 22 can be directly connected to the hydraulic pump 21 on the same axis, or a speed transmission unit can be provided between the engine 22 and the hydraulic pump 21.

[0054] In this embodiment, the control unit 4 includes a main controller and an ECU controller 41 for controlling the gear position of the engine 22. The main controller is communicatively connected to the detection unit 3.

[0055] To achieve the above objectives, this utility model also provides a working machine, which includes the hydraulic system described above. Since the working machine adopts all the technical solutions of the above embodiments, it at least has the beneficial effects brought about by the above embodiments, and will not be repeated here.

[0056] In the description of this utility model, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0057] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0058] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0059] Although embodiments of the present invention have been described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A hydraulic system, characterized in that, The hydraulic system includes; The oil pump unit (2) includes a hydraulic pump (21) and a drive unit that is drivenly connected to the hydraulic pump (21); The actuation unit includes an actuating element (11) connected to the output oil circuit of the hydraulic pump (21) and a reversing control valve (12) disposed between the output oil circuit and the actuating element (11). The detection unit (3) is used to detect the valve core position of the reversing control valve (12); The control unit (4) is communicatively connected to the detection unit (3) and is used to control the rotational speed of the driving device.

2. The hydraulic system according to claim 1, characterized in that, The detection unit (3) is a Hall sensor.

3. The hydraulic system according to claim 1, characterized in that, The detection unit (3) is at least one of ultrasonic detection element, eddy current detection element, optical detection element, magnetic detection element, circuit continuity detection element or infrared detection element.

4. The hydraulic system according to claim 1, characterized in that, The detection unit (3) is at least one of a mechanical switch, a contact switch, a potentiometer, a strain gauge, or a pressure sensor.

5. The hydraulic system according to any one of claims 1 to 4, characterized in that, The reversing control valve (12) includes a valve body and a valve core, the valve core being movably disposed within the valve body, and the detection unit (3) being mounted on the valve body and used to monitor the position of the valve core relative to the valve body.

6. The hydraulic system according to any one of claims 1 to 4, characterized in that, The reversing control valve (12) includes a valve body and a valve core, the valve core being movably disposed within the valve body, and the detection unit (3) being disposed independently of the valve body and used to monitor the position of the valve core relative to the valve body.

7. The hydraulic system according to any one of claims 1 to 4, characterized in that, The reversing control valve (12) includes a valve body and a valve core. The valve core is movably disposed in the valve body and at least one end is a handle control end. The handle control end is connected to an external operating handle (5). The detection unit (3) is used to detect the position of the operating handle (5). The control unit (4) is used to convert the position of the operating handle (5) into the position of the valve core according to the preset relationship between "operating handle position - valve core position".

8. The hydraulic system according to any one of claims 1 to 4, characterized in that, The hydraulic pump (21) is a fixed displacement pump, and the driving device is an engine (22).

9. The hydraulic system according to claim 8, characterized in that, The engine (22) is coaxially and directly connected to the hydraulic pump (21), or a speed transmission unit is provided between the engine (22) and the hydraulic pump (21).

10. A type of operating machinery, characterized in that, Includes the hydraulic system according to any one of claims 1 to 9.

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