Mechanical synchronous hydraulic system under overloading working condition

Abstract

The utility model discloses a mechanical synchronous hydraulic system under an overloading working condition, which comprises a proportional valve, a balance valve, an anti-explosion valve, a first oil cylinder and a second oil cylinder, the proportional valve comprises a reversing valve and a pressure compensation valve, and the reversing valve is connected with the pressure compensation valve; a port A of the proportional valve is respectively communicated with a rod cavity of the first oil cylinder and a rod cavity of the second oil cylinder, and a port B of the proportional valve is respectively communicated with a rodless cavity of the first oil cylinder and a rodless cavity of the second oil cylinder; the rod cavity and the rodless cavity of the first oil cylinder and the rod cavity and the rodless cavity of the second oil cylinder are each provided with an anti-explosion valve. And the balance valve is arranged on an oil path between the proportional valve and the anti-explosion valve. According to the utility model, the problems of shaking and abnormal sound generated in the stretching process of the oil cylinder can be effectively solved.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic control technology, and in particular, to a mechanical synchronous hydraulic system under overload conditions. Background Technology

[0002] Typically, when a hydraulic cylinder extends, it needs to overcome an external force, meaning the direction of the force on the cylinder is opposite to the direction of extension; this is called a positive load. Another common force condition in construction machinery is when the direction of the force on the cylinder is the same as the direction of extension; this is called an overload condition. Overload conditions are also quite common in construction machinery, and they are further divided into extension overload and retraction overload. The vast majority of overload conditions are cylinder retraction overload conditions. Due to structural layout limitations, multiple cylinders are often used to control the movement of the same load. Existing mechanical synchronous hydraulic systems for overload conditions are not suitable for all overload conditions. If existing mechanical synchronous hydraulic systems are used to control cylinder extension overload conditions, the cylinder is very prone to vibration and abnormal noise during extension, which can seriously damage the hydraulic system, affecting operational accuracy and reducing system efficiency.

[0003] Existing patent application number CN202221911652.7 discloses a hydraulic system with hydraulically controlled directional control for controlling multiple cylinders, including a hydraulically controlled directional valve, a first explosion-proof valve, a second explosion-proof valve, a dual proportional pressure reducing valve, an accumulator, a first gripper cylinder, and a second gripper cylinder. Port A of the hydraulically controlled directional valve is connected to the rodless chamber of both the first and second gripper cylinders, and port B is connected to the rod chamber of both the first and second gripper cylinders. The first explosion-proof valve is installed on the rodless chamber of the first gripper cylinder, and the second explosion-proof valve is installed on the rodless chamber of the second gripper cylinder; the first and second explosion-proof valves are connected. The accumulator is connected to the dual proportional pressure reducing valve, which is electrically connected to the hydraulically controlled directional valve. Although the patent can ensure synchronous extension and retraction of the hydraulic cylinder, if the pipeline of the hydraulic system bursts, the load cannot remain completely still, resulting in abnormal noise and vibration of the hydraulic cylinder. Summary of the Invention

[0004] This utility model primarily addresses the problem that existing mechanical synchronous hydraulic systems used for cylinder retraction under overload conditions, when controlling cylinder extension, are prone to vibration and abnormal noise during extension, causing serious damage to the hydraulic system, affecting operational accuracy, and reducing system efficiency. The present invention provides a mechanical synchronous hydraulic system for overload conditions.

[0005] A mechanical synchronous hydraulic system for overload conditions includes a proportional valve, a balance valve, an explosion-proof valve, a first cylinder, and a second cylinder. The proportional valve includes a directional valve and a pressure compensation valve. The directional valve and the pressure compensation valve are connected via an oil circuit, and a check valve is provided on the oil circuit connecting the directional valve and the pressure compensation valve. Port A of the proportional valve is connected to the rod chamber of both the first and second cylinders, and port B of the proportional valve is connected to the rodless chamber of both the first and second cylinders. The balance valve is located on the oil circuit between the proportional valve and the explosion-proof valve.

[0006] The explosion-proof valve includes a first explosion-proof valve, a second explosion-proof valve, a third explosion-proof valve, and a fourth explosion-proof valve. The first explosion-proof valve and the third explosion-proof valve are connected via an oil circuit, and the second explosion-proof valve and the fourth explosion-proof valve are also connected via an oil circuit. The first explosion-proof valve is connected to the rodless chamber of the first hydraulic cylinder, the second explosion-proof valve is connected to the rod-side chamber of the first hydraulic cylinder, the third explosion-proof valve is connected to the rodless chamber of the second hydraulic cylinder, and the fourth explosion-proof valve is connected to the rod-side chamber of the second hydraulic cylinder.

[0007] Furthermore, the proportional valve also includes a pressure reducing valve, an electro-proportional pressure reducing valve, a flow valve, and an LS relief valve. The pressure reducing valve is connected to the electro-proportional pressure reducing valve, the electro-proportional pressure reducing valve is electrically connected to the directional valve, and the flow valve is connected to the LS relief valve.

[0008] Furthermore, it also includes a hydraulic power unit, a return oil relief valve, a check valve, and a high-pressure filter. The return oil relief valve is connected to the T port of the proportional valve via a return oil circuit. The check valve is located on the oil circuit between the high-pressure filter and the hydraulic power unit, and the oil outlet of the hydraulic power unit is connected to the oil inlet of the check valve.

[0009] Furthermore, the hydraulic power unit consists of a diesel engine and a main hydraulic pump connected together.

[0010] Furthermore, a pressure sensor is connected to the return oil overflow valve.

[0011] Furthermore, the hydraulic power unit, the return oil relief valve, and the proportional valve are all connected to the oil tank.

[0012] Furthermore, the directional valve is a three-position six-way proportional directional valve.

[0013] Furthermore, the pressure oil output by the electro-proportional pressure reducing valve controls the movement of the main valve core of the directional valve. The displacement distance of the main valve core is proportional to the input current, and the output flow rate of the main valve core is proportional to the displacement.

[0014] Furthermore, the electro-proportional pressure reducing valve includes a first electro-proportional pressure reducing valve and a second electro-proportional pressure reducing valve. The first electro-proportional pressure reducing valve is provided with a first electromagnetic coil, and the second electro-proportional electromagnetic valve is provided with a second electromagnetic coil. The reversing valve is electrically connected to the first electromagnetic coil and the second electromagnetic coil, respectively.

[0015] Furthermore, the first and second hydraulic cylinders are installed upside down above the load.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0017] This application comprises a proportional valve, an explosion-proof valve, a balance valve, a first hydraulic cylinder, and a second hydraulic cylinder. The proportional valve includes a directional valve and a pressure compensation valve. Port A of the proportional valve is connected to the rod chambers of both the first and second hydraulic cylinders, and port B is connected to the rodless chambers of both the first and second hydraulic cylinders. Explosion-proof valves are installed on both the rod and rodless chambers of the first and second hydraulic cylinders. The balance valve is located in the oil circuit between the proportional valve and the explosion-proof valve. The pressure reducing valve is connected to the electro-proportional pressure reducing valve, which is electrically connected to the directional valve. The flow valve is connected to the LS relief valve. This invention, through the combination of a balance valve and an explosion-proof valve and the oil circuit design, ensures that the hydraulic cylinders can still operate smoothly during external load changes. This results in smooth cylinder operation without vibration or abnormal noise, thereby improving the stability, safety, and efficiency of the hydraulic system. The addition of explosion-proof valves in series—specifically, the first and third explosion-proof valves connected to the rodless chambers of the two cylinders, and the second and fourth explosion-proof valves connected to the rod chambers of the two cylinders—ensures synchronized cylinder extension and retraction, guaranteeing smooth cylinder extension and retraction. This further enhances system stability and safety, ensuring that the load does not drop rapidly even in the event of hydraulic pipe damage. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a mechanical synchronous hydraulic system operating under overload conditions.

[0019] Figure 2 This is a schematic diagram of a mechanical synchronous hydraulic system using an electrically controlled valve.

[0020] In the diagram: 1. Diesel engine; 2. Main hydraulic pump; 3. Check valve; 4. High-pressure filter; 5. Return oil relief valve; 6. Proportional valve; 61. Three-way flow valve; 62. LS relief valve; 63. Flow valve; 64. Three-position six-way proportional directional valve; 65. Secondary relief valve; 66. Pressure compensation valve; 67. Electro-proportional pressure reducing valve; 671. First electro-proportional pressure reducing valve; 672. Second electro-proportional pressure reducing valve; 68. Pressure reducing valve; 7. Balance valve; 8. Load; 9. Explosion-proof valve; 91. First explosion-proof valve; 92. Second explosion-proof valve; 93. Third explosion-proof valve; 94. Fourth explosion-proof valve; 10. First cylinder; 11. Second cylinder; 12. Pressure sensor;

[0021] P. High-pressure oil port; T. Return oil port; LS. Load feedback oil; L. Unloading oil port; A, B. Working oil.

[0022] 131. First solenoid valve; 132. Second solenoid valve; 133. Third solenoid valve; 134. Fourth solenoid valve. Detailed Implementation

[0023] To clearly illustrate the technical features of this utility model application, the present utility model will be described in detail below through specific embodiments and in conjunction with the accompanying drawings.

[0024] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below.

[0025] Furthermore, 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0026] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," 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 communication connection; 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. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0027] In this application, unless otherwise expressly specified and limited, the "above" or "below" of the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. In the description of this specification, references to terms such as "an 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 this application. 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 can be combined in any suitable manner in one or more embodiments or examples.

[0028] Example 1

[0029] like Figure 1 As shown, a mechanical synchronous hydraulic system under overload conditions includes a proportional valve 6, a balance valve 7, an explosion-proof valve 9, a first cylinder 10, and a second cylinder 11. The proportional valve 6 includes a directional valve and a pressure compensation valve 66. The directional valve and the pressure compensation valve 66 are connected via an oil circuit, and a check valve is provided on this connecting oil circuit. Port A of the proportional valve 6 is connected to the rod chamber of the first cylinder 10 and the rod chamber of the second cylinder 11, respectively. Port B of the proportional valve 6 is connected to the rodless chamber of the first cylinder 10 and the rodless chamber of the second cylinder 11, respectively. Explosion-proof valves 9 are provided on both the rod chamber and the rodless chamber of the first cylinder 10, and on both the rod chamber and the rodless chamber of the second cylinder 11. The balance valve 7 is located on the oil circuit between the proportional valve 6 and the explosion-proof valve 9. Four... An explosion-proof valve 9 is provided, wherein the first explosion-proof valve 91 is connected to the third explosion-proof valve 93, the second explosion-proof valve 92 is connected to the fourth explosion-proof valve 94, and the first explosion-proof valve 91 is connected to the rodless chamber of the first cylinder 10, the second explosion-proof valve 92 is connected to the rod chamber of the first cylinder 10, the third explosion-proof valve 93 is connected to the rodless chamber of the second cylinder 11, and the fourth explosion-proof valve 94 is connected to the rod chamber of the second cylinder 11. Two series-connected balance valves 7 are provided between the proportional valve 6 and the explosion-proof valve 9 to ensure that the hydraulic cylinder can still operate smoothly during changes in external load or directional valve switching, so that the entire hydraulic system operates smoothly and the hydraulic cylinder will not produce vibration or abnormal noise, thereby improving the stability, safety and efficiency of the hydraulic system. The addition of the explosion-proof valve 9 ensures that the load will not drop rapidly even in the event of damage to the hydraulic oil pipe.

[0030] like Figure 1As shown, this embodiment provides a mechanical synchronous hydraulic system under overload conditions, which further includes a hydraulic power unit, a return oil relief valve 5, a one-way valve 3, and a high-pressure filter 4. The hydraulic power unit, the return oil relief valve 5, and the proportional valve 6 are all connected to the oil tank. The hydraulic power unit includes a diesel engine 1 and a main hydraulic pump 2. The one-way valve 3 is located between the main hydraulic pump 2 and the high-pressure filter 4, and the oil inlet of the one-way valve 3 is connected to the oil outlet of the main hydraulic pump 2. The oil outlet of the one-way valve 3 is connected to the high-pressure filter 4. The diesel engine 1 is driven by the main hydraulic pump 2. The diesel engine 1 provides mechanical energy to the main hydraulic pump 2. The high-pressure oil output by the main hydraulic pump 2 enters the high-pressure filter 4 through the check valve 3. After being filtered by the high-pressure filter 4, the hydraulic oil reaches the P port of the proportional valve 6. At the same time, the high-pressure oil at the P port is reduced by the pressure reducing valve 68 and then reaches the first electro-proportional pressure reducing valve 671 and the second electro-proportional pressure reducing valve 672. The first electro-proportional pressure reducing valve 671 is equipped with a first electromagnetic coil, and the second electro-proportional solenoid valve 672 is equipped with a second electromagnetic coil. The three-position six-way proportional directional valve 64 is electrically connected to the first electromagnetic coil and the second electromagnetic coil respectively.

[0031] When the first electromagnetic coil is energized and connected to the directional valve, the main valve core of the directional valve is in the upper position. The displacement distance of the main valve core is proportional to the input current, and the output flow rate of the main valve core is proportional to the displacement. The hydraulic oil from port P of the proportional valve 6 reaches the pressure compensation valve 66 through the three-position six-way proportional directional valve 64. The hydraulic oil then reaches the balance valve 7 through port B of the three-position six-way proportional directional valve 64. It then enters the rodless chambers of the first cylinder 10 and the second cylinder 11 through the oil circuit via the explosion-proof valve 9. The rodless chambers of the first cylinder 10 and the second cylinder 11 are respectively equipped with explosion-proof valves 9, and the first explosion-proof valve 91 is connected to the third explosion-proof valve 93. Under the action of the hydraulic oil, the oil rods of the two cylinders extend synchronously, thereby driving the load to move. The pressure oil in the rod chamber returns to the oil tank through the pipeline, realizing the synchronous extension of the two hydraulic cylinders and ensuring the stability of the hydraulic system.

[0032] Example 2

[0033] like Figure 1 As shown, a mechanical synchronous hydraulic system under overload conditions is described in this embodiment. When the second electromagnetic coil of the second electro-proportional pressure reducing valve 67 is energized, it simultaneously connects to the three-position six-way proportional directional valve, causing the main valve core of the directional valve to be in the lower position. At this time, the hydraulic oil at port P reaches the pressure compensation valve 66 through the three-position six-way proportional directional valve 64. The hydraulic oil then reaches the balance valve 7 through port A of the three-position six-way proportional directional valve 64, and then enters the rod chambers of the first cylinder 10 and the second cylinder 11 through the oil circuit and explosion-proof valve 9, respectively. Explosion-proof valve 9 is installed in the rod chambers of the first cylinder 10 and the second cylinder 11, and the second explosion-proof valve 92 is connected to the fourth explosion-proof valve 94. Under the action of the hydraulic oil, the oil rods of the two cylinders retract synchronously, and the pressure oil in the rodless chamber flows back to the oil tank through the pipeline.

[0034] like Figure 1 As shown, in this embodiment, when there is no input to the first electro-proportional pressure reducing valve 671 and the second electro-proportional pressure reducing valve 672, the main valve core of the three-position six-way proportional directional valve 64 is in the neutral position. At this time, the LS pressure oil fed back by the load 8 is unloaded through the flow valve 63. The maximum LS pressure value of the LS relief valve 62 is set. When the pressure of the hydraulic system reaches or exceeds the set maximum LS pressure value, the LS relief valve 62 opens. The excess pressure oil reaches the return oil port T of the proportional valve 6 through the LS relief valve 62 and then returns to the oil tank, thereby ensuring that the pressure in the system is within a safe range.

[0035] Example 3

[0036] like Figure 2 As shown, a mechanical synchronous hydraulic system under overload conditions differs from Embodiments 1 and 2 above. In this embodiment, an electrically controlled valve replaces the explosion-proof valve 9. The electrically controlled valve includes a first electrically controlled valve 131, a second electrically controlled valve 132, a third electrically controlled valve 133, and a fourth electrically controlled valve 134. The first electrically controlled valve 131 is connected to the rodless chamber of the first cylinder 10, the second electrically controlled valve 132 is connected to the rod chamber of the first cylinder 10, the third electrically controlled valve 133 is connected to the rodless chamber of the second cylinder 11, and the fourth electrically controlled valve 134 is connected to the rod chamber of the second cylinder 11.

[0037] When the first electromagnetic coil is energized, the three-position six-way proportional directional valve 64 operates in its upper position. Hydraulic oil flows out from port B of the three-position six-way proportional directional valve 64 and enters the rodless chamber of the first cylinder 10 and the second cylinder 11. The rodless chambers of the first cylinder 10 and the second cylinder 11 are connected to an electric control valve, and the first electric control valve 131 is connected to the third electric control valve 133. Under the action of the hydraulic oil, the oil rods of the two cylinders extend synchronously.

[0038] When the second electromagnetic coil is energized, the three-position six-way proportional directional valve 64 operates in its lower position. Hydraulic oil flows out from port A of the three-position six-way proportional directional valve 64 and enters the rod chambers of the first cylinder 10 and the second cylinder 11. The rod chambers of the first cylinder 10 and the second cylinder 11 are connected to an electric control valve, and the second electric control valve 132 is connected to the fourth electric control valve 134. Under the action of the hydraulic oil, the rods of the two cylinders retract synchronously.

[0039] When neither the first nor the second electromagnetic coil has any input, the main valve core of the three-position six-way proportional directional valve 64 is in the neutral position. At this time, the LS pressure oil fed back by the load 8 is unloaded through the flow valve 63, and the maximum LS pressure value of the LS relief valve 62 is set.

[0040] In this embodiment, by connecting the solenoid valves in series, even if any valve in the hydraulic system malfunctions during the extension, retraction, and shutdown operations, the system will not stop erroneously, and other components can still operate normally. During the switching of the directional valve position or changes in load, the cylinder will not vibrate or make abnormal noises, ensuring the stability and safety of the system. At the same time, the use of solenoid valves can precisely adjust and control the flow rate.

[0041] In the accompanying drawings, the same or similar reference numerals correspond to the same or similar components; the positional relationships depicted in the drawings are for illustrative purposes only and should not be construed as limiting this patent. Clearly, the above-described embodiments of this utility model are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A mechanically synchronized hydraulic system for overload conditions, characterized in that, The system includes a proportional valve, a balance valve, an explosion-proof valve, a first hydraulic cylinder, and a second hydraulic cylinder. The proportional valve includes a directional valve and a pressure compensation valve. The directional valve and the pressure compensation valve are connected via an oil circuit, and a check valve is provided on the oil circuit connecting the directional valve and the pressure compensation valve. Port A of the proportional valve is connected to the rod chamber of both the first and second hydraulic cylinders, and port B of the proportional valve is connected to both the rodless chamber of both the first and second hydraulic cylinders. The balance valve is located on the oil circuit between the proportional valve and the explosion-proof valve. The explosion-proof valve includes a first explosion-proof valve, a second explosion-proof valve, a third explosion-proof valve, and a fourth explosion-proof valve. The first explosion-proof valve and the third explosion-proof valve are connected via an oil circuit, and the second explosion-proof valve and the fourth explosion-proof valve are also connected via an oil circuit. The first explosion-proof valve is connected to the rodless chamber of the first hydraulic cylinder, the second explosion-proof valve is connected to the rod-side chamber of the first hydraulic cylinder, the third explosion-proof valve is connected to the rodless chamber of the second hydraulic cylinder, and the fourth explosion-proof valve is connected to the rod-side chamber of the second hydraulic cylinder.

2. The mechanical synchronous hydraulic system under overload conditions according to claim 1, characterized in that, The proportional valve also includes a pressure reducing valve, an electro-proportional pressure reducing valve, a flow valve, and an LS relief valve. The pressure reducing valve is connected to the electro-proportional pressure reducing valve via an oil circuit. The electro-proportional pressure reducing valve is electrically connected to the directional valve. The flow valve is connected to the LS relief valve via an oil circuit.

3. The mechanical synchronous hydraulic system under overload conditions according to claim 1, characterized in that, It also includes a hydraulic power unit, a return oil relief valve, a check valve, and a high-pressure filter. The return oil relief valve is connected to the T port of the proportional valve via a return oil circuit. The check valve is located on the oil circuit between the high-pressure filter and the hydraulic power unit, and the oil outlet of the hydraulic power unit is connected to the oil inlet of the check valve.

4. The mechanical synchronous hydraulic system under overload conditions according to claim 3, characterized in that, The hydraulic power unit consists of a diesel engine and a main hydraulic pump connected together, with the main hydraulic pump connected to the oil tank.

5. A mechanical synchronous hydraulic system under overload conditions according to claim 3, characterized in that, The return oil overflow valve is connected to a pressure sensor.

6. The mechanical synchronous hydraulic system under overload conditions according to claim 3, characterized in that, Both the return oil overflow valve and the proportional valve are connected to the oil tank.

7. The mechanical synchronous hydraulic system under overload conditions according to claim 1, characterized in that, The directional valve is a three-position six-way proportional directional valve.

8. A mechanical synchronous hydraulic system under overload conditions according to claim 2, characterized in that, The pressure oil output by the electro-proportional pressure reducing valve controls the movement of the main valve core of the directional valve. The displacement distance of the main valve core is proportional to the input current, and the output flow rate of the main valve core is proportional to the displacement.

9. A mechanical synchronous hydraulic system under overload conditions according to claim 8, characterized in that, The electro-proportional pressure reducing valve includes a first electro-proportional pressure reducing valve and a second electro-proportional pressure reducing valve. The first electro-proportional pressure reducing valve is provided with a first electromagnetic coil, and the second electro-proportional pressure reducing valve is provided with a second electromagnetic coil. The reversing valve is electrically connected to the first electromagnetic coil and the second electromagnetic coil, respectively.

10. A mechanical synchronous hydraulic system under overload conditions according to claim 1, characterized in that, The first and second hydraulic cylinders are installed upside down above the load.

Images