Servo hydraulic cylinder control system

Abstract

The utility model discloses a servo hydraulic cylinder control system, which relates to the technical field of hydraulic control and comprises a servo valve, a port P of the servo valve is communicated with an oil supply port, and a port A of the servo valve is communicated with a rodless cavity of a hydraulic cylinder. A first one-way valve is arranged between the servo valve and the oil supply port, an oil outlet of the first one-way valve is communicated with the oil supply port, and an oil inlet of the first one-way valve is communicated with the servo valve; a second one-way valve is arranged between the servo valve and the rodless cavity of the hydraulic cylinder, an oil inlet of the second one-way valve is communicated with the servo valve, and an oil outlet of the second one-way valve is communicated with the rodless cavity of the hydraulic cylinder. By arranging the first one-way valve and the second one-way valve, pressure fluctuation in an oil supply and return system can be prevented from being transmitted to the servo valve, so that the pressure at the port P and the port A of the servo valve is relatively stable, and accurate control work of the servo valve is facilitated.

Description

TECHNICAL FIELD

[0001] The utility model relates to hydraulic control technical field especially relates to a kind of servo hydraulic cylinder control system. BACKGROUND

[0002] With the development of hydraulic industry, the hydraulic actuator has higher and higher requirements for hydraulic control mechanism, such as high control accuracy, fast dynamic response, strong anti-interference ability, etc. The servo valve can accurately control the spool movement according to the electric signal, and then change the valve port opening, realize the accurate regulation of flow and pressure, which makes the motion control of hydraulic cylinder more accurate, and is suitable for application scenarios with high precision requirements, such as precision machining, aerospace equipment, etc. At the same time, the servo valve has fast dynamic response ability, which can adjust and control the parameters in the hydraulic system in a very short time, which can improve the work efficiency and production efficiency for control systems that need fast response, such as mechanical arm in automatic production line. In addition, servo valve is often used in closed-loop control system, which detects the change of system output through feedback mechanism, and adjusts the input accordingly, so as to effectively suppress interference and compensate parameter change, improve the stability and precision of the system.

[0003] However, although the servo valve has many advantages in the hydraulic cylinder control system, its application also faces some challenges, such as high cost, complex maintenance, etc. Therefore, in actual application, it is necessary to provide effective protection for it to reduce maintenance cost and prolong the service life of servo valve. UTILITY MODEL CONTENT

[0004] The utility model aims at providing a kind of servo hydraulic cylinder control system to solve the problems existing in the prior art, by setting first check valve and second check valve, prevent oil backflow, stabilize servo valve inlet pressure, protect servo valve from load impact.

[0005] To achieve the above-mentioned purpose, the utility model provides the following scheme:

[0006] A servo hydraulic cylinder control system, comprising a servo valve, the P port of the servo valve is communicated with the oil supply port, the A port of the servo valve is communicated with the rodless chamber of the hydraulic cylinder; a first check valve is arranged between the servo valve and the oil supply port, the oil outlet of the first check valve is communicated with the oil supply port, and the oil inlet of the first check valve is communicated with the servo valve; a second check valve is arranged between the servo valve and the rodless chamber of the hydraulic cylinder, the oil inlet of the second check valve is communicated with the servo valve, and the oil outlet of the second check valve is communicated with the rodless chamber of the hydraulic cylinder.

[0007] In an exemplary embodiment, the X port of the servo valve is communicated with the external control oil port.

[0008] In an exemplary embodiment, the Y port of the servo valve is communicated with the oil drain port.

[0009] In an example embodiment, the T port of the servo valve is communicated with the oil return port.

[0010] In an example embodiment, a third one-way valve is arranged between the servo valve and the oil return port, an oil inlet of the third one-way valve is communicated with the servo valve, and an oil outlet of the third one-way valve is communicated with the oil return port.

[0011] In an example embodiment, an electromagnetic overflow valve is further included, an oil inlet of the electromagnetic overflow valve is communicated with the rodless chamber of the hydraulic cylinder, and an oil outlet of the electromagnetic overflow valve is communicated with the oil return port.

[0012] In an example embodiment, the first one-way valve and the second one-way valve are liquid-controlled one-way valves, which are respectively a first liquid-controlled one-way valve and a second liquid-controlled one-way valve.

[0013] In an example embodiment, an electromagnetic valve is further included, a P port of the electromagnetic valve is communicated with the oil supply port, and B ports of the electromagnetic valve are communicated with control oil ports of the first liquid-controlled one-way valve and the second liquid-controlled one-way valve.

[0014] In an example embodiment, Y ports of the first liquid-controlled one-way valve and the second liquid-controlled one-way valve are communicated with the oil drain port.

[0015] In an example embodiment, a T port of the electromagnetic valve is communicated with the oil return port.

[0016] The utility model discloses relative to prior art has obtained following technical effect:

[0017] 1、 by setting first one-way valve and second one-way valve, work stretches out, and the oil liquid of unstable pressure is cut off by first one-way valve after oil supply port starts to supply oil, and after the oil pressure tends to be stable, the stable oil liquid enters servo valve through electromagnetic valve and opens first one-way valve, when working retracts, the oil liquid in the rodless chamber of hydraulic cylinder flows out under the drive of the oil pressure in the hydraulic rod chamber, and the oil liquid of unstable pressure is cut off by second one-way valve, and after the oil pressure tends to be stable, the stable oil liquid enters servo valve through electromagnetic valve and opens second one-way valve. Therefore, first one-way valve and second one-way valve can block the transmission of pressure fluctuation in oil supply and oil return system to servo valve, so that the pressure at servo valve P port and A port is relatively stable, which is beneficial to the accurate control of servo valve.

[0018] The other technical solutions disclosed by the utility model also have the following technical advantages:

[0019] 2. By installing a third check valve between the servo valve and the return port, with the inlet of the third check valve connected to the servo valve and the outlet of the third check valve connected to the return port, backflow of oil from the return port can be prevented, thus avoiding damage to the valve core and other components of the servo valve by the backflowing oil, which would affect the normal operation and lifespan of the servo valve.

[0020] 3. By installing an electromagnetic relief valve, the inlet of the valve is connected to the rodless chamber of the hydraulic cylinder, and the outlet is connected to the return port. The electromagnetic relief valve enables the third action of the hydraulic cylinder: stopping. When stopping is required, the electromagnetic relief valve opens when energized, or automatically opens when the pressure reaches the set pressure. Oil from the rodless chamber flows into the return port through the electromagnetic relief valve, stopping the cylinder. During operation, abnormal situations may occur in the hydraulic system, causing abnormal pressure increases. The electromagnetic relief valve can automatically open to guide excess pressurized oil back to the oil tank, preventing serious accidents caused by excessive system pressure. When the hydraulic system malfunctions and requires emergency stopping, the working oil circuit of the hydraulic system can be closed by controlling the opening and closing state of the electromagnetic relief valve, thus achieving the emergency stop function of the hydraulic system. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A schematic diagram of a servo hydraulic cylinder control system disclosed in a specific embodiment of this utility model;

[0023] Among them, 1. Oil port of the rod chamber of the hydraulic cylinder; 2. Oil supply port; 3. External control oil port; 4. Oil return port; 5. Oil drain port; 6. Third check valve; 7. First hydraulic control check valve; 8. Servo valve; 9. Solenoid relief valve; 10. Hydraulic cylinder; 11. Second hydraulic control check valve; 12. Solenoid valve. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Those skilled in the art can easily understand other advantages and effects of the present utility model from the content disclosed in this specification. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0025] It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding. They are not intended to limit the implementation of this utility model and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of this utility model, should still fall within the scope of the technical content disclosed herein. In the description of this utility model, it should be understood that the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are merely for the convenience of describing this utility model and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Therefore, features specified with "first," "second," etc., may explicitly or implicitly include one or more of those features. In the description of this utility model, unless otherwise stated, "multiple" means two or more.

[0026] It should also be noted that in the embodiments of this application, the same reference numerals are used to denote the same component or the same part.

[0027] The purpose of this invention is to provide a servo hydraulic cylinder control system to solve the problems existing in the prior art. By setting a first check valve and a second check valve, backflow of oil is prevented, the inlet pressure of the servo valve is stabilized, and the servo valve is protected from load impact.

[0028] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] Please refer to Figure 1 This embodiment provides a servo hydraulic cylinder control system, including a servo valve 8. The P port of the servo valve 8 is connected to the oil supply port 2, and the A port of the servo valve 8 is connected to the rodless chamber of the hydraulic cylinder 10. The rod chamber of the hydraulic cylinder 10 is connected to the oil port 1 of the rod chamber. A first check valve is provided between the servo valve 8 and the oil supply port 2. The oil outlet of the first check valve is connected to the oil supply port 2, and the oil inlet of the first check valve is connected to the servo valve 8. A second check valve is provided between the servo valve 8 and the rodless chamber of the hydraulic cylinder 10. The oil inlet of the second check valve is connected to the servo valve 8, and the oil outlet of the second check valve is connected to the rodless chamber of the hydraulic cylinder 10.

[0030] Specifically, the X port of servo valve 8 is connected to the external control oil port 3, the Y port of servo valve 8 is connected to the drain port 5, and the T port of servo valve 8 is connected to the return oil port 4.

[0031] The first and second check valves are hydraulically controlled check valves, namely the first hydraulically controlled check valve 7 and the second hydraulically controlled check valve 11. The system also includes a solenoid valve 12 that controls the opening and closing of the first hydraulically controlled check valve 7 and the second hydraulically controlled check valve 11. The P port of the solenoid valve 12 is connected to the oil supply port 2, the T port of the solenoid valve 12 is connected to the oil return port 4, the B port of the solenoid valve 12 is connected to the oil control port of the first hydraulically controlled check valve 7 and the second hydraulically controlled check valve 11, and the Y port of the first hydraulically controlled check valve 7 and the second hydraulically controlled check valve 11 is connected to the oil drain port 5.

[0032] In this embodiment, the hydraulic cylinder 10 is hydraulically controlled to perform two actions: working extension and working retraction. The working principle is as follows:

[0033] This embodiment provides five oil ports: oil port 1 in the rod chamber of the hydraulic cylinder (this oil port does not enter the system circuit), oil supply port 2, external control oil port 3, oil return port 4, and oil drain port 5; oil supply port 2 is connected to the pipeline leading out from the oil supply pump outlet or high-pressure accumulator, etc., and oil return port 4 is connected to the pipeline of the oil tank.

[0034] When the working cylinder extends, the oil from the external control port 3 flows into the X port of the servo valve 8. The control signal puts the servo valve 8 in the right position, activating the electromagnet of the solenoid valve 12, putting the solenoid valve 12 in the left position. The oil from the supply port 2 enters the P port of the solenoid valve 12, and then enters the control port of the first hydraulic control check valve 7 and the second hydraulic control check valve 11 from the B port. The first hydraulic control check valve 7 is opened, allowing the oil from the supply port 2 to flow from the outlet of the first hydraulic control check valve 7 into the inlet of the first hydraulic control check valve 7, and then into the P port of the servo valve 8. It then flows out from the A port, and then flows into the rodless chamber of the hydraulic cylinder 10 through the second hydraulic control check valve 11. The oil in the rod chamber of the hydraulic cylinder 10 flows out and enters the oil port 1 of the rod chamber of the hydraulic cylinder, and the working cylinder extends.

[0035] When oil supply port 2 begins supplying oil, the unstable oil pressure is stopped by the first hydraulically controlled check valve 7. Once the oil pressure stabilizes, the first hydraulically controlled check valve 7 is opened by the solenoid valve 12, allowing the stable oil to enter the servo valve 8. Therefore, the first hydraulically controlled check valve 7 can prevent pressure fluctuations in the oil supply system from being transmitted to the servo valve 8, making the pressure at port P of the servo valve 8 relatively stable, which is beneficial for the precise control of the servo valve 8.

[0036] When the working cylinder retracts, the oil in port 1 of the rod chamber of the hydraulic cylinder enters the rod chamber of the hydraulic cylinder 10. At the same time, the oil in port 3 flows into port X of the servo valve 8. The control signal makes the servo valve 8 in the left position, which connects the electromagnet of the solenoid valve 12, making the solenoid valve 12 in the left position. The oil in port 2 enters port P of the solenoid valve 12. The oil enters port B of the solenoid valve 12 and then port B of the second hydraulic control check valve 11. The second hydraulic control check valve 11 is opened, so that the oil in the rodless chamber of the hydraulic cylinder 10 can flow from the outlet of the second hydraulic control check valve 11 into the inlet of the second hydraulic control check valve 11, and then into port A of the servo valve 8. From port A, it flows to port T and finally into port 4, and the working cylinder retracts.

[0037] In this process, the oil in the rodless chamber of the hydraulic cylinder 10 flows out under the pressure of the oil in the rod chamber. The unstable oil pressure is stopped by the second hydraulically controlled check valve 11. After the oil pressure stabilizes, the second hydraulically controlled check valve 11 is opened by the solenoid valve 12, and the stabilized oil then enters the servo valve 8. Therefore, the second hydraulically controlled check valve 11 can prevent pressure fluctuations in the return oil system from being transmitted to the servo valve 8, making the pressure at port A of the servo valve 8 relatively stable, which is beneficial to the precise control of the servo valve 8.

[0038] Furthermore, a third check valve 6 is provided between the servo valve 8 and the return port 4. The inlet of the third check valve 6 is connected to the servo valve 8, and the outlet of the third check valve 6 is connected to the return port 4. By providing the third check valve 6, backflow of oil in the return port 4 can be prevented, thus avoiding damage to the valve core and other components of the servo valve 8 by the backflowing oil, which would affect the normal operation and lifespan of the servo valve 8.

[0039] In a preferred embodiment, the rodless chamber of the hydraulic cylinder 10 is connected to the return port 4 via an electromagnetic relief valve 9. Specifically, the inlet of the electromagnetic relief valve 9 is connected to the rodless chamber of the hydraulic cylinder 10, and the outlet of the electromagnetic relief valve 9 is connected to the return port 4. The third action of the hydraulic cylinder 10, namely, stopping, can be achieved through the electromagnetic relief valve 9.

[0040] When it is necessary to stop, the electromagnetic relief valve 9 is energized and opens, or the electromagnetic relief valve 9 automatically opens when the pressure reaches the set pressure. The oil in the rodless chamber of the hydraulic cylinder 10 flows into the return port 4 through the electromagnetic relief valve 9, and the cylinder stops.

[0041] During operation, the hydraulic system may experience abnormal situations that cause the system pressure to rise abnormally. The electromagnetic relief valve 9 can automatically open to guide the excess pressurized oil back to the oil tank, thus preventing serious accidents caused by excessive system pressure.

[0042] When the hydraulic system malfunctions and requires an emergency stop, the working oil circuit of the hydraulic system can be closed by controlling the opening and closing state of the solenoid relief valve 9, thereby realizing the emergency stop function of the hydraulic system.

[0043] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0044] If this utility model discloses or relates to mutually fixedly connected parts or structural components, then, unless otherwise stated, a fixed connection can be understood as: a detachable fixed connection (e.g., using bolts or screws), or a non-detachable fixed connection (e.g., riveting, welding). Of course, mutually fixed connections can also be replaced by an integral structure (e.g., manufactured using a casting process) (except where it is obviously impossible to use an integral forming process).

[0045] In addition, unless otherwise stated, the terms used to indicate positional relationships or shapes in any of the technical solutions disclosed in this utility model above include states or shapes that are similar to, close to, or approximate with them.

[0046] Any component provided by this utility model can be assembled from multiple individual components, or it can be a single component manufactured by a one-piece molding process.

[0047] Any adaptive changes made according to actual needs are within the protection scope of this utility model.

[0048] It should be noted that, for those skilled in the art, it is obvious that this utility model is not limited to the details of the above exemplary embodiments, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this utility model is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this utility model. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0049] This utility model uses specific examples to illustrate its principles and implementation methods. The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the idea of ​​this utility model. In summary, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A servo hydraulic cylinder control system, characterized in that: The system includes a servo valve, wherein the P port of the servo valve is connected to the oil supply port, and the A port of the servo valve is connected to the rodless chamber of the hydraulic cylinder; a first check valve is provided between the servo valve and the oil supply port, wherein the oil outlet of the first check valve is connected to the oil supply port, and the oil inlet of the first check valve is connected to the servo valve; and a second check valve is provided between the servo valve and the rodless chamber of the hydraulic cylinder, wherein the oil inlet of the second check valve is connected to the servo valve, and the oil outlet of the second check valve is connected to the rodless chamber of the hydraulic cylinder.

2. The servo hydraulic cylinder control system according to claim 1, characterized in that: The X port of the servo valve is connected to the external oil control port.

3. The servo hydraulic cylinder control system according to claim 1, characterized in that: The Y port of the servo valve is connected to the oil drain port.

4. The servo hydraulic cylinder control system according to claim 1, characterized in that: The T-port of the servo valve is connected to the oil return port.

5. The servo hydraulic cylinder control system according to claim 4, characterized in that: A third check valve is provided between the servo valve and the return port. The inlet of the third check valve is connected to the servo valve, and the outlet of the third check valve is connected to the return port.

6. The servo hydraulic cylinder control system according to claim 1, characterized in that: It also includes an electromagnetic relief valve, the oil inlet of which is connected to the rodless chamber of the hydraulic cylinder, and the oil outlet of which is connected to the return port.

7. The servo hydraulic cylinder control system according to any one of claims 1-6, characterized in that: The first check valve and the second check valve are hydraulically controlled check valves, namely the first hydraulically controlled check valve and the second hydraulically controlled check valve.

8. The servo hydraulic cylinder control system according to claim 7, characterized in that: It also includes a solenoid valve, wherein the P port of the solenoid valve is connected to the oil supply port, and the B port of the solenoid valve is connected to the oil control port of the first hydraulic check valve and the second hydraulic check valve.

9. The servo hydraulic cylinder control system according to claim 8, characterized in that: The Y-ports of the first hydraulic check valve and the second hydraulic check valve are connected to the drain port.

10. The servo hydraulic cylinder control system according to claim 8, characterized in that: The T-port of the solenoid valve is connected to the oil return port.

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