Electro-hydraulic actuating mechanism and double-feedback control method

Abstract

The invention discloses an electro-hydraulic actuating mechanism and a double-feedback control method, and relates to the field of electro-hydraulic execution.The electro-hydraulic actuating mechanism comprises an anti-breaking assembly and a switching module, and protection upgrading of the physical level is achieved through the arrangement of the anti-breaking assembly. The anti-breaking assembly comprises a movable part and a feedback part for detecting the position of the movable part, the executing mechanism can be installed through the arrangement of the movable part, the opening degree of the valve can be achieved, and the switching module comprises a control part, a local control cabinet and a hydraulic executing mechanism; the control piece transmits an action instruction to the local control cabinet; the local control cabinet conveys a hydraulic instruction to the hydraulic execution mechanism; detecting a first feedback signal and a second feedback signal through a hydraulic actuating mechanism; and the second feedback signal is directly transmitted to the control element. A thick rod of the feedback connecting rod replaces a thin rod to be embedded in the positioning hole, so that the stress bearing limit of the feedback connecting rod is improved, and the overall stability is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electro-hydraulic actuation, and in particular to an electro-hydraulic actuating mechanism and a dual feedback control method. Background Art

[0002] In the field of industrial automation, electro-hydraulic actuators are key equipment for achieving precise control of valve opening. As an advanced control device, REXA electro-hydraulic actuators are widely used in industries such as petroleum, chemical, and energy. Traditional REXA actuators mainly use a single feedback control method, receiving feedback signals from the valve position through a servo card to achieve precise control of the valve opening.

[0003] Although the single feedback control method can achieve control of the valve opening to a certain extent, there are problems in practical applications, such as the thread root is easily broken by lateral force, the valve loses control after the feedback rod breaks, and there is no effective means to avoid valve loss of control. Therefore, a new type of actuator is needed to improve the reliability and safety of the equipment, avoid unit shutdown caused by valve loss of control, and ensure precise control of the valve under various working conditions. Summary of the invention

[0004] In view of the problems existing in the above-mentioned electro-hydraulic actuator, the present invention is proposed.

[0005] Therefore, the problem to be solved by the present invention is how to improve the reliability of the device and how to improve the safety of the valve.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: an electro-hydraulic actuator, comprising an anti-break component, including a movable part and a feedback part for detecting the position of the movable part; a switching module, including a control part, a local control cabinet and a hydraulic actuator; the control part transmits action instructions to the local control cabinet; the local control cabinet transmits hydraulic instructions to the hydraulic actuator; a first feedback signal and a second feedback signal are detected by the hydraulic actuator; the second feedback signal is directly transmitted to the control part.

[0007] As a preferred solution of the electro-hydraulic actuator of the present invention, the movable part includes a valve stem and a connecting block fixedly connected to the valve stem; the valve stem moves up and down to control the opening and closing of the valve; the connecting block moves simultaneously with the valve stem.

[0008] As a preferred solution of the electro-hydraulic actuator of the present invention, the movable part further comprises a guide rod, one end of the connecting block slides vertically on the guide rod; and the other end of the connecting block is provided with a positioning hole.

[0009] As a preferred solution of the electro-hydraulic actuator of the present invention, the feedback member includes a feedback connecting rod and a fixing nut, and the feedback connecting rod is provided with a thread that matches the fixing nut.

[0010] As a preferred solution of the electro-hydraulic actuator of the present invention, the feedback connecting rod is divided into two parts: a thick rod and a thin rod, and the thin rod is provided with a thread that cooperates with the fixing nut.

[0011] As a preferred solution of the electro-hydraulic actuator of the present invention, wherein: the thick rod is embedded in the positioning hole, the diameter of the thick rod is approximately equal to the inner diameter of the positioning hole, and the thick rod can be embedded in the positioning hole; the diameter of the thin rod is smaller than the diameter of the thick rod.

[0012] As a preferred solution of the electro-hydraulic actuator described in the present invention, wherein: a servo card is installed in the local control cabinet, and a switching button is provided on the local control cabinet, and the switching button can switch between manual and automatic; the action instructions include control instructions, inching instructions and switching instructions, and the hydraulic actuator controls the valve opening according to the hydraulic instructions output by the servo card.

[0013] Another object of the present invention is to provide a dual feedback control method, which is applied to the above-mentioned electro-hydraulic actuator, the method comprising outputting a control instruction from the control element to the local control cabinet; the hydraulic actuator starts to detect a first feedback signal and a second feedback signal; the control element starts to detect the deviation between the first feedback signal and the second feedback signal; when it is detected that the deviation between the first feedback signal and the second feedback signal is greater than 5%, it is determined that the valve is in a fault state;

[0014] The control component outputs a switching instruction; the switching button is switched to a manual mode.

[0015] As a preferred solution of the dual feedback control method described in the present invention, when the switch button is in automatic mode, the hydraulic actuator detects the first feedback signal and transmits the first feedback signal to the local control cabinet, which then transmits the first feedback signal to the control component for display; the deviation between the control instruction and the first feedback signal is calculated by the servo card inside the local control cabinet, and the hydraulic instruction is output to the hydraulic actuator according to the deviation to realize valve closed-loop control.

[0016] As a preferred solution of the dual feedback control method of the present invention, when the switch button is switched to manual mode, the control component outputs a jog command to perform valve open-loop control.

[0017] The beneficial effects of the present invention are:

[0018] 1. Improve the reliability of the device and avoid stress concentration on the weakest position of the feedback rod;

[0019] 2. When the servo control causes the valve to lose control, the valve can be controlled by manual jog to avoid the valve losing control;

[0020] 3. By adding an independent feedback device, the control method of the valve is optimized, and it can be switched to manual control when the feedback deviation is large. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0022] Figure 1 This is the scene diagram of the electro-hydraulic actuator.

[0023] Figure 2 This is the structural diagram of the feedback connecting rod of the electro-hydraulic actuator.

[0024] Figure 3 Flow chart of the dual feedback control method. DETAILED DESCRIPTION

[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0026] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0027] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it an embodiment that is mutually exclusive with other embodiments, either individually or selectively.

[0028] Example 1

[0029] Reference Figure 1, which is the first embodiment of the present invention, provides an electro-hydraulic actuator, which includes an anti-breaking component 100 and a switching module 200. The physical level protection upgrade is achieved by setting the anti-breaking component 100, so that the bearing threshold of the feedback connecting rod 102a is improved.

[0030] Specifically, the anti-breaking assembly 100 includes a movable part 101 and a feedback part 102 for detecting the position of the movable part 101. The movable part 101 can be provided to realize the installation of the actuator and the opening of the valve.

[0031] Preferably, the switching module 200 includes a control component 201, a local control cabinet 202 and a hydraulic actuator 203;

[0032] The control element 201 transmits action instructions to the local control cabinet 202;

[0033] The local control cabinet 202 transmits hydraulic instructions to the hydraulic actuator 203;

[0034] Detecting the first feedback signal and the second feedback signal 207 through the hydraulic actuator 203;

[0035] The second feedback signal 207 is directly transmitted to the control element 201 .

[0036] During use, according to the prior art, the force borne by the root of the feedback connecting rod is very limited, so it is easy to break at the root of the thread when subjected to lateral force. However, we replace the thin rod 102a-2 with the thick rod 102a-1 of the feedback connecting rod 102a and embed it into the positioning hole 101b-1, which increases the stress bearing limit of the feedback connecting rod 102a, thereby greatly improving the overall stability.

[0037] Example 2

[0038] Reference Figure 1 and Figure 2 , which is the second embodiment of the present invention, and this embodiment is based on the previous embodiment.

[0039] Specifically, the movable member 101 includes a valve stem 101a and a connecting block 101b fixedly connected to the valve stem 101a;

[0040] The valve stem 101a moves up and down to control the opening and closing of the valve;

[0041] The connecting block 101b moves simultaneously with the valve stem 101a.

[0042] Preferably, the movable member 101 further includes a guide rod 101c, and one end of the connecting block 101b slides vertically on the guide rod 101c;

[0043] The other end of the connection block 101b is provided with a positioning hole 101b-1.

[0044] Preferably, the feedback member 102 includes a feedback connecting rod 102a and a fixing nut 102b, and the feedback connecting rod 102a is provided with a thread that matches the fixing nut 102b.

[0045] Preferably, the feedback connecting rod 102a is divided into two parts, namely a thick rod 102a-1 and a thin rod 102a-2, and the thin rod 102a-2 is provided with a thread that matches with the fixing nut 102b.

[0046] Preferably, the thick rod 102a-1 is embedded in the positioning hole 101b-1, the diameter of the thick rod 102a-1 is approximately equal to the inner diameter of the positioning hole 101b-1, and the thick rod 102a-1 can be embedded in the positioning hole 101b-1;

[0047] The diameter of the thin rod 102a-2 is smaller than the diameter of the thick rod 102a-1.

[0048] Preferably, a servo card is installed in the local control cabinet 202, and a switch button 202a is provided on the local control cabinet 202, and the switch button 202a can switch between manual and automatic;

[0049] Action instructions include control instructions, jog instructions, and switching instructions;

[0050] The hydraulic actuator 203 controls the valve opening according to the hydraulic command output by the servo card.

[0051] When in use, first insert the feedback connecting rod 102a into the positioning hole 101b-1 so that the thick rod 102a-1 of the feedback connecting rod 102a is located in the positioning hole 101b-1, and then fix the feedback connecting rod 102a and the connecting block 101b through the fixing nut 102b, and then turn on the power to make the entire mechanism start to operate.

[0052] Example 3

[0053] Reference Figure 3 , which is the third embodiment of the present invention, and is based on the first two embodiments.

[0054] Specifically, the control instruction is output from the control element 201 to the local control cabinet 202;

[0055] The hydraulic actuator 203 starts to detect the first feedback signal and the second feedback signal 207;

[0056] The control element 201 starts to detect the deviation between the first feedback signal and the second feedback signal 207;

[0057] When it is detected that the deviation between the first feedback signal and the second feedback signal 207 is greater than 5%, it is determined that the valve is in a fault state;

[0058] The control element 201 outputs a switching instruction;

[0059] The switch button 202a is switched to the manual mode.

[0060] Preferably, when the switch button 202a is in the automatic mode, the hydraulic actuator 203 detects the first feedback signal and transmits the first feedback signal to the local control cabinet 202, and the local control cabinet 202 transmits the first feedback signal to the control element 201 for display;

[0061] The servo card inside the local control cabinet 202 calculates the deviation between the control command and the first feedback signal, and outputs the hydraulic command to the hydraulic actuator 203 according to the deviation to realize the valve closed-loop control.

[0062] Preferably, when the switch button 202a is switched to the manual mode, the control element 201 outputs a jog command to perform valve open-loop control.

[0063] When in use, the control component 201 outputs a control command to the local control cabinet 202, the hydraulic actuator 203 detects a first feedback signal and transmits the signal to the local control cabinet 202, the local control cabinet 202 then transmits the first feedback signal to the control component 201 for display, the local control cabinet 202 is installed on site, a servo controller is installed inside the local control cabinet 202, the servo card calculates the deviation between the valve control command and the first feedback signal, and outputs a hydraulic command to the hydraulic actuator 203 according to the deviation, so as to realize valve closed-loop control, which is an automatic state;

[0064] The hydraulic actuator 203 controls the valve opening according to the hydraulic command output by the servo card, and directly sends the second feedback signal 207 to the control element 201. The local control cabinet 202 adds a switching button 202a. In the manual state, the deviation between the command and the feedback is no longer detected, and the open-loop control is realized by button jogging;

[0065] The control element 201 detects the deviation between the first feedback signal and the second feedback signal 207. When the deviation between the first feedback signal and the second feedback signal 207 is large, it is determined that the valve is in a fault state, and the control element 201 outputs a switching instruction, and the valve control is switched to a manual mode.

[0066] When the valve is switched to the manual mode, the control element 201 can output a jog command to perform open-loop control of the valve.

[0067] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. An electro-hydraulic actuator, characterized in that: include, An anti-break component (100) comprises a movable part (101) and a feedback part (102) for detecting the position of the movable part (101); A switching module (200) comprises a control component (201), a local control cabinet (202) and a hydraulic actuator (203); The control component (201) transmits an action instruction to the local control cabinet (202); The local control cabinet (202) transmits hydraulic instructions to the hydraulic actuator (203); Detecting a first feedback signal and a second feedback signal through the hydraulic actuator (203); The second feedback signal is directly transmitted to the control element (201).

2. The electro-hydraulic actuator according to claim 1, characterized in that: The movable part (101) comprises a valve stem (101a) and a connecting block (101b) fixedly connected to the valve stem (101a); The valve stem (101a) moves up and down to control the opening and closing of the valve; The connecting block (101b) and the valve stem (101a) move simultaneously.

3. The electro-hydraulic actuator according to claim 2, characterized in that: The movable member (101) further comprises a guide rod (101c), and one end of the connecting block (101b) slides vertically on the guide rod (101c); The other end of the connection block (101b) is provided with a positioning hole (101b-1).

4. The electro-hydraulic actuator according to claim 3, characterized in that: The feedback member (102) comprises a feedback connecting rod (102a) and a fixing nut (102b), and the feedback connecting rod (102a) is provided with a thread that matches the fixing nut (102b).

5. The electro-hydraulic actuator according to claim 4, characterized in that: The feedback connecting rod (102a) is divided into two parts: a thick rod (102a-1) and a thin rod (102a-2), and the thin rod (102a-2) is provided with a thread that matches the fixing nut (102b).

6. The electro-hydraulic actuator according to claim 5, characterized in that: The thick rod (102a-1) is embedded in the positioning hole (101b-1), the diameter of the thick rod (102a-1) is approximately equal to the inner diameter of the positioning hole (101b-1), and the thick rod (102a-1) can be embedded in the positioning hole (101b-1); The diameter of the thin rod (102a-2) is smaller than the diameter of the thick rod (102a-1).

7. The electro-hydraulic actuator according to claim 6, characterized in that: A servo card is installed in the local control cabinet (202), and a switch button (202a) is provided on the local control cabinet (202), wherein the switch button (202a) can be switched between manual and automatic. The action instructions include control instructions, jog instructions and switching instructions; The hydraulic actuator (203) controls the valve opening according to the hydraulic command output by the servo card.

8. A dual feedback control method, characterized in that: Applied to the electro-hydraulic actuator as claimed in claim 7, the control method comprises: Outputting control instructions from the control element (201) to the local control cabinet (202); The hydraulic actuator (203) starts detecting the first feedback signal and the second feedback signal; The control element (201) starts detecting a deviation between the first feedback signal and the second feedback signal; When it is detected that the deviation between the first feedback signal and the second feedback signal is greater than 5%, it is determined that the valve is in a fault state; The control element (201) outputs a switching instruction; The switch button (202a) is switched to manual mode.

9. The dual feedback control method according to claim 8, characterized in that: When the switch button (202a) is in automatic mode, the hydraulic actuator (203) detects the first feedback signal and transmits the first feedback signal to the local control cabinet (202), and the local control cabinet (202) transmits the first feedback signal to the control element (201) for display; The deviation between the control instruction and the first feedback signal is calculated by a servo card inside the local control cabinet (202), and a hydraulic instruction (205) is output to the hydraulic actuator (203) according to the deviation, thereby realizing valve closed-loop control.

10. The dual feedback control method according to claim 9, characterized in that: When the switch button (202a) is switched to the manual mode, a jog command is output through the control element (201) to perform valve open-loop control.

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