A pneumatic control valve viscosity failure test device and test analysis method thereof

Abstract

The present invention discloses a pneumatic control valve viscous fault test device and a test and analysis method thereof, and relates to the technical field of valve equipment. The viscous fault generating device of the test device comprises a left clamping block, a right clamping block and a friction rod, and the friction force on the friction rod can be changed by adjusting the clamping block, wherein the clamping block can move along the slide groove formed by the support frame and the clamping cover, and the friction force is indirectly represented by the force condition of the force transmission rod collected by the thrust sensor. The present invention can obtain the controller output curve, valve position curve, friction force curve and dynamic and static friction force f of the whole process of the actuator action through the proposed test and analysis method. d 、f s , which can fully reflect the nonlinear characteristics of viscosity faults. Based on the above data, the viscosity mechanism of the control valve can be studied to verify the reliability of different viscosity models. In addition, it can also be used to study the fault diagnosis and compensation methods of the viscosity characteristics of pneumatic control valves.

Description

Technical Field

[0001] The invention belongs to the field of valve testing devices, and in particular relates to a pneumatic regulating valve viscous fault testing device and a testing and analyzing method thereof. Background Art

[0002] Pneumatic control valves are the most commonly used actuators in industrial circuits. However, due to aging and other problems, the friction between the seal and the valve stem is often too large, resulting in a sudden jump before the valve stem slides, i.e., a sticking fault, which causes the circuit to oscillate, thereby affecting product quality, system energy consumption, and factory profits. Therefore, it is particularly important to study the mechanism of sticking faults, establish a reliable sticking model, and study the fault diagnosis and compensation methods of the sticking characteristics of pneumatic control valves. At present, most of the above studies are carried out using data-driven methods, that is, various parameter data when the pneumatic control valve has a sticking fault are required. Since the sticking fault is mainly caused by friction, the valve position of the actuator cannot change linearly according to the signal of the controller, so the friction force, valve position signal, and controller output signal are important data to reflect the sticking fault. At present, the devices and methods for obtaining the above data by changing the degree of sticking fault, i.e., the friction force, through the test device are mostly too complicated. For example, the friction force requires the installation of strain gauges or the knowledge of the friction coefficient of the friction pair in advance, and the methods for changing the friction force are mostly uncontrollable and easy to damage the valve stem, such as causing valve stem wear, eccentricity, and other problems. Therefore, how to effectively and controllably change the degree of sticking failure of the regulating valve without damaging the actuator and quickly and conveniently obtain important data reflecting sticking failure such as friction force, valve position signal and controller output signal is a problem that needs to be solved today. Summary of the invention

[0003] The purpose of the present invention is to overcome the defects in the prior art and provide a pneumatic control valve viscous fault test device and a test analysis method thereof.

[0004] The specific technical solutions adopted by the present invention are as follows:

[0005] In a first aspect, the present invention provides a pneumatic control valve viscous fault test device, including a pneumatic diaphragm actuator, a positioner, a data acquisition card, a controller, a host computer and a viscous fault generating device;

[0006] The sticking fault generating device comprises a left clamping block, a right clamping block and a friction rod; a vertical friction rod is clamped between the left clamping block and the right clamping block, the left clamping block and the right clamping block are located in the same horizontal plane and are arranged symmetrically relative to the axial direction of the friction rod; a friction elastic ring is provided at the contact point between the left clamping block and the right clamping block and the friction rod, and the friction rod can slide vertically relative to the friction elastic ring; the horizontal clamping force on the friction rod can be changed by an adjusting piece between the left clamping block and the right clamping block, and the upper part of the friction rod is coaxially detachably fixedly connected with the lower part of the valve stem of the pneumatic diaphragm actuator; the outer ends of the left clamping block and the right clamping block are respectively placed on the top of the two support frames The two outer ends can be detachably fixed to the support frame through a clamping cover, and the vertical pressure applied to the outer ends can be adjusted through the clamping cover; a slide groove for placing the outer ends and providing a degree of freedom for the clamping block to slide in the horizontal direction is formed between the clamping cover and the support frame; thrust sensors that can contact the bottom surfaces of the corresponding outer ends are fixed on the tops of the two support frames, and the thrust sensors are respectively connected to the input ends of the data acquisition card, the output ends of the controller are respectively connected to the input ends of the data acquisition card and the positioner, the output end of the positioner is connected to the input end of the data acquisition card, and the output end of the data acquisition card is connected to the host computer.

[0007] Preferably, the friction rod and the valve stem are connected via threads.

[0008] Preferably, the left clamping block and the right clamping block each include a clamping end, a force transmission rod and an outer end portion; the clamping end is used to clamp the friction rod, and an arc-shaped groove for placing the friction rod and the friction elastic ring is provided on a side adjacent to the friction rod; the clamping end of the left clamping block is provided with a plurality of penetrating bolt grooves along the circumferential direction, and the clamping end of the right clamping block is provided with a plurality of penetrating through-hole grooves along the circumferential direction, and the number and position of the bolt grooves and the through-hole grooves correspond to each other; the adjusting part includes a locking bolt and a locking nut, and the locking bolt can pass through the bolt groove and the through-hole groove in turn and be tightened and fixed by the locking nut.

[0009] Furthermore, the top and bottom of the arc-shaped groove are provided with raised limit pieces, and the limit pieces are used to prevent the friction elastic ring from moving up and down.

[0010] Preferably, the friction elastic ring is detachably sleeved on the outside of the friction rod, and the material is rubber, carbon fiber or flexible graphite.

[0011] Preferably, the support frame is vertically fixed on a support base, and the support base can be fixed to the ground by a plurality of circumferentially arranged anchor bolts.

[0012] Furthermore, the clamping cover is provided with a plurality of penetrating bolt holes in the circumference thereof, and is fixed to the support frame by means of clamping bolts penetrating the bolt holes, so as to provide a pre-tightening force to the thrust sensor component, so that the force direction of the thrust sensor component remains vertically downward.

[0013] Furthermore, the pneumatic diaphragm actuator and the positioner are both fixed to the support base via a support frame.

[0014] In a second aspect, the present invention provides a test and analysis method using any of the pneumatic control valve viscous fault test devices described in the first aspect, which is specifically as follows:

[0015] S1: Before the test starts, install the pneumatic diaphragm actuator on the viscous fault generating device to ensure that the friction rod and the valve stem are not eccentric; change the horizontal clamping force of the left clamping block and the right clamping block on the friction rod through the adjusting piece to generate positive pressure on the friction rod, and ensure that after the test starts, a sufficiently large friction force can be generated between the friction rod and the friction elastic ring to reflect the nonlinear characteristics of the viscous fault; provide a preload force to the thrust sensor by adjusting the clamping cover to keep the force direction of the thrust sensor vertically downward; the signals of the two thrust sensors are connected to the AI0 input channel of the data acquisition card in one way and to the AI1 input channel of the data acquisition card in the other way; the controller output signal OP is connected to the positioner in one way and to the AI2 input channel of the data acquisition card in the other way; the valve position signal MV output by the positioner is connected to the AI3 input channel of the data acquisition card;

[0016] S2: At the beginning of the test, the controller outputs a sinusoidal control signal OP to make the valve stem reciprocate up and down; when the control signal OP starts to increase and the valve stem tends to move downward, the left clamping block and the right clamping block are subjected to a vertical downward force to compress the cover to apply a preload force F to the thrust sensor. 左压紧 and F 右压紧 , friction force f, self-weight G, vertical upward force and support force F provided by thrust sensor 左 and F 右 According to the force balance, the combined force F measured by the two thrust sensors is F = 左压紧 +F 右压紧 +G+f, where F=F 左 +F 右 ; Let F initial =F 左压紧 +F 右压紧 + G, then F = F initial +f; At the beginning of the test, the friction rod and the friction elastic ring do not move relative to each other, and the friction force f increases with the increase of the control signal OP. When the valve stem thrust is greater than the maximum static friction force f s When the valve stem and friction rod begin to move downward, the friction force f reaches the maximum static friction force f s Then it immediately becomes sliding friction f d, and remains basically unchanged; when the control signal OP begins to decrease and the valve stem tends to move upward, the direction of the friction force on the left clamping block and the right clamping block changes to vertically upward, then the support force measured by the two thrust sensors is F = F initial -f, at this time, the friction force f also reaches the maximum static friction force f s Then it immediately becomes sliding friction f d , and remains basically unchanged; under the action of the periodic control signal OP, the above process is repeated;

[0017] S3: After the test, the OP, MV, and F can be obtained using the data acquisition card. 左 and F 右 signal and transmit it to the host computer; on the host computer, 左 and F 右 The signals are combined to obtain the Ft curve, and the Ft curve is shifted down by F initial The size becomes the ft curve, and f is obtained by summing and averaging the absolute values ​​of different peaks and troughs of ft. s , by maintaining the ft curve at f d The absolute value of nearby data is summed and averaged to get f d , the OP-t curve can be obtained through the controller, and the MV-t curve can be obtained through the positioner; the MV-OP curve can be obtained with MV as the vertical coordinate and OP as the horizontal coordinate.

[0018] As a preferred method, by changing the preload force F on the left and right sides 左压紧 and F 右压紧 , so that F initial >f s .

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention can effectively and controllably change the degree of sticking failure of the regulating valve without damaging the actuator through the sticking failure generating device, generate friction forces of different magnitudes, and simulate the friction force between the valve stem and the sealing component in practice; the controller output curve, valve position curve, friction force curve, and dynamic and static friction force f of the whole process of the actuator action can be quickly and conveniently obtained through the proposed test analysis method. d 、f s , and there is no need to know the friction coefficient of the friction pair in advance, so the nonlinear characteristics of the viscous fault can be fully reflected; the test device can be used to study the viscous mechanism of the control valve and verify the reliability of different viscous models. In addition, it can also be used to study the fault diagnosis and compensation method of the viscous characteristics of pneumatic control valves. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1This is the general diagram of the pneumatic control valve sticking failure test device;

[0022] Figure 2 It is a cross-sectional view of the device where the sticking failure occurs;

[0023] Figure 3 A three-dimensional diagram of the device that causes the sticking fault;

[0024] Figure 4 It is a three-dimensional diagram of the left clamping block;

[0025] Figure 5 This is the force analysis diagram of the clamping block;

[0026] Figure 6 For process control systems;

[0027] Figure 7 are force variation curves, (a) is the variation curve of the force F exerted on the thrust sensor over time t, (b) is the variation curve of the friction force f exerted on the valve stem over time t;

[0028] Figure 8 This is the overall architecture diagram of the test system.

[0029] In the figure: 1. anchor bolt; 2. support base; 3. thrust sensor component; 4. right clamping block; 5. clamping cover; 6. locking bolt; 7. locking nut; 8. friction rod; 9. friction elastic ring; 10. left clamping block; 11. clamping bolt; 12. valve stem; 1001. bolt groove; 1002. arc groove; 1003. force transmission rod; 8-01. positioner; 8-02. controller; 8-03. left thrust sensor; 8-04. right thrust sensor; 8-05. data acquisition card; 8-06. host computer. DETAILED DESCRIPTION

[0030] The present invention is further described and illustrated below in conjunction with the accompanying drawings and specific embodiments. The technical features of each embodiment of the present invention can be combined accordingly without conflicting with each other.

[0031] like Figure 1 As shown, a pneumatic control valve viscous fault test device provided by the present invention mainly includes a pneumatic diaphragm actuator, a positioner 8-01, a data acquisition card 8-05, a controller 8-02, a host computer 8-06 and a viscous fault generating device. Among them, the pneumatic diaphragm actuator is an existing mechanism, and the structure and connection method of the viscous fault generating device are specifically described below.

[0032] like Figure 2 and 3As shown, the sticking fault generating device mainly includes a left clamping block 10, a right clamping block 4 and a friction rod 8. The left clamping block 10 and the right clamping block 4 clamp the friction rod 8 together, the friction rod 8 is vertically arranged, the left clamping block 10 and the right clamping block 4 are located in the same horizontal plane and are arranged axially symmetrically relative to the friction rod 8.

[0033] In this embodiment, the left clamping block 10 and the right clamping block 4 can adopt a horizontal T-shaped structure, including a vertical section and a horizontal section; wherein the vertical section serves as a clamping end for clamping the friction rod 8, and the horizontal section includes the force transfer rod 1003 of the main body and an outer end away from the clamping end.

[0034] In the sticking fault generating device, a friction elastic ring 9 is provided at the contact point between the left clamping block 10 and the right clamping block 4 and the friction rod 8, and the friction rod 8 can slide vertically relative to the friction elastic ring 9. In this embodiment, the friction elastic ring 9 can be sleeved on the outside of the friction rod 8, and then clamped and fixed by the left clamping block 10 and the right clamping block 4. The left clamping block 10 and the right clamping block 4 are detachably fixed by an adjusting member, and the horizontal clamping force on the friction rod 8 can also be changed by the adjusting member. The upper part of the friction rod 8 is coaxially detachably fixedly connected with the lower part of the valve stem 12 of the pneumatic diaphragm actuator. In this embodiment, the friction rod 8 and the valve stem 12 can be connected by a threaded connection. This connection method ensures that the two move synchronously in the same vertical direction without eccentricity. The friction force does not directly act on the valve stem 12, but acts on the friction rod 8 to prevent the valve stem 12 from being worn.

[0035] In this embodiment, if Figure 4As shown, in the clamping ends of the left clamping block 10 and the right clamping block 4, an arc groove 1002 for placing the friction rod 8 and the friction elastic ring 9 is provided on one side adjacent to the friction rod 8. The clamping end of the left clamping block 10 is provided with a plurality of (four in this embodiment) through bolt grooves 1001 along the circumferential direction, and the clamping end of the right clamping block 4 is provided with a plurality of (four in this embodiment) through hole grooves along the circumferential direction, and the number and position of the bolt grooves 1001 and the through hole grooves correspond. The adjusting member includes a locking bolt 6 and a locking nut 7, and the locking bolt 6 can pass through the bolt groove 1001 and the through hole groove in turn and be tightened and fixed by the locking nut 7. In actual use, the contact pressure between the friction elastic ring 9 and the friction rod 8 is changed by rotating the four locking nuts 7 on the right clamping block 4, so as to achieve adjustable friction force. The locking bolt 6 is clamped by the bolt groove 1001 to prevent the locking bolt 6 from rotating when the locking nut 7 is rotated. The friction elastic ring 9 can be clamped by the arc groove 1002 to prevent the friction elastic ring 9 from moving relative to the left clamping block 10 and the right clamping block 4 in the vertical direction, ensuring that only the friction rod 8 slides in the vertical direction. The friction force exerted on the friction rod 8 in the vertical direction is transmitted to the thrust sensor 3 through the force transmission rod 1003. The top and bottom of the arc groove 1002 are provided with raised limiters, which are used to prevent the friction elastic ring 9 from moving up and down.

[0036] In this embodiment, the friction elastic ring 9 is detachably sleeved on the outside of the friction rod 8, and the material can be elastic materials such as rubber, carbon fiber, and flexible graphite, so as to ensure that the friction rod 8 is not easily completely stuck, thereby increasing the service life of the friction rod 8. When the friction elastic ring 9 and the friction rod 8 are severely worn during use and cannot provide a large friction force, they can be disassembled and replaced.

[0037] In the sticking fault generating device, the outer ends of the left clamping block 10 and the right clamping block 4 are respectively placed on the top of the two support frames, and the two outer ends can be detachably fixed to the support frames through the clamping cover 5, and the vertical pressure applied to the outer ends can be adjusted through the clamping cover 5. In this embodiment, the clamping cover 5 is circumferentially arranged with four bolt holes, and the clamping bolt 11 and the clamping cover 5 clamp the force transmission rod 1003 and the thrust sensor 3 to provide a pre-tightening force to the thrust sensor 3, so as to ensure that the direction of the force applied to the thrust sensor 3 remains unchanged and is always vertically downward.

[0038] In the sticking fault generating device, a slide groove is formed between the clamping cover 5 and the support frame, and the slide groove can place the outer end and can provide a degree of freedom for the clamping block to slide in the horizontal direction. The tops of the two support frames are fixed with thrust sensors 3 (i.e., left thrust sensor 8-03 and right thrust sensor 8-04, respectively) that can contact the bottom surface of the corresponding outer end. The thrust sensors 3 are respectively connected to the input end of the data acquisition card 8-05, the output end of the controller 8-02 is respectively connected to the input end of the data acquisition card 8-05 and the positioner 8-01, the output end of the positioner 8-01 is connected to the input end of the data acquisition card 8-05, and the output end of the data acquisition card 8-05 is connected to the host computer 8-06. In actual use, the force transmission rod 1003 can move along the slide groove formed by the support frame and the clamping cover 5. When the friction force is changed, the horizontal relative position of the left clamping block 10 and the right clamping block 4 needs to change. The slide groove provides a degree of freedom in the horizontal direction of the clamping block, so that the force transfer rod 1003 can move freely horizontally when the locking nut 7 is rotated.

[0039] In actual application, the support frame is vertically fixed on the support base 2, and the support base 2 can be fixed to the ground through a plurality of circumferentially arranged anchor bolts 1. The pneumatic diaphragm actuator and the positioner 8-01 can also be fixed to the support base 2 through the support frame.

[0040] like Figure 5-8 As shown, a test and analysis method using the above-mentioned pneumatic control valve viscosity failure test device provided by the present invention is as follows:

[0041] S1: Before the test starts, install the pneumatic diaphragm actuator on the viscous fault generating device to ensure that the friction rod 8 and the valve stem 12 are not eccentric. By rotating the locking nut 7, change the horizontal clamping force of the left clamping block 10 and the right clamping block 4 on the friction rod 8, so that positive pressure is generated on the friction rod 8, and ensure that after the test starts, a sufficiently large friction force can be generated between the friction rod 8 and the friction elastic ring 9 to reflect the nonlinear characteristics of the viscous fault. By rotating the clamping bolt 11, a pre-tightening force is provided to the thrust sensor 3 so that the force direction of the thrust sensor 3 remains vertically downward. The signals of the two thrust sensors 3 are connected to the AI0 input channel of the data acquisition card 8-05, and the other is connected to the AI1 input channel of the data acquisition card 8-05. Specifically, the signal of the right thrust sensor 8-04 is connected to the AI0 input channel of the data acquisition card 8-05, and the signal of the left thrust sensor 8-03 is connected to the AI1 input channel of the data acquisition card 8-05. The output signal OP of controller 8-02 is connected to positioner 8-01 in one way and to the AI2 input channel of data acquisition card 8-05 in the other way. The valve position signal MV output by positioner 8-01 is connected to the AI3 input channel of data acquisition card 8-05.

[0042] S2: At the beginning of the test, the controller 8-02 outputs a sinusoidal control signal OP to make the valve stem 12 reciprocate up and down. When the control signal OP starts to increase and the valve stem 12 tends to move downward, the left clamping block 10 and the right clamping block 4 are subjected to a vertical downward force to press the cover 5 to apply a preload force F to the thrust sensor 3. 左压紧 and F 右压紧 , friction force f, self-weight G, vertical upward force and support force F provided by thrust sensor 3 左 and F 右 According to the force balance, the combined force F measured by the two thrust sensors 3 is F = 左压紧 +F 右压紧 +G+f, where F=F 左 +F 右 Let F initial =F 左压紧 +F 右压紧 + G, then F = F initial +f. At the beginning of the test, the friction rod 8 and the friction elastic ring 9 do not move relative to each other, and the friction force f increases as the control signal OP increases. When the thrust of the valve stem 12 is greater than the maximum static friction force f s When the valve stem 12 and the friction rod 8 start to move downward, the friction force f reaches the maximum static friction force f s Then it immediately becomes sliding friction f d , and remains basically unchanged. When the control signal OP begins to decrease and the valve stem 12 tends to move upward, the direction of the friction force on the left clamping block 10 and the right clamping block 4 changes to vertically upward, and the support force measured by the two thrust sensors 3 is F = F initial -f, at this time, the friction force f also reaches the maximum static friction force f s Then it immediately becomes sliding friction f d , and remains basically unchanged. Under the action of the periodic control signal OP, the above process is repeated.

[0043] It should be noted that in order to ensure that the direction of the support force F is always vertically downward, F initial >f s , that is, by changing the preload force F on the left and right sides 左压紧 、F 右压紧 Meet the conditions and try to ensure that the preload forces on the left and right sides are close.

[0044] S3: After the test, OP, MV, and F can be obtained using data acquisition card 8-05. 左 and F 右 The signal is transmitted to the host computer 8-06. 左 and F 右 The signals are combined to obtain the Ft curve, and the Ft curve is shifted down by Finitial The size becomes the ft curve, and f is obtained by summing and averaging the absolute values ​​of different peaks and troughs of ft. s , by maintaining the ft curve at f d The absolute value of nearby data is summed and averaged to get f d , the OP-t curve can be obtained through the controller 8-02, and the MV-t curve can be obtained through the positioner 8-01. The MV-OP curve can be obtained with MV as the ordinate and OP as the abscissa. Then, the sticking fault of the pneumatic control valve can be analyzed based on the obtained MV-OP curve.

[0045] The above-described embodiment is only a preferred solution of the present invention, but it is not intended to limit the present invention. A person skilled in the relevant technical field may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present invention.

Claims

1. A pneumatic control valve viscous fault test device, characterized in that: It includes a pneumatic film actuator, a positioner (8-01), a data acquisition card (8-05), a controller (8-02), a host computer (8-06) and a sticking fault generating device; The sticking fault generating device comprises a left clamping block (10), a right clamping block (4) and a friction rod (8); a vertical friction rod (8) is clamped between the left clamping block (10) and the right clamping block (4); the left clamping block (10) and the right clamping block (4) are located in the same horizontal plane and are arranged axially symmetrically with respect to the friction rod (8); a friction elastic ring (9) is provided at the contact point between the left clamping block (10) and the right clamping block (4) and the friction rod (8); the friction rod (8) can slide vertically relative to the friction elastic ring (9); the horizontal clamping force on the friction rod (8) can be changed between the left clamping block (10) and the right clamping block (4) by an adjusting member, and the upper part of the friction rod (8) is coaxially detachably fixedly connected with the lower part of the valve stem (12) of the pneumatic diaphragm actuator; the outer ends of the left clamping block (10) and the right clamping block (4) are respectively placed at two At the top of the support frame, the two outer ends can be detachably fixed to the support frame through a clamping cover (5), and the vertical pressure applied to the outer ends can be adjusted through the clamping cover (5); a slide groove for placing the outer ends and providing a degree of freedom for the clamping block to slide in the horizontal direction is formed between the clamping cover (5) and the support frame; thrust sensors (3) that can contact the bottom surfaces of the corresponding outer ends are fixed on the tops of the two support frames, and the thrust sensors (3) are respectively connected to the input ends of the data acquisition card (8-05), the output ends of the controller (8-02) are respectively connected to the input ends of the data acquisition card (8-05) and the positioner (8-01), the output end of the positioner (8-01) is connected to the input end of the data acquisition card (8-05), and the output end of the data acquisition card (8-05) is connected to the host computer (8-06).

2. A pneumatic control valve viscous failure test device according to claim 1, characterized in that: The friction rod (8) and the valve stem (12) are connected via threads.

3. A pneumatic control valve viscous failure test device according to claim 1, characterized in that: The left clamping block (10) and the right clamping block (4) both comprise a clamping end, a force transmission rod (1003) and an outer end; the clamping end is used to clamp the friction rod (8), and an arc groove (1002) for placing the friction rod (8) and the friction elastic ring (9) is provided on a side adjacent to the friction rod (8); the clamping end of the left clamping block (10) is provided with a plurality of bolt grooves (1001) extending therethrough along the circumferential direction, and the clamping end of the right clamping block (4) is provided with a plurality of through hole grooves extending therethrough along the circumferential direction, and the number and position of the bolt grooves (1001) and the through hole grooves correspond to each other; the adjusting member comprises a locking bolt (6) and a locking nut (7), and the locking bolt (6) can pass through the bolt groove (1001) and the through hole groove in sequence and be tightened and fixed by the locking nut (7).

4. A pneumatic control valve viscous failure test device according to claim 3, characterized in that: The top and bottom of the arc-shaped groove (1002) are both provided with raised stoppers, which are used to prevent the friction elastic ring (9) from moving up and down.

5. The pneumatic control valve viscous failure test device according to claim 1, characterized in that: The friction elastic ring (9) is detachably sleeved on the outside of the friction rod (8), and is made of rubber, carbon fiber or flexible graphite.

6. A pneumatic control valve viscous failure test device according to claim 1, characterized in that: The support frame is vertically fixed on the support base (2), and the support base (2) can be fixed on the ground by a plurality of circumferentially arranged anchor bolts (1).

7. A pneumatic control valve viscous failure test device according to claim 6, characterized in that: The clamping cover (5) is provided with a plurality of through bolt holes in the circumference thereof, and is fixed to the support frame by means of clamping bolts (11) passing through the bolt holes, so as to provide a pre-tightening force to the thrust sensor component (3), so that the force direction of the thrust sensor component (3) remains vertically downward.

8. The pneumatic control valve viscous failure test device according to claim 6, characterized in that: The pneumatic film actuator and the positioner (8-01) are both fixed on the support base (2) via a support frame.

9. A test and analysis method using the pneumatic control valve viscous fault test device according to any one of claims 1 to 8, characterized in that: The details are as follows: S1: Before the test begins, the pneumatic diaphragm actuator is installed on the viscous fault generating device to ensure that the friction rod (8) and the valve stem (12) are not eccentric; the horizontal clamping force of the left clamping block (10) and the right clamping block (4) on the friction rod (8) is changed by adjusting the adjusting member to generate positive pressure on the friction rod (8) to ensure that after the test begins, a sufficiently large friction force can be generated between the friction rod (8) and the friction elastic ring (9) to reflect the nonlinear characteristics of the viscous fault; the thrust sensor (3) is provided with a preload by adjusting the clamping cover (5) to make the thrust sensor (3) The force direction of the force sensor device (3) is maintained vertically downward; one channel of the signals of the two thrust sensor devices (3) is connected to the AI0 input channel of the data acquisition card (8-05), and the other channel is connected to the AI1 input channel of the data acquisition card (8-05); one channel of the output signal OP of the controller (8-02) is connected to the positioner (8-01), and the other channel is connected to the AI2 input channel of the data acquisition card (8-05); the valve position signal MV output by the positioner (8-01) is connected to the AI3 input channel of the data acquisition card (8-05); S2: At the beginning of the test, the controller (8-02) outputs a sinusoidal control signal OP to make the valve stem (12) move up and down. When the control signal OP starts to increase and the valve stem (12) tends to move downward, the left clamping block (10) and the right clamping block (4) are subjected to a vertical downward force, and the preload force F applied by the compression cover (5) to the thrust sensor (3) is 左压紧 and F 右压紧 , friction force f, self-weight G, and the vertical upward force is supported by the thrust sensor (3) 左 and F 右 According to the force balance, the support force measured by the two thrust sensors (3) is F = F 左压紧 +F 右压紧 +G+f, where F=F 左 +F 右 ; Let F initial =F 左压紧 +F 右压紧 + G, then F = F initial +f; at the beginning of the test, the friction rod (8) and the friction elastic ring (9) do not move relative to each other, and the friction force f increases as the control signal OP increases. When the thrust of the valve stem (12) is greater than the maximum static friction force f s When the valve stem (12) and the friction rod (8) begin to move downward, the friction force f reaches the maximum static friction force f s Then it immediately becomes sliding friction f d , and remains basically unchanged; when the control signal OP begins to decrease and the valve stem (12) tends to move upward, the direction of the friction force on the left clamping block (10) and the right clamping block (4) changes to vertically upward, and the support force measured by the two thrust sensors (3) is F = F initial -f, at this time, the friction force f also reaches the maximum static friction force f s Then it immediately becomes sliding friction f d , and remains basically unchanged; under the action of the periodic control signal OP, the above process is repeated; S3: After the test, the data acquisition card (8-05) can be used to obtain OP, MV, F 左 and F 右 signal and transmit it to the host computer (8-06); on the host computer (8-06), 左 and F 右 The signals are combined to obtain the Ft curve, and the Ft curve is shifted down by F initial The size becomes the ft curve, and f is obtained by summing and averaging the absolute values ​​of different peaks and troughs of ft. s , by maintaining the ft curve at f d The absolute value of nearby data is summed and averaged to get f d , the OP-t curve can be obtained through the controller (8-02), and the MV-t curve can be obtained through the positioner (8-01); the MV-OP curve can be obtained with MV as the vertical coordinate and OP as the horizontal coordinate.

10. The test analysis method according to claim 9, characterized in that: By changing the preload force F on the left and right sides 左压紧 and F 右压紧 , so that F initial >f s .

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