Valve pressure test tool

Abstract

This invention discloses a valve pressure testing fixture, including a portal frame; a single-sided clamping mechanism including a chuck, a pressure claw cylinder, and a locking pressure claw. The chuck is fixedly installed inside the lower side of the portal frame, and multiple clamping claws are provided on the chuck. A pressure claw cylinder is vertically fixed on the upper side of the clamping claws, and a locking pressure claw is fixed on the upper free end of the pressure claw cylinder. A pump valve platform is fixed below the locking pressure claw. The multiple locking pressure claws and the pump valve platform form a single-sided fixation on the valve. The lower free end of the pressure cylinder is opposite to the chuck. A pump pressure pipe is provided on the upper side of the chuck, and a lower sealing plate is provided on the pump valve platform. The pump pressure pipe is connected to the lower sealing plate to pressurize the valve. This device can achieve single-sided sealing pressure testing of valves, as well as double-sided sealing by compression from both sides of the valve. It can solve the problems of single-sided and double-sided pressure testing. Furthermore, due to the use of hydraulic compression sealing, it has the advantages of speed and efficiency, avoiding the cumbersome operation of installing and removing bolts.

Description

Technical Field

[0001] This invention relates to the field of valve maintenance equipment technology, specifically to a valve pressure testing fixture. Background Technology

[0002] Valve repair pressure testing is a familiar task for marine engineering repair personnel. For each valve being repaired, a corresponding blind flange needs to be custom-made based on the valve flange size and pressure rating. The blind flange is then fixed to the corresponding valve port flange, and after tightening the valve, the test hose is connected to the blind flange thread. The pressure test is then performed according to the valve's required pressure. This manual blind flange tightening method is inefficient and requires the use of gaskets, bolts, and homemade blind flanges, increasing labor intensity, maintenance costs, and overall work efficiency.

[0003] To address this, prior art application CN201120321003.7 discloses a rapid valve pressure testing device, making the pressure testing operation quick, convenient, and simple. It includes a portal frame, with a pad installed on the inner top of the portal frame. A downward-pushing hydraulic jack is mounted on the lower surface of the pad, and a regulating valve is located below the hydraulic jack. An upper blind plate and a lower blind plate are respectively installed above and below the regulating valve. The upper blind plate abuts against the hydraulic jack, and the lower blind plate is fixedly connected to the base of the portal frame. The upper and lower blind plates are also sealed to the regulating valve via rubber sealing rings. The lower blind plate and the rubber sealing rings are also welded with a pressure testing tool interface and a pressure gauge interface. This device achieves a hydraulically tightened seal at both ends of the valve during pressure testing, helping to improve the sealing efficiency of the valve end face and accelerate the valve pressure testing speed. Its defects are: (1) The blind plates on both sides of the lower frame of the portal frame are affected by the width of the portal frame. The blind plates on both sides are in a suspended state. During the pressure test, they are prone to warping under pressure, which affects the sealing effect. Especially when testing large-diameter butterfly valves, the risk of leakage on both sides is greater. (2) Since it must seal the flanges on both sides of the valve at the same time when pressurizing the valve, the valve should be in the open state. This pressure test mainly detects the leakage of the valve core. However, the internal leakage of the valve cannot be detected. That is, when performing a single-sided sealing test on the valve, the device cannot achieve the same result. That is, it can only seal one side of the flange. The single-sided sealing test is to put the valve in the closed position, seal one side of the flange and pressurize that side. (3) The upper frame of the portal frame of the device is fixed. Therefore, the valve must be inserted into the frame from the side. For larger valves, the self-weight is large, and it is difficult to insert them from the side. It is also easy to wear the flange surface when inserting them.

[0004] In view of the above, it is necessary to propose a valve pressure testing fixture to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to solve the above-mentioned technical problems by providing a valve pressure testing fixture.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a valve pressure testing fixture, comprising a portal frame, wherein a top pressure cylinder is fixedly mounted on the upper truss;

[0007] A single-sided clamping mechanism includes a chuck part, a pressure claw cylinder, and a locking pressure claw. The chuck part is fixedly installed inside the lower side of the portal frame. Multiple grippers are provided on the chuck part. A pressure claw cylinder is vertically fixed on the upper side of the grippers. A locking pressure claw is fixed on the upper free end of the pressure claw cylinder. A pump valve platform is fixed below the locking pressure claw. Multiple locking pressure claws and the pump valve platform form a single-sided fixation of the valve. The lower free end of the top pressure cylinder is arranged opposite to the chuck part.

[0008] The upper side of the chuck is provided with a pump pressure pipe, and the pump valve platform is provided with a lower sealing plate. The pump pressure pipe is connected to the lower sealing plate to pressurize the valve.

[0009] Furthermore, the upper truss of the portal frame can be opened, allowing the upper side of the portal frame to be open for the valve to be vertically hoisted in. The first end of the upper truss is hinged to a column on one side of the portal frame, and the second end of the portal frame has a U-shaped opening. The upper truss rotates through the U-shaped opening and is engaged with the column on the other side. The top of the column is equipped with a locking nut.

[0010] Furthermore, it also includes a base plate and a molding die. The base plate includes a first lower plate, a second lower plate, a support tube, and side ribs. A support tube is fixed between the first lower plate and the second lower plate. Several side ribs for reinforcement are provided around the support tube. The first lower plate is fitted and sealed with the lower sealing plate. The second lower plate is fitted with the valve flange. The diameter of the second lower plate is larger than that of the first lower plate.

[0011] The mold is frustum-shaped and includes a connecting flange, an upper sealing plate, and a skirt. The skirt is formed into a flared shape with a smaller upper end and a larger lower end. The upper end of the skirt is fixedly connected to the connecting flange, and the lower end is fixedly connected to the upper sealing plate. The upper sealing plate has the same diameter as the second lower plate.

[0012] Furthermore, it includes a chassis and a turntable. The portal frame is fixedly mounted on the chassis, and one side column of the portal frame is vertically fixed at the center of the chassis as a central column. The turntable is rotatably connected to the chassis with the central column as the center. The turntable is provided with multiple clamping stations, and each station is provided with a single-sided clamping mechanism.

[0013] Furthermore, a slewing bearing is provided between the chassis and the turntable to improve support stability; it also includes a rotation drive mechanism, which includes a drive gear ring and a drive motor. The drive gear ring is fixedly mounted on the lower end face of the turntable, and the drive motor is fixedly mounted on the chassis. The output end of the drive motor is connected to the drive gear ring through a gear meshing.

[0014] Furthermore, the chuck section is provided with a gripper drive mechanism, which drives the grippers on the single-sided clamping mechanism to move synchronously. Each chuck section is provided with two gripper drive mechanisms, which are arranged along the radial direction of the turntable as an outer drive mechanism and an inner drive mechanism. The chassis is provided with a drive rack that cooperates with the gripper drive mechanism. The drive rack is arranged in an arc shape and includes an outer ring rack and an inner ring rack. The outer ring rack cooperates with the outer drive mechanism, and the inner ring rack cooperates with the inner drive mechanism.

[0015] Furthermore, the outer ring rack and the inner ring rack are respectively arranged on both sides of the portal frame.

[0016] Furthermore, the gripper drive mechanism includes a central rod, a clutch gear, a chuck gear, and a push rod cylinder. The central rod is rotatably connected to the side of the chuck portion. The chuck gear is fixedly located at one end of the central rod inside the chuck portion, and the clutch gear is rotatably connected to the other end. The clutch gear can slide a short distance along the axis of the central rod. Friction discs are respectively provided at the contact ends of the central rod and the clutch gear. The push rod cylinder is fixedly located inside the turntable and is positioned opposite to the central rod. The free end of the push rod cylinder pushes the clutch gear closer to the central rod, causing the two friction discs to come into contact. The clutch gear is rotatably connected to the free end of the push rod cylinder.

[0017] Furthermore, a grating ring is provided on the outer periphery of the friction disc of the central rod, and a displacement sensor is provided on one side of the push rod cylinder. The grating ring cooperates with the displacement sensor, and the displacement sensor controls the push rod cylinder to retract when it detects that the grating ring has stopped rotating.

[0018] Furthermore, it also includes a central rotary joint, which is located at the bottom of the central column and provides hydraulic oil to the pressure claw cylinder, push rod cylinder and pump pressure pipe.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. This device can perform single-sided sealing pressure testing on valves, as well as double-sided sealing by compression from both sides of the valve. It can solve the problems of single-sided and double-sided pressure testing. Furthermore, due to the use of hydraulic compression sealing, it has the advantages of speed and efficiency, avoiding the tedious operation of installing and removing bolts.

[0021] 2. The chuck section achieves a centered clamping effect on the valve, allowing the valve to be precisely concentrically placed on the pump and valve platform during hoisting, thereby avoiding uneven force due to eccentricity during compression sealing.

[0022] 3. When pressurizing large-diameter valves such as butterfly valves, using a base plate and a pressure mold can expand the applicability of large-size valves.

[0023] 4. Using multiple clamping stations on the turntable can improve the efficiency of valve pressure testing. During the pressure testing process, other stations can disassemble the valves that have finished pressure testing and carry out the hoisting and fixing of new valves, realizing assembly line-style rotating operation. Attached Figure Description

[0024] Figure 1 This is one of the side views of the first embodiment of the present invention;

[0025] Figure 2 This is a second side view of the first embodiment of the present invention;

[0026] Figure 3 This is a top view of the valve pressure testing fixture of the present invention;

[0027] Figure 4 This is a perspective view of the third embodiment of the present invention;

[0028] Figure 5 This is an internal sectional view of the third embodiment of the present invention;

[0029] Figure 6 This is a bottom view of the turntable;

[0030] Figure 7 This is a 3D view of the chassis;

[0031] In the diagram: 1. Portal frame; 2. Top-pressing cylinder; 3. Single-sided clamping mechanism; 4. Chuck section; 5. Claw cylinder; 6. Locking claw; 7. Pump valve platform; 8. Pump pressure pipe; 9. Lower sealing plate; 10. Upper truss; 11. Base plate; 12. Press mold; 13. First lower plate; 14. Second lower plate; 15. Connecting flange; 16. Upper sealing plate; 17. Chassis; 18. Turntable; 19. Slewing bearing; 20. Drive surface gear ring; 21. Drive motor; 22. Outer ring rack; 23. Inner ring rack; 24. Center rod; 25. Clutch gear; 26. Top rod cylinder; 27. Friction disc; 28. Grating ring; 29. ​​Displacement sensor; 30. Central rotary joint. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0033] Example 1:

[0034] A valve pressure testing fixture, such as Figure 1 As shown in Figure 2, the system includes a portal frame 1. A top-pressure cylinder 2 is fixedly mounted on the upper truss 10. The top-pressure cylinder 2 applies downward pressure to seal the flange on the upper side of the valve. A single-sided clamping mechanism 3 is positioned below the top-pressure cylinder 2. This single-sided clamping mechanism 3 has two functions: first, it cooperates with the top-pressure cylinder 2 to achieve a pressure seal on both sides of the valve flange to be tested; second, it can be used to perform a single-sided pressure test on the lower flange of the valve. Specifically, the single-sided clamping mechanism 3 includes a chuck 4 and a pressure... The chuck part 4 is fixedly installed inside the lower side of the portal frame 1. The chuck part 4 is similar to the existing three-jaw chuck structure, but it does not rotate. Multiple jaws are provided on the chuck part 4, and bolts on the side of the chuck can drive multiple jaws to move simultaneously, achieving centering tightening or loosening. A pressure jaw cylinder 5 is vertically fixed on the upper side of the jaws. When the jaws move, the pressure jaw cylinder 5 moves. A locking pressure jaw 6 is fixedly installed on the upper free end of the pressure jaw cylinder 5. A pump-valve platform 7 is fixedly installed below the claw 6. It can be understood that the movement of the claw causes the pressure claw cylinder 5 to move radially along the chuck portion 4, allowing for concentric positioning of the suspended valve. However, this method is not suitable when the valve is already on the pump-valve platform 7, especially with heavy valves. Due to the large weight of the valve, the friction between it and the pump-valve platform 7 is significant, and forcibly moving the valve laterally using the pressure claw cylinder 5 would damage the equipment. When the valve is suspended, the force required to push it laterally is smaller, allowing for more efficient operation. With the movement of the pressure claw cylinder 5 for concentric positioning, the valve position can be well kept concentric with the chuck part 4. At this time, the retracting pressure claw cylinder 5 uses the locking pressure claw 6 to press and fix this side. After fixing, the pressure operation can be performed. The upper side of the chuck part 4 is provided with a pump pressure pipe 8, and the pump valve platform 7 is provided with a lower sealing plate 9. The pump pressure pipe 8 is connected to the high pressure oil supply end. The connection between the pump pressure pipe 8 and the lower sealing plate 9 is for valve pressure. High pressure oil can enter the valve through the lower sealing plate 9. The lower sealing plate 9 is used to achieve a good seal with the valve flange.

[0035] The specific fixing can be divided into two methods:

[0036] I. For example Figure 1As shown in the figure, this is a schematic diagram of pressurizing a butterfly valve with a large diameter. The diameter of the butterfly valve exceeds the maximum clamping range of the chuck. This embodiment also includes a base plate 11 and a pressure mold 12. The base plate 11 and the pressure mold 12 are used to achieve the function of "diameter expansion". Specifically, the base plate 11 includes a first lower plate 13, a second lower plate 14, a support tube, and side ribs. A support tube is fixed between the first lower plate 13 and the second lower plate 14. The lower end of the support tube can be connected to the lower sealing plate 9, and the upper end can be connected to the upper second lower plate 14. When oil is supplied, the oil passes through the lower sealing plate 9 and the first lower plate 13 into the support tube, and then enters the valve through the second lower plate 14. Several side ribs are provided around the support tube for reinforcement. The ribs can improve the overall strength and prevent overturning under compression. The first lower plate 13 is fitted and sealed with the lower sealing plate 9. The second lower plate 14 is fitted with the valve flange. The diameter of the second lower plate 14 is larger than that of the first lower plate 13. The larger diameter of the second lower plate 14 is used to achieve the function of diameter expansion.

[0037] Correspondingly, the mold 12 is frustum-shaped and includes a connecting flange 15, an upper sealing plate 16, and a skirt. The skirt is formed into a flared shape with a smaller upper end and a larger lower end. The upper sealing plate 16 and the second lower plate 14 have the same diameter and are used to directly seal with the flanges on both sides of the valve. The upper end of the skirt is fixedly connected to the connecting flange 15, and the lower end is fixedly connected to the upper sealing plate 16. The skirt is used to achieve the function of connection and support. Ribs can also be added inside it. After the upper end is fixed to the top pressure cylinder 2, the lifting can be controlled by the top pressure cylinder 2.

[0038] II. Figure 2 As shown in the figure, this is a schematic diagram of pressurizing a valve that can be directly clamped. The chuck-controlled pressure claw cylinder 5 has the maximum clamping range. When the valve flange diameter is smaller than this range, the valve can be directly hoisted and kept concentric as described above, and then lowered so that the lower flange of the valve fits against the lower sealing plate 9. At this time, the pressure claw cylinder 5 is controlled to retract, and the locking pressure claw 6 is used to pull down the lower flange of the valve, thereby pressing the flange and the lower sealing plate 9 tightly to seal. This embodiment can achieve a single-sided seal of the valve. This single-sided seal is used to pressurize the valve for internal leakage. The advantage of this embodiment is that the internal leakage point of the valve core can be directly observed from the open upper flange opening, which facilitates targeted maintenance of the valve and improves the quality of subsequent valve maintenance.

[0039] Example 2:

[0040] Among the shortcomings of the prior art exemplified in the background section, the valve needs to be inserted from the side of the gate frame 1, which is inconvenient and easily scratches the sealing surface. This embodiment further improves upon this problem, specifically, as follows: Figure 2 , Figure 3As shown, the upper truss 10 of the portal frame 1 is designed to be rotatable and openable. When the upper truss 10 rotates, the upper side of the portal frame 1 opens, allowing space for the valve to be vertically hoisted into position, thus avoiding the risk of abrading the sealing surface by inserting it from the side. The first end of the upper truss 10 is hinged to a column on one side of the portal frame 1, as shown. Figure 3 The dotted line shows the upper truss 10 in the rotated open state. The second end of the portal frame 1 has a U-shaped opening. The upper truss 10 rotates through the U-shaped opening and is inserted into the column on the other side. The top of the column has a locking nut. The U-shaped opening on the side allows the upper truss 10 to be connected or separated from the column on the other side and fixed by locking bolts. Its strength is not significantly weakened compared to the fixed upper beam, and its performance is better.

[0041] Example 3:

[0042] The above embodiments describe the pressure testing process for individual valves. Installing or removing valves during this process takes a considerable amount of time. To improve the efficiency of the pressure testing process and create conditions for the installation of valves that will be pressure tested later, thereby saving installation time and increasing efficiency, this device is further improved.

[0043] Specifically, such as Figure 4 As shown, the system includes a chassis 17 and a turntable 18. The portal frame 1 is fixedly mounted on the chassis 17, and one side column of the portal frame 1 is vertically fixed at the center of the chassis 17 as the central column. The turntable 18 is rotatably connected to the chassis 17 with the central column as the center. The turntable 18 is provided with multiple clamping stations, each station is provided with a single-sided clamping mechanism 3. By setting multiple clamping stations, loading and unloading operations can be performed during the valve pressure test, thereby improving the efficiency of the valve pressure test. That is, the station located under the portal frame 1 is the pressure test station. When the turntable 18 rotates counterclockwise, the left side of the portal frame 1 is the unloading side, used to release the valve after pressure test, and the right side of the portal frame 1 is the loading side, used to clamp the new valve for replacement. The station opposite the portal frame 1 is the loading station. During the time interval when the turntable 18 stops during pressure test, the valve after pressure test is lifted out and the new valve is lifted in.

[0044] like Figure 5 , Figure 7As shown, due to the weight of the valve and the pressure applied to the turntable 18 during pressurization, an overturning moment is exerted on it when it is placed on the turntable 18. Therefore, in order to balance this moment and allow the turntable 18 to rotate freely, a slewing bearing 19 is provided between the chassis 17 and the turntable 18 to improve support stability. The slewing bearing 19 is a commonly used rotating support in the prior art, which can provide stable support force and has good performance under heavy loads. It also includes a rotation drive mechanism, which is used to drive the turntable 18 to rotate counterclockwise. It can be understood that the rotation direction of the turntable 18 is not restricted. The rotation angle of the turntable 18 can be controlled by the drive surface gear ring 20 and the drive motor 21. The drive surface gear ring 20 is fixedly installed on the lower end face of the turntable 18 with the tooth surface of the drive surface gear ring 20 facing downward. The drive motor 21 is fixedly installed on the chassis 17. The output end of the drive motor 21 is connected to the drive surface gear ring 20 through gear meshing. It can be understood that in order to improve the rotation accuracy of the turntable 18, a servo motor can be used, or limit switches can be set to stop when each clamping station reaches directly below the gantry frame 1.

[0045] The chuck section 4 is equipped with a jaw drive mechanism, which drives the jaws on the single-sided clamping mechanism 3 to move synchronously. Each chuck section 4 has two jaw drive mechanisms, which are arranged radially along the turntable 18 as an outer drive mechanism and an inner drive mechanism. Rotating either of the two jaw drive mechanisms can clamp or release the chuck section 4. This design principle is the same as that of the existing three-jaw chuck, and the internal structure can also be used accordingly. Figure 6 As shown, the difference lies in that the two gripper drive mechanisms are arranged radially along the turntable 18; furthermore, a drive rack that cooperates with the gripper drive mechanism is provided on the chassis 17, such as... Figure 7 As shown, the drive rack is arranged in an arc shape, including an outer ring rack 22 and an inner ring rack 23. The outer ring rack 22 cooperates with the outer drive mechanism, and the inner ring rack 23 cooperates with the inner drive mechanism. The outer ring rack 22 and the inner ring rack 23 are respectively arranged on both sides of the portal frame 1. It can be understood that since both the outer ring rack 22 and the inner ring rack 23 are not half-circles, for example, if a new valve is hoisted and positioned at the clamping station opposite to the portal frame 1, when the turntable 18 rotates, the station moves counterclockwise, and the outer ring rack 22 engages with the outer drive mechanism, which can drive the chuck part 4 to clamp the valve. Since there is no inner ring rack 23 on this side, this side is used for clamping the chuck part 4. Figure 7As shown, the outer ring rack 22 and the inner ring rack 23 meet on the lower side of the portal frame 1. When the station reaches the portal frame 1, it disengages from the outer ring rack 22 and then pressurizes the valve. After pressurization, the turntable 18 is controlled to rotate, so that the inner drive mechanism of the station contacts the inner ring rack 23. At this time, the chuck part 4 can be controlled to release the valve. After the station rotates one revolution and resets, the pressurized valve can be lifted out and replaced with a new valve. The advantage of this embodiment is that it can realize assembly line pressurization operation. As the turntable 18 rotates, one side of the chassis 17 is clamped and fixed, and the other side is released. The two ends where they meet are used for pressurization and valve replacement, which effectively improves the operating efficiency.

[0046] Furthermore, since the lengths of the outer ring rack 22 and the inner ring rack 23 are fixed, and the number of rotations of the rack to drive the gripper drive mechanism varies depending on the diameter of the valve flange, it is necessary to design a structure that can automatically disconnect the drive when the gripper drive mechanism clamps the flange.

[0047] Specifically, such as Figure 5 As shown, the gripper drive mechanism includes a central rod 24, a clutch gear 25, a chuck gear, and a push rod cylinder 26. The central rod 24 is rotatably connected to the side of the chuck portion 4. The chuck gear is fixedly installed at one end of the central rod 24 inside the chuck portion 4. The central rod 24 functions similarly to the bolts on the side of the chuck in the prior art, driving the coiled screw inside the chuck to rotate, thereby driving the gripper to move. The difference is that the clutch gear 25 is rotatably connected to the other end of the central rod 24. The clutch gear 25 can slide a short distance along the axis of the central rod 24. The clutch gear 25 can engage and disengage from the central rod 24. When the two are engaged, the clutch gear 25 directly drives the central rod 24 to rotate. When the chuck is clamped, the clutch gear 25 will disengage from the central rod 24, thereby disengaging the drive.

[0048] As shown in the figure, friction discs 27 are respectively provided at the contact ends of the center rod 24 and the clutch gear 25. By pressing the clutch gear 25 onto the center rod 24, the friction discs 27 of the two are brought into contact, and the friction force drives the center rod 24 to rotate. The push rod cylinder 26 is fixedly installed in the turntable 18 and is positioned opposite to the center rod 24. The free end of the push rod cylinder 26 pushes the clutch gear 25 closer to the center rod 24, causing the two friction discs 27 to fit together. The clutch gear 25 is rotatably connected to the free end of the push rod cylinder 26. When the push rod cylinder 26 is oiled... When the pressure control extends, its end pushes the clutch gear 25 toward the center rod 24 and clamps it, thus engaging the two. Since the clutch gear 25 is rotatably connected to the free end of the push rod cylinder 26, the rotation of the clutch gear 25 does not affect the pushing force of the push rod cylinder 26. Therefore, the relative movement of the outer ring rack 22 and the inner ring rack 23 can be used to drive the center rod 24 to rotate. When the flange is clamped, the friction force can no longer drive the center rod 24 to rotate. At this time, the clutch gear 25 should be separated from the center rod 24 as soon as possible to disengage the drive.

[0049] Specifically, the friction disc 27 of the central rod 24 is provided with a grating ring 28 on its outer periphery. The grating ring 28 is a grid structure with evenly spaced holes around the friction disc 27. A displacement sensor 29 is provided on one side of the push rod cylinder 26. The grating ring 28 cooperates with the displacement sensor 29. When the displacement sensor 29 detects that the grating ring 28 stops rotating, it controls the push rod cylinder 26 to retract. When the central rod 24 rotates, the displacement sensor 29 can capture the rotation signal, causing the push rod cylinder 26 under its control to push out. When the central rod 24 stops rotating, that is, when the chuck clamps, the grating ring 28 stops rotating. The displacement sensor 29 can capture the signal using the spaced grid, and then control the push rod cylinder 26 to retract. At this time, the clutch gear 25 disengages from the central rod 24, breaking the transmission.

[0050] It is understandable that the structure in this embodiment needs to keep the hydraulic oil circuit unobstructed at all times during the rotation of the turntable 18. The oil supply pipes of each hydraulic oil circuit are concentrated at the center of the turntable 18, and a central rotary joint 30 is set at this location on the chassis 17. The central rotary joint 30 is already maturely used in excavator technology and will not be described in detail here. The central rotary joint 30 is set at the bottom of the central column. The central rotary joint 30 provides hydraulic oil to the pressure claw cylinder 5, the push rod cylinder 26, and the pump pressure pipe 8. In this way, it can be ensured that each oil circuit remains unobstructed during the rotation of the turntable 18.

[0051] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A valve pressure testing fixture, comprising a portal frame (1), characterized in that, A top pressure cylinder (2) is fixedly installed on the upper truss (10); The single-sided clamping mechanism (3) includes a chuck part (4), a pressure claw cylinder (5), and a locking pressure claw (6). The chuck part (4) is fixedly installed inside the lower side of the portal frame (1). Multiple claws are provided on the chuck part (4). A pressure claw cylinder (5) is vertically fixed on the upper side of the claw. A locking pressure claw (6) is fixed on the upper free end of the pressure claw cylinder (5). A pump valve platform (7) is fixed below the locking pressure claw (6). Multiple locking pressure claws (6) and the pump valve platform (7) form a single-sided fixation of the valve. The lower free end of the top pressure cylinder (2) is set opposite to the chuck part (4). The chuck part (4) is provided with a pump pressure pipe (8) on its upper side, and the pump valve platform (7) is provided with a lower sealing plate (9). The pump pressure pipe (8) is connected to the lower sealing plate (9) to pressurize the valve. Includes a chassis (17) and a turntable (18). The portal frame (1) is fixedly mounted on the chassis (17), and one side column of the portal frame (1) is vertically fixed at the center of the chassis (17) as the central column. The turntable (18) is rotatably connected to the chassis (17) with the column as the center. The turntable (18) is provided with multiple clamping stations, and each station is provided with a single-sided clamping mechanism (3). The chuck section (4) is provided with a gripper drive mechanism, which drives the gripper on the single-sided clamping mechanism (3) to move synchronously. Each chuck section (4) is provided with two gripper drive mechanisms. The two gripper drive mechanisms are arranged in the radial direction of the turntable (18) as an outer drive mechanism and an inner drive mechanism. The chassis (17) is provided with a drive rack that cooperates with the gripper drive mechanism. The drive rack is arranged in an arc shape and includes an outer ring rack (22) and an inner ring rack (23). The outer ring rack (22) cooperates with the outer drive mechanism, and the inner ring rack (23) cooperates with the inner drive mechanism. The outer ring rack (22) and the inner ring rack (23) are respectively arranged on both sides of the portal frame (1); The gripper drive mechanism includes a central rod (24), a clutch gear (25), a chuck gear, and a push rod cylinder (26). The central rod (24) is rotatably connected to the side of the chuck portion (4). The chuck gear is fixedly located at one end of the central rod (24) inside the chuck portion (4), and the other end is rotatably connected to the clutch gear (25). The clutch gear (25) can slide a short distance along the axis of the central rod (24). The contact ends of the central rod (24) and the clutch gear (25) are respectively provided with friction discs (27). The push rod cylinder (26) is fixedly located inside the turntable (18) and is opposite to the central rod (24). The free end of the push rod cylinder (26) pushes the clutch gear (25) to move closer to the central rod (24), so that the two friction discs (27) are in contact. The free end of the clutch gear (25) is rotatably connected to the free end of the push rod cylinder (26).

2. The valve pressure testing fixture according to claim 1, characterized in that, The upper truss (10) of the portal frame (1) can be opened, so that the upper side of the portal frame (1) is open for the valve to be vertically hoisted in. The first end of the upper truss (10) is hinged to a column on one side of the portal frame (1). The second end of the portal frame (1) is provided with a U-shaped opening. The upper truss (10) rotates through the U-shaped opening and is inserted into the column on the other side. The top of the column is provided with a locking nut.

3. The valve pressure testing fixture according to claim 1, characterized in that, It also includes a base plate (11) and a molding die (12). The base plate (11) includes a first lower plate (13), a second lower plate (14), a support tube, and side ribs. A support tube is fixed between the first lower plate (13) and the second lower plate (14). Several side ribs for reinforcement are provided around the support tube. The first lower plate (13) is in contact with the lower sealing plate (9) for sealing. The second lower plate (14) is in contact with the valve flange. The diameter of the second lower plate (14) is larger than that of the first lower plate (13). The mold (12) is frustum shaped and includes a connecting flange (15), an upper sealing plate (16), and a skirt. The skirt is formed into a flared shape with a smaller upper end and a larger lower end. The upper end of the skirt is fixedly connected to the connecting flange (15), and the lower end is fixedly connected to the upper sealing plate (16). The upper sealing plate (16) has the same diameter as the second lower plate (14).

4. The valve pressure testing fixture according to claim 1, characterized in that, A slewing bearing (19) for improving support stability is provided between the chassis (17) and the turntable (18); it also includes a rotation drive mechanism, which includes a drive surface gear ring (20) and a drive motor (21). The drive surface gear ring (20) is fixedly installed on the lower end face of the turntable (18), and the drive motor (21) is fixedly installed on the chassis (17). The output end of the drive motor (21) is meshed with the drive surface gear ring (20) through gears.

5. The valve pressure testing fixture according to claim 1, characterized in that, The friction disc (27) of the central rod (24) is provided with a grating ring (28) on its outer periphery, and a displacement sensor (29) is provided on one side of the push rod cylinder (26). The grating ring (28) cooperates with the displacement sensor (29). When the displacement sensor (29) monitors the grating ring (28) and stops rotating, it controls the push rod cylinder (26) to retract.

6. The valve pressure testing fixture according to claim 1, characterized in that, It also includes a central rotary joint (30), which is located at the bottom of the central column and provides hydraulic oil to the pressure claw cylinder (5), the push rod cylinder (26) and the pump pressure pipe (8).

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