Creep deformation detection device for steel pipe
By designing the inner and outer clamping parts and cooperating with the hydraulic cylinder, the problem of steel pipe deformation due to clamping during creep testing was solved, thus achieving accurate creep testing.
Patent Information
- Application Number
- CN202520348539.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-28
- Publication Date
- 2026-01-30
- Estimated Expiration
- 2035-02-28
AI Technical Summary
In existing technologies, the gripper jaws can easily cause steel pipes to deform, affecting the accuracy of creep detection.
The design employs internal and external clamping sections, using ball bearings and clamping bolts to clamp the steel pipe from both inside and outside. Combined with pressure applied by a hydraulic cylinder for creep detection, this prevents the steel pipe from deforming.
This effectively avoids deformation of the steel pipe during the clamping process, ensuring the accuracy of creep test data.
Smart Images
Figure CN223856921U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a kind of creep detection devices for steel pipe. BACKGROUND
[0002] Metal material is often subjected to external pressure when working, and will creep during long-term compression, that is, slow and continuous plastic deformation occurs. In high temperature and high pressure environments, metal materials need to be subjected to creep detection. Currently, creep detection is performed by clamping both ends of the material with a jaw, applying a certain pressure and maintaining it for a certain period of time to measure the deformation. However, the jaw can deform the steel pipe when clamping the steel pipe, affecting the smooth progress of the test and the accuracy of the test data. SUMMARY
[0003] To solve the problem of deformation of the steel pipe during creep detection of steel pipe materials, the present application provides a creep detection device for steel pipe, which includes a detection frame, two clamping parts and a hydraulic cylinder. The upper and lower clamping parts are respectively an upper clamping part and a lower clamping part. The cylinder barrel of the hydraulic cylinder is fixed on the top plate of the detection frame, and the piston rod of the hydraulic cylinder is connected with the upper clamping part freely downward through the top plate. The lower clamping part is installed on the bottom plate of the detection frame, and the two clamping parts are opposite to each other.
[0004] Each clamping part includes an inner extrusion part and an outer extrusion part. The inner extrusion part includes a base, an extrusion block, a locking bolt and a clamping part. The extrusion block is located on one side of the base facing the other clamping part. The base and the extrusion block are both circular with the axis extending in the vertical direction. The screw rod of the locking bolt is freely threaded through the extrusion block and the base in sequence and then screwed with a locking nut. The locking nut is located on the side of the base away from the extrusion block. The extrusion block has a counterbore on the side away from the base. The inner periphery of the counterbore is a regular polygon. The head of the locking bolt is located in the counterbore, and the outer periphery of the head of the locking bolt is a regular polygon with the same shape as the inner periphery of the counterbore, so that the locking bolt cannot rotate relative to the extrusion block.
[0005] The outer side of the base facing the extrusion block has a first conical surface with a small end facing the extrusion block. The outer side of the extrusion block facing the base has a second conical surface with a small end facing the base. The first conical surface and the second conical surface form an annular groove therebetween, and the axial section of the annular groove is a trapezoid with a large end facing outward. The elastic extrusion part is located in the annular groove. The elastic extrusion part includes an elastic ring in the shape of a ring and a ball set on the elastic ring. When the locking nut is screwed in the direction of the extrusion block, the first conical surface and the second conical surface can be brought closer to each other, the ball can be extruded outward, and the ball can be made to exceed the outer periphery of the base and the extrusion block in the radial direction. The locking bolts of the two clamping parts are coaxially arranged.
[0006] The outer extrusion part comprises a locking ring fixed on the base, a clamping bolt extending along the radial direction of the locking ring is screwed on the locking ring, the clamping bolt is screwed on the locking ring from the outside to the inside, an annular gap for inserting the steel pipe to be tested is formed between the locking ring and the inner extrusion part, and the locking screw extends into the annular gap after penetrating the locking ring. Specifically, the elastic ring is a rubber ring, a helical spring or a bellows. The helical spring is also called a spring contact finger, a contact spring or a ring spring, and specifically is a spiral spring with no end.
[0007] In use of the application, first, the height of the upper clamping part is adjusted so that the distance between the upper clamping part and the lower clamping part is not less than the length of the steel pipe to be tested, then one end of the steel pipe to be tested is inserted into the annular gap of the lower clamping part, then the steel pipe to be tested is extended in the vertical direction, the locking nut of the lower clamping part is screwed, the balls of the lower clamping part are moved outward in the radial direction and tightly extruded on the inner wall of the steel pipe to be tested, then the clamping bolt of the lower clamping part is screwed, the abutting block of the lower clamping part is tightly abutted on the outer wall of the steel pipe to be tested, and the fixation of the lower end of the steel pipe to be tested is completed.
[0008] The piston rod of the hydraulic cylinder is extended downward, the upper clamping part is pushed downward, the upper end of the steel pipe to be tested is inserted into the annular gap of the upper clamping part, the locking nut of the upper clamping part is screwed, the balls of the upper clamping part are moved outward in the radial direction and tightly extruded on the inner wall of the steel pipe to be tested, then the clamping bolt of the upper clamping part is screwed, the abutting block of the upper clamping part is tightly abutted on the outer wall of the steel pipe to be tested, and the fixation of the upper end of the steel pipe to be tested is completed.
[0009] The hydraulic cylinder is started, the steel pipe to be tested is applied with a set pressure, and the deformation of the steel pipe to be tested is detected after a period of time, so that the data of the creep test of the steel pipe to be tested is obtained.
[0010] Since the steel pipe to be tested can be clamped from the inside and the outside by the balls and the clamping bolts, the deformation of the steel pipe to be tested due to clamping is avoided.
[0011] Further, in order to improve the contact area and the clamping firmness, the abutting block is fixed on the end of the clamping bolt extending into the annular gap.
[0012] Further, in order to improve the clamping firmness, the abutting block is provided with teeth on the side facing the inner extrusion part.
[0013] Further, in order to facilitate disassembly, the locking ring is screwed on the outer wall of the base in a threaded manner.
[0014] Further, in order to avoid synchronous rotation of the extrusion block when the locking nut is screwed, at least three guide rods are provided on the extrusion block, the at least three guide rods are uniformly and spacedly arranged around the locking screw, a guide hole is provided on the base corresponding to each guide rod, and the guide rod is slidingly inserted into the corresponding guide hole.
[0015] Further, in order to facilitate the screwing of the locking nut, the piston rod of the hydraulic cylinder is fixedly connected to the base of the upper clamping part through at least three upper connecting rods, the at least three upper connecting rods are arranged at intervals around the locking bolt of the upper clamping part, and an upper fastening channel is formed between at least two adjacent upper connecting rods, and a screwing tool can screw the locking nut of the upper clamping part through the upper fastening channel;
[0016] The base is fixedly connected to the base of the lower clamping part through at least three lower connecting rods, the at least three lower connecting rods are arranged at intervals around the locking bolt of the lower clamping part, and a lower fastening channel is formed between at least two adjacent lower connecting rods, and a screwing tool can screw the locking nut of the lower clamping part through the lower fastening channel. BRIEF DESCRIPTION OF DRAWINGS
[0017] Figure 1 is a structural schematic diagram of an embodiment of the present application.
[0018] Figure 2 is a structural schematic diagram of a clamping part.
[0019] Figure 3 is a structural schematic diagram in a working state. DETAILED DESCRIPTION
[0020] Referring to Figure 1 and Figure 2 , a creep detection device for a steel pipe includes a detection frame 10, two clamping parts, and a hydraulic cylinder 40, the detection frame 10 includes a base plate 13, four vertical columns 11 fixed in a rectangular shape on the base plate, and a top plate 12 fixed at the top of the vertical columns.
[0021] The cylinder barrel 41 of the hydraulic cylinder is fixed to the upper side of the top plate by bolts, and a rod passing hole is formed in the top plate for the piston rod 42 of the hydraulic cylinder to pass through. The two clamping parts are an upper clamping part 20 and a lower clamping part 30, the piston rod of the hydraulic cylinder freely passes through the top plate to connect the upper clamping part, the lower clamping part is installed on the base plate of the detection frame, and the two clamping parts are opposite to each other.
[0022] The two clamping parts have the same structure and are arranged relative to a horizontal plane, and the structure of the two clamping parts will be described below by taking the upper clamping part 20 as an example.
[0023] The upper clamping part includes an inner extrusion part and an outer extrusion part 22, the inner extrusion part includes a base 21, an extrusion block 23, a locking bolt 24, and a clamping part, the extrusion block is located on the side of the base facing the lower clamping part 30, the base and the extrusion block are both circular with the axis extending in the vertical direction, and the outer diameters of the base and the extrusion block are the same.
[0024] A first bolt hole 121 extending in the vertical direction is arranged at the center of the base, a second bolt hole 233 extending in the vertical direction is arranged at the center of the extrusion block, and the shank 241 of the locking bolt 24 is freely threaded through the second bolt hole 233 and the first bolt hole 121 in sequence and is screwed with a locking nut 243, so that the locking nut is located on the side of the base away from the extrusion block. The end of the second bolt hole 233 away from the base is radially outwardly expanded to form a counterbore 234, the inner circumferential surface of the counterbore is a regular hexagon, the bolt head 242 of the locking bolt is located in the counterbore, and the outer circumferential surface of the bolt head 242 of the locking bolt is a regular hexagon, that is, the outer circumferential surface of the bolt head of the locking bolt is a regular polygon with the same shape as the inner circumferential surface of the counterbore, so that the locking bolt cannot rotate relative to the extrusion block.
[0025] The outer side of the end of the base towards the extrusion block has a first conical surface 214 with a small end towards the extrusion block, and the outer side of the end of the extrusion block towards the base has a second conical surface 232 with a small end towards the base, and the first conical surface and the second conical surface form an annular groove 26 therebetween, and the axial section of the annular groove is a trapezoid with a large end outward. The elastic extrusion part 25 is located in the annular groove, and the elastic extrusion part 25 includes an elastic ring 251 in the form of a ring and a ball 252 sleeved on the elastic ring, when the locking nut is screwed in the direction of the extrusion block, the first conical surface and the second conical surface can be brought close to each other, the ball is extruded outward, and the ball is made to protrude outward beyond the outer circumferential surface of the base and the outer circumferential surface of the extrusion block in the radial direction.
[0026] Specifically, in the present embodiment, the elastic ring 251 is a helical spring, also known as a spring contact finger, a contact finger spring or a ring spring, and specifically, it is a spiral spring with no end. It can be understood that in another embodiment, the elastic ring can also be a rubber ring or a bellows.
[0027] The outer extrusion part 22 includes a locking ring 221 and a connecting ring 222, the locking ring 221 and the connecting ring 222 are in one-piece structure, the locking ring is located radially outward of the connecting ring, the connecting ring is screwed on the outer wall of the base in a threaded manner, and the locking ring extends towards the extrusion block and exceeds the central axis of the ball 252 in the height direction, so that an annular gap for inserting the steel pipe 80 to be tested is formed between the locking ring and the inner extrusion part.
[0028] The clamping bolt 223 extending in the radial direction of the locking ring is screwed on the locking ring, the clamping bolt is screwed on the locking ring from the outside to the inside, the locking bolt penetrates through the locking ring and extends into the annular gap, and the abutting block 224 is fixed on the end of the clamping bolt extending into the annular gap, and the teeth are arranged on the side of the abutting block towards the inner extrusion part.
[0029] Three guide rods 231 are arranged on the extrusion block and evenly spaced around the locking bolt, and a guide hole 213 is arranged on the base corresponding to each guide rod, and the guide rod is slidingly inserted into the corresponding guide hole.
[0030] A transition plate 43 is welded to the lower end of the piston rod of the hydraulic cylinder, and the transition plate is horizontally arranged, and three upper connecting rods 44 are welded to the lower surface of the transition plate, and the lower ends of the three upper connecting rods are welded to the base of the upper clamping part 20, and the three upper connecting rods are evenly spaced around the locking bolt of the upper clamping part, and an upper fastening channel is formed between any two adjacent upper connecting rods, and a wrench or other rotating tool can be used to rotate the locking nut of the upper clamping part through the upper fastening channel.
[0031] Three lower connecting rods 131 are welded to the upper surface of the base plate, and the upper ends of the three lower connecting rods are welded to the base of the lower clamping part 30, and the three lower connecting rods are evenly spaced around the locking bolt of the lower clamping part, and a lower fastening channel is formed between any two adjacent lower connecting rods, and a wrench or other rotating tool can be used to rotate the locking nut of the lower clamping part through the lower fastening channel. The locking bolts of the two clamping parts are coaxially arranged.
[0032] The use method of the present application is described below, please refer to Figure 3 In use, first adjust the height of the upper clamping part, so that the distance between the upper clamping part and the lower clamping part is not less than the length of the steel pipe to be tested 80, then insert one end of the steel pipe to be tested into the annular gap of the lower clamping part, then extend the steel pipe to be tested in the vertical direction, rotate the locking nut of the lower clamping part to make the rolling balls of the lower clamping part move outward in the radial direction and tightly press on the inner wall of the steel pipe to be tested, then rotate the clamping bolt of the lower clamping part to make the pressing block of the lower clamping part tightly press on the outer wall of the steel pipe to be tested, and the fixation of the lower end of the steel pipe to be tested is completed.
[0033] Make the piston rod of the hydraulic cylinder extend downward, push the upper clamping part downward, insert the upper end of the steel pipe to be tested into the annular gap of the upper clamping part, rotate the locking nut of the upper clamping part to make the rolling balls of the upper clamping part move outward in the radial direction and tightly press on the inner wall of the steel pipe to be tested, then rotate the clamping bolt of the upper clamping part to make the pressing block of the upper clamping part tightly press on the outer wall of the steel pipe to be tested, and the fixation of the upper end of the steel pipe to be tested is completed.
[0034] Start the hydraulic cylinder to apply a set pressure to the steel pipe to be tested, and after a period of time, detect the deformation of the steel pipe to be tested to obtain the data of the creep test of the steel pipe to be tested.
[0035] Since the rolling balls and the clamping bolt can be used to clamp the steel pipe to be tested from the inside and the outside, the deformation of the steel pipe to be tested caused by clamping is avoided.
Claims
1. A creep detection device for a steel pipe, characterized by, The device comprises a detection frame, two clamping parts and a hydraulic cylinder, the two clamping parts are respectively upper clamping part and lower clamping part, the cylinder barrel of the hydraulic cylinder is fixed on the top plate of the detection frame, the piston rod of the hydraulic cylinder freely penetrates the top plate downward and is connected with the upper clamping part, the lower clamping part is installed on the bottom plate of the detection frame, and the two clamping parts are opposite to each other; Each clamping part comprises an inner extrusion part and an outer extrusion part, the inner extrusion part comprises a base, an extrusion block, a locking bolt and a clamping part, the extrusion block is located on the side of the base facing the other clamping part, the base and the extrusion block are both circular with the axis extending in the vertical direction, the screw rod of the locking bolt freely penetrates the extrusion block and the base in sequence and is screwed with a locking nut, the locking nut is located on the side of the base away from the extrusion block, the extrusion block has a counterbore on the side away from the base, the inner periphery of the counterbore is a regular polygon, the head of the locking bolt is located in the counterbore, and the outer periphery of the head of the locking bolt is a regular polygon with the same shape as the inner periphery of the counterbore, so that the locking bolt cannot rotate relative to the extrusion block; The outer side of the end of the base facing the extrusion block has a first conical surface with a small end facing the extrusion block, the outer side of the end of the extrusion block facing the base has a second conical surface with a small end facing the base, the first conical surface and the second conical surface form an annular groove, the axial section of the annular groove is a trapezoid with a large end facing outward, the elastic extrusion part is located in the annular groove, the elastic extrusion part comprises a ring-shaped elastic ring and a ball sleeved on the elastic ring, when the locking nut is screwed in the direction of the extrusion block, the first conical surface and the second conical surface can be close to each other, the ball is extruded outward, and the ball is extruded outward in the radial direction and exceeds the outer periphery of the base and the outer periphery of the extrusion block, the locking bolts of the two clamping parts are coaxially arranged; The outer extrusion part comprises a locking ring fixed on the base, a clamping bolt extending in the radial direction of the locking ring is screwed on the locking ring, the clamping bolt is screwed on the locking ring from the outside to the inside, and the annular gap for inserting the steel pipe to be measured is formed between the locking ring and the inner extrusion part, and the clamping bolt penetrates the locking ring and extends into the annular gap.
2. The creep detection device of claim 1, wherein A pressing block is fixed on the end of the clamping bolt extending into the annular gap.
3. The creep detection device of claim 2, wherein, Teeth are arranged on the side of the pressing block facing the inner extrusion part.
4. The creep detection device of claim 1, wherein The locking ring is screwed on the outer wall of the base in a threaded manner.
5. The creep detection device of claim 1, wherein The elastic ring is a rubber ring, an inclined coil spring or a bellows.
6. The creep detection device of claim 1, wherein At least three guide rods are arranged on the extrusion block and uniformly spaced around the locking bolt, and a guide hole corresponding to each guide rod is arranged on the base, and the guide rod is slidably inserted into the corresponding guide hole.
7. The creep detection device of claim 1, wherein The piston rod of the hydraulic cylinder is fixedly connected to the base of the upper clamping part through at least three upper connecting rods, the at least three upper connecting rods are arranged around the locking bolt of the upper clamping part and are spaced apart, and at least two adjacent upper connecting rods form an upper fastening channel, and a tightening tool can pass through the upper fastening channel to tighten the locking nut of the upper clamping part; The bottom plate is fixedly connected to the base of the lower clamping part through at least three lower connecting rods, the at least three lower connecting rods are arranged at intervals around the locking bolts of the lower clamping part, and at least a lower fastening channel is formed between two adjacent lower connecting rods, and a screwing tool can pass through the lower fastening channel to screw the locking nut of the lower clamping part.