CN216899903U

CN216899903U - Annular clamping device for pipe tensile test

Info

Publication number: CN216899903U
Application number: CN202220208346.0U
Authority: CN
Inventors: 徐建红; 徐建; 金肃静; 孟春云
Original assignee: Zhejiang Scientific Research Institute of Transport
Current assignee: Zhejiang Scientific Research Institute of Transport
Priority date: 2022-01-24
Filing date: 2022-01-24
Publication date: 2022-07-05
Anticipated expiration: 2032-01-24

Abstract

The utility model discloses an annular clamping device for a pipe tensile test, which relates to the technical field of pipe tensile tests and comprises an outer package assembly and an inner lining assembly, wherein the outer package assembly is used for clamping a pipe from the outside, the inner lining assembly is used for clamping the pipe from the inside, the outer package assembly comprises split type annular sleeves, the annular sleeves are movably connected with each other, the inner lining assembly comprises a pull rod connected with a power element and a sleeve rod connected to the outside of the pull rod in a sliding mode, the position of the sleeve rod is fixed, a circumferential part of the pull rod, which is close to one end of the pipe, is radially and rotatably connected with a plurality of supporting pieces, the supporting pieces are all connected with inner lining plates tightly attached to the inner wall of the pipe, the middle parts of the supporting pieces are all rotatably connected with inclined pulling pieces, and the inclined pulling pieces are all rotatably connected to the circumferential part of the sleeve rod. Has the following beneficial effects: the utility model provides the outer package assembly for clamping the sample from the outside and the lining assembly for clamping the sample from the inside, thereby greatly improving the operability and the accuracy; the sample is clamped inside and outside simultaneously, so that the device is very firm, uniform and reliable.

Description

Annular clamping device for pipe tensile test

Technical Field

The utility model relates to the technical field of pipe tensile tests, in particular to an annular clamping device for a pipe tensile test.

Background

The metal tensile test is a test method for measuring material characteristics of metal under axial tensile load, and can measure parameters such as yield strength, tensile strength, elongation after fracture and the like of the metal material. At present, the main detection method for the metal material tensile test is section 1 of the metal material tensile test: the method comprises a room temperature test method (GB/T228.1-2010) and a sampling method for a metal material sample, namely a steel and steel product mechanical property test sampling position and sample preparation (GB/T2975-2018), wherein for a tensile sample of a metal pipe, a full-section sample is used when a machining and testing machine allows. At present, a testing machine is basically a wedge-shaped clamp for a metal tensile test, and for a metal pipe test, if a full-section sample is used, when the test machine clamp clamps the sample, the sample is crushed by the clamp due to the hollow sample, so that the sample is often damaged before approaching a clamping area during the tensile test, and the actual characteristics of the material cannot be accurately measured.

The existing scheme generally comprises the steps of machining a metal sample, taking a strip-shaped sample, and then carrying out a tensile test on a testing machine. The main defects are as follows: (1) extra machining equipment is needed, the machining requirement on the machining equipment is high, and a sample cannot be damaged in the machining process; (2) the requirement on the machining precision of the sample is high, the highest dimensional tolerance is +/-0.02 mm, the lowest dimensional tolerance is +/-0.15 mm, if the machining precision does not meet the requirement, the sampling machining needs to be carried out again, and the working efficiency is low; (3) the method comprises the following steps that a strip-shaped sample is taken as an arc-shaped surface, the calculation process of the cross section of the sample is complex, and the calculation result of the cross section has certain deviation, so that the calculation accuracy of the subsequent test result is influenced; (4) the installation requirement of bar sample is high, and in the installation, must carefully install, ensures that the sample geometry is central, and sample upper and lower keeps vertical and even atress. In conclusion, the existing pipe test scheme has high requirements on test conditions, and the test accuracy and operability are not high.

SUMMERY OF THE UTILITY MODEL

1. Technical problem to be solved by the utility model

Aiming at the technical problems that the existing pipe test scheme has high requirements on test conditions and has low test accuracy and operability, the utility model provides the annular clamping device for the pipe tensile test, which has high accuracy and operability, has low requirements on the test conditions, does not need additional machining equipment and is more energy-saving.

2. Technical scheme

In order to solve the problems, the technical scheme provided by the utility model is as follows:

the utility model provides an annular clamping device for tubular product tensile test, is including the inside lining subassembly that is used for following the outsourcing subassembly of outside centre gripping tubular product and follows inside centre gripping tubular product, the outsourcing subassembly includes split type ring cover, swing joint between the ring cover, the inside lining subassembly is including the pull rod and the loop bar of sliding connection in the pull rod outside that are connected with power element, loop bar rigidity, the circumference position of the one end of being close to tubular product of pull rod radially rotates and is connected with a plurality of supports, the support all is connected with the interior welt of hugging closely with the tubular product inner wall, the middle part of support all rotates and is connected with oblique drawing piece, oblique drawing piece all rotate connect in the circumference position of loop bar, the outsourcing subassembly with the inside lining subassembly is symmetrical structure and centre gripping in the both ends of tubular product.

Optionally, the outside rigid coupling of loop bar has pipy latch closure, the one end that is close to tubular product of latch closure is equipped with the hook-like back-off structure of annular, the one end that is close to the latch closure of ring cover is equipped with a plurality of build boards, build the board with the ring cover corresponds the rigid coupling respectively, build be equipped with on the board with back-off structure complex lock is protruding.

Optionally, the contact surface of the inverted buckle structure and the buckle protrusion is an inclined surface, and the deeper the buckle between the inverted buckle structure and the buckle protrusion is, the closer the structure plate is to the center of the pull rod.

Optionally, the ring sleeves are arc-shaped, the ring sleeves are symmetrically distributed, and the symmetrical ring sleeves are connected through fixing bolts.

Optionally, the ring sleeves on the same side are of split structures, the split ring sleeves are rotatably connected through a round rod, annular structures arranged at intervals are arranged on the ring sleeves, round holes used for passing through the round rod are arranged in the annular structures, and the annular structures of the ring sleeves are matched with each other at intervals.

Optionally, a gap is left between the symmetrical annular sleeves.

Optionally, the support member is pivotally connected to a middle portion of the inner liner.

Optionally, the arc-shaped outer surface of the inner lining plate is provided with insections.

Optionally, the inner surface of the circular sleeve is provided with insections.

3. Advantageous effects

Compared with the prior art, the technical scheme provided by the utility model has the following beneficial effects:

according to the technical scheme provided by the utility model, the outer package assembly for clamping the sample from the outside and the lining assembly for clamping the sample from the inside are arranged, the outer package assembly annularly wraps the sample, the lining assembly circumferentially clamps the sample from the inside, additional machining equipment is not needed for machining the sample, the sample is not needed to be processed, the requirement on machining precision is not involved, and the operability and the accuracy are greatly improved; the test sample is clamped inside and outside simultaneously, so that the test sample is very firm, uniform and reliable, the tensile test of the pipe can be carried out by using the full-section test sample completely, and the test sectional area is accurately and comprehensively calculated; an adjustable gap is formed between the circular sleeves of the outer package assembly, the inner lining plate of the lining assembly can be contracted and expanded, the outer package assembly can be suitable for pipes with different pipe diameters in a certain range, the inner lining plate has an elastic working range, the construction plate is contracted, and a sample can be automatically centered geometrically after the inner lining plate is expanded; whole clamping device modularized design divide into outsourcing subassembly and inside lining subassembly, and the installation is all comparatively simple and convenient with the dismantlement, need not use too many extra appurtenance, and work efficiency is high.

Drawings

Fig. 1 is a schematic structural diagram of an annular clamping device for a tube tensile test according to an embodiment of the present invention.

Fig. 2 is a schematic structural diagram of an inner liner assembly of an annular clamping device for a tube tensile test according to an embodiment of the present invention.

Fig. 3 is a sectional view a-a of an annular clamping device for a tube tensile test according to an embodiment of the present invention.

Fig. 4 is a B-B sectional view of an annular clamping device for a tube tensile test according to an embodiment of the present invention.

Fig. 5 is a schematic structural diagram of an outer package assembly of an annular clamping device for a tube tensile test according to an embodiment of the present invention.

Fig. 6 is an axial view of an outer package assembly of an annular clamping device for a tube tensile test according to an embodiment of the present invention.

Fig. 7 is a cross-sectional view of an outer package assembly of an annular clamping device for a tube tensile test according to an embodiment of the present invention.

Fig. 8 is a schematic structural diagram of a buckle portion of an annular clamping device for a tube tensile test according to an embodiment of the present invention.

1. An outsourcing component; 2. a liner assembly; 3. a sample; 4. a power element; 5. a pull rod; 6. a cross beam of the testing machine; 7. looping; 8. a loop bar; 9. a diagonal pull member; 10. a support member; 11. an inner liner plate; 12. a build plate; 13. a circular ring sleeve; 14. fixing the bolt; 15. a round bar; 16. an inner protrusion; 17. insection; 18. a back-off structure; 19. and (5) buckling the bulges.

Detailed Description

For a further understanding of the present invention, reference will now be made in detail to the embodiments illustrated in the drawings.

The present application will be described in further detail with reference to the following drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant invention and are not limiting of the utility model. It should be noted that, for convenience of description, only the portions related to the present invention are shown in the drawings. The terms first, second, and the like in the present invention are provided for convenience of describing the technical solution of the present invention, and have no specific limiting effect, but are all generic terms, and do not limit the technical solution of the present invention. It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art. The technical solutions in the same embodiment and the technical solutions in different embodiments can be arranged and combined to form a new technical solution without contradiction or conflict, and the technical solutions are within the scope of the present invention.

Examples

With reference to the attached drawings 1-8, the annular clamping device for the pipe tensile test comprises an outer package component 1 and an inner lining component 2, wherein the outer package component 1 is used for clamping a pipe from the outside, the inner lining component 2 is used for clamping the pipe from the inside, the pipe is tubular, when a test machine clamp clamps a sample 3, the sample 3 is hollow, the sample 3 is guided to be clamped by the clamp to be flattened, the outer package component 1 and the inner lining component 2 simultaneously clamp the inner wall and the outer wall of the sample 3, the pipe is only subjected to the pressure on the surface of the inner wall and the surface of the outer wall which are perpendicular to the pipe at the moment, and the pipe is not easy to deform. Outsourcing subassembly 1 includes split type ring cover 13, swing joint between the ring cover 13, split type ring cover 13 can be one installation when the installation, swing joint between the ring cover 13, the installation of being convenient for more. The lining assembly 2 comprises a pull rod 5 connected with a power element 4 and a sleeve rod 8 connected with the outer part of the pull rod 5 in a sliding way, in the embodiment, the power element 4 is a small hydraulic oil cylinder, the pull rod 5 is connected with the sleeve rod 8 in a sliding way, and the pull rod 5 and the sleeve rod 8 are used for controlling a support 10 at the end part of the pull rod 5 and a diagonal pulling piece 9. The position of the loop bar 8 is fixed, the loop bar 8 is connected with the cross beam 6 of the testing machine, and the loop bar 8 is fixed. The circumference part of one end of the pull rod 5, which is close to the pipe, is radially and rotatably connected with a plurality of supporting pieces 10, in the embodiment, the supporting pieces 10 are strip-shaped pieces with hinged structures at two ends, the supporting pieces 10 are all connected with lining plates 11 which are tightly attached to the inner wall of the pipe, one end of each supporting piece 10 is hinged to the middle of each lining plate 11, each lining plate 11 is an arc-shaped plate with a certain length, the cross section of each lining plate 11 is arc-shaped and is used for being matched with the inner wall of the pipe in shape so as to be tightly attached to the inner wall, the pressure of each lining plate 11 on the pipe is dispersed, the pipe is prevented from being damaged by stress concentration, and meanwhile, the contact area is increased so as to increase the friction force. The middle part of each supporting part 10 is hinged with an inclined pulling part 9, each inclined pulling part 9 is a strip-shaped part with hinged structures at two ends, each inclined pulling part 9 is hinged to the circumferential position of the end part of the sleeve rod 8, the pull rod 5 is in sliding connection with the sleeve rod 8, the supporting parts 10 form a lever structure by taking the hinged positions of the supporting parts and the pull rods 5 as fulcrums in the sliding process, the inclined pulling parts 9 rotate around the hinged positions of the inclined pulling parts and the sleeve rods 8, the pull rods 5 move upwards in the state of fig. 2 due to the fact that the sleeve rods 8 are fixed, the pull rods 5 are close to the end parts of the sleeve rods 8, the hinged positions of the supporting parts 10 and the inner lining plates 11 obtain a radial outward movement trend, and the inner lining plates 11 obtain radial outward pressure and act on the pipes. The outsourcing subassembly 1 with inside lining subassembly 2 is symmetrical structure and centre gripping in the both ends of tubular product, and sample 3 of upper and lower fixed tubular product is used for tensile test.

The outside rigid coupling of loop bar 8 has tubulose latch closure 7, and latch closure 7 can adopt welded connection mode rigid coupling to loop bar 8, and the rigid coupling loop bar 8 is in order to make loop bar 8 can drive latch closure 7 and move together. The one end that is close to tubular product of latch closure 7 is equipped with annular hook-shaped back-off structure 18, the one end that is close to of ring cover 13 the latch closure 7 is equipped with a plurality of structure boards 12, structure board 12 with ring cover 13 corresponds the rigid coupling respectively, be equipped with on the structure board 12 with back-off structure 18 complex lock arch 19. As shown in fig. 8, the contact surface between the inverted structure 18 and the fastening protrusion 19 is an inclined surface, and the deeper the fastening between the inverted structure 18 and the fastening protrusion 19 is, the closer the structural plate 12 is to the center of the pull rod 5. When the structural plate 12 is closed to the center of the pull rod 5, the annular sleeve 13 is driven to close to the center of the pull rod 5, the annular sleeve 13 can be squeezed inwards to be tightened, friction force is improved, and clamping force for clamping the pipe is increased.

The ring cover 13 is arc-shaped, the ring cover 13 is symmetrically distributed, the symmetrical distribution is the symmetrical distribution of the axial visual angle, and as shown in fig. 6, the symmetrical ring cover 13 is connected through a fixing bolt 14. Gaps are reserved between the symmetrical circular ring sleeves 13, the clamping force of the circular ring sleeves 13 can be enhanced by screwing the fixing bolts 14, the diameters of applicable pipes of the circular ring sleeves 13 are within a certain range, and the clamping of the pipes with multiple pipe diameters is realized.

The ring sleeves 13 on the same side are of split structures, the split ring sleeves 13 are rotatably connected through round rods 15, annular structures arranged at intervals are arranged on the ring sleeves 13, round holes used for passing through the round rods 15 are formed in the annular structures, and the annular structures of the ring sleeves 13 are matched with each other at intervals. The round rod 15 passes through the round holes of the adjacent circular sleeves 13, so that the circular sleeves 13 are connected together and the circular sleeves 13 can rotate. The ring cover 13 can rotate relatively, and the ring cover 13 uses round bar 15 to form lever structure as the fulcrum, and fixing bolt 14 acts on the power of ring cover 13 and makes ring cover 13 around the inside extrusion of fulcrum, has improved ring cover 13's clamping-force, avoids fixing bolt 14's fastening force too much to act on ring cover 13 itself simultaneously.

The arc-shaped outer surface of the lining plate 11 is provided with insections 17, as shown in fig. 3, in this embodiment, the insections 17 are diamond-shaped for increasing friction force and preventing the sample 3 of the pipe from sliding. The inner surface of the ring sleeve 13 is provided with insections 17, as shown in fig. 7, in this embodiment, the insections 17 are diamond-shaped, and are used for improving friction force and preventing the sample 3 of the pipe from sliding.

The working principle is as follows:

step one, sampling the pipe, wherein the shape of the sample 3 is still tubular, but the length of the sample is shorter than that of the original pipe, the diameter of the selected sample 3 is smaller than the maximum limit diameter of the lining plate 11 when the lining plate is opened, the total length of the sample 3 is about 600mm, and the diameter of the selected steel pipe is approximately matched with the diameter of the lining plate 11 when the lining plate is opened. The extreme position of the opening of the inner lining 11 should theoretically not have an outward pressure, so that an approximate, not-desirable limit value is selected here.

And step two, as shown in figure 1, a cross beam 6 of the testing machine is fixedly connected with a loop bar 8, the whole device is of a symmetrical structure and needs to be clamped at two ends of a sample 3, and the whole device is divided into an upper clamping device and a lower clamping device. The position of a crossbeam 6 of the testing machine is adjusted, so that the distance between the upper clamping device and the lower clamping device is slightly larger than the length of the sample 3, and the slightly larger distance is between 0 percent and 30 percent, the pull rod 5 of the upper clamping device is adjusted to move downwards by the power element 4, the pull rod 5 of the lower clamping device is adjusted to move upwards by the power element 4, a plurality of arc-shaped lining plates 11 of the lining assembly 2 are radially folded, and the diameter of each lining plate 11 is smaller than the inner diameter of the sample 3. The power element 4 is a small hydraulic oil cylinder which is controlled by a worker to stretch or push the pull rod 5.

And step three, placing the lining assembly 2 of the upper clamping device inside the upper end of the sample 3 to ensure that the circular arc-shaped lining plate 11 is completely inside the sample 3, and if the support 10 is partially outside the sample 3 and exceeds the connection point due to the connection of the lining plate 11 and the support 10 being point connection, the lining plate 11 is overturned, and pressure cannot be applied to the sample 3. The pull rod 5 of the upper clamping device is adjusted to move upwards by a small hydraulic oil cylinder, so that the arc-shaped inner lining plate 11 is outwards expanded until the arc-shaped inner lining plate is attached to the inner wall of the sample 3 and generates pressure, at the moment, as shown in fig. 2, the axial angle between the supporting piece 10 and the sample 3 is alpha, alpha is 60-80 degrees, alpha is too small, the diameter of the inner lining plate 11 is too small, alpha is too large, and the inner lining plate 11 is inwards contracted after being outwards expanded, so that the clamping of the sample 3 is not facilitated;

step four, attaching an outer wrapping plate of the outer wrapping component 1 to the outer wall of the sample 3, adjusting the upper position and the lower position of the buckle 7 to enable an annular inverted buckle structure 18 at the lower end of the buckle 7 to be slightly lower than a buckling bulge 19 in the construction plate 12, then installing another outer wrapping plate, screwing the fixing bolts 14 on two side edges of the outer wrapping component 1, adjusting the position of the loop bar 8, and enabling the buckle 7 to move upwards until the inverted buckle structure 18 at the lower end of the buckle 7 is contacted with the buckling bulge 19 in the construction plate 12;

and step five, adjusting the position of a lower cross beam of the testing machine, placing the lining assembly 2 of the lower clamping device in the lower end of the sample 3, and installing the lower clamping device in a structure symmetrical to the upper clamping device according to the step two to the step four when the lower clamping device is installed, so that the installation of the whole clamping device is completed.

The present invention and its embodiments have been described above schematically, without limitation, and what is shown in the drawings is only one of the embodiments of the present invention, and the actual structure is not limited thereto. Therefore, without departing from the spirit of the present invention, a person of ordinary skill in the art should understand that the present invention shall not be limited to the embodiments and the similar structural modes without creative design.

Claims

1. The utility model provides an annular clamping device for tubular product tensile test which characterized in that, is including the inside lining subassembly that is used for the outsourcing subassembly of follow outside centre gripping tubular product and follows inside centre gripping tubular product, the outsourcing subassembly includes split type ring cover, swing joint between the ring cover, the inside lining subassembly is including the pull rod that is connected with power element and the loop bar of sliding connection in the pull rod outside, the loop bar rigidity, the circumference position of the one end of being close to tubular product of pull rod radially rotates and is connected with a plurality of supports, the support all is connected with the interior welt of hugging closely with the tubular product inner wall, the middle part of support all rotates and is connected with oblique pull, oblique pull all rotate connect in the circumference position of loop bar, the outsourcing subassembly with the inside lining subassembly is symmetrical structure and centre gripping in the both ends of tubular product.

2. The annular clamping device for the tube tensile test according to claim 1, wherein a tubular buckle is fixedly connected to the outside of the loop bar, an annular hook-shaped inverted buckle structure is arranged at one end of the buckle close to the tube, a plurality of construction plates are arranged at one end of the ring sleeve close to the buckle, the construction plates and the ring sleeve are respectively and correspondingly fixedly connected, and a buckling protrusion matched with the inverted buckle structure is arranged on each construction plate.

3. The annular clamping device for the pipe tensile test according to claim 2, wherein the contact surface between the inverted structure and the buckling protrusion is an inclined surface, and the deeper the buckling between the inverted structure and the buckling protrusion is, the closer the structural plate is to the center of the pull rod.

4. The annular clamping device for the pipe tensile test according to claim 1, wherein the annular sleeves are arc-shaped and symmetrically distributed, and the symmetrical annular sleeves are connected through fixing bolts.

5. The annular clamping device for the pipe tensile test is characterized in that the annular sleeves on the same side are of split structures, the split annular sleeves are rotatably connected through a round rod, annular structures arranged at intervals are arranged on the annular sleeves, round holes used for the round rod to pass through are formed in the annular structures, and the annular structures of the annular sleeves are matched with each other at intervals.

6. An annular clamping device for a pipe tensile test according to claim 4, wherein a gap is left between the symmetrical annular sleeves.

7. An annular clamping device for a pipe tensile test according to claim 1, wherein the supporting member is rotatably connected to the middle part of the inner lining plate.

8. The annular clamping device for the pipe tensile test is characterized in that the arc-shaped outer surface of the inner lining plate is provided with insections.

9. An annular clamping device for a pipe tensile test according to claim 1, wherein the inner surface of the annular sleeve is provided with insections.