Elastic pipe pressure balancing device and impact test method

Abstract

A pressure balancing device and impact testing method for an elastic pipe is disclosed. The open end of a cup-shaped body of a cylinder is provided with a first connecting portion and a first impact portion. The closed end of the cup-shaped body is a first sliding portion, and a sliding hole is provided at the bottom of the cup-shaped body. A piston member includes a rod-shaped body with a piston disc at one end, the outer circumference of the piston disc slidingly engaging with the inner wall of the cup-shaped body, and a second sliding portion slidingly engaging with the sliding hole at the other end of the rod-shaped body. A sealing groove is provided in the middle of a plate-shaped body of a mounting plate, the inner wall of which slides with the first sliding portion, and the end of the second sliding portion is connected to a fixed hole. When the first connecting portion is connected to the first connecting end and the second connecting portion on the plate-shaped body is connected to the second connecting end, an outer cavity is formed outside the cup-shaped body and an inner cavity is formed inside the cup-shaped body, and the pressure is adjusted by a pressurized medium. This ensures that the elastic pipe can be subjected to an axial impact load without substantially changing its axial mechanical state, allowing accurate axial compression / tensile impact testing.

Description

Technical Field

[0001] The present invention relates to the technical field of pipeline component testing, in particular to an elastic connecting pipe pressure balancing device and an impact testing method. Background Art

[0002] The main body of the flexible pipe is an elastic pipe fitting. This flexible pipe fitting can be a metal bellows or a flexible pipe fitting made of metal, non-metal, or composite materials. The pipe ends can be connected to the pipeline through flanges, clamps, threaded connections, etc. When the pressure in the pipe changes, the flexible pipe fitting in its free state will expand and contract significantly along the axial direction.

[0003] Flexible pipes are widely used in applications such as shipbuilding. Under normal operating conditions, the internal pressure of some flexible pipes can reach several megapascals. If these pipes are not up to standard, the combined effects of steady-state pressure loads and transient shocks can damage the pipes, leading to leakage of high-pressure gas or liquid and potentially causing accidents. To ensure safety, flexible pipes must undergo impact testing before use.

[0004] Impact mechanical properties testing is generally a test method to determine the safety, reliability and effectiveness of military and civilian equipment when subjected to external forces. It often requires that the test sample be in the rated working state and the elastic connecting pipe needs to be axially limited. Otherwise, the pipeline will elongate significantly under the working internal pressure of up to several MPa, thereby deviating from the working state.

[0005] Currently, rigid / elastic components are usually used to directly fix the flanges at both ends of the pipeline for axial limitation. Although this method limits the elongation of the elastic nozzle, it significantly changes the axial mechanical state of the test system where the elastic nozzle is located, resulting in the inability to effectively transfer the axial impact load to the elastic nozzle, making it impossible to accurately perform mechanical property tests. Summary of the Invention

[0006] In response to the shortcomings of the above-mentioned existing production technology, the applicant provides an elastic pipe pressure balancing device and an impact testing method, so that when the elastic pipe is subjected to an axial impact load, the axial mechanical state can basically remain unchanged, the impact load can be effectively transmitted to the elastic pipe, and at the same time, the elastic pipe can accurately carry out axial compression / tensile impact tests under rated working pressure and rated working length.

[0007] The technical solutions adopted in the present invention are as follows:

[0008] An elastic pipe pressure balancing device, the elastic pipe comprises an elastic pipe, one end of the elastic pipe is a first connecting end, and the other end of the elastic pipe is a second connecting end.

[0009] It includes a cylinder body, a piston member and a mounting plate;

[0010] The cylinder body has a structure as follows: comprising a cup-shaped body, wherein an open end of the cup-shaped body is provided with a first connecting portion with an annular structure, the first connecting portion being used for sealingly connecting with the first connecting end, a first impact portion with an annular structure being provided above the middle portion of the first connecting portion, the first impact portion and the first connecting portion being concentric with the cup-shaped body, an outer peripheral surface of the closed end of the cup-shaped body being a first sliding portion, and a sliding hole being provided at the center of the bottom of the cup-shaped body;

[0011] The piston member comprises a rod-shaped body, one end of which is provided with a piston disc, the outer circumference of which is sealed and slidably fitted with the inner wall of the cup-shaped body, and the outer circumference of the other end of the rod-shaped body is a second sliding portion, which is sealed and slidably fitted with the sliding hole;

[0012] The mounting plate has a structure comprising a plate-like body, a sealing groove with an upward opening provided in the middle of the plate-like body, an inner wall surface of the sealing groove being sealed and slidingly matched with the first sliding portion, a second connecting portion being provided on the plate-like body at the periphery of the sealing groove, the second connecting portion being used for sealingly connecting with the second connecting end, a fixing hole being provided at the bottom of the sealing groove, an end portion of the second sliding portion being detachably fixedly connected to the fixing hole, and a second impact portion being provided at the periphery of the plate-like body;

[0013] When the first connection portion is sealedly connected to the first connection end and the second connection portion is sealedly connected to the second connection end, the elastic tube is located outside the cup-shaped body, an outer cavity is formed between the outside of the cup-shaped body and the elastic tube, and an inner cavity is formed between the inside of the cup-shaped body and the piston;

[0014] The outer cavity is filled with a first pressurized medium through the first pressurized port, and the inner cavity is filled with a second pressurized medium through the second pressurized port.

[0015] As a further improvement of the above technical solution:

[0016] The first pressurized medium includes gas and liquid, and the first connecting portion is provided with the first pressurized port, through which gas is filled into the outer cavity;

[0017] A first liquid injection port is further provided on the first connecting portion. The first liquid injection port is communicated with the outer cavity and is used to inject liquid into the outer cavity.

[0018] The second pressurized medium includes gas and liquid, and the piston disc is provided with a second pressurized port, through which gas is filled into the inner cavity;

[0019] A second liquid injection port is also provided on the piston disc, the second liquid injection port is communicated with the inner cavity, and the second liquid injection port is used to inject liquid into the inner cavity.

[0020] When the elastic tube is in the initial state, the gas height in the outer cavity is h0:

[0021]

[0022] In formula (1):

[0023] Δh: Rated maximum deformation of the elastic tube (positive for compression and negative for tension);

[0024] δ: The percentage change of the allowable pressure in the external cavity during the test (positive for compression and negative for tension);

[0025] m: Multivariate index.

[0026] A through hole is also provided at the bottom of the sealing groove.

[0027] The lower surface of the bottom of the cup-shaped body cooperates with the bottom of the sealing groove. A limiting portion is provided on the rod-shaped body between the piston disc and the second sliding portion, and the limiting portion cooperates with the bottom of the cup-shaped body.

[0028] An elastic connecting pipe impact test method comprises the following steps:

[0029] S1: The elastic tube and the pressure balancing device are assembled. A first pressurized medium is charged into the outer cavity through the first pressurized port, and a second pressurized medium is charged into the inner cavity through the second pressurized port. The pressure in the outer cavity is equal to the rated working pressure of the elastic tube. The pressure in the inner cavity is adjusted to maintain the rated working length of the elastic tube. After adjustment, the elastic tube is in its initial state.

[0030] After step S1 is completed, the elastic nozzle is subjected to an axial compression impact test. The steps are as follows:

[0031] S12: Assemble the pressure balancing device equipped with the elastic pipe with the mechanical properties testing machine, and place the pressure balancing device directly below the impact hammer of the mechanical properties testing machine, with the axis of the elastic pipe coinciding with the axis of the impact hammer;

[0032] S13: Lower the impact hammer to make the elastic pipe axially compressed.

[0033] The first connecting end and the cylinder body slide toward the mounting plate, and the elastic pipe is compressed, with the compression amount being less than or equal to the rated maximum deformation;

[0034] After step S1 is completed, the steps for performing an axial tensile impact test on the elastic tube are as follows:

[0035] S22: Assemble the pressure balancing device equipped with the elastic pipe with the mechanical properties testing machine, and place the pressure balancing device directly below the impact hammer of the mechanical properties testing machine, with the axis of the elastic pipe coinciding with the axis of the impact hammer;

[0036] S23: Lower the impact hammer to make the elastic pipe axially tensile.

[0037] The first connecting end and the cylinder body slide in a direction away from the mounting plate, and the elastic connecting pipe is stretched, with the stretching amount being less than or equal to the rated maximum deformation amount.

[0038] As a further improvement of the above technical solution:

[0039] In step S1: the first pressurized medium filled into the outer cavity includes gas and liquid. When the elastic pipe is in the initial state, the gas height in the outer cavity is h0:

[0040]

[0041] In formula (1):

[0042] Δh: Rated maximum deformation of the elastic tube (positive for compression and negative for tension);

[0043] δ: The percentage change of the allowable pressure in the external cavity during the test (positive for compression and negative for tension);

[0044] m: Multivariate index.

[0045] When using the hammer method:

[0046] In step S12: placing the pressure balancing device equipped with the elastic pipe on the test collision base of the mechanical properties testing machine, with the first impact part facing the impact hammer of the mechanical properties testing machine, and installing an impact head on the first impact part. The impact head has a conical disc structure, so that when the impact hammer descends, it hits the middle part of the impact head;

[0047] In step S13: the impact hammer is lowered to strike the impact head, while the second connecting end, the piston member and the mounting plate remain in the same position;

[0048] In step S22: multiple columns of the bracket are placed on the test collision foundation, and the lower surface of the horizontal mounting plate connected to the multiple columns is connected to the first impact part, so that the pressure balance device is in a suspended state; multiple columns of the impact column are connected to the second impact part, so that the impact plate connected to the multiple columns is located above the horizontal mounting plate, and the impact plate corresponds to the impact hammer;

[0049] In step S23: the impact hammer is lowered to strike the impact plate, so that the elastic pipe is axially stretched, and the positions of the first connecting end and the cylinder body remain unchanged.

[0050] When using the drop method:

[0051] In step S12: the second impact part of the pressure balancing device equipped with an elastic pipe is connected to the lower surface of the impact hammer of the mechanical properties testing machine, the pressure balancing device is in a suspended state, the first impact part is facing the test collision base of the mechanical properties testing machine, and the impact head is installed on the first impact part. The impact head has a conical disc structure, so that when the impact hammer descends, the middle part of the impact head contacts the test collision base;

[0052] In step S13: when the impact hammer descends, the pressure balancing device falls from a specified height, the first impact portion contacts and squeezes the test collision base, causing the elastic tube to be axially compressed, and the second connecting end, the piston member, and the mounting plate remain in position relative to the impact hammer;

[0053] In step S22: multiple columns of the bracket are mounted on the lower surface of the impact hammer, and a horizontal mounting plate connected to the multiple columns is connected to the first impact part, so that the pressure balance device is suspended in the air and the first impact part faces the test collision foundation; the impact column is placed on the test collision foundation, and the multiple columns of the impact column are aligned with the second impact part, and the impact hammer is lowered so that the multiple columns contact the second impact part;

[0054] In step S23: when the impact hammer descends, the pressure balancing device falls from a specified height, the second impact part contacts and squeezes the column, causing the elastic pipe to be axially stretched, and the first connecting end and the cylinder body remain in position relative to the impact hammer.

[0055] The beneficial effects of the present invention are as follows:

[0056] The present invention has a compact and reasonable structure and is easy to operate. The cylinder body and the piston member installed on the mounting plate slide and seal together. The sliding and sealing matching structure of the cylinder body and the mounting plate allows the deformation of the elastic pipe to be limited to axial expansion and contraction deformation when the elastic pipe is installed on the device, so that the impact load is effectively transmitted to the elastic pipe. When the elastic pipe is installed on the device, the cylinder body, the mounting plate and the elastic pipe are enclosed to form an outer cavity, and an inner cavity is formed between the cylinder body and the piston member. By filling the outer cavity and the inner cavity with pressurized medium to adjust the initial state of the elastic pipe before the test, the elastic pipe can basically maintain the rated axial mechanical state when subjected to the axial impact load, thereby realizing that the elastic pipe can accurately carry out axial compression / tensile impact test under the rated working pressure and rated working length.

[0057] At the same time, the present invention also has the following advantages:

[0058] (1) The pressure balance device is universal. Without disassembling the elastic pipe, it is only necessary to replace the action position of the impact hammer of the mechanical properties testing machine and the pressure balance device, and change the way the pressure balance device is placed on the test collision base to switch the experimental conditions of the axial compression / tensile impact test, thereby simplifying the impact test steps of the elastic pipe and improving the test efficiency.

[0059] (2) By setting two interfaces on the first connection part for injecting gas and liquid respectively, due to the poor compressibility of liquid, a part of the space is filled with liquid to reduce the volume of gas, thereby reducing the energy stored by gas compression. When the elastic tube is damaged before reaching the rated working pressure during pressurization or when it is damaged during the impact test, the release of energy can be reduced, thereby ensuring safety during the test.

[0060] (3) On the basis of the test condition of the rated maximum deformation, the pressure change of the entire outer cavity is limited to obtain the height of the air cavity in the initial state, and the test conditions are more accurately defined, so that the state closer to the working pressure of the elastic pipe can be simulated during the test, making the impact test results more accurate.

[0061] (4) By setting two interfaces on the piston disc for injecting gas and liquid respectively, since the compressibility of liquid is poor, a part of the space is filled with liquid to reduce the volume of gas, making the operation process of gas pressurization more convenient and converting the pressure change into the relative displacement of the cylinder, piston and mounting disc more sensitive.

[0062] (5) By cooperating the bottom lower surface of the cup-shaped body with the bottom of the sealing groove and the limiting portion with the bottom of the cup-shaped body, the structure of the pressure balancing device itself is used as a limiting structure to limit the maximum deformation of the elastic connecting pipe during the axial compression / tensile impact test, thereby simplifying the number of auxiliary tooling used in the test process other than the pressure balancing device. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 It is a structural schematic diagram of the present invention.

[0064] Figure 2 It is an exploded view of the present invention.

[0065] Figure 3 It is an exploded view of the present invention (another perspective).

[0066] Figure 4 It is an axonometric cross-sectional view of the present invention.

[0067] Figure 5 It is a cross-sectional view of the present invention.

[0068] Figure 6 It is a structural schematic diagram of the cylinder body of the present invention.

[0069] Figure 7 It is a structural schematic diagram of the cylinder body of the present invention (another perspective).

[0070] Figure 8 Schematic diagram of the structure of the piston member of the present invention.

[0071] Figure 9 Schematic diagram of the structure of the piston member of the present invention (from another perspective).

[0072] Figure 10 It is a structural schematic diagram of the installation disk of the present invention.

[0073] Figure 11 This is a schematic structural diagram of the mounting plate of the present invention (from another perspective).

[0074] Figure 12 It is a structural schematic diagram of the present invention when used for axial compression impact test of elastic connecting pipe.

[0075] Figure 13 This is a schematic structural diagram of the present invention when used for an axial compression impact test of an elastic connecting pipe (from another perspective).

[0076] Figure 14 It is a schematic structural diagram of the present invention when used for axial tensile impact test of elastic connecting pipe.

[0077] Figure 15 This is a schematic structural diagram of the present invention used for an axial tensile impact test of an elastic connecting pipe (when an impact column is used).

[0078] Figure 16 Schematic diagram of the liquid level of the pressurized medium in the outer cavity and the inner cavity of the present invention.

[0079] in:

[0080] 1. Cylinder; 101. First connecting portion; 102. First sliding portion; 103. Cup-shaped body; 104. First impact portion; 105. First pressurizing port; 106. First liquid injection port; 107. Sliding hole;

[0081] 2. Piston member; 201. Piston plate; 202. Second sliding portion; 203. Rod-shaped body; 204. Position limiting portion; 205. Second pressurizing port; 206. Second liquid injection port;

[0082] 3. Mounting plate; 301. Second connecting portion; 302. Sealing groove; 303. Plate-shaped body; 304. Fixing hole; 305. Through hole; 306. Second impact portion;

[0083] 4. Elastic pipe; 401. First connection end; 402. Second connection end; 403. Elastic pipe;

[0084] 5. Bracket; 501. Horizontal mounting plate; 502. Column; 6. Impact head; 7. Support ring; 8. Impact column; 801. Impact plate; 802. Column;

[0085] A, external cavity; A1, air cavity; A2, liquid cavity; B, internal cavity. DETAILED DESCRIPTION

[0086] The specific embodiments of the present invention will be described below with reference to the accompanying drawings.

[0087] Example 1

[0088] like Figure 1-Figure 5 As shown, the elastic tube pressure balancing device of this embodiment is assembled with the elastic tube 4, so that the elastic tube 4 can maintain the rated working length while bearing the rated working pressure, and can basically not change the axial mechanical state of the elastic tube 4 when subjected to axial impact load, so that the impact load is effectively transmitted to the elastic tube 4, so that the elastic tube 4 can accurately carry out axial compression / tensile impact tests under the rated working pressure and rated working length. The specific scheme is as follows.

[0089] The elastic connecting pipe 4 includes an elastic tube 403, one end of which is a first connecting end 401, and the other end of which is a second connecting end 402. The elastic connecting pipe 4 can have various structures. The elastic tube 403 can be a metal bellows or a flexible tube made of metal, non-metal, or a composite material. The first connecting end 401 and the second connecting end 402 can be a bolted flange structure, a clamped flange structure, or a threaded pipe section.

[0090] The pressure balancing device includes a cylinder body 1 , a piston member 2 and a mounting plate 3 .

[0091] like Figure 1-Figure 7 As shown, the structure of the cylinder body 1 is as follows: it includes a cup-shaped body 103, the open end of the cup-shaped body 103 is provided with a first connecting part 101 with an annular structure, the first connecting part 101 is used to be sealed and connected with the first connecting end 401, and a first impact part 104 with an annular structure is provided above the middle of the first connecting part 101. The first impact part 104 and the first connecting part 101 are concentric with the cup-shaped body 103, the outer peripheral surface of the closed end of the cup-shaped body 103 is the first sliding part 102, and a sliding hole 107 is provided in the bottom center of the cup-shaped body 103.

[0092] Specifically, the specific structure of the first connection part 101 and the connection structure and sealing method with the first connection end 401 are related to the structural form of the first connection end 401. When the first connection end 401 is a bolt connection flange structure, the first connection part 101 is also a bolt connection flange structure and is connected to the first connection end 401 through fasteners and sealing rings. Figure 5 、 Figure 7 shown.

[0093] like Figure 1-Figure 5 、 Figure 8-Figure 9As shown, the structure of the piston member 2 is: it includes a rod-shaped body 203, a piston disk 201 is set at one end of the rod-shaped body 203, the outer peripheral surface of the piston disk 201 is sealed and slidably matched with the inner wall surface of the cup-shaped body 103, and the outer peripheral surface of the other end of the rod-shaped body 203 is a second sliding part 202, which is sealed and slidably matched with the sliding hole 107.

[0094] Specifically, the structure in which the outer circumferential surface of the piston disc 201 and the inner wall surface of the cup-shaped body 103 are sealed and slidably matched can be achieved by providing a sealing groove on the outer circumferential surface of the piston disc 201 and installing a sealing ring in the sealing groove; the structure in which the second sliding portion 202 and the sliding hole 107 are sealed and slidably matched can be achieved by providing a sealing groove in the sliding hole 107 and installing a sealing ring in the sealing groove, as shown in FIG. Figure 4 、 Figure 5 shown.

[0095] like Figure 1-Figure 5 、 Figure 10-11 As shown, the structure of the mounting plate 3 is as follows: it includes a plate-like body 303, a sealing groove 302 with an opening facing upward is provided in the middle of the plate-like body 303, the inner wall surface of the sealing groove 302 is sealed and slidably matched with the first sliding part 102, a second connecting part 301 is provided on the plate-like body 303 at the periphery of the sealing groove 302, the second connecting part 301 is used for sealing connection with the second connecting end 402, a fixing hole 304 is provided at the bottom of the sealing groove 302, the end of the second sliding part 202 is detachably fixedly connected to the fixing hole 304, and a second impact part 306 is provided at the periphery of the plate-like body 303.

[0096] Specifically, the structure in which the inner wall surface of the sealing groove 302 is sealed and slidingly matched with the first sliding portion 102 can be achieved by providing a sealing groove on the inner wall surface of the sealing groove 302 and installing a sealing ring in the sealing groove; the sealing connection structure between the second connecting portion 301 and the second connecting end 402 is related to the structural form of the second connecting end 402. When the second connecting end 402 is a bolted flange structure, the second connecting portion 301 is also a bolted flange structure and is connected to the second connecting end 402 by fasteners and a sealing ring, such as Figure 5 、 Figure 10As shown; there is a certain gap between the inner wall of the elastic tube 403 and the outer wall surface of the cup-shaped body 103; the specific structure of the detachable fixed connection between the fixing hole 304 and the end of the second sliding portion 202 can be various. The fixing hole 304 can be directly threadedly connected to the end of the second sliding portion 202. For ease of installation, a threaded hole can also be provided at the end of the second sliding portion 202, and a stepped hole structure is provided in the fixing hole 304. The stepped hole structure cooperates with the outer periphery of the end of the second sliding portion 202 to limit the installation depth of the second sliding portion 202 in the fixing hole 304. The end of the second sliding portion 202 is fixed by a fastener after passing through the fixing hole 304, as shown Figure 5 As shown, in this case, when performing the axial compression impact test, a support ring 7 needs to be provided below the plate-like body 303 to avoid the fastening nut ( Figure 13 ), of course, the structure for avoiding the fastening nut can also be directly set on the plate-like body 303; the number of the second impact portion 306 set on the periphery of the plate-like body 303 should be multiple, and evenly distributed with the axis of the elastic tube 4 as the center.

[0097] like Figure 5 As shown, when the first connecting portion 101 is sealedly connected to the first connecting end 401 and the second connecting portion 301 is sealedly connected to the second connecting end 402, the elastic tube 403 is located outside the cup-shaped body 103, and an outer cavity A is formed between the outer portion of the cup-shaped body 103 and the elastic tube 403. Specifically, the outer cavity A is enclosed by the cylinder body 1, the mounting plate 3 and the elastic connecting pipe 4; because the piston disc 201 and the second sliding portion 202 on the piston member 2 are respectively sealed with the cup-shaped body 103, an inner cavity B is formed between the interior of the cup-shaped body 103 and the piston member 2; because the first sliding portion 102 can slide relative to the inner wall surface of the sealing groove 302, the volume of the outer cavity A is variable when the elastic connecting pipe 4 is extended and retracted, and because the piston member 2 can slide relative to the cup-shaped body 103, the volume of the inner cavity B is variable; specifically, when the first connecting end 401 and the second connecting end 402 are both flange structures, the second connecting portion 301 is a sealing surface structure that cooperates with the second connecting end 402, as shown Figure 10 shown.

[0098] The specific structure and setting method of the sealing connection mentioned above are related to the design pressure in the outer cavity A or the inner cavity B.

[0099] The outer cavity A is filled with a first pressurized medium through the first pressurized port 105 and the inner cavity B is filled with a second pressurized medium through the second pressurized port 205 .

[0100] Specifically, the first pressurizing port 105 and the second pressurizing port 205 can be set at any position as long as they can be connected to the outer cavity A and the inner cavity B respectively and can realize other functions of the device at the same time. Generally, a gaseous first pressurizing medium and a second pressurizing medium are used, such as compressed air. Gas is convenient for pressurization operation, and because gas is compressible, it is convenient to introduce the rated maximum deformation of the elastic tube 4 into the test condition control in the impact test room. The extreme working condition of the elastic tube 4 is used as the test condition for quantitatively evaluating the quality and mechanical properties of the elastic tube 4. The rated maximum deformation is used as a quantitative parameter of the impact characteristic parameter of the elastic tube 4, that is, when the elastic tube 4 is changed to the rated maximum deformation during the impact test without being damaged, it serves as a criterion for judging whether the elastic tube meets the requirements and as a termination condition for the mechanical property test. By filling the pressurized medium, the pressure of the outer cavity A and the inner cavity B is adjusted so that the outer cavity A is equal to the rated working pressure of the elastic tube 4, and the pressure of the inner cavity B is adjusted so that the elastic tube 4 remains at the rated working length, which serves as the initial state of the elastic tube 4 before the axial compression / tensile impact test.

[0101] Through the sliding and sealing cooperation between the cylinder body 1 and the piston member 2 installed on the mounting plate 3, the sliding and sealing cooperation structure of the cylinder body 1 and the mounting plate 3, when the elastic tube 4 is installed on the device, the deformation of the elastic tube 4 is limited to axial expansion and contraction deformation, so that the impact load is effectively transmitted to the elastic tube 4; when the elastic tube 4 is installed on the device, the cylinder body 1, the mounting plate 3 and the elastic tube 4 are enclosed to form an outer cavity A, and an inner cavity B is formed between the cylinder body 1 and the piston member 2. By filling the outer cavity A and the inner cavity B with pressurized medium, the initial state of the elastic tube 4 before the test is adjusted, so that the bellows can basically maintain the rated axial mechanical state when subjected to axial impact load, thereby realizing that the elastic tube 4 can accurately carry out axial compression / tensile impact test under rated working pressure and rated working length.

[0102] When the elastic pipe 4 is subjected to an axial compression impact test, the hammer method is used as an example. Figure 12 、 Figure 13 As shown:

[0103] Place the pressure balancing device equipped with the elastic pipe 4 on the test collision foundation, and make the pressure balancing device directly below the impact hammer of the mechanical properties testing machine, so that the impact hammer is facing the first impact part 104;

[0104] When the impact hammer strikes the first impact portion 104 , the elastic connecting pipe 4 is compressed.

[0105] The impact head 6 may also be mounted on the first impact portion 104 , and the impact hammer may impact the center of the impact head 6 .

[0106] When the elastic tube 4 is compressed, the maximum downward movement distance of the cylinder 1 is the rated maximum deformation. The travel of the cylinder 1 can be limited by a limiting structure. This limiting structure can be a limiting column installed on the external test collision base of the pressure balance device, and the limit is achieved by the height difference between the upper end of the limiting column and the impact head 6.

[0107] When the elastic pipe 4 is subjected to an axial tensile impact test, the hammer method is used as an example. Figure 14 As shown:

[0108] The bracket 5 is placed on the test collision foundation and located below the impact hammer of the mechanical properties testing machine. The pressure balance device equipped with the elastic pipe 4 is connected to the bracket 5 so that the pressure balance device is in a suspended state. The connection part between the bracket 5 and the pressure balance device is the first impact part 104. The specific structure of the bracket 5 is as follows: it includes a horizontal mounting plate 501, the lower surface of the horizontal mounting plate 501 is connected to the first impact part 104, and the outer periphery of the horizontal mounting plate 501 is installed with a column 502. When the elastic pipe 4 is subjected to an axial tensile impact test, the column 502 is located outside the pressure balance device, such as Figure 14 shown.

[0109] The impact column 8 is mounted on the second impact part 306. The impact column 8 has a structure as follows: it includes a plurality of columns 802 connected to the second impact part 306, and a plurality of columns 802 are simultaneously connected to an impact plate 801. The impact plate 801 is located above the horizontal mounting plate 501. The impact plate 801 corresponds to the impact hammer. Figure 15 shown.

[0110] When the impact hammer strikes the impact plate 801 , the elastic pipe 4 is stretched.

[0111] When the elastic tube 4 is stretched, the maximum distance the mounting plate 3 moves downward is the rated maximum deformation. A limiting structure can be used to limit the travel of the mounting plate 3. This limiting structure can be the upper surface of the test collision base, combined with the bracket 5 to limit the height at which the pressure balance device is suspended.

[0112] The mechanical properties testing machine used for the axial compression / tensile impact test (including the impact hammer and the test collision base located at the bottom of the mechanical properties testing machine) is a conventional mechanical properties testing device. When the pressure balance device is used to perform the impact test on the elastic tube 4, it can be operated in conjunction with the above-mentioned impact head 6, bracket 5, and impact column 8. The drop method can also be used for impact testing. During the test, the deformation and limit principles of the elastic tube 4 are the same as those of the hammer method.

[0113] The specific dimensions and strength design of the cylinder body 1, the piston member 2 and the mounting plate 3 are designed accordingly based on the elastic connecting pipe 4 that is actually required to be tested.

[0114] The pressure balancing device is universal. Without disassembling the elastic pipe 4, it is only necessary to replace the action parts of the impact hammer of the mechanical properties testing machine and the pressure balancing device, and change the way the pressure balancing device is placed on the test collision base to switch the experimental conditions of the axial compression / tensile impact test, thereby simplifying the impact test steps of the elastic pipe 4 and improving the test efficiency.

[0115] Example 2:

[0116] This embodiment further optimizes the design based on the first embodiment.

[0117] like Figure 1-Figure 7 As shown, the first pressurized medium includes gas and liquid, and a first pressurized port 105 is provided on the first connecting portion 101, and gas is filled into the outer cavity A from the first pressurized port 105;

[0118] A first liquid injection port 106 is further provided on the first connecting portion 101 . The first liquid injection port 106 is communicated with the outer cavity A and is used to inject liquid into the outer cavity A.

[0119] By providing two interfaces on the first connection portion 101 for injecting gas and liquid respectively, since liquid has poor compressibility, a portion of the space is filled with liquid, reducing the volume of the gas, thereby reducing the energy stored in the gas compression. When the elastic tube 4 breaks before reaching the rated working pressure during pressurization or breaks during the impact test, the release of energy can be reduced, thereby ensuring safety during the test.

[0120] Furthermore, further design is made on how to set the volume of gas and liquid in the outer cavity A.

[0121] When the elastic tube 4 is in the initial state, the gas height in the outer cavity A is h0. Figure 16 shown.

[0122]

[0123] In formula (1):

[0124] Δh: rated maximum deformation of the elastic tube 4 (positive for compression and negative for tension);

[0125] δ: The allowable percentage change in pressure within the outer chamber A during the test (compression is positive, tension is negative). δ is used to ensure that the pressure change within the outer chamber A caused by deformation of the elastic tube 4 is sufficiently small, and that the pressure of the outer chamber A of the elastic tube 4 deviates sufficiently from the rated working pressure to make the impact of the pressure change on the impact characteristic parameter measurement results negligible. During actual testing, for the elastic tube 4 with a rated working pressure of 4.5 MPa, a value of ±5% is recommended.

[0126] m: variable index, related to the flow velocity of the gas. When the flow is fast, it is close to the adiabatic process m=1.4.

[0127] The specific derivation process of formula (1) is as follows, and combined with Figure 16 To explain:

[0128] The limit working condition during the test is that the length change value of the elastic connecting pipe 4 during the impact test is the rated maximum deformation Δh. The value of Δh is different for elastic connecting pipes 4 of different specifications.

[0129] When the elastic takeover 4 is in the initial state, such as Figure 5 As shown, the outer cavity A consists of an air cavity A1 and a liquid cavity A2, wherein the volume of the air cavity A1 is V0, the pressure of the air cavity A1 is the rated working pressure p0 of the elastic connecting pipe 4, and the height of the air cavity A1 is h0.

[0130] When the elastic tube 4 is in an extreme working condition, the volume of the air cavity A1 is V, the pressure of the air cavity A1 after the elastic tube 4 is impacted is p, the height of the air cavity A1 is h, and the height of the liquid cavity A2 remains unchanged.

[0131] Then: pV m =p0V0 m (1.1)

[0132] h=h0-Δh (1.2)

[0133] Furthermore, the average cross-sectional area (annular) of the outer cavity A is S, then:

[0134] V=Sh (1.3)

[0135] V0=Sh0 (1.4)

[0136] again:

[0137]

[0138] Substituting (1.2)-(1.5) into (1.1) we obtain:

[0139] (1+δ)·p0(S·(h0-Δh)) m =p0(Sh0) m (1.6)

[0140] Solving for h0 yields: That is formula (1).

[0141] On the basis of the test condition determined by the rated maximum deformation, the pressure change of the entire outer cavity A is limited to obtain the height of the air cavity A1 in the initial state. This more accurately defines the test conditions, simulates a state closer to the working pressure of the elastic tube 4 during the test, and makes the impact test results more accurate.

[0142] like Figure 1-Figure 5 , Figure 8-Figure 7 As shown, the second pressurized medium includes gas and liquid, and a second pressurized port 205 is provided on the piston disc 201, and gas is filled into the inner cavity B from the second pressurized port 205;

[0143] A second liquid injection port 206 is further provided on the piston disc 201 . The second liquid injection port 206 is communicated with the inner cavity B and is used to inject liquid into the inner cavity B.

[0144] By setting two interfaces on the piston disc 201 for injecting gas and liquid respectively, since the compressibility of liquid is poor, a part of the space is filled with liquid to reduce the volume of gas, making the operation process of gas pressurization more convenient, and the pressure change is converted into the relative displacement of the cylinder body 1, piston member 2 and mounting disc 3 more sensitive.

[0145] like Figure 5 、 Figure 11 、 Figure 12 As shown, a through hole 305 is further provided at the bottom of the sealing groove 302. The through hole 305 is used for exhaust and maintenance, and water leakage in the inner cavity B can be discovered in time.

[0146] In order to avoid the need to set a limiting structure outside the pressure balancing device during the impact test, limit the maximum deformation of the elastic pipe 4, and simplify the operation of the test process, a limiting structure is set on the main structure of the pressure balancing device to control the maximum deformation of the elastic pipe 4 during the test to be the rated maximum deformation.

[0147] like Figure 1-Figure 5 As shown, the bottom lower surface of the cup-shaped body 103 cooperates with the bottom of the sealing groove 302 , and a limiting portion 204 is provided on the rod-shaped body 203 between the piston disc 201 and the second sliding portion 202 , and the limiting portion 204 cooperates with the bottom of the cup-shaped body 103 .

[0148] Specifically:

[0149] When the axial compression impact test is performed and the compression degree of the elastic tube 4 reaches the rated maximum deformation, the limiting portion 204 contacts the bottom of the cup-shaped body 103 , limiting the impact force from further compressing the elastic tube 4 .

[0150] When the axial tensile impact test is performed and the stretching degree of the elastic tube 4 reaches the rated maximum deformation, when the bottom lower surface of the cup-shaped body 103 contacts the bottom of the sealing groove 302 , the impact force is limited to stretch the elastic tube 4 to a greater extent.

[0151] By cooperating the bottom lower surface of the cup-shaped body 103 with the bottom of the sealing groove 302, and the limiting portion 204 with the bottom of the cup-shaped body 103, the structure of the pressure balancing device itself is used as a limiting structure to limit the maximum deformation of the elastic connecting pipe 4 during the axial compression / tensile impact test, thereby simplifying the number of auxiliary tooling used in the test process other than the pressure balancing device.

[0152] like Figure 1-Figure 5 As shown, the limiting portion 204 is a stepped structure, and the outer diameter of the rod-shaped body 203 between the limiting portion 204 and the piston plate 201 is larger than the outer diameter of the second sliding portion 202. This limiting structure is simple and easy to process and assemble.

[0153] Example 3:

[0154] like Figure 5 、 Figure 12-15 As shown, the method for performing an elastic pipe impact test based on the structure of the pressure balancing device in Example 1 includes the following steps:

[0155] S1: The elastic tube 4 is assembled with the pressure balancing device. The first pressurized medium is charged into the outer chamber A through the first pressurized port 105, and the second pressurized medium is charged into the inner chamber B through the second pressurized port 205. The pressure in the outer chamber A is the rated working pressure of the elastic tube 4. The pressure in the inner chamber B is adjusted to maintain the rated working length of the elastic tube 4. After adjustment, the elastic tube 4 is in the initial state.

[0156] After step S1 is completed, the elastic tube 4 is subjected to an axial compression impact test, and the steps are as follows:

[0157] S12: Assemble the pressure balancing device equipped with the elastic pipe 4 with the mechanical properties testing machine, and place the pressure balancing device directly below the impact hammer of the mechanical properties testing machine, with the axis of the elastic pipe 4 coinciding with the axis of the impact hammer;

[0158] In step S12, a limiting structure may be used to limit the maximum compression of the elastic pipe 4. The limiting structure may be a limiting fixture provided outside the pressure balancing device or an internal structure of the pressure balancing device.

[0159] S13: The impact hammer is lowered to apply axial pressure to the elastic tube 4. The first connecting end 401 and the cylinder body 1 slide toward the mounting plate 3. The elastic tube 4 is compressed, and the compression amount is less than or equal to the rated maximum deformation amount.

[0160] In step S13, the compression amount of the elastic pipe 4 is determined according to the specific test conditions:

[0161] When conducting an axial compression impact strength test, the elastic tube 4 needs to be compressed to the rated maximum deformation;

[0162] When conducting the axial compression impact stiffness test, multiple impacts are required to gradually increase the deformation of the elastic tube 4, and the maximum deformation does not exceed the rated maximum deformation;

[0163] After step S1 is completed, the steps for performing an axial tensile impact test on the elastic tube 4 are as follows:

[0164] S22: Assemble the pressure balancing device equipped with the elastic pipe 4 with the mechanical properties testing machine, and position the pressure balancing device directly below the impact hammer of the mechanical properties testing machine, with the axis of the elastic pipe 4 coinciding with the axis of the impact hammer;

[0165] In step S22, a limiting structure may be used to limit the maximum stretching amount of the elastic pipe 4. The limiting structure may be a limiting fixture provided outside the pressure balancing device or an internal structure of the pressure balancing device.

[0166] S23: Lower the impact hammer to make the elastic pipe 4 axially tensile.

[0167] The first connecting end 401 and the cylinder body 1 slide in a direction away from the mounting plate 3, and the elastic tube 4 is stretched, and the stretching amount is less than or equal to the rated maximum deformation amount;

[0168] In step S23, the stretching amount of the elastic tube 4 is determined according to the specific test conditions:

[0169] When performing an axial tensile impact strength test, the elastic tube 4 needs to be stretched to the rated maximum deformation;

[0170] When performing the axial tensile impact stiffness test, multiple impacts are required to gradually increase the deformation of the elastic tube 4, with the maximum deformation not exceeding the rated maximum deformation.

[0171] In the elastic pipe impact test method, the pressure balance device ensures that the elastic pipe 4 is under the rated working pressure and rated working length, ensuring that the bellows can basically maintain the rated axial mechanical state when subjected to axial impact loads. This allows the elastic pipe 4 to accurately carry out axial compression / tensile impact tests under the rated working pressure and rated working length. Without disassembling the elastic pipe 4, the experimental conditions of the axial compression / tensile impact test can be switched by simply replacing the impact point of the impact hammer and the pressure balance device in the mechanical properties testing machine and changing the placement of the pressure balance device on the test collision base. This simplifies the impact test steps of the elastic pipe 4 and improves test efficiency.

[0172] Example 4:

[0173] like Figure 5 、 Figure 12-16 As shown, the elastic pipe impact test method of Example 3 is further optimized:

[0174] In step S1: the first pressurized medium filled into the outer chamber A includes gas and liquid. When the elastic pipe 4 is in the initial state, the gas height in the outer chamber A is h0:

[0175]

[0176] In formula (1):

[0177] Δh: rated maximum deformation of the elastic tube 4 (positive for compression and negative for tension);

[0178] δ: The percentage change of the allowable pressure in the outer cavity A during the test (positive for compression and negative for tension);

[0179] m: Multivariate index.

[0180] Formula (1) is the same as that in Example 2.

[0181] On the basis of the test condition determined by the rated maximum deformation, the pressure change of the entire outer cavity A is accurately limited to obtain the height of the air cavity A1 in the initial state. The test conditions are more accurately defined, so that the state closer to the working pressure of the elastic connecting pipe 4 is simulated during the test process, making the impact test results more accurate.

[0182] Embodiment 5:

[0183] like Figure 5 、 Figure 12-15 As shown, the method of the impact test of the elastic pipe in Example 3 is further refined by using the hammer method, and includes the following steps:

[0184] S1: The elastic tube 4 is assembled with the pressure balancing device. The first pressurized medium is charged into the outer chamber A through the first pressurized port 105, and the second pressurized medium is charged into the inner chamber B through the second pressurized port 205. The pressure in the outer chamber A is the rated working pressure of the elastic tube 4. The pressure in the inner chamber B is adjusted to maintain the rated working length of the elastic tube 4. After adjustment, the elastic tube 4 is in the initial state.

[0185] After step S1 is completed, the elastic tube 4 is subjected to an axial compression impact test, and the steps are as follows:

[0186] S12: The pressure balancing device equipped with the elastic pipe 4 is placed on the test collision base of the mechanical properties testing machine, with the first impact portion 104 facing the impact hammer of the mechanical properties testing machine. At the same time, an impact head 6 is installed on the first impact portion 104. The impact head 6 has a conical disc structure so that the impact hammer strikes the middle of the impact head 6 when it descends. At the same time, the pressure balancing device is located directly below the impact hammer of the mechanical properties testing machine, and the axis of the elastic pipe 4 coincides with the axis of the impact hammer.

[0187] In step S12, the maximum distance that the cylinder body 1 can move downward can be limited. The limiting structure can be a limiting fixture provided on the outside of the pressure balancing device, or a structure inside the pressure balancing device. When the limiting structure is a limiting fixture provided on the outside of the pressure balancing device, the limiting structure can be a limiting column provided on the test collision foundation outside the pressure balancing device, and the limiting is performed by the height difference between the upper end of the limiting column and the impact head 6.

[0188] S13: The impact hammer is lowered to strike the impact head 6. The second connecting end 402, the piston member 2, and the mounting plate 3 remain in position, so that the elastic tube 4 is axially compressed. The first connecting end 401 and the cylinder body 1 slide toward the mounting plate 3, and the elastic tube 4 is compressed. The compression amount is less than or equal to the rated maximum deformation.

[0189] In step S13 , the impact hammer descends and strikes the impact head 6 , so that the impact position of the impact hammer is transformed into a point, so that the impact force on the elastic connecting pipe 4 is more uniform.

[0190] After step S1 is completed, the steps for performing an axial tensile impact test on the elastic tube 4 are as follows:

[0191] S22: Place the multiple columns 502 of the bracket 5 on the test collision foundation, connect the lower surface of the horizontal mounting plate 501 connected to the multiple columns 502 to the first impact part 104, so that the pressure balancing device is suspended in the air; connect the multiple columns 802 of the impact column 8 to the second impact part 306, so that the impact plate 801 connected to the multiple columns 802 is located above the horizontal mounting plate 501, and the impact plate 801 corresponds to the impact hammer; at the same time, the pressure balancing device is located directly below the impact hammer of the mechanical properties testing machine, and the axis of the elastic pipe 4 coincides with the axis of the impact hammer;

[0192] In step S22, the maximum downward movement distance of the mounting plate 3 may be limited. The limiting structure may be a limiting structure provided outside the pressure balancing device, and may be implemented by testing the upper surface of the collision base in combination with the bracket 5 to limit the height of the pressure balancing device suspended in the air. The limiting structure may also be an internal structure of the pressure balancing device.

[0193] S23: Lower the impact hammer to hit the impact plate 801, so that the elastic tube 4 is axially stretched, the first connection end 401 and the cylinder body 1 remain in position, the first connection end 401 and the cylinder body 1 slide in the direction away from the mounting plate 3, and the elastic tube 4 is stretched, and the stretching amount is less than or equal to the rated maximum deformation.

[0194] Example 6:

[0195] like Figure 5 、 Figure 12-15As shown, the method of the elastic pipe impact test in Example 3 is further refined based on the method of the drop method, including the following steps:

[0196] S1: The elastic tube 4 is assembled with the pressure balancing device. The first pressurized medium is charged into the outer chamber A through the first pressurized port 105, and the second pressurized medium is charged into the inner chamber B through the second pressurized port 205. The pressure in the outer chamber A is the rated working pressure of the elastic tube 4. The pressure in the inner chamber B is adjusted to maintain the rated working length of the elastic tube 4. After adjustment, the elastic tube 4 is in the initial state.

[0197] After step S1 is completed, the elastic tube 4 is subjected to an axial compression impact test, and the steps are as follows:

[0198] S12: Assemble the pressure balancing device equipped with the elastic pipe 4 to the mechanical properties testing machine, and position the pressure balancing device directly below the impact hammer of the mechanical properties testing machine, with the axis of the elastic pipe 4 coinciding with the axis of the impact hammer. In step S12: connect the second impact portion 306 of the pressure balancing device equipped with the elastic pipe 4 to the lower surface of the impact hammer of the mechanical properties testing machine, with the pressure balancing device suspended in the air and the first impact portion 104 facing the test collision base of the mechanical properties testing machine. Simultaneously, an impact head 6 is mounted on the first impact portion 104. The impact head 6 has a conical disc-shaped structure, so that when the impact hammer descends, the center of the impact head 6 contacts the test collision base.

[0199] In step S12, the maximum distance that the cylinder body 1 can move upward can be limited. The limiting structure can be a limiting fixture provided on the outside of the pressure balancing device, or a structure inside the pressure balancing device. When the limiting structure is a limiting fixture provided on the outside of the pressure balancing device, the limiting structure can be a limiting column provided on the impact hammer, and the limiting is performed by the height difference between the lower end of the limiting column and the impact head 6.

[0200] S13: When the impact hammer descends, the pressure balancing device falls from a specified height. The first impact portion 104 contacts and squeezes the test collision base, causing the elastic tube 4 to be axially compressed. The second connecting end 402, the piston member 2, and the mounting plate 3 remain in the same position relative to the impact hammer. The first connecting end 401 and the cylinder body 1 slide toward the mounting plate 3, causing the elastic tube 4 to be compressed. The compression amount is less than or equal to the rated maximum deformation.

[0201] After step S1 is completed, the steps for performing an axial tensile impact test on the elastic tube 4 are as follows:

[0202] S22: Install the multiple columns 502 of the bracket 5 on the lower surface of the impact hammer, and connect the horizontal mounting plate 501 connected to the multiple columns 502 to the first impact part 104, so that the pressure balancing device is suspended in the air, with the first impact part 104 facing the test collision foundation; place the impact column 8 on the test collision foundation, and align the multiple columns 802 of the impact column 8 with the second impact part 306. Lower the impact hammer until the multiple columns 802 contact the second impact part 306; and ensure that the pressure balancing device is directly below the impact hammer of the mechanical properties testing machine, with the axis of the elastic pipe 4 coinciding with the axis of the impact hammer.

[0203] In step S22, the maximum upward movement distance of the mounting plate 3 can be limited. The limiting structure can be a limiting structure provided outside the pressure balancing device. The limiting function can be achieved by the distance between the end of the column 802 and the upper surface of the test collision foundation. When the horizontal mounting plate 501 abuts the test collision foundation or the impact plate 801 connected to multiple columns 802, the elastic tube 4 is stretched to the maximum extent.

[0204] S23: When the impact hammer descends, the pressure balancing device falls from the specified height, and the second impact part 306 contacts and squeezes the column 802, causing the elastic tube 4 to be axially stretched. The first connection end 401 and the cylinder body 1 remain in the same position relative to the impact hammer. The first connection end 401 and the cylinder body 1 slide in the direction away from the mounting plate 3, and the elastic tube 4 is stretched, and the stretching amount is less than or equal to the rated maximum deformation.

[0205] In the fifth and sixth embodiments, by adopting external tooling structures such as the impact head 6, the bracket 5 and the impact column 8, it is achieved that after the elastic pipe 4 is installed in the pressure balancing device, the axial compression / tensile impact test can be performed using the hammer method and the drop method. This is not only convenient to operate and ensures that the elastic pipe 4 is evenly compressed, but also facilitates the control of the maximum deformation of the elastic pipe 4.

[0206] The above description is an explanation of the present invention, not a limitation of the present invention. The scope of the present invention is defined in the claims. Any modifications may be made within the scope of protection of the present invention.

Claims

1. An elastic pipe pressure balancing device, the elastic pipe (4) comprising an elastic pipe (403), one end of the elastic pipe (403) being a first connecting end (401), and the other end of the elastic pipe (403) being a second connecting end (402). The pressure balancing device comprises a cylinder (1), a piston (2) and a mounting plate (3); The structure of the cylinder body (1) includes a cup-shaped body (103), an open end of the cup-shaped body (103) is provided with a first connecting portion (101) with an annular structure, the first connecting portion (101) is used for sealing connection with the first connecting end (401), a first impact portion (104) with an annular structure is provided above the middle of the first connecting portion (101), the first impact portion (104) and the first connecting portion (101) are concentric with the cup-shaped body (103), the outer peripheral surface of the closed end of the cup-shaped body (103) is a first sliding portion (102), and a sliding hole (107) is provided at the center of the bottom of the cup-shaped body (103); The structure of the piston member (2) includes a rod-shaped body (203), a piston disc (201) is provided at one end of the rod-shaped body (203), the outer peripheral surface of the piston disc (201) is sealed and slidably matched with the inner wall surface of the cup-shaped body (103), and the outer peripheral surface of the other end of the rod-shaped body (203) is a second sliding portion (202), and the second sliding portion (202) is sealed and slidably matched with the sliding hole (107); The structure of the mounting plate (3) comprises a plate-like body (303), a sealing groove (302) with an opening facing upward is provided in the middle of the plate-like body (303), an inner wall surface of the sealing groove (302) is sealed and slidingly matched with the first sliding part (102), a second connecting part (301) is provided on the plate-like body (303) at the periphery of the sealing groove (302), the second connecting part (301) is used for sealing connection with the second connecting end (402), a fixing hole (304) is provided at the bottom of the sealing groove (302), an end portion of the second sliding part (202) is detachably fixedly connected to the fixing hole (304), and a second impact part (306) is provided at the periphery of the plate-like body (303); When the first connecting portion (101) is sealedly connected to the first connecting end (401) and the second connecting portion (301) is sealedly connected to the second connecting end (402), the elastic tube (403) is located outside the cup-shaped body (103), an outer cavity (A) is formed between the outside of the cup-shaped body (103) and the elastic tube (403), and an inner cavity (B) is formed between the inside of the cup-shaped body (103) and the piston member (2); The pressure balancing device further comprises a first pressurizing port (105) and a second pressurizing port (205); the outer cavity (A) is filled with a first pressurizing medium through the first pressurizing port (105), and the inner cavity (B) is filled with a second pressurizing medium through the second pressurizing port (205); Adjust the pressure of the outer cavity (A) and the inner cavity (B) so that the pressure of the outer cavity (A) is equal to the rated working pressure of the elastic tube (4), and adjust the pressure of the inner cavity (B) so that the elastic tube (4) is kept at the rated working length state, which serves as the initial state of the elastic tube (4) before the axial compression / tensile impact test; When the elastic pipe (4) is subjected to an axial compression impact test by hammering: A pressure balancing device equipped with an elastic connecting pipe (4) is placed on a test collision foundation, and the pressure balancing device is located directly below the impact hammer of the mechanical properties testing machine, so that the impact hammer is directly opposite to the first impact part (104). When the impact hammer impacts the first impact part (104), the elastic connecting pipe (4) is compressed; When the elastic pipe (4) is subjected to an axial tensile impact test by hammering: Place the bracket (5) on the test collision foundation and under the impact hammer of the mechanical properties testing machine. A pressure balancing device equipped with an elastic pipe (4) is connected to a bracket (5) so that the pressure balancing device is in a suspended state. The bracket (5) includes a horizontal mounting plate (501). A column (502) is mounted on the periphery of the horizontal mounting plate (501). The column (502) is located outside the pressure balancing device. The lower surface of the horizontal mounting plate (501) is connected to the first impact portion (104). An impact column (8) is installed on the second impact portion (306), the structure of the impact column (8) comprising a plurality of columns (802) connected to the second impact portion (306), an impact plate (801) connected to the plurality of columns (802), the impact plate (801) being located above the horizontal mounting plate (501), the impact plate (801) corresponding to the impact hammer, and when the impact hammer strikes the impact plate (801), the elastic connecting pipe (4) is stretched; The first pressurized medium includes gas and liquid, and the first connecting portion (101) is provided with a first pressurized port (105), through which gas is filled into the outer cavity (A); A first liquid injection port (106) is also provided on the first connecting portion (101), the first liquid injection port (106) being in communication with the outer cavity (A), and the first liquid injection port (106) being used to inject liquid into the outer cavity (A); When the elastic pipe (4) is in the initial state, the gas height in the outer cavity (A) is h 0: （1） In formula (1): : The rated maximum deformation of the elastic connecting pipe (4), where compression is positive and tension is negative; : During the test, the percentage change of the allowable pressure in the outer cavity (A), compression is positive and tension is negative; : Variable index.

2. The elastic pipe pressure balancing device according to claim 1, characterized in that: The second pressurized medium includes gas and liquid, and the piston disc (201) is provided with a second pressurized port (205), through which gas is filled into the inner cavity (B); A second liquid injection port (206) is also provided on the piston disc (201), the second liquid injection port (206) being in communication with the inner cavity (B), and the second liquid injection port (206) is used to inject liquid into the inner cavity (B).

3. The elastic pipe pressure balancing device according to claim 2, characterized in that: A through hole (305) is also provided at the bottom of the sealing groove (302).

4. The elastic pipe pressure balancing device according to claim 1, characterized in that: The lower surface of the bottom of the cup-shaped body (103) cooperates with the bottom of the sealing groove (302), and a limiting portion (204) is provided on the rod-shaped body (203) between the piston disc (201) and the second sliding portion (202), and the limiting portion (204) cooperates with the bottom of the cup-shaped body (103).

5. A method for elastic pipe impact testing using the elastic pipe pressure balancing device according to claim 1, characterized in that: The following steps are involved: S1: The elastic connecting pipe (4) is assembled with the pressure balancing device, and the first pressurized medium is charged into the outer chamber (A) through the first pressurized port (105), and the second pressurized medium is charged into the inner chamber (B) through the second pressurized port (205). The pressure in the outer chamber (A) is the rated working pressure of the elastic connecting pipe (4). By adjusting the pressure in the inner chamber (B), the elastic connecting pipe (4) maintains the rated working length. After adjustment, the elastic connecting pipe (4) is in the initial state. After step S1 is completed, the elastic tube (4) is subjected to an axial compression impact test, and the steps are as follows: S12: Assemble the pressure balancing device equipped with the elastic pipe (4) with the mechanical properties testing machine, and place the pressure balancing device directly below the impact hammer of the mechanical properties testing machine, with the axis of the elastic pipe (4) coinciding with the axis of the impact hammer; S13: Lower the impact hammer to compress the elastic pipe (4) axially. The first connecting end (401) and the cylinder body (1) slide toward the mounting plate (3), and the elastic connecting pipe (4) is compressed, with the compression amount being less than or equal to the rated maximum deformation amount; After step S1 is completed, the steps for performing an axial tensile impact test on the elastic tube (4) are as follows: S22: Assemble the pressure balancing device equipped with the elastic pipe (4) with the mechanical properties testing machine, and place the pressure balancing device directly below the impact hammer of the mechanical properties testing machine, with the axis of the elastic pipe (4) coinciding with the axis of the impact hammer; S23: Lower the impact hammer to make the elastic pipe (4) axially tensile. The first connecting end (401) and the cylinder body (1) slide in a direction away from the mounting plate (3), and the elastic connecting pipe (4) is stretched, with the stretching amount being less than or equal to the rated maximum deformation amount.

6. The elastic connecting pipe impact test method according to claim 5, characterized in that: In step S1: the first pressurized medium filled in the outer chamber (A) includes gas and liquid. When the elastic connecting pipe (4) is in the initial state, the gas height in the outer chamber (A) is h 0: （1） In formula (1): : The rated maximum deformation of the elastic connecting pipe (4), where compression is positive and tension is negative; : During the test, the percentage change of the allowable pressure in the outer cavity (A), compression is positive and tension is negative; : Variable index.

7. The elastic connecting pipe impact test method according to claim 5, wherein: When using the hammer method: In step S12: the pressure balancing device equipped with the elastic pipe (4) is placed on the test collision base of the mechanical properties testing machine, and the first impact part (104) is directed toward the impact hammer of the mechanical properties testing machine, and the impact head (6) is installed on the first impact part (104), and the impact head (6) is a conical disc structure, so that the impact hammer strikes the middle part of the impact head (6) when it descends; In step S13: the impact hammer is lowered to strike the impact head (6), and the positions of the second connecting end (402), the piston member (2) and the mounting plate (3) remain unchanged; In step S22: multiple columns (502) of the bracket (5) are placed on the test collision foundation, and the lower surface of the horizontal mounting plate (501) connected to the multiple columns (502) is connected to the first impact part (104), so that the pressure balance device is in a suspended state; multiple columns (802) of the impact column (8) are connected to the second impact part (306), so that the impact plate (801) connected to the multiple columns (802) is located above the horizontal mounting plate (501), and the impact plate (801) corresponds to the impact hammer; In step S23: the impact hammer is lowered to strike the impact plate (801), so that the elastic connecting pipe (4) is axially stretched, and the positions of the first connecting end (401) and the cylinder body (1) remain unchanged.

8. The elastic connecting pipe impact test method according to claim 5, wherein: When using the drop method: In step S12: the second impact part (306) of the pressure balancing device equipped with the elastic pipe (4) is connected to the lower surface of the impact hammer of the mechanical properties testing machine, the pressure balancing device is in a suspended state, the first impact part (104) is facing the test collision base of the mechanical properties testing machine, and the impact head (6) is installed on the first impact part (104). The impact head (6) is a conical disc structure, so that when the impact hammer descends, the middle part of the impact head (6) contacts the test collision base; In step S13: when the impact hammer descends, the pressure balancing device falls from a specified height, the first impact portion (104) contacts and squeezes the test collision base, causing the elastic connecting pipe (4) to be axially compressed, and the second connecting end (402), the piston member (2) and the mounting plate (3) remain in the same position relative to the impact hammer; In step S22: multiple columns (502) of the bracket (5) are mounted on the lower surface of the impact hammer, and the horizontal mounting plate (501) connected to the multiple columns (502) is connected to the first impact part (104), so that the pressure balance device is in a suspended state and the first impact part (104) faces the test collision foundation; the impact column (8) is placed on the test collision foundation, and the multiple columns (802) of the impact column (8) are aligned with the second impact part (306), and the impact hammer is lowered so that the multiple columns (802) are in contact with the second impact part (306); In step S23: when the impact hammer descends, the pressure balancing device falls from a specified height, the second impact portion (306) contacts and squeezes the column (802), causing the elastic connecting pipe (4) to be axially stretched, and the first connecting end (401) and the cylinder body (1) remain in the same position relative to the impact hammer.

Images