A testing device for a hydraulic tensioner

Abstract

The present application discloses a test device for a hydraulic tensioner, comprising: a hollow oil cylinder, the hollow oil cylinder including an oil cylinder body and a hydraulic piston that slides up and down relative to the oil cylinder body; the oil cylinder body is fixedly installed on a first mounting plate; a hollow cavity is provided at the center of the oil cylinder body; a pressure sensor for detecting the oil pressure value inside the oil cylinder body; a test screw rod that passes through the hollow cavity of the oil cylinder body, the upper section of the test screw rod extends upward out of the hollow oil cylinder and is connected to the tensioner to be tested, and the lower section of the test screw rod extends downward out of the hollow oil cylinder; further comprising a clamping member, a support plate and a driving unit. In the present application, the test bolt is fixed, and the measured pulling force of the tensioner to be tested is calculated by detecting the reaction force output by the tensioner when stretching the test bolt. Through the ingenious cooperation of the test screw rod and the clamping member and the driving member, the stability of the test screw rod during the test is ensured, making the detection / calibration result more accurate.

Description

Technical Field

[0001] The invention relates to the technical field of tensile testing, in particular to a testing device for a hydraulic tensile device. Background Art

[0002] Hydraulic tensioner is the abbreviation of bolt hydraulic tensioner. It uses the hydraulic source provided by the hydraulic booster pump (ultra-high pressure hydraulic pump) to determine the tension according to the tensile strength, yield coefficient and elongation of the material. The tension generated by the ultra-high pressure oil pump makes the bolts to be stretched in their elastic deformation zone, and the bolt diameter is slightly deformed, so that the nut is easy to loosen. In addition, it can also be used as a device for applying axial force to hydraulic interference connection for top pressure installation. The biggest advantage of the tensioner is that it can tighten and remove multiple bolts at a fixed value at the same time, and the force is evenly distributed. It is a safe, efficient and fast tool and the best way to tighten and remove bolts of various specifications. It is used in petrochemical, nuclear power, wind power, hydropower, thermal power, ships, railways, aerospace, mining, heavy machinery and other fields.

[0003] The existing patent CN202020169592.0 discloses a portable hydraulic bolt tensioner test device, including a pad 2, a stud 3, the pad 2 is connected to the stud 3 by a screw 7, a protective cover 9 is arranged in the middle of the stud 3, the protective cover 9 is connected to a tension sensor 4, a strain gauge is arranged on the tension sensor 4, the strain gauge is connected to a socket 11, the socket 11 is arranged on the housing 10, and the housing 10 is connected to the tension sensor 4 by a screw 8; a gasket 1 is arranged on the outer surface of the upper end of the stud 3, a nut 5 is also connected to the upper end of the stud 3, and a flat washer 6 is arranged between the nut 5 and the gasket 1; the top of the stud 3 is connected to a hydraulic tensioner 13. The patent detects the magnitude of the external force on the strain gauge by a tension sensor and combines it with the oil pressure value of the high-pressure oil on the hydraulic tensioner to complete the calibration of the hydraulic tensioner. Therefore, the accuracy of the hydraulic tensioner calibration is closely related to the installation position and form of the strain gauge. However, the accurate and stable installation of the strain gauge is difficult to control in practice, which can easily affect the calibration accuracy of the hydraulic tensioner. Summary of the invention

[0004] The purpose of the present invention is to provide a testing device for a hydraulic tensioner, which fixes a test bolt and calculates the actual tensile force of the tensioner to be tested by detecting the reaction force output externally when the tensioner stretches the test bolt. By cleverly cooperating the test screw and the clamping part and the driving part, the stability of the test screw during the test is ensured, thereby making the detection / calibration result more accurate.

[0005] The present application discloses a testing device for a hydraulic tensioner, comprising: a hollow oil cylinder, the hollow oil cylinder including an oil cylinder body and a hydraulic piston that slides up and down relative to the oil cylinder body; the oil cylinder body is fixedly installed on a first mounting plate; a hollow cavity is provided at the center of the oil cylinder body; a pressure sensor for detecting the oil pressure value inside the oil cylinder body; a testing screw rod that passes through the hollow cavity of the oil cylinder body, the upper section of the testing screw rod extends upward out of the hollow oil cylinder and is connected to the tensioner to be tested, and the lower section of the testing screw rod extends downward out of the hollow oil cylinder; a clamping member that is detachably connected to the lower section of the testing screw rod, and the clamping member cooperates with the oil cylinder body for fixing the testing screw rod; a support plate located directly below the oil cylinder body; a driving unit that acts below the support plate for adjusting the distance between the support plate and the oil cylinder body, and the upper surface of the support plate acts on the clamping member to drive the clamping member to closely cooperate with or move up and down away from the oil cylinder body.

[0006] Further, a plurality of grooves are provided on the lower section of the testing screw rod, the clamping member includes a left clamping member and a right clamping member that cooperate with each other, and protrusions corresponding to the grooves on the lower section of the testing screw rod are provided on the inner walls of the left clamping member and the right clamping member, and the left clamping member and the right clamping member enclose and are clamped with the lower section of the testing screw rod.

[0007] Further, the height of the hollow cavity of the oil cylinder body is less than the height of the oil cylinder body, and a tapered mating cavity is formed below the oil cylinder body where the hollow cavity is located; semi-tapered steps are provided above both the left clamping member and the right clamping member, and the steps of the left clamping member and the right clamping member enclose a hollow cone, and the cone is adapted to the mating cavity of the oil cylinder body.

[0008] Further, T-shaped handles for easy hand-holding are provided on the outer surfaces of both the left clamping member and the right clamping member.

[0009] Further, an arc transition section A1 is formed at the transition between the upper section and the middle section of the testing screw rod, and the transition between the middle section and the lower section of the testing screw rod is an arc transition section A2 with a gradually increasing diameter.

[0010] Further, the part of the oil cylinder body near the lower end of the hollow cavity is a polyhedron structure B2 with a regular polygon cross-section, and a polyhedron structure B1 with a regular polygon cross-section is arranged in a circle where the arc transition section A2 is connected to the lower section of the testing screw rod, and the polyhedron structure B1 is adapted to the polyhedron structure B2.

[0011] Further, the driving unit includes a cam mechanism and a driving handle, and the cam mechanism includes a cam and a push rod connected to the cam; the top end of the push rod is threadedly connected to the support plate.

[0012] Further, the support plate includes a support surface and a connecting cylinder located below the support surface; the top end of the push rod is threadedly connected to the connecting cylinder, and by rotating the support surface, the length of the push rod extending into the connecting cylinder can be adjusted.

[0013] Further, it further includes a second mounting plate and a Π-shaped bracket fixedly connected to the second mounting plate; the top end of the push rod vertically penetrates through the Π-shaped bracket and is threadedly connected to the connecting cylinder; the cam is located in the middle of the Π-shaped bracket, and a central shaft horizontally penetrates through the Π-shaped bracket and the center of the cam; a driving handle is fixedly connected to one end of the central shaft through a bushing for driving the cam to rotate so as to drive the push rod to jack up.

[0014] Beneficial effects: The testing device for a hydraulic tensioner disclosed in this application can detect and calibrate hydraulic tensioners of different specifications by replacing the test bolt, with a wide application range, strong versatility and simple operation. To ensure safety during the testing process, the transition parts between the upper section and the middle section, and between the middle section and the lower section of the test screw are designed as arc transition sections with gradually changing diameters to eliminate stress concentration during the stretching process. The matching arrangement of the polyhedron structure B2 in the hollow cavity of the cylinder body and the polyhedron structure B2 around the test screw strengthens the radial stability of the test screw relative to the cylinder body, preventing the test screw from slipping relative to the cylinder body during the stretching process; the groove structure at the lower section of the test screw cooperates with the protrusion of the clamping part to ensure that the screw structure is not prone to axial displacement during the stretching process; the tapered mating cavity of the cylinder body and the tapered mating connection of the clamping part stably clamp the test screw, which can effectively eliminate the influence of the loosening of the test screw on the test result during the stretching process, with high test accuracy and obvious effect in achieving the relative stability of the test screw and the tensioner to be tested. The driving unit drives the clamping part to be separated from or combined with the cylinder body through the support plate, without manual tightening, and the operation is convenient and effective. Description of the Drawings

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0016] Figure 1 is the front sectional view of the testing device of this application;

[0017] Figure 2 is the three-dimensional schematic diagram of some components of the testing device of this application;

[0018] Figure 3 is the three-dimensional schematic diagram of the test screw;

[0019] Figure 4 is the three-dimensional schematic diagram of the cylinder body;

[0020] Figure 5 is Figure 4 the front sectional view of the cylinder body;

[0021] Figure 6 It is a three-dimensional schematic diagram of the clamping member;

[0022] In the figure: 10, test screw; 11, upper section of the test screw; 12, middle section of the test screw; 13, lower section of the test screw; 131, groove; 110, transition piece; 20, cylinder body; 21, hollow cavity; 22, mating cavity; 23, concave cavity; 24, oil injection hole; 201, hydraulic piston; 30, clamping member; 41, supporting plate; 42, guiding support; 43, ∏-shaped bracket; 441, push rod; 442, cam; 443, central shaft; 444, bushing; 445, driving handle; 50, stretcher to be tested; 60, first mounting plate. Specific embodiments

[0023] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present invention.

[0024] A test device for a hydraulic stretcher is used to test the tensile force (or load) of the stretcher and calibrate the stretcher 50 to be tested according to the test results. The test device includes a workbench and a test assembly installed on the workbench.

[0025] The workbench includes a frame support and a first mounting plate 60 and a second mounting plate provided on the frame support. The second mounting plate is arranged parallel to and below the first mounting plate 60. The main function of the workbench is to fix the test assembly, and the test assembly is fixedly installed on the workbench to facilitate the test of the stretcher. The specific structure of the workbench is not limited to this.

[0026] As Figure 1 and Figure 2 shown, the test assembly includes a test screw 10, a test hollow oil cylinder, a mounting assembly, and a pressure sensor.

[0027] The hollow oil cylinder includes a cylinder body 20 and a hydraulic piston 201. The outer edge of the cylinder body 20 is fixedly connected to the first mounting plate 60 and sinks below the first mounting plate 60. As Figure 4 、 Figure 5As shown in the figure, the cylinder body 20 is of a cylindrical structure, provided with a circular concave cavity 23. There are two oil inlet holes 24 at the bottom of the concave cavity. The hydraulic piston is located in the concave cavity, and a sealing ring is also provided between the hydraulic piston and the cylinder. During the test, the upper surface of the hydraulic piston 201 abuts against the stretching device to be tested through the transition piece 110. In the working state, hydraulic oil is injected into the concave cavity through the oil inlet hole, and the oil inlet is closed. The hydraulic piston is compressed downward under the reaction force of the stretching device to be tested, so that the pressure in the concave cavity continuously increases.

[0028] The center of the cylinder body 20 is provided with a hollow cavity 21 and a frustum-shaped mating cavity 22. The frustum-shaped mating cavity 22 is located below the hollow cavity 21. A polyhedron structure B2 with a regular polygon cross-section is provided around the part of the cylinder body 20 near the lower end of the hollow cavity (i.e., the connection between the central control cavity 21 and the mating cavity 22).

[0029] The diameter of the maximum cross-section of the test screw rod is smaller than the inner diameter of the hollow cavity 21 of the cylinder body 20, so that the test screw rod can pass through the center of the cylinder body 20. As Figure 3 shown, the upper section 11 of the test screw rod is of a threaded structure, located above the first mounting plate 60, and is connected to the stretching device to be tested in a mating manner. The lower section 13 of the test screw rod is provided with a plurality of grooves 131, which cooperate with the protrusions provided on the inner surface of the clamping member 30. The transition section between the upper section 11 of the test screw rod and the middle section of the test screw rod forms an arc transition section A1, and the transition between the middle section of the test screw rod and the lower section 13 of the test screw rod is an arc transition section A2 with a gradually increasing diameter. The reason for setting each connection part into an arc transition is to eliminate the stress concentration generated during the stretching process. If each connection part is made into a right-angle connection, the connection part is likely to break during the stretching process. Considering the easy implementation of the thread relief link in the manufacturing process of the test screw rod, the middle section of the test screw rod is designed to be inwardly contracted. Among them, the diameter of the lower section 13 of the test screw rod is larger than the diameter of the upper section 11 of the test screw rod. This is to ensure that during the stretching process, the lower section 13 of the test screw rod can maintain better stability. The lower section 13 of the test screw rod is relatively thick, and when the upper section 11 of the test screw rod is subjected to an external tensile force, the entire test screw rod has better resistance to tensile force.

[0030] Furthermore, as Figure 5 shown, a circle of the cylinder body 20 near the lower end of the hollow cavity 21 is designed as a polyhedron structure B2 with a regular polygon cross-section. A circle where the arc transition section A2 is connected to the lower section of the test screw rod is provided with a polyhedron structure B1 with a regular polygon cross-section. The polyhedron structure B1 is connected to the polyhedron structure B2 in a mating manner, so as to strengthen the stability of the test screw rod relative to the cylinder body 20, prevent the test screw rod from slipping relative to the cylinder during the stretching process, and also make the screw structure not easily rotate radially during the stretching process.

[0031] The installation assembly includes a clamping member 30, a transition connecting member, and a driving unit.

[0032] As Figure 6 shown, the clamping member 30 includes a left clamping member and a right clamping member that cooperate with each other. Both the left clamping member and the right clamping member are semi-circular rings that cooperate with each other. The inner walls of the left clamping member and the right clamping member are both provided with protrusions corresponding to the grooves of the lower section 13 of the test screw. The left clamping member and the right clamping member enclose and are clamped with the lower section 13 of the test screw, wrapping around the periphery of the lower section 13 of the test screw. Both the left clamping member and the right clamping member are provided with semi-conical steps above. The steps of the left clamping member and the right clamping member together form a hollow frustum. The frustum is adapted to the mating cavity 22 of the oil cylinder body 20. During the process of fixing the test screw, the frustum of the clamping member extends into the mating cavity of the oil cylinder body and abuts against the periphery of the mating cavity of the oil cylinder body. For easy disassembly, T-shaped handles for easy hand-holding are provided on the outer sides of the left clamping member and the right clamping member.

[0033] The transition connecting member includes a support plate 41 and a ∏-shaped bracket 43 that are arranged opposite to each other up and down. The support plate 41 is located directly below the oil cylinder body 20 and is used to adjust the relative position between the clamping member 30 and the oil cylinder body 20 to ensure that the test screw is in a clamped state. The left clamping member and the right clamping member are placed on the support plate 41. The ∏-shaped bracket 43 is fixed to the second mounting plate.

[0034] The driving unit includes a cam 442 mechanism and a driving handle 445. The cam 442 mechanism includes a cam 442 and a push rod 441 connected to the cam 442. The cam 442 is located in the middle of the ∏-shaped bracket 43. A central shaft 443 horizontally penetrates both sides of the ∏-shaped bracket 43 and the center of the cam 442.

[0035] Specifically, the support plate 41 includes a support surface and a connecting cylinder located below the support surface. The top end of the push rod 441 vertically penetrates the ∏-shaped bracket 43 and is threadedly connected to the connecting cylinder. By rotating the support surface, the length of the push rod 441 extending into the connecting cylinder can be adjusted. The driving handle 445 is fixedly connected to one end of the central shaft 443 through a bushing 444 and is used to drive the cam 442 to rotate so as to drive the push rod 441 to push upward.

[0036] A guiding support 42 is also provided between the support plate 41 and the ∏-shaped bracket 43. The push rod 441 passes through the guiding support 42 and is connected to the connecting cylinder.

[0037] When starting to work,

[0038] (1) The test screw passes through the hollow cavity of the oil cylinder body 20 from top to bottom and is placed on the support plate 41;

[0039] (2) The left clamping member and the right clamping member are respectively clamped with the lower section 13 of the test screw from both sides;

[0040] (3) Rotate the support surface adjusting push rod of the rotating pallet 41 to extend the length into the connecting cylinder (i.e., adjust the relative distance between the pallet 41 and the push rod 441 to the preset position); rotate the driving handle 445, drive the cam 442 to rotate through the central shaft 443, thereby driving the push rod 441 to push the pallet 41 upward, so that the upper tapered table of the clamping member 30 extends into the mating cavity 22 of the cylinder body 20 and closely cooperates with the cylinder body. The polyhedron structure B1 of the test screw cooperates with the polyhedron structure B2 of the cylinder body to fix the test screw; here, the processes of thread adjustment and handle rotation can be carried out alternately;

[0041] (4) Provide hydraulic oil to the stretching device to be tested. The stretching device to be tested acts on the test screw and stretches the test screw upward. At this time, the bottom of the stretching device to be tested generates a reaction force on the hydraulic piston 201 through the transition member 110, and the reaction force is transmitted to the inner cavity of the cylinder body 20 (the inner cavity of the cylinder body 20 is filled with hydraulic oil) through the hydraulic piston 201;

[0042] Obtain the first oil pressure value of the hydraulic oil provided to the stretching device to be tested. Since the cross-sectional area of the inner cavity of the cylinder of the stretching device to be tested is known, the theoretical tensile force of the stretching device to be tested can be obtained; detect the second oil pressure value of the inner cavity of the cylinder through the pressure sensor. Since the cross-sectional area of the inner cavity of the cylinder is known, the measured tensile force of the stretching device to be tested can be obtained;

[0043] (5) Compare the theoretical tensile force and the measured tensile force of the stretching device to be tested, and calibrate the stretching device to be tested.

[0044] In addition, practice has proved that a huge tensile force will be generated during the stretching process. It is difficult to ensure the stability of the screw relative to the hydraulic stretching device through gaskets and pads, which will affect the accuracy of the test results. The structure for fixing the test screw in this application relies on the structural cooperation between different components to fix the test screw at the center of the cylinder body, with good stability and simple operation.

[0045] It should be noted that when testing stretching devices of different models, different test screws need to be replaced. When replacing the test screw, rotate the driving handle 445 in the reverse direction, drive the cam 442 to rotate in the reverse direction through the central shaft 443, thereby driving the push rod 441 to lower the pallet 41, so that the upper end of the clamping member 30 is separated from the mating cavity 22 of the cylinder body 20. At this time, the upper end of the clamping member is still located in the mating cavity and cannot be disassembled from the test screw. It is necessary to rotate the support surface of the pallet 41 in the reverse direction and adjust the length of the push rod extending into the connecting cylinder so that the gap between the support surface of the pallet and the mating cavity of the cylinder body becomes larger until the clamping member can be separated from the test screw and taken out from the bottom of the cylinder body. The operation process is simple and labor-saving. In addition, when carrying out the production and processing of a series of test screws, only the diameter of the thread structure in the upper section of different test screws needs to be adjusted, the middle section size is adjusted adaptively according to the upper section, and the lower section of the test screw cooperates with the cylinder body, and the structural dimensions still remain unified.

[0046] The reason for placing the test screw through the hollow cavity of the oil cylinder body 20 from top to bottom onto the support plate 41 is to shorten the overall height of the test device. Of course, if the distance between the support plate 41 and the hollow oil cylinder is set sufficiently, the test screw can also pass through the center of the oil cylinder from bottom to top.

[0047] The test equipment of the present application is used to test a tensioner of model HSR2, and three groups of test data are obtained, as shown in Table 1. Through comprehensive calculation of the three groups of data, the theoretical pressure and measured tensile force under different set pressures are obtained, as shown in Table 2. It can be seen that the test equipment disclosed in the present application has obvious effects in realizing the stability of the test screw and the tensile device to be tested, can effectively eliminate the adverse effects brought by the external environment during the stretching process, the test average error is within 1 percentage point, and the test accuracy is high.

[0048] Table 1

[0049]

[0050] Table 2

[0051]

[0052] As described above, one or more embodiments are provided in combination with specific contents, and it is not determined that the specific implementation of the present application is only limited to these descriptions. Any method, structure, etc. similar or identical to the present application, or any technical deduction or replacement made under the premise of the concept of the present application should be regarded as the protection scope of the present application.

Claims

1. A test device for a hydraulic stretcher, comprising: A hollow oil cylinder, which includes a cylinder body and a hydraulic piston that slides up and down relative to the cylinder body; The cylinder body is fixedly installed on a first mounting plate; a hollow cavity is provided at the center of the cylinder body; A pressure sensor, which is used to detect the oil pressure value inside the cylinder body; A test screw rod, which passes through the hollow cavity of the cylinder body. The upper section of the test screw rod extends upward out of the hollow oil cylinder and is connected to the stretcher to be tested. The lower section of the test screw rod extends downward out of the hollow oil cylinder. Multiple grooves are provided on the lower section of the test screw rod. A circle near the lower end of the hollow cavity of the cylinder body is designed as a polyhedron structure B2 with a regular polygon cross-section. A circle of the lower section of the test screw rod is set as a polyhedron structure B1 with a regular polygon cross-section. The polyhedron structure B1 is connected in a matching manner with the polyhedron structure B2; A clamping member, which is detachably connected to the lower section of the test screw rod. The clamping member includes a left clamping part and a right clamping part that cooperate with each other. Raised parts corresponding to the grooves on the lower section of the test screw rod are provided on the inner walls of the left clamping part and the right clamping part. The left clamping part and the right clamping part enclose and are clamped with the lower section of the test screw rod; the clamping member cooperates with the cylinder body to fix the test screw rod; A support plate, which is located directly below the cylinder body; a driving unit, which acts below the support plate and is used to adjust the distance between the support plate and the cylinder body. The upper surface of the support plate acts on the clamping member to drive the clamping member to closely cooperate with or move up and down away from the cylinder body.

2. The test equipment for a hydraulic tensioner according to claim 1, characterized in that T-shaped handles for easy hand-holding are provided on the outer surfaces of the left clamping part and the right clamping part.

3. The testing device for a hydraulic tensioner according to claim 1, characterized in that, An arc transition section A1 is formed at the transition between the upper section and the middle section of the test screw rod, and the transition between the middle section and the lower section of the test screw rod is an arc transition section A2 with a gradually increasing diameter.

4. The test device for a hydraulic tensioner according to claim 1, characterized in that, The driving unit includes a cam mechanism and a driving handle. The cam mechanism includes a cam and a push rod connected to the cam; the top end of the push rod is threadedly connected to the support plate.

5. The testing device for a hydraulic stretcher according to claim 4, characterized in that, The support plate includes a support surface and a connecting cylinder located below the support surface; the top end of the push rod is threadedly connected to the connecting cylinder, and by rotating the support surface, the length of the push rod extending into the connecting cylinder can be adjusted.

6. The test device for a hydraulic tensioner according to claim 5, characterized in that, It also includes a second mounting plate and a ∏-shaped bracket fixedly connected to the second mounting plate; The top end of the push rod vertically penetrates through the ∏-shaped bracket and is threadedly connected to the connecting cylinder; the cam is located in the middle of the ∏-shaped bracket. A central shaft horizontally penetrates through the ∏-shaped bracket and the center of the cam; a driving handle is fixedly connected to one end of the central shaft through a bushing and is used to drive the cam to rotate so as to drive the push rod to push upward.

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