Device and method for measuring pre-tightening axial force of installed bolt

Abstract

The invention belongs to the technical field of mechanical part assembly, and discloses a pre-tightening axial force measuring device and a pre-tightening axial force measuring method for an installed bolt. The device comprises a tensioner and a displacement detection piece, and the tensioner can be connected to a to-be-measured piece and a power source; the displacement detection piece is arranged on any side of the stretcher, and the displacement detection piece is used for detecting the displacement stretching distance of the to-be-measured piece; the tensioner is configured to be capable of stretching the to-be-measured piece, and stopping stretching and providing a stretching force value when the displacement detection piece detects that the to-be-measured piece has a sudden displacement change. According to the pre-tightening axial force measuring device for the installed bolt, the pre-tightening axial force of the assembled bolt can be measured, the measuring precision is high, and the reliability and the consistency of the assembled bolt are improved.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical parts assembly, and in particular to a device and method for measuring the pre-tightening axial force of installed bolts. Background Art

[0002] In the assembly process of mechanical devices such as gearboxes, hydraulic tensioners are often used to tighten the bolts to ensure that the tightening of the bolts meets the design requirements. Specifically, the bolts with assembled nuts are tightened and fixed through a hydraulic source, the bolts are stretched to a preset length under hydraulic pressure, and then the bolts inside the hydraulic tensioner are twisted through the opening reserved by the hydraulic tensioner to achieve tightening between the bolts and the assembled nuts.

[0003] However, the above-mentioned bolt and nut tightening and assembly process is uncontrollable, and it is impossible to determine whether the pre-tightening axial force of the bolt meets the design requirements after the bolt is installed. Therefore, the tightening forces of multiple bolts installed on the same assembly plane are often different, resulting in uneven stress distribution on the plane, causing sealing problems and consistency problems, such as oil leakage in the gearbox. Therefore, in the prior art, when tightening and assembling the gearbox through a hydraulic tensioner, it is necessary to stretch the same bolt multiple times to ensure that the stretching distance meets the standard, so as to achieve the same pre-tightening axial force for each bolt, which will result in low production efficiency.

[0004] Therefore, there is an urgent need for a preload axial force measuring device and a measuring method for installed bolts to solve the above technical problems. Summary of the invention

[0005] An object of the present invention is to provide a preload axial force measuring device for installed bolts, which can measure the preload axial force of the assembly bolts with high measurement accuracy, thereby improving the reliability and consistency of the assembly bolts.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] The device for measuring the preload force of installed bolts consists of:

[0008] A stretcher, the stretcher can be connected to the object to be measured, and the stretcher can be connected to a power source;

[0009] A displacement detection member, which is disposed on either side of the stretcher and is used to detect the displacement stretching distance of the piece to be measured;

[0010] The stretcher is configured to stretch the piece to be measured, and stop stretching and provide a stretching force value when the displacement detection component detects a sudden displacement change of the piece to be measured.

[0011] Optionally, the stretcher includes a shell and a stretching member, wherein the stretching member is disposed through the shell and can be connected to the workpiece to be measured to drive the workpiece to be measured to be stretched.

[0012] Optionally, the displacement detection member is detachably connected to the housing or the assembly end surface of the piece to be measured, and the displacement detection member is used to detect the displacement change of the piece to be measured; or,

[0013] The displacement detecting member is detachably connected to the tensile member or the member to be measured, and the displacement detecting member is used to detect the displacement change of the tensile member or the member to be measured.

[0014] Optionally, the displacement detecting member is detachably connected to the housing or the assembly end surface, and the displacement detecting member is arranged opposite to the assembly nut of the piece to be measured to detect the displacement change of the assembly nut; or

[0015] The displacement detecting member is detachably connected to the housing or the assembly end surface. A detection sheet is provided on the piece to be measured. The displacement detecting member is arranged opposite to the detection sheet to detect displacement changes of the detection sheet.

[0016] Optionally, the detection piece is fixedly disposed on the assembly bolt of the piece to be measured; or the detection piece is fixedly disposed on the end surface of the assembly nut; or the detection piece is vertically disposed on the outer periphery of the assembly nut.

[0017] Optionally, the displacement detecting member is detachably connected to the tensile member or the member to be measured, and the displacement detecting member is arranged opposite to the assembly end face of the member to be measured to detect the relative displacement change between the tensile member and the assembly end face, or to detect the relative displacement change between the member to be measured and the assembly end face; or,

[0018] The above-mentioned displacement detection member can be detachably connected to the above-mentioned stretching member or the above-mentioned member to be measured. The above-mentioned displacement detection member is arranged opposite to any side wall of the above-mentioned shell along the movement direction of the above-mentioned stretching member to detect the relative displacement change between the above-mentioned stretching member and any side wall of the above-mentioned shell along the movement direction of the above-mentioned stretching member, or to detect the relative displacement change between the above-mentioned member to be measured and any side wall of the above-mentioned shell along the movement direction of the above-mentioned stretching member.

[0019] Optionally, a fixing seat is provided at one end of the displacement detecting member away from the detecting end, and the fixing seat is detachably connected to any side of the stretcher.

[0020] Optionally, the fixing seat and the stretcher are magnetically connected, threadedly connected, limit-connected or clamped.

[0021] Optionally, a controller is further included, and the power source and the displacement detection member are both electrically connected to the controller, and the controller is used to control and receive measurement information of the displacement detection member, and to control the opening or closing of the power source.

[0022] Another object of the present invention is to provide a method for measuring the preload axial force of an installed bolt, which can measure the preload axial force of the assembly bolt with high measurement accuracy, thereby improving the reliability and consistency of the assembly bolt.

[0023] To achieve this object, the present invention adopts the following technical solutions:

[0024] The method for measuring the preload axial force of an installed bolt uses the above-mentioned preload axial force measuring device for an installed bolt. The method for measuring the preload axial force of an installed bolt comprises the following steps:

[0025] S10: Install the tensioner to the assembly bolts of the piece to be measured, and install the displacement detection member to any side of the tensioner;

[0026] S20: Turn on the power source to drive the stretching member of the stretcher to move, and drive the member to be measured to move; detect the displacement change of the member to be measured or the stretching member in real time through the displacement detection member until a sudden displacement change occurs in the member to be measured or the stretching member, turn off the power source and record the stretching force of the stretcher to obtain the preload axial force of the member to be measured.

[0027] Beneficial effects of the present invention:

[0028] The present invention provides a pre-tightening axial force measuring device and method for installed bolts. By setting a tensioner on the piece to be measured, the stretching of the piece to be measured can be achieved, and the displacement change of the piece to be measured can be detected by a displacement detection part; so that when the pre-tightening axial force of the piece to be measured is measured, the tensioning part continuously applies a tensile force to the piece to be measured until the displacement detection part detects a sudden change in the displacement of the piece to be measured, and the tensile force value at this time is the pre-tightening axial force of the piece to be measured. Through the accurate measurement of the pre-tightening axial force of the installed piece to be measured, the measurement can be performed after the installation of the piece to be measured is completed, avoiding product quality problems caused by poor assembly or inconsistent pre-tightening axial forces of each piece to be measured on the same assembly end face, and improving the assembly reliability of the piece to be measured and the consistency of the piece to be measured on the same assembly end face. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the first structure of a pre-tightening axial force measuring device for an installed bolt provided in the first embodiment of the present invention;

[0030] Figure 2This is a second structural schematic diagram of the preload axial force measuring device for installed bolts provided in the first embodiment of the present invention;

[0031] Figure 3 This is a third structural schematic diagram of the preload axial force measuring device for installed bolts provided in the first embodiment of the present invention;

[0032] Figure 4 This is a fourth structural schematic diagram of the preload axial force measuring device for installed bolts provided in the first embodiment of the present invention;

[0033] Figure 5 This is a fifth structural schematic diagram of the preload axial force measuring device for installed bolts provided in the first embodiment of the present invention;

[0034] Figure 6 This is a sixth structural schematic diagram of the preload axial force measuring device for installed bolts provided in the first embodiment of the present invention;

[0035] Figure 7 This is a seventh structural schematic diagram of the preload axial force measuring device for installed bolts provided in the first embodiment of the present invention;

[0036] Figure 8 This is an eighth structural schematic diagram of the preload axial force measuring device for installed bolts provided in the first embodiment of the present invention;

[0037] Fig. 9 This is a schematic diagram of the first structure of a pre-tightening axial force measuring device for an installed bolt provided in the second embodiment of the present invention;

[0038] Fig.10 This is a second structural schematic diagram of the preload axial force measuring device for installed bolts provided in the second embodiment of the present invention.

[0039] In the figure:

[0040] 10. tensioner; 11. housing; 12. tensioning member;

[0041] 21. Displacement detection member; 22. Fixed seat;

[0042] 200, part to be measured; 210, assembly bolt; 220, assembly nut; 300, assembly end face; 400, detection piece. DETAILED DESCRIPTION

[0043] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0044] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0046] In the description of this embodiment, the terms "upper", "lower", "left", "right", etc., and the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of description and simplified operation, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0047] Refer to the following Figures 1 to 10 The device and method for measuring the pre-tightening axial force of installed bolts provided by the present invention are described.

[0048] Embodiment 1

[0049] Please refer to Figures 1 to 8 The present embodiment provides a pre-tightening axial force measuring device for installed bolts, which includes a tensioner 10 and a displacement detection member 21. The tensioner 10 can be connected to a workpiece 200 to be measured, and the tensioner 10 can be connected to a power source; the displacement detection member 21 is arranged on either side of the tensioner 10, and the displacement detection member 21 is used to detect the displacement stretching distance of the workpiece 200 to be measured; the tensioner 10 is configured to be able to stretch the workpiece 200 to be measured, and when the displacement detection member 21 detects a sudden displacement change of the workpiece 200 to be measured, the stretching is stopped and a stretching force value is provided.

[0050] It should be noted that the aforementioned object to be measured 200 includes an assembly bolt 210 and an assembly nut 220 that have been installed.

[0051] The preload axial force measuring device for installed bolts in this embodiment can achieve the stretching of the piece 200 to be measured by setting the tensioner 10 on the piece 200 to be measured, and detect the displacement change of the piece 200 to be measured by the displacement detection member 21; so that when the preload axial force of the piece 200 to be measured is measured, the tension member 12 continuously applies the tensile force to the piece 200 to be measured until the displacement detection member 21 detects that the displacement of the piece 200 to be measured has a sudden change, and the tensile force value at this time is the preload axial force of the piece 200 to be measured. Through the accurate measurement of the preload axial force of the installed piece 200 to be measured, the measurement can be performed after the piece 200 to be measured is installed, avoiding the product quality problems caused by poor assembly or inconsistent preload axial forces of each piece 200 to be measured on the same assembly end face 300, and improving the assembly reliability of the piece 200 to be measured and the consistency of the piece 200 to be measured on the same assembly end face 300.

[0052] Optionally, the power source may be a hydraulic source, which has the advantages of high flexibility, high efficiency, high stability, etc. and has a wide range of applications.

[0053] Optionally, the displacement detection member 21 is a displacement sensor, which has the advantages of good smoothness, excellent resolution, good wear resistance, long life, and high reliability.

[0054] Specifically, the stretcher 10 includes a housing 11 and a stretching member 12, wherein the stretching member 12 is disposed through the housing 11 and can be connected to the workpiece 200 to be measured, so as to drive the workpiece 200 to be measured to be stretched. When in use, the stretching member 12 can move linearly along the housing 11 through the drive of a power source, thereby applying a stretching force to the workpiece 200 to be measured, until the stretching force is not less than the preloaded axial force of the workpiece 200 to be measured, and the stretching of the workpiece 200 to be measured can be achieved.

[0055] Furthermore, the displacement detection member 21 in this embodiment can be detachably connected to the housing 11 or the assembly end face 300 of the piece to be measured 200, and the displacement detection member 21 is used to detect the displacement change of the piece to be measured 200; that is, the displacement detection member 21 is installed on a relatively fixed structure and will not undergo a large displacement, so that the displacement change of the piece to be measured 200 can be obtained by detecting these moving structures of the piece to be measured 200.

[0056] Please refer to Figure 1 and Figure 2 In some optional embodiments, the displacement detection member 21 is detachably connected to the housing 11 or the assembly end surface 300, and the displacement detection member 21 is arranged opposite to the assembly nut 220 of the piece to be measured 200 to detect the displacement change of the assembly nut 220. That is, by detecting the displacement change of the assembly nut 220, the displacement change of the piece to be measured 200 can be obtained, thereby realizing the displacement change detection function of the displacement detection member 21.

[0057] Please refer to Figures 3 to 8 In some other optional embodiments, the displacement detection member 21 is detachably connected to the housing 11 or the assembly end surface 300, and a detection sheet 400 is provided on the member to be measured 200. The displacement detection member 21 is arranged opposite to the detection sheet 400 to detect the displacement change of the detection sheet 400. That is, by detecting the displacement change of the detection sheet 400, the displacement change of the member to be measured 200 can be obtained, thereby realizing the displacement change detection function of the displacement detection member 21.

[0058] like Figure 3 and Figure 4 As shown, specifically, the detection piece 400 is fixedly arranged on the assembly bolt 210 of the part to be measured 200. By fixedly connecting the detection piece 400 and the assembly bolt 210, the displacement of the detection piece 400 can be equivalent to the displacement of the assembly bolt 210 in the part to be measured 200, so that the displacement detection part 21 can detect the displacement change of the part to be measured 200 by detecting the displacement change of the detection piece 400.

[0059] Or, if Figure 5 and Figure 6 As shown, the detection piece 400 is fixedly arranged on the end face of the assembly nut 220; such arrangement makes the detection piece 400 parallel and fixed to the assembly nut 220, and the displacement of the detection piece 400 is equivalent to the displacement of the assembly nut 220 of the piece to be measured 200, so that the displacement detection piece 21 can detect the displacement change of the piece to be measured 200 by detecting the displacement change of the detection piece 400.

[0060] Or, if Figure 7 and Figure 8 As shown, the detection piece 400 is vertically arranged on the outer periphery of the assembly nut 220; such arrangement enables the detection piece 400 to be fixedly connected to the assembly nut 220 and the plane of the detection piece 400 to be parallel to the end face of the assembly nut 220, so that the displacement of the detection piece 400 can be equal to the displacement of the assembly nut 220 of the piece to be measured 200, thereby realizing the detection of the displacement change of the piece to be measured 200 by the displacement detection piece 400.

[0061] Of course, the detection piece 400 is extended out of the stretcher 10, and a through hole needs to be opened on the corresponding tooling, and the through hole extends through the movement direction of the workpiece 200 to avoid movement interference between the detection piece 400 and the corresponding tooling.

[0062] It is understandable that the above-mentioned displacement detection members 21 are all arranged at the top of the corresponding detection end (including the assembly nut 220 and the detection sheet 400). In other embodiments, the displacement detection member 21 can also be arranged at the bottom of the corresponding detection end (including the assembly nut 220 and the detection sheet 400), and the displacement change of the measured member 200 can also be detected.

[0063] Of course, in other embodiments, the object detected by the displacement detection member 21 may also be adaptively changed according to actual needs, which is not specifically limited here.

[0064] Please refer to Figures 1 to 8 Furthermore, a fixing seat 22 is provided at one end of the displacement detecting member 21 away from the detecting end, and the fixing seat 22 is detachably connected to any side of the stretcher 10 . The fixing seat 22 is configured to carry the displacement detecting member 21 and to be connected to the stretcher 10 .

[0065] Optionally, the fixing seat 22 and the stretcher 10 are magnetically connected, threadedly connected, limitedly connected or clamped. All of the above connection methods can achieve a detachable connection between the stretcher 10 and the displacement detection member 21. Exemplarily, in this embodiment, the two are magnetically connected to facilitate disassembly and assembly.

[0066] Specifically, a plurality of magnetic elements are disposed on the fixing surface of the fixing seat 22 , and the magnetic elements are magnetically connected to the stretcher 10 to achieve a magnetic connection between the fixing seat 22 and the stretcher 10 .

[0067] Correspondingly, the housing 11 or the stretching member 12 of the stretcher 10 are both made of ferromagnetic materials to achieve the attraction of the two. Optionally, the magnetism of the stretcher 10 is opposite to the magnetism of the magnetic attraction member of the fixing seat 22, so that the stretcher 10 can be attracted to the magnetic attraction member.

[0068] Specifically, the fixing seat 22 also has a mounting surface, and a fixing groove is formed on the mounting surface for mounting and fixing the displacement detection member 21. Optionally, the displacement detection member 21 and the fixing groove are fixed by means of interference fit, snap-fit ​​or other fixed connection, which is not specifically limited here.

[0069] In this embodiment, the preload axial force measuring device for installed bolts also includes a controller, and the power source and the displacement detection member 21 are both electrically connected to the controller. The controller is used to control and receive the measurement information of the displacement detection member 21, and is used to control the opening or closing of the power source. When in use, the controller controls the power source to drive the tensioner 10 to apply a tensile force to the piece to be measured 200, and at the same time turns on the displacement detection member 21 for measurement, until the displacement detection member 21 detects a sudden change in displacement and sends a corresponding electrical signal to the controller. The controller receives the signal and controls the power source to close and obtains the tensile force signal of the tensioner 10, so that the preload axial force of the piece to be measured 200 can be obtained.

[0070] It is understandable that the controller may use a digital operation electronic system such as a PLC (Programmable Logic Controller) to perform the above control and signal reception. This is common knowledge and will not be elaborated here.

[0071] Since the hydraulic oil in the oil cylinder will generate heat during the use of the tensioner 10, the working efficiency of the tensioner 10 will be reduced, the energy loss will be increased, and the service life of the tensioner 10 will be affected. Therefore, in this embodiment, the preload axial force measuring device for the installed bolts also includes a temperature detection component and a pressure detection component, which are both arranged in the oil cylinder of the tensioner 10 to detect the temperature of the hydraulic oil, realize real-time monitoring of the temperature and pressure of the hydraulic oil, and avoid the influence on the service life of the tensioner 10 caused by using the tensioner 10 under excessively high oil temperature and oil pressure.

[0072] Furthermore, the preload axial force measuring device for installed bolts is also equipped with a cooling structure, which is arranged at the supply pipeline of the hydraulic oil to cool the hydraulic oil.

[0073] It is understandable that the cooling structure can be a semiconductor cooling structure, a radiator, a liquid cooling structure, etc., as long as it can achieve heat exchange and cooling of the hydraulic oil, and no specific limitation is made here.

[0074] The present embodiment also provides a method for measuring the pre-tightening axial force of an installed bolt, which uses the pre-tightening axial force measuring device for an installed bolt as described in any of the above-mentioned schemes, and the method for measuring the pre-tightening axial force of an installed bolt includes the following steps: S10: installing the assembly bolt 210 of the tensioner 10 to the part to be measured 200, and installing the displacement detection component 21 to either side of the tensioner 10; S20: turning on the power source to drive the tensioning component 12 of the tensioner 10 to move, and drive the part to be measured 200 to move; detecting the displacement change of the part to be measured 200 or the tensioning component 12 in real time through the displacement detection component 21 until a sudden displacement change occurs in the part to be measured 200 or the tensioning component 12, turning off the power source and recording the tensioning force of the tensioner 10 to obtain the pre-tightening axial force of the part to be measured 200.

[0075] The method for measuring the preload axial force of an installed bolt can detect the preload axial force of the installed part 200 to be measured by using a preload axial force measuring device for the installed bolt, thereby determining whether the installation of the part 200 to be measured meets the requirements, thereby improving the reliability and consistency of the installation of the part 200 to be measured.

[0076] Embodiment 2

[0077] This embodiment provides a device and method for measuring the preload axial force of an installed bolt. The difference between this embodiment and the first embodiment is that the installation position of the displacement detection member 21 is different.

[0078] Please refer to Fig. 9 and Fig.10 Specifically, the displacement detecting member 21 is detachably connected to the tensile member 12 or the member to be measured 200. The displacement detecting member 21 is used to detect the displacement change of the tensile member 12 or the member to be measured 200, that is, the displacement detecting member 21 is installed in a moving structure. By detecting the displacement change between the tensile member 12 and other relatively fixed structures, the displacement change of the member to be measured 200 can be obtained.

[0079] Please refer to Fig. 9 In some optional embodiments, the displacement detecting member 21 is detachably connected to the tensile member 12, and the displacement detecting member 21 is arranged relative to the assembly end face 300 of the member to be measured 200 to detect the relative displacement change between the tensile member 12 and the assembly end face 300, so as to obtain the displacement change of the member to be measured 200, thereby realizing the displacement change detection function of the displacement detecting member 21.

[0080] Alternatively, the displacement detection member 21 can be detachably connected to the workpiece 200 to be measured, and the displacement detection member 21 is arranged relative to the assembly end face 300 of the workpiece 200 to be measured, so as to detect the relative displacement change between the workpiece 200 to be measured and the assembly end face 300, thereby realizing the displacement change detection function of the displacement detection member 21. Of course, the displacement detection member 21 can also be supported by arranging a bearing structure on the workpiece 200 to be measured, so that the displacement detection member 21 can detect the relative displacement change between the workpiece 200 to be measured and the assembly end face 300. For details, please refer to Figure 2 , Figure 4 , Figure 6 and Figure 8 , the displacement detection member 21 is arranged at the position of the detection piece 400 or the assembly nut 220 and a corresponding detection structure is added to the assembly end surface 300 .

[0081] Please refer to Fig.10 In some other optional embodiments, the displacement detecting member 21 is detachably connected to the stretching member 12, and the displacement detecting member 21 is arranged opposite to any side wall of the shell 11 along the movement direction of the stretching member 12 to detect the relative displacement change between the stretching member 12 and any side wall of the shell 11 along the movement direction of the stretching member 12, so as to obtain the displacement change of the measured member 200, thereby realizing the displacement change detection function of the displacement detecting member 21.

[0082] Alternatively, the displacement detection member 21 can be detachably connected to the object to be measured 200, and the displacement detection member 21 is arranged opposite to any side wall of the housing 11 along the movement direction of the tensile member 12 to detect the relative displacement change between the object to be measured 200 and any side wall of the housing 11 along the movement direction of the tensile member 12, so as to obtain the displacement change of the object to be measured 200, thereby realizing the displacement change detection function of the displacement detection member 21. For details, please refer to Figure 1 , the displacement detection member 21 can be set at the position of the assembly nut 220.

[0083] Of course, the displacement detection member 21 can also be supported by providing a bearing structure on the workpiece 200 to be measured, and the detection structure is provided on the housing 11, and the detection structure is provided in parallel with any side wall of the housing 11 along the movement direction of the tensile member 12, and the two are provided oppositely, so that the displacement detection member 21 can detect the relative displacement change between the workpiece 200 to be measured and the assembly end face 300. For details, please refer to Figure 3 , Figure 5 and Figure 7 , just swap the positions of the displacement detection member 21 and the detection sheet 400.

[0084] Of course, in other embodiments, the object detected by the displacement detection member 21 may also be adaptively changed according to actual needs, which is not specifically limited here.

[0085] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A device for measuring the preload force of installed bolts, characterized in that: include: A stretcher (10), the stretcher (10) being connectable to the object to be measured (200), and the stretcher (10) being connectable to a power source; a displacement detection member (21), the displacement detection member (21) being arranged on either side of the stretcher (10), the displacement detection member (21) being used to detect the displacement stretching distance of the object to be measured (200); The stretcher (10) is configured to stretch the object to be measured (200), and to stop stretching and provide a stretching force value when the displacement detection element (21) detects a sudden displacement change of the object to be measured (200).

2. The preload axial force measuring device for installed bolts according to claim 1, characterized in that: The stretching device (10) comprises a housing (11) and a stretching member (12); the stretching member (12) is disposed through the housing (11) and can be connected to the object to be measured (200) to drive the object to be measured (200) to be stretched.

3. The preload axial force measuring device for installed bolts according to claim 2, characterized in that: The displacement detection member (21) is detachably connected to the housing (11) or the assembly end surface (300) of the object to be measured (200), and the displacement detection member (21) is used to detect the displacement change of the object to be measured (200); or, The displacement detection member (21) is detachably connected to the stretching member (12) or the member to be measured (200), and the displacement detection member (21) is used to detect displacement changes of the stretching member (12) or the member to be measured (200).

4. The preload axial force measuring device for installed bolts according to claim 3, characterized in that: The displacement detection member (21) is detachably connected to the housing (11) or the assembly end surface (300), and the displacement detection member (21) is arranged opposite to the assembly nut (220) of the object to be measured (200) to detect the displacement change of the assembly nut (220); or The displacement detection member (21) is detachably connected to the housing (11) or the assembly end surface (300); a detection sheet (400) is provided on the object to be measured (200); the displacement detection member (21) and the detection sheet (400) are arranged opposite to each other to detect displacement changes of the detection sheet (400).

5. The preload axial force measuring device for installed bolts according to claim 4, characterized in that: The detection piece (400) is fixedly arranged on the assembly bolt (210) of the object to be measured (200); or the detection piece (400) is fixedly arranged on the end surface of the assembly nut (220); or the detection piece (400) is vertically arranged on the outer periphery of the assembly nut (220).

6. The preload axial force measuring device for installed bolts according to claim 3, characterized in that: The displacement detection member (21) is detachably connected to the tensile member (12) or the member to be measured (200), and the displacement detection member (21) is arranged opposite to the assembly end surface (300) of the member to be measured (200) to detect the relative displacement change between the tensile member (12) and the assembly end surface (300), or to detect the relative displacement change between the member to be measured (200) and the assembly end surface (300); or, The displacement detection member (21) is detachably connected to the stretching member (12) or the member to be measured (200); the displacement detection member (21) is arranged opposite to any side wall of the housing (11) along the moving direction of the stretching member (12) to detect the relative displacement change between the stretching member (12) and any side wall of the housing (11) along the moving direction of the stretching member (12), or to detect the relative displacement change between the member to be measured (200) and any side wall of the housing (11) along the moving direction of the stretching member (12).

7. The preload axial force measuring device for installed bolts according to claim 1, characterized in that: A fixing seat (22) is provided at one end of the displacement detection member (21) away from the detection end, and the fixing seat (22) is detachably connected to any side of the stretcher (10).

8. The preload axial force measuring device for installed bolts according to claim 7, characterized in that: The fixing seat (22) and the stretcher (10) are magnetically connected, threadedly connected, position-limited connected or clamped.

9. The preload axial force measuring device for installed bolts according to any one of claims 1 to 8, characterized in that: It also includes a controller, the power source and the displacement detection element (21) are both electrically connected to the controller, and the controller is used to control and receive measurement information of the displacement detection element (21), and to control the opening or closing of the power source.

10. A method for measuring the preload axial force of an installed bolt, characterized in that: Using the preload axial force measuring device for an installed bolt according to any one of claims 1 to 9, the preload axial force measuring method for an installed bolt comprises the following steps: S10: Installing the tensioner (10) to the assembly bolts (210) of the object to be measured (200), and installing the displacement detection element (21) to either side of the tensioner (10); S20: Turn on the power source to drive the stretching member (12) of the stretcher (10) to move, and drive the piece to be measured (200) to move; detect the displacement change of the piece to be measured (200) or the stretching member (12) in real time through the displacement detection member (21) until the piece to be measured (200) or the stretching member (12) has a sudden displacement change, turn off the power source and record the stretching force of the stretcher (10), and obtain the preload axial force of the piece to be measured (200).

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