Multi-bolt tightening sequence and fitting correlation test device

Abstract

The invention discloses a multi-bolt tightening sequence and fitting correlation test device, which comprises a tightening torque measuring device, a pre-tightening force measuring device, a connected piece group, a plurality of groups of tested bolts, a clamp and an information acquisition and display device. The connected piece group is positioned and fixed in the clamp, the plurality of groups of tested bolts are connected to the connected piece group, and each tested bolt comprises a screw rod and a nut which is in threaded connection with the outer circle of the screw rod. And the tightening torque measuring device is positioned above the measured bolt and is used for applying torque to the measured bolt and nut and transmitting torque force information to the information acquisition and display device. The pre-tightening force measuring device is connected with a screw rod of the bolt to be measured and is used for acquiring information of pre-tightening force borne by the screw rod and transmitting the information to the information acquisition and display device. The device provided by the invention can be used for researching and measuring the pre-tightening force change condition of other bolts caused by the change of various tightening conditions of different bolts, so that the pre-tightening force is accurately controlled, and the reliability of the connecting bolt group of the aero-engine rotor system is improved.

Description

Technical Field

[0001] The invention relates to the technical field of assembly, and in particular to a test device for correlation between tightening sequence and fit of multiple bolts. Background Art

[0002] Aiming at the common technical problems of large deviation of thread preload in traditional torque method and insufficient stability of assembly process, and facing the high-precision thread connection requirements of new generation aircraft engines, especially the service performance goals of low vibration, long life and high reliability of the whole machine, a type of aircraft engine high-pressure rotor is taken as the research object to explore the tightening process methods of key threaded fasteners and build advanced thread tightening technical standards, which is very important and urgent for model application verification. However, since the internal bolt connection of aircraft engines is not assisted by gaskets and other accessories, the tightening of adjacent bolts has relatively serious interference with the middle bolts. The existing bolt tightening test device can only test the preload of a single bolt at the same time, and cannot study the mutual interference between adjacent bolt groups.

[0003] When testing on an existing bolt tightening test bench, the test piece is first fixed on the test bench, then the bolt is inserted into the test piece, and a nut is screwed onto the bolt, and the nut is tightened by an electric tightening shaft, and finally the pre-tightening force is measured by a force sensor or an ultrasonic sensor, and a single bolt tightening curve can be obtained.

[0004] The existing test device has this defect: the traditional bolt tightening test device can only tighten a single bolt and study the relationship between torque, angle and preload. However, in flange parts, tightening a single bolt will also affect the already tightened bolts. This effect is called elastic interaction between bolts. The closer the distance between the two bolts, the greater the elastic interaction between the bolts. Therefore, it is necessary to study the mutual influence of preload between adjacent bolts or spaced bolts. However, since the internal bolt connection of the aircraft engine is not assisted by accessories such as gaskets, the tightening of adjacent bolts has a relatively serious interference with the middle bolt. The elastic interaction between bolts is an important component that affects the bolt connection of the aircraft engine. It is relatively limited to only study the influence of a single bolt on the connection. Summary of the invention

[0005] The present invention provides a multi-bolt tightening sequence and fit correlation test device to solve the technical problem that the existing bolt tightening test device can only perform a tightening test on a single bolt at the same time to test the preload force and cannot study the mutual interference between adjacent bolt groups.

[0006] The technical solution adopted by the present invention is as follows:

[0007] A test device for the correlation between tightening sequence and fit of multiple bolts, comprising: a tightening torque meter and a preload force detector, a connected component group for simulating the actual installation condition of the bolts, multiple groups of tested bolts for testing, a fixture for installing the connected component group, and an information collection and display device for displaying torque and preload force, wherein the tightening torque meter and the preload force detector are respectively connected to the information collection and display device; the fixture is fixedly supported on a test bench, the connected component group is positioned and fixed in the fixture, multiple groups of tested bolts are sequentially connected to the connected component group at intervals, and each tested bolt comprises a screw rod penetrating and connecting the connected component group, and a nut threadedly connected to the outer circle of the extended end of the screw rod extending out of the connected component group; the tightening torque meter is located above the tested bolt, and is used to apply torque to the tested bolt nut and transmit torque force information to the information collection and display device; the preload force detector is connected to the screw rod of the tested bolt, and is used to obtain preload force information on the screw rod and transmit it to the information collection and display device.

[0008] Furthermore, the connected parts group includes an upper connected part, a middle connected part and a lower connected part which are stacked up and down in sequence, the screw of the bolt to be tested is threadedly penetrated from bottom to top to connect the lower connected part, the middle connected part and the upper connected part and then extends out, and the nut thread is installed on the outer circle of the extended end of the screw; the clamp includes a clamp body and multiple groups of fasteners, the clamp body is provided with a receiving groove for accommodating and positioning the connected parts group, the connected parts group is positioned and installed in the receiving groove, and is detachably fixed to the clamp body by multiple groups of fasteners.

[0009] Furthermore, the connected member group is a sector segment formed by circumferentially cutting a circular ring; and the accommodating groove is a sector groove adapted to the sector segment.

[0010] Furthermore, the clamp body includes a mounting plate and two legs connected to both sides of the mounting plate; the accommodating groove is formed by concave processing on the upper surface of the mounting plate, and the bottom of the accommodating groove is also provided with a window that is penetrated so that the bolt head of the screw is exposed from the bottom of the mounting plate; the accommodating groove and the window are both notched grooves formed by cutting a notch in the axial direction of the mounting plate so that part of the connected component group is exposed.

[0011] Furthermore, the preload force detector includes an ultrasonic preload force sensor for measuring preload force information using ultrasonic waves, and an ultrasonic probe holder for installing the ultrasonic preload force sensor; the ultrasonic preload force sensor is mounted on the ultrasonic probe holder, and the ultrasonic probe holder is connected to the bolt head of the screw so that the ultrasonic preload force sensor presses against the end face of the bolt head, and the output end signal line of the ultrasonic preload force sensor passes through the ultrasonic probe holder and is connected to the information acquisition and display device.

[0012] Furthermore, the ultrasonic probe holder is a magnetic part with magnetism, on which is provided a first inner groove formed by the inner concave of the top surface, a first mounting hole formed by the inner concave of the bottom of the first inner groove, and a first wire groove processed through the bottom of the first mounting hole; the first inner groove is sleeved and connected to the bolt head of the screw; the ultrasonic preload force sensor is positioned and installed in the first mounting hole, and its output end signal line passes through the first wire groove and then extends out to connect to the information acquisition and display device.

[0013] Furthermore, the preload force detector includes a force sensor installed on the outer circle of the screw to obtain preload force information. The force sensor is installed in the connected component group, and its output end signal line passes through the connected component group and is connected to the information collection and display device.

[0014] Furthermore, the middle connected part is provided with a second inner groove and a second wire groove formed by inward concave processing on its surface, and a second mounting hole is formed by inward concave processing on the bottom of the second inner groove and is penetrated, and the second wire groove connects the second inner groove; the force sensor is positioned and installed in the second inner groove, and its output end signal line is accommodated in the second wire groove, and is connected to the information collection and display device after being transmitted out of the second wire groove; the screw rod of the bolt to be measured is passed through the second inner groove and the second mounting hole.

[0015] Furthermore, the tightening torque meter includes an electric tightening shaft, a dynamic torque sensor and a nut tightening sleeve which are connected in sequence; the information acquisition and display device is a sensor acquisition card, and the dynamic torque sensor and the preload force meter are respectively connected to the sensor acquisition card.

[0016] Furthermore, the tightening torque meter includes a torque wrench and a nut tightening sleeve connected in sequence; the information collection and display device includes a first digital display screen built into the torque wrench and an external second digital display screen, and the preload force meter is connected to the second digital display screen.

[0017] The present invention has the following beneficial effects:

[0018] When the test device of the present invention is used to perform a bolt tightening test, the pre-tightening force changes of other bolts (reference bolts in the present invention) caused by changes in various tightening conditions of different bolts can be studied and measured by using a separate tightening method of sequentially tightening a single variable bolt (studying the influence of tightening a single variable bolt on the change of the pre-tightening force of the reference bolt), or a parallel tightening method of sequentially and simultaneously tightening a plurality of variable bolts (studying the influence of simultaneous tightening of a plurality of variable bolts on the change of the pre-tightening force of the reference bolt). This solves the technical problem in the prior art that only a single bolt can be tightened at the same time and the mutual interference between adjacent bolt groups cannot be studied. The pre-tightening force of the bolt is precisely controlled, and the reliability of the connecting bolt group of the aircraft engine rotor system is improved, which is of great significance to ensuring the reliability of the threaded connection of the aircraft engine rotor.

[0019] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0021] Figure 1 It is a partial cross-sectional front view structural schematic diagram of Example 1 of a test device for correlation between tightening sequence and fit of multiple bolts of the present invention;

[0022] Figure 2 yes Figure 1 Schematic diagram of the spatial structure of the middle fixture body;

[0023] Figure 3 yes Figure 1 A schematic diagram of the partial cross-sectional spatial structure of the ultrasound probe holder;

[0024] Figure 4 It is a partial cross-sectional front view structural schematic diagram of Example 2 of the multi-bolt tightening sequence and fit correlation test device of the present invention;

[0025] Figure 5 yes Figure 4 A schematic diagram of the top view of the structure of the middle-layer connected parts;

[0026] Figure 6 yes Figure 5 AA section structural diagram;

[0027] Figure 7 This is a partial cross-sectional front view structural diagram of Example 3 of the multi-bolt tightening sequence and fit correlation test device of the present invention.

[0028] 1. Tightening torque meter; 11. Electric tightening shaft; 12. Dynamic torque sensor; 13. Nut tightening sleeve; 14. Torque wrench; 2. Preload force detector; 21. Ultrasonic preload force sensor; 22. Ultrasonic probe holder; 221. First inner groove; 222. First mounting hole; 223. First wire groove; 23. Force sensor; 3. Connected parts group; 31. Upper connected parts; 32. Middle connected parts; 321. Second inner groove; 322. Second mounting hole; 323. Second wire groove; 33. Lower connected parts; 4. Bolt to be measured; 41. Screw; 42. Nut; 5. Clamp; 51. Clamp body; 511. Accommodating groove; 512. Window; 52. Fastener; 6. Information acquisition and display device; 61. Sensor acquisition card; 62. Second digital display screen. DETAILED DESCRIPTION

[0029] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0030] Reference Figure 1 , Figure 4 and Figure 7 The preferred embodiment of the present invention provides a test device for the correlation between tightening sequence and fit of multiple bolts, comprising: a tightening torque meter 1 and a preload force detector 2, a connected component group 3 for simulating the actual installation condition of the bolts, multiple groups of tested bolts 4 for testing, a fixture 5 for installing the connected component group 3, and an information collection and display device 6 for displaying torque and preload force, and the tightening torque meter 1 and the preload force detector 2 are respectively connected to the information collection and display device 6. The fixture 5 is fixedly supported on the test bench, the connected component group 3 is positioned and fixed in the fixture 5, and multiple groups of tested bolts 4 are sequentially connected to the connected component group 3 at intervals, and each tested bolt 4 includes a screw rod 41 penetrating and connecting the connected component group 3, and a nut 42 threadedly connected to the outer circle of the extended end of the screw rod 41 extending out of the connected component group 3. The tightening torque meter 1 is located above the tested bolt 4, and is used to apply torque to the nut 42 of the tested bolt 4 and transmit torque information to the information collection and display device 6. The preload force detector 2 is connected to the screw rod 41 of the bolt 4 to be measured, so as to obtain the preload force information of the screw rod 41 and transmit it to the information acquisition and display device 6 .

[0031] When the test device of the present invention is used to perform a bolt tightening test, the connected component group 3 is first installed and positioned in the fixture 5, and then a plurality of tested bolts 4 are sequentially connected to the connected component group 3 at intervals to simulate the actual installation condition of the bolts, and during the connection process of the tested bolts 4, the preload force meter 2 is connected to one of the tested bolts 4 so that the tested bolt 4 forms a reference bolt, and the remaining tested bolts 4 form variable bolts; then the tightening torque meter 1 and the preload force meter 2 are connected to the information collection and display device 6, and the preload force meter 2 is turned on. Then start the test. First, connect the tightening torque meter 1 to the nut of the reference bolt and gradually apply the target torque T. When the target torque T is reached, the target torque T and the preload force F are displayed and recorded through the information acquisition and display device 6. Then, remove the tightening torque meter 1 from the nut of the reference bolt and connect it to the nut of one of the variable bolts. Then, start the tightening torque meter 1 to apply the target torque T. When the target torque T is reached, the target torque T and the preload force F1 are displayed and recorded through the information acquisition and display device 6 (because the preload force detector 2 is always connected to the reference bolt, F1 is the preload force of the reference bolt). Then, the remaining variable bolts are measured in the same way. bolts to obtain target torque T and preload F2, target torque T and preload F3, ... target torque T and preload Fn; or, remove the tightening torque meter 1 from the nut of the reference bolt and then connect it to the nuts of multiple variable bolts at the same time, then start the tightening torque meter 1 to apply the target torque T, and when the target torque T is reached, display and record the target torque T and preload F1 through the information acquisition and display device 6, and then measure the remaining variable bolts in the same way (at least two groups of variable bolts are connected for each measurement) to obtain target torque T and preload F2, target torque T and preload F3, ... target torque T and preload Fm.

[0032] When the test device of the present invention is used to perform a bolt tightening test, the pre-tightening force changes of other bolts (reference bolts in the present invention) caused by changes in various tightening conditions of different bolts can be studied and measured by using a separate tightening method of sequentially tightening a single variable bolt (studying the influence of tightening a single variable bolt on the change of the pre-tightening force of the reference bolt), or a parallel tightening method of sequentially and simultaneously tightening a plurality of variable bolts (studying the influence of simultaneous tightening of a plurality of variable bolts on the change of the pre-tightening force of the reference bolt). This solves the technical problem in the prior art that only a single bolt can be tightened at the same time and the mutual interference between adjacent bolt groups cannot be studied. The pre-tightening force of the bolt is precisely controlled, and the reliability of the connecting bolt group of the aircraft engine rotor system is improved, which is of great significance to ensuring the reliability of the threaded connection of the aircraft engine rotor.

[0033] Alternatively, if Figure 1 , Figure 4 and Figure 7As shown, the connected parts group 3 includes an upper connected part 31, a middle connected part 32 and a lower connected part 33 which are stacked up in sequence, and a screw rod 41 of the bolt 4 to be tested is threadedly penetrated from bottom to top to connect the lower connected part 33, the middle connected part 32 and the upper connected part 31 and then extends out, and a nut 42 is threadedly mounted on the outer circle of the extended end of the screw rod 41.

[0034] Recombination Figure 2 As shown, the fixture 5 includes a fixture body 51 and multiple sets of fasteners 52. The fixture body 51 is provided with a receiving groove 511 for accommodating and positioning the connected component group 3. The connected component group 3 is positioned and installed in the receiving groove 511, and is detachably fixed to the fixture body 51 by multiple sets of fasteners 52. During installation, the upper connected component 31, the middle connected component 32, and the lower connected component 33 are first fixed and overlapped using fasteners 52, and then multiple pairs of tested bolts 4 are installed on the connected component group 3, and the nuts 42 are pre-tightened by manual tightening. Since the positioning tolerance of the bolt holes is relatively high, the fasteners 52 should be used first. In the present invention, fastening screws are used to install and position, and then other tested bolts 4 are installed. Finally, the entire connected component group 3 is installed on the fixture 5 using fastening screws. In other embodiments, the form of the fixture 5 is not limited to the connection method shown in the present application, and a fixture that can grab multiple bolt simulation parts, such as a bench vise and a three-jaw chuck, can also be used.

[0035] Preferably, if Figure 2 and Figure 5 As shown, the connected component group 3 is a fan-shaped segment formed by circumferential cutting of a circular ring. The accommodating groove 511 is a fan-shaped groove adapted to the fan-shaped segment. During design, in order to study the elastic interaction between flange bolts, the best way is to manufacture a flange simulation part, and then conduct a simulated tightening experiment on the simulation part to analyze the influence of the elastic interaction between the bolts. However, for large-diameter flanges, the cost of directly processing the simulation part is extremely high, and the structure of some flanges is complex. Simulation experiments after processing will cause unnecessary waste. Therefore, it is necessary to invent a structure that can simulate the state of tightening multiple bolts without processing the entire flange, and at the same time complete the collection requirements of preload-torque-angle, which is used to study the elastic interaction between bolts, so that the structural setting "the connected component group 3 is a fan-shaped segment formed by circumferential cutting of a circular ring" appears to solve this problem.

[0036] Specifically, when the connected component group 3 is designed, the inner diameter and outer diameter of the connected component group 3 are consistent with the inner diameter and outer diameter of the flange mounting edge, and the thickness of the connected component group 3 is the same as the thickness of the flange mounting edge, but the connected component group 3 only takes a sector shape with several bolt holes, which simplifies other structures of the flange mounting edge, retains the accuracy of the experiment, saves experimental materials and reduces costs. In other embodiments, the shape of the connected component group 3 is not limited to the sector shape, and can also be a rectangular, irregular shape, etc., which is tightened with multiple bolts on a flange, a cylinder body, etc.

[0037] Alternatively, if Figure 1-2 As shown, the clamp body 51 includes a mounting plate and two legs connected to both sides of the mounting plate. The receiving groove 511 is formed by the inner concave processing of the upper surface of the mounting plate, and the bottom of the receiving groove 511 is also provided with a window 512 that is set through, so that the bolt head of the screw rod 41 is exposed from the bottom of the mounting plate. The receiving groove 511 and the window 512 are notched grooves formed by cutting a notch in the axial direction of the mounting plate, so that the connected component group 3 is partially exposed to observe the state of the connected component group 3, and the legs are fixed by anchor bolts.

[0038] Optionally, the first embodiment of the preload force detector 2 is as follows: Figure 1 and Figure 3 As shown, the preload force detector 2 includes an ultrasonic preload force sensor 21 for measuring preload force information using ultrasonic waves, and an ultrasonic probe holder 22 for mounting the ultrasonic preload force sensor 21. The ultrasonic preload force sensor 21 is mounted on the ultrasonic probe holder 22, and the ultrasonic probe holder 22 is connected to the bolt head of the screw rod 41 so that the ultrasonic preload force sensor 21 presses against the end face of the bolt head, and the output end signal line of the ultrasonic preload force sensor 21 passes through the ultrasonic probe holder 22 and is connected to the information acquisition and display device 6.

[0039] In this option, if Figure 1 and Figure 3 As shown, the ultrasonic probe holder 22 is a magnetic part with magnetism, on which there are provided a first inner groove 221 formed by the inner concave of the top surface, a first mounting hole 222 formed by the inner concave of the bottom of the first inner groove 221, and a first wire groove 223 through-machined by the bottom of the first mounting hole 222. The first inner groove 221 is sleeved and connected to the bolt head of the screw rod 41. The ultrasonic preload force sensor 21 is positioned and installed in the first mounting hole 222, and its output end signal line passes through the first wire groove 223 and then extends out to connect to the information collection and display device 6. In this embodiment, the ultrasonic probe holder 22 tightly connects the ultrasonic preload force sensor 21 and the bolt head of the bolt 4 to be measured, ensuring real-time measurement of the preload force.

[0040] Optionally, a second embodiment of the preload force detector 2, such as Figure 4-Figure 7As shown, the preload force detector 2 includes a force sensor 23 mounted on the outer circle of the screw 41 to obtain preload force information. The force sensor 23 is mounted in the connected component group 3, and its output signal line passes through the connected component group 3 and is connected to the information collection and display device 6.

[0041] In this option, if Figure 5-6 As shown, the middle layer connected member 32 is provided with a second inner groove 321 and a second wire groove 323 formed by the inner concave processing of the surface thereof, and a second mounting hole 322 formed by the inner concave processing of the groove bottom of the second inner groove 321 and penetrating therethrough, and the second wire groove 323 is connected to the second inner groove 321. The force sensor 23 is positioned and installed in the second inner groove 321, and its output end signal line is accommodated in the second wire groove 323, and is connected to the information acquisition and display device 6 after passing through the second wire groove 323. The screw of the bolt 4 to be measured is provided with the second inner groove 321 and the second mounting hole 322. Preferably, as Figure 5-6 As shown, in the second embodiment of the preload force meter 2, a force sensor 23 is installed on the outer circle of the screw rod 41 of each group of measured bolts 4, and the middle connected part 32 is correspondingly provided with a second inner groove 321, a second mounting hole 322 and a second wire groove 323, so that when replacing a different reference bolt for measurement, there is no need to disassemble the connected part group 3, thereby improving the measurement efficiency and reducing the operation steps.

[0042] The second embodiment of the preload force measuring device 2 is different from the first embodiment in that: in the second embodiment, a force sensor 23 is placed in a hole on the middle layer of the connected member 32, and the force sensor 23 is connected to the information acquisition and display device 6 through the output signal line, and the preload force generated when the bolt is tightened is converted into an electrical signal through the force sensor 23, and then the electrical signal is converted into the amount of bolt preload force through the information acquisition and display device 6, so as to obtain the change amount of the reference bolt preload force during the tightening process of multiple measured bolts 4, that is, the force sensor 23 replaces the ultrasonic preload force sensor 21 to measure the preload force of the bolt. Compared with the first embodiment, the second embodiment has the following disadvantages:

[0043] 1) The middle layer connected member 32 needs to be designed with a second inner groove 321 for installing the force sensor 23, so the design of the middle layer connected member 32 is relatively complicated;

[0044] 2) Due to the size limitation of the force sensor 23, the sizes of the bolt 4, the upper connected part 31, the middle connected part 32, and the lower connected part 33 cannot be too small, so too small bolts and flange mounting edges cannot be measured;

[0045] 3) The force sensor 23 needs to be installed in the middle-layer connected component 32 in advance. For a multi-bolt structure, there must be as many force sensors 23 as there are bolts 4 to be tested. Compared with the ultrasonic preload force sensor 21, the experimental cost is increased.

[0046] Compared with the first embodiment, the second embodiment has the following advantages:

[0047] The multiple force sensors 23 simultaneously measure the forces of the multiple bolts 4 to be measured, so that the comparison is more accurate and comprehensive.

[0048] Optionally, tighten the first embodiment of the torque meter 1, such as Figure 1 and Figure 4 As shown, the tightening torque meter 1 includes an electric tightening shaft 11, a dynamic torque sensor 12 and a nut tightening sleeve 13 connected in sequence. In this optional solution, the inner surface of the lower end of the nut tightening sleeve 13 is consistent with the outer surface of the nut 42 to be measured, the lower end of the nut tightening sleeve 13 is sleeved on the nut 42, and the upper end is connected to the output end of the electric tightening shaft 11 through a flexible coupling; the dynamic torque sensor 12 is installed between the electric tightening shaft 11 and the nut tightening sleeve 13. Adaptively, the first embodiment of the information acquisition and display device 6, such as Figure 1 and Figure 4 As shown, the information acquisition and display device 6 is a sensor acquisition card 61 , and the dynamic torque sensor 12 and the preload force detector 2 are respectively connected to the sensor acquisition card 61 .

[0049] Optionally, tighten the second embodiment of the torque meter 1, such as Figure 7 As shown, the tightening torque meter 1 includes a torque wrench 14 and a nut tightening sleeve 13 connected in sequence. Figure 7 As shown, the information collection and display device 6 includes a first digital display screen built into the torque wrench 14 and an external second digital display screen 62 , and the preload force detector 2 is connected to the second digital display screen 62 .

[0050] The second embodiment consisting of the tightening torque meter 1 and the information collection and display device 6 is different from the first embodiment consisting of the tightening torque meter 1 and the information collection and display device 6 in that:

[0051] 1) The electric tightening shaft 11 is replaced by a torque wrench 14, and the torque wrench 14 has a digital display screen, which can display the size of the tightening torque, and the tester can record the torque size when the bolt is tightened.

[0052] 2) By placing a force sensor 23 in a groove in the middle layer of the connecting member 32, the force sensor 23 is connected to the second digital display screen 62 through the output signal line. The second digital display screen 62 can directly display the size of the preload force of the force sensor 23, but cannot record the process quantity. It can only record the final value of the preload force of the force sensor 23 after each tightening step.

[0053] 3) The torque is controlled by replacing the electric tightening shaft 11 with the torque wrench 14 and the input torque is recorded. The bolt pre-tightening force value is recorded by replacing the ultrasonic pre-tightening force sensor 21 with the force sensor 23 .

[0054] Compared with the first embodiment consisting of the tightening torque meter 1 and the information collection and display device 6, the second embodiment consisting of the tightening torque meter 1 and the information collection and display device 6 has the following disadvantages:

[0055] 1) The accuracy of the torque wrench 14 is smaller than that of the electric tightening shaft 11;

[0056] 2) Data acquisition is not done through a data acquisition card, but through a first digital display screen on the torque wrench 14 and a second digital display screen 62 connected to the force sensor 23. Through the first digital display screen and the second digital display screen 62, we cannot obtain the process quantities of torque and preload during the bolt tightening process, but can only obtain the stage points of torque and preload;

[0057] 3) Similarly, the use of force sensors 23 will be limited by the size of the sensor and cannot measure too small bolts, and multiple force sensors 23 will increase the design complexity of the middle-layer connected member 32;

[0058] The second embodiment consisting of the tightening torque meter 1 and the information collection and display device 6 has the following advantages compared to the first embodiment consisting of the tightening torque meter 1 and the information collection and display device 6:

[0059] The torque wrench 14 is used to replace the electric tightening shaft 11, and the digital display screen is used to replace the data acquisition card. Although the number of force sensors 23 is increased, the total cost is still greatly reduced.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A test device for the correlation between tightening sequence and fit of multiple bolts, characterized in that: include: A tightening torque meter (1) and a preload force detector (2), a connected component group (3) for simulating the actual installation condition of bolts, a plurality of groups of tested bolts (4) for testing, a fixture (5) for installing the connected component group (3), and an information collection and display device (6) for displaying torque and preload force, wherein the tightening torque meter (1) and the preload force detector (2) are respectively connected to the information collection and display device (6); The fixture (5) is fixedly supported on the test bench, the connected component group (3) is positioned and fixed in the fixture (5), and a plurality of groups of tested bolts (4) are sequentially connected to the connected component group (3) at intervals, and each tested bolt (4) comprises a screw rod (41) penetrating and connected to the connected component group (3), and a nut (42) threadedly connected to the outer circle of the extended end of the screw rod (41) extending out of the connected component group (3); The tightening torque meter (1) is located above the bolt (4) to be tested, and is used to apply torque to the nut (42) of the bolt (4) to be tested and transmit torque force information to the information collection and display device (6); The preload force detector (2) is connected to the screw rod (41) of the bolt (4) to be measured, so as to obtain the preload force information of the screw rod (41) and transmit it to the information acquisition and display device (6).

2. The multi-bolt tightening sequence and fit correlation test device according to claim 1, characterized in that: The connected member group (3) comprises an upper connected member (31), a middle connected member (32) and a lower connected member (33) which are stacked up and down in sequence. The screw rod (41) of the bolt (4) to be tested is threadedly connected to the lower connected member (33), the middle connected member (32) and the upper connected member (31) in sequence from bottom to top and then extends out. The nut (42) is threadedly mounted on the outer circle of the extended end of the screw rod (41). The clamp (5) comprises a clamp body (51) and a plurality of sets of fasteners (52); the clamp body (51) is provided with a receiving groove (511) for receiving and positioning the connected component group (3); the connected component group (3) is positioned and installed in the receiving groove (511) and is detachably fixed to the clamp body (51) by the plurality of sets of fasteners (52).

3. The multi-bolt tightening sequence and fit correlation test device according to claim 2, characterized in that: The connected component group (3) is a fan-shaped segment formed by cutting the circular ring in the circumferential direction; The accommodating groove (511) is a fan-shaped groove adapted to the fan-shaped segment.

4. The multi-bolt tightening sequence and fit correlation test device according to claim 2, characterized in that: The clamp body (51) comprises a mounting plate and two legs supported and connected to two sides of the mounting plate; The accommodating groove (511) is formed by inwardly processing the upper surface of the mounting plate, and a window (512) is also provided through the bottom of the accommodating groove (511) so that the bolt head of the screw rod (41) is exposed from the bottom of the mounting plate; The accommodating groove (511) and the window (512) are both notched grooves formed by cutting a notch in the axial direction of the mounting plate, so that the connected component group (3) is partially exposed.

5. The multi-bolt tightening sequence and fit correlation testing device according to claim 1, characterized in that: The preload force detector (2) comprises an ultrasonic preload force sensor (21) for detecting preload force information using ultrasonic waves, and An ultrasonic probe holder (22) for mounting an ultrasonic preload force sensor (21); The ultrasonic preload force sensor (21) is mounted on the ultrasonic probe holder (22), and the ultrasonic probe holder (22) is connected to the bolt head of the screw rod (41) so that the ultrasonic preload force sensor (21) presses against the end surface of the bolt head, and the output end signal line of the ultrasonic preload force sensor (21) passes through the ultrasonic probe holder (22) and is connected to the information collection and display device (6).

6. The multi-bolt tightening sequence and fit correlation test device according to claim 5, characterized in that: The ultrasonic probe holder (22) is a magnetic member with magnetism, and is provided with a first inner groove (221) formed by an inner concave top surface, a first mounting hole (222) formed by an inner concave bottom of the first inner groove (221), and a first wire groove (223) through-machined at the bottom of the first mounting hole (222); The first inner groove (221) is sleeved and connected to the bolt head of the screw rod (41); The ultrasonic preload force sensor (21) is positioned and installed in the first installation hole (222), and the output end signal line thereof passes through the first line groove (223) and then extends out to connect to the information collection and display device (6).

7. The multi-bolt tightening sequence and fit correlation test device according to claim 2, characterized in that: The preload force detector (2) comprises a force sensor (23) mounted on the outer circle of a screw rod (41) to obtain preload force information. The force sensor (23) is mounted in a connected component group (3), and a signal line at its output end passes through the connected component group (3) and is then connected to an information acquisition and display device (6).

8. The multi-bolt tightening sequence and fit correlation testing device according to claim 7, characterized in that: The middle layer connected member (32) is provided with a second inner groove (321) and a second wire groove (323) formed by inner concave processing on its surface, and a second mounting hole (322) formed by inner concave processing on the groove bottom of the second inner groove (321) and penetrating therethrough, and the second wire groove (323) is connected to the second inner groove (321); The force sensor (23) is positioned and installed in the second inner groove (321), and the output end signal line is accommodated in the second line groove (323), and is connected to the information collection and display device (6) after being transmitted out of the second line groove (323); The screw rod of the bolt (4) to be tested is provided with a second inner groove (321) and a second mounting hole (322).

9. The multi-bolt tightening sequence and fit correlation testing device according to claim 1, characterized in that: The tightening torque meter (1) comprises an electric tightening shaft (11), a dynamic torque sensor (12) and a nut tightening sleeve (13) which are connected in sequence; The information acquisition and display device (6) is a sensor acquisition card (61), and the dynamic torque sensor (12) and the preload force detector (2) are respectively connected to the sensor acquisition card (61).

10. The multi-bolt tightening sequence and fit correlation testing device according to claim 1, characterized in that: The tightening torque meter (1) comprises a torque wrench (14) and a nut tightening sleeve (13) which are connected in sequence; The information collection and display device (6) comprises a first digital display screen built into the torque wrench (14) and an external second digital display screen (62), and the preload force detector (2) is connected to the second digital display screen (62).

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