Bolt pretightening force detection device and detection method

Abstract

The invention discloses a bolt pre-tightening force detection device and method, and belongs to the technical field of bolt pre-tightening force detection. The clamping jaw clamps the motor to drive the screw rod to rotate, the nut sleeve drives the stainless steel reed to move up and down, the detected bolt is loosened or clamped, and the clamping force is effectively controlled. When the nut sleeve moves downwards, the ultrasonic sensor is driven to move downwards, the ultrasonic sensor is pressed on the top plane of the detected bolt through the spring, elastic contact is achieved, meanwhile, the bolt is clamped by the clamping jaw, and bolt pre-tightening force detection is carried out. On the basis that the adjacent bolts serve as supporting points, walking on any path under most conditions can be achieved, and the device is simple and small in structure, quite small in needed operation space and suitable for most application scenes. According to the method, bolt pre-tightening force risk assessment indexes are established, and hidden dangers such as deviation, fluctuation, unbalance loading, overload and looseness of the whole set of bolt pre-tightening force of the detected object can be assessed according to the detection result.

Description

Technical Field

[0001] The invention relates to a bolt pre-tightening force detection device, in particular to a bolt pre-tightening force detection device and a detection method, belonging to the technical field of bolt pre-tightening force detection. Background Art

[0002] There is a large demand for high-strength bolt preload testing in industrial fields such as petrochemicals, electric power, wind power, and large steel structures. Bolt preload testing is an important means to ensure production safety and avoid accidents.

[0003] Commonly used measurement methods include torque method, angle measurement method, strain method, dynamometer method, ultrasonic detection method, etc. Among them, the electromagnetic ultrasonic detection method is the fastest growing method in recent years.

[0004] There are a huge number of industrial bolts that need to be inspected. Currently, they are generally inspected one by one manually, which is time-consuming and labor-intensive.

[0005] Now, solutions such as robotic arms and robots have been developed. However, existing technical means such as robotic arms and robots use the structural body of the object to be inspected as a support point to achieve walking and complete bolt inspection one by one. The device structure is relatively complex and the cost is high. The required operating space is large and it is not applicable in many scenarios. Therefore, a bolt preload force detection device and detection method are designed to solve the above problems. Summary of the invention

[0006] The main purpose of the present invention is to provide a bolt preload detection device and a detection method.

[0007] The purpose of the present invention can be achieved by adopting the following technical solutions:

[0008] A bolt preload force detection device comprises an angle adjustment arm set, and hinge seats are hinged at both ends of the angle adjustment arm set;

[0009] A rotating mechanism is provided between the hinge seat and the shell, for adjusting the rotating angle between the hinge seat and the shell;

[0010] A bolt clamping mechanism and an ultrasonic sensor for bolt detection are arranged inside the housing.

[0011] Preferably, the angle adjustment arm group includes a first swing arm, a second swing arm and a pitch adjustment motor. The first swing arm is hinged to the second swing arm, and the angle between the first swing arm and the second swing arm is adjusted by the pitch adjustment motor. Both ends of the first swing arm and the second swing arm are hinged with hinge seats.

[0012] Preferably, the rotating mechanism includes a rotating motor and a reduction gear. The rotating motor is installed inside the shell, the output end of the rotating motor is installed with a reduction gear and a hinge seat is installed through the reduction gear, and a swing arm motor for adjusting the hinge seat and the angle of the angle adjustment arm group is arranged on the inner side of the hinge seat.

[0013] Preferably, the clamping mechanism includes a clamping motor, a clamping hinge, a spring, a clamping claw, a nut sleeve, and a screw rod;

[0014] A claw clamping motor is installed at the top of the shell, a screw rod is installed at the output end of the claw clamping motor, and a nut sleeve is sleeved and meshed on the outside of the screw rod, a spring is installed on the outside of the nut sleeve, claws are installed at both ends of the spring, and the upper and middle parts of the claws are hinged to the bottom end of the shell.

[0015] Preferably, an ultrasonic sensor is installed in the compression spring in the bottom tube of the nut sleeve.

[0016] A method for detecting a bolt preload comprises the following steps:

[0017] Step 1: Set the number, distribution, spacing and travel path of the bolts to be inspected;

[0018] Step 2: Drive the spacing adjustment motor to adjust the spacing of the detection components to make it the same as the spacing of the bolts; determine the rotation angle and the swing arm angle;

[0019] Step 3: The detection device is placed at the initial bolt position, the motor drives the nut sleeve to move down, the claws are clamped, and the sensor moves down and presses against the top plane of the bolt;

[0020] Step 4: Use ultrasonic sensors to complete the preload force detection of the two bolts;

[0021] Step 5: Release the claw of the left component, rotate the second swing arm, rotate the hinge seat on the right, rotate the second swing arm, move the left component to the third bolt position to be tested, clamp the claw, and perform preload test;

[0022] Step 6: Determine whether the bolt inspection is completed;

[0023] Step 7: After the detection is completed, the claws of the components on both sides are loosened and the detection device is removed. If the detection is not completed, the claws of the right component are loosened, the first swing arm rotates, the left hinge seat rotates, the first swing arm rotates, the right component moves to the fourth bolt position to be detected, the claws are clamped, and the preload force detection is performed;

[0024] Step 8: Determine again whether the bolt inspection is completed. If it is completed, loosen the claws of the components on both sides and remove the inspection device. If it is not completed, proceed to step 5;

[0025] Step 9: After completion, characteristic parameter calculation and bolt preload risk assessment are performed, and a test report is automatically generated.

[0026] Beneficial technical effects of the present invention:

[0027] The present invention provides a bolt preload detection device and a detection method, wherein a claw clamping motor is fixed in a detection component housing, drives a lead screw to rotate, and drives a stainless steel spring sheet to move up and down through a nut sleeve, thereby realizing the opening and clamping of left and right claws, and is used to loosen or clamp the detected bolt; the spring sheet is divided into two pieces, an upper piece and an lower piece, and an arc-shaped middle piece, which can effectively control the clamping force and realize elastic contact between the claw and the detected bolt; the claw is an arc-shaped piece, and after clamping, the arc surface contacts at least four vertices of the hexagon of the bolt head to ensure stability; while the nut sleeve moves downward, it drives an ultrasonic sensor to move downward, and relies on a spring to press the ultrasonic sensor to the top plane of the detected bolt to realize elastic contact, and at the same time the claw clamps the bolt to implement bolt preload detection.

[0028] By driving and controlling each motor, the left and right detection components can be clamped, loosened, adjusted, rotated, swung, and other operations can be achieved, and can be flipped at any angle; the device uses adjacent bolts as support points and can achieve arbitrary path walking in most cases.

[0029] The device of the present invention detects the preload force of two bolts each time, and after completing one movement, moves to the positions of two adjacent bolts to carry out detection, thereby significantly improving the detection efficiency. The device has a simple and compact structure, requires very little operating space, can be used in narrow spaces, and is suitable for most scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of the structure of a detection device according to a preferred embodiment of a bolt preload detection device and a detection method of the present invention;

[0031] Figure 2 A schematic top view of a detection device according to a preferred embodiment of a bolt preload detection device and detection method of the present invention;

[0032] Figure 3 A schematic diagram of the claw structure of a preferred embodiment of a bolt preload force detection device and detection method according to the present invention;

[0033] Figure 4 It is a schematic diagram of the walking process of plane linear distribution bolt detection according to a preferred embodiment of a bolt preload detection device and detection method of the present invention;

[0034] Figure 5 A schematic diagram of a flange bolt detection walking process according to a preferred embodiment of a bolt preload detection device and detection method of the present invention;

[0035] Figure 6A schematic diagram of a walking process of detecting right-angled bolts according to a preferred embodiment of a bolt preload force detection device and detection method of the present invention;

[0036] Figure 7 The present invention is a flowchart of a preferred embodiment of a bolt preload detection device and detection method according to the present invention.

[0037] In the figure: 1-housing, 2-rotating motor, 3-reduction gear, 4-swing arm motor, 5-hinge seat, 6-claw clamping motor, 7-cover plate, 8-first swing arm, 9-pitch adjustment motor, 10-second swing arm, 11-claw hinge, 12-claw, 13-detected bolt, 14-compression spring, 15-ultrasonic sensor, 16-screw, 17-nut sleeve, 18-spring. 100-left component, 200-right component. DETAILED DESCRIPTION

[0038] In order to make the technical solution of the present invention more clear and specific to those skilled in the art, the present invention is further described in detail below in conjunction with embodiments and drawings, but the implementation manner of the present invention is not limited thereto.

[0039] like Figure 1-Figure 6 As shown, a bolt preload force detection device provided in this embodiment includes an angle adjustment arm group, and hinge seats 5 are hinged at both ends of the angle adjustment arm group;

[0040] A rotating mechanism is provided between the hinge seat 5 and the housing 1 for adjusting the rotation angle between the hinge seat 5 and the housing 1;

[0041] A bolt clamping mechanism and an ultrasonic sensor 15 for detecting bolt pre-tightening force are arranged inside the housing 1 .

[0042] In this embodiment, the angle adjustment arm group includes a first swing arm 8, a second swing arm 10 and a pitch adjustment motor 9. The first swing arm 8 is hinged to the second swing arm 10, and the angle between the first swing arm 8 and the second swing arm 10 is adjusted by the pitch adjustment motor 9. Both ends of the first swing arm 8 and the second swing arm 10 are hinged with a hinge seat 5.

[0043] In this embodiment, the rotating mechanism includes a rotating motor 2 and a reduction gear 3. The rotating motor 2 is installed inside the shell 1, the reduction gear 3 is installed at the output end of the rotating motor 2, and a hinge seat 5 is installed through the reduction gear 3. A swing arm motor 4 for adjusting the hinge seat 5 and the angle of the angle adjustment arm group is arranged on the inner side of the hinge seat 5.

[0044] In this embodiment, the clamping mechanism includes a clamping motor 6, a clamping hinge 11, a spring 18, a clamping claw 12, a nut sleeve 17, and a screw rod 16;

[0045] A claw clamping motor 6 is installed at the top of the shell 1, a screw rod 16 is installed at the output end of the claw clamping motor 6, and a nut sleeve 17 is sleeved and meshed on the outer side of the screw rod 16, a spring 18 is installed on the outer side of the nut sleeve 17, claws 12 are installed at both ends of the spring 18, and the upper and middle parts of the claws 12 are hinged to the bottom end of the shell 1.

[0046] In this embodiment, an ultrasonic sensor 15 is installed in the bottom tube of the nut sleeve 17 to compress the spring 14 .

[0047] The device is composed of two identical left and right detection components, which are connected in the middle by a first and a second swing arm; the first and second swing arms are hinged and driven by a distance-adjusting motor, and the angle between the first and second swing arms can be adjusted to achieve the adjustment of the distance between the left and right detection components.

[0048] The first and second swing arms are connected to the detection assembly through hinges and driven by a swing arm motor to achieve swing angle adjustment of the swing arms.

[0049] The hinge seat is driven by a rotary motor through a reduction gear and can rotate relative to the housing to adjust the rotation angle of the swing arm.

[0050] The jaw clamping motor is fixed in the detection component housing, driving the screw to rotate, and driving the stainless steel spring to move up and down through the nut sleeve to realize the opening and clamping of the left and right jaws, which is used to loosen or clamp the detected bolt; the spring is divided into two pieces, the upper and lower pieces, and the middle piece is arc-shaped, which can effectively control the clamping force and realize the elastic contact between the jaw and the detected bolt; the jaw is arc-shaped, and after clamping, the arc surface contacts at least the four vertices of the hexagon of the bolt head to ensure stability; when the nut sleeve moves downward, it drives the ultrasonic sensor to move downward, and relies on the spring to press the ultrasonic sensor against the surface of the detected bolt to realize elastic contact, and at the same time the jaw clamps the bolt to implement bolt preload force detection.

[0051] By driving and controlling each motor, the left and right detection components can be clamped, loosened, adjusted, rotated, swung, and other operations can be achieved, and can be flipped at any angle; the device uses adjacent bolts as support points and can achieve arbitrary path walking in most cases.

[0052] The device of the present invention detects the preload force of two bolts each time, and after completing one movement, moves to the positions of two adjacent bolts to carry out detection, thereby significantly improving the detection efficiency. The device has a simple and compact structure, requires very little operating space, can be used in narrow spaces, and is suitable for most scenarios.

[0053] For bolts distributed in a plane and in a straight line, the walking process of the device of the present invention is as follows: Figure 4As shown. After completing the preload force test of the two bolts on the left at the initial position, the left detection component claw is released, the right swing arm motor drives the second swing arm to rotate 90° clockwise, the right rotation motor drives the right hinge seat to rotate 180°, the right swing arm motor drives the second swing arm to rotate 90° clockwise, the left detection component moves to the third detected bolt position, and the claw is clamped; using similar operations, the right detection component moves to the fourth detected bolt position, and the claw is clamped; the preload force test of the two bolts on the right is completed. And so on.

[0054] against Figure 5 The flange bolts shown in the figure have a similar walking process. The only difference is that the rotating motor drives the hinge seat to rotate by an angle of

[0055] For vertically distributed bolts, the walking process of the device of the present invention is as follows: Figure 6 As shown. After completing the preload force detection of the two bolts on the left at the initial position, the upper detection component claw is released, the lower swing arm motor drives the second swing arm to rotate 90° clockwise, the upper swing arm motor drives the first swing arm to rotate 45° clockwise, the lower rotation motor drives the right hinge seat to rotate 180°, the lower swing arm motor drives the second swing arm to rotate 45° clockwise, the upper detection component moves to the third detected bolt position, the claw is clamped; using similar operations, the lower detection component moves to the fourth detected bolt position, the claw is clamped; the preload force detection of the two bolts below is completed. And so on. The swing arm motor drives the swing arm to rotate ±45°, which can complete the detection of two bolts perpendicular to each other, or move from two bolts on the vertical plane to two detected bolt positions on the horizontal plane.

[0056] A method for detecting a bolt preload comprises the following steps:

[0057] Step 1: Set the number, distribution, spacing and travel path of the bolts to be inspected;

[0058] Step 2: Drive the spacing adjustment motor to adjust the spacing of the detection components to make it the same as the spacing of the bolts; determine the rotation angle and the swing arm angle;

[0059] Step 3: The detection device is placed at the initial bolt position, the motor drives the nut sleeve to move down, the claws are clamped, and the sensor moves down and presses against the top plane of the bolt;

[0060] Step 4: Use ultrasonic sensors to complete the preload force detection of the two bolts;

[0061] Step 5: Loosen the claw of the left component, rotate the right swing arm, rotate the right hinge seat, rotate the right swing arm, move the left component to the third bolt position to be tested, clamp the claw, and perform preload force test;

[0062] Step 6: Determine whether the bolt inspection is completed;

[0063] Step 7: After the test is completed, the claws of the components on both sides are loosened and the test device is removed. If the test is not completed, the claws of the right component are loosened, the left swing arm rotates, the left hinge seat rotates, the left swing arm rotates, the right component moves to the fourth bolt position to be tested, the claws are clamped, and the preload force test is performed;

[0064] Step 8: Determine again whether the bolt inspection is completed. If it is completed, loosen the claws of the components on both sides and remove the inspection device. If it is not completed, proceed to step 5;

[0065] Step 9: After completion, calculate the characteristic parameters of the bolts and conduct a risk assessment of the preload force, and automatically generate a test report.

[0066] The present invention establishes a bolt preload risk assessment index, and assesses the abnormal risk of the entire set of bolt preloads of the inspected object according to the inspection results.

[0067] Parameters involved:

[0068] The number of bolts N of the object to be tested is taken as an example below for the sake of convenience.

[0069] Rated bolt preload P e

[0070] Measured single bolt preload P i

[0071] Measured average bolt preload

[0072] Measured maximum bolt preload

[0073] Measured minimum bolt preload

[0074] Preload deviation factor: Used to measure the degree to which the overall preload force deviates from the rated value;

[0075] Preload fluctuation factor: Used to measure the fluctuation between the preload forces of each bolt;

[0076] Bolt overload risk factors: Used to measure the overload degree of a single bolt;

[0077] Bolt loosening risk factors: Used to measure the looseness of a single bolt;

[0078] Bolt overload risk factor: used to measure the degree of overload risk in a local area; it can be used to evaluate whether the preload of several adjacent bolts in a local area is generally too large or too small, and the level of safety risk.

[0079] Divide the N bolts of the object to be evaluated into n areas, and each area has M bolts after rounding. Assume that the first bolt is marked as j, and the partitions are (j~M+j-1), (M+j~2M+j-1), (2M+j~3M+j-1), (3M+j~4M+j-1), and so on.

[0080] Calculate the average measured bolt preload in each of the above areas:

[0081]

[0082] Get the maximum value among them and minimum value And find the maximum difference: P difj =P maxj -P minj

[0083] Then, after the N bolts of the evaluated object are divided into n regions from any position, the maximum regional preload mean difference is:

[0084] Bolt eccentric loading risk factor: Used to measure the risk of overloading in a local area;

[0085] Evaluate the risk index of the measured flange bolt preload:

[0086] ε=a 1 ε 1 +a 2 ε 2 +a 3 ε 3 +a 4 ε 4 +a 5 ε 5

[0087] Each coefficient a i The value of is determined according to the flange structure, position, diameter, pressure level, fluid medium, material and other characteristics and standards.

[0088] The bolt preload risk index can comprehensively evaluate the potential risks of flange bolt preload deviation, fluctuation, eccentric loading, overloading, loosening, etc.

[0089] The above description is only a further embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and concepts of the present invention within the scope disclosed by the present invention, which belong to the protection scope of the present invention.

Claims

1. A bolt preload force detection device, characterized in that: It comprises an angle adjustment arm group, and hinge seats (5) are hingedly connected at both ends of the angle adjustment arm group; A rotating mechanism is provided between the hinge seat (5) and the housing (1) for adjusting the rotation angle between the hinge seat (5) and the housing (1); A bolt clamping mechanism and an ultrasonic sensor (15) for detecting the bolt pre-tightening force are arranged inside the housing (1).

2. A bolt preload force detection device according to claim 1, characterized in that: The angle adjustment arm group comprises a first swing arm (8), a second swing arm (10) and a pitch adjustment motor (9); the first swing arm (8) and the second swing arm (10) are hingedly connected, and the angle between the first swing arm (8) and the second swing arm (10) is adjusted by the pitch adjustment motor (9); both ends of the first swing arm (8) and the second swing arm (10) are hingedly connected with hinge seats (5).

3. A bolt preload force detection device according to claim 2, characterized in that: The rotating mechanism comprises a rotating motor (2) and a reduction gear (3); the rotating motor (2) is installed inside the housing (1); the reduction gear (3) is installed at the output end of the rotating motor (2); and a hinge seat (5) is installed through the reduction gear (3); and a swing arm motor (4) for adjusting the hinge seat (5) and the angle of the angle-adjusting arm group is arranged inside the hinge seat (5).

4. A bolt preload detection device according to claim 3, characterized in that: The clamping mechanism comprises a clamping motor (6), a clamping hinge (11), a spring (18), a clamping claw (12), a nut sleeve (17), and a screw rod (16); A claw clamping motor (6) is installed at the top of the housing (1), a screw rod (16) is installed at the output end of the claw clamping motor (6), and a nut sleeve (17) is sleeved and meshed on the outer side of the screw rod (16), a spring (18) is installed on the outer side of the nut sleeve (17), claws (12) are installed at both ends of the spring (18), and the upper and middle parts of the claws (12) are hinged to the bottom end of the housing (1).

5. A bolt preload force detection device according to claim 4, characterized in that: An ultrasonic sensor (15) is installed in the compression spring (14) in the bottom tube of the nut sleeve (17).

6. A bolt preload force detection method, based on a bolt preload force detection device according to any one of claims 1 to 5, characterized in that: The steps include: Step 1: Set the number, distribution, spacing and travel path of the bolts to be inspected; Step 2: Drive the spacing adjustment motor to adjust the spacing of the detection components to make it the same as the spacing of the bolts; determine the rotation angle and the swing arm angle; Step 3: The detection device is placed at the initial bolt position, the motor drives the nut sleeve to move down, the claws are clamped, and the sensor moves down and presses against the top plane of the bolt; Step 4: Use ultrasonic sensors to complete the preload force detection of the two bolts; Step 5: Loosen the claw of the left component, rotate the right swing arm, rotate the right hinge seat, rotate the right swing arm, move the left component to the third bolt position to be tested, clamp the claw, and perform preload force test; Step 6: Determine whether the bolt inspection is completed; Step 7: After the test is completed, the claws of the components on both sides are loosened and the test device is removed. If the test is not completed, the claws of the right component are loosened, the left swing arm is rotated, the left hinge seat is rotated, and the left swing arm is rotated to move the right component to the fourth bolt position to be tested, and the claws are clamped to perform preload force test; Step 8: Determine again whether the bolt inspection is completed. If it is completed, loosen the claws of the components on both sides and remove the inspection device. If it is not completed, proceed to step 5; Step 9: After completion, characteristic parameter calculation and bolt preload risk assessment are performed, and a test report is automatically generated.

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