A real-time device for precise preload testing of high-strength bolts
By combining an ultrasonic probe with a sliding ring and ball bearings, the design error caused by the thickness of the pressure sensor was solved, thus achieving accuracy and stability in the preload testing of high-strength bolts.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHEJIANG YELING IND CO LTD
- Filing Date
- 2025-09-22
- Publication Date
- 2026-05-26
AI Technical Summary
In existing high-strength bolt preload testing devices, the thickness and stiffness of the pressure sensor can alter the original design structure, leading to design errors and increasing the elastic elongation of the bolt shank, thus affecting test accuracy.
An ultrasonic probe and an error reduction mechanism are used. The ultrasonic probe forms an acoustic coupling with the bolt surface, and the friction force is transmitted by a sliding ring and balls to convert the rotational motion of the nut into axial movement, thus ensuring the stability of the probe and the accuracy of the test data.
This improved the accuracy of high-strength bolt preload testing, reduced the interference of friction on force measurement, and ensured the stability and accuracy of test data.
Smart Images
Figure CN224286208U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of engineering testing technology, and in particular relates to a real-time testing device for the precise preload of high-strength bolts. Background Technology
[0002] In the field of mechanical connections, high-strength bolt connections are one of the most critical and fundamental connection forms in modern major engineering structures and high-end equipment manufacturing. Their reliability directly determines the safety, stability, and service life of the entire structure. From wind turbine generators, large bridges, and super high-rise buildings to aerospace vehicles and heavy machinery, all rely on the enormous clamping force provided by a large number of high-strength bolts.
[0003] Chinese patent CN222153350U discloses a real-time testing device for the precise preload force of high-strength bolts, comprising: a base; a first pressure sensor stacked on the base; a sealing assembly including a first gasket, a seal, and a second gasket, wherein the first gasket is stacked on the first pressure sensor, and the seal is sandwiched between the first gasket and the second gasket; and a bolt to be tested, which sequentially passes through the second gasket, the seal, the first gasket, and the first pressure sensor and is connected to the base.
[0004] As shown above, the device uses a pressure sensor for testing. However, as a load-bearing component, its thickness and stiffness will slightly change the original design structure. This will not only introduce design errors and cause deviations between theoretical calculations and actual conditions, but its own thickness will also increase the effective clamping length of the bolt, resulting in a larger elastic elongation of the bolt shank under the same preload. Utility Model Content
[0005] To address the shortcomings of existing technologies, this invention provides a real-time testing device for the precise preload of high-strength bolts, solving the problem of errors caused by friction and the thickness of the bolt itself in pressure sensor testing.
[0006] To achieve the above objectives, this utility model is implemented through the following technical solution: a real-time testing device for the precise preload of high-strength bolts, comprising a base plate, four sliding shafts fixedly connected to the top of the base plate, a testing mechanism being provided on the four sliding shafts, and an error reduction mechanism being provided on the top of the base plate;
[0007] The testing mechanism includes a first fixed plate slidably connected to the outer wall of four sliding shafts. Two positioning shafts are fixedly connected to the top of the first fixed plate. A housing is inserted into the outer wall of each of the two positioning shafts. A first telescopic shaft is fixedly connected to the inner wall of the housing. An ultrasonic probe is fixedly connected to the bottom of the first telescopic shaft. A first spring is fixedly connected to the top of the ultrasonic probe. Two lead screws are threadedly connected to the inner wall of the first fixed plate. A limit shaft is rotatably connected to the side of each of the two lead screws that are close to each other. Fixing components are provided on both sides of the first fixed plate.
[0008] Preferably, the end of the first spring away from the ultrasonic probe is fixedly connected to the inner wall of the housing, the first telescopic shaft is located inside the first spring, the outer wall of the limiting shaft is inserted into the inner wall of the housing, and the outer walls of the two limiting shafts are slidably connected to the inner wall of the first fixing plate.
[0009] Preferably, the fixing assembly includes two second telescopic shafts fixedly connected to the outer wall of the first fixing plate, and a limiting plate fixedly connected to the side of the two second telescopic shafts that are far apart from each other. The sliding part of the inner wall of the limiting plate has two first fixing shafts, and the outer walls of the two first fixing shafts are fixedly connected to the outer wall of the first fixing plate.
[0010] Preferably, a second spring is fixedly connected to the side of the limiting plate near the second telescopic shaft, the side of the second spring away from the limiting plate is fixedly connected to the outer wall of the first fixing plate, the second telescopic shaft is located inside the second spring, and a cross-shaped locking block is fixedly connected to the bottom of the first fixing plate.
[0011] Preferably, the error reduction mechanism includes a second fixing plate fixedly connected to the outer wall of the four sliding shafts. Two second fixing shafts are fixedly connected to the outer wall of the second fixing plate. The outer walls of the two second fixing shafts are engaged with the inner wall of the limiting plate. A test bolt is provided on the inner wall of the second fixing plate. The test bolt has a slot adapted to the cross-shaped locking block. The bottom of the second fixing plate contacts a first test plate, and the bottom of the first test plate contacts a second test plate.
[0012] Preferably, the bottom of the second test plate is fixedly connected to a plurality of support members, and the bottom of the plurality of support members is fixedly connected to a first sliding ring. A ball is slidably connected to the inner wall of the first sliding ring, and a second sliding ring is slidably connected to the outer wall of the ball. The outer wall of the second sliding ring is slidably connected to the outside of the first sliding ring.
[0013] This utility model has the following beneficial effects:
[0014] 1. This high-strength bolt precision preload real-time testing device, by manually pulling and releasing the limiting plate, uses the reaction force of the second spring to automatically engage with the second fixed shaft, thereby quickly locking the height of the first fixed plate. Finally, by pressing down the housing, it moves downward along the positioning shaft. During this process, the built-in first spring continuously applies pressure to the first telescopic shaft and the ultrasonic probe, ensuring acoustic coupling between the probe and the lower surface of the first fixed plate. Then, rotating the screw drives the limiting shaft to clamp the housing, ultimately completing the rigid fixation of the entire measuring device. This ensures the stability of the ultrasonic probe during the measurement process and improves the accuracy of the preload test data.
[0015] 2. The high-strength bolt precision preload real-time testing device, by placing the first test plate and the second test plate under the second fixed plate and fitting them onto the test bolt, the tightening action of the nut directly squeezes the second sliding ring. Utilizing friction, the rotational motion of the nut is effectively converted into the rotation and axial movement of the second sliding ring. This motion, through the ball bearings, can smoothly push the first sliding ring to generate an upward axial displacement, thereby applying a uniform clamping force to the first test plate and the second test plate. This ensures the smooth application of clamping force and minimizes the interference of irregular friction on force measurement.
[0016] Of course, any product implementing this utility model does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description
[0017] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is a schematic diagram of the overall structure of this utility model;
[0019] Figure 2 This is a schematic diagram of the positioning shaft structure of this utility model;
[0020] Figure 3 This utility model Figure 2 Enlarged structural diagram at point A in the middle;
[0021] Figure 4 This is a schematic diagram of the cross-shaped locking block structure of this utility model;
[0022] Figure 5 This is a schematic diagram of the first telescopic shaft structure of this utility model;
[0023] Figure 6This is a schematic diagram of the test bolt structure of this utility model;
[0024] Figure 7 This is a schematic diagram of the structure of the second test plate of this utility model;
[0025] Figure 8 This is a schematic diagram of the ball bearing structure of this utility model.
[0026] The attached diagram lists the components represented by each number as follows:
[0027] 1. Base plate; 101. Sliding shaft; 2. Testing mechanism; 201. First fixed plate; 202. Positioning shaft; 203. Housing; 204. First telescopic shaft; 205. Ultrasonic probe; 206. First spring; 207. Lead screw; 208. Limiting shaft; 209. Second telescopic shaft; 210. Limiting plate; 211. Second spring; 212. First fixed shaft; 213. Cross block; 3. Error reduction mechanism; 301. Second fixed plate; 302. Second fixed shaft; 303. Test bolt; 304. First test plate; 305. Second test plate; 306. Support component; 307. First sliding ring; 308. Ball bearing; 309. Second sliding ring. Detailed Implementation
[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0029] This utility model provides two technical solutions:
[0030] Figures 1-5 The first embodiment of a real-time testing device for the precise preload of high-strength bolts is shown: it includes a base plate 1, four sliding shafts 101 fixedly connected to the top of the base plate 1, a testing mechanism 2 on the four sliding shafts 101, and an error reduction mechanism 3 on the top of the base plate 1;
[0031] The testing mechanism 2 includes a first fixed plate 201 slidably connected to the outer wall of four sliding shafts 101. Two positioning shafts 202 are fixedly connected to the top of the first fixed plate 201. A housing 203 is inserted into the outer wall of each of the two positioning shafts 202. A first telescopic shaft 204 is fixedly connected to the inner wall of the housing 203. An ultrasonic probe 205 is fixedly connected to the bottom of the first telescopic shaft 204. A first spring 206 is fixedly connected to the top of the ultrasonic probe 205. Two lead screws 207 are threadedly connected to the inner wall of the first fixed plate 201. Limiting shafts 208 are rotatably connected to the side of each lead screw 207 that is close to each other. Fixing components are provided on both sides of the first fixed plate 201. The end of the first spring 206 away from the ultrasonic probe 205 is fixedly connected to the inner wall of the housing 203. The first telescopic shaft 204 is located inside the first spring 206. The outer wall of the limiting shaft 208 is inserted into the inner wall of the housing 203. The outer walls of the two limiting shafts 208 are slidably connected to the inner wall of the first fixed plate 201.
[0032] The fixing assembly includes two second telescopic shafts 209 fixedly connected to the outer wall of the first fixing plate 201. Limiting plates 210 are fixedly connected to the sides of the two second telescopic shafts 209 that are far apart from each other. The sliding parts on the inner wall of the limiting plate 210 have two first fixing shafts 212. The outer walls of the two first fixing shafts 212 are fixedly connected to the outer wall of the first fixing plate 201. A second spring 211 is fixedly connected to the side of the limiting plate 210 near the second telescopic shafts 209. The side of the second spring 211 away from the limiting plate 210 is fixedly connected to the outer wall of the first fixing plate 201. The second telescopic shafts 209 are located inside the second springs 211. A cross-shaped locking block 213 is fixedly connected to the bottom of the first fixing plate 201.
[0033] First, move the first fixing plate 201 upwards, then place the test bolt 303 into the second fixing plate 301. Next, move the first fixing plate 201 downwards so that the cross-shaped locking block 213 can engage with the test bolt 303, fixing the rotation angle of the test bolt 303. Before moving the first fixing plate 201 downwards, manually pull the limiting plate 210 to stretch the second telescopic shaft 209 and the second spring 211. Then, when the second fixing shaft 302 is aligned with the limiting plate 210, release the limiting plate 210. At this time, due to the second spring 211... The reaction force pulls the limiting plate 210 to move, causing it to engage with the second fixed shaft 302, thus fixing the first fixed plate 201. At this point, the housing 203 is fastened into the positioning shaft 202. During this process, the first fixed plate 201 compresses the ultrasonic probe 205, causing the first telescopic shaft 204 and the first spring 206 to retract. However, due to the reaction force of the first spring 206, it continues to compress the ultrasonic probe 205, ensuring that the ultrasonic probe 205 remains tightly against the first fixed shaft 302. On plate 201, ultrasonic testing is performed on test bolt 303. When housing 203 is in the correct position, screw 207 is manually rotated, causing limit shaft 208 to move on the first fixing plate 201 and engage with housing 203, fixing the position of housing 203. The cross-shaped locking block 213 engages with the head of test bolt 303, effectively limiting its rotation during tightening and providing a basis for precise torque application. During the fixing process, by manually pulling and releasing limit plate 210, the reaction force of second spring 211 causes it to automatically engage with the second fixing plate. The shaft 302 quickly locks the height of the first fixed plate 201. Finally, the housing 203 is pressed down to make it move down along the positioning shaft 202. During this process, the built-in first spring 206 continuously applies pressure to the first telescopic shaft 204 and the ultrasonic probe 205 to ensure that the probe and the lower surface of the first fixed plate 201 form acoustic coupling. Then, the screw 207 is rotated to drive the limiting shaft 208 to clamp the housing 203, thus completing the rigid fixation of the entire measuring device. This ensures the stability of the ultrasonic probe 205 during the measurement process and improves the accuracy of the preload test data.
[0034] Figure 3 , Figures 6-8The second embodiment is shown. The main difference between this embodiment and the first embodiment of the real-time testing device for the precise preload of high-strength bolts is that the error reduction mechanism 3 includes a second fixing plate 301 fixedly connected to the outer wall of the four sliding shafts 101. Two second fixing shafts 302 are fixedly connected to the outer wall of the second fixing plate 301. The outer walls of both second fixing shafts 302 are engaged with the inner wall of the limiting plate 210. A test bolt 303 is provided on the inner wall of the second fixing plate 301. The test bolt 303 has an opening inside that matches the cross-shaped locking block 213. The slot is fitted with a second fixed plate 301 with a first test plate 304 at the bottom, and a second test plate 305 at the bottom of the first test plate 304. Several support members 306 are fixedly connected to the bottom of the second test plate 305, and a first sliding ring 307 is fixedly connected to the bottom of the several support members 306. A ball bearing 308 is slidably connected to the inner wall of the first sliding ring 307, and a second sliding ring 309 is slidably connected to the outer wall of the ball bearing 308. The outer wall of the second sliding ring 309 is slidably connected to the outer side of the first sliding ring 307.
[0035] Then, the first test plate 304 and the second test plate 305 are placed below the second fixed plate 301, on the test bolt 303. The nut is then rotated, causing it to press against the second sliding ring 309. Due to friction, the second sliding ring 309 rotates and moves upwards. This rotation, in turn, causes the ball bearing 308 to rotate. Due to the transmission of force, the first sliding ring 307 is subjected to pressure from the ball bearing 308 and moves upwards. During the tightening of the nut, due to elastic deformation, the test bolt 303 is slightly stretched. This stretching can be detected by the ultrasonic probe 205. The mechanism allows for real-time observation of changes in preload. After placing the first test plate 304 and the second test plate 305 below the second fixed plate 301 and fitting them onto the test bolt 303, the tightening of the nut directly compresses the second sliding ring 309. Utilizing friction, the rotational motion of the nut is effectively converted into the rotation and axial movement of the second sliding ring 309. This motion, through the ball bearing 308, smoothly pushes the first sliding ring 307 to generate an upward axial displacement, thereby applying a uniform clamping force to the first test plate 304 and the second test plate 305. This ensures the smooth application of clamping force and minimizes the interference of irregular friction on force measurement.
[0036] Furthermore, all content not described in detail in this specification is existing technology known to those skilled in the art, and the model parameters of each electrical component are not specifically limited; conventional equipment can be used.
[0037] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
[0038] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A real-time testing device for the precise preload of high-strength bolts, comprising a base plate (1), wherein four sliding shafts (101) are fixedly connected to the top of the base plate (1), characterized in that, A testing mechanism (2) is provided on the four sliding shafts (101), and an error reduction mechanism (3) is provided on the top of the base plate (1); The testing mechanism (2) includes a first fixed plate (201) slidably connected to the outer wall of four sliding shafts (101). Two positioning shafts (202) are fixedly connected to the top of the first fixed plate (201). A housing (203) is inserted into the outer wall of each of the two positioning shafts (202). A first telescopic shaft (204) is fixedly connected to the inner wall of the housing (203). An ultrasonic probe (205) is fixedly connected to the bottom of the first telescopic shaft (204). A first spring (206) is fixedly connected to the top of the ultrasonic probe (205). Two lead screws (207) are threadedly connected to the inner wall of the first fixed plate (201). A limit shaft (208) is rotatably connected to the side of each of the two lead screws (207) that are close to each other. Fixing components are provided on both sides of the first fixed plate (201).
2. The real-time accurate preload testing device for high-strength bolts according to claim 1, characterized in that, The end of the first spring (206) away from the ultrasonic probe (205) is fixedly connected to the inner wall of the housing (203). The first telescopic shaft (204) is located inside the first spring (206). The outer wall of the limiting shaft (208) is inserted into the inner wall of the housing (203). The outer walls of the two limiting shafts (208) are slidably connected to the inner wall of the first fixing plate (201).
3. The real-time accurate preload testing device for high-strength bolts according to claim 2, characterized in that, The fixing assembly includes two second telescopic shafts (209) fixedly connected to the outer wall of the first fixing plate (201). The two second telescopic shafts (209) are respectively fixedly connected to a limiting plate (210) on the side away from each other. The sliding part of the inner wall of the limiting plate (210) has two first fixing shafts (212). The outer walls of the two first fixing shafts (212) are fixedly connected to the outer wall of the first fixing plate (201).
4. The real-time accurate preload testing device for high-strength bolts according to claim 3, characterized in that, The limiting plate (210) is fixedly connected to a second spring (211) on the side near the second telescopic shaft (209). The side of the second spring (211) away from the limiting plate (210) is fixedly connected to the outer wall of the first fixing plate (201). The second telescopic shaft (209) is located inside the second spring (211). A cross-shaped locking block (213) is fixedly connected to the bottom of the first fixing plate (201).
5. The real-time accurate preload testing device for high-strength bolts according to claim 1, characterized in that, The error reduction mechanism (3) includes a second fixing plate (301) fixedly connected to the outer wall of four sliding shafts (101). The outer wall of the second fixing plate (301) is fixedly connected to two second fixing shafts (302). The outer walls of the two second fixing shafts (302) are engaged with the inner wall of the limiting plate (210). The inner wall of the second fixing plate (301) is provided with a test bolt (303). The test bolt (303) has a slot that matches the cross-shaped locking block (213). The bottom of the second fixing plate (301) contacts a first test plate (304). The bottom of the first test plate (304) contacts a second test plate (305).
6. The real-time accurate preload testing device for high-strength bolts according to claim 5, characterized in that, The bottom of the second test plate (305) is fixedly connected to a plurality of support members (306), and the bottom of the plurality of support members (306) is fixedly connected to a first sliding ring (307). The inner wall of the first sliding ring (307) is slidably connected to a ball (308), and the outer wall of the ball (308) is slidably connected to a second sliding ring (309). The outer wall of the second sliding ring (309) is slidably connected to the outside of the first sliding ring (307).