A pre-tightening force loading device and a loading method

Abstract

This invention discloses a preload loading device and method. The loading device includes a limiter, an extension section, and a nut tightening section. The limiter is connected to the upper end face of the preload rod and is used to limit the preload rod. The extension section is located below the limiter and includes an upper end plate, a lower end plate, and several extension supports. The upper end plate contacts the lower end face of the limiter, and the lower end plate contacts the end face of the equipment. The length of the extension supports is adjustable, and several extension supports are evenly distributed circumferentially between the upper and lower end plates and perpendicular to the end face of the equipment. Each extension support is equipped with a displacement sensor. The nut tightening section is located between the extension supports and is used to tighten the nut to the preload rod. The method includes applying preload and locking the nut, and sequentially disassembling the device to complete the loading operation. This invention, through the cooperation of the limiter and the extension section, combined with the real-time monitoring of the displacement sensors, effectively suppresses off-center loading, ensures vertical application of preload, and achieves precise control of the force on the end face.

Description

Technical Field

[0001] This invention relates to the field of assembly equipment, and more specifically, to a preload loading device and loading method. Background Technology

[0002] In the field of large-scale equipment assembly, to ensure the structural rigidity and stability between mechanisms, stringent requirements are typically placed on the perpendicularity of the applied preload and the uniformity of the force on the end faces. This requirement is particularly prominent in particle accelerators, nuclear fusion experimental devices, and high-energy physics equipment—the linear magnets in such equipment are responsible for generating specific magnetic fields, and their performance is highly dependent on the structural rigidity and magnetic field uniformity between magnet modules. Therefore, in engineering practice, a precise and controllable preload is usually applied along the magnet axis, and the quality of this preload application directly affects the reliability and magnetic field quality of the equipment.

[0003] However, existing preload methods have many shortcomings, specifically in the following two aspects: First, the single-rod loading accuracy is insufficient. It is difficult to ensure the perpendicularity of the screw during the pre-tightening process by manual means or simple hydraulic tools. When an excessively large pre-tightening force is applied, additional bending moment is easily generated, leading to loading instability and thus affecting the stability of the structural stiffness.

[0004] Secondly, there is a lack of consistency in the coordination of multiple rods. Given the structural characteristics of a linear magnet with a vacuum chamber and multiple preload rods evenly distributed around its circumference, existing loading methods cannot effectively guarantee the consistency and accuracy of the preload force of each rod. This can easily lead to uneven stress on the magnet end face, thereby distorting the designed magnetic field distribution and affecting equipment performance.

[0005] Therefore, there is an urgent need for a new preload loading device and method to solve the problem that existing loading methods in the assembly of large equipment cannot guarantee the vertical application of preload and precise control of end face force. Summary of the Invention

[0006] To address the problem that existing preload loading devices cannot guarantee the vertical application of preload and precise control of end face force in the assembly of large equipment, this invention provides a preload loading device and loading method, the purpose of which is to enable the vertical application of preload and precise control of end face force.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: According to a first aspect of the present invention, a preload loading device is provided, comprising a limiter, an extension portion, and a nut tightening portion arranged coaxially; the limiter is connected to the upper end face of a preload rod that needs to be preloaded, and is used to limit the preload rod. The extension portion is located below the limiter, and includes an upper end plate, a lower end plate, and several extension supports. Both the upper and lower end plates have through holes at their centers, the diameter of which is larger than the diameter of the pre-tensioning rod. The upper end face of the upper end plate contacts the lower end face of the limiter, and the lower end face of the lower end plate contacts the end face of the equipment that needs to be pre-tensioned by the pre-tensioning rod. The length of the extension supports is adjustable, and several extension supports are evenly distributed circumferentially between the upper and lower end plates and perpendicular to the end face of the equipment. Each extension support is equipped with a displacement sensor; The nut tightening part is located between several circumferentially distributed elongated supports and is used to tighten the nut to the preload rod.

[0008] Preferably, it also includes a synchronization control unit connected to the displacement sensor and each elongation support, for synchronously loading the length of each elongation support.

[0009] Preferably, the device also includes pressure sensors located at the ends of several of the elongation supports, and the pressure sensors are also connected to the synchronization control unit.

[0010] Preferably, the elongation support is a hydraulic cylinder, a pneumatic cylinder, or an electric cylinder.

[0011] Preferably, the lower end face of the upper end plate and the upper end face of the lower end plate are respectively provided with grooves at the contact points with the upper and lower ends of the extension support, and the size of the grooves matches the size of the end face of the extension support.

[0012] Preferably, the limiter consists of a limit plate and a limit screw. The limit plate has a disc-shaped structure. The limit screw is fixedly disposed at the center of the lower end face of the limit plate. The upper end face of the pre-tightening rod is provided with a threaded hole that matches the limit screw. The limit screw and the pre-tightening rod are fixedly connected by threads.

[0013] Preferably, the nut tightening part includes a fixed sleeve, a driving sleeve, and a plurality of driving gears arranged coaxially. The fixed sleeve and the driving sleeve are hollow cylindrical structures. The fixed sleeve and the extension part are detachably fixedly connected. The driving sleeve is located inside the fixed sleeve. The inner side of the fixed sleeve and the outer side of the driving sleeve are provided with longitudinal gear teeth. The outer side of the driving gear is also provided with matching longitudinal gear teeth. The plurality of driving gears are located between the fixed sleeve and the driving sleeve and are connected by rolling longitudinal gear teeth. The inner side of the drive sleeve matches the outer side of the nut that needs to be tightened, thereby constraining and driving the nut to rotate and tighten to the end face of the equipment.

[0014] Preferably, the connection between the lower end plate and the fixed sleeve is provided with a plurality of axially extending guide rods, and the fixed sleeve is provided with guide grooves in the circumferential direction, and the guide rods are inserted into and connected with the guide grooves.

[0015] Preferably, the nut tightening part further includes a drive motor connected to the drive sleeve, wherein the drive motor controls the rotation of the drive sleeve to drive the nut to rotate and tighten.

[0016] According to a second aspect of the present invention, a preload loading method is provided, comprising: S1. Select the nut specification according to the diameter of the preload rod and the required preload strength, and select a nut tightening part that matches the nut specification; S2. Sequentially, put the lower end plate, nut, nut tightening part and upper end plate onto the pretensioning rod, and then fix the limiter to the upper end of the pretensioning rod; S3. Install several extension supports evenly and vertically between the upper end plate and the lower end plate in the circumferential direction, and adjust the length of each extension support until the upper end face of the upper end plate abuts against the lower end face of the limiter and the lower end face of the lower end plate abuts against the end face of the equipment. S4. Control each extension support to extend synchronously to ensure that the length of each extension support is equal, and stop extending when the extension support reaches the predetermined extension amount; S5. Control the nut tightening part to drive the nut to rotate and tighten it to the end face of the equipment; S6. Shorten the length of the extension support to relieve the force, and then unload the limiter, upper end plate, extension support, nut tightening part and lower end plate in sequence to complete one pre-tightening loading operation.

[0017] In summary, compared with the prior art, the technical solutions conceived in this invention have the following technical effects: 1. This invention provides a preload loading device, which, through the cooperation of a limiter and an extension part, enables the preload rod to achieve axial tension preload as the extension part linearly extends. Combined with the real-time monitoring of the length of the extension support by a displacement sensor, it effectively suppresses off-center loading, ensures vertical application of preload, and achieves precise control of the end face force.

[0018] 2. By installing pressure sensors at the ends of the extension supports, the present invention can collect pressure data at each contact point in real time and upload it to the synchronous control unit. When there are differences in pressure at each extension support, it can automatically adjust to ensure multi-point synchronous loading and precise control of preload, forming a closed-loop control circuit and further improving vertical loading accuracy.

[0019] 3. This invention fixes the limiting screw at the center of the lower end face of the limiting plate, and provides a threaded hole on the upper end face of the pretensioning rod that matches the limiting screw. At the same time, the entire loading device is detachable, so only the limiting plate of the corresponding specification needs to be replaced to adapt to pretensioning rods of different sizes. In addition, the fixed sleeve and the driving sleeve adopt a separable structure with a drive gear connection, and the driving sleeve can be flexibly replaced according to the size of the nut to achieve quick-change adaptation of the pretensioning device.

[0020] 4. The preload loading device provided by this invention has a compact overall structure, is easy to disassemble, and is convenient to operate. It is suitable for various large equipment assembly scenarios that require precise control of preload. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the preload loading device provided by the present invention.

[0022] Figure 2 A schematic diagram of the linear magnet device used in the preload loading device provided by the present invention.

[0023] Figure 3 This is a schematic diagram of the assembly of the limiter and the preload rod of the preload loading device provided by the present invention.

[0024] Figure 4 This is a schematic diagram of the nut tightening part of the preload loading device provided by the present invention.

[0025] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures. Wherein: 1-Limiter, 2-Upper end plate, 3-Extension support, 4-Nut tightening part, 5-Lower end plate, 6-Preload rod, 7-Equipment end face, 11-Limiting plate, 12-Limiting screw, 41-Fixing sleeve, 42-Drive sleeve, 43-Drive gear, 44-Guide groove, 51-Guide rod, 61-Threaded hole. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0027] In this invention, the terms "first," "second," etc., used in the invention and accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0028] This invention is particularly suitable for large equipment assembly scenarios, typically as follows: Figure 2The diagram shows a large-diameter linear magnet. This type of magnet plays a crucial role in generating specific magnetic fields in fields such as particle accelerators, nuclear fusion experiments, and high-energy physics equipment. Its central region typically houses core components such as beam detection devices and vacuum chambers, making it impossible to utilize the central space for a pre-tightening mechanism. Therefore, multiple pre-tightening rods are arranged circumferentially on the outer side of the magnet, and overall pre-tightening is achieved by tightening and locking nuts. However, large-diameter linear magnets require extremely high consistency in pre-tightening force and precision in the direction of force application. Traditional manual tightening or simple hydraulic methods are insufficient to ensure balanced force on each pre-tightening rod, easily leading to uneven force on the end faces and consequently deteriorating the magnetic field distribution quality. Therefore, this invention provides the following specific implementation scheme to systematically solve the above problems.

[0029] A first aspect of the present invention provides a preload loading device, such as... Figure 1 As shown, it includes a limiter 1, an extension part, and a nut tightening part 4 arranged coaxially; the limiter 1 is connected to the upper end face of the pre-tightening rod 6 that needs to be pre-tightened, and is used to ensure the radial displacement constraint between the loading device and the pre-tightening rod 6, while limiting the pre-tightening rod 6 and transmitting the pre-tightening force to the pre-tightening rod.

[0030] The elongated portion is located below the limiter 1. The elongated portion includes an upper end plate 2, a lower end plate 5, and several elongation supports 3. The upper end plate 2 and the lower end plate 5 are both disc-shaped structures with through holes at their centers. The diameter of the through holes is larger than the diameter of the pretensioning rod 6. The upper end face of the upper end plate 2 is in contact with the lower end face of the limiter 1, and the lower end face of the lower end plate 5 is in contact with the end face 7 of the equipment that needs to be pretensioned by the pretensioning rod 6. The length of the elongation supports 3 is adjustable. Several elongation supports 3 are evenly distributed circumferentially between the upper end plate 2 and the lower end plate 5 and are perpendicular to the end face 7 of the equipment. The upper end plate 2 and the lower end plate 5 are used to evenly transmit the pressure generated during the elongation process of the elongation supports 3 to the end face 7 of the equipment and the pretensioning rod 6, avoiding stress concentration and ensuring that the end face 7 of the equipment and the pretensioning rod 6 are subjected to uniform force.

[0031] When the extension support 3 performs the extension action, since its upper and lower ends are vertically set between the upper end plate 2 and the lower end plate 5, it will push the upper end plate 2 to support the limit plate 1 to move upward and the lower end plate 5 to press against the equipment end face 7. That is, the pre-tightening force is transmitted to the limiter 1 and the equipment end face 7 through the upper end plate 2 and the lower end plate 5. At the same time, since the end of the pre-tightening rod 6 of the limiter 1 is fixedly connected, it can drive the pre-tightening rod 6 to stretch and apply the pre-tightening force evenly to the equipment end face 7.

[0032] Each elongation support 3 is equipped with a displacement sensor to monitor the elongation of the elongation support 3 in real time.

[0033] The nut tightening part 4 is located between several circumferentially distributed elongation supports 3, and is used to tighten the nut onto the preload rod 6 after the elongation part reaches a predetermined elongation amount, so as to lock the preload force.

[0034] Specifically, the extension support 3 is preferably a hydraulic cylinder that can be controlled in real time. Under different conditions, it can also be a pneumatic cylinder or an electric cylinder or other telescopic structure. For example, the hydraulic drive can be replaced with an electric drive to adapt to clean environments or special control requirements. This is not limited here.

[0035] Furthermore, it also includes a synchronous control unit connected to the displacement sensor and each elongation support 3, which is used to adjust the hydraulic or power supply of each elongation support 3 in real time to control each elongation support 3 to elongate synchronously and equally, so as to ensure that the end face 7 of the equipment is uniformly stressed.

[0036] Furthermore, the system also includes pressure sensors located at the ends of several of the extension supports 3. These sensors can be located at the contact points between the upper end plate 2 or the lower end plate 5 and the extension support 3, or directly on the end face of the extension support 3. The pressure sensors are also connected to the synchronization control unit to monitor and provide feedback on the actual force applied to the pretensioning rod in real time, and to further adjust the length of each extension support 3. When the extension support 3 reaches the predetermined elongation amount according to the preset program or when the pressure sensor feedback indicates that the target pretensioning force value has been reached, the extension support 3 stops elongating, allowing the pretensioning rod 6 to reach the required tension state.

[0037] Specifically, the lower end face of the upper end plate 2 and the upper end face of the lower end plate 5 are respectively provided with grooves at the contact points with the upper and lower ends of the extension support 3. The size of the grooves matches the size of the end face of the extension support 3, which is used to accurately position the extension support 3.

[0038] In some embodiments, the limiter 1 consists of a limit plate 11 and a limit screw 12, such as Figure 3 As shown, the limiting plate 11 has a disc-shaped structure, and the limiting screw 12 is fixedly disposed at the center of the lower end face of the limiting plate 11. The upper end face of the preload rod 6 is provided with a threaded hole 61 that matches the limiting screw 12. The limiting screw 12 and the preload rod 6 are fixedly connected by threads. The thread specification of the limiting screw 12 can be selected and designed according to the expected preload force provided by the preload rod, in conjunction with the GB / T 196-2025 standard manual.

[0039] In some embodiments, the nut tightening part 4 includes a fixed sleeve 41, a drive sleeve 42, and a plurality of drive gears 43 arranged coaxially, such as Figure 4As shown, the fixed sleeve 41 and the driving sleeve 42 are hollow cylindrical structures. The fixed sleeve 41 is detachably fixedly connected to the extension portion. The driving sleeve 42 is located inside the fixed sleeve 41. The inner side of the fixed sleeve 41 and the outer side of the driving sleeve 42 are provided with longitudinal gear teeth. The outer side of the driving gear 43 is also provided with matching longitudinal gear teeth. Several driving gears 43 are located between the fixed sleeve 41 and the driving sleeve 42 and are connected by rolling longitudinal gear teeth.

[0040] The inner surface of the drive sleeve 42 matches the outer surface of the nut to be tightened, thereby constraining and driving the nut to rotate and tighten to the end face 7 of the equipment. The size of the drive sleeve 42 can be matched and replaced according to the required nut size.

[0041] Specifically, the lower end plate 5 is provided with a plurality of axially extending guide rods 51 at the connection between it and the fixed sleeve 41. The fixed sleeve 41 is provided with guide grooves 44 in the circumferential direction. The guide rods 51 are inserted into and connected with the guide grooves 44 to constrain the fixed sleeve to rotate around the axis during the tightening of the nut.

[0042] Furthermore, the nut tightening part 4 also includes a drive motor connected to the drive sleeve 42. The drive motor can preset multiple torque values ​​to adapt to different preload locking requirements. After the extension part completes the preload loading stage, the drive motor controls the drive sleeve 42 to rotate and drive the nut to rotate and tighten onto the preload rod 6 at a preset torque value until the nut abuts against the end face 7 of the device, automatically completing the preload locking.

[0043] In some embodiments, the nut tightening part is provided with a nut pre-storage structure for storing nuts of various types, so as to improve the efficiency and versatility of the pre-tightening operation.

[0044] A second aspect of the present invention provides a loading method, comprising: S1. Select the nut specification according to the diameter of the preload rod and the required preload strength, and select the nut tightening part 4 that matches the nut specification; S2. Sequentially, the lower end plate 5, nut, nut tightening part 4 and upper end plate 2 are fitted onto the pretensioning rod 6, and then the limiter 1 is fixed to the upper end of the pretensioning rod 6. S3. Install several extension supports 3 evenly and vertically between the upper end plate 2 and the lower end plate 5 in the circumferential direction, and adjust the length of each extension support 3 until the upper end surface of the upper end plate 2 abuts against the lower end surface of the limiter 1 and the lower end surface of the lower end plate 5 abuts against the end surface 7 of the equipment. S4. Control each extension support 3 to extend synchronously to ensure that the length of each extension support 3 is equal. Stop extending when the extension support 3 reaches the predetermined extension amount. S5. Control nut tightening part 4 drives the nut to rotate and tighten to the end face 7 of the equipment; S6. After the nut is tightened, shorten the length of the extension support 3 to relieve the force. At this time, the preload is maintained by the tightened nut. Unload the limiter 1, upper end plate 2, extension support 3, nut tightening part 4 and lower end plate 5 in sequence to complete one preload loading operation.

[0045] Furthermore, multiple pre-tightening rods 6 are provided on the end face 7 of the equipment. By applying the loading method to the multiple pre-tightening rods 6 simultaneously, the pre-tightening force of each pre-tightening rod on the end face of the equipment can be increased synchronously, reducing bending moment and further improving the verticality and stability of the entire end face of the equipment. This method is suitable for scenarios with high requirements for the coordination and consistency of multiple rods, such as pre-tightening of large-diameter linear magnets.

[0046] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A preload loading device, characterized in that, It includes a limiter (1) arranged coaxially, an extension part and a nut tightening part (4); the limiter (1) is connected to the upper end face of the pre-tightening rod (6) that needs to be pre-tightened, and is used to limit the pre-tightening rod (6); The extension portion is located below the limiter (1). The extension portion includes an upper end plate (2), a lower end plate (5), and several extension supports (3). The upper end plate (2) and the lower end plate (5) are both provided with through holes in their centers. The diameter of the through holes is larger than the diameter of the pre-tightening rod (6). The upper end face of the upper end plate (2) is in contact with the lower end face of the limiter (1), and the lower end face of the lower end plate (5) is in contact with the end face (7) of the equipment that needs to be pre-tightened by the pre-tightening rod (6). The length of the extension supports (3) is adjustable. Several extension supports (3) are evenly distributed circumferentially between the upper end plate (2) and the lower end plate (5) and are perpendicular to the end face (7) of the equipment. Each elongation support (3) is equipped with a displacement sensor; The nut tightening part (4) is located between several circumferentially distributed elongated supports (3) and is used to tighten the nut to the preload rod (6).

2. The preload loading device as described in claim 1, characterized in that, It also includes a synchronization control unit connected to the displacement sensor and each elongation support (3) for synchronously loading the length of each elongation support (3).

3. The preload loading device as described in claim 2, characterized in that, It also includes pressure sensors located at the ends of several of the elongation supports (3), which are also connected to the synchronization control unit.

4. The preload loading device as described in claim 3, characterized in that, The elongation support (3) is a hydraulic cylinder, a pneumatic cylinder, or an electric cylinder.

5. The preload loading device as described in claim 4, characterized in that, The lower end face of the upper end plate (2) and the upper end face of the lower end plate (5) are respectively provided with grooves at the contact points with the upper and lower ends of the extension support (3), and the size of the grooves matches the size of the end face of the extension support (3).

6. The preload loading device as described in claim 5, characterized in that, The limiter (1) consists of a limit plate (11) and a limit screw (12). The limit plate (11) has a disc-shaped structure. The limit screw (12) is fixedly located at the center of the lower end face of the limit plate (11). The upper end face of the pre-tightening rod (6) is provided with a threaded hole (61) that matches the limit screw (12). The limit screw (12) and the pre-tightening rod (6) are fixedly connected by threads.

7. The preload loading device according to any one of claims 1-6, characterized in that, The nut tightening part (4) includes a fixed sleeve (41), a driving sleeve (42) and a plurality of driving gears (43) arranged coaxially. The fixed sleeve (41) and the driving sleeve (42) are hollow cylindrical structures. The fixed sleeve (41) is detachably fixedly connected to the extension part. The driving sleeve (42) is located inside the fixed sleeve (41). The inner side of the fixed sleeve (41) and the outer side of the driving sleeve (42) are provided with longitudinal gear teeth. The outer side of the driving gear (43) is also provided with matching longitudinal gear teeth. A plurality of driving gears (43) are located between the fixed sleeve (41) and the driving sleeve (42) and are connected by rolling longitudinal gear teeth. The inner side of the drive sleeve (42) matches the outer side of the nut that needs to be tightened, and is used to constrain and drive the nut to rotate and tighten to the end face (7) of the equipment.

8. The preload loading device as described in claim 7, characterized in that, A plurality of axially extending guide rods (51) are provided at the connection between the lower end plate (5) and the fixed sleeve (41). The fixed sleeve (41) is provided with guide grooves (44) in the circumferential direction. The guide rods (51) are inserted into the guide grooves (44) for connection.

9. The preload loading device as described in claim 8, characterized in that, The nut tightening part (4) also includes a drive motor connected to the drive sleeve (42), which drives the nut to rotate and tighten by controlling the rotation of the drive sleeve (42).

10. A loading method based on the preload loading device according to any one of claims 1-9, characterized in that, include: S1. Select the nut specification according to the diameter of the preload rod and the required preload strength, and select the nut tightening part that matches the nut specification (4). S2. In sequence, put the lower end plate (5), nut, nut tightening part (4) and upper end plate (2) onto the pretension rod (6), and then fix the limiter (1) to the upper end of the pretension rod (6); S3. Install several extension supports (3) evenly and vertically between the upper end plate (2) and the lower end plate (5) along the circumference, and adjust the length of each extension support (3) until the upper end surface of the upper end plate (2) abuts against the lower end surface of the limiter (1) and the lower end surface of the lower end plate (5) abuts against the end surface of the equipment (7). S4. Control each extension support (3) to extend synchronously to ensure that the length of each extension support (3) is equal. When the extension support (3) reaches the predetermined extension amount, it stops extending. S5, Control nut tightening part (4) drives the nut to rotate and tighten to the end face (7) of the equipment; S6. Shorten the length of the extension support (3) to relieve the force, and unload the limiter (1), upper end plate (2), extension support (3), nut tightening part (4) and lower end plate (5) in sequence to complete one pre-tightening loading operation.

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