Novel pre-tightening mechanism

Abstract

According to the technical scheme, the novel pre-tightening mechanism is characterized in that the novel pre-tightening mechanism comprises a fastening table, a fixing frame is fixedly installed on the top face of the fastening table, a power cylinder is fixedly installed on the top face of the fastening table, a cylinder shaft is arranged in the power cylinder, and limiting shells are arranged on one side of the power cylinder and the top face of the fixing frame; the pre-pressing assembly is arranged on the inner circle wall face of the limiting shell and used for pre-pressing a workpiece, by arranging the sliding sleeve, when the power cylinder is started, if the plug bolt generates the circumferential rotation tendency due to the factors such as uneven spring compression and mechanical assembly errors, the thrust bearing immediately plays a role, a shaft ring of the thrust bearing and the plug bolt are fixedly arranged in a sleeving mode, and therefore the thrust bearing is prevented from being damaged. When the thrust bearing tends to rotate along with the plug bolt, the rolling body of the thrust bearing rolls between the shaft ring and the seat ring, the shaft ring is allowed to rotate to a certain degree relative to the seat ring, circumferential rotation stress is converted into rolling friction in the bearing, and it is guaranteed that the whole pre-pressing process is stable and orderly.

Description

Technical Field

[0001] This utility model relates to the field of mechanical tooling technology, specifically to a novel pre-tightening mechanism. Background Technology

[0002] Machine tool fixtures are process equipment used in metal cutting to accurately position and firmly clamp workpieces for machining. Their main function is to clamp the workpiece securely, ensuring it does not leave its correct position when subjected to external forces during machining. In existing technology, for horizontally advancing side-pressure machine tool fixtures, before the workpiece is clamped by the cylinder after positioning, manual support is often required to prevent the workpiece from falling or shifting. This manual support prevents workers from operating with both hands and also poses safety hazards and risks of injury from crushing.

[0003] For example, Chinese Patent Publication No. CN215659157U discloses a spring-floating pre-clamping structure, including a fixed pressure head, a movable pressure head, and a power cylinder. The fixed pressure head and the movable pressure head are horizontally coaxially arranged. A spring-floating pre-clamping mechanism is provided between the power cylinder and the movable pressure head to push the movable pressure head to apply a pre-clamping force to the workpiece. The spring-floating pre-clamping mechanism consists of a floating sleeve and a pressure spring. The movable pressure head is installed at the front end of the floating sleeve, and the pressure spring is pressed between the floating sleeve and the cylinder body of the power cylinder. A plug screw is fixedly installed at the front end of the cylinder rod of the power cylinder to push the movable pressure head horizontally forward to cooperate with the fixed pressure head to clamp the workpiece. The front end of the plug screw slides into the cavity of the floating sleeve, and the front end of the plug screw is formed with an enlarged head body. An elastic movement space for pre-clamping is left between the front end face of the enlarged head body and the movable pressure head. This utility model is safe and reliable, easy to operate, simple to maintain, and can effectively prevent the workpiece from falling before and after clamping.

[0004] Currently, there are still some shortcomings in the spring floating pre-clamping structure. For example, during the movement of the screw, the spring is further compressed. During the compression of the spring, there is a certain rotational stress, which will cause circumferential rotational stress to the workpieces at both ends, affecting the implementation of the process. Utility Model Content

[0005] To address the shortcomings of existing technologies, this utility model provides a novel pre-tightening mechanism that solves the problems mentioned in the background section.

[0006] The above-mentioned technical objective of this utility model is achieved through the following technical solution:

[0007] A novel pre-tightening mechanism includes: a fastening platform, a fixing frame fixedly mounted on the top surface of the fastening platform, a power cylinder fixedly mounted on the top surface of the fastening platform, a cylinder shaft disposed inside the power cylinder, and limit shells disposed on one side of the power cylinder and the top surface of the fixing frame, one of the limit shells being disposed inside a movable pressure head, and the other limit shell being disposed inside a fixed pressure head; and a pre-tightening assembly disposed on the inner circular wall surface of the limit shell for pre-tightening the workpiece.

[0008] Preferably, the pre-tightening assembly includes: a sliding sleeve, which is movably fitted inside the limiting shell, a plug bolt being movably fitted inside the sliding sleeve, a through hole on one side of the sliding sleeve, a threaded hole on one end of the cylinder shaft, the plug bolt being threadedly connected to the threaded hole, a spring being provided inside the limiting shell, a thrust bearing being fixedly installed on the inner circular wall of the through hole, and the plug bolt being fixedly fitted together with the shaft ring of the thrust bearing.

[0009] Preferably, the inner circular wall of the limiting shell has two limiting grooves, and the outer circular wall of the sliding sleeve has two limiting blocks fixedly installed, with the limiting blocks slidably sleeved together with the limiting grooves.

[0010] Preferably, a groove is provided on one side of both the fixed pressure head and the movable pressure head, a first magnetic block is fixedly installed on the inner circular wall of the groove, an installation ring is fixedly installed on the inner circular wall of the sliding sleeve, and a second magnetic block is fixedly installed on the inner circular wall of the installation ring, and the first magnetic block and the second magnetic block are attracted to each other.

[0011] Preferably, two rubber posts are fixedly installed on one side of the plug bolt.

[0012] Preferably, an anti-slip pad is adhered to one side of both the fixed pressure head and the movable pressure head.

[0013] Preferably, a connecting plate is fixedly installed on both sides of the limiting shell. Two connecting holes are opened on one side of the connecting plate. A connecting bolt is threaded into the connecting hole and connected to the power cylinder. A fixing plate is fixedly installed on the bottom surface of the limiting shell. Two fixing holes are opened on one side of the fixing plate. A fixing bolt is threaded into the fixing hole and connected to the fastening table.

[0014] In summary, the present invention has the following main advantages:

[0015] By incorporating a thrust bearing, when the power cylinder is not activated, the spring is in a naturally extended state or has a certain pre-compression. Its elastic force is transmitted through components such as the sliding sleeve and the plug bolt, maintaining a certain initial distance between the movable and fixed pressure heads. This distance facilitates the placement and initial positioning of the workpiece. When the power cylinder is activated, the plug bolt is threadedly connected to the cylinder shaft, and the extension of the cylinder shaft causes the plug bolt to move synchronously. During this movement, the plug bolt is subjected to axial thrust from the cylinder shaft. Furthermore, due to the presence of the spring, if the plug bolt exhibits a tendency to rotate circumferentially due to uneven spring compression or mechanical assembly errors, the thrust bearing immediately comes into play. Its shaft ring is fixedly fitted to the plug bolt. As the plug bolt tends to rotate, the rolling elements of the thrust bearing roll between the shaft ring and the seat ring, allowing the shaft ring to rotate relative to the seat ring to a certain extent. This converts the circumferential rotational stress into rolling friction within the bearing, preventing the stress from being transmitted to the sliding sleeve and subsequent components, thus ensuring a stable and orderly pre-tightening process. Attached Figure Description

[0016] Figure 1 This is a three-dimensional structural schematic diagram of the present invention;

[0017] Figure 2 This is a cross-sectional view of the limiting shell structure of this utility model;

[0018] Figure 3 This is a schematic diagram of the through hole structure of this utility model;

[0019] Figure 4 This is a cross-sectional structural diagram of the sliding sleeve of this utility model.

[0020] Reference numerals: 1. Fastening platform; 2. Fixing frame; 3. Fixing pressure head; 4. Power cylinder; 5. Cylinder shaft; 6. Movable pressure head; 7. Limiting shell; 8. Sliding sleeve; 9. Spring; 10. Threaded hole; 11. Plug bolt; 12. Through hole; 13. Thrust bearing; 14. Limiting groove; 15. Limiting block; 16. Anti-slip pad; 17. Groove; 18. First magnetic block; 19. Mounting ring; 20. Second magnetic block; 21. Connecting plate; 22. Connecting hole; 23. Connecting bolt; 24. Fixing plate; 25. Fixing bolt; 26. Fixing hole; 27. Rubber column. Detailed Implementation

[0021] 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.

[0022] refer to Figure 1 - Figure 4 A novel pre-tightening mechanism includes: a fastening platform 1, a fixing frame 2 fixedly mounted on the top surface of the fastening platform 1, a power cylinder 4 fixedly mounted on the top surface of the fastening platform 1, a cylinder shaft 5 disposed inside the power cylinder 4, and a limit shell 7 disposed on one side of the power cylinder 4 and the top surface of the fixing frame 2, wherein a movable pressure head 6 is disposed inside one limit shell 7 and a fixed pressure head 3 is disposed inside the other limit shell 7; and a pre-tightening assembly disposed on the inner circular wall surface of the limit shell 7 for pre-tightening the workpiece.

[0023] By setting up the power cylinder 4, when in use, the operator places the workpiece between the fixed pressure head 3 and the movable pressure head 6, starts the power cylinder 4, pushes the cylinder shaft 5 to extend, and the movement of the cylinder shaft 5 directly drives the movable pressure head 6 connected to it to move. The movable pressure head 6 moves closer to the fixed pressure head 3, and the distance between the two gradually decreases. Together with the fixed pressure head 3, it applies a clamping force to the workpiece, and fixes the workpiece firmly in the preset position to meet the needs of subsequent process operations such as processing and inspection.

[0024] As a further embodiment of this utility model, the pre-tightening assembly includes: a sliding sleeve 8, which is movably fitted inside the limiting shell 7. A plug bolt 11 is movably fitted inside the sliding sleeve 8. A through hole 12 is provided on one side of the sliding sleeve 8. A threaded hole 10 is provided at one end of the cylinder shaft 5. The plug bolt 11 is threadedly connected to the threaded hole 10. A spring 9 is provided inside the limiting shell 7. A thrust bearing 13 is fixedly installed on the inner circular wall of the through hole 12. The plug bolt 11 is fixedly fitted together with the shaft ring of the thrust bearing 13.

[0025] By setting the thrust bearing 13, when the power cylinder 4 is not started, the spring 9 is in a naturally extended state or has a certain pre-compression. Its elastic force is transmitted through components such as the sliding sleeve 8 and the plug bolt 11, so that the movable pressure head 6 and the fixed pressure head 3 maintain a certain initial distance. This distance facilitates the placement and initial positioning of the workpiece. When the power cylinder 4 is started, since the plug bolt 11 is threadedly connected to the threaded hole 10 of the cylinder shaft 5, the extension of the cylinder shaft 5 drives the plug bolt 11 to move synchronously. During the movement of the bolt 11, it is subjected to the axial thrust of the cylinder shaft 5 on the one hand, and on the other hand, due to the presence of the spring 9, if the bolt 11 tends to rotate circumferentially due to factors such as uneven compression of the spring 9 or mechanical assembly errors, the thrust bearing 13 immediately comes into play. Its shaft ring is fixedly sleeved with the bolt 11. When the bolt 11 has a tendency to rotate, the rolling elements of the thrust bearing 13 roll between the shaft ring and the seat ring, allowing the shaft ring to rotate relative to the seat ring to a certain extent, converting the circumferential rotational stress into rolling friction inside the bearing, avoiding the stress from being transmitted to the sliding sleeve 8 and subsequent components, and ensuring that the entire pre-tightening process is stable and orderly.

[0026] As a further embodiment of this utility model, the inner circular wall of the limiting shell 7 is provided with two limiting grooves 14, and the outer circular wall of the sliding sleeve 8 is fixedly installed with two limiting blocks 15, which are slidably sleeved together with the limiting grooves 14.

[0027] By setting the limit block 15, the sliding sleeve 8 can move strictly along the trajectory of the limit groove 14 during the movement of the piston bolt 11 driven by the cylinder shaft 5, which effectively avoids the sliding sleeve 8 from deflecting. At the same time, it avoids the sliding sleeve 8 from excessively compressing the spring 9, which would affect the service life of the spring 9.

[0028] As a further embodiment of this utility model, a groove 17 is provided on one side of both the fixed pressure head 3 and the movable pressure head 6. A first magnetic block 18 is fixedly installed on the inner circular wall of the groove 17, and an installation ring 19 is fixedly installed on the inner circular wall of the sliding sleeve 8. A second magnetic block 20 is fixedly installed on the inner circular wall of the installation ring 19. The first magnetic block 18 and the second magnetic block 20 are attracted to each other.

[0029] By setting the first magnetic block 18, when the first magnetic block 18 and the second magnetic block 20 are attracted to each other, during the operation of the pre-clamping assembly driven by the power cylinder 4, even if there are brief power fluctuations, vibrations or external interference forces, this magnetic attraction can help the fixed pressure head 3 and the movable pressure head 6 maintain the clamping state of the workpiece. At the same time, when the fixed pressure head 3 or the movable pressure head 6 is damaged, the pressure head can be pulled out, which is convenient for the staff to replace quickly.

[0030] As a further embodiment of this utility model, two rubber posts 27 are fixedly installed on one side of the plug bolt 11;

[0031] By setting the rubber column 27, when the return speed of the plug bolt 11 is too fast or the stroke is too large, the rubber column 27 will contact the thrust bearing 13 first. The elastic deformation of the rubber column 27 will absorb the excess kinetic energy of the plug bolt 11, effectively preventing the plug bolt 11 from directly impacting the thrust bearing 13 and improving the service life of the thrust bearing 13.

[0032] As a further embodiment of this utility model, an anti-slip pad 16 is adhered to one side of the fixed pressure head 3 and the movable pressure head 6.

[0033] By setting the anti-slip pad 16, when the fixed pressure head 3 and the movable pressure head 6 clamp the workpiece, the anti-slip pad 16 can significantly increase the friction with the workpiece surface, effectively preventing the workpiece from shifting due to vibration, external impact and other factors during processing, ensuring that the processing accuracy is maintained and greatly reducing the scrap rate.

[0034] 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 novel pre-tensioning mechanism, characterized in that, include: A fastening platform (1) is provided with a fixing frame (2) fixedly installed on the top surface of the fastening platform (1). A power cylinder (4) is fixedly installed on the top surface of the fastening platform (1). A cylinder shaft (5) is provided inside the power cylinder (4). A limit shell (7) is provided on one side of the power cylinder (4) and on the top surface of the fixing frame (2). A movable pressure head (6) is provided inside one of the limit shells (7), and a fixed pressure head (3) is provided inside the other limit shell (7). A pre-tightening assembly is disposed on the inner circular wall of the limiting shell (7) for pre-tightening the workpiece.

2. The novel pre-tensioning mechanism according to claim 1, characterized in that, The pre-compression assembly includes: A sliding sleeve (8) is movably fitted inside the limiting shell (7). A plug bolt (11) is movably fitted inside the sliding sleeve (8). A through hole (12) is provided on one side of the sliding sleeve (8). A threaded hole (10) is provided at one end of the cylinder shaft (5). The plug bolt (11) is threadedly connected to the threaded hole (10). A spring (9) is provided inside the limiting shell (7). A thrust bearing (13) is fixedly installed on the inner circular wall of the through hole (12). The plug bolt (11) is fixedly fitted together with the shaft ring of the thrust bearing (13).

3. The novel pre-tensioning mechanism according to claim 2, characterized in that, The inner circular wall of the limiting shell (7) has two limiting grooves (14), and the outer circular wall of the sliding sleeve (8) has two limiting blocks (15) fixedly installed. The limiting blocks (15) are slidably sleeved together with the limiting grooves (14).

4. A novel pre-tensioning mechanism according to claim 2, characterized in that, Both the fixed pressure head (3) and the movable pressure head (6) have a groove (17) on one side. A first magnetic block (18) is fixedly installed on the inner circular wall of the groove (17). An installation ring (19) is fixedly installed on the inner circular wall of the sliding sleeve (8). A second magnetic block (20) is fixedly installed on the inner circular wall of the installation ring (19). The first magnetic block (18) and the second magnetic block (20) are attracted to each other.

5. A novel pre-tensioning mechanism according to claim 2, characterized in that, Two rubber posts (27) are fixedly installed on one side of the plug bolt (11).

6. A novel pre-tensioning mechanism according to claim 1, characterized in that, Anti-slip pads (16) are adhered to one side of the fixed pressure head (3) and the movable pressure head (6).

7. A novel pre-tightening mechanism according to claim 1, characterized in that, Both sides of the limiting shell (7) are fixedly installed with connecting plates (21). Two connecting holes (22) are opened on one side of the connecting plate (21). Connecting bolts (23) are threaded inside the connecting holes (22). The connecting bolts (23) are connected to the power cylinder (4). A fixing plate (24) is fixedly installed on the bottom surface of the limiting shell (7). Two fixing holes (26) are opened on one side of the fixing plate (24). Fixing bolts (25) are threaded inside the fixing holes (26). The fixing bolts (25) are threaded together with the fastening table (1).

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