A cut-off cap

Abstract

The utility model discloses a cut -off cover relates to fastener technical field. The utility model discloses a cover body, shelter and vulnerable part, the cover body is provided with the passage, the vulnerable part is connected with the cover body, the shelter is connected with vulnerable part, the shelter is located the axial direction of the passage, one side of vulnerable part is provided with the jack, the cover body is provided with the axial limiting portion for limiting the axial movement of cover body. The utility model discloses the axial limiting portion with one side setting up the jack of vulnerable part cooperation, can set up cut -off structure at the end of bolt and cut -off cover cooperation part, cut -off structure inserts the jack, and when tightening cut -off cover, cut -off structure will directly extrude vulnerable part, and the acting force between cut -off structure and vulnerable part is converted because not with the friction of pressure change this variable, therefore, the calculation is simpler when designing, reaches the effect of reducing design difficulty.

Description

Technical Field

[0001] This utility model relates to the field of fastener technology, and specifically provides a cutting cap. Background Technology

[0002] Bolts are common fasteners in existing technology, used in conjunction with nuts to achieve secure connections between various workpieces and structures. In certain specific applications, high precision is required for the bolt preload, necessitating that the bolts reach a specified preload.

[0003] Patent application CN108006043A, entitled "A Bolt and a Torque-Controlled Nut," discloses a bolt and a torque-controlled nut. The bolt has a second threaded section at its top, and the torque-controlled nut has a vulnerable part and a shielding part. The second threaded section has a marking part, and the shielding part covers the marking part. The torque-controlled nut has an internal thread, and the second threaded section has an external thread. The torque-controlled nut is connected to the second threaded section via the mating of the internal and external threads. When tightening the bolt, the torque-controlled nut is turned, moving towards the nut. The second threaded section approaches and eventually abuts against the vulnerable part or the shielding part. When the torque of the torque-controlled nut reaches a specified value, the second threaded section applies a sufficiently large axial force to the vulnerable part, causing it to break or be damaged. After the vulnerable part is damaged, the shielding part connected to it detaches, exposing the marking part. Once the staff observes the marking and confirms that the torque-controlled nut is connected to the second screw, they can determine that the bolt preload has reached the required level, allowing them to judge the bolt preload without the aid of other tools.

[0004] However, the bolts and torque-controlled nuts disclosed in the aforementioned patents require a complex design process. The torque of tightening the torque-controlled nut is converted into an axial force exerted by the second screw on the vulnerable part. The torque corresponding to the damage to the vulnerable part is then calculated based on this axial force. This conversion involves calculating the frictional force between the threads of the torque-controlled nut and the second screw, which changes continuously as the torque-controlled nut is tightened. When designing bolts suitable for different preloads, each bolt requires complex calculations, making the design very difficult. Furthermore, if the internal thread of the torque-controlled nut is removed, it is prone to detaching from the second screw during use, and it cannot drive the bolt to rotate, thus failing to control the torque. Utility Model Content

[0005] This utility model provides a cutting cap to solve the problems of existing torque nuts easily falling off and failing to drive bolts to rotate after the threads are removed.

[0006] The technical solution of this utility model is as follows:

[0007] A cutting cap includes a cap body, a shielding part, and a vulnerable part. The cap body is provided with a channel. The vulnerable part is connected to the cap body. The shielding part is connected to the vulnerable part. The shielding part is located in the axial direction of the channel. An insertion hole is provided on one side of the vulnerable part. The cap body is provided with an axial limiting part for restricting the axial movement of the cap body.

[0008] In this design, an axial limiting part prevents the cover from moving axially, thus preventing it from detaching from the bolts and facilitating worker confirmation that the bolts have been tightened using the cut-off cover. The axial limiting part, in conjunction with a vulnerable part with an insertion hole on one side, allows for a cutting structure to be installed at the end of the bolt-cutting cover mating section. This cutting structure is inserted into the insertion hole, and when the cut-off cover is tightened, it directly compresses the vulnerable part. Since there is no variable frictional force that changes with pressure, the force calculation between the cutting structure and the vulnerable part is simpler during design, reducing design complexity. Furthermore, because precise calculation of frictional force is not required when the cut-off cover mates with the bolts, thread finishing is unnecessary, reducing machining difficulty and costs.

[0009] Preferably, the axial limiting portion includes a locking groove formed on the inner side of the cover body.

[0010] In this design, a locking groove is used as an axial limiting part. When the cover moves in the axial direction, the locking structure that cooperates with the locking groove enters the locking groove, and the locking groove can play the role of axial limiting. The inner side of the cover is machined.

[0011] Preferably, the locking groove is an annular groove.

[0012] In this solution, an annular groove is used as the locking groove. When the cover is fitted onto the bolt, the locking structure on the bolt that matches the locking groove does not need to be aligned with the locking structure, thus reducing the difficulty of operation.

[0013] Preferably, in order to facilitate the calculation of the force corresponding to the damage of the vulnerable part, the vulnerable part is provided with a positive pressure surface, which is located on the wall of the insertion hole.

[0014] In this scheme, setting a positive pressure surface allows the cut-off structure on the bolt to be connected to the vulnerable part through a surface. The surface contact method makes it easier to determine the force-bearing area of ​​the vulnerable part, thereby facilitating the calculation of the force on the vulnerable part.

[0015] Preferably, to further address the problem of computational complexity, the positive pressure surface and the axis of the cover are located in the same plane.

[0016] In this design, because the positive pressure surface and the axis of the cover are located in the same plane, and the vulnerable part rotates with the cover when the cover is turned, it exerts a circumferential force on the cutting structure of the bolt. At this time, the positive pressure surface of the vulnerable part will be subjected to a tangential reaction force. This design allows for direct conversion between torque and pressure on the positive pressure surface, making it simpler to calculate the torque corresponding to the damage of the vulnerable part, thereby reducing the design complexity.

[0017] To improve the stability of the cap under stress, the cut cap includes at least two vulnerable parts, with insertion holes constructed between adjacent vulnerable parts.

[0018] In this solution, the cut-off cover is equipped with at least two vulnerable parts, each of which serves as a stress point, making the cover more stable under stress. This also solves the problem of inaccurate torque and torque corresponding to the breakage of vulnerable parts caused by uneven stress on the cover and resulting in skewness.

[0019] To further improve the uniformity of stress on the cover and ensure accurate correspondence between the design torque and the fracture of vulnerable parts, each vulnerable part is symmetrical about the axis of the cover.

[0020] In this design, the centrally symmetrical method of turning the cover can further ensure that the overall force on the cover is evenly distributed, thus preventing the cover from tilting.

[0021] If the shape of the vulnerable part of each cut-off cap is designed separately, there will be a problem of high design cost. Therefore, the vulnerable part is provided with a vulnerable structure to reduce the strength of the vulnerable part.

[0022] In this solution, a uniformly sized vulnerable part can be designed first. Based on the preload force of the bolt, corresponding vulnerable structures are then machined onto this uniformly sized vulnerable part, ensuring that the vulnerable part breaks when the bolt reaches the corresponding preload force. Since the vulnerable structures for various cut-off caps can be machined onto the same vulnerable part, only the shape and dimensions of the vulnerable structure need to be calculated during the design phase, thus reducing design costs.

[0023] Preferably, a first guide surface is provided on the side of the cover away from the vulnerable part, and a second guide surface is provided on the opening of the locking groove, with the second guide surface located on the side closer to the vulnerable part.

[0024] In this design, the first guide surface and the second guide surface can serve as guides to prevent the bolt ends from getting stuck against the side of the cover or locking groove, thus reducing the difficulty of fitting the cover onto the bolt.

[0025] Preferably, the channel is a stepped hole, and the locking groove is located at the end with the larger diameter of the stepped hole.

[0026] In this design, stepped holes allow structures such as positioning rings and anti-reverse rings to be installed inside the cover body, preventing the cover body from detaching from the bolts after it is connected to the bolts.

[0027] The beneficial effects of this utility model are:

[0028] The axial limiting part of this utility model cooperates with the vulnerable part with an insertion hole on one side. A cutting structure can be set at the end of the part where the bolt and the cutting cover cooperate. When the cutting structure is inserted into the insertion hole and the cutting cover is tightened, the cutting structure will directly squeeze the vulnerable part. Since there is no variable such as friction force that changes with pressure, the calculation of the force between the cutting structure and the vulnerable part is simpler during the design, thus reducing the design difficulty. Attached Figure Description

[0029] To more clearly illustrate the technical solution 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.

[0030] Figure 1 This is a schematic diagram of the structure of Embodiment 1;

[0031] Figure 2 This is a top view of Embodiment 1;

[0032] Figure 3 This is a top view of Embodiment 2;

[0033] Figure 4 This is a cross-sectional view of Example 3;

[0034] Figure 5 This is an exploded view of the present invention and the bolt;

[0035] Figure 6 This is a partial cross-sectional view of the present invention in conjunction with bolts, anti-reverse rings, and locking structures;

[0036] Figure 7 This is a partial cross-sectional view of the present invention in conjunction with bolts, rubber rings, and locking structures;

[0037] Figure 8 A partial sectional view of this utility model in conjunction with bolts, anti-reverse rings, and a locking structure with stepped holes.

[0038] In the above figures, the corresponding reference numerals are as follows:

[0039] 1. Cover; 2. Vulnerable part; 3. Covering part; 4. Positive pressure surface; 5. Locking groove; 6. First inclined surface; 7. Second inclined surface; 8. Rubber ring; 9. Vulnerable groove; 10. Bolt; 11. Insertion hole; 12. Anti-reverse ring; 101. Second screw; 102. Protrusion; 103. Groove. Detailed Implementation

[0040] The technical solution of this utility model will be clearly and completely described in conjunction with the accompanying drawings and through specific embodiments.

[0041] Example 1:

[0042] like Figure 1 As shown, this embodiment provides a cutting cap, including a cap body 1, a shielding part 3, a vulnerable part 2, and a locking groove 5. The cap body 1 is nut-shaped, meaning its outer surface is a hexagonal prism, facilitating wrench operation. A channel is provided along the axial direction of the cap body 1, extending through both the upper and lower ends, with openings on both sides. The vulnerable part 2 connects to the inner surface of the channel in the cap body 1, or it connects to the end face of the cap body 1. An insertion hole is provided on one side of the vulnerable part 2. The locking groove 5 is located on the inner surface of the channel. Its function is to restrict the position of the cap body 1 along the axial direction, preventing it from moving and thus preventing the cutting cap from detaching from the bolt.

[0043] The outer surface of the cover 1 can also be in the shape of a quadrangular prism or an octagonal prism. The channel on the cover 1 refers to the hole opened on the cover 1. The shape of the hole is a circular hole or a prism hole, and the axis of the hole coincides with the axis of the cover 1.

[0044] The cutting cap in this embodiment is used to mate with a specific bolt 10. A second screw 101 is provided at the top of the bolt 10, and a cutting structure extending axially is provided at the end of the second screw 101. An insertion hole is provided for inserting the cutting structure when screwed in. When the cutting cap mates with the bolt 10, the second screw 101 is provided at the top of the bolt 10, and a marking portion is provided at the top of the second screw 101. The marking portion can be a coating of a different color applied to the top of the second screw 101. The shielding portion 3 is used to shield the marking portion, and the shielding portion 3 is connected to the vulnerable portion 2. The position of the shielding portion 3 corresponds to the marking portion. Normally, the marking portion is located on the end face of the second screw 101, and the shielding portion 3 is located at the center of the channel of the cap body 1. The shielding portion 3 can be an opaque sheet material such as a rectangular sheet or a circular sheet, used to shield the marking portion on the bolt 10.

[0045] like Figure 2 and Figure 5As shown, the vulnerable part 2 is provided with a positive pressure surface 4, which is located in the same plane as the axis of the cover 1. With the positive pressure surface 4, only a protrusion 102 needs to be provided on the end face of the second screw 101. The protrusion 102 serves as a cutting structure on the second screw 101, used to cut off the protrusion 102. In use, the protrusion 102 is inserted into the insertion hole. Tightening the cover 1 causes the protrusion 102 to abut against the positive pressure surface 4. When the cutting cover is tightened, the torque can be transmitted to the second screw 101 through the cutting cover, causing the entire bolt 10 to rotate. Because the positive pressure surface 4 and the axis of the cover 1 are located in the same plane, the pressure exerted by the torque on the positive pressure surface 4 is perpendicular to the positive pressure surface 4. Therefore, the force on the vulnerable part 2 can be directly calculated through the torque, thereby designing the shape or size of the vulnerable part 2 without the need for multiple force conversions, reducing design complexity. It should be noted that the purpose of providing the positive pressure surface 4 is to facilitate the calculation of the stress on the vulnerable part 2, reducing the design workload. Similarly, the vulnerable part 2 in this embodiment can also contact the protrusion 102 through a curved or irregular surface. It is only necessary to calculate the stress condition of the vulnerable part 2 so that the vulnerable part 2 can break when the bolt 10 reaches the warning force.

[0046] The vulnerable part 2 connects the cover 1 and the shielding part 3, and the positive pressure surface 4 is a plane. The other surfaces of the vulnerable part 2 can be planes or curved surfaces. For ease of calculation, the vulnerable part 2 can be shaped as a quadrangular prism. Compared with irregular shapes, it is easier to calculate the magnitude of the force corresponding to the breakage or damage of the vulnerable part 2.

[0047] The cut-off cap can have only one vulnerable part 2. When only one vulnerable part 2 is provided, when the cut-off cap is turned, the torque is transmitted to the bolt 10 through the vulnerable part 2. At this time, the only stress point between the cut-off cap and the bolt 10 is the vulnerable part 2, and the vulnerable part 2 is not centered, which can easily cause the cut-off cap to be misaligned. This causes the pressure direction on the positive pressure surface 4 to be tilted relative to the positive pressure surface 4, which may cause the vulnerable part 2 to break if the torque on the bolt 10 is inaccurate, potentially affecting the accuracy of the preload of the bolt 10.

[0048] The cut-off cover can also be provided with two or more vulnerable parts 2. When the cut-off cover is provided with two or more vulnerable parts 2, it is preferable to arrange each vulnerable part 2 evenly along the circumference of the cover body 1, so that the cover body 1 is subjected to uniform force, avoids the cover body 1 from tilting during the tightening process, and ensures that the vulnerable part 2 breaks when the bolt 10 is under accurate preload. Insertion holes are constructed between each vulnerable part 2 to facilitate the insertion of each protrusion 102.

[0049] In use, the cover 1 needs to be fitted onto the second stud of the bolt 10 from top to bottom, with the vulnerable part 2 and the shielding part 3 located on the side away from the second stud. To avoid the end face of the second stud abutting against the lower end face of the cover 1 and affecting assembly efficiency, a first inclined surface 6 can be provided at the opening at the bottom of the cover 1. The first inclined surface 6 serves as a guide, allowing the top of the second stud to slide along the first inclined surface 6 when it contacts it, thus sliding the top of the second stud into the through hole of the cover 1. This facilitates the quick fitting of the cover 1 onto the second stud 101, increasing the speed of cover 1 fitting.

[0050] like Figure 4 As shown, the locking groove 5 is used to lock the position of the cover 1. The locking groove 5 serves as an axial limiting part to restrict the axial movement of the cover 1. Unlike threaded connections, the locking groove 5 restricts the axial movement of the cover 1 while allowing the cover 1 to rotate freely relative to the bolt.

[0051] Because the cover 1 of this application transmits torque to the bolt 10 through the positive pressure surface 4 of the vulnerable part 2, it is not necessary to provide threads on the inner surface of the cover 1. This also makes it easy for the cover 1 to detach from the bolt 10.

[0052] The locking groove 5 is preferably an annular groove. The annular groove does not require alignment between the locking groove 5 and the locking structure on the bolt 10, thus reducing the complexity of operation. The locking structure on the bolt 10 can be an elastic rubber ring 8. An annular groove 103 can also be provided on the outer surface of the second stud of the bolt 10, so that the rubber ring 8 is located in the groove 103, preventing the rubber ring 8 from moving along the axis of the second stud. The rubber ring 8 is stuck in the locking groove 5, which can prevent the cover 1 from moving relative to the rubber ring 8 along the axis of the second stud, thereby achieving the function of locking the position of the cover 1.

[0053] like Figure 6 and Figure 7 As shown, similarly, the locking groove 5 can also be a rectangular groove, a circular groove, etc., located on the inner side of the cover 1. In this case, an elastic block corresponding to the position of the locking groove 5 needs to be set in the groove 103 of the second stud, so that the elastic block can be locked in the corresponding locking groove 5. The elastic blocks can be connected to each other by metal wires, which are located in the groove 103 of the second stud and do not affect the movement of the cover 1. In this case, the position of the locking groove 5 needs to be aligned with the elastic block, so it has the disadvantage of being more cumbersome to operate compared to an annular groove.

[0054] When the locking groove 5 is an annular groove, if the axis of the cover 1 is misaligned relative to the axis of the second stud during the process of fitting the cover 1 onto the second stud, the second stud may abut against the locking groove 5, affecting the continued fitting of the cover 1. Therefore, a second inclined surface 7 is provided on the side of the locking groove 5 near the vulnerable part 2 and the blocking part 3. The second inclined surface 7 guides the end of the second stud to move into the through hole of the cover 1, making the fitting process of the cover 1 smoother. The locking structure can then employ a locking ring, rubber ring, or similar structure.

[0055] Example 2:

[0056] This embodiment two provides a cutting cap. Unlike embodiment one, the vulnerable part 2 in this embodiment two is provided with a vulnerable structure.

[0057] like Figure 3 As shown, in this second embodiment, the vulnerable part 2 is provided with vulnerable structures such as vulnerable grooves 9 and vulnerable holes. The vulnerable grooves 9 or vulnerable holes reduce the strength of the vulnerable part 2, allowing it to break under the designed pressure of the positive pressure surface 4.

[0058] When the cut-off cover is used in different scenarios, the preload requirements of different bolts 10 are different. In this case, the pressure corresponding to the fracture of the vulnerable part 2 can be calculated by the preload, and then the size and position of the vulnerable groove 9 or vulnerable hole can be calculated based on this pressure, so that the cut-off cover meets the usage requirements of the bolt 10. Furthermore, this design method changes the strength of the vulnerable part 2 by machining different vulnerable grooves 9 or vulnerable holes on the vulnerable part 2 of the same specification and shape, which can improve the versatility of the cut-off cover and reduce costs.

[0059] For example, in two different application scenarios, both require the use of M17 bolts 10, but with different preloads. In these cases, the overall dimensions of the cut-off caps corresponding to the M17 bolts 10 are the same, but because the preloads are different, only the corresponding vulnerable part 2 needs to differ. The vulnerable part 2 needs to break under different preloads on the bolts 10. In this situation, the size and location of the vulnerable groove 9 or vulnerable hole can be calculated, and then the vulnerable hole or vulnerable groove 9 can be machined on the vulnerable part 2 to meet the application requirements, ensuring that the vulnerable part 2 breaks under the required preload on the bolts 10.

[0060] Example 3:

[0061] This embodiment three provides a cutting cap. Unlike embodiment one, the axial limiting part used to restrict the axial movement of the cap 1 is different in this embodiment three.

[0062] Optionally, a limiting hole can be provided on the side of the cover 1, with the limiting hole arranged radially along the cover 1, for inserting a limiting pin. A groove 103 is provided on the second screw 101, and the end of the limiting pin is inserted into the groove 103, so that the limiting pin can prevent the cover 1 from detaching from the second screw 101. The limiting pin can be permanently driven into the limiting hole, that is, the limiting pin and the limiting hole are interference-fitted, and the limiting pin cannot be removed after being driven into the limiting hole, thus preventing the cover 1 from being removed from the second screw 101 due to the limiting pin detaching from the limiting hole.

[0063] Example 4:

[0064] This embodiment four provides a cutting cover, which differs from embodiment one in that the channel provided in the cover body 1 is a stepped hole.

[0065] like Figure 8 As shown, the stepped hole is divided into a small-diameter section and a large-diameter section. The vulnerable part 2 is connected to the small-diameter section of the stepped hole, while the locking groove 5 is set on the large-diameter section of the stepped hole. The stepped hole allows structures such as the anti-reverse ring and rubber ring to be located in the large-diameter section, thus enabling the anti-reverse ring and rubber ring to be connected to the cover 1 first. When the cover 1 is connected to the second screw 101, the anti-reverse ring and rubber ring naturally move with the cover 1 and are engaged in the groove 103 on the second screw 101.

Claims

1. A cut-off cap characterized by, It includes a cover (1), a shielding part (3) and a vulnerable part (2). The cover (1) is provided with a channel. The vulnerable part (2) is connected to the cover (1). The shielding part (3) is connected to the vulnerable part (2). The shielding part (3) is located in the axial direction of the channel. An insertion hole is provided on one side of the vulnerable part (2). The cover (1) is provided with an axial limiting part for restricting the axial movement of the cover (1).

2. A cut-off cap according to claim 1, wherein The axial limiting part includes a locking groove (5) formed on the inner side of the cover (1).

3. A cut-off cap according to claim 2, wherein The locking groove (5) is an annular groove.

4. A cutting cap according to claim 1, characterized in that, The vulnerable part (2) is provided with a positive pressure surface (4), which is located on the wall of the insertion hole.

5. A cutting cap according to claim 4, characterized in that, The positive pressure surface (4) and the axis of the cover (1) are located in the same plane.

6. A cutting cap according to claim 1, characterized in that, It includes at least two vulnerable parts (2), and there is a socket between adjacent vulnerable parts.

7. A cutting cap according to claim 6, characterized in that, Each vulnerable part (2) is evenly distributed along the circumferential direction relative to the axis of the cover (1).

8. A cutting cap according to claim 1, characterized in that, The vulnerable part (2) is provided with a vulnerable structure, which reduces the strength of the vulnerable part (2).

9. A cutting cap according to claim 2, characterized in that, A first guide surface (6) is provided on the side of the cover (1) away from the vulnerable part (2), and a second guide surface (7) is provided on the opening of the locking groove (5). The second guide surface (7) is located on the side close to the vulnerable part (2).

10. A cutting cap according to claim 2, characterized in that, The channel is a stepped hole, and the locking groove (5) is located at the end with the larger diameter of the stepped hole.

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