Positive and negative tooth combined threaded connection structure

Abstract

The utility model discloses a positive and negative tooth combined threaded connection structure which comprises a connecting piece, a connected piece, a connecting nut and a bolt. The connecting piece, the connected piece and the connecting nut are all provided with mounting holes for bolts to penetrate through. A nut end is arranged at one end, far away from the connecting piece, of the connected piece, and an internal thread is arranged at the nut end; the connecting nut comprises a nut main body and an outer nut extending outwards; the outer nut is provided with an internal thread and an external thread, the nut body is provided with an internal thread, the internal thread of the nut body is connected with the internal thread of the outer nut to form a complete internal thread of the connecting nut, and the external thread of the outer nut and the internal thread of the nut end form a first thread pair; the internal thread of the connecting nut and the bolt form a second thread pair, and the looseness of the first thread pair is larger than that of the second thread pair.

Description

Technical Field

[0001] This utility model belongs to the field of bolt and nut connection technology, specifically relating to a combination of positive and negative threaded connections. Background Technology

[0002] Vibration can cause bolts to loosen or wear out, which over time can lead to the failure of bolt preload, resulting in relative displacement between the connectors and between the connectors and the bolts and nuts, thus losing the connection function. Utility Model Content

[0003] Purpose of the utility model: To address the shortcomings of the prior art, this utility model proposes a combined positive and negative thread connection structure, which can be used in all fields requiring bolt and nut combination connections.

[0004] Technical solution: A combined positive and negative threaded connection structure, comprising: a connector, a connected part, a connecting nut, and a bolt; the connector, the connected part, and the connecting nut are all provided with mounting holes for the bolt to pass through; a nut end is provided at the end of the connected part away from the connector, and the nut end is provided with internal threads; the connecting nut includes a nut body and an outwardly extending outer nut; the outer nut is provided with internal threads and external threads, and the nut body is provided with internal threads, the internal threads of the nut body and the internal threads of the outer nut are continuous to form a complete internal thread of the connecting nut, and the external threads of the outer nut and the internal threads of the nut end form a first thread pair; the internal threads of the connecting nut and the bolt form a second thread pair, and the looseness of the first thread pair is greater than the looseness of the second thread pair.

[0005] Furthermore, it also includes a counternut; the counternut is fixedly connected to the top of the bolt.

[0006] Furthermore, the direction of the internal thread at the nut end is opposite to the direction of the internal thread of the connecting nut.

[0007] Furthermore, the pitch of the internal thread at the nut end is greater than the pitch of the internal thread of the connecting nut.

[0008] Furthermore, the direction of the external thread of the outer nut is opposite to the direction of the internal thread of the connecting nut.

[0009] Furthermore, the diameter of the mounting hole is the same as the diameter of the bolt.

[0010] Beneficial effects: Compared with the prior art, this utility model has the following advantages:

[0011] (1) The connected parts of this utility model are effectively connected by bolts and nuts, and the connection between the nut end of the connected parts and the outer nut of the connecting nut greatly increases the connection rigidity between the connected parts and the bolts and nuts, and eliminates the relative displacement between the connected parts and between the connected parts and the bolts and nuts caused by the gap caused by the bolt hole being larger than the bolt diameter.

[0012] (2) This utility model can greatly reduce problems such as bolt loosening and wear of connector end face caused by vibration, and greatly improve the stability of the connection structure; at the same time, this utility model is more convenient and labor-saving to install, and the double nut method can better ensure bolt loosening prevention.

[0013] (3) This utility model adds an internal thread to the nut end of the connected parts. After installation, the connecting nut and the nut end of the connected parts are fixed relative to each other to form a connecting part and achieve the overall effect. If relative lateral displacement is to occur, not only must the end face overcome the friction force, but it must also climb along the thread angle, which increases the difficulty of displacement. This climbing will also greatly increase the bolt preload. Therefore, this utility model makes it more difficult and smaller to cause lateral relative displacement between the two connecting parts through the rigid transmission of the bolt, thus protecting the connected parts and the internal objects on the end face of the connected parts.

[0014] (4) The pitch of the internal thread of the nut end of the connected part designed in this utility model is greater than the pitch of the internal thread of the connecting nut, so that the lifting angle of the two threads is inconsistent when loosening occurs, thus locking the nut; and physically ensuring that the looseness of the thread pair formed by the two is greater than that of the thread pair formed by the connecting nut and the bolt, ensuring that the looseness of the thread pair is greater after tightening. In the double nut tightening, its direction is opposite to that of the opposing nut, ensuring that the friction force between the two nuts is greater, thus playing an overall anti-loosening role;

[0015] (5) The connecting nut designed in this utility model has reversed internal and external threads, and the pitch of the internal thread of the nut end of the connected part is greater than the pitch of the internal thread of the connecting nut. Once both thread pairs are engaged, the nut will move in the opposite direction to the bolt when rotated. Therefore, the bolt can be tightened unilaterally by rotating the bolt without the need for additional nut fixing, making the installation more convenient and reliable.

[0016] (6) This utility model greatly increases the connection rigidity between the connected parts and the bolt and nut while effectively connecting the bolt and nut, and eliminates the relative displacement between the connecting parts and between the connecting parts and the bolt and nut caused by the gap generated when the bolt hole is larger than the bolt diameter, thereby reducing or eliminating bolt loosening and wear of the end face of the connecting parts caused by vibration, and greatly improving the structural stability. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a combined positive and negative thread connection structure proposed in this utility model;

[0018] Figure 2 This is a structural diagram of a DN15 flange made using a combined positive and negative thread connection structure proposed in this utility model. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of this utility model.

[0020] like Figure 1 As shown, this embodiment proposes a combined positive and negative threaded connection structure, which mainly includes: a connector 1, a connected component 2, a connecting nut 3, a counter nut 4, and a bolt 5. The connected component 2 is provided with a nut end 21. The connecting nut 3 includes a nut body 31 and an outwardly extending outer nut 32. The internal thread of the outer nut 32 is continuous with the internal thread of the nut body 31 and matches the thread of the bolt 5. The external thread of the outer nut 32 matches the internal thread of the nut end 21 on the connected component 2, that is, the connected component 2 is threadedly connected to the outer nut 32 of the connecting nut 3 through its nut end 21.

[0021] After bolt 5 passes through the through hole of connector 1, it forms a threaded connection with the internal thread of connecting nut 3, which is already threaded with the connected part 2. After bolt 5 passes through connecting nut 3, it is fixed with the internal thread of counter nut 4, thus completing the connection between connector 1 and connected part 2. Counter nut 4 is used to fix the top of bolt 5, serving as a double nut to prevent loosening. In this embodiment, the rigidity of the bolts makes it more difficult and less significant for the two connectors to undergo lateral relative displacement.

[0022] The details of the connection structure in this embodiment will now be further explained. The internal thread of the nut end 21 on the connected part 2 is opposite to the internal thread of the connecting nut 3, and the pitch of the internal thread of the nut end 21 on the connected part 2 is greater than the pitch of the internal thread of the connecting nut 3, making its threaded pair more loose than the threaded pair formed by the connecting nut 3 and the bolt 5. The external thread of the connecting nut 3 is opposite to the internal thread. The external thread diameter is reduced according to the pitch, increasing the mating clearance between the threads. That is, the internal thread of the nut end 21 on the connected part 2 connects with the external thread of the connecting nut 3 and increases the mating clearance. Through the clearance, the positional requirements of the multi-hole connector can be reduced, thereby eliminating overall machining errors, reducing precision requirements and costs, and replacing fine machining with rough machining.

[0023] In this embodiment, the mating clearance between the internal thread of the nut end 21 and the external thread of the outer nut 32 can be adjusted appropriately to facilitate the concentricity requirements when installing multiple bolts.

[0024] In this embodiment, the through hole that mates with bolt 5 is designed according to the same specification reamed hole bolt mating method, so that the through hole of the bolt connection is infinitely reduced to close to the bolt diameter, eliminating the possibility of lateral displacement.

[0025] Figure 2 A schematic diagram is shown showing the application of the positive and negative thread combination connection structure proposed in this embodiment to a DN15 flange structure.

Claims

1. A combined positive and negative threaded connection structure, characterized in that: include: Connector (1), connected part (2), connecting nut (3) and bolt (5); The connector (1), the connected part (2), and the connecting nut (3) are all provided with mounting holes for the bolt (5) to pass through; A nut end (21) is provided at the end of the connected member (2) away from the connecting member (1), and the nut end (21) is provided with internal thread; The connecting nut (3) includes a nut body (31) and an outwardly extending outer nut (32); the outer nut (32) is provided with an internal thread and an external thread, the nut body (31) is provided with an internal thread, the internal thread of the nut body (31) is connected with the internal thread of the outer nut to form a complete internal thread of the connecting nut (3), and the external thread of the outer nut (32) and the internal thread of the nut end (21) form a first thread pair; the internal thread of the connecting nut (3) and the bolt (5) form a second thread pair, and the looseness of the first thread pair is greater than that of the second thread pair.

2. The combined positive and negative thread connection structure according to claim 1, characterized in that: It also includes a top nut (4); the top nut (4) is fixedly connected to the top of the bolt (5).

3. The combined positive and negative thread connection structure according to claim 1, characterized in that: The direction of the internal thread of the nut end (21) is opposite to the direction of the internal thread of the connecting nut (3).

4. The combined positive and negative thread connection structure according to claim 1, characterized in that: The pitch of the internal thread of the nut end (21) is greater than the pitch of the internal thread of the connecting nut (3).

5. The combined positive and negative thread connection structure according to claim 1, characterized in that: The direction of the external thread of the outer nut (32) is opposite to the direction of the internal thread of the connecting nut (3).

6. The combined positive and negative thread connection structure according to claim 1, characterized in that: The diameter of the mounting hole is the same as the diameter of the bolt (5).

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