Anti-loosening rivet bolt

Abstract

The invention relates to the technical field of threaded fastener connection, and is a kind of anti-loosening riveted bolt, wherein the bolt rod (1) of the bolt protrudes from the other side outer wall, and the diameter of the bolt rod (1) is consistent throughout the entire length; a locking ring (2) with a flange is sleeved on the protruding end of the bolt rod (1), and the flange surface is in close contact with the other side outer wall, and is squeezed and deformed by a riveting tool, formed and engaged on the thread of the screw rod (1), and is pressed against the other side outer wall; a section of the protruding end of the bolt rod (1) and engaged with the riveted locking ring (2) has thread sections (11, 13) of opposite rotation directions; the locking ring (2) has an inward protrusion (21) at the outer side opening of the locking ring (2) sleeved with the bolt rod (1), and the protrusion height is equivalent to the height of the thread. Theoretically, it can achieve the goal of never loosening. The extrusion force of riveting can be increased, and riveted bolts of the same shape, mass and weight can provide a larger tensile load, and the size can be reduced, the material consumption can be reduced, the weight of the riveted bolt can be reduced, and the cost can be reduced.

Description

Technical Field

[0001] The invention relates to the technical field of threaded fastener connection, in particular to a riveted bolt structure. Background Art

[0002] Fasteners are the most widely used mechanical parts, involving machinery, chemical industry, petroleum, construction, transportation, bridges, automobiles, ships, aerospace, military and national defense, and are almost everywhere.

[0003] Fasteners are a general term for a type of mechanical parts used to fasten two or more parts (or components) into a whole. They are also called standard parts in the market. The most commonly used is the bolt connection structure. Bolts are a type of fastener consisting of a head and a screw (a cylinder with external threads). They need to be matched with nuts to fasten two parts with through holes. This type of connection is called bolt connection. When the two parts need to be separated, the two parts can be easily separated by unscrewing the nut from the bolt.

[0004] This method is the most traditional and widely used structure. However, in the long history of use, users are dissatisfied in some occasions. Since the screw of the bolt is threaded, the nut will naturally loosen along the thread after being tightened for a long time. Therefore, washers and spring washers are produced, which do provide some improvement and can appropriately resist and reduce the loosening caused by vibration.

[0005] In some fastening occasions, it is not necessary to loosen and separate after fastening. It is a one-time and permanent fastening, such as the assembly of buildings and the construction of bridges. It is hoped that the joint and fastening are as tight and firm as possible, and there is no need to disassemble and separate. Therefore, people invented a riveting connection method, and the most common structure is rivets. However, the preload of traditional rivets is relatively low, and the preload dispersion of a group of rivets is large, which cannot meet the requirements of friction-type connections of steel structures.

[0006] In order to overcome the shortcomings of traditional rivets, people have come up with the riveting bolt connection method. After the bolt is inserted into the two parts with through holes to be fastened, a section is exposed, and a metal lock ring is put on. The metal lock ring is squeezed and deformed by the extrusion force on the outer periphery. The inner wall of the metal lock ring and the texture of the bolt are inlaid with each other to form an inner texture, which ensures that the lock ring and the bolt are tightly fastened together and do not fall off. The inner wall of the metal lock ring is deformed by cold work. Due to the characteristics of cold work hardening of metal materials, the hardness and strength of the texture are significantly improved, which plays a good bite effect and has a strong fastening force. However, the usual threaded connection will loosen to varying degrees over time. This riveting method has opened up new ideas for people. Since it is composed of later sleeves, extrusions, and deformations, the shortcomings of the bolt can be completely corrected. No spiral pattern is set on the bolt. When designing, a series of concave and convex ring grooves are set up in succession. Such a shape structure can effectively prevent the threaded connection from loosening due to vibration, thereby causing the connection to fail.

[0007] However, people's pursuit of product requirements is endless, and they want to further improve and upgrade on the original basis.

[0008] According to analysis, the effective cross-sectional area of ​​the ring groove rivet is calculated according to the minimum diameter of the ring groove. It is smaller than the nominal cross-sectional area of ​​the bolt with the same diameter, so its minimum tensile load is also smaller.

[0009] After the bolt of the riveted bolt is inserted into the through hole of the fastener, a locking ring is put on the other side for riveting (after riveting, the locking ring is equivalent to a nut). The riveting tool used is composed of two cylindrical parts that can slide axially against each other. The inner cylinder pulls the protruding end of the bolt outward, and the outer cylinder presses the end of the locking ring. Driven by the hydraulic system, they move relatively, squeezing the outer cylinder of the locking ring, and squeezing the material of the inner wall of the locking ring into the thread groove of the bolt to form a female ring groove, similar to a nut that bites into the male ring groove on the bolt and is tightened together.

[0010] In order to pull one end of the bolt, the bolt end of the prior art riveting bolt must have a short tail of a male ring groove with a reduced diameter, so that the inner wall of the end of the inner cylinder of the riveting tool also has a female ring groove with the same diameter to cooperate and pull outward. The reason for this diameter reduction is that in order to grasp the ring groove of the bolt end at the end of the inner cylinder, a three-jaw spring chuck mechanism is set. When clamping, the three-jaw spring chuck is opened and then closed. After closing, this mechanism must be accommodated in the outer cylinder without affecting the axial displacement between each other. Therefore, the diameter of the bolt end has to be reduced. However, this reduction brings great disadvantages, greatly reducing the minimum tensile load of the entire bolt, that is, the preload after the bolt is riveted is reduced, which is near the lower limit of the value specified by the national standard. This state will reduce the fatigue resistance of the bolt connection pair after installation. Theory and practice have proved that the greater the tension on the bolt during riveting, the greater the clamping force of the lock ring after riveting. This not only improves the fatigue resistance after installation, but also improves the stability of the structure. The tensile force that a bolt can withstand depends on the diameter of the bolt screw and is determined by the minimum diameter. Due to the structural reasons of the riveting tool, the riveting bolt has to adopt such a structure, which cannot exert the tensile force of the same diameter screw and can give a greater extrusion pressure, and cannot give full play to its fastening force. This is also a very heavy loss and cost.

[0011] The connection method of riveting bolts has been introduced for decades. Some industry insiders say that there has been no improvement or change for about 80 years since World War II. The technicians in this field are in agony and in a dilemma. When choosing the ring groove installation, the axial force is not applied to weaken the tightness of the fastening, and the thread installation has the risk of loosening and hidden dangers. Sometimes it is necessary to increase the volume and weight, or adopt other methods, which of course also brings other adverse consequences. Moreover, in some occasions, such as large overpasses, railways, viaducts, and aerospace vehicles, a slight improvement will have immeasurable technical value, economic value, scientific and technological value, social value, and market value. People have been wandering for decades, hoping for solutions and measures to improve. Summary of the invention

[0012] The purpose of the present invention is to provide a riveted bolt connection structure which has the maximum tensile load of a high-strength bolt and can prevent the threaded connection from loosening due to vibration or natural factors over time.

[0013] The purpose of the present invention is achieved by the following technical solutions:

[0014] A kind of anti-loosening rivet bolt,

[0015] A through hole is provided between two or more workpieces for fastening and connecting, a bolt is inserted into the through hole from one side, and the fastening surface of the bolt head abuts against the outer wall of one side of the through hole, characterized in that:

[0016] The bolt rod of the bolt extends out of the outer wall on the other side, and the diameter of the bolt rod is consistent throughout the entire length;

[0017] A locking ring with a flange is placed on the protruding end of the bolt rod, with the flange surface close to the outer wall on the other side, and is deformed and formed by a riveting tool to bite on the thread of the screw rod and press tightly on the outer wall on the other side;

[0018] A section of the bolt rod protruding end engaging with the riveted lock ring has thread sections with opposite rotation directions;

[0019] An inward protrusion is provided at the outer hole of the locking ring which is sleeved with the bolt rod, and the height of the protrusion is equivalent to the height of the thread.

[0020] After riveting using this technical solution, the material of the lock ring is squeezed into the thread grooves of the left-hand thread and the right-hand thread at the same time, restraining each other, so that the lock ring and the bolt are tightly combined together, and no displacement can occur between the bolt and the lock ring.

[0021] It is well known to those skilled in the art that when a length of the locking ring is engaged with threads of opposite directions, the directions of the forces and decomposition forces caused by the thread directions are exactly opposite, so it is impossible for the riveting to loosen over time after use.

[0022] According to the technical solution, there is no section with a reduced diameter at the end of the bolt rod, so there is no problem of axial weakening in bearing tensile load during riveting. The tensile force on the bolt during riveting and extrusion can be increased, and the pre-tightening force of the pre-bolted connection pair after riveting can be improved.

[0023] The protrusion plays a role similar to the internal thread of a nut, so that the locking ring can move along the thread of the bolt rod and fit closely with the structural workpiece, which is easy to operate, especially when the bolt rod is in a nearly vertical position, which can prevent the locking ring from falling before riveting, and is easy to operate.

[0024] Furthermore, a section of the bolt rod protruding end that engages with the riveted lock ring has thread sections of the same length and opposite rotation directions.

[0025] Furthermore, there is a transition zone between the two threads with opposite rotation directions at the extended end of the bolt rod, the diameter of which is not less than the diameter of the thread blank, and the axial width is less than or equal to one pitch.

[0026] Furthermore, the inner diameter of the locking ring is greater than or equal to the outer diameter of the bolt.

[0027] The advantages and beneficial effects of this technical solution.

[0028] Since "the protruding end of the bolt rod and the riveted lock ring have threaded sections with opposite rotation directions in a section of length", it can be inferred from common sense that it can theoretically achieve the goal of never loosening.

[0029] "There is no section with a reduced diameter at the end of the bolt rod, so there is no problem of axial weakening in bearing tensile load during riveting, and the extrusion force of riveting can be increased." The technical advantages brought by this structure are also significant. Therefore:

[0030] Riveted bolts of the same shape, quality and weight can provide greater tensile load resistance, which is very valuable for aviation, aerospace, viaducts and other occasions where the usage is large and weight is very important.

[0031] Under the condition of requiring the same tensile strength and tightening force, it is also very valuable to reduce the size, reduce the amount of material, and reduce the weight of the riveted bolts, which reduces costs and has a competitive advantage in any occasion. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a structural diagram of the anti-loosening riveted bolt of the present invention, with the bolt rod and the locking ring in a disengaged state;

[0033] Figure 2 The anti-loosening riveting bolt of the present invention, the bolt rod and the locking ring are in a screwed state, and a structural diagram of the riveting tool is attached;

[0034] Figure 3 For Figure 2 The extrusion die is screwed on the extended end of the bolt rod and pulled axially outward, and the lock ring is squeezed;

[0035] Figure 4 This is a prior art diagram of a short tail nail structure with a reduced diameter at the bolt end of a riveted bolt;

[0036] Figure 5 It is a structural schematic diagram of a short tail nail of a riveting bolt in the prior art, and a three-jaw spring chuck of a riveting tool in an open state;

[0037] Figure 6 It is a structural schematic diagram of the prior art of riveting a short tail nail of a riveting bolt, a riveting tool three-jaw spring chuck closed, and a squeeze lock ring state.

[0038] In the figure, 1. bolt rod, 12. transition zone, 11. one-way thread, 13. other-way thread, 14. bolt head, 2. locking ring, 21. protrusion, 3. workpiece, 4. tension sleeve, 5. extrusion die. DETAILED DESCRIPTION

[0039] The structure of the present invention is further described in detail below with reference to the accompanying drawings.

[0040] A kind of anti-loosening rivet bolt,

[0041] Two or more workpieces 3 for fastening are provided with through holes, bolts are inserted into the through holes from one side, and the fastening surface of the bolt head 14 abuts against the outer wall of one side of the through hole, characterized in that:

[0042] The bolt rod 1 of the bolt extends out of the outer wall on the other side, and the diameter of the bolt rod 1 is consistent throughout the entire length;

[0043] The locking ring 2 with flange is placed on the protruding end of the bolt rod 1, and the flange surface is close to the outer wall of the other side. It is squeezed and deformed by the riveting tool, formed and bitten on the thread of the screw rod 1, and pressed tightly on the outer wall of the other side.

[0044] A section of the bolt rod 1 where the protruding end engages with the riveted lock ring 2 has thread sections 11 and 13 with opposite rotation directions;

[0045] An inward protrusion 21 is provided at the outer hole of the locking ring 2 which is sleeved with the bolt rod 1 , and the height of the protrusion is equivalent to the height of the thread.

[0046] The bolt rod 1 has threaded sections 11 and 13 of the same length and opposite rotation directions in a length where the protruding end of the bolt rod 1 engages with the riveted lock ring 2. A better effect is that the lengths of the two threads are the same or similar and are subjected to similar tensile loads, which is beneficial to the service life of the screw rod.

[0047] The bolt rod 1 has a transition zone 12 between two threads of opposite directions at the extended end, the diameter of which is not less than the diameter of the thread blank, and the axial width is less than or equal to one pitch. There must be a transition zone 12 between the two threads of opposite directions, which is convenient and advantageous for manufacturing and use.

[0048] The inner diameter of the locking ring is greater than or equal to the outer diameter of the bolt 1. During the riveting process, the locking ring 2 needs to move and slide on the outer surface of the bolt 1, so there is such a technical requirement. For a bolt with a diameter of about 10 mm, the gap between the two is greater than about 0.2-0.4 mm. The protrusion 21 needs to be able to rotate smoothly into the threaded connection section of the bolt.

[0049] The present invention is not limited to the above-mentioned embodiments. Based on the technical solution disclosed in the present invention, technicians in this field can make some substitutions and deformations to some technical features therein according to the disclosed technical content without creative labor, and these substitutions and deformations are all within the protection scope of the present invention.

Claims

1. An anti-loosening riveted bolt, A through hole is provided on two or more workpieces (3) for fastening and connecting, a bolt is inserted into the through hole from one side, and a fastening surface of the bolt head (14) abuts against an outer wall of one side of the through hole, wherein the feature is: The bolt rod (1) of the bolt extends out of the other side outer wall, and the diameter of the bolt rod (1) is consistent over the entire length; A locking ring (2) including a flange is sleeved on the protruding end of the bolt rod (1), with the flange surface in close contact with the outer wall on the other side, and is deformed and shaped by a riveting tool to bite into the thread of the bolt rod (1), and is pressed tightly against the outer wall on the other side; An inward protrusion (21) is provided at the outer opening of the lock ring (2) which is sleeved with the bolt rod (1), and the height of the protrusion is equivalent to the height of the thread; The bolt rod (1) has threaded sections (11, 13) of the same length and opposite rotation directions in a section of the length where the protruding end of the bolt rod (1) engages with the riveted lock ring (2); A transition zone (12) having a diameter not less than the diameter of the thread blank is provided between two thread sections with opposite rotation directions at the protruding end of the bolt rod (1), and the axial width is less than or equal to one thread pitch.

2. The anti-loosening rivet bolt according to claim 1, characterized in that: The inner diameter of the locking ring is greater than or equal to the outer diameter of the bolt rod (1).

Images