CN210106381U

CN210106381U - Self-locking thread pair

Info

Publication number: CN210106381U
Application number: CN201920151259.4U
Authority: CN
Inventors: 武筱茜; 武安民
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-01-29
Filing date: 2019-01-29
Publication date: 2020-02-21
Anticipated expiration: 2029-01-29

Abstract

The utility model discloses a self-locking thread is vice, it is vice including first screw thread pair and second screw thread, the vice horizontal frictional force that increases first screw thread pair outside first screw thread is fixed to the second screw thread pair, increases the external screw thread work piece of external screw thread as the vice external screw thread work piece of second screw thread at the vice internal screw thread work piece surface of first screw thread. The utility model discloses an effectual threaded connection of having solved of double thread secondary effect because the difference in temperature, the impact, vibration and variable load effect down the screw thread pair rotatory easily not hard up, increased threaded connection's validity, solved the reliance of threaded connection intensity to working face hardness, intensity, eliminate threaded connection to the requirement by connecting piece intensity hardness, and threaded connection must have the reliance of certain pretightning force. Therefore, the defects of the thread pair are overcome, the application field of the thread pair is expanded, and the use safety is improved.

Description

Self-locking thread pair

Technical Field

The utility model relates to a pair of auto-lock screw thread belongs to the vice technical field of screw thread.

Background

The thread has external and internal threads which together form a screw pair. The screw thread is divided into a screw thread for connection and a screw thread for transmission according to the working property. The equivalent friction angle of the connecting thread is larger, which is beneficial to realizing reliable connection; the equivalent friction angle of the transmission screw thread is smaller, which is beneficial to improving the transmission efficiency. The screw thread is a key part of the screw coupling and screw drive, and the characteristics and applications of several common screw threads in machines are described as follows:

1. triangular thread: the tooth form angle is large, the self-locking performance is good, and the tooth root is thick and the strength is high, so the tooth form angle is mainly used for connection.

2. The Pipe Thread has a tooth form angle α of 55 degrees (60 degrees), a circular arc crest, no radial clearance between screwed threads, good tightness, and a nominal diameter of the Pipe, is widely used for the connection of water, gas, hydraulic pressure, lubrication and other pipeline systems, and comprises two common Pipe threads, namely a straight Pipe and a tapered Pipe, 1) NPT, PT, G and the like, 1) NPT is the abbreviation of national (American) Pipe Thread, belongs to the American standard 60-degree tapered Pipe Thread, is used in North America, and is the abbreviation of Pipe Thread, namely 55-degree sealing conical Pipe Thread, belongs to the Whitneh Thread family, is mostly used in Europe and English countries, is commonly used in the water and gas Pipe industry, the taper 1:16, and is used in the national standard GB/T7306-2000, and the national Law of the national Law is ZG..3) G is 55-degree non-sealing Pipe Thread, and belongs to the Whitneh Thread family.

3. In the rectangular thread, the thread form is square, the thread form angle α is 0 degrees, the thread thickness is half of the thread pitch, the equivalent friction coefficient is small, the efficiency is high, but the root strength is low, the axial clearance caused by thread abrasion is difficult to compensate, the centering precision is low, and the finish machining is difficult, so the thread is less adopted.

4. The trapezoidal thread has the tooth form of an isosceles trapezoid, the tooth form angle α is 30 degrees, the efficiency is lower than that of a rectangular thread, but the trapezoidal thread is easy to process, good in centering performance and high in root strength, and when a split nut is adopted, a gap caused by abrasion can be eliminated, so that the trapezoidal thread is widely applied to spiral transmission.

5. Zigzag threads: the flank angle of the working surface of the zigzag thread is 3, the flank angle of the non-working surface is 30, and the helical thread has the advantages of high efficiency of the rectangular thread and high strength of the root of the trapezoidal thread, can only bear unidirectional load, and is suitable for unidirectional bearing helical transmission. The thread has high strength and is used for a force transmission screw stressed in one direction; such as screw presses, jacks, etc.

The threaded connection has the advantages of simple structure, convenient assembly and disassembly and wide application. The defects are that the device is easy to lose efficacy and needs to be pre-tightened and anti-loose on occasions with larger stress and larger temperature difference. This drawback has always plagued the development and use of thread pairs. Furthermore, the surface of the connection piece must have a certain strength and hardness for the threaded connection, otherwise failure to achieve the required preload force can cause failure of the threads, which limits the use of the threaded connection. The effectiveness of a threaded workpiece depends on the accuracy of the thread making of the workpiece, the fit of the thread pair, sufficient pretension, and the requirements on the surface quality and strength of the connection. The combination of the two methods makes the threaded connection easy to loosen and not become a hidden danger of equipment all the time. A large amount of manual periodic inspection and pre-tightening are required.

Why will the threads loosen and fail?

When the object is placed on an inclined plane, it is subjected to two components of downward gravity and horizontal force of transverse movement, and when the transverse component is greater than friction force, the object can be slided along the inclined plane. The compressed thread pair also has the following reason: because the screw thread is an equidistant spiral line, any section of screw thread is an oblique line, the pressure applied to the bolt is decomposed into an axial component force and a transverse component force, when the pressed screw thread pair is subjected to certain vibration, and the transverse component force in the instantaneous time is greater than the friction force, the screw thread connection can be slowly rotated along the oblique plane, the time is long, and the screw thread pair is loosened. Under-pretightening force or failure will also cause the transverse component force to be larger than the friction force, and will rotate the screw slowly along the inclined plane.

SUMMERY OF THE UTILITY MODEL

Utility model purpose: for solving among the prior art screw thread pair produces unfavorable condition such as the pretightning force is not enough or became invalid easily, the utility model discloses a self-locking screw thread pair applies to all vice installations of being used for the screw thread, locking, and is sealed, connects, location and moving mechanical grouping.

The technical scheme is as follows: the utility model discloses a pair of auto-lock screw thread, it is vice including first screw thread pair and second screw thread, the vice horizontal frictional force that increases first screw thread pair outside first screw thread is fixed to the second screw thread pair.

Preferably, an external thread is added on the outer surface of the internal thread workpiece of the first thread pair to serve as an external thread workpiece of the second thread pair.

Preferably, the external thread workpiece of the second thread pair is of a structure with a taper, and the internal thread workpiece of the second thread pair is of a structure matched with the taper of the external thread workpiece of the second thread pair.

Preferably, a plurality of equal communicated grooves are formed in the common section of the internal thread workpiece of the first thread pair and the external thread workpiece of the second thread pair.

Preferably, the taper of the external thread workpiece of the second thread pair meets the requirement that the required torque is reached before the maximum stroke of the second thread pair is reached, so that the thread pair at the tail part of the first thread pair is completely jointed and reaches the required pressure.

Preferably, the thread pitch of the external thread workpiece of the second thread pair is different from the thread pitch of the internal thread workpiece of the second thread pair.

Preferably, the tooth root and tooth height of the external thread workpiece of the second thread pair are not equal to those of the internal thread workpiece of the second thread pair.

Has the advantages that: compared with the prior art, the utility model, have following advantage:

1. the utility model discloses an effectual threaded connection of having solved of double thread secondary effect is because the difference in temperature, assaulted, and vibration and variable load effect are vice rotatory easily not hard up of screw thread down.

2. The utility model discloses increased threaded connection's validity, the security has solved threaded connection intensity to the reliance of working face hardness, intensity, eliminates threaded connection to the requirement by connecting piece intensity hardness, and threaded connection must have the reliance of certain pretightning force.

3. Because the second thread pair makes the laminating between the first thread pair with the pressure that produces increase the rigidity that the external screw thread work piece of first thread pair and the internal thread work piece of first thread pair combine, reduced outside complicated operating mode to the influence of first thread pair, effectual shrink with avoided the vice possibility that takes place relative displacement of first thread. Because the increase of the thread pair and the relative enhancement of the connection rigidity of the external thread work piece of the first thread pair connected by the thread pair and the internal thread work piece of the first thread pair, the failure that the objects such as seals in the connectors such as a threaded connector are shaken to generate abrasion and alternating extrusion due to insufficient rigidity of the connector or the existence of a gap between threads under the action of external force is avoided more effectively, and the elements such as the seals in the first thread pair are effectively protected.

4. Also can pass through to the article that needs use screw thread rotational positioning the utility model discloses a precision problem that the elimination screw thread clearance arouses is vice, improves rotational positioning's precision and stability.

5. Because the second thread pair makes the laminating between the first thread pair, has reduced threaded connection validity to screw member manufacturing accuracy and complex dependency, has improved threaded connection's safety and validity greatly.

Drawings

Fig. 1 is a schematic structural view of the present invention; wherein, 1 is the external thread work piece of the first thread pair, 2 is the internal thread work piece of the first thread pair, 3 is the external thread work piece of the second thread pair, 4 is the internal thread work piece of the second thread pair;

FIG. 2 is a schematic diagram of the application of the external screw thread work piece of the second screw thread pair and the internal screw thread work piece of the second screw thread pair;

fig. 3 is a schematic diagram of the slotting of the present invention.

Detailed Description

The method of the present invention is further described with reference to the accompanying drawings.

The utility model discloses the inside and outside double thread of application is vice, and the vice horizontal friction force that increases the internal thread pair of external screw thread effectively solves the internal thread pair in the difference in temperature, strikes, and vibration and variable load effect lower screw thread pair rotation easily not hard up problem. The utility model discloses can not need the pretightning force just can make the vice auto-lock of screw thread, do not take place the displacement. The requirement of threaded connection on pretightening force is reduced, the application range of the threaded connection on soft metal and low-strength objects is expanded, and the application field of the threaded connection is expanded. The failure caused by the manufacturing error between the thread pairs can be effectively controlled through the taper, the requirement on the manufacturing precision of the threads is lowered, and the stability and the sealing performance of the joint are greatly improved in pipeline connection. The utility model discloses also can utilize in order to eliminate the error that the screw thread clearance brought in various spiral lifting location, improve reciprocating motion's precision, eliminate vice relative vibration of screw thread and the displacement that the atress causes repeatedly of screw thread, increase the stability after the location.

The structure of the utility model is shown in figure 1 in detail, including first screw thread pair and second screw thread pair, the second screw thread pair is fixed and is increased the vice horizontal frictional force of first screw thread pair outside first screw thread pair. The first thread pair satisfies threaded connection's needs as the thread pair of normal work, including the vice external screw thread work piece of first thread 1 and the vice internal screw thread work piece 2 of first thread, the vice conduct locking thread of second thread is vice for paste die and produce certain positive pressure and play the self-locking action between the first thread pair, including the vice external screw thread work piece of second thread 3 and the vice internal screw thread work piece 4 of second thread. And adding external threads on the outer surface of the internal thread workpiece 2 of the first thread pair to serve as an external thread workpiece 3 of the second thread pair.

As shown in fig. 2, the utility model discloses a vice external screw thread work piece 3 of second screw thread is for having the tapering structure, and vice internal screw thread work piece 4 of second screw thread is for the structure with the vice external screw thread work piece 3 taper fit of second screw thread, and the tapering of the vice external screw thread work piece 3 of second screw thread satisfies that the second screw thread is vice not reach required moment of torsion before the maximum stroke and make the laminating of the completion of the afterbody screw thread in the first screw thread is vice and reach required pressure.

As shown in fig. 3, a plurality of slots are formed on the second thread pair external thread workpiece 3, and since the first thread pair internal thread workpiece 2 and the second thread pair external thread workpiece 3 are of an integral structure, the slots penetrate from the thread surface of the first thread pair internal thread workpiece 2 to the thread surface of the second thread pair external thread workpiece 3.

The utility model discloses a thread crest angle of vice external screw thread work piece of second screw thread 3 is unequal with the thread crest angle of vice internal screw thread work piece of second screw thread 4, and the tooth root tooth and the tooth height of vice internal screw thread work piece of second screw thread 4 are inequality.

Example (b):

the first thread pair of the embodiment completes the functions of the existing thread during normal operation, the manufacture size, precision, tolerance, strength grade of the first thread pair external thread workpiece 1 are equal to the requirements of the existing thread connection, the manufacture of the first thread pair internal thread workpiece 2 is matched with the first thread pair external thread workpiece 1, the size, the precision, the tolerance, the strength grade and the requirement of the existing threaded connection are equal, the length is only doubled, this vice internal thread work piece of first screw thread 2 length increases the outside tapered external screw thread that increases and offer a plurality of flutings according to tapering and diameter size, makes things convenient for vice internal thread work piece of first screw thread 2 to shrink when receiving the extrusion, plays the effect similar to opening type elasticity cylindric lock, makes the vice tail portion of first screw thread paste to hug closely and dies to eliminate the screw thread clearance and increase radial pressure between the vice first screw thread, increases the frictional force between the pair first screw thread.

Vice external screw thread work piece 3 of second screw thread and vice interior work piece 4 connection work of second screw thread, vice internal screw thread work piece 4 of second screw thread is gone upward along the conical surface along the vice external screw thread work piece 3 rotation of second screw thread, and continuous extrusion that goes upward makes vice internal screw thread work piece 2 of first screw thread constantly shrink and pastes tight vice external screw thread work piece 1 of first screw thread, and the vice internal screw thread work piece of continuous increase first screw thread 2 and the vice external screw thread work piece 1 pressure before of first screw thread are until required pressure forms.

The second thread pair external thread workpiece 3 is manufactured with maximum tolerance according to the material performance of the first thread pair, the taper is determined by the required strength grade, and the requirements that the second thread pair reaches the required torque before reaching the maximum stroke, the threads between the tail parts of the first thread pair are completely jointed and reach the required pressure are met. The number of slots is determined by the required pressure, material and diameter. Under the premise of meeting the requirements, necessary grease or powder lubrication is added between the thread pairs according to working condition requirements, so that the friction force of the second thread pair is eliminated, and the strength failure of the second thread pair internal thread workpiece 4 caused by the thermal deformation of the second thread pair internal thread workpiece 4 due to the additional resistance and friction heat brought by friction is eliminated or reduced. Meanwhile, the friction and the looseness prevention between the second thread pairs are controlled by using a method of unequal thread angles, and the root angles and the tooth heights of the internal threads and the external threads are made into unequal shapes according to requirements, so that the friction force between the second thread pairs is reduced, and the pressing force is increased, as shown in detail in figure 2.

Claims

1. Self-locking thread pair, its characterized in that: including first screw thread pair and second screw thread pair, the vice horizontal frictional force that increases first screw thread pair outside first screw thread pair is fixed to second screw thread pair, increases the external screw thread work piece as the vice external screw thread work piece of second screw thread at the vice internal screw thread work piece surface of first screw thread, the vice external screw thread work piece of second screw thread is for having the tapering structure, and the vice internal screw thread work piece of second screw thread is the structure with the vice external screw thread work piece taper fit of second screw thread a plurality of equal intercommunication flutings have been seted up on the vice internal screw thread work piece of first screw thread and the vice external screw thread work piece of second screw thread common section, the tapering of the vice external screw thread work piece of second screw thread satisfies that second screw thread pair does not reach required moment of torsion before reaching the maximum stroke and makes the vice completion of vice afterbody screw thread of first screw thread paste and.

2. The self-locking thread pair according to claim 1, wherein: and the thread pitch of the external thread workpiece of the second thread pair is different from the thread pitch of the internal thread workpiece of the second thread pair.

3. The self-locking thread pair according to claim 1, wherein: the tooth root and tooth height of the external thread workpiece of the second thread pair are not equal to those of the internal thread workpiece of the second thread pair.