CN113898656A

CN113898656A - Anti-loosening connecting structure and locomotive

Info

Publication number: CN113898656A
Application number: CN202111202229.XA
Authority: CN
Inventors: 张同玲; 安令云; 刘菁
Original assignee: CRRC Datong Co Ltd
Current assignee: CRRC Datong Co Ltd
Priority date: 2021-10-15
Filing date: 2021-10-15
Publication date: 2022-01-07

Abstract

The disclosure relates to an anti-loosening connecting structure and a locomotive, wherein a spring washer penetrates through a bolt and is in contact with one side, far away from an installation body, of a flat washer, and a nut is in threaded connection with the bolt and compresses the spring washer. The outer diameter of the flat washer is larger than that of the spring washer, the spring washer stretches from a flattening state, the contact between the spring washer and the flat washer is changed from surface contact to line contact, the pressure in unit area is increased, the friction force between the spring washer and the flat washer is increased, meanwhile, the spring washer increases the elastic extension amount of the bolt, and loosening is effectively prevented. The self-locking nut made of all-metal materials can avoid loosening of bolts caused by high temperature, the spring washer can compensate loosening caused by pretightening force change caused by vibration impact, and the resilience force generated by the spring washer is uniform in stress. The threads of the nut and bolt can be reused without damage. The anti-loose connecting structure comprises fewer parts and is simple in structure.

Description

Anti-loosening connecting structure and locomotive

Technical Field

The utility model relates to a rail locomotive technical field particularly, relates to a locking connection structure and locomotive.

Background

The running part of the locomotive is influenced by variable loads, impacts, vibrations and environmental temperature changes of different degrees in the process of running a circuit for a long time, and when the threaded connection with pretightening force is influenced by the complex loads and the temperature changes, the nut can be loosened and rotated, so that the pretightening force is gradually reduced or even eliminated, and the threaded connection is failed.

The existing anti-loose connection adopts a friction anti-loose mode, a mechanical anti-loose mode or a riveting anti-loose mode, some anti-loose performances are unreliable, and some anti-loose performances are inherently reliable without the impact of high-speed operation and strong vibration, but the structure is complex, or the reusability is not good.

It is to be noted that the information disclosed in the above background section is only for enhancement of understanding of the background of the present disclosure, and thus may include information that does not constitute prior art known to those of ordinary skill in the art.

Disclosure of Invention

The purpose of the disclosure is to overcome the defects that the existing anti-loose connection mode is complex in structure or poor in reusability, and provide an anti-loose connection structure and a locomotive.

According to an aspect of the present disclosure, a locking connection structure is provided, including an installation body, a bolt, a flat washer and a spring washer, the installation body is provided with an installation hole, the bolt is in threaded connection in the installation hole, the flat washer passes through the bolt and contacts with one side of the installation body, the spring washer passes through the bolt and contacts with one side of the flat washer far away from the installation body, the outer diameter of the flat washer is larger than the outer diameter of the spring washer, the nut is in threaded connection with the bolt, and the nut is a self-locking nut made of metal.

In one embodiment of the present disclosure, the torque of the nut is set such that the pre-tightening force reaches more than 50% of the yield axial force of the bolt.

In one embodiment of the present disclosure, the spring washer is a conical spring washer, and a contact surface of the spring washer with the lock nut is provided with an uneven rough surface.

In one embodiment of the present disclosure, the nut includes a nut body and a locking portion, and the locking portion is provided with a notch structure, and the notch structure is spread and locked to the bolt by means of a resilient force.

In one embodiment of the present disclosure, the notch structure includes a continuous or intermittent notch circumferentially provided in the side wall of the locking portion, and the thread of the bolt is screwed into the notch.

In one embodiment of the disclosure, the notch structure comprises two notches arranged at different positions along the axial direction, and the length of each notch is greater than or equal to half of the perimeter of the locking part.

In an embodiment of the disclosure, the notch structure includes a notch, the notch extends along the axial direction to form the locking portion into two opposite limiting blocks, and the distance between the two limiting blocks is gradually reduced along the direction away from the nut body.

In one embodiment of the disclosure, the notch structure includes three notches, one notch extends along the axial direction to form the locking part into two opposite limiting blocks, and the other two notches are arranged on one side of the two limiting blocks, which are close to each other.

In one embodiment of the present disclosure, the nut is made of carbon steel and alloy steel, wherein: the 8-grade nuts with the specification of M4-M16 are made of 35 steel, the 8-grade nuts and the 10-grade nuts with the specification of M16-M30 are made of 45 steel quenching and 40Cr or 35CrMo, and the nuts with the specification of more than 10 grade are made of 40Cr or 35 CrMo;

and (3) carrying out quenching and tempering heat treatment on 8-grade nuts and 10-grade nuts with the specification of more than M16, wherein the quenching and tempering hardness of the 8-grade nuts is HV 233-353, and the quenching and tempering hardness of the 10-grade nuts is HV 272-353.

According to another aspect of the present disclosure, there is provided a locomotive including the check link structure of one aspect of the present disclosure.

According to the anti-loosening connecting structure, the spring washer penetrates through the bolt and is in contact with one side, far away from the installation body, of the flat washer, and the nut is in threaded connection with the bolt and compresses the spring washer. The outer diameter of the flat washer is larger than that of the spring washer, the spring washer stretches from a flattening state, the contact between the spring washer and the flat washer is changed from surface contact to line contact, the pressure in unit area is increased, the friction force between the spring washer and the flat washer is increased, meanwhile, the spring washer increases the elastic extension amount of the bolt, and loosening is effectively prevented. The self-locking nut made of all-metal materials can avoid loosening of bolts caused by high temperature, the spring washer can compensate loosening caused by pretightening force change caused by vibration impact, and the resilience force generated by the spring washer is uniform in stress. The threads of the nut and bolt can be reused without damage. The anti-loose connecting structure comprises fewer parts and is simple in structure.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and together with the description, serve to explain the principles of the disclosure. It is to be understood that the drawings in the following description are merely exemplary of the disclosure, and that other drawings may be derived from those drawings by one of ordinary skill in the art without the exercise of inventive faculty.

Fig. 1 is a schematic structural diagram of an anti-loose connection structure according to an embodiment of the present disclosure.

Fig. 2 is a schematic structural diagram of a spring washer according to an embodiment of the present disclosure.

Fig. 3 is a schematic structural diagram of another spring washer according to an embodiment of the present disclosure.

Fig. 4 is a schematic structural diagram of a nut according to an embodiment of the present disclosure.

Fig. 5 is a schematic structural diagram of another nut according to an embodiment of the present disclosure.

In the figure: 1-mounting body, 2-bolt, 3-plain washer, 4-spring washer, 5-nut, 51-nut body, 52-locking part, 53-notch structure, 531-notch, 6-nesting.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus their detailed description will be omitted. Furthermore, the drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale.

Although relative terms, such as "upper" and "lower," may be used in this specification to describe one element of an icon relative to another, these terms are used in this specification for convenience only, e.g., in accordance with the orientation of the examples described in the figures. It will be appreciated that if the device of the icon were turned upside down, the element described as "upper" would become the element "lower". When a structure is "on" another structure, it may mean that the structure is integrally formed with the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure via another structure.

The terms "a," "an," "the," "said," and "at least one" are used to indicate the presence of one or more elements/components/parts/etc.; the terms "comprising" and "having" are intended to be inclusive and mean that there may be additional elements/components/etc. other than the listed elements/components/etc.; the terms "first," "second," and "third," etc. are used merely as labels, and are not limiting on the number of their objects.

In the related art, in modern machines, such as rolling stock, where high speed, precision, and heavy load are one of the important development indicators. Loosening and loosening of the anti-loosening connecting structure can reduce the working reliability of the equipment and cause serious consequences. The influence factors of the reliability of the anti-loosening connecting structure mainly include: thread tension, working load, working temperature, structural form, structural material, structural surface friction state. The reason for the loosening of the bolt connection mainly includes the following reasons: 1. fatigue and damage deformation of the fit between thread forms; 2. the connecting surface deforms to generate looseness; 3, the looseness is generated under the action of complex load. In order to solve the problems of looseness, looseness and breakage of the anti-loosening connecting structure, the existing anti-loosening connecting structure generally has friction anti-loosening, mechanical anti-loosening and riveting anti-loosening.

The friction anti-loose comprises double-nut anti-loose, flat washer anti-loose or nylon insert locking nut anti-loose. The defects of the modes are that the initial pretightening force is reduced along with impact, vibration, variable load and environmental temperature change, the local plastic deformation is generated at the root of the engaged threads to the micro-slip between the engaged threads along with the increase of the vibration times, the contact pressure is reduced, the lost pretightening force is increased, and the thread connection is failed. Mechanical anti-loosening is the use of a stop to directly limit the relative rotation of the thread pairs, which makes disassembly inconvenient. Riveting and anti-loosening are realized by adopting methods such as point filling, welding, bonding and the like after screwing, so that the screw pair loses the characteristics of a kinematic pair and becomes non-detachable connection. The bolt rod has the disadvantages that the bolt rod can be used only once, and is difficult to disassemble, and the bolt pair needs to be damaged for disassembly.

The part anti-loosening connecting structure has unreliable anti-loosening performance and cannot bear the impact of high-speed operation and strong vibration. Part of anti-loose connecting structures are firm and reliable, but the structures are complicated, or the reusability is not good, and the anti-loose connecting structures cannot withstand the impact of high-speed operation and strong vibration.

The loosening process of the anti-loosening connecting structure is divided into two stages, the first stage is a stage of generating plastic deformation, the loosening of threaded connection is avoided from the first stage of inhibiting the loosening, and high-strength and high-toughness materials are mainly selected to avoid the plastic deformation generated in the early loosening period. The second stage is relative movement of the thread pairs, and the main method is to increase friction force and prevent slippage between the thread pairs. In view of the above two aspects, the embodiments of the present disclosure provide an anti-loose connection structure.

As shown in fig. 1 to 5, the anti-loose connection structure comprises an installation body 1, a bolt 2, a flat washer 3 and a spring washer 4, wherein the installation body 1 is provided with an installation hole, the bolt 2 is in threaded connection in the installation hole, the flat washer 3 penetrates through the bolt 2 and contacts with one side of the installation body 1, the spring washer 4 penetrates through the bolt 2 and contacts with one side of the flat washer 3, which is far away from the installation body 1, the outer diameter of the flat washer 3 is larger than that of the spring washer 4, a nut 5 is in threaded connection with the bolt 2, and the nut 5 is a self-locking nut made of metal.

A spring washer 4 passes through the bolt 2 and contacts the side of the flat washer 3 remote from the mounting body 1, and a nut 5 is screwed to the bolt 2 and presses the spring washer 4. The outer diameter of the flat washer 3 is larger than that of the spring washer 4, the spring washer 4 is stretched from a flattened state, the contact between the spring washer 4 and the flat washer 3 is changed from surface contact to line contact, the pressure per unit area is increased, and therefore the friction force between the spring washer 4 and the flat washer 3 is increased, and meanwhile, the spring washer 4 increases the elastic elongation of the bolt 2, and effectively prevents loosening. The self-locking nut made of all-metal materials can avoid loosening of the bolt 2 caused by high temperature, the spring washer 4 can compensate loosening caused by pretightening force change caused by vibration impact, and the resilience force generated by the spring washer 4 is uniform. The nut 5 and the thread of the bolt 2 can be reused without being damaged. The anti-loose connecting structure comprises fewer parts and is simple in structure.

As shown in fig. 1, the anti-loose connection structure includes a mounting body 1, a bolt 2, a flat washer 3 and a spring washer 4, the mounting body 1 may be a traveling part of a locomotive, the mounting body 1 is provided with a mounting hole, the mounting hole is provided with an internal thread, and the mounting hole may penetrate through the mounting body 1. The bolt 2 comprises an end head and a stud coaxially arranged on one side of the end head, the stud is provided with an external thread, and the external thread axially extends from a certain position of the stud to one side far away from the end head. The bolt 2 penetrates through the installation body 1, the end head of the bolt is tightly abutted to one side of the installation body 1, and the stud penetrates out from the other side of the installation body 1. The flat washer 3 penetrates through the stud to be in contact with the other side of the installation body 1, the spring washer 4 penetrates through the bolt 2 to be in contact with one side, far away from the installation body 1, of the flat washer 3, and the outer diameter of the flat washer 3 is larger than that of the spring washer 4. The nut 5 is provided with a connecting hole, the connecting hole is provided with an internal thread matched with the external thread of the stud, the nut 5 is connected with the bolt 2 in a threaded mode and compresses the spring washer 4, and the spring washer 4 is flattened to be tightly attached to the flat washer 3.

The flat washer 3 is added to prevent the pretightening force from being reduced due to the fact that the nut 2 rotates and retreats because of the change of contact pressure on the contact surface. The outer diameter of the flat washer 3 is larger than that of the spring washer 4, the spring washer 4 extends from a flattening state, when looseness occurs, the contact between the spring washer 4 and the flat washer 3 is changed from surface contact to line contact, friction force is increased, the elastic elongation of the bolt 2 is increased by the spring washer 4, and looseness can be effectively prevented.

As shown in fig. 2 and 3, the spring washer 4 is a conical spring washer, which can compensate the looseness caused by the pretightening force change caused by the vibration impact, and the resilience force generated by the conical spring washer is uniformly stressed, thereby avoiding the defect that the resilience force of other spring washers is not uniform enough.

The contact surface between the spring washer 4 and the self-locking nut may be a smooth surface or an uneven rough surface, for example: the contact surface of the spring washer 4 and the self-locking nut is provided with stripes extending along the radial direction. The spring washer 4 may be a single layer, double layer or multi-layer mosaic structure.

When the spring washer 4 is provided with a multi-layer mosaic structure, the spring washer comprises a nesting 6 and a plurality of conical spring washers which are sequentially fixed on the nesting 6 along the axial direction. For example: a 2-layer, 3-layer or 4-layer conical spring washer may be employed.

It should be noted that the conical spring washer is not limited to the structure shown in the drawings, and other various types of conical spring washers for increasing the friction force may be used instead.

The nut 5 is a self-locking nut made of metal, and is anti-loose by using an all-metal nut, so that the bolt 2 caused by high temperature can be prevented from loosening.

From the material aspect: the nut 5 is made of carbon steel and alloy steel meeting the specification of GB/T3098.9, the 8-grade nut with the specification of M4-M16 can be made of 35 steel, the 8-grade and 10-grade nuts with the specification of M16-M30 can be made of 45 steel quenching, 40Cr or 35CrMo, and the nut with more than 10 grades is preferably made of 40Cr or 35CrMo, as shown in figure 1.

The heat treatment of the nut 5 is carried out according to GB/T3098.9, and the 8-grade nut with the specification of M16 or below can not be subjected to the heat treatment, but cold heading forming or cold drawing steel with high carbon content in the specification of material chemical composition is preferably adopted for processing. The 8-grade nut with the specification of more than M16 is subjected to quenching and tempering heat treatment, the quenching and tempering hardness is HV 233-353 specified in GB/T3098.9, and HV 241-266 can be selected from other 8-grade nuts. The 10-grade nut is subjected to heat treatment, and the hardening and tempering hardness is HV 272-353, which is usually controlled to HV 280-313. For high-strength nuts of class 10 and above, the specification of M16 or above, the upper limit of the heat-treated and heat-treated hardness range specified in GB/T3098.9 is set. The heat treatment is to avoid the oxidation and decarburization of the thread as much as possible except for ensuring that the hardness and the structure meet the requirements. A gap is reserved when the nut 5 is punched and locked, and the nut 5 and the bolt 2 are prevented from being fastened when being assembled as much as possible.

From the structural aspect, the nut 5 may include a nut body 51 and a locking portion 52, the nut body 51 may be hexagonal prism shaped, and the locking portion 52 may be cylindrical, prismatic or other shapes. The locking portion 52 has a through hole of the same size and coaxial with the connection hole, and the through hole is also provided with an internal thread adapted to the external thread of the stud. In addition to the above, the locking portion 52 is provided with the notch structure 53, and the notch structure 53 is spread and locked to the bolt 2 by the resilient force. The notch structure 53 may be disposed along the circumferential direction of the locking portion 52, or may be disposed along the axial direction of the locking portion 52.

When the notch structure 53 is provided along the circumferential direction of the locking portion 52, the notch structure 53 includes a continuous or intermittent notch 531 provided along the circumferential direction on the side wall of the locking portion 52, and the thread of the bolt 2 is screwed into the notch 531. The pitch of the internal thread in the through hole meets the requirement that when the nut 5 is axially stretched or compressed, the thread space on two sides of the notch structure 53 is changed, so that the nut 5 is matched with the bolt 2 to generate self locking. When the slit 531 is a continuous slit, the slit 531 may be provided as a spiral slit. As shown in fig. 4, when the notch 531 is an intermittent notch, the notch structure 53 may include two notches 531 axially disposed at different positions, and the length of each notch 531 is greater than or equal to half of the circumference of the locking portion 52.

When the notch structure 53 is disposed along the axial direction of the locking portion 52, the notch structure 53 may include a notch 531, the notch 531 is disposed to extend along the axial direction of the locking portion 52, the locking portion 52 is divided into two opposite limiting blocks, and the distance between the two limiting blocks is gradually reduced along the direction away from the nut body 51. When the nut 5 is connected with the bolt 2, the distance between the two limiting blocks is expanded, and the two limiting blocks are close to each other and closely contact with the bolt 2 based on resilience force.

As shown in fig. 5, the notch structure 53 may also be combined in a circumferential direction and an axial direction of the locking portion 52. The notch structure 53 includes three notches 531, one notch 531 extends along the axial direction to divide the locking portion 52 into two opposite limiting blocks, and the other two notches 531 are disposed on the side where the two limiting blocks are close to each other and extend along the circumferential direction. The distance between two stoppers of incision 531 is propped up one, and two stoppers are based on resilience force and are close to each other and closely contact with bolt 2, and the screw thread interval of the incision 531 both sides that extend along circumference changes, and the external screw thread on the double-screw bolt is tightly embraced to the internal thread that the through-hole warp, makes this nut 5 and bolt 2 cooperation produce the auto-lock.

The slit 531 extending in the axial direction is a wedge-shaped slit, that is, the distance between the slits 531 extending in the axial direction is gradually reduced from the end of the locking portion 52 away from the nut body 51 to the end close to the nut body 51. The remaining two circumferentially extending slits 531 are inclined gradually from the axial center to the edge toward the end near the nut body 51. The two circumferentially extending slits 531 are also wedge-shaped slits, and the distance between the two circumferentially extending slits 531 gradually increases from the axis to the edge toward the end close to the nut body 51.

According to different assembly requirements, the effective torque is properly controlled within a specified screwing maximum torque range. According to the assembly structure and the sequence shown in the attached figure 3, the bolt 2, the flat washer 3, the spring washer 4 and the nut 5 are assembled in sequence according to the figure. The torque of the nut 5 is set to enable the pretightening force to reach more than 50% of the yield axial force of the bolt 2, and the anti-loosening performance of the anti-loosening connecting structure can be effectively improved.

The effective torque can be controlled within the range specified in table 1.

When the moment is larger, the self-locking and anti-loosening effect is optimal, otherwise, the self-locking and anti-loosening effect is weakened. When the clamping torque is required in the assembly, particularly the mounting torque value of the small-specification nut 5 is small, the self-locking effective torque of the nut 5 occupies a larger proportion than the self-locking effective torque, and the assembly clamping torque is properly increased, so that the fastening of the connecting piece can be ensured without loosening and losing efficacy when the specified torque is reached. The assembly moment requirement of the nut 5 with larger specification is generally large in value, and can not be increased as required.

The nut 5 is fitted to the bolt 2 of the same grade so that damage to the threaded portion can be avoided. The torque wrench is used for twisting 30 revolutions per minute to avoid dead locking. When screwing up, the minimum screwing-in to the head end 3 of the nut 5 is ensured to be buckled, and the maximum screwing-in to the head end 6 of the nut 5 is ensured to be buckled.

It can be seen that one of the self-locking nuts uses the self-locking nut made of the specific metal material of the bolt 2, the corresponding heat treatment mode is adopted, the two spring washers and the flat washer are used in a combined mode, and the other spring washer and the flat washer apply certain tightening torque, so that the problem that the anti-loosening connecting structure of the locomotive running part is loosened due to vibration, impact, environment temperature and the like is solved.

The disclosed embodiments provide a locomotive. The locomotive includes the locking connection structure of any one of the above of this disclosure.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

Claims

1. A loose-proof connection structure, comprising:

the mounting body is provided with a mounting hole;

the bolt is in threaded connection with the mounting hole;

a flat washer passing through the bolt and contacting one side of the mounting body;

the spring washer penetrates through the bolt and is in contact with one side, away from the mounting body, of the flat washer, and the outer diameter of the flat washer is larger than that of the spring washer;

and the nut is in threaded connection with the bolt and is a self-locking nut made of metal.

2. The loose-proof connection structure according to claim 1, wherein the torque of the nut is set so that the preload force reaches 50% or more of the yield axial force of the bolt.

3. The loose-prevention coupling structure as claimed in claim 1, wherein the spring washer is a tapered spring washer, and a contact surface of the spring washer with the lock nut is provided with an uneven rough surface.

4. The anti-loose connection structure according to claim 1, wherein the nut includes a nut body and a locking portion, the locking portion is provided with a notched structure, and the notched structure is spread and locked to the bolt by a resilient force.

5. The anti-loosening connection structure according to claim 4, wherein the notch structure comprises a continuous or intermittent notch circumferentially provided in the side wall of the locking portion, and the thread of the bolt is screwed into the notch.

6. The anti-loose connection structure as claimed in claim 5, wherein the notch structure comprises two notches arranged at different positions along the axial direction, and the length of each notch is greater than or equal to half of the circumference of the locking part.

7. The anti-loose connection structure as claimed in claim 4, wherein the notch structure comprises a notch extending along an axial direction to divide the locking portion into two opposite limiting blocks, and a distance between the two limiting blocks is gradually reduced along a direction away from the nut body.

8. The anti-loose connecting structure according to claim 4, wherein the notch structure comprises three notches, one notch extends along the axial direction to divide the locking portion into two opposite limiting blocks, and the other two notches are arranged on the sides of the two limiting blocks, which are close to each other.

9. The anti-loose connection structure according to claim 1, wherein the nut is made of carbon steel and alloy steel, wherein: the 8-grade nuts with the specification of M4-M16 are made of 35 steel, the 8-grade nuts and the 10-grade nuts with the specification of M16-M30 are made of 45 steel quenching and 40Cr or 35CrMo, and the nuts above 10 grades are made of 40Cr or 35 CrMo;

10. A locomotive comprising the anti-loose connection structure of any one of claims 1 to 9.