CN2378564Y

CN2378564Y - Expanded double-screw bolt

Info

Publication number: CN2378564Y
Application number: CN 98240204
Authority: CN
Inventors: 张树春
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-08-23
Filing date: 1998-08-23
Publication date: 2000-05-17
Anticipated expiration: 2008-08-23

Abstract

The utility model relates to an expansion type and double-head screw post, which is a special form of the double-head screw posts. The expansion type and double-head screw post is mainly composed of an expansion screw rod, a hollow double-head screw post, a locking nut, etc. An expansion head with a taper or an expansion ring on the expansion screw bolt is mutually squeezed with an expansion cavity with a taper of the hollow double-head screw post by screwing the locking nut tightly. Screw threads on the end part of the hollow double-head screw post with an expansion seam are prompted to expand along a circumferential direction. Thus, lateral pressing force is generated for a screw thread pair under the condition of no pretightened force moment. So the screw threads are contacted uniformly. The stress of the screw threads is reduced remarkably. The screw threads are protected effectively to be safe from damages. In addition, transverse and locking force moment generated. The double-head screw post is ensured to be locked per se by connecting reliably.

Description

The expansion stud

The expansion stud belongs to a kind of special shape of stud in the threaded fastener.

Stud is a kind of form of threaded fastener, and it is bigger to be mainly used in one of connected piece thickness, need make compact structure or because of dismantling the place that frequently should not adopt Bolt Connection.Because one of the threaded piece during stud connects (generally being tapped parts) is one with coupled, a series of problem in use just occurred.At first, because frequent dismounting is is very easily worn and torn the screw thread on coupled; Secondly, the effect of dynamic load in the working procedure causes the screw thread generation fatigue damage on coupled; Also have reasons such as the not high and additional load of machining accuracy is excessive, cause screw thread that plastic deformation often takes place; On the screw pair greasy dirt or the like is arranged in addition.The result of these combined factors effects, one side reduce the self-lock ability of screw thread or lose and the phenomenon of relaxing; Screw thread take place to be destroyed and lost efficacy; Simultaneously, because the screw thread on coupled is repaired difficulty, cause the application of stud to be subjected to certain restriction.

For a kind of stud form with high self-locking property is provided, connect and relax easily thereby fundamentally solve stud, and with problems such as button at the bottom of the parts that double-screw bolt cooperates is easy to wear, special proposition the utility model.

The utility model mainly is made up of hollow stud, expansive screw and locking nut etc.; Expansive screw is made up of the expansion-head and the expanding ring of screw rod and band tapering, and the big end of expansion-head is provided with springhole; The inner chamber of hollow stud is made up of expansion chamber two-part of cylindrical cavity and band tapering; Expansion chamber is positioned at the end thread position of hollow stud, on the screw thread at hollow stud expansion chamber position, cut one or more vertically along the circumferential equally distributed dilatation joint that certain-length and width are arranged, and communicate with expansion chamber: expansive screw penetrates in the center hole of hollow stud, and screw portion on the expansive screw and hollow stud inner chamber or expanding ring endoporus have certain clearance; The expansion chamber of expansion-head on the expansive screw or expanding ring and hollow stud end portions constitutes tapering movingly; The screw portion of expansive screw stretches out hollow stud; The locking nut spinner is on the screw thread of expansive screw end.Screw locking nut, then expansive screw and hollow stud inner chamber produce relative movement vertically, cause the conical surface mutual extrusion of the conical surface and the stud expansion chamber of expansive screw expansion-head or expanding ring; Owing to be furnished with dilatation joint on the expansion chamber, thereby make the screw thread edge at hollow stud expansion position circumferentially produce significant elastic expansion; By elastic expansion with (interior) screw thread on the screw thread of hollow stud and nut or coupled along circumferentially compressing, thereby form horizontal locking torque, and screw pair evenly and is fully contacted.

Because the expansion characteristics of expansion stud makes stud in use, the screw thread at its expansion chamber position and join the enough horizontal locking torques of formation between the platform screw thread accordingly.The vertical locking torque superposition that produces when this horizontal locking torque and double-screw bolt pretension forms than the simple vertically bigger locking torque in length and breadth of locking torque together, thereby can make double-screw bolt connect locking more reliably, avoids double-screw bolt to connect the phenomenon of relaxing; Simultaneously, because of screw pair along laterally compressing, make that stressed between the screw thread that screws evenly the load scope increases, and has reduced stress and the additional stress amplitude on the screw thread significantly, thereby can protect screw thread to avoid destroying effectively; Have, the expansion stud can carry out under the condition of no pre-fastening moment the expansion of bottom thread (promptly with the screw thread that screws of button at the bottom of the parts), thereby can play horizontal pressuring action more fully again; In addition, carry out lateral expansion locking in advance by coupled screw pair to stud and cooperation with it, can avoid stud upper end nut pretension or when unclamping stud rotate, thereby avoid under high load turn to the wearing and tearing of coupled screw thread.By contrast, common double header stud and expansion bolt all can not possess these advantages.

Fig. 1 is the utility model embodiment one structural representation;

Fig. 2 is the sectional drawing of Figure 1A portion;

Fig. 3 is the sectional drawing of Figure 1B portion;

Fig. 4 is the utility model embodiment two structural representations;

Fig. 5 is the sectional drawing of Fig. 4 A portion;

Fig. 6 is the sectional drawing of Fig. 4 B portion.

For further specifying the utility model, it is as follows that the spy enumerates embodiment:

＜embodiment one 〉

With reference to figure 1, Fig. 2 and Fig. 3.Present embodiment mainly is made up of expansive screw 1, locking nut 2 and hollow stud 3.Expansive screw 1 is made up of the expansion-head 9 of cylindrical screw and band tapering, in the end of expansion-head 9 springhole 8 is arranged vertically.The inner chamber of hollow stud is made up of cylindrical cavity and expansion chamber 6; On the lower thread of hollow stud, have the dilatation joint that communicates with expansion chamber 7 that two edges circumferentially are symmetrically distributed vertically; On the top of hollow stud one cubic boss 5 is arranged, be used for screwing in or screwing out hollow stud; On the screw thread of the top of hollow stud, also be distributed with cotter-pin hold 4 for the locking usefulness of hexagon slotted nut.Expansive screw 1 is positioned at the center hole of hollow stud 3, and the screw portion on it stretches out the center hole of hollow stud, and the cylindrical cavity of screw rod and hollow stud has certain clearance; The expansion-head on the expansive screw and the expansion chamber of hollow stud constitute cone match; Locking nut and expansive screw screw, and are pressed on the end face of hollow stud four directions boss.Screw locking nut, make expansive screw and hollow stud produce axial relative movement.Expansion-head and expansion chamber mutual extrusion are to the expansion chamber generation expansive force of hollow stud.Dilatation joint makes near the hollow stud expansion chamber screw thread along circumferentially producing significant the expansion under the effect of expansive force, thereby (interior) screw thread on the screw thread of hollow stud bottom and coupled is laterally compressed.Springhole on the expansion-head can make the expansion-head high resilience, stores more energy in the process that expands, thereby can keep the swelling state of stud lower thread for more time.

＜embodiment two 〉

With reference to figure 4, Fig. 5 and Fig. 6.Present embodiment is made up of expansive screw 1, locking nut 2, expanding ring 10 and hollow stud 3.Expansive screw is made up of the expansion-head 9 of cylindrical screw and band tapering, in the end of swollen long head one springhole 8 is arranged vertically.The inner chamber of hollow stud is made up of cylindrical cavity and expansion chamber 6,11.On the lower thread of hollow stud, have the dilatation joint 7 that communicates with expansion chamber 6 that two edges circumferentially are symmetrically distributed vertically; Have two dilatation joints 12 that communicate with expansion chamber 11 on the screw thread of top.On the top of hollow stud, also be provided with cotter-pin hold 4 for the locking usefulness of hexagon slotted nut.Expansive screw is positioned at the center hole of hollow stud, and the screw portion on it stretches out the center hole of expanding ring, and the cylindrical cavity of screw rod and hollow stud and the endoporus of expanding ring have certain clearance; Expansion-head on the expansive screw and the expansion chamber of hollow stud 6 constitute cone match; Locking nut is buckled on the expansive screw, and is pressed in the expanding ring end; Expanding ring and expansion chamber 11 constitute cone match.Screw locking nut, make expansive screw and hollow stud produce axial relative movement.Expansion-head and expansion chamber 6 are along conical surface mutual extrusion, to the expansion chamber 6 generation expansive forces of hollow stud.Dilatation joint 7 makes near the hollow stud expansion chamber 6 screw thread along circumferentially producing significant the expansion under the effect of expansive force, impels (interior) screw thread on the screw thread of hollow stud bottom and coupled laterally to compress; Equally, expanding ring 10 and expansion chamber 11 laterally compress the screw thread on hollow stud top and (interior) screw thread on the nut along conical surface mutual extrusion, and nut is played the locking effect.Springhole on the expansion-head can make the expansion-head high resilience, stores more energy in inflation process, thereby can keep the swelling state of stud upper and lower part screw thread for more time.During design, make expansion-head can guarantee to cooperate conical surface self-locking reliably vertically with the taper value of expansion chamber 6; Make the taper value of expanding ring and expansion chamber 11 break away from the self-locking scope reliably.So that satisfy expansion locking under no pretension state and disassemble or assemble needs easily.

Claims

1, the expansion stud is characterized in that, this stud mainly is made up of hollow stud, expansive screw and locking nut etc.; Expansive screw is made up of the expansion-head or the expanding ring of straight-bar and band tapering, and the big end of expansion-head is provided with springhole; The inner chamber of hollow stud is made up of expansion chamber two-part of cylindrical cavity and band tapering; Expansion chamber is positioned at the end thread position of hollow stud, on the screw thread at hollow stud expansion chamber position, cuts one or more vertically along the circumferential equally distributed dilatation joint that certain-length and width are arranged, and communicates with expansion chamber; Expansive screw penetrates in the center hole of hollow stud, and screw portion on the expansive screw and hollow stud inner chamber or expanding ring endoporus have certain clearance; The expansion chamber of expansion-head on the expansive screw or expanding ring and hollow stud end portions constitutes tapering movingly; The screw portion of expansive screw stretches out hollow stud; The locking nut spinner is on the screw thread of expansive screw end.

2, expansion stud according to claim 1 is characterized in that, the upper end portion of hollow stud is provided with cubic boss, on the screw thread of upper end, along circumferentially having some uniform cotter-pin holds; The lower end of hollow stud promptly plants into end and is provided with expansion chamber, and has the dilatation joint of some symmetrical distributions vertically; Locking nut is pressed in the end of hollow stud four directions boss.

3, expansion stud according to claim 1 is characterized in that, the upper and lower end screw thread position of hollow stud respectively has an expansion chamber; Each expansion chamber respectively has the dilatation joint of some symmetrical distributions vertically; Locking nut is pressed in the big end of expanding ring; The expansion chamber on hollow stud top and expanding ring constitute tapering movingly; The expansion chamber of bottom and the expansion-head on the expansive screw constitute tapering movingly.

4, expansion stud according to claim 3 is characterized in that, expanding ring and double-screw bolt upper end expansion chamber cooperate taper value, make the moving pair of this tapering avoid self-locking reliably.