Two-piece screw-in type back bolt

Abstract

The utility model relates to the technical field of engineering construction connecting pieces. The two-piece screw-in type back bolt comprises a bolt and an expansion cylinder part which are in threaded connection, the expansion cylinder part comprises a limiting boss part and an expansion sleeve which are sequentially arranged in the axial direction, and clamping jaws which are distributed in the circumferential direction are arranged at the bottom of the expansion cylinder part; the axial projection area of the expansion cylinder part is located in the axial projection area range of the limiting boss part; the limiting boss part is matched with a mounting hole in the hanging frame, the cross section of the outer wall of the limiting boss part is of a non-circular structure, the bolt comprises a head part and a screw rod part which are sequentially arranged in the axial direction, and the head part is used for abutting against the hanging frame; and the axial length of the expansion sleeve is the same as that of the screw rod part. According to the utility model, a three-piece sleeve type is changed into a two-piece sleeve type, so that the anchoring effect can still be realized while parts are omitted. According to the utility model, the axial length of the expansion sleeve is equal to the axial length of the screw part, so that the screwing depth of the screw is controlled, and the problem of plate penetration is avoided.

Description

Technical Field

[0001] The utility model relates to the field of engineering construction connectors, in particular to a back bolt. Background Art

[0002] Back bolts are used to connect plates and steel structures. They can resist vibration loads and wind loads. They have good load-bearing capacity and ideal anchoring effect.

[0003] Traditional screw-in bolts consist of a screw, a lock nut, and an expansion sleeve. When used, the expansion sleeve is connected to the screw and placed into the mounting hole. The screw is then driven by a driver, and as the screw moves downward, the bottom of the screw moves into the claws of the expansion sleeve, which then expand radially outward and engage the plate. The lock nut then secures the bracket through which the bolt passes. This traditional screw-in bolt can easily lead to excessive screw insertion during the screw threading process, resulting in plate penetration. Utility Model Content

[0004] In view of the problems existing in the prior art, the present invention provides a two-piece screw-in back bolt to solve at least one of the above technical problems.

[0005] To achieve the above-mentioned object, the present invention provides a two-piece screw-in back bolt, comprising a threaded bolt and an expansion sleeve, characterized in that the expansion sleeve comprises a limiting boss portion and an expansion cylinder portion sequentially arranged along the axial direction, the bottom of the expansion cylinder portion is provided with circumferentially arranged claws, the limiting boss portion and the expansion cylinder portion are provided with internal threads that penetrate each other and are threadedly connected to the bolt;

[0006] The axial projection area of ​​the expansion cylinder portion is within the axial projection area of ​​the limiting boss portion;

[0007] The limiting boss portion matches the mounting hole on the bracket, and the cross section of the outer wall of the limiting boss portion is a non-circular structure;

[0008] The bolt comprises a head and a screw portion sequentially arranged along the axial direction, wherein the head is used to abut against the bracket;

[0009] The axial length of the expansion sleeve is the same as the axial length of the screw portion.

[0010] By optimizing the back bolt structure, this utility model changes the three-piece set to a two-piece set, eliminating components while still achieving the desired anchoring effect. In this utility model, the axial length of the expansion sleeve is the same as the axial length of the screw portion. When the head portion abuts against the limiting boss portion, the bottom of the screw portion is flush with the bottom of the expansion barrel portion, thereby controlling the screw insertion depth and avoiding the problem of plate penetration.

[0011] During use, the expansion sleeve is connected to the screw rod and then installed into the mounting hole of the thin plate. The mounting hole of the hanger passes through the limiting boss portion, and the hanger prevents the expansion sleeve from rotating. The driving member drives the bolt to move, and as the bolt moves downward, the bottom of the bolt moves to the claw, which then expands radially outward and engages the thin plate. During the screwing process, once the head abuts against the hanger, the hanger is installed.

[0012] Further preferably, mutually parallel planes are provided on opposite sides of the limiting boss portion.

[0013] Further preferably, the limiting boss portion is a crescent structure, an outer polygonal structure or a waist-circular structure.

[0014] Further preferably, the limiting boss portion is an outer hexagonal structure.

[0015] Further preferably, the expansion cylinder portion is inserted into the mounting hole of the plate, and the limiting boss portion is exposed outside the plate;

[0016] The outer surface of the plate is in close contact with the hanger, and the mounting hole of the hanger passes through the limiting boss portion;

[0017] The head of the bolt abuts against the bracket.

[0018] Further preferably, the thickness of the plate is less than 2 cm.

[0019] Further preferably, the plate is a stone plate.

[0020] Further preferably, a buffer pad is adhered to one side of the hanger adjacent to the plate.

[0021] Further preferably, the cushioning pad is an EVA pad.

[0022] Further preferably, the axial length of the limiting boss portion is not greater than the thickness of the bracket.

[0023] Further preferably, the bottom of the expansion cylinder is provided with circumferentially arranged strip-shaped notches, and the strip-shaped notches separate adjacent claws;

[0024] The bottom of the claw is provided with a protrusion extending outward;

[0025] When the screw portion does not extend into the claw portion, the expansion cylinder portion is provided with a claw portion that retracts inward;

[0026] When the screw portion extends into the claw, the claw portion of the expansion cylinder portion expands outward, and the outer diameter of the claw portion of the expansion cylinder portion is greater than the outer diameter of the top of the expansion cylinder portion.

[0027] Beneficial effects:

[0028] The device realizes the rapid assembly of the hanger, simplifies the assembly steps of the hanger, and simplifies the materials required for the hanger assembly from a three-piece set of materials to a two-piece set of materials. At the same time, it also effectively avoids the problem of thin plate penetration caused by excessive screwing of bolts. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A structural diagram of the utility model;

[0030] Figure 2 It is a structural schematic diagram of the utility model from another perspective;

[0031] Figure 3 This is a cross-sectional view of the utility model when it is in conjunction with the plate and the hanger;

[0032] Figure 4 This is a schematic diagram of the structure of the bolt of the utility model;

[0033] Figure 5 This is a structural diagram of the expansion sleeve of the utility model.

[0034] Among them: 1 is a bolt, 2 is an expansion sleeve, 3 is a plate, 4 is a bracket, 11 is a head, 12 is a screw rod, 21 is a limiting boss part, and 22 is an expansion cylinder part. DETAILED DESCRIPTION

[0035] The present invention will be further described below with reference to the accompanying drawings.

[0036] See also Figures 1 to 5Specific embodiment 1: A two-piece screw-in back bolt comprises a threaded bolt 1 and an expansion sleeve 2. The expansion sleeve 2 comprises a limiting boss portion 21 and an expansion cylinder portion 22 arranged in sequence along the axial direction. The bottom of the expansion cylinder portion 22 is provided with circumferentially arranged claws. The limiting boss portion 21 and the expansion cylinder portion 22 are provided with internal threads that penetrate and communicate with each other and are threadedly connected to the bolt. The axial projection area of ​​the expansion cylinder portion is located within the axial projection area of ​​the limiting boss portion 21. The limiting boss portion 21 matches the mounting hole on the hanger 4. The cross-section of the outer wall of the limiting boss portion 21 is a non-circular structure. The limiting boss portion 21 is used to limit the screw-in depth of the bolt 1. The bolt 1 comprises a head portion 11 and a screw portion 12 arranged in sequence along the axial direction. The head portion 11 is used to abut the hanger 4. The axial length of the expansion sleeve 2 is the same as the axial length of the screw portion 12. The utility model optimizes the back bolt structure, changes the three-piece set to a two-piece set, omitting components while still achieving the anchoring effect. In this utility model, the axial length of the expansion sleeve 2 is equal to the axial length of the screw portion 12. When the head portion 11 abuts the limiting boss portion 21, the bottom of the screw portion 12 is flush with the bottom of the expansion barrel portion, thereby controlling the screw insertion depth and avoiding the problem of plate penetration. The axial vertical projection area of ​​the limiting boss portion is located within the range of the vertical projection area of ​​the head portion on the side adjacent to the screw portion.

[0037] The opposite sides of the limiting boss portion 21 are provided with mutually parallel planes.

[0038] The limiting boss portion 21 is a crescent structure, an outer polygonal structure or a waist-circular structure.

[0039] The limiting boss portion 21 is an outer hexagonal structure.

[0040] The expansion cylinder is inserted into the mounting hole of plate 3, with the limiting boss 21 exposed outside the plate 3. The outer surface of plate 3 is in close contact with the hanger 4, and the mounting hole of hanger 4 passes through the limiting boss 21. The head 11 of bolt 1 abuts against hanger 4. Plate 3 is less than 2 cm thick and is made of stone. A cushioning pad is attached to the side of hanger 4 adjacent to plate 3.

[0041] The cushioning pad is an EVA pad.

[0042] The axial length of the limiting boss portion 21 is not greater than the thickness of the hanger 4 .

[0043] The bottom of the expansion cylinder is provided with circumferentially arranged strip-shaped notches, which separate adjacent claws; the bottom of the claw is provided with a protrusion extending outward; when the screw portion 12 is not inserted into the claw, the claw portion of the expansion cylinder is retracted; when the screw portion 12 is inserted into the claw, the claw portion of the expansion cylinder is expanded outward, and the outer diameter of the claw portion of the expansion cylinder is larger than the outer diameter of the top of the expansion cylinder.

[0044] During use, the expansion sleeve is connected to the screw rod and then installed into the mounting hole of the thin plate. The mounting hole of the hanger passes through the limiting boss portion 21, and the hanger prevents the expansion sleeve 2 from rotating. The driving member drives the bolt 1, and as the bolt 1 is moved downward, the bottom of the bolt 1 moves to the claw, which then expands radially outward and engages the thin plate. During the screwing process, once the head 11 abuts the hanger, the hanger is installed.

[0045] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. Two-piece screw-in back bolt, including a threaded bolt and an expansion sleeve, characterized in that: The expansion sleeve includes a limiting boss portion and an expansion cylinder portion sequentially arranged along the axial direction, the bottom of the expansion cylinder portion is provided with circumferentially arranged claws, and the limiting boss portion and the expansion cylinder portion are provided with internal threads that penetrate each other and are threadedly connected to the bolt; The axial projection area of ​​the expansion cylinder portion is within the axial projection area of ​​the limiting boss portion; The limiting boss portion matches the mounting hole on the bracket, and the cross section of the outer wall of the limiting boss portion is a non-circular structure; The bolt comprises a head and a screw portion sequentially arranged along the axial direction, wherein the head is used to abut against the bracket; The axial length of the expansion sleeve is the same as the axial length of the screw portion.

2. The two-piece screw-in back bolt according to claim 1, characterized in that: The opposite sides of the limiting boss portion are provided with planes parallel to each other.

3. The two-piece screw-in back bolt according to claim 1, characterized in that: The limiting boss portion is a crescent structure, an outer polygonal structure or a waist-circular structure.

4. The two-piece screw-in back bolt according to claim 1, characterized in that: The limiting boss portion is an outer hexagonal structure.

5. The two-piece screw-in back bolt according to claim 1, characterized in that: The expansion cylinder portion is inserted into the mounting hole of the plate, and the limiting boss portion is exposed outside the plate; The outer surface of the plate is in close contact with the hanger, and the mounting hole of the hanger passes through the limiting boss portion; The head of the bolt abuts against the bracket.

6. The two-piece screw-in back bolt according to claim 5, characterized in that: The thickness of the board is less than 2 cm.

7. The two-piece screw-in back bolt according to claim 5, characterized in that: The plate is a stone plate.

8. The two-piece screw-in back bolt according to claim 5, characterized in that: A buffer pad is adhered to one side of the hanger adjacent to the plate.

9. The two-piece screw-in back bolt according to claim 8, characterized in that: The cushioning pad is an EVA pad.

10. The two-piece screw-in back bolt according to claim 5, characterized in that: The axial length of the limiting boss portion is no greater than the thickness of the hanger.

Images