Internal expansion fastening pin assembly

Abstract

The utility model discloses an internal expansion fastening pin assembly which comprises an expansion screw and an expansion screw sleeve. The upper section of the expansion screw is a threaded connection section, and the lower section of the expansion screw is a circular truncated cone section which converges downwards; an internal thread matched with the threaded connection section of the expansion screw is machined on the upper section of an inner hole of the expansion screw sleeve, a circular-truncated-cone-shaped positioning face matched with the circular-truncated-cone section of the expansion screw is machined on the lower section of the inner hole of the expansion screw sleeve, and expansion notches evenly distributed in the circumferential direction are axially formed in the lower section of the expansion screw sleeve; the axial length of the expansion notch is matched with the axial length of the circular-truncated-cone-shaped positioning face. The expansion screw is in threaded connection with an inner hole of the expansion screw sleeve, and the expansion screw extrudes the part, where the positioning notch is machined, of the expansion screw sleeve through a circular truncated cone section of the lower section of the expansion screw to expand in the radial direction, so that the connecting piece is fixed. According to the internal expansion fastening pin assembly, the cabin section can be quickly mounted and dismounted without tapping.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of inner expansion dowel pin assemblies, belong to fastener technical field. BACKGROUND

[0002] National standard fastening screw is generally used to fix the relative position of two cabin sections, and when used, the fastening screw is screwed into the screw hole of the machine part to be fixed, and the end of the screw is pressed on the surface of another machine part. However, when the two cabin sections made of high-strength steel material are butt-jointed, it is difficult to tap threads after punching, and the tap is easily broken in the cabin section and difficult to remove, resulting in serious consequences of cabin section scrap. SUMMARY

[0003] The utility model aims at solving the problem of difficulty in tapping threads after punching and low efficiency when the two cabin sections made of high-strength steel material are butt-jointed, and provides an inner expansion dowel pin assembly.

[0004] The utility model aims to realize the following technical scheme:

[0005] The utility model relates to an inner expansion dowel pin assembly, which comprises an expansion screw and an expansion sleeve.

[0006] The upper section of the expansion screw is a threaded connection section, and the lower section of the expansion screw is a downward converging circular cone section.

[0007] The inner hole of the expansion sleeve is machined with internal threads matching the threaded connection section of the expansion screw in the upper section, and the lower section of the inner hole of the expansion sleeve is machined with a circular cone positioning surface matching the circular cone section of the expansion screw, and the lower section of the expansion sleeve is axially provided with circumferentially distributed expansion notches; the axial length of the expansion notches matches the axial length of the circular cone positioning surface.

[0008] The expansion screw is threaded in the inner hole of the expansion sleeve, and the circular cone section of the lower section of the expansion screw expands radially by extruding the part of the expansion sleeve where the positioning notches are machined, realizing the fixation of the connecting piece.

[0009] To improve the fastening effect of the dowel pin assembly, the outer wall of the expansion sleeve is machined with knurling.

[0010] Working process

[0011] When the two cabin bodies are butted, corresponding fastening through holes are formed on the butting end plates of the two cabin bodies, the diameters of the fastening through holes match the outer diameters of the expansion screw sleeves, when assembling, the fastening through holes of the butting end plates of the two cabin bodies are aligned, then the expansion screw sleeves are inserted into the aligned two fastening through holes, and the parts of the expansion screw sleeve processing positioning notches are simultaneously located in the two fastening through holes, finally the expansion screw is screwed, the expansion screw sleeve processing positioning notch part is radially expanded by the circular cone section of the lower section of the expansion screw, and the butting end plates of the two cabin bodies are fixed.

[0012] Advantageous effects

[0013] The inner expansion fastening pin assembly of the utility model realizes that the inner expansion fastening pin can be installed in the light hole state when cabin sections are connected, and threads do not need to be tapped. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is a structure sectional view of the utility model inner expansion fastening pin assembly;

[0015] Figure 2 It is a structure view of the expansion screw in the utility model inner expansion fastening pin assembly;

[0016] Figure 3 It is a half sectional view of the expansion screw sleeve in the utility model inner expansion fastening pin assembly;

[0017] Figure 4 It is an installation schematic view of the utility model inner expansion fastening pin assembly;

[0018] In the drawing, 1-expansion screw, 2-expansion screw sleeve, 3-upper cabin body, 4-lower cabin body. DETAILED DESCRIPTION

[0019] The content of the utility model will be further described below in combination with the drawings and examples.

[0020] Examples

[0021] As Figure 1 shown, the utility model discloses an inner expansion fastening pin assembly, which comprises an expansion screw 1 and an expansion screw sleeve 2.

[0022] As Figure 2 shown, the upper section of the expansion screw 1 is a threaded connection section, and the lower section of the expansion screw 1 is a circular cone section converging downward.

[0023] As Figure 3As shown, the inner hole upper section of the expansion sleeve 2 is machined with internal threads matching the threaded connection section of the expansion screw 1, the inner hole lower section of the expansion sleeve 2 is machined with a circular truncated cone locating surface matching the circular truncated cone section of the expansion screw 1, and the lower section of the expansion sleeve 2 is axially opened with circumferentially distributed expansion notches; the axial length of the expansion notches matches the axial length of the circular truncated cone locating surface.

[0024] The expansion screw 1 is threaded in the inner hole of the expansion sleeve 2, and the circular truncated cone section of the lower section of the expansion screw 1 extrudes the part of the expansion sleeve 2 machined with the locating notches to radially expand, thereby realizing the fixation of the connecting member.

[0025] To improve the fastening effect of the tight pin assembly, the outer wall of the expansion sleeve 2 is knurled.

[0026] Figure 4 The installation schematic diagram of the inner expansion tight pin assembly;

[0027] When the upper and lower two section cabin bodies are butted, first, corresponding fastening through holes are respectively opened on the butt joint end plates of the two section cabin bodies, the hole diameter of the fastening through holes matches the outer diameter of the expansion sleeve 2; during assembly, the fastening through holes of the butt joint end plate of the upper cabin body 3 and the butt joint end plate of the lower cabin body 4 are aligned, then the expansion sleeve 2 is inserted into the two aligned fastening through holes, and the part of the expansion sleeve 2 machined with the locating notches is simultaneously located in the two fastening through holes; finally, the expansion screw 1 is screwed, the circular truncated cone section of the lower section of the expansion screw 1 extrudes the part of the expansion sleeve 2 machined with the locating notches to radially expand, thereby realizing the fixation of the butt joint end plates of the two section cabin bodies.

Claims

1. An internally expanding dowel pin assembly, comprising: The expansion screw and the expansion sleeve are included; The upper section of the expansion screw is a threaded section, and the lower section of the expansion screw is a downward converging frustum section; The inner hole of the expansion sleeve is processed with internal threads matched with the threaded section of the expansion screw, and the lower section of the inner hole of the expansion sleeve is processed with a frustum positioning surface matched with the frustum section of the expansion screw, and the lower section of the expansion sleeve is axially opened with circumferentially distributed expansion notches; the axial length of the expansion notches matches the axial length of the frustum positioning surface; The expansion screw is threaded in the inner hole of the expansion sleeve, and the frustum section of the lower section of the expansion screw extrudes the part of the expansion sleeve processed with the positioning notches to expand radially, so as to realize the fixation of the connecting piece.

2. An internally expanding dowel pin assembly as defined in claim 1 wherein, The outer wall of the expansion sleeve is processed with knurling.

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