CN103867543B - Expansion screw - Google Patents

Abstract

The invention discloses an expansion screw, which comprises a core nail and a pipe sleeve wrapped on the periphery of the core nail, wherein a cylindrical section is integrally formed at the lower end of the core nail, an axial notch is formed in the cylindrical section, a cone is connected with the lower opening end of the pipe sleeve, the diameter of the circular surface of the cone is larger than that of the pipe sleeve, a gap is reserved between the lower opening end of the pipe sleeve and the cone, and the length of the cylindrical section is larger than the height of the cone. Compared with the prior art, the invention has the beneficial effects that: the expansion screw is convenient to pull out, the damage to the mounting surface is small, the attractiveness of the mounting surface cannot be influenced, and the detached components can be reused.

Description

an expansion screw

technical field

The invention relates to an expansion screw.

Background technique

Existing expansion screws are generally referred to as metal expansion screws. Expansion screws use wedge-shaped inclination to promote expansion to generate friction and grip force to achieve a fixing effect. One end of the screw is provided with threads, and the threaded end of the screw is connected with a nut. There is a taper at the other end, and the diameter of the taper end is larger than the diameter of the screw. The outer circumference of the screw is surrounded by a circle of iron cylinder, and some are steel pipe sleeves. The length of the iron cylinder or steel pipe sleeve is less than the length of the screw, and the iron cylinder or steel pipe sleeve There are several cutouts at the end near the taper of the screw, and the screw and the iron cylinder or steel pipe wrapped around it are inserted into the hole punched in the wall, and then the lock nut is rotated to pull the screw outward through the thread transmission, and the screw's The taper is pulled into the iron cylinder or steel pipe sleeve, and the cut end of the iron cylinder or steel pipe sleeve is expanded under the extrusion of the screw taper end, so it is tightly fixed on the wall, generally used for guardrails, awnings, air conditioners Fastening on cement, brick and other materials.

However, the expansion screw is difficult to disassemble, and the installation surface will be greatly damaged when it is forcibly removed. If only the part protruding from the installation surface is sawed off, the part inside the installation surface cannot be taken out, which may hinder the next installation. It also affects the aesthetics of the installation surface.

Contents of the invention

The above problems to be solved by the present invention are aimed at the disadvantages of the above-mentioned prior art that it is difficult to disassemble, cause great damage to the installation surface, and affect the appearance of the installation surface, etc., and provide an easy-to-remove device that has little damage to the installation surface and does not affect the appearance of the installation surface. Expansion screw.

In order to solve the problems of the technologies described above, the technical solution adopted in the present invention is:

An expansion screw, including a mandrel and a sleeve wrapped around the mandrel, the outer diameter of the mandrel is equal to the inner diameter of the mandrel, the length of the mandrel is greater than the length of the sleeve, and a cylindrical section is integrally formed at the lower end of the mandrel , the cylindrical section is provided with an axial cut, the lower opening end of the pipe sleeve is connected with a cone, and the cone tip of the cone is upward, the diameter of the circular surface of the cone is larger than the diameter of the pipe sleeve, and the lower opening end of the pipe sleeve There is a gap with the cone, and the length of the cylinder section is greater than the height of the cone.

A shaft shoulder is provided at the upper opening end of the pipe sleeve.

The pipe sleeve is a steel pipe sleeve.

The thickness of the wall of the cylindrical section is smaller than the width of the gap between the lower opening end of the sleeve and the cone.

A ring of reinforcing edges for increasing hardness is provided at the outer wall of the lower opening end of the pipe sleeve.

Compared with the prior art, the beneficial effect of the present invention is: when a force is applied to the top of the mandrel, the cylindrical section at the bottom of the mandrel expands outwards under the extrusion of the cone and is inserted into the inner wall of the mounting hole, thereby locking It has a fixed effect, but when it needs to be disassembled, you only need to pull out the core nail, and under the gathering effect of the reinforcing edge at the lower opening end of the sleeve, the cylindrical section inserted into the inner wall of the installation hole shrinks radially inward, which is easy to pull out, and it is very convenient for installation. The damage to the surface is small, and the appearance of the installation surface will not be affected, and the removed parts can be reused.

Description of drawings

Fig. 1 is the structural representation of expansion screw of the present invention;

Among them, 1. Core nail, 2. Pipe sleeve, 3. Cylinder section, 4. Cone, 5. Reinforcing edge.

detailed description

The preferred technical solutions of the present invention will be described in detail below in conjunction with the accompanying drawings.

As shown in Figure 1, an expansion screw includes a core nail 1 and a sleeve 2 wrapped around the core nail 1. The outer diameter of the core nail 1 is equal to the inner diameter of the sleeve 2, and the length of the core nail 1 is greater than that of the sleeve 2. length, the lower end of the mandrel 1 is integrally formed with a cylindrical section 3, which is provided with an axial cutout, and the lower opening end of the sleeve 2 is connected with a cone 4, and the cone point of the cone 4 is upward, The diameter of the circular surface of the cone 4 is greater than the diameter of the pipe cover 2, there is a gap between the lower open end of the pipe cover 2 and the cone 4, and the length of the cylinder section 3 is greater than the height of the cone 4.

The upper opening end of the pipe sleeve 2 is provided with a shaft shoulder, which can buckle the installation surface, so as to prevent the pipe sleeve 2 from being nailed into the pre-drilled installation hole when the mandrel is hammered.

The pipe sleeve 2 is a steel pipe sleeve.

The thickness of the wall of the cylindrical section 3 is smaller than the width of the gap left between the lower open end of the sleeve 2 and the cone 4 .

The outer wall of the lower opening end of the pipe sleeve 2 is provided with a ring of reinforced edges 5 that strengthen the hardness. When the expansion screw is removed and the core nail 1 is pulled outward, the reinforced edge 5 has the effect of gathering the cylindrical section 3, so that it can Pull out the mandrel 1 easily, and then take out the sleeve 2.

Compared with the prior art, the beneficial effect of the present invention is: when a force is applied to the top of the mandrel, the cylindrical section at the bottom of the mandrel expands outwards under the extrusion of the cone and is inserted into the inner wall of the mounting hole, thereby locking It has a fixed effect, but when it needs to be disassembled, you only need to pull out the core nail, and under the gathering effect of the reinforcing edge at the lower opening end of the sleeve, the cylindrical section inserted into the inner wall of the installation hole shrinks radially inward, which is easy to pull out, and it is very convenient for installation. The damage to the surface is small, and the appearance of the installation surface will not be affected, and the removed parts can be reused.

During operation, put the mandrel 1 together with the sleeve 2 into the pre-drilled installation hole, then apply force to the mandrel 1, beat the mandrel 1 into the sleeve 2, and the cylindrical section at the lower end of the mandrel 1 3 Under the guidance and extrusion of the cone body 4, it expands radially outward, passes through the gap between the sleeve 2 and the cone body 4, and inserts into the wall of the installation hole to complete the locking of the expansion screw of the present invention position.

If the expansion screw does not need to be used, it is only necessary to pull out the core nail 1, and the cylindrical section 3 inserted into the wall of the installation hole is under the combined action of the outward pulling force and the gathering effect of the reinforcing edge 5 at the lower opening end of the sleeve 2 , the cylindrical section 3 is drawn radially inwards and is easy to be pulled out. When the mandrel 1 is pulled out, the sleeve 2 can be pulled out easily. The structure is simple and reasonable, and it is easy to operate.

Claims (1)

1. An expansion screw, comprising a mandrel and a sleeve wrapped around the mandrel, the outer diameter of the mandrel is equal to the inner diameter of the mandrel, and the length of the mandrel is greater than the length of the mandrel, characterized in that: at the lower end of the mandrel A cylindrical section is integrally formed, and an axial cut is provided on the cylindrical section. A cone is connected to the lower opening end of the sleeve, and the cone tip of the cone is upward. The diameter of the circular surface of the cone is larger than the diameter of the sleeve. There is a gap between the lower opening end of the pipe sleeve and the cone, and the length of the cylinder section is greater than the height of the cone; a shaft shoulder is provided at the upper opening end of the pipe sleeve; the pipe sleeve is a steel pipe sleeve; The thickness of the wall of the cylindrical section is smaller than the width of the gap between the lower opening end of the pipe sleeve and the cone; a ring of reinforcing edges for strengthening hardness is provided on the outer wall of the lower opening end of the pipe sleeve.