Expansion screw principle, what is the working principle of expansion screws

This is the ** of the expansion bolt, which consists of three parts, 1Screw 2Sleeve (with a notch at the bottom end) 3

Fasteners (washers and nuts). Before installation, the bottom hole is generally 2mm larger than the bolt specification, the screw and the sleeve are nailed into the hole together, the workpiece to be fixed is placed and the nut is tightened with a wrench, there is a certain friction between the sleeve and the bottom hole to fix it relative to the bottom hole, the screw is rotated and lifted relative to the sleeve, the cone surface of the bottom end of the screw will be propped up at the bottom of the sleeve, and the sleeve will be bracked up more when the nut is tightened, so that the friction between the sleeve and the bottom hole can not be pulled out.

The expansion screw is generally said to be a metal expansion screw, and the fixing of the expansion screw is to use the wedge-shaped slope to promote the expansion to produce friction grip and wrapping force to achieve the fixing effect. The screw is threaded at one end and taper at the other. The outer bread is an iron sheet (some are steel pipes), and half of the iron cylinder (steel pipe) has a number of incisions, and they are stuffed into the holes made in the wall together, and then the lock nut, the nut pulls the screws outward, and pulls the taper into the iron cylinder, and the iron cylinder is opened, so it is tightly fixed on the wall, and is generally used for the fastening of protective fences, awnings, air conditioners, etc. on cement, bricks and other materials.

However, it is not very reliable to fix, and if the load is shaken largely, it may loosen, so it is not recommended for the installation of ceiling fans, etc.

Principle of fixation. The expansion screw is composed of parts such as a screw and an expansion tube, and the tail of the screw is conical, and the inner diameter of the cone is larger than the inner diameter of the expansion tube. When the nut is tightened, the screw moves outward, and the cone part moves through the axial movement of the thread, and then forms a great positive pressure on the peripheral surface of the expansion tube, and the angle of the cone is very small, so that the friction self-locking between the wall, the expansion pipe and the cone is formed, and then the fixing effect is achieved.

The spring washer on the expansion screw is a standard part, because its opening is staggered and elastic, so it is called a spring washer, and the function of the spring washer is to use the sharp sharp corners of the wrong mouth to pierce into the nut and flat gasket to prevent the nut from loosening.

The washer is also a standard part, which distributes the pressure of the nut evenly over the part to be connected.

The principle is very simple, that is, when the screw is inserted, the diameter of the expanded tube is expanded, and the pressure is applied to the drilled wall of the wall, so as to increase the friction force, which greatly exceeds the pulling force of the screw to ensure that it will not be pulled out.

The steel expansion bolt is the relative motion of the screw and the nut to make the tapered compass extrude the outer sleeve to expand the diameter, and exert pressure on the borehole wall of the wall.

The expansion screw is the one of nylon, right? For example, if its diameter is 8mm, the drill bit that is driven into it is also 8mm, right, isn't it stretched out by screwing? Isn't it impossible to get out?

And the iron one is also the same principle, which is to stretch it out. There's nowhere to find the diagram, if you think about the principle, you can also get one to try.

Expansion screws are needed in many places in life, metal and cement materials need expansion screws to be fixed, and expansion screws are also needed to install air conditioners. There are many other places that need to be used. So how does an expansion screw work?

What are the steps to use expansion screws? Let's take a look.

1. The principle of fixing expansion screws.

The expansion screw is fixed by the friction of the inclination, when the nut is tightened, the screw will move outward through the thread, the expansion pipe and the composite cable around the periphery will produce positive pressure, and the wall, the expansion tube and the cone will achieve the fixed effect.

Second, the expansion screw use steps.

After looking at the principle of fixing the expansion screw, let's take a look at the steps of using the expansion screw, and the installation steps of the expansion screw are as follows:

1. When installing, the electric hammer drill bit needs to be 2m larger than the expansion screw, so that the depth and size of the hole will be more suitable.

2. After drilling the corresponding holes, put the screws and expansion tubes into the holes, and tighten the mounting parts and fixings.

3. Choose the right fastening tool according to the variety of bolts.

4. Choose a dead wrench or a live wrench when installing metal fixings.

5. Use a plum screwdriver when installing plastic fixings.

7. Tighten to the corresponding degree as required.

Precautions for using expansion screws

1. The depth of punching should be determined according to the length of the expansion pipe, and some residues after punching the hole need to be cleaned up.

Summary: After reading the above, I believe you have a deeper understanding of the working principle of expansion screws and the use of expansion screws. In ordinary life, we may not pay attention to the use of expansion screws in life, we hang ** on the wall, install the device shelf, etc.

If you are not a veteran, it is recommended not to install it without authorization, as it is easy to cause damage to the wall with raw hands.

1. The fixing principle of the expansion screw: the fixing of the expansion screw is to use the slope of the expansion to promote the expansion to produce a friction front rough grip and wrapping force to achieve the fixing effect. The screw is threaded at one end and has a verterate at the other.

Outer bread a steel sheet, half of the iron cylinder has a number of incisions, put them together into the hole in the wall, and then lock the nut, the nut pulls the screw outward, pulls the vertebral into the steel cylinder, the steel cylinder is opened, so it is tightly fixed on the wall, generally used for the fastening of protective fences, canopies, air conditioners and other materials such as cement and bricks.

2. Crack loss, but its fixation is not very reliable, if the load has a large vibration, it may loosen, so it is not recommended for the installation of ceiling fans. The principle of the expansion bolt is to hit the expansion bolt into the hole on the ground or wall, tighten the nut on the expansion bolt with a wrench, the bolt goes out, but the metal sleeve outside does not move, so that the big head under the bolt expands the metal sleeve to make it full of the hole, at this time, the expansion bolt can not be withdrawn.