What is Guide Bush in Injection Mold?

What is guide bush?

Guide Bush is used in conjunction with the guide pin, play a guiding role. Generally, the clearance is very small, within 0.05mm. The guide pin and guide bushing are injection mold components generally used in injection molds or some machinery to ensure the accuracy of movement.

Guide bush function

The guide bushing in the injection mold plays an extremely important role in modern parts processing and is also one of the most important parts of the current injection mold production process. Its good characteristics have been widely used in many industries such as machinery and automobile manufacturing. So what is the role of leadership in the injection mold production process?

The guide bushing in the injection mold’s function is to guide. The role of the guide device of the injection mold is to guide the upper mold and the lower mold to match in the correct position.

The most common guide device is the guide bushing and guide pin. In addition, a large injection mold may be equipped with a guide plate, and a micro die may be provided with a guide tube, which has the same function as the guide bushing and guide sleeve pin.

Guide bush material

The material of the guide bushing is generally selected from bearing steel, hot work dies steel, easy cut iron, etc., and largely use of bearing steel SUJ2 material, which greatly enhances the durability and interchangeability of the guide bushing in terms of guiding performance.

Guide bushing and its components constitute the outer guide bushing component and the inner guide bushing component, which have a beautiful metallic luster.

The roundness of the guide bushing has very high requirements. The center hole is mainly used to grind the outer diameter with a cylindrical grinder, when using a cylindrical grinder to grind the outer diameter, the center hole must be held against the center hole to rotate the guide bushing grind.

The angle of the inclined guide bushing of the injection mold usually adopts two inclination angles of 20 degrees or 25 degrees. Generally, 20 degrees is used. If the distance of the sliding block is a little bit longer, then use the 25 degrees’. If the distance is longer, it needs to use hydraulic or pneumatic methods.

The outer cylindrical surface has a high dimensional tolerance level and a small surface roughness value Ra value, the measures taken are that the requirements for the division of processing stages, the selection of machine tools, and the control of cutting parameters should be the same as the processing of the inner cylindrical surface. In addition, the process route is rough turning-semi-finishing turning-rough grinding-fine grinding.

Height is an important in injection mold production

The guide bush has two main functions, guiding and supporting. The former is to guide the upper mold and the lower mold to align in the correct position. The most common one is that there is no guide bushing and guide sleeve pin. In addition, there can also be certain support for the upper film bushing.

Considering that the sliding fit of the guide bushing and the guide pin is relatively frequent, it needs to have better lubrication performance, and a lubricating oil groove needs to be opened. In order to ensure the working strength of guide bushing, it should be in a fixed position with a diameter that is about twice the diameter of its working part.

Causes of damage to the guide bushing

If the quality of the guide bushing material is poor, the quality will be affected due to incorrect heat treatment or low hardness during processing. There is a gap between the guide bushing and the guide pin and no lubricant is added in time, which will ultimately affect its service life.

In addition, there are problems in design. If the passing through the knife hole is not fully considered, the result will inevitably make the guide bushing lose its support and become a positioning mechanism. In addition to the above two factors, there will be other reasons for normal use. If the related operation methods were not correct and not standardized during installation, and some operators did not carry out timely maintenance and maintenance after they were used. It is also easy to cause damage to the guide bushing.