Function and working principle of linear guide

Time:2021-07-14     View:800

The slider is a mold component that can slide perpendicular to the mold opening and closing direction or at a certain angle with the mold opening and closing direction during the mold opening action. When the product structure makes the mold can not be demolded normally without using the slider, the slider must be used. The material itself has appropriate hardness and wear resistance, enough to withstand the friction of movement. The hardness of the cavity part or core part on the slider should be the same level as the other parts of the mold core.
Definition: Linear guides, also known as linear guides, slides, linear guides, and linear slides, are used for linear reciprocating motion applications, and can bear a certain torque, and can achieve high-precision linear motion under high load. It is called linear guide in the mainland, and generally called linear guide or linear slide in Taiwan.
Classification: Divided into square ball linear guide, double-axis core roller linear guide, single-axis core linear guide.
Function: The function of linear guide motion is to support and guide the moving parts, and make reciprocating linear motion in a given direction. Depending on the nature of friction, linear motion guides can be divided into sliding friction guides, rolling friction guides, elastic friction guides, fluid friction guides and other types. Linear bearings are mainly used in automated machinery, such as machine tools imported from Germany, bending machines, laser welding machines, etc. Of course, linear bearings and linear shafts are matched. Linear guides are mainly used in mechanical structures that require relatively high precision. There is no intermediate medium between the moving elements and fixed elements of the linear guide, but rolling steel balls.
Self-aligning ability:
The DF (45-°45)° combination from the arc groove can be absorbed by the inside of the linear rail slider even if the mounting surface is somewhat deviated by the elastic deformation of the steel ball and the transfer of the contact point during installation. Produces the effect of self-aligning ability and obtains high-precision and stable smooth movement.
Interchangeable
Due to strict control over the manufacturing precision, the size of the linear guide rail can be maintained within a certain level, and the slider has a retainer design to prevent the steel ball from falling off. Therefore, the precision of some series is interchangeable. Customers can order guide rails or The sliding block can also be stored separately from the guide rail and the sliding block to reduce storage space.
High rigidity in all directions
The use of four-row arc grooves and a 45-degree contact angle of four rows of steel balls allows the steel balls to achieve an ideal two-point contact structure, which can withstand the load from up and down and left and right directions; when necessary, preload can be applied to increase rigidity.
working principle:
It can be understood as a kind of rolling guide, in which the steel ball rolls infinitely between the slider and the guide rail, so that the load platform can easily move with high precision along the guide rail and reduce the friction coefficient to the usual traditional sliding guide. One-fiftieth, high positioning accuracy can be easily achieved. The design of the final unit between the slider and the guide rail enables the linear guide to bear the load in all directions, such as up, down, left, and right at the same time. The patented recirculation system and simplified structural design make the HIWIN linear guide more smooth and low-noise movement.
Slider-the movement is transformed from a curve to a straight line. The new guide rail system enables the machine tool to obtain rapid feed speed. In the case of the same spindle speed, rapid feed is a characteristic of linear guides. Linear guides, like flat guides, have two basic elements; one as a guide is a fixed element, and the other is a moving element. Since the linear guide is a standard component, it is for machine tool manufacturers. The only thing to do is to process the plane of a mounting rail and adjust the parallelism of the rail. Of course, in order to ensure the accuracy of the machine tool, a small amount of scraping of the bed or column is essential. In most cases, the installation is relatively simple. The guide rail as the guide is hardened steel, which is placed on the installation plane after fine grinding. Compared with flat guide rails, the cross-sectional geometry of linear guide rails is more complicated than that of flat guide rails. The reason for the complexity is that grooves need to be machined on the guide rails to facilitate the movement of sliding elements. The shape and number of grooves depend on the machine tool to complete. Function. For example: a guide rail system that bears both linear force and subversive moment is compared with a guide rail that only bears linear force. The design is very different.
The basic function of the fixed element (guide rail) of the linear guide system is like a bearing ring, and the bracket for mounting the steel ball is shaped like a "v". The bracket wraps the top and both sides of the rail. In order to support the working parts of the machine tool, a set of linear guide has at least four supports. Used to support large working parts, the number of brackets can be more than four.
When the working parts of the machine tool move, the steel balls circulate in the groove of the bracket, and the wear of the bracket is distributed to each steel ball, thereby prolonging the service life of the linear guide. In order to eliminate the gap between the bracket and the guide rail, the preload can improve the stability of the guide rail system and the preload can be obtained. It is to install an oversized steel ball between the guide rail and the bracket. The diameter tolerance of the steel ball is ±20 microns, with 0.5 micron increments. The steel balls are screened and classified and installed on the guide rails respectively. The size of the preload depends on the force acting on the steel balls. If the force acting on the steel ball is too large and the preload time is too long, resulting in increased stent movement resistance, there will be a balance problem; in order to improve the sensitivity of the system and reduce the movement resistance, the preload should be reduced accordingly , And in order to improve the accuracy of the motion and the retention of the accuracy, it is required to have enough pre-adding negative numbers, which are two contradictory aspects.
If the working time is too long, the steel ball begins to wear, and the preload on the steel ball begins to weaken, resulting in a decrease in the movement accuracy of the working parts of the machine tool. If you want to maintain the initial accuracy, you must replace the rail bracket, or even replace the rail. If the rail system has a preload effect. The accuracy of the system has been lost, and the only way is to replace the rolling elements.
The design of the guide rail system strives to have the largest contact area between the fixed element and the moving element. This not only improves the carrying capacity of the system, but also the system can withstand the impact force generated by intermittent cutting or gravity cutting, spread the force widely, and expand the bearing capacity. The area of force. In order to achieve this, there are various groove shapes of the guide rail system. There are two representative ones, one is called Gothic (pointed arch), the shape is the extension of a semicircle, and the contact point is the apex; the other The species is arc-shaped and can also play the same role. No matter what kind of structure, there is only one purpose, and strive to have more rolling steel ball radius contact with the guide rail (fixed element). The factor that determines the performance characteristics of the system is: how the rolling elements contact the guide rail, which is the key to the problem.
Application areas:
1. Linear guides are mainly used in automated machinery, such as machine tools imported from Germany, paper bowl machines, laser welding machines, etc. Of course, linear guides and linear axes are used as a set.
2. Linear guides are mainly used in mechanical structures with relatively high precision requirements. There is no intermediate medium between the moving and fixed components of the linear guide, but rolling steel balls. Because the rolling steel ball is suitable for high-speed motion, has a small friction coefficient and high sensitivity, it can meet the working requirements of moving parts, such as the tool holder and carriage of the machine tool. If the force acting on the steel ball is too large, the steel ball will withstand the preload for too long, which will increase the movement resistance of the bracket.
Use note:
Linear guides are precision parts, so they require considerable caution when using them. Even if high-performance linear guides are used, if they are used improperly, the expected performance will not be achieved, and the linear guides are likely to be damaged. Therefore, pay attention to the following matters when using linear guides:
Prevent rust
When picking up the linear guide directly by hand, wash away the sweat from your hands and apply high-quality mineral oil before operation. Pay special attention to rust prevention during the rainy season and summer.
Keep the environment clean
Keep the linear guide and its surroundings clean, even if tiny dust invisible to the naked eye enters the guide, it will increase the wear, vibration and noise of the guide.
Install carefully
The linear guide should be carefully used and installed, and strong punching is not allowed, the direct hitting of the guide with a hammer is not allowed, and the pressure transmission through the rolling elements is not allowed.
Appropriate installation tools
Use appropriate and accurate installation tools for linear guides. Try to use special tools, and try to avoid using cloth and short fibers.
Clean the guide rails:
Guide rails and linear shafts are one of the core components of the equipment, and their function is to play a guiding and supporting role. In order to ensure the high processing accuracy of the machine, the guide rails and straight lines are required to have high guiding accuracy and good movement stability. During the operation of the equipment, due to the large amount of corrosive dust and smoke generated during the processing of the processed parts, these smoke and dust will be deposited on the surface of the guide rail and linear shaft for a long time, which has a great impact on the processing accuracy of the equipment, and will Corrosion points are formed on the surface of the linear axis of the guide rail, which shortens the service life of the equipment. In order to make the machine work normally and stably and ensure the processing quality of the products, the daily maintenance of the guide rail and linear axis must be done carefully. Note: Please prepare dry cotton cloth and lubricating oil to clean the guide rail. The guide rail of the engraving machine is divided into linear guide rail and roller guide rail. Cleaning the linear guide: first move the laser head to the far right (or left), find the linear guide, wipe it with a dry cotton cloth until it is bright and dust-free, and add a little lubricating oil (sewing machine oil can be used, do not use machine oil) , Slowly push the laser head from side to side several times to distribute the lubricating oil evenly. Cleaning the roller guide rail: move the beam to the inside, open the end covers on both sides of the machine, find the guide rails, wipe the areas where the guide rails on both sides are in contact with the rollers with a dry cotton cloth, and then move the beam to clean the remaining areas.
Development Overview:
The sustained and rapid growth of China's economy has provided huge market space for linear guide products. The strong temptation of the Chinese market has made the world focus on the Chinese market. In just a few decades of reform and opening up, China's linear guide manufacturing industry The huge production capacity formed has made the world look at it with admiration. With the continuous expansion of China's power industry, data communication industry, urban rail transit industry, automobile industry, shipbuilding and other industries, the demand for linear guides will also grow rapidly, and the linear guide industry has huge development potential in the future.
Industrial Process Equipment
Mold is an important process equipment for the production of various industrial products. With the rapid development of the plastic industry and the promotion and application of plastic products in the aviation, aerospace, electronics, machinery, shipbuilding and automotive industries, the requirements for molds are increasing. The higher the higher, the traditional mold design methods can no longer meet the requirements of today. Compared with traditional mold design, computer-aided engineering (CAE) technology is either in terms of improving productivity, ensuring product quality, or reducing costs and reducing labor intensity. , Both have great advantages.