In modern industrial society, with the prosperity of consumption, in daily necessities, food, medicine, cosmetics and other industries, enterprises need to use new science and technology to improve productivity and create more value, and the delivery conveyor can be quantitative and smooth transport productions. Especially in the post-packaging production line, the conveyor can smoothly and safely transport items such as bottles (round bottles or bottles with special-shaped cross-sections). And the bottles and cans are introduced into the production machinery such as labeling machine in order to complete a series of production processes such as labeling and sleeve labeling, cleaning and drying.
How to ensure that bottles or cans enter various packaging machines in an orderly manner on the conveyor chain? An important device is needed here: the screw rod for entering and exiting bottles.
Bottle in and out screw mechanism of the screw conveyor: it is a constant speed mechanism driven by the transmission system of the conveying equipment, which transfers the bottle or material transported by the conveying device to the screw conveyor through the star wheel, so that the material or bottle can work under the push of the spiral rotation. And the bottles will also be separated into formations with a certain interval by the spiral groove during the process of advancing.
1. Material requirements for the screw mechanism.
The screw is the core part used in the canning production line of food and medicine. Due to the large number of bottles pushes, it is prone to wear and tear. If the bottle it pushes is made of glass, the bottle is also easy to break, so it is required to minimize the impact when pushing the bottle, so the screw should have high wear resistance, high strength, Self-lubricating, no internal stress, no deformation, easy to process and replace. And usually made of engineering plastics, black oil-impregnated nylon.
2. Structural requirements of the screw mechanism.
The screw conveyor is equipped with a screw that pushes the bottle, which plays a very important role in the subsequent packaging production process. In order to further ensure the smoothness and stability of pushing the bottle, the structure of the screw is also very important.
To meet the technical requirements of fixed-distance separation and timing push, the screw must meet the following conditions: (1) The container must move smoothly along the screw; (2) The container can be smoothly introduced into the spiral groove; (3) The container and the star wheels fit smoothly.
1. Design requirements of the screw
According to the structural requirements, there are the following design requirements for the screw rod.
There must be no impact when the bottle enters the screw conveyor and contacts the screw to ensure the integrity and safety of the product. Therefore, in actual use, according to the different laws of motion, the applicable occasions range from low speed and light load to high speed and heavy load. The movement law of the bottle is reflected in the design of the helix. The screw needs to be designed as an acceleration section that changes according to a certain curve. In the design of the helix, a flexible impact or no impact design is usually used to avoid rigid impact.
For example: the movement law of the cycloid sine acceleration is 0 at the beginning and end of the container stroke. This is a no-shock design, suitable for high-speed and light-load conditions. This design is suitable for smooth delivery of the screw during the start-up phase. It is applicable to the assembly line; the motion law of cosine acceleration can ensure that when the screw is running at the maximum acceleration, the torque is relatively small, the impact is flexible, and the start is relatively stable. It is suitable for medium-speed and medium-load conditions, and also meets many medium and low speeds of conveying and filling requirements.
Regarding the screw technology of conveyor line equipment, the screw can usually be divided into three-stage combined screw (that is, the simplified design of the screw), that is the constant speed section is equal pitch, the entry end of the bottle; the variable speed section, the middle transition of conveying materials section; and then through the constant acceleration section, the output end is smoothly connected with the star wheel. Of course, if each production enterprise has special requirements, it can also carry out other forms of screw combination for the screw at the entry end according to the production process of the enterprise itself.
Input end: The input end adopts the form of equidistant screw, which is more conducive to the smooth entry of the container, so as to better reduce the vibration phenomenon. In order to facilitate the production and processing of the screw, the input end of the screw is often made into a cone. The shape length is about 15% of the total length.
Intermediate transition section: In order to better meet the functional requirements of the intermediate section, it is necessary to design the screw into a shape that changes according to a certain curve, so that each street joint on the screw conveyor line has a corresponding equal helix angle, speed and acceleration, effectively reducing the impact of the bottle, thus better ensuring a smooth connection.
Output end: As for the output end, since the pitch of the star wheel is generally greater than the center distance when the two bottles are in contact, it needs to be designed as a variable pitch, and the pitch is gradually increased according to the law of constant acceleration until the pitch increases to the same as the star wheel. The wheel pitches are equal.
Of course, the required screw can also be designed according to the process requirements of different enterprises, but in processing, the more complex the curve is, the more difficult it is to process. Ordinary machine tools and economical CNC machine tools do not have the function of processing screw rods. Therefore, when designing the screw, it is possible to simplify the helical curve, mainly the medium and low speed screw, change the intermediate transition section into a constant acceleration section, and remove the complicated transition curve, and the constant velocity section at the output end is used as an extension of the terminal pitch. After the design and processing of the bottle, the screw that enters the bottle will not have a great impact on the smooth delivery of the bottle.
Screw Mechanism on Sunswell 12,000BPH Glass Bottle Line
