Extruder die for pearl wool based on servo control to adjust die gap

Abstract

This utility model discloses a die for an EPE foam extruder that adjusts the die gap based on servo control. The die includes a first filter plate, a mandrel, a second filter plate, an inner die, and an outer die. The second filter plate is threadedly connected to the inner die. The die also includes a hollow rotating platform and a drive mechanism. The hollow rotating platform is fixedly mounted on the second filter plate, and its output end is connected to the inner die via a sliding key for driving the inner die to rotate. The drive mechanism includes a servo motor and a reducer, connected to the hollow rotating platform. The drive mechanism is also connected to a servo controller, which has an operation panel for receiving adjustment commands and controlling and driving the inner die to rotate. This utility model achieves high-precision online non-destructive adjustment, significantly improving production efficiency and product quality.

Description

Technical Field

[0001] This utility model relates to the field of plastic product processing equipment, specifically to an extruder die for producing pearl cotton through physical extrusion foaming of polyethylene, and in particular, an pearl cotton extruder die based on servo control to adjust the die gap. Background Technology

[0002] In the production of EPE (physical extrusion foamed polyethylene), adjusting the die gap of the extruder is a crucial step in ensuring product quality. The size and precision of the die gap directly determine the thickness, foaming ratio, width, and product qualification rate of the extruded EPE products.

[0003] Currently, the widely used traditional EPE foam extruders typically adjust the die gap by fixing the inner die and rotating the outer die. Specifically, the operator manually rotates a large round nut, causing the outer die to move axially (inwards or outwards) relative to the fixed inner die, thus increasing or decreasing the gap. However, this adjustment method relies heavily on experience and feel; the adjustment amount is entirely determined by the operator's judgment, lacking quantitative standards and making accuracy difficult to guarantee. Furthermore, the adjustment process is highly destructive. Because the large round nut and other adjustment devices are tightly wrapped inside the extruded tubular EPE foam, adjustments must first tear or destroy the currently producing tubular EPE foam product. After adjustment, the tubular product must be pulled up again and reconnected to the subsequent traction mechanism. Each adjustment requires destroying the product, and after adjustment, the extrusion must stabilize before measuring product parameters (such as thickness, foaming ratio, and width). If the parameters do not meet the standards, the "destruction-adjustment-restart-measurement" cycle must be repeated. This not only leads to low production efficiency but also generates a large amount of waste, resulting in a serious waste of raw materials and energy.

[0004] Therefore, there is an urgent need to develop a die device for pearl cotton extruders that can achieve high-precision, non-destructive online adjustment of the die gap, so as to improve production efficiency, reduce scrap rate and improve product quality. Utility Model Content

[0005] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows:

[0006] The pearl cotton extruder die based on servo control for adjusting the die gap includes a first filter plate fixed to the extruder head, a mandrel fixed to the first filter plate, a second filter plate fixedly connected to the first filter plate, an inner die, and an outer die fixed to the tail of the mandrel. The second filter plate has an internal thread on the side facing the inner die, and the head of the inner die has an external thread that meshes with the internal thread of the second filter plate, forming a threaded pair.

[0007] Mouth molds also include:

[0008] Hollow rotating platform: It is fixedly installed on the second filter plate, and its output end is connected to the inner mold through a sliding key connection to drive the inner mold to rotate.

[0009] Drive mechanism: includes a servo motor and a reducer, connected to the hollow rotary platform;

[0010] The drive mechanism is also connected to a servo controller, which is equipped with an operation panel to receive adjustment commands and control and drive the inner mold to rotate.

[0011] Furthermore, the sliding key connection method is as follows: the outer surface of the inner mold is provided with an axial keyway, and the inner side of the output end of the hollow rotating platform is provided with a key block that cooperates with the keyway.

[0012] Furthermore, the sliding key connection method is as follows: the inner side of the output end of the hollow rotary platform is provided with an axial keyway, and the outer surface of the inner mold is provided with a key block that cooperates with the keyway.

[0013] Furthermore, the servo motor and reducer are integrated inside the hollow rotating platform.

[0014] Furthermore, the servo motor and reducer are separately connected to the hollow rotary platform via a coupling.

[0015] Furthermore, the operation panel is a digital operation panel, used to directly input the target adjustment value of the die opening gap.

[0016] The beneficial effects of this utility model are:

[0017] 1. Achieves high-precision online non-destructive adjustment: The inner mold rotation is controlled by a servo drive system, and the threaded pair is used to accurately convert it into axial displacement. The gap can be adjusted by directly inputting values ​​during production without stopping the machine or damaging the product, completely avoiding the scrap caused by repeated debugging in traditional methods.

[0018] 2. Significantly improves production efficiency and product quality: The adjustment process is fast and precise (accuracy can reach the micron level), which greatly shortens the product changeover time and ensures the consistency and stability of parameters such as product thickness and foaming ratio, thereby comprehensively improving production efficiency and economic benefits. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model;

[0020] Figure 2 This is a schematic diagram of the structure of a traditional die for an extruder.

[0021] The markings in the diagram are: 1. Servo controller; 2. Control panel; 3. First filter plate; 4. Head connecting bolt; 5. Diverter cone; 6. Drive mechanism; 7. Second filter plate; 8. Drive mechanism fixing bolt; 10. Inner mold; 11. Core rod; 12. Outer mold; 13. Outer mold fixing bolt; 14. Thrust washer; 15. Filter plate connecting bolt; 16. Tubular pearl cotton. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings. It should be noted that this embodiment is only intended to fully disclose the present invention and is not intended to limit the scope of protection of the present invention.

[0023] This utility model provides a servo-controlled die gap adjustment system for pearl cotton extruders. Its core lies in a complete overhaul of the traditional die adjustment mechanism, achieving digital, precise, and online adjustment of the die gap. The structure of this utility model consists of a basic fixing part, a motion execution part, and a drive control part.

[0024] Reference Figure 1 and Figure 2 The basic fixing part of this utility model structure is consistent with the traditional die structure, including:

[0025] Core rod 11: The core component that forms the hollow structure of the pearl cotton tubular product. The core rod 11 and the first filter plate 3 are fixed to the extruder head together by the die head connecting bolt 4.

[0026] First filter plate 3: It is fixed to the machine head by the machine head connecting bolt 4, which helps to fix the core rod 11 and ensures its stable position.

[0027] The second filter plate 7 is fixedly connected to the first filter plate 3 by filter plate connecting bolts 15 and is fastened together with the first filter plate 3 to the extruder head. It has a hole in the center for the core rod 11 to pass through. One of the core functions of the second filter plate 7 is to connect the inner mold 10. In the traditional die, the inner mold 10 is fixed to the second filter plate 7 by multiple sets of bolts, which is absolutely fixed throughout the production process. The core feature of the second filter plate 7 of this utility model is that it has an internal thread on the side facing the inner mold 10, and an external thread that meshes with it is processed on the outer cylindrical surface of the head of the inner mold 10 (the end near the extruder head), forming a threaded pair that can convert rotational motion into linear motion.

[0028] Outer mold 12: It is fixed to the tail of the mandrel 11 by outer mold fixing bolts 13; unlike the traditional die structure, the outer mold 12 of this utility model remains fixed throughout the entire production process.

[0029] The die gap refers to the annular gap formed between the inner die 10 and the outer die 12.

[0030] The motion execution part of this utility model includes:

[0031] Inner mold 10: The outer cylindrical surface of its head (near the head end) is machined with an external thread, which precisely meshes with the internal thread on the second filter plate 7 to form a precision threaded pair; the outer surface of its body is machined with at least one axial keyway.

[0032] Hollow Rotary Platform: As the final output actuator of the servo drive system, it is fixedly mounted on the second filter plate 7 via drive mechanism fixing bolts 8. The hollow rotary platform is a high-precision mechatronic rotary motion actuator. Its core feature is that its output shaft is a through-hole structure, allowing the inner mold 10 to pass through it. A key block (not shown in the figure) is fixedly installed in the output inner hole of the hollow rotary platform by welding or set screws. This key block is preferably made of high-strength alloy steel to withstand the transmission torque. The key block is precisely embedded in the keyway of the inner mold 10, forming a sliding key connection. This connection method achieves decoupling of power transmission and motion, enabling the hollow rotary platform to effectively transmit rotational torque to the inner mold 10, driving it to rotate, while allowing the inner mold 10 to slide freely axially along its axis under the guidance of the keyway.

[0033] Correspondingly, the inner mold 10 is connected to the sliding key of the hollow rotating platform, and its keyway can also be set in the output inner hole of the hollow rotating platform, and the key block can also be set on the inner mold 10.

[0034] The drive control part of this utility model includes:

[0035] Drive mechanism 6: Includes servo motors and reducers, and is usually integrated with the hollow rotary platform.

[0036] Taking the TWD TX200 hollow rotary platform as an example, it features an integrated structure that incorporates a servo motor, a high-precision reducer (such as a planetary reducer), a high-rigidity crossed roller bearing, and a high-resolution encoder. Its working principle is as follows: the servo motor receives commands from the controller and rotates. The power is increased / decreased by the reducer to amplify the output torque, which is then output through a through-hole shaft supported by the crossed roller bearing. The built-in encoder provides real-time feedback on the angular position of the output shaft, forming a closed-loop control system that ensures extremely high control precision.

[0037] The hollow rotary platform can also adopt a split structure, where the servo motor and reducer are independent units connected to a hollow platform body via couplings. However, the integrated structure has the advantages of more compact structure, more precise control, and easier installation, making it a more preferred implementation solution.

[0038] Servo controller 1 (usually located in the electrical control cabinet) is electrically connected to drive mechanism 6 via power cable and feedback cable. It is used to receive control commands and process encoder feedback signals, forming a high-precision closed-loop motion control system.

[0039] Control Panel 2: Connected to Servo Controller 1, and installed in a convenient location for operation. Control Panel 2 is a digital operation panel, allowing operators to directly input precise gap adjustment values ​​(millimeters) or commands such as target angles and number of revolutions.

[0040] The working principle and adjustment process of this utility model are as follows:

[0041] When production requires adjusting the thickness or foaming ratio of the pearl cotton product, the operator can directly input the required adjustment amount (e.g., increase the gap by 0.025mm) on the control panel 2 without stopping the machine.

[0042] After receiving the command, the servo motor in the drive mechanism 6 starts working. The output of the servo motor is amplified by the reducer and then transmitted to the hollow rotating platform, driving its output inner hole and the key block inside to rotate.

[0043] The rotation of the key block drives the inner mold 10 to rotate synchronously via the sliding key connection.

[0044] Since the inner mold 10 engages with the internal thread on the fixed second filter plate 7 through the external thread of its head, the rotational motion of the inner mold 10 is forcibly converted into precise axial linear motion according to the principle of thread transmission.

[0045] Specifically: when it is necessary to reduce the die opening clearance, the inner die 10 is controlled to move closer to the outer die 12 (i.e., Figure 1 Move axially to the right (from the center).

[0046] When it is necessary to increase the die clearance, control the inner die 10 to move away from the outer die 12 (i.e., Figure 1 Move from the center to the left (axial direction).

[0047] Throughout the adjustment process, all external structures, including the outer mold 12, the first filter plate 4, the second filter plate 5, and the core rod 3, remain fixed. Therefore, the shape of the tubular pearl cotton 16 extruded from the die is completely undisturbed, achieving truly non-destructive online adjustment. After adjustment, product parameters (thickness, width, etc.) stabilize rapidly, with almost no transitional waste.

[0048] Compared to traditional structures (see...) Figure 2 ):

[0049] Traditional die-cutting uses a method of "fixing the inner die and manually rotating the outer die". During adjustment, the tubular pearl cotton 16 wrapped around the outer die must be torn off, and the outer die fixing bolts 13 must be manually pried to move the outer die. The adjustment process is cumbersome, laborious, inaccurate, and produces a lot of waste.

[0050] In contrast, this utility model, through its ingenious "outer mold fixed, servo-driven inner mold rotation" structure, combined with the mechanical design of "sliding key to transmit torque" and "threaded pair to convert motion", achieves a breakthrough adjustment method that does not damage the product, produces no waste, and has high production efficiency.

[0051] Furthermore, a significant advantage of this invention lies in its ability to achieve high-precision die gap adjustment. The hollow rotary platform boasts extremely high indexing accuracy (up to 0.005 degrees, or 0.3 arcminutes). This means the servo system can drive the inner mold 10 to perform extremely small and precise angular displacements, which can be converted into micron-level axial displacements. Driving the inner mold 10 to rotate allows for precise changes in the die gap down to the micrometer level. For example, when the foaming ratio is maintained at 40, a die gap of 0.1 mm yields a 4 mm thick pearl cotton product. When the die gap is precisely adjusted to increase by 2.5 micrometers (0.025 mm), the die gap becomes 0.125 mm, resulting in a 5 mm thick pearl cotton product.

[0052] The above description is merely a preferred embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the technical scope disclosed in this utility model, based on the technical solution and inventive concept of this utility model, should be included within the protection scope of this utility model.

Claims

1. A servo-controlled extruder die for adjusting the die gap of pearl cotton, comprising a first filter plate fixed to the extruder head, a mandrel fixed to the first filter plate, a second filter plate fixedly connected to the first filter plate, an inner die, and an outer die fixed to the tail of the mandrel, characterized in that: The second filter plate has an internal thread on the side facing the inner mold, and the head of the inner mold has an external thread that meshes with the internal thread of the second filter plate, forming a threaded pair. The die also includes: Hollow rotating platform: It is fixedly installed on the second filter plate, and its output end is connected to the inner mold through a sliding key connection to drive the inner mold to rotate. Drive mechanism: includes a servo motor and a reducer, connected to the hollow rotary platform; The drive mechanism is also connected to a servo controller, which is equipped with an operation panel to receive adjustment commands and control and drive the inner mold to rotate.

2. The extruder die for pearl cotton according to claim 1, characterized in that: The sliding key connection method is as follows: the outer surface of the inner mold is provided with an axial keyway, and the inner side of the output end of the hollow rotating platform is provided with a key block that cooperates with the keyway.

3. The extruder die for pearl cotton according to claim 1, characterized in that: The sliding key connection method is as follows: the inner side of the output end of the hollow rotating platform is provided with an axial keyway, and the outer surface of the inner mold is provided with a key block that cooperates with the keyway.

4. The extruder die for pearl cotton according to claim 1, characterized in that: The servo motor and reducer are integrated inside the hollow rotating platform.

5. The extruder die for pearl cotton according to claim 1, characterized in that: The servo motor and reducer are connected separately to the hollow rotary platform via a coupling.

6. The extruder die for pearl cotton according to claim 1, characterized in that: The control panel is a digital control panel, used to directly input the target adjustment value of the die opening clearance.

Images