Air protection ring structure of cooling air ring of film blowing equipment

Abstract

An air protection ring structure of a cooling air ring of film blowing equipment comprises a cooling air ring body, the cooling air ring body is provided with an annular air outlet, an air protection ring assembly is arranged above the annular air outlet, and the air protection ring assembly is divided into a plurality of layers of air protection rings up and down; the wind protection ring located on the uppermost layer comprises an annular inner ring body and an annular outer ring body which are arranged in a split mode, and a bearing is arranged between the annular inner ring body and the annular outer ring body. A plurality of inner adjusting holes are formed in the annular inner ring body, a plurality of outer adjusting holes are formed in the annular outer ring body, and the inner adjusting holes and the outer adjusting holes are the same in aperture; the lower end of the annular outer ring body is integrally connected with a convex edge, and outer teeth are formed on the convex edge; a transmission gear is further installed on the cooling air ring body and meshed with the outer teeth of the annular outer ring body. A stepping motor for driving the transmission gear to rotate is also arranged; a plurality of ultrasonic sensing range finders used for detecting the positions of film bubbles are further installed on the upper edge of the annular inner ring body of the uppermost layer of the wind protection ring. The bubble stabilizing device can adjust the flowing mode of airflow and improve the bubble stabilizing effect.

Description

Technical Field

[0001] This utility model belongs to the technical field of plastic film processing equipment, and particularly relates to a protective ring structure for a cooling air ring of a blown film equipment. Background Technology

[0002] When a blown film extrusion machine is operating, molten plastic material is extruded from the annular die opening to form an annular film bubble. Simultaneously, pressurized gas is blown into the bubble to inflate it. Furthermore, the extruded film bubble reaches a high temperature, necessitating cooling using a cooling air ring. This cooling air ring has an annular outlet; during operation, cooling airflow is blown from the outlet towards the outer surface of the film bubble, thus cooling it. To extend the cooling time, control the cooling effect, and ensure stable operation before complete solidification, some blown film extrusion machines also include an annular protective ring on the cooling air ring. This protective ring is located above the annular outlet, confining the cooling airflow upwards through the annular gap between the outer surface of the film bubble and the inner surface of the protective ring. This stabilizes the airflow and extends the cooling time, thereby controlling the cooling effect.

[0003] However, the cooling airflow of existing blown film equipment can only flow upward from the annular gap between the outer surface of the film bubble and the inner surface of the air shield. The airflow pattern is singular and cannot be adjusted according to the site conditions. In particular, when the radial distance between the film bubble and the inner surface of the air shield is large, the air shield has a poor bubble stabilization effect because the film bubble is relatively far away from the air shield. Utility Model Content

[0004] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a protective ring structure for the cooling air ring of a blown film equipment, which can adjust the airflow pattern and improve the bubble stabilization effect.

[0005] The objective can be achieved through the following scheme: a protective ring structure for a cooling air ring of a blown film equipment, comprising a cooling air ring body, the cooling air ring body having an annular air outlet, and a protective ring assembly above the annular air outlet, the protective ring assembly being divided into several upper and lower protective rings; in each pair of adjacent upper and lower protective rings, the diameter of the upper protective ring is larger than the diameter of the lower protective ring, and the lower part of the upper protective ring is fitted around the outer periphery of the lower protective ring; characterized in that the uppermost protective ring comprises a separately arranged annular inner ring body and an annular outer ring body, the annular outer ring body fitting around the annular inner ring body, and a bearing being provided between the two; the annular inner ring body has multiple inner adjustment holes, and the annular outer ring body has... Multiple external adjustment holes, with the same diameter as the internal and external adjustment holes, and the positions of the internal and external adjustment holes correspond one-to-one; a raised edge is integrally connected to the lower end of the annular outer ring, and the raised edge forms external teeth; a transmission gear is also installed on the cooling air ring body, and the transmission gear meshes with the external teeth of the annular outer ring; a stepper motor is also provided to drive the transmission gear to rotate; several ultrasonic sensor rangefinders for detecting the position of the membrane bubble are also installed on the upper edge of the annular inner ring of the uppermost air shield, and each ultrasonic sensor rangefinder is evenly distributed along the circumference of the air shield; a central controller is also provided, and each ultrasonic sensor rangefinder is connected to the central controller, which is connected to the stepper motor.

[0006] The cooling air ring body is also equipped with a movable ring support. The uppermost air shield, transmission gear, stepper motor and movable ring support are fixed together. At least three vertical lead screw mechanisms are provided between the cooling air ring body and the movable ring support. Each vertical lead screw mechanism is evenly arranged along the circumference of the cooling air ring body. The vertical lead screw of each lead screw mechanism is rotatably mounted on the cooling air ring body. Each vertical lead screw is screwed to the movable ring support by threads. Each vertical lead screw is equipped with a lead screw motor to drive its rotation.

[0007] This utility model has the following advantages and effects:

[0008] I. This utility model can adjust the overlap between the inner and outer adjustment holes of the uppermost wind shield ring. Based on real-time needs, it guides a portion of the airflow to leave the membrane bubble first along the horizontal centrifugal direction from the inner and outer adjustment holes, and the proportion of this airflow can be adjusted as needed. Furthermore, when a large radial distance is detected between the membrane bubble and the inner surface of the uppermost wind shield ring, the overlap between the inner and outer adjustment holes can be increased, allowing more cooling airflow to leave the membrane bubble first along the horizontal centrifugal direction. This reduces the cooling degree of the membrane bubble and alleviates the air pressure in the space between the membrane bubble and the inner surface of the wind shield ring, thereby increasing the degree of membrane bubble inflation, reducing the radial distance between the membrane bubble and the inner surface of the uppermost wind shield ring, and bringing the membrane bubble closer to the inner surface of the uppermost wind shield ring, thus making the membrane bubble operation more stable.

[0009] Second, this utility model can adjust the vertical overlap between the uppermost and second-uppermost wind shield rings, thereby adjusting the height of the entire wind shield ring assembly, which can adapt to the needs of changes in the height position of the membrane bubble condensation line. Attached Figure Description

[0010] Figure 1 This is a cross-sectional structural diagram of a specific embodiment of the present invention.

[0011] Figure 2 yes Figure 1 A magnified view of part B in the diagram.

[0012] Figure 3 yes Figure 2 A schematic diagram showing the changing states of the structure.

[0013] Figure 4 yes Figure 1 Schematic diagram of the AA section structure.

[0014] Figure 5 yes Figure 4 A magnified view of part of C.

[0015] Figure 6 yes Figure 4 The diagram shows the usage changes of the structure.

[0016] Figure 7 yes Figure 6 A magnified view of part of D. Detailed Implementation

[0017] Figure 1 , Figure 2 , Figure 4 , Figure 5As shown, the cooling air ring structure of a blown film equipment in this embodiment includes a cooling air ring body 1, an annular air outlet 10, and a protective air ring assembly above the annular air outlet 10. The protective air ring assembly is divided into upper and lower protective air rings, namely an upper protective air ring and a lower protective air ring 2. The diameter of the upper protective air ring is larger than the diameter of the lower protective air ring 2, and the lower part of the upper protective air ring is fitted around the outer perimeter of the lower protective air ring. The upper protective air ring includes a separate annular inner ring body 31 and an annular outer ring body 32, and the annular outer ring body 32 is fitted around the annular inner ring body 31. A bearing 30 is provided between the inner ring body 31 and the outer ring body 2. The lower part of the inner ring body 31 is fitted around the outer periphery of the lower wind shield 2. The inner ring body 31 has multiple inner adjustment holes 310, and the outer ring body 32 has multiple outer adjustment holes 320. The diameters of the inner adjustment holes 310 and the outer adjustment holes 320 are the same, and the positions of the inner adjustment holes 310 and the outer adjustment holes 320 are matched one-to-one. The lower end of the outer ring body 32 is integrally connected with a flange 33, which has external teeth. A transmission is also installed on the cooling air ring body 1. Gear 4, the transmission gear 4 meshes with the outer teeth of the annular outer ring body 32; a stepper motor 41 is also provided to drive the transmission gear 4 to rotate; four ultrasonic sensor rangefinders 5 for detecting the position of the membrane bubble are also installed on the upper edge of the annular inner ring body of the upper air shield, and each ultrasonic sensor rangefinder 5 is evenly distributed along the circumference of the air shield; a central controller is also provided, and each ultrasonic sensor rangefinder 5 is connected to the central controller, which is connected to each stepper motor 41; a movable annular bracket 6 is also provided on the cooling air ring body 1, and the upper air shield ( The cooling ring body 1 includes an inner ring body 31 and an outer ring body 32, a transmission gear 4, a stepper motor 41, and a movable ring bracket 6, which are fixed together. Four vertical lead screw mechanisms 7 are provided between the cooling ring body 1 and the movable ring bracket 6. Each vertical lead screw mechanism 7 is evenly arranged along the circumference of the cooling ring body 1. The vertical lead screw 71 of each lead screw mechanism 7 is rotatably mounted on the cooling ring body 1. Each vertical lead screw 71 is screwed to the movable ring bracket 6 by threads. Each vertical lead screw 71 is equipped with a lead screw motor 9 that drives its rotation.

[0018] The working principle of the above embodiments is as follows:

[0019] During operation, the cooling airflow is blown out from the annular outlet 10 of the cooling air ring body 1, and then flows upward through the annular gap between the membrane bubble 8 and the wind guard ring. During this process, each ultrasonic rangefinder 5 continuously detects the horizontal radial distance between itself and the membrane bubble 8. The central controller calculates the average value of the measurement results from each ultrasonic rangefinder 5 (to avoid deviations caused by membrane bubble swaying). When the distance between the membrane bubble 8 and the upper wind guard ring is detected to be too large, the stepper motor 41 drives the transmission gear 4 to rotate. The transmission gear 4 drives the outer annular ring body 32 to rotate relative to the inner annular ring body 31 through the external teeth of the convex edge 33, increasing the overlap between the inner adjustment hole 310 and the outer adjustment hole 320, or even allowing them to completely overlap. Figure 4 , Figure 5 As shown, more cooling airflow leaves the membrane bubble first along the horizontal centrifugal direction from the inner and outer regulating holes. This reduces the cooling degree of the membrane bubble and alleviates the air pressure in the space between the membrane bubble and the inner surface of the wind shield, thereby increasing the degree of membrane bubble inflation and reducing the radial distance between the membrane bubble and the inner surface of the uppermost wind shield, bringing the membrane bubble closer to the inner surface of the uppermost wind shield, thus making the membrane bubble operation more stable. Conversely, if it is detected that the membrane bubble is too close to the upper wind shield, the annular outer ring 32 is driven to rotate in the opposite direction relative to the annular inner ring 31, reducing the overlap between the inner regulating hole 310 and the outer regulating hole 320, or even completely misaligning them, as shown. Figure 6 , Figure 7 As shown, this allows the distance between the membrane bubble and the upper air shield to return to the normal range.

[0020] The condensation position (vertical position of the condensation line) varies depending on the membrane bubble material. Furthermore, during production, adjustments to process parameters may also cause changes in the vertical position of the membrane bubble's condensation line. In both cases, the vertical lead screw 71 of the lead screw mechanism 7 can be rotated by the lead screw motor 9, causing the movable annular support 6 to rise and fall. This, in turn, causes the inner annular ring 31, the outer annular ring 32, the transmission gear 4, the stepper motor 41, and the ultrasonic sensor rangefinder 5 to rise and fall synchronously, thereby adjusting the height of the air shield assembly to adapt to different membrane bubbles or different process parameters. The state of the air shield assembly after being raised is adjusted as follows: Figure 3 As shown, the state of the windshield assembly after lowering is as follows: Figure 2 As shown.

Claims

1. A protective ring structure for a cooling air ring of a blown film equipment, comprising a cooling air ring body, the cooling air ring body having an annular air outlet, and a protective ring assembly above the annular air outlet, the protective ring assembly being divided into several upper and lower protective rings; in every two adjacent upper and lower protective rings, the diameter of the upper protective ring is larger than the diameter of the lower protective ring, and the lower part of the upper protective ring is fitted around the outer periphery of the lower protective ring; characterized in that, The uppermost air shield consists of a separate inner and outer ring. The outer ring fits over the inner ring, with a bearing between them. The inner ring has multiple inner adjustment holes, and the outer ring has multiple outer adjustment holes. The inner and outer adjustment holes have the same diameter, and their positions correspond one-to-one. The lower end of the outer ring has an integrally formed flange with external teeth. A transmission gear is also installed on the cooling air ring body, meshing with the external teeth of the outer ring. A stepper motor drives the transmission gear. Several ultrasonic rangefinders for detecting the position of the membrane bubble are installed along the upper edge of the inner ring of the uppermost air shield. These ultrasonic rangefinders are evenly distributed around the circumference of the air shield. A central controller is also provided, with each ultrasonic rangefinder connected to it, which in turn connects to the stepper motor.

2. The wind shield structure of a cooling air ring of a film blowing apparatus according to claim 1, characterized in that: The cooling air ring body is also equipped with a movable ring support. The uppermost air shield, transmission gear, stepper motor and movable ring support are fixed together. At least three vertical lead screw mechanisms are provided between the cooling air ring body and the movable ring support. Each vertical lead screw mechanism is evenly arranged along the circumference of the cooling air ring body. The vertical lead screw of each lead screw mechanism is rotatably mounted on the cooling air ring body. Each vertical lead screw is screwed to the movable ring support by threads. Each vertical lead screw is equipped with a lead screw motor to drive its rotation.

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