Granulating device of extruder

Abstract

The utility model discloses a pelletizing device of an extruder, which comprises a mounting shaft fixed on a die head of the extruder, a pelletizing cutter holder rotatably mounted on the mounting shaft, a belt pulley arranged on the pelletizing cutter holder, a plurality of pelletizing blades fixedly mounted on the pelletizing cutter holder, and a cutting edge of each pelletizing blade covering an extrusion hole of the die head. The cutting edge of the pelletizing blade comprises an inner cutting edge surface close to the die head and an outer cutting edge surface far away from the die head, an inner included angle is formed between the inner cutting edge surface and the plane of the die head, an outer included angle is formed between the outer cutting edge surface and the plane of the die head, and the inner included angle and the outer included angle are both acute angles; a gap adjusting device for adjusting the gap between the cutting edge of the pelletizing blade and the die head is mounted on the mounting shaft, and the pelletizing device can avoid adhesion of materials and can adjust the gap between the pelletizing blade and the die head.

Description

Technical Field

[0001] The utility model relates to the technical field of extruders, in particular to a pelletizing device of an extruder. Background Art

[0002] In the plastic extrusion industry, the extruder is a commonly used plastics machine. The extruder relies on the pressure and shear force generated by the rotation of the screw to fully plasticize and evenly mix the material. The material is then extruded through the die head and pelletized using a pelletizer. Currently, conventional pelletizers mainly include a sliding base on which a motor that drives the pelletizer to rotate is fixedly mounted. During use, the base is axially slid to align the pelletizer with the plane of the die head. The motor is then started to drive the pelletizer to rotate, thereby pelletizing the melt extruded by the extruder.

[0003] Polylactic acid (PLA) is a synthetic material made from corn, wheat and other starches, which are fermented into lactic acid, polymerized and spun. This material is biodegradable, making it an emerging material that can be widely used in daily life. Among them, PLA foamed material formed by adding PLA to a foaming agent can be used as a filler. Its main process is to add PLA raw materials and foaming agents into the extruder together. After being heated and plasticized by the extruder, it will foam when extruded from the extrusion hole of the die head. The extrusion speed of this material is very fast, and the extruded material has a certain viscosity. Therefore, when using a conventional pelletizing device for pelletizing, the cutting edge of the pelletizing blade will adhere to the material during rapid cutting, and the material will become more and more sticky, which will eventually lead to the situation where it cannot be cut.

[0004] In addition, the current pelletizing tool is matched with the die head by sliding a sliding base. The matching gap between the pelletizing tool and the die head cannot be accurately adjusted. This also leads to the inability to accurately adjust the gap of the pelletizing tool when cutting PLA foam materials, and also causes the material to stick to the tool. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a pelletizing device for an extruder, which can avoid the adhesion of materials and can adjust the gap between the pelletizing blade and the die head.

[0006] In order to solve the above technical problems, the technical solution of the present utility model is: a pelletizing device of an extruder, comprising a mounting shaft fixed to the die head of the extruder, a pelletizer seat being rotatably mounted on the mounting shaft, a pulley being provided on the pelletizer seat, a plurality of pelletizer blades being fixedly mounted on the pelletizer seat, the blades of the pelletizer blades covering the extrusion hole of the die head, the blades of the pelletizer blades comprising an inner blade surface close to the die head and an outer blade surface away from the die head, an inner angle being formed between the inner blade surface and the plane of the die head, an outer angle being formed between the outer blade surface and the plane of the die head, and both the inner angle and the outer angle being acute angles; a gap adjusting device for adjusting the gap between the blades of the pelletizer blades and the die head is installed on the mounting shaft.

[0007] As a preferred solution, the gap adjustment device includes an adjusting screw sleeve threadedly mounted on the mounting shaft, the adjusting screw sleeve is located on the outside of the pelletizer seat, and a compression spring is mounted on the mounting shaft, and the elastic force of the compression spring forces the pelletizer seat to rest against the adjusting screw sleeve.

[0008] As a preferred solution, the pelletizer blade includes a blade body and a connecting part, the blade body is provided with the cutting edge, the connecting part is provided with an axial adjustment groove, a fixing screw is installed in the axial adjustment groove, and the fixing screw fixes the connecting part to the pelletizer seat.

[0009] As a preferred solution, a first bearing mounting hole and a second bearing mounting hole are provided on the pelletizer seat, a first bearing is installed in the first bearing mounting hole with clearance fit, a second bearing is embedded and fixed in the second bearing mounting hole, the first bearing is closer to the die head than the second bearing, the inner rings of the first bearing and the second bearing are sleeved on the mounting shaft, one end of the compression spring presses on the first bearing, and the other end presses on the second bearing.

[0010] As a preferred solution, a plurality of mounting planes are provided on the pelletizer seat, and the connecting portion is fixed on the mounting planes in a one-to-one correspondence by at least two fixing screws.

[0011] As a preferred solution, a central raised plane is provided on the plane of the die head, and the extrusion hole is within the range of the central raised plane.

[0012] As a preferred solution, the inner angle is 10-20°.

[0013] As a preferred solution, the number of the pelletizing blades is four and they are evenly distributed around the circumference.

[0014] After adopting the above technical solution, the effect of the utility model is as follows: the pelletizing device includes a mounting shaft fixed on the die head of the extruder, a pelletizer seat is rotatably mounted on the mounting shaft, a pulley is provided on the pelletizer seat, and a plurality of pelletizer blades are fixedly mounted on the pelletizer seat, the blades of the pelletizer blades cover the extrusion hole of the die head, the blades of the pelletizer blades include an inner blade surface close to the die head and an outer blade surface away from the die head, an inner angle is formed between the inner blade surface and the plane of the die head, an outer angle is formed between the outer blade surface and the plane of the die head, and both the inner angle and the outer angle are acute angles; the mounting shaft is fixed on the pelletizer seat, and the pelletizer seat is provided with a pulley, and a plurality of pelletizer blades are fixedly mounted on the pelletizer seat, the blades of the pelletizer blades cover the extrusion hole of the die head, the blades of the pelletizer blades include an inner blade surface close to the die head and an outer blade surface away from the die head, an inner angle is formed between the inner blade surface and the plane of the die head, and an outer angle is formed between the outer blade surface and the plane of the die head, and both the inner angle and the outer angle are acute angles; A gap adjustment device for adjusting the gap between the blade of the pelletizer blade and the die head is installed. Therefore, the pelletizer blade of the pelletizer device is fixed on the pelletizer knife seat, and the pelletizer knife seat is directly fixed to the die head through the installation shaft, without the need for a sliding machine seat, thus saving space. At the same time, an inner angle is formed between the inner blade surface and the plane of the die head, and an outer angle is formed between the outer blade surface and the plane of the die head. In this way, only the blade of the pelletizer blade is close to the die head, and the material will not adhere to the inner blade surface during pelletizing. The gap between the blade of the pelletizer blade and the die head can be adjusted by the gap adjustment device to meet the pelletizing requirements of the PLA foam material.

[0015] Furthermore, since the gap adjustment device includes an adjusting screw sleeve threadedly mounted on the mounting shaft, the adjusting screw sleeve is located on the outside of the pelletizer seat, and a compression spring is mounted on the mounting shaft, the elastic force of the compression spring forces the pelletizer seat to rest against the adjusting screw sleeve. By rotating the adjusting screw sleeve, the pelletizer seat can be axially squeezed to make the blade close to the plane of the die head, thereby reducing the gap. When the gap needs to be increased, the adjusting screw sleeve is rotated in the opposite direction, and the compression spring forces the pelletizer seat to always be in contact with the adjusting screw sleeve, so that the blade is always kept at an appropriate gap, which is convenient for pelletizing without sticking.

[0016] Since the pelletizer blade includes a blade body and a connecting part, the blade body is provided with the cutting edge, the connecting part is provided with an axial adjustment groove, a fixing screw is installed in the axial adjustment groove, and the fixing screw fixes the connecting part to the pelletizer seat. The axial adjustment groove can facilitate the adjustment of the fixed position of the connecting part.

[0017] Furthermore, since a central raised plane is provided on the plane of the die head, the extrusion hole is within the range of the central raised plane, which can reduce the contact surface between the blade and the die head plane and avoid wear of the blade.

[0018] Furthermore, since a plurality of mounting planes are provided on the pelletizer seat, the connecting portion is fixed on the mounting planes in a one-to-one correspondence by at least two fixing screws, which facilitates the stable fixation of the connecting portion and the mounting planes. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Figure 1 It is a three-dimensional diagram of an embodiment of the utility model;

[0021] Figure 2 This is a front view of an embodiment of the utility model;

[0022] Figure 3 It is a right side view of an embodiment of the utility model;

[0023] Figure 4 yes Figure 3 Sectional view along AA;

[0024] Figure 5 It is a partial structural diagram of an embodiment of the utility model;

[0025] In the accompanying drawings: 1. Mounting shaft; 2. Pelletizer seat; 21. Mounting plane; 3. Pulley; 4. Pelletizer blade; 41. Inner blade surface; 42. Outer blade surface; 43. Connecting portion; 44. Axial adjustment groove; 45. Fixing screw; 5. Extruder; 6. Central raised plane; 7. Adjusting screw sleeve; 8. Compression spring; 9. First bearing; 10. Second bearing; 11. Die head. DETAILED DESCRIPTION

[0026] The present invention will be described in further detail below through specific embodiments.

[0027] like Figure 1-5 As shown, a pelletizing device of an extruder includes a mounting shaft 1 fixed to a die head 11 of the extruder, a pelletizer seat 2 being rotatably mounted on the mounting shaft 1, a pulley 3 being provided on the pelletizer seat 2, a plurality of pelletizer blades 4 being fixedly mounted on the pelletizer seat 2, the blades of the pelletizer blades 4 covering the extrusion holes 5 of the die head 11, the blades of the pelletizer blades 4 including an inner blade surface 41 close to the die head 11 and an outer blade surface 42 away from the die head 11, an inner angle being formed between the inner blade surface 41 and the plane of the die head 11, an outer angle being formed between the outer blade surface 42 and the plane of the die head 11, and both the inner angle and the outer angle being acute angles; a gap adjusting device for adjusting the gap between the blade of the pelletizer blade 4 and the die head 11 is installed on the mounting shaft 1.

[0028] In this embodiment, a central raised plane 6 is provided on the plane of the die head 11, and the extrusion hole 5 is within the range of the central raised plane 6. The gap adjustment device includes an adjusting screw sleeve 7 threadedly mounted on the mounting shaft 1. The adjusting screw sleeve 7 is located outside the pelletizer seat 2. A compression spring 8 is mounted on the mounting shaft 1. The elastic force of the compression spring 8 forces the pelletizer seat 2 to rest against the adjusting screw sleeve 7. The angle of the inner angle is usually set to 10-20°, and the number of pelletizer blades 4 is four and evenly distributed around the circumference. Of course, the angle of the inner angle can also be set to other angles between 21-45° according to needs, and the number of pelletizer blades 4 can also be set to five, six, seven, etc. according to needs.

[0029] The pelletizer blade 4 comprises a blade body and a connecting portion 43. The blade body is provided with a cutting edge. The connecting portion 43 is provided with an axial adjustment slot 44. A set screw 45 is installed in the axial adjustment slot 44, securing the connecting portion 43 to the pelletizer holder 2. The pelletizer holder 2 is provided with mounting holes for a first bearing 9 and a second bearing 10. The first bearing 9 is installed in the first bearing 9 mounting hole with a clearance fit, while the second bearing 10 is embedded and secured in the second bearing 10 mounting hole. The first bearing 9 is closer to the die head 11 than the second bearing 10. The inner races of the first and second bearings 9 and 10 fit over the mounting shaft 1. One end of the compression spring 8 presses against the first bearing 9, and the other end presses against the second bearing 10. The pelletizer holder 2 is provided with several mounting surfaces 21. The connecting portion 43 is secured to each of these mounting surfaces 21 by at least two of the set screws 45, one for each.

[0030] When in use, the pelletizer blade 4 is fixed on the pelletizer seat 2, and the pelletizer seat 2 is directly fixed on the die head 11 through the mounting shaft 1, and an inner angle is formed between the inner blade surface 41 and the plane of the die head 11, and an outer angle is formed between the outer blade surface 42 and the plane of the die head 11. In this way, only the blade of the pelletizer blade 4 is close to the die head 11, and the material will not adhere to the inner blade surface 41 during pelletizing. In addition, the gap adjustment device can adjust the gap between the blade of the pelletizer blade 4 and the die head 11, and the gap between the blade and the die head 11 can be adjusted by the axial adjustment slot 4. Adjusting the connection portion 43 to the appropriate fixed position, the elastic force of the compression spring 8 forces the pelletizer seat 2 to rest against the adjusting screw sleeve 7. Rotating the adjusting screw sleeve 7 axially squeezes the pelletizer seat 2, bringing the blade closer to the plane of the die head 11, thereby reducing the gap. When the gap needs to be increased, the adjusting screw sleeve 7 is rotated in the opposite direction. The compression spring 8 forces the pelletizer seat 2 to maintain contact with the adjusting screw sleeve 7, thus maintaining the appropriate gap between the blades and pelletizers, preventing sticking during pelletizing and meeting the pelletizing requirements of PLA foam materials. Furthermore, the extrusion hole 5 is within the range of the central raised plane 6, reducing contact between the blade and the plane of the die head 11 and extending its service life.

[0031] The air circuit system, actuators such as servo motors, gear transmission mechanisms, and lead screw and nut mechanisms mentioned in this embodiment are all current conventional technologies. The specific structures and principles and other designs of the cylinders, motors, and other transmission mechanisms are disclosed in detail in the "Mechanical Design Manual, Fifth Edition", the 28th printing of the fifth edition in Beijing in April 2008, which belongs to the existing technology and its structure is clear. The SMC training textbook "Modern Practical Pneumatic Technology, 3rd Edition" published by the Machinery Industry Press on August 1, 2008 discloses in detail the vacuum components, gas circuits, and program control, indicating that the air circuit structure in this embodiment is also existing technology and is clear. The book "Motor Drive and Speed ​​Regulation" published by the Chemical Industry Press on July 1, 2015 also introduces the control of the motor and the travel switch in detail. Therefore, the circuit and air circuit connections are clear.

[0032] The above-described embodiments are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Various modifications and alterations to the technical solutions of the present invention, without departing from the spirit of the present invention, should fall within the scope of protection defined in the claims of the present invention.

Claims

1. A pelletizing device for an extruder, characterized in that: The invention comprises a mounting shaft fixed on the die head of the extruder, a pelletizer seat being rotatably mounted on the mounting shaft, a pulley being provided on the pelletizer seat, and a plurality of pelletizer blades being fixedly mounted on the pelletizer seat, the blades of the pelletizer blades covering the extrusion hole of the die head, the blades of the pelletizer blades comprising an inner blade surface close to the die head and an outer blade surface away from the die head, an inner angle being formed between the inner blade surface and the plane of the die head, an outer angle being formed between the outer blade surface and the plane of the die head, and both the inner angle and the outer angle being acute angles; a gap adjusting device for adjusting the gap between the blade of the pelletizer blade and the die head is installed on the mounting shaft.

2. The pelletizing device of an extruder according to claim 1, characterized in that: The gap adjustment device includes an adjusting screw sleeve threadedly mounted on the mounting shaft, the adjusting screw sleeve is located on the outside of the pelletizer seat, and a compression spring is mounted on the mounting shaft, the elastic force of the compression spring forces the pelletizer seat to rest against the adjusting screw sleeve.

3. The pelletizing device of an extruder according to claim 2, characterized in that: The pelletizing blade includes a blade body and a connecting portion, the blade body is provided with the cutting edge, the connecting portion is provided with an axial adjustment groove, a fixing screw is installed in the axial adjustment groove, and the fixing screw fixes the connecting portion to the pelletizing blade seat.

4. A pelletizing device for an extruder according to claim 3, characterized in that: The pelletizer seat is provided with a first bearing mounting hole and a second bearing mounting hole, the first bearing mounting hole is clearance-fittedly mounted with a first bearing, the second bearing mounting hole is embedded and fixed with a second bearing, the first bearing is closer to the die head than the second bearing, the inner rings of the first bearing and the second bearing are sleeved on the mounting shaft, one end of the compression spring presses on the first bearing, and the other end presses on the second bearing.

5. The pelletizing device of an extruder according to claim 3, characterized in that: The pelletizer seat is provided with a plurality of mounting planes, and the connecting portion is fixed on the mounting planes in a one-to-one correspondence by at least two fixing screws.

6. The pelletizing device of an extruder according to claim 1, characterized in that: A central raised plane is provided on the plane of the die head, and the extrusion hole is within the range of the central raised plane.

7. The pelletizing device of an extruder according to claim 1, characterized in that: The inner angle is 10-20°.

8. The pelletizing device of an extruder according to claim 1, characterized in that: The number of the pelletizing blades is four and they are evenly distributed around the circumference.

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